JP2010078719A - Toner for electrostatic charge image development and developer for electrostatic charge image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner that is fixed at a low temperature, suppresses hot offset and gives stable and high picture qualities in long-term use. <P>SOLUTION: The toner for electrostatic charge image development comprises toner base particles, and as an external additive of the toner base particles, at least metatitanic acid particles and silicone oil-treated silica. The toner base particles contain at least a binder resin, a coloring material and a release agent. The amount of free silicone oil in the silicone oil-treated silica is in a proportion of 0.01 mass% to 1 mass%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic image developing toner and an electrostatic image developing developer.

  An electrophotographic method for visualizing image information through an electrostatic latent image is currently used in various fields (see, for example, Patent Document 1 and Patent Document 2). In this electrophotographic method, an electrostatic latent image is generally formed on the surface of a photoreceptor in a charging / exposure process, and an electrostatic charge image developer (hereinafter simply referred to as “developer”) containing toner in a development process. ) To develop the electrostatic latent image to form a toner image, transfer the toner image onto a transfer material such as paper or sheet in the transfer process, and use heat, solvent, pressure, etc. in the fixing process. Then, the toner image is fixed on a transfer material to obtain an image.

  Since the latter half of the 1980s, there has been a strong demand for miniaturization and high functionality in electrophotographic technology, and in particular, with regard to full color image quality, high-quality quality close to high-quality printing and silver salt photography is desired. Digitization processing is indispensable as a means for achieving high image quality, and as an effect of digitization, complicated image processing can be performed at high speed. Digitization makes it possible to control characters and photographic images separately, and the reproducibility of both qualities is greatly improved compared to analog technology. Particularly for photographic images, the fact that gradation correction and color correction are possible is a great effect, and it is advantageous over analog in terms of gradation characteristics, definition, sharpness, color reproduction, and graininess.

  On the other hand, it is necessary to faithfully form a latent image created by an optical system as an image output, and as a toner, an activity aiming at faithful reproduction is accelerating as the particle diameter is further reduced. Therefore, in addition to the reduction in toner particle size, improvement of basic characteristics in transfer and fixing characteristics is further important in order to stably obtain high image quality.

In addition, in order to reduce the amount of energy used in copying machines and printers, a technique for fixing toner with lower energy is desired. Therefore, there is an increasing demand for toner for electrophotography that can be fixed at a lower temperature.
Here, as a means for lowering the fixing temperature of the toner, a technique for lowering the glass transition point of the toner resin (binder) is generally used. On the other hand, from the viewpoint of preventing powder aggregation (blocking) and the viewpoint of storage stability of the toner on the fixed image, the glass transition point of the binder is practically 50 ° C., preferably 60 ° C. or more. It is. It is also possible to lower the fixing temperature by using a plasticizer.

Furthermore, a method using a crystalline resin for toner for the purpose of achieving both blocking prevention and low-temperature fixing is known (for example, see Patent Document 3).
The advantages of the crystalline resin include offset prevention (for example, see Patent Document 4), pressure fixing (for example, see Patent Document 5), and the like.

Among crystalline resins, polyester resin is expected to improve the fixability to paper (for example, see Patent Document 6). This is a technique in which an amorphous polyester resin having a glass transition temperature of 40 ° C. or higher and a crystalline polyester resin having a melting point of 130 to 200 ° C. are mixed and used. Furthermore, a technique for realizing low-temperature fixing by mixing a low-melting crystalline resin and an amorphous resin and controlling the degree of compatibilization has been proposed (see, for example, Patent Document 7 and Patent Document 8).
US Pat. No. 2,297,691 U.S. Pat. No. 2,357,809 Japanese Patent Publication No. 56-13943 Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 63-25335 Japanese Examined Patent Publication No.62-39428 JP 2004-206081 A Japanese Patent Laid-Open No. 2004-50478

  An object of the present invention is to provide a toner and a developer for developing an electrostatic charge image that can be fixed at a low temperature, suppress the occurrence of hot offset, and obtain a stable image quality over a long period of use.

The invention according to claim 1
Toner base particles containing at least a crystalline resin, a coloring material, and a release agent;
As an external additive for the toner base particles, at least metatitanic acid particles and silicone oil-treated silica,
In the silicone oil-treated silica, the amount of free silicone oil is 0.01% by mass or more and 1% by mass or less.

The invention according to claim 2
2. The electrostatic charge developing toner according to claim 1, wherein the coverage of the toner base particles with the metatitanic acid particles is 30% or more and 100% or less.

The invention according to claim 3
An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to claim 1 and a carrier.

According to the first aspect of the present invention, it is possible to suppress the occurrence of hot offset and to obtain a stable high image quality over a long period of use, as compared with the case where the fixing is performed at a low temperature and this configuration is not provided.
According to the second aspect of the present invention, the occurrence of hot offset is further suppressed compared to the case where the present configuration is not provided, and an effect is obtained that a stable high image quality can be obtained over a long period of use.
According to the third aspect of the present invention, it is possible to suppress the occurrence of hot offset and to obtain a stable high image quality over a long period of use, as compared with the case where the fixing is performed at a low temperature and this configuration is not provided.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

<< Toner for electrostatic charge development >>
The toner for developing an electrostatic charge image according to the exemplary embodiment includes toner base particles and an external additive. The toner base particles contain at least a crystalline resin, a color material, and a release agent. The external additive contains at least metatitanic acid particles and silicone oil-treated silica. The amount of free silicone oil in the silicone oil-treated silica is 0.01% by mass or more and 1% by mass or less.

The reason why the electrostatic charge image developing toner of the present embodiment is fixed at a low temperature, the occurrence of hot offset is suppressed, and a stable high image quality can be obtained over a long period of use is estimated as follows. However, it is not limited by the following assumptions.
“Hot offset” refers to a phenomenon in which a part of toner adheres to a roll or a belt when an image is fixed by a roll method or a belt method.

  In the toner for developing an electrostatic charge image of this embodiment, a crystalline resin is used as a resin for toner base particles. The crystalline resin has a sharp melt property, and additionally has an effect of lowering the apparent glass transition temperature when it is compatible with the amorphous resin. Therefore, by using the crystalline resin, the fixing temperature of the electrostatic image developing toner can be lowered.

  On the other hand, it is effective to externally add silica treated with silicone oil in order to achieve a long-term stable chargeability of the developer. However, when silica is added to a toner containing a crystalline resin, the silicone oil applied to the silica thickens the crystalline resin and release agent contained in the toner base particles during fixing, resulting in hot offset. It is thought that it becomes easy to make it.

  Therefore, in order to obtain hot offset resistance, it is necessary to control the amount of silicone oil that thickens the crystalline resin and the release agent during fixing. However, it is possible to obtain hot offset resistance only by reducing the amount of silicone oil treated, but long-term stable chargeability cannot be maintained.

  As a result of intensive studies by the present inventors, it has been found that, by setting the amount of free silicone oil in the silicone oil-treated silica to 0.01 mass% or more and 1 mass% or less, hot offset resistance and long-term charging stability can be obtained. I found it. The following actions / functions are presumed.

In general, when silica is treated with silicone oil, it is classified into two types of silicone oils: silicone oil fixed to the silica surface layer and silicone oil that is free from silica. As a result of intensive studies by the present inventors, it has been clarified that the cause of the hot offset is a silicone oil that is present in a free state. It is presumed that the hot offset property is lowered by mixing the crystalline resin or the release agent exuded from the toner base particles by heating at the time of fixing and the free silicone oil. In particular, when a crystalline resin is used as the binder resin, the influence of hot offset due to the released silicone oil increases.
Therefore, in order to improve the hot offset resistance, it is effective to control the amount of silicone oil that is present free.

