JP2021152624A - toner - Google Patents

Abstract

To provide a toner capable of suppressing ghost images while suppressing fogging.SOLUTION: A toner is provided, comprising toner particles containing a binder resin and a colorant, and silica particles provided on surfaces of the toner particles. Primary particles of the silica particles have a number average particle diameter of 50-300 nm, inclusive. Assuming that elements detected in an x-ray fluorescence analysis of the silica particles are all oxides, mass concentration of ZrO2 is 20-1000 ppm, inclusive, when the total mass of all oxides is defined as 1.SELECTED DRAWING: None

Description

The present invention relates to a toner for developing an electrostatic charge image used in an electrophotographic method, an electrostatic recording method, and the like.

In the electrophotographic method, the step of developing an electrostatic latent image is to form a toner image by adhering triboelectric toner onto the electrostatic latent image by utilizing the electrostatic force of the electrostatic latent image. .. Toner for developing an electrostatic latent image includes a non-magnetic toner that does not contain a magnetic substance and a magnetic toner in which a magnetic substance is dispersed in a resin. Of these, the non-magnetic toner is directly supported on the developer carrier, and the triboelectric one is mixed with the one-component system for developing the electrostatic latent image and the magnetic carrier and formed on the developer carrier by the magnetic carrier. There is a two-component system in which what is supported by a magnetic brush develops an electrostatic latent image. In particular, the latter is preferably used for a full-color image forming apparatus such as a full-color copier or a full-color printer that requires high image quality.
In the following, a two-component developer that uses a magnetic carrier will be described.
It has become necessary to use small particle size toner in response to recent high image quality. That is, it is necessary to improve the image quality by improving the fine line reproducibility and the dot reproducibility in the image by reducing the particle size of the toner. However, the smaller the particle size, the easier it is for the toner to slip through the cleaning blade, which makes cleaning defects more likely to occur and the image quality more likely to deteriorate. Therefore, in order to improve the image quality by reducing the particle size of the toner, it is important to prevent such cleaning defects.
Conventionally, in order to solve such a problem of poor cleaning, a method has been proposed in which an external additive is retained in a blade edge portion to form a blocking layer, and toner particles are blocked to stabilize cleaning (see Patent Document 1). ).

JP-A-2002-318467

However, in the method of Patent Document 1, it is necessary to transfer the external additive from the toner particles in order to form a blocking layer. Although the toner can be blocked by this blocking layer, the external additive itself transferred to form the blocking layer may slip through the blade and remain on the photoconductor.
On the other hand, in order to improve the image quality, it is necessary to suppress "fog" on the non-image region on the photoconductor by the toner having a low charge amount. Therefore, it is necessary to design the toner so that a sufficient amount of charge can be applied to the toner by triboelectric charging with the carrier. Therefore, a method is used in which an external additive that is in the negative direction on the charging series with respect to the carrier is externally added to the toner surface. In particular, since silica is located in the negative direction, a silica external additive is often used as an external additive. Further, in order to allow efficient contact between the carrier and the silica surface and triboelectric charging, a silica external additive having a relatively large particle size is often selected as the silica external additive to be arranged on the toner surface.
In the toner designed in this way, when the external additive is transferred to the blade edge portion to form a blocking layer in order to prevent the blade from slipping through, the above-mentioned silica external additive passes through the blade and remains on the surface of the photoconductor. Therefore, the following problems may occur.
That is, the silica external additive remaining on the surface of the photoconductor may pass through the blade and then undergo a charging step, and the external additive may be strongly negatively charged due to the strong negative property of the silica external additive. This charge-up may occur locally at the top of the silica external additive remaining on the surface of the photoconductor. At that time, when a silica external additive having a relatively large particle size is used for the above-mentioned reason, a large negative potential is generated at a relatively high position from the surface of the photoconductor due to the large particle size of the external additive. Then, a locally large negative potential generated at a relatively high position from the surface of the photoconductor may form a “pull-in electric field” that draws the negatively charged toner toward the surface of the photoconductor in the vicinity of the surface of the photoconductor. And ghost may be generated by this "pull-in electric field". That is, when continuously forming an image, the silica external additive adheres to the photoconductor at the previous image forming portion. As a result of the silica external additive passing through the blade and being charged, this "pull-in electric field" is generated, and in the next image formation, the toner is developed in the image forming portion before the silica external additive is attached. There is a problem that ghosts may occur in this way.

The present inventors make silica particles having an average number of primary particles of 50 nm or more and 300 nm or less present on the surface of toner particles containing a binder resin and a colorant. In addition, zirconium contained in the silica particles is regarded as an oxide in all the elements detected in the fluorescent X-ray analysis, and _{the mass concentration of ZrO 2} is 20 ppm or more when the total mass of all oxides is 1. It has been found that ghosting can be suppressed while suppressing image deterioration such as fog by setting the amount to 1000 ppm or less.
That is, the toner of the present invention is a toner containing toner particles containing a binder resin and a colorant, and a toner having silica particles on the surface of the toner particles.
The number average particle size of the primary particles of the silica particles is 50 nm or more and 300 nm or less.
In the fluorescent X-ray analysis of the silica particles, it is considered that all the detected elements are oxides, and ZrO ₂ is contained at a mass concentration of 20 ppm or more and 1000 ppm or less when the total mass of all oxides is 1. It is a toner to be used.

It is possible to provide a toner capable of outputting image quality with suppressed ghost while suppressing image deterioration such as fog.

It is explanatory drawing which shows an example of the toner particle surface treatment apparatus. It is explanatory drawing of the test chart used for the evaluation of a ghost. It is explanatory drawing of the area (a), (b) after passing the test chart shown in FIG. It is explanatory drawing when the ghost occurs after passing the test chart shown in FIG.

In the present invention, the description of "○○ or more and XX or less" and "○○ to XX" indicating a numerical range means a numerical range including a lower limit and an upper limit which are end points, unless otherwise specified.

The toner of the present invention is a toner having toner particles containing a binder resin and a colorant and silica particles on the surface of the toner particles.
The number average particle size of the primary particles of the silica particles is 50 nm or more and 300 nm or less.
In the fluorescent X-ray analysis of the silica particles, it is considered that all the detected elements are oxides, and ZrO ₂ is contained at a mass concentration of 20 ppm or more and 1000 ppm or less when the total mass of all oxides is 1. It is a toner to be used.

The toner of the present invention has silica particles having an average number of primary particles of 50 nm or more and 300 nm or less on the surface of the toner particles.

By setting the average particle size of the number of primary particles of the silica particles on the surface of the toner particles to 50 nm or more, the carriers and the surface of the silica particles can easily come into contact with each other in the developer, and the silica particles are efficiently triboelectricly charged. The amount can be applied to the toner, and the occurrence of fog can be prevented.

At the same time, by setting the number average particle size of the primary particles of the silica particles to 300 nm or less and containing zirconium on the surface of the silica particles, the "pull-in electric field" generated when the silica particles adhere to the photoconductor is suppressed and ghosts are suppressed. It can be suppressed. Since zirconium has relatively high conductivity even when oxidized, it is possible to suppress the "pull-in electric field" by suppressing the localization of negative charges on the surface of silica particles over time, which continues to contribute to the suppression of ghosts. it is conceivable that.

_{In order to exert such an effect, zirconium has a mass concentration of ZrO 2} of 20 ppm or more when the total mass of all oxides is set to 1 assuming that all the elements detected in the fluorescent X-ray analysis are oxides. It needs to be contained.

On the other hand, by suppressing the content of zirconium to 1000 ppm or less, it is possible to suppress leakage of toner charge due to excessive increase in conductivity and prevent fog.

Further, in the above-mentioned silica particles contained in the toner of the present invention, when iron considers that all the elements detected in the fluorescent X-ray analysis are oxides and the total mass amount of all oxides is 1, Fe ₂ It is preferable that the mass concentration of O ₃ is 100 ppm or more for suppressing ghosts.

Iron is cheaper than other metals and is relatively resistant to oxidation, and therefore tends to maintain high conductivity on the silica surface. Therefore, when used in combination with zirconium, it is thought that the "pull-in electric field" can be suppressed by suppressing the localization of negative charges on the surface of the silica particles even after a longer period of time, which will continue to contribute to the suppression of ghosts.

Further, by suppressing the above-mentioned content in iron to 5000 ppm or less, it is possible to suppress leakage of toner charge due to excessive increase in conductivity and prevent fog.

Further, it is preferable that the silica particles contained in the toner of the present invention contain aluminum as follows. _{That is, it is a ghost that aluminum is contained as a mass concentration of Al 2} O ₃ of 500 ppm or more and 20000 ppm or less when the total mass amount of all oxides is assumed to be 1 assuming that all the detected elements in fluorescent X-ray analysis are oxides. Preferred for suppression. By being contained in the above range, in addition to imparting conductivity, the silica particles are appropriately positively charged by being oxidized to alumina, suppressing excessive negative charging of the silica particles and creating a "pull-in electric field". It is possible to suppress ghosts while suppressing fog.

