JP6384226B2 - Electrostatic image developing toner, electrostatic image developer, toner cartridge, developer cartridge, process cartridge, image forming method, and image forming apparatus - Google Patents

Description

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

A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image (electrostatic latent image) is formed on a photoreceptor (image carrier) by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and a transfer and fixing process. It is visualized through. The developer used here includes a two-component developer comprising a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone. The toner is usually produced by using a thermoplastic resin as a pigment. In addition, a kneading and pulverizing method is used in which melt-kneading is performed together with a release agent such as a charge control agent and wax, and the mixture is cooled, finely pulverized, and further classified. In these toners, if necessary, inorganic and organic particles for improving fluidity and cleaning properties may be added to the toner particle surfaces.
In Patent Document 1, in a toner having at least a binder resin, a colorant, a wax, and hydrophobic titanium oxide fine particles, the toner has an endothermic curve in a differential thermal analysis (DSC) measurement in a temperature range of 30 to 150 ° C. The peak temperature of the maximum endothermic peak is in the range of 50 to 100 ° C., and the hydrophobic titanium oxide fine particles are surface-treated with at least silicone oil or silicone varnish, and 2θ = 20.0 to 40.40 in X-ray diffraction. The toner is characterized in that the intensity ratio (Ia / Ib) between the maximum intensity Ia and the minimum intensity Ib in the range of 0 deg is 5.0 ≦ Ia / Ib ≦ 12.0.
Patent Document 2 discloses that a toner having at least a resin, a colorant, a release agent, and inorganic fine particles has at least two types of titanium oxide as the inorganic fine particles, and the crystal form of the titanium oxide is one of It is anatase type, the other is rutile type, and the number average particle diameter of the titanium oxide is Da: more than 20 nm and not more than 60 nm, the other is Db: not less than 40 nm and not more than 100 nm, and Da <Db The toner is characterized by that.

JP-A-2005-173208 JP 2005-107427 A

  An object of the present invention is to provide a toner for developing an electrostatic charge image in which the density change of an image is suppressed and the occurrence of color streaks is suppressed in both environments of low temperature and low humidity and high temperature and high humidity. is there.

The above-described problems of the present invention have been solved by means described in the following <1> and <3> to <8>. It is described below together with <2> which is a preferred embodiment.
<1> It has colored particles containing a colorant and a binder resin, two or more kinds of inorganic particles are externally added to the surface of the colored particles, and the two or more kinds of inorganic particles are metatitanic acid particles and In the CuKα characteristic X-ray diffraction, the metatitanic acid particles containing silica particles have a maximum diffraction peak at a black angle 2θ = 27.5 °, and the crystallite diameter calculated from the peak is 12 to 16 nm. A toner for developing an electrostatic image, wherein the silica particles have a volume average particle diameter of 50 to 200 nm,
<2> The toner for developing an electrostatic charge image according to <1>, wherein the metatitanic acid particles have a number average particle diameter of 20 to 50 nm.
<3> An electrostatic charge image developer comprising the electrostatic charge image developing toner according to <1> or <2> and a carrier,
<4> a toner cartridge containing the electrostatic image developing toner according to <1> or <2>;
<5> a developer cartridge containing the electrostatic charge image developer according to <3>,
<6> a process cartridge including a developer holder that contains the electrostatic image developer according to <3> and holds and conveys the electrostatic image developer;
<7> A latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and development for forming the toner image by developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner. And a fixing step for fixing the toner image transferred to the surface of the transfer medium, wherein the developer is <1> or <2>. An image forming method using the toner for developing an electrostatic image according to claim 1 or the electrostatic image developer according to <3>;
<8> Image carrier, charging unit for charging the image carrier, exposure unit for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier, and development including toner Developing means for developing the electrostatic latent image with an agent to form a toner image, transfer means for transferring the toner image from the image holding member to the surface of the transfer target, and toner transferred to the surface of the transfer target An image forming apparatus comprising: a fixing unit that fixes an image; and the developer for developing an electrostatic charge image according to <1> or <2> as the developer, or the electrostatic image developer according to <3>. apparatus.

According to the invention described in <1> above, the density change of the image is suppressed in both environments of low temperature and low humidity and high temperature and high humidity, and color Thus, it is possible to provide a toner for developing an electrostatic charge image in which the occurrence of the toner is suppressed.
According to the invention described in the above <2>, the density change of the image is suppressed in both the low temperature and low humidity environment and the high temperature and high humidity environment, compared with the case where the present configuration is not provided, and more It is possible to provide a toner for developing an electrostatic charge image in which the generation of color stripes is also suppressed.
According to the invention described in the above <3>, the density change of the image is suppressed in both environments of low temperature and low humidity and high temperature and high humidity as compared with the case without this configuration, and Thus, it is possible to provide an electrostatic charge image developer in which the occurrence of the above is suppressed.
According to the invention described in <4> above, the density change of the image is suppressed in both environments of low temperature and low humidity and high temperature and high humidity, and color Therefore, it is possible to provide a toner cartridge containing toner for developing an electrostatic charge image in which the occurrence of the toner is suppressed.
According to the invention described in <5> above, compared to the case where the present configuration is not provided, the density change of the image is suppressed under both low temperature and low humidity and high temperature and high humidity environments, and color streaking Therefore, it is possible to provide a developer cartridge containing an electrostatic charge image developer in which the occurrence of the above is suppressed.
According to the invention described in <6> above, an image can be obtained in any environment of low temperature and low humidity and high temperature and high humidity as compared with the case without this configuration as compared with the case without this configuration. Therefore, it is possible to provide a process cartridge containing an electrostatic charge image developer in which the density change of the toner is suppressed and the generation of color streaks is also suppressed.
According to the invention described in the above <7>, the density change of the image is suppressed in both environments of low temperature and low humidity and high temperature and high humidity, and color It is possible to provide an image forming method in which the occurrence of the above is suppressed.
According to the invention described in <8> above, an image can be obtained in any environment of low temperature and low humidity and high temperature and high humidity as compared with the case without this configuration, compared with the case without this configuration. Therefore, it is possible to provide an image forming apparatus in which the density change of the color is suppressed and the generation of color streaks is also suppressed.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention.

