JP2010217588A - Toner and method of manufacturing the same, developer, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner onto which low-cost titanium oxide subjected to surface-modifying process is added, wherein the toner can keep frictional charge amount stable, is able to maintain stable frictional chargeability that causes less environmental fluctuations, and does not cause abnormal images due to adhesion to a photoreceptor, the adhesion occurring, when a toner image is developed, and to provide a method of manufacturing the toner. <P>SOLUTION: The method of manufacturing the toner includes a mixing step of mixing a toner base, containing at least a binder resin and a colorant with the titanium oxide containing zinc ion, where a silane condensate is siloxane-bonded on the surface of the titanium oxide; and cooling the resultant product. When one execution of the mixing step is counted as a single cycle, mixing step is repeated up to three to seven cycles. In the toner manufacturing method, the ratio of the mixing time to the cooling time (mixing time/cooling time) in the mixing step is 0.5 to 2.0, and the rate of liberation of the titanium oxide to the toner base by an ultrasonic vibration method is 20 to 25%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, and the like, a method for producing the toner, a developer, and an image forming method.

  In the developing process, a developer used in electrophotography, electrostatic recording, electrostatic printing, and the like is once attached to an image carrier such as a photoreceptor on which an electrostatic image is formed. Next, after being transferred from the photoreceptor to a recording medium such as transfer paper in the transfer process, it is fixed on the paper surface in the fixing process. At that time, as a developer for developing an electrostatic charge image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer not requiring a carrier are known. Yes. In the two-component development method using the two-component developer, the developer deteriorates due to the toner adhering to the carrier surface, and only the toner is consumed, so the toner concentration in the developer is lowered, so the carrier The mixing ratio must be maintained at a constant ratio, and the developing device becomes relatively large. On the other hand, in the one-component developing method using the one-component developer, the size of the apparatus has been further reduced due to higher functions of the developing roller and the like.

  In recent years, office automation and colorization have further progressed in offices, and not only copying originals consisting only of conventional characters, but also pictorials read from graphs created with personal computers, images taken with digital cameras, scanners, etc. Opportunities to output manuscripts with printers and make many copies as presentation materials are increasing. The printer output image has a complicated structure mixed in one original such as a solid image, a line image, and a halftone image, and various demands are increasing along with a demand for high reliability of the image.

Electrophotographic processes using a one-component developer are classified into a magnetic one-component development method using a magnetic toner and a non-magnetic one-component development method using a non-magnetic toner.
In the magnetic one-component development method, a magnetic carrier containing a magnetic material such as magnetite is held using a developer carrying member provided with a magnetic field generating means such as a magnet, and developed by thinning the layer with a layer thickness regulating member. In recent years, many have been put to practical use in small printers. However, there is a drawback that the magnetic material is colored, and most of them are black and difficult to colorize.

  In contrast, in the non-magnetic one-component development method, since the toner does not have a magnetic force, a toner replenishing roller or the like is pressed against the developer carrying member to supply the toner onto the developer carrying member and electrostatically hold the layer. The film is developed with a thin layer by a thickness regulating member. This has the advantage that it does not contain a colored magnetic material, so it can be used for colorization. Furthermore, since a magnet is not used for the developer carrier, the device can be further reduced in weight and cost. It has been put to practical use.

  On the other hand, in the two-component development method, a carrier is used as a means for charging and transporting toner, and the toner and the carrier are sufficiently stirred and mixed in the developing device, and then transported to the developer carrying member for development. Even in use, it is possible to maintain stable chargeability and transportability, and it is easy to cope with high-speed developing devices.

  In particular, in the non-magnetic one-component developing method, the toner (developer) is usually transported by at least one toner transport member, and the electrostatic latent image formed on the latent image carrier is developed by the transported toner. In this case, the thickness of the toner layer on the surface of the toner conveying member must be as thin as possible. This is also true when a two-component developer having a very small diameter carrier is used, and a one-component developer is used and a toner having a high electric resistance is used. Sometimes this toner needs to be charged by a developing device, so the toner layer thickness must be significantly reduced. This is because if the toner layer is thick, only the surface of the toner layer is charged, and the entire toner layer is difficult to be uniformly charged. For this reason, the toner is required to maintain a quicker charging speed and an appropriate charge amount.

  Therefore, a charge control agent and an external additive have been conventionally added to stabilize the charge of the toner. The charge control agent functions to control the triboelectric charge amount of the toner and maintain the triboelectric charge amount. Typical examples of the negatively chargeable charge control agent include monoazo dyes, salicylic acid, naphthoic acid, metal salts or metal complexes of dicarboxylic acids, diazo compounds, and complex compounds with boron. Examples of the positively chargeable representative charge control agent include quaternary ammonium salt compounds, imidazole compounds, nigrosine, and azine dyes.

  However, some of these charge control agents have a chromatic color, and many cannot be used for color toners. In addition, some of these charge control agents are poorly compatible with the binder resin, so that those present on the surface of the toner that are greatly involved in charging are likely to be detached, resulting in variations in toner charging. There is a drawback that the developing sleeve is easily contaminated and the photosensitive member filming is likely to occur.

  Therefore, in the prior art, a good image can be obtained in the initial stage, but the image quality gradually changes, causing a phenomenon such as background smudges and blurring. In particular, when applied to color copying and continuously used while replenishing toner, the charge amount of the toner decreases, resulting in an image that differs significantly from the color tone of the initial copied image, and it cannot withstand long-term use. The image forming unit called a process cartridge had to be replaced at an early stage just by copying about one sheet. For this reason, the load on the environment is large, and it takes time and effort for the user. Furthermore, since many process cartridges contain heavy metals such as chromium, they are becoming a problem from the viewpoint of safety.

  In recent years, the demand for printers has expanded, the size and speed of devices have increased, and the cost has been reduced. As a result, higher reliability and longer life have been required for devices, and toner characteristics can be maintained over a long period of time. Although there is a demand, the charge control agent cannot maintain its charge control effect, contaminates the developing sleeve and the layer thickness regulating member (blade and roller), and lowers the toner charging performance and causes photoconductor filming. There is a problem of doing.

  In addition, a process that develops in a short time by using a small amount of developer due to downsizing and speeding up, and a developer having better charge rising property is required. Regarding development, various development methods have been proposed for both two-component and one-component developers, but it is excellent in that it can be reduced in size and weight, and non-magnetic one-component development that eliminates the need for a carrier is used for printers Is suitable. In this non-magnetic one-component development system, toner replenishment to the developing roller and toner retention of the developing roller are poor, so the toner is forcibly rubbed against the developing roller or the amount of toner on the developing roller is regulated by a blade. To do. As a result, the toner tends to film on the developing roller, resulting in a problem that the life of the developing roller is shortened and the charge amount of the toner becomes unstable. This also prevents good development.

  In view of this, research has been conducted on external additives that have functions of controlling and maintaining the triboelectric charge amount of the toner and improving the toner transportability, developability, transferability, storage stability, and the like. In order to improve these characteristics, it is disclosed that hydrophobic silica is added to the toner. However, silica alone is too charged, and transferability is too good to cause defects such as dust and scattering. There is a problem of doing.

Thus, for example, it is disclosed that titanium oxide or titanium oxide surface-treated with a coupling agent is added to the toner.
Patent Document 1 proposes hydrophobizing titanium oxide using dialkyldihalogenated silane, trialkylhalogenated silane, trialkylalkoxysilane, or dialkoxysilane.
Patent Document 2 proposes a toner in which toner base particles are mixed and adhered with titanium oxide powder that is hydrophobized with an alkyltrialkoxysilane having an alkyl group having 6 to 8 carbon atoms.
Patent Document 3 proposes a toner using anatase type titanium oxide. Patent Document 4 proposes a toner using amorphous titanium oxide fine particles that have been surface-treated with a coupling agent. Patent Document 5 proposes titanium oxide fine particles produced by a wet method and subjected to surface treatment.
However, with the toner using titanium oxide described in Patent Documents 1 to 5, sufficient charging stability, fluidity and environmental stability cannot be obtained over time, and abnormal images due to adhesion to the photoreceptor are not obtained. appear.

As the method for producing the toner, when an external additive is added to the toner particles at the time of toner production, a mixture of a shear rate calculated from the tip speed of the blade in the mixer and the clearance between the mixer inner wall and the external additive is mixed. By setting the time within a specific range, there has been proposed a toner having high triboelectric chargeability and good fluidity and causing no transfer failure or image quality defect (see Patent Document 6).
In addition, the external additive is adjusted by setting the average height, mixing blade diameter, rotation speed, and mixing time within the specified range from the bottom of the mixer before mixing of the mixture of the toner base and the external additive charged into the mixer. A method has been proposed in which the agglomerates are crushed and the crushed external additive is reliably attached or embedded in the toner base (see Patent Document 7).

  In addition, by setting the external addition temperature when mixing the toner particles and inorganic fine particles to a temperature within a specific range with respect to the glass transition temperature of the toner particles, the inorganic fine particles are reliably embedded in the toner particles and continuous printing is performed. An electrophotographic toner that can suppress image defects such as a decrease in print density has been proposed (see Patent Document 8).

  Further, a method has been proposed in which fluidity is improved by adding and mixing external additives other than titanium oxide among the two types of hydrophobic metal oxides, and then adding and mixing titanium oxide (see Patent Document 9). ).

In addition, using Henschel type mixer, the blade diameter and inner dimension depth of the mixer, the rotation speed of the blade and the mixing time are used as the processing conditions, and the relationship with the charge amount after 10 minutes is specified. Therefore, a toner manufacturing method capable of realizing stable chargeability has been proposed (see Patent Document 10). However, in this proposal, there is no verification result of the adhesion rate and release rate of the external additive, and it is considered that the effect is due to the free additive.
Also, in Patent Document 11, contrary to the recent increase in the speed of printing presses, there is a problem that ground stains and internal contamination problems are caused by falling in the machine from the developing sleeve due to the toner spent as agitation in the developing unit. In a toner with little carrier spent even if it is used for a long time, the adhesion strength is adjusted by the evaluation of the liberation rate of the external additive, and the liberation rate of titanium oxide is regulated. However, in this proposal, there is a problem in the test method, the disclosure of the manufacturing method (mixing process) is not enough, and there is no realization even with the surface treatment of the external additive, and the problem can be solved only with the current combination. However, there are limits to each element of manufacturing conditions (shearing force, temperature, mixing order) and the like. In Patent Documents 12 and 13, the adhesion rate of the external additive is analyzed.
In addition, regarding the test method of the release rate of external addition, for example, in Patent Document 14, since the released external additive has been discarded, the actual release rate cannot be analyzed. In other words, the aggregated additive of about 1 μm is separated by filter paper and added to the adhering component. Therefore, after calculating the adhesion rate from fluorescent X-ray analysis, the method for obtaining the difference from the total content of the additive is free. It cannot be treated as an ingredient. For this reason, the liberation rate in Patent Document 14 lacks accuracy and is not a quantitative analysis.

  In response to the recent demands for higher speed, higher image quality, and higher durability, the types and number of external additives that are indispensable for the construction of toner are diversifying. Further, it is necessary to attach an external additive having a small particle diameter to the advancing toner, and it has become impossible to uniformly adhere to the toner surface by the conventional mixing method and mixing technique. Appropriate adhesion conditions are required for diversified external additives, which is a problem in conventional mixing methods and techniques.

As a result of investigating the strength of the adhesive force with external additives in various mixing methods, the present inventors have found that there are the following patterns. For example, in the case of a blender that mixes at a relatively low energy, such as a V-type blender, there is a peak in a partial region where the adhesive force is weak with respect to the mixing energy, and the mixing dispersion force is weak. Will be observed.
In addition, in the case of a medium class method such as a Henschel mixer, the adhesion rate has a peak at the center with respect to the mixing energy, and a moderately weak adherence skirt occurs on the left and right. Even with high mixing energy and strong adhesion, such as high energy blenders such as mixers and mechano-fusions, which are relatively affected by the number of blade rotations, there is a partial peak and the adhesion state is moderate or weak. There is also a problem that the adhesion of the external additive to the toner cannot be made uniform.

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention can stably control and maintain the triboelectric charge amount of toner, can maintain a stable triboelectric charge property with little environmental fluctuation, and is generated during development of a toner image. An electrostatic image developing toner externally added with surface-modified titanium oxide that does not cause abnormal images due to adhesion to the surface, a method for producing an electrostatic image developing toner, a developer, and an image forming method The purpose is to provide.

As a result of intensive studies by the present inventors in order to solve the above-described problems, zinc ions are particularly selected from transition metals as means for suppressing aggregation between particles in the surface treatment of titanium oxide used as an additive. Select and use as anchor treatment before hydrophobization treatment, so that the hydrophobic film treated with siloxane-bonded silane condensate is resistant to shearing force and gives relatively strong mixing energy in the mixing process during toner production I found out that it would be possible.
Under normal manufacturing conditions, there are toners with weak adhesion to the mixing energy, and the adhesion of external additives varies, and these low adhesion toners eventually cause external additives to peel off. It was found that various problems were caused by the shearing force at the time of stirring with the carrier particles and the abrasion with the photoconductor in the developing part.
Therefore, the present inventors have examined the use of titanium oxide that has been subjected to zinc ion treatment in the preceding step of the titanium oxide hydrophobization treatment to control the adhesion and mixing state to be appropriate for each, and as a result, the titanium oxide mixing step In regard to the manufacturing method in (1), it has been found that the middle class mixing method is most suitable in terms of the energy of the mixing method, i.e., in this mixing method, by reducing the amount of the weak adhesion to the limit, It has been found that the above problem can be effectively solved by making the adhesive force of the agent to the toner uniform.

