JP2016062082A - Toner for electrostatic charge image development, electrostatic charge image developer, image forming method, and image forming apparatus, and toner set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that can suppress the occurrence of fogging and has excellent color reproducibility in images to be formed.SOLUTION: There is provided a toner for electrostatic charge image development that contains toner base particles including at least a binder resin and colorant, and metatitanic acid particles, as an external additive, having a crystallite diameter of 12.0 to 16.0 nm, subjected to hydrophobing treatment, and having an absolute specific gravity of 2.5 to 3.3 g/cm. It is preferable that the number average particle diameter of the metatitanic acid particles is 20 to 60 nm, and the coverage of the toner base particles with the metatitanic acid particles is 20 to 50%.SELECTED DRAWING: None

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, an image forming method, an image forming apparatus, and a toner set.

  A method of visualizing image information through an electrostatic latent image, such as electrophotography, is currently widely used in various fields. In the electrophotographic method, the electrostatic latent image on the surface of the photosensitive member (image holding member) is developed with a developer containing toner through a charging step, an exposure step, and the like, and the electrostatic process is performed through a transfer step, a fixing step and the like. The latent image is visualized.

As conventional toners, for example, those described in Patent Documents 1 to 3 are known.
Patent Document 1 discloses a toner particle containing at least an amorphous resin, a crystalline resin, a colorant, a release agent, and metatitanic acid particles, and a number average particle diameter of 10 nm to 50 nm. And an external additive containing at least the hydrophobized metatitanic acid and the hydrophobized silicon oxide having a number average particle size of 30 nm to 180 nm in the release agent domain of the toner particles. An electrostatic charge image developing toner containing the metatitanic acid particles and having a shape factor SF1 of 135 to 150 is described.
In Patent Document 2, in an electrophotographic toner containing at least two kinds of external additives, the external addition process for adding the external additives is composed of a plurality of stages, and the metatitanic acid fine particles are externally added as the external additives in the final stage. A toner for electrophotography is described.
Patent Document 3 discloses an electrostatic charge image developing toner having at least toner particles and hydrophobic titanium oxide fine particles, and the hydrophobic titanium oxide fine particles have a range of 2θ = 20.0 to 40.0 deg in X-ray diffraction. A toner for developing an electrostatic charge image, wherein the intensity ratio (I _a / I _b ) of the maximum intensity I _a and the minimum intensity I _b is 5.0 ≦ I _a / I _b ≦ 12.0. Has been.

JP 2010-78862 A JP 2007-322939 A JP-A-10-207117

  An object of the present invention is to provide an electrostatic image developing toner that can suppress the occurrence of fog in an image to be formed and has excellent color reproducibility.

The above-described problems of the present invention have been solved by means described in the following <1> and <4> to <7>. It is shown below with <2> and <3> which are preferable embodiments.
<1> Toner base particles containing a binder resin and a colorant and, as an external additive, a crystallite diameter of 12.0 to 16.0 nm, a hydrophobic treatment, and a true specific gravity of 2.5 to An electrostatic charge image developing toner comprising: 3.3 g / cm ³ of metatitanic acid particles;
<2> The electrostatic charge image developing toner according to <1>, wherein the number average particle diameter of the metatitanic acid particles is 20 to 60 nm, and the coverage of the toner base particles with the metatitanic acid particles is 20 to 50%. ,
<3> The electrostatic charge image developing toner according to <1> or <2>, wherein the toner has a volume average particle size of 3.0 to 7.0 μm.
<4> An electrostatic image developer comprising the electrostatic image developing toner according to any one of <1> to <3> and a carrier,
<5> A charging step for charging at least the image carrier, an exposure step for forming an electrostatic latent image on the surface of the image carrier, and an electrostatic image developer for forming the electrostatic latent image formed on the surface of the image carrier. A developing step for forming a toner image by developing the toner image, a transfer step for transferring the toner image formed on the surface of the image carrier to the surface of the transfer target, and a fixing step for fixing the toner image, An image forming method, wherein the developer is the electrostatic charge image developing toner according to any one of <1> to <3>, or the electrostatic charge image developer according to <4>;
<6> An image carrier, a charging unit for charging the image carrier, an exposure unit for exposing the charged image carrier to form an electrostatic latent image on the image carrier, and a developer. A developing unit that develops an electrostatic latent image to form a toner image; a transfer unit that transfers the toner image from the image holding member to a transfer target; and a fixing unit that fixes the toner image; An image forming apparatus, wherein the developer is the electrostatic image developing toner according to any one of <1> to <3>, or the electrostatic image developer according to <4>;
<7> The electrostatic image developing toner according to any one of <1> to <3>, wherein the colorant is a cyan colorant, and <1> to <3>, wherein the colorant is a magenta colorant. The electrostatic image developing toner according to any one of the above, the electrostatic image developing toner according to any one of <1> to <3>, wherein the colorant is a yellow colorant, and the colorant. A toner set comprising at least the electrostatic image developing toner according to any one of <1> to <3>, which is a black colorant.

According to the invention described in <1> above, as an external additive, the crystallite diameter is 12.0 to 16.0 nm, the surface is hydrophobized, and the true specific gravity is 2.5 to 3.3 g / cm ^3. As compared with the case of not containing metatitanic acid particles, it is possible to provide an electrostatic image developing toner that can suppress the occurrence of fog in an image to be formed and is excellent in color reproducibility.
According to the invention described in <2> above, the number average particle diameter of the metatitanic acid particles is less than 20 nm or more than 60 nm, or the coverage of the toner base particles with the metatitanic acid particles is less than 20% or more than 50%. Compared to the case, it is possible to provide an electrostatic image developing toner that is superior in color reproducibility in an image to be formed.
According to the invention described in the above <3>, the electrostatic charge image developing toner which is superior in color reproducibility in an image to be formed compared to a case where the volume average particle diameter of the toner is less than 3.0 μm or more than 7.0 μm Can be provided.
According to the invention described in <4> above, as an external additive for the toner, the crystallite diameter is 12.0 to 16.0 nm, the surface is hydrophobized, and the true specific gravity is 2.5 to 3.3 g / Compared to the case where no metatitanic acid particles of cm ³ are contained, it is possible to provide an electrostatic charge image developer that can suppress the occurrence of fog in an image to be formed and has excellent color reproducibility.
According to the invention described in <5> above, as an external additive for the toner, the crystallite diameter is 12.0 to 16.0 nm, the surface is hydrophobized, and the true specific gravity is 2.5 to 3.3 g / Compared with the case where no metatitanic acid particles of cm ³ are contained, it is possible to provide an image forming method that can suppress the occurrence of fog in an image to be formed and is excellent in color reproducibility.
According to the invention described in <6>, the external additive of the toner has a crystallite diameter of 12.0 to 16.0 nm, a hydrophobic treatment, and a true specific gravity of 2.5 to 3.3 g / Compared to the case where no metatitanic acid particles of cm ³ are contained, it is possible to provide an image forming apparatus that can suppress the occurrence of fog in an image to be formed and is excellent in color reproducibility.
According to the invention described in <7> above, as an external additive for each color toner, the crystallite diameter is 12.0 to 16.0 nm, the surface is hydrophobized, and the true specific gravity is 2.5 to 3.3 g. As compared with the case where no metatitanic acid particles of / cm ³ are contained, it is possible to provide a toner set that is superior in color reproducibility in an image to be formed.