Hereinafter, the present embodiment will be described.
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. For example, if “A to B” is a numerical value range, “A or more and B or less” or “B or more and A or less” is represented.

(Static image developing toner)
The electrostatic image developing toner of the present embodiment (hereinafter also simply referred to as “toner”) has colored particles containing a colorant and a binder resin, and two or more kinds of inorganic particles are formed on the surface of the colored particles. The two or more kinds of inorganic particles include metatitanic acid particles and silica particles, and the metatitanic acid particles have a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction. And the crystallite diameter calculated from the peak is 12 to 16 nm, and the volume average particle diameter of the silica particles is 50 to 200 nm.

Since the charge amount of toner differs greatly between low temperature and low humidity and high temperature and high humidity, it is difficult to maintain a constant image density in any of these environments. Therefore, it is conceivable to maintain high image density by suppressing high charging in low-temperature and low-humidity environments, reducing environmental differences in charge amount by using titanium oxide with high charge exchange properties as an external additive. It has been.
However, when images with low image density are continuous under low temperature and low humidity, the adhesion between the toner and the member is strong, and the external additive tends to be buried, so the transferability cannot be maintained and the density decreases. . On the other hand, by using metatitanic acid having a higher moisture content than titania and low resistance, even when buried near the outermost surface of the charge toner, the toner surface resistance can be lowered and charge exchange can be imparted. Even when the image density continues, the density can be kept constant.
On the other hand, when images with low image density are continuous under high temperature and high humidity, the adhesion between the toner and the member is strong, and the external additive tends to be buried, so the transferability cannot be maintained and the density decreases. End up. On the other hand, by using a large-diameter silica having a particle diameter of 50 to 200 nm, a spacer maintaining effect can be imparted and the concentration can be maintained constant.
However, when metatitanic acid and large-diameter silica are used in combination, the particle resistance difference between metatitanic acid and large-diameter silica existing on the outermost surface of the toner is large and the electrostatic repulsion is strong. Become. Therefore, when printing with a high image density continues, the large-diameter silica is detached from the developed toner and is excessively supplied to the cleaning blade portion, so that the large-diameter silica slips through and color streaks occur.
As described above, it is not possible to suppress color streaking even when an image pattern with a high image density continues while maintaining a constant density regardless of the environment and the image density.

As a result of intensive studies, the present inventors, as an external additive, have a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and a crystallite diameter calculated from the peak is as follows. By using together the metatitanic acid particles of 12 to 16 nm and the large-diameter silica having a volume average particle size of 50 to 200 nm, the change in the density of the image is suppressed under any environment of low temperature and low humidity and high temperature and high humidity, In addition, the inventors have found that it is possible to provide a toner for developing an electrostatic image in which generation of color streaks is suppressed, and the present invention has been completed.
The mechanism of action is unknown, but by using specific metatitanic acid, the particle resistance can be increased without reducing the water content of metatitanic acid. While ensuring the effect of suppressing fluctuations in image density, the amount of desorption of large-diameter silica is reduced by reducing electrostatic repulsion with large-diameter silica, and color streaks due to slipping through the cleaning blade are suppressed. Estimated that you can. With the above-described action, it is considered that the color streak can be improved even when an image pattern with a high image density continues while maintaining a constant image density regardless of temperature and humidity and image density.
Hereinafter, each component and physical property value constituting the toner will be described in detail.

<External additive>
In the electrostatic image developing toner of this embodiment, two or more kinds of inorganic particles are externally added as external additives to the surface of the colored particles, and the two or more kinds of inorganic particles are metatitanic acid particles and silica. The metatitanic acid particles have a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak is 12 to 16 nm. The volume average particle diameter of the silica particles is 50 to 200 nm.
In the electrostatic image developing toner of this embodiment, metatitanic acid particles and silica particles having a volume average particle size of 50 to 200 nm are used in combination, and the crystallite size of metatitanic acid is controlled to 12 to 16 nm.

[Metatitanic acid particles]
In the electrostatic charge image developing toner of this embodiment, two or more kinds of inorganic particles are externally added as external additives to the surface of the colored particles, and the two or more kinds of inorganic particles include metatitanic acid particles. .
The metatitanic acid particles have a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and a crystallite diameter calculated from the peak is 12 to 16 nm.
In this embodiment, what was synthesize | combined by sulfuric acid hydrolysis reaction as a metatitanic acid particle may be used. Specifically, for example, a wet precipitation method in which ilmenite is used as an ore, dissolved in sulfuric acid to separate iron powder, and TiOSO ₄ is hydrolyzed to produce Ti (OH) ₂ is used.
Moreover, the metatitanic acid particles used in the present embodiment may be metatitanic acid as the main component. That is, the ratio of metatitanic acid to the total weight of metatitanic acid particles is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 95% or more, and 99% by weight or more. It is particularly preferred that
Moreover, as a metatitanic acid particle used for this embodiment, the thing hydrophobized is used. The hydrophobic treatment method is not particularly limited, and treatment is performed using a known hydrophobic treatment 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. These may be used individually by 1 type and may use 2 or more types together.

  As the silane coupling agent, for example, any of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyl Triethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- (trimethylsilyl) ) Urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysila , Γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyl Examples include trimethoxysilane 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 metatitanic acid.
The treatment amount of the coupling agent is preferably 5 parts by mass or more and 80 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of metatitanic acid. If the treatment amount is less than 5 parts by mass, water repellency may not be imparted to the metatitanic acid, and if it exceeds 80 parts by mass, the treatment agent itself aggregates and the surface treatment may not be performed evenly.

