JP6163896B2 - Non-magnetic one-component toner, electrostatic charge image developer, process cartridge, image forming method, and image forming apparatus - Google Patents

Description

  The present invention relates to a non-magnetic one-component toner, an electrostatic charge image developer, a process cartridge, an image forming method, and an image forming apparatus.

In recent years, the electrophotographic process has been widely used not only for copiers but also for office network printers, personal computer printers, on-demand printers, etc. due to the development of equipment in the information society and the enhancement of communication networks. Regardless of color, high image quality, high speed, high reliability, miniaturization, weight reduction, and energy saving performance are increasingly required.
In an electrophotographic process, an electrostatic charge image is usually formed on a photosensitive member (image holding member) using a photoconductive substance by various means, and the electrostatic charge image is developed with toner, and then exposed to light. After the toner image on the body is transferred to a recording medium such as paper with or without an intermediate transfer body, the transferred image is fixed to the recording medium, and a fixed image is formed through a plurality of processes. .
One development method using electrophotography is a one-component development method. The one-component development method is broadly divided into a magnetic one-component development method using magnetic toner and a non-magnetic one-component development method using non-magnetic toner, and the non-magnetic one-component development method is selected from the viewpoint of colorization. Often.

Patent Document 1 discloses a toner comprising colored resin particles and resin fine particles attached to the surface of the colored resin particles and having a volume particle diameter smaller than that of the colored resin particles, wherein the volume average of the colored resin particles A toner is disclosed wherein R0 / r is 150 or less, where R0 (μm) is the particle diameter and r (μm) is the volume average particle diameter of the resin fine particles.
Patent Document 2 discloses an electrophotographic dry toner containing at least a polyester-based resin, a release agent, a colorant and resin fine particles, wherein at least the release agent and the colorant are dispersed in the polyester-based resin, and then pulverized. And 70% or more of the surface of the core particle obtained by classification is coated with resin fine particles, the resin fine particles are at least one selected from acrylic resin fine particles or methacrylic resin fine particles, and the interface The toner is dispersed in pure water containing 0.2% of an activator, and the detachment rate of resin fine particles after irradiation with ultrasonic waves (50 kHz, 100 W) for 10 minutes is less than 5%, A positively chargeable electrophotographic dry toner is disclosed.
Further, in Patent Document 3, in an image forming toner comprising toner base particles containing at least a binder resin, a colorant and a release agent and an external additive, at least a part of the surface of the toner base particles is formed. An image forming toner characterized by having a resin film portion formed by forming a resin powder into a film is disclosed.
Patent Document 4 discloses a toner for developing an electrostatic charge image, wherein the toner has a volume average particle diameter of 2.0 to 7.1 μm and the surface state of the toner is in a scab shape. ing.

JP 2012-68331 A JP 2012-63602 A JP 2009-150954 A JP 2004-86131 A

  The problem to be solved by the present invention is to provide a non-magnetic one-component toner capable of obtaining an image with little density unevenness.

Said subject was solved by the means as described in <1> and <4>-<7> below. It is described below together with <2> and <3> which are preferred embodiments.
<1> Contains toner base particles including at least a binder resin and a colorant, the binder resin includes a crystalline resin, and is embedded in a state in which the resin particles are partially exposed on the surface of the toner base particles. A non-magnetic one-component toner, wherein a maximum diameter of a portion of the resin particles embedded in the toner base particles is larger than a maximum diameter of a portion exposed on the surface of the toner base particles,
<2> The non-magnetic one-component toner according to <1>, wherein an average primary particle size of the resin particles is 40 nm or more and 300 nm or less.
<3> The non-magnetic one-component toner according to <1> or <2>, wherein the resin particles have positive chargeability,
<4> An electrostatic charge image developer comprising the nonmagnetic one-component toner according to any one of <1> to <3>,
<5> Development that is detachable from the image forming apparatus, contains the non-magnetic one-component toner according to any one of <1> to <3>, and holds and conveys the non-magnetic one-component toner A process cartridge comprising means,
<6> A latent image forming 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 toner to form a toner image, and the toner image And a fixing step of fixing the toner image transferred to the surface of the transfer material, wherein the toner is any one of <1> to <3>. An image forming method characterized by being a non-magnetic one-component toner,
<7> An image holding member, a charging unit that charges the image holding member, an exposure unit that exposes the charged image holding member to form an electrostatic latent image on the surface of the image holding member, and the static A developing unit that develops the electrostatic latent image to form a toner image, a transfer unit that transfers the toner image from the image holding member to the surface of the transfer target, and a toner image transferred to the surface of the transfer target are fixed. An image forming apparatus, wherein the toner is the non-magnetic one-component toner according to any one of <1> to <3>.

According to the invention described in <1> above, it is possible to provide a non-magnetic one-component toner capable of obtaining an image with less density unevenness as compared with the case where the present configuration is not provided.
According to the invention described in <2> above, an image with less density unevenness can be obtained as compared with the case where the average primary particle diameter of the resin particles is less than 40 nm or more than 300 nm. A magnetic one-component toner can be provided.
According to the invention described in <3>, it is possible to provide a non-magnetic one-component toner capable of obtaining an image with less density unevenness as compared with the case where the resin particles do not have positive chargeability. .
According to the invention described in <4> above, it is possible to provide an electrostatic charge image developer capable of obtaining an image with less density unevenness as compared with the case where the present configuration is not provided.
According to the invention described in <5>, it is possible to provide a process cartridge including a non-magnetic one-component toner capable of obtaining an image with less density unevenness as compared with the case where the present configuration is not provided.
According to the invention described in <6>, it is possible to provide an image forming method capable of obtaining an image with less density unevenness as compared with the case where the present configuration is not provided.
According to the invention described in <7>, it is possible to provide an image forming apparatus capable of obtaining an image with less density unevenness as compared with the case where the present configuration is not provided.

FIG. 6 is a schematic diagram illustrating an example of a state in which resin particles are partially exposed on the surface of toner base particles in the nonmagnetic one-component toner of the present embodiment. 1 is a schematic cross-sectional view showing an example of a tandem type image forming apparatus preferably used in the present embodiment. 1 is a schematic diagram illustrating an example of a developing device using a nonmagnetic one-component toner or a nonmagnetic one-component developer according to an exemplary embodiment.

Hereinafter, the present embodiment will be described.
In the present embodiment, the description “X to Y” represents not only a range between X and Y but also a range including X and Y that are both ends thereof. For example, if “X to Y” is a numerical value range, it represents “X or more and Y or less” or “X or less and Y or more” depending on the numerical value.