  Hereinafter, this embodiment will be described in detail. In the present embodiment, the description “A to B” represents not only a range between A and B but also a range including A and B at both ends thereof.

(Electrostatic image developing toner)
The electrostatic image developing toner of the present embodiment (hereinafter also simply referred to as “toner”) has toner base particles containing a binder resin and a colorant, and a crystallite diameter of 12.0 to as an external additive. And metatitanic acid particles having a true specific gravity of 2.5 to 3.3 g / cm ³ and having a hydrophobization treatment of 16.0 nm.

As a result of detailed studies by the present inventors, it has been found that the metatitanic acid particles hydrophobized to suppress the occurrence of fogging in the formed image are effective as an external additive. It was found that there was a problem that the color reproducibility deteriorated due to scattering due to the crystal structure and scattering due to the hydrophobic treatment of the metatitanic acid particle surface. The deterioration of color reproducibility appears more prominently as deterioration of saturation in secondary colors including special colors such as green, orange and violet.
As a result of further studies by the present inventors, as an external additive, the crystallite diameter is 12.0 to 16.0 nm, the surface is hydrophobized, and the true specific gravity is 2.5 to 3.3 g / cm ³ . It has been found that by containing metatitanic acid, an electrostatic charge image developing toner having excellent color reproducibility can be obtained by suppressing the occurrence of fog in the formed image. The mechanism by which detailed effects are manifested is unknown.

<Metatitanic acid particles>
The electrostatic charge image developing toner of this embodiment has a crystallite diameter of 12.0 to 16.0 nm as an external additive, a hydrophobic treatment, and a true specific gravity of 2.5 to 3.3 g / cm ³ . Contains certain metatitanic acid particles.
The metatitanic acid particles are particles containing TiO (OH) ₂ as a main component, and the content of TiO (OH) ₂ is preferably 50% by weight, and 80% by weight with respect to the total weight of the particles. More preferably, it is more preferably 90% by weight.
Examples of other components in the metatitanic acid particles include TiO ₂ and a compound derived from a surface treatment agent described later.
In this embodiment, what was synthesize | combined by the sulfuric acid method as metatitanic acid may be used.
As the sulfuric acid method, titanium ore, ilmenite ore (FeTiO ₃ ), titanium oxide (TiO ₂ ), etc. are heated and dissolved in concentrated sulfuric acid to prepare a solution of titanium sulfate (Ti (SO ₄ ) ₂ ). A preferred method is to obtain particulate metatitanic acid by heat hydrolysis.

The crystallite diameter of the metatitanic acid particles is 12.0 to 16.0 nm, preferably 12.0 to 15.0 nm, and more preferably 12.0 to 14.0 nm. Within the above range, scattering by the metatitanic acid particles is appropriate, and the color reproducibility in the image is excellent.
The “crystallite” in this embodiment means individual single crystals constituting a polycrystal or a single crystal observed in an amorphous state.
The method for measuring the crystallite size of the metatitanic acid particles in the present embodiment is as follows.
The peak of the (101) plane of the metatitanic acid particles is measured by powder X-ray diffraction method, and the average value L of the crystallite diameter can be obtained from the following formula (1) of Scherrer. The crystallite diameter of
L = Kλ / (βcos θ) (1)
Here, K is a constant, λ is a wavelength, β is a half width, and θ is an incident angle.

True specific gravity of the metatitanic acid particles are 2.5~3.3g / cm ^3, is preferably 2.6~3.1g / cm ^3, is 2.7~2.9g / cm ³ It is more preferable. Within the above range, scattering by the metatitanic acid particles is appropriate, and the color reproducibility in the image is excellent.
The true specific gravity of the metatitanic acid particles is the specific gravity of the substance itself constituting the metatitanic acid particles that do not include voids and is also called true density.
The true specific gravity of the metatitanic acid particles in the present embodiment employs a value measured according to a method (pycnometer method) defined in JIS K5600-11-1.

The metatitanic acid particles are particles whose surfaces are hydrophobized.
The method for hydrophobizing metatitanic acid particles is not particularly limited, and the treatment can be performed using a known hydrophobizing agent.
Although there is no restriction | limiting in particular as a hydrophobization processing agent, For example, coupling agents, such as a silane coupling agent, a titanate coupling agent, or an aluminum coupling agent, or silicone oil etc. are mentioned. The hydrophobizing agent may be used alone or in combination of two or more.

As the silane coupling agent, for example, any of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, hexamethyldisilazane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, isobutyltrimethoxysilane, octyltrimethoxysilane, dimethyldimethoxy Silane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, Hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- (trimethylsilyl) urea tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyl Examples include trimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane.
Examples of other coupling agents include titanate coupling agents and aluminate coupling agents.
In order to perform the hydrophobic treatment using the coupling agent, the coupling agent may be added to the slurry of the metatitanic acid particles.
Examples of the silicone oil used for the hydrophobizing treatment include dimethyl silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, and the like.
Examples of the method for hydrophobizing using silicone oil include a general spray drying method, but are not particularly limited as long as the surface treatment can be performed.
In the present embodiment, metatitanic acid particles hydrophobized with alkoxysilane are preferred from the viewpoint of uniform treatment (high degree of hydrophobization).
Among these, as the hydrophobizing agent, hexamethyldisilazane, isobutyltrialkoxysilane, octyltrialkoxysilane, and silicone oil are preferable.
The amount of the hydrophobizing agent used is preferably 5 to 80 parts by weight and more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the metatitanic acid particles.

The number average particle diameter of the metatitanic acid particles is preferably 20 to 60 nm, more preferably 20 to 50 nm, and still more preferably 20 to 40 nm.
In the present embodiment, the number average particle diameter of the metatitanic acid particles refers to a particle diameter measured by the following method.
The externally added toner is observed using a scanning electron microscope (SEM), and the particle diameter of the external additive adhering to the toner surface is measured. The measurement conditions are a magnification of 30,000, a visual field: two visual fields, and a measurement number of 100. The particle diameter refers to the diameter of a circle having an area equal to the observed projected area of the external additive.
Based on the measurement results, the particle diameter is plotted as the X axis and the number of particles (external additives) at each particle diameter is plotted as the Y axis, and the particle diameter corresponding to the peak is defined as the number average particle diameter. When two or more peaks are present, the particle diameter corresponding to each peak is defined as the number average particle diameter.