Further, the above-mentioned silica particles contained in the toner of the present invention may be silica-bonded particles having a plurality of primary silica particles bonded to each other and having a number average density (ψSi) of 0.90 or less and 0.40 or more. preferable.

Here, the density is an index showing the characteristics of the constricted portion of the shape of the silica particles, and is a small value when the silica particles are silica-bonded particles. Specifically, the density is a value obtained by dividing the projected area when the external additive is projected onto a two-dimensional image by the area of the external additive surrounded by the envelope. That is, it is a value obtained by dividing the projected area of the external additive by the convex area of the external additive. Here, the convex area is the area of the portion surrounded by the envelope created based on the contour of the target external additive. The density is greater than 0 and takes a value of 1 or less, and the smaller the density, the more or larger the constricted part, and the more complicated the shape is.

When the number average density, which is the number average of the above-mentioned density, is within the above range, the number of contact points with the toner particle surface tends to increase, the adhesion to the toner particle surface becomes strong, and excessive migration to the drum surface occurs. Ghosts are suppressed by suppressing.

The average number of maximum ferret diameters of the silica-bonded particles is preferably 100 nm or more and 500 nm or less. That is, it is preferably 500 nm or less in order to more sufficiently suppress the "pull-in electric field" and more easily suppress ghosts when transferred to the surface of the photoconductor. In addition, in order to make it easier to suppress fog by making the toner charge amount sufficient by projecting the surface of the silica-bonded particles in the toner and efficiently triboelectricly charging them with the carriers, the maximum ferret diameter of the silica-bonded particles is set. The number average value is preferably 100 nm or more.

Further, the coverage of the above-mentioned silica particles contained in the toner of the present invention on the surface of the toner particles is preferably 10% or more. When the coverage of the silica particles is 10% or more, the carriers and the surface of the silica particles easily come into contact with each other in the developing agent, and the toner can be efficiently charged by triboelectric charging to impart a sufficient amount of charge to the toner. , The occurrence of fog can be prevented.

Further, it is preferable that the toner of the present invention has SrTiO ₃ particles externally added to the surface of the toner particles. The _{average number of maximum ferret diameters of the SrTiO 3} particles is preferably 30 nm or more and 80 nm or less.

When the _{average number of the maximum ferret diameters of the SrTiO 3} particles is in this range, it is easy to get caught in the constricted portion or the intricate shape of the silica-bonded particles. As a result, even if the silica-bonded particles migrate to the drum surface, SrTiO ₃ can easily migrate in close proximity to the drum surface. Since SrTiO ₃ has a positive charge polarity, it is possible to alleviate the negative charge of the silica-bonded particles, suppress the "pull-in electric field", and suppress ghosting.

In order to exhibit such an effect, _{the coverage of the SrTiO 3} particles covering the surface of the toner particles is preferably 5% or more.

Further, in order to sufficiently charge the toner and further suppress the occurrence of fog, _{the coverage of SrTiO 3} particles is preferably 50% or less.

Further, when the SrTiO ₃ particles are transferred from the toner particles to the surface of the photoconductor, the above-mentioned "pull-in electric field" due to the silica external additive remaining on the surface of the photoconductor may be strengthened. In that case, ghosts may easily occur. Therefore, _{the adhesion rate of SrTiO 3} particles is preferably 80% or more.

Further, for the following reasons, it is preferable that the binder resin contained in the toner particles of the present invention contains polyester.

That is, since the binder resin contains a polyester resin, good low-temperature fixability can be maintained. Further, when silica-bonded particles having a low number average density are externally added, voids are likely to be formed between the toner particles and the silica-bonded particles because the silica-bonded particles have a constricted shape. Therefore, the efficiency of heat transfer to the toner particles during fixing tends to be disadvantageous, but the inclusion of the polyester resin can suppress the occurrence of the disadvantage. For this reason, it is preferable that the binder resin contained in the toner particles of the present invention contains polyester.

In addition to that, it is preferable that the toner particles of the present invention contain crystalline polyester in order to realize better low temperature fixability.

Next, a preferred embodiment and the like will be described.

<Silica particles>
The silica particles used in the present invention are particles _{containing silica (that is, SiO 2} ) as a main component, and may be particles manufactured from a silicon compound such as water glass or alkoxysilane, or quartz is pulverized. It may be a particle obtained from the above.

Specific examples thereof include silica particles produced by the sol-gel method, precipitated silica particles produced by the precipitation method, aqueous colloidal silica particles, fumed silica particles obtained by the vapor phase method, and fused silica particles. Among these, the sedimentation method or sol-gel silica is preferable, and the sedimentation method is particularly preferable, in order to control the shape to have the above-mentioned number average density.

Precipitated silica is produced as follows.

An aqueous solution of water glass, which is an aqueous solution of sodium silicate, is prepared, and the prepared aqueous solution of water glass is brought into contact with mineral acid. Sulfuric acid is usually used as the mineral acid to be contacted.

The method of contact is not limited, but it is preferable to contact them little by little. For example, one solution may be placed in a container and the other solution may be dropped onto the container.

Further, this contact is preferably performed so that both solutions are efficiently mixed, and therefore, it is preferably performed under stirring. Therefore, it is preferable that the container can be agitated. For example, it is preferable to put the aqueous solution of water glass in a container that can be agitated and add sulfuric acid to the aqueous solution while stirring.

The contact between the water glass and sulfuric acid is preferably performed at a relatively high temperature, preferably 50 ° C. or higher and 80 ° C. or lower.

In this way, the water glass and sulfuric acid are brought into contact with each other to cause a reaction. The pH value at which this contact is made is generally about 7 to 10. Then, the pH value decreases with this contact, and when the pH value becomes 7 to 8 or less, silica is formed and precipitated.

The end point of the dropping is set to a pH value of 7 or less, and the dropping is preferably continued until the pH value is in the range of 2 or more and 5 or less.

The silica particles thus generated and grown as particles settle by growing and agglutinating. The water is then separated and removed by filtration, centrifugation or other suitable means to recover the precipitated silica. Silica particles are obtained by washing if necessary, then drying by a method such as heating and further grinding.

In addition, the sedimentation silica produced in this way has the characteristic of being easily pulverized because it forms secondary particles by loose aggregation. Furthermore, in this method, silica particles having different characteristics can be obtained by changing the reaction conditions and the post-treatment step regarding physical properties such as surface area, pore size, and dispersed particle size.

In addition, the specific surface area is higher than that of silica particles obtained by other production methods, the primary particle agglomeration structure is also developed, and the pore volume tends to be high.

Next, the silica particles thus produced contain zirconium, preferably iron and aluminum.

As a method for incorporating these metals into silica particles, a vapor deposition method, a sputtering method, a PVD method and the like can be used, but the sputtering method is preferable from the viewpoint of simplicity.

By such a method, the silica particles used in the present invention can be obtained by adding zirconium, preferably iron and aluminum to the surface of the silica particles.

<Strontium titanate particles>
The strontium titanate particles preferably used in the present invention can be produced, for example, by a normal pressure heating reaction method. At this time, it is preferable to use a mineral acid defibrated product of a hydrolyzate of the titanium compound as the titanium oxide source, and to use a water-soluble acidic metal compound as the metal source other than titanium. Then, it can be produced by a method of reacting the mixed liquid of the raw materials while adding an alkaline aqueous solution at 60 ° C. or higher, and then treating with an acid.

Hereinafter, the atmospheric heating reaction method will be described.

As the titanium oxide source, a mineral acid gelatinized product of a hydrolyzate of a titanium compound is used. _{Preferably, metatitanic acid having an SO 3} content of 1.0% by mass or less, more preferably 0.5% by mass or less obtained by the sulfuric acid method is adjusted to a pH of 0.8 or more and 1.5% or less with hydrochloric acid. Use the one that has been deflated.

On the other hand, as a metal source other than titanium, metal nitrate or hydrochloride can be used.

As the nitrate, for example, strontium nitrate can be used. As the hydrochloride salt, for example, strontium chloride can be used. Since the strontium titanate particles obtained here have a perovskite crystal structure, they are preferable in that the environmental stability of charging is further improved.

As the alkaline aqueous solution, caustic alkali can be used, but among them, the sodium hydroxide aqueous solution is preferable.