1. Non-magnetic one-component toner The non-magnetic one-component toner of the present embodiment (hereinafter also simply referred to as “toner”) contains toner base particles containing at least a binder resin and a colorant, and the binder resin is crystalline. A resin resin is embedded in a state where the resin particles are partially exposed on the surface of the toner base particles, and the maximum diameter of the portion of the resin particles embedded in the toner base particles is exposed on the surface of the toner base particles. It is characterized in that it is larger than the maximum diameter of the portion that has been formed.

When continuous printing, especially low-image-density printing is performed by the non-magnetic one-component development method, and the toner on the developing roll is consumed and replaced, the toner charge distribution expands and high-charged toner that is not developed or transferred is developed. It remains on the roll. The inventors of the present invention have found that a conveyance failure and a development failure occur due to a charge difference with the newly supplied toner and mutual charging, resulting in density unevenness.
In the two-component development system, the toner is conveyed to the developing roll via the carrier. The carrier is detached from the developing roll by the magnetic repulsive force, and a new carrier and toner are supplied, so that the problem that the charging of the toner is stable and the density unevenness does not occur cannot occur. This is a problem specific to the development system.
As a result of intensive studies by the inventors, the toner contains toner base particles containing at least a binder resin and a colorant, the binder resin contains a crystalline resin, and the resin particles are on the surface of the toner base particles. A non-magnetic one-component toner that is embedded in a partially exposed state and has a maximum diameter of a portion embedded in the toner base particles of the resin particles larger than a maximum diameter of a portion exposed on the surface of the toner base particles Thus, the present inventors have found that an image with little density unevenness can be obtained.

  Although the detailed mechanism is not clear, the resin particles are selectively embedded in the crystalline resin part exposed on the toner surface, so the resin particles are better dispersed (smaller domains) than the conventional formulation. Since there are many sites, a desired charge level can be obtained, and polarization on the toner surface can be suppressed, resulting in a sharp charge distribution. In addition, since a crystalline resin with higher charge leakage compared to other toner constituent materials is present in the vicinity of the resin particles that function as charging sites, development is possible during continuous output, particularly at low image density. Even when there is no toner replacement on the roll, the generation of excessively charged toner can be suppressed, and the highly charged toner that is difficult to be developed / transferred is not generated. Even when a high halftone image is output, it is estimated that an image with less density unevenness can be obtained by using the non-magnetic one-component toner of this embodiment without causing a decrease in image density.

(Toner mother particles)
(1) Binder Resin The binder resin contained in the toner base particles is not particularly limited as long as it contains at least a crystalline resin. For example, styrene such as styrene, parachlorostyrene, α-methylstyrene, etc. Class: methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, Esters having a vinyl group such as 2-ethylhexyl methacrylate; Vinyl nitriles such as acrylonitrile and methacrylonitrile; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc. Vinyl Ton acids, ethylene, propylene, homopolymer consisting of a monomer, such as polyolefins such as butadiene, or a copolymer obtained by combining two or more of these, 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.

The toner according to the exemplary embodiment includes at least a crystalline resin as a binder resin in the toner base particles. The toner base particles have a crystalline resin and partially embedded resin particles exposed on the surface, so that the crystalline resin having a high charge leakage property and the resin particles functioning as a charging site act in concert. However, even when there is no toner replacement on the developing roll during continuous output, particularly at low image density, it is possible to suppress the generation of excessively charged toner and high charge that is difficult to develop / transfer. It is estimated that no toner is generated and an image with little density unevenness can be obtained.
Further, in the toner of the present exemplary embodiment, compared to the amorphous resin portion on the surface of the toner base particle, a large amount of the resin particle is exposed on the surface and embedded in the crystalline resin portion on the surface of the toner base particle. Is preferred.
The content of the crystalline resin in the binder resin in the toner base particles is preferably 5 to 30% by weight, more preferably 10 to 20% by weight, based on the total weight of the binder resin. More preferably, it is ˜15% by weight. With the above aspect, an image with less density unevenness can be obtained.

As the crystalline resin, a crystalline polyester resin is preferable from the viewpoint of chargeability.
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 aliphatic dicarboxylic acid content is 80 mol% or more, the crystallinity of the polyester resin is excellent and the melting point is moderate, so that the embedding form controllability of the particles, toner blocking resistance, and image storage stability are achieved. 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 the melting point is moderate, so that the embedded form controllability of the particles, toner blocking resistance, image storage stability, and Excellent 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 particle embedding form controllability, peelability and low-temperature fixability, and offset can be further reduced.
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 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, 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.

(2) 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.

(3) Release agent In the exemplary 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 fixing and image quality characteristics can be achieved.

(4) Other Components In this embodiment, the toner base particles may contain other components in addition to the above components. Other components are not particularly limited, and examples include charge control agents, inorganic particles, organic particles, lubricants, and abrasives.

(Resin particles)
The non-magnetic one-component toner of the present embodiment is embedded with the resin particles partially exposed on the surface of the toner base particles, and the maximum diameter of the portion of the resin particles embedded in the toner base particles is the toner. The toner is larger than the maximum diameter of the portion exposed on the surface of the mother particle.
FIG. 1 is a schematic diagram illustrating an example of a state in which resin particles are partially exposed on the surface of toner base particles in the nonmagnetic one-component toner of the present embodiment.
In FIG. 1, the resin particles 104 are embedded in the surface 102 of the toner base particles 110 in the nonmagnetic one-component toner of the present embodiment with the binder resin 106 partially exposed. In the resin particle 104, the maximum diameter L 1 of the portion 104 a embedded in the toner base particle 110 is larger than the maximum diameter L 2 of the portion 104 b exposed on the toner base particle surface 102.
Further, the embedding depth of the resin particles 104 in the toner base particles 110 is L3.
Needless to say, the binder resin 106 may contain a toner component such as a colorant (not shown) or a release agent (not shown).