The content of metatitanic acid particles contained in the toner as an external additive is preferably 0.1 to 10 parts by weight and preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the toner base particles. Is more preferable, and it is still more preferable that it is 0.3-2 weight part.
In the electrostatic charge image developing toner of this embodiment, the coverage of the toner base particles with the metatitanic acid particles is preferably 20 to 50%, and more preferably 30 to 40%.
As a method for measuring the coverage of toner base particles with metatitanic acid particles in this embodiment, a scanning electron microscope S4700 (manufactured by Hitachi, Ltd.) was used, and 100 fields of toner particle surfaces were observed at a magnification of 10,000 times. Thereafter, the observed image of the toner surface is obtained by calculating the area of the portion of the toner surface where the metatitanic acid particles are adhered using an area analysis tool of image processing analysis software WinROOF (manufactured by Mitani Corporation).

<Toner base particles>
The electrostatic image developing toner of this embodiment contains toner base particles.
The toner base particles used in this embodiment contain at least a binder resin and a colorant, and if necessary, contain a release agent and the like.

-Binder resin-
The binder resin contained in the toner base particles is not particularly limited. For example, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic Esters having a vinyl group such as n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile, methacrylate Vinyl nitriles such as ronitrile; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Polyethylene such as ethylene, propylene and butadiene Homopolymer consisting of a monomer such as olefins include, or copolymers obtained by combining two or more kinds, even mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.

Styrene resin, (meth) acrylic resin, and styrene- (meth) acrylic copolymer resin are obtained by known methods, for example, by combining styrene monomers and (meth) acrylic acid monomers alone or in appropriate combination. It is done. “(Meth) acryl” is an expression including both “acryl” and “methacryl”.
When using a styrene resin, a (meth) acrylic resin or a copolymer resin thereof as a binder resin, the weight average molecular weight Mw is 20,000 or more and 100,000 or less, and the number average molecular weight Mn is 2,000 or more and 30,000 or less. It is preferable to use the thing of the range.

Among these, as the binder resin, a polyester resin is preferable.
The polyester resin used in this embodiment is synthesized from a polyol component and a polycarboxylic acid component by polycondensation. In addition, in this embodiment, a commercial item may be used as said polyester resin, and what was synthesize | combined suitably may be used.
Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid And aromatic dicarboxylic acids such as dibasic acids. Furthermore, these anhydrides and these lower alkyl esters are also exemplified, but not limited thereto.
Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, anhydrides thereof, and the like. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.
Furthermore, it is more preferable to contain a dicarboxylic acid component having an ethylenically unsaturated double bond in addition to the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having an ethylenically unsaturated double bond is preferably used to prevent hot offset at the time of fixing in that it can be radically crosslinked through the ethylenically unsaturated double bond. Examples of such dicarboxylic acids include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid, maleic acid and the like are mentioned in terms of cost.

Examples of the polyhydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2 -Bisphenol A alkylene (carbon number 2 to 4) oxide adduct (average number of added moles 1.5 to 6) such as bis (4-hydroxyphenyl) propane, ethylene glycol, propylene glycol, neopentyl glycol, 1, 4 -Butanediol, 1,3-butanediol, 1,6-hexanediol and the like.
Examples of the trihydric or higher polyhydric alcohol include sorbitol, pentaerythritol, glycerol, trimethylolpropane and the like.
In the amorphous polyester resin (also referred to as “non-crystalline polyester resin”), among the raw material monomers described above, a dihydric or higher secondary alcohol and / or a divalent or higher aromatic carboxylic acid compound is preferable. Examples of the dihydric or higher secondary alcohol include a propylene oxide adduct of bisphenol A, propylene glycol, 1,3-butanediol, and glycerol. In these, the propylene oxide adduct of bisphenol A is preferable.
As the divalent or higher aromatic carboxylic acid compound, terephthalic acid, isophthalic acid, phthalic acid and trimellitic acid are preferable, and terephthalic acid and trimellitic acid are more preferable.

Further, it is preferable to use a crystalline polyester resin as a part of the binder resin in order to impart low-temperature fixability to the toner.
The crystalline polyester resin is preferably composed of an aliphatic dicarboxylic acid and an aliphatic diol, and more preferably a linear dicarboxylic acid or a linear aliphatic diol having 4 to 20 carbon atoms in the main chain portion. The linear type is excellent in the crystallinity of the polyester resin and has an appropriate crystal melting point, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability. Further, when the carbon number is 4 or more, the ester bond concentration is low, the electric resistance is moderate, and the toner charging property is excellent. Further, when it is 20 or less, it is easy to obtain practical materials. The carbon number is more preferably 14 or less.

Examples of the aliphatic dicarboxylic acid suitably used for the synthesis of the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelinic acid, sebacic acid, 1,9-nonane. Dicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid An acid, 1,18-octadecanedicarboxylic acid or the like, or a lower alkyl ester or an acid anhydride thereof may be mentioned, but not limited thereto. Among these, considering availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable.
Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,14-eicosandecanediol and the like, but are not limited thereto. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

Among the polyvalent carboxylic acid components, the content of the aliphatic dicarboxylic acid is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic dicarboxylic acid is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, and therefore toner blocking resistance and image storage stability. And it is excellent in low-temperature fixability.
Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic diol component is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, so that it is excellent in toner blocking resistance, image storage stability, and low-temperature fixability.

In the present embodiment, the melting temperature Tm of the crystalline polyester resin is preferably 50 to 100 ° C, more preferably 50 to 90 ° C, and still more preferably 50 to 80 ° C. The above range is preferable because it is excellent in peelability and low-temperature fixability and further reduces offset.
Here, for the measurement of the melting temperature of the crystalline polyester resin, a differential scanning calorimeter was used, and JIS K-7121 was measured at a temperature rising rate of 10 ° C. per minute from room temperature (20 ° C.) to 180 ° C. : It can obtain | require as a melting peak temperature of the input compensation differential scanning calorimetry shown to 87. In addition, although crystalline polyester resin may show a some melting peak, in this embodiment, let the maximum peak be melting temperature.

On the other hand, the glass transition temperature (Tg) of the amorphous polyester resin is preferably 30 ° C. or higher, more preferably 30 to 100 ° C., and still more preferably 50 to 80 ° C. If it is in the above range, since it is in a glass state in use, toner particles do not aggregate due to heat and pressure received during image formation, and do not adhere and accumulate in the machine, and stable image forming ability over a long period of time. can get.
Here, the glass transition temperature of the non-crystalline polyester resin refers to a value measured by a method (DSC method) defined in ASTM D3418-82.
Moreover, the measurement of the glass transition temperature in this embodiment can be measured by, for example, “DSC-20” (manufactured by Seiko Denshi Kogyo Co., Ltd.) according to the differential scanning calorimetry, and specifically, about 10 mg of a sample. Is heated at a constant rate of temperature increase (10 ° C./min), and the glass transition temperature is obtained from the intersection of the baseline and the endothermic peak tilt line.