  As a result of further diligent investigations by the present inventors based on the above findings, as a result of research on a Henschel mixer, the cooling cycle of the rotating blade tip is used as a means for keeping the energy given to the toner constant. As a result of analyzing the swirling state of the air flow in the mixing tank as a mixing blender, the rotation is increased and the highest energy is efficiently given to the toner, so that the external additive has a uniform adhesion to the toner. It was found that it can be realized.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A mixing step of mixing and cooling a toner base containing at least a binder resin and a colorant and titanium oxide containing zinc ions and having a silane condensate bonded to the surface is defined as one cycle. A toner production method in which the mixing step is repeated for 3 to 7 cycles,
Ratio of mixing time and cooling time in the mixing step (mixing time / cooling time) is 0.5 to 2.0,
A method for producing a toner, characterized in that a release rate of titanium oxide with respect to a toner base by an ultrasonic vibration method is 20% to 25%.
In the method for producing a toner according to <1>, the adhesion rate of titanium oxide (titania) in the external additive is uniform, and the release rate of titanium oxide to the toner base by the ultrasonic vibration method is 20 to 25%. As a result, the chargeability of the toner has been improved, especially the environmental stability has been improved, and a high charge amount can be maintained even when used continuously for a long time in an environment from high temperature and high humidity to low temperature and low humidity. In addition, it is possible to obtain a copy image with a stable image quality with little occurrence of reverse polarity toner and no fog. In particular, when a surface modifying agent having a negative polar group is used in combination, durability and charging environmental stability can be further improved, and cost can be further reduced.
<2> The toner according to <1>, wherein a titanium oxide liberated substance with respect to a toner base is extracted as a solubilized component in an aqueous solution containing a surfactant, and a titanium oxide liberation rate is determined by atomic absorption spectrometry.
In the method for producing a toner according to <2>, the surfactant having a function of solubilizing hydrophobic fine particles among the surfactants by an operation of separating the adhering component and the free component by an ultrasonic vibration method Quantification from the aqueous solution component in which the free component was solubilized significantly increased the quantitative accuracy. Accordingly, it is possible to accurately analyze the mixing energy for externally adding the additive and the amount of change in the free component under the manufacturing conditions.
<3> The toner according to <2>, wherein the release rate of titanium oxide is determined by a plasma spectroscopic analysis (ICP) method.
In the toner production method described in <3>, a range up to several ppm order can be accurately analyzed by plasma spectroscopic analysis using an atomic absorption analyzer.
<4> The method for producing a toner according to any one of <1> to <3>, wherein the mixing means used in the mixing step is a mixer having a stirring blade, and the mixing time of one cycle is within 1 minute. .
In the method for producing a toner according to <4>, the mixing condition is such that the liberation rate of titanium oxide is adjusted to 20 to 25%, and the toner is produced from a specific condition setting using a Henschel mixer. The manufactured toner has an appropriate chargeability, and can prevent toner scattering and dirt.
<5> The toner production method according to any one of <1> to <4>, wherein the zinc ion content is 50 μg to 100 μg per 1 g of titanium oxide.
In the method for producing a toner according to <5>, aggregation between the titanium oxide particles can be suppressed and the toner can be uniformly adhered to the toner base. It is possible to obtain toner that does not scatter.
<6> The method for producing a toner according to any one of <1> to <5>, wherein a silane condensate is bonded to the titanium oxide surface by a silane coupling treatment.
<7> The method for producing a toner according to any one of <1> to <6>, wherein the titanium oxide contains a fluorine atom, and the content of the fluorine atom is 0.1% by mass to 2.6% by mass. It is.
In the method for producing a toner according to <7>, when the titanium oxide contains fluorine atoms in the range of 0.1 to 2.3% by weight, the above-described water repellency characteristics are obtained, and the charging characteristics are LL environment. The level change of the charge amount from the H to the HH environment is reduced. As a result, it is possible to obtain a stable copy image having no abnormal image (filming) even when used continuously for a long time.
<8> The method for producing a toner according to any one of <1> to <7>, wherein the titanium oxide is a rutile type titanium oxide.
In the method for producing a toner according to <8>, since the carrier spent is suppressed by adopting a crystal structure of the rutile body and the adhesion efficiency of the toner base material is excellent in the mixing process, the charging characteristic of the toner is the LL environment. The level change of the charge amount from the H to the HH environment is reduced. Therefore, even if it is used continuously for a long time, it is possible to maintain a high charge amount, generate less reverse polarity toner, and obtain a stable copy image with no fog.
<9> The method for producing a toner according to any one of <1> to <8>, wherein an average particle diameter (D ₅₀ ) of titanium oxide is 0.05 μm to 0.1 μm.
<10> The method for producing a toner according to any one of <1> to <9>, wherein the toner base further contains at least one of a release agent and a charge control agent.
<11> The method for producing a toner according to any one of <1> to <10>, wherein the toner base is prepared by a pulverization method.
<12> The method for producing a toner according to any one of <1> to <11>, wherein silica is further adhered or fixed to the surface of the toner base.
In the method for producing a toner described in <12>, by further using silica, it is possible to stably control and maintain the rising of the charge with stable chargeability and the sufficient triboelectric charge amount of the toner. In addition, it can maintain stable triboelectric chargeability with little environmental fluctuations, has excellent toner transportability, developability, transferability, and storage stability, and does not generate abnormal images due to adhesion to the photoreceptor. A toner can be obtained.
<13> A toner produced by the method for producing a toner according to any one of <1> to <12>.
In the toner according to <13>, the adhesion rate of titanium oxide (titania) is uniform in the external additive, and the release rate of titanium oxide to the toner base by the ultrasonic vibration method is 20 to 25%. As a result, the chargeability of the toner particles is improved, especially the environmental stability is improved, and even when used continuously for a long period of time in an environment from high temperature and high humidity to low temperature and low humidity, a high charge amount is maintained. Therefore, it is possible to obtain a copy image having a stable image quality with little occurrence of reverse polarity toner and no fogging. In particular, when a surface modifying agent having a negative polar group is used in combination, durability and charging environmental stability can be further improved, and cost can be further reduced.
<14> A developer comprising the toner according to <13>.
<15> A toner-containing container filled with the toner according to <13>.
<16> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, An image forming method comprising at least a transfer step of transferring a visible image to a recording medium and a fixing step of fixing the transfer image transferred to the recording medium,
The toner is the toner according to <13>, wherein the toner is an image forming method.
<17> An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to make it visible An image forming apparatus having at least developing means for forming an image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
The toner is the toner according to <13>, wherein the toner is an image forming apparatus.
<18> An electrostatic latent image carrier and at least developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a visible image, and forming an image A process cartridge that is detachable from the apparatus body,
The toner is the toner according to <13>, wherein the toner is a process cartridge.

  According to the present invention, the conventional problems can be solved, the triboelectric charge amount of the toner can be stably controlled and maintained, and the triboelectric chargeability can be maintained with little environmental fluctuation. An electrostatic image developing toner externally added with surface-modified titanium oxide that does not generate an abnormal image due to adhesion to a photoreceptor, which occurs during development of the toner image, and a method for producing the electrostatic image developing toner Can be provided.

FIG. 1 is a schematic view showing an example of the process cartridge of the present invention. FIG. 2 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention. FIG. 3 is a schematic explanatory view showing another example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention. FIG. 4 is a schematic explanatory view showing an example of carrying out the image forming method of the present invention by the image forming apparatus (tandem color image forming apparatus) of the present invention. FIG. 5 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG.

(Toner and toner production method)
The toner production method of the present invention comprises a mixing step of mixing and cooling a toner base containing at least a binder resin and a colorant and titanium oxide containing zinc ions and having a silane condensate bonded to the surface. 1 cycle, the mixing step is repeated 3 to 7 cycles,
Ratio of mixing time and cooling time in the mixing step (mixing time / cooling time) is 0.5 to 2.0,
The liberation rate of titanium oxide with respect to the toner base by the ultrasonic vibration method is 20% to 25%.
The toner of the present invention is manufactured by the toner manufacturing method of the present invention,
Hereinafter, the details of the toner of the present invention will be clarified through the description of the toner production method of the present invention.

In the toner production method of the present invention, a specific surface-treated titanium oxide is used in a mixing method in which a rotary blade is attached in a fixed mixing tank and two or more raw material powders are mixed using the rotary blade. A mixing step of mixing the toner with the toner base.
The surface-modified titanium oxide particles are crushed by a jet mill or the like, and then the toner base is adhered. The order of addition may be selected depending on the action of the additive.
First, in order to improve fluidity, storage stability, developability, and transferability as a developer, inorganic fine particles such as hydrophobic silica fine powder are first added to and mixed with the toner base. The mixer may be mixed with titanium oxide. A general powder mixer may be used as the mixer, but it is preferable that the mixer can be equipped to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually. You may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. A strong load may be given first, then a relatively weak load, or vice versa.

  Examples of the mixer include a V-type mixer, a rocking mixer, a Roedige mixer, a Nauter mixer, and a Henschel mixer, but the volumetric mixing operation is preferably about 60 to 80% of the total volume. Specifically, a super mixer capable of high-speed rotation with a general Henschel mixer is used. Specifically, the toner base and the additive (mixing medium) are put into the mixing chamber. At this time, the rotary blade is preferably a two-stage type, and the toner base and the additive (mixing medium) are put on the wall of the mixing chamber by the rotational force. It is pushed and swiveled, gathered by the tip of the rotating blade, and mixed. Furthermore, once peeled off from the wall surface by the deflector, it is dispersed and pressed again against the mixing chamber wall to be swirled and mixed. This operation is repeated to achieve stable mixing.

The temperature in the jacket is controlled within a temperature range of 20 ° C. to 35 ° C., and the rotation speed of the stirring blade is preferably around 1000 rpm, and if it exceeds 1200 rpm, there is a risk of increased frictional heat. Since it accompanies, it is not preferable.
The ratio of the mixing time and the cooling time in the mixing step (mixing time / cooling time) is 0.5 to 2.0, preferably 0.5 to 1.0. When the cooling time is shorter than the operation time, the frictional heat rises, the additive is buried, the toner fluidity is hindered, and the formation of aggregates is increased.
It is preferable that the mixing time of one cycle in the mixing step is within 1 minute.
The mixing step of mixing the toner base and titanium oxide containing zinc ions and having a silane condensate bonded to the surface with a siloxane bond and cooling is made one cycle, and the mixing step is repeated 3 to 7 cycles. If the number of repetitions of the cycle is small, the adhesive force is weak, and when used as a developer, the free additive may cause a problem of carrier spent and a cause of the quality problem targeted by the present invention.

  Further, from the side, an air flow source for further mixing and dispersing the powder layer flowing in the apparatus may be provided to increase the mixing efficiency. The size is about one third of the diameter of the rotary blade. Diameters can be used. That is, when the mixing blade rotates at a high speed, a swirling flow is generated and two or more kinds of particles are mixed. The required adhesion strength is determined by the tip peripheral speed obtained and the rotational speed of the mixing blade.

<Titanium oxide>
The titanium oxide is not particularly limited, and a known titanium oxide can be used, but it is a rutile type titanium oxide in that the carrier spent is suppressed and the adhesion efficiency to the toner base is excellent in the mixing step. Is preferred.
The titanium oxide is generally produced by a wet method and a gas phase method. In general, gold ore, pyrite, plate titanium stone, ilmenite and the like are used as ores containing titanium. There is a sulfuric acid method in which concentrated sulfuric acid is added to these ores to dissolve them, or a chlorine method in which these ores are dehydrated with carbon materials and exposed to chlorine gas. In either case, titanium hydroxide Ti (OH) ₂ is purified, and crystals of TiO ₂ are precipitated by hydrolysis in the final stage. For this reason, there are some water-soluble components. These are alkali metal ions and acid components contained in ores and catalysts and processing agents used in the production process, such as PO ₄ ²⁻ , SO ₄ ²⁻ , Cl ⁻ , Na ⁺ , Mg ²⁺ , Li ^{+ and the} like. Can be mentioned. These water-soluble components are known to affect the chargeability and volume resistance of the toner, and it is said that a high charge amount is maintained by controlling to less than 0.2% by mass. However, in addition to the content of the water-soluble component, it also depends on the water content of titanium oxide and the functional group intervening on the particle surface.

