JP6245000B2 - Toner for electrostatic image development - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner used in electrophotography, electrostatic photography and the like.

  In general, an electrophotographic method forms an electrostatic latent image on a photoconductive photoreceptor by various methods, and then visualizes the latent image using an electrostatic charge image developing toner (hereinafter abbreviated as “toner”). After that, there is a step of transferring the toner visible image onto a transfer material such as paper and fixing the toner image by heating or pressurizing. Various methods are known as these steps, and those suitable for each image forming process are employed.

One of the typical toner manufacturing methods is a pulverization method that melts and mixes various materials such as binder resins, colorants, and charge control agents, and then pulverizes and classifies them into fine powders. In general, it is widely used regardless of color, monochrome, and various development methods. In addition, research and development of polymerized toners are actively conducted to meet the demand for higher speed and higher image quality in recent electrophotography. Since the particle size of the polymerized toner is easier to control than the pulverized toner, it is possible to obtain toner mother particles having a small particle size suitable for high image quality.
Further, since the toner can be encapsulated by controlling the particle structure, there is an advantage that a toner excellent in heat resistance and low-temperature fixability can be obtained.

In addition to the toner particle size reduction as described above, various studies have been made to achieve control of chargeability and fluidity for obtaining a stable high image quality.
For example, in order to obtain appropriate chargeability and transferability of the toner, titania, silica composite oxide particles and silica having a specific carbon content are used in combination to suppress toner charge reduction and control adhesion to the transfer medium. A technique is known (Patent Document 1).

JP2012-145918A JP 2007-264142 A

In JP-A-2012-145918, in order to make charging property and adhesion between particles appropriate, the composite oxide particles of titania and silica and the carbon content different from the composite oxide particles are 2.8% to 6%. It has been reported that 0.0 mass% silica particles are used in combination with a toner (Patent Document 1). As a result of the inventor's investigation, the toner added with the composite oxide particles of titania and silica has good image density, toner consumption, and solid followability, but performance is not sufficient for poor cleaning. Okay (corresponding to Comparative Example 2 of the present application). The inventor presumes that the cause of this poor cleaning is that the lubricity between the cleaning blade and the photoconductor is insufficient and the photoconductor is damaged. In order to solve the poor cleaning, the present inventor has a specific surface area smaller than 40 m ² / g as disclosed in Japanese Patent Application Laid-Open No. 2007-264142 with respect to a formulation in which composite oxide particles of titania and silica are added. Addition of particle size silica (corresponding to Comparative Example 3 of the present application), addition of higher fatty acid metal salt (corresponding to Comparative Examples 1 and 2 of the present application), and the combined use thereof (corresponding to Comparative Examples 4 and 5 of the present application) .

However, it has been found that the addition of large particle size silica reduces the image density, and the higher fatty acid metal salt deteriorates the solid followability depending on the number of added parts.
As described above, there has not yet been provided a toner that appropriately controls the fluidity / chargeability of the toner and has the image density, solid followability, toner consumption, and cleaning properties.

The present invention has been made in view of the above problems, and its object is to provide a toner for developing an electrostatic image having excellent image density and solid followability, low toner consumption, and excellent cleaning properties. is there.
The present inventor has repeatedly studied in order to solve the above-described problems, and has obtained a toner having a composite oxide particle having a specific structure, silica particles having a specific surface area, and a specific number of higher fatty acid metal salts. I found that the problem could be solved. That is, the gist of the present invention is as follows.
1. A toner having toner base particles containing a binder resin, a colorant and a wax, and an external additive, the external additive comprising composite oxide particles (a), silica particles (b), and a higher fatty acid metal salt ( a toner for developing an electrostatic charge image, which contains c) and satisfies the following (A) to (C):
(A) The composite oxide particles (a) have a core-shell structure, and the core portion of the composite oxide particles (a) contains titania and the shell portion contains silica. (B) The silica particles The specific surface area of (b) is 40 m ² / g or more and 120 m ² / g or less. (C) The addition amount of the higher fatty acid metal salt (c) is 100 parts by mass or more and 100 parts by mass of toner base particles. 1. It is below mass parts. The content of silica in the composite oxide particles (a) satisfying (A) is 6% by mass or more and 20% by mass or less. The toner for developing an electrostatic charge image according to 1.
3. Silica (b) satisfying (B) is negatively charged, Or 2. The toner for developing an electrostatic charge image according to 1.
4). The carbon content in the silica (b) satisfying (B) is 0.5% by mass or more and 2.5% by mass or less. To 3. The toner for developing an electrostatic image according to any one of the above.

  The present invention provides a toner having a composite oxide particle having a specific structure, a silica particle having a specific specific surface area, and a specific number of higher fatty acid metal salts as an external additive. The toner consumption is good and the cleaning property is excellent.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be arbitrarily modified without departing from the gist of the present invention.

<Configuration of Toner of the Present Invention>
The toner of the present invention has an external additive, and the external additive contains composite oxide particles (a), silica particles (b), and higher fatty acid metal salts (c), and the following (A) to (A C) is satisfied.
(A) The composite oxide particles (a) have a core-shell structure, and the core portion of the composite oxide particles (a) contains titania and the shell portion contains silica. (B) The silica particles (B) The specific surface area is 40 m ² / g or more and 120 m ² / g or less. (C) The addition amount of the higher fatty acid metal salt (c) is 100 parts by mass or more and 100 parts by mass of the toner base particles. Less than part by mass

The present invention combines the composite oxide particles (a) having a specific structure and physical properties with silica particles (b) having a specific carbon content and higher fatty acid metal salts (c) at a specific mass ratio, It is possible to design a toner that has both the advantages of silica particles and titania that have a sufficiently high charge amount and quick start-up, and sufficient cleaning performance.

<Regarding Compound Oxide Particle (a) and Condition (A) of the Present Invention>
The external additive used in the present invention contains composite oxide particles (a) having a core-shell structure containing titania and silica, and the core portion of the composite oxide particles (a) contains titania, and the shell Part contains silica.

  The content of silica in the composite oxide particles (a) is not particularly limited as long as the effect of the present invention is not significantly impaired, but is preferably 6% by mass or more and 20% by mass or less for the reason described later. The lower limit is more preferably 8% by mass or more, and still more preferably 10% by mass or more. On the other hand, the upper limit is more preferably 18% by mass or less, and still more preferably 16% by mass or less. If the content of silica in the composite oxide particles (a) is too small, the required charge amount may not be obtained, fogging may occur, and solid followability may deteriorate. Moreover, fluidity | liquidity also deteriorates and a solid followable | trackability may also be deteriorated. On the other hand, if the content of silica in the composite oxide particles (a) is excessive, the flowability is excessive, so that the cleaning property is deteriorated and the rising of the charge is lowered. May not catch up, causing fogging and poor solid followability.

  The average primary particle size of the composite oxide particles (a) is not particularly limited as long as the effects of the present invention are not significantly impaired, but the lower limit is usually 10 nm or more, preferably 12 nm or more, and particularly preferably 14 nm or more. On the other hand, the upper limit is usually 24 nm or less, preferably 22 nm or less, and particularly preferably 20 nm or less. If the average primary particle size of the composite oxide particles (a) is too small, embedding in the toner base particles becomes remarkable, the fluidity may deteriorate in the latter half of the printing durability, and there is a possibility that blurring may occur. On the other hand, if it is too large, the fluidity imparting effect is small, so that the solid followability is deteriorated, it is difficult to adhere to the toner base particles, and member contamination due to detachment may occur. The average primary particle size of the composite oxide particles (a) is measured by the method described in the examples.