Factors that affect the particle size of the obtained metal titanate particles in the production method include the pH at which metatitanic acid is deflated with hydrochloric acid, the mixing ratio of the titanium oxide source and the metal source other than titanium, and the initial stage of the reaction. Titanium oxide source concentration, etc. can be mentioned. Further, the temperature at which the alkaline aqueous solution is added, the addition rate, the reaction time, the stirring conditions and the like can be mentioned. In particular, if the reaction is stopped by rapidly lowering the temperature of the system by adding it to ice water after adding an alkaline aqueous solution, the reaction can be forcibly stopped while the crystal growth is saturated, resulting in a wide particle size distribution. Easy to get. A wide particle size distribution can also be obtained by making the state of the reaction system non-uniform by reducing the stirring speed or changing the stirring method.

These factors can be appropriately adjusted to obtain metal titanate particles having a desired particle size and particle size distribution. In addition, it is preferable to prevent the mixing of carbon dioxide gas by reacting in a nitrogen gas atmosphere in order to prevent the formation of carbon dioxide in the reaction process.

The mixing ratio of the titanium oxide source and the metal source other than titanium during the reaction is 0.90 or more and 1 in the molar ratio of _{MXO / TiO 2 when the metal other than titanium is indicated by M and the oxide thereof is indicated by MXO.} It is preferably .40 or less, and more preferably 1.05 or more and 1.20 or less. However, X is 1 when M is an alkaline earth metal and 2 when M is an alkali metal.

When MXO / TiO ₂ (molar ratio) is 1.00 or less, not only the metal titanate but also unreacted titanium oxide is likely to remain in the reaction product. Metal sources other than titanium have relatively high solubility in water, whereas titanium oxide sources have low solubility in water. _{Therefore, when MXO / TiO 2} (molar ratio) is 1.00 or less, the reaction product is Not only the metal titanate but also unreacted titanium oxide tends to remain.

The concentration of the titanium oxide source at the initial stage of the reaction is preferably 0.050 mol / L or more and 1.300 mol / L or less, and 0.080 mol / L or more and 1.200 mol / L or less as _{TiO 2.} Is more preferable.

By increasing the concentration of the titanium oxide source at the initial stage of the reaction, the number average particle size of the primary particles of the metal titanate particles can be reduced.

When the alkaline aqueous solution is added, a pressure vessel such as an autoclave is required at 100 ° C. or higher, and a practically suitable range is 60 ° C. or higher and 100 ° C. or lower.

As for the addition rate of the alkaline aqueous solution, the slower the addition rate, the larger the particle size of metal titanate particles can be obtained, and the faster the addition rate, the smaller the metal titanate particle size can be obtained. The addition rate of the alkaline aqueous solution is preferably 0.001 equivalent / h or more and 1.2 equivalent / h or less, and more preferably 0.002 equivalent / h or more and 1.1 equivalent / h or less with respect to the charged raw material. .. These can be appropriately adjusted according to the particle size to be obtained.

In the production method, it is preferable that the metal titanate particles obtained by the atmospheric heating reaction are further acid-treated. Performing normal pressure thermal reaction, in producing the metal titanate particles, the mixing ratio of the metal source other than the titanium oxide source and titanium in MXO / TiO ₂ (molar ratio), if it exceeds 1.00, the following Things are likely to happen. That is, the unreacted metal source other than titanium remaining after the reaction is completed reacts with carbon dioxide gas in the air to easily generate impurities such as metal carbonate. Further, if impurities such as metal carbonate remain on the surface, it becomes difficult to uniformly coat the surface treatment agent due to the influence of the impurities when performing the surface treatment for imparting hydrophobicity. Therefore, after adding the alkaline aqueous solution, it is advisable to carry out acid treatment in order to remove the unreacted metal source.

In the acid treatment, it is preferable to adjust the pH to 2.5 or more and 7.0 or less using hydrochloric acid, and more preferably to adjust the pH to 4.5 or more and 6.0 or less. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. When sulfuric acid is used, metal sulfate having low solubility in water is likely to be generated.

Strontium titanate, which is preferably used in the present invention, is not particularly limited as long as it can be surface-treated and can be produced in a cubic or rectangular parallelepiped shape. Further, as a method of controlling the shape of the metal titanate particles, a dry mechanical treatment method may be used.

The surface treatment agent is not particularly limited, and examples thereof include a disilylamine compound, a halogenated silane compound, a silicone compound, and a silane coupling agent.

The disilylamine compound is a compound having a disilylamine (Si—N—Si) moiety. Examples of the disilylamine compound include hexamethyldisilazane (HMDS), N-methyl-hexamethyldisilazane or hexamethyl-N-propyldisilazane. Examples of halogenated silane compounds include dimethyldichlorosilane.

Examples of silicone compounds include silicone oil or silicone resin (varnish). Examples of silicone oils include dimethyl silicone oils, methylphenyl silicone oils, α-methylstyrene modified silicone oils, chlorphenyl silicone oils and fluorine modified silicone oils. Examples of the silicone resin (varnish) include methyl silicone varnish and phenylmethyl silicone varnish.

Examples of the silane coupling agent include a silane coupling agent having an alkyl group and an alkoxy group, a silane coupling agent having an amino group and an alkoxy group, or a fluorine-containing silane coupling agent. More specifically, as a silane coupling agent, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethyldiethoxysilane, triethylmethoxysilane, triethyldiethoxysilane, γ-gly Sidoxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyldimethoxymethylsilane or γ-aminopropyldiethoxymethylsilane, 3 , 3,3-Trifluoropropyldimethoxysilane, 3,3,3-trifluoropropyldiethoxysilane, perfluorooctylethyltriethoxysilane, 1,1.1-trifluorohexyldiethoxysilane and the like.

In particular, it is preferably treated with a fluorine-based silane coupling agent such as trifluoropropyltrimethoxysilane or perfluorooctylethyltriethoxysilane.

The amount of the treating agent is preferably 0.5 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the strontium titanate particles.

The above-mentioned surface treatment agent may be used alone or in combination of two or more.

<Bundling resin>
The toner particles in the present invention need to contain a polyester resin as a binder resin from the viewpoint of low temperature fixability. Further, it may be a hybrid resin in which a polyester resin and a vinyl resin are mixed or both are partially reacted.

The monomers used in the polyester unit of the polyester resin include polyvalent alcohol (divalent or trivalent or higher alcohol), polyvalent carboxylic acid (divalent or trivalent or higher carboxylic acid), its acid anhydride or its lower grade. Alkyl esters are used. Here, in order to exhibit "strain curability", it is effective to partially crosslink the amorphous resin in the molecule in order to prepare a branched polymer, and for that purpose, a polyfunctional compound having a trivalent or higher valence is effective. It is preferable to use. Therefore, it is preferable that the raw material monomer of the polyester unit contains a carboxylic acid having a valence of trivalent or higher, an acid anhydride thereof or a lower alkyl ester thereof, and / or an alcohol having a valence of trivalent or higher.

As the polyhydric alcohol monomer used in the polyester unit of the polyester resin, the following polyhydric alcohol monomer can be used.

The divalent alcohol component includes ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-Hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydride bisphenol A, bisphenol represented by the formula (A) and derivatives thereof;

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ及びｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０以上１０以下である。）

(In the formula, R is an ethylene or propylene group, x and y are integers of 0 or more, and the average value of x + y is 0 or more and 10 or less.)

Diols represented by the formula (B);

Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. , 1,2,5-pentantriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene Can be mentioned. Of these, glycerol, trimethylolpropane, and pentaerythritol are preferably used. These divalent alcohols and trihydric or higher alcohols can be used alone or in combination of two or more.

The following polyvalent carboxylic acid monomers can be used as the polyvalent carboxylic acid monomer used in the polyester unit of the polyester resin.

Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebatic acid, azelaic acid, and malonic acid. n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, anhydrides of these acids and Examples thereof include these lower alkyl esters. Of these, maleic acid, fumaric acid, terephthalic acid, and n-dodecenyl succinic acid are preferably used.

Examples of the trivalent or higher valent carboxylic acid, its acid anhydride or its lower alkyl ester include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalentricarboxylic acid and 1,2,4-naphthalenetricarboxylic acid. , 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra ( Methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empoltrimeric acid, acid anhydrides thereof or lower alkyl esters thereof. Of these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof is preferably used because it is inexpensive and reaction control is easy. These divalent carboxylic acids and the like and trivalent or higher carboxylic acids can be used alone or in combination of two or more.

The method for producing the polyester unit of the present invention is not particularly limited, and a known method can be used. For example, the above-mentioned alcohol monomer and carboxylic acid monomer are charged at the same time and polymerized through an esterification reaction, a transesterification reaction, and a condensation reaction to produce a polyester resin. The polymerization temperature is not particularly limited, but is preferably in the range of 180 ° C. or higher and 290 ° C. or lower. When polymerizing the polyester unit, for example, a polymerization catalyst such as a titanium-based catalyst, a tin-based catalyst, zinc acetate, antimony trioxide, or germanium dioxide can be used. In particular, the binder resin of the present invention is more preferably a polyester unit polymerized using a tin-based catalyst.