The maximum diameter of the resin particle embedded in the toner base particle and the maximum diameter of the resin particle exposed on the surface of the toner base particle are embedded in the toner with an embedding agent such as epoxy resin, diamond knife, etc. And cut the surface of the embedded product until a sufficient cross-section of the toner can be secured to make a measurement sample, and the maximum diameter of the embedded resin particles near the toner base particle surface is 100 particles or more Measure, extract 30% of the particles with larger particle size and take the average value.
Specifically, the following measurement methods can be preferably exemplified.
After embedding the toner with a bisphenol A liquid epoxy resin and a curing agent, a cutting sample is prepared. Next, the cutting sample is cut at −100 ° C. using a cutting machine using a diamond knife (for example, LEICA ultramicrotome (manufactured by Hitachi High-Technologies Corporation)) to prepare an observation sample. The cross section of the toner is observed with a transmission electron microscope (for example, S-4800 field emission scanning electron microscope (manufactured by Hitachi, Ltd.)) at a magnification of about 20,000 times. The maximum diameter of the embedded resin particles in the vicinity of the surface of the toner base particles is measured by 100 or more particles, 30% of the particles having the larger particle diameter are extracted, and the maximum portion of the resin particles embedded in the toner base particles is measured. The diameter and the maximum diameter of the portion of the resin particle exposed on the surface of the toner base particle are measured, and the average value is calculated.

The maximum diameter (average maximum diameter) of the resin particles embedded in the toner base particles is preferably 80 to 100% of the particle diameter (average primary particle diameter) of the resin particles. It is more preferable that the length is 100%, and it is more preferable that the length is 95 to 100%. Within the above range, the resin particles are sufficiently buried in the surface of the toner base particles, and an image with less density unevenness can be obtained.
Further, the maximum diameter (average maximum diameter) of the portion of the resin particles exposed on the surface of the toner base particles may be 5 to 50% of the particle diameter (average primary particle diameter) of the resin particles. Preferably, the length is 10 to 50%, more preferably 20 to 50%. Within the above range, the resin particles are sufficiently exposed on the surface of the toner base particles, the charge distribution of the whole toner becomes narrower, and an image with less density unevenness can be obtained.

Further, the depth of the resin particles embedded in the toner base particles (average depth) is preferably 30 to 95% of the particle size (average primary particle size) of the resin particles, The length is more preferably 40 to 90%, and further preferably 50 to 90%. Within the above range, the resin particles are sufficiently embedded and exposed on the surface of the toner base particles, the charge distribution of the entire toner becomes narrower, and an image with less density unevenness can be obtained.
For example, in the cross section of the toner as shown in FIG. 1, the depth of the portion of the resin particle embedded in the toner base particle is a straight line connecting two points where the resin particle surface and the toner base particle surface are in contact with the toner base particle. It is obtained by measuring the distance between the straight line passing through the deepest part of the resin particle buried in and parallel to the straight line. The depth (average depth) of the portion of the resin particle embedded in the toner base particle is the maximum diameter of the portion of the resin particle embedded in the toner base particle or the surface of the toner base particle of the resin particle. It is measured by the same method as the maximum diameter of the part.

The material of the resin particles is not particularly limited. For example, styrene resin such as polystyrene; (meth) acrylic resin such as polymethyl methacrylate; fluorine resin such as polyvinylidene fluoride; melamine resin, urea resin, and azo dye are dispersed. And nitrogen atom-containing resins such as the above-mentioned resins.
Among these, a (meth) acrylic resin or a nitrogen atom-containing resin is preferable, a (meth) acrylic resin having a cycloalkyl group in the side chain is more preferable, and poly (meth) acrylic acid cyclohexyl is still more preferable.

The resin particles are preferably resin particles having positive chargeability. With the above aspect, an image with less density unevenness can be obtained.
Further, when the resin particles are resin particles having positive chargeability, the binder resin of the toner base particles is preferably a polyester resin. In the above embodiment, polarization on the toner surface is suppressed, and an image with less density unevenness can be obtained.
Examples of the material of the resin particles having positive charge include nitrogen atom-containing resin and (meth) acrylic resin.
The chargeability of the resin particles may be controlled by surface treating the resin particles by a known method.

The average primary particle size of the resin particles is preferably 10 to 500 nm, more preferably 20 to 400 nm, still more preferably 40 to 300 nm, and particularly preferably 40 to 100 nm. Within the above range, the embedding of the resin particles on the surface of the toner base particles can be easily controlled, and an image with less density unevenness can be obtained.
The shape of the resin particles is not particularly limited, and may be various shapes such as a spherical shape, a needle shape, a spindle shape, and an indeterminate shape, but a spherical shape is preferable.
There is no restriction | limiting in particular as a manufacturing method of a resin particle, Although what is necessary is just to manufacture by a well-known method, the spray-drying method is illustrated preferably.

(External additive)
In the present embodiment, the nonmagnetic one-component toner preferably contains an external additive.
It does not specifically limit as an external additive, What is necessary is just to select suitably from a well-known external additive, Although an inorganic particle and an organic particle are illustrated, An inorganic particle is preferable.

Examples of inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, and chloride. Examples include cerium, bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among these, silica particles and titanium oxide particles are preferable.
Examples of the material of the organic particles include particles such as polystyrene, polymethyl methacrylate, and polyvinylidene fluoride.
In addition, the surface of these inorganic particles is preferably hydrophobized in advance in order to impart toner fluidity and chargeability. Examples of the hydrophobic treatment include a treatment method such as immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents, and the like. These may be used alone or in combination of two or more.

One type of external additive may be used alone, or two or more types may be used in combination. Although not particularly limited, two or more types are preferably used in combination, and two types are more preferably used in combination.
The volume average particle diameter of the external additive is preferably 1 to 200 nm, more preferably 5 to 150 nm, and still more preferably 5 to 120 nm.
The addition amount of the external additive is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, with respect to 100 parts by weight of the toner base particles. More preferably, it is 5 parts by weight.

(Toner production method and toner physical properties)
<Toner physical properties>
The volume average particle diameter of the toner is preferably 2 μm or more and 12 μm or less, more preferably 2.5 μm or more and 10 μm or less, and further preferably 3 μm or more and 9 μm or less. When the volume average particle diameter of the toner is in the above range, the fluidity is excellent and a high-resolution image can be obtained.
The average particle diameter of particles such as toner and toner base particles is suitably measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). In this case, measurement is performed using an optimum aperture depending on the particle size level of the particles. A cumulative distribution is drawn from the smaller diameter side with respect to the particle size range (channel) divided on the basis of the particle size distribution, and the particle diameter at 50% accumulation is defined as volume D _50v and number D _50p . The volume average particle diameter is calculated as D _50v, the number average particle size is calculated as D _50p.

The shape factor SF1 of the toner base particles is preferably from 125 to 140, more preferably from 125 to 135, and still more preferably from 130 to 135.
The shape factor SF1 of the toner base particles is obtained by the following formula.
Formula: Shape factor SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner base particles, and A represents the projected area of the toner base particles.
The shape factor 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 the toner base particles dispersed on the surface of the slide glass is taken into a Luzex image analyzer through a video camera, the maximum length and the projected area of 100 toner base particles are obtained, calculated by the above formula, and the average Obtained by determining the value.

