JP6983545B2 - toner - Google Patents

Description

The present invention relates to toners used in electrophotographic and image forming methods for visualizing electrostatic charge images.

The electrophotographic image forming apparatus is required to be maintenance-free and the apparatus configuration to be simplified, and as a developing method capable of coping with these demands, there is a contact developing method using a non-magnetic one-component developer.
In the one-component contact developing method, stress is applied to the toner by rubbing between the toner regulating member and the developer carrier. For this reason, the silica particles added to the surface of the toner mother particles are likely to be embedded, and the chargeability of the toner is lowered, or the toner-derived components are fused to the toner regulating member to cause charging defects and image defects. do. Therefore, it is necessary to solve these problems in order to output a higher quality image for a long period of time by the one-component contact developing method. Further, with the recent spread of copying machines and printers using the electrophotographic method, further speeding up, long life, and high image quality are required in the one-component contact developing method.

As a problem associated with the increase in speed, when the toner supported on the developer carrier is conveyed, the toner is detached from the developer carrier and the toner adheres to the inside of the apparatus or the non-image area. be. In order to suppress this, it is necessary that the electrostatic adhesion force when the toner is supported on the carrier is superior to the centrifugal force applied to the toner by the rotation of the carrier. In other words, in order to cope with the high speed, one of the solutions is to design the toner so that the charge of the toner rises quickly.

In order to solve the above problems, it is necessary to reduce the damage of the toner at the time of rubbing and to improve the fluidity of the toner in order to improve the charge rise. In order to improve the fluidity of the toner, a technique for externally adding a small-diameter external additive is disclosed (Patent Document 1). In this technology, the fluidity and charge are improved by the alumina particles treated with fluorine silane, but even if only the alumina particles are externally added, the charge is temporarily charged, but the charge is attenuated due to the low resistance of the alumina particles. Toner is detached from the developer carrier.

As another technique, a technique for increasing the coverage of toner with silica particles is disclosed. However, if the toner coverage is increased only with the silica particles, the surface of the toner matrix particles becomes too high in resistance, charge-up occurs, and the image density stability deteriorates. For the purpose of avoiding this, a technique of coating the surface of the toner mother particles with silica particles and alumina particles is disclosed (Patent Document 2). Patent Document 2 discloses a technique in which silica particles are used to create a highly coated state, and alumina particles are added thereto to suppress electrostatic aggregation, improve charge rise, and improve ghosting. As a result of the examination by the present inventors, it was found that further improvement is necessary for the developing streaks in the high temperature and high humidity environment.

Japanese Unexamined Patent Publication No. 2004-352591 Japanese Unexamined Patent Publication No. 2013-156618

Hidetoshi Tsuchida, 3 others, "Chemical Structure and Static Charging of Polymers", Industrial Chemistry Magazine, 1966, Vol. 69, No. 10, p. 1978-1983 "A survey of hammett mice constants and resonance and field parameters" Chemical Reviews 1991, Vol. 91, p. 165-195 "Linear free energy relations. V. Triboelectric charging of organic solids" Journal of the American Chemical Society 1975, Vol. 97, p. 3832-3833

As a result of the studies by the present inventors, it is difficult to sufficiently cope with the increase in speed only by adding silica particles or alumina particles to the toner as described in Patent Document 2 above. It became clear.
In particular, it was found that further improvement is required for developing streaks in a high-temperature and high-humidity environment in which high fluidity is difficult to obtain due to the influence of water cross-linking force and the like.
An object of the present invention is to provide a toner capable of solving the above problems.
Specifically, even in a high-speed system, the image density is stable, fog is less likely to occur, and image harmful effects (dropping phenomenon) and development streaks caused by the desorption of toner from the developer carrier are less likely to occur. To provide toner.

The present invention is a toner mother particle containing a binder resin and a colorant, and a toner containing inorganic fine particles.
The inorganic fine particles contain alumina particles A and silica particles B, and the inorganic fine particles contain alumina particles A and silica particles B.
The coverage X of the surface of the toner matrix particles by the silica particles B as measured by X-ray photoelectron spectroscopy (ESCA) is 50.0% or more and 95.0% or less.
The alumina particles A are
(I) The number average particle size (D1 _a ) of the primary particles is 5 nm or more and 100 nm or less.
(Ii) The present invention relates to a toner having a partial structure a represented by the following formula (1) on the surface of the alumina mother particle.
R _{1 -Si-O 3/2} formula (1)
(In the formula (1), R ₁ is a functional group having a substituent having a Hammett substituent constant σ _m (meta) of 0.25 or more at the terminal).

According to the present invention, even in a high-speed system, the image density is stable, fog is less likely to occur, and image harmful effects (dropping phenomenon) and development streaks caused by the desorption of toner from the developer carrier occur. It is possible to provide difficult toner.

It is a schematic block diagram of the image forming apparatus which concerns on Example to which this invention is applied. It is a schematic block diagram of the process cartridge which concerns on Example to which this invention is applied.

As described above, it has been preferable to coat the surface of the toner matrix particles with silica particles as one means of improving the fluidity and chargeability of the toner in order to cope with the high speed. By covering the toner, the fluidity of the toner is improved and the toner is less susceptible to the influence of rubbing on the toner regulating portion due to the high speed. Further, when the toner is supported on the developer carrier, the electrostatic adhesion force of the toner exceeds the centrifugal force acting on the developer carrier, and the toner develops the latent image on the image carrier. It is necessary that the toner charge rises quickly and that the toner does not charge up.

As a result of studies by the present inventors, it was found that by adding alumina particles having a particle size within a predetermined range, the electrostatic adhesion force does not become too small, and stable chargeability of the toner can be obtained. The image carrier is also referred to as a photoconductor drum below.

However, it was found that the conventional alumina causes adhesion to the blade of the regulation part. The present inventors consider this reason as follows. As the speed increases, triboelectric charging between the blade of the regulation section and the toner tends to occur. In general, alumina shows positive chargeability to negatively charged toner, and it is considered that the factor is that alumina particles are charged and easily adhere to the blade as the speed increases. Therefore, after diligent studies, it was found that it is necessary to have a specific partial structure on the surface of the alumina mother particles. It was found that having a specific partial structure has the effect of suppressing development streaks due to adhesion to the blade while stabilizing the chargeability of the toner.

An example in which a partial structure as in the present invention is applied to alumina is disclosed in Patent Document 1. However, in this example, the purpose is to obtain good fluidity and chargeability in place of the silica particles, and it is not intended to be applied to a toner coated with silica particles. Further, in the study by the present inventors, the development streak, which is the subject of the present invention, is a problem that has become apparent by coating with silica particles in order to cope with high speed. That is, when the alumina particles were applied when the coverage with the silica particles was small, the alumina particles were embedded in the toner mother particles, and adhesion to the blade could not be confirmed.

As described above, as a result of diligent studies, the present inventors have controlled the coverage with silica particles and added alumina particles having a specific partial structure on the surface layer, which is good even in a high-speed system. We have found that an image can be obtained and have reached the present invention.

Specifically, the present inventors
Toner mother particles containing a binder resin and a colorant, and toner containing inorganic fine particles.
The inorganic fine particles contain alumina particles A and silica particles B, and the inorganic fine particles contain alumina particles A and silica particles B.
The coverage X of the surface of the toner matrix particles by the silica particles B as measured by X-ray photoelectron spectroscopy (ESCA) is 50.0% or more and 95.0% or less.
The alumina particles A are
(I) The number average particle size (D1 _a ) of the primary particles is 5 nm or more and 100 nm or less.
(Ii) It is necessary that the surface of the alumina mother particle is a particle having a partial structure a represented by the following formula (1).
R _{1 -Si-O 3/2} formula (1)
(In the formula (1), R ₁ is a functional group having a substituent having a Hammett substituent constant σ _m (meta) of 0.25 or more at the terminal).

The coverage X can be calculated from the ratio of the detection intensity of the Si element when the toner is measured to the detection intensity of the Si element when the silica particle simple substance is measured by ESCA. The coverage X indicates the ratio of the area actually covered by the silica particles on the surface of the toner mother particles.

It is sufficient for the toner to set the coverage X of the surface of the toner mother particles by the silica particles B, which is measured by X-ray photoelectron spectroscopy (ESCA), to 50.0% or more and 95.0% or less. Gives fluidity. Further, by appropriately covering the surface of the toner mother particles with silica particles, the adhesiveness between the toners can be reduced. As a result, deterioration of the toner due to rubbing in the vicinity of the regulation blade is suppressed.
The coverage X of the surface of the toner mother particles by the silica particles B is preferably 60.0% or more and 95.0% or less. The above-mentioned coverage can be adjusted by adjusting the number average particle diameter (D1 _b ) of the primary particles of the silica particles B and the addition amount of the silica particles B.

The number average particle size (D1 _b ) of the primary particles of the silica particles B is preferably 5 nm or more and 50 nm or less, and more preferably 5 nm or more and 30 nm or less. By setting the number average particle size (D1 _b ) of the primary particles of the silica particles B in this range, the toner can be easily disintegrated into individual particles even when the toner is stressed in the vicinity of the regulation blade. It is preferable because the chargeability of the toner can be sufficiently obtained. The number average particle size of the primary particles of the silica particles B can be controlled by adjusting the production conditions at the time of manufacturing the silica.