Further, the acid value of the polyester resin is 5 mgKOH / g or more and 20 mgKOH / g or less, and the hydroxyl value is 20 mgKOH / g or more and 70 mgKOH / g or less. Can be kept low. Therefore, it is preferable from the viewpoint of fog suppression.

Further, the binder resin may contain the following as the main component of the polyester resin. Examples thereof include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and its substitution products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, and styrene-vinylnaphthalin. Sterite-based copolymers such as polymers, styrene-acrylic acid ester copolymers, and styrene-methacrylic acid ester copolymers; styrene-based copolymer resins, polyvinyl chlorides, phenol resins, naturally modified phenol resins, and natural resin modified malein. Examples thereof include acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyethylene resin and polypropylene resin.

Further, the binder resin may be used by mixing a low molecular weight resin and a high molecular weight resin. The content ratio of the high molecular weight resin to the low molecular weight resin is preferably 40/60 or more and 85/15 or less on a mass basis from the viewpoint of low temperature fixability and hot offset resistance.

The toner particles in the present invention may contain crystalline polyester, if necessary. The crystalline polyester is not particularly limited, and known ones can be used, but saturated polyester is preferable. A crystalline resin is a resin that exhibits a clear melting point in differential scanning calorimetry.

Further, it is preferably a condensate of an aliphatic dicarboxylic acid, an aliphatic diol, and an aliphatic monocarboxylic acid. It is preferable to contain an aliphatic monocarboxylic acid as a constituent component of the crystalline polyester because the molecular weight and the hydroxyl value of the crystalline polyester can be easily adjusted and the affinity with the wax can be controlled.

The content of the crystalline polyester is preferably 0.1 part by mass or more and 10 parts by mass or less, and more preferably 0.2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the binder resin.

<Colorant>
The toner particles in the present invention may contain a colorant. Examples of the colorant include the following.

Examples of the black colorant include those colored black with carbon black; a yellow colorant, a magenta colorant, and a cyan colorant. A pigment may be used alone as the colorant, but it is more preferable to use a dye and a pigment in combination to improve the sharpness from the viewpoint of the image quality of a full-color image.

Examples of the magenta toner pigment include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; I. Pigment Violet 19; C.I. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

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

Examples of the cyan toner pigment include the following. C. I. Pigment Blue 2, 3, 15: 2, 15: 3, 15: 4, 16, 17; C.I. I. Bat Blue 6; C.I. I. Acid blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalocyanine groups are substituted in the phthalocyanine skeleton.

Examples of dyes for cyan toner include C.I. I. Solvent blue 70 can be mentioned.

Examples of the pigment for yellow toner include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. I. Bat Yellow 1, 3, 20.
Examples of the dye for yellow toner include C.I. I. Solvent Yellow 162 can be mentioned.

These colorants can be used alone or in admixture, and even in the form of a solid solution. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner.

The content of the colorant is preferably 0.1 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the total amount of the resin components.

<Developer>
The toner in the present invention can be used as a one-component developer, but it can also be mixed with a magnetic carrier and used as a two-component developer in order to suppress charge localization on the toner surface.

Examples of the magnetic carrier include iron oxide; metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth, their alloy particles, and their oxide particles; A generally known material such as a magnetic material such as ferrite; a magnetic material-dispersed resin carrier containing the magnetic material and a binder resin that holds the magnetic material in a dispersed state (so-called resin carrier); can be used.

When the toner is mixed with a magnetic carrier and used as a two-component developer, the mixing ratio of the magnetic carriers at that time shall be 2% by mass or more and 15% by mass or less as the toner concentration in the two-component developer. Is preferable, and more preferably 4.0% by mass or more and 13.0% by mass or less.

<Toner manufacturing method>
The method for producing the toner particles is not particularly limited, but the pulverization method is preferable from the viewpoint of dispersing the toner material such as a pigment.

Hereinafter, the toner manufacturing procedure by the pulverization method will be described.

In the raw material mixing step, as a material constituting the toner particles, for example, other components such as a binder resin, a mold release agent, a colorant, and if necessary, a charge control agent are weighed and blended in a predetermined amount and mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

Next, the mixed materials are melt-kneaded to disperse pigments and the like in the binder resin. In the melt-kneading process, a batch-type kneader such as a pressure kneader or a Bambary mixer or a continuous-type kneader can be used, and a single-screw or twin-screw extruder has become the mainstream because of its superiority in continuous production. ing. For example, KTK type twin-screw extruder (manufactured by Kobe Steel), TEM type twin-screw extruder (manufactured by Toshiba Machinery Co., Ltd.), PCM kneader (manufactured by Ikegai Iron Works), twin-screw extruder (manufactured by KCC). ), Co-kneader (manufactured by Bus Co., Ltd.), Kneedex (manufactured by Nippon Coke Industries Co., Ltd.), etc. Further, the resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water or the like in the cooling step.

Then, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the crushing step, coarse crushing is performed with a crusher such as a crusher, a hammer mill, or a feather mill. Further, for example, pulverization is performed by a cryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), a turbo mill (manufactured by turbo industry), or an air jet type pulverizer. Then, if necessary, the classification is performed using an inertial classification type elbow jet, a centrifugal force classification type turboplex, a TSP separator, a classification machine such as a faculty, or a sieving machine. Elbow jets are manufactured by Nittetsu Mining Co., Ltd., and turboplexes, TSP separators, and faculty are manufactured by Hosokawa Micron. After that, the surface of the toner particles is treated by heating to fix the external additive to the toner particles.

For example, the surface treatment apparatus shown in FIG. 1 can be used to perform surface treatment with hot air. The mixture quantitatively supplied by the raw material quantitative supply means 1 is guided to the introduction pipe 3 installed on the vertical line of the raw material supply means by the compressed gas adjusted by the compressed gas adjusting means 2. The mixture that has passed through the introduction pipe is uniformly dispersed by the conical protruding member 4 provided in the central portion of the raw material supply means, and is guided to the supply pipe 5 in eight directions that spread radially to perform heat treatment. Guided to. At this time, the flow of the mixture supplied to the treatment chamber is regulated by the regulating means 9 for regulating the flow of the mixture provided in the treatment chamber. Therefore, the mixture supplied to the treatment chamber is heat-treated while swirling in the treatment chamber, and then cooled.

The hot air for heat-treating the supplied mixture is supplied from the hot air supply means 7, and is introduced by spirally swirling the hot air into the processing chamber by the swirling member 13 for swirling the hot air. As its configuration, the swirling member 13 for swirling the hot air has a plurality of blades, and the swirling of the hot air can be controlled by the number and angles thereof. The temperature of the hot air supplied to the processing chamber at the outlet of the hot air supply means 7 is preferably 100 ° C. to 300 ° C. If the temperature at the outlet of the hot air supply means is within the above range, it is possible to uniformly spheroidize the toner particles while preventing fusion and coalescence of the toner particles due to overheating of the mixture. Become.

Further, the heat-treated heat-treated toner particles are cooled by the cold air supplied from the cold air supply means 8, and the temperature supplied from the cold air supply means 8 is preferably −20 ° C. to 30 ° C. When the temperature of the cold air is within the above range, the heat-treated toner particles can be efficiently cooled, and fusion and coalescence of the heat-treated toner particles are prevented without hindering the uniform spheroidizing treatment of the mixture. be able to. The absolute water content of the cold air ^{is preferably 0.5 g / m 3} or more and 15.0 g / m ³ or less.

Next, the cooled heat-treated toner particles are recovered by the recovery means 10 at the lower end of the processing chamber. A blower (not shown) is provided at the tip of the collecting means, and the suction is conveyed by the blower (not shown).

Further, the powder particle supply port 14 is provided so that the swirling direction of the supplied mixture and the swirling direction of the hot air are in the same direction, and the recovery means 10 of the surface treatment device is a swirling powder particle. It is provided on the outer peripheral portion of the processing chamber so as to maintain the turning direction. Further, the cold air supplied from the cold air supply means 8 is configured to be supplied horizontally and tangentially from the outer peripheral portion of the apparatus to the peripheral surface of the processing chamber. The swirling direction of the toner supplied from the powder supply port, the swirling direction of the cold air supplied from the cold air supply means, and the swirling direction of the hot air supplied from the hot air supply means are all in the same direction. Therefore, turbulent flow does not occur in the processing chamber, the swirling flow in the device is strengthened, a strong centrifugal force is applied to the toner, and the dispersibility of the toner is further improved. Can be obtained.