Examples of the silicone oil used for the hydrophobic 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.
The treatment amount of the silicone oil is preferably 10 parts by mass or more and 40 parts by mass or less, more preferably 20 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the metatitanic acid particles.
In the present embodiment, metatitanic acid particles hydrophobized with alkoxysilane are preferred from the viewpoint of high degree of hydrophobicity.

Ilmenite ore (FeTiO ₃ ) is heated and dissolved in concentrated sulfuric acid to separate the iron powder to obtain TiOSO ₄ . Furthermore, a precipitate of TiO (OH) ₂ is produced by thermal hydrolysis. This is filtered, washed repeatedly with water, and then dried at 150 ° C.
Next, heating and baking are performed at 500 ° C. for 120 minutes to obtain a dried body of TiO (OH) ₂ . The crystal state can be adjusted by adjusting the temperature and time at this time. However, it is difficult to stably obtain a target crystallite diameter of 12 to 16 nm.
At the time of the water washing, the solid content after washing is mixed and stirred with 10 ppm polycarboxylic acid and water, dried, and then subjected to a firing step to stably obtain a crystallite diameter of 12 to 16 nm. it can. This is presumably because the presence of polycarboxylic acid makes the oxidation moderate and the particle bonding also gentle.
In addition, the crystallite diameter referred to here represents the average diameter of the smallest unit crystallite constituting the crystal.
The crystallite diameter can be determined as follows.
The target crystal is measured using an X-ray diffractometer, and obtained from the following Scherrer equation.
D = K × λ / (β × cosθ)
D: crystallite diameter (nm), K: Scherrer constant, λ: X-ray wavelength, β: diffraction line broadening, θ: diffraction angle (2θ / θ)

The number average particle diameter of the metatitanic acid particles is preferably 20 nm or more and 50 nm or less, more preferably 20 nm or more and 45 nm or less, and further preferably 20 nm or more and 40 nm or less.
The particle size of the metatitanic acid particles is adjusted by the amount of the hydrophobizing agent at the time of hydrophobizing treatment and the temperature at the time of adding the hydrophobizing agent.
The specific surface area by the BET method of metatitanic acid particles is preferably 100~200cm ² / g, more preferably 120~200cm ² / g, further preferably 130~170cm ² / g .

  The amount of metatitanic acid particles contained in the toner as an external additive is preferably 0.5 parts by mass or more and 2.0 parts by mass or less, more preferably 0.6 parts by mass or more and 1. 2 parts by mass or less. If the addition amount is within the above range, the toner surface coverage is in an appropriate range, so that the powder fluidity is good, and the toner in which the release of the metatitanic acid particles, which is the cause of the decrease in the electric resistance of the carrier, is suppressed can get.

[Silica particles]
In the electrostatic charge image developing toner of this embodiment, two or more kinds of inorganic particles are externally added as external additives to the surface of the colored particles, and the two or more kinds of inorganic particles contain silica particles.
The silica particles have a volume average particle size of 50 to 200 nm.
Examples of the silica particles include silica particles such as fumed silica, colloidal silica, and silica gel. Further, the silica particles may be subjected to a surface treatment, and for example, the silica particles may be subjected to a surface treatment with a silane coupling agent, a silicone oil or the like to be hydrophobized. Examples of the surface treatment include a silane coupling agent that easily obtains chargeability and fluidity.

  The volume average particle diameter of the silica particles is 50 to 200 nm, and more preferably 80 to 200 nm. If it is 50 nm or more, the effect as a spacer is sufficiently exhibited, and if it is 200 nm or less, the release of silica particles is suppressed.

There is no restriction | limiting in particular as a preparation method of a silica particle, if it is a well-known preparation method, For example, a vapor phase manufacturing method, a wet manufacturing method, a sol gel manufacturing method etc. are mentioned.
The addition amount of the silica particles is preferably such that the coverage is 10 to 50% with respect to the colored particles, and more preferably 15 to 45%. Sufficient charge exchange properties can be obtained with an addition amount with a coverage of the above, and detachment from the toner is suppressed with an addition amount with a coverage of 50% or less.

[Other external additives]
In addition, other external additives may be externally added to the electrostatic charge image developing toner of the exemplary embodiment as long as the purpose is not impaired, and only titanium-based particles and silica-based particles may be used.
Examples of other external additives include inorganic particles such as alumina and cerium oxide, and organic particles such as polymethyl methacrylate (PMMA) particles.

<Colored particles>
The colored particles in the electrostatic image developing toner of this embodiment contain at least a colorant and a binder resin.
The colored particles may contain other components such as a release agent in addition to these components.

[Colorant]
The colored particles contain a colorant.
The colorant may be a dye or a pigment, but is preferably a pigment from the viewpoint of light resistance and water resistance. Further, the colorant is not limited to a colored colorant, and includes a white colorant and a colorant having a metal color.
Examples of colorants include carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose. Bengal, Quinacridone, Benzidine Yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment red 238, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 is used.

In this embodiment, the content of the colorant in the electrostatic image developing toner is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the binder resin.
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.

[Binder resin]
The transparent toner of this embodiment preferably contains at least a binder resin.
Binder resins include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl acetate, methyl acrylate, acrylic Α-methylene aliphatic monocarboxylic acid ester such as ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl methyl ether, Examples thereof include homopolymers or copolymers of vinyl ethers such as vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone.
Particularly typical binder resins include polystyrene resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride. Examples include copolymers, polyethylene, and polypropylene. Further examples include polyester resins, polyurethane resins, epoxy resins, silicone resins, polyamide resins, modified rosin resins, paraffins, and waxes. Among these, a polyester resin is particularly 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, and thus 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 can further reduce 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. The crystalline polyester resin may show a plurality of melting peaks, but in the present embodiment, the maximum peak is regarded as the 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 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 is reached, cool, and obtain the desired reactant Manufactured by doing.

  Further, the content of the binder resin in the transparent toner of the present embodiment is not particularly limited, but is preferably 75 to 99.5% by weight with respect to the total weight of the electrostatic image developing toner, and is preferably 85 to 85%. It is more preferably 99% by weight, and still more preferably 90 to 99% by weight. Within the above range, the fixing property, storage property, powder property, charging property and the like are excellent.