The amount of the silica particles B added is preferably 2.0 parts by mass or more and 5.0 parts by mass or less, and more preferably 2.0 parts by mass or more and 4.0 parts by mass with respect to 100 parts by mass of the toner particles. It is as follows. By setting the addition amount of the silica particles B in this range, appropriate fluidity can be given to the toner, and agglomerates of the external additive are less likely to occur, which is preferable.

The silica particles are fine powders produced by vapor phase oxidation of a silicon halogen compound, and so-called dry silica or fumed silica is preferable for imparting fluidity and charge to the toner. For example, it utilizes the pyrolysis oxidation reaction of silicon tetrachloride gas in oxyhydrogen flame, and the basic reaction formula is as shown below. The particle size of the silica particles can be changed by changing the flow rate of silicon tetrachloride gas or the like.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

Further, as the silica particles, it is preferable to hydrophobize the silica fine powder produced by the vapor phase oxidation of the silicon halogen compound.
It is preferable that the specific surface area of the silica particles after the surface treatment by nitrogen adsorption measured by the BET method is 30 m ² / g or more and 300 m ^{2 / g or less.}

The number average particle size (D1 _a ) of the primary particles of the alumina particles A is 5 nm or more and 100 nm or less. By setting the number average particle size (D1 _a ) of the primary particles of the alumina particles A in this range, the chargeability of the toner is stabilized, the toner electrostatic adhesion force is not excessively reduced, and the drop-off phenomenon does not occur. A good image can be obtained with. It is preferably 5 nm or more and 50 nm or less, and more preferably 5 nm or more and 30 nm or less. The particle size of the alumina particles can be controlled by adjusting the production conditions and the production method at the time of producing alumina.

The coverage of the surface of the toner matrix particles with the alumina particles A, as measured by X-ray photoelectron spectroscopy (ESCA), is preferably 7.0% or more and 50.0% or less. By setting the coverage of the alumina particles A within this range, it is easy to obtain an effect of suppressing fog by stabilizing the charge of the toner and sufficient fluidity. The coverage with the alumina particles A is preferably 10.0% or more and 40.0% or less. The coverage can be adjusted by adjusting the number average particle size (D1 _a ) of the primary particles of the alumina particles and the amount of the alumina particles added.

The alumina particles of the present invention are inorganic fine particles generally used as an external additive, for example, particles that are more easily charged positively than untreated silica particles. Since the chargeability of particles is caused by the surface layer of the material, the present inventors first considered changing the chargeability by surface treatment in order to secure the rising property of charge. When surface-treated, the chargeability is negative when the structure of the surface layer, especially the side chain has a greater effect than the main chain, especially the terminal effect, and the functional group of the side chain is electron-withdrawing. It is known that when it is charged and electron-donating, it becomes positively charged. (See Non-Patent Document 1). Therefore, when a structure is formed on the surface layer of alumina by silane coupling treatment or the like, it is considered that the chargeability of the alumina particles can be controlled by the functional group of the side chain. There is Hammett equation as an index of whether the substituent of the functional group is electron-withdrawing property or electron-donating property. Hammett's law is an empirical rule that shows the effect of substituents on the reaction and equilibrium of benzene derivatives, and Hammett's substituent constant σ _m (meth) quantifies the degree of electron donating and electron-withdrawing properties of substituents. It can be said that the value has been changed (see Non-Patent Document 2). It is also known that there is a linear relationship between Hammett's substituent constant σ _m (meta) and the logarithm of the amount of charge (see Non-Patent Document 3).

From the above, it was considered that the development streaks would be improved by forming a partial structure having a functional group having a large _{σ m} (meth) value, which is an electron-withdrawing property, on the surface layer of the alumina particles. As a result of diligent studies, the present inventors have _{a substituent in which R 1 of the} partial structure a represented by the formula (1) has a Hammett substituent constant σ _m (meth) of 0.25 or more at the terminal. It has been found that when it is a functional group, the development streaks are improved. Hammett's substituent constant σ _m (meta) is 0.25 or more. Substituents include -CF ₃ , -C ₆ F ₅ (pentafluorophenyl group), -NCO, -CCl ₃ , -NO ₂ , -COOH. And so on.
When _{the substituent constant σ m} (meta) of Hammett, which is the substituent of _{R 1} at the end, is 0.40 or more, the rising property of charging is further improved.
Further, _{when the substituent of R 1} at the terminal is CF _3, it is preferable because the development streaks are further improved.

R _{1 -Si-O 3/2} formula (1)
(In the formula (1), R ₁ is a functional group having a substituent having a Hammett substituent constant σ _m (meta) of 0.25 or more at the terminal).

_{Incidentally,} notation and R 1 _{-Si-O 3/2} represents the partial structure within the area surrounded by the rectangle indicated by broken lines _{below, -O 3/2} is
As shown in (a) below, three oxygens shared with Si atoms outside the region, or as shown in (b) below, two oxygens shared with Si atoms outside the region, titanium. It shows that it has one oxygen shared with the strontium acid mother particle.

（＊は、チタン酸ストロンチウム母粒子との結合部を表す。）

(* Represents the bond with the strontium titanate matrix.)

As described above, the reason why the developed streaks are improved by the alumina particles having a specific partial structure on the surface layer is considered as follows. Since the partial structure a on the surface layer of the alumina particles has an electron-attracting functional group, it has a function of diffusing the charge charged by silica, whereby the regulating blade and the alumina particles are rubbed and charged up. It is considered that the charge is prevented. Therefore, it is considered that the adhesive force of the alumina particles to the regulation blade is reduced and the developing streaks are improved.

Further, by setting the abundance ratio of the partial structure a represented by the formula (1) to 0.100 or more and 0.450 or less on the surface of the alumina particles, it is preferable that development streaks are less likely to occur. The abundance ratio is more preferably 0.250 or more and 0.450 or less, and further preferably 0.300 or more and 0.450 or less. The abundance ratio of the partial structure a is measured using X-ray photoelectron spectroscopy (ESCA). Alumina particles were measured by ESCA, and the value obtained by dividing the surface atomic concentration (atomic%) by the number of atoms contained in the partial structure a was taken as the abundance on the surface of the partial structure a. The measurement method will be described later.

The reason why the development streaks are improved by setting the abundance ratio of the partial structure a in the above range has not been completely clarified, but since the partial structure a has an electron-withdrawing functional group, silica is used. It is considered that there is a function to diffuse the charged charge. As a result, it is considered that the regulation blade and the alumina particles are prevented from being rubbed and charged up. In addition, since the charge is stable, fog is suppressed in a high temperature and high humidity environment. The abundance ratio of the alumina particles of the partial structure a represented by the formula (1) on the surface can be controlled by a combination of a surface treatment method and a treatment agent.

The alumina particles A preferably contain the surface modifier in an amount of 4.0% by mass or more and 7.0% by mass or less. Here, the surface modifier is a treatment agent for forming a partial structure a on the surface layer of the alumina particles. Within this range, the effect of improving the development streaks of the alumina particles can be easily obtained.
A surface coating with a silane coupling agent can be used to obtain the partial structure a. As the silane coupling agent, a fluoroalkylsilane coupling agent, an isocyanate silane coupling agent, or the like can be used. As the silane coupling agent, it is more preferable to use a silane coupling agent having _{R 1 having 10 or less carbon atoms.} Preferred examples include 3,3,3-trifluoropropyltrimethoxysilane.

In addition to the partial structure a, the partial structure b represented by the formula (2) may be present on the surface of the alumina particles. Having the partial structure b is preferable because the hydrophobicity of the alumina particles is improved and the chargeable environmental stability is improved. Examples of the surface treatment agent used for forming the partial structure b on the surface layer of the alumina particles include hexamethyldisilazane (HMDS), methyltrimethoxysilane, octyltrimethoxysilane, isobutyltrimethoxysilane, and n-propyltri. Examples thereof include methoxysilane and hexyltrimethoxysilane. Particularly preferably, an alkylsilane coupling agent having an alkyl group having 3 or more and 6 or less carbon atoms _{in R 2 is used.} Among them, isobutyltrimethoxysilane is preferable for obtaining hydrophobicity.

R _{2 -Si-O 3/2} formula (2)
(In formula (2), R ₂ is an alkyl group)

Alumina particles may be surface-treated with silicone oil or the like as another surface treatment. As the silicone oil, one having a viscosity at 25 ° C. of 30 to 1,000 mm ² / sec is preferably used. Examples thereof include dimethyl silicone oil, methyl phenyl silicone oil, α-methyl styrene modified silicone oil, chlorphenyl silicone oil and fluorine modified silicone oil.