Since titanium oxide particles are inherently hydrophilic and contain cations and anions that dissociate, the water-soluble component is said to contain such cations and anions. I am letting.
In the present invention, it is preferable to contain 50 μg to 100 μg of zinc ions per 1 g of titanium oxide, and more preferably 55 μg to 80 μg. If the zinc ion content is less than 50 μg, the reaction with the silane coupling agent may be hindered, and the original hydrophobizing ability may be lost, and if it exceeds 100 μg, the solubility may decrease. .
Since it is oriented on the surface of the titanium oxide particles, the reactivity with the surface modifier is also balanced, and as a result, it has an effect on the uniformity of the gelled hydrophobized film.
Here, as a means for analyzing zinc ions contained in the titanium oxide, for example, qualitative analysis by the following ion chromatograph method and quantitative measurement can be performed by a multi-inspection calibration method.
IC-7000P manufactured by Yokogawa Electric Co., Ltd. is used. For cation, column ICS-C15, precolumn ICS-C16 column temperature 40 ° C., sample amount 50 μL, solution is HNO ₃ (5 mM), removal solution is water of the same concentration. On the other hand, Na oxide was used, and in the anion measurement, column ICS-A23, pre-column ICS-A26 column temperature 40 ° C., sample amount 50 μL, dissolved solution Na ₂ CO ₃ (2.5 mM) / NaHNO ₃ (1.2 mM) The removal solution was 15 mM sulfuric acid and the flow rate was 1.0 ml / min.

It is considered that the function of the zinc element is not so strong as a cation. Accordingly, the content of the other cationic water-soluble component is not particularly limited and can be appropriately selected according to the purpose, preferably 0.2% by mass or more, and 0.2% by mass to 0.5% by mass. Is more preferable, and 0.2 mass% to 0.4 mass% is still more preferable. If the amount of the cation water-soluble component is less than 0.2% by mass, the cleaning step for purification may increase and the cost may increase. Problems remain in the decomposition reaction. In addition, as an anion, it is preferable that chlorine ion is contained in the range of 10 μg to 20 μg and sulfate ion in the range of 5 μg to 150 μg.
The amount of the water-soluble component can be determined according to, for example, JIS K5116-1973.

  The method for treating the titanium oxide with zinc ions is not particularly limited and may be appropriately selected depending on the purpose. For example, by using a zinc ion-containing solution such as an aqueous zinc chloride solution, immersion, spraying, or the like. What is necessary is just to process a titanium oxide. Moreover, it can also process with the chloride and sulfate of zinc in the manufacturing process of a titanium oxide, and can also process with the zinc ion containing solution as mentioned above after purchasing a commercially available titanium oxide.

Next, the obtained zinc ion-treated titanium oxide is subjected to, for example, silane coupling treatment, thereby generating a silane condensate having a siloxane bond on the surface thereof.
The surface treatment method using the silane coupling treatment is generally used in a wide range of fields, and a surface treatment method using a sol-gel method is generally performed. When the normal silane coupling treatment and the silane coupling treatment in the present invention are compared, the feature of the present invention is that the titanium oxide particle surface is treated with zinc ions, thereby performing an anchor treatment with a zinc element. In addition to suppressing aggregation between titanium oxide particles and selecting an organic solvent that is less susceptible to electrostatic repulsion that affects the particles, the titanium oxide particles were treated with a silane coupling treatment method to form a polysiloxane bond on the surface. The silane condensate having a network structure is present. In addition to having water repellency, the film of the silane condensate thus obtained is more resistant to physical impact than the surface treated with a silane coupling agent due to the effect of the anchor treatment. Excellent wear resistance and strength. For this reason, it has several times the strength of conventional carrier particles and other physical friction and wear compared to those obtained by conventional surface treatment, and even as a developer (carrier particles) wear resistance Is excellent.
Since the surface treatment in the present invention has a remarkable effect as compared with the normal surface treatment, the surface treatment in the present invention is also referred to as a surface modification treatment in order to distinguish it from the conventional surface treatment.

The difference between the surface modification and the surface treatment is such that the effect is greatly different in this way, but the synthesis method is also different. For example, the surface treatment method and the surface modification synthesis method are different, and there is no restriction on the content of general titanium oxide, particularly water-soluble components (see Japanese Patent No. 3018858). Moreover, in the cation and the anion, there is no problem even if there is an intervention of a halogen element such as Na, Li, NO ₂ , NO ₃ , or Cl. However, zinc ion is a necessary ion as a cation contained in titanium oxide, and is involved as an indispensable element for generation of silanolation from a sol-gel reaction using a silane coupling agent. As described in general literature, the reaction process proceeds by the hydrolysis mechanism from the intervention of water, and thus pH adjustment is required. In the surface modification in the present invention, it is not necessary to use water, and a major difference is that a network structure is generated from dealcoholization by a condensation reaction, and this brings about the above-described effects. Strong water repellency extremely suppresses (decreases) the hygroscopic property due to environmental fluctuations, and the surface-modified layer is hardly detached even when mixed with continuous carrier particles.

  In the present invention, quality maintenance in environmental fluctuations and long-term continuous running is an important characteristic. Especially when it is used as a developer, it is added to wear resistance with carrier particles, spent, filming on the surface of the photoreceptor. The performance of the external additive is essential. However, in the conventional test methods for evaluating the degree of hydrophobicity, there is a poor correlation between long-term running and print quality against environmental fluctuations, and in particular, there was no significant difference between those with a degree of hydrophobicity exceeding 30. Was also an issue. Therefore, since the water repellency evaluation method described later has a preferable result without picking up the influence of alcohols as compared with the conventional evaluation method, the following water repellency evaluation method was adopted.

A method for evaluating the water repellency of the titanium oxide is shown below.
First, after weighing 0.02 g of titanium oxide powder, 25 ml of ion-exchanged water at 25 ° C. is weighed in a 50 ml beaker, and the water surface is stopped so as not to shake. The weighed titanium oxide fine powder is introduced into the center of the liquid surface, and after the addition, the time from the rising to the immersion is measured. In the initial stage of charging, all remain floating on the liquid surface, but with time, water permeates into the particles, soaks in the liquid and becomes cloudy.
When surface-modified titanium oxide that floats on the water surface for 10 minutes or more and does not immerse is used as a two-component developer, it has excellent wear resistance with carrier particles. On the other hand, when surface-modified titanium oxide that was immersed in less than 10 minutes was used as a two-component developer, the amount of charge with stirring was changed. In other words, titanium oxide that is immersed in less than 10 minutes cannot sufficiently suppress fluctuations in charging.
The surface-modified titanium oxide is prevented from entering water for 10 minutes or more as compared with a normal surface-treated product, floats on the surface of the water, and takes 10 times or more time to be immersed. It is characterized by having water repellency.

The titanium oxide preferably contains a fluorine atom, and can be realized by using, for example, a silane coupling agent having a fluoroalkyl group at the time of silane coupling treatment. The content of the fluorine atom is preferably 0.1% by mass to 2.6% by mass, and more preferably 0.8% by mass to 2.2% by mass. When the content exceeds 2.6% by mass, the raw material cost may increase, and when it is less than 0.1% by mass, the effect may not be sufficiently exhibited.
Here, the content of the fluorine atom can be quantified by, for example, an automatic combustion halogen sulfur analysis system (combustion tube air method-ion chromatography method), Yanaco combustion device + Dionex ion chromatography ICS200 type.

  It is known that the amount of water-soluble components of titanium oxide affects the surface treatment in a technique for performing surface treatment with a coupling agent or the like for enhancing the function of titanium oxide. The present invention further modifies the essential properties of titanium oxide by surface modification treatment (hard treatment) compared to surface treatment (soft treatment), and the electrical resistance and charging characteristics of the resulting titanium oxide after surface modification. Also came to be affected. Furthermore, the secondary aggregation property of titanium oxide is changed depending on the degree of dispersion in the surface modification treatment.

  In general, a uniform treatment and a high dispersion treatment can be considered to maintain the primary particle size.However, since titanium oxide alone has many problems such as an increase in charging with time and adhesion to the photoreceptor, surface modification treatment is required. The above-mentioned problems can be solved by the fluorosilane modifier. In addition, since the particle size distribution after the surface modification treatment is determined by controlling the titanium particle diameter before the treatment, the problem of secondary agglomeration that has conventionally occurred in the surface treatment is eliminated, and although the present invention is a result, Then, although the degree of dispersion was increased, the above-mentioned problems were solved by setting the resistance low.

The purpose can be achieved even by using an alkoxylane compound which is a generally known silane coupling agent. However, the fluorine compound is preferably a perfluoroalkyl group, represented by a general formula of CnF _{2n + 1} , and n is 1 to 1 An integer of 12 is preferable, and these compounds can be selected from commercially available silane coupling agents, fluorine treatment agents used in water repellent treatment, and the like. In particular, the network structure of the hydrophobic group generated by the condensation reaction from the silane coupling agent is preferably a silane compound containing a fluorine compound.

Since the toner of the present invention obtains a negatively chargeable toner in charge characteristics, it is preferable that the surface treatment layer of the fluorosilane compound is thin, and fine particles are also preferable from the viewpoint of uniform chargeability. That is, a production method in which silanolization in the surface treatment step is reacted without using any mixed solvent of water is preferable. For example, water is used in the production methods described in Japanese Patent No. 3700263 and Japanese Patent No. 3018858.
The condensation reaction defines conditions for completing the reaction so that the silane compound does not pass through the residual silanol compound so that a siloxane bond is easily generated. That is, it is considered that the surface-modified titanium oxide particle surface is present in a polysiloxane-bonded network structure, and the stretching vibrations of various siloxane bonds are identified and verified by infrared spectroscopic analysis.
As described above, the surface modification in the present invention is characterized by interposing a multi-layer structure via a polysiloxane bond.

In the present invention, the production process for carrying out the surface modification treatment of titanium oxide is carried out in an organic solvent, but the average particle size of titanium oxide (D ₅₀ , primary particle size, before silane coupling treatment) 0.1 μm is preferable. When the average particle size is less than 0.05 μm, cohesion between particles is strong, and titanium oxide having a suitable particle size may not be produced. When the average particle size exceeds 0.1 μm, the particle size is too large. When used with toner external additives, abnormal images (streaks and unevenness) may occur.
Here, for the measurement of the average particle diameter (D ₅₀ ), for example, a UPA series particle size distribution measuring machine manufactured by NIKKISO can be used.
The specific surface area of the surface modification of titanium oxide ^is preferably 60m ² / g~160m 2 / g.

-Measurement of liberation rate and adhesion rate of titanium oxide-
As a method for measuring the release rate and adhesion rate of the titanium oxide, it is preferable to use an ultrasonic vibration method. Conventional methods for measuring the liberation rate are mostly methods for obtaining the liberation rate of Ti atoms derived from additives based on C atoms using a particle analyzer. In this method, only the additive release state of the initial toner is reflected, and there is a problem that the release rate after the toner collides and rubs between the carrier and the development unit in the development unit cannot be reflected.
In the ultrasonic vibration method, a toner is sufficiently immersed in an aqueous solution, and components having a weak adhesive force of an external additive are separated by a shearing force such as stirring.
The ultrasonic vibration method is a measurement method that reflects the release rate of the additive released from the toner after being sufficiently stressed by the development unit described above. In this case, the toner can be prevented from dropping from the developing sleeve even when subjected to a stirring stress over time.

Details of the ultrasonic vibration method will be described below.
First, 4.4 ml of 3% emulgen (manufactured by Kao Corporation) is added to 100 ml of ion-exchanged water, and stirred for 1 minute to prepare solution A. Next, 5 g of the sample initial toner is added to the solution A, shaken 20 times, the toner is wetted, and after confirming a dispersed state without floating or separation, the sample is left for 30 minutes to prepare a liquid B.
Next, the liquid B is shaken 5 times to disperse the toner, and then the vibrating part enters 2.5 cm into the liquid B with an ultrasonic homogenizer (VCX750, manufactured by SONICS), with an output energy of 30%. Vibrate for 1 minute to prepare liquid C.
Next, the liquid C is allowed to stand for 10 minutes, and then filtered using a filter paper, 100 CIRCLES (manufactured by Toyo Filter Paper Co., Ltd.). The toner remaining on the filter paper is collected and dried in a constant temperature bath at 40 ° C. for 8 hours.
Next, 3 g of the toner obtained after drying, an automatic pressure molding machine (T-BRB-32, manufactured by Maekawa), a load of 6.0 t, a pressure time of 60 sec, and pelletized to a diameter of 3 mm and a thickness of 2 mm, Sample toner after processing.
Next, the sample initial toner not subjected to the above treatment is similarly formed into a pellet having a diameter of 3 mm and a thickness of 2 mm to obtain a pre-treatment sample toner.
Next, the content of Ti element in the pellet toner sample is measured by quantitative analysis with a fluorescent X-ray apparatus (ZSX-100e, manufactured by Rigaku Corporation). A calibration curve is prepared in advance, and the adhesion rate of the additive is calculated by the following formula.
<Formula 1>
Adhesion rate (%) = (Ti element content after ultrasonic vibration treatment) / (Ti element content of sample before treatment) × 100

Next, for the liberation rate, the filtrate C is weighed to 100 ml with ion-exchanged water, and the Ti element is quantified with Shimadzu ICPS7500. The standard solution is a standard solution for atomic absorption analysis (manufactured by Kanto Chemical Co., Ltd.) A calibration curve in which the concentration of the content is changed in advance is drawn, and the Ti element and Si element contained in the filtrate C are quantified.
The liberation rate is expressed as a value obtained by dividing the concentration contained in the filtrate by the addition amount, but may be expressed as a content (ppm). Analysis of elements contained in the filtrate is preferable because plasma spectroscopic analysis is excellent in accuracy.
Although there is a method to calculate the difference from the total content of titanium oxide after calculating the adhesion rate from the fluorescent X-ray analysis by the test method described above, the liberation rate fluctuates and becomes a lower value than the actual value, and lacks accuracy. Therefore, sufficient quantitative analysis cannot be obtained. Therefore, in the present invention, analysis is performed by sampling from the filtrate.