  The amount of the composite oxide particles (a) added to 100 parts by mass of the toner base particles is not particularly limited as long as the effects of the present invention are not significantly impaired, but the lower limit is usually 0.3 parts by mass or more, preferably 0.45 parts by mass or more, more preferably 0.6 parts by mass or more. On the other hand, the upper limit is usually 1.4 parts by mass or less, preferably 1.3 parts by mass or less, and more preferably 1.2 parts by mass or less. If the amount of the composite oxide particles (a) added is too small, sufficient charge rising property and fluidity cannot be obtained, and fogging due to insufficiently charged toner and solid blurring may occur. On the other hand, if the amount is too large, the toner charge amount distribution becomes wide, and transfer efficiency and toner consumption amount may deteriorate.

  The method for producing the composite oxide particles (a) used in the present invention is not particularly limited and can be prepared by a known method. For example, it is produced by the method described in Japanese Patent Application No. 8-253321, JP-A-2006-511638, JP-A-2006-306651, and WO2009 / 084184.

<Regarding Condition (B) of the Present Invention>
The external additive used in the present invention contains silica particles (b) different from the composite oxide particles (a). The silica particles (b) are used in the state of being attached or fixed to the toner surface as an external additive for the toner. In the present invention, the specific surface area of the silica particles (b) usually needs to be 40 m ² / g or more and 120 m ² / g or less. The lower limit of the specific surface area of the silica particles (b) is preferably 45 m ² / g or more, particularly preferably 50 m ² / g or more. On the other hand, the upper limit is preferably 119 m ² / g or less, particularly preferably 118 m ² / g or less. If the specific surface area of the silica particles (b) is too large, a sufficient spacer effect cannot be obtained, causing OPC filming and embedding of small particle size external additives in the toner base particles. In some cases, poor cleaning due to poor fluidity may occur in the second half of printing. On the other hand, if it is too small, it may be difficult to adhere to the toner base particles, and member contamination due to detachment may occur. The specific surface area of the silica particles (b) is measured by the method described in the examples.

  The addition amount of the silica particles (b) with respect to 100 parts by mass of the toner base particles is not particularly limited as long as the effects of the present invention are not significantly impaired, but the lower limit is usually 0.10 parts by mass or more, preferably 0.00. It is 15 parts by mass or more, more preferably 0.20 parts by mass or more. On the other hand, the upper limit is usually 3.0 parts by mass or less, preferably 2.5 parts by mass or less, and more preferably 2.0 parts by mass or less. If the added amount of silica particles (b) is too small, sufficient fluidity may not be obtained and cleaning may be poor. On the other hand, if the added amount is too large, detachment from the toner base particles becomes remarkable, and member contamination occurs. In addition, fogging may occur due to the toner charge amount distribution being broad.

  The carbon content in the silica particles (b) is not particularly limited, but is preferably 0.5% by mass or more and 2.5% by mass or less for the reason described later. The lower limit of the carbon content in the silica particles (b) is more preferably 0.6% by mass or more, and particularly preferably 0.7% by mass or more. On the other hand, the upper limit is more preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less. When the carbon content of the silica particles is too low, the hydrophobicity is insufficient, the charge amount decreases due to moisture absorption, etc., fogging occurs, or the developer and the image are stained due to toner scattering. There is. If the carbon content of the silica particles is excessive, fogging occurs due to the toner charge amount distribution being broad, and the silica aggregates to provide sufficient fluidity when added to the toner. In other words, there may be a solid follow-up failure or a cleaning failure. The carbon content in the silica particles is measured by the method described in the examples.

The type of the particles (b) is not particularly limited, but it is preferable to use negatively charged silica particles as the particles (b) from the viewpoint of charging characteristics and fluidity.
Specific examples of the silica particles (b) as described above include NAX50, NX90G, NX90S (all manufactured by Nippon Aerosil Co., Ltd.) surface-treated with hexamethyldisilazane.
The method for producing the silica particles (b) used in the present invention is not particularly limited and can be prepared by a known method, but those produced by a dry method are preferred. The dry method here refers to the entire production method by reaction in the gas phase, such as flame hydrolysis of a silicon compound, oxidation by a flame combustion method, or a combination of these reactions.

<Regarding Condition (C) of the Present Invention>
The amount of the higher fatty acid metal salt particles used in the present invention needs to be 0.1 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the toner base particles. The lower limit of the addition amount of higher fatty acid metal salt particles to 100 parts by mass of toner base particles is preferably 0.15 parts by mass or more, and more preferably 0.2 parts by mass or more. On the other hand, an upper limit becomes like this. Preferably it is 0.45 mass part or less, More preferably, it is 0.4 mass part or less. If the amount of the higher fatty acid metal salt particles is too small, a sufficient concentration may not be obtained. On the other hand, if the amount is too large, fogging may occur due to the toner charge amount distribution being broad.

  Examples of the higher fatty acid metal salt particles include metal stearates such as zinc stearate and calcium stearate, and metal laurates such as zinc laurate and calcium laurate. Among these, metal stearate is preferred from the viewpoint of good heat resistance of metal salt particles, ease of production, and easy handling, and zinc stearate that is particularly effective is more preferred. preferable.

The volume average particle diameter of the higher fatty acid metal salt particles is not particularly limited as long as the effects of the present invention are not significantly impaired, but the lower limit is usually 700 nm or more, preferably 800 nm or more. On the other hand, the upper limit is usually 1100 nm or less, preferably 1000 nm or less.

<External additive (d)>
The toner of the present invention may have, together with the silica particles (b), particles (d) (hereinafter referred to as particles (d)) that are charged with a polarity opposite to that of the silica particles (b). The addition amount of the particles (d) used in the present invention is not particularly limited as long as the effects of the present invention are not significantly impaired, but the lower limit is 4.0 with respect to the total addition amount of silica (b) and particles (d). % By mass or more is preferable, and 8.0% by mass or more is particularly preferable. On the other hand, the upper limit is usually 41% by mass or less, preferably 33% by mass or less, and more preferably 25% by mass or less.

Since the particles (d) adhere to and desorb from the toner base particles, the toner becomes highly charged and uniform, and is stable even in a high temperature and high humidity environment. The charge polarity and charge amount are measured by the method described in the examples.
The type of the particles (d) is not particularly limited, but it is preferable to use positively charged silica particles from the viewpoint of charging characteristics and fluidity. In addition, melamine resin particles and positively chargeable acrylic resins can also be used.

  The average primary particle size of the positively chargeable silica particles is not particularly limited as long as the effects of the present invention are not significantly impaired, but is usually 30 nm or less, preferably 25 nm or less, and more preferably 20 nm or less. It is preferably 15 nm or less. On the other hand, it is usually 5 nm or more, preferably 6 nm or more, and more preferably 7 nm or more. If the average primary particle size is too small, embedding in the toner base particles becomes remarkable, and an expected increase in charge amount may not be obtained and fogging may occur. If the average primary particle size is too large, the positively-charged silica particles themselves are easily detached from the toner base particles, which may cause member contamination.

