JP2013190615A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, developer cartridge, process cartridge, image forming method, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development capable of providing images with less image quality failure even under a low-temperature and low-humidity condition.SOLUTION: A toner for electrostatic charge image development contains toner base particles, and an external additive externally added to the toner base particles. The external additive contains composite particles containing silica and titania, and silica particles having the number average particle diameter of 60 nm or more and 600 nm or less; and the abundance ratio of titanium atoms relative to silicon atoms on a toner outermost surface is 5 atom% or less.

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a developer cartridge, a process cartridge, an image forming method, and an image forming apparatus.

A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image (electrostatic latent image) is formed on a photoreceptor (image carrier) by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and a transfer and fixing process. It is visualized through. The developer used here includes a two-component developer comprising a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone. The toner is usually produced by using a thermoplastic resin as a pigment. In addition, a kneading and pulverizing method is used in which melt-kneading is performed together with a release agent such as a charge control agent and wax, cooling, pulverization, and further classification. In these toners, if necessary, inorganic and organic particles for improving fluidity and cleaning properties may be added to the toner particle surfaces.
Examples of conventional toner include toners described in Patent Document 1 or 2.
In Patent Document 1, at least colored resin particles formed by a wet method and an electrostatic charge image developing toner containing an external additive, silica having a number average primary particle size of 35 to 100 nm is used as the external additive. -An electrostatic charge image developing toner is disclosed, wherein titania composite oxide particles are used, and the content of titania in the silica-titania composite oxide particles is 5 to 45 wt%.
In Patent Document 2, at least the surface of the electrostatic latent image carrier is charged by a charging unit, the step of forming an electrostatic latent image on the surface of the electrostatic latent image carrier by an exposure unit, and the electrostatic latent image And developing the toner image with a developing means, transferring the developed toner image onto a recording medium with a transfer means, and fixing the transferred toner image with a fixing means. The charging means for charging the surface of the electrostatic latent image carrier is a charging roller for contacting and charging the electrostatic latent image carrier, and the ten-point average surface roughness Rz is 5 The toner to be attached to the electrostatic latent image by the developing means is composed of a toner base material containing at least a binder resin, a coloring material, and a release agent and an external additive, and the external additive is composed of titanium oxide and oxide. Complex acid consisting of silicon The composite oxide has a core-shell structure in which the core portion contains titanium oxide and the shell portion contains silicon oxide, the titanium oxide content is 80 to 95% by weight, and the BET of the composite oxide An image forming method having a specific surface area of 50 to 100 m ² / g is disclosed.

JP 2009-237338 A JP 2010-20024 JP

  An object of the present invention is to provide an electrostatic image developing toner capable of obtaining an image with little image quality defect even under low temperature and low humidity.

The above-described problems of the present invention have been solved by means described in the following <1> and <4> to <9>. It is described below together with <2> and <3> which are preferred embodiments.
<1> A toner base particle and an external additive externally added to the toner base particle, wherein the external additive includes silica and titania composite particles, and a number average particle diameter of 60 nm to 600 nm. A toner for developing an electrostatic charge image, comprising a certain silica particle, wherein an abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 5 atm% or less,
<2> The toner for developing an electrostatic charge image according to <1>, wherein the number average particle diameter of the silica particles is from 80 nm to 500 nm.
<3> The electrostatic charge image developing toner according to <1> or <2>, wherein the abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 1 to 5 atm%.
<4> An electrostatic image developer comprising the electrostatic image developing toner according to any one of <1> to <3> and a carrier,
<5> Toner cartridge containing the electrostatic image developing toner according to any one of <1> to <3>
<6> A developer cartridge containing the electrostatic image developer according to <4>,
<7> A process cartridge comprising a developer holder that contains the electrostatic image developer according to <4> and holds and conveys the electrostatic image developer.
<8> A latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and a developing step for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image. And a fixing step for fixing the toner image transferred to the surface of the transfer body, and the developer is any one of <1> to <3> An image forming method using the electrostatic image developing toner according to claim 1 or the electrostatic charge image developer according to <4>,
<9> Image carrier, charging unit for charging the image carrier, exposure unit for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier, and development including toner Developing means for developing the electrostatic latent image with an agent to form a toner image, transfer means for transferring the toner image from the image holding member to the surface of the transfer target, and toner transferred to the surface of the transfer target An electrostatic image developing toner according to any one of <1> to <3>, or an electrostatic charge image developing according to <4>. An image forming apparatus comprising an agent.

According to the inventions described in the above <1> and <3>, there is provided an electrostatic charge image developing toner capable of obtaining an image with less image quality defect even at a low temperature and low humidity as compared with the case without this configuration. can do.
According to the invention described in the above <2>, the electrostatic charge image development can obtain an image with less density fluctuation even at low temperature and low humidity as compared with the case where the number average particle diameter of silica particles is less than 80 nm and more than 500 nm. Toner can be provided.
According to the invention described in <4>, it is possible to provide an electrostatic charge image developer capable of obtaining an image with less image quality defects even at low temperature and low humidity as compared with the case where the present configuration is not provided.
According to the invention described in <5>, the toner containing the electrostatic charge image developing toner that can obtain an image with less image quality defect even at low temperature and low humidity as compared with the case without this configuration A cartridge can be provided.
According to the invention described in <6>, the developer containing the electrostatic charge image developer capable of obtaining an image with less image quality defect even at low temperature and low humidity as compared with the case without the present configuration. A cartridge can be provided.
According to the invention described in the above <7>, a process cartridge containing an electrostatic charge image developer capable of obtaining an image with less image quality defect even at a low temperature and low humidity as compared with the case without this configuration. Can be provided.
According to the invention described in <8> above, it is possible to provide an image forming method capable of obtaining an image with few image quality defects even at low temperature and low humidity as compared with the case where the present configuration is not provided.
According to the invention described in <9>, it is possible to provide an image forming apparatus capable of obtaining an image with less image quality defects even at low temperature and low humidity as compared with the case where the present configuration is not provided.

Hereinafter, the present embodiment will be described.
In the present embodiment, the description “A to B” represents not only a range between A and B but also a range including A and B at both ends thereof. For example, if “A to B” is a numerical value range, “A or more and B or less” or “B or more and A or less” is represented.

(Static image developing toner)
The electrostatic image developing toner of the present embodiment (hereinafter also simply referred to as “toner”) contains toner base particles and an external additive externally added to the toner base particles. , Composite particles containing silica and titania (hereinafter also simply referred to as “composite particles”), and silica particles having a number average particle diameter of 60 nm to 600 nm (hereinafter also referred to as “large diameter silica particles”). And the abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 5 atm% or less.