<Toner production method>
In this embodiment, the method for producing the toner mother particles is not particularly limited except that at least a crystalline resin is used as the binder resin, and may be produced by a known method.
For example, after mixing components such as a binder resin, a colorant, and if necessary, a release agent and a charge control agent, the above materials are melt-kneaded using a kneader, an extruder, etc., and then obtained. After coarsely pulverizing the melt-kneaded material, it is finely pulverized with a jet mill or the like, and a kneading and pulverizing method using an air classifier to obtain toner particles of the desired particle size; A method of changing the shape by force or thermal energy; the binder resin is emulsified, and the formed dispersion is mixed with a dispersion of a colorant, if necessary, a release agent, a charge control agent, etc., and agglomerated Emulsion aggregation method to obtain toner particles by heat fusion; suspension of monomer, colorant, and release agent, charge control agent, etc. to obtain binder resin in aqueous solvent Suspension polymerization method to polymerize the binder; binder resin, colorant, and if necessary, release agent, charge control Such dissolution suspension method to granulate solution such agents are suspended in an aqueous solvent; is used. Further, a manufacturing method may be performed in which the toner particles obtained by the above method are used as a core, and agglomerated particles are further adhered and heated and fused to form a core-shell structure.
Among these, the non-magnetic one-component toner (toner base particles) in the present embodiment is preferably a toner produced using a kneading and pulverizing method or an emulsion aggregation method.

As a method of embedding the toner base particles with the resin particles partially exposed, a mechanical treatment that gives mechanical force such as impact, pressure, shear, etc. in a state where the toner base particles and the resin particles are mixed. The method including the process performed by is preferable. More preferably, the mechanical treatment is a mechanical dry treatment.
As an apparatus used for the mechanical dry processing, ongmill (manufactured by Hosokawa Micron Co., Ltd.), hybridization (manufactured by Nara Machinery Co., Ltd.), kryptron (manufactured by Earth Technica Co., Ltd.), nobilta (Hosokawa Micron Co., Ltd.) (Co., Ltd.)) is particularly preferred. Further, the toner of this embodiment can be obtained by controlling the peripheral speed of the stirring blade, the stirring time, the glass transition temperature of the toner base particles and the resin particles, and the temperature in the apparatus at the time of stirring.

  A method for externally adding the external additive to the toner base particles is not particularly limited, and a known method can be used. Specifically, for example, a method of adhering to the surface of the toner base particles by a dry method using a mixer such as a V blender or a Henschel mixer, a surface after dispersing external additives in a liquid, and then adding to the toner in a slurry state and drying the surface Examples of the method of adhering to the toner or the wet method include a method of drying while spraying a slurry on a dry toner.

2. Electrostatic Image Developer The electrostatic image developer of this embodiment contains at least the nonmagnetic one-component toner of this embodiment. If necessary, other known components may be contained.
Further, the electrostatic image developer of this embodiment is a non-magnetic one-component developer, and can be suitably used as an electrostatic image developer by a non-magnetic one-component contact development system. It is particularly preferable to use it in an image forming apparatus using a cleaning method.

3. Process Cartridge, Image Forming Method, and Image Forming Apparatus An image forming method according to the present embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of an image carrier, a developer layer on a developing roll, and the image A developing process for developing the electrostatic latent image by contacting the holding body to form a toner image, a transferring process for transferring the toner image to the transfer target, and a fixing process for fixing the toner image on the transfer target And the toner is the non-magnetic one-component toner of the present embodiment, or the developer is the electrostatic charge image developer of the present embodiment.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that forms an electrostatic latent image on the charged surface of the image carrier, A developing unit that develops the electrostatic latent image as a toner image with a developer containing toner; a transfer unit that transfers the toner image formed on the surface of the image holding member to the surface of the transfer target; Fixing means for fixing the toner image transferred onto the surface of the transfer body, wherein the toner is a non-magnetic one-component toner according to the present embodiment, or the developer is an electrostatic charge image developer according to the present embodiment. It is characterized by being.

  Each process and each means are general per se, and are described in, for example, Japanese Patent Application Laid-Open No. 2012-203369. 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 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.
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 have a cleaning step for removing the electrostatic charge image developer remaining on the image carrier, but preferably does not have a cleaning step.

  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 of 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. 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 transfer member; and A fixing unit that fixes the toner image transferred to the surface, and the developer containing the toner preferably contains the electrostatic image developing toner of the present embodiment.
The image forming apparatus of the present exemplary 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. In addition, it may include a static elimination means or the like 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.

An example of an image forming apparatus that develops using a non-magnetic one-component developer will be described below with reference to FIGS.
FIG. 2 is a schematic diagram illustrating a configuration example of a tandem image forming apparatus for forming an image by the image forming method of the present embodiment. In the illustrated image forming apparatus 100, four electrophotographic photosensitive members (image holders) 1 </ b> Y, 1 </ b> M, 1 </ b> C, and 1 </ b> K are arranged in parallel along the intermediate transfer belt 20 in a housing 50. The electrophotographic photoreceptors 1K, 1C, 1M, and 1Y are, for example, yellow in the electrophotographic photoreceptor 1Y, magenta in the electrophotographic photoreceptor 1M, cyan in the electrophotographic photoreceptor 1C, and black in the electrophotographic photoreceptor 1K. Each image can be formed.

Each of the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 2Y, 2M, 2C, and 2K, and the developing device 4Y along the rotation direction. 4M, 4C, 4K, primary transfer rolls 5Y, 5M, 5C, 5K are arranged. In this case, each electrophotographic photosensitive member and the developing device can be mounted as the same unit, that is, a process cartridge. The primary transfer rolls 5Y, 5M, 5C, and 5K are in contact with the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K through the intermediate transfer belt 20, respectively.
Further, an exposure device 3 is disposed at a predetermined position in the housing 50, and a light beam emitted from the exposure device 3 is irradiated onto the surfaces of the charged electrophotographic photoreceptors 1Y, 1M, 1C, and 1K. Is possible. Thus, the charging, exposure, development, and primary transfer processes are sequentially performed in the rotation process of the electrophotographic photoreceptors 1Y, 1M, 1C, and 1K, and the toner images of the respective colors are transferred onto the intermediate transfer belt 20 in an overlapping manner. The
Here, the charging rolls 2Y, 2M, 2C, and 2K apply a voltage to the photoconductor by bringing a conductive member (charging roll) into contact with the surface of the electrophotographic photoconductors 1Y, 1M, 1C, and 1K. Is charged to a predetermined potential (charging step). 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 device 3, an optical system device 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 photoreceptors 1Y, 1M, 1C, and 1K in a desired image manner. be able to.
The developing devices 4Y, 4M, 4C, and 4K can be performed using a general developing device that develops by contacting non-magnetic one-component toner or non-magnetic one-component developer described later (developing step). Such a developing device is not particularly limited as long as non-magnetic one-component toner or non-magnetic one-component developer is used, and a known one can be appropriately selected according to the purpose. In the primary transfer process, a primary transfer bias having a polarity opposite to that of the toner on the image carrier is applied to the primary transfer rolls 5Y, 5M, 5C, and 5K, whereby each color is transferred from the image carrier to the intermediate transfer belt 20. The toner is sequentially primary transferred.