As the melamine-based resin, melamine / urea / formaldehyde co-condensation resin, melamine / benzoguanamine / formaldehyde co-condensation resin and the like can be used as long as melamine is the main component in addition to so-called melamine / formaldehyde condensation resin.
The average primary particle size of the melamine-based resin is preferably 80 nm or more, more preferably 120 nm or more, and particularly preferably 150 nm or more. Further, it is preferably 300 nm or less, more preferably 270 nm or less, and particularly preferably 250 nm or less. If the average primary particle size is too small, the adhesion to the toner base particles becomes too strong, and the expected amount of charge cannot be improved and fogging may occur. On the other hand, if it is too large, the melamine-based resin itself tends to be detached from the toner base particles, which may cause contamination of the member as in the case of the positively charged silica.
The average primary particle diameter of the particles (d) is measured by the method described in the examples.
Specific examples of the particles (d) that are charged with the opposite polarity to the silica particles (b) that satisfy the above average primary particle size include H30TA (manufactured by Wacker Chemical Co., Ltd.).

The amount of the particles (d) added is preferably 0.5 parts by mass or less, more preferably 0.4 parts by mass or less, and particularly preferably 0.3 parts by mass or less with respect to 100 parts by mass of the toner base particles. Moreover, 0.05 mass part or more is preferable and 0.10 mass part or more is especially preferable. If the addition amount is too large, excessive reversely charged particles may reduce the toner charge amount and fog may occur. When the addition amount is too small, the reverse charging effect when the particles (d) are detached from the mother particles cannot be obtained sufficiently, and fogging may occur due to a decrease in the charge amount of the toner. In addition, when the reversely charged particles are also acting as a fluidity improver, if the addition amount is too small, the toner fluidity may be lowered, resulting in poor cleaning. In order to reduce toner consumption, it is important to suppress fogging, to control toner fluidity, and to respond appropriately to control of the toner supply amount on the machine side.

  The method for producing the particles (d) is not particularly limited and can be prepared by a known method, but those produced by a dry method are preferred. The dry method here refers to the entire production method by reaction in the gas phase, such as flame hydrolysis of a silicon compound, oxidation by a flame combustion method, or a combination of these reactions.

<Other configuration and production method of toner base particles>
The volume median diameter of the toner base particles of the present invention is not particularly limited, but is usually 2.5 μm or more, preferably 3.0 μm or more, and more preferably 3.5 μm or more. Moreover, it is 10 micrometers or less normally, it is preferable that it is 9.0 micrometers or less, and it is more preferable that it is 8.0 micrometers or less. If the volume median diameter of the toner is too large, the charge amount per unit weight will be small, and the possibility of fogging and toner scattering may increase.If it is too small, the charge amount per unit weight will be excessive. It may be easy to cause problems such as extreme image density reduction. The volume median diameter is measured by the method described in the examples.

  The average circularity of the toner base particles of the present invention is usually 0.945 or more and preferably 0.950 or more. Moreover, it is 0.990 or less normally, and it is preferable that it is 0.985 or less. If the circularity is too large, slipping in the cleaning part is likely to occur, and the image may be defective. On the other hand, if the circularity is too small, the inorganic particles may be rolled on the surface of the mother particles due to mechanical stress in the machine. The effect of the present invention may not be maintained until the end. The circularity of the toner base particles of the present invention is measured by the method described in the examples.

The constituent material of the toner of the present invention is not particularly limited, and includes at least a binder resin and a colorant, and includes a charge control agent, a wax, and other additives as necessary.
The production method of the toner base particles of the present invention is not limited, and a conventionally used method such as a pulverization method, a wet method, a method of spheroidizing the toner by a mechanical impact force, heat treatment or the like can be used. Examples of the wet method include a suspension polymerization method, an emulsion polymerization aggregation method, a dissolution suspension method, and an ester extension method.
In the pulverization method, a binder resin, a colorant, and other components as required are weighed and blended together and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Next, the blended and mixed toner raw materials are melt-kneaded to melt the resins, and colorants and the like are dispersed therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. For the kneading machine, a single-screw or twin-screw extruder is used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by K.C.K. , Bus Co., Ltd. co-kneader. Further, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading and becomes a cooled product through a process of cooling by water cooling or the like.

The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, pulverization is performed with a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nisshin Engineering Co., Ltd. or the like. After that, if necessary, the particles are classified using a classifier such as an inertia classification type elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or a centrifugal classification type turboplex (manufactured by Hosokawa Micron Co., Ltd.). obtain. Further, the toner may be spheroidized using a conventionally used method.
After obtaining the toner base particles, the toner can be obtained through a processing step of adding an external additive and, if necessary, other processing steps.

Examples of the wet method include an emulsion polymerization aggregation method, a suspension polymerization method, a dissolution suspension method, and the like, and any method may be used and is not particularly limited.
When producing toner mother particles by the emulsion polymerization aggregation method, usually a polymerization step of polymerizing polymer particles to obtain a polymer particle dispersion, a mixing step of mixing the polymer particle dispersion and the colorant particle dispersion, Aggregation step of adding a coagulant to the mixture and agglomerating to a predetermined particle size to obtain particle aggregates (aggregated particles), fusing step of overheating and fusing the agglomerated particles to form fused particles, and thereafter filtration and washing And a step of taking out toner mother particles such as a drying step.

  In the present invention, as a method for producing a suspension polymerization toner, a coloring agent, a polymerization initiator, and, if necessary, additives such as a wax, a polar resin, a charge control agent and a crosslinking agent in the above-mentioned binder resin monomer Is added to prepare a monomer composition which is uniformly dissolved or dispersed. This monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer and the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, polymerization is performed by stirring to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. These are collected by washing and filtration, and dried to obtain toner mother particles. After obtaining the toner base particles, the toner can be obtained through a processing step of adding an external additive and, if necessary, other processing steps.

In the dissolution suspension method, a solution phase obtained by dissolving a binder resin in an organic solvent and adding and dispersing a colorant is dispersed in a water phase containing a dispersant by mechanical shearing force to form droplets. In this method, the organic solvent is removed from the droplets to produce toner particles.
The ester elongation polymerization method mixes and emulsifies the oil phase in which wax, polyester resin, pigment, etc. are dispersed with the water phase to which the particle size control agent and surfactant are added, and creates oil droplets. This is a method for producing toner particles by converging and forming a polymer resin component on the surface of the toner oil droplets by extension reaction and removing the solvent inside the oil droplets.

In the present invention, as the binder resin contained in the toner, resins conventionally used as the binder resin for toner can be appropriately used.
The binder resin used when the toner base particles are produced by a pulverization method includes polystyrene, a styrene-substituted homopolymer, a styrene copolymer, acrylic acid, methacrylic acid, polyester resin, polyamide resin, epoxy resin, Examples include xylene resins and silicone resins. These resins may be used alone or in combination.

  Examples of the binder resin used when the toner base particles are produced by a polymerization method include vinyl polymerizable monomers capable of radical polymerization. Examples include styrene, styrene derivatives, acrylic polymerizable monomers, methacrylic polymerizable monomers, vinyl esters, vinyl ethers, vinyl ketones, and the like. These resins may be used alone or in combination of two or more.

