JP6167869B2 - Electrostatic image developer, process cartridge, image forming method, and image forming apparatus - Google Patents

Description

  The present invention relates to 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. One-component development methods are broadly divided into magnetic one-component development methods using magnetic toner and non-magnetic one-component development methods using non-magnetic toner, and non-magnetic one-component development method is selected from the viewpoint of colorization. Often done.
Patent Document 1 includes a supply roller that supplies toner to a developing roller, and a toner that is thinned on the peripheral surface of the developing roller is supplied to a contacted photoreceptor surface by a metal regulating blade. A negatively chargeable toner for use in a non-magnetic one-component developing method for developing an electrostatic latent image into a toner image, comprising a base toner composed of at least a binder resin and a color pigment, an external additive composed of inorganic fine particles, and a base material It includes an external additive composed of resin fine particles having a volume average particle size ratio of 1/85 to 1/15 to toner particles and a coverage of the toner particles on the surface of 0.5% to 10%. A non-magnetic one-component toner is disclosed.
Further, Patent Document 2 discloses a developing device including a developing roll having silicone rubber at least on a surface portion, and a blade for applying a charge while regulating the thickness of a toner layer formed on the developing roll to be constant. In a non-magnetic one-component developing method in which a toner image is formed while contacting a photosensitive member and the developing roll, non-magnetic one-component toner having inorganic fine particles hydrophobized with silicone oil added to the surface is used. A developing method characterized by this is disclosed.

JP 2004-109201 A JP-A-9-146295

  An object of the present invention is to provide an electrostatic charge image developer capable of obtaining a good line image in which toner scattering is suppressed without impairing fixing performance even when toner consumption is advanced.

The above problems have been solved by the means described in <1>, <7>, <8> and <10> below. It describes below with <2>-<6> and <9> which are preferable embodiments.
<1> A toner base particle containing at least a binder resin and a colorant, a nonmagnetic one-component toner containing an external additive, and a resin particle to which inorganic particles are attached, wherein the inorganic particles are: Electrostatic charge image development characterized by containing 0.05 to 5.0 parts by weight of resin particles with inorganic particles attached to 100 parts by weight of non-magnetic one-component toner on the surface Agent,
<2> The electrostatic charge image developer according to <1>, wherein the shape factor SF1 of the nonmagnetic one-component toner is 130 or less, and the shape factor SF1 of the resin particles to which the inorganic particles are attached is 130 or more and 180 or less. ,
<3> When the number average maximum length of the non-magnetic one-component toner is ML1 and the number average maximum length of the resin particles to which the inorganic particles are attached is ML2, the following formula (1) is satisfied, <1> or <2> The electrostatic image developer according to the description,
0.5 ≦ ML2 / ML1 ≦ 3.0 (1)

<4> The electrostatic charge image developer according to any one of <1> to <3>, wherein the number average maximum length (ML2) of the resin particles to which the inorganic particles are attached is 2 μm or more and 30 μm or less.
<5> The electrostatic charge image developer according to any one of <1> to <4>, wherein the inorganic particles are silicone oil-treated silica particles having a number average particle diameter of 5 nm to 30 nm.
<6> The electrostatic charge image developer according to any one of <1> to <5>, wherein the non-magnetic one-component toner has positive chargeability,
<7> The electrostatic latent image which is attached to and detached from the image forming apparatus, contains the electrostatic charge image developer according to any one of <1> to <6>, and is formed on the surface of the image carrier. A process cartridge comprising developing means for developing a toner image by developing with an electrostatic charge image developer;
<8> A latent image forming step of forming an electrostatic latent image on the surface of the image carrier, a developer layer is formed on the developing roll, and the electrostatic latent image is developed in contact with the image carrier to develop a toner image. A developing step for transferring the toner image to a transfer member, and a fixing step for fixing the toner image on the transfer member, wherein the developer is <1> to <6>. An image forming method comprising the electrostatic charge image developer according to any one of the above,
<9> The image forming method according to <8>, further comprising a cleaning step of recovering the external additive and / or residual toner on the image carrier to a developing device via a developing roll.
<10> An image carrier, a charging unit that charges the image carrier, an exposure unit that exposes the charged image carrier to form an electrostatic latent image on the surface of the image carrier, and a developer. Developing means for developing an electrostatic latent image to form a toner image, transfer means for transferring the toner image from the image carrier to the surface of the transfer target, and fixing the toner image transferred to the surface of the transfer target An image forming apparatus, wherein the developer is the electrostatic charge image developer according to any one of <1> to <6>.

According to the invention described in <1> above, a good line in which toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case without this configuration. An electrostatic charge image developer capable of obtaining an image can be provided.
According to the invention described in <2> above, the shape factor SF1 of the non-magnetic one-component toner exceeds 130, or the shape factor SF1 of the resin particles to which the inorganic particles adhere is less than 130 or more than 180. Thus, it is possible to provide an electrostatic charge image developer capable of obtaining a better line image in which toner scattering is suppressed without impairing fixing performance even when toner consumption is advanced.
According to the invention described in <3> above, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced, as compared with the case where the present configuration is not provided. It is possible to provide an electrostatic charge image developer capable of obtaining a straight line image.
According to the invention described in <4> above, even when the toner consumption has progressed as compared with the case where the number average maximum length (ML2) of the resin particles to which the inorganic particles adhere is less than 2 μm or more than 30 μm. It is possible to provide an electrostatic charge image developer capable of obtaining a better line image in which toner scattering is suppressed without impairing the fixing performance.
According to the invention described in <5> above, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case without the present configuration. It is possible to provide an electrostatic charge image developer capable of obtaining a linear image.
According to the invention described in <6>, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case without the present configuration. It is possible to provide an electrostatic charge image developer capable of obtaining a straight line image.
According to the invention described in <7>, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case where the present configuration is not provided. A process cartridge capable of obtaining a line image can be provided.
According to the invention described in <8>, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case where the present configuration is not provided. An image forming method capable of obtaining a line image can be provided.
According to the invention described in <9> above, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case without the present configuration. It is possible to provide an image forming method capable of obtaining a straight line image.
According to the invention described in <10>, the toner scattering is suppressed without impairing the fixing performance even when the toner consumption is advanced as compared with the case where the present configuration is not provided. An image forming apparatus capable of obtaining a line image can be provided.