〔Release agent〕
The colored particles may contain a release agent.
Examples of the release agent include paraffin wax such as low molecular weight polypropylene and low molecular weight polyethylene; silicone resin; rosins; rice wax; carnauba wax;
50-100 degreeC is preferable and, as for the melting temperature of these mold release agents, 60-95 degreeC is more preferable.
The content of the release agent in the colored particles is preferably 0.5 to 15% by weight, and more preferably 1.0 to 12% by weight. If the content of the release agent is 0.5% by weight or more, peeling failure particularly in the case of oilless fixing is prevented. If the content of the release agent is 15% by weight or less, deterioration of toner fluidity can be prevented, and image quality and image formation reliability can be maintained.

[Other additives]
In addition to the above-described components, various components such as an internal additive and a charge control agent may be added to the colored particles as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys, and magnetic materials such as compounds containing these metals.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

<Toner characteristics>
In the present embodiment, the electrostatic charge image developing toner preferably has a shape factor SF1 of 115 to 140, more preferably 120 to 138.
Here, the shape factor SF1 is obtained by the following equation.
SF1 = ((ML) ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.
SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analysis apparatus. For example, an optical microscope image of particles dispersed on the surface of a slide glass is transmitted through a video camera. It is calculated by taking in a Luzex image analyzer, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and determining the average value.

  In this embodiment, the electrostatic charge image developing toner has a volume average particle size of preferably 3.0 to 9.0 μm, more preferably 3.1 to 8.5 μm, and still more preferably 3.2 to 8.0 μm. . When the volume average particle diameter is 3 μm or more, the fluidity is hardly lowered and the chargeability is easily maintained. If the volume average particle size is 9 μm or less, the resolution is unlikely to decrease. The volume average particle diameter is measured with a measuring machine such as Coulter Multisizer II (manufactured by Beckman Coulter, Inc.).

(Method for producing toner for developing electrostatic image)
The method for producing the electrostatic image developing toner of the present embodiment is not particularly limited as long as the toner of the present embodiment can be obtained. For example, a binder resin and, if necessary, a release agent, a charge control agent and the like are kneaded. , Pulverization, classification, kneading pulverization method, method of changing the shape of particles obtained by kneading pulverization method with mechanical impact force or thermal energy, emulsion polymerization of binder resin polymerizable monomer The dispersion was mixed with a release agent, and if necessary, a dispersion such as a charge control agent, and then aggregated and heat-fused to obtain toner particles. Mixing the dispersion with a dispersion of a release agent and, if necessary, a charge control agent, agglomerating and heat-fusing to obtain toner particles, a polyester agglomeration method for obtaining a binder resin, and a polymerizable monomer for obtaining a binder resin Solution of body, mold release agent, and charge control agent if necessary Suspension polymerization that suspends polymerization, a binder resin, a release agent, and, if necessary, a solution such as a charge control agent suspended in an aqueous solvent and granulated by suspension are used. . Further, a manufacturing method may be performed in which the toner particles obtained by the above method are used as a core, and further, aggregated particles are attached and heat-fused to have a core-shell structure.
Among these, it is preferable to prepare toner particles by a kneading pulverization method, an emulsion polymerization aggregation method, and a polyester aggregation method, and it is more preferable to prepare toner particles by a polyester aggregation method.

<Colored particle production process>
The method for producing an electrostatic charge image developing toner of the present embodiment includes a step of producing colored particles including a colorant and a binder resin (colored particle producing step).
The method for producing the colored particles in the colored particle production step is not particularly limited, and is produced by a dry method such as a kneading pulverization method or a wet method such as a melt suspension method, an emulsion aggregation method, or a dissolution suspension method. A well-known method is mentioned.

<External addition process>
The method for producing a toner for developing an electrostatic charge image according to this embodiment includes an external addition step of externally adding an external additive to the colored particles.
A method for externally adding the external additive to the toner in the external addition step is not particularly limited, and a known method can be used. For example, a mechanical method or a chemical method is used. Specifically, for example, a method of adhering to the surface of the colored particles by a dry method using a mixer such as a V blender or a Henschel mixer, an external additive is dispersed in a liquid, and then added to a toner in a slurry state and dried. Examples of the adhering method or the wet method include a method of drying while spraying a slurry on a dry toner.

(Electrostatic image developer)
The electrostatic image developing toner of this embodiment is used as a non-magnetic one-component developer or a two-component developer. When used as a two-component developer, it is used by mixing with a carrier.
The carrier that can be used in the two-component developer is not particularly limited, and a known carrier is used. Examples thereof include magnetic metals such as iron oxide, nickel and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the surface of the core material, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.
Coating resins and matrix resins used for carriers include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic. Examples include, but are not limited to, acid copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, and epoxy resins.
Examples of the conductive material include metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black, but are not limited thereto. It is not something.

  Examples of the core material of the carrier include magnetic metals such as iron, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, glass beads, and the like. Preferably there is. The volume average particle size of the core material of the carrier is preferably in the range of 10 μm to 500 μm, and more preferably in the range of 30 μm to 100 μm.

In order to coat the surface of the carrier core material with a resin, there may be mentioned a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include an immersion method in which the carrier core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed onto the surface of the carrier core material, and the carrier core material is fluidized air. A fluidized bed method in which the coating layer forming solution is sprayed in a state of being suspended by the above, a kneader coater method in which the carrier core material and the coating layer forming solution are mixed in a kneader coater, and the solvent is removed.

  The mixing ratio (weight ratio) of the electrostatic image developing toner of the exemplary embodiment and the carrier in the two-component developer is preferably in the range of toner: carrier = 1: 100 to 30: 100. A range of 100 to 20: 100 is more preferable.