Then, it is divided into two parts on the fine powder side and the coarse powder side. For example, it is divided into two using an inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.). A desired amount of an external additive is externally added to the surface of each of the divided heat-treated toner particles. As a method of externalizing, a mixing device such as a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, etc. is used as an externalizing machine to stir and mix. Alternatively, a method of stirring and mixing using a mixing device such as Mechanohybrid (manufactured by Nippon Coke Industries Co., Ltd.) or Nobilta (manufactured by Hosokawa Micron Co., Ltd.) as an external attachment can be mentioned. At that time, if necessary, an external additive such as a fluidizing agent may be further externally treated.

Methods for measuring various physical properties of toner and raw materials will be described below.

<Washing method>
In the present invention, the washing treatment was carried out as follows. In a sucrose aqueous solution prepared by dissolving 20.7 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) in 10.3 g of ion-exchanged water, put the surfactant Contaminone N6 cc in a 30 cc glass vial and mix well to mix the dispersion liquid. To make. Here, as the contaminanton N, for example, a neutral detergent for cleaning a precision measuring instrument having a pH of 7, which comprises a nonionic surfactant, an anionic surfactant, and an organic builder can be used. As the glass vial, for example, VCV-30 manufactured by Nichiden Rika Glass Co., Ltd., outer diameter: 35 mm, height: 70 mm can be used. 1.0 g of toner is added to this vial, and the mixture is allowed to stand until the toner naturally settles to prepare a pretreatment dispersion. This dispersion was shaken with a shaker (YS-8D type: manufactured by Yayoi Co., Ltd.) at a shaking speed of 200 rpm for 5 minutes to separate the inorganic fine particles from the surface of the toner particles. The toner in which the inorganic fine particles remain and the desorbed inorganic fine particles are separated by using a centrifuge. The centrifugation step was performed at 3700 rpm for 30 minutes. Toner with residual inorganic fine particles is collected by suction filtration and dried to obtain toner after washing with water.

<Measurement method of sticking rate>
The sticking rate is measured as follows. First, the strontium titanate particles contained in the toner before the water washing treatment are quantified. This measures the Sr element intensity in the toner using a wavelength dispersive fluorescent X-ray analyzer Axios advanced (manufactured by PANalytical). Next, the Sr element strength of the toner after the water washing treatment is measured in the same manner. The adhesion rate is determined by (Sr element strength of toner after washing with water / Sr element strength in toner) × 100 (%).

<Measurement method of strontium titanate coverage and silica particle coverage>
Twenty toner surface images taken by Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation) are randomly sampled.

The image information can be obtained from the image analysis software Image-Pro Plus ver. It is binarized by utilizing the fact that the brightness of the toner particle surface portion and the external additive portion differs depending on 5.0 (Nippon Roper Co., Ltd.). By this binarization, the area of the external additive portion and the area of the toner particle portion (including the area of the external additive portion) are divided into toner.

The area of the external additive portion is composed of silica-bonded particles and strontium titanate, and can be distinguished by the shape as follows. That is, the shape of the silica particles is amorphous or spherical, whereas the strontium titanate particles have a rectangular parallelepiped or cube shape with rounded corners.

By distinguishing by this shape, the area SSrTIO ₃ occupied by strontium titanate is determined from the area of the external additive portion.

Then, the coverage (%) σSrTiO _{3 of the toner particles by the SrTiO 3} particles is calculated by the following formula.
σSrTiO ₃ (%) = SSrTiO ₃ / Stoner × 100

Similarly, the area SSi occupied by the silica particles in the area of the external additive portion is determined by distinguishing by the above shape. Then, the coverage (%) σSi of the toner particles by the silica particles is calculated by the following formula.
σSi (%) = SSi / Stoner × 100

<Number average particle size RSi of primary particles forming silica particles and average number RCSi of maximum ferret diameter of silica-bonded particles>
Adjust the measurement sample. To about 5 mg of the external additive, 1 ml of isopropanol is added and dispersed with an ultrasonic disperser (ultrasonic cleaner) for 5 minutes. Next, one drop of the above dispersion was added to a microgrid (150 mesh) with a support film for TEM, and the mixture was dried to prepare a measurement sample.

Next, an image is acquired by a transmission electron microscope (TEM) at a magnification (for example, 200 k to 1 M times) at which the silica particles in the visual field can be sufficiently length-measured under the condition of an acceleration voltage of 200 kV, and 100 are randomly measured. The number average particle size is obtained from the measurement of the particle size of the primary particles forming the individual silica particles. Further, when the silica particles are silica-bonded particles, the number average value of the maximum ferret diameter is obtained from the measurement of the maximum ferret diameter of the 100 silica particles. The particle size and maximum ferret diameter of the primary particles of each of these silica particles may be measured manually or by using a measuring tool.

<Measurement method of average density ψSi of number of silica particles>
In the image of silica particles obtained by the transmission electron microscope (TEM) described above, the silica particle region and the non-silica particle region are classified by binarization based on the difference in brightness.

The binarization conditions can be appropriately selected by the observation device. Image analysis software Image J is used for binarization.

From the obtained binarized image, the number average density of silica particles is calculated as follows by performing particle analysis with the image analysis software Image J. That is, the image analysis software Image J defines the numerical range of the density under the name of Solidity.

The above is performed for 100 binarized images, and the average value is taken as the average density of the number of silica particles.

<Measurement method of softening point of resin>
The softening point of the resin is measured using a constant load extrusion type thin tube rheometer "Flow Tester CFT-500D" (manufactured by Shimadzu Corporation) according to the manual attached to the device. In this device, while applying a constant load from the top of the measurement sample with a piston, the temperature of the measurement sample filled in the cylinder is raised and melted, and the melted measurement sample is pushed out from the die at the bottom of the cylinder. A flow curve showing the relationship between and temperature can be obtained.

In the present invention, the softening point is the "melting temperature in the 1/2 method" described in the manual attached to the "flow characteristic evaluation device flow tester CFT-500D". The melting temperature in the 1/2 method is calculated as follows. First, 1/2 of the difference between the piston descent amount Smax at the time when the outflow ends and the piston descent amount Smin at the time when the outflow starts is obtained (this is defined as X. X = (Smax-Smin) / 2). Then, the temperature of the flow curve when the amount of descent of the piston becomes X in the flow curve is the melting temperature in the 1/2 method.

As a measurement sample, about 1.0 g of resin was compression-molded in an environment of 25 ° C. using a tablet molding compressor (for example, NT-100H, manufactured by NPA System Co., Ltd.) at about 10 MPa for about 60 seconds. Use a columnar one with a diameter of about 8 mm.

The measurement conditions of CFT-500D are as follows.
Test mode: Hot compress start temperature: 40 ° C
Achieved temperature: 200 ° C
Measurement interval: 1.0 ° C
Temperature rise rate: 4.0 ° C / min Piston cross-sectional area: 1.000 cm ²
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheating time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0 mm

<Method of measuring the content of zirconium, iron, and aluminum in silica particles>
The content of zirconium, iron, and aluminum in the silica particles used in the present invention can be measured by a fluorescent X-ray analyzer. For example, a wavelength dispersive fluorescent X-ray analyzer Axios advanced (manufactured by PANalytical) is used. Then, 2 g of the sample is weighed on a cup with a special PP (polypropylene) film attached to the bottom surface of a cup dedicated to powder measurement recommended by PANalytical, and a layer is formed uniformly on the bottom surface to cover the bottom surface. Then, the elements from Na to U in the silica particles are measured by the FP method in an atmospheric pressure He atmosphere. At that time, assuming that all the detected elements are oxides, and assuming that their total mass is 100%, ZrO ₂ and Fe ₂ O ₃ and Al ₂ O with respect to the total mass by software SpectraEvolution (version 5.0L) are used. _{The content (mass%) of 3} is calculated as an oxide conversion value.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the number of copies and% of Examples and Comparative Examples are all based on mass.

<Production example of strontium titanate particles>
After the metatitanic acid obtained by the sulfuric acid method was deironed and bleached, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralized to pH 5.8 with hydrochloric acid and washed with filtered water. Water was added to the washed cake to make _{a slurry of 1.85 mol / L as TiO 2} , and then hydrochloric acid was added to adjust the pH to 1.4 for degluing treatment.

1.88 mol of desulfurized and deglued metatitanium acid _{was collected as TiO 2} and placed in a 3 L reaction vessel.

2.16 mol of an aqueous solution of strontium chloride was added to the deflated metatitanium acid slurry so that the SrO / TiO ₂ mol ratio was 1.15. The TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 12 mol / L sodium hydroxide aqueous solution was added over 40 minutes. Stirring was continued at a temperature of 95 ° C. for 45 minutes to complete the reaction.

The reaction slurry was cooled to 40 ° C., hydrochloric acid was added until the pH reached 4.9, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron Co., Ltd.). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 95 m / sec for 10 minutes. Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed. The slurry containing the precipitate was adjusted to 40 ° C., and hydrochloric acid was added to adjust the pH to 2.5.

