JP2005165089A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner having excellent developing property and favorable resolution and transfer property. <P>SOLUTION: In the toner comprising color particles containing a resin and a colorant and at least two kinds of silica particles: (1) the first silica particles (A) contain a titanium element, satisfies 0.7≤(Ia<SB>1</SB>/Ib<SB>1</SB>)≤2.0 and 0.7≤(Ia<SB>2</SB>/Ib<SB>2</SB>)≤2.0 in X-ray diffraction, wherein Ia<SB>1</SB>is the maximum intensity at 2θ=25.3°, Ib<SB>1</SB>is the average intensity at 2θ=25.3±2.0°, Ia<SB>2</SB>is the maximum intensity at 2θ=27.5°, and Ib<SB>2</SB>is the average intensity at 2θ=27.5±2.0°, and has 30 to 100 nm number average particle size (RA); and (2) the second silica particles (B) have 100 to 500 nm number average particle size (RB) which is different from that of the first silica particles (A), with the surfaces subjected to hydrophobic treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toner for visualizing an electrostatic latent image in electrophotography and electrostatic recording, and relates to a toner having stable charging characteristics, excellent transfer characteristics, high definition, and high image quality. .

  In recent years, electrophotographic apparatuses have been required to have specifications such as light weight and low power consumption with simpler elements while achieving colorization, high definition, and high image quality. Against this background, demands for high definition and high image quality of electrophotography are increasing in the market, and attempts to achieve high image quality and full color are being made in this technical field. As a result, the performance required for the toner becomes higher, and technical improvements are particularly desired in terms of developability and transferability.

  In particular, when obtaining a full-color image in terms of transferability, each color toner is developed and transferred in the same way to obtain a visible image by superimposing three or four color toners. Otherwise, there is a concern that the color reproducibility is inferior or the color tone is uneven.

  In order to improve the transferability of the toner, it is necessary to reduce the adhesion of the toner to the electrostatic latent image carrier. For this purpose, the toner particle shape is made spherical or the inorganic fine particles are adhered to the toner particle surface. It is effective.

  However, there are various technical problems to satisfy the above characteristics. For example, when small spherical toner particles are used to improve image quality and transferability, a large amount of external additives such as silica fine particles and titania fine particles are used to further improve toner fluidity and transferability. Then, since the amount of the external additive added to the toner increases, the problem that the amount of the external additive that adheres to the surface of the photoreceptor also increases becomes significant. If the amount of the above external additive is reduced so that the sticking does not occur, not only the fluidity becomes insufficient, but also toner aggregation occurs due to stress in the developing device at the time of printing and a solid image is displayed. Invite problems of white spots.

  In order to solve such a problem, a specific external additive is added to spherical toner particles having a shape factor SF1 of 100 to 130 and having a volume average particle diameter of 3 to 7 μm, which is reduced to 3 to 7 μm in Patent Document 1 and the like. It is proposed that the above problems can be solved by using it.

  However, in the above document, although high transferability can be expected from the shape of the toner particles, it contains at least two kinds of external additives, and the content thereof is 8.0% by mass or less with respect to the toner particles. Therefore, there is a concern about detachment from the toner particle surface. In particular, when the shape of the toner particles is closer to a true sphere, the adhesion parameter of the external additive to the toner particle surface is less likely to be trapped by irregularities on the particle surface, and the electrostatic control is large. Therefore, when the charge becomes supersaturated, it is expected that the external additive particles will repel each other and increase the amount of external additives released from the toner. Since the agent cannot be collected, there is a problem that the photosensitive member is scraped or the charging characteristics of the toner itself become unstable.

  From these points, in recent years, a method of externally adding inorganic fine particles to a toner has been proposed and widely used for the purpose of improving the flow characteristics and charging characteristics of the toner.

Examples of such inorganic fine particles that are widely used include (i) inorganic fine particles surface-treated with silicone oil, silicone varnish, silane compound, or
(Ii) A surface-treated thiania or a surface treated with aminosilane is preferably used (Patent Documents 2 to 19).

In particular, in Patent Document 3, a low bulk density metal having an amino group on the particle surface and having a specific surface area of at least 50 m ² / g, the —OH group being blocked, and the surface being positively charged or zero. Proposed for oxide powders. However, since the chargeability on the surface of the metal oxide is to be controlled by the treatment agent, it is not preferable because the micro charge amount distribution on the silica particle surface is broad or the toner charge amount distribution is broad.

  Further, in these proposals and the like, the effect of increasing fluidity is seen, but there is room for further improvement in the case of using a toner having a smaller particle size, especially the lack of inorganic fine particles from the toner surface, In terms of liberation, it is not clear, and the amount of missing inorganic fine particles for obtaining a stable charge amount is not clear. Even if a certain amount of inorganic fine particles are added, if the amount of inorganic fine particles retained on the toner surface is unstable, fogging will increase in a large number of images printed under a high humidity environment, etc. Problems such as unevenness are likely to occur.

  Furthermore, (iii) those to which two types of inorganic fine particles are added are preferably used (Patent Documents 20 to 37).

  However, in these proposals, although the electrophotographic characteristics are certainly improved, the uniformity of hydrophobicity is insufficient, and sufficient triboelectric charge cannot be obtained by leaving under high humidity or for a long period of time. In some cases, this causes a decrease in fog and fogging.

  Alternatively, the triboelectric charge amount becomes excessive under low humidity, and image density unevenness and fogging may occur.

  Insufficient releasability from the drum of the toner could not be obtained, resulting in insufficient transferability, resulting in a decrease in transfer efficiency and loss of transfer. . Furthermore, when applied to full-color toners, it was not particularly severely satisfactory.

  Furthermore, Patent Documents 38 and 39 propose a toner containing a high-temperature vapor phase oxide of a silicon halogen compound and a halogen compound of a specific metal.

  However, this silica is presumed to have an adverse effect because it is vapor phase oxidized at a high temperature. In addition, since it is only for the purpose of adjusting the charge of silica, the content of the titanium compound is high, and furthermore, the transferability of the toner having excellent low-temperature fixability and oilless fixability is not fully considered. There was a problem to be improved.

  Patent Document 40 suggests that by defining the liberation rate of silica and titania-based external additives, a reduction in the amount of toner carried on the sleeve surface can be prevented, and a stable image density can be obtained. However, in the literature, the toner base particles used are toner particles obtained by a pulverization method, and since no special surface treatment or the like has been performed, it is difficult to obtain high transferability. It is possible that there will be many, and it is easy to analogize the possibility of problems that affect image quality such as filming.

  Recently, in Patent Documents 41 to 45, the free state of the external additive is represented by defining the difference in the average particle diameter of the toner to which the toner base particles and the external additive are attached. This document suggests that the presence of toner to which the external additive is not uniformly adhered stays at the member portion that regulates the developer on the surface of the sleeve, thereby suppressing the occurrence of slipping. However, in this document, there is no description regarding a two-component developer obtained by mixing and preparing a toner and a carrier, and the stress state to which the toner is subjected in the developing unit is unknown. In addition, since no specific means for producing the toner is described, whether or not the surface effect state of the toner particle, which is a parameter that greatly contributes to the adhesion of the external additive to the toner particle, is unknown and the suggested effect can be obtained. There are many unclear points regarding.

  In Patent Document 46, the silica surface is coated with a hydroxide or oxide of titanium, zirconium, tin, aluminum in an aqueous system, and surface treatment with an alkoxysilane is further performed in the aqueous system, whereby the surface chargeability of silica is improved. Proposed methods for controlling.

  However, even if an attempt is made to coat the silica surface with titanium, zirconium, tin, aluminum hydroxide or oxide in an aqueous system, it is difficult to obtain sufficient reactivity and adhesion.

  Further, even if the surface treatment can be performed satisfactorily, it is considered that the characteristics of different metals existing in the vicinity of the surface of the silica particles have a strong influence on the toner. In the case of the above metal, the charge polarity and the surface electrical resistance change greatly, and it is assumed that the chargeability and charge amount distribution of the toner are adversely affected.

  Thus, it has become clear that the presence of the external additive on the toner surface is important mainly on the means for achieving stabilization of charging characteristics.

JP-A-10-207113 Japanese Patent Publication No.53-22447 Japanese Patent Publication No. 1-31442 JP 58-216252 A JP 59-201063 A JP-A-64-88554 Japanese Examined Patent Publication No. 3-39307 Japanese Patent Laid-Open No. 4-9860 JP-A-4-204750 JP-A-4-214568 JP-A-4-340558 Japanese Patent Laid-Open No. 5-19528 JP-A-5-61224 JP-A-5-66608 JP-A-5-94037 Japanese Patent Laid-Open No. 5-119517 JP-A-5-139748 Japanese Patent Laid-Open No. 6-11886 Japanese Unexamined Patent Publication No. 6-11887 Japanese Patent Publication No. 2-27664 JP-A-60-238847 JP-A 61-188546 JP 61-188547 A JP-A 61-249059 JP-A-62-174772 Japanese Patent Laid-Open No. 2-151872 JP-A-2-222966 JP-A-2-291565 JP-A-4-204751 JP-A-4-264453 JP-A-4-280255 JP-A-4-345168 JP-A-4-345169 JP-A-4-348354 JP-A-5-113688 JP-A-5-346682 Japanese Patent Laid-Open No. 10-186723 JP-A-11-174721 JP-A-11-174726 Japanese Patent Laid-Open No. 11-258847 JP 2000-47417 A JP 2000-47418 A JP 2000-47425 A JP 2000-47426 A JP 2000-47479 A JP 2002-029730 A

An object of the present invention is to provide a toner that solves the problems described above.

  An object of the present invention is to provide a toner having excellent developability and good resolution and transferability.

  Another object of the present invention is to provide a toner capable of forming a clear image without fogging, having a high image density, excellent fine line reproducibility, highlight portion gradation, and excellent durability stability. It is in.

The present invention relates to a toner having colored particles containing a resin and a colorant, and at least two types of silica particles.
(1) The first silica particles (A) contain a titanium element, and in X-ray diffraction,
0.7 ≦ (Ia ₁ / Ib ₁ ) ≦ 2.0 and 0.7 ≦ (Ia ₂ / Ib ₂ ) ≦ 2.0
(Ia ₁ indicates the maximum intensity at 2θ = 25.3, Ib ₁ indicates the average intensity at 2θ = 25.3 ± 2.0 deg, Ia ₂ indicates the maximum intensity at 2θ = 27.5, and Ib 1 ₂ shows the average value of intensity at 2θ = 27.5 ± 2.0 deg.)
And the number average particle size (RA) is 30 to 100 nm,
(2) The second silica particle (B) is a silica particle having a number average particle size (RB) of 100 to 500 nm and having a hydrophobized surface, unlike the first silica particle (A). The present invention relates to a toner.

  The present inventors have found that by using silica particles having different particle diameters, the flowability of the toner itself is enhanced and high developability is achieved, thereby achieving high transfer characteristics even in a multiple transfer system or the like. It was.

  Furthermore, the present inventors have found that the presence of one silica particle as a composite oxide has a charging stability in any environment, little scattering, and excellent toner reproducibility.

  A toner that achieves excellent developability, transferability, fixability, and durability can be obtained.

As a result of intensive studies on the chargeability and transferability of the silica particles on the toner having excellent low-temperature fixability and oil-less fixability, the inventors have externally added at least two types of silica particles to the toner surface. Is preferable, and as each characteristic,
1) By controlling the chargeability of silica, which is known as a strong negative material, from weak negative to weak positive, it is possible to impart more ideal characteristics to the toner;
2) At least two types of silica particles having different particle diameters are externally added to the toner surface, thereby improving developability and obtaining high transfer characteristics;
It has been found that this is achieved by imparting.

  Regarding the control of the chargeability of silica from weak negative to weak positive, it has been found that a great effect can be obtained by arranging titanium element, which is a weak positive material, in silica particles. The inventors have found that the chargeability of the silica particles can be controlled without adversely affecting the titanium element by making the titanium element have no crystal system.

When the titanium element in the silica particles has the crystallinity of titanium oxide, the characteristics of the titanium element become remarkable, the positiveness increases, the adhesion between the titanium element exposed on the surface and the surface treatment agent decreases, and the particle size Since distribution control becomes difficult and the adverse effect on the toner characteristics is great, it is not preferable.

  The first silica particles (A) of the present invention have an intensity Ib which is an average value of intensity Ia at 2θ = 25.3 and 27.5 deg and intensity at 2θ + 2.0 deg and 2θ−2.0 deg in X-ray diffraction. The ratio (Ia / Ib) is a physical property value related to the crystal form of titanium oxide contained in silica.