(Cartridge, image forming method, and image forming apparatus)
Next, the cartridge of this embodiment will be described.
The cartridge of the present embodiment is a cartridge that contains at least the electrostatic image developing toner of the present embodiment or the electrostatic image developer of the present embodiment. In addition, it is preferable that the cartridge of this embodiment is detachable from the image forming apparatus.
When used in a developing device, an image forming method, or an image forming apparatus, it may be a toner cartridge that contains toner alone, or a developer cartridge that contains the electrostatic charge image developer of this embodiment. Further, developing means for developing the electrostatic latent image formed on the image carrier with the electrostatic image developing toner of the present embodiment or the electrostatic image developer of the present embodiment to form a toner image. It may be a process cartridge provided at least. The process cartridge according to the present embodiment preferably includes a developer holder that accommodates the electrostatic charge image developer according to the present embodiment and holds and conveys the electrostatic charge image developer.
In addition, the process cartridge according to the present embodiment may include other members such as a charge removing unit as necessary.

The image forming method of the present embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner. A developing step for forming a toner image, a transfer step for transferring the toner image formed on the surface of the image holding member to the surface of the transfer target, and a fixing step for fixing the toner image transferred on the surface of the transfer target. The developer containing the toner preferably includes the electrostatic image developing toner of the exemplary embodiment.
In addition, the image forming method of the present embodiment may include a cleaning step of removing toner remaining on the surface of the photoconductor after the transfer step with a cleaning blade in contact with the surface of the photoconductor.
The developer containing the toner may be the electrostatic image developing toner of this embodiment or the two-component developer containing the electrostatic image developing toner of this embodiment and a carrier.
As an image forming method of the present embodiment, a developer containing the electrostatic image developing toner of the present embodiment is prepared, and an electrostatic image is formed and developed by a conventional electrophotographic copying machine using the developer. The toner image is electrostatically transferred onto a transfer paper and fixed by a heating fixing device to form a copy image.
The image forming method of the present embodiment may be a non-magnetic one-component development method.

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 recording medium, known media can be used, for example, paper used for electrophotographic copying machines, printers, OHP sheets, etc. For example, the surface of plain paper is made of resin, etc. Coated coated paper, art paper for printing, and the like can be suitably used.

  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.

The image forming apparatus according to this 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 surface of the image carrier. Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image; transfer means for transferring the toner image from the image holding member to the surface of the transferred body; and the transferred body And a fixing unit that fixes the toner image transferred on the surface, and the developer is preferably provided with the electrostatic image developing toner of the present embodiment or the electrostatic 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 holding member, the charging unit, the exposure unit, the developing unit, and the transfer unit as described above, but other necessary. Depending on the situation, a fixing means, a cleaning means, a static elimination means and the like may be included.
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.

An example of the image forming apparatus of the present embodiment will be described with reference to FIG. 1, but the present embodiment is not limited at all. FIG. 1 is a schematic cross-sectional view showing an example of an image forming apparatus using the two-component developer of the present embodiment.
FIG. 1 is a schematic diagram illustrating a configuration example of an image forming apparatus for forming an image by the image forming method of the present embodiment. In the illustrated image forming apparatus 200, four electrophotographic photosensitive members (image holding members) 401 a to 401 d are arranged in parallel along the intermediate transfer belt 409 in a housing 400. The electrophotographic photoreceptors 401a to 401d form, for example, images in which the electrophotographic photoreceptor 401a is yellow, the electrophotographic photoreceptor 401b is magenta, the electrophotographic photoreceptor 401c is cyan, and the electrophotographic photoreceptor 401d is black. Is possible.

Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can be supplied with toner of four colors of black, yellow, magenta and cyan accommodated in the toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively intermediate transfer belts. 409 is in contact with the electrophotographic photoreceptors 401a to 401d.
Further, an exposure device 403 is disposed at a predetermined position in the housing 400, and it becomes possible to irradiate the surfaces of the charged electrophotographic photosensitive members 401a to 401d with a light beam emitted from the exposure device 403. ing. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.
Here, the charging rolls 402a to 402d apply a voltage to the photosensitive member by bringing a conductive member (charging roll) into contact with the surface of the electrophotographic photosensitive members 401a to 401d to charge the surface of the photosensitive member to a predetermined potential. (Charging process). In addition to the charging roll shown in this embodiment, charging by a contact charging method may be performed using a charging brush, a charging film, a charging tube, or the like. Moreover, you may charge by the non-contact system using a corotron or a scorotron.

As the exposure apparatus 403, an optical system apparatus or the like that can expose a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surfaces of the electrophotographic photosensitive members 401a to 401d can be used.
As the developing devices 404a to 404d, a general developing device that develops the two-component electrostatic image developer in contact or non-contact with the developer can be used (developing step). Such a developing device is not particularly limited as long as a two-component electrostatic image developer is used, and a known one can be appropriately selected according to the purpose. In the primary transfer step, a primary transfer bias having a polarity opposite to that of the toner on the image carrier is applied to the primary transfer rollers 410a to 410d, so that each color toner is sequentially transferred from the image carrier to the intermediate transfer belt 409. Next transferred.
The cleaning blades 415a to 415d are for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process, and the electrophotographic photosensitive member cleaned by this cleaning process is repeatedly used in the above-described image forming process. Is done. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409.
By applying a secondary transfer bias having a reverse polarity to the toner on the intermediate transfer member to the secondary transfer roll 413, the toner is secondarily transferred from the intermediate transfer belt to the recording medium. The intermediate transfer belt 409 that has passed between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed near the drive roll 406 or a static eliminator (not shown). It is repeatedly used for the next image forming process. Further, a tray (recording medium tray) 411 is provided at a predetermined position in the housing 400, and the recording medium 500 such as paper in the tray 411 is moved by the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