A conventionally known method is applied to the method for treating alumina particles used in the present invention. That is, while sufficiently stirring the alumina particles to be treated mechanically, a silane coupling agent such as a surface modifier or a hydrophobizing agent is added dropwise or by spraying. At this time, it is desirable to add diethylamine or the like as a catalyst for enhancing the reactivity of the silane coupling agent, or to blow ammonia gas. Further, depending on the viscosity of the silane coupling agent to be used, a solvent such as ethanol, acetone or hexane can be used as the diluent. After the treatment agent is added, the reaction is completed by heating at a temperature in the range of 100 ° C. to 300 ° C. under a nitrogen atmosphere, and the solvent is removed.

When the surface treatment is performed by using the alkylsilane coupling agent and the fluorine-based silane coupling agent in combination, it is preferable to treat them separately in order to control the abundance ratio of the partial structure. The "divided treatment" means, for example, that the surface of alumina particles is sprayed with an alkylsilane coupling agent and then dried for a predetermined time, and then a fluorine-based silane coupling agent is sprayed and then dried for a predetermined time. Means to let you.

The method for producing the toner mother particles in the present invention is not particularly limited. For example, it can be obtained by a method for directly producing toner particles in an aqueous medium (hereinafter, also referred to as a polymerization method) such as an emulsion aggregation method, a suspension polymerization method, an interfacial polymerization method, or a dispersion polymerization method, or a pulverization method or a pulverization method. Examples thereof include a method of thermally spheroidizing the obtained toner particles.

Among them, an emulsification / aggregation method or a suspension polymerization method is preferably used, in which the toner mother particles are easily aligned in a substantially spherical shape, the charge distribution is excellent in uniformity, and the resin particles having excellent sharp melt property can be easily incorporated.
In the suspension polymerization method, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is added to an aqueous medium, and the polymerizable monomer composition is granulated in the aqueous medium to granulate. This is a production method for obtaining toner particles by polymerizing the polymerizable monomer contained in the particles of the polymerized monomer composition.

The emulsification / aggregation method is a production method for producing toner particles by preparing a resin fine particle dispersion liquid sufficiently small with respect to a target particle size in advance and aggregating the resin fine particles in an aqueous medium.
That is, in the emulsification and aggregation method, toner is produced through a dispersion step, an aggregation step, a fusion step, and a subsequent cooling step. In the dispersion step, a fine particle dispersion liquid made of a constituent material of toner is prepared. In the agglutination step, the fine particles made of the constituent materials of the toner are agglutinated, and the particle size is controlled until the particle size of the toner is reached. In the fusion step, the resin contained in the obtained agglomerated particles is fused.
Hereinafter, the emulsion aggregation method will be described in detail, but the present invention is not limited thereto.

Examples of the binder resin used for the toner of the present invention include the following. Stylized monomers such as styrene, parachlorostyrene, α-methylstyrene; acrylic acid such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, etc. Ester monomers; methacrylic acid ester monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylic nitrile; vinyl ethyl ether, vinyl isobutyl Vinyl ethers such as ethers; homopolymers or copolymers (vinyl-based resins) of vinyl methyl ketones, vinyl ethyl ketones, vinyl isopropenyl ketones.

In addition, homopolymers or copolymers (olefin resins) of olefins such as ethylene, propylene, butadiene, and isoprene; non-vinyl condensation of epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc. Examples thereof include based resins and graft polymers of these non-vinyl condensed resins and vinyl monomers.
These resins may be used alone or in combination of two or more.

Of these, a polyester resin having a sharp melt property and having excellent strength even with a low molecular weight is preferable.
Examples of the colorant used in the toner of the present invention include known organic pigments or dyes, carbon black, and magnetic materials.

Examples of the cyan colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound.
Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds and the like.

Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254, C.I. I. Pigment Violet 19 and the like.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds and the like.
Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, Examples thereof include 174, 175, 176, 180, 181 and 191 and 194.

Examples of the black colorant include carbon black, a magnetic material, or a black colorant using a yellow colorant, a magenta colorant, and a cyan colorant.
These colorants can be used alone or in admixture, and even in the form of a solid solution. The colorant may be selected from the viewpoints of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner particles.
The content of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin.

The resin fine particle dispersion is prepared by a known dispersion method. Specifically, it is advisable to add an aqueous medium, an emulsifier, or the like to the binder resin and disperse it using a device such as a clear mix, a homomixer, or a homogenizer that applies a high-speed shearing force. That is, it is a method of producing a resin fine particle dispersion in an aqueous medium by emulsification using an external shearing force.

On the other hand, phase inversion emulsification in which the binder resin is dissolved in a solvent, dispersed in an aqueous medium together with an emulsifier, a polymer electrolyte, etc. in the form of particles using a disperser such as a homogenizer, and then heated or depressurized to remove the solvent. A resin fine particle dispersion may be prepared by the method. Alternatively, in the case of a resin fine particle dispersion containing resin fine particles having a vinyl-based monomer as a constituent element, the resin fine particle dispersion may be produced by carrying out emulsion polymerization using an emulsifier.

The colorant fine particle dispersion may be produced by dispersing the colorant fine particles in an aqueous medium.
The colorant particles are dispersed by a known method. For example, a media type disperser such as a rotary shear homogenizer, a ball mill, a sand mill, and an attritor, a high pressure collision type disperser, and the like are preferably used. In particular, the "nanomizer" manufactured by Yoshida Kikai Kogyo Co., Ltd., the "ultimizer" manufactured by Sugino Machine Limited, and the "nanodisizer LPN series" manufactured by Serendip, which are high-pressure collision type dispersers, are preferably used.

The emulsifier that can be used when preparing the dispersion is not particularly limited, and examples thereof include the following. Anionic surfactants such as sulfate ester salt type, sulfonate type, phosphoric acid ester type, soap type; cationic surfactant such as amine salt type and quaternary ammonium salt type; polyethylene glycol type, alkylphenol ethylene oxide adduct type , Nonionic surfactants such as polyhydric alcohols. The emulsifier may be used alone or in combination of two or more.

Specific examples of the anionic surfactant include the following. Fatty acid substances such as potassium laurate, sodium oleate, sodium castor oil; sulfate esters such as octyl sulphate, lauryl sulphate, lauryl ether sulphate, nonylphenyl ether sulphate; lauryl sulphonate, dodecylbenzene sulfonate, triisopropylnaphthalene sulphonate, dibutyl Alkyl naphthalene sulfonates such as naphthalene sulfonate; Sulfonates such as naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate; lauryl phosphate, isopropyl phosphate, nonyl Phosphate esters such as phenyl ether phosphate; Dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate; Sulfon succinates such as lauryl disodium sulfosuccinate.

Specific examples of the cationic surfactant include the following. Amine salts such as laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate; lauryltrimethylammonium chloride, dilauryldimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium Grade 4 such as chloride, lauryldihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium etosulfate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzenetrimethylammonium chloride, alkyltrimethylammonium chloride. Ammonium salts.

Specific examples of the nonionic surfactant include the following. Alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; alkylphenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; poly Alkyl esters such as oxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene laurylamino ether, polyoxyethylene stearylamino ether, polyoxyethylene oleylamino ether, polyoxyethylene soybean amino ether, poly Alkylamines such as oxyethylene beef amino ether; Alkylamides such as polyoxyethylene lauric acid amide, polyoxyethylene stearate amide, polyoxyethylene oleic acid amide; polyoxyethylene castor oil ether, polyoxyethylene rapeseed oil ether Vegetable oil ethers such as; lauric acid diethanolamide, stearic acid diethanolamide, alkanolamides such as oleic acid diethanolamide; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmiate, polyoxyethylene sorbitan monostearate, Solbitan ester ethers such as polyoxyethylene sorbitan monooleate.

(Agglutination process)
In the agglutination step, a mixed solution in which a resin fine particle dispersion, a colorant fine particle dispersion, and other components are mixed is prepared. Then, each fine particle contained in the prepared mixed liquid is agglutinated to form agglomerated particles having a target toner particle size. At this time, it is preferable to add and mix the agglutinating agent and appropriately apply heating and / or mechanical power as necessary to form agglomerated particles in which the resin fine particles, the colorant fine particles, and other components are aggregated.

Further, if necessary, the aggregated particles may have a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles. Aggregated particles having a core / shell structure may be prepared, for example, as follows.

As a first agglutination step for forming core agglutinating particles, each fine particle contained in the mixed solution is agglutinated to form agglutinated particles, and an agglutinated particle dispersion is prepared. At this time, for example, a pH adjuster, a flocculant, and a stabilizer are added and mixed in the mixed solution, and heating and / or mechanical power is appropriately applied to form core agglomerated particles.

Examples of the pH adjuster include alkalis such as ammonia and sodium hydroxide, and acids such as nitric acid and citric acid.
Examples of the flocculant include monovalent metal salts such as sodium and potassium; divalent metal salts such as calcium and magnesium; trivalent metal salts such as iron and aluminum; alcohols such as methanol, ethanol and propanol. ..

Examples of the stabilizer include mainly a polar surfactant itself or an aqueous medium containing the same. For example, when the polar surfactant contained in the various dispersions is anionic, a cationic stabilizer can be selected.
It is preferable to add and mix the flocculant and the like at a temperature equal to or lower than the glass transition temperature of the binder resin contained in the mixed solution. When mixing is performed under these temperature conditions, agglutination proceeds in a stable state.