More specifically, the first silica particles (A) of the present invention are titanium compound-containing silica particles containing a titanium element, and in X-ray diffraction, the maximum intensity Ia ₁ and 2θ + 2.0 deg and 2θ at 2θ = 25.3. The ratio (Ia ₁ / Ib ₁ ) of the intensity Ib ₁ that is the average value of the intensity at −2.0 deg is 0.7 ≦ Ia ₁ / Ib ₁ ≦ 2.0, and the maximum intensity Ia _{2 at} 27.5 deg The ratio (Ia ₂ / Ib ₂ ) of the intensity Ib ₂ , which is the average value of the intensity at 2θ + 2.0 deg and 2θ−2.0 deg, is 0.7 ≦ Ia ₂ / Ib ₂ ≦ 2.0. To do.

  Satisfying the above relational expression means that the titanium element contained in the silica does not have crystallinity.

  In general, it is known that titanium oxide has several peaks in X-ray diffraction. It is known that there is a characteristic and large peak around 2θ = 25.3 when the crystal system is anatase type, and around 2θ = 27.5 when the crystal system is rutile type.

  In addition, in X-ray diffraction, amorphous silica has no peak and tends to increase in intensity gradually from around 2θ = 10 deg to around 2θ = 21 deg, and gradually decreases in intensity from around 2θ = 22 deg to around 2θ = 40 deg. Show the trend.

  That is, in the X-ray diffraction, the titanium element-containing silica of the present invention that satisfies the above-mentioned relational expression clearly defines that the titanium element does not have a crystal characteristic of titanium oxide.

  The raw material and production method of the silica particles (A) of the present invention are not particularly limited, but production examples are shown below.

  The silica particles (A) containing a titanium element used in the present invention can be obtained by heating and baking a mixture of a siloxane containing no halogen and a volatile titanium element in a gas phase.

  Here, examples of the siloxane include linear organosiloxanes, cyclic organosiloxanes, and mixtures thereof, and those containing no halogen are preferable.

  Examples of the organosiloxane include hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and the like. These siloxanes do not contain halogens such as chlorine and are preferably obtained by purification. These can be used alone or in combination of two or more.

  Moreover, there is no restriction | limiting in particular in a volatile titanium element, What is necessary is just to have volatile property, such as a chloride, an alkoxide, and acetylacetonate of titanium, and to thermally decompose or hydrolyze in a gaseous phase. These can be used alone or in combination of two or more.

  A mixture of these siloxanes and volatile titanium elements is introduced into the burner in liquid form and sprayed with a nozzle attached to the tip of the burner and burned, or the mixture of siloxanes and volatile titanium elements is heated, The steam may be introduced into the burner and burned.

  Since the silica particles containing the titanium element thus obtained have the titanium element uniformly dispersed, the chargeability is good, and the uniform reactivity with the surface treatment agent is excellent. Preferred for use in

  On the other hand, silica containing a titanium element can also be obtained by baking a mixture of a silicon halogen compound and a titanium halogen compound at a high temperature in a gas phase, but the crystallinity as in the present invention is exhibited from the characteristics of the raw materials. No titanium element-containing silica can be obtained.

  In addition, since a large amount of a halogen compound is used as a starting material, the generated silica particles contain chlorine as an impurity. This impurity chlorine greatly affects the chargeability of the toner. In particular, in a toner containing a release agent, the adverse effect is remarkable, and toner scattering and fogging in a high temperature and high humidity environment become a problem. Therefore, in the present invention, it can be said that it is not preferable to use a large amount of a halogen compound as a starting material.

  Furthermore, the silica of the present invention can also be obtained by mixing silica fine particles and amorphous titanium oxide fine particles and firing at a low temperature of about 800 ° C. However, since silica fine particles and amorphous titanium oxide fine particles are used as raw materials, it is difficult to obtain a uniform dispersed state, and the charge amount distribution tends to be broad.

  In addition, when the firing temperature is higher than 800 ° C., the crystal growth of the amorphous titanium oxide fine particles proceeds remarkably, so that titanium element-containing silica particles that do not exhibit crystallinity as in the present invention cannot be obtained.

  The titanium element content contained in the titanium element-containing silica particles is preferably 0.1 to 20 parts by mass (per 100 parts by mass of the titanium element-containing silica particles). If the titanium element content is more than 20 parts by mass, the negativeness of silica is extremely lowered, the toner charge amount distribution becomes broad, and an appropriate charge amount cannot be maintained. On the other hand, if the titanium element content is less than 0.1 parts by mass, the negative characteristics of silica will be remarkably exhibited, and the charge amount of the toner in a low humidity environment will become extremely high.

  Examples of the surface treatment agent for the titanium element-containing silica particles of the present invention include coupling agents such as known silane coupling agents, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, silicone oils, silicone varnishes, and the like. Can be used.

  For example, alkyl alkoxysilanes such as dimethyldimethoxysilane, trimethylethoxysilane, butyltrimethoxysilane, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethyl Silane coupling agents such as chlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane can be used.

  The surface treatment agent for the titanium element-containing silica particles of the present invention is preferably treated with a silazane compound or a silazane compound and silicone oil, and preferably treated with hexamethyldisilazane and dimethylsilicone oil. And transferability are preferable.

  The addition amount of the treatment agent is preferably 1 to 30 parts by mass, more preferably 3 parts with respect to 100 parts by mass of the titanium element-containing silica particles in order to prevent the particles from aggregating and maximize the properties of the treatment agent. -20 mass parts is good.

  In the present invention, surface treatment of titanium element-containing silica particles includes methods such as a wet method and a dry method, but the present invention is not particularly limited to these methods.

The BET of the silica particles (A) of the present invention is preferably 10 to 100 m ² / g.

When the BET specific surface area of the silica particles (A) is smaller than 10 m ² / g, it indicates that the particle size is large and that aggregates or coarse particles are present. Problems such as scratches and deformation or damage to the cleaning means such as the cleaning blade are likely to occur. In addition, if the particle size of the titanium element-containing silica particles is large, the titanium element-containing silica particles are easily released from the toner particles, and a large amount of the free titanium element-containing silica particles remain in the developing machine or adhere to various devices in the image forming apparatus main body. Unfavorable because it has an adverse effect.

When the BET specific surface area of the silica particles (A) is larger than 100 m ² / g, the amount of moisture adsorbed on the titanium element-containing silica particles increases, which adversely affects the charging characteristics of the toner and easily causes image quality deterioration.

  The silica particles (A) of the present invention are preferably added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner particles. When the addition amount is less than 0.1 parts by mass, the effect of improving the chargeability and transferability is small. On the other hand, when the addition amount exceeds 5 parts by mass, the fluidity of the toner is greatly reduced, so that uniform charging is inhibited.

  As the second silica particles (B) in the present invention, fine powder silica such as wet-process silica and dry-process silica, and surface treatment with silane compound, organosilicon compound, titanium coupling agent, silicone oil, etc. In a known sol-gel method, the solvent is removed from the silica sol suspension obtained by hydrolyzing and condensing the alkoxysilane or alkoxysilane with a catalyst in an organic solvent in which water is present, and dried to form particles. The obtained silica core is subjected to the same surface treatment or the like.

For example, the dry process silica is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is called so-called dry process silica or fumed silica, and is manufactured by a conventionally known technique. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction formula is as follows.
SiCl ₄ + 2H ₄ + O ₂ → SiO ₂ + 4HCl

  The hydrophobizing method is applied by chemical or physical treatment with an organosilicon compound that reacts or physically adsorbs with silica particles.

  As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound. Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane. , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, Examples include 1,3-diphenyltetramethyldisiloxane and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and containing a hydroxyl group bonded to one Si at each terminal unit. These are used alone or as a mixture of two or more.

  In addition, a coupling agent having an amino group or a product treated with silicone oil may be used as necessary to achieve the object of the present invention.

In the present invention, the second silica particles (B) are characterized by using hydrophobized silica particles having a particle diameter different from that of the silica particles (A). As a result of intensive studies focusing on transferability,
The number average particle diameter (RA) of the silica particles (A) and the number average particle diameter (RB) of the silica particles (B) are in a relationship of RA <RB, and the number average particle diameter (RA) of the silica particles (A) It was found that particularly high transferability can be obtained when) is 100 nm or less.

  It is considered essential that both high chargeability and high releasability are indispensable as the characteristics required for the external additive for obtaining high transfer characteristics. In particular, with the recent spread of color printers and the like, multiple transfer systems are becoming mainstream in electrophotography, and it is considered important to use toner that exhibits high charging characteristics.

  However, simply increasing the charging characteristics makes it difficult for the toner particles to move in the electric field, making it difficult to obtain the desired toner loading and image density.

  In the present invention, it has been found that by using two types of silica particles as external additives, both high charge imparting properties and toner particle releasability (toner separation) can be achieved. In particular, the flowability and transferability can be improved at the same time by combining the silica particles with a small particle size and the silica particles with a large particle size, and charging stability is achieved by incorporating a titanium element into the small particle size silica particles. It became a thing.

  Since the silica particles (A) of the present invention contain a titanium element, it is easy to control the negative chargeability as a toner. Therefore, even when the temperature and humidity environment changes, it is possible to exhibit stable charging characteristics. In addition, it is particularly preferable to have a fluidizing agent characteristic that toner fluidity can be easily imparted by setting the number average particle size to 30 to 100 nm.

  When the number average particle size is smaller than 30 nm, the toner particles are easily embedded on the surface of the toner particles, so that toner deterioration is likely to occur at an early stage, durability is lowered, and polishing properties are also lowered. Further, aggregated particles are easily generated, and the fluidity of the toner is remarkably reduced.

  On the other hand, when the average particle size is larger than 100 nm, the fluidity of the toner is lowered, so that the charge is likely to be non-uniform, and as a result, the image quality is deteriorated, the toner is scattered, and the fog is likely to occur. In addition, the surface of the photosensitive member is easily damaged, which causes image defects. In addition, a problem such as deformation or damage of a cleaning member such as a cleaning blade is likely to occur.

  Regarding the polishing and removal of the surface of the photosensitive member and its deposits, when the toner is cleaned from the surface of the photosensitive member, the toner temporarily stays on the surface of the photosensitive member and a pressure bonding portion of a cleaning member such as a cleaning blade. Silica particles (A) present on the surface of the staying toner particles serve to polish and remove the surface of the photoreceptor and its deposits. However, the silica particles (A) containing the titanium element are not embedded in the toner particle surface, are dispersed in the toner in a state close to the primary particle size without aggregates, and are uniformly present on the toner particle surface. It is preferable.

  In order for the silica particles (A) to have suitable polishing properties, the number average particle diameter is 30 to 100 nm, and the prescribed intensity ratio in X-ray diffraction of the titanium compound-containing silica particles shows the value of the present invention. Is very effective.

  The silica particles (A) of the present invention are preferably added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner particles. When the addition amount is less than 0.1 parts by mass, the effect of improving the chargeability and transferability is small. On the other hand, when the addition amount exceeds 5 parts by mass, the fluidity of the toner is greatly reduced, so that uniform charging is inhibited.

  The number average particle diameter (RB) of the second silica particles (B) of the present invention is preferably 100 to 300 nm, more preferably 100 to 200 nm.

  In order to achieve high transferability, which is one of the objects of the present invention, the first silica particles (A) are different from the first silica particles (A) in providing fluidity to the toner and charging stability against environmental changes. ) Mainly serves as a transfer agent.

  Since the second silica particles (B) of the present invention have a large average particle diameter (RB) of 100 to 300 nm, they act as spacer particles between the toner particles when externally added to the toner surface.

  In particular, the lower the degree of circularity of the toner particles, the more the effect can be exhibited. The reason is considered to be that, due to the spacer effect, the contact opportunity between particles tends to change from surface contact to point contact, so that high transfer characteristics can be expressed.

  When the number average particle diameter is less than 100 nm, the fluidity imparting property to the toner is maintained, but the spacer effect is difficult to obtain, and it is difficult to obtain high transferability particularly in the multiple transfer system.

  On the other hand, when the number average particle diameter is larger than 300 nm, not only the fluidity of the toner is remarkably lowered but also the toner is easily scattered and fogged. Furthermore, the charge controllability in the silica particles (A) is also hindered, and the change in charge amount due to environmental fluctuations becomes large.

  In order to obtain higher transfer characteristics, the silica particles (B) preferably have a sharp particle size distribution, more preferably monodisperse particles.

  The silica particles (B) of the present invention are preferably added in an amount of 1.0 to 5.0 parts by mass with respect to 100 parts by mass of the toner particles. When the added amount is less than 1.0 part by mass, the present silica particles (B) are difficult to work as a spacer effect, and the transferability improving effect is small. On the other hand, when the addition amount exceeds 5 parts by mass, the fluidity of the toner is greatly reduced, so that uniform charging is inhibited.