  On the other hand, metatitanic acid particles are generally flat or plate-like, and when added as an external additive, they tend to adhere strongly because of their large contact area with the toner base particles. For this reason, metatitanic acid particles are unlikely to be detached or unevenly distributed from the toner base particles due to developer stress, and are fixed on the toner surface.

Accordingly, the metatitanic acid particles uniformly distributed on the toner surface prevent the crystalline resin and the release agent leached from the toner base particles by fixing from coming into contact with the free silicone oil. As a result, the mixing of the crystalline resin or the release agent in the fixing with the silicone oil that is present free is suppressed, and the hot offset resistance is improved without deteriorating the charging stability. The heating time for the toner at the time of normal fixing is about 0.1 seconds at the longest, and it is sufficient that the crystalline resin or the release agent can be prevented from coming into contact with the released silicone oil for that time. This is particularly effective when silicone oil-treated silica having a free oil amount in a specific range is used.
In the following, materials used for the electrostatic image developing toner of the present embodiment will be described first.

<Toner base particles>
The toner base particles contain at least a crystalline resin, a color material, and a release agent. If necessary, it contains a non-crystalline resin and additives described later.

(Binder resin)
In the toner for developing an electrostatic charge image of the present embodiment (hereinafter sometimes simply referred to as “toner”), at least a crystalline resin is used as a binder resin for toner base particles. By using a crystalline resin, the fixing temperature is lowered. More preferably, a crystalline resin and an amorphous resin are used in combination. By using these resins in combination as a binder resin for the toner to achieve an appropriate compatibility state, in addition to the sharp melt properties inherent to crystalline resins, sharp melt properties and low temperature fixability are achieved by the plasticizing effect of the compatible portions. Is played. In addition, the proper compatibility improves the dispersibility of the crystalline resin and improves the toner strength.

  The content ratio of the crystalline resin and the non-crystalline resin in the toner base particles is preferably a mass ratio of crystalline resin: non-crystalline resin = 4: 96 or more and 20:80 or less, and 6:94 or more and 15 : It is more preferable that it is 85 or less, and it is still more preferable that it is 8:92 or more and 10:90 or less.

The crystalline resin is preferably used in the range of 5% by mass to 30% by mass, more preferably in the range of 8% by mass to 20% by mass, among the components constituting the toner base particles.
If the content of the crystalline resin is in the above range, the strength of the fixed image, particularly scratching strength, is high and scratches are difficult to be obtained, and sharp melt properties derived from the crystalline resin are obtained, ensuring low-temperature fixability. On the other hand, toner blocking resistance and image storage stability are exhibited.

The “crystalline resin” refers to a resin having a clear endothermic peak, not a stepwise change in endothermic amount in differential scanning calorimetry (DSC). Specifically, it means that the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C.
On the other hand, a resin having a half width exceeding 6 ° C. or a resin having no clear endothermic peak means an amorphous resin. As the amorphous resin used in the present invention, it is preferable to use a resin in which no clear endothermic peak is observed.

  The crystalline resin is not particularly limited as long as it is a resin having crystallinity, and specific examples include crystalline polyester resins and crystalline vinyl resins. Crystalline polyester is preferable from the viewpoint of fixing property to paper at the time of fixing, charging property, and adjusting the melting point within a preferable range. Further, an aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

  The crystalline polyester resin and all other polyester resins used in the toner of this embodiment are synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In this embodiment, a commercially available product may be used as the polyester resin, or a synthesized product may be used.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids, and the like. These may be used alone or in combination of two or more. Furthermore, these anhydrides and these lower alkyl esters are also exemplified, but not limited thereto.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

Furthermore, it is more preferable to contain a dicarboxylic acid component having a double bond in addition to the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having a double bond is suitable from the viewpoint of preventing hot offset at the time of fixing because it crosslinks radically through the double bond.
Examples of such a dicarboxylic acid having a double bond include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid, maleic acid and the like are mentioned in terms of cost.

  On the other hand, the polyhydric alcohol component is preferably an aliphatic diol, and more preferably a linear aliphatic diol having a main chain portion having 7 to 20 carbon atoms. When the aliphatic diol is a linear type, the crystallinity of the polyester resin is maintained, and the lowering of the melting point is suppressed, so that the toner blocking resistance, the image storage stability, and the low-temperature fixability are excellent. Further, when the number of carbon atoms is 7 or more and 20 or less, the melting point when polycondensation with the aromatic dicarboxylic acid can be kept low and the low-temperature fixability is excellent, while the material is practically easily available. The number of carbon atoms in the main chain portion is more preferably 7 or more and 14 or less.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester according to this embodiment include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, and the like, but are not limited thereto.

Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

  Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90% or more. When the content of the aliphatic diol component is within the above range, the crystallinity of the polyester resin is maintained, and the lowering of the melting point can be suppressed, so that the toner blocking resistance, the image storage stability, and the low-temperature fixability are excellent.

  In addition, in the crystalline polyester according to the present embodiment, a monovalent acid such as acetic acid or benzoic acid or a monovalent acid such as cyclohexanol benzyl alcohol is used for the purpose of adjusting the acid value or the hydroxyl value, if necessary. Alcohol is also used.

  There is no restriction | limiting in particular as a manufacturing method of crystalline polyester resin, It can manufacture with the general polyester polymerization method which makes an acid component and an alcohol component react. For example, direct polycondensation, transesterification, and the like can be mentioned.

  The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower. The reaction system is reduced in pressure as necessary, and the reaction is carried out while removing water and alcohol generated by condensation. When the monomer is not dissolved or compatible with the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. When a monomer having poor compatibility exists in the copolymerization reaction, the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  The crystalline polyester resin particle dispersion is prepared by emulsifying and dispersing the resin by adjusting the acid value of the resin or using an ionic surfactant.

  Catalysts that can be used in the production of crystalline polyester resins include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compounds: Phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like, and specific examples include the following compounds.

  For example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium Tetrapropoxide, titanium tetraisoproxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, naphthenic acid Zirconium, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Sufaito, tris (2, 4-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

On the other hand, crystalline vinyl resins include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, and (meth) acrylic acid. Decyl, undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate And vinyl resins using long-chain alkyl and alkenyl (meth) acrylic acid esters.
In the present specification, the description “(meth) acryl” means to include both “acryl” and “methacryl”.

As melting | fusing point of crystalline resin, Preferably it is 50 degreeC or more and 100 degrees C or less, More preferably, they are 60 degreeC or more and 80 degrees C or less, More preferably, they are 55 degreeC or more and 70 degrees C or less. When the melting point of the crystalline resin is within the above range, the toner storage stability and the storage stability of the toner image after fixing are excellent and sufficient low-temperature fixing performance is exhibited.
The crystalline resin may show a plurality of melting peaks, but in this embodiment, the maximum peak is regarded as the melting point.

The crystalline resin preferably has a weight average molecular weight (Mw) of 5000 or more and 60000 or less, more preferably 8000 or more and 50000, as measured by a gel permeation chromatography (GPC) method in which tetrahydrofuran (THF) is soluble. The number average molecular weight (Mn) is preferably from 4,000 to 10,000, the molecular weight distribution Mw / Mn is preferably from 2 to 10, and more preferably from 3 to 9.
When the weight average molecular weight and the number average molecular weight are within the above ranges, it is easy to achieve both low-temperature fixability and hot offset resistance.

  A known resin material can be used as the amorphous resin, and an amorphous polyester resin is particularly preferable. The non-crystalline polyester resin used in the present embodiment is obtained mainly by condensation polymerization of polyvalent carboxylic acids and polyhydric alcohols.

When an amorphous polyester resin is used, it is advantageous in that the resin particle dispersion can be easily prepared by adjusting the acid value of the resin or emulsifying and dispersing the resin using an ionic surfactant.
Examples of polyvalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalene dicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl And aliphatic carboxylic acids such as succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. You may use 1 type, or 2 or more types of these polyhydric carboxylic acid.