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.

The electrostatic image developer of this embodiment is a toner base particle containing at least a binder resin and a colorant, and a non-magnetic one-component toner containing an external additive (hereinafter also simply referred to as “toner”). In addition, resin particles having inorganic particles attached thereto (hereinafter also referred to as “specific resin particles”), the inorganic particles having oil on the surface, and with respect to 100 parts by weight of the non-magnetic one-component toner, It contains 0.05 to 5.0 parts by weight of resin particles to which inorganic particles are adhered.
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.

The electrostatic charge image developer of this embodiment is a non-magnetic one-component developer and uses a non-magnetic one-component contact development system. It is particularly preferable to use it in an image forming apparatus using a cleanerless (simultaneous development cleaning) system.
Conventionally, when a toner, particularly a spherical toner, is subjected to high stress like non-magnetic one-component development, the burying of the external additive on the toner surface is promoted, so that the number of printed sheets increases and the toner particle surface becomes uneven due to the external additive. Disappears and it becomes very easy to roll. It has been found that when such toner enters the nip portion of the fixing device at a high speed, the toner particles roll and are visually recognized as scattering of line images and characters. It has been found that, particularly when fixing at high speed, the impact when entering the nip portion of the fixing device is large, which causes more significant scattering. On the other hand, if the toner has not deteriorated, the toner particles are unlikely to roll due to the irregularities caused by the external additive on the surface of the toner particles, so that the toner image hardly scatters.

The inventors of the present invention have made extensive studies to prevent electrostatic splatter in which non-magnetic one-component toner is mixed with resin particles to which inorganic particles having oil on the surface adhere to the image scattering at the time of toner deterioration as described above. It has been found that by using an image developer, image scattering can be prevented without hindering fixing performance, and the present invention has been completed. Although the mechanism is not necessarily clear, the following mechanism of action is presumed.
When the resin particles having inorganic particles having oil attached to the surface and the non-magnetic one-component toner are stirred in the cartridge, the oil released from the surface of the inorganic particles proceeds to the non-magnetic one-component toner. At this time, the resin particles to which the inorganic particles are attached are difficult to be developed together with the toner particles, or if the number of prints advances by adjusting the charging property so that the toner particles are not transferred and recollected by the developing machine even if developed, The resin particle concentration to which the inorganic particles adhere is concentrated. Therefore, the amount of oil transferred to the non-magnetic one-component toner is small at the beginning, but the amount of oil attached to the non-magnetic one-component toner increases as the number of printed sheets increases. When oil is supplied to the non-magnetic one-component toner in the state where the external additive has been buried, the oil adheres to the surface of the toner base particles, so that the oil migrates to the entire toner particles without impairing the fixing property. By applying an appropriate adhesion force between the paper and the toner particles, it is possible to prevent image scattering during fixing.
On the other hand, when the oil is excessively supplied in the initial state where there is no toner deterioration, since the external additive is not buried on the surface, the oil easily moves to the external additive itself. However, it has been found that the external additive to which oil adheres acts to increase the viscosity of the wax or resin, thereby hindering the fixability, and in particular, causing a fixing failure in high-speed fixing. Therefore, at the initial stage, it is preferable that the transfer of the oil to the non-magnetic one-component toner is small.
That is, in this embodiment, the oil supply is reduced at the initial stage of printing, and the oil supply is increased as the toner consumption (that is, toner deterioration) progresses, so that the image is scattered from the initial stage until the toner is used up without impairing the fixing property. It is estimated that it can be prevented.
Hereinafter, this embodiment will be described in more detail.

1. Electrostatic Image Developer The electrostatic image developer of this embodiment contains resin particles to which nonmagnetic one-component toner and inorganic particles are attached.
1-1. Non-magnetic one-component toner In this embodiment, the non-magnetic one-component toner contains toner base particles and an external additive. The toner base particles contain a binder resin and a colorant, and if necessary, a release agent and the like.

1-1. Toner base particles (1) Binder resin The binder resin contained in the toner base particles is not particularly limited, but examples thereof include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, acrylic acid Vinyl such as ethyl, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate Esters having a group; vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; ethylene, propylene Emissions, a homopolymer consisting of a monomer, such as polyolefins such as butadiene, or a copolymer obtained by combining two or more kinds, even mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.

Styrene resin, (meth) acrylic resin, and styrene- (meth) acrylic copolymer resin are obtained by known methods, for example, by combining styrene monomers and (meth) acrylic acid monomers alone or in appropriate combination. It is done. “(Meth) acryl” is an expression including both “acryl” and “methacryl”.
The polyester resin can be obtained by selecting and combining suitable ones from a dicarboxylic acid component and a diol component, and synthesizing them using a conventionally known method such as a transesterification method or a polycondensation method.

  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 to 150,000, and the number average molecular weight Mn is 2,000 to 30,000. It is preferable to use the thing of the range. On the other hand, when a polyester resin is used as the binder resin, a resin having a weight average molecular weight Mw of 5,000 or more and 80,000 or less and a number average molecular weight Mn of 2,000 or more and 10,000 or less may be used. preferable.