The release rate of titanium oxide with respect to the toner base by the ultrasonic vibration method determined as described above is 20% to 25%. Further, the adhesion rate of titanium oxide to the toner base is preferably 80% to 75%.
If the liberation rate is less than 20%, the titanium oxide is excessively adhered to the toner base, and the titanium oxide is buried in the base due to the agitation stress of the developing unit. When the toner is buried in the toner base, the function of suppressing the charge amount of the toner does not work, and the toner charge amount is increased, so that the image density is decreased. On the other hand, when the release rate exceeds 25%, the release amount of titanium oxide from the toner base increases due to stirring over time, the spent adherent to the carrier, the developer's triboelectric charging ability is inferior, and the toner drops from the development sleeve May occur.

The titanium oxide used in the present invention is one obtained by further neutralizing titanium tetrachloride and crystallizing it by dehydration. The reaction solution is selected from alcohols using a silane coupling agent comprising a trifluorosilane compound.
The surface treatment with elemental zinc can be done with zinc chloride or sulfate in the titanium oxide manufacturing process, and after the purchase of commercially available titanium oxide, it can be treated with the zinc chloride described above. is there. For example, zinc ion contained in titanium oxide subjected to zinc treatment in the production process of titanium oxide is 58 μg and is a rutile type having a water-soluble component of 0.2% by mass or more. This was dispersed in toluene (nonpolar solvent) having a solid content concentration of about 40% ± 2%, and 0.05 μm to 0.00 mm using a bead mill having a particle diameter of 0.5 mm (made by Imex Corporation, bead mill machine NVM-2 type). Crush and pulverize to a range of 1 mm. This solution is mixed with an alcohol solvent in which a trifluorosilane compound is dissolved and transferred to a 1 L four-necked flask (250 g of titanium oxide is adjusted to a 40% solution with a toluene solvent, 500 g of a adjusting solution, and trifluorotrimethoxysilane 20% methanol solution is 180 g). While stirring at 60 rpm, the reaction is allowed to proceed for about 6 hours while raising the temperature to 60 ° C. in an oil bath. Next, the solvent toluene and methanol are vaporized while the temperature is raised to 130 ° C., the inner bath temperature is confirmed to 130 ° C., and the mixture is left to stand for 6 hours.

A small amount of the surface-treated product of titanium oxide collected in the above reaction process was collected and analyzed with GAS CHROMATGRAPH GC-14 manufactured by Shimadzu Corporation. When an unreacted trifluorosilane compound remains after GC analysis, a peak is detected at 110 ° C. to 150 ° C., but disappears when the surface treatment (condensation reaction) is completed. From the above, the distinction between the conventional manufacturing methods can be determined by this Rt.
Hereinafter, although the synthesis example of a titanium oxide is shown, it is not restrict | limited to these.

(Synthesis Example A)
40 g of trifluoropropyltrimethoxysilane (manufactured by Dow Chemical Co., Ltd., Z-6333 CAS No 429-60-7) is dissolved in 200 g of an ethanol solvent.
Next, 40 g of trifluoropropyltrimethoxysilane (manufactured by Dow Chemical Co., Ltd., Z-6333 CAS No 429-60-7) is dissolved in 200 g of an ethanol solvent.
Next, the zinc ion of the zinc treatment which processed TTO series titanium oxide by Ishihara Sangyo Co., Ltd. with the zinc chloride aqueous solution was measured by the ion chromatograph method, and the value of 58 micrograms was obtained by the analytical value.
Next, titanium oxide having a water-soluble component of 0.31% by mass was dispersed in a toluene solvent so as to have a solid content concentration of 37%, and a bead mill having a bead diameter of 0.5 mm (bead mill machine NVM-2 manufactured by Imex Co., Ltd.). For about 2 hours to obtain particles having an average particle size of 0.047 μm (measured using NIKKISO, Microtrac UPA-150). Thereafter, 630 g was weighed.
Next, the silane solution and titanium oxide solvent were mixed and transferred to a 1 L four-necked flask installed in an oil bath. The temperature was raised to 60 ° C. while stirring at 60 rpm using a stirrer, and the reaction was carried out for 6 to 7 hours. Warmed up. At this time, the amounts of ethanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. A sample was collected and a solvent, the unreacted remaining amount of the silane coupling agent, and the progress of silanolation were judged by gas chromatography.
When the temperature reached 90% by mass with respect to the amount of solvent used in the prescription, the set temperature was raised to 130 ° C. to 140 ° C., and the temperature rise in the tank was confirmed (if the increase was slow, the pressure was reduced appropriately) Also good). When the temperature in the tank exceeded 110 ° C., the decompression was stopped and baking was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak generated by the silanolation reaction was burned out. A sample is taken, and the amount of solvent in gas chromatographic analysis, in particular, the amount of methanol becomes 180 ppm, which is the end point.
As a result of the above reaction, 223 g of a surface-treated sample of sample titanium oxide was collected. The adhesion amount of trifluoromethoxysilane at this time was 2.0 mass% with respect to titanium oxide. As described above, the synthesis was performed by the sol-gel method.

(Synthesis Example B)
40 g of trifluoropropyltrimethoxysilane (manufactured by Toray Industries, Inc., Z-6333) and methyltrimethoxysilane (Toray Z-6366) are dissolved in an equivalent amount of methanol in 200 g of methanol.
Next, TTO series titanium oxide manufactured by Ishihara Sangyo Co., Ltd. was treated with the same zinc chloride aqueous solution as in Synthesis Example A above. Zinc ions contained in titanium oxide were measured by an ion chromatograph method, and an analytical value of 68 μg was obtained. It was. Disperse titanium oxide with a water-soluble component of 0.31% by mass in a toluene solvent so that the solid content concentration is 37%, and a bead mill (bead mill machine NVM-2 type, manufactured by IMEX) with a bead diameter of 0.5 mm. The resulting mixture was pulverized for about 2 hours to obtain particles having an average particle size of 0.047 μm (measured using NIKISO, Microtrac UPA-150). As in Synthesis Example A, 630 g was weighed.
Furthermore, the silane solution and the titanium oxide solvent are mixed and placed in an oil bath and transferred to a 1 L four-necked flask. The temperature is raised to 60 ° C. while stirring at 60 rpm using a stirrer, and the reaction is performed for 6 to 7 hours. Warmed up. At this time, the amount of ethanol and toluene is collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent is calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When the temperature reaches 90% by mass with respect to the amount of solvent used in the prescription, the set temperature is raised to 130 ° C to 140 ° C to check the temperature rise in the tank, and the degree of pressure reduction is adjusted to adjust the temperature rise. did. When the temperature in the tank exceeded 110 ° C., the decompression was stopped and baking was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak generated by the silanolation reaction was burned out. The end point of firing is determined when a sample is collected and the amount of solvent in gas chromatographic analysis, particularly the amount of methanol is 190 ppm or less. 221 g of a surface-treated product of sample titanium oxide was collected. The adhesion amount of trifluoromethoxysilane at this time was 2.0 mass% with respect to titanium oxide. The above was carried out in the synthesis example of the sol-gel method.

(Synthesis Example C)
40 g of trifluoropropyltrimethoxysilane (manufactured by Toray Industries, Inc., Z-6333) and methyltrimethoxysilane (Toray Z-6366) in an equivalent ratio were dissolved in 200 g of a methanol solvent.
Next, the zinc ion by the ion chromatograph method which implemented the titanium oxide made by KEMIRA by the processing method mentioned above was 96 micrograms. Further, a water-soluble component of titanium oxide is 0.31% by mass, titanium oxide is dispersed in a toluene solvent so that the solid content concentration is 37%, and a bead mill having a bead diameter of 0.5 mm (bead mill manufactured by Imex Corporation). Machine NVM-2 type) for about 2 hours to obtain particles having an average particle size of 0.047 μm (measured using NIKKISO, Microtrac UPA-150). 630 g of this was weighed.
Next, the surface treatment method was performed by the sol-gel method according to the above synthesis example.
First, the silane solution and titanium oxide solvent are mixed and placed in an oil bath and transferred to a 1 L four-necked flask. The temperature is raised to 60 ° C. while stirring at 60 rpm using a stirrer, and the reaction is performed for 6 to 7 hours. Warmed up. At this time, the amounts of methanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When the temperature reaches 90% by mass with respect to the amount of solvent used in the prescription, the set temperature is raised to 130 ° C. to 140 ° C., the rise of the temperature in the tank is confirmed, and the degree of increase is adjusted by adjusting the degree of pressure reduction. Adjusted. When the temperature in the tank exceeded 110 ° C., the decompression was stopped and firing was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak generated by the silanolation reaction was burned out. The end point of firing is determined when a sample is collected and the amount of solvent in gas chromatographic analysis, particularly the amount of methanol is 190 ppm or less. 221 g of a surface-treated product of sample titanium oxide was collected. The adhesion amount of trifluoromethoxysilane at this time was 2.0 mass% with respect to titanium oxide.

  In the present invention, as an external additive externally added to the toner base, it is possible to use commonly used silicon dioxide in addition to titanium oxide, and a hydrophobized product is preferable, and a primary particle diameter of 0.01 μm to Particularly preferred is 0.20 μm hydrophobized silica.

  By attaching such an external additive to the surface of the toner base, the necessary fluidity of the toner is imparted, and the charging property of the toner is stabilized. The developability from the roller to the photoreceptor is improved. In particular, when an external additive for a toner containing a polyester resin as a binder resin is used, a toner with stable chargeability can be obtained.

The amount of the external additive added is preferably 0.5 parts by mass to 10 parts by mass, and more preferably 0.8 parts by mass to 4.0 parts by mass with respect to 100 parts by mass of the toner base. As a result, the thin layer of the toner on the developing roller becomes uniform, and the unevenness of the thin layer is greatly improved. Further, a long stir of the developing roller causes white streaks due to the fusion of the toner to the stirring developer coating blade. To prevent. When the addition amount is out of the above range, the thin layer of the toner on the developing roller becomes non-uniform, and when the toner is uniformly developed and an image cannot be obtained, or white streaks due to the fusion of the toner to the stirring developer coating blade are caused. May occur. When the addition amount is less than 0.5 parts by mass, sufficient fluidity of the toner cannot be obtained and a necessary amount of toner is not supplied to the developing roller, or the toner is too charged and sufficient toner is insufficient. Development may not be performed. On the other hand, when the added amount exceeds 10 parts by mass, the chargeability of the toner is too low, and the toner may scatter from the developing roller or cause background stains.
The toner base means particles in the middle of production containing materials other than additives, at least a binder resin, and a colorant.

The inorganic fine particles as the external additive preferably contain hydrophobic inorganic fine particles having a number average particle diameter in the range of 80 nm to 500 nm, and the inorganic fine particles are more preferably hydrophobized silica. When the inorganic fine particles having a large particle size adhere to the surface of the toner, they contribute to charging property and fluidity at the time of friction with the carrier, and are less buried in the toner base. In addition, the spacer effect reduces the frictional collision and prevents titanium oxide having a small particle diameter from falling off the toner surface.
When the number average particle diameter of the inorganic fine particles is less than 80 nm, the carrier friction causes the toner to be buried in the toner base, or the spacer effect is small, and the small-diameter titanium oxide easily falls off the toner surface. The toner is likely to fall from the sleeve due to. When the number average particle size of the inorganic fine particles exceeds 500 nm, the particle size is large, so that the total area that can come into contact with the toner surface when mixed with the toner base is small, and it is not added sufficiently to the toner and remains free. The contribution to the fluidity and chargeability is weakened, and the stress that the fluidity deteriorates is more likely to be subjected to development agitation, so that the carrier spent on titanium oxide progresses and the frictional charging ability of the carrier decreases, resulting in In some cases, toner may fall from the developing sleeve.

  The adhering state of the hydrophobized material on the particle surface of the external additive can be observed with a TEM image after freezing and cutting with a cryo-freezing apparatus. Therefore, it can be observed that the polysiloxane condensate is coated on the surface of the titanium oxide particles in a network shape, but the coverage is preferably in the range of 1% by mass to 3% by mass with respect to titanium oxide. If the covering ratio exceeds 3% by mass, it is not preferable because it leads to variations in the amount of charge when it is converted to a toner, the effect of increasing the charge, and the cost of raw materials. On the other hand, if the coverage is less than 1% by mass, a sufficient water repellency effect cannot be exhibited sufficiently, and fluctuations in the charge amount over time with stirring with carrier particles cannot be suppressed.

<Toner>
The toner contains at least a binder resin and a colorant, and further contains other components as necessary.

-Binder resin-
The binder resin may be a known resin, and is not particularly limited. However, a polyester resin is preferably used as the binder resin for full-color toner from the viewpoint of color developability and image strength. In a color image, several types of toner layers are stacked several times, so that the toner layer becomes thick, causing cracks and defects in the image due to insufficient strength of the toner layer, and loss of appropriate gloss. For this reason, a polyester resin is preferably used in order to maintain an appropriate gloss and excellent strength.