Since titania has a low resistance, it has an excellent charge exchange property. It has also been found that transfer maintenance and high fluidity can be obtained by adding large-diameter silica to the toner surface.
The inventors of the present invention have developed that the large-diameter silica is liberated due to the electrostatic interaction of titania under low temperature and low humidity, and the large-diameter silica adheres to the carrier, thereby reducing the charge amount of the carrier and high area coverage, It has been found that when the amount of toner supply is large, the contamination of the carrier is promoted, the image density changes, and the image quality is poor.
As a result of intensive studies, the present inventors have used composite particles containing silica and titania as external toner additives and large-diameter silica particles, and the ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 5 atm. It has been found that by setting the ratio to not more than%, liberation of large-diameter silica is suppressed, and poor image quality can be prevented even under low temperature and low humidity.
Hereinafter, each component and physical property value constituting the toner will be described in detail.

<Abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner>
In the toner of this embodiment, the abundance ratio of titanium atoms to silicon atoms on the toner outermost surface is 5 atm% (atomic%) or less. That is, when the abundance of silicon atoms on the outermost surface of the toner is A (atm%) and the abundance of titanium atoms is B (atm%), it means that (B / A) × 100 is 5 atm% or less. .
The abundance ratio is preferably 0.1 atm% or more, more preferably 0.3 atm% or more, and further preferably 1 atm% or more. With the above aspect, an image with little density fluctuation and poor image quality can be obtained even under low temperature and low humidity.
When the ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 0.1 atm% or more, the charge exchange function is sufficient and image fogging is suppressed. Moreover, the transfer to the carrier of a large diameter silica particle is suppressed as it is 5 atm% or less, and area coverage dependence is suppressed.

The abundance ratio of titanium atoms to silica atoms on the outermost surface of the toner is measured by X-ray photoelectron spectroscopy (XPS). The measurement method is not particularly limited as long as it is an X-ray photoelectron spectroscopic analysis method. Specifically, XPS measurement is performed using an X-ray photoelectron spectroscopic analyzer (JPS9000MX, manufactured by JEOL Ltd.). The measurement is performed under the measurement conditions of an acceleration voltage of 10 kV and a current value of 30 mA.
In XPS measurement, it is possible to measure the element distribution on the very surface (several nm) of a substance.

The fact that the abundance ratio of titanium atoms to silicon atoms on the toner surface is 5 atm% or less means that most of the surface (surface layer) of the composite particles containing silica and titania is silica, and there is little titania exposed on the surface. Means.
In some cases, the toner base particles contain a small amount of titanium atoms as a catalyst or the like.

(External additive)
The toner according to the exemplary embodiment includes an external additive externally added to the toner base particles, and the external additive includes composite particles containing silica and titania, and silica particles having a number average particle diameter of 60 nm to 600 nm. including.
The toner according to the exemplary embodiment may include one kind of each of composite particles containing silica and titania and silica particles having a number average particle diameter of 60 nm to 600 nm, or two or more kinds. . Further, the toner of the present exemplary embodiment may include external additives other than composite particles containing silica and titania and silica particles having a number average particle diameter of 60 nm to 600 nm.
As an external addition method of the external additive in the toner of the exemplary embodiment, for example, a method in which the toner base particles and the external additive are mixed by using a Henschel mixer or a V blender is exemplified. In addition, when the toner base particles are produced by a wet method, external addition can also be performed by a wet method.

<Composite particles containing silica and titania>
The toner of this embodiment includes composite particles containing silica and titania as external additives. By having composite particles containing silica and titania as external additives, contact between large-diameter silica particles and titania, which will be described later, is reduced while maintaining charge exchange properties, and surface charge becomes non-uniform (surface charge difference) The image density can be suppressed even in high area coverage by suppressing the polarization of charging of the large-diameter silica resulting from the above, and suppressing the liberation of the large-diameter silica and adhesion (migration) to the carrier.
It is assumed that the charged state of the large-diameter silica is polarized by contact with other materials containing titania, so that the transition to carriers is promoted. By making composite particles containing silica and titania, the charge difference is reduced. It is thought that.
In the composite particles, when the titania is completely covered with silica, the charge exchange property is not sufficiently maintained. The partial coating can be confirmed by observing the toner slice with a transmission electron microscope (TEM).

In the toner of the exemplary embodiment, the content of the composite particles containing silica and titania is not particularly limited, but is preferably 0.3 to 10% by weight with respect to the total weight of the toner, 0.5 to It is more preferably 5% by weight, and still more preferably 0.8 to 2.0% by weight.
In the toner of the present exemplary embodiment, the content ratio of the large-diameter silica particles and the composite particles containing silica and titania is not particularly limited, but the weight ratio (silica particles: composite particles) is 50: 1. It is preferably ˜1: 10, more preferably 40: 1 to 1: 5, and still more preferably 30: 1 to 1: 1.

The method for producing composite particles containing silica and titania is not particularly limited, but a step of preparing an alkali catalyst solution containing an alkali catalyst in a solvent containing alcohol, and a metal alkoxide monomer in the alkali catalyst solution And a step of supplying the alkali catalyst to produce particles.
The method for preparing the metal alkoxide monomer may be a method of mixing a tetraalkoxytitanium monomer in a tetraalkoxysilane monomer, a method of mixing a tetraalkoxysilane monomer in a tetraalkoxytitanium monomer, or dropping a tetraalkoxysilane. Alternatively, tetraalkoxytitanium may be dropped and particle-grown after particle formation, or tetraalkoxysilane may be dropped and particle-grown after tetraalkoxytitanium is dropped and granulated.

-Preparation process-
The method for producing composite particles containing silica and titania preferably includes a step (preparation step) of preparing an alkaline catalyst solution containing an alkali catalyst in a solvent containing alcohol.
A preparation process should just prepare the solvent containing alcohol, add an alkali catalyst to this, and prepare an alkali catalyst solution.
The solvent containing alcohol may be a solvent of alcohol alone or, if necessary, ketones such as water, acetone, methyl ethyl ketone, methyl isobutyl ketone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, It may be a mixed solvent with other solvents such as ethers such as dioxane and tetrahydrofuran. In the case of a mixed solvent, the amount of alcohol relative to the other solvent is preferably 80% by weight or more, and more preferably 90% by weight or more.
Examples of the alcohol include lower alcohols such as methanol and ethanol.
The alkali catalyst is a catalyst for accelerating the reaction (hydrolysis reaction, condensation reaction) of the metal alkoxide of tetraalkoxysilane and tetraalkoxytitanium, for example, a base such as ammonia, urea, monoamine, quaternary ammonium salt, etc. And ammonia is particularly preferable.
The concentration (content) of the alkali catalyst is preferably 0.6 mol / L or more and 0.85 mol / L. Within the above range, when tetraalkoxysilane is supplied in the particle generation process, the dispersibility of the core particles in the growth process of the generated core particles becomes stable, and coarse aggregates such as secondary aggregates suppress the generation. , It can be suppressed to gelation. In addition, the density | concentration of an alkali catalyst is a density | concentration with respect to an alcohol catalyst solution (an alkali catalyst + solvent containing alcohol).