The intermediate transfer belt 20 is supported with a predetermined tension by a drive roll 22 and a backup roll 24, and can be rotated without causing deflection due to the rotation of these rolls. The secondary transfer roll 26 is disposed so as to contact the backup roll 24 via the intermediate transfer belt 20.
By applying a secondary transfer bias having a reverse polarity to the toner on the intermediate transfer belt 20 to the secondary transfer roll 26, the toner is secondarily transferred from the intermediate transfer belt 20 to the recording medium P. The intermediate transfer belt 20 passing between the backup roll 24 and the secondary transfer roll 26 is cleaned by, for example, a cleaning unit 30 having a cleaning blade disposed in the vicinity of the drive roll 22 or a static eliminator (not shown). Then, it is repeatedly used for the next image forming process. Further, a tray (recording medium tray) 40 is provided at a predetermined position in the housing 50, and the recording medium P such as paper in the tray 40 is transferred by the transfer roll 30 to the intermediate transfer belt 20 and the secondary transfer roll. Then, the paper is sequentially transported between the two fixing rolls 28 in contact with each other and then discharged to the outside of the housing 50. The image forming apparatus according to the present embodiment is more preferably an apparatus that does not include the cleaning unit 30.

Next, the developing device will be described in detail.
As shown in FIG. 3, the developing device 4 is disposed so as to abut on the image carrier 1 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) 1. A developing roll 52 that can be driven to rotate in the B direction, a bias power source 54 connected to the developing roll 52, and a position downstream of the contact portion between the developing roll 52 and the image carrier 1 in the rotating direction of the developing roll 52. Further, a developer scraping member 56 that is disposed so as to be in pressure contact with the developing roll 52 and is rotatable in the direction of arrow C so as to run against the rotation of the developing roll 52, and the developing roll in the rotating direction of the developing roll 52. A toner layer disposed so as to contact the developing roller 52 at a position downstream of the pressure contact portion between the developer 52 and the developer scraping member 56 and upstream of the contact portion between the developing roller 52 and the image carrier 1. Regulating member 58 A housing 62 which is located on the opposite side of the developing roll 52 from the side on which the image carrier 1 is disposed and has an opening on the side on which the developing roll 52 is disposed; and an agitator 60 disposed in the housing 62. Consists of

  The toner layer regulating member 58 is once fixed to the opening of the housing 62 so as to close the opening of the housing 62. Further, the side opposite to the side where the toner layer regulating member 58 is attached (the upper side of the opening) (the lower side of the opening) of the casing 62 covers the lower side of the developing roll 52 and the developer scraping member 56. It is configured as follows. Here, the developer (electrostatic image developer) 64 is disposed so as to be deposited on the lower side of the casing 62, and a space between the lower side of the developing roll 52 and the lower side of the opening of the casing 62. Is deposited so as to cover the developer scraping member 56. Further, the developer 64 is appropriately supplied from the inside of the housing 62 to the opening side of the housing 62 where the developing roll 1 is disposed by an agitator 60 provided in the housing 62.

  When developing, first, the developer 64 in the housing 62 is supplied from the agitator 60 to the surface of the developing roll 52 by the developer scraping member 56. Next, the developer 64 attached to the surface of the developing roll 52 is attached by the toner layer regulating member 58 so as to form a toner layer having a uniform thickness on the surface of the developing roll 52. Subsequently, it adheres to the surface of the developing roll 52 according to the potential difference between the surface of the image carrier 1 on which an electrostatic latent image (not shown) is formed and the developing roll 52 to which a bias voltage is applied by the bias power source 54. The non-magnetic one-component toner in the developing agent 64 is transferred to the image carrier 1 side, and the electrostatic latent image is developed. Note that the developer 64 remaining on the surface of the developing roll 52 after the development is scraped off by the developer scraping member 56.

In this embodiment, it is preferable to further include a cleaning step of recovering the external additive of the image carrier to the developing device via the developing roll. Referring to FIG. 3, in this embodiment, an external additive (not shown) remaining on the image carrier 1 after the transfer process is transferred to the developing roller 52 by contact between the image carrier 1 and the developing roller 52. And is preferably collected by the developing device 4. As a result, the transfer residual toner on the image carrier is cleaned without separately providing an image carrier cleaning means or a cleaning step.
In the above cleaning step, it is preferable that the transfer residual toner on the photoreceptor is also collected by the developing device via the developing roll.

In the present embodiment, the image carrier and the developing roll are preferably in contact with each other while rotating in the forward direction as shown in FIG. By contacting while rotating in the forward direction, the contact time can be increased.
At this time, the relative speed of the developing roll with respect to the image carrier is preferably 1.1 to 2.5 times. That is, when the rotation speed of the image carrier is 1, the rotation speed of the developing roll is preferably 1.1 to 2.5. By making the rotation speed of the developing roll faster than the rotation speed of the image holding member, it is possible to increase the development amount (amount of nonmagnetic one-component toner transferred to the photoreceptor), which is preferable.
The relative speed of the developing roll with respect to the image carrier is preferably 1.1 times to 2.5 times, more preferably 1.15 times to 2.0 times, and 1.2 times to 1.8 times. More preferably, it is doubled.

In the present embodiment, the image forming apparatus preferably includes a process cartridge. That is, it is preferable that each electrophotographic photosensitive member and the developing device can be mounted as a process cartridge.
The process cartridge according to the present embodiment is attached to and detached from the image forming apparatus, accommodates the electrostatic charge image developer according to the present embodiment, and the electrostatic latent image formed on the surface of the image carrier is transferred to the electrostatic charge image developer. The image forming apparatus includes a developing unit that develops and forms a toner image.