Mixing can be performed using, for example, a homogenizer, a mixer, or the like.
In the second agglutination step for forming the shell layer, a resin fine particle dispersion containing the second resin fine particles is used on the surface of the core agglutinating particles obtained in the first agglutination step, and the second resin fine particles are used. Is a step of forming a coating layer (shell layer). As a result, aggregated particles having a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles can be obtained.

The second resin fine particles may be the same as or different from the first resin fine particles. In addition, the first and second agglutination steps may be repeated in a plurality of steps in stages.

(Fusion process)
The fusion step is a step of heating and fusing agglomerated particles having a core / shell structure.
Before entering the fusion step, the above-mentioned pH adjuster, polar surfactant, non-polar surfactant and the like can be appropriately added in order to prevent fusion between the toner particles.
The heating temperature is equal to or higher than the glass transition temperature of the resin contained in the aggregated particles having a core / shell structure (when there are two or more types of resin, the glass transition temperature of the resin having the highest glass transition temperature) or higher. It suffices if it is below the decomposition temperature of.

Therefore, the heating temperature varies depending on the type of resin constituting the resin fine particles and cannot be unconditionally defined, but is generally equal to or higher than the glass transition temperature of the resin contained in the aggregated particles having a core / shell structure 140. It is about ℃ or less. The heating can be performed using a known heating device.

The fusion time is short if the heating temperature is high, and long if the heating temperature is low. That is, the fusion time cannot be unconditionally defined because it depends on the heating temperature, but is generally about 30 minutes or more and 10 hours or less.
Further, the fusion step may include a primary fusion step and a secondary fusion step. In the primary fusion step, the core agglutinated particles obtained in the first agglutination step are heat-fused to obtain core particles. In the secondary fusion step, the second resin fine particles are adhered to the surface of the obtained core particles, a coating layer (shell layer) is formed, and then heat fusion is performed to obtain resin particles having a core / shell structure.

The weight average particle size (D4) of the toner mother particles obtained by the present invention is preferably 4.5 μm or more and 7.0 μm or less, and more preferably 5.0 μm or more and 6.5 μm or less.
Toner can be obtained by mixing the toner mother particles with silica particles, alumina particles, or other external additives. Mixers to be added to the toner matrix particles include FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), super mixer (manufactured by Kawata Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), and hybridizer (manufactured by Hosokawa Micron Co., Ltd.). (Made by Machinery Works).

In addition, examples of the sieving device used for sieving the coarse particles after external addition include the following. Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resona Sheave, Gyroshifter (manufactured by Tokuju Kosakusho Co., Ltd.); Vibrasonic System (manufactured by Dalton Co., Ltd.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turbo Screener (manufactured by Freund Turbo Co., Ltd.); Microshifter (manufactured by Makino Sangyo Co., Ltd.).

As other external additives, the following may be contained. Fluorine resin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, zinc oxide, oxides such as tin oxide, strontium titanate, barium titanate, calcium titanate, strontium zirconate and calcium zirconate. Compound oxides; calcium carbonate, carbonate compounds such as magnesium carbonate, etc.

The image forming method to which the present invention is applied will be described below with reference to FIG.
FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 using an image forming method to which the toner of the present invention can be applied. The image forming apparatus 100 is a full-color laser printer that employs an in-line method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material (for example, recording paper, plastic sheet, cloth, etc.) according to the image information. The image information is input to the image forming apparatus main body 100A from an image reading device connected to the image forming apparatus main body 100A or a host device such as a personal computer communicably connected to the image forming apparatus main body 100A.

The image forming apparatus 100 is a first, second, and third image forming unit for forming an image of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. , Has a fourth image forming unit SY, SM, SC, SK. The first to fourth image forming portions SY, SM, SC, and SK are arranged in a row in a direction intersecting the vertical direction.

The configurations and operations of the first to fourth image forming units SY, SM, SC, and SK are substantially the same except that the colors of the formed images are different. Therefore, in the following, if no particular distinction is required, the subscripts Y, M, C, and K given to the code to indicate that the element is provided for any of the colors are omitted and collectively. explain.

The image forming apparatus 100 has four drum-type electrophotographic photoconductors arranged side by side in a direction intersecting the vertical direction, that is, a photoconductor drum 1 as a plurality of image carriers. The photoconductor drum 1 is rotationally driven by a drive means (drive source) (not shown) in the direction of arrow A (clockwise) shown in the figure. A charging roller 2 as a charging means and a scanner unit (exposure device) 3 as an exposure means are arranged around the photoconductor drum 1. The charging roller 2 evenly charges the surface of the photoconductor drum 1. The scanner unit (exposure device) 3 irradiates a laser based on the image information to form an electrostatic image (electrostatic latent image) on the photoconductor drum 1. Further, a developing unit (developer) 4 as a developing means and a cleaning member 6 as a cleaning means are arranged around the photoconductor drum 1. The developing unit (developer) 4 develops the electrostatic image as a toner image. The cleaning member 6 removes the toner (transfer residual toner) remaining on the surface of the photoconductor drum 1 after transfer. Further, an intermediate transfer belt 5 as an intermediate transfer body is arranged so as to face the four photoconductor drums 1. The intermediate transfer belt 5 transfers the toner image on the photoconductor drum 1 to the recording material 12.

The developing unit 4 preferably uses a non-magnetic one-component developer toner as the developing agent. Further, the developing unit 4 performs reverse development by bringing a developing roller (described later) as a developing agent carrier into contact with the photoconductor drum 1. That is, the developing unit 4 is a portion (image section, exposure section) in which the toner charged with the same polarity as the charging polarity of the photoconductor drum 1 (negative polarity in this embodiment) is attenuated by exposure on the photoconductor drum 1. ) To develop the electrostatic image.

A process cartridge 7 in which the photoconductor drum 1 and the charging roller 2 as a process means acting on the photoconductor drum 1, the developing unit 4, and the cleaning member 6 are integrated, that is, integrally made into a cartridge is preferable. Used for. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 via mounting means such as a mounting guide and a positioning member provided on the image forming apparatus main body 100A. The process cartridges 7 for each color all have the same shape, and the process cartridges 7 for each color contain yellow (Y), magenta (M), cyan (C), and black (K) colors, respectively. Contains toner.

The intermediate transfer belt 5 formed of the endless belt as the intermediate transfer body abuts on all the photoconductor drums 1 and circulates (rotates) in the direction of arrow B (counterclockwise) in the drawing. The intermediate transfer belt 5 is hung on the drive roller 51, the secondary transfer opposed roller 52, and the driven roller 53 as a plurality of support members.

On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 as primary transfer means are arranged side by side so as to face each photoconductor drum 1. The primary transfer roller 8 presses the intermediate transfer belt 5 toward the photoconductor drum 1 to form a primary transfer portion N1 in which the intermediate transfer belt 5 and the photoconductor drum 1 come into contact with each other. Then, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 8 from a primary transfer bias power supply (high voltage power supply) as a primary transfer bias applying means (not shown). As a result, the toner image on the photoconductor drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5.

Further, a secondary transfer roller 9 as a secondary transfer means is arranged at a position facing the secondary transfer facing roller 52 on the outer peripheral surface side of the intermediate transfer belt 5. The secondary transfer roller 9 presses against the secondary transfer opposed roller 52 via the intermediate transfer belt 5 to form a secondary transfer portion N2 in which the intermediate transfer belt 5 and the secondary transfer roller 9 come into contact with each other. Then, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 9 from a secondary transfer bias power supply (high voltage power supply) as a secondary transfer bias applying means (not shown). As a result, the toner image on the intermediate transfer belt 5 is transferred (secondary transfer) to the recording material 12.

At the time of image formation, first, the surface of the photoconductor drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photoconductor drum 1 is scanned and exposed by a laser beam corresponding to the image information emitted from the scanner unit 3, and an electrostatic image according to the image information is formed on the photoconductor drum 1. .. Next, the electrostatic image formed on the photoconductor drum 1 is developed as a toner image by the developing unit 4. The toner image formed on the photoconductor drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8.
For example, at the time of forming a full-color image, the above-mentioned process is sequentially performed in the first image forming unit SY, the second image forming unit SM, the third image forming unit SC, and the fourth image forming unit SK. Toner images of each color are sequentially superimposed on the intermediate transfer belt 5 and primary transfer is performed.

After that, the recording material 12 is transferred to the secondary transfer unit N2 in synchronization with the movement of the intermediate transfer belt 5. The four-color toner image on the intermediate transfer belt 5 is collectively secondarily transferred onto the recording material 12 by the action of the secondary transfer roller 9 which is in contact with the intermediate transfer belt 5 via the recording material 12. Toner.