An example of an image forming apparatus that develops using a non-magnetic one-component developer will be described below with reference to FIGS. 2 can be used in each of the developing devices 404a to 404d in FIG. 1 to form an image in the same manner.
The electrostatic charge image developing toner of this embodiment is also suitably used as a non-magnetic one-component developer. The non-magnetic one-component development method is a development method in which the stress on the toner surface is stronger than the two-component development method, and the silica-based particles used as the external additive are easily embedded in the toner. By using the image developing toner, it is considered that silica-based particles are suppressed from being embedded in the toner even in the non-magnetic one-component developing system.
As shown in FIG. 2, the developing device 10 is disposed so as to abut on an image carrier 26 that can be rotated in the direction of arrow A by a drive source (not shown), and the arrow moves along with the rotation of the image carrier (photoreceptor) 26. A developing roller 12 that can be driven to rotate in the B direction, a bias power source 14 connected to the developing roller 12, and a position downstream of the contact portion between the developing roller 12 and the image carrier 26 in the rotating direction of the developing roller 12. In addition, a toner scraping member 16 that is disposed so as to be in pressure contact with the developing roll 12 and is rotatable in the direction of arrow C so as to run against the rotation of the developing roll 12, and in the rotating direction of the developing roll 12, the developing roll 12 And a toner layer reference disposed so as to contact the developing roll 12 at a position downstream of the pressure contact portion between the toner scraping member 16 and upstream of the contact portion between the developing roll 12 and the image carrier 26. The member 18 is located on the side opposite to the side on which the image carrier 26 of the developing roll 12 is disposed, and the housing 22 having an opening on the side on which the developing roll 12 is disposed. And an agitator 20.

  The toner layer regulating member 18 is once fixed to the opening of the housing 22 so as to close the opening of the housing 22. The side of the opening of the housing 22 opposite to the side on which the toner layer regulating member 18 is attached (upper side of the opening) (lower side of the opening) covers the lower side of the developing roll 12 and the toner scraping member 16. It is configured. Here, the toner (nonmagnetic one-component developer) 24 is disposed so as to be deposited on the lower side of the casing 22, and a space between the lower side of the developing roll 12 and the lower side of the opening of the casing 22. Is deposited so as to cover the toner scraping member 16. The toner 24 is appropriately supplied from the inside of the housing 22 to the opening side of the housing 22 where the developing roll 12 is disposed by an agitator 20 provided in the housing 22.

  When developing, first, the toner 24 in the housing 22 is supplied from the agitator 20 to the surface of the developing roll 12 by the toner scraping member 16. Next, the toner 24 attached to the surface of the developing roll 12 is attached by the toner layer regulating member 18 so as to form a toner layer having a uniform thickness on the surface of the developing roll 12. Subsequently, it adheres to the surface of the developing roll 12 according to the potential difference between the surface of the image carrier 26 on which an electrostatic latent image (not shown) is formed and the developing roll 12 to which a bias voltage is applied by the bias power supply 14. The toner 24 is transferred to the developing roll 12 side, and the electrostatic latent image is developed. The toner 24 remaining on the surface of the developing roll 12 after the development is scraped off by the toner scraping member 16.

  Hereinafter, although this embodiment is described in detail with examples, this embodiment is not limited in any way. In the following description, “parts” means “parts by weight” unless otherwise specified.

(Measurement method of volume average particle diameter of colored particles and volume average particle diameter or number average particle diameter of external additive)
The volume average particle diameter of the colored particles and the volume average particle diameter or number average particle diameter of the external additive were measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). As the electrolytic solution, ISOTON-II (manufactured by Beckman Coulter, Inc.) was used.
As a measuring method, first, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this is added to 100 ml to 150 ml of the electrolytic solution. Added. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size is 2.0 μm or more and 60 μm or less using the Coulter Multisizer II with an aperture having an aperture diameter of 100 μm The particle size distribution of particles in the range was measured. The number of particles to be measured was 50,000.
Draw a cumulative distribution from the small diameter side for the number or volume for the divided particle size range (channel) for the measured particle size distribution. It is defined as

(Production of toner)
<Synthesis of non-crystalline polyester resin>
In a heat-dried two-necked flask, 90 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, 10 mol parts of ethylene glycol, 80 mol parts of terephthalic acid, and isophthalic acid 20 mol part as a raw material, dibutyltin oxide is added as a catalyst, nitrogen gas is introduced into the container and heated in an inert atmosphere, and then subjected to a copolycondensation reaction at 150 to 230 ° C. for about 12 hours, The pressure was gradually reduced at 210 to 250 ° C. to synthesize an amorphous polyester resin (1).
The weight average molecular weight (Mw) of the amorphous polyester resin (1) was 23,200. The acid value of the amorphous polyester resin (1) was 14.2 KOH mg / g. The glass transition temperature (Tg) of the amorphous polyester resin (1) was 62 ° C.

(Production of metatitanic acid particles)
The metatitanic acid particles used in the examples are shown below.
Metatitanic acid particles (1): Crystallite diameter 12.5 nm
Metatitanic acid particles (2): Crystallite diameter 15.7 nm
Metatitanic acid particles (3): Crystallite diameter 14.0 nm
Metatitanic acid particles (4): Crystallite diameter 11.0 nm
Metatitanic acid particles (5): crystallite diameter 18.2 nm

<Preparation of metatitanic acid particles (1)>
Ilmenite ore (FeTiO ₃ ) was heated and dissolved in concentrated sulfuric acid to separate the iron powder to obtain TiOSO ₄ . Further, a precipitate of TiO (OH) ₂ was generated by heating hydrolysis, and after filtration and repeated washing with water, 10 ppm (mass) of polycarboxylic acid and 100 times (mass) of TiO (OH) _{2 were obtained.} ) Was added and sufficiently stirred, and then dried at 150 ° C. Next, heating and firing were performed at 500 ° C. for 80 minutes to obtain a TiO (OH) ₂ precipitate . Next, TiO (OH) ₂ obtained in water was dispersed, and 5% by weight of solid content of isobutylmethoxysilane was added dropwise with stirring at a temperature of 25 ° C. Next, this was filtered and water washing was repeated. The obtained TiO (OH) ₂ surface-treated with isobutylmethoxysilane was dried at 150 ° C.
The metatitanic acid particles (1) had a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak was 12.5 nm.