  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 preferably 70 to 98% by weight, and more preferably 80 to 95% by weight. When the content of the binder resin is within the above range, good fixability can be obtained.

(2) Colorant In this embodiment, the toner base particles contain a colorant for the purpose of coloring the resulting image.
A known colorant can be used as the colorant, and may be arbitrarily selected from the viewpoints of hue angle, saturation, lightness, 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 used 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 transparent toner not containing a colorant. It is suitably used as a transparent 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.

  The said mold release agent may be used individually by 1 type, or may use 2 or more types together. The release agent is preferably contained in the range of 1 to 20% by weight and more preferably in the range of 3 to 15% by weight with respect to 100% 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. Examples of other components include a charge control agent, inorganic particles, organic particles, a lubricant, Examples include abrasives.
<Charge control agent>
In this embodiment, a charge control agent may be added to the toner base particles and the specific resin particles in order to control the chargeability. For example, as a positively chargeable charge control agent, a nigrosine dye, a quaternary ammonium salt such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like, phosphonium which is an analog thereof Onium salts such as salts, and lake pigments thereof; triphenylmethane dyes; metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate; Examples thereof include guanidine compounds, imidazole compounds, and aminoacrylic resins.
Examples of the negatively chargeable charge control agent include trimethylethane dyes, metal complex salts of salicylic acid, metal complex salts of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes, etc. Examples include heavy metal-containing acid dyes, calixarene type phenolic condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like.
These charge control agents may be used alone or in combination of two or more.

  The addition amount of the charge control agent is preferably 0.1 to 10% by weight, more preferably 1 to 6% by weight, based on the toner base particles. When the addition amount is within the above range, good chargeability can be obtained.

1-2. External Additive In the present embodiment, the non-magnetic one-component toner contains toner base particles and an external additive.
In the present embodiment, the “external additive” means particles that are externally added to the toner base particles and are developed and transferred together with the toner base particles. As will be described later, the external additive has a strong adhesive force with the toner base particles and hardly separates from the surface of the toner base particles as long as it is simply dispersed in water.
It does not specifically limit as an external additive, What is necessary is just to select suitably from a well-known external additive, and an inorganic particle and an organic particle are illustrated.

  Inorganic fine particles are generally used for the purpose of improving fluidity, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, Examples include wollastonite, diatomaceous earth, cerium chloride, bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among them, silica fine particles and titanium oxide fine particles are preferable, and hydrophobized fine particles are particularly preferable.

  The organic fine particles are generally used for the purpose of improving cleaning properties and transfer properties, and specific examples include polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and the like.

An external additive may be used individually by 1 type, may use 2 or more types together, and is not specifically limited.
The average primary particle diameter of the external additive is preferably 1 nm or more and 200 nm or less, more preferably 15 to 170 nm, and still more preferably 25 to 140 nm.
The addition amount of the external additive is preferably in the range of 0.01 to 20 parts by weight with respect to 100 parts by weight of the toner base particles. The amount is more preferably 0.2 to 5 parts by weight, and still more preferably 0.5 to 3 parts by weight.
The average primary particle size of the external additive can be determined as follows. The surface of the toner is magnified 10,000 to several tens of thousands times with a scanning electron microscope, and the maximum portion of the external additive adhering to the surface is measured from the photograph. 100 particles are measured, and the average value is defined as the average primary particle size of the external additive. Note that large external additives that are not considered to have a primary particle size are not included in the above 100.
The method for producing the external additive is not particularly limited, but for example, it can be produced by a known method for producing sol-gel silica. In general, it can be produced by the sol-gel method at a boundary of 20 nm, and when it is larger than that, it can be produced by the deflagration method.

(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 within the above range, the fluidity is excellent and a high-resolution image can be obtained.
A Coulter Multisizer II type (manufactured by Beckman Coulter, Inc.) can be used for measuring the average particle size of particles such as toner and toner base particles. In this case, measurement can be 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 can be obtained as D _50v, it can be calculated as a number average particle diameter D _50p.

The shape factor SF1 of the toner is preferably 130 or less. When the shape factor is 130 or less, the degree of burying of the external additive on the toner surface is uniform (uniform), and therefore, it is possible to prevent deterioration of fixability due to oil transfer to the external additive during toner deterioration. .
The shape factor of the toner is more preferably from 100 to 130, further preferably from 103 to 126, and particularly preferably from 105 to 122.

  The number average value (number average maximum length) of the maximum toner length ML is preferably 2 μm or more and 10 μm or less, more preferably 2.4 μm or more and 9 μm or less, and preferably 2.8 μm or more and 8 μm or less. Further preferred. When the number average maximum length of the toner is within the above range, an excellent fluidity and high resolution image can be obtained. The number average maximum length of the toner is obtained as the number average value of the maximum length ML of the particles obtained by the measurement of SF1 described later.

The shape factor SF1 and the maximum length ML are measured as follows. That is, an optical microscope image of the developer spread on the slide glass is taken into a Luzek image analyzer via a video camera, and the maximum length (ML) and projection area (A) are set for 100 or more toner particles and specific resin particles. taking measurement. At this time, the number average value of ML and the number average value of the shape factor are obtained by the following equation (2).
SF1 = (π / 4) × (ML ² / A) × 100 (2)
In this embodiment, the toner shape factor SF1 and the number average value of the maximum length (number average maximum length) are measured with the nonmagnetic one-component toner after the addition of the external additive. Since the particle diameter of the external additive is sufficiently small with respect to the particle diameter, the toner base particle shape factor SF1 and the number average maximum length may be approximated.