As the monomer, a polymerizable monomer having an acidic group (hereinafter sometimes simply referred to as an acidic monomer), a polymerizable monomer having a basic group (hereinafter simply referred to as a basic monomer) Any polymerizable monomer having no acidic group or basic group (hereinafter sometimes referred to as other monomer) can be used.
Among the above-described polymerization methods, when the toner mother particles are produced using the emulsion polymerization aggregation method, in the emulsion polymerization step, the polymerizable monomer is usually polymerized in an aqueous medium in the presence of an emulsifier. At this time, when supplying the polymerizable monomer to the reaction system, each monomer may be added separately, or a plurality of types of monomers may be mixed in advance and added simultaneously. The monomer may be added as it is, or may be added as an emulsion mixed and adjusted in advance with water or an emulsifier.

  As the acidic monomer, a polymerizable monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, cinnamic acid, a polymerizable monomer having a sulfonic acid group such as sulfonated styrene, Examples thereof include polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide. Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. And (meth) acrylic acid ester having an amino group. These acidic monomers and basic monomers may be used singly or as a mixture of a plurality of types, and may exist as a salt with a counter ion. Among these, it is preferable to use an acidic monomer, more preferably acrylic acid and / or methacrylic acid.

  The total amount of the acidic monomer and the basic monomer in 100 parts by mass of the total polymerizable monomer constituting the binder resin is usually 0.05 parts by mass or more, preferably 0.5 parts by mass or more. Especially preferably, it is 1.0 mass part or more. Further, it is usually 10 parts by mass or less, preferably 5 parts by mass or less.

  Examples of other polymerizable monomers include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, and pn-nonylstyrene, methyl acrylate, Acrylic esters such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n methacrylate -Methacrylic acid esters such as butyl, isobutyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylic De, N, N-dibutyl acrylamide, and the like, the polymerizable monomer may be used singly, or may be used in combination.

  Furthermore, when the binder resin is a cross-linked resin, a polyfunctional monomer having radical polymerizability is used together with the above polymerizable monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, Examples include diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and diallyl phthalate. It is also possible to use a polymerizable monomer having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radically polymerizable bifunctional polymerizable monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional polymerizable monomers may be used alone or as a mixture of plural kinds.

  When the binder resin is polymerized by an emulsion polymerization aggregation method, a known surfactant can be used as an emulsifier. As the surfactant, one or more surfactants selected from cationic surfactants, anionic surfactants, and nonionic surfactants can be used in combination.

Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and examples of the anionic surfactant include And fatty acid soap such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. Is mentioned.

  The amount of the emulsifier used in the production of the toner base particles using the emulsion polymerization aggregation method is not particularly limited, but is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. . In addition, these emulsifiers can be used as protective colloids, for example, one or more of partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol and cellulose derivatives such as hydroxyethyl cellulose.

  The volume average particle diameter of the polymer primary particles obtained by the emulsion polymerization aggregation method is usually 0.02 μm or more, preferably 0.05 μm or more, particularly preferably 0.1 μm or more. Further, it is usually 3 μm or less, preferably 2 μm or less, particularly preferably 1 μm or less. If the particle size is too small, it may be difficult to control the aggregation rate in the aggregation process. If it is too large, the particle size of the toner particles obtained by aggregation tends to be large, and a toner having the target particle size is obtained. May be difficult.

  When the toner base particles are produced using the emulsion polymerization aggregation method, a known polymerization initiator can be used as necessary, and the polymerization initiators can be used alone or in combination of two or more. For example, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, and the like, and redox initiators combining these persulfates as a component with a reducing agent such as acidic sodium sulfite, hydrogen peroxide, 4,4 Water-soluble polymerization initiators such as' -azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydropeoxide, etc., and these water-soluble polymerization initiators as a component combined with a reducing agent such as ferrous salt Redox initiator systems, benzoyl peroxide, 2,2′-azobis-isobutyronitrile, and the like are used. These polymerization initiators may be added to the polymerization system before, simultaneously with the addition of the monomer, or after the addition, and these addition methods may be combined as necessary.

  In the case of producing toner base particles using the emulsion polymerization aggregation method, a known chain transfer agent can be used as necessary. Specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen. , Carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is used in an amount of 0 to 5% by mass based on the polymerizable monomer.

  In the case of producing toner base particles using an emulsion polymerization aggregation method, a known suspension stabilizer can be used as necessary. Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate calcium hydroxide, magnesium hydroxide and the like. These may be used alone or in combination of two or more. The suspension stabilizer is usually used in an amount of 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

Both the polymerization initiator and the suspension stabilizer may be added to the polymerization system at any time before, simultaneously with, or after the addition of the polymerizable monomer. You may combine.
In addition, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

The toner of the present invention may contain wax for imparting releasability. Any wax can be used as long as it has releasability.
Specifically, for example, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymer polyethylene, paraffin waxes, ester waxes having a long chain aliphatic group such as behenyl behenate, montanate ester, stearyl stearate, etc. , Plant waxes such as hydrogenated castor oil, carnauba wax, ketones having long chain alkyl groups such as distearyl ketone, silicones having alkyl groups, higher fatty acids such as stearic acid, long chain aliphatic alcohols such as eicosanol, glycerin, Examples thereof include carboxylic acid esters of polyhydric alcohols obtained from polyhydric alcohols such as pentaerythritol and long chain fatty acids, or higher fatty acid amides such as partial esters, oleic acid amides and stearic acid amides, and low molecular weight polyesters.

  Among these waxes, in order to improve fixability, the melting point of the wax is usually 30 ° C. or higher, preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Moreover, it is 100 degrees C or less normally, 90 degrees C or less is more preferable, and 80 degrees C or less is especially preferable. If the melting point is too low, the wax may be exposed on the surface after fixing, and stickiness may occur. On the other hand, if the melting point is too high, the fixability at low temperatures may be poor.

As the wax compound species, higher fatty acid ester waxes are preferable. Specific examples of higher fatty acid ester waxes include behenyl behenate, stearyl stearate, stearates of pentaerythritol, montanic acid glycerides, etc., and fatty acids having 15 to 30 carbon atoms and 1 to 5 valent alcohols. Esters are preferred. Moreover, as an alcohol component which comprises ester, a C1-C30 thing is preferable in the case of monohydric alcohol, and a C3-C10 thing is preferable in the case of a polyhydric alcohol.
The above waxes may be used alone or in combination. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature for fixing the toner.

  In the present invention, when the wax is contained, the amount of the wax is not particularly limited, but is usually 1 part by mass or more, preferably 2 parts by mass or more, particularly preferably 5 parts by mass with respect to 100 parts by mass of the toner. More than a part. Moreover, it is 40 mass parts or less normally, Preferably it is 35 mass parts or less, Most preferably, it is 30 mass parts or less. If the wax content in the toner is too low, performance such as high-temperature offset may not be sufficient, while if it is too high, the blocking resistance may not be sufficient, or the wax may leak from the toner and contaminate the device. Sometimes.

  A known colorant can be arbitrarily used as the colorant of the present invention. Specific examples of the colorant include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, Any known dyes and pigments such as disazo dyes and condensed azo dyes can be used alone or in combination. In the case of a full color toner, it is preferable to use benzidine yellow for yellow, monoazo and condensed azo dyes, magenta for quinacridone and monoazo dyes, and cyan for phthalocyanine blue. The colorant is preferably used so as to be 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer primary particles.