The polyester resin can be generally obtained by an esterification reaction of a polyhydric alcohol and a polycarboxylic acid.
Among the monomers constituting the polyester resin, the alcohol monomer includes a trifunctional or higher polyfunctional monomer, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol. Diols such as 1,4-butadieneol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxypropylenated bisphenol Bisphenol A alkylene oxide adducts such as A, other dihydric alcohols, or sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripe Taerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, tri Examples include methylolpropane, 1,3,5-trihydroxybenzene, and other trihydric or higher polyhydric alcohols.

  Among these monomers constituting the polyester resin, those using a bisphenol A alkylene oxide adduct as the main component monomer are preferably used. When a bisphenol A alkylene oxide adduct is used as a constituent monomer, a polyester having a relatively high glass transition point is obtained due to the nature of the bisphenol A skeleton, and the copy blocking resistance and heat resistant storage stability are good. In addition, the presence of alkyl groups on both sides of the bisphenol A skeleton acts as a soft segment in the polymer, and the color developability and image strength during toner fixing are improved. Of the bisphenol A alkylene oxide adducts, those having an ethylene group or a propylene group are preferably used.

  Among the monomers constituting the polyester resin, examples of the acid monomer include trifunctional or higher polyfunctional monomers such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid. Acids, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, or alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid, anhydrides of these acids, alkyl Esters, other divalent carboxylic acids, and 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid Acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicar Xyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and anhydrides thereof, alkyl ester, alkenyl ester, aryl ester Other trivalent or higher carboxylic acids can be mentioned.

  Specific examples of the alkyl ester, alkenyl ester or aryl ester described herein include triethyl 1,2,4-benzenetricarboxylate, trimethyl 1,2,4-benzenetricarboxylate, triethyl 1,2,4-benzenetricarboxylate. 1,2,4-benzenetricarboxylic acid tri-n-butyl, 1,2,4-benzenetricarboxylic acid isobutyl, 1,2,4-benzenetricarboxylic acid tri-n-octyl, 1,2,4-benzenetricarboxylic acid tri 2-ethylhexyl, 1,2,4-benzenetricarboxylic acid tribenzyl, 1,2,4-benzenetricarboxylic acid tris (4-isopropylbenzyl) and the like.

  There is no restriction | limiting in particular in the manufacturing method of the said polyester resin, Esterification reaction can be performed by a well-known method. The transesterification can also be performed by a known method, and a known transesterification catalyst can be used. Examples thereof include magnesium acetate, zinc acetate, manganese acetate, calcium acetate, tin acetate, lead acetate, and titanium tetrabutoxide. The polycondensation reaction can be performed by a known method, and a known polymerization catalyst can be used. Specific examples include antimony trioxide and germanium dioxide.

-Colorant-
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), Cadmium yellow, Yellow iron oxide, Ocher, Yellow lead, Titanium yellow, Polyazo yellow, Oil yellow, Hansa yellow (GR, A, RN, R), Pigment yellow L, Benzidine yellow (G, GR) , Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Red 4R, Parallel , Faise red, parachloroortho nitroaniline red, risor fast scarlet G, brilliant fast scarlet, brilliant carmine BS, permanent red (F2R, F4R, FRL, FRLL, F4RH), fast scarlet VD, Belkan Fast Rubin B, brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, rhodamine lake Y, alizarin lake, thioindigo red B, thioindigo maroon, oil le Quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkaline blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Glee Nlake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc Hana, Litobon and the like. These may be used individually by 1 type and may use 2 or more types together.

The content of the colorant in the toner material is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. When the content is less than 1% by mass, the coloring power of the toner may be reduced. When the content is more than 15% by mass, the dispersion of the pigment in the toner may be poorly dispersed. The characteristics may be degraded.
The colorant may be used as a master batch combined with a resin. Examples of such resins include polyesters, styrene or substituted polymers thereof, styrene copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and epoxy resins. , Epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax , Etc. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polymer of styrene or a substituted product thereof include polystyrene, poly (p-chlorostyrene), and polyvinyl toluene. Examples of the styrene copolymer include styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer. Copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic copolymer Acid butyl copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene- Acrylonitrile-indene copolymer, steel Down - maleic acid copolymer, styrene - maleic acid ester copolymers and the like.

  The master batch can be manufactured by applying a high shear force and mixing or kneading the resin and the colorant. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove water and the organic solvent. For mixing or kneading, for example, a high shear dispersion device such as a three-roll mill can be used.

  The toner of the present invention may further contain known components such as a release agent, a charge control agent, and a magnetic material, if necessary.

-Release agent-
As the release agent, it is preferable to contain a wax in the manufactured toner in order to give the toner releasability. The melting point of the wax is preferably 40 ° C to 120 ° C, more preferably 50 ° C to 110 ° C. When the melting point of the wax is excessive, fixing property at a low temperature may be insufficient, and when it is excessively low, offset resistance and durability may be deteriorated. ). That is, the melting peak value when a sample of several mg is heated at a constant rate of temperature rise, for example (10 ° C./min) is defined as the melting point.

  Examples of the wax include solid paraffin wax, microcrystalline wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketone, fatty acid metal salt wax, fatty acid ester wax, and partially saponified fatty acid ester wax. , Silicone varnish, higher alcohol, carnauba wax and the like. Moreover, polyolefins, such as low molecular weight polyethylene and a polypropylene, are mentioned. Among these, polyolefins having a softening point by the ring and ball method of 70 ° C. to 150 ° C. are preferable, and polyolefins having a softening point of 120 ° C. to 150 ° C. are particularly preferable. In addition to synthetic waxes, natural waxes such as carnauba wax can also be used, and it is preferable to make use of the advantages of natural products in combination.

-Charge control agent-
Examples of the charge control agent include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified quaternary ammonium salts). ), Alkylamide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine-based surfactant, salicylic acid metal salt, salicylic acid derivative metal salt, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Commercially available products may be used as the charge control agent, such as bontron 03 of nigrosine dye, bontron P-51 of quaternary ammonium salt, bontron S-34 of metal-containing azo dye, oxynaphthoic acid metal complex E-82 of salicylic acid-based metal complex, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR-147, a boron complex (Japan Carri Manufactured by Toto), copper phthalocyanine, perylene, quinacridone, azo pigments, polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium bases.

  The content of the charge control agent is preferably 0.1 parts by mass to 10 parts by mass, and more preferably 0.2 parts by mass to 5 parts by mass with respect to 100 parts by mass of the binder resin. When the content is less than 0.1 parts by mass, the charge controllability may not be obtained. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too large and the effect of the main charge control agent is reduced. As a result, the electrostatic attractive force with the developing roller increases, which may lead to a decrease in toner fluidity and a decrease in image density.

-Magnetic material-
The toner of the present invention may be a magnetic toner containing a magnetic material. Examples of the magnetic material include iron oxide (magnetite, ferrite, hematite, etc.), metal (iron, cobalt, nickel, etc.), the metal and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth. , Calcium, cadmium, manganese, selenium, titanium, tungsten, vanadium and other alloys or mixtures thereof. These may be used individually by 1 type and may use 2 or more types together.
The content of the magnetic material is preferably 5 parts by mass to 150 parts by mass with respect to 100 parts by mass of the binder resin.

  The method for producing the toner of the present invention is not particularly limited, and any conventionally known pulverization method or polymerization method may be used. As the pulverization method, for example, a production method including a step of mechanically mixing toner components including at least a binder resin and a colorant, a step of melt-kneading, a step of pulverization, and a step of classification can be applied. In addition, in the mechanical mixing step and the melt-kneading step, a production method is also included in which powder other than the particles obtained as a product obtained in the pulverization or classification step is returned and reused.

  Powders other than the particles used as products (secondary products) are generated in the finely divided and coarse particles other than the components that become products of the desired particle size obtained in the pulverization process after the melt-kneading process and the subsequent classification process. It means fine particles and coarse particles other than the components that become products having a desired particle size. In the step of mixing and melt-kneading such a by-product, it is preferable to mix 1 to 20 parts by mass of the by-product with the raw material and preferably 100 parts by mass of the main raw material.

  The mixing step of mechanically mixing the toner component including at least the binder resin and the colorant, and the mixing step of mechanically mixing the toner component including the binder resin, the colorant, and the charge control agent are usually performed by rotating wings. What is necessary is just to perform on normal conditions using a mixer etc., and there is no restriction | limiting in particular.

  When the above mixing process is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Kay Sea Kay Co., Ltd., PCM type twin screw extruder manufactured by Ikegai Iron Works, Conyder manufactured by Buss Co., Ltd. Etc. are preferably used. It is important that this melt-kneading is performed under appropriate conditions that do not cause the molecular chains of the binder resin to be broken. Specifically, the melt kneading temperature should be performed with reference to the softening point of the binder resin. If the temperature is too low from the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed.

  When the melt-kneading step is completed, the kneaded product is then pulverized. In this pulverization step, it is preferable to first coarsely pulverize and then finely pulverize. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used. After the pulverization step is completed, the pulverized product is classified in an air current such as centrifugal force to produce a developer having a predetermined particle size, for example, an average particle size of 5 μm to 20 μm.

In producing the toner of the present invention, an external additive is added to and mixed with the toner base produced as described above in order to improve the fluidity, storage stability, developability and transferability as a developer. For mixing external additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually. Of course, you may change the rotation speed of a mixer, rolling speed, time, temperature, etc. A strong load may be given first, then a relatively weak load, and vice versa. As an example of the mixing equipment that can be used, a Henschel mixer is suitable. As specific conditions, the temperature control in the first jacket is controlled to a temperature range of 25 ° C. to 35 ° C., and the rotation speed of the stirring blade is About 1000 rpm is preferable, and exceeding 1200 rpm is undesirable because there is a danger of increased frictional heat. Further, the mixing time is 60 seconds as compared with the 30-second operation which depends on the toner capacity. The cooling cycle is repeated 3 to 7 times. For example, when the cooling time is shorter than the operation time, the frictional heat rises and the additive is buried, resulting in toner fluidity. Hinders the formation of aggregates. If the number of repetitions of the cycle is small, the adhesive force is weak, and if it is used as a developer, it causes a problem of carrier spent and a cause of the quality problem targeted by the present invention.
Further, from the side, an air flow source for further mixing and dispersing the powder layer flowing in the apparatus may be provided to increase the mixing efficiency. The size is about one third of the diameter of the rotary blade. Can be used. That is, when the mixing blade rotates at a high speed, a swirling flow is generated and two or more kinds of particles are mixed. The required adhesion strength is determined by the tip peripheral speed obtained and the rotational speed of the mixing blade.

<Two-component developer>
The toner of the present invention may be used as a two-component developer using a carrier. The carrier used here may be any conventional system such as iron powder, ferrite, magnetite, and glass beads. These carriers may be resin-coated. In this case, examples of the resin used include polyfluorocarbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, acrylic resin, and silicone resin. Among these, the silicone coat carrier is excellent from the viewpoint of the developer life. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used.
These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance. In general, the mixing ratio of the toner and the carrier in the two-component developer is preferably 0.5 part by mass to 20.0 parts by mass with respect to 100 parts by mass of the carrier.

<Process cartridge>
The process cartridge used in the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image, and the electrostatic latent image carried on the electrostatic latent image carrier using a toner and makes it visible. Development means for forming an image, and other means appropriately selected as necessary.
The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, and is preferably provided detachably in the image forming apparatus of the present invention described later.

Here, for example, as shown in FIG. 1, the process cartridge includes an electrostatic latent image carrier 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and further, if necessary. And other means. In FIG. 1, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.
Next, the image forming process using the process cartridge shown in FIG. 1 will be described. The electrostatic latent image carrier 101 is charged by the charging unit 102 while being rotated in the direction of the arrow, and exposure 103 by the exposure unit (not shown). An electrostatic latent image corresponding to the exposure image is formed on the surface. The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the latent electrostatic image bearing member after the image transfer is cleaned by the cleaning unit 107, further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

(Image forming method)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transferring step, and a fixing step, preferably including a cleaning step, and other steps appropriately selected as necessary. For example, a static elimination process, a recycling process, a control process, etc. are included.
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and preferably includes a cleaning unit. In addition, other means appropriately selected as necessary, for example, static elimination means, recycling means, control means, and the like are provided.

  The electrostatic latent image forming step can be performed by the electrostatic latent image forming unit, the developing step can be performed by the developing unit, the transfer step can be performed by the transferring unit, and the fixing step. Can be performed by the fixing unit, the cleaning step can be performed by the cleaning unit, and the other steps can be performed by the other unit.

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

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to.
The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.