  The binder resin used in the toner of the present invention includes (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, or (c) a hybrid resin and a vinyl polymer. Or a resin selected from (d) a mixture of a polyester resin and a vinyl copolymer, or (e) a mixture of a hybrid resin and a polyester resin. The molecular weight distribution measured by chromatography (GPC) has a main peak in the region of molecular weight 3,500 to 30,000, preferably in the region of molecular weight 5,000 to 20,000, and Mw / Mn is preferably 5.0 or more.

  When the main peak is in a region having a molecular weight of less than 3,500, the hot offset resistance of the toner is insufficient. On the other hand, when the main peak is in the region where the molecular weight exceeds 30,000, sufficient low-temperature fixability of the toner cannot be obtained, and application to high-speed fixing becomes difficult. Moreover, when Mw / Mn is less than 5.0, it becomes difficult to obtain good offset resistance.

  When a polyester resin is used as the binder resin, alcohol and carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, or the like can be used as a raw material monomer. Specifically, for example, as the dihydric alcohol 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 -Alkylene oxide adducts of bisphenol A such as bis (4-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, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.

  Acidic components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or their anhydrides; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or their anhydrides; 6-12 carbon atoms Succinic acid substituted with an alkyl group or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid, or anhydrides thereof.

  Among these, in particular, a bisphenol derivative represented by the following general formula (1) is used as a diol component, and a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof. Acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component, and a polyester resin obtained by condensation polymerization of these as a black toner for full color image formation has good charging characteristics This is preferable.

  Further, when a hybrid resin having a polyester unit and a vinyl polymer unit is used as a binder resin, further improved wax dispersibility, low-temperature fixability, and offset resistance can be expected. The “hybrid resin component” used in the present invention means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester are formed by a transesterification reaction, preferably a vinyl polymer. A graft copolymer (or block copolymer) is used in which is a trunk polymer and a polyester unit is a branched polymer.

  Examples of the vinyl monomer for producing the vinyl resin include the following. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Styrene and derivatives thereof such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated such as butadiene and isoprene Polyenes; vinyl chloride, vinyl chloride, vinyl bromide, fluoride Vinyl halides such as vinyl; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate Α-methylene aliphatic monocarboxylic acid esters such as octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate Propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-acrylate Acrylic esters such as lorethyl and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole; N-vinyl compounds such as N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  Further, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Alkenyl succinic acid half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester unsaturated dibasic acid half ester; dimethylmaleic acid, dimethyl fumaric acid unsaturated dibasic acid ester; acrylic acid, Α, β-unsaturated acids such as phosphoric acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group such as alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid, acid anhydrides and monoesters thereof.

  Furthermore, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy- And monomers having a hydroxy group such as 1-methylhexyl) styrene.

  In the toner of the present invention, the vinyl polymer unit of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. In this case, the crosslinking agent used is Examples of aromatic divinyl compounds include divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, and 1,4-butanediol di Examples include acrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate, and the above compounds in which acrylate is replaced by methacrylate; linked by an alkyl chain containing an ether bond. As diacrylate compounds For example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and those obtained by replacing acrylates of the above compounds with methacrylate Examples of diacrylate compounds linked by a chain containing an aromatic group and an ether bond include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4 ) -2,2-bis (4-hydroxyphenyl) propane diacrylate and those obtained by replacing the acrylate of the above compound with methacrylate.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

  In the present invention, it is preferable that a monomer component capable of reacting with both resin components is contained in the vinyl polymer component and / or the polyester resin component. Examples of monomers that can react with the vinyl polymer among the monomers constituting the polyester resin component include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Among the monomers constituting the vinyl polymer component, those capable of reacting with the polyester resin component include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method of obtaining a reaction product of a vinyl polymer and a polyester resin, either a polymer containing a monomer component capable of reacting with each of the vinyl polymer and the polyester resin listed above is present, or either A method obtained by polymerizing both resins is preferred.

  Examples of the polymerization initiator used for producing the vinyl polymer of the present invention include 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvalero). Nitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 1, 1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl- 4-methoxyvaleronitrile, 2,2′-azobis (2-methyl-propane), methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexane Ketone peroxides such as Sanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroper Oxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl Peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, -N-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t -Butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxy Benzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy 2-ethylhexanoate, di-t-butyl peroxyhexa Idro terephthalate, di -t- butyl peroxy azelate and the like.

Examples of the production method capable of preparing the hybrid resin used in the toner of the present invention include the following production methods (1) to (6).
(1) A method in which a vinyl polymer, a polyester resin, and a hybrid resin component are blended after production. The blend is produced by dissolving and swelling in an organic solvent (for example, xylene) and then distilling off the organic solvent. The hybrid resin component is synthesized by separately producing a vinyl polymer and a polyester resin, dissolving and swelling in a small amount of an organic solvent, adding an esterification catalyst and an alcohol, and performing a transesterification reaction by heating. The ester compound used can be used.
(2) A method of producing a polyester unit and a hybrid resin component in the presence of a vinyl polymer unit in the presence of the vinyl polymer unit. The hybrid resin component is produced by a reaction between a vinyl polymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or polyester. Also in this case, an organic solvent can be appropriately used.
(3) A method for producing a vinyl polymer unit and a hybrid resin component in the presence of the polyester unit after the production. The hybrid resin component is produced by a reaction between a polyester unit (a polyester monomer can be added if necessary) and a vinyl monomer and / or vinyl polymer unit.
(4) After the production of the vinyl polymer unit and the polyester unit, a hybrid resin component is produced by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) in the presence of these polymer units. Also in this case, an organic solvent can be appropriately used.
(5) After producing the hybrid resin component, a vinyl polymer unit and a polyester unit are produced by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) and performing an addition polymerization and / or a condensation polymerization reaction. Is done. In this case, as the hybrid resin component, those produced by the production methods (2) to (4) can be used, and those produced by a known production method can be used as necessary. Furthermore, an organic solvent can be used as appropriate.
(6) A vinyl polymer unit, a polyester unit, and a hybrid resin component are produced by mixing a vinyl monomer and a polyester monomer (alcohol, carboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reaction. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (5) above, the polymer unit having a plurality of different molecular weights and crosslinks can be used as the vinyl polymer unit and / or the polyester unit.

  The binder resin contained in the color toner of the present invention includes a mixture of the polyester and vinyl polymer, a mixture of the hybrid resin and vinyl polymer, a vinyl resin in addition to the polyester resin and the hybrid resin. A mixture of polymer may be used. Preferably, a hybrid resin is contained.

  The glass transition temperature of the binder resin contained in the toner of the present invention is preferably 40 to 90 ° C, more preferably 45 to 85 ° C. The acid value of the resin is preferably 1 to 40 mgKOH / g.

  The toner of the present invention contains one or more release agents.

  Examples of the release agent used in the present invention include the following. Low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax; block of aliphatic hydrocarbon wax Copolymers; waxes mainly composed of fatty acid esters such as carnauba wax and montanic acid ester wax; and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax.

  Examples thereof include partially esterified products of fatty acids such as behenic acid monoglycerides and polyhydric alcohols; methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and the like. Particularly preferred waxes are aliphatic hydrocarbon waxes such as paraffin wax, polyethylene, and Fischer-Tropsch wax, which have a short molecular chain and little steric hindrance and excellent mobility.

  In the molecular weight distribution of the wax, the main peak is preferably in the region of molecular weight 350-2400, more preferably in the region of 400-2000. By giving such a molecular weight distribution, it is possible to impart favorable thermal characteristics to the toner.

  The endothermic curve in the differential thermal analysis (DSC) measurement of the release agent used in the present invention has one or a plurality of endothermic peaks in the temperature range of 30 to 200 ° C., and the temperature of the maximum endothermic peak in the endothermic peak. Tsc is preferably 65 ° C. <Tsc <105 ° C., more preferably 70 ° C. <Tsc <90 ° C. When the temperature is 65 ° C. or lower, the anti-blocking property is inferior. When the temperature is 105 ° C. or higher, low-temperature fixing desired from the viewpoint of energy saving cannot be performed, and a load requiring considerable pressure is required even in the fixing configuration. .

  Moreover, as addition amount of the mold release agent used for this invention, content with respect to 100 mass parts of binder resin is 1-10 mass parts, Preferably it is good to use 2-8 mass parts. If the amount is less than 1 part by mass, the amount is small so that it must be used with a considerable amount of heat and pressure in order to come out on the surface of the toner at the time of melting and exhibit releasability. On the other hand, when the amount exceeds 10 parts by mass, the amount of the release agent in the toner is too large, so that transparency and charging characteristics are inferior.

  Further, the method for adding the release agent is not particularly limited. Usually, the resin is added to the toner by a method of dissolving the resin in a solvent, raising the temperature of the resin solution, adding and mixing with stirring, or a method of mixing at the time of kneading.

  As the colorant of the present invention, known dyes and / or pigments are used.

  As a coloring pigment for magenta toner, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 155, 163, 202, 206, 207, 209; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Although the pigment may be used alone, it is more preferable from the viewpoint of the image quality of the full color image to improve the sharpness by using the dye and the pigment together.

  Examples of the magenta toner dye include C.I. I solvent red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; I. Disper thread 9; I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. B. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; I. Basic dyes such as basic violet 1,3,7,10,14,15,21,25,26,27,28 are listed.

  Examples of the color pigment for cyan toner include C.I. I. Pigment blue 2, 3, 15, 16, 17; I. Bat Blue 6; C.I. I. Acid Blue 45 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on a phthalocyanine skeleton having a structure represented by the following formula.

〔式中、ｎは１〜５の整数を示す。〕

[In formula, n shows the integer of 1-5. ]

  As a coloring pigment for yellow, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 97, 155, 180; I. Vat yellow 1, 3, 20 etc. are mentioned.

  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.

  As the black colorant used in the present invention, carbon black, a magnetic material, and a color toned to black using the yellow / magenta / cyan colorant shown above can be used.

  The amount of the colorant used is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, and most preferably 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  As a method for producing the toner particles used in the present invention, the constituent materials are well kneaded by a heat kneader such as a hot roll, a kneader, and an extruder, then mechanically pulverized, and the pulverized powder is classified to obtain toner particles. A method of obtaining toner particles by dispersing a material such as a colorant in a binder resin solution and then spray-drying; a monomer obtained by mixing a predetermined material with a polymerizable monomer to constitute the binder resin; A toner production method or the like by suspension polymerization in which toner particles are obtained by obtaining a composition and polymerizing an emulsified suspension of the composition can be applied.

  In the present invention, an organic metal compound can be contained in the toner. As the organometallic compound used in the present invention, a compound of an aromatic carboxylic acid and a divalent or higher metal is preferable.

  Examples of the aromatic carboxylic acid include the following three compounds.

〔式中、Ｒ₁乃至Ｒ₇は同一又は異なる基を示し、水素原子、炭素数１〜１２のアルキル基、炭素数２〜１２のアルケニル基、−ＯＨ，−ＮＨ₂，−ＮＨ（ＣＨ₃），−Ｎ（ＣＨ₃）₂，−ＯＣＨ₃，−Ｏ（Ｃ₂Ｈ₅），−ＣＯＯＨ又は−ＣＯＮＨ₂を示す。〕

[Wherein, R _{1 to} R ₇ represent the same or different groups, and are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, —OH, —NH ₂ , —NH (CH ₃ ), —N (CH ₃ ) ₂ , —OCH ₃ , —O (C ₂ H ₅ ), —COOH or —CONH ₂ . ]

Preferable R ₁ includes a hydroxyl group, an amino group, and a methoxy group, and among them, a hydroxyl group is preferable. As the aromatic carboxylic acid, a dialkyl salicylic acid such as di-tert-butylsalicylic acid is particularly preferable.

The metal forming the organometallic compound is preferably a divalent or higher valent metal atom. Examples of the divalent metal include Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Pb ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Zn ²⁺ and Cu ²⁺ . As the divalent metal, Zn ²⁺ , Ca ²⁺ , Mg ²⁺ and Sr ²⁺ are preferable. Examples of the trivalent or higher metal include Al ³⁺ , Cr ³⁺ , Fe ³⁺ and Ni ³⁺ . Among these metals, Al ³⁺ , Fe ³⁺ , Cr ³⁺ and Zn ²⁺ are preferable, and Al ³⁺ is particularly preferable.

  In the present invention, the organometallic compound is preferably an aluminum compound of di-tert-butylsalicylic acid or a zinc compound of di-tert-butylsalicylic acid.

  The metal compound of the aromatic carboxylic acid is prepared by, for example, dissolving an aromatic carboxylic acid in an aqueous sodium hydroxide solution, dropping an aqueous solution in which a divalent or higher valent metal atom is melted into the aqueous sodium hydroxide solution, stirring with heating, After adjusting the pH of the aqueous solution to cool to room temperature, a metal compound of an aromatic carboxylic acid can be synthesized by filtration and washing with water. However, it is not limited only to the above synthesis method.