In the present embodiment, the nonmagnetic one-component toner is preferably a positively chargeable nonmagnetic one-component toner.
When the toner is positively charged, the adhesion amount of the toner base particles and the oil can be maintained at an appropriate amount due to the electrostatic adhesion force between the toner base particles and the oil, and the image scattering at the time of fixing can be prevented.

<Toner production method>
In the present exemplary embodiment, the toner manufacturing method is not particularly limited, and may be manufactured 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 production 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 give a core-shell structure.
Among these, it is preferable to produce the toner of this embodiment using a kneading and pulverizing method or an emulsion aggregation method.

  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. Resin particles with specific inorganic particles (specific resin particles)
The electrostatic image developer of this embodiment contains a non-magnetic one-component toner and resin particles to which inorganic particles are attached, and the inorganic particles have oil on the surface. The resin particles having inorganic particles having oil attached to the surface are also referred to as “specific resin particles”. In addition, when it is simply referred to as “resin particles”, it means resin particles to which inorganic particles are not attached.
In the present embodiment, the specific resin particles are difficult to be electrostatically developed on the photosensitive member side during the image forming process because it is difficult to retain a charge on the surface. In the case of the contact development method, it is assumed that a certain amount of specific resin particles move to the photoreceptor side, but since the charge amount is very small, it is not transferred to the transfer target in the transfer process, In the next cycle, it is considered that the toner is collected again at the developing unit at the developing nip portion.

(1) Resin particle In this embodiment, as resin particle, a well-known resin can be used, for example, a polyester resin, a styrene resin, a styrene- (meth) acrylic copolymer resin, a polyvinyl chloride resin, a phenol resin. Acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin, polyether polyol resin, etc. They can be used alone or in combination.
Among these, as the resin particles, particles made of the same resin as the binder resin contained in the toner base particles are preferable in terms of excellent adhesion of inorganic particles. More specifically, preferred examples include polyester resins, styrene resins, (meth) acrylic resins, and styrene- (meth) acrylic copolymer resins.

  The weight average molecular weight of the resin constituting the resin particles is preferably 3,000 to 150,000, and more preferably 5,000 to 100,000. A weight average molecular weight within the above range is preferable because the hardness of the resin particles is in an appropriate range, the adhesion of inorganic particles is excellent, and scratches on the photoreceptor are suppressed.

(2) Inorganic particles In the present embodiment, the specific resin particles are resin particles to which inorganic particles are attached, and the inorganic particles have oil on the surface. The inorganic particles are preferably those obtained by oil-treating the surface of the inorganic particles that are the core, and hereinafter, the inorganic particles that are the core are also referred to as “core inorganic particles”.
Examples of the core 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 oxidation. Examples thereof include particles of chromium, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica particles are particularly preferable.

Examples of the oil that the inorganic particles have on the surface include paraffinic oil, naphthenic oil, poly-α-olefin, SL oil, fluorine oil, and silicone oil. Among these, silicone oil is particularly preferable. In the present embodiment, the inorganic particles are particularly preferably silica particles treated with silicone oil (silicone oil-treated silica particles).
Silicone oils include dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, amino modified silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, carbinol modified silicone oil, methacryl modified silicone oil, mercapto modified silicone oil. Phenol-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, higher fatty acid amide-modified silicone oil, modified fluorine-modified silicone oil, and the like can be used. In particular, dimethyl silicone oil, alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, and higher fatty acid amide-modified silicone oil are preferable from the viewpoint of adhesion to toner particles.

  Although it does not specifically limit as a processing method of oil, The direct mixing method which mixes core inorganic particles and oil using mixers, such as a Henschel mixer, the method of spraying oil to inorganic powder, or oil in a suitable solvent After dissolving or dispersing, a method of adding inorganic powder and mixing to remove the solvent can be used. A method using a sprayer is more preferable in that the production of inorganic powder aggregates is relatively small.

  The amount of oil treated is preferably 5 to 80 parts by weight, more preferably 8 to 60 parts by weight, and still more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the core inorganic particles. When the oil processing amount is within the above range, the amount of transfer to the toner is appropriate.

The number average particle diameter of the inorganic particles is preferably 5 nm or more and 30 nm or less. More preferably, they are 6 nm or more and 25 nm or less, More preferably, they are 7 nm or more and 20 nm or less.
When the number average particle diameter of the inorganic particles is 5 nm or more, since the burying in the resin particles is suppressed, a sufficient amount of oil can be supplied, and an effect of preventing toner image scattering can be obtained. If the number average particle size of the inorganic particles is 30 nm or less, the separation of the inorganic particles hardly occurs, and fixing inhibition due to the transfer of the inorganic particles to the toner can be prevented.
The number average particle diameter of the inorganic particles is measured by photographing the inorganic particles using a scanning electron microscope and analyzing the image based on the photographed image.

In the present embodiment, the amount of inorganic particles added to the resin particles is preferably 0.4 to 10.0 parts by weight, and 0.6 to 8.0 parts by weight with respect to 100 parts by weight of the resin particles. It is more preferable that the amount is 0.8 to 6.0 parts by weight.
When the amount of the inorganic particles added to the resin particles is within the above range, an appropriate amount of oil can be supplied to the toner particles, image scattering is prevented, and fixing inhibition due to transfer of the inorganic particles to the toner is prevented. Is preferable.

In this embodiment, the content of the specific resin particles is 0.05 parts by weight or more and 5.0 parts by weight or less with respect to 100 parts by weight of the toner. More preferably, they are 0.1 weight part or more and 4.0 weight part or less, More preferably, they are 0.2 weight part or more and 3.0 weight part or less.
When the content is 0.05 parts by weight or more, a sufficient amount of oil can be supplied after toner deterioration, and image scattering can be prevented. If the content is 5.0 parts by weight or less, initial fixing inhibition is not caused.