Next, 4.6% by mass of isobutyltrimethoxysilane and 4.6% by mass of trifluoropropyltrimethoxysilane with respect to the solid content were added after stirring and mixing for 1 hour, and stirring and holding were continued for 10 hours. A 5 mol / L sodium hydroxide solution was added to adjust the pH to 6.2, and stirring was continued for 1 hour. The cake obtained by filtration and washing was dried in the air at 130 ° C. for 8 hours to obtain strontium titanate particles.

The number average particle size of the strontium titanate thus obtained was about 40 nm.

<Production example of silica particles 1>
The silica particles 1 were produced by the so-called sedimentation method as follows.
12.6 liters of water was placed under stirring in a 3 L volume settling container equipped with a metal stirring rod, a dropping nozzle (Teflon (registered trademark) microtube pump), a heating device, and a thermometer at 80 ° C. Heated to.

Then, a water glass solution (mass ratio 3.4: 1 = SiO ₂ 26.8% and Na ₂ O 7.85%; density 1.352 g / ml) was added so that the pH value became 8.5.

Then, while maintaining the solution temperature at 80 ° C., silica for 230 minutes by simultaneously adding 56.7 ml / min of water glass (the above composition) and sulfuric acid (50%) in an amount whose pH value is always maintained at 8.5. Was settled. Subsequently, only sulfuric acid (50%) was added dropwise to acidify the pH value to 3.5, and this pH value was used as the end point. Then, the precipitated silica was separated from the suspension, washed with water, dried at 105 ° C. to 110 ° C., and then pulverized with an experimental pin mill to obtain a silica pulverized product.

Next, the obtained pulverized silica body was slightly coated with zirconium, aluminum, and iron by a magnetron sputtering method to obtain silica particles 1 as a silica conjugate.

Table 1 shows the number average particle diameter of the primary particles of the silica particles 1, the number average value of the maximum ferret diameter of the silica particles 1, and the number average consistency density. _{Further, ZrO 2} , Al ₂ O ₃ , and Fe ₂ O when the total mass of all oxides is assumed to be 1 assuming that all the elements contained in the silica particles 1 detected in the fluorescent X-ray analysis are oxides. _{The mass concentration of 3} is shown in Table 1.

<Production example of silica particles 2 to 6>
In the production example of silica particles 1, the number average density and the number average particle diameter of the primary particles were changed. At this time, the amounts of trace amounts of zirconium, aluminum, and iron coated by the magnetron sputtering method were changed. In this way, silica particles 2 to 6 were obtained as silica-bonded particles. Table 1 shows the number average particle diameter of the primary particles of the silica particles 2 to 6, the number average value of the maximum ferret diameter of the silica particles 2 to 6, and the number average consistency density. _{Further, ZrO 2} and Al ₂ O contained in the silica particles 2 to 6 when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. _3. The mass concentration of Fe ₂ O ₃ is shown in Table 1.

<Production example of silica particles 7>
The silica particles 7 were produced by the so-called sol-gel method as follows.

-Preparation of alkaline catalyst solution (1) 640 parts of methanol, 10% ammonia in a glass reaction vessel with a volume of 3 L equipped with a metal stirring rod, a dropping nozzle (Teflon (registered trademark) microtube pump), and a thermometer. 87 parts of water was added, and the mixture was stirred and mixed to obtain an alkaline catalyst solution (1). The amount of ammonia catalyst in the alkaline catalyst solution (1): the amount of NH ₃ (NH ₃ [mol] / (ammonia water + methanol) [L]) was 0.61 mol / L.

-Preparation of silica fine particle suspension (1) The alkaline catalyst solution (1) was replaced with nitrogen. Then, while stirring the alkaline catalyst solution (1), 125 parts of tetramethoxysilane (TMS) and _{80 parts of aqueous ammonia having a catalyst (NH 3} ) concentration of 4.4% were simultaneously added dropwise in the following supply amounts. Initiation was performed to obtain a suspension of silica fine particles (silica fine particle suspension (1)).

Here, the amount of tetramethoxysilane (TMS) supplied was 13 g / min, that is, 0.0046 mol / (mol · min) with respect to the total number of mols of methanol in the alkaline catalyst solution (1).

The supply amount of 4.4% ammonia water was 4 g / min with respect to the total supply amount (0.0855 mol / min) of tetraalkoxysilane supplied per minute. This corresponds to 0.29 mol / min with respect to 1 mol of the total supply of tetraalkoxysilane supplied per minute.

-Hydrophobic treatment of silica fine particles 5.59 parts of trimethylsilane was added to 200 parts (solid content 13.985%) of the silica fine particle suspension (1) to perform hydrophobization treatment. Then, using a hot plate, it was heated at 65 ° C. and dried to generate silica-bonded particles.

Then, by slightly coating zirconium, aluminum, and iron by a magnetron sputtering method, silica particles 7 were obtained as silica conjugate particles coated with these metals.

Table 1 shows the number average density of the silica particles 7 thus obtained, the number average particle diameter of the primary particles, and the number average value of the maximum ferret diameter. _{Further, ZrO 2} , Al ₂ O ₃ , contained in the silica particles 7, when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is set to 1. The mass concentration of Fe ₂ O ₃ is shown in Table 1.

<Production example of silica particles 8 to 12>
In the production example of the silica particles 7, the number average density and the number average particle diameter of the primary particles were changed. At this time, the amounts of trace amounts of zirconium, aluminum, and iron coated by the magnetron sputtering method were changed. In this way, silica particles 8 to 12 were obtained as silica-bonded particles. Table 1 shows the number average particle diameter of the primary particles of silica particles 8 to 12, the number average value of the maximum ferret diameter of silica particles 8 to 12, and the number average consistency density. _{Further, ZrO 2} and Al ₂ O contained in the silica particles 8 to 12 when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. _3. The mass concentration of Fe ₂ O ₃ is shown in Table 1.

<Production example of silica particles 13>
The silica particles 13 were produced by the so-called sol-gel method as follows.

To a 3 liter glass reactor equipped with a stirrer, a dropping funnel and a thermometer, 589.8 g of methanol, 42.0 g of water and 47.2 g of 26% by mass aqueous ammonia were added and mixed.

The obtained solution was adjusted to 35 ° C., and 1100.0 g (7.23 mol) of tetramethoxysilane and 395.4 g of 5.3 mass% aqueous ammonia were started to be added simultaneously with stirring.

Tetramethoxysilane was added dropwise over 6 hours, and aqueous ammonia was added dropwise over 5 hours. After the dropping was completed, the mixture was further hydrolyzed for 0.5 hour to obtain a methanol-aqueous dispersion of hydrophilic spherical sol-gel silica fine particles.

Next, the ester adapter and the cooling tube were attached to the glass reactor, and the dispersion was sufficiently dried under reduced pressure at 80 ° C. The above steps were carried out several tens of times, and the obtained silica particles were crushed with a parvelizer (manufactured by Hosokawa Micron Co., Ltd.).

Then, 500 g of silica particles were charged into a polytetrafluoroethylene inner cylinder type stainless autoclave having an internal volume of 1000 ml. After replacing the inside of the autoclave with nitrogen gas, 0.5 g of HMDS (hexamethyldisilazane) and 0.1 g of water are atomized with a two-fluid nozzle while rotating the stirring blade attached to the autoclave at 400 rpm to silica. The powder was sprayed evenly. After stirring for 30 minutes, the autoclave was sealed and heated at 200 ° C. for 2 hours. Subsequently, the system was depressurized while being heated to perform deammonia removal.

The silica particles thus produced were almost single particles with almost no primary particles bonded to each other. Then, the obtained silica single particles were slightly coated with zirconium, aluminum, and iron by a magnetron sputtering method to obtain silica particles 13 as silica single particles coated with these metals.

Table 1 shows the number average density of the silica particles 13 and the number average particle diameter of the primary particles. _{Further, ZrO 2} , Al ₂ O ₃ , contained in the silica particles 13 when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is set to 1. The mass concentration of Fe ₂ O ₃ is shown in Table 1.

<Production example of silica particles 14 to 24>
In the production example of the silica particles 13, the number average particle diameter of the primary particles was changed. At this time, the amounts of trace amounts of zirconium, aluminum, and iron coated by the magnetron sputtering method were changed. Silica particles 14 to 24 were obtained as silica single particles.

At this time, the silica particles 17 to 24 were not coated with aluminum, the silica particles 19 to 24 were not coated with iron, and the silica particles 23 and 24 were not coated with zirconium. Table 1 shows the number average density of each silica particle and the number average particle size of the primary particles. _{Further, ZrO 2} and Al ₂ O contained in the silica particles 17 to 24 when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. _3. The mass concentration of Fe ₂ O ₃ is shown in Table 1.