The weight average molecular weight of the crystalline polyester resin is preferably 10,000 to 60,000, more preferably 15,000 to 45,000, and still more preferably 20,000 to 30,000. .
The weight average molecular weight of the amorphous polyester resin is preferably 5,000 to 100,000, more preferably 10,000 to 90,000, and 20,000 to 80,000. Is more preferable.
It is preferable that the weight average molecular weights of the crystalline polyester resin and the non-crystalline polyester resin are within the above ranges because both the image strength and the fixability can be achieved. All of the above weight average molecular weights can be obtained by molecular weight measurement by gel permeation chromatography (GPC) method in which tetrahydrofuran (THF) is soluble. The molecular weight of the resin is calculated by using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample by measuring THF soluble material with THF solvent using TSK-GEL (GMH (manufactured by Tosoh Corporation)) etc. Is done.

The acid value of the crystalline polyester resin and the amorphous polyester resin is preferably 1 to 50 mgKOH / g, more preferably 5 to 50 mgKOH / g, and still more preferably 8 to 50 mgKOH / g. . The above range is preferable because it is excellent in fixing characteristics and charging stability.
If necessary, a monovalent acid such as acetic acid or benzoic acid or a monovalent alcohol such as cyclohexanol benzyl alcohol may be used for the purpose of adjusting the acid value or the hydroxyl value.

The production method of the polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. Depending on the type, it will be manufactured separately. Further, it is preferable to use a polycondensation catalyst such as a metal catalyst or a Bronsted acid catalyst.
The polyester resin may be produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the above polyhydric alcohol and polyvalent carboxylic acid, if necessary, a catalyst, and blended in a reaction vessel equipped with a thermometer, a stirrer, a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas), Heat at 150 ° C to 250 ° C to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value or molecular weight is reached, cool, and target reactant Manufactured by obtaining.

The glass transition temperature of the binder resin is preferably in the range of 40 ° C. or higher and 80 ° C. or lower. When the glass transition temperature is in the above range, the minimum fixing temperature is easily maintained.
The content of the binder resin in the toner base particles is not particularly limited, but is preferably 10 to 95% by weight, more preferably 25 to 90% by weight, based on the total weight of the toner. More preferably, it is 45 to 85% by weight. Within the above range, the fixing property, the charging property and the like are excellent.

-Colorant-
In this embodiment, the toner base particles contain a colorant for the purpose of coloring the resulting image.
A known colorant may be used as the colorant, and may be arbitrarily selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, dispersibility in the toner, and the like.
The colorant may be a dye or a pigment, but is preferably a pigment from the viewpoint of light resistance and water resistance. The colorant is not limited to a colored colorant, and may be a white colorant or a colorant exhibiting a metallic color.

For example, in cyan toner, as the colorant, for example, C.I. I. Pigment Blue 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 13, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 17, 23, 60, 65, 73, 83, 180, C.I. I. Vat cyan 1, 3 and 20, etc., bitumen, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, first sky blue, indanthrene blue BC cyan pigment, C.I. I. Cyan dyes such as solvent cyan 79 and 162 are used.
In the magenta toner, as the colorant, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 70, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 185, 202, 206, 207, 209, 238, etc., pigment violet 19 magenta pigments, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 100, 109, 121, C . I. Disper thread 9, C.I. I. Basic Red 1, 2, 9, 9, 13, 14, 15, 17, 17, 18, 22, 23, 24, 27, 29, 32, 34, the same 35, 36, 37, 38, 39, 40, etc. Magenta dyes, etc., Bengala, Cadmium Red, Lead Tan, Mercury Sulfide, Cadmium, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red, Calcium Salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B and the like are used.
In the yellow toner, as the colorant, for example, C.I. I. Pigment Yellow 2, 3, 15, 15, 17, 74, 93, 97, 128, 155, 180, 185, 139, and the like are used.
In the black toner, as the colorant, for example, carbon black, activated carbon, titanium black, magnetic powder, Mn-containing nonmagnetic powder, or the like is used. Further, black toner may be obtained by mixing yellow, magenta, cyan, red, green, and blue pigments.
As the colorant, a surface-treated colorant or a pigment dispersant may be used. By selecting the type of the colorant, color toners such as yellow toner, magenta toner, cyan toner, and black toner are prepared.

  The amount of the colorant to be used is not particularly limited, but is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the toner base particles. Moreover, as a coloring agent, these pigments, dyes, etc. can be used individually by 1 type, or 2 or more types can be used together.

  In this embodiment, a color image may be formed as a toner set including a clear toner (transparent toner) that does not contain a colorant. It is suitably used as a clear toner for obtaining a good gloss image by transferring and fixing a color toner image desired to give gloss to the top or the periphery thereof.

-Release agent-
In this embodiment, the toner base particles preferably contain a release agent.
Specific examples of the release agent include, for example, ester wax, polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene, but polyglycerin wax, microcrystalline wax, paraffin wax, carnauba wax, sazol wax, and montanic acid. Ester wax, deoxidized carnauba wax, palmitic acid, stearic acid, montanic acid, brandic acid, eleostearic acid, valinalic acid and other unsaturated fatty acids, stearyl alcohol, aralkyl alcohol, bephenyl alcohol, carnauvyl alcohol, ceryl Saturated alcohols such as alcohol, melyl alcohol, or long-chain alkyl alcohols having a long-chain alkyl group; polyhydric alcohols such as sorbitol; linoleic acid amide Fatty acid amides such as oleic acid amide and lauric acid amide; saturated fatty acid bisamides such as methylene bis stearic acid amide, ethylene bis capric acid amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide, ethylene bis oleic acid amide, Unsaturated fatty acid amides such as hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, N′-di Aromatic bisamides such as stearyl isophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally called metal soap); aliphatic hydrocarbon wax with styrene or Waxes grafted with vinyl monomers such as crylic acid; Fatty acids such as behenic acid monoglycerides and partially esterified products of polyhydric alcohols; Methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils, etc. Is mentioned.

A mold release agent may be used individually by 1 type, or may use 2 or more types together.
The content of the release agent is preferably 1 to 20 parts by weight and more preferably 3 to 15% by weight with respect to 100 parts by weight of the toner base particles. Within the above range, both good fixability and image quality characteristics can be achieved.

-Other external additives-
The electrostatic image developing toner of this embodiment may contain an external additive other than the metatitanic acid particles described above.
As the external additive other than the above-mentioned metatitanic acid particles, known external additives can be used, and examples thereof include inorganic particles and organic particles. It is also preferable that the amount is small.
As other external additives, silica particles are preferably exemplified.