  In the present embodiment, the shape factor SF1 of the specific resin particles is preferably 130 or more and 180 or less. More preferably, it is 134 or more and 170 or less, More preferably, it is 136 or more and 160 or less. When the shape factor SF1 is 180 or less, good contact with the colored particles is maintained, so that stable oil supply is possible and image scattering can be prevented. If the shape factor SF1 is 130 or more, it is possible to prevent deterioration of the fixability due to the specific resin particles being transferred to the paper.

In the present embodiment, the number average value (number average maximum length) of the maximum length of the specific resin particles is preferably 2 μm to 30 μm. When the number average maximum length of the specific resin particles is 2 μm or more, the oil can be uniformly supplied to the toner particles. Further, when the thickness is 30 μm or less, it is possible to prevent deterioration of fixability due to the specific resin particles being transferred to the paper.
The number average maximum length of the specific resin particles is more preferably 2.5 μm to 25 μm, and further preferably 3 μm to 20 μm.
In the present embodiment, the shape factor SF1 and the number average maximum length of the specific resin particles are measured with the specific resin particles after the inorganic particles are attached, but the particle size of the inorganic particles is smaller than the particle size of the resin particles. Since the diameter is sufficiently small, the resin particle shape factor SF1 and the number average maximum length may be approximated.

In this embodiment, when the number average maximum length of the non-magnetic one-component toner is ML1, and the number average maximum length of the specific resin particles is ML2, it is preferable that the following formula (1) is satisfied.
0.5 ≦ ML2 / ML1 ≦ 3.0
More preferably, ML2 / ML1 is 0.6 to 2.8, and more preferably 0.8 or more and 2.6 or less.
When ML2 / ML1 is 0.5 or more, stable oil supply is possible, and image scattering can be prevented. When ML2 / ML1 is 3.0 or less, it is possible to prevent deterioration of fixability due to the specific resin particles being transferred to the paper.

(Method for producing specific resin particles)
The specific resin particles can be produced, for example, by the following method. After forming resin particles by a known method, it is obtained by mixing with inorganic particles whose surfaces have been oil-treated in advance using a Henschel mixer or the like.
Other components may be added to the resin particles as appropriate. For example, a charge control agent is exemplified, and the charge control agent is the same as the charge control agent exemplified as the additive for the toner base particles.

In the present embodiment, the specific resin particles are not attached to or embedded in the toner base particles like the external additive, and it is preferable that the specific resin particles and the non-magnetic one-component toner exist independently.
Since the external additive adheres to the toner base particles, when a non-magnetic one-component toner containing the external additive and toner base particles is dispersed in an aqueous solution, a certain external force such as ultrasonic vibration must be applied. For example, most of the external additives are not separated from the toner base particles and are attached to the toner base particles.
On the other hand, when the electrostatic charge image developer of this embodiment is placed in water, if dispersed in an aqueous solution, 75% by weight or more of the specific resin particles are present independently without adhering to the non-magnetic one-component toner. That is confirmed. 85% by weight or more of the specific resin particles are preferably present independently, and more preferably 90% by weight or more.
As described above, the external additive is attached to the toner base particles, and as described above, when simply dispersed in an aqueous solution, the external additive present independently is generally 40% by weight or less, It is preferably 30% by weight or less, and more preferably 20% by weight or less.
In the above test, ion-exchanged water containing a surfactant is preferably used as the aqueous solution, and nonmagnetic one-component toner or electrostatic image development is performed with respect to 100 parts by weight of the aqueous solution (water temperature 25 ° C.). The agent will be tested by adding 2 parts by weight. The aqueous solution is preferably an aqueous solution containing 0.2% by weight of a surfactant (polyoxyethylene (10) octylphenyl ether, manufactured by Wako Pure Chemical Industries, Ltd.).
A treated sample obtained by stirring the toner dispersion in a beaker with a magnetic stirrer at 500 rpm for 30 seconds is then applied to a centrifuge with a 50 cc sedimentation tube, and the toner particles are separated at 10,000 rpm for 2 minutes to obtain a supernatant. After the removal, particles externally added to the toner are washed away with pure water to obtain a toner sample. Next, a powder toner sample is obtained by drying at room temperature (25 ° C.) for 20 hours or more, and the ratio of specific resin particles detached by the difference from untreated toner is obtained.

2. 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 developer is the electrostatic charge image developer of this embodiment.
In addition, the image forming apparatus of the present embodiment forms an electrostatic latent image on the surface of the image carrier by exposing the image carrier, a charging unit that charges the image carrier, and exposing the charged image carrier. An exposure unit; a developing unit that develops the electrostatic latent image with a developer to form a toner image; a transfer unit that transfers the toner image from the image holding member to the surface of the transfer target; and the surface of the transfer target Fixing means for fixing the toner image transferred to the toner image, and the developer is the electrostatic charge image developer of this embodiment.

  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 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 further include a recycling step. The recycling step is a step of transferring the electrostatic charge image developing toner collected in the cleaning step of the toner remaining on the image carrier (photosensitive member) to the developer tank. 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. In this embodiment, a mode in which toner is collected simultaneously with development is preferable.

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 to form a toner image; transfer means for transferring the toner image from the image carrier to the surface of the transfer body; and transferring the toner image to the surface of the transfer body And a fixing unit for fixing the toner image.
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. 1 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.
As the developing devices 4Y, 4M, 4C, and 4K, a general developing device that performs development by bringing a nonmagnetic one-component toner or a nonmagnetic one-component developer described later into contact can be used (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. 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 32 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.