<Production example of amorphous polyester resin>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 73.3 parts (0.20 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 22.4 parts (0.13 mol; 82.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Adipic acid: 4.3 parts (0.03 mol; 18.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Titanium tetrabutoxide (esterification catalyst): 0.51 part The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, after replacing the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 4.5 hours while stirring at a temperature of 202 ° C. to obtain an amorphous polyester resin as a binder resin. The softening point of the obtained amorphous polyester resin was 90 ° C.

<Production example of styrene acrylic resin>
850 g of xylene was placed in a 2-liter glass four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen introduction tube, and the temperature was raised to 150 ° C. after nitrogen replacement.

・ Styrene 1700 parts ・ n-Butyl acrylate 250 parts ・ Polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane 50 parts ・ Dicumyl peroxide 80 parts Then, mix the above materials. It was added dropwise from the dropping funnel over 4 hours and aged at 150 ° C. for 4 hours. Then, the temperature was raised to 200 ° C., and xylene was distilled off under reduced pressure to obtain a styrene acrylic resin as a binder resin. The softening point of the obtained styrene acrylic resin was 108 ° C.

<Synthetic example of crystalline polyester resin>
Dodecane diol: 34.5 parts (0.29 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Sebacic acid: 65.5 parts (0.28 mol; 100.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
The above materials were weighed in a condenser tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 3 hours while stirring at a temperature of 140 ° C.

-Tin 2-ethylhexanoate: 0.5 parts by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 4 hours while maintaining the temperature at 200 ° C., and then in the reaction vessel. The pressure was gradually released and returned to normal pressure to obtain a crystalline polyester resin. The softening point was 82 ° C.

(Toner manufacturing example)
<Manufacturing example of toner 1>
The type of binding resin is amorphous polyester resin.
・ 100 parts of binding resin ・ 5 parts of crystalline polyester resin ・ Fischer-Tropsch wax (melting point: 90 ° C) 6 parts ・ C.I. I. Pigment Blue 15:34 Part 4 After premixing the above materials with a Henschel mixer (FM-75 type, manufactured by Mitsui Mine Co., Ltd.), 160 by a twin-screw kneading extruder (PCM-30 type, manufactured by Ikegai Corp.). It was melt-kneaded at ° C.

The obtained kneaded product was cooled, roughly pulverized to 1 mm or less with a hammer mill, and then finely pulverized with a mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.).

The obtained finely pulverized product was classified using a faculty (F-300, manufactured by Hosokawa Micron Co., Ltd.). The operating conditions were a classification rotor rotation speed of 11000 rpm and a distributed rotor rotation speed of 7200 rpm. In this way, toner particles 1 were obtained.

Then
-Toner particles 1 100 parts-Sieve particles 1 7.7 parts-Strontium titanate particles 3.1 parts Rotate the raw materials shown in the above formulation using a Henshell mixer (FM-10C type, manufactured by Nippon Coke Co., Ltd.). After mixing with a number of 67s ^-1 (4000 rpm) and a rotation time of 2 min, the toner 1 was obtained by passing through an ultrasonic vibrating sieve having a mesh size of 54 μm.

<Manufacturing example of toners 2 to 24>
In the production example of toner 1, the toner 1 is produced except that the type of binder resin, the presence or absence of crystalline polyester, the amount of strontium titanate added, and the type and amount of silica particles added are changed as shown in Table 2. The same operation as in the example was carried out to obtain toners 2 to 24.

Table 2 shows the coverage and adhesion of strontium titanate and the coverage of silica in the toners 1 to 24.

<Production example of magnetic core particles>
・ Process 1 (weighing / mixing process):
Fe ₂ O ₃ 62.7 parts MnCO ₃ 29.5 parts Mg (OH) ₂ 6.8 parts SrCO ₃ 1.0 parts The ferrite raw materials were weighed so as to have the above composition ratio. Then, it was pulverized and mixed for 5 hours with a dry vibration mill using stainless beads having a diameter of 1/8 inch.

-Step 2 (temporary firing step):
The obtained pulverized product was made into pellets of about 1 mm square by a roller compactor. Coarse powder was removed from the pellets with a vibrating sieve having an opening of 3 mm, and then fine powder was removed with a vibrating sieve having an opening of 0.5 mm. It was calcined at a temperature of 1000 ° C. for 4 hours at 01% by volume) to prepare calcined ferrite. The composition of the obtained calcined ferrite is as follows.
(MnO) a (MgO) b (SrO) c (Fe ₂ O ₃ ) d
In the above formula, a = 0.257, b = 0.117, c = 0.007, d = 0.393

-Step 3 (crushing step):
The obtained calcined ferrite was crushed to about 0.3 mm with a crusher, and then 30 parts of water was added to 100 parts of the calcined ferrite using zirconia beads having a diameter of 1/8 inch, and the mixture was pulverized with a wet ball mill for 1 hour. .. The obtained slurry was pulverized with a wet ball mill using alumina beads having a diameter of 1/16 inch for 4 hours to obtain a ferrite slurry (a finely pulverized product of calcined ferrite).

・ Process 4 (granulation process):
To 100 parts of calcined ferrite, 1.0 part of ammonium polycarboxylic acid as a dispersant and 2.0 parts of polyvinyl alcohol as a binder were added to the ferrite slurry, and the particles were made into spherical particles by a spray dryer (manufacturer: Ohkawara Kakohiki). Granulated. After adjusting the particle size of the obtained particles, the particles were heated at 650 ° C. for 2 hours using a rotary kiln to remove organic components of the dispersant and the binder.

-Step 5 (firing step):
In order to control the firing atmosphere, the temperature was raised from room temperature to a temperature of 1300 ° C. in 2 hours under a nitrogen atmosphere (oxygen concentration 1.00% by volume) in an electric furnace, and then the temperature was 1150 ° C. for 4 hours. Then, over 4 hours, the temperature was lowered to 60 ° C., the nitrogen atmosphere was returned to the atmosphere, and the mixture was taken out at a temperature of 40 ° C. or lower.

・ Process 6 (sorting process):
After crushing the agglomerated particles, the low magnetic force product is cut by magnetic force beneficiation and sieved with a sieve having a mesh size of 250 μm to remove coarse particles. Magnetic core particles were obtained.

<Preparation of coating resin>
Cyclohexyl methacrylate monomer 26.8% by mass
Methyl methacrylate monomer 0.2% by mass
Methyl Methacrylate Macromonomer 8.4% by Mass
(Macromonomer having a methacryloyl group at one end and having a weight average molecular weight of 5000)
Toluene 31.3% by mass
Methyl ethyl ketone 31.3% by mass
Azobisisobutyronitrile 2.0% by mass
Among the above materials, cyclohexyl methacrylate monomer, methyl methacrylate monomer, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone are put into the following apparatus. That is, it is placed in a four-port separable flask equipped with a reflux condenser, a thermometer, a nitrogen introduction tube and a stirrer. Then, nitrogen gas was introduced to create a sufficiently nitrogen atmosphere. Then, the mixture was heated to 80 ° C., azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours for polymerization. Hexane was injected into the obtained reaction product to precipitate and precipitate a copolymer, and the precipitate was filtered off and then vacuum dried to obtain a coating resin 1.

Next, 30 parts of the coating resin 1 was dissolved in 40 parts of toluene and 30 parts of methyl ethyl ketone to obtain a polymer solution (solid content: 30% by mass).

<Preparation of coating resin solution>
Polymer solution (resin solid content concentration 30%) 33.3% by mass
Toluene 66.4% by mass
Carbon Black Regal330 (manufactured by Cabot) 0.3% by mass
(Primary particle size 25 nm, nitrogen adsorption specific surface area 94 m ² / g, DBP oil absorption 75 mL / 100 g)
Was dispersed in a paint shaker for 1 hour using zirconia beads having a diameter of 0.5 mm. The obtained dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution.

<Manufacturing example of magnetic carrier>
(Resin coating process):
The magnetic core particles and the coating resin solution were charged into the vacuum degassing type kneader maintained at room temperature (the amount of the coating resin solution charged is 2.5 parts as a resin component with respect to 100 parts of the magnetic core particles. amount). After the addition, the mixture was stirred at a rotation speed of 30 rpm for 15 minutes, the solvent was volatilized above a certain level (80% by mass), the temperature was raised to 80 ° C. while mixing under reduced pressure, toluene was distilled off over 2 hours, and then the mixture was cooled. The obtained magnetic carrier is separated into low magnetic force products by magnetic beneficiation, passed through a sieve having an opening of 70 μm, and then classified by a wind power classifier. Got

<Production example of developer 1>
92.0 parts of magnetic carrier and 8.0 parts of toner 1 were mixed by a V-type mixer (V-20, manufactured by Seishin Enterprise Co., Ltd.) to obtain a developer 1.