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

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner of the present invention, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using, for example, the toner of the present invention, and can be appropriately selected from known ones. For example, the toner of the present invention is contained and the static Preferable examples include at least a developing device capable of applying the electrostatic image developing toner to the electrostatic latent image in contact or non-contact.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer that frictionally stirs and charges a toner for developing an electrostatic charge image and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and stirred, and the toner toner for developing an electrostatic image is charged by friction at that time, and is held on the surface of the rotating magnet roller in a raised state. A brush is formed. Since the magnet roller is arranged in the vicinity of the electrostatic latent image carrier (photosensitive member), a part of the electrostatic charge image developing toner constituting the magnetic brush formed on the surface of the magnet roller is Then, it moves to the surface of the electrostatic latent image carrier (photoconductor) by an electric attractive force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, and the developer may be a one-component developer or a two-component developer. The toner contained in the developer is the toner of the present invention.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image to a recording medium, and there are a case of using an intermediate transfer member and a step of directly transferring to a printing paper, both of which are the image forming method of the present invention. That is, although it differs between monochrome transfer and color transfer methods, in the case of color transfer, a mode in which a visible image is first transferred onto the intermediate transfer member and then the visible image is secondarily transferred onto the recording medium is preferable. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner, as the toner, and transferring the composite transfer image onto a recording medium A mode including a secondary transfer step is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) using the visible image as a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. For example, a transfer belt is preferably used for color correspondence.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

-Fixing process and fixing means-
The fixing step is a step of fixing the visible image transferred to the recording medium using the fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or may be applied to the toner of each color. On the other hand, it may be carried out simultaneously at the same time in a state of being laminated.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressing roller, a combination of a heating roller, a pressing roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

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

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

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

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

  One mode of carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 2 includes a photosensitive drum 10 as the electrostatic latent image carrier, a charging roller 20 as the charging unit, an exposure device 30 as the exposure unit, and a developing unit. A developing device 40, an intermediate transfer member 50, a cleaning device 60 as the cleaning unit having a cleaning blade, and a static elimination lamp 70 as the static elimination unit.

  The intermediate transfer member 50 is an endless belt, and is designed so as to be movable in the direction of the arrow in the figure by three rollers 51 that are arranged on the inner side and stretch the belt. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. An intermediate transfer member cleaning blade 90 is disposed in the vicinity of the intermediate transfer member 50, and a transfer bias for transferring a visible image (toner image) to the recording medium 95 (secondary transfer) is applied. Possible transfer rollers 80 as the transfer means are arranged to face each other. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the visible image on the intermediate transfer member 50 is connected to the electrostatic latent image carrier 10 in the rotation direction of the intermediate transfer member 50. The contact portion between the intermediate transfer member 50 and the contact portion between the intermediate transfer member 50 and the recording medium 95 is disposed.

  The developing device 40 includes a developing belt 41 as a developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Yes. The black developing unit 45K includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched by a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier 10.

  In the image forming apparatus 100 shown in FIG. 2, for example, the charging roller 20 charges the photosensitive drum 10 uniformly. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 3 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 2, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and Except for the fact that the cyan developing unit 45C is arranged directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The tandem image forming apparatus shown in FIG. 4 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15 and 16, and can be rotated clockwise in FIG. 4. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is disposed in the vicinity of the support roller 15. The intermediate transfer body 50 stretched by the support roller 14 and the support roller 15 is a tandem type in which four image forming means 18 of yellow, cyan, magenta, and black are arranged in parallel and facing each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem image forming apparatus, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. .

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem type developing device 120 is a static image as shown in FIG. An electrostatic latent image carrier 10 (an electrostatic latent image carrier 10K for black, an electrostatic latent image carrier 10Y for yellow, an electrostatic latent image carrier 10M for magenta, and an electrostatic latent image carrier 10C for cyan); The electrostatic latent image bearing member 10 is uniformly charged, and the electrostatic latent image bearing member is exposed (L in FIG. 5) for each color image corresponding to each color image information. An exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and each color toner (black toner, yellow toner, magenta toner, and cyan toner) Develop with A developing device 61 for forming a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a cleaning device 63, and a static eliminator 64 are provided. Each single color image (black image, yellow image, magenta image, and cyan image) can be formed based on the color image information. The black image, the yellow image, the magenta image, and the cyan image formed in this manner are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15 and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 10C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 145, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

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

<Measurement of fluorine content>
The content of fluorine atoms in titanium oxide was measured by an automatic combustion halogen sulfur analysis system (combustion tube air method-ion chromatography method).

<Measurement of zinc ion content>
As a means for analyzing zinc ions contained in titanium oxide, qualitative analysis by the following ion chromatograph method and quantitative measurement can be performed by a multi-inspection curve method.
IC-7000P manufactured by Yokogawa Electric Co., Ltd. is used. For cation, column ICS-C15, precolumn ICS-C16, column temperature 40 ° C., sample amount 50 μL, solution is HNO ₃ (5 mM), and removal solution has the same concentration. On the other hand, Na hydride was used. On the other hand, in the anion measurement, column ICS-A23, precolumn ICS-A26 column temperature 40 ° C., sample amount 50 μL, dissolved solution Na ₂ CO ₃ (2.5 mM) / NaHNO ₃ (1.2 mM) ), 15 mM sulfuric acid was used as the removal solution, and the flow rate was 1.0 ml / min.

<Average particle size of titanium oxide>
The average particle diameter of titanium oxide was measured using a UPA series particle size distribution measuring machine manufactured by NIKKISO.

(Synthesis Example 1)
-Production of surface-modified titanium oxide-
Ishihara Sangyo Co., Ltd. TTO-51N, which is a raw material, titanium tetrachloride was hydrolyzed with sodium hydroxide and then subjected to a baking treatment, followed by a surface treatment with a zinc chloride aqueous solution in the surface treatment step. Thereafter, titanium oxide (ion chromatographic analysis value: zinc ion 55 μg) that has been subjected to washing and drying treatment and pulverization finish treatment is used, and a toluene / methanol solvent (7: 1) is used so that the solid concentration is 37%. And 40 g of trifluoropropyltrimethoxysilane (manufactured by Dow Chemical Co., Ltd., Z-6333 CAS No 429-60-7) is added, and a bead mill having a bead diameter of 0.5 mm (manufactured by IMEX, bead mill machine, NVM-2 type). Was used for about 2 hours to obtain particles having an average particle size of 0.047 μm (measured using a Microtrac UPA-150, manufactured by NIKKISO), and 630 g was weighed.
Next, the silane solution and the titanium oxide dispersion solution are mixed and transferred to a 1 L four-necked flask installed in an oil bath. The temperature is raised to 60 ° C. while stirring at 60 rpm using a stirrer, and the reaction is performed for 6 to 7 hours. The temperature was warmed to 80 ° C. At this time, the amounts of ethanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When the temperature reaches 90% by mass with respect to the amount of solvent used in the prescription, the set temperature is raised to 130 ° C. to 140 ° C., the rise of the temperature in the tank is confirmed, and the degree of increase is adjusted by adjusting the degree of pressure reduction. Adjusted. When the temperature in the tank exceeded 110 ° C., the decompression was stopped and baking was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak generated by the silanolation reaction disappeared. A sample is taken, and the amount of solvent, particularly the amount of methanol in gas chromatographic analysis is 180 ppm, which is the end point. 223 g of a surface-treated titanium oxide sample was collected. The adhesion amount of trifluoromethoxysilane at this time was 2.0 mass% with respect to titanium oxide.
The average particle diameter (D ₅₀ ) of the obtained titanium oxide was 0.080 nm.

(Synthesis Example 2)
-Production of surface-modified titanium oxide-
Ishihara Sangyo Co., Ltd. Prototype MPT881 Disperse 0.35% by weight of titanium oxide in water soluble component in 20% aqueous solution of zinc chloride so that the solid content concentration of MPT881 titanium oxide is 37% and bead diameter 0.5mm. The agglomerates were softly crushed in about 1 hour using a bead mill (manufactured by Imex Co., Ltd., bead mill machine NVM-2 type) and subjected to surface treatment. After obtaining particles having an average particle diameter of 0.047 μm at this time (measured using a Microtrac UPA-150, manufactured by NIKKISO), 630 g was weighed.
The surface-treated sample was subjected to ion chromatography using IC-7000P manufactured by Yokogawa Electric Corporation. The column ICS-C15 and precolumn ICS-C16 column temperature were 40 ° C. for the cation, the sample amount was 50 μL, and the solution was HNO ₃ ( 5 mM), the same concentration of sodium hydroxide was used as the removal solution. On the other hand, in anion measurement, column ICS-A23, precolumn ICS-A26 column temperature 40 ° C., sample amount 50 μL, solution is Na ₂ CO ₃ (2.5 mM) / NaHNO ₃ (1.2 mM), and removal solution is 15 mM. As a result, the zinc ion was 83.25 μg. Then, it dried under reduced pressure and used this as a sample.
Next, 40 g of perfluoroalkylethylene oxide adduct (F446, manufactured by Dainippon Ink and Chemicals, Inc.) is mixed with the titanium oxide dispersion as a silane solution and transferred to a 1 L four-necked flask installed in an oil bath, using a stirrer. While stirring at 60 rpm, the temperature was raised to 60 ° C. and reacted for 6 to 7 hours to warm the temperature to 80 ° C. At this time, the amounts of ethanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When it reaches 90% by mass with respect to the amount of solvent used in the prescription, the temperature is raised from 130 ° C to 140 ° C, the rise in the tank temperature is checked, and the degree of decompression is adjusted to adjust the rise. did. When the temperature in the tank exceeded 110 ° C., the decompression was stopped and baking was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak produced by the silarization reaction was burned out. A sample is taken and the amount of solvent for gas chromatography analysis, particularly the amount of methanol becomes 180 ppm, which is the end point. 223 g of a surface-treated titanium oxide sample was collected. The amount of fluorine adhering to the titanium oxide at this time was 1.2% by mass with respect to the titanium oxide.
The average particle diameter (D ₅₀ ) of the obtained titanium oxide was 0.093 nm.

(Synthesis Example 3)
-Production of surface-modified titanium oxide-
Ishihara Sangyo Co., Ltd. Prototype MPT881 Disperse 0.35% by weight of titanium oxide in water soluble component in 15% aqueous solution of zinc sulfate so that the solid content concentration of MPT881 titanium oxide is 30%. The aggregate was softly crushed in about 0.5 hours using a 5 mm bead mill (made by Imex, bead mill machine NVM-2 type), and surface treatment was performed. After obtaining particles having an average particle size of 0.047 μm at this time (measured using NIKKISO, Microtrac UPA-150), 600 g was weighed.
The surface-treated sample was subjected to ion chromatography using IC-7000P manufactured by Yokogawa Electric Corporation. The column ICS-C15 and precolumn ICS-C16 column temperature were 40 ° C. for the cation, the sample amount was 50 μL, and the solution was HNO ₃ ( 5 mM), the removal solution uses Na hydroxide of the same concentration, while in the anion measurement, the column ICS-A23 and precolumn ICS-A26 column temperature is 40 ° C., the sample amount is 50 μL, and the solution is Na ₂ CO ₃ (2. 5 mM) / NaHNO ₃ (1.2 mM), the removal solution was 15 mM sulfuric acid, and the flow rate was measured at 1.0 ml / min. As a result, the zinc ion was 63.02 μg. Thereafter, it was dried under reduced pressure and used as a sample.
Next, the above-mentioned titanium oxide is dispersed in a toluene / methanol mixed solvent (7: 1) so as to have a solid content concentration of 37%, and further trifluoropropyltrimethoxysilane (manufactured by Toray Industries, Inc., Z-6333), and Methyltrimethoxysilane (Toray Z-6366) in an equal ratio of 40 g was used as a silane solution and mixed with the titanium oxide dispersion. Thereafter, the mixture was crushed for about 2 hours using a bead mill having a bead diameter of 0.5 mm (manufactured by Imex Corporation, bead mill machine NVM-2 type) to obtain particles having an average particle diameter of 0.047 μm (manufactured by NIKKISO, Microtrac). 630 g was weighed after measurement using UPA-150.
Next, it was placed in an oil bath, transferred to a 1 L four-necked flask, heated to 60 ° C. while stirring at 60 rpm using a stirrer, reacted for 6 to 7 hours, and heated to 80 ° C. At this time, the amounts of methanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When the temperature reaches 90% by mass with respect to the amount of solvent used in the prescription, the set temperature is raised to 130 ° C. to 140 ° C., the rise of the temperature in the tank is confirmed, and the degree of increase is adjusted by adjusting the degree of pressure reduction. Adjusted. When the temperature in the tank exceeded 110 ° C., the decompression was stopped and baking was performed for about 6 hours. At this time, the sample was sampled, and it was confirmed that the Rt peak generated by the silanolation reaction was burned out. The end point of firing is determined when the sample is collected and the amount of solvent and the amount of methanol in the gas chromatography analysis are 190 ppm or less. 221 g of a surface-treated product of sample titanium oxide was collected. The adhesion amount of trifluoromethoxysilane at this time was 2.0 mass% with respect to titanium oxide.
The average particle diameter (D ₅₀ ) of the obtained titanium oxide was 0.075 nm.