Next, the developing device will be described in detail.
As shown in FIG. 2, the developing device 4 is arranged 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 (photoconductor) 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 roll 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 roll 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

  Note that one end of the toner layer regulating member 58 is 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 52 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. At this time, the non-magnetic one-component toner and the external additive recovery aid are adhered on the developing roll 52 so as to form a toner layer having a uniform thickness. 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.
As the developing roll 52, a known metal roll or elastic roll can be used. As the layer regulating member 58, a known metal blade or elastic blade can be used.

  In the exemplary embodiment, it is preferable that the image forming apparatus further includes a cleaning step of collecting the transfer residual toner of the image carrier in the developing device via the developing roll. Referring to FIG. 2, in this embodiment, toner (not shown) remaining on the image carrier 1 after the transfer process is transferred to the development roller 52 due to the contact between the image carrier 1 and the development roller 52. However, it 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 this 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. “Parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.

(Measurement of average primary particle size and volume average particle size)
In this embodiment, the average primary particle diameter of the external additive and the number average particle diameter of the inorganic particles are set to 100 for the external additive on the surface of the particles in the toner using a scanning electron microscope S4700 (manufactured by Hitachi, Ltd.). Individual images were taken and calculated based on the taken images using image processing analysis software WinRoof (manufactured by Mitani Corporation).
Similarly, the number average maximum length of specific resin particles and toner was determined by measuring the maximum diameter of 100 particles from an optical micrograph using a Luzex image analyzer and calculating the average value.

(Evaluation of separation state of specific resin particles)
In order to clarify the difference between the specific resin particles and the external additive in the present embodiment, an evaluation result using the produced toner is shown. Toner sample 1 was prepared by stirring 100 parts by weight of toner base particles and 2.0 parts by weight of specific resin particles 1 at a Henschel mixer at 2500 rpm for 10 minutes.
Similarly, 100 parts by weight of toner base particles, 0.8 parts by weight of silica particles 1 having an average primary particle diameter of 60 nm and 1.2 parts by weight of silica particles 2 having an average primary particle diameter of 140 nm as external additives are added to a Henschel mixer at 2500 rpm. The toner sample 2 was prepared by stirring for 10 minutes.
When the toner sample prepared by the above method is dispersed in water containing a surfactant and stirred with a magnetic stirrer at 500 rpm for 30 seconds, the amount of particles detached from the toner particles is measured. As a result of measuring the amount of particles, 86% of specific resin particles were separated from toner sample 1 after treatment with respect to specific resin particles contained in untreated toner, whereas toner sample 2 was untreated toner On the other hand, only 16% of silica (external additive) was separated. Usually, silica externally added to the toner has a small particle size and strongly adheres to the surface of the toner base particles, but the specific resin particles have a large particle size and most of them exist independently of the toner particles. Indicated.

(Specific resin particles)
<Preparation of specific resin particle 1>
Styrene-n-butyl acrylate copolymer 1 99.8 parts (Tg = 55 ° C., weight average molecular weight Mw = 50,000, copolymerization ratio 81:19)
Charge control agent 1 0.2 part (made by Orient Chemical Industry Co., Ltd., trade name BONTRON P-51)
The above composition was powder-mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a preset temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized, and classified.
To 100 parts of the obtained particles, 1.8 parts of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 1. SF1 of the obtained resin particle 1 was 148, and the number average maximum length ML2 was 9.2 μm.

<Preparation of specific resin particle 2>
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification. Further, hot air treatment was performed with a hot air spheronizer “Surfusing System SFS-3 type” (manufactured by Nippon Pneumatic Industry Co., Ltd.).
To 100 parts of the obtained particles, 2.0 parts of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 2. SF1 of the obtained resin particle 2 was 126, and the number average maximum length ML2 was 8.7 μm.

<Preparation of specific resin particle 3>
Styrene-n-butyl acrylate copolymer 2 99.8 parts (Tg = 63 ° C., weight average molecular weight Mw = 72,000, copolymerization ratio 84:16)
Charge control agent 1 0.2 parts The above composition was powder mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, coarsely pulverized, finely pulverized, and classified.
To 100 parts of the obtained particles, 1.0 part of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 3. SF1 of the obtained resin particle 3 was 185, and the number average maximum length ML2 was 16 μm.

<Preparation of specific resin particle 4>
Styrene-n-butyl acrylate copolymer 3 99.8 parts (Tg = 55 ° C., weight average molecular weight Mw = 29,000, copolymerization ratio 81:19)
Charge control agent 1 0.2 parts The above composition was powder mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, coarsely pulverized, finely pulverized, and classified. Thereafter, spheronization treatment was performed using the hot-air spheronization apparatus used for the specific resin particles 2.
To 100 parts of the obtained particles, 2.5 parts of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 4. SF1 of the obtained resin particle 4 was 138, and the number average maximum length ML2 was 2.5 μm.

<Preparation of specific resin particle 5>
Styrene-n-butyl acrylate copolymer 4 99.8 parts (Tg = 66 ° C., weight average molecular weight Mw = 65,000, copolymerization ratio 85:15)
Charge control agent 1 0.2 parts The above composition was powder mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, coarsely pulverized, finely pulverized, and classified.
To 100 parts of the obtained particles, 0.9 part of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 5. SF1 of the obtained resin particle 5 was 166, and the number average maximum length ML2 was 20 μm.

<Preparation of specific resin particle 6>
Styrene-n-butyl acrylate copolymer 5 99.8 parts (Tg = 54 ° C., weight average molecular weight Mw = 24,000, copolymerization ratio 79:21)
Charge control agent 1 0.2 parts The above composition was powder mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, coarsely pulverized, finely pulverized, and classified. Thereafter, spheronization treatment was performed using the hot-air spheronization apparatus used for the specific resin particles 2.
To 100 parts of the obtained particles, 3.0 parts of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 6. SF1 of the obtained resin particle 6 was 134, and the number average maximum length ML2 was 1.9 μm.