  The organometallic compound is used in an amount of 0.1 to 10 parts by mass (more preferably 0.2 to 5 parts by mass) per 100 parts by mass of the binder resin in terms of adjusting the viscoelastic characteristics and triboelectric charging characteristics of the toner. preferable.

  In the toner of the present invention, a compound other than the above-mentioned organometallic compound can be used as a charge control agent, if necessary, in order to further stabilize the chargeability.

  Examples of the charge control agent include nigrosine and imidazole compounds. The charge control agent is used in an amount of 0.1 to 10 parts by mass, preferably 0.1 to 7 parts by mass, per 100 parts by mass of the binder resin.

  In the present invention, when the toner is positively charged, it is preferable to add nigrosine, a triphenylmethane compound, a rhodamine dye, polyvinylpyridine, or the like as a charge control agent exhibiting positive chargeability.

  When producing a color toner, it is preferable to use a colorless or light-colored positive charge control agent that does not affect the color tone of the toner.

  In the present invention, one of the characteristics is that either the silica particles (A) or the silica particles (B) are processed on the surface of the toner base particles by using an impact type powder processing apparatus or the like.

  Various methods and apparatuses have been proposed as apparatuses for performing surface treatment.

  For example, there are an impact type powder processing apparatus using a rotating blade and a powder processing apparatus for applying heat treatment. An impact type powder processing apparatus using a rotating blade is disclosed in Y.W. Takayama, Y .; Kikuchi and K.K. Ono: ZAIRYO GIJUTSU Vol. 8, no. 8, 10, (1990). In addition, a hybridization system (Japanese Patent Laid-Open No. Sho 62-83029) commercialized as a product of Nara Machinery Co., Ltd. and an impact type fine crusher (Japanese Patent Publication No. Sho 42-27021) manufactured by Turbo Industry Co., Ltd. are used. Thus, there has been proposed a method for performing powder processing on the surface of powder particles (Japanese Patent Publication No. 5-265331, Japanese Patent Application Laid-Open No. 7-244399). In the present invention, impact type powder processing other than heat treatment is proposed. If it is a device, there is no restriction.

  As a more preferable embodiment in the present invention, it is found that the silica particles (A) are fixed to the toner base particles by the impact type powder processing apparatus as described above, and more preferable electrophotographic characteristics are exhibited. It was.

  In the present invention, the two types of silica particles (A) and (B) are externally mixed by a mixing and stirring device represented by a Henschel mixer or the like, depending on the desired number of added parts of the toner base particles, as in the general external addition method. It is processed.

  Originally, it is believed that the properties of the silica particles (A) and (B) are usefully fixed on the surface of the toner base particles by the treatment, but depending on the ordinary stirring and mixing device, the toner Although the external additive can be dispersed more uniformly with respect to the bulk amount of the toner, the external additive from the surface of the toner base particle is not always satisfactory in terms of adhesion to the surface of the toner base particle. Participation of particles is also a concern that can be easily inferred.

  In the silica particles (A) and (B) according to the present invention, since the silica particles (A) contain a titanium element in particular, the release rate with respect to the toner base particles tends to increase.

  Therefore, the characteristics of the silica particles (A) described herein are stably provided even in long-term use conditions by firmly fixing to the toner base particles with the impact type powder device as described above and suppressing the release rate. It becomes possible to do.

  The liberation rate of the silica particles (A) and (B) according to the present invention will be described.

  The liberation rate of the silica particles is measured by a particle analyzer (PT1000: manufactured by Yokogawa Electric Corporation), and the liberation rate is 0.1 to 30.00%. Preferably 0.1 to 2.00%, most preferably 0.1 to 0.5%.

  The particle analyzer performs measurement based on the principle described on pages 65-68 of the Japan Hardcopy 97 papers. Specifically, the apparatus introduces fine particles such as toner into the plasma one by one, and can know the element of the luminescent material, the number of particles, and the particle size of the particles from the emission spectrum of the fine particles.

In the present invention, SiO ₂ has been added as a fluidizing agent, an essential component of the also present invention that SiO ₂ isolation ratio is 0.1 to 30.0%, of SiO ₂ free The rate is preferably 0.1 to 2.0%, more preferably 0.1 to 0.5%. The liberation rate of SiO ₂ is measured by the particle analyzer described above. As a specific measurement method, silicon atoms (measurement wavelength 288.160 nm) are measured by channel 2, and the liberation rate of SiO ₂ is calculated by the following formula. Ask for.
SiO ₂ liberation rate (%) = 100 × (number of light emission of silicon atom only / carbon atom)
(The number of times of emission of silicon atoms emitted at the same time + the number of times of emission of only silicon atoms)

As a result of investigations by the present inventors, when the liberation rate of SiO ₂ is less than 0.1%, fogging increases and roughness occurs in the latter half of the multi-image printing test, particularly under high temperature and high humidity. In general, external additives are likely to be embedded due to the stress of a regulating member in a high-temperature environment, and the flowability of toner is inferior to that in the initial stage after printing a large number of sheets. It is done. However, such a problem hardly occurs when the liberation rate of SiO ₂ is 0.1% or more. This is because if the SiO ₂ is present to some extent (SiO ₂ liberation rate is 0.1% or more), the fluidity of the toner becomes good, so that embedding due to durability is difficult to occur and the toner is caused by stress. embedding SiO ₂ adhered even occur, free SiO ₂ is believed to be due to reduction in the fluidity of the toner is reduced by adhering to the toner surface.

On the other hand, the free SiO ₂ SiO ₂ free rate is more than 30.0% is contaminate the charging regulation member, undesirably resulting in an increase of fog. In such a state, the toner charging uniformity is also impaired, and the transfer efficiency is also lowered. For this reason, it is important that the liberation rate of silica is 0.1 to 30.0%.

  The average circularity of the toner of the present invention is 0.940 or more and 0.965 or less. The toner and the average circularity are preferably 0.945 or more and 0.960 or less in order to achieve both transferability and developability.

  If the average circularity of the toner is lower than 0.940, the spheronization process is insufficient, the control of the presence of the release agent is insufficient, and the low-temperature fixability may be slightly inferior, or the transfer efficiency may deteriorate. is there.

  When the average circularity of the toner exceeds 0.960, the transfer efficiency is considerably improved in the initial stage, but the developability is inferior, and the transferability after the endurance may be inferior. This is thought to be due to the exudation of the mold release agent caused by performing the spheroidization treatment for a long time. The average circularity of the toner can be adjusted by a toner particle manufacturing method or a known spheroidizing method by applying mechanical force or heat to the toner particle.

  One feature of the toner of the present invention is that the transmittance of light having a wavelength of 600 nm in a dispersion obtained by dispersing the toner in a 45% by volume methanol aqueous solution is 10% or more and 70% or less.

  By being in the above range, when a toner having a toner weight average particle size of 4.0 to 7.0 μm is used in a high-speed machine, it is possible to achieve both satisfactory low-temperature fixability and developability, and high This is preferable for forming a gloss image.

  The inventors of the present invention have found that the presence of the release agent near the surface of the toner particles is very important for satisfying these characteristics, and the results are obtained when a methanol aqueous solution containing about 45% by volume of methanol is used. Since the sensitivity to the difference in wettability between the resin and the release agent is good, a 45% by volume aqueous solution of methanol is used.

  The transmittance of the toner in a 45 volume% methanol aqueous solution may become a large value when the particle size of the toner is decreased and the surface area of the toner is increased.

  In particular, in a toner having a small particle size such as 3.0 to 8.0 μm as in the present invention, the properties of the toner surface are easily affected by the dispersion state of the release agent, the dispersed particle size, etc. Even in the case, the transmittance varies greatly. The transmittance increases when a large amount of release agent is present in the vicinity of the surface, or when the release agent is in a poorly dispersed state and a large lump of release agent cues to the toner surface. This is presumably because, in the case described above, the wettability of the toner with respect to the water-methanol solution is deteriorated and the toner is difficult to disperse.

  When the transmittance is less than 10%, the abundance of the release agent in the vicinity of the toner surface is small, and the developability after durability is very good, but the low-temperature fixability and gloss may be lowered. When the transmittance exceeds 70%, the low-temperature fixability is improved, but the release agent migrates from the toner, contaminates the surface of the developing sleeve, magnetic carrier, etc., and the developability may decrease with durability. .

  Such transmittance is adjusted, for example, by controlling various conditions such as the temperature and time of pulverization and shape adjustment during the production of toner particles, the type of release agent used and the type of dispersant for the release agent. It is possible. The transmittance can be measured using a spectrophotometer.

  The toner according to the present invention can be mixed with a magnetic carrier and used as a two-component developer.

  Carrier particles using the toner of the present invention in a two-component developer are conventionally known iron powder carriers and ferrite carriers. These carrier particles often use a resin-coated carrier in which the surface of the core material is coated with a resin, can make resistance suitable, and have excellent charge controllability, and thus have been used so far.

  However, the specific gravity of these carriers is relatively high, and from the viewpoints of high-speed rotation and durability, there still remains a problem that toner deterioration tends to proceed and developability is lowered.

  For this reason, the present invention can be suitably embodied by using a magnetic material-dispersed resin carrier as the carrier particles used in the present invention.

  The magnetic material-dispersed resin carrier can be easily controlled to have a desired magnetization amount, surface state, and resistance according to the magnetic properties, type, particle size and content of the magnetic material used, and sharpness of carrier particle size distribution and Characterized by high sphericity.

  When a two-component developer is prepared by mixing with the toner in the present invention, the mixing ratio is 2 to 15% by mass, preferably 3 to 13% by mass, more preferably 4 to 10% as the toner concentration in the developer. Good results are usually obtained with mass%.

  When the toner concentration is less than 2% by mass, the image density tends to be low, and when a toner containing a release agent is used, the developer is likely to deteriorate, which is not preferable. When the amount exceeds 15% by mass, the toner charge amount distribution becomes wide and fog and in-machine scattering occur, which is not preferable.

  The measuring method of each physical property value used in the present invention will be described below.

1. Method for Measuring Ia and Ib of Silica Particles X-ray diffraction measurement of the silica of the present invention is performed under the following conditions using CuKα rays and using the silica powder as a sample.

Used measuring machine / Mach Science, full automatic X-ray diffractometer MXP18
X-ray tube / Cu
Tube voltage / 50KV
Tube current / 300mA
Scan method / 2θ / θ scan Scan speed / 4deg. / Min
Sampling interval / 0.020 deg.
Start angle (2θ) / 3deg.
Stop angle (2θ) / 60 deg.
Divergence slit / 0.5 deg.
Scattering slit / 0.5 deg.
Receiving slit / 0.3mm.
Uses curved monochromator

2. Method for Measuring Titanium Compound Content of Silica Particles The amount of Ti is determined using a fluorescent X-ray analyzer SYSTEM 3080 (manufactured by Rigaku Corporation). It can be measured by performing fluorescent X-ray analysis according to JIS K0119 general X-ray fluorescence analysis rules.

3. Method for Measuring Primary Average Particle Size of Silica Particles The primary particle size is determined by observing the silica particles of the present invention with a transmission electron microscope and measuring the major axis of 100 particles to determine the number average particle size. The particle diameter on the toner particles is observed with a scanning electron microscope, and the major axis of 100 particles is measured to determine the number average particle diameter. The magnification at the time of measurement is 40,000 to 60,000 times, and targets particles of 0.5 nm or more.

4). As a measuring device for measuring the particle size distribution of toner particles , Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Inc.) is used. As the electrolytic solution, an about 1% NaCl aqueous solution is used. As the electrolytic solution, an electrolytic solution prepared using primary sodium chloride or, for example, ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan) can be used.

  As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzenesulfone hydrochloride) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of the sample are measured for each channel by the measuring device using a 100 μm aperture as the aperture. The volume distribution and the number distribution are calculated. From these obtained distributions, the weight average particle diameter of the sample is determined.

  As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32-40.30 μm are used.

5). Measuring method of maximum endothermic peak of toner The maximum endothermic peak of toner can be measured according to ASTM D3418-82 using a differential thermal analyzer (DSC measuring device) and DSC2920 (TA Instruments Japan). .

  As a measuring method, 5 to 20 mg, preferably 10 mg of a measurement sample is accurately weighed. This is put into an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min and normal temperature and humidity in a measurement temperature range of 30 to 200 ° C. An endothermic peak in the temperature range of 30 to 200 ° C. is obtained during this temperature raising process. When there are a plurality of peaks, the highest endothermic peak is the one having the highest height from the baseline in the region above the endothermic peak due to the resin.