-Other ingredients-
In this embodiment, the toner base particles may contain other components in addition to the above components. There is no restriction | limiting in particular as another component, A well-known component is mentioned, For example, a lubricant, an abrasive | polishing agent, etc. are mentioned.

-Toner characteristics-
The volume average particle size of the toner according to the exemplary embodiment is preferably 2 to 9 μm, and more preferably 3.0 to 7.0 μm. The effect of this embodiment is more exhibited as it is the said range.
The volume average particle diameter of the toner is preferably measured using Coulter Multisizer-II type (Beckman-Coulter) and the electrolyte is ISOTON-II (Beckman-Coulter).
Specific examples of the measurement method include the following methods.
As a dispersant, 1.0 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate. This is added to 100 ml of the electrolytic solution to prepare an electrolytic solution in which the sample is suspended. The electrolyte in which the sample was suspended was dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles of 1 to 30 μm was measured using the Coulter Multisizer-II type with an aperture diameter of 50 μm. Average distribution and number average distribution are obtained. The number of particles to be measured is 50,000.

Further, it is preferable that the particle size distribution of the toner of the present embodiment is narrow, and more specifically, 16% diameter (abbreviated as _D16v ) and 84% diameter ( _D84v ) in terms of the toner having a smaller volume particle diameter. Is expressed as a square root (GSDv), that is, GSDv represented by the following formula is preferably 1.21 or less, more preferably 1.19 or less, and 1.17 or less. Is particularly preferred.
GSDv = {(D _84v ) / (D _16v )} ^0.5 (1)
(In the formula (1), D _84v and D _16v are particle sizes that are 84% and 16% cumulative when a volume cumulative distribution curve is drawn from the small particle size side with respect to each divided particle size range. )
When the GSDv is in the above range, the generation of particles with an excessively large toner charge amount is suppressed, so that deterioration of fine line reproducibility of multi-order colors is further suppressed.

Furthermore, the toner of the present embodiment preferably has a shape factor SF1 in the range of 110 to 140, and more preferably in the range of 110 to 130. When the shape is spherical in this range, transfer efficiency and image density are improved, and a high-quality image is formed.
Here, the shape factor SF1 is obtained by the following equation (E).
SF1 = (ML ² / A) × (π / 4) × 100 Formula (E)
In the above formula (E), ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and can be calculated as follows, for example. That is, an optical microscope image of particles scattered on the surface of the slide glass is taken into a Luzex image analyzer through a video camera, the maximum length and projected area of 100 particles are obtained, calculated by the above formula (E), and the average value is It is obtained by seeking.

-Toner production method-
The method for producing the toner used in the exemplary embodiment is not particularly limited, and the toner is produced by a known dry method such as a kneading / pulverizing method or a wet method such as an emulsion aggregation method or a suspension polymerization method. Among these methods, the emulsion aggregation method is preferable.
Hereinafter, a method for producing the toner of this embodiment by the emulsion aggregation method will be described in detail.

  The emulsion aggregation method has an emulsification step of emulsifying the raw material constituting the toner to form resin particles (emulsion particles), an aggregation step of forming aggregates of the resin particles, and a fusion step of fusing the aggregates. .

-Emulsification process For example, it is preferable to produce the resin particle dispersion by applying a shearing force to a solution obtained by mixing an aqueous medium and a resin with a disperser. At that time, it is more preferable to form particles by lowering the viscosity of the resin component by heating. A dispersant may be used for stabilizing the dispersed resin particles. Further, if the resin is oily and dissolves in a solvent having a relatively low solubility in water, the resin is dissolved in those solvents and dispersed in an aqueous medium together with a dispersant and a polymer electrolyte, and then heated or The resin particle dispersion may be prepared by evaporating the solvent under reduced pressure.
Examples of the aqueous medium include water such as distilled water and ion-exchanged water; alcohols; and the like, but preferably only water.
Examples of the dispersant used in the emulsification step include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate; sodium dodecylbenzenesulfonate, Anionic surfactants such as sodium octadecyl sulfate, sodium oleate, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, amphoteric such as lauryldimethylamine oxide Ionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene Surfactants such as nonionic surfactants such as alkyl amines; and the like are; tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, inorganic salts such as barium carbonate.

Examples of the disperser used for preparing the emulsion include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser.
As the size of the resin particles, the average particle size (volume average particle size) is preferably in the range of 60 nm to 300 nm, and more preferably in the range of 150 nm to 250 nm. Within the above range, the cohesiveness of the resin particles is sufficient, and the particle size distribution of the toner can be narrowed.

In preparing the release agent dispersion, the release agent is dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid or a polymer base, and then heated to a temperature equal to or higher than the melting temperature of the release agent. Dispersion treatment is performed using a homogenizer or a pressure discharge type disperser capable of applying a strong shearing force while heating. By undergoing such treatment, a release agent dispersion can be obtained.
By the dispersion treatment, a release agent dispersion liquid containing release agent particles having a volume average particle diameter of preferably 1 μm or less can be obtained. A more preferable volume average particle diameter of the release agent particles is 100 nm or more and 500 nm or less.

Aggregation step In the aggregation step, a resin particle dispersion, a release agent dispersion, a colorant particle dispersion, etc. are mixed to form a mixed solution, and heated at a temperature not higher than the glass transition temperature of the amorphous resin particles. It is preferable to aggregate to form aggregated particles. Aggregated particles are formed by acidifying the pH of the mixed solution under stirring.
The pH is preferably 2 or more and 7 or less, more preferably 2.2 or more and 6 or less, and more preferably 2.4 or more and 5 or less in view of narrowing the particle size distribution of the toner. At this time, it is also effective to use a flocculant.
In the aggregation step, the release agent dispersion may be added and mixed at once with various dispersions such as a resin particle dispersion, or may be added in multiple portions.

As the flocculant, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a divalent or higher metal complex are preferably used. In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are further improved.
Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Among these, an aluminum salt and a polymer thereof are particularly preferable. By increasing the number of additions of the inorganic metal salt, a toner having a smaller GSDv can be obtained.

  Further, a toner having a configuration in which the surface of the core aggregated particles is coated with the resin particles may be prepared by additionally adding resin particles when the aggregated particles have a desired particle size (coating step). In this case, the release agent is less likely to be exposed on the toner surface, which is a preferable configuration from the viewpoint of chargeability and developability. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

-Fusion process In the fusion process, the agglomeration is stopped by raising the pH of the suspension of aggregated particles to a range of 3 to 9 under stirring conditions according to the aggregation process. It is preferable to fuse the aggregated particles by heating at a temperature equal to or higher than the melting temperature. Further, when the aggregated particles are coated with the amorphous resin, it is preferable that the amorphous resin is also fused to cover the core aggregated particles. The heating time may be as long as fusion is performed, and preferably 0.5 hours or more and 10 hours or less.
Cooling is performed after the fusion to obtain fused particles. In the cooling step, crystallization may be promoted by so-called gradual cooling, in which the cooling rate is reduced in the vicinity of the melting temperature of the crystalline resin (in the range of melting temperature ± 10 ° C.).