<Particle production process>
The method for producing composite particles containing silica and titania preferably includes a step of supplying particles of the metal alkoxide monomer and the alkali catalyst into the alkali catalyst solution to generate particles (particle generation step).
In the particle generation step, a metal alkoxide and an alkali catalyst are respectively supplied into an alkali catalyst solution, and the metal alkoxide is reacted (hydrolysis reaction, condensation reaction) in the alkali catalyst solution to generate composite silica particles. It is preferable that it is a process to perform. In this particle generation step, metal alkoxide core particles are generated at the initial supply stage of the metal alkoxide, and then composite silica particles are generated through the growth of the core particles. For example, the supply amount of the metal alkoxide is preferably 0.001 mol / (mol · min) or more and 0.01 mol / (mol · min) or less with respect to the number of moles of alcohol in the alkali catalyst solution.
By setting the supply amount of the metal alkoxide within the above range, the generation of coarse aggregates is small and atypical silica particles are easily generated. The supply amount of the metal alkoxide indicates the number of moles of metal alkoxide supplied per minute with respect to 1 mol of alcohol in the alkali catalyst solution.

On the other hand, examples of the alkali catalyst supplied into the alkali catalyst solution include those exemplified above. The alkali catalyst to be supplied may be the same type as the alkali catalyst previously contained in the alkali catalyst solution, or may be a different type, but is preferably the same type. The supply amount of the alkali catalyst is preferably 0.1 mol or more and 0.4 mol or less with respect to 1 mol of the total supply amount supplied per minute of the metal alkoxide. Here, in the particle generation step, the metal alkoxide and the alkali catalyst are supplied into the alkali catalyst solution, respectively. This supply method may be a continuous supply method or an intermittent supply. It may be a system to do.
In the particle generation step, the temperature in the alkali catalyst solution (temperature at the time of supply) is preferably 5 ° C. or more and 50 ° C. or less, for example.

Through the above steps, composite particles containing silica and titania are obtained. In this state, the obtained composite particles containing silica and titania can be obtained in the form of a dispersion, but may be used as a composite particle dispersion containing silica and titania as they are, or the solvent and the silica and titania may be removed. The powder may be taken out and used as a composite particle-containing powder. When used as a dispersion, the solid content concentration may be adjusted by diluting or concentrating with water or alcohol as necessary. Further, the composite particle dispersion containing silica and titania may be used after solvent substitution with other water-soluble organic solvents such as alcohols, esters, and ketones.
On the other hand, when used as a powder of composite particles containing silica and titania, it is necessary to remove the solvent from the dispersion. As this solvent removal method, 1) the solvent was removed by filtration, centrifugation, distillation, etc. Thereafter, known methods such as a method of drying with a vacuum dryer, a shelf dryer, etc., 2) a method of directly drying the slurry with a fluidized bed dryer, a spray dryer or the like can be used. Although a drying temperature is not specifically limited, It is preferable that it is 200 degrees C or less.
The dried composite particles containing silica and titania are preferably subjected to crushing and sieving to remove coarse particles and aggregates as necessary. The crushing method is not particularly limited, and examples thereof include a method performed by a dry pulverizer such as a jet mill, a vibration mill, a ball mill, and a pin mill. Examples of the sieving method include a method using a known method such as a vibration sieve or a wind sieving machine.

  The composite particles containing silica and titania may be used by hydrophobizing the surface of the composite particles with a hydrophobizing agent. Examples of the hydrophobizing agent include known organosilicon compounds having an alkyl group (eg, methyl group, ethyl group, propyl group, butyl group). Specific examples include, for example, silazane compounds (eg, methyl trimethyl compound). Silane compounds such as methoxysilane, dimethyldimethoxysilane, trimethylchlorosilane, and trimethylmethoxysilane, hexamethyldisilazane, tetramethyldisilazane, and the like. The hydrophobizing agent may be used alone or in combination. Among these hydrophobizing agents, organosilicon compounds having a trimethyl group such as trimethylmethoxysilane and hexamethyldisilazane are suitable. The amount of the hydrophobizing agent used is not particularly limited, but in order to obtain a hydrophobizing effect, for example, it is preferably 1% by weight or more and 100% by weight or less with respect to the composite particles, and 5% by weight. More preferably, it is 80 weight% or less.

As a method for obtaining a hydrophobic particle dispersion subjected to a hydrophobic treatment with a hydrophobic treatment agent, for example, a necessary amount of a hydrophobic treatment agent is added to the composite particle dispersion, and the mixture is stirred at 30 ° C. or higher and 80 ° C. or lower with stirring. A method of obtaining a hydrophobic particle dispersion by subjecting the particles to a hydrophobization treatment by reacting in a temperature range can be mentioned.
On the other hand, as a method of obtaining hydrophobic composite particles of powder, after obtaining a hydrophobic particle dispersion by the above method, drying by the above method to obtain a powder of hydrophobic particles, the particle dispersion is dried. After obtaining a hydrophilic particle powder, a method of obtaining a hydrophobic particle powder by adding a hydrophobizing agent and applying a hydrophobic treatment, and obtaining a hydrophobic particle dispersion, followed by drying to make the hydrophobic Examples thereof include a method of obtaining a powder of hydrophobic particles by obtaining a powder of hydrophobic particles and then applying a hydrophobic treatment by adding a hydrophobizing agent. Here, as a method for hydrophobizing the powder particles, the hydrophilic particles of the powder are stirred in a treatment tank such as a Henschel mixer or a fluidized bed, and a hydrophobizing agent is added thereto, There is a method in which the hydrophobizing agent is gasified by heating and reacted with silanol groups on the surface of powder particles. Although processing temperature is not specifically limited, For example, it is preferable that it is 80 to 300 degreeC, and it is more preferable that it is 120 to 200 degreeC.