(Synthesis Example 4)
-Treatment of titanium oxide not applicable to zinc ion treatment-
A titanium oxide (MT series, water soluble component 0.31%) manufactured by Teika Co. made by a wet method was used and dispersed in a toluene / methanol solvent (7: 1) so that the solid content concentration was 37%. Furthermore, 40 g of trifluoropropyltrimethoxysilane (Dow Chemical Co., Ltd., Z-6333 CAS No. 429-60-7) was added, and a bead mill having a bead diameter of 0.5 mm (made by IMEX, bead mill machine NVM-2 type) was used. After pulverizing for a time, particles having an average particle size of 0.047 μm were obtained (measured using NIKKISO, Microtrac UPA-150), and 630 g was weighed.
Next, the silane solution and the titanium oxide solvent are mixed and transferred to a 1 L four-necked flask installed in an oil bath. The temperature is raised to 60 ° C. while stirring at 60 rpm using a stirrer, and the reaction is performed for 6 to 7 hours. Heated at 0 ° C. At this time, the amounts of ethanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected, and the unreacted residual amount of the solvent, the silane coupling agent, and the progress of silanolation were determined by gas chromatography.
When the temperature reaches 90% by mass with respect to the solvent amount of the prescription use amount, the set temperature is raised to 80 ° C. to 90 ° C. to confirm the rise of the temperature in the tank, and if the rise is slow, the pressure may be reduced. When the temperature in the tank exceeded 90 ° C., the decompression was stopped and firing was performed for about 6 hours. At this time, the sample was sampled, and the Rt peak generated by the silanolation reaction did not completely disappear and remained. A sample was taken, and the amount of solvent in gas chromatographic analysis, particularly the amount of methanol, reached 180 ppm, which was the end point.
213 g of a surface-treated product of titanium oxide was collected. The adhesion amount of trifluoromethoxysilane at this time was 0.11% by mass with respect to titanium oxide.
When the absorbance of the obtained surface-treated titanium oxide was measured, the transmittance at 300 nm was 25%, and the transmittance at 600 nm was 97%. The sample was measured for water repellency and hydrophobicity.
The average particle diameter (D ₅₀ ) of the obtained titanium oxide was 0.075 nm.

(Synthesis Example 5)
-Production of titanium oxide-
40 g of trifluoropropyltrimethoxysilane (manufactured by Dow Chemical Co., Ltd., Z-6333 CAS No 429-60-7) was dissolved in 200 g of an ethanol solvent. Using titanium oxide made by a wet method (MT series, water-soluble component 0.31%), titanium dioxide is dispersed in a toluene solvent to a solid content concentration of 37%, and the bead diameter is 0. After crushing for about 2 hours using a 5 mm bead mill (made by Imex Corporation, bead mill machine NVM-2 type), particles having an average particle size of 0.047 μm were obtained (measured using NIKKISO Microtrac UPA-150). 630 g was weighed.
Subsequently, it moved to the installed 1L four necked flask, and it heated up at 60 degreeC, stirring at 60 rpm using a stirrer, and made it react for 6 to 7 hours, and heated temperature at 80 degreeC. At this time, the amounts of ethanol and toluene were collected from the mouth of the four-necked flask through a cooling tube, and the amount of solvent was calculated. Samples were collected and gas chromatographed to determine the unreacted remaining amount of solvent, silane coupling agent, and the progress of silanolation.
When the temperature reaches 90% by mass with respect to the amount of solvent used in the prescription, the set temperature is raised to 80 ° C. to 90 ° C., the temperature rise in the tank is confirmed, and if the rise is slow, the pressure may be reduced. When the temperature inside the tank exceeded 90 ° C., the decompression was stopped and the mixture was baked for about 6 hours. At this time, the sample was sampled, and the Rt peak generated by the silanolation reaction did not completely disappear and remained. A sample was taken, and the amount of solvent in gas chromatographic analysis, particularly the amount of methanol, reached 180 ppm, which was the end point. A sample of 215 g of a surface-treated titanium oxide was collected.
The adhesion amount of trifluoromethoxysilane at this time was 0.08% by mass with respect to titanium oxide.
The average particle diameter (D ₅₀ ) of the obtained titanium oxide was 0.068 nm.

Example 1
-Toner prescription-
Polyester resin (number average molecular weight Mn: 4,300, weight average molecular weight Mw: 12,700, glass transition point Tg: 55 ° C.) 100 parts by mass Carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) -3 parts by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Carnauba wax ... 3 parts by mass

-Manufacture of toner base-
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with an air classifier to prepare a black toner base having a particle size distribution of 4 μm to 20 μm and an average particle size (D ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the obtained classified toner base was weighed and put into a mixing chamber of a Henschel supermixer, 0.1 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and surface modified titanium oxide of Synthesis Example 1 in an amount of 0. 2 kg was mixed at high speed with a Henschel type super mixer. The temperature in the first jacket at this time was controlled to 25 ° C. to 30 ° C., the rotation speed of the stirring blade was 1,000 rpm, 30 seconds of operation and 60 seconds of cooling were carried out seven times. A toner was prepared.
The release rate and adhesion rate of titanium oxide of the obtained toner were measured as follows. The results are shown in Table 1.

<Adhesion rate of titanium oxide>
First, 4.4 ml of 3% Emulgen (manufactured by Kao Corporation) was added to 100 ml of ion-exchanged water, and stirred for 1 minute to prepare Solution A.
Next, 5 g of the sample initial toner was added to the solution A, shaken 20 times, the toner was wetted, and after confirming a dispersed state without floating or separation, the solution A was left for 30 minutes to prepare a liquid B.
Next, the liquid B is shaken 5 times to disperse the toner, and then an ultrasonic homogenizer (VCX750, manufactured by SONICS) is used to enter the vibration part 2.5 cm into the liquid B with an output energy of 30%. The liquid C was produced by vibrating for 1 minute.
Next, the liquid C is allowed to stand for 10 minutes, and then filtered using a filter paper, 100 CIRCLES (manufactured by Toyo Filter Paper Co., Ltd.). The toner remaining on the filter paper is collected and dried in a constant temperature bath at 40 ° C. for 8 hours.
Next, 3 g of the toner obtained after drying, an automatic pressure molding machine (T-BRB-32, manufactured by Maekawa), a load of 6.0 t, a pressure time of 60 sec, and pelletized to a diameter of 3 mm and a thickness of 2 mm, Sample toner after processing.
Next, the sample initial toner not subjected to the above treatment is similarly formed into a pellet having a diameter of 3 mm and a thickness of 2 mm to obtain a pre-treatment sample toner.
Next, the content of Ti element in the pellet toner sample was measured by quantitative analysis using a fluorescent X-ray apparatus (ZSX-100e, manufactured by Rigaku Corporation). A calibration curve was prepared in advance, and the adhesion rate of titanium oxide was calculated by the following mathematical formula.
<Formula 1>
Adhesion rate (%) = (Ti element content after ultrasonic vibration treatment) / (Ti element content of sample before treatment) × 100

<Titanium oxide liberation rate>
Next, for the liberation rate, the filtrate C is weighed to 100 ml with ion-exchanged water, and the Ti element is quantified with Shimadzu ICPS7500. The standard solution is a standard solution for atomic absorption analysis (manufactured by Kanto Chemical Co., Ltd.) A calibration curve in which the concentration of the content was changed in advance was drawn, and the Ti element and Si element contained in the filtrate C were quantified.
The liberation rate of titanium oxide was expressed as a value obtained by dividing the concentration contained in the filtrate by the added amount.

(Example 2)
-Toner prescription-
Polyester resin (number average molecular weight Mn: 6,100, weight average molecular weight Mw: 202,500, glass transition point Tg: 65 ° C.) ... 100 parts by mass Cyan dye (Linol blue FG-7350, Toyo Ink Manufacturing Co., Ltd.) 3 parts by mass)-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Mixture of carnauba wax 60% and rice wax 40% ... 4 parts by mass Part

-Manufacture of toner base-
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with a wind classifier to prepare a cyan toner base material having a particle size distribution of 4 μm to 20 μm and an average particle diameter (D ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the resulting cyan toner base material after classification was weighed and put into a mixing chamber of the same Henschel supermixer as in Example 1, and 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.) was synthesized. The surface-modified titanium oxide (0.2 kg) was mixed at a high speed with a Henschel mixer. At this time, the temperature in the first jacket was controlled to 20 ° C. to 30 ° C., the rotation speed of the stirring blade was 1,000 rpm, 30 seconds of operation and 60 seconds of cooling were performed seven times. A cyan toner was prepared.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3
-Toner prescription-
Polyester resin (number average molecular weight Mn: 6,100, weight average molecular weight Mw: 202,500, glass transition point Tg: 65 ° C.) 100 parts by mass Quinacridone magenta (CI Pigment Red122) -3 parts by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-A mixture of carnauba wax 60% and rice wax 40% ... 4 parts by mass

-Manufacture of toner base-
The mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with an air classifier to prepare a magenta toner base material having a particle size distribution of 4 μm to 20 μm and an average particle size (D ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the obtained magenta toner base after classification is mixed at a high speed with 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.) and 0.2 kg of the surface-modified titanium oxide of Synthesis Example 1 using a Henschel type super mixer. The temperature in the first jacket at this time was controlled to 25 ° C. to 30 ° C., the rotation speed of the stirring blade was 1,000 rpm, and the cycle of 30 seconds of operation and 60 seconds of cooling was performed 7 times. A magenta toner was prepared.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 4
-Toner prescription-
Polyester resin (number average molecular weight Mn: 4,300, weight average molecular weight Mw: 12,700, glass transition point Tg: 55 ° C.) 100 parts by mass Carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) -3 parts by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Mixture of carnauba wax 60% and rice wax 40% ... 4 parts by mass

-Manufacture of toner base-
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with an air classifier to prepare a black toner base having a particle size distribution of 4 μm to 20 μm and an average particle size (D ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the obtained classified toner base was weighed and put into a mixing chamber of a Henschel supermixer, 0.1 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and surface-modified titanium oxide 0 of Synthesis Example 2 2 kg was mixed at high speed with a Henschel type super mixer. The stirring condition was such that the temperature in the first jacket was controlled at 30 ° C. to 34 ° C., the rotation speed of the stirring blade was 900 rpm, 30 seconds of operation and 30 seconds of cooling cycle were performed 5 times, and the black toner of Example 4 was produced. did.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Example 5)
The mixture obtained in Example 2 was kneaded with an extruder, pulverized with a jet mill, then classified with an air classifier, and a cyan toner base having a particle size distribution of 4 μm to 20 μm and an average particle size (D ₅₀ ) of 8 μm. Was made.
With respect to 30 kg of the resulting cyan toner base after classification, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.) and 0.2 kg of surface-modified titanium oxide of Synthesis Example 2 were mixed at the same speed as in Example 4. By mixing, a cyan toner of Example 5 was produced.

(Example 6)
-Toner prescription-
Polyester resin (number average molecular weight Mn: 4,300, weight average molecular weight Mw: 12,700, glass transition point Tg: 55 ° C.) 100 parts by mass Carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) -3 parts by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Mixture of carnauba wax 60% and rice wax 40% ... 4 parts by mass

-Manufacture of toner base-
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with a wind classifier to prepare a black toner base having a particle size distribution of 4 μm to 20 μm and an average particle size (D ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the obtained classified toner base was weighed and put into a mixing chamber of a Henschel type super mixer, 0.1 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and surface modified titanium oxide of Synthesis Example 3 in an amount of 0. 1 kg was mixed at high speed with a Henschel type supermixer. The stirring conditions were such that the temperature in the first jacket was controlled between 30 ° C. and 34 ° C. The rotation speed of the stirring blade was 900 rpm, 30 seconds of operation and 30 seconds of cooling cycle 5 times The black toner of Example 6 was produced.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Example 7)
-Toner prescription-
Polyester resin (number average molecular weight Mn: 6,100, weight average molecular weight Mw: 202,500, glass transition point Tg: 65 ° C.) 100 parts by mass Yellow dye (CI Pigment Yellow 180) 3 parts by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Mixture of carnauba wax 60% and rice wax 40% ... 4 parts by mass

-Manufacture of toner base-
The above mixture is kneaded with an extruder, pulverized with a jet mill, and then classified with a wind classifier to prepare a yellow toner base with an average particle size (D ₅₀ ) of 8 μm and a particle size distribution of 4 μm to 20 μm. did.