The fused particles (toner mother particles) obtained by fusing can be made into toner mother particles through a solid-liquid separation process such as filtration, and a washing process and a drying process as necessary.
Further, a step of externally adding an external additive containing metatitanic acid particles to the obtained toner base particles is performed.
The method for externally adding an external additive to the surface of the toner base particles in the external addition step is not particularly limited, and a known method is used. For example, a mechanical method or a chemical method is used. It is done.
Further, if necessary, coarse particles of toner may be removed after external addition using an ultrasonic sieving machine, a vibration sieving machine, a wind sieving machine, or the like.

(Toner set)
The toner set of the present embodiment may be a toner set including at least the electrostatic image developing toner of the present embodiment. However, the electrostatic image developing toner of the present embodiment in which the colorant is a cyan colorant and the colorant include The electrostatic image developing toner of this embodiment which is a magenta colorant, the electrostatic image developing toner of this embodiment where the colorant is a yellow colorant, and the electrostatic image of this embodiment where the colorant is a black colorant. And at least developing toner. With the above aspect, the effect of the present embodiment is more exerted, and the occurrence of fogging can be further suppressed in the formed image, and the color reproducibility is excellent.
More preferably, the toner set of this embodiment further includes at least one of the electrostatic image developing toners of this embodiment in which the colorant is green, orange, violet, or a metallic colorant.

(Electrostatic image developer)
The electrostatic charge image developer of the present exemplary embodiment (hereinafter sometimes referred to as “developer”) is not particularly limited as long as it contains the electrostatic charge image developing toner of the exemplary embodiment. May be a one-component developer used in the above, or a two-component developer containing a toner and a carrier. In the case of a one-component developer, a toner containing magnetic metal particles or a non-magnetic one-component toner containing no magnetic metal particles may be used.

The carrier is not particularly limited as long as it is a known carrier, and iron powder carriers, ferrite carriers, surface-coated ferrite carriers, and the like are used. Each surface-added powder may be used after a desired surface treatment.
Specific examples of the carrier include the following resin-coated carriers. Examples of the carrier core particle include normal iron powder, ferrite, and magnetite molding, and the volume average particle size is preferably 30 to 200 μm.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, acrylic acid 2 -Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, etc. Vinyl nitriles; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl Homopolymers such as vinyl ketones such as ketones; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers comprising two or more types of monomers Furthermore, silicone resins containing methyl silicone, methyl phenyl silicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by weight and more preferably in the range of 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the core particles.

  For the production of the carrier, a heating type kneader, a heating type Henschel mixer, a UM mixer, or the like is used. Depending on the amount of the coating resin, a heating type fluidized rolling bed, a heating type kiln, or the like is used.

When a carrier in which ferrite particles are used as a core and coated with a resin in which carbon black or the like as a conductive agent and melamine beads or the like as a charge control agent are dispersed in methyl acrylate or ethyl acrylate and styrene or the like is used as a carrier, Since the resistance controllability is excellent even when the film thickness is increased, the image quality and the image quality maintenance are excellent, which is more preferable.
The mixing ratio of the toner and the carrier in the developer is not particularly limited and is selected according to the purpose.

(Image forming method)
An image forming method using the toner of this embodiment will be described. The toner of the exemplary embodiment is used in an image forming method using a known electrophotographic method. Specifically, it is used in an image forming method having the following steps.
That is, a preferable image forming method includes at least a charging step for charging the image carrier, an exposure step for forming an electrostatic latent image on the surface of the image carrier, and an electrostatic latent image formed on the surface of the image carrier. A developing step of developing with an electrostatic charge image developer to form a toner image, a transferring step of transferring the toner image formed on the surface of the image carrier to the surface of the transfer target, and a fixing step of fixing the toner image; The developer is the electrostatic charge image developing toner of the present embodiment or the electrostatic charge image developer of the present embodiment. Further, the transfer step may use an intermediate transfer member that mediates transfer of the toner image from the electrostatic latent image holding member to the transfer target.
It is also preferable to have a cleaning step for removing residual toner on the surface of the image carrier after transfer.

Each of the above steps is a general step per se, and is described in, for example, JP-A-56-40868 and JP-A-49-91231. Note that the image forming method of the present embodiment can be carried out by using a known image forming apparatus such as a copying machine or a facsimile machine.
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an image carrier (photoconductor).
The developing step is a step of developing the electrostatic latent image with a developer layer on a developer holding member to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developing toner of this embodiment.
The transfer step is a step of transferring the toner image onto a transfer target. Examples of the transfer medium in the transfer process include an intermediate transfer medium and a recording medium such as paper.
In the fixing step, for example, there is a method of forming a copy image by fixing the toner image transferred onto the transfer paper by a heating roller fixing device in which the temperature of the heating roller is set to a constant temperature.
The cleaning step is a step of removing the electrostatic charge image developer remaining on the image carrier.
As the transfer target, a recording medium such as an intermediate transfer member or paper can be used.
Examples of the recording medium include paper used for electrophotographic copying machines and printers, OHP sheets, etc., for example, coated paper whose surface is coated with resin, art paper for printing, and the like. Etc. can be used suitably.

  The image forming method of the present embodiment may further include a recycling step. The recycling step is a step of transferring the electrostatic charge image developing toner collected in the cleaning step to a developer layer. The image forming method including the recycling process is performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. Further, the present invention may be applied to a recycling system in which the cleaning process is omitted and toner is collected simultaneously with development.

(Image forming device)
The image forming apparatus of this embodiment will be described with reference to an image forming apparatus using the electrostatic image developing toner of this embodiment.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the image carrier, and an exposure unit that exposes the charged image carrier to form an electrostatic latent image on the image carrier. A developing unit that develops the electrostatic latent image with a developer to form a toner image, a transfer unit that transfers the toner image from the image holding member to a transfer target, and a fixing unit that fixes the toner image. It is preferable that the developer is the electrostatic charge image developing toner of the present embodiment or the electrostatic charge image developer of the present embodiment.
The image forming apparatus of the present embodiment is not particularly limited as long as it includes at least the image carrier, the charging unit, the exposure unit, the developing unit, the transfer unit, and the fixing unit as described above. Although not necessary, a cleaning means, a static elimination means, and the like may be included as necessary.
In the transfer unit, the transfer may be performed twice or more using an intermediate transfer member. Examples of the transfer medium in the transfer unit include an intermediate transfer medium and a recording medium such as paper.