  The present embodiment will be further described below with reference to examples, but the present embodiment is not limited to these examples. Unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”.

<Method for Measuring Volume Average Particle Size of Toner and Toner Base Particle>
The volume average particle diameters of the toner and toner base particles were measured using a Coulter Multisizer II (manufactured by Beckman-Coulter). As the electrolytic solution, ISOTON-II (manufactured by Beckman-Coulter) 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.
For the divided particle size range (channel), draw the cumulative distribution from the smaller diameter side with respect to the divided particle size range (channel), and define the 50% cumulative particle size as the weight average particle size or volume average particle size, respectively. To do.

<Measurement of molecular weight>
For the measurement of the molecular weight, the weight average molecular weight Mw and the number average molecular weight Mn were measured by gel permeation chromatography (GPC) under the conditions described below. At a temperature of 40 ° C., a solvent (tetrahydrofuran) is flowed at a flow rate of 1.2 ml per minute, and 3 mg of a tetrahydrofuran sample solution having a concentration of 0.2 g / 20 ml is injected as a sample weight for measurement. When measuring the molecular weight of a sample, select the measurement conditions that fall within the range in which the logarithm of the molecular weight of the prepared calibration curve and the count number are linear, using several monodisperse polystyrene standard samples. . In addition, the reliability of the measurement results is that the NBS706 polystyrene standard sample performed under the above measurement conditions is
Weight average molecular weight Mw = 28.8 × 10 ⁴
Number average molecular weight Mn = 13.7 × 10 ⁴
Can be confirmed.
Further, as the GPC column, TSK-GEL, GMH (manufactured by Tosoh Corporation), etc. satisfying the above conditions were used.

<Measurement of average particle diameter of particles and resin particles in dispersion>
The average particle size of the particles and resin particles in the dispersion was measured with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.).

<Measurement of resin particle in resin dispersion or glass transition point of resin>
A differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC50) was used to measure the glass transition temperature Tg of the resin.

Example 1
<Preparation of resin particle 1>
An anion activator Dowfax (manufactured by Dow Chemical Co., Ltd.) 0.2 parts by weight dissolved in 50 parts by weight of ion-exchanged water is placed in a flask, and 100 parts by weight of cyclohexyl methacrylate is added and dispersed and emulsified. Then, 5 parts by weight of ion-exchanged water in which 0.6 part by weight of ammonium persulfate was dissolved was slowly stirred and mixed for 10 minutes. Next, after sufficiently replacing the inside of the system with nitrogen, the flask was heated with an oil bath while stirring until the inside of the system reached 70 ° C. to carry out emulsion polymerization. The resulting resin dispersion was filtered and freeze-dried to obtain polycyclohexyl methacrylate.
10 parts of polycyclohexyl methacrylate was dissolved in 90 parts of toluene and sprayed by spray drying to obtain resin particles 1 having an average primary particle size of 70 nm.

<Preparation of non-crystalline polyester resin>
Bisphenol A ethylene oxide 2 mol adduct: 10 mol%
Bisphenol A propylene oxide 2 mol adduct: 40 mol%
Terephthalic acid: 50 mol%
A monomer equipped with the above composition ratio is charged into a flask equipped with a stirrer, nitrogen introduction tube, temperature sensor, and rectifying column, and the temperature is raised to 190 ° C. over 1 hour, and the reaction system is stirred uniformly. After confirming the above, 1.0% by weight of dibutyltin oxide was added. Further, while distilling off the generated water, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 2.5 hours, with a glass transition temperature of 62 ° C. and a weight average molecular weight. An amorphous polyester resin having a (Mw) of 35,000 was obtained.

<Preparation of crystalline polyester resin 1>
50% by mole of sebacic acid, 50% by mole of 1,6-hexanediol and 0.3% by weight of dibutyltin oxide were mixed in a flask, heated to 240 ° C. in a reduced pressure atmosphere, and dehydrated for 6 hours to form a crystalline polyester. Resin 1 was obtained.

<Preparation of Toner 1>
Amorphous polyester resin: 76 parts Crystalline polyester resin 1:12 parts Carbon black (Mitsubishi Chemical Corporation, trade name # 25B): 6 parts Paraffin wax (Nihon Seiki Co., Ltd., trade name HNP9): 6 parts The above composition was powder-mixed with a Henschel mixer, heat kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized, and classified.
Hot air treatment was performed with a hot air spheronizer “Surfusing System SFS-3” (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain toner base particles 1 having a volume average particle diameter D ₅₀ of 7.2 μm.

<Resin particle coating>
Toner mother particles 1: 100 parts Resin particles 1:20 parts The above composition was mixed with a Henschel mixer to obtain pre-dispersed mother particles 1.
Then, while maintaining the temperature inside the Nobilta NOB-300 (manufactured by Hosokawa Micron Corporation) at 45 ° C., the mixture was stirred at 3,000 rpm for 10 minutes to obtain resin particle-coated toner base particles 1.

<Production of toner>
Resin particle-coated toner base particles 1: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts Toner 1 was obtained by mixing the above composition with a Henschel mixer.
The obtained toner 1 was evaluated by the following evaluation method. The evaluation results are shown in Table 1.

<Resin particle state evaluation method>
Resin particle-coated toner base particles (or toner) are embedded to produce a section, the cross-section is observed, the maximum diameter of the embedded resin particles near the toner base particle surface is measured 100 particles, 30 particles having a larger particle size are extracted, the maximum diameter of the resin particles embedded in the toner base particles, the maximum diameter of the exposed portions of the toner base particles, and the resin particles embedded from the toner base particle surfaces. Each depth was measured, and an average value was calculated.

<Image density unevenness evaluation method>
The evaluation was performed using a DocuPrint P300d manufactured by Fuji Xerox Co., Ltd., which adopted a non-magnetic one-component contact development method and a simultaneous development cleaning method as an image forming apparatus.
Using the above image forming apparatus, a full-tone halftone image (image density of 30%) was printed immediately after 3,000 A4 images having an image density of 1.0% were continuously printed in an environment of a temperature of 15 ° C. and a humidity of 15%. .
At this time, the density of the upper part and the lower part of the halftone image was measured and judged by the value of the density difference (Δ density).
◎: Δ concentration value is 0.1 or less ○: Δ concentration value is more than 0.1 and 0.2 or less △: Δ concentration value is more than 0.2 and 0.3 or less ×: Δ concentration value is Greater than 0.3

(Comparative Example 1)
<Preparation of Toner 2>
Toner base particles 2 having a volume average particle diameter D ₅₀ of 7.4 μm are obtained by the same production method except that the non-crystalline polyester resin is changed to 88 parts and the crystalline resin is changed to 0 parts. It was.
Toner 2 was prepared in the same manner as toner 1 except that toner base particle 2 was used instead of toner base particle 1.
The obtained toner 2 was evaluated by the evaluation method described above. The evaluation results are shown in Table 1.