<Preparation of metatitanic acid particles (2)>
The metatitanic acid particles (1) were prepared by the same method as the metatitanic acid particles (1) except that the drying time was 135 minutes and the amount of polycarboxylic acid added was 8 ppm.
The metatitanic acid particles (2) had a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak was 15.7 nm.

<Preparation of metatitanic acid particles (3)>
The metatitanic acid particles (1) were produced by the same method as the metatitanic acid particles (1) except that the drying time was 100 minutes.
The metatitanic acid particles (3) had a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak was 14.0 nm.

<Preparation of metatitanic acid particles (4)>
The metatitanic acid particles (1) were prepared by the same method as the metatitanic acid particles (1) except that the drying temperature was 490 ° C., the drying time was 75 minutes, and the amount of polycarboxylic acid added was 15 ppm.
The metatitanic acid particles (4) had a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak was 11.0 nm.

<Preparation of metatitanic acid particles (5)>
The metatitanic acid particles (1) were prepared by the same method as the metatitanic acid particles (1) except that the drying temperature was 520 ° C., the drying time was 150 minutes, and the amount of polycarboxylic acid added was 0 ppm.
The metatitanic acid particles (5) had a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak was 18.2 nm.

(Preparation of silica particles)
The silica particles used in the examples are shown below.
Silica particles (1): Volume average particle size 65 nm
Silica particles (2): Volume average particle size 180 nm
Silica particles (3): Volume average particle size 130 nm
Silica particles (4): volume average particle size 40 nm
Silica particles (5): Volume average particle size 230 nm

<Preparation of silica particles (1)>
150 parts of tetramethoxysilane is stirred at 280 rpm while 150 parts of 25% by weight aqueous ammonia is added dropwise at 30 ° C. over 5 hours in the presence of 100 parts of ion-exchanged water and 100 parts of 25% by weight alcohol. The silica sol suspension obtained by this reaction is centrifuged, separated into wet silica gel, alcohol and aqueous ammonia, and the separated wet silica gel is dried at 120 ° C. for 2 hours, and then 100 parts of silica and 500 parts of ethanol are mixed. Was put into an evaporator and stirred for 15 minutes while maintaining the temperature at 40 ° C. Next, 10 parts of dimethyldimethoxysilane was added to 100 parts of silica, and the mixture was further stirred for 15 minutes. Finally, the temperature was raised to 90 ° C. and ethanol was dried under reduced pressure. The treated product was taken out and further vacuum dried at 120 ° C. for 30 minutes. The dried silica was pulverized to obtain silica particles (1) having a volume average particle diameter of 65 nm.

<Preparation of silica particles (2)>
The production method of silica particles (1) was the same as that of silica particles (1) except that 25% by weight of ammonia water was added at 150 rpm while dropping 150 parts of ammonia water over 5 hours. To obtain silica particles (2) having a volume average particle diameter of 180 nm.

<Preparation of silica particles (3)>
The production method of silica particles (1) was the same as that of silica particles (1) except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 5 hours. To obtain silica particles (3) having a volume average particle size of 130 nm.

<Preparation of silica particles (4)>
The production method of silica particles (1) was the same as that of silica particles (1) except that 25% by weight of ammonia water was added with stirring at 305 rpm while dropping 150 parts of ammonia water over 5 hours. Thus, silica particles (4) having a volume average particle diameter of 40 nm were obtained.

<Preparation of silica particles (5)>
The production method of silica particles (1) was the same as that of silica particles (1) except that 25 wt% aqueous ammonia was added at 150 rpm while dropping 150 parts of aqueous ammonia over 5 hours. To obtain silica particles (5) having a volume average particle size of 230 nm.

<Preparation of release agent dispersion>
・ 50 parts of paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point: 75 ° C.) 0.5 part of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 200 parts or more were mixed, heated to 95 ° C., and dispersed using a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin Co., Ltd.) to prepare a release agent dispersion (solid content concentration: 20%) in which the release agent was dispersed. The volume average particle diameter of the release agent in the release agent dispersion was 0.23 μm.

<Preparation of colorant dispersion>
-Cyan pigment (Daiichi Seika Kogyo Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine) 1,000 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 15 parts-Ion exchange More than 9,000 parts of water is mixed, dissolved, and dispersed for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine, HJP30006) to disperse the colorant (cyan pigment). A colorant dispersion was prepared, and the volume average particle size of the colorant (cyan pigment) in the colorant dispersion was 0.16 μm, and the solid content concentration was 20% by weight.

Example 1
<Preparation of colored particles (1)>
-Mixing process-
Amorphous polyester resin dispersion (1) 267 parts Colorant dispersion 25 parts Release agent dispersion 40 parts Anionic surfactant (Taika Power, manufactured by Teika Co., Ltd.) 2.0 parts The mixture was placed in a container, and the homogenizer (Ultra Turrax T50, manufactured by IKA) was used. The homogenizer was rotated at 4,000 rpm and dispersed and mixed for 10 minutes while applying a shearing force. Next, 2.0 parts of a 10% aqueous nitric acid solution of polyaluminum chloride (PAC) as a flocculant (the content of nitric acid was 0.05 N) was gradually added dropwise, and the rotation speed of the homogenizer was set to 5, The mixture was dispersed for 15 minutes at 000 rpm and mixed to obtain a raw material dispersion.

-Aggregation process-
Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 42 ° C. At this time, the pH of the raw material dispersion was adjusted to a range of 3.2 or more and 3.8 or less using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The raw material dispersion was kept in the above pH range and allowed to stand for about 2 hours to form aggregated particles. The volume average particle diameter of the aggregated particles was 5.4 μm.