  Of these polyvalent carboxylic acids, aromatic carboxylic acids are preferably used, and trivalent or higher carboxylic acids (trimerits) together with dicarboxylic acids to form a crosslinked structure or a branched structure in order to ensure good fixability. It is preferable to use an acid or an acid anhydride thereof in combination.

  Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And the like; and aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. One or more of these polyhydric alcohols may be used.

  Of these polyhydric alcohols, aromatic diols and alicyclic diols are preferred, and among these, aromatic diols are more preferred. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure.

  In addition, monocarboxylic acid and / or monoalcohol is further added to the polyester resin obtained by polycondensation of polycarboxylic acid and polyhydric alcohol to esterify the hydroxyl group and / or carboxyl group at the polymerization terminal. The acid value of the polyester resin may be adjusted.

  Examples of the monocarboxylic acid include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride, etc., and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, trifluoroethanol, Examples include trichloroethanol, hexafluoroisopropanol, and phenol.

  The polyester resin is produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the above polyhydric alcohol and polyvalent carboxylic acid, if necessary, a catalyst, and blended in a reaction vessel equipped with a thermometer, a stirrer, a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas) Heating at 150 ° C. or more and 250 ° C. or less to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value is reached, cool the target reactant Manufactured by acquiring.

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. The amount of such a catalyst added is preferably 0.01% by mass or more and 1.00% by mass or less based on the total amount of raw materials.

The amorphous resin used for the toner base particles according to the exemplary embodiment has a weight average molecular weight (Mw) of 5,000 or more and 1,000,000 by molecular weight measurement by gel permeation chromatography (GPC) method in which tetrahydrofuran (THF) is soluble. The molecular weight (Mn) is preferably 2000 or more and 10,000 or less, and the molecular weight distribution Mw / Mn is 1.5 or more and 100 or less. Preferably, it is 2 or more and 60 or less.
When the weight average molecular weight and the number average molecular weight are within the above ranges, it is easy to achieve both low-temperature fixability, hot offset resistance, and document storage stability.

  In the present embodiment, the molecular weight of the resin is measured with a THF solvent by using a TSO-soluble GPC / HLC-8120, a Tosoh column / TSKgel SuperHM-M (15 cm), and a monodisperse polystyrene. The molecular weight was calculated using a molecular weight calibration curve prepared with a standard sample.

The acid value (mg number of KOH required to neutralize 1 g of resin) of the non-crystalline polyester resin ensures that the molecular weight distribution as described above can be easily obtained and that the toner particles are granulated by the emulsion dispersion method. 1 mg KOH / g or more and 30 mg KOH / g or less because it is easy to maintain and the environmental stability (chargeability stability when temperature / humidity changes) of the obtained toner is good. Is preferred.
The acid value of the non-crystalline polyester resin is adjusted by controlling the carboxyl group at the terminal of the polyester by the blending ratio and reaction rate of the raw material polycarboxylic acid and polyhydric alcohol. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

  A styrene acrylic resin may be used as a known non-crystalline resin. Examples of the monomer include styrenes such as styrene, parachlorostyrene, and α-methylstyrene: methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, and acrylic acid. Esters having a vinyl group such as 2-ethylhexyl, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate: Vinyl nitriles such as acrylonitrile and methacrylonitrile: Vinyl methyl ether Vinyl ethers such as vinyl isobutyl ether: vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc .: polyolefins such as ethylene, propylene, butadiene, etc. A copolymer obtained by combining two or more of these, or a mixture thereof, and further, an epoxy resin, a polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, a polyether resin, a non-vinyl condensation resin, or these It is also possible to use a mixture of a vinyl resin and a graft polymer obtained when a vinyl monomer is polymerized in the presence of these.

The glass transition temperature of the amorphous resin used in this embodiment is preferably 35 ° C. or more and 100 ° C. or less, and is 50 ° C. or more and 80 ° C. or less from the viewpoint of the balance between storage stability and toner fixing property. More preferably.
When the glass transition temperature of the amorphous resin is within the above range, toner blocking during storage or in the developing device (a phenomenon in which toner particles aggregate and become agglomerates) is prevented, and the fixing temperature of the toner is kept low. It is done.

The softening point of the amorphous resin is preferably in the range of 80 ° C. or higher and 130 ° C. or lower. More preferably, it is the range of 90 degreeC or more and 120 degrees C or less.
When the softening point of the amorphous resin is within the above range, the toner and toner image stability after fixing and storage are excellent, and the low-temperature fixing property is also excellent.
The softening point of the amorphous resin is as follows: flow tester (manufactured by Shimadzu Corporation: CFT-500C), preheating: 80 ° C./300 sec, plunger pressure: 0.980665 MPa, die size: 1 mmΦ × 1 mm, heating rate: 3.0 It refers to an intermediate temperature between the melting start temperature and the melting end temperature under the condition of ° C / min.

  In the present exemplary embodiment, a preferable toner base particle form is present in the core part constituting the central part of the toner particle and the periphery thereof from the viewpoint that charging property and storage property are improved by including a release agent. And a shell portion.

When the toner base particles according to this embodiment use a crystalline resin and an amorphous resin as a binder resin, each resin may exist in any form in the toner. From the viewpoint of making the crystalline resin on the toner surface uniform and improving the chargeability and storage stability, toner mother particles containing a crystalline resin in the core are preferred.
Furthermore, it is preferable that the core portion contains a crystalline resin and an amorphous resin from the viewpoint of improving the storage stability when the crystalline resin and the amorphous resin are compatible.

  The content ratio of the crystalline resin and the amorphous resin in the core part is preferably a mass ratio of crystalline resin: noncrystalline resin = 2: 98 or more and 16:84 or less, but 5:95 or more and 14:86. More preferably, it is more preferably 7:93 or more and 13:87 or less.

In the shell portion, it is preferable to use an amorphous resin as a binder resin from the viewpoint of preventing the release agent component and the crystalline resin component from being exposed from the core portion, and improving the chargeability and storage stability.
The content ratio of the crystalline resin and the amorphous resin in the shell part is preferably a mass ratio of crystalline resin: noncrystalline resin = 0: 100 to 2:98, and 0: 100 to 1:99. More preferably, it is 0: 100 or more and 0.5: 99.5 or less.

(Release agent)
As the release agent used for the toner base particles according to the exemplary embodiment, it is preferable to use a substance having a main maximum peak measured in accordance with ASTM D3418-8 in the range of 50 ° C. or more and 140 ° C. When the main maximum peak is within the above range, the occurrence of offset during fixing is suppressed, the image surface is smooth, and the gloss is excellent.

  For example, DSC-7 manufactured by Perkin Elmer is used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.

  Further, the viscosity η1 at 160 ° C. of the release agent is preferably in the range of 20 mPa · s to 200 mPa · s. When the viscosity η1 is within the above range, the occurrence of hot offset during high-temperature fixing and excessive exudation of wax in the fixed image (hereinafter sometimes referred to as wax offset) can be suppressed.

  Further, the ratio (η2 / η1) of the viscosity η1 at 160 ° C. and the viscosity η2 at 200 ° C. of the release agent is preferably in the range of 0.5 to 0.7. When η2 / η1 is within the above range, the occurrence of hot offset and wax offset is suppressed, and the peeling stability is excellent.

  Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones having a softening point by heating, fatty acids such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide. Amides, carnauba wax, rice wax, candelilla wax, plant waxes such as tree wax, jojoba oil, animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Minerals, petroleum-based waxes, and modified products thereof may be used.

  These release agents are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and heated with a homogenizer or pressure discharge type disperser that can be heated to the melting point or higher and subjected to strong shearing. A release agent dispersion liquid containing particles of release agent having a particle diameter of 1 μm or less is prepared.