The recording material 12 to which the toner image is transferred is conveyed to the fixing device 10 as a fixing means. When heat and pressure are applied to the recording material 12 in the fixing device 10, the toner image is fixed to the recording material 12.
Further, the primary transfer residual toner remaining on the photoconductor drum 1 after the primary transfer step is removed and recovered by the cleaning member 6. Further, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is cleaned by the intermediate transfer belt cleaning device 11.
It should be noted that the image forming apparatus 100 can also form a monochromatic or multicolor image using only one desired image forming unit or using only some (but not all) image forming units. It has become like.

Next, the overall configuration of the process cartridge 7 mounted on the image forming apparatus 100 will be described.
FIG. 2 is a schematic cross-sectional view (main cross section) of the process cartridge 7 as viewed along the longitudinal direction (rotational axis direction) of the photoconductor drum 1. The posture of the process cartridge 7 in FIG. 2 is a posture in a state of being mounted on the image forming apparatus main body, and when the positional relationship and direction of each member of the process cartridge are described below, the positional relationship and direction in this posture. Etc. are shown.

The process cartridge 7 is configured by integrating a photoconductor unit 13 including a photoconductor drum 1 and the like and a developing unit 4 including a developing roller 17 and the like.
The photoconductor unit 13 has a cleaning frame body 14 as a frame body that supports various elements in the photoconductor unit 13. A photoconductor drum 1 is rotatably attached to the cleaning frame 14 via a bearing (not shown). The photoconductor drum 1 is rotationally driven in the direction of arrow A (clockwise) according to the image forming operation by transmitting the driving force of a driving motor as a driving means (driving source) (not shown) to the photoconductor unit 13. Will be done. In the present invention, the photoconductor drum 1, which is the center of the image forming process, uses an organic photoconductor drum in which an undercoat layer, a carrier generation layer, and a carrier transfer layer, which are functional films, are sequentially coated on the outer peripheral surface of an aluminum cylinder. Is preferable.

Further, in the photoconductor unit 13, a cleaning member 6 and a charging roller 2 are arranged so as to be in contact with the peripheral surface of the photoconductor drum 1. The transfer residual toner removed from the surface of the photoconductor drum 1 by the cleaning member 6 is dropped and accommodated in the cleaning frame body 14.
The charging roller 2, which is a charging means, is driven to rotate by pressure-contacting the roller portion of the conductive rubber with the photoconductor drum 1.

A predetermined DC voltage is applied to the core metal of the charging roller 2 with respect to the photosensitive drum 1, whereby a uniform dark potential (Vd) is formed on the surface of the photosensitive drum 1 (charging step). The spot pattern of the laser light emitted from the scanner unit 3 described above corresponding to the image data exposes the photosensitive drum 1, and the exposed portion loses the charge on the surface due to the carriers from the carrier generation layer, and the potential is reached. Decreases. As a result, an electrostatic latent image including a portion exposed to a predetermined bright potential (Vl) and a portion not exposed to a predetermined dark potential (Vd) is formed on the photosensitive drum 1. ..

On the other hand, the developing unit 4 has a developing chamber in which a developing roller 17 and a toner supply roller 20 are arranged. The developing roller 17 is a developer carrier for supporting the toner 80. The toner supply roller 20 is a supply member that supplies toner to the developing roller 17.
The toner supply roller 20 forms a contact portion N (a portion where the toner is sandwiched between the developing roller 17 and the toner supply roller 20) between the developing roller 17 and the developing roller 17. At the contact portion N, the developing roller 17 and the toner supply roller 20 rotate so that the surface of the developing roller 17 and the surface of the toner supply roller 20 advance in the same direction.

A stirring and transporting member 22 is provided in the toner accommodating chamber 18. The stirring and transporting member 22 is also for stirring the toner stored in the toner storage chamber 18 and for transporting the toner toward the upper part of the toner supply roller 20 in the direction of the arrow G in the drawing.

The developing blade 21 is arranged below the developing roller 17 and is in contact with the developing roller 17 at a counter, and regulates the coating amount of the toner supplied by the toner supply roller 20 and applies an electric charge. As the developing blade 21, for example, a leaf spring-shaped thin plate made of SUS having a thickness of 0.1 mm is used, and a contact pressure is formed by using the spring elasticity of the thin plate, and the surface thereof abuts on the toner and the developing roller 17. Will be done. As the developing blade, a thin metal plate such as phosphor bronze or aluminum may be used. Further, the surface of the developing blade 21 may be coated with a thin film such as polyamide elastomer, urethane rubber or urethane resin.

The toner is triboelectrically charged by rubbing between the developing blade 21 and the developing roller 17, and is charged, and at the same time, the layer thickness is regulated. Further, in the present invention, it is preferable to apply a predetermined voltage to the developing blade 21 from a blade bias power source (not shown) to stabilize the toner coat layer.

The developing roller 17 and the photoconductor drum 1 rotate so that their surfaces move in the same direction (direction from bottom to top in FIG. 2) at the facing portion.
In FIG. 2, the developing roller 17 is arranged in contact with the photoconductor drum 1, but the developing roller 17 is arranged close to the photoconductor drum 1 at a predetermined interval. May be good.

Toner negatively charged by triboelectric charging with respect to a predetermined DC bias applied to the developing roller 17 is transferred from the potential difference to only the bright potential portion in the developing portion in contact with the photoconductor drum 1 and is static. Visualize the electro-latent image.
It is preferable that the surfaces of the toner supply roller 20 and the developing roller 17 rotate in the same direction at the contact portion N. In FIG. 2, the toner supply roller 20 rotates in the direction of arrow E (clockwise), and the developing roller 17 rotates in the direction of arrow D (counterclockwise). As a result, the load on the toner can be reduced and high image quality can be maintained even after long-term use. The toner supply roller 20 is an elastic sponge roller in which a foam layer is formed on the outer periphery of the conductive core metal. The toner supply roller 20 and the developing roller 17 are in contact with each other with a predetermined intrusion amount, that is, the toner supply roller 20 has a recessed amount ΔE formed into a concave shape by the developing roller 17. In the present invention, the penetration amount is preferably 0.3 to 1.5 mm, more preferably 0.7 to 1.2 mm, in view of the balance between the peelability of the development residual toner and the load on the toner. ..

The toner supply roller 20 and the developing roller 17 rotate in the same direction with a peripheral speed difference at the contact portion N, and this operation removes the toner supply from the toner supply roller 20 to the developing roller 17. Is going. At that time, the amount of toner supplied to the developing roller can be adjusted by adjusting the potential difference between the toner supply roller and the developing roller. In the present invention, the peripheral speed of the supply roller is preferably 110 to 250%, more preferably 150 to 200% of the peripheral speed of the developing roller. A DC bias may be applied to the toner supply roller.

The method for measuring various physical properties of the toner of the present invention will be described below.
When measuring the physical properties of alumina particles, silica particles, or toner particles from a toner to which alumina particles or silica particles are added, it is possible to separate the alumina particles, silica particles, or other external additive from the toner. can. The toner is ultrasonically dispersed in methanol to remove alumina particles, silica particles and other external additives, and the toner is allowed to stand for 24 hours. Toner particles can be isolated by separating and recovering the precipitated toner particles and the alumina particles, silica particles, and other external additives dispersed in the supernatant, and sufficiently drying them. Further, by treating the alumina particles, silica particles and other external additives from the supernatant by centrifugation, the alumina particles, silica particles and other external additives can be isolated.

An example of a specific method is as follows. When the silica particles and alumina particles separated from the toner are used as the measurement sample, the silica particles and the alumina particles are separated from the toner by the following procedure.
Add 160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a high-concentration sucrose solution. 31 g of the high-concentration sucrose solution and 6 mL of contaminone N are placed in a centrifuge tube to prepare a dispersion. Contamination N will be described later. 1 g of toner is added to this dispersion, and the toner lumps are loosened with a spatula or the like.

The centrifuge tube is shaken for 20 minutes using a KM Shaker model VSX (manufactured by Iwaki Sangyo) under the condition of 350 reciprocations per minute. After shaking, the solution is replaced with a glass tube for a swing rotor (50 mL), and centrifugation is performed in a centrifuge under the conditions of ^{58s -1 for 30 minutes.} In the glass tube after centrifugation, toner is present in the uppermost layer, and silica particles and alumina particles are present in the aqueous solution side of the lower layer. The lower aqueous solution is collected and centrifuged to separate the sucrose from the silica particles and the alumina particles, and the silica particles and the alumina particles are collected. After further separating the silica particles and the alumina particles by repeating centrifugation, the dispersion is dried to isolate the silica particles and the alumina particles.

<Method for quantifying silica particles>
3 g of toner is placed in an aluminum ring having a diameter of 30 mm, and pellets are prepared at a pressure of 10 tons. Then, the intensity of silicon (Si) is obtained by wavelength dispersive fluorescent X-ray analysis (XRF) (Si intensity-1).
The measurement conditions may be those optimized by the XRF device to be used, but the series of intensity measurements shall be performed under the same conditions.