-Fusion process-
Next, 100 parts of the amorphous polyester resin dispersion (1) was additionally added to the raw material dispersion, and the resin particles of the amorphous polyester resin (1) were adhered to the surface of the aggregated particles. Furthermore, the temperature of the raw material dispersion was raised to 44 ° C., and aggregated particles were prepared using an optical microscope and Multisizer II while confirming the size and form of the particles. Thereafter, in order to fuse the aggregated particles, a sodium hydroxide aqueous solution was dropped into the raw material dispersion to adjust the pH to 7.5, and then the raw material dispersion was heated to 95 ° C. Thereafter, the raw material dispersion was allowed to stand for 3 hours to fuse the aggregated particles. After confirming that the aggregated particles were fused with an optical microscope, the colored particle dispersion was cooled at a temperature lowering rate of 1.0 ° C./min.

-Washing process-
Next, the colored particle dispersion was filtered, and the colored particles after solid-liquid separation were dispersed in ion-exchanged water at 30 ° C., which is 20 times the solid content of the colored particles, and filtered by stirring for 20 minutes. . This process was repeated 5 times, and it was confirmed that the filtrate had a conductivity of 25 μS. The colored particles were filtered and dried with a freeze dryer to obtain colored particles (1).

-External addition process-
100 parts of colored particles, 1.84 parts of metatitanic acid particles (1) and 0.98 parts of silica particles (1) were placed in a Henschel mixer and mixed at a rotational speed of 2,200 rpm for 2.5 minutes. Further, sieving was performed with a 45 μm sieving mesh to obtain an externally added toner (1).

(Examples 2-5, Comparative Examples 1-4)
<Preparation of Externally Added Toners (2) to (9)>
The metatitanic acid particles and the silica particles were prepared in the same manner as in the externally added toner (1) except that the particles were changed to those shown in Table 1, respectively.

<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) were added to a kneader, and a perfluorooctylmethyl acrylate-methyl methacrylate copolymer (polymerization ratio: 20 / 80, Tg: 72 ° C., weight average molecular weight: 72,000, manufactured by Soken Chemical Co., Ltd.) 150 parts dissolved in 700 parts of toluene, mixed at room temperature for 20 minutes, then heated to 70 ° C. under reduced pressure After drying, it was taken out to obtain a coat carrier. 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 shape factor SF1 of the carrier was 122.

<Production of developer>
The obtained externally added toner (1) to externally added toner (9) and a carrier are placed in a V blender at a ratio of externally added toner: carrier = 5: 95 (weight ratio), stirred for 20 minutes, and developed with a developer ( 1) to (9) were obtained and evaluated.

<Evaluation>
The 700 Digital Color Press remodeling machine manufactured by Fuji Xerox Co., Ltd. equipped with the obtained electrostatic charge image developer was used. The evaluation was carried out under the same conditions after leaving the toner and the device for 1 day under the conditions of the respective temperatures and relative humidity.

[Concentration change]
Condition 1: Evaluation is started in the same environment after being left for one day at low temperature and low humidity (10 ° C, 15%).
Condition 2: Evaluation is started in the same environment after being left for 1 day under high temperature and high humidity (28 ° C, 85%).
Under each of the above conditions, a patch was prepared and the image density was confirmed (density 1). Subsequently, a patch was produced again after outputting 100,000 images with an image density of 1% continuously, and the image density was confirmed (density 2).
The image density was measured using an image densitometer X-RITE 938 (manufactured by X-RITE).
A Δ concentration value represented by the following formula was calculated from the concentration 1 and the concentration 2 and evaluated according to the following criteria.
Δ concentration = | concentration 1−concentration 2 |
G1: 0 <Δ concentration ≦ 0.2
G2: 0.2 <Δ concentration ≦ 0.3
G3: 0.3 <Δ concentration

<Color streak evaluation>
The 700 Digital Color Press remodeling machine manufactured by Fuji Xerox Co., Ltd. equipped with the obtained electrostatic charge image developer was left at high temperature and high humidity (28 ° C., 85%) for 1 day, and an image with an area coverage of 1% was obtained as 100, 000 sheets were output continuously.
The color streak generation was visually observed on 100 sheets of 99,900 to 100,000 sheets, and evaluated according to the following criteria.
G1: No color streaking G2: 0 sheets <color streaking ≦ 5 sheets G3: 5 sheets <color streaking

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3,110 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer roller 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K toner cartridge 10Y, 10M, 10C, 10K unit 20 intermediate transfer belt 22 drive roller 24 support roller 26 secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
29 Heating means (heater)
30 Intermediate transfer member cleaning device 32 Detection member 34 Conveying belt P, 300 Recording paper (transferred material)

Claims (8)

Having colored particles including a colorant and a binder resin;
Two or more kinds of inorganic particles are externally added to the surface of the colored particles,
The two or more kinds of inorganic particles include metatitanic acid particles and silica particles,
The metatitanic acid particles have a maximum diffraction peak at a black angle 2θ = 27.5 ° in CuKα characteristic X-ray diffraction, and the crystallite diameter calculated from the peak is 12 to 16 nm,
The toner for developing an electrostatic charge image, wherein the silica particles have a volume average particle diameter of 50 to 200 nm.   The toner for developing an electrostatic charge image according to claim 1, wherein the number average particle diameter of the metatitanic acid particles is 20 to 50 nm.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1 and a carrier.   A toner cartridge containing the electrostatic image developing toner according to claim 1.   A developer cartridge containing the electrostatic charge image developer according to claim 3.   A process cartridge comprising a developer holder that contains the electrostatic image developer according to claim 3 and that holds and conveys the electrostatic image developer. A latent image forming step for forming an electrostatic latent image on the surface of the image carrier;
A development step of developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
A transfer step of transferring the toner image onto the surface of the transfer target; and
A fixing step of fixing the toner image transferred to the surface of the transfer target,
An image forming method using the electrostatic charge image developing toner according to claim 1 or the electrostatic charge image developer according to claim 3 as the developer. 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 surface of the image carrier;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image from the image carrier to the surface of the transfer target;
Fixing means for fixing the toner image transferred to the surface of the transfer target,
An image forming apparatus comprising the electrostatic image developing toner according to claim 1 or the electrostatic charge image developer according to claim 3 as the developer.

Images