The release agent is preferably used in the range of 0.5% by mass or more and 15% by mass or less, more preferably in the range of 1% by mass or more and 12% by mass or less, among the components constituting the toner base particles. .
When the content of the release agent is in the above range, the occurrence of offset in fixing is suppressed, the image surface is smooth, and the gloss is excellent.

(Coloring material)
The color material used for the toner base particles according to the exemplary embodiment is not particularly limited and may be a known color material, which is appropriately selected according to the purpose.

  When a pigment is used as the coloring material of the toner of the present embodiment, one kind may be used alone, or two or more kinds of pigments of the same system may be mixed and used. Two or more different types of pigments may be mixed and used.

Examples of black pigments include carbon black and magnetic powder.
Examples of yellow pigments include Hansa Yellow, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Slen Yellow, Quinoline Yellow, and Permanent Yellow NCG.
Red pigments include Bengala, Watch Young Red, Permanent Red 4R, Resol Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Eoxin Red, Alizarin Lake Etc.
Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate and so on. Moreover, these are mixed and used in the state of a solid solution.

  These pigments are dispersed by a known method. For example, a rotary-type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, or a high-pressure counter-collision type dispersing machine is preferably used. These pigments are dispersed in an aqueous solvent using a homogenizer as described above using a polar ionic surfactant to produce a colorant particle dispersion.

  Further, a dye may be used as the color material of the toner of the present embodiment. For example, acridine, xanthene, azo, benzoquinone, azine, anthraquinone, dioxazine, thiazine, azomethine, indigo, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane, Examples include various dyes such as diphenylmethane, thiazole, and xanthene. Moreover, a disperse dye, an oil-soluble dye, etc. are mentioned.

  One type of dye may be used alone, or two or more types of dyes of the same type may be mixed and used. Also, two or more different types of dyes may be mixed and used. Further, a dye and a pigment may be used in combination.

  The content of the coloring material is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin, but the range of the numerical value is within a range that does not impair the smoothness of the image surface after fixing. Of these, the larger number is preferable. Increasing the content of the colorant is advantageous in that the thickness of the image can be reduced when an image having the same density is obtained, which is effective in preventing offset.

(Method for producing toner mother particles)
Hereinafter, a method for producing toner mother particles will be described focusing on a method for producing toner mother particles having a core / shell structure.

  The toner base particles according to the exemplary embodiment are preferably manufactured by a wet manufacturing method in which the toner base particles are manufactured in an acidic or alkaline aqueous medium. Examples of the wet production method include an agglomeration / unification method, a suspension polymerization method, a dissolution suspension granulation method, a dissolution suspension method, a dissolution emulsion aggregation aggregation method, and the like.

  When the toner production method of the present exemplary embodiment is produced by the aggregation and coalescence method, the method preferably includes at least the following first aggregation step, the following second aggregation step, and the following fusion and coalescence step.

-First aggregation step-
A resin particle dispersion in which first resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are mixed, and the first resin is mixed. Core agglomerated particles including particles, the colorant particles, and the release agent particles are formed.

-Second aggregation step-
A shell layer containing second resin particles is formed on the surface of the core aggregated particles to obtain core / shell aggregated particles.

-Fusion / unification process-
In the second agglomeration step, the core / shell agglomerated particles are heated to the glass transition temperature of the first resin particles or the second resin particles to be fused and united.

In the first aggregation step, first, a resin particle dispersion, a colorant particle dispersion, and a release agent particle dispersion are prepared.
The resin particle dispersion is prepared by dispersing the first resin particles prepared by emulsion polymerization or the like in a solvent using an ionic surfactant.
The colorant particle dispersion is obtained by using the ionic surfactant opposite to the ionic surfactant used in the preparation of the resin particle dispersion to obtain the colorant particles of a desired color such as black, blue, red, yellow, etc. It adjusts by making it disperse | distribute in a solvent.
The release agent particle dispersion also disperses the release agent in water together with a polymer electrolyte such as an ionic surfactant, polymer acid or polymer base, and heats above the melting point and imparts strong shear. The particles are adjusted by a homogenizer or a pressure discharge type disperser.

  Next, the resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed to hetero-aggregate the first resin particles, the colorant particles, and the release agent particles to obtain a desired toner diameter. Aggregated particles (core aggregated particles) including first resin particles, colorant particles, and release agent particles having substantially the same diameter are formed.

  In the second aggregating step, the second resin particles are adhered to the surface of the core agglomerated particles obtained in the first aggregating step by using a resin particle dispersion containing the second resin particles, and the desired thickness is obtained. By forming the coating layer (shell layer), aggregated particles (core / shell aggregated particles) having a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles are obtained. In addition, the 2nd resin particle used in this case may be the same as the 1st resin particle, and may differ.

  The particle diameters of the first resin particles, the second resin particles, the colorant particles, and the release agent particles used in the first and second aggregating steps are adjusted to a desired value for the toner diameter and the particle size distribution. In order to facilitate this, it is preferably 1 μm or less, and more preferably in the range of 100 nm to 300 nm.

  The particle size of the resin particle dispersion thus obtained is measured by, for example, a laser diffraction particle size distribution measuring device (LA-700, manufactured by Horiba, Ltd.).

  In the first aggregation step, it is also preferable to shift in advance the balance of the amounts of the two polar ionic surfactants (dispersing agents) contained in the resin particle dispersion and the colorant particle dispersion. For example, an inorganic metal salt such as calcium nitrate or a polymer of an inorganic metal salt such as barium sulfate is ionically neutralized and heated below the glass transition temperature of the first resin particles to form core agglomerated particles. Is produced.

  In this case, in the second agglomeration step, the resin particle dispersion treated with the polarity and amount of dispersant that compensates for the deviation in the balance between the two polar dispersants described above is placed in a solution containing core agglomerated particles. Further, if necessary, the core / shell aggregated particles are produced by heating slightly below the glass transition temperature of the core aggregated particles or the second resin particles used in the second aggregation step as necessary. In addition, the 1st and 2nd aggregation process may be repeatedly performed in multiple steps stepwise.

Next, in the fusion / union process, the core / shell aggregated particles obtained through the second aggregation process are used as a first or second resin particle contained in the core / shell aggregated particles in a solution. The toner is obtained by heating to above the glass transition temperature (if the resin type is two or more, the glass transition temperature of the resin having the highest glass point transition temperature), fusing and coalescence.
After completion of the fusion / unification process, the toner formed in the solution is dried through a known washing process, solid-liquid separation process, and drying process to obtain a toner.

  In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

(Physical properties of toner base particles)
The toner mother particles preferably have a volume average particle size of 3 μm to 9 μm, preferably 3.5 μm to 8.5 μm, and more preferably 4 μm to 8 μm.
As a measuring method of the volume average particle diameter of the toner base particles, for example, a Coulter Multisizer-II type is used. Specific measurement methods will be described in Examples.

Further, the shape factor of the toner base particles is preferably 115 or more and 140 or less, preferably 118 or more and 138 or less, and more preferably 120 or more and 136 or less.
Here, the shape factor SF1 is obtained by the following equation (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer. Specific measurement methods will be described in Examples.

<External additive>
The toner of this embodiment includes at least metatitanic acid particles and silicone oil-treated silica as external additives for the toner base particles. This silicone oil-treated silica has a free silicone oil content of 0.01% by mass or more and 1% by mass or less. The toner of this embodiment may further contain other external additives.

(Metatitanic acid particles)
Metatitanic acid means a titanic acid hydrate TiO ₂ · nH ₂ O with n = 1.
The metatitanic acid particles are usually purified by a wet method in which a chemical reaction is performed in a solvent. The wet method is divided into a sulfuric acid method and a hydrochloric acid method. In the sulfuric acid method, the following reaction proceeds in the liquid phase, and TiO (OH) ₂ is obtained by hydrolysis.