The image carrier and each of the above-described units can preferably use the configurations described in the respective steps of the image forming method. As each of the above-described means, a known means in the image forming apparatus can be used. In addition, the image forming apparatus according to the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus according to the present embodiment may simultaneously perform a plurality of the above-described means.
The image forming apparatus according to the present exemplary embodiment preferably includes a cleaning unit that removes the electrostatic charge image developer remaining on the image carrier.
Examples of the cleaning means include a cleaning blade and a cleaning brush, and a cleaning blade is preferable.

  In this image forming apparatus, for example, the part including the developing unit may be a cartridge structure (process cartridge) that is detachable from the main body of the image forming apparatus. As the process cartridge, a developer holding body is used. The process cartridge of the present embodiment is preferably used that includes at least the electrostatic charge image developing developer of the present embodiment.

(Toner cartridge, developer cartridge, and process cartridge)
The toner cartridge of the present embodiment is a toner cartridge that contains at least the electrostatic image developing toner of the present embodiment.
The developer cartridge of this embodiment is a developer cartridge that contains at least the electrostatic charge image developer of this embodiment.
The process cartridge of the present embodiment is a process cartridge including a developer holder that contains the electrostatic charge image developer of the present embodiment and holds and conveys the electrostatic charge image developer. The electrostatic latent image formed on the surface is developed with the electrostatic charge image developing toner or the electrostatic charge image developer to form a toner image, and the image carrier and the surface of the image carrier are charged. And at least one selected from the group consisting of a cleaning means for removing the toner remaining on the surface of the image carrier, and the electrostatic charge image developing toner of this embodiment, or The process cartridge preferably contains at least the electrostatic charge image developer of the present embodiment.

The toner cartridge of this embodiment is preferably detachable from the image forming apparatus. That is, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, the toner cartridge of the present embodiment in which the toner of the present embodiment is stored is preferably used.
The developer cartridge of the present embodiment is not particularly limited as long as it contains the electrostatic charge image developer containing the electrostatic charge image developing toner of the present embodiment. For example, the developer cartridge is attached to or detached from an image forming apparatus including a developing unit, and the electrostatic image developer including the electrostatic image developing toner of the present embodiment is used as a developer to be supplied to the developing unit. It is what is stored.
The developer cartridge may be a cartridge that stores toner and a carrier, or may be a cartridge that stores toner alone and a cartridge that stores a carrier separately.
It is preferable that the process cartridge of the present embodiment is attached to and detached from the image forming apparatus.
In addition, the process cartridge according to the present embodiment may include other members such as a static elimination unit as necessary.
As the toner cartridge and the process cartridge, known configurations may be employed. For example, Japanese Patent Application Laid-Open Nos. 2008-209489 and 2008-203736 are referred to.

  Hereinafter, the present embodiment will be described in detail with reference to examples. However, the present embodiment is not limited only to the following examples. In the following description, “parts” means “parts by weight” unless otherwise specified. In addition, “primary particle size” in the following represents “volume average primary particle size”.

<Preparation of metatitanic acid particles 1>
Ilmenite ore (FeTiO ₃ ) was heated and dissolved in concentrated sulfuric acid to separate the iron powder, and TiOSO ₄ was obtained. Further, a precipitate of TiO (OH) ₂ was produced by thermal hydrolysis, which was filtered and washed with water repeatedly, and then 10 ppm (weight) of polycarboxylic acid and 100 times (weight) of TiO (OH) _2. ) Was added and sufficiently stirred, and then dried at 150 ° C. Next, baking was performed at 700 ° C. for 1 minute and at 500 ° C. for 80 minutes (hereinafter referred to as two-stage baking temperature and time). Next, 100 parts by weight of the obtained titanium oxide was dispersed in 1,000 parts by weight of water, and 10% by weight of isobutylmethoxysilane was added dropwise with stirring at a temperature of 25 ° C. Next, this was filtered and water washing was repeated. The obtained titanium oxide surface-treated with isobutylmethoxysilane was dried at 150 ° C. to obtain metatitanic acid particles 1.

<Preparation of Metatitanic Acid Particles 2-11>
In the production of the metatitanic acid particles 1, metatitanic acid particles 2 to 11 were produced in the same manner except that the amount of polycarboxylic acid described in Table 1, firing conditions, and surface treatment conditions were changed.

Example 1
<Preparation of Toner 1>
<< Preparation of toner mother particles >>
-Preparation of polyester resin dispersion-
-Ethylene glycol (Wako Pure Chemical Industries, Ltd.): 37 parts-Neopentyl glycol (Wako Pure Chemical Industries, Ltd.): 65 parts-1,9-nonanediol (Wako Pure Chemical Industries, Ltd.) : 32 parts terephthalic acid (manufactured by Wako Pure Chemical Industries, Ltd.): 96 parts The above monomer was charged into a flask and raised to a temperature of 200 ° C over 1 hour, confirming that the reaction system was uniformly stirred. Thereafter, 1.2 parts of dibutyltin oxide was added. Further, while distilling off the generated water, the temperature was increased from the same temperature to 240 ° C. over 6 hours, and the dehydration condensation reaction was continued at 240 ° C. for another 4 hours. A polyester resin having 13,000 and a glass transition point of 62 ° C. was obtained.
Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 parts per minute. A 0.37% diluted aqueous ammonia solution obtained by diluting reagent ammonia water with ion-exchanged water is put into a separately prepared aqueous medium tank, and the polyester is heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Simultaneously with the resin melt, it was transferred to the Cavitron. The Cavitron was operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ^2. Resin particles having an average particle diameter of 160 nm, a solid content of 30%, a glass transition point of 62 ° C., and a weight average molecular weight Mw of 13,000 were obtained. A dispersed amorphous polyester resin dispersion was obtained.

-Preparation of cyan colorant dispersion-
-Cyan pigment (Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.): 10 parts-Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts-Ion-exchanged water: 80 parts These components were mixed and dispersed with a high-pressure impact disperser Ultimateizer [HJP30006, manufactured by Sugino Machine Co., Ltd.] for 1 hour to obtain a colorant dispersion having a volume average particle size of 180 nm and a solid content of 20%.

-Preparation of violet colorant dispersion-
In the preparation of the cyan colorant dispersion, the colorant may be a violet pigment [C. I. A violet colorant dispersion was prepared in the same manner except that it was changed to CI Pigment Violet 37, manufactured by BAFS.

-Preparation of release agent dispersion-
-Paraffin wax [HNP 9, Nippon Seiwa Co., Ltd.]: 50 parts-Anionic surfactant [Neogen SC, Daiichi Kogyo Seiyaku Co., Ltd.]: 2 parts-Ion-exchanged water: 200 parts Heat to 120 ° C., thoroughly mix and disperse with IKA's Ultra Turrax T50, then disperse with a pressure discharge homogenizer, and release agent dispersion with a volume average particle size of 200 nm and a solid content of 20% Got.