<Production example of developing agents 2 to 24>
In the production example of the developing agent 1, the same operations were carried out except for the changes as shown in Table 3, to obtain the developing agents 2 to 24.

[Example 1]
The following evaluations were carried out using a Canon full-color copying machine imagePRESS C800 or a modified machine thereof.

The image forming apparatus has a photoconductor that forms an electrostatic latent image as an image carrier, and has a developing step of developing the electrostatic latent image of the photoconductor as a toner image with a two-component developer.

Further, it has a transfer step of transferring the developed toner image to the intermediate transfer body and then transferring the toner image of the intermediate transfer body to the paper, and has a fixing step of fixing the toner image on the paper by heat.

The developer 1 was put into the developer of the cyan station of this image forming apparatus, and the following evaluation was performed.

<Ghost evaluation>
The ghost was evaluated as follows.

A modified machine of the above image forming apparatus was used. The modification point is that the mechanism for discharging the excess magnetic carrier inside the developing device from the developing device has been removed.

The amount of toner loaded on the paper in the FFH image (solid image) was adjusted to ^{0.45 mg / cm 2.} FFH is a value obtained by displaying 256 gradations in hexadecimal, 00H is the first gradation of 256 gradations (white background portion), and FFH is the 256th gradation of 256 gradations (solid portion). ..

Then, after passing 999 sheets of the solid black vertical band as shown in FIG. 2 and the test chart which is solid white except for the vertical band in succession, the 1000th sheet was flown in the same job as a full halftone image. .. The paper passing direction is shown in FIG. On the halftone image, the image densities of the area (a) through which the solid black vertical band in FIG. 3 was passed and the area (b) through which the solid white was passed were measured, and the ghost was determined by the difference in shade. evaluated. The case where ghost occurs is shown in FIG.

The image density was measured using an X-Rite color reflection densitometer (X-Rite 500 Series, manufactured by X-Rite).

The measurement was performed in a normal temperature and humidity (NN) environment (temperature 23 ° C., relative humidity 50% or more and 60% or less), in a room temperature low humidity (NL) environment (temperature 23 ° C., relative humidity 5%), and high temperature and high humidity (HH). Perform in an environment (temperature 30 ° C., relative humidity 80%). Among them, the value with the highest concentration difference was defined as the concentration difference and ranked as follows.

(Evaluation criteria: Ghost)
A: The concentration difference between the region (a) and the region (b) is less than 0.02 (excellent).
B: The concentration difference between the region (a) and the region (b) is 0.02 or more and less than 0.04 (slightly superior).
C: The concentration difference between the region (a) and the region (b) is 0.04 or more and less than 0.06 (allowable level in the present invention).
D: The concentration difference between the region (a) and the region (b) is 0.06 or more and less than 0.10 (a level unacceptable in the present invention).

<Low temperature fixability (lower limit temperature that can be fixed)>
A developer containing a two-component developer 1 was mounted on the cyan station of a Canon full-color copier imagePRESS C800 remodeling machine, and the remodeling was performed so that an image could be formed with the fixing device removed. Then, an unfixed toner image (hereinafter, unfixed image) was formed on the evaluation paper. For the evaluation, plain paper for color copiers and printers, GF-C157 (A4, 157 g / cm ² ) (sold by Canon Marketing Japan Inc.) was used.

Actually, the development conditions are appropriately adjusted so that the amount of toner on the FFH image (hereinafter, solid part) is 1.2 mg / cm ² , 3 cm from the tip of the A4 vertical evaluation paper, and the center of the evaluation paper. An unfixed image of 2 cm × 10 cm was formed at the position of. The unfixed image was humidity-controlled for 24 hours in a low-humidity low-temperature environment (15 ° C./10% Rh).

Subsequently, the fixing device was taken out from the Canon full-color copying machine imagePRESS C800, and a fixing test jig was prepared so that the process speed and the temperature of the upper and lower fixing members could be controlled independently. The fixability evaluation was carried out in a low temperature and low humidity environment (15 ° C./10% Rh), and the fixing test jig adjusted to a process speed of 400 mm / sec was used.

In the actual evaluation, the unfixed image was passed while adjusting the upper belt temperature of the fixing test jig in the range of 100 ° C to 200 ° C every 5 ° C, and the lower belt temperature was fixed at 100 ° C during that time. Evaluation was performed in the state.

The fixed image passed through the fuser is rubbed 5 times with a lens cleaning wiper (manufactured by Dasper Ozu Corporation) with a load of 4.9 kPa, and the density reduction rate of the image density before and after rubbing is reduced to 10% or less. This point was defined as the fixing temperature.

Based on the criterion of not being able to fix when the density drops more than 10%, the lowest upper belt set temperature that does not exceed the image density drop rate of 10% was set as the low temperature fixing temperature and evaluated according to the following evaluation criteria. ..

(Evaluation criteria: Low temperature fixability)
A: Less than 130 ° C (excellent)
B: 130 ° C or higher and lower than 150 ° C (slightly superior)
C: 150 ° C or higher and lower than 160 ° C (allowable level in the present invention)
D: 160 ° C or higher (a level unacceptable in the present invention)

<Cover>
The fog concentration (%) was measured as follows. Immediately after the 20,000th image was output with GF-C157 (A4, 157 g / cm ² ) (sold by Canon Marketing Japan Inc.), plain paper for color copiers and printers, solid white paper was passed through. .. Then, using "REFLECTMER MODEL TC-6DS" (manufactured by Tokyo Denshoku Co., Ltd.), the fog density (%) was calculated from the difference between the whiteness of the white background of the measured image and the whiteness of the transfer paper. .. An amber filter was used as the filter. The smaller the value, the better the fog level.

(Evaluation criteria)
A: Fog concentration less than 0.5% (excellent)
B: Fog concentration 0.5% or more and less than 1.0% (slightly superior)
C: Fog concentration 1.0% or more and less than 2.0% (allowable level in the present invention)
D: Fog concentration 2.0% or more (a level unacceptable in the present invention)

The results are shown in Table 4.

[Examples 2 to 20, Comparative Examples 1 to 4]
The evaluation was carried out in the same manner as in Example 1 except that the developing agents 2 to 24 were used instead of the developing agent 1. The results are shown in Table 4.

From the above results, the following was shown. That is, the average particle size of the number of primary particles of silica particles externally attached to the surface of the toner particles is 50 nm or more and 300 nm or less. _{In addition, the silica particles contain ZrO 2} having a mass concentration of 20 ppm or more and 1000 ppm or less when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. By externally adding silica particles satisfying these conditions, it is possible to suppress ghosting while suppressing the occurrence of fog, and therefore it is possible to provide a high-quality image.

1. 1. Raw material quantitative supply means, 2. Compressed gas flow rate adjusting means, 3. Introductory tube, 4. Protruding member, 5. Supply pipe, 6. Processing room, 7. Hot air supply means, 8. Cold air supply means, 9. Regulatory means, 10. Recovery means, 11. Hot air supply means outlet, 12. Distributor, 13. Swivel member, 14. Powder particle supply port

Claims (9)

Toner particles containing a binder resin and a colorant, and toner having silica particles on the surface of the toner particles.
The number average particle size of the primary particles of the silica particles is 50 nm or more and 300 nm or less.
In the fluorescent X-ray analysis of the silica particles, it is considered that all the detected elements are oxides, and ZrO ₂ is contained at a mass concentration of 20 ppm or more and 1000 ppm or less when the total mass of all oxides is 1. Toner to do. _{The silica particles contain Fe 2} O ₃ having a mass concentration of 100 ppm or more and 5000 ppm or less when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. The toner according to claim 1. _{The silica particles contain Al 2} O ₃ having a mass concentration of 500 ppm or more and 20000 ppm or less when all the elements detected in the fluorescent X-ray analysis are regarded as oxides and the total mass of all oxides is 1. The toner according to claim 1 or 2. The silica particles are toners having silica-bonded particles formed by bonding primary silica particles, and the average number of maximum ferret diameters of the silica-bonded particles is 100 nm or more and 500 nm or less, and the silica-bonded particles. When the number average density of particles is ψSi, the ψSi is 0.40 ≦ ψSi ≦ 0.90.
The toner according to any one of claims 1 to 3. The toner according to any one of claims 1 to 4, wherein the coverage of the toner particles with the silica particles is 10% or more. The toner according to any one of claims 1 to 5, which has _{SrTiO 3} particles on the surface of the toner particles, and the coverage of the toner particles by the _{SrTiO 3 particles is 5% or more and 50% or less.} .. The toner according to any one of claims 1 to 6, wherein _{the adhesion rate of the SrTiO 3 particles is 80% or more.} The toner according to any one of claims 1 to 7, wherein the binder resin contains a polyester resin. The toner according to any one of claims 1 to 8, wherein the toner particles contain crystalline polyester.

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