<Silica particles having a number average particle diameter of 60 nm to 600 nm>
The toner of the exemplary embodiment includes silica particles (also referred to as large-diameter silica or large-diameter silica particles) having a number average particle diameter of 60 nm or more and 600 nm or less as an external additive. By having large-diameter silica particles as an external additive, an image in which poor image quality is suppressed can be obtained.
When the number average particle diameter of the large-diameter silica particles is 60 nm or more, the spacer effect between the mother particles is sufficiently exerted, and the image density fluctuation due to burying over time is suppressed. Further, when it is 600 nm or less, the fluidity is excellent, and the image density fluctuation is suppressed even in high area coverage.
From the viewpoint of achieving both the spacer effect and fluidity, the number average particle diameter is more preferably 80 to 500 nm, and more preferably 100 nm to 200 nm. When the number average particle diameter is within the above range, an image in which density fluctuation is suppressed can be obtained.

  The number average particle size of the large-diameter silica particles is suitably measured by Coulter Multisizer II (manufactured by Beckman Coulter, Inc.).

Examples of the silica particles include fumed silica, colloidal silica, silica gel and the like, and are used without particular limitation.
Moreover, the said large diameter silica particle may be hydrophobized with the silane coupling agent etc. which are mentioned later, for example.
The hydrophobizing treatment may be performed by immersing the inorganic particles in a hydrophobizing agent. Although there is no restriction | limiting in particular as said hydrophobic treatment agent, For example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, silane coupling agents are preferable.

As the silane coupling agent, for example, any one of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used.
Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- ( Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane , Γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

  The amount of the hydrophobizing agent varies depending on the type of the particles and cannot be specified, but is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the particles, and 5 to 20 parts by weight. It is more preferable that In the present embodiment, commercially available products are also preferably used as the hydrophobic silica particles that have been subjected to a hydrophobic treatment.

  In the toner of the exemplary embodiment, the content of the large-diameter silica particles is not particularly limited, but is preferably 0.3 to 35% by weight, and preferably 1 to 30% by weight with respect to the total weight of the toner. More preferred is 3 to 25% by weight.

<Other external additives>
The toner of the present exemplary embodiment may include external additives other than the composite particles and the large-diameter silica particles (also referred to as “other external additives”).
The content of other external additives in the toner of the exemplary embodiment is preferably smaller than each of the composite particles and the large-diameter silica particles.
Other external additives are not particularly limited, and known inorganic particles and organic particles are used as toner external additives. For example, silica, alumina, titanium oxide (titanium oxide, metatitanic acid, etc.), oxidation, etc. Examples thereof include inorganic particles such as cerium, zirconia, calcium carbonate, magnesium carbonate, calcium phosphate, and carbon black, and resin particles such as vinyl resin, polyester resin, and silicone resin. Further, the other external additives may be those that have been subjected to the hydrophobic treatment described above.
The average primary particle size of other external additives is preferably 3 to 500 nm, more preferably 5 to 100 nm, still more preferably 5 to 50 nm, and particularly preferably 5 to 40 nm. .

  Specifically, the toner particles include, for example, a binder resin and, if necessary, a colorant, a release agent, and other additives.

  The binder resin is not particularly limited. For example, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, acrylic Esters having vinyl groups such as lauryl acid, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; single quantities of polyolefins such as ethylene, propylene and butadiene Homopolymer consisting of, or a copolymer obtained by combining two or more kinds, even mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.

Styrene resin, (meth) acrylic resin, and styrene- (meth) acrylic copolymer resin are obtained by known methods, for example, by combining styrene monomers and (meth) acrylic acid monomers alone or in appropriate combination. It is done. “(Meth) acryl” is an expression including both “acryl” and “methacryl”.
The polyester resin can be obtained by selecting and combining suitable ones from a dicarboxylic acid component and a diol component, and synthesizing them using a conventionally known method such as a transesterification method or a polycondensation method.

  When using a styrene resin, a (meth) acrylic resin or a copolymer resin thereof as a binder resin, the weight average molecular weight Mw is 20,000 or more and 100,000 or less, and the number average molecular weight Mn is 2,000 or more and 30,000 or less. It is preferable to use the thing of the range. On the other hand, when a polyester resin is used as the binder resin, a resin having a weight average molecular weight Mw of 5,000 or more and 40,000 or less and a number average molecular weight Mn of 2,000 or more and 10,000 or less may be used. preferable.

  The glass transition temperature of the binder resin is preferably in the range of 40 ° C. or higher and 80 ° C. or lower. When the glass transition temperature is in the above range, the minimum fixing temperature is easily maintained.

  The colorant is not particularly limited as long as it is a known colorant. For example, carbon black such as furnace black, channel black, acetylene black, and thermal black, inorganic pigments such as bengara, bitumen, and titanium oxide, fast yellow, disazo Azo pigments such as yellow, pyrazolone red, chelate red, brilliant carmine, para brown, phthalocyanine pigments such as copper phthalocyanine, metal-free phthalocyanine, flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, dioxazine violet Examples thereof include cyclic pigments.

As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.
The content of the colorant is preferably in the range of 1% by weight to 30% by weight with respect to the total weight of the binder resin.

  Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters Wax; and the like, but is not limited thereto.

  The melting point of the release agent is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of storage stability. Moreover, it is preferable that it is 110 degrees C or less from a viewpoint of offset resistance, and it is more preferable that it is 100 degrees C or less.

  The content of the release agent is preferably 1% by weight to 15% by weight, more preferably 2% by weight to 12% by weight, and still more preferably 3% by weight to 10% by weight.

  Examples of other additives include magnetic substances, charge control agents, inorganic powders, and the like.

<Manufacturing method>
The toner base particles used in the exemplary embodiment are not particularly limited by the production method, and a known method can be used. Specific examples include the following methods.
The production of the toner base particles is obtained, for example, by a kneading and pulverizing method in which a binder resin, a colorant, a release agent, and a charge control agent, if necessary, are kneaded, pulverized, and classified; To change the shape of the particles by mechanical impact force or thermal energy; dispersion of emulsified binder resin, dispersion of colorant, release agent, and charge control agent as required An emulsion aggregation method in which toner particles are obtained by mixing, aggregating and heating and fusing the solution; emulsion polymerization of a polymerizable monomer of a binder resin, and a formed dispersion, a colorant, a release agent, and , An emulsion polymerization aggregation method to obtain toner particles by mixing with a dispersion such as a charge control agent, if necessary, and then fusing and heat-fusing; a polymerizable monomer for obtaining a binder resin, a colorant, A suspension polymerization method in which a release agent and, if necessary, a solution such as a charge control agent are suspended in an aqueous solvent for polymerization; Resin and a colorant, releasing agent, and dissolution suspension method and granulated with a solution such as a charge control agent is suspended in an aqueous solvent optionally; or the like can be used. In addition, a manufacturing method may be performed in which the toner base particles obtained by the above method are used as a core, and aggregated particles are further adhered and heat-fused to have a core-shell structure.
Among these, the toner of the exemplary embodiment is preferably a toner (emulsion aggregation toner) obtained by an emulsion aggregation method or an emulsion polymerization aggregation method.