Number of primary particles Silica particles having an average particle size of 12 nm are added in an amount of 1.0% by mass based on the toner and mixed using a coffee mill. After mixing, pelletization is performed in the same manner as described above, and then the strength of Si is determined in the same manner as described above (Si strength-2).
Number of primary particles Silica particles with an average particle size of 12 nm were added and mixed in an amount of 2.0% by mass and mixed with toner, and the Si strength was increased in the same manner as above. Obtained (Si strength-3, Si strength-4).
The silica content (% by mass) in the toner is calculated by the standard addition method using Si strengths -1 to 4.

<Method for quantifying alumina particles>
For the quantification of alumina particles, in the above-mentioned method for quantifying silica particles, the strength of aluminum (Al) is determined, and the 12 nm silica particles used in the standard addition method are converted into alumina particles having an average number of primary particles of 15 nm. Quantify in the same way except to change.

<Measuring method of coverage X with silica particles and coverage with alumina particles>
The coverage X of the silica particles on the surface of the toner mother particles and the coverage of the alumina particles are calculated as follows.
Elemental analysis of the surface of the toner particles is performed using the following device under the following conditions.
-Measuring device: Quantum2000 (trade name, manufactured by ULVAC-PHI Co., Ltd.)
・ X-ray source: Monochrome Al Kα
-Xray Setting: 100 μmφ (25W (15KV))
・ Photoelectron extraction angle: 45 degrees ・ Neutralization condition: Combined use of neutralization gun and ion gun ・ Analysis area: 300 μm × 200 μm
-Pass Energy: 58.70eV
-Step size: 0.125 eV
・ Analysis software: Maltipak (ULVAC-PHI, Inc.)

Here, for the calculation of the quantitative values of Si atom and Al atom, C 1s (BE 280-295 eV), O 1s (BE 525-540 eV) and Si 2p (BE 95-113 eV). ), Al 2p (BE 71-77eV) peaks were used. Let Y1 be the quantitative value of the Si element obtained here, and Z1 be the quantitative value of the Al element.

Next, elemental analysis of the silica particles and the alumina particles was performed in the same manner as in the elemental analysis of the surface of the toner particles described above. do.
The coverage X of the surface of the toner particles by the silica particles and the coverage by the alumina particles are defined by the following formulas using the above Y1, Y2, Z1 and Z2.
Coverage with silica particles X (area%) = Y1 / Y2 × 100
Coverage with alumina particles (area%) = Z1 / Z2 x 100

In addition, in order to improve the accuracy of this measurement, it is preferable to measure Y1 and Y2 twice or more. When the quantitative values Y2 and Z2 are obtained, if the silica particles and alumina particles used for the external addition can be obtained, the measurement may be performed using them.

<Measuring method of number average particle size of silica particles and primary particles of alumina particles>
The average particle size of the number of primary particles of silica particles and alumina particles is the silica particles and alumina on the surface of the toner particles photographed by Hitachi Ultra High Resolution Electromagnetic Discharge Scanning Electron Microscope S-4800 (Hitachi High Technologies America, Ltd.). Calculated from particle images. The image shooting conditions of S-4800 are as follows.

(1) Sample preparation A thin layer of conductive paste is applied to a sample table (aluminum sample table 15 mm x 6 mm), and toner is sprayed on it. Further air blow to remove excess toner from the sample table and allow it to dry sufficiently. Set the sample table on the sample holder and adjust the sample table height to 36 mm with the sample height gauge.

(2) Setting of S-4800 observation conditions The average particle size of the number of primary particles of silica particles and alumina particles is calculated using the image obtained by observing the backscattered electron image of S-4800. Since the backscattered electron image has less particle charge-up than the secondary electron image, the particle size can be measured with high accuracy.

Inject liquid nitrogen into the anti-contamination trap attached to the housing of S-4800 until it overflows, and let it stand for 30 minutes. Start "PCSTEM" of S-4800 and perform flushing (cleaning of FE chip which is an electron source). Click the acceleration voltage display part of the control panel on the screen and press the [Flushing] button to open the flushing execution dialog. Confirm that the flushing intensity is 2, and execute. Confirm that the emission current due to flushing is 20 to 40 μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press [Origin] on the control panel to move the sample holder to the observation position.

Click the acceleration voltage display to open the HV setting dialog, and set the acceleration voltage to [0.8 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select [Top (U)] and [+ BSE] for the SE detector, and select [+ BSE] in the selection box to the right of [+ BSE]. L. A. 100] is selected to set the mode for observing with a backscattered electron image. Similarly, in the [Basic] tab of the operation panel, set the probe current of the electro-optical system condition block to [Normal], the focal mode to [UHR], and the WD to [3.0 mm]. Press the [ON] button on the acceleration voltage display of the control panel to apply the acceleration voltage.

(3) Calculation of number average particle size (D1) of primary particles of silica particles and alumina particles Drag the inside of the magnification display section of the control panel to set the magnification to 100,000 (100k) times. Rotate the focus knob [COARSE] on the operation panel to adjust the aperture alignment when the focus is reached to some extent. Click [Align] in the control panel to display the alignment dialog, and select [Beam]. Rotate the STIGMA / ALIGNMENT knobs (X, Y) on the control panel to move the displayed beam to the center of the concentric circles. Next, select [Aperture] and turn the STIGMA / ALIGNMENT knobs (X, Y) one by one to stop the movement of the image or adjust it to the minimum movement. Close the aperture dialog and focus with autofocus. Repeat this operation twice more to focus.

Then, the particle size of at least 300 silica particles and alumina particles on the surface of the toner particles is measured to determine the average particle size. Here, since some silica particles and alumina particles exist as agglomerates, the maximum diameters of those that can be confirmed as primary particles are obtained, and the obtained maximum diameters are arithmetically averaged to obtain the primary particles of the silica particles and the alumina particles. The number average particle size (D1) of is obtained.

Whether the observed particles are silica particles or alumina particles is determined by STEM-EDS measurement. The measurement conditions are as follows.
JEM2800 type transmission electron microscope: Acceleration voltage 200kV
EDS detector: JED-2300T (manufactured by JEOL Ltd., element area 100 mm ² ) is used. EDS analyzer: Noran System7 (Thermo Fisher Scientific) is used.
X-ray storage rate: 10000-15,000 cps
Dead time: Adjust the electron dose to 20 to 30%, and perform EDS analysis (total number of times 100 times or measurement time 5 minutes).

<Identification of partial structure on the surface of alumina particles>
Identification of the partial structure on the surface of the alumina particles is performed by a time-of-flight secondary ion mass spectrometer (TOF-SIMS). The following device is used under the following conditions to identify the partial structure from the fragment peak on the surface layer of the alumina particles.
-Measuring device: TRIFT-IV (trade name, manufactured by ULVAC-PHI, Inc.)
・ Primary ion: Au ₃ ⁺
-Raster size: 100 μm x 100 μm
・ Neutralizing electron gun: used

<Abundance ratio of partial structure a on the surface of alumina particles>
Elemental analysis of the surface of alumina particles is performed using the following equipment under the following conditions.
-Measuring device: Quantum2000 (trade name, manufactured by ULVAC-PHI Co., Ltd.)
・ X-ray source: Monochrome Al Kα
-Xray Setting: 100 μmφ (25W (15KV))
・ Photoelectron extraction angle: 45 degrees ・ Neutralization condition: Combined use of neutralization gun and ion gun ・ Analysis area: 300 μm × 200 μm
-Pass Energy: 58.70eV
・ Step size: 0.125eV
・ Analysis software: Maltipak (ULVAC-PHI, Inc.)

The surface concentration (atomic%) of each element was calculated from the measured peak intensity of each element.
Based on the surface concentration of each element, each element was assigned to each identified partial structure, and the abundance of each partial structure was specified. The abundance of the alumina particle bulk material was the atomic concentration of Al. From the above, the abundance ratio of the partial structure a is represented by the following formula (3).
Abundance ratio of partial structure a = abundance of partial structure a / (abundance of partial structure a + abundance of partial structure b + abundance of other structure 1 + ... + Al atomic concentration) Equation (3)

<Measuring method of weight average particle size (D4) and number average particle size (D1) of toner particles>
The weight average particle size (D4) and the number average particle size (D1) of the toner particles are calculated as follows. As the measuring device, a precision particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter Co., Ltd.) equipped with a 100 μm aperture tube by the pore electric resistance method is used. The attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter Co., Ltd.) is used for setting the measurement conditions and analyzing the measurement data. The measurement is performed with 25,000 effective measurement channels.

As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so that the concentration becomes about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter Co., Ltd.) can be used. ..
Before measuring and analyzing, the dedicated software was set as follows.

In the dedicated software "Change standard measurement method (SOMME) screen", set the total count number in the control mode to 50,000 particles, measure once, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter. The value obtained by using Coulter Co., Ltd.) is set. By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1,600 μA, the gain to 2, and the electrolyte to ISOTON II, and check “Flash of aperture tube after measurement”.

In the dedicated software "Pulse to particle size conversion setting screen", set the bin spacing to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.
The specific measurement method is as follows.