6). Method for measuring molecular weight by GPC The molecular weight of a chromatogram by gel permeation chromatograph (GPC) is measured under the following conditions.

  Resin adjusted to 0.05 to 0.6% by mass as a sample concentration by stabilizing the column in a heat chamber at 40 ° C., and flowing tetrahydrofuran (THF) as a solvent at a flow rate of 1 ml / min. Measurement is performed by injecting 50 to 200 μl of a THF sample solution. An RI (refractive index) detector is used as the detector.

As the column, in order to accurately measure a molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, μ-styragel 500, 103, 104, 105 manufactured by Waters And combinations of shodex KA-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko KK are preferred.

In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Manufactured by Toyo Soda Kogyo Co., Ltd. and having molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples.

  The resin for forming the coating layer is obtained by placing carrier particles in methyl ethyl ketone so as to have a concentration of 10% by mass, and dispersing for 2 minutes using an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios). The filtrate obtained by filtering through a membrane filter having an opening of 0.2 μm is used.

7). Measuring method of toner particle aggregation degree To measure the toner particle aggregation degree, a powder tester P-100 (manufactured by Hosokawa Micron Corporation) is used, and sieves are arranged in the order of 143 μm, 76 μm, and 36 μm from the top on a vibration table. set. The vibration swing width is set to 0.5 mm, the vibration time is set to 15 seconds, and 5 g of toner is gently put on and vibrated. After the vibration is stopped, the mass remaining on each sieve is measured.

(Amount of toner remaining on upper screen) ÷ 5 (g) × 100... A
(Amount of toner remaining on the middle screen) ÷ 5 (g) × 100 × 0.6... B
(The amount of toner remaining on the lower screen) ÷ 5 (g) × 100 × 0.2... C
a + b + c = calculation degree (%)

8). Method for measuring the triboelectric charge amount of the toner The triboelectric charge amount of the toner of the present invention can be determined by the following method.

  First, the toner and the magnetic carrier are mixed so that the toner mass becomes 5% by mass, and then mixed for 120 seconds with a turbula mixer. This developer is put in a metal container with a 635 mesh conductive screen at the bottom, sucked with a suction machine, and the mass difference before and after suction and the potential accumulated in a capacitor connected to the container are measured. To do. At this time, the suction pressure is 250 mmH2O. From the mass difference, the stored potential, and the capacitance of the capacitor, the triboelectric charge amount of the toner is calculated using the following formula.

9. Permeability in 45% by volume methanol aqueous solution (i) Preparation of toner dispersion An aqueous solution having a volume mixing ratio of methanol: water of 45:55 is prepared. 10 ml of this aqueous solution is placed in a 30 ml sample bottle (Nippon Denka Glass: SV-30), and 20 mg of toner is impregnated on the liquid surface to cover the bottle.

  Then, it is made to shake for 5 seconds at 150 rpm with a Yayoi type shaker (model: YS-LD). At this time, the angle of shaking is such that the shaking column moves 15 degrees forward and 20 degrees backward, assuming that the vertical (vertical) of the shaker is 0 degree. The sample bottle is fixed to a fixing holder (with the sample bottle lid fixed on the extension at the center of the column) attached to the tip of the column. After removing the sample bottle, the dispersion after 30 seconds is used as a dispersion for measurement.

(Ii) Transmittance measurement The dispersion obtained in (i) is placed in a 1 cm square quartz cell, and the transmittance at a wavelength of 600 nm of the dispersion after 10 minutes using a spectrophotometer MPS2000 (manufactured by Shimadzu Corporation) ( %).
Transmittance (%) = I / I ₀ × 100 (I... Incident light beam I ₀ ... Transmitted light beam)

10. Measuring method of average circularity of toner The average circularity of toner is obtained when the circularity distribution of the toner is divided into i, the central circularity of each divided section is Ci, and the frequency of the section is f. And the value obtained by the following formula (1). The circularity (Ci) is an index indicating the degree of unevenness of the toner particles, and is a value obtained by the following formula (2).

  In the formula (2), “particle projected area” is the area of the binarized toner particle image, and “peripheral length of the particle projected image” is a contour obtained by connecting the edge points of the toner particle image. It is defined as the length of the line. The circularity is 1.000 when the toner particles are completely spherical, and the more complicated the surface shape, the smaller the circularity.

  The circularity and the average circularity can be measured using a flow type particle image measuring device “FPIA-1000 type” (manufactured by Sysmex Corporation).

  As a specific measurement method, 10 ml of ion-exchanged water from which impure solids and the like are previously removed is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, and then further measurement is performed. Add 0.02 g of sample and disperse uniformly.

  As a means for dispersing, an ultrasonic disperser “UH-50 type” (manufactured by SMT Co.) equipped with a titanium alloy chip having a diameter of 5 mm as a vibrator is used. Use a dispersion process for 5 minutes to obtain a dispersion for measurement. During the dispersion treatment, the dispersion is appropriately cooled so that the temperature does not exceed 40 ° C.

  The dispersion concentration is readjusted so that the toner particle concentration during measurement is 3000 to 10,000 particles / μl, and the circularity of 1000 or more toner particles is measured using the flow type particle image measuring device. After the measurement, using this data, the average circularity of the toner particles is obtained with data of 0.6 μm or more and 377.4 μm or less.

  In addition, by adjusting the concentration of the dispersion appropriately and using the flow type particle image measuring apparatus, the equivalent circle diameter, equivalent circle number average particle diameter, particle diameter standard deviation, circularity standard deviation, and the like of the toner are obtained. It is possible.

(Image forming method, image forming apparatus)
The image forming method in the present invention will be described. The image forming apparatus will be described together with the image forming method.

  The image forming method (apparatus) of the present invention comprises a charging step (means) for uniformly charging the surface of the electrostatic latent image carrier, and an exposure step of exposing the surface of the electrostatic latent image carrier to form an electrostatic latent image ( Means), a developing step (means) for developing a latent image on the surface of the electrostatic latent image carrier using a developer layer containing toner formed on the surface of the developer carrier, and a toner image A transfer step (means) for transferring the toner image onto the transfer member, and a fixing step (means) for fixing the toner image on the transfer member. The toner for developing an electrostatic charge image of the present invention is used as the toner. Use.

  In the image forming method (apparatus) of the present invention, by using the toner for developing an electrostatic image of the present invention, transferability is good for a long period of time, high image quality, and generation of image defects can be suppressed.

  The image forming method (apparatus) of the present invention uses the toner for developing an electrostatic charge image of the present invention, so that the toner remaining on the surface of the electrostatic latent image carrier due to contact with an elastic blade or the like is transferred to the electrostatic latent image carrier. The present invention can also be applied to an image forming method (apparatus) that does not have a cleaning process (means) for removing the surface while wearing it.

  As the electrostatic latent image carrier, a known layer such as an organic type or amorphous silicon can be used as the photosensitive layer. When the electrostatic latent image bearing member is cylindrical, it can be obtained by a known manufacturing method such as surface processing after extrusion molding of aluminum, aluminum alloy, SUS, or the like. Is preferably a small diameter of 50 mm or less. It is also possible to use a belt-like electrostatic latent image carrier.

  As the charging step (means), conventionally known methods such as non-contact charging by corotron or the like and contact charging of a charging roll, a charging film, a brush or the like can be applied, but a contact charger is preferably used from the viewpoint of ozone generation amount.

  A conventionally known method can be applied to the exposure step (means), and an electrostatic latent image is formed on a latent image carrier such as a photosensitive layer or a dielectric layer by electrophotography or electrostatic recording.

  In the development step (means), the developer layer containing the toner formed on the surface of the developer carrying member is conveyed to the development nip, and the developer layer and the electrostatic latent image holding member are brought into contact with each other in the developing unit or at a certain gap. The electrostatic latent image is developed with toner while applying a bias between the developer carrying member and the latent image holding member. As the developer, a two-component developer that charges a toner using a carrier or a one-component developer that forms a thin layer on a developer carrying member using an elastic blade or the like and charges the toner is used.

  The transfer process (means) is a contact type transfer in which a transfer roller, a transfer belt, or the like is pressed against the electrostatic latent image holding body to transfer the toner image to the transfer body, or a non-contact type in which the image is transferred to the transfer body using a corotron or the like. Used. The transfer process (means) includes a first transfer process (means) for primarily transferring the toner image formed on the electrostatic latent image carrier onto the intermediate transfer member, and transferring the toner image transferred onto the intermediate transfer member. It is particularly preferable to include a second transfer step (means) for secondary transfer to the body.

  Specifically, for example, in a full-color image forming apparatus, yellow, magenta, cyan, and black toners are directly transferred to a transfer body using a transfer roll, a conveyance belt, or the like around which a transfer body (for example, paper) is wound. In particular, an indirect transfer method in which four-color toner is transferred onto the intermediate transfer member in a multiple transfer (primary transfer) and then transferred onto the transfer member (secondary transfer) is particularly suitable. The intermediate transfer member may be belt-shaped or cylindrical, and a conventionally known one can be used.

  In the fixing step (means), the toner image transferred to the transfer member is fixed by a fixing device. As the fixing means, a heat fixing method using a heat roll is preferably used.

  FIG. 1 is a schematic explanatory diagram of a tandem apparatus suitably used in the image forming method (apparatus) of the present invention. The image forming apparatus 100 includes an image forming unit 1Y, an image forming unit 1M, an image forming unit 1C, an image forming unit 1K, an intermediate transfer body 9, a paper feeding unit 10, a transport unit 11, and a secondary transfer. Transfer means 12, fixing means 13, and stretching rolls 21 to 24.

  The image forming unit 1Y, the image forming unit 1M, the image forming unit 1C, and the image forming unit 1K are units of an image forming apparatus that form toner images of yellow, magenta, cyan, and black, respectively. The image forming unit 1Y, the image forming unit 1M, the image forming unit 1C, and the image forming unit 1K are arranged in series in this order with respect to the traveling direction of the endless intermediate transfer member 9 stretched by the stretch rolls 21 to 24. It is arranged. The intermediate transfer member 9 includes an electrostatic latent image carrier 2Y, an electrostatic latent image carrier 2M, an electrostatic latent image carrier 2C, and an electrostatic latent image carrier K provided in each image forming unit. The transfer means 6Y, the transfer means 6M, the transfer means 6C, and the transfer means 6K that are arranged to face each other are inserted.

  The image forming unit 1Y, the image forming unit 1M, the image forming unit 1C, and the image forming unit 1K are respectively electrostatic latent image carriers 2Y, 2M, 2C, and 2K, and charging units 3Y, 3M, 3C, 3K, Exposure means 4Y, 4M, 4C, 4K, developing means 5Y, 5M, 5C, 5K, and static elimination means 8Y, 8M, 8C, 8K.

  Electrostatic latent images are formed on the electrostatic latent image carriers 2Y, 2M, 2C, and 2K by charging units 3Y, 3M, 3C, and 3K and exposure units 4Y, 4M, 4C, and 4K, respectively. The electrostatic latent image becomes a toner image by the developing units 5Y, 5M, 5C, and 5K. This toner image is transferred onto the intermediate transfer member 9 by the transfer means 6Y, 6M, 6C, 6K. After the transfer, the image is erased by the static eliminating means 8Y, 8M, 8C, 8K remaining on the surface of the electrostatic latent image carrier.

  The image forming unit 1Y, the image forming unit 1M, the image forming unit 1C, and the image forming unit 1K form toner images of yellow, magenta, cyan, and black, respectively. Multi-stage transfer is performed on the intermediate transfer member 9 that proceeds in the direction from the unit 1Y to the image forming unit 1K to form an image.

  Further, the toner image on the intermediate transfer body 9 is transferred to a transfer body such as paper by the transfer means 12 for secondary transfer, and the toner image is fixed by the fixing means 13. In this way, an image is formed.

  Examples of production and examples relating to the present invention are shown below, but the present invention is not limited to these examples.

Production Example of Titanium Element-Containing Silica Particles (A) (Titanium Element-Containing Silica Particles A-1)
92 parts by mass of hexamethyldisiloxane and 8 parts by mass of titanium tetrapropoxide are sufficiently mixed at room temperature. This mixture was sprayed to form fine droplets, introduced into the burner together with oxygen, air and propane, and subjected to flame hydrolysis at a flame temperature of 2300 ° C. to obtain untreated titanium element-containing silica.

  Next, the surface treatment of the titanium element-containing silica is performed. 100 parts by mass of the titanium element-containing silica was put into a stirrer, and a mixed solution of 10 parts by mass of hexamethyldisilazane and 10 parts by mass of hexane was sprayed and stirred. Next, 5 parts by mass of dimethyl silicone oil and 10 parts by mass of hexane were sprayed and stirred. Thereafter, the obtained fine powder was heated to 120 ° C. and stirred, and the solvent was dried to obtain titanium element-containing silica particles A-1.