(Example 2)
Toner 3 was produced in the same manner as toner 1 except that resin particle 2 (polycyclohexyl methacrylate particles, average primary particle size: 30 nm) was used instead of resin particle 1.
The obtained toner 3 was evaluated by the evaluation method described above. The evaluation results are shown in Table 1.

(Example 3)
Toner 4 was prepared in the same manner as toner 1 except that resin particle 3 (polycyclohexyl methacrylate particles, average primary particle size: 350 nm) was used instead of resin particle 1.
The obtained toner 4 was evaluated by the evaluation method described above. The evaluation results are shown in Table 1.

(Comparative Example 2)
Toner 5 was produced in the same manner as toner 2 except that resin particle 3 (polycyclohexyl methacrylate particles, average primary particle size: 350 nm) was used instead of resin particle 1.
The obtained toner 5 was evaluated by the evaluation method described above. The evaluation results are shown in Table 1.

<Preparation of resin particle 2>
Resin particles 2 having an average primary particle size of 100 nm were obtained by the same production method except that 100 parts by weight of hexyl methacrylate of resin particles 1 were changed to 80 parts by weight of hexyl methacrylate and 20 parts by weight of methyl methacrylate.

Example 4
<Preparation of Toner 6>
Toner base particles 1 having a volume average particle diameter D ₅₀ of 7.4 μm were obtained by the same production method except that the non-crystalline polyester resin was changed to 84 parts and the crystalline resin was changed to 4 parts. .
Furthermore,
Toner mother particles: 100 parts Resin particles 2:10 parts The above composition was mixed with a Henschel mixer to obtain pre-dispersed mother particles.
Then, while maintaining the temperature in the Nobilta NOB-300 (manufactured by Hosokawa Micron Corporation) at 40 ° C., the mixture was stirred at 3,000 rpm for 10 minutes to obtain resin particle-coated toner base particles.
after that,
Resin particle-coated toner base particles: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts Toner 6 was obtained by mixing the above composition with a Henschel mixer.

(Example 5)
<Preparation of Toner 7>
A toner base particle having a volume average particle diameter D ₅₀ of 7.3 μm was obtained by the same production method except that the amorphous polyester resin was changed to 80 parts and the crystalline resin changed to 8 parts. Resin fine particle treatment and silica particle treatment of Toner 6 were performed to obtain Toner 7.

(Example 6)
<Preparation of Toner 8>
Toner 6 having a volume average particle diameter D ₅₀ of 7.2 μm was obtained by the same production method except that the non-crystalline polyester resin was changed to 76 parts and the crystalline resin was changed to 12 parts. The toner 6 was obtained by subjecting the toner 6 to resin fine particle treatment and silica particle treatment.

(Example 7)
<Preparation of Toner 9>
Toner 6 having a volume average particle diameter D ₅₀ of 7.5 μm was obtained by the same production method except that the non-crystalline polyester resin was changed to 72 parts and the crystalline resin was changed to 16 parts. The toner 9 was obtained by subjecting the toner 6 to resin fine particle treatment and silica particle treatment.

(Example 8)
<Preparation of Toner 10>
Toner 6 having a volume average particle diameter D ₅₀ of 7.1 μm was obtained by the same production method except that the non-crystalline polyester resin was changed to 70 parts and the crystalline resin was changed to 20 parts. The toner 10 was obtained by subjecting the toner 6 to resin fine particle treatment and silica particle treatment.

(Comparative Example 3)
<Preparation of Toner 11>
To the mother particles obtained in the preparation of the toner 8 Toner mother particles 1: 100 parts Resin particles 2:10 parts The above composition was mixed with a Henschel mixer to obtain pre-dispersed mother particles.
after that,
Preliminary dispersed particle-coated toner base particles 1: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts The above composition was mixed with a Henschel mixer to obtain toner 11.

(Comparative Example 4)
<Preparation of Toner 12>
Toner 8 was obtained by the same production method except that the temperature inside the Nobilta NOB-300 (manufactured by Hosokawa Micron Corporation) apparatus was changed to 50 ° C.

(Comparative Example 5)
<Preparation of Toner 13>
Amorphous polyester resin: 66 parts Crystalline polyester resin 1: 12 parts Resin particles 2: 10 parts Carbon black (Mitsubishi Chemical Corporation, trade name # 25B): 6 parts Paraffin wax (Nippon Seiki Co., Ltd.) , Trade name HNP9): 6 parts The above composition was powder-mixed with a Henschel mixer, heat-kneaded with an extruder at a preset temperature of 100 ° C, cooled, coarsely pulverized, finely pulverized, and classified.
Hot air treatment was performed with a hot air spheronizer “Surfusing System SFS-3” (manufactured by Nippon Pneumatic Industry Co., Ltd.) to obtain toner base particles having a volume average particle diameter D ₅₀ of 7.3 μm. after that,
Toner base particles 1: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts The above composition was mixed with a Henschel mixer to obtain toner 13.

<Preparation of crystalline polyester resin particle dispersion 1>
Crystalline polyester resin 1: 50 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts Ion-exchanged water: 200 parts The above components are heated to 120 ° C, and Ultrata made by IKA After sufficiently dispersing with Lux T50, the mixture was dispersed with a pressure discharge type homogenizer and collected when the volume average particle diameter reached 180 nm. Thus, a crystalline polyester resin fine particle dispersion 1 having a solid content of 20% by weight was obtained.

<Preparation of Amorphous Polyester Resin Particle Dispersion 1>
The amorphous polyester resin was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. A 0.37 wt% diluted ammonia water obtained by diluting reagent ammonia water with ion-exchanged water is placed in a separately prepared aqueous medium tank and heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Simultaneously with the polyester 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 to obtain an amorphous polyester resin dispersion 1 having a volume average particle size of 160 nm and a solid content of 20% by weight.

<Preparation of colorant dispersion>
Carbon black (Mitsubishi Chemical Corporation, trade name # 25B): 20 parts Anionic surfactant (Neogen SC, Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts Ion-exchanged water: 80 parts Mixing the above components Then, dispersion was performed for 1 hour using a high-pressure impact disperser Ultimateizer (HJP30006, manufactured by Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion having a volume average particle size of 180 nm and a solid content of 20% by weight.