<Preparation of specific resin particle 7>
Styrene-n-butyl acrylate copolymer 6 99.8 parts (Tg = 64 ° C., weight average molecular weight Mw = 83,000, copolymerization ratio 84:16)
Charge control agent 1 0.2 parts The above composition was powder mixed with a Henschel mixer, and this was heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, coarsely pulverized, finely pulverized, and classified.
To 100 parts of the obtained particles, 0.7 part of dimethyl silicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 7. SF1 of the obtained resin particle 7 was 173, and the number average maximum length ML2 was 31 μm.

<Preparation of specific resin particle 8>
To 100 parts of silica particles (number average particle diameter 4 nm) produced by a vapor phase method, 30 parts of dimethyl silicone oil (KF-96-200cs, manufactured by Shin-Etsu Chemical Co., Ltd.) is spray-dried to obtain the surface of the silica particles. Processed. The surface-treated silica particles were crushed to obtain dimethyl silicone oil-treated silica particles 2.
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification.
To 100 parts of the obtained particles, 1.4 parts of dimethyl silicone oil-treated silica 2 was mixed with a Henschel mixer to obtain resin particles 8. SF1 of the obtained resin particle 8 was 148, and the number average maximum length ML2 was 9.2 μm.

<Preparation of specific resin particle 9>
To 100 parts of silica particles (number average particle size 35 nm) produced by a gas phase method, 15 parts of dimethyl silicone oil (KF-96-200cs, manufactured by Shin-Etsu Chemical Co., Ltd.) is spray-dried to obtain the surface of the silica particles. Processed. The surface-treated silica particles were crushed to obtain dimethyl silicone oil-treated silica particles 3.
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification.
To 100 parts of the obtained particles, 3.0 parts of dimethyl silicone oil-treated silica 3 was mixed with a Henschel mixer to obtain resin particles 9. SF1 of the obtained resin particle 9 was 148, and the number average maximum length ML2 was 9.2 μm.

<Preparation of specific resin particle 10>
To 100 parts of silica particles (number average particle diameter 8 nm) produced by a gas phase method, 20 parts of dimethyl silicone oil (KF-96-200cs, manufactured by Shin-Etsu Chemical Co., Ltd.) is spray-dried to obtain the surface of the silica particles. Processed. The surface-treated silica particles were pulverized to obtain dimethyl silicone oil-treated silica particles 4.
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification.
Resin particles 10 were obtained by mixing 100 parts of the obtained particles with 0.3 part of dimethyl silicone oil-treated silica 4 using a Henschel mixer. SF1 of the obtained resin particle 10 was 148, and the number average maximum length ML2 was 9.2 μm.

<Preparation of specific resin particles 11>
To 100 parts of silica particles (number average particle diameter 25 nm) prepared by a vapor phase method, 15 parts of dimethyl silicone oil (KF-96-200cs, manufactured by Shin-Etsu Chemical Co., Ltd.) is spray-dried to obtain the surface of the silica particles. Processed. The surface-treated silica particles were pulverized to obtain dimethyl silicone oil-treated silica particles 5.
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification.
100 parts of the obtained particles were mixed with 10.2 parts of dimethyl silicone oil-treated silica 5 using a Henschel mixer to obtain resin particles 11. SF1 of the obtained resin particle 11 was 148, and the number average maximum length ML2 was 9.2 μm.

<Preparation of specific resin particles 12>
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 1 0.2 parts The above composition is powder-mixed with a Henschel mixer, this is heat-kneaded with an extruder at a set temperature of 100 ° C, and after cooling, Coarse pulverization, fine pulverization, and classification. Thereafter, spheronization treatment was performed using the hot-air spheronization apparatus used for the specific resin particles 2.
To 100 parts of the obtained particles, 2.4 parts of dimethylsilicone oil-treated silica 1 (manufactured by Cabot, trade name TS720, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 12. SF1 of the obtained resin particles 12 was 140, and the number average maximum length ML2 was 7.4 μm.

<Preparation of specific resin particles 13>
Styrene-n-butyl acrylate copolymer 1 99.8 parts Charge control agent 0.2 parts The above composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C, cooled, Grinding, fine grinding, and classification.
To 100 parts of the obtained particles, 1.8 parts of hexamethyldisilazane (HMDS) -treated silica (Nippon Aerosil, trade name RX200, number average particle size 12 nm) was mixed with a Henschel mixer to obtain resin particles 13. SF1 of the obtained resin particle 13 was 148, and the number average maximum length ML2 was 9.2 μm.

(Non-magnetic one-component toner)
<Preparation of Nonmagnetic One-Component Toner 1>
86 parts of styrene-n-butyl acrylate copolymer 7 (Tg = 58 ° C., molecular weight Mw = 40,000, copolymerization ratio 81:19)
Carbon black (Mitsubishi Chemical Corporation, trade name # 25B) 6 parts Charge control agent 1 part (Oriento Chemical Co., Ltd., trade name BONTRON N-04)
Paraffin wax (Nippon Seiki Co., Ltd., trade name HNP9) 7 parts The above composition is mixed with powder using a Henschel mixer, heat-kneaded using an extruder with a set temperature of 100 ° C, cooled, coarsely pulverized, and 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.
Next, 0.6 parts of silica particles (manufactured by Nippon Aerosil Co., Ltd., trade name RA200H) are added to 100 parts of the obtained toner base particles 1 and mixed with a Henschel mixer, and the positively charged nonmagnetic one is added. Component toner 1 was obtained. The toner 1 thus obtained had a shape factor SF1 of 121 and a number average maximum length ML1 of 6.2 μm.