-Mixing process of external additives-
30 kg of the resulting classified toner base was weighed and placed in a mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and surface-modified titanium oxide of Synthesis Example 3 in an amount of 0. 3 kg was mixed at high speed with a Henschel mixer. The stirring condition was such that the temperature in the first jacket was controlled at 20 ° C. to 30 ° C., the rotation speed of the stirring blade was 800 rpm, 60 seconds of operation and 30 seconds of cooling cycle were performed five times, and the yellow toner of Example 7 was produced. did.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Example 8)
30 kg of the toner base after the classification used in Example 1 was weighed and put into a mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and surface modification of Synthesis Example 3 0.3 kg of titanium oxide was mixed at a high speed with a Henschel type supermixer. The stirring conditions were such that the temperature in the first jacket was controlled at 20 ° C. to 30 ° C. The rotation speed of the stirring blade was 800 rpm, 60 seconds of operation, and 40 seconds of cooling. The black toner of Example 8 was produced by repeating the cycle seven times.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
Using 0.2 kg of titanium oxide of Synthesis Example 4, weigh 30 kg of the toner base after classification in Example 1 and put it into the mixing chamber of a Henschel type super mixer, and then add 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.). The stirring conditions were high-speed mixing with a Henschel mixer. The stirring conditions were controlled at a temperature in the first jacket of 35 ° C to 40 ° C. The rotation speed of the stirring blade was 800 rpm, 60 seconds operation and 20 seconds cooling cycle were performed three times. The black toner of Example 1 was produced.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
Weigh 30 kg of the pre-classified toner base manufactured with the same toner manufacturing formula as in Example 1 and put it into the mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.) and synthesis. The surface-modified titanium oxide 0.3 kg of Example 1 was mixed at a high speed with a Henschel mixer. The stirring conditions were such that the temperature in the first jacket was controlled at 35 ° C. to 40 ° C., and the rotation speed of the stirring blade was 800 rpm for 60 seconds. A black toner of Comparative Example 2 was produced by performing a cooling cycle of 20 seconds three times.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
Weigh 30 kg of the pre-classified toner base produced with the toner production formulation described in Example 1 and put it into the mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, Nippon Aerosil Co., Ltd.) MT-150A titanium oxide (0.3 kg) manufactured by Co., Ltd. was mixed at a high speed with a Henschel mixer. This cycle was carried out twice with cooling for 20 seconds to produce a black toner of Comparative Example 3.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 4)
It carried out according to the synthesis example 2 of Unexamined-Japanese-Patent No. 2004-245948. That is, 300 g of titanium oxide (Taika, MT-150A) having a primary average particle size of 0.015 μm containing 0.35% of a water-soluble component made by a wet method was dissolved in 25 g of isobutylmethoxysilane. It was added to the toluene solution and dispersed with stirring. Thereafter, the solvent was dried up and pulverized with a jet mill to obtain titanium oxide after the coupling agent treatment.
Using this titanium oxide, weigh 30 kg of the toner base after the classification manufactured according to the toner production formulation described in Example 1 and put it into a mixing chamber of a Henschel type super mixer, and then silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.). Along with 0.2 kg, 0.2 kg of the above titanium oxide was mixed at high speed with a Henschel type supermixer, and a toner of Comparative Example 4 was produced under the same conditions as Comparative Example 3.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 5)
30 kg of the toner base after the classification obtained in Example 2 was weighed and put into a mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.) and MT-150A manufactured by Teika Co., Ltd. 0.3 kg of titanium oxide was mixed at high speed with a Henschel mixer. In this stirring condition, the temperature in the first jacket was controlled to 35 ° C. to 40 ° C., the rotation speed of the stirring blade was 1,200 rpm, mixing was performed for 70 seconds and cooling for 100 seconds, and this cycle was performed twice. A cyan toner was prepared.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 6)
Weigh 30 kg of the cyan toner base material after the classification obtained in Example 2 and put it into a mixing chamber of a Henschel type super mixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), MT- manufactured by Teika Co., Ltd. High-speed mixing of 0.3 kg of 150A titanium oxide was performed with a Henschel mixer. In this stirring condition, the temperature in the first jacket was controlled to 35 ° C. to 40 ° C., the rotation speed of the stirring blade was 1,200 rpm, mixing was performed for 70 seconds and cooling for 70 seconds, and this cycle was repeated 5 times. A cyan toner was prepared.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 7)
-Toner prescription-
Polyester resin (number average molecular weight Mn: 4,300, weight average molecular weight Mw: 12700, glass transition point Tg: 55 ° C.) 100 parts by mass Carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) 3 Part by mass-Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) ... 1 part by mass-Carnauba wax ... 3 parts by mass

-Manufacture of toner-
The above mixture was kneaded with an extruder, pulverized with a jet mill, and then classified with a wind classifier to prepare a black toner base material having a particle size distribution of 4 μm to 20 μm and an average particle diameter D ( ₅₀ ) of 8 μm.

-Mixing process of external additives-
30 kg of the classified toner base obtained in Comparative Example 1 was weighed and placed in a mixing chamber of a Henschel supermixer, 0.2 kg of silicon dioxide (R972, manufactured by Nippon Aerosil Co., Ltd.), and titanium oxide of Synthesis Example 5 in an amount of 0. 3 kg was mixed at high speed with a Henschel mixer. In this stirring condition, the temperature in the first jacket was not controlled in particular, and the rotation speed of the stirring blade was 1,200 rpm, mixing was performed for 70 seconds and cooling for 120 seconds, and this cycle was performed once. The black toner of Example 7 was produced.
With respect to the obtained toner, the adhesion rate and release rate of titanium oxide were measured in the same manner as in Example 1. The results are shown in Table 1.

<Image evaluation>
It was set in a digital color printer (manufactured by Ricoh Co., Ltd., IPSIO Color 8500), and image evaluation was performed in “LL environment” and “HH environment”. For each item, the following evaluation was performed after 10,000 sheets of 7% image area running output. Therefore, the initial image density means the image density after 10,000 sheets are run. The “LL environment” refers to an environment of 15% RH at 10 ° C., and the “HH environment” refers to an environment of 80% RH at 30 ° C.

<(1) Image density>
After outputting a solid image to 6000 paper manufactured by Ricoh Co., Ltd., the image density after initial and 30,000 sheets was measured by X-Rite (manufactured by X-Rite), and this was performed for four colors alone, and the average was obtained. Evaluation was made according to the following criteria.
〔Evaluation criteria〕
×: Image density is 1.0 or more and less than 1.4 ○: Image density is 1.4 or more and less than 1.8 ◎: Image density is 1.8 or more and less than 2.2

<(2) Abnormal image (filming)>
The solid image surface after 10,000 sheets (initial) and after output of 30,000 sheets was evaluated for the occurrence of white spots, and the level that could be detected with the naked eye was determined as occurring, and evaluated according to the following criteria.
〔Evaluation criteria〕
◎: No white spots occurred in 100 samples sampled ○: White spots occurred in a ratio of 2% to less than 10% △: White spots occurred in a ratio of 10% to less than 20% ×: 20% White spots were generated at the above rate <Charge amount>
Regarding the charge amount, the charge amount of the toner on the developing roller of the copying machine was measured by a suction method.

<(3) Fine line reproducibility>
The 600 dpi fine line image after outputting 30,000 sheets was output to 6000 paper manufactured by Ricoh Co., Ltd., and the degree of blurring of the fine line was compared with a stage sample and evaluated in four stages of x, Δ, ○, and ◎. The rank improves in the order of ×, Δ, ○, ◎.

<(4) Background dirt>
The blank paper image after outputting 30,000 sheets is stopped during development, the developer on the photoconductor after development is transferred to tape, and the difference from the image density of the untransferred tape is measured by 938 Spectrodensitometer (X-Rite). ), And evaluated in four stages: x, Δ, ○, and ◎. The smaller the difference in image density, the better the background dirt, and the better the rank in the order of x, Δ, ○, ◎.

＊割合は、混合工程における混合時間と冷却時間の比（混合時間／冷却時間）を表す。
＊回数は、繰り返しサイクル数を表す。

* The ratio represents the ratio of mixing time and cooling time in the mixing step (mixing time / cooling time).
* The number of times represents the number of repeated cycles.

  From the results in Tables 1 and 2, when the toners of Examples 1 to 8 were set in a digital full color printer (Ricoh Co., Ltd., IPSiOColor 8500) to form an image, the obtained image was clear and abnormal, such as background stains. Was not seen. When the developing roller was visually observed, the toner thin layer on the roller was uniform. The amount of charge on the developing roller was measured by a suction method. As a result, the black toner was −32.5 μC / g, the yellow developer was −32 μC / g, the magenta developer was −31 μC / g, and the cyan developer was −31.5 μC. / G. Images were formed in the same manner under high-temperature and high-humidity conditions at 27 ° C. and 80% RH, and under low-temperature and low-humidity conditions at 10 ° C. and 15% RH, but no change was observed and a good image was formed. In addition, when a durability test was performed for a total of 40,000 sheets of full-color images in each environment continuously at room temperature, low temperature and low humidity, high temperature and high humidity, and normal temperature, no significant change was observed in the fixed images, and 40,000 sheets. The image of the eyes was clear and clear. When the developing roller was visually observed, there was no significant change in the toner thin layer on the roller. At this time, the charge amount of the developer was yellow developer-30.5 μC / g, magenta developer-30.2 μC / g. g, cyan developer-30.3 μC / g, and black developer-31.8 μC / g. The developing roller, blade, and photoreceptor were visually observed, but no filming was observed.

  On the other hand, the toners of Comparative Examples 1 to 7 were set on a digital full color printer (manufactured by Ricoh Co., Ltd., IPSiOColor 8500) in an MM environment to form an image. The obtained initial images were clear and soiled. No abnormalities were found. Thereafter, the developing roller was visually observed at the end of 30,000 sheets running, and the toner thin layer on the roller was uniform. When the charge amount on the developing roller was measured by a suction method, it was -25.2 μC / g to −22.1 μC / g. When an image was formed under high-temperature and high-humidity conditions of 80% RH at 27 ° C., a blurred image was obtained. Further, when the same image was formed under low temperature and low humidity conditions of 15% RH at 10 ° C., a faint image having a low ID was obtained. When a durability test using full-color images was performed under normal conditions at room temperature, low temperature and low humidity, high temperature and high humidity, and normal temperature, abnormalities such as background stains, dust, and streaks occurred on the images. When the developing roller was visually observed at this time, streaks were generated in the circumferential direction in the toner thin layer on the roller. When the charge amount of the developer was measured, it was deteriorated from yellow to black. That is, the toners of Comparative Examples 1 to 7 were affected by environmental fluctuations, and the amount of charge was easily attenuated and filming occurred.

  The toner of the present invention and its production method are widely used in, for example, laser printers, direct digital plate-making machines, full-color copiers using direct or indirect electrophotographic multicolor image development systems, full-color laser printers, full-color plain paper fax machines, etc. Is done.

10 Electrostatic latent image carrier (photosensitive drum)
10K Electrostatic latent image carrier for black 10Y Electrostatic latent image carrier for yellow 10M Electrostatic latent image carrier for magenta 10C Electrostatic latent image carrier for cyan 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device DESCRIPTION OF SYMBOLS 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 Second Traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Development roller La 44Y Development roller 44M Development roller 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 switching claw 56 discharge roller 57 discharge tray 58 corona charger 60 cleaning device 61 developing device 62 transfer charger 63 photoconductor cleaning device 64 discharger 70 discharge lamp 80 transfer roller 90 cleaning device 95 transfer paper 100 image forming device 101 photoconductor DESCRIPTION OF SYMBOLS 102 Charging means 103 Exposure 104 Developing means 105 Recording medium 107 Cleaning means 108 Transfer means 120 Tandem type developer 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Addition Roller 125 Heat source 126 Cleaning roller 127 Temperature sensor 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating roller 146 Paper feed path 147 Conveyance roller 148 Paper feed path 150 Copier main body 160 Charging device 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)

JP 56-128956 A JP 59-52255 A JP 60-112052 A Japanese Patent No. 2623919 Japanese Patent No. 3322858 Japanese Patent No. 2921174 JP 2003-255608 A JP 2000-267354 A Japanese Patent No. 3417213 JP 2006-227189 A JP 2006-323368 A Japanese Patent No. 3129074 JP 2000-122336 A JP 2006-154387 A

Claims (15)

A mixing step of mixing and cooling a toner base containing at least a binder resin and a colorant and titanium oxide containing zinc ions and having a silane condensate bonded to the surface is made one cycle. A method for producing a toner that repeats 3-7 cycles,
Ratio of mixing time and cooling time in the mixing step (mixing time / cooling time) is 0.5 to 2.0,
A method for producing a toner, wherein a release rate of titanium oxide to a toner base by an ultrasonic vibration method is 20% to 25%.   The method for producing a toner according to claim 1, wherein a free product of titanium oxide with respect to the toner base is extracted as a solubilized component in an aqueous solution containing a surfactant, and the release rate of titanium oxide is obtained by atomic absorption spectrometry.   The method for producing a toner according to claim 2, wherein the release rate of titanium oxide is determined by a plasma spectroscopic analysis (ICP) method.   4. The method for producing a toner according to claim 1, wherein the mixing means used in the mixing step is a mixer having a stirring blade, and the mixing time of one cycle is within 1 minute.   The method for producing a toner according to claim 1, wherein the zinc ion content is 50 μg to 100 μg per 1 g of titanium oxide.   The method for producing a toner according to claim 1, wherein a silane condensate is bonded to the surface of titanium oxide by a silane coupling treatment.   The method for producing a toner according to claim 1, wherein the titanium oxide contains a fluorine atom, and the content of the fluorine atom is from 0.1% by mass to 2.6% by mass.   The method for producing a toner according to claim 1, wherein the titanium oxide is a rutile type titanium oxide. The method for producing a toner according to claim 1, wherein the titanium oxide has an average particle diameter (D ₅₀ ) of 0.05 μm to 0.1 μm.   The toner production method according to claim 1, wherein the toner base further contains at least one of a release agent and a charge control agent.   The method for producing a toner according to claim 1, wherein the toner base is produced by a pulverization method.   The method for producing a toner according to claim 1, wherein silica is further adhered or fixed to the surface of the toner base.   A toner manufactured by the method for manufacturing a toner according to claim 1.   A developer comprising the toner according to claim 13. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a visible image, and the visible image An image forming method including at least a transfer step of transferring the image to a recording medium and a fixing step of fixing the transferred image transferred to the recording medium,
An image forming method, wherein the toner is the toner according to claim 13.

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