FeTiO ₃ + 2H ₂ SO ₄ → FeSO ₄ + TiOSO ₄ + 2H ₂ O
TiOSO ₄ + 2H ₂ O → TiO (OH) ₂ + H ₂ SO ₄

In the hydrochloric acid wet method, first, chlorination is performed by the same method as the dry method to produce titanium tetrachloride, then dissolved in water, and then hydrolyzed while adding a strong base to TiO (OH) _2. Is obtained. This is represented by the chemical reaction formula as follows.

TiCl ₄ + H ₂ O → TiOCl ₂ + 2HCl
TiOCl ₂ + 2H ₂ O → TiO (OH) ₂ + 2HCl

  Generally, the shape of metatitanic acid particles is flat or plate-like. When the shape of the metatitanic acid particle is approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped are short side a, middle side b, and long side c in order from the shortest side, the short side a (flat or plate-like thickness) is: It is preferably 1 nm or more and 40 nm or less, and more preferably 3 nm or more and 30 nm or less. The middle side b is preferably 2 nm or more and 45 nm or less, and more preferably 4 nm or more and 40 nm or less. The long side c is preferably 5 nm or more and 50 nm or less, and more preferably 7 nm or more and 40 nm or less.

  The short side a, the middle side b, and the long side c are measured from a scanning electron micrograph of 100 metatitanic acid particles, and an average value thereof is calculated.

The average particle size of the metatitanic acid particles is preferably 5 nm to 40 nm, more preferably 8 nm to 35 nm, and still more preferably 10 nm to 30 nm.
The average particle diameter of the metatitanic acid particles is determined by the following formula from the average values of the short side a, the middle side b, and the long side c. Specific measurement methods will be described in Examples.
Average particle diameter of flat or plate-like metatitanic acid particles = (average value of middle side b + average value of long side c) / 2

The metatitanic acid particles preferably have an electric resistance of 10 ¹⁰ Ω · cm or more from the viewpoint of obtaining high transferability without generating reverse polarity toner even when the transfer electric field is increased. More preferably, it is 10 ¹⁰ Ω · cm or more and 10 ¹⁵ Ω · cm or less, and further preferably 10 ¹¹ Ω · cm or more and 10 ¹⁴ Ω · cm or less.

The coverage of the toner base particles with the metatitanic acid particles is preferably 30% or more and 100% or less, more preferably 40% or more and 100% or less, and further preferably 50% or more and 90% or less. Yes.
When the coverage of the toner base particles with the metatitanic acid particles is within the above range, mixing of the free silicone oil with the crystalline resin or the release agent is effectively suppressed.

  Here, the coverage of the toner base particles with the metatitanic acid particles is obtained by image analysis of a photograph of the toner. Specifically, for example, a cross-sectional photograph of one toner particle is taken with a high-resolution electron microscope JEM-2010 (JEOL Ltd.), the surface of the toner particle cross-section is observed, and the surface coating state on the entire particle surface is evaluated. Details will be described in Examples.

The amount of the metatitanic acid particles added to the toner base particles varies depending on the particle size of the toner base particles, the composition of the developer holder, etc., but is 0.1 mass per 100 parts by mass of the toner base particles. Part or more and 5.0 parts by mass or less are preferable, and 0.2 part by mass or more and 2.0 parts by mass or less are more preferable.
When the addition amount of the metatitanic acid particles is within the above range, the toner has sufficient fluidity, has excellent low-temperature fixability, suppresses a decrease in light transmission, and has a color developability of the superimposed base color. Hard to interfere.

The metatitanic acid particles according to this embodiment may be subjected to a surface treatment with a surface treatment agent.
Examples of the surface treatment method for metatitanic acid particles include a method in which a surface treatment agent such as a silane compound is reacted with TiO (OH) ₂ produced in the wet process, followed by filtration, washing, drying, and pulverization. In this method, there is no high-temperature firing step of several hundred degrees, strong bonding between titanium does not occur, and aggregation is unlikely to occur, and the particles are taken out in a primary particle state. The surface treatment agent TiO _{(OH) 2} is to react directly, TiO a large amount of surface treatment agent is applied _{(OH) 2} is realized.

  The surface treatment agent for metatitanic acid particles is preferably one that does not thermally decompose at the reaction treatment temperature, such as a silane compound, such as an alkylalkoxysilane compound, a fluorine-containing silane compound, chlorosilane, silazane, and a special silylating agent. Can be mentioned.

The surface treatment amount of the metatitanic acid particles with the surface treatment agent is 30% by mass or more, more preferably 40% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 70% by mass with respect to 100% by mass of the original titanium compound. % Or less is particularly preferable.
When the processing amount is within the above range, the surface treatment agent is sufficiently applied to the surface, and good transferability is realized over a long period of time.

(Silicone oil-treated silica)
In the silicone oil-treated silica used as an external additive, the silica particles serving as the core are not particularly limited, and silica particles produced by a known method or commercially available silica particles can be applied.

  As the silica particles, monodispersed spherical silica or monodispersed spherical organic particles are preferably used. In the present embodiment, monodispersed spherical silica is more preferably used from the viewpoint that it is monodispersed and spherical, so that it is uniformly dispersed on the surface of the toner particles and a stable spacer effect can be obtained.

  Monodispersed spherical silica can be obtained by a sol-gel method that is a wet method. The particle size of the monodispersed spherical silica can be freely controlled by the weight ratio of alkoxysilane, ammonia, alcohol, water, reaction temperature, stirring rate, and supply rate in the sol-gel method hydrolysis and condensation polymerization step. Monodisperse and spherical shapes can also be achieved by making this method.

A known silicone oil is applied to the silicone oil for surface-treating the silica particles.
Silicone oils include dimethyl silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, carboxyl-modified silicone oil, epoxy-modified silicone oil, fluorine-modified silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, methylphenyl silicone oil, Methyl hydrogen silicone oil, mercapto modified silicone oil, higher fatty acid modified silicone oil, phenol modified silicone oil, methacrylic acid modified silicone oil, polyether modified silicone oil, methyl styryl modified silicone oil and the like can be used.
The silicone oil used for the surface treatment may be used alone or in combination of two or more.

  In the present embodiment, silicone oil-treated silica having a free silicone oil amount of 0.01% by mass or more and 1% by mass or less is used as an external additive. The amount of free silicone oil is preferably 0.1% by mass or more and 1% by mass or less, more preferably 0.15% by mass or more and 0.9% by mass or less, and 0.2% by mass or more. More preferably, it is 0.8 mass% or less.

The method for determining the amount of free oil of the external additive from the toner will be described below, but it can of course be determined from the external additive alone.
2 g of toner is added to 40 ml of an aqueous solution of 0.2% by mass of a surfactant (polyoxyethylene (10) octylphenyl ether having a polyoxyethylene polymerization degree of 10 manufactured by Wako Pure Chemical Industries, Ltd.) so that the toner is dispersed. Disperse thoroughly. In this state, an ultrasonic homogenizer US300T (manufactured by Nippon Seiki Seisakusho) is used, and ultrasonic vibration with an output of 20 W and a frequency of 20 kHz is applied for 1 minute to desorb external additive particles.
Thereafter, the toner is separated under a condition of 3000 rpm × 7 minutes through a 50 ml centrifuge with a sedimentation tube (compact cooling high-speed centrifuge Model M160 IV, manufactured by Sakuma Seisakusho Co., Ltd.). After removal with FHLP02500), and further removal with a membrane filter having a pore size of 0.22 μm (GSEP047S0) and a pore size of 0.025 μm (VSWP02500), the furnace liquid is dried. If the sample amount necessary for measurement cannot be collected, the same operation is repeated until the sample amount necessary for measurement can be collected. NMR measurement is performed using 10 mg of the dried residue.