  The presence of titanium element in the silica particles was confirmed by EDAX (non-dispersive X-ray diffraction analyzer).

  Production examples of titanium element-containing silica particles A-1 are shown in Table 1.

(Titanium element-containing silica particles A-2)
Titanium element-containing silica particles A-2 are the same as titanium element-containing silica particles A-1, except that 1.5 parts by mass of titanium tetraisopropoxide is used and the amount of dimethyl silicone oil added is 10 parts by mass. Got.

(Titanium element-containing silica particles A-3)
Titanium element-containing silica particles A-3 were obtained in the same manner as titanium element-containing silica particles A-1, except that the reaction temperature was 2500 ° C. and dimethyl silicone oil was not used.

(Titanium element-containing silica particles A-4)
Titanium element-containing silica particles A-4 were obtained in the same manner as titanium element-containing silica particles A-2 except that 13 parts by mass of titanium tetraisopropoxide was used.

(Titanium element-containing silica particles A-5)
Titanium element-containing silica particles A-5 were obtained in the same manner as titanium element-containing silica particles A-2 except that 23 parts by mass of titanium tetraisopropoxide was used.

(Titanium element-containing silica particles A-6)
Titanium element-containing particles A-6 are the same as titanium element-containing silica particles A-2 except that 28 parts by mass of titanium tetraisopropoxide is used and the reaction temperature is 2000 ° C. by controlling the amount of propane supplied. Got.

(Titanium element-containing silica particles A-7)
Titanium element-containing silica particles A except that the propane supply amount is controlled to set the reaction temperature to 4200 ° C., that 7 parts by mass of dimethyldichlorosilane is added instead of hexamethyldisilazane, and that no dimethyl silicone oil is used. -4, titanium element-containing silica particles A-7 were obtained.

(Titanium element-containing silica particles A-8)
Except for controlling the propane supply amount to set the reaction temperature to 1400 ° C., adding 20 parts by mass of dimethyldichlorosilane, and not using dimethyl silicone oil, the same as titanium element-containing silica particles A-7. Titanium element-containing silica particles A-8 were obtained.

(Titanium element-containing silica particles A-9)
Titanium compound-containing silica particles A-9 were obtained in the same manner as titanium compound-containing silica particles A-4 except that hexamethyldisiloxane and titanium tetrachloride were used as raw materials.

(Titanium element-containing silica particles A-10)
Using silicon tetrachloride and titanium tetraisopropoxide as raw materials, controlling the propane supply amount and firing at 1000 ° C., except that dimethyl silicone oil is not used, similar to titanium compound-containing silica particles A-4, Titanium element-containing silica particles A-10 were obtained. The particle size at this time was 68 μm, and the BET specific surface area was 34 m ² / g.

(Titanium element-containing silica particles A-11)
Using titanium tetrachloride and titanium tetrachloride as raw materials, firing at 1000 ° C. by controlling the amount of propane supplied, and using titanium element in the same manner as the titanium compound-containing silica particles A-4 except that dimethyl silicone oil is not used. Contained silica particles A-11 were obtained. The particle diameter at this time was 70 μm, and the BET specific surface area was 35 m ² / g.

(Titanium element-containing silica particles A-12)
After 90 parts by mass of a silica sol having a BET specific surface area of 120 m ² / g and 10 parts by mass of a titania sol having a BET specific surface area of 200 m ² / g are sufficiently mixed in a wet manner, dehydration and drying are performed, and further, baking is performed at 300 ° C. for 3 hours. To obtain a mixed oxide. Then, the titanium element containing silica particle A-12 was obtained by carrying out surface treatment similarly to the titanium element containing silica particle A-3.

(Titanium element-containing silica particles A-13)
Titanium element-containing silica particles A-13 were obtained in the same manner as titanium element-containing silica particles A-12, except that firing was performed at 1000 ° C.

(Titanium element-containing silica particles A-14)
Titanium element-containing silica particles A-14 were obtained in the same manner as titanium element-containing silica particles A-13, except that firing was performed at 300 ° C.

(Titanium element-containing silica particles A-15)
Titanium element-containing silica particles A-15 were obtained in the same manner as titanium element-containing silica particles A-13 except that anatase-type titanium oxide having a BET specific surface area of 180 m ² / g was used.

(Titanium element-containing silica particles A-16)
Titanium element-containing silica particles A-16 were obtained in the same manner as titanium element-containing silica particles A-15 except that firing was performed at 1000 ° C.

Production example of hydrophobic silica particles (B) (hydrophobic silica particles B-1)
50 g of dry (fumed silica) silica (specific surface area 20 m ² / g, adsorbed moisture 0.4 mass%, surface OH number 1.5 / nm ² , apparent specific gravity 50 g / l, average in a 2 liter reactor The primary particle diameter was 100 nm, and was heated to 290 ° C. in a fluidized state. After replacing the inside of the reactor with nitrogen gas, water was supplied so that the partial pressure of water vapor was 0.2 kg / cm ² , the reactor was sealed, and hexamethyldisilazane was further divided into 2.0 kg / cm. It sprayed inside so that it might become ² , and the trimethylsilylation reaction was started in the fluidization state of the silica.

  The above reaction was continued for 60 minutes, and then the reaction was terminated. After completion of the reaction, the removal of excess hexamethyldisilazane and by-products from the hydrophobic silica was carried out by opening the autoclave and depressurizing it, followed by washing with a nitrogen gas stream, and the hydrophobic silica particles B-1 were removed. Obtained.

(Hydrophobic silica particles B-2)
Hydrophobic silica particles B-2 were obtained by the same production method as the hydrophobic silica particles B-1, except that the heating temperature in the fluidized state was 260 ° C. At this time, the primary particle size was about 140 nm.

(Hydrophobic silica particles B-3)
20 g of spherical silica, 100 g of methanol, 2 g of water, and 0.01 g (0.2 mmol) of KF were placed in a 500 ml reactor equipped with a stirrer, a thermometer and a condenser and mixed with stirring. 2 g (19 mmol) of trimethylmethoxysilane was added dropwise thereto, and the mixture was stirred and aged at room temperature for 1 hour. Next, the treated silica in the suspension after aging is filtered off with a Buchner funnel, washed with distilled water and then with acetone, and then treated with a vacuum dryer at 80 ° C. and 10 mmHg for 2 hours to remove the solvent, Silica particles B-3 whose surface was trimethylsilylated were obtained. At this time, the primary particle size was about 2000 nm.

(Hydrophobic silica particles B-4)
A hydrophobic silica particle B-4 was obtained by performing the same reaction and treatment as the hydrophobic silica particle B-3 except that trimethylmethoxysilane was changed to 2 g (13 mmol) of vinyltrimethoxysilane. At this time, the primary particle size was about 250 nm.

(Hydrophobic silica particles B-5)
The monodispersed spherical silica obtained by the sol-gel method was subjected to 10% HMDS treatment to obtain hydrophobic silica B-5. At this time, the primary particle size was about 120 nm.

(Hydrophobic silica particles B-6)
The same treatment as that for hydrophobic silica particles B-5 was performed to obtain hydrophobic silica particles B-6. At this time, the primary particle size was about 150 nm.

(Hydrophobic silica particles B-7)
In the production example of hydrophobic silica particles B-1, hydrophobic silica particles B-7 were obtained in the same manner except that the dry silica used had a specific surface area of 300 m ² and a particle diameter of 7 nm. At this time, the primary particle diameter was about 15 nm.

Production example of binder resin for toner (hybrid resin production example)
As a vinyl copolymer, 2.0 mol of styrene, 0.21 mol of 2-ethylhexyl acrylate, 0.14 mol of fumaric acid, 0.03 mol of α-methylstyrene dimer, and 0.05 mol of dicumyl peroxide are put into a dropping funnel. .

  In addition, 7.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane; 0 mol, 3.0 mol of terephthalic acid, 1.9 mol of trimellitic anhydride, 5.0 mol of fumaric acid and 0.2 g of dibutyltin oxide are put into a 4-liter 4-necked flask made of glass, a thermometer, a stirring rod, a condenser and nitrogen The inlet tube was installed and placed in a mantle heater.

  Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually increased while stirring, and while stirring at a temperature of 145 ° C., the monomer of the vinyl resin, the crosslinking agent and the polymerization initiator were added from the previous dropping funnel. It was dripped over 4 hours. Next, the temperature was raised to 200 ° C. and reacted for 4 hours to obtain a hybrid resin. The results of molecular weight measurement by GPC are shown in Table 1.

(Example of polyester resin production)
3.6 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.6 mol of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.7 mol of terephthalic acid, 1.4 mol of trimellitic anhydride, 2.4 mol of fumaric acid and 0.12 g of dibutyltin oxide are placed in a 4-liter glass four-necked flask, a thermometer, a stirring rod, a condenser and a nitrogen inlet tube Was placed in a mantle heater. Under a nitrogen atmosphere, reaction was performed at 215 ° C. for 5 hours to obtain a polyester resin. The results of molecular weight measurement by GPC are shown in Table 1.

(Example of styrene-acrylic resin production)
-70 parts by mass of styrene-24 parts by mass of n-butyl acrylate-6 parts by mass of monobutyl maleate-1 part by mass of di-t-butyl peroxide Stir the above components in 200 parts by mass of xylene in a four-necked flask. Then, the inside of the container was sufficiently replaced with nitrogen, and the temperature was raised to 120 ° C., followed by dropwise addition over 3.5 hours. Further, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain a styrene-acrylic resin. The results of molecular weight measurement by GPC are shown in Table 1.

Mold release agent used in this example

Production example of carrier particles (Production example 1 of carrier core)
4.0% by mass and 2.0% by mass of a silane coupling agent (3- (2- Aminoethylaminopropyl) trimethoxysilane) was added and mixed and stirred at 100 ° C. or higher in a container to make each fine particle lipophilic.

-Phenol 10 parts by mass-Formaldehyde solution (formaldehyde 37% by weight aqueous solution) 6 parts by mass-59 parts by weight of the above treated magnetite-25 parts by weight of the above treated hematite 25 parts by weight of the above materials, 28 parts by weight of ammonia water, 10 parts by weight of water The portion was placed in a flask, heated and maintained at 85 ° C. over 30 minutes with stirring and mixing, and cured by polymerization for 3 hours.

  Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 mmHg or less) at a temperature of 60 ° C. to obtain spherical carrier core particles (1) having an average particle diameter of 33 μm in a state where magnetic materials were dispersed.

(Carrier Core Production Example 2)
3.0% by mass of a silane coupling agent (3- (2-aminoethylaminopropyl) trimethyl) with respect to a magnetite powder having a number average particle size of 0.35 μm and a hematite powder having a number average particle size of 0.30 μm. Methoxysilane) was added and mixed and stirred at 100 ° C. or higher in a container to make each fine particle lipophilic.

-Phenol 10 parts by mass-Formaldehyde solution (formaldehyde 37 mass% aqueous solution) 6 parts by mass-Treated magnetite 76 parts by mass-Treated hematite 8 parts by mass The above materials, 28 mass% ammonia water 5 parts by mass, water 10 masses The portion was placed in a flask, heated and maintained at 85 ° C. over 30 minutes with stirring and mixing, and cured by polymerization for 3 hours.

  Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 mmHg or less) at a temperature of 60 ° C. to obtain spherical carrier core particles (2) having an average particle diameter of 32 μm in a state where the magnetic material was dispersed.

(Carrier Core Production Example 3)
2.0% by mass of titanium coupling agent isopropyltri (N-aminoethyl-aminoethyl) titanate is added to magnetite powder having a number average particle size of 0.25 μm, and high-speed mixing and stirring is performed at 100 ° C. or higher in a container. Then, the fine particles were made oleophilic.

-Phenol 10 parts by mass-Formaldehyde solution (formaldehyde 37% by weight aqueous solution) 8 parts by weight-The above treated magnetite 82 parts by weight The above materials, 28 parts by weight ammonia water 6 parts by weight, water 10 parts by weight are placed in a flask and stirred. While mixing, the temperature was raised to 85 ° C. in 30 minutes and the mixture was polymerized for 3 hours to be cured.

  Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 mmHg or less) at a temperature of 60 ° C. to obtain spherical carrier core particles (3) having an average particle diameter of 35 μm in a state where the magnetic material was dispersed.

(Carrier Core Production Example 4)
The mixture was weighed so that Fe2O3 = 50 mol%, CuO = 16 mol%, and MgO = 34 mol% in terms of molar ratio, and mixed for 10 hours using a ball mill.

  This was calcined at 900 ° C. for 2 hours, pulverized with a ball mill, and further granulated with a spray dryer. This was sintered at 1150 ° C. for 10 hours, pulverized and further classified to obtain spherical carrier core particles (4) having an average particle diameter of 34 μm.