  The toner base particles produced as described above preferably have a volume average particle diameter in the range of 2 to 8 μm, and more preferably in the range of 3 to 7 μm. When the volume average particle size is 2 μm or more, the fluidity of the toner is good and sufficient charging ability is imparted from the carrier, so that fogging in the background portion and density reproducibility are unlikely to occur. . Further, when the volume average particle size is 8 μm or less, the effect of improving the reproducibility, gradation and graininess of fine dots is good, and a high-quality image can be obtained. The volume average particle size is measured with Coulter Multisizer II (manufactured by Beckman Coulter, Inc.).

  The toner base particles are preferably pseudo-spherical from the viewpoint of improving developability and transfer efficiency and improving image quality. The sphericity of the toner base particles can be expressed by using the shape factor SF1 of the following formula, but the average value (average shape factor) of the shape factor SF1 of the toner base particles used in this embodiment is 160. Is preferably in the range of 115 or more and less than 155, and more preferably in the range of 120 or more and less than 140. When the average value of the shape factor SF1 is less than 160, good transfer efficiency is obtained and the image quality is excellent.

In the above formula, ML represents the maximum length of each toner base particle, and A represents the projected area of each toner base particle.
The average value of the shape factor SF1 (average shape factor) is obtained by taking 1,000 toner images magnified 250 times from an optical microscope to an image analyzer (LUZEX III, manufactured by Nireco Corporation), and the maximum From the length and the projected area, the value of the SF1 is obtained for each particle and averaged.

(Electrostatic image developer)
The toner for developing an electrostatic charge image of this embodiment is suitably used as an electrostatic charge image developer.
The electrostatic image developer of this embodiment is not particularly limited except that it contains the electrostatic image developing toner of this embodiment, and can take an appropriate component composition depending on the purpose. When used alone, the toner for developing an electrostatic image of this embodiment is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, it is prepared as a two-component electrostatic image developer. .
As a one-component developer, a method in which a charged toner is formed by frictional charging with a developing sleeve or a charging member, and development is performed according to an electrostatic latent image is also applied.

  In the present embodiment, the development method is not particularly defined, but the two-component development method is preferable. Further, the carrier is not particularly defined as long as the above conditions are satisfied. Examples of the carrier core material include magnetic metals such as iron, steel, nickel, and cobalt, alloys of these with manganese, chromium, rare earth, and the like, and Magnetic oxides such as ferrite and magnetite are mentioned, and from the viewpoint of core material surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferably mentioned.

  The carrier used in this embodiment is preferably formed by coating the surface of the core material with a resin. There is no restriction | limiting in particular as said resin, According to the objective, it selects suitably. Moreover, it is preferable that the resin film and / or electroconductive particle are disperse | distributed in the said resin in the film by the said resin. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. The average particle size of the resin particles is preferably 0.1 to 2 μm, and more preferably 0.2 to 1 μm. When the average particle size of the resin particles is 0.1 μm or more, the resin particles are excellent in dispersibility in the coating, whereas when the average particle size is 2 μm or less, the resin particles are not easily dropped from the coating.

The method for forming the coating is not particularly limited. For example, the resin particles such as crosslinkable resin particles and / or the conductive particles, and a styrene acrylic resin, a fluorine resin, a silicone resin as a matrix resin, etc. And a method of using a film-forming solution containing the above resin in a solvent.
Specifically, the carrier core material is immersed in the film forming liquid, a spray method in which the film forming liquid is sprayed on the surface of the carrier core material, and the carrier core material is floated by flowing air And kneader coater method in which the film forming solution is mixed and the solvent is removed. Among these, the kneader coater method is preferable in the present embodiment.

  In the two-component electrostatic charge image developer, the mixing ratio of the toner and the carrier of this embodiment is preferably 2 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier. Moreover, the preparation method of a developing agent is not specifically limited, For example, the method of mixing with a V blender etc. is mentioned.

(Image forming method)
The electrostatic image developer (electrostatic image developing toner) is used in an image forming method of an electrostatic image developing system (electrophotographic system).
The image forming method of the present embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner. A developing step for forming an image, a transferring step for transferring the toner image to the surface of the transfer member, and a fixing step for fixing the toner image transferred to the surface of the transfer member. The toner for developing an electrostatic charge image of the form or the electrostatic charge image developer of the present embodiment is used.
The image forming method of the present embodiment preferably includes a cleaning step in addition to the above steps.

Each of the above steps is a general step per se, and is described in, for example, JP-A-56-40868 and JP-A-49-91231. Note that the image forming method of the present embodiment can be carried out by using a known image forming apparatus such as a copying machine or a facsimile machine.
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an image carrier (photoconductor).
The developing step is a step of developing the electrostatic latent image with a developer layer on a developer holding member to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developing toner of this embodiment.
The transfer step is a step of transferring the toner image onto a transfer target. Examples of the transfer medium in the transfer process include an intermediate transfer medium and a recording medium such as paper.
In the fixing step, for example, there is a method of forming a copy image by fixing the toner image transferred onto the transfer paper by a heating roller fixing device in which the temperature of the heating roller is set to a constant temperature.
The cleaning step is a step of removing the electrostatic charge image developer remaining on the image carrier.
Further, the image forming method of the present embodiment preferably includes the cleaning step, and more preferably includes a step of removing the electrostatic charge image developer remaining on the image carrier with a cleaning blade.
As the recording medium, known media can be used, for example, paper used for electrophotographic copying machines, printers, OHP sheets, etc. For example, the surface of plain paper is made of resin, etc. Coated coated paper, art paper for printing, and the like can be suitably used.

  The image forming method of the present embodiment may further include a recycling step. The recycling step is a step of transferring the electrostatic charge image developing toner collected in the cleaning step to a developer layer. The image forming method including the recycling process is performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. Further, the present invention may be applied to a recycling system in which the cleaning process is omitted and toner is collected simultaneously with development.