  The blending of the colorant in the emulsion polymerization aggregation method is usually performed in an aggregation step. A dispersion of polymer primary particles and a dispersion of colorant particles are mixed to form a mixed dispersion, which is then aggregated to form a particle aggregate. The colorant is preferably used in the state of being dispersed in water in the presence of an emulsifier, and the volume average particle size of the colorant particles is usually 0.01 μm or more, preferably 0.05 μm or more. Further, it is usually 3 μm or less, preferably 1 μm.

In the present invention, a charge control agent may be used as necessary. When the charge control agent is used, any known one can be used alone or in combination. For example, azine series such as quaternary ammonium salt, nigrosine, processed nigrosine, and alkyl nigrosine as a positive charge control agent. Examples include black dyes, processed nigrosine compounds, guanidine compounds, triphenylsulfonium compounds, resin-based charge control agents, amide group-containing compounds, and basic / electron-donating metal substances. Aromatic oxycarboxylics as negatively chargeable charge control agents Acid-based, aromatic dicarboxylic acid metal chelates, monoazo metal-containing complex compounds, organic acid metal salts, metal-containing dyes, diphenylhydroxy complex compounds, iron-containing azo compounds, home appliance control agents for emulsion polymerization, various metal oxycarboxylic acids Complex compounds, calixarene compounds, phenolic compounds, resin-based charge control agents, naphtha Lumpur compounds and their metal salts, urethane compounds, and acidic or electron-withdrawing organic substances.

  In addition, when the toner of the present invention is used as a toner other than a black toner in a color toner or a full color toner, it is preferable to use a charge control agent that is colorless or light-colored and does not impair the color tone of the toner. As a charge control agent, a quaternary ammonium salt compound, as a negative charge control agent, a metal salt with zinc or aluminum of salicylic acid or alkylsalicylic acid, a metal complex, a metal salt of benzylic acid, a metal complex, an amide compound, Preference is given to hydroxynaphthalene compounds such as phenolic compounds, naphthol compounds, phenolamide compounds, and 4,4′-methylenebis [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene].

  In the toner of the present invention, when a charge control agent is contained in the toner using an emulsion polymerization aggregation method, the charge control agent is added together with a polymerizable monomer or the like at the time of emulsion polymerization, or polymer primary particles and a colorant. Or the like in the agglomeration step, or after the polymer primary particles and the colorant are agglomerated to almost the target particle size. Among these, it is preferable to disperse the charge control agent in water using a surfactant and add it to the aggregation step as a dispersion having a volume average particle size of 0.01 μm or more and 3 μm or less.

In the emulsion polymerization aggregation method, the aggregation is usually carried out in a tank equipped with a stirrer, but there are a heating method, a method of adding an electrolyte, and a method of combining them. When polymer primary particles are agglomerated with stirring to obtain particle aggregates of the desired size, the particle size of the particle aggregates is controlled based on the balance between the agglomeration force between the particles and the shearing force due to agitation. However, the cohesive force can be increased by heating or adding an electrolyte. In the present invention, the electrolyte in the case of performing aggregation by adding an electrolyte may be either an organic salt or an inorganic salt. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgC
l ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na, and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

In the toner of the present invention, the amount of electrolyte added varies depending on the type of electrolyte, target particle size, etc., but is usually 0.05 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. .1 part by mass or more is preferable. Moreover, it is 25 mass parts or less normally, 15 mass parts or less are preferable, and especially 10 mass parts or less are preferable. If the addition amount is too small, the progress of the agglutination reaction is delayed, and fine powders of 1 μm or less remain even after the agglomeration reaction, and the average particle size of the obtained particle aggregate may not reach the target particle size. On the other hand, if the amount is too large, rapid aggregation tends to occur and it is difficult to control the particle size, and the resulting aggregated particles may include problems such as inclusion of coarse powder or irregular shapes. The aggregation temperature in the case of performing aggregation by adding an electrolyte is usually 20 ° C. or higher, preferably 30 ° C. or higher. Moreover, it is 70 degrees C or less normally, Preferably it is 60 degrees C or less.
The aggregation temperature in the case of performing aggregation only by heating without using an electrolyte is usually (Tg-20) ° C. or higher, preferably (Tg-10) ° C. or higher, where Tg is the glass transition temperature of the polymer primary particles. . Moreover, it is below Tg normally and is below (Tg-5) degreeC.

  The time required for agglomeration is optimized depending on the shape of the apparatus and the processing scale, but in order for the toner particle size to reach the target particle size, it is usually held at the predetermined temperature for at least 30 minutes. desirable. The temperature rise until reaching the predetermined temperature may be raised at a constant rate, or may be raised stepwise.

  If necessary, particles having adhered or fixed resin particles may be formed on the surface of the particle aggregate after the above-described aggregation treatment. In some cases, the chargeability and heat resistance of the obtained toner can be improved by attaching or fixing the resin particles whose properties are controlled to the surface of the particle aggregate, and the effect of the present invention can be further enhanced. .

  When resin particles having a glass transition temperature higher than that of the polymer primary particles are used as the resin particles, it is preferable because blocking resistance can be further improved without impairing fixing properties. The volume average particle diameter of the resin particles is usually 0.02 μm or more, preferably 0.05 μm or more. Moreover, it is 3 micrometers or less normally, and 1.5 micrometers or less are preferable. As the resin particles, those obtained by emulsion polymerization of monomers similar to the polymerizable monomers used for the above-mentioned polymer primary particles can be used.

  Resin particles are usually used as a dispersion dispersed in water or a liquid mainly composed of water with a surfactant. However, when a charge control agent is added after the aggregation treatment, charge control is performed on the dispersion containing particle aggregates. It is preferable to add the resin particles after adding the agent.

  In order to increase the stability of the particle aggregate obtained in the aggregation step, it is preferable to perform fusion in the aggregated particles in the aging step after the aggregation step. The temperature of the aging step is usually at least Tg of the polymer primary particles, preferably at least 5 ° C higher than Tg, and usually at most 80 ° C higher than Tg, preferably at most 50 ° C higher than Tg. The time required for the aging step varies depending on the shape of the target toner, but after reaching the glass transition temperature or higher of the polymer primary particles, it is usually held for 0.1 to 10 hours, preferably 1 to 6 hours. Is desirable.

  In addition, it is preferable to add a surfactant or raise the pH value after the aggregation process, preferably before the aging process or during the aging process. As the surfactant used here, one or more emulsifiers can be selected from the emulsifiers that can be used when producing the polymer primary particles. In particular, the emulsifiers used when producing the polymer primary particles. It is preferable to use the same. The addition amount in the case of adding the surfactant is not limited, but is usually 0.1 parts by mass or more, preferably 1 part by mass or more, particularly preferably 3 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. It is. Moreover, it is 20 mass parts or less normally, Preferably it is 15 mass parts or less, Most preferably, it is 10 mass parts or less. After the aggregation process, before the completion of the ripening process, by adding a surfactant or raising the pH value, it is possible to suppress aggregation of the particle aggregates aggregated in the aggregation process, In some cases, the generation of coarse particles can be suppressed.