Proton NMR is measured using AL-400 (magnetic field 9.4T (H nucleus 400 MHz)) manufactured by JEOL. A sample, a deuterated chloroform solvent, and TMS as a reference substance are filled into a sample tube (diameter 5 mm) made of zirconia. Set this sample tube, for example, frequency: Δ87 kHz / 400 MHz (= Δ20 ppm), measurement temperature: 25 ° C., number of integration: 16 times, resolution 0.24 Hz (about 32000 points) The amount of free surface treatment agent is converted using the calibration curve from the peak intensity.
For example, when dimethyl silicone oil is used as the free surface treatment agent, NMR measurement is performed on the untreated external additive base material and dimethyl silicone oil (shake about 5 levels), and the amount of free surface treatment agent And a calibration curve of NMR peak intensity.

Silicone oil-treated silica having an amount of free silicone oil in the above range is produced as follows.
In the treatment of the silicone oil, the particles are suspended in a dry method such as a spray drying method in which silicone oil or a solution containing silicone oil is sprayed on particles suspended in the gas phase, or in a solution containing a treatment agent. Processing is performed by a wet method of dipping and drying. After the surface treatment, it is produced by removing the excessively treated silicone oil by immersing it again in a solvent such as ethanol and drying the solvent.

  In addition, what is necessary is just to repeatedly perform the process of drying after being immersed in the said solvent, in order to reduce the amount of free silicone oil more.

The amount of silicone oil treated in the treated silica is preferably 5% by mass or more and 30% by mass or less, preferably 5% by mass or more and 20% by mass or less with respect to the mass of the silica particles serving as the core, from the viewpoint of long-term chargeability stabilization. % Or less, more preferably 5% by mass or more and 15% by mass or less.
The above-mentioned treatment amount refers to the amount of silicone oil used for the external additive core during the surface treatment, not the amount of silicone oil actually treated on the external additive particles.

The average particle diameter of the silicone oil-treated silica is preferably 20 nm to 250 nm, more preferably 30 nm to 200 nm, and still more preferably 40 nm to 150 nm.
When the average particle diameter of the silica is within the above range, it is preferable from the viewpoint of obtaining the fluidity and good transferability of the toner.
The average particle size of the silicone oil-treated silica is measured from a scanning electron micrograph, and the average value is calculated.

In the toner according to the exemplary embodiment, the addition mass ratio of the silicone oil-treated silica and the metatitanic acid particles (metatitanic acid particles / silicone oil-treated silica) is preferably 0.5 or more and 5 or less, and 0.8 or more and 4 More preferably, it is more preferably 1 or more and 3 or less.
When the additive mass ratio is within the above range, improvement in hot offset resistance and good chargeability over a long period of time are realized.

<Other additives>
Various additives may be added to the toner of the exemplary embodiment as necessary. Examples of the additive include other fluidizing agents, cleaning aids such as polystyrene particles, polymethyl methacrylate particles, and polyvinylidene fluoride particles, or transfer aids.

<Toner>
The electrostatic charge developing toner is produced by adding at least the metatitanic acid particles and the silicone oil-treated silica to the toner base particles and stirring them with a Henschel mixer or the like.

In the exemplary embodiment, the volume average particle diameter of the entire toner including the external additive is preferably in the range of 3 μm to 9 μm, and more preferably in the range of 4 μm to 8 μm. When the volume average particle size is in the above range, the chargeability, developability, and image resolution are excellent.
The method for measuring the volume average particle diameter of the toner is the same as the method for measuring the volume average particle diameter of the toner base particles.

  As a toner particle size distribution index, the volume average particle size distribution index GSDv is preferably 1.3 or less, more preferably 1.28 or less, and even more preferably 1.26 or less. When the volume distribution index GSDv is within the above range, the resolution of the image is excellent.

The ratio GSDv / GSDp between the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is preferably 0.9 or more, more preferably 0.95 or more, and 1.0 or more. More preferably.
When GSDv / GSDp is within the above range, the chargeability is excellent and the occurrence of image defects such as fog is suppressed.

The GSDv and GSDp are obtained by the following method.
The particle size distribution is obtained by a method similar to the method for measuring the volume average particle size of the toner base particles described above. For the particle size range (channel) obtained by dividing the measured particle size distribution, a cumulative distribution is drawn from the small diameter side to each of the volume and the number, and the particle size at which accumulation is 16% is defined as D16v and D16p. % Are defined as D50v and D50p, respectively. Further, D84v and D84p are defined similarly.
Using these, the volume average particle size distribution index (GSDv) is, (D84v / ^D16v) obtained from ^0.5, the number average particle distribution index (GSDp) is calculated from (D84p / ^{D16p) 0.5.}

Further, the shape factor of the entire toner is preferably 115 or more and 140 or less, preferably 118 or more and 135 or less, and more preferably 120 or more and 130 or less.
The shape factor of the toner is obtained by the same method as the method for obtaining the shape factor of the toner base particles described above.

<< Developer for electrostatic image development >>
Next, the developer for developing an electrostatic charge image will be described.
The developer for developing an electrostatic charge image including the toner for developing electrostatic charge of the present embodiment may be a one-component developer composed only of toner or a two-component developer composed of toner and carrier. From the viewpoint of charge maintenance and stability, a two-component developer is preferable.
The carrier is preferably a carrier coated with a resin. Below, a carrier is demonstrated.

<Carrier core>
The carrier core material preferably has an electric resistance of 1 × 10 ^7.5 Ω · cm to 1 × 10 ^9.5 Ω · cm. If this electrical resistance is within the above range, even when the toner concentration in the developer is reduced by repeated copying, the injection of charges into the carrier is suppressed, and the phenomenon of development by the carrier itself is suppressed.

  The material of the carrier core material is not particularly limited as long as the above conditions are satisfied. For example, magnetic metals such as iron, steel, nickel and cobalt, alloys of these with manganese, chromium and rare earths, and ferrite and magnetite And the like. Among these, ferrite, particularly an alloy with manganese, lithium, strontium, magnesium or the like is preferable from the viewpoint of core surface properties and core material resistance.

<Carrier-coated resin material>
The carrier coating resin is selected according to the charging polarity applied to the toner. For example, carrier coating resins include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate Α-methylene fatty acid monocarboxylic acids such as n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; vinylnitriles such as acrylonitrile and methacrylonitrile; Vinyl pyridines such as vinyl pyridine and 4-vinyl pyridine; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl kets such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone Homopolymers such as olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; or copolymers composed of two or more monomers; Examples include silicone resins including methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like. However, it is not limited to these.
These may be used individually by 1 type and may use 2 or more types together.

In the carrier, it is preferable that at least conductive particles are dispersed in the coating film coated with the coating resin. When conductive particles are dispersed in the coating film, the conductive film is uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even so, carrier deterioration is prevented for a long time.
Here, the conductivity means, for example, a volume resistivity of less than 10 ⁷ Ω · cm. The same applies hereinafter unless otherwise specified.

As conductive particles, metal particles such as gold, silver and copper, carbon black particles, semiconductive oxide particles such as titanium oxide and zinc oxide, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate Examples thereof include particles whose surface such as powder is covered with tin oxide, carbon black, metal or the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, carbon black particles are preferable from the viewpoints of production stability, cost, conductivity, and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of about 50 ml / 100 g or more and 250 ml / 100 g or less is preferable because of excellent production stability.

<Carrier manufacturing method>
In the carrier, specifically, as a method of coating the surface of the core material (carrier core material) with the coating resin, a dipping method of immersing in a coating film forming liquid containing the coating resin, a coating film forming liquid is used as the carrier Examples thereof include a spraying method in which the surface of the core material is sprayed and a kneader coater method in which the carrier core material is mixed with a coating film forming liquid in a state where the carrier core material is suspended by flowing air, and the solvent is removed. Among these, the kneader coater method is preferable in the present embodiment.
The solvent used in the coating film forming solution is not particularly limited as long as it can dissolve only the coating resin, and can be selected from known solvents such as toluene, Aromatic hydrocarbons such as xylene, ketones such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran and dioxane.