(1) Put about 200 mL of the electrolytic aqueous solution in a glass 250 mL round bottom beaker dedicated to Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise in 24 s ^-1 . Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the analysis software.
(2) Put about 30 mL of the electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, Wako Pure Chemical Industries, Ltd. ) Is diluted 3 times by mass with ion-exchanged water, and about 0.3 mL of the diluted solution is added.

(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and an ultrasonic disperser "Ultrasonic Dispension System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W is prepared. .. 3.3 L of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 mL of the contaminantinon N is added into the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker is maximized.

(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. For ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 to 40 ° C.
(6) Using a pipette, drop the aqueous electrolyte solution of (5) in which toner is dispersed into the round-bottomed beaker of (1) installed in the sample stand, and adjust the measured concentration to about 5%. .. Then, the measurement is performed until the number of measured particles reaches 50,000.

(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) and the number average particle size (D1) are calculated. When the "average diameter" of the analysis / volume statistical value (arithmetic mean) screen is the weight average particle size (D4) when the graph / volume% is set in the dedicated software, and the graph / number% is set. , The "average diameter" of the "analysis / number statistical value (arithmetic mean)" screen is the number average particle size (D1).

Hereinafter, examples of the present invention will be described. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, the parts used in the examples are based on mass.

<Manufacturing of alumina particles 1>
100 g of untreated alumina particles (number of primary particles average particle size 15 nm; hereinafter also referred to as alumina base material 1) obtained by the heat-dried vapor phase method was placed in a stainless steel reaction vessel and placed in a nitrogen atmosphere. The following treatment agent 1 was sprayed at room temperature with stirring. After the spraying was completed, the mixture was further stirred at room temperature for 30 minutes.
Treatment agent 1:
Isobutyltrimethoxysilane 5g
n-hexane 30mL

Then, the following treatment agent 2 was sprayed at room temperature. After the spraying was completed, the mixture was further stirred at room temperature for 30 minutes, heated from the outside under a nitrogen stream, heated to 200 ° C. over 30 minutes, and then allowed to cool to room temperature to obtain alumina particles 1. Table 1 shows the physical characteristics of the obtained alumina particles 1.
Treatment agent 2:
3,3,3-trifluoropropyltrimethoxysilane 5g
n-hexane 30mL

<Manufacturing of alumina particles 2-5>
Alumina particles 2 to 5 were prepared in the same manner as in the alumina particles 1 except that the treatment type and amount of the treatment agent and the alumina base material were changed as shown in Table 1. Incidentally, the alumina base materials 2 and 3 are alumina particles obtained by the vapor phase method, and the number average particle size of the primary particles of the base material 2 is 8 nm, and the number average particle size of the primary particles of the base material 3 is 40 nm. there were.

<Manufacturing of alumina particles 6>
100 g of untreated alumina particles (number of primary particles average particle size 15 nm; hereinafter also referred to as alumina base material 1) obtained by the heat-dried vapor phase method was placed in a stainless steel reaction vessel and placed in a nitrogen atmosphere. The following treatment agents 1 and 2 were simultaneously sprayed at room temperature with stirring. After the spraying was completed, the mixture was further stirred at room temperature for 50 minutes. Then, it was heated from the outside under a nitrogen stream, heated to 200 ° C. over 30 minutes, and then allowed to cool to room temperature to obtain alumina particles 6. Table 1 shows the physical characteristics of the obtained alumina particles 6.

<Manufacturing of alumina particles 7 and 8>
Alumina particles 7 and 8 were prepared in the same manner as the alumina particles 6 except that the treatment type and amount of the treatment agent were changed as shown in Table 1.

<Manufacturing of alumina particles 9 to 12>
Alumina particles 9 to 12 were prepared in the same manner as in the alumina particles 1 except that the treatment type and amount of the treatment agent and the alumina base material were changed as shown in Table 1. Incidentally, the alumina base material 4 was alumina particles obtained by a thermal decomposition method of ammonium aluminum carbonate, and the number average particle size of the primary particles was 80 nm.

<Manufacturing of alumina particles 13 to 15>
Alumina particles 13 to 15 were prepared in the same manner as the alumina particles 6 except that the treatment type and amount of the treatment agent and the alumina base material were changed as shown in Table 1. Incidentally, the alumina base material 5 was alumina particles obtained by a thermal decomposition method of ammonium aluminum carbonate, and the number average particle size of the primary particles was 120 nm.

<Manufacturing of silica particles>
The silica particles shown in Table 2 were prepared.

〇 Method for manufacturing toner matrix particles (manufacturing of aqueous dispersion 1 of resin fine particles)
0.15 g of anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .: Neogen RK) and 3.15 g of N, N-dimethylaminoethanol (basic substance) are dissolved in 146.70 g of ion-exchanged water (aqueous medium). To prepare a dispersion medium solution. This dispersion medium liquid was placed in a 350 mL pressure-resistant round-bottomed stainless steel container, and then 150 g of the following "polyester resin A" pulverized product was added and mixed.
"Polyester resin A":
(Composition (Molecular Ratio) / Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane : Terephthalic acid: Fumaric acid: Trimellitic acid = 25: 25: 26: 20: 4, Mn (number average molecular weight): 3,500, Mw (weight average molecular weight): 10,300,
Mw / Mn: 2.9, Tm (melting point): 96 ° C,
Tig (glass transition start temperature): 53 ° C, Teg (glass transition end temperature): 58 ° C)

Next, the high-speed shear emulsifying device Clairemix (manufactured by M-Technique Co., Ltd .: CLM-2.2S) was hermetically connected to the pressure-resistant round-bottomed stainless steel container. The mixture in the container was heated and pressurized at 115 ° C. and 0.18 MPa, and the rotor rotation speed of Claremix was set to 300 s ^-1 and shear-dispersed for 30 minutes. ^{Then, while maintaining the rotation of 300 s -1} until the temperature reached 50 ° C., cooling was performed at a cooling rate of 2.0 ° C./min to obtain an aqueous dispersion 1 of resin fine particles.

As a result of electron microscope observation (10,000 times), the average minor axis of the resin fine particles was 0.22 μm, the average major axis was 0.56 μm, and the average major axis / minor axis was 2.72. The proportion of particles having a major axis / minor axis of 1.5 or more and 10 or less was 98%, and the proportion of particles smaller than 1.5 was 2%. Further, the median diameter (D50) of the resin fine particles measured by using a laser diffraction / scattering particle size distribution measuring device (manufactured by HORIBA, Ltd .: LA-950) is 0.22 μm, which is 95% particles. The diameter was 0.27 μm.

(Preparation of water-based dispersion 2 of resin fine particles)
Polyester resin E 60g
((Composition (Molecular Ratio) / Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) Propane: Ethylene Glycol: Terephthalic Acid: Maleic Acid: Trimellitic Acid = 35:15:33:15 : 2), Mn: 4,600, Mw: 16,500, Mp (main peak molecular weight): 10,400, Mw / Mn: 3.6, Tig: 64 ° C, Teg: 70 ° C, acid value: 13 mgKOH / g)
Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .: Neogen RK) 0.3 g
N, N-dimethylaminoethanol 1.5g
Tetrahydrofuran 200g

The above was mixed and dissolved, and the ultra-high-speed stirring device T.I. K. The mixture was stirred at ^67s-1 for 40 minutes using Robomix (manufactured by Primix Corporation). Further, 180 g of ion-exchanged water was added dropwise to obtain an aqueous dispersion 2 of resin fine particles.
The median diameter based on the volume distribution of the resin fine particles measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by HORIBA, Ltd .: LA-950) is 0.18 μm, and the 95% particle size is 0.25 μm. Met.

(Aqueous dispersion of colorant fine particles)
Colorant: C.I. I. Pigment Blue 15: 3 (manufactured by Dainichiseika Kogyo Co., Ltd.) 100g
Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .: Neogen RK) 15 g
Ion-exchanged water 885g

The above is mixed, dissolved, and dispersed for about 1 hour using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) to disperse the colorant. (Participation concentration 10% by mass) was prepared. The median diameter based on the volume distribution of the colorant fine particles was 0.2 μm.

(Aqueous dispersion of mold release agent fine particles)
Ester wax (behenic behenate, melting point 75 ° C) 100 g
Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .: Neogen RK) 10 g
Ion-exchanged water 880g

After putting the above into a mixing container equipped with a stirrer, heat it to 90 ° C. and use Clairemix W Motion (manufactured by M-Technique Co., Ltd.) to create a shear stirring part with a rotor outer diameter of 3 cm and a clearance of 0.3 mm. The dispersion treatment was carried out for 60 minutes under the following conditions.
・ Rotor rotation speed 317s ^-1 and screen rotation speed 317s ^-1
After that, by cooling to 40 ° C. under the cooling treatment conditions of rotor rotation speed 17s- ¹ and screen rotation speed 0s- ¹ and cooling rate of 10 ° C./min, an aqueous dispersion of mold release agent fine particles (solid content concentration 10 mass) was obtained. %) Was obtained. The median diameter based on the volume distribution of the release agent fine particles was 0.15 μm.