<Preparation of wax dispersion>
Paraffin wax (Nippon Seiki Co., Ltd., trade name HNP9): 20 parts Anionic surfactant (Neogen SC, Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts Ion-exchanged water: 80 parts Mixing the above ingredients Then, after heating to 100 ° C. and sufficiently dispersing with IKA's Ultra Turrax T50, it is dispersed with a pressure discharge type gorin homogenizer to give a release agent dispersion having a volume average particle size of 200 nm and a solid content of 20% by weight. Obtained.

<Preparation of toner mother particles 4>
Crystalline polyester resin particle dispersion 1:12 parts Amorphous polyester resin particle dispersion 1:76 parts Colorant dispersion: 6 parts Wax dispersion: 6 parts Ion exchange water: 80 parts Above in a round stainless steel flask And thoroughly mixed and dispersed with an Ultra Turrax T50. Next, 0.4 part of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. Further, the flask was heated to 50 ° C. with stirring in an oil bath for heating. Hold at 50 ° C. for 3 hours.
Thereafter, the pH of the system was adjusted to 8.5 with a 0.5N aqueous sodium hydroxide solution, and then the stainless steel flask was sealed, heated to 90 ° C. while continuing stirring using a magnetic seal, and maintained for 3 hours.
After completion of the reaction, the mixture was cooled, filtered, thoroughly washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. Next, vacuum drying was performed for 12 hours to obtain toner base particles 4 having a volume average particle diameter D ₅₀ of 6.8 μm.

<Preparation of toner mother particles 5>
Toner base particles 5 having a volume average particle diameter D ₅₀ of 6.6 μm were obtained by the same production method except that the following steps were changed in the production of toner base particles 4.
Crystalline polyester resin particle dispersion 1: 6 parts Amorphous polyester resin particle dispersion 1:82 parts Colorant dispersion: 6 parts Wax dispersion: 6 parts Ion exchange water: 80 parts

<Preparation of toner mother particles 6>
Toner base particles 6 having a volume average particle diameter D ₅₀ of 6.9 μm were obtained by the same production method except that the following changes were made in the production of toner base particles 4.
Crystalline polyester resin particle dispersion 1: 0 parts Amorphous polyester resin particle dispersion 1:88 parts Colorant dispersion: 6 parts Wax dispersion: 6 parts Ion exchange water: 80 parts

Example 9
<Preparation of Toner 14>
Toner mother particles 4: 100 parts Resin particles 1:25 parts The above composition was mixed by a Henschel mixer to obtain pre-dispersed mother particles.
Then, while maintaining the temperature in the Nobilta NOB-300 (manufactured by Hosokawa Micron Corporation) at 40 ° C., the mixture was stirred at 3,000 rpm for 10 minutes to obtain resin particle-coated toner base particles.
after that,
Resin particle-coated toner base particles: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts The above composition was mixed with a Henschel mixer to obtain toner 14.

(Example 10)
<Preparation of Toner 15>
Toner mother particles 5: 100 parts Melamine resin particles (Eposter S: manufactured by Nippon Shokubai Co., Ltd.): 15 parts The above composition was mixed with a Henschel mixer to obtain pre-dispersed mother particles.
Then, while maintaining the temperature in the Nobilta NOB-300 (manufactured by Hosokawa Micron Corporation) at 50 ° C., the mixture was stirred at 3,000 rpm for 10 minutes to obtain resin particle-coated toner base particles.
after that,
Resin particle-coated toner base particles: 100 parts Silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.): 0.8 parts The above composition was mixed with a Henschel mixer to obtain toner 15.

(Comparative Example 6)
<Preparation of Toner 16>
A toner 16 was obtained by the same production method except that the toner base particles 5 were changed to the toner base particles 6 in the production method of the toner 15.

  The “maximum diameter of the resin particle embedded portion” in Table 1 specifically means “the maximum diameter of the resin particle embedded in the toner base particle”. Specifically, the “maximum diameter” means “the maximum diameter of the resin particles exposed on the surface of the toner base particles”.

  1, 1Y, 1M, 1C, 1K: electrophotographic photosensitive member (image carrier), 2Y, 2M, 2C, 2K: charging roll, 3: exposure device, 4, 4Y, 4M, 4C, 4K: developing device, 5Y 5M, 5C, 5K: primary transfer roll, 20: intermediate transfer belt, 22: drive roll, 24: backup roll, 26: secondary transfer roll, 28: fixing roll, 30: cleaning unit, 32: transfer roll, 40: tray (recording medium tray), 50: housing, 52: developing roll, 54: bias power source, 56: developer scraping member, 58: toner layer regulating member, 60: agitator, 62: housing, 64: Developer: 100: Image forming apparatus, 102: Surface of toner base particle, 104: Resin particle, 104a: Part of resin particle embedded in toner base particle, 104b: Resin particle The portion exposed on the surface of the toner base particles, 106: binder resin, 110: toner base particles, L1: the maximum diameter of the portion of the resin particles embedded in the toner base particles, L2: the surface of the toner base particles in the resin particles L3: Depth of resin particle embedded in toner base particle 110

Claims (7)

Containing toner base particles containing at least a binder resin and a colorant;
The binder resin includes a crystalline resin;
The resin particles are embedded on the surface of the toner base particles in a partially exposed state,
The maximum diameter of the portion that is buried in toner base particles of the resin particles, the toner base particle surfaces to much larger than the maximum diameter of the exposed portion,
The non-magnetic one-component toner , wherein the resin particles include a (meth) acrylic resin having a cycloalkyl group in a side chain .   The nonmagnetic one-component toner according to claim 1, wherein an average primary particle size of the resin particles is 40 nm or more and 300 nm or less.   The nonmagnetic one-component toner according to claim 1, wherein the resin particles have a positive charging property. An electrostatic charge image developer comprising the non-magnetic one-component toner according to claim 1. A developing unit that is detachable from the image forming apparatus and that contains the non-magnetic one-component toner according to any one of claims 1 to 3 and holds and conveys the non-magnetic one-component toner. Characteristic process cartridge. A latent image forming step for 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 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,
The image forming method according to claim 1, wherein the toner is the non-magnetic one-component toner according to claim 1. 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 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,
The image forming apparatus according to claim 1, wherein the toner is the nonmagnetic one-component toner according to claim 1.

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