(Manufacture example 1 of coating resin)
4-neck with 100 parts by mass of monomer unit of CH ₃ — (CH ₂ ) CO—O—CH ₂ —CF ₂ —CF ₃ arranged with a reflux condenser, a thermometer, a nitrogen suction pipe and a mixing type stirring device To the flask, 100 parts by mass of toluene, 100 parts by mass of methyl ethyl ketone, and 2.0 parts by mass of azobisisovaleronitrile were added, and the mixture was maintained at 70 ° C. for 10 hours under a nitrogen stream. Mass%). The weight average molecular weight by the gel permeation chromatogram (GPC) of the graft copolymer (a) was 40,000.

(Manufacture example 2 of coating resin)
2 parts by mass of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and having a weight average molecular weight of 5,000, CH ₃ — (CH ₂ ) CO—O—CH ₂ —CH ₂ — (CF ₂ ) ₇ —CF ₃ Are added to a 4-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a mixing type stirring apparatus, and further 90 parts by mass of toluene and 110 parts of methyl ethyl ketone. Part by mass and 2.0 parts by mass of azobisisovaleronitrile were added and kept at 70 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer (b) solution (solid content: 33% by mass). The weight average molecular weight by the gel permeation chromatogram (GPC) of the graft copolymer (b) was 35,000.

(Manufacture example 3 of coating resin)
5 parts by weight of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and a weight average molecular weight of 9,000, CH ₃ — (CH ₂ ) CO—O—CH ₂ —CH ₂ — (CF ₂ ) ₉ —CF ₃ Are added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a stirring type stirring device, and further 90 parts by mass of toluene and methyl ethyl ketone 110 are added. Mass parts and 0.7 parts by mass of azobisisovaleronitrile were added, and the mixture was kept at 70 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer (c) solution (solid content: 33% by mass). The weight average molecular weight by the gel permeation chromatogram (GPC) of the graft copolymer (c) was 150,000.

(Manufacture example 4 of coating resin)
2 parts by mass of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and a weight average molecular weight of 5,500, CH ₃ — (CH ₂ ) CO—O—CH ₂ —CH ₂ — (CF ₂ ) ₇ —CF ₃ 20 parts by mass of monomer and 78 parts by mass of methyl methacrylate are added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a mixing type stirring apparatus, and further 90 parts by mass of toluene and methyl ethyl ketone 110 are added. Part by mass and 2.0 parts by mass of azobisisovaleronitrile were added, and the mixture was kept at 70 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer (d) solution (solid content: 33% by mass). The weight average molecular weight by the gel permeation chromatogram (GPC) of the graft copolymer (d) was 39,500.

(Method for manufacturing magnetic carrier 1)
With respect to 30 parts by mass of the graft copolymer (a) solution, 0.5 part by mass of silica particles having a maximum peak particle size of 320 nm based on the number distribution and 100 parts by mass of toluene are mixed well by a homogenizer.

Next, while the carrier core (1) and 2000 parts by mass were stirred while continuously applying a shearing stress, the coating solution was gradually added, and the solvent was volatilized at 70 ° C. to perform resin coating on the carrier surface. . The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, cooled, crushed, classified by a 200 mesh sieve, average particle size 33 μm, true specific gravity 3.59 g / cm ³ , A magnetic carrier 1 having a magnetization intensity of 39 Am ² / kg, a specific resistance of 8 × 10 ¹² Ω · cm, and a powder contact angle of 101 ° was obtained.

(Method for producing magnetic carrier 2)
1 part by mass of silica particles having a maximum peak particle size of 320 nm based on the number distribution, 1 part by mass of carbon black having a maximum peak particle size of 35 nm based on the number distribution, and 60 parts by mass of toluene based on 60 parts by mass of the graft copolymer (a) solution. The mass part is mixed well by a homogenizer.

Next, while the carrier core (1) and 2000 parts by mass were stirred while continuously applying a shearing stress, the coating solution was gradually added, and the solvent was volatilized at 70 ° C. to perform resin coating on the carrier surface. . The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, cooled, crushed, classified by a 200 mesh sieve, average particle size 33 μm, true specific gravity 3.57 g / cm ³ , A magnetic carrier 2 having a magnetization intensity of 39 Am ² / kg, a specific resistance of 7 × 10 ¹² Ω · cm, and a contact angle of powder of 102 ° was obtained.

(Method for producing magnetic carrier 3)
3 parts by mass of silica particles having a maximum peak particle size of 290 nm based on the number distribution, 2 parts by mass of carbon black having a maximum peak particle size of 35 nm based on the number distribution, and 60 parts by mass of 60 parts by mass of the graft copolymer (b) solution. Thoroughly mix the parts by mass with a homogenizer.

Next, while the carrier core (1) and 2000 parts by mass were stirred while continuously applying a shearing stress, the coating solution was gradually added, and the solvent was volatilized at 70 ° C. to perform resin coating on the carrier surface. . The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, cooled, crushed, classified by a 200 mesh sieve, average particle size 33 μm, true specific gravity 3.55 g / cm ³ , A magnetic carrier 3 having a magnetization intensity of 38 Am ² / kg, a specific resistance of 4 × 10 ¹² Ω · cm, and a contact angle of 120 ° of powder was obtained.

(Method for manufacturing magnetic carrier 4)
7 parts by mass of titanium oxide particles having a maximum peak particle size of 140 nm based on the number distribution, 7 parts by mass of carbon black having a maximum peak particle size of 14 nm based on the number distribution, and 210 parts by mass of the graft copolymer (b) solution, toluene Mix 500 parts by mass well with a homogenizer.

Next, 2,000 parts by mass of the carrier core (1) was put in a fluidized bed coating apparatus, and the coating liquid was sprayed to perform resin coating on the carrier surface at 70 ° C. The resin-coated magnetic carrier particles were heat-treated while forming a fluidized bed at 100 ° C. for 2 hours, and were taken out after cooling while maintaining the fluidized bed. After pulverization, it is classified with a 200-mesh sieve, the average particle size is 35 μm, the true specific gravity is 3.54 g / cm ³ , the magnetization strength is 38 Am ² / kg, the specific resistance is 5 × 10 ¹⁴ Ω · cm, and the powder contacts A magnetic carrier 4 having an angle of 110 ° was obtained.

(Method for manufacturing magnetic carrier 5)
2 parts by mass of titanium oxide particles having a maximum peak particle size of 140 nm based on the number distribution and tin oxide having a maximum peak particle size of 103 nm based on the number distribution (Pastran 4310 Mitsui Kinzoku Co., Ltd.) with respect to 60 parts by mass of the graft copolymer (c) solution 6 parts by mass and 200 parts by mass of toluene are mixed well by a homogenizer.

Next, while the carrier core (1) and 2000 parts by mass were stirred while continuously applying shear stress, the above coating solution was gradually added, and coating was performed in the same manner as in Example 1 to obtain an average particle size of 33 μm. A magnetic carrier 5 having a specific gravity of 3.59 g / cm ³ , a magnetization strength of 38 Am ² / kg, a specific resistance of 9 × 10 ¹² Ω · cm, and a powder contact angle of 105 ° was obtained.

(Method for manufacturing magnetic carrier 6)
For 90 parts by mass of the graft copolymer (b) solution, 4.5 parts by mass of silica particles having a maximum peak particle size of 290 nm based on the number distribution, 3 parts by mass of carbon black having a maximum peak particle size of 29 nm based on the number distribution, Mix 200 parts by mass of toluene well with a homogenizer.

Next, the carrier core (1) is changed to the carrier core (3), 2000 parts by mass, the coating liquid is gradually added while stirring while continuously applying shear stress, and the solvent is volatilized at 70 ° C. Resin coating was applied to the surface. The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, cooled, crushed, classified by a 200 mesh sieve, average particle size 32 μm, true specific gravity 3.60 g / cm ³ , A magnetic carrier 6 having a magnetization intensity of 49 Am ² / kg, a specific resistance of 4 × 10 ¹¹ Ω · cm, and a powder contact angle of 115 ° was obtained.

(Method for manufacturing magnetic carrier 7)
3 parts by mass of a crosslinked polymethyl methacrylate particle having a maximum peak particle size of 220 nm based on the number distribution obtained by soap-free emulsion polymerization and 90 ppm by mass of the graft copolymer (b) solution, and a maximum peak particle size based on the number distribution 3 parts by mass of 29 nm carbon black and 200 parts by mass of toluene are mixed well by a homogenizer.

Next, the carrier core (1) is changed to the carrier core (3), 2000 parts by mass, and the coating liquid is gradually added while stirring while continuously applying shear stress. A resin coat was applied to A magnetic carrier 7 having an average particle diameter of 35 μm, a true specific gravity of 3.62 g / cm ³ , a magnetization strength of 61 Am ² / kg, a specific resistance of 7 × 10 ¹⁰ Ω · cm, and a powder contact angle of 107 ° was obtained.

(Method for producing magnetic carrier 8)
With respect to 30 parts by mass of the graft copolymer (a) solution, 0.5 part by mass of silica particles having a maximum peak particle size of 320 nm based on the number distribution and 100 parts by mass of toluene are mixed well by a homogenizer.

Next, the carrier core (1) is changed to the carrier core (4), 2000 parts by mass, the coating liquid is gradually added while stirring while continuously applying shear stress, and the solvent is volatilized at 70 ° C. Resin coating was applied to the surface. The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, cooled, crushed, classified by a 200 mesh sieve, average particle size 35 μm, true specific gravity 5.04 g / cm ³ , A magnetic carrier 8 having a magnetization strength of 60 Am ² / kg, a specific resistance of 5 × 10 ⁸ Ω · cm, and a contact angle of 103 ° of powder was obtained.

(Method for producing magnetic carrier 9)
100 parts by mass of a silicone resin (SR 2411 manufactured by Toray Dow Silicone Co., Ltd., 10% by mass), 3 parts by mass of γ-aminopropyltrimethoxysilane, and 200 parts by mass of toluene are mixed and changed to a carrier core (1) and 1000 parts by mass. The above coating solution was gradually added while stirring while continuously applying stress, and the solvent was volatilized at 70 ° C. to perform resin coating on the carrier surface.

The resin-coated magnetic carrier particles were heat-treated with stirring at 200 ° C. for 1 hour, cooled, crushed, classified with a 200-mesh sieve, average particle size 34 μm, true specific gravity 3.55 g / cm ³ , A magnetic carrier 9 having a magnetization intensity of 38 Am ² / kg, a specific resistance of 5 × 10 ¹³ Ω · cm, and a powder contact angle of 100 ° was obtained.

  A toner was prepared by the following method using the above materials.

(Toner Production Example 1)
Hybrid resin 100 parts by weight Wax A 3 parts by weight 1,4-di-t-butylsalicylic acid aluminum compound 2 parts by weight Cyan pigment (Pigment Blue 15: 3) 5 parts by weight Mixing, melt-kneading with a twin-screw extrusion kneader, after cooling, coarsely pulverized to about 1-2 mm using a hammer mill, then finely pulverized to a particle size of 20 μm or less with an air jet type fine pulverizer, Cyan particles 1 (classified product) were obtained.

  1.0 part of titanium element-containing silica particles A-1 (primary particle size 70 nm) and 1.0 part of hydrophobic silica particles B-1 (primary particle size 120 nm) are externally added to the cyan particles using a Henschel mixer. Thus, Toner 1 was obtained.

  The weight average diameter of this toner 1 was 6.8 μm, the average circularity was 0.950, and the permeability in a 45 volume% methanol aqueous solution was 30%. Details are shown in Table 3.

(Toner Production Example 2)
A toner 2 was obtained in substantially the same manner except that the wax A was changed to the wax B in the toner production example 1.

  This toner 2 had a weight average diameter of 6.8 μm, an average circularity of 0.946, and a permeability of 45% in methanol by volume of 45%. Details are shown in Table 3.

(Toner Production Example 3)
A toner 3 was obtained in substantially the same manner except that the wax A was changed to the wax C in the toner production example 1.

  This toner 3 had a weight average diameter of 6.5 μm, an average circularity of 0.947, and a permeability of 21% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 4)
In Toner Production Example 3, toner 4 was obtained in substantially the same manner except that 50 parts by mass of each of the binder resin and the polyester resin were used.

  The toner 4 had a weight average diameter of 7.0 μm, an average circularity of 0.950, and a transmittance of 60% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 5)
In Toner Production Example 4, Toner 5 is used in substantially the same manner except that Wax D is used instead of Wax A, and no aluminum 1,4-di-t-butylsalicylate is used. Got.

  The weight average diameter of this toner 5 was 5.8 μm, the average circularity was 0.944, and the permeability in a 45 volume% methanol aqueous solution was 53%. Details are shown in Table 3.