(Image forming device)
The image forming apparatus according to this embodiment includes an image carrier, a charging unit that charges the image carrier, and an exposure unit that exposes the charged image carrier to form an electrostatic latent image on the surface of the image carrier. Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image; transfer means for transferring the toner image from the image holding member to the surface of the transferred body; and the transferred body Fixing means for fixing the toner image transferred on the surface, and the developer for developing an electrostatic image of the present embodiment or the electrostatic image developer of the present embodiment is used as the developer. .
The image forming apparatus of the present embodiment is not particularly limited as long as it includes at least the image holding member, the charging unit, the exposure unit, the developing unit, and the transfer unit as described above, but other necessary. Depending on the situation, a fixing means, a cleaning means, a static elimination means and the like may be included.
In the transfer unit, the transfer may be performed twice or more using an intermediate transfer member. Examples of the transfer medium in the transfer unit include an intermediate transfer medium and a recording medium such as paper.

The image carrier and each of the above-described units can preferably use the configurations described in the respective steps of the image forming method. As each of the above-described means, a known means in the image forming apparatus can be used. In addition, the image forming apparatus according to the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus according to the present embodiment may simultaneously perform a plurality of the above-described means.
The image forming apparatus according to the present exemplary embodiment preferably includes a cleaning unit that removes the electrostatic charge image developer remaining on the image carrier.
Examples of the cleaning means include a cleaning blade and a cleaning brush, and a cleaning blade is preferable.
Preferred examples of the cleaning blade material include urethane rubber, neoprene rubber, and silicone rubber.

(Toner cartridge, developer cartridge, and process cartridge)
The toner cartridge of this embodiment is a toner cartridge that contains at least the toner for developing an electrostatic charge image of this embodiment.
The developer cartridge of this embodiment is a developer cartridge that contains at least the electrostatic charge image developer of this embodiment.
The process cartridge according to the present embodiment includes a developing unit that develops the electrostatic latent image formed on the surface of the image carrier with the electrostatic image developing toner or the electrostatic image developer to form a toner image. And at least one selected from the group consisting of an image carrier, a charging unit for charging the surface of the image carrier, and a cleaning unit for removing the toner remaining on the surface of the image carrier, This is a process cartridge containing at least the electrostatic image developing toner of the present embodiment or the electrostatic image developer of the present embodiment.

The toner cartridge of this embodiment is preferably detachable from the image forming apparatus. That is, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, the toner cartridge of the present embodiment in which the toner of the present embodiment is stored is preferably used.
The developer cartridge of the present embodiment is not particularly limited as long as it contains the electrostatic charge image developer containing the electrostatic charge image developing toner of the present embodiment. The developer cartridge is, for example, attached to and detached from an image forming apparatus including a developing unit, and includes the electrostatic image developer according to the present embodiment as a developer to be supplied to the developing unit. Is stored.
The developer cartridge may be a cartridge that stores toner and a carrier, or may be a cartridge that stores toner alone and a cartridge that stores a carrier separately.
It is preferable that the process cartridge of the present embodiment is attached to and detached from the image forming apparatus.
In addition, the process cartridge according to the present embodiment may include other members such as a static elimination unit as necessary.
As the toner cartridge and the process cartridge, known configurations may be adopted. For example, Japanese Patent Application Laid-Open Nos. 2008-209489 and 2008-233736 are referred to.

  Hereinafter, although this embodiment is described in detail with examples, this embodiment is not limited in any way. In the following description, “parts” means “parts by weight” unless otherwise specified.

<Measuring method of abundance ratio of titanium atom to silicon atom on toner outermost surface>
The abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is measured by XPS measurement using an X-ray photoelectron spectrometer (JPS 9000 MX, manufactured by JEOL Ltd.) under measurement conditions of an acceleration voltage of 10 kV and a current value of 30 mA. did.

<Method for Measuring Volume Average Particle Diameter of Toner Base Particle>
The volume average particle diameter of the toner base particles was measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). As the electrolytic solution, ISOTON-II (manufactured by Beckman Coulter, Inc.) was used.
As a measuring method, first, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this is added to 100 ml to 150 ml of the electrolytic solution. Added. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size is 2.0 μm or more and 60 μm or less using the Coulter Multisizer II with an aperture having an aperture diameter of 100 μm. The particle size distribution of particles in the range was measured. The number of particles to be measured was 50,000.
For the divided particle size range (channel), draw the cumulative distribution from the small diameter side with respect to the divided particle size range (channel), and define the 50% cumulative particle size as the heavy average particle size or volume average particle size, respectively. To do.

<Measurement of resin particle in resin dispersion or glass transition point of resin>
A differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC50) was used to measure the glass transition temperature Tg of the resin.

<Preparation of Composite Particle 1 Containing Silica and Titania>
To a glass reaction vessel equipped with a stirrer, a dropping nozzle, and a thermometer, 400 parts of methanol and 66 parts of 10% aqueous ammonia (NH ₄ OH) were added and mixed to obtain an alkali catalyst solution. The amount of catalyst in the alkaline catalyst solution at this time: the amount of NH ₃ (NH ₃ / (NH ₃ + methanol + water)) was 0.68 mol / L. Further, a metal alkoxide mixed monomer was prepared by adding 5.0% of tetramethoxysilane to tetrabutoxy titanium, and after adjusting the alkali catalyst solution to 25 ° C., with stirring, 200 parts of the metal alkoxide mixed monomer and 158 parts of 3.8% aqueous ammonia (NH ₄ OH) was added at a flow rate so that the amount of NH ₃ was 0.27 mol per mol of the total amount of metal alkoxide mixed monomer supplied per minute. At the same time, the addition was started, and dripping was performed over 60 minutes to obtain a suspension of silica particles. However, the supply amount of the metal alkoxide mixed monomer was 0.0017 mol / (mol · min) with respect to the number of moles of alcohol in the alkali catalyst solution.
300 parts of this composite silica slurry was distilled off by heating distillation, 300 parts of pure water was added, and then dried with a freeze dryer to obtain titania particles (composite particles) coated with silica.
Further, 7 parts of hexamethyldisilazane was added to 35 parts of the titania particles coated with silica and reacted at 150 ° C. for 2 hours to obtain titania particles (composite particles 1) coated with hydrophobic silica.
In addition, it was confirmed by observation of the section | slice by TEM that it was partially coat | covered with the silica.

<Preparation of Composite Particle 2 Containing Silica and Titania>
Composite particle 2 was prepared in the same manner as composite particle 1 except that 1.0% tetramethoxysilane was added to tetrabutoxy titanium to prepare a metal alkoxide mixed monomer.

<Preparation of Composite Particle 3 Containing Silica and Titania>
Composite particle 3 was prepared in the same manner as composite particle 1 except that 0.1% of tetramethoxysilane was added to tetrabutoxytitanium to prepare a metal alkoxide mixed monomer.