  Examples of the present embodiment will be described below, but the present embodiment is not limited to these examples. In the following description, “part” means “part by mass” unless otherwise specified.

<Measuring method of various characteristics>
(Toner particle size and particle size distribution measurement method)
When toner particles or particles in the dispersion are 2 μm or more, Coulter Multisizer-II type (manufactured by Beckman-Coulter) is used as the measuring device, and ISOTON-II (manufactured by Beckman-Coulter) is used as the electrolyte .
0.5 to 50 mg of a measurement sample is added to 2 ml of an aqueous solution containing 5% by mass of sodium alkylbenzenesulfonate as a dispersant. This was added to 100 to 150 ml of the electrolytic solution.
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 2 to 60 μm is measured using the Coulter counter TA-II with an aperture diameter of 100 μm. Volume average distribution and number average distribution were determined. The number of particles to be measured was 50,000.

The particle size distribution was determined by the following method.
For the particle size range (channel) obtained by dividing the measured particle size distribution, a cumulative distribution is drawn from the small diameter side to each of the volume and the number, and the particle size at which accumulation is 16% is defined as D16v and D16p. % Are defined as D50v and D50p, respectively. Further, D84v and D84p are defined similarly. Let D50v be the volume average particle size.
Using these, volume average particle size distribution index (GSDv) is, (D84v / ^D16v) determined than ^0.5, the number average particle distribution index (GSDp) was calculated from (D84p / ^{D16p) 0.5.}

Further, when the toner particles or the particles in the dispersion were less than 2 μm, the measurement was performed using a laser diffraction type particle size distribution analyzer (LA-700: manufactured by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This was added to the cell until the appropriate concentration was reached, waited for about 2 minutes, and measured when the concentration in the cell became almost stable.
The method for obtaining the particle size distribution and the volume average particle size is the same as in the case of the particles having a particle size of 2 μm or more.

(Measuring method of average particle diameter of silica)
The diameter of 100 externally added silicas was measured from a scanning electron micrograph, and the average value was calculated.

(Measuring method of average particle diameter of metatitanic acid particles)
The average particle diameter of the metatitanic acid particles was determined by measuring 100 metatitanic acid particles using a scanning electron micrograph and calculating the average value.
The shape of the surface-treated metatitanic acid particles was approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped were set as the short side a, the middle side b, and the long side c in order from the shortest side, and the average value was obtained by the following formula.
Average particle diameter of flat or plate-like metatitanic acid particles = (average value of middle side b + average value of long side c) / 2

(Method of measuring surface coverage with metatitanic acid particles)
The surface coverage with metatitanic acid particles was determined by the following method.
(1) A measurement sample is prepared by dispersing toner in a two-component mixed epoxy resin and allowing it to stand for one day to solidify.
(2) A section having a thickness of 100 nm is cut out from the measurement sample with a microtome.
(3) The slice is placed on a copper mesh, set in a high resolution electron microscope JEM-2010 (JEOL Ltd.), and photographed at 500,000 times with an applied voltage of 200 kV.
(4) The negative is stretched from 3 times to 10 times and printed.
(5) The cross section of the toner is observed by printing according to the procedures of (1) to (4), and the surface covering state on the entire surface of the toner is evaluated. The coverage is obtained from the following formula.
Coverage ratio = (length of the portion where the metatitanic acid particles adhere to the toner surface / toner outer peripheral length) × 100 (%)
In the present invention, the average coverage of 10 toners is defined as the surface coverage. The volume average particle diameter of the toner was measured using a Coulter Multisizer manufactured by Beckman Coulter.

(Measurement method of weight average molecular weight)
The weight average molecular weight was measured under the following conditions.
GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. As experimental conditions, the sample concentration was 0.5%, and the flow rate was 0.6 ml / min. The experiment was conducted using a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

(Shape factor)
The toner shape factor SF1 is obtained by taking the optical microscope image of the toner dispersed on the surface of the slide glass into a Luzex image analyzer through a video camera, obtaining the maximum length and projected area of 500 or more toner particles, and using the following formula (1) And the average value was obtained.
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

(Measurement of acid value)
Weigh accurately 1 to 20 g of sample (resin), add 100 ml of the ethyl ether-ethyl alcohol mixture or benzene-ethyl alcohol mixture, and a few drops of phenolphthalein solution as an indicator, and make sure that the sample is completely dissolved. Shake.
After the sample is dissolved, titrate with the alcoholic potassium hydroxide solution, and when the indicator is light red for 30 seconds, the end point of neutralization is obtained. From the amount used at that time, the acid value (AV) is obtained by the following formula. It was.
AV = (B × 5.61) ÷ M
Here, AV represents the acid value (mg KOH / g), B represents the amount of use of 0.1 mol / liter potassium hydroxide ethyl alcohol solution (ml), and M represents the mass (g) of the sample.

<Preparation of toner base particles>
-Preparation of crystalline polyester resin dispersion-
A heat-dried three-necked flask was charged with 98 mol% dimethyl sebacate, 2 mol% dimethyl-5-sulfonate sodium, 100 mol% ethylene glycol, and 0.3 parts by mass of dibutyltin oxide as a catalyst. The air in the container was brought into an inert atmosphere with nitrogen gas, and the mixture was stirred and refluxed at 180 ° C. for 5 hours with mechanical stirring.

Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled, the reaction was stopped, and a crystalline polyester resin was synthesized.
The weight average molecular weight (Mw) of the obtained crystalline polyester resin was 9700 by molecular weight measurement (polystyrene conversion) by gel permeation chromatography.

  Next, using a crystalline polyester resin, a resin particle dispersion was prepared with the following composition.

Crystalline polyester resin 90 parts by weight Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku) 1.8 parts by weight Ion-exchanged water 210 parts by weight

  The above mixture is heated to 100 ° C. and sufficiently dispersed with IKA Ultra Tarrax T50, followed by dispersion treatment with a pressure discharge type gorin homogenizer for 1 hour, a crystalline resin having a center diameter of 200 nm and a solid content of 20% by mass. A particle dispersion was obtained.

-Preparation of non-crystalline polyester dispersion-
Terephthalic acid: 30 mol%
Fumaric acid: 70 mol%
Bisphenol A ethylene oxide 2 mol adduct 20 mol%
Bisphenol A propylene oxide adduct 80mol%

The above monomer is charged into a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying column, and heated to 190 ° C. over 1 hour, and the reaction system is uniformly stirred. After confirming this, 1.2 parts by mass of dibutyltin oxide was added.
Further, while distilling off the water produced, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 3 hours. The acid value was 12.0 mg / KOH, weight average molecular weight A melt of 9700 amorphous polyester resin was obtained.

Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min.
Separately prepared aqueous medium tank is filled with 0.37% by weight diluted ammonia water diluted with ion-exchanged water with reagent-exchanged water, and heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Then, it was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) together with the melted amorphous polyester resin.

A Cavitron is operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to obtain an amorphous resin dispersion composed of an amorphous polyester resin having an average particle size of 0.16 μm and a solid content of 30% by mass. It was.

-Preparation of colorant dispersion-
Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika) 45 parts by weight Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku) 5 parts by weight Ion-exchanged water 200 parts by weight

  The above were mixed and dissolved, and dispersed with a homogenizer (IKA Ultra Tarrax) for 10 minutes to obtain a colorant dispersion having a central particle size of 168 nm and a solid content of 22.0% by mass.

-Preparation of release agent dispersion-
Paraffin wax HNP9 (melting point 75 ° C .: manufactured by Nippon Seiki) 45 parts by weight Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku) 5 parts by weight ion-exchanged water 200 parts by weight

  The above compounded solution is heated to 95 ° C., sufficiently dispersed with IKA Ultra Tarrax T50, and then dispersed with a pressure discharge type gorin homogenizer to disperse the release agent having a center diameter of 200 nm and a solid content of 20.0% by mass. A liquid was obtained.