(Production of cyan toner)
-Polyester resin dispersion: 200 parts-Cyan colorant dispersion: 25 parts-Release agent dispersion: 25 parts-Polyaluminum chloride: 0.4 parts-Ion-exchanged water: 100 parts The mixture was thoroughly mixed and dispersed using IKA Ultra Turrax, and the flask was heated to 48 ° C. with stirring in an oil bath for heating. After maintaining at 48 ° C. for 20 minutes, 70 parts of the same polyester resin dispersion as above was gradually added thereto.
Then, after adjusting the pH in the system to 8.0 using a sodium hydroxide aqueous solution having a concentration of 0.5 mol / L, the stainless steel flask is sealed, and the stirring shaft seal is magnetically sealed while stirring is continued. Heat to 90 ° C. and hold for 3 hours. After completion of the reaction, the temperature lowering rate was cooled at 2 ° C./min, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed using 3,000 parts of ion exchange water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was further repeated 6 times. When the pH of the filtrate became 7.54 and the electric conductivity was 6.5 μS / cm, No. 2 was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner base particles 1.
The number average particle size of toner base particles 1 was measured with a Coulter Multisizer II type (manufactured by Beckman Coulter, Inc.). As a result, it was 5.0 μm and SF1 was 130.
Further, 2.0% by weight of metatitanic acid particles 1 were added to this toner and mixed with a Henschel mixer to obtain a cyan toner.

<Production of violet toner>
A violet toner was produced in the same manner as the cyan toner except that the colorant dispersion was changed to a violet colorant dispersion.

<Creation of carrier>
1,000 parts of Mn—Mg ferrite (volume average particle size: 50 μm, manufactured by Powder Tech Co., Ltd., shape factor SF1: 120) are charged into a kneader, and 100 parts of cyclohexyl acrylate resin (weight average molecular weight: 50,000) is added. A solution dissolved in 700 parts of toluene is added, mixed at room temperature (25 ° C.) for 20 minutes, heated to 70 ° C., dried under reduced pressure, taken out, and a carrier in which the magnetic core is coated with a coating layer (coated carrier) Got. Further, the obtained coated carrier was sieved with a mesh having an opening of 75 μm, and coarse powder was removed to obtain a carrier. The carrier shape factor SF1 was 124.

<Preparation of electrostatic charge image developer>
The obtained toner and carrier were put in a V blender at a ratio of toner: carrier = 8: 92 (weight ratio) and stirred for 20 minutes to obtain a cyan developer and a violet developer.

<Cover evaluation>
Fill the developer of the DocuCentreColor400 modified machine manufactured by Fuji Xerox Co., Ltd. with the above-mentioned cyan developer, and use color paper (J paper) manufactured by Fuji Xerox Co., Ltd. at 32 ° C / 80% RH (under high temperature and high humidity) ), 10,000 solid images with an area coverage of 50% were printed, and fogging evaluation and image density were measured. The evaluation of fogging was performed according to the following criteria by observing the 10,000th non-image. The results are shown in Table 2.

[Cover]
◎: Fog is not observed. ○: Fog is observed with a loupe, but there is no practical problem. △: Fog is slightly observed by visual observation. ×: Fog is observed remarkably.

<Color reproducibility evaluation>
After cleaning the main body, developer, and toner cartridge of DocuCentre Color 400CP manufactured by Fuji Xerox Co., Ltd. in an environmental room with a temperature of 25 ° C and a humidity of 50%, thoroughly removing the developer and toner set up to that point. Each cyan developer and each violet developer were put into a developing unit, and a replenishing toner was put into each toner cartridge. And the following evaluation was performed.

-Color gamut evaluation (secondary color)-
The developing toner amount of single-color 100% image on paper OS coated was adjusted to 4.0 g / ^{m 2,} a size of 5 cm × 5 cm, cyan toner 100% and consisting of violet toner 100% cyan / violet secondary color image And the saturation (c ^* = [(a ^* ) ² + (b ^* ) ² ] ^0.5 ) of the obtained image was measured. For the measurement, X-Rite 939 (aperture 4 mm) was used, and the image plane was randomly measured 10 times and averaged. Table 2 shows the density results and the saturation results.
The evaluation was performed based on the following.

[Cyan / violet secondary color saturation]
G5: 66 or more G4: 62 or more and less than 66 G3: 58 or more and less than 62 G2: 56 or more and less than 58 G1: less than 56 Cyan / violet secondary color saturation (c ^* ) increases as the color saturation increases. It is an acceptable range.

(Examples 2-8 and Comparative Examples 1-5)
In the production of the cyan toner, the violet toner, the cyan developer, and the violet developer of Example 1, Examples 2 to 8 and Comparative Example 1 were performed in the same manner except that the toners shown in Table 2 were changed. ˜5 electrostatic image developer and electrostatic image developer were prepared, respectively. The obtained electrostatic charge image developing toner and the electrostatic charge image developer were evaluated in the same manner as in Example 1. The evaluation results are summarized in Table 2.

Claims (7)

Toner base particles containing at least a binder resin and a colorant;
And metatitanic acid particles having a crystallite diameter of 12.0 to 16.0 nm, hydrophobized, and a true specific gravity of 2.5 to 3.3 g / cm ³ as an external additive. An electrostatic charge image developing toner.   2. The electrostatic charge image developing toner according to claim 1, wherein the number average particle diameter of the metatitanic acid particles is 20 to 60 nm, and the coverage of the toner base particles with the metatitanic acid particles is 20 to 50%.   The electrostatic charge image developing toner according to claim 1, wherein the toner has a volume average particle diameter of 3.0 to 7.0 μm.   An electrostatic charge image developer containing the electrostatic charge image developing toner according to claim 1 and a carrier. A charging step for charging at least the image carrier;
An exposure step of forming an electrostatic latent image on the surface of the image carrier;
A developing step of developing the electrostatic latent image formed on the surface of the image carrier with an electrostatic charge image developer to form a toner image;
A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the transfer target;
A fixing step of fixing the toner image,
The image forming method, wherein the developer is the electrostatic image developing toner according to any one of claims 1 to 3 or the electrostatic image developer according to claim 4. An image carrier,
Charging means for charging the image carrier;
Exposure means for exposing the charged image carrier to form an electrostatic latent image on the image carrier;
Developing means for developing the electrostatic latent image with a developer to form a toner image;
Transfer means for transferring the toner image from the image carrier to a transfer medium;
Fixing means for fixing the toner image,
An image forming apparatus, wherein the developer is the electrostatic image developing toner according to any one of claims 1 to 3 or the electrostatic image developer according to claim 4. The electrostatic image developing toner according to any one of claims 1 to 3, wherein the colorant is a cyan colorant;
The electrostatic image developing toner according to claim 1, wherein the colorant is a magenta colorant;
The electrostatic image developing toner according to any one of claims 1 to 3, wherein the colorant is a yellow colorant;
A toner set comprising at least the electrostatic image developing toner according to claim 1, wherein the colorant is a black colorant.