By heat treatment in the aging step, the polymer primary particles in the aggregate are fused and integrated, and the toner particle shape as the aggregate becomes close to a spherical shape. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. In addition, the shape of the toner particles can be made nearly spherical. According to such an aging process, by controlling the temperature and time of the aging process, the shape of the polymer primary particles is agglomerated, a potato type with advanced fusion, a spherical form with further fusion For example, various shapes of toner can be manufactured according to the purpose.
The obtained particles are subjected to solid-liquid separation by a known method, the particles are collected, and washed and dried as necessary to obtain target toner mother particles.

<External addition process>
The toner of the present invention can be obtained by externally adding the above-described composite oxide particles (a), silica particles (b) and higher fatty acid metal salts (c) to the surface of the toner base particles. In the range not impairing the above-mentioned silica particles (b), the particles (d) of reverse chargeability and other particles known as external additives are used in combination and added to the toner base particles. It may be adhered or fixed to the surface.

  Examples of the particles other than the composite oxide particles (a), silica particles (b), higher fatty acid metal salts (c), and particles (d) described above include, for example, titania, aluminum oxide (alumina), zinc oxide as inorganic particles. , Tin oxide, barium titanate, strontium titanate, hydrotalcite, etc., methacrylic acid ester polymer particles, acrylic acid ester polymer particles, styrene-methacrylic acid ester copolymer particles, styrene-acrylic acid ester co Examples thereof include organic resin particles such as polymer particles.

  The compounding ratio of the composite oxide particles (a), silica particles (b), higher fatty acid metal salts (c), particles (d) and other particles is not particularly limited, and the composite oxide particles (a) and silica particles (b ), The amount of the total external additive composed of the higher fatty acid metal salt (c), the particles (d), and other particles is not particularly limited, but the amount of the total external additive used with respect to 100 parts by mass of the toner base particles. Is usually 1.3 parts by mass or more, preferably 1.4 parts by mass or more, and is usually 3.7 parts by mass or less, preferably 3.6 parts by mass or less. If the amount used is too small, the surface of the base particle surface of the external additive becomes conspicuous and the fog may deteriorate. On the other hand, if the amount is too large, there may be an image defect due to the missing of the cleaning blade due to excessive fluidity. The coverage of the mother particle surface with the external additive is measured by the method described in the examples.

  The order of attaching or fixing the other particles to the surface of the toner base particles is not particularly limited, but the composite oxide particles (a), silica particles (b), higher fatty acid metal salts (c) and particles (d) are not limited. May be used together, or may be added separately without being used together.

  In the present invention, the method of adhering or fixing the composite oxide particles (a), the silica particles (b), the higher fatty acid metal salt (c), the particles (d) and other particles to the surface of the toner base particles is particularly preferable. There is no limitation, and a mixer generally used for the production of toner can be used. Specifically, it is made by stirring and mixing with a mixer such as a Henschel mixer, a V-type blender, a Redige mixer, or a Q-mixer.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, “part” means “part by mass”, and “%” means “% by mass”.

<Measurement method of average particle diameter of polymer primary particles>
Nikkiso Co., Ltd., Model: Microtrac Nanotrac 150 (hereinafter abbreviated as “Nanotrack”), according to the instruction manual of NanoTrack, using its analysis software Microtrac Particle Analyzer Ver10.1.2.-019EE Using ion-exchanged water having a degree of 0.5 μS / cm as a dispersion medium, the measurement was performed by the method described in the instruction manual under the following conditions or by inputting the following conditions.

Solvent refractive index: 1.333
・ Measurement time: 100 seconds
・ Number of measurements: 1 time
-Particle refractive index: 1.59
・ Transparency: Transmission
・ Shape: Spherical shape
Density: 1.04

<Method for Measuring Volume Median Diameter (Dv50) of Toner Particles>
Use Beckman Coulter's Multisizer III (aperture diameter 100 μm) (hereinafter abbreviated as “Multisizer”), use the company's Isoton II as the dispersion medium, and disperse so that the dispersoid concentration is 0.03% by mass. And measured. The measurement particle diameter range is from 2.00 to 64.00 μm, and this range is discretized into 256 divisions so as to be equidistant on a logarithmic scale, and the volume calculated based on the statistical values on the basis of the volume is the volume. The median diameter (Dv50) was used.

<Measurement method of circularity>
In the present invention, the “average circularity” is determined by dispersing toner base particles in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) so as to be in the range of 5720 to 7140 particles / μL. The measurement is performed under the following apparatus conditions using a company (former Toa Medical Electronics Co., Ltd., FPIA 3000), and the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-Number of detected HPFs: 2000 to 2500 The following are measured by the above apparatus and automatically calculated and displayed in the above apparatus, but "circularity" is defined by the following equation.

[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
And 2000-2500 which is the number of HPF detection is measured, and the arithmetic average (arithmetic mean) of the circularity of each individual particle is displayed on the apparatus as “average circularity”.

[Measurement Method of Glass Transition Temperature (Tg) of Core Resin and Shell Resin of Mother Particle]
It was measured by DSC7 manufactured by PerkinElmer. 10 mg of sample is put in an aluminum pan, heated from 30 ° C. to 100 ° C. in 7 minutes, rapidly cooled from 100 ° C. to −20 ° C., and heated from −20 ° C. to 100 ° C. in 12 minutes. The Tg value observed when the temperature was increased was used. When there are a plurality of endothermic peaks, the lowest endothermic peak temperature is defined as Tg. The core resin and the shell resin are measured by drying the water in the dispersion, and when the endothermic peak of the wax particles interferes, a polymer without wax particles is produced.

<Method for measuring average primary particle size of external additive>
The average primary particle size of the external additive of the present invention can be measured using a transmission electron microscope image. For example, on a transmission electron microscope image, several thousands of particles are randomly selected from the target external additive, and the average primary particle diameter is obtained by the number average of the particle diameters or the BET specific surface area measurement value is used. There is a method for obtaining a converted equivalent diameter.

<Method for measuring BET specific surface area of external additive and toner>
Measurement is performed by a one-point method using liquid nitrogen using a Macsorb model-1208 manufactured by Mountec Co., Ltd. Specifically, it is as follows.
First, about 1.0 g of a measurement sample is filled in a glass dedicated cell (hereinafter, this sample filling amount is referred to as A (g)). Next, the cell is set on the measuring device main body, dried and deaerated at 200 ° C. for 20 minutes in a nitrogen atmosphere, and then the cell is cooled to room temperature. Thereafter, while the cell is cooled with liquid nitrogen, a measurement gas (mixed gas of 30% primary nitrogen and 70% helium) is flowed into the cell at a flow rate of 25 mL / min, and the amount of measurement gas adsorbed V (cm ³ ) Measure. When the total surface area of the sample is S (m ² ), the desired BET specific surface area (m ² / g) can be calculated by the following calculation formula.

(BET specific surface area) = S / A
= [K. (1-P / P0) .V] / A
K: Gas constant (4.29 in this measurement)
P / P0: relative pressure of the adsorbed gas, 97% of the mixing ratio (0.29 in this measurement)

<Method for measuring carbon content of composite oxide particles and silica particles>
Measurement was carried out by a combustion method using EMIA-110 manufactured by Horiba. Specifically, 0.1 g of the sample was carefully evaluated as a magnetic board, burned at about 1,200 ° C., and the carbon content was measured.