<Large diameter silica particles>
The silica particles used in the examples are shown below.
Silica particles A: number average particle diameter 60 nm
Silica particle B: number average particle diameter 80 nm
Silica particle C: number average particle diameter 120 nm
Silica particle D: number average particle diameter 200 nm
Silica particle E: number average particle diameter 500 nm
Silica particles F: number average particle diameter 600 nm

<Preparation of large-diameter silica particles>
-Production of silica particles A-
150 parts of tetramethoxysilane is stirred at 280 rpm while 150 parts of 25% by weight aqueous ammonia is added dropwise at 30 ° C. over 5 hours in the presence of 100 parts of ion-exchanged water and 100 parts of 25% by weight alcohol. The silica sol suspension obtained by this reaction is centrifuged, separated into wet silica gel, alcohol and aqueous ammonia, and the separated wet silica gel is dried at 120 ° C. for 2 hours, and then 100 parts of silica and 500 parts of ethanol are mixed. Was put into an evaporator and stirred for 15 minutes while maintaining the temperature at 40 ° C. Next, 10 parts of dimethyldimethoxysilane was added to 100 parts of silica, and the mixture was further stirred for 15 minutes. Finally, the temperature was raised to 90 ° C. and ethanol was dried under reduced pressure. The treated product was taken out and further vacuum dried at 120 ° C. for 30 minutes. The dried silica was pulverized to obtain silica particles A having an average particle size of 60 nm.

-Preparation of silica particles B-
In the preparation of silica particles A, the average particle diameter was the same as that for silica particles A except that 25 wt% ammonia water was added at 150 rpm while dropping 150 parts of ammonia water over 4 hours. 80 nm silica particles B were obtained.

-Preparation of silica particles C-
In the preparation of silica particles A, the average particle diameter was the same as that for silica particles A except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 3 hours. 120 nm silica particles C were obtained.

-Preparation of silica particles D-
In the preparation of silica particles A, the average particle size was the same as that for silica particles A except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 3 hours. 200 nm silica particles D were obtained.

-Preparation of silica particles E-
In the preparation of silica particles A, the average particle size was the same as that for silica particles A except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 1 hour. 500 nm silica particles E were obtained.

-Preparation of silica particles F-
In the preparation of silica particles A, the average particle diameter was the same as that of silica particles A except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 1 hour. 600 nm silica particles F were obtained.

<Preparation of toner base particles>
-Preparation of crystalline polyester resin dispersion-
In a heat-dried three-necked flask, 45 mol parts of 1,9-nonanediol, 55 mol parts of dodecanedicarboxylic acid and 0.05 mol parts of dibutyltin oxide as a catalyst were added, and the air in the container was reduced to nitrogen by depressurization. Under an inert atmosphere with gas, the mixture was stirred and refluxed at 180 ° C. for 2 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 5 hours. When it became viscous, it was air-cooled, the reaction was stopped, and a crystalline polyester resin was synthesized. It was 25,000 when the weight average molecular weight (Mw) of the obtained crystalline polyester resin was measured by the gel permeation chromatography (polystyrene conversion). Next, 3,000 parts of the obtained amorphous polyester resin, 10,000 parts of ion-exchanged water, and surfactant dodecylbenzenesulfonic acid were added to an emulsification tank of a high-temperature and high-pressure emulsifier (Cabitron CD1010, slit: 0.4 mm). After adding 90 parts of sodium, the mixture was heated and melted to 130 ° C., dispersed at 110 ° C. at a flow rate of 3 L / m for 30 minutes at 1,0000 revolutions, passed through a cooling tank, and a non-crystalline resin particle dispersion (high temperature. A high-pressure emulsifier (Cabitron CD1010, slit 0.4 mm) was recovered to obtain a crystalline resin particle dispersion.

-Preparation of amorphous polyester resin dispersion-
15 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane and 85 mol parts of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 10 mol parts of terephthalic acid, 67 mol parts of fumaric acid, 3 mol parts of n-dodecenyl succinic acid, 20 mol parts of trimellitic acid, and these acid components (terephthalic acid, n-dodecenyl succinic acid, trimellitic acid, 0.05 mol part of dibutyltin oxide is added to the total number of moles of fumaric acid), nitrogen gas is introduced into the container and the temperature is maintained in an inert atmosphere, and then heated at 150 to 230 ° C. The copolycondensation reaction was carried out for 20 hours. Thereafter, the pressure was gradually reduced at 210 ° C. to 250 ° C. to synthesize an amorphous polyester resin. The weight average molecular weight Mw of this resin was 65,000. Next, 3,000 parts of the obtained amorphous polyester resin, 10,000 parts of ion-exchanged water, and surfactant dodecylbenzenesulfonic acid were added to an emulsification tank of a high-temperature and high-pressure emulsifier (Cabitron CD1010, slit: 0.4 mm). After adding 90 parts of sodium, it is heated and melted to 130 ° C., and then dispersed at 110 ° C. at a flow rate of 3 L / m for 30 minutes at 10,000 rpm, and passed through a cooling tank to pass through an amorphous resin particle dispersion (high-temperature A high-pressure emulsifier (Cabitron CD1010, slit 0.4 mm) was recovered to obtain an amorphous resin particle dispersion.

-Preparation of colorant dispersion-
-Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Kogyo Co., Ltd.): 1,000 parts by weight-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 150 parts by weight-Ion exchange Water: 4,000 parts by weight The above blended solution is mixed and dissolved, and dispersed for 1 hour with a high-pressure impact disperser Ultimateizer (HJP30006, manufactured by Sugino Machine Co., Ltd.), and the color has a volume average particle size of 180 nm and a solid content of 20%. An agent dispersion was obtained.

-Preparation of release agent dispersion-
Paraffin wax HNP9 (melting point 75 ° C .: Nippon Seiki Co., Ltd.): 46 parts by weight Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight Ion-exchanged water: 200 parts by weight Part above is heated to 100 ° C. and sufficiently dispersed with IKA Ultra Tarrax T50, then dispersed with a pressure discharge type gorin homogenizer, and a release agent dispersion having a center diameter of 200 nm and a solid content of 20.0% by weight. Got.