<Manufacturing of toner particles 1>
Aqueous dispersion of resin fine particles 1 40.0 g
Water-based dispersion of colorant fine particles 12.0 g
18.0 g of aqueous dispersion of mold release agent fine particles
1% by mass calcium chloride aqueous solution 20.0 g
Ion-exchanged water 110.0 g

The above was mixed and dispersed using a homogenizer (manufactured by IKA: Ultratarax T50), and then heated to 45 ° C. in a water bath while stirring with a stirring blade. After holding at 45 ° C. for 1 hour, when observed with an optical microscope, it was confirmed that aggregated particles having an average particle size of about 5.3 μm were formed (aggregation step).

After adding 40.0 g of a 5 mass% trisodium citrate aqueous solution, the temperature was raised to 85 ° C. and held for 120 minutes while continuing stirring to obtain an aqueous dispersion containing fused core particles (primary fusion step). ). When the particle size of the core particles was measured, the weight average particle size (D4) was 5.4 μm.

Then, while continuing stirring, water was put into the water bath to cool the aqueous dispersion of the core particles to 25 ° C. (cooling step).
Next, 12.1 g of the aqueous dispersion 2 of the resin fine particles was added.
Then, the mixture was stirred for 10 minutes, and 60.0 g of a 2 mass% calcium chloride aqueous solution was added dropwise to raise the temperature to 35 ° C. In this state, a small amount of the liquid was extracted at any time, passed through a 2 μm microfilter, and stirring was continued at 35 ° C. until the filtrate became transparent (adhesion step).

After confirming that the filtrate became transparent, the resin fine particles adhered to the core particles, and the shell adherent was formed, the aqueous dispersion of the shell adhering body was heated to 40 ° C. and stirred for 1 hour. Then, 35.0 g of a 5 mass% trisodium citrate aqueous solution was added, the temperature was raised to 65 ° C., and the mixture was stirred for 3.0 hours (secondary fusion step).
Then, the obtained liquid was cooled to 25 ° C., filtered and separated into solid and liquid, 800 g of ion-exchanged water was added to the solid content, and the mixture was stirred and washed for 40 minutes. After that, filtration and solid-liquid separation were performed again.
As described above, filtration and washing were repeated until the electric conductivity of the filtrate became 150 μS / cm or less in order to eliminate the influence of the residual surfactant.
Next, the obtained solid content was dried to obtain toner mother particles (toner particles 1). The weight average particle size (D4) of the toner mother particles was 6.2 μm.

<Example 1>
To 100 parts of the obtained toner mother particles (toner particles 1), the external additives shown in Table 3 were added and externally added by FM mixer 10C (manufactured by Nippon Coke Industries, Ltd.). The conditions were as follows: toner particle charge amount: 1.8 kg, rotation speed: 58s ^-1 , and external addition time: 30 minutes.
Then, the toner 1 was obtained by sieving with a mesh having an opening of 200 μm. The formulation and physical characteristics of the toner 1 are as shown in Table 3. The evaluation test described later was performed using the obtained toner. The evaluation results are shown in Table 4.

<Evaluation test>
The toner was evaluated by modifying a commercially available laser printer LaserJet Enterprise Color M553dn (manufactured by Hulett Packard) and a process cartridge and performing a durability test. The process speed was set to 300 mm / sec. The main body has a mechanism in which the surfaces of the cartridges rotate in the same direction at the contact portion between the toner supply roller and the toner carrier roller. Due to this mechanism, the friction at the abutting portion is small and the toner is not easily triboelectrically charged. Therefore, if the toner charge is small, development battering is likely to occur.

Further, the product toner was removed from the inside of the cartridge, cleaned by air blow, and then filled with 200 g of toner to be evaluated. As the evaluation paper, CS-680 sold by Canon Marketing Japan Co., Ltd. was used. Durability evaluation is based on a high temperature and high humidity environment (temperature 30.0 ° C / relative humidity 80%) where embedding of external additives is likely to occur in addition to a normal temperature and humidity environment (temperature 25.0 ° C / relative humidity 50%). ).

<Developability>
The evaluation of developability is a mode in which the horizontal line pattern with a print rate of 1% is set as 2 sheets / job, and the machine is temporarily stopped between jobs and then the next job is started. An image printing test of 000 sheets was carried out. The image density of the first image and the image density of the 20,000th image were measured.

As for the image density, a solid image of a 5 mm circle was output, and the reflection density was measured using an X-Rite 500 series (manufactured by Video Jet X-Rite Co., Ltd.), which is a reflection densitometer. The larger the value, the better the developability, and the smaller the difference between the values before and after the durability, the more stable the product.

<Cover>
Immediately after the 20,000th image was output for the evaluation of developability, solid white paper was passed through, the worst value of the reflection density on the white background was Ds, and the average reflection density of the transfer material before image formation was Dr. And Dr-Ds was used as a cover value. A reflection densitometer (reflect meter model TC-6DS (with) Tokyo Denshi) was used to measure the reflection density on a white background, and an amber light filter was used as the filter. The smaller the value, the better the fog level.

<Development dropout>
After the 20,000th image was output in the evaluation of developability, the development dropout was evaluated.
A: No drop in the developing area B: There is some drop in the drum, but there is no drop in the image C: No drop in the image

<Development streaks>
After outputting the 20000th image in the evaluation of developability ^{, a halftone image having a toner loading amount of 0.2 mg / cm 2} was created, and the image and the developing roller were visually evaluated.
(Evaluation criteria)
A: No vertical streaks can be seen on the developing rollers or on the halftone image.
B: Although the developing roller has 1 to 3 fine streaks in the circumferential direction, no vertical streaks can be seen on the halftone image.
C: There are several fine streaks in the circumferential direction on the developing roller, and several fine streaks can be seen on the halftone image. However, it can be erased by image processing.
D: Many streaks are seen on the developing roller and on the halftone image, and cannot be erased by image processing.

<Examples 2 to 16>
Toners 2 to 16 were obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Table 3 shows various physical characteristics of the toner.
Table 4 shows the results of evaluation in the same manner as in Example 1.
<Comparative Example 1>
Toner 17 was obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Table 3 shows various physical characteristics of the toner.
Table 4 shows the results of evaluation in the same manner as in Example 1. Since _{the substituent constant σ m} (meta) of Hammett, which is the substituent that _{R 1} has at the end, is less than 0.25, the development streaks deteriorated.

<Comparative Example 2>
Toner 18 was obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Table 3 shows various physical characteristics of the toner.
Table 4 shows the results of evaluation in the same manner as in Example 1. Since the grain size of the alumina particles 13 (alumina base material 5) is large, dripping occurred.

<Comparative Example 3>
Toner 19 was obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Table 3 shows various physical characteristics of the toner.
Table 4 shows the results of evaluation in the same manner as in Example 1. Due to the small coverage of the silica particles, fog and fluffing occurred.
<Comparative Example 4>
Toner 20 was obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Table 3 shows various physical characteristics of the toner.
Table 4 shows the results of evaluation in the same manner as in Example 1. Since silica particles were not used together, fog and fluffing occurred.

1 Photoconductor drum, 4 developing unit, 7 process cartridge, 13 photoconductor unit, 15 developing chamber, 17 developing roller (developer carrier), 18 toner storage chamber, 20 toner supply roller (toner supply member), 22 stirring and transporting Members, 30 developing openings, 80 toners, 100 image forming equipment

Claims (7)

Toner mother particles containing a binder resin and a colorant, and toner containing inorganic fine particles.
The inorganic fine particles contain alumina particles A and silica particles B, and the inorganic fine particles contain alumina particles A and silica particles B.
The coverage X of the surface of the toner matrix particles by the silica particles B as measured by X-ray photoelectron spectroscopy (ESCA) is 50.0% or more and 95.0% or less.
The alumina particles A are
(I) The number average particle size (D1 _a ) of the primary particles is 5 nm or more and 100 nm or less.
(Ii) A toner characterized by having particles having a partial structure a represented by the following formula (1) on the surface of alumina mother particles.
R _{1 -Si-O 3/2} formula (1)
(In the formula (1), R ₁ is a functional group having a substituent having a Hammett substituent constant σ _m (meta) of 0.25 or more at the terminal.) The toner according to claim 1, wherein the abundance ratio of the partial structure a on the surface of the alumina particles A measured by X-ray photoelectron spectroscopy (ESCA) is 0.100 or more and 0.450 or less. The first or second claim, wherein the abundance ratio of the partial structure a on the surface of the alumina particles A measured by X-ray photoelectron spectroscopy (ESCA) is 0.250 or more and 0.450 or less. toner. The toner according to any one of claims 1 to 3, wherein the substituent of the R ₁ at the terminal is CF _3. The toner according to any one of claims 1 to 4, wherein the alumina particles A are particles having a partial structure b represented by the following formula (2).
R _{2 -Si-O 3/2} formula (2)
(In formula (2), R ₂ is an alkyl group.) The toner according to any one of claims 1 to 5 , wherein the amount of the silica particles B added is 2.0 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles. The toner according to any one of claims 1 to 6 , wherein the number average particle diameter (D1 _b ) of the primary particles of the silica particles B is 5 nm or more and 50 nm or less.

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