<Measurement method of charge amount>
In the present invention, the charge amount of the inorganic particles is measured under the following conditions.
Carrier at a temperature of 23 ° C. and a humidity of 55%: Uncoated ferrite carrier (particle size 80 μm, manufactured by Powdertech) 19.8 g
Inorganic particles: 0.2g
Is placed in a 20 ml glass bottle and left for 12 hours or longer. Thereafter, the mixture is mixed 50 times by hand shaking and stirred for 1 minute at an amplitude of 1.0 cm and a shaking speed of 500 rpm.

0.2 g is taken out from the glass bottle and measured with the blow-off TB-200 apparatus manufactured by Toshiba Chemical under the following settings.
N2 pressure gauge: 1.0Kg / cm ²
SET TIME: 20.0sec
Wire mesh set on Faraday gauge (Stainless steel: 400 mesh)
The charge amount Q / M (μC / g) per unit mass can be obtained by calculating the read value Q (μC) by the following formula.
Q / M (μC / g) = − (Q (μC) / (measured mass (g))

<Measurement method of true specific gravity>
The true specific gravity was measured according to JIS-K-0061 5-2-1 using a Le Chatelier specific gravity bottle. The operation was performed as follows.
(1) About 250 ml of ethyl alcohol is put into a Lechatelier specific gravity bottle and adjusted so that the meniscus is at the position of the scale.
(2) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature reaches 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(3) About 100 g of a sample is weighed and its mass is set to W.
(4) Put the weighed sample in a specific gravity bottle to remove bubbles.
(5) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature becomes 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(6) The true specific gravity is calculated by the following formula.
D = W / (L2-L1)
S = D / 0.9982

In the formula, D is the density of the sample (20 ° C.) (g / cm ³ ), S is the true specific gravity of the sample (20 ° C.), W is the apparent mass of the sample (g), and L1 is before the sample is placed in the specific gravity bottle. Meniscus reading (20 ° C.) (ml), L2 is the meniscus reading (20 ° C.) (ml) after placing the sample in the density bottle, 0
. 9982 is the density of water at 20 ° C. (g / cm ³ ).

[Manufacture of mother particles]
<Preparation of wax / long-chain polymerizable monomer dispersion A1>
Paraffin wax (Nippon Seiki Co., Ltd., HNP-9) 27 parts, stearyl acrylate (Tokyo Kasei Co., Ltd.) 2.8 parts, 20% sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D) 1.9 parts (abbreviated as “20% DBS aqueous solution”) and 68.3 parts of demineralized water were heated to 90 ° C. and stirred for 10 minutes using a homomixer (Mark IIf model manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, this dispersion was heated to 90 ° C., and circulation emulsification was started under a pressure condition of 25 MPa using a homogenizer (manufactured by Gorin, 15-M-8PA type). A wax / long-chain polymerizable monomer dispersion A1 (emulsion solid content concentration = 30.2%) was prepared by dispersing until the diameter (MV) reached 250 nm.

<Preparation of polymer primary particle dispersion A1>
35.6 parts of wax / long chain polymerizable monomer dispersion A1 and 259 parts of demineralized water are added to a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device. Was heated to 90 ° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and an aqueous emulsifier solution was added over 5 hours from the start of polymerization while stirring was continued. The time when the mixture of the monomers and the emulsifier aqueous solution was started to be dropped was set as the polymerization start, and the following initiator aqueous solution was added over 4.5 hours from 30 minutes after the start of the polymerization. The aqueous solution of the agent was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Monomers]
Styrene 76.8 parts Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Trichlorobromomethane 1.0 part Hexanediol diacrylate 0.7 part
[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part demineralized water 67.1 parts
[Initiator aqueous solution]
8% aqueous hydrogen peroxide solution 15.5 parts 8% L (+)-ascorbic acid aqueous solution 15.5 parts
[Additional initiator aqueous solution]
8% L (+)-ascorbic acid aqueous solution 14.2 parts After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white primary polymer particle dispersion A1. The volume average particle diameter (MV) measured using a nanotrack was 280 nm, and the solid content concentration was 21.1%.

<Manufacture of mother particle A>
Polymer primary particle dispersion A1 90 parts as solid content Polymer primary particle dispersion A1 10 parts as solid content (added later)
Carbon Black Dispersion (Mitsubishi Chemical Corporation MA100S) 6.0 parts 20% DBS aqueous solution as a colorant solid content 0.1 parts as a solid content Using the above components, mother particles were produced by the following procedure.

Polymer primary particle dispersion A1 and 20% DBS aqueous solution were charged into a mixer equipped with a stirrer (double helical blade), heating / cooling device, concentrating device, and raw material / auxiliary charging device, and an internal temperature of 12
Mix uniformly at 5 ° C. for 5 minutes. Subsequently, while continuing stirring at an internal temperature of 12 ° C., 0.52 parts of 5% aqueous solution of ferrous sulfate as FeSO ₄ · 7H ₂ O was added over 5 minutes, and then the colorant fine particle dispersion A was added over 5 minutes. The mixture was uniformly mixed at an internal temperature of 12 ° C., and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content with respect to the resin solid content was 0.10 parts). Thereafter, the temperature was raised to 53 ° C. over 75 minutes, and further raised to 56 ° C. over 90 minutes. Here, when the volume median diameter was measured using a multisizer, it was 5.2 μm. Thereafter, the polymer primary particle dispersion A1 (addition after addition) was added over 3 minutes and held for 60 minutes, and then a 20% DBS aqueous solution (6 parts as solids) was added over 10 minutes. The temperature was raised to 90 ° C. over 30 minutes and held for 75 minutes.

  Thereafter, the slurry obtained by cooling to 30 ° C. over 20 minutes was extracted, and suction filtration was performed with an aspirator using 5 types C (No5C manufactured by Toyo Roshi Kaisha, Ltd.) filter paper. The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), and ion-exchanged water having an electric conductivity of 1 μS / cm was added and stirred to uniformly disperse, and then stirred for 30 minutes. .

  After that, again using 5 kinds C (No. 5C manufactured by Toyo Roshi Kaisha, Ltd.) filter paper, suction filtration is performed with an aspirator, and the solid matter remaining on the filter paper is equipped with a stirrer (propeller blade) and has an electric conductivity of 1 μS / cm. It moved to the container containing ion-exchange water, and it was made to disperse | distribute uniformly by stirring and was stirred for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm.

The cake obtained here was spread on a stainless pad so as to have a height of 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain mother particles A. The resulting toner base particle A had a volume median diameter of 6.3 μm and an average circularity of 0.960.
In Examples and Comparative Examples, the following silica particles X and Y were used.
Silica particle X: The raw material is prepared by a wet method, and the surface is treated with hexamethyldisilazane. (BET
: 42.95 m ² / g, true specific gravity 2.2, negative chargeability)
Silica particle Y: The raw material is prepared by a wet method, and the surface is treated with hexamethyldisilazane. (BET
: 36.53 m2 / g, true specific gravity 2.2, negative chargeability)
In the examples and comparative examples, the following titania, silica composite oxide particles P, and titania r were used.
Titania and silica composite oxide particles P
(Average primary particle diameter: 18 nm, BET: 56.1 m ² / g, charge amount: −138.3 μC / g)
Titania
(Average primary particle size: 15 nm, BET: 91.0 m ² / g, charge amount: −30.4 μC / g)

[Example 1]
<Manufacture of toner A>
1.0 part of silica particles X, 0.6 part of titania and silica composite oxide particles P, positively charged silica (average primary particle size 8 nm, BET: 118.8 m) with respect to base particle A (100 parts) ² / g, charge amount: +509.3 μC / g, true specific gravity 2.2) is added 0.225 parts, higher fatty acid metal salt (average primary particle size 900 nm, BET: 10.64 m ² / g, charge amount) : 50.9μC / g)
Toner A was obtained by stirring and mixing with a Henschel mixer at 3000 rpm for 15 minutes and sieving.