-Production of toner particles 1-
Amorphous resin resin dispersion 256.7 parts by weight Crystalline resin dispersion 33.3 parts by weight Colorant dispersion 27.3 parts by weight Release agent dispersion 35 parts by weight

  The above was thoroughly mixed and dispersed with Ultra Turrax T50 in a round stainless steel flask. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 48 ° C. with stirring in an oil bath for heating. After maintaining at 48 ° C. for 60 minutes, 70.0 parts by mass of the amorphous resin dispersion was gradually added thereto.

  Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 96 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.

  After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  When the particle diameter at this time was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of toner particles 2-
Toner particles 2 were produced in the same manner as toner particles 1 except that the crystalline resin component of toner particles 1 was replaced with an amorphous resin.

  When the particle diameter at this time was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.24. Moreover, it was observed that the shape factor of the particle | grains calculated | required by the shape observation by Luzex was 132.

<External additive>
-Titanium A-
As titanium A, metatitanic acid having an average particle diameter of 20 nm (STT100H, manufactured by Titanium Industry Co., Ltd.) was used.

-Titanium B-
As titanium B, titanium oxide having an average particle diameter of 20 nm (manufactured by Teika Co., Ltd., MT-3103) was used.

-Silica A-
Silica having a surface treatment amount of 5% by mass and an average particle size of 80 nm was prepared by a sol-gel method. The process of immersing the silica in ethanol and drying the ethanol was repeated three times to produce silica A treated with silicone oil.
The amount of free silicone oil of silica A obtained was 0.2% by mass.

-Silica B-
In the production of silica A, silica B treated with silicone oil was produced in the same manner except that the step of immersing in ethanol and drying ethanol was performed once.
The amount of free silicone oil in silica B obtained was 0.8% by mass.

-Silica C-
Silica oil-treated silica C was produced in the same manner as in the production of silica A, except that the silicone oil was replaced with fluorine-modified silicone oil (FL100, manufactured by Shin-Etsu Chemical Co., Ltd.).
The amount of free silicone oil of silica C obtained was 0.3% by mass.

-Silica D-
In the production of silica A, silica D treated with silicone oil was produced in the same manner except that the steps of immersing in ethanol and drying ethanol were not performed.
The amount of free silicone oil in the obtained silica D was 2.6% by mass.

<External toner>
-External toner A-
To 100 parts by mass of toner particles 1, 1.5 parts by mass of titanium A and 2.0 parts by mass of silica A were added and stirred for 10 minutes at 2500 rpm in Henschel mixer to prepare externally added toner A.
The coverage of toner particles 1 with titanium A was measured and found to be 55%.

-External toner B-
Externally added toner B was prepared in the same manner as externally added toner A, except that titanium A was changed to titanium B.
The coverage of the toner particles 1 with titanium B was 50%.

-External toner C-
Externally added toner C was prepared in the same manner as externally added toner A except that silica A was changed to silica B.

-External toner D-
Externally added toner D was prepared in the same manner as externally added toner A, except that silica A was changed to silica C.

-External toner E-
Externally added toner E was prepared in the same manner as externally added toner A, except that silica A was changed to silica D.

-External toner F-
Externally added toner F was prepared in the same manner as externally added toner A, except that the amount of titanium A added was changed to 1.0 part by mass.
The coverage of the toner particles 1 with titanium A was 40%.

-External toner G-
Externally added toner G was prepared in the same manner as externally added toner A, except that the amount of titanium A added was changed to 2.0 parts by mass.
The coverage of the toner particles 1 with titanium A was 75%.

-External toner H-
An external toner H was prepared in the same manner as the external toner A except that the toner particles 1 were replaced with the toner particles 2.

-External toner I-
Externally added toner I was prepared in the same manner as externally added toner A except that toner particle 1 was replaced with toner particle 2 and silica A was replaced with silica B.

-External toner J-
Externally added toner J was prepared in the same manner as externally added toner A, except that toner particle 1 was replaced with toner particle 2 and silica A was replaced with silica C.

-External toner K-
Externally added toner K was prepared in the same manner as externally added toner A, except that toner particle 1 was replaced with toner particle 2 and silica A was replaced with silica D.

<Creation of carrier>
Ferrite particles (average particle size 50 μm, volume electric resistance 3 × 10 ⁸ Ω · cm) 100 parts by mass Toluene 14 parts by mass Perfluorooctylethyl acrylate / methyl methacrylate copolymer (copolymerization ratio 40:60, Mw = 50,000) 1.6 parts by mass Carbon black (VXC-72; manufactured by Cabot) 0.12 parts by mass Cross-linked melamine resin (number average particle size; 0.3 μm) 0.3 parts by mass

  Among the above components, the components except for the ferrite particles are dispersed with a stirrer for 10 minutes to prepare a film forming liquid, and the film forming liquid and the ferrite particles are put into a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes. After that, the pressure was reduced and toluene was distilled off, and a resin film was formed on the surface of the ferrite particles to produce a carrier.

<Developer preparation>
Developer A was prepared by stirring 4 parts of external additive toner A and 96 parts of carrier in a V-type blender for 5 minutes. Similarly, externally added toners B to K were also prepared and used as developers B to K, respectively.

<Evaluation>
-Low temperature fixing evaluation-
Using DocuCentreColor400CP (manufactured by Fuji Xerox Co., Ltd.), the toner amount was 15.0 g / m ² and an image of 4 × 4 cm was created using C2 paper. The image was fixed by a fixing machine modified so that the fixing temperature was fixed at 150 ° C., and 10 sheets were printed continuously. The results are shown in Tables 1 and 2 with ◯ when fixed and × when not fixed.

−Hot offset evaluation−
The toner amount was set to 15.0 g / m ² using DocuCentreColor400CP (Fuji Xerox Co., Ltd.), and a 4 × 4 cm image was created using C2 paper. This was fixed at a process speed of 600 mm / sec, and the image was fixed by a fixing machine modified so that the fixing temperature was fixed at 190 ° C. and 230 ° C., and 10 sheets were printed.

A: Hot not generated at fixing temperatures of 190 ° C. and 230 ° C. ○: Hot offset generated at fixing temperature of 230 ° C. or less, and no hot generated at fixing temperature of 190 ° C. x: Four or more sheets at fixing temperature of 230 ° C. or fixing Hot offset occurs at least one sheet at 190 ° C

-Evaluation of charging stability-
Evaluation was performed using DocuCentreColor400CP (Fuji Xerox Co., Ltd.). The toner amount is 6.0 g / m ² , C4 paper is used, three 4 × 4 cm images are created, and the actual machine evaluation is performed on 100,000 sheets. The initial charge amount of the developer and the charge amount after 100,000 sheets Compared.

From the results of Table 1, the developers of Examples 1 to 5 are superior to Comparative Examples 1 to 3 in terms of low-temperature fixability, suppression of hot offset, and stability of chargeability in long-term use. I understand.
In addition, as shown in Table 2, it can be seen that when the crystalline resin is not used as the binder resin, the hot offset property does not depend on the amount of free silicone oil.

Claims (3)

Toner base particles containing at least a crystalline resin, a coloring material, and a release agent;
As an external additive for the toner base particles, at least metatitanic acid particles and silicone oil-treated silica,
The electrostatic charge developing toner wherein the amount of free silicone oil in the silicone oil-treated silica is 0.01% by mass or more and 1% by mass or less.   2. The electrostatic charge developing toner according to claim 1, wherein the coverage of the toner base particles with the metatitanic acid particles is 30% or more and 100% or less.   An electrostatic charge image developing developer comprising: the electrostatic charge image developing toner according to claim 1; and a carrier.