(Toner Production Example 6)
In Toner Production Example 5, toner 6 is obtained in substantially the same manner except that 50 parts by mass of each of styrene acrylic resin and hybrid resin are used as binder resins and wax E is used instead of wax D. It was.

  The toner 6 had a weight average diameter of 6.4 μm, an average circularity of 0.952, and a permeability in an aqueous solution of 45% by volume of methanol of 58%. Details are shown in Table 3.

(Toner Production Example 7)
A toner 7 was obtained in substantially the same manner except that the wax B was used instead of the wax D in the toner production example 5.

  The toner 7 had a weight average diameter of 5.3 μm, an average circularity of 0.960, and a permeability of 28% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 8)
A toner 8 was obtained in substantially the same manner except that the wax B was used instead of the wax E in the toner production example 6.

  The weight average diameter of this toner 8 was 7.1 μm, the average circularity was 0.946, and the permeability in a 45 volume% methanol aqueous solution was 59%. Details are shown in Table 3.

(Toner Production Example 9)
A toner 9 was obtained in substantially the same manner except that the wax E was used instead of the wax B in the toner production example 8.

  The toner 9 had a weight average diameter of 4.8 μm, an average circularity of 0.952, and a transmittance of 66% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 10)
Toner 10 was obtained in substantially the same manner except that in the toner production example 9, a polyester resin was used as the binder resin.

  The toner 10 had a weight average diameter of 5.9 μm, an average circularity of 0.950, and a permeability of 51% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 11)
In Toner Production Example 1, P.P. 15 instead of cyan pigment (Pigment Blue 15: 3) Y. 180, and 1.0 part by mass of titanium element-containing silica A-2 (primary particle size 63 nm) and 1.5 parts by mass of hydrophobic silica particles B-2 having a primary particle size of 110 nm are used as external additives. Except for this, the toner 11 was obtained in substantially the same manner.

  The toner 11 had a weight average diameter of 6.9 μm, an average circularity of 0.953, and a transmittance of 28% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 12)
In Toner Production Example 1, P.P. 15 instead of cyan pigment (Pigment Blue 15: 3) Y. A toner 12 was obtained in substantially the same manner except that 74 was used.

  The toner 12 had a weight average diameter of 6.2 μm, an average circularity of 0.938, and a permeability of 29% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 13)
Toner 13 was obtained in substantially the same manner as in Toner Production Example 1, except that a hybridizer machine manufactured by Nara Machinery Co., Ltd. was used and titanium element-containing silica A-1 was fixed to the toner base particles.

  The toner 13 had a weight average diameter of 6.1 μm, an average circularity of 0.958, and a transmittance of 70% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 14)
In Toner Production Example 10, the production conditions were changed using styrene-acrylic resin, and 1.0 part by mass of titanium element-containing silica A-3 (primary particle size 81 nm) as an external additive and a hydrophobic particle having a primary particle size of 130 nm Toner 14 was obtained in substantially the same manner except that 2.0 parts by mass of functional silica particles B-3 were contained.

  The toner 18 had a weight average diameter of 7.6 μm, an average circularity of 0.951, and a transmittance of 30% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 15)
In Toner Production Example 10, wax F is used and, as an external additive, 1.0 part by mass of titanium element-containing silica A-1 and 1.0 part by mass of hydrophobic silica particles having a primary particle size of 120 nm are contained. Except for this, toner 15 was obtained in substantially the same manner.

The toner 15 had a weight average diameter of 7.1 μm, an average circularity of 0.944, and a transmittance of 7% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.
(Toner Production Example 16)
Toner 16 was obtained in substantially the same manner as in Toner Production Example 15 except that wax G was used instead of wax F.

  The toner 16 had a weight average diameter of 7.6 μm, an average circularity of 0.951, and a permeability of 71% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 17)
In Toner Production Example 1, the same procedure was performed except that titanium element-containing silica particles A-4 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-5 were used instead of hydrophobic silica particles B-1. Toner 17 was obtained.

  The toner 17 had a weight-average diameter of 6.8 μm, an average circularity of 0.947, and a permeability in a 45% by volume aqueous methanol solution of 53%. Details are shown in Table 3.

(Toner Production Example 18)
In Toner Production Example 4, the same procedure was performed except that titanium element-containing silica particles A-4 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-5 were used instead of hydrophobic silica particles B-1. Toner 18 was obtained.

  The toner 18 had a weight average diameter of 6.7 μm, an average circularity of 0.951, and a permeability of 41% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 19)
In Toner Production Example 5, the same procedure was performed except that titanium element-containing silica particles A-9 were used instead of titanium element-containing silica particles A-1, and that hydrophobic silica particles B-6 were used instead of hydrophobic silica particles B-1. Toner 19 was obtained.

  The weight average diameter of the toner 19 was 6.3 μm, the average circularity was 0.962, and the permeability in a 45% by volume aqueous methanol solution was 61%. Details are shown in Table 3.

(Toner Production Example 20)
In Toner Production Example 6, the same procedure was performed except that titanium element-containing silica particles A-10 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-6 were used instead of hydrophobic silica particles B-1. Toner 20 was obtained.

  The toner 20 had a weight average diameter of 6.8 μm, an average circularity of 0.950, and a transmittance of 57% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 21)
In Toner Production Example 8, the same procedure was performed except that titanium element-containing silica particles A-11 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-2 were used instead of hydrophobic silica particles B-1. Toner 21 was obtained.

  The toner 21 had a weight average diameter of 7.3 μm, an average circularity of 0.945, and a transmittance of 60% in a methanol 45 volume% aqueous solution. Details are shown in Table 3.

(Toner Production Example 22)
In Toner Production Example 9, the same procedure was performed except that titanium element-containing silica particles A-12 were used instead of titanium element-containing silica particles A-1, and that hydrophobic silica particles B-3 were used instead of hydrophobic silica particles B-1. Toner 21 was obtained.

  The toner 21 had a weight average diameter of 5.4 μm, an average circularity of 0.950, and a permeability of 62% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 23)
Toner 23 was obtained in the same manner as in Toner Production Example 1 except that titanium element-containing silica particles A-6 were used instead of titanium element-containing silica particles A-1.

  The toner 23 had a weight-average diameter of 6.7 μm, an average circularity of 0.948, and a permeability in a 45% by volume methanol aqueous solution of 48%. Details are shown in Table 3.

(Toner Production Example 24)
Toner 24 was obtained in the same manner as in Toner Production Example 1 except that titanium element-containing silica particles A-7 were used instead of titanium element-containing silica particles A-1.

  The toner 24 had a weight average diameter of 6.6 μm, an average circularity of 0.950, and a permeability of 42% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 25)
Toner 25 was obtained in the same manner as in Toner Production Example 1 except that titanium element-containing silica particles A-8 were used instead of titanium element-containing silica particles A-1.

  The toner 25 had a weight average diameter of 6.6 μm, an average circularity of 0.950, and a permeability of 46% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 26)
In Toner Production Example 12, the procedure was the same except that titanium element-containing silica particles A-13 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-4 were used instead of hydrophobic silica particles B-1. Toner 26 was obtained.

  The toner 26 had a weight average diameter of 6.4 μm, an average circularity of 0.938, and a permeability of 31% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 27)
In Toner Production Example 2, the procedure was the same except that titanium element-containing silica particles A-14 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-4 were used instead of hydrophobic silica particles B-1. Toner 27 was obtained.

  The toner 27 had a weight-average diameter of 6.8 μm, an average circularity of 0.967, and a permeability in a 45% by volume aqueous methanol solution of 53%. Details are shown in Table 3.

(Toner Production Example 28)
In Toner Production Example 4, the same procedure was performed except that titanium element-containing silica particles A-15 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-7 were used instead of hydrophobic silica particles B-1. Toner 28 was obtained.

  The toner 28 had a weight average diameter of 7.1 μm, an average circularity of 0.954, and a transmittance of 61% in a 45 volume% methanol aqueous solution. Details are shown in Table 3.

(Toner Production Example 29)
In Toner Production Example 5, the procedure was the same except that titanium element-containing silica particles A-16 were used instead of titanium element-containing silica particles A-1, and hydrophobic silica particles B-7 were used instead of hydrophobic silica particles B-1. Toner 29 was obtained.

  The weight average diameter of the toner 29 was 7.1 μm, the average circularity was 0.963, and the permeability in a 45 volume% methanol aqueous solution was 48%. Details are shown in Table 3.

<Example 1>
To 92 parts by mass of the magnetic carrier 1 obtained above, 8 parts by mass of toner 1 was added and mixed with a V-type mixer or the like to obtain a start developer. Details are shown in Table 1.

  Using this developer, Canon's full-color copier CLC5000 remodeled machine (with a laser spot diameter reduced so that a secondary transfer mechanism can be mounted, output can be made at 600 dpi, and the surface of the fixing roller of the fixing unit is changed to a PFA tube, oil The image formation evaluation was performed using a device with the coating mechanism removed and a modified CLC5000. The developing condition is that the developing sleeve and the photosensitive member are rotated in the forward direction in the developing region, the developing sleeve is 1.85 times the photosensitive member, Vd−600V, Vl−110V, Vdc−450V, Vpp2 kV, frequency 1 8 kHz.

  These evaluation results are shown in Table 2. The image evaluation items and evaluation criteria are shown below.

(1) Transfer efficiency Using a color copier CLC5000 (manufactured by Canon Inc.), using a chart on which a plurality of circle or band images can be formed, tap the remaining transfer portion on the drum and on the intermediate transfer member onto the paper. The density applied is D1, and the density transferred to the paper and taped is D2.
Transfer efficiency (%) = D2 / (D1 + D2) × 100.

(2) Scattering The image scattering was evaluated by evaluating the image scattering of a horizontal line pattern in which 4-dot horizontal lines were printed every 176 dot spaces, using the above-described image drawing tester.
◎: Image with little image scattering even by magnified observation ○: Image with little image scattering even by magnified observation ○ △: Text blurs slightly due to scattering Δ: Due to scattering, line thickness becomes uneven ×: Due to scattering , Some small characters are crushed

(3) Dot reproducibility A 30H image was formed using the toner and the remodeling machine, this image was visually observed, and the dot reproducibility of the image was evaluated based on the following criteria. 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.
A: Smooth and smooth.
B: I don't feel a lot of rustling.
C: Although there is a slight feeling of roughness, it is at a level where there is no practical problem.
D: There is a feeling of roughness and is a problem.
E: There is a very rough feeling.

<Examples 2 to 22>
Tables 1 and 2 show the toners used in Examples 2 to 22 and the evaluation results.

<Comparative Examples 1-7>
Tables 1 and 2 show the toners used in Comparative Examples 1 to 7 and the evaluation results.

Claims (10)

In a toner having colored particles containing a resin and a colorant and at least two types of silica particles,
(1) The first silica particles (A) contain a titanium element, and in X-ray diffraction,
0.7 ≦ (Ia ₁ / Ib ₁ ) ≦ 2.0 and 0.7 ≦ (Ia ₂ / Ib ₂ ) ≦ 2.0
(Ia ₁ indicates the maximum intensity at 2θ = 25.3, Ib ₁ indicates the average intensity at 2θ = 25.3 ± 2.0 deg, Ia ₂ indicates the maximum intensity at 2θ = 27.5, and Ib 1 ₂ shows the average value of intensity at 2θ = 27.5 ± 2.0 deg.)
And the number average particle size (RA) is 30 to 100 nm,
(2) The second silica particles (B) are silica particles having a number average particle size (RB) of 100 to 500 nm and having a hydrophobic surface, unlike the first silica particles (A). Toner.   2. The toner according to claim 1, wherein the number average particle diameter (RA) of the silica particles (A) and the number average particle diameter (RB) of the silica particles (B) satisfy RA <RB.   The toner according to claim 1, wherein the silica particles (A) contain 0.1 to 20 parts by mass of titanium element (per 100 parts by mass of titanium element-containing silica particles).   The toner according to any one of claims 1 to 3, wherein the liberation rate of the silica particles (A) + silica particles (B) from the toner surface is 0.1 to 0.5.   The toner according to claim 1, wherein the number average particle diameter (RA) of the silica particles (A) is 30 to 70 nm.   The toner according to claim 1, wherein the number average particle diameter (RB) of the silica particles (B) is 100 to 300 nm.   7. The toner according to claim 1, wherein either the silica particle (A) or the silica particle (B) is processed on the toner surface by an impact type powder processing apparatus.   The toner according to claim 1, wherein the toner has a weight average particle diameter of 3.0 to 8.0 μm.   The toner according to claim 1, wherein an average circularity of the toner is 0.940 or more and 0.965 or less. The toner according to claim 1, wherein the toner has a transmittance of 10 to 70 in a 45 volume% methanol aqueous solution.