[Example 2]
<Manufacture of toner B>
In Example 1, Toner B was obtained in the same manner as in Example 1 except that the addition part of the higher fatty acid metal salt was changed to 0.2 part.

Example 3
<Manufacture of toner C>
In Example 1, Toner C was obtained in the same manner as in Example 1 except that the addition part of the higher fatty acid metal salt was changed to 0.1 part.

[Comparative Example 1]
<Manufacture of toner D>
In Example 1, Toner D was obtained in the same manner as in Example 1 except that 0.05 part of the higher fatty acid metal salt was added.

[Comparative Example 2]
<Manufacture of toner E>
In Example 1, Toner E was obtained in the same manner as in Example 1 except that the added part of the higher fatty acid metal salt was changed to 0 part.

<Manufacture of toner F>
In Example 1, Toner F was obtained in the same manner as in Example 1 except that the addition part of the higher fatty acid metal salt was changed to 0 part and 0.5 part of silica Y was added.
<Manufacture of toner G>
A toner G was obtained in the same manner as in Example 1 except that 0.5 part of silica Y was added.

<Manufacture of toner H>
In Example 1, Toner H was obtained in the same manner as in Example 1 except that the addition part of the higher fatty acid metal salt was 0.2 part and 0.5 part of silica Y was added.
<Manufacture of Toner I>
In Example 1, a toner H was obtained in the same manner as in Example 1 except that titania r was used in place of titania and silica composite oxide particles P.

<Manufacture of toner J>
In Example 1, toner J was obtained in the same manner as in Example 1 except that titania r was used in place of titania and silica composite oxide particles P, and the number of added higher fatty acid metal salt was 0.2 parts. .
<Manufacture of toner K>
In Example 1, toner K was obtained in the same manner as in Example 1 except that titania r was used instead of titania and silica composite oxide particles P, and the number of added higher fatty acid metal salt was 0.1 parts. .

<Manufacture of toner L>
In Example 1, a toner L was obtained in the same manner as in Example 1 except that titania r was used in place of the titania and silica composite oxide particles P, and the number of added higher fatty acid metal salt was 0 parts.
<Manufacture of toner M>
In Example 1, titania r was used in place of titania and silica composite oxide particles P, the addition part of the higher fatty acid metal salt was 0 part, and 0.5 part of silica Y was added. Thus, Toner M was obtained.

<Manufacture of toner N>
In Example 1, toner N was obtained in the same manner as in Example 1 except that titania r was used instead of titania and silica composite oxide particles P, and 0.5 part of silica Y was added.
<Manufacture of toner O>
Example 1 Example 1 except that titania r was used in place of titania and silica composite oxide particles P, the addition part of the higher fatty acid metal salt was 0.2 part, and 0.5 part of silica Y was added. In the same manner as above, a toner O was obtained.
The details of the external additive formulations of Examples and Comparative Examples are shown in Table 1.

<Evaluation method>
The obtained toner was evaluated for actual shooting on the following items.
1. 1. Cleanability 2. Image density 3. Toner consumption The solid followability evaluation results are shown in Table-2.

<Method of live-action test>
For live-action test, non-magnetic two-component contact development method, using organic photoreceptor (OPC), roller charging, process speed 154.0 mm / second, tandem method, intermediate transfer method, thermal fixing method, blade drum cleaning method A full color printer was used.
After printing several sheets under an environment of 25 ° C. and 50%, a chart with a printing rate of 5% was printed up to a total of 36,000 sheets. Then, every 500 prints in the 2,000 prints, a toner weight measurement, a solid image and a density measurement image are printed, and the presence or absence of streaks (cleaning property) due to scratches on the OPC surface is determined by OPC. The actual product and images were visually confirmed. The criteria for determining the cleaning property are as follows.
○: No scratches on the OPC surface and no streaks appear on the image Δ: No scratches are observed on the OPC surface, but no streaks appear on the image ×: Scratches on the OPC surface and streaks on the image Both are recognized, causing problems in actual use.

<Toner consumption>
The criteria for determining the toner consumption are as follows.
○: Average consumption per 1000 sheets is less than 18 g. Δ: Average consumption per 1000 sheets is 18 g or more and less than 20 g. ×: Average consumption per 1000 sheets is 20 g or more.

<Image density>
For the measurement of the image density, a spectral densitometer 500 series (manufactured by X-Rite Co., Ltd.) was used, and the measurement was carried out with a viewing angle of 10 ° and an observation condition of F2.
Judgment criteria are as follows.
○: ΔID is 1.25 or more Δ: ΔID is 1.14 or more and less than 1.25 ×: ΔID is less than 1.14

<Flat followability>
The criteria for determining the solid followability are as follows.
○: A flat image with good followability is obtained. △: The followability is slightly inferior and there is a slight difference in density of the developing roller cycle in the solid image, but there is no problem in practical use. In the solid image, there is a clear gradation difference in the developing roller cycle, which hinders practical use.

From the above results, compared with Examples 1 and 2 and Comparative Examples 1 and 2 which are less than the amount of metal fatty acid zinc specified in the present invention, the present invention has a good CL defect and a sufficiently high image density. It can be seen that the performance is compatible. Further, it can be seen that the image density of the present invention is sufficiently high when compared with Examples 1 and 2 and Comparative Examples 4 and 5 using silica smaller than the specific surface area of the silica particles defined in the present invention. Further, when Examples 1, 2 and 3 are compared with Comparative Examples 6, 7 and 8 using titania other than the composite oxide defined in the present invention, the present invention has reduced toner consumption, and solid tracking. It can be seen that the product has sufficient performance.

Claims (4)

A toner having toner base particles containing a binder resin, a colorant, and a wax, and an external additive, the external additive being a surface treated with composite oxide particles (a) and hexamethyldisilazane. A toner for developing an electrostatic charge image, which contains particles (b) and a higher fatty acid metal salt (c) and satisfies the following (A) to (C).
(A) The composite oxide particles (a) have a core-shell structure, and the composite oxide particles (a)
Ones of the core portions contain titania shell portion specific surface area containing silica (B) the silica particles (b) is less than ^{40 m} 2 / g or more 120 m ² / g
The addition amount of the high-grade fatty acid metal salt (c) is at most 0.5 part by mass or more 0.1 part by mass relative to consist only (C) toner base particles 100 parts by weight 2. The electrostatic image developing toner according to claim 1, wherein the content of silica in the composite oxide particles (a) satisfying (A) is 6% by mass or more and 20% by mass or less. The electrostatic image developing toner according to claim 1 or 2, wherein the silica (b) satisfying the (B) is negatively charged. Wherein (B) that satisfies silica (b) the carbon content of any one of claims 1 to 3, characterized in that at most 2.5% by mass to 0.5% by mass of Toner for developing electrostatic images.