-Production of toner base particles 1-
Amorphous resin dispersion: 256.8 parts by weight Crystalline resin dispersion: 33.2 parts by weight Colorant dispersion: 27.4 parts by weight Release agent dispersion: 35 parts by weight In a stainless steel flask, Ultra Thalax T50 was sufficiently mixed and dispersed. Next, 0.20 part by weight of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 48 ° C. with stirring in an oil bath for heating. After maintaining at 48 ° C. for 60 minutes, 70.0 parts by weight of the amorphous resin dispersion was gradually added thereto. Thereafter, the pH of the system was adjusted to 8.0 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 96 ° C. while continuing to stir using a magnetic seal for 3 hours. Retained. After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes. This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours. The particle diameter at this time was measured by Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and the volume average particle diameter was 5.8 μm. In addition, the particle shape factor SF1 obtained by shape observation with Luzex was 129.

-Preparation of toner base particles 2-
Styrene-butyl acrylate copolymer (composition ratio 75/25, weight average molecular weight: 80,000) resin particle dispersion: 26 parts Hexahedral magnetite (manufactured by Toda Kogyo Co., Ltd .: MTH009F, particle size 0.2 μm): 50 parts ・ Negative charge control agent (Fe-containing azo dye): 1 part ・ Low molecular weight polypropylene (softening point: 149 ° C.): 2 parts ・ Low molecular weight polyethylene (softening point: 120 ° C.): 1 part The powder was mixed with a mixer, and this was heat-kneaded with an extruder having a set temperature of 140 ° C. and a screw rotation speed of 200 rpm. The outlet temperature at this time was 190 degreeC. The kneaded product was cooled and coarsely pulverized to obtain a pulverized product having a volume average diameter of 6.9 μm. Further, the toner obtained by classifying the pulverized product was measured with Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and the volume average particle diameter was 6.5 μm. Further, the particle shape factor SF1 obtained from the shape observation by Luzex was 155.

<Production of toner>
According to Table 1, toner base particles, silica particles as external additives and composite particles were mixed with a Henschel mixer at 3,600 rpm for 10 minutes to obtain a toner.
Regarding the external additive coverage of the obtained toner, the surface of the toner particle was observed after observing 100 fields of the toner particle surface at a magnification of 10,000 using a scanning electron microscope S4700 (manufactured by Hitachi, Ltd.). Is obtained by calculating the area of the toner surface where the external additive is attached using the area analysis tool of image processing analysis software WinROOF (manufactured by Mitani Shoji Co., Ltd.). Was 54%.

<Creation of carrier>
Ferrite particles (average particle size 50 μm, volume electric resistance 3 × 10 8 Ω · cm): 100 parts by weight Toluene: 14 parts by weight Perfluorooctylethyl acrylate / dimethylaminoethyl methacrylate copolymer (copolymerization ratio 90:10, Mw = 50,000): 1.6 parts by weight Carbon black (VXC-72; manufactured by Cabot Corporation): 0.12 parts by weight Among the above components, components other than ferrite particles are dispersed with a stirrer for 10 minutes to form a film. Prepare the solution, put the coating solution and ferrite particles in a vacuum degassing kneader, stir at 60 ° C. for 30 minutes, and then reduce the pressure by distilling off the toluene to form a resin coating on the ferrite particle surface. The carrier was manufactured.

<Production of developer>
The obtained toner of each example and the above-described carrier were placed in a V blender at a weight ratio of 5:95 and stirred for 20 minutes to obtain a developer.

  The obtained developer was filled in Docu Center Color 400 (Fuji Xerox Co., Ltd.), and the following evaluation was performed.

<Evaluation>
The above-mentioned Docu Center Color400 manufactured by Fuji Xerox Co., Ltd. equipped with the obtained electrostatic charge image developer was left under low temperature and low humidity (20 ° C., 50%) for 1 day, and then an image with an area coverage of 1% was continuously printed on 100,000 sheets. Output. Thereafter, using C2 paper manufactured by Fuji Xerox Co., Ltd., image forming conditions were adjusted so that the image density was within the range of 1.0 to 1.5, and a 5 cm × 5 cm patch was output (density 1). Subsequently, 100,000 images with an area coverage of 50% were output continuously. Thereafter, using a C2 paper manufactured by Fuji Xerox Co., Ltd., a patch of 5 cm × 5 cm was output again under the same image forming conditions as when the patch having a density of 1 was formed, and the image density was measured (density 2).

[Image density fluctuation evaluation (Δ image density (SAD) evaluation)]
The value of Δ image density (SAD) represented by the following formula was calculated from the density 1 and density 2 and evaluated according to the following criteria. The image density was measured with an image densitometer X-RITE 938 (manufactured by X-RITE).
Δ image density = | density 1−density 2 |
The evaluation criteria are as follows.
A: 0 ≦ Δ image density (SAD) ≦ 0.1
○: 0.1 <Δ image density (SAD) ≦ 0.2
×: 0.2 <Δ image density (SAD)

[Image quality evaluation]
Regarding the total output of 200,000 sheets, the images were checked every 1,000 sheets (200 sheets in total), and the number of sheets with image quality defects (color streaks, color loss, etc.) was counted.
◎: poor image quality ≦ 1 image ○: 1 image <image quality failure ≦ 3 images ×: 3 images <image quality failure

  The evaluation results in each example and comparative example are summarized in Table 1.

Claims (9)

Toner base particles, and
Containing an external additive externally added to the toner base particles,
The external additive includes composite particles containing silica and titania, and silica particles having a number average particle diameter of 60 nm or more and 600 nm or less,
A toner for developing an electrostatic charge image, wherein an abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 5 atm% or less.   The toner for developing an electrostatic charge image according to claim 1, wherein the number average particle diameter of the silica particles is from 80 nm to 500 nm.   The toner for developing an electrostatic charge image according to claim 1, wherein an abundance ratio of titanium atoms to silicon atoms on the outermost surface of the toner is 1 to 5 atm%.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1 and a carrier.   A toner cartridge containing the electrostatic image developing toner according to claim 1.   A developer cartridge containing the electrostatic charge image developer according to claim 4.   5. A process cartridge comprising a developer holder that contains the electrostatic charge image developer according to claim 4 and holds and conveys the electrostatic charge image developer. A latent image forming step for forming an electrostatic latent image on the surface of the image carrier;
A developing step of forming a toner image by developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner;
A transfer step of transferring the toner image onto the surface of the transfer target; and
A fixing step of fixing the toner image transferred to the surface of the transfer target,
An image forming method using the electrostatic image developing toner according to claim 1 or the electrostatic image developer according to claim 4 as the developer. An image carrier,
Charging means for charging the image carrier;
Exposure means for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image from the image carrier to the surface of the transfer target;
Fixing means for fixing the toner image transferred to the surface of the transfer target,
An image forming apparatus comprising the electrostatic image developing toner according to claim 1 or the electrostatic charge image developer according to claim 4 as the developer.