<Preparation of non-magnetic one-component toner 2>
In the production of the non-magnetic one-component toner 1, toner base particles 2 were obtained in the same manner except that the classification conditions were changed and the hot air treatment was not performed. To 100 parts of the obtained toner base particles 2, 0.6 parts of silica particles (product name: RA200H, manufactured by Nippon Aerosil Co., Ltd.) are added and mixed with a Henschel mixer, and the positively charged nonmagnetic one-component toner 2 is added. Got. The toner 2 thus obtained had a shape factor SF1 of 133 and a number average maximum length ML1 of 7.5 μm.

<Preparation of non-magnetic one-component toner 3>
In the production of the non-magnetic one-component toner 1, toner base particles 3 were obtained in the same manner except that the classification conditions were changed. 0.6 parts of silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.) are added to 100 parts of the obtained toner base particles 3 and mixed with a Henschel mixer. Got. The toner 3 thus obtained had a shape factor SF1 of 110 and a number average maximum length ML1 of 3.3 μm.

<Preparation of Nonmagnetic One-Component Toner 4>
In the production of the nonmagnetic one-component toner 1, toner base particles 4 were obtained in the same manner except that the classification conditions were changed. To 100 parts of the toner base particles 4 obtained, 0.6 part of silica particles (trade name RA200H manufactured by Nippon Aerosil Co., Ltd.) is added and mixed with a Henschel mixer, and the positively charged nonmagnetic one-component toner 4 is added. Got. The toner 4 thus obtained had a shape factor SF1 of 126 and a number average maximum length ML1 of 10.6 μm.

<Preparation of Nonmagnetic One-Component Toner 5>
Styrene-n-butyl acrylate copolymer 7 86 parts Carbon black (Mitsubishi Chemical Co., Ltd., trade name # 25B) 6 parts Charge control agent 2 1 part (Oriento Chemical Co., Ltd., trade name BONTRON E-84 )
Paraffin wax (Nippon Seiki Co., Ltd., trade name HNP9) 7 parts The above composition is mixed with powder using a Henschel mixer, heat-kneaded using an extruder with a set temperature of 100 ° C, cooled, coarsely pulverized, and 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 5.
Next, 0.6 parts of silica particles (manufactured by Nippon Aerosil Co., Ltd., trade name R974) are added to 100 parts of the obtained toner base particles 5 and mixed with a Henschel mixer, and the negatively charged nonmagnetic one Component toner 5 was obtained. The toner 5 thus obtained had a shape factor SF1 of 121 and a number average maximum length ML1 of 6.2 μm.

<Preparation of Nonmagnetic One-Component Toner 6>
(Preparation of resin fine particle dispersion)
Styrene (manufactured by Wako Pure Chemical Industries, Ltd.) 78 parts n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 22 parts β-carboxyethyl acrylate (manufactured by Rhodia Nikka Co., Ltd.) 2 parts A raw material solution was prepared. Separately, 1 part of an anionic surfactant (Dowfax 2A-1, manufactured by Dow Chemical) dissolved in 140 parts of ion-exchanged water was added to the raw material solution, dispersed and emulsified in the flask, and stirred slowly for 10 minutes. -While mixing, 10 parts of ion-exchanged water in which 1.2 parts of ammonium persulfate was dissolved was added. Next, after sufficiently replacing the system with nitrogen, the flask was heated with an oil bath while stirring until the system reached 70 ° C., and emulsion polymerization was continued as it was for 5 hours to obtain a volume average particle size of 200 nm, solid content. A 40% by weight resin fine particle dispersion was obtained. The resin fine particles obtained had a glass transition temperature Tg of 56.0 ° C. and a weight average molecular weight Mw = 45,000.

(Preparation of colorant particle dispersion)
Carbon black (trade name # 25B, manufactured by Mitsubishi Chemical Corporation) 20 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 80 parts Dispersion was carried out for 1 hour with an 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 release agent 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 80 parts After heating to 100 ° C. and sufficiently dispersing with IKA Ultra Turrax T50, it was dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a volume average particle size of 200 nm and a solid content of 20% by weight. .

(Preparation of charge control agent particle dispersion)
Charge control agent 20 parts (manufactured by Orient Chemical Co., Ltd., trade name BONTRON N-04)
Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 80 parts The above components were heated to 120 ° C and sufficiently dispersed with IKA's UltraTurrax T50, then pressure Dispersion treatment was performed with a discharge type homogenizer, and the particles were collected when the volume average particle diameter reached 180 nm. In this way, a charge control agent particle dispersion having a solid content of 20% by weight was obtained.

[Preparation of toner mother particles 6]
Resin fine particle dispersion 165 parts Colorant dispersion 30 parts Release agent dispersion 35 parts Charge control agent dispersion 5 parts Ion-exchanged water 400 parts Ultra Turrax (T50, manufactured by IKA) in a round stainless steel flask ) Was thoroughly mixed and dispersed. Next, 0.4 part of aluminum sulfate was added to the obtained dispersion, and the dispersion operation was continued with an ultra turrax.
Thereafter, the flask was heated to 53 ° C. with stirring in an oil bath for heating. After maintaining at 53 ° C. for 60 minutes, 50 parts of a resin fine particle dispersion was further slowly added. Thereafter, the pH of the system was adjusted to 5.6 with a 0.5 N aqueous sodium hydroxide solution, and then the stainless steel flask was sealed and heated to 97 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.
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. The separated solid was further thoroughly washed with ion-exchanged water, and then No. 1 was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner base particles 6.
To 100 parts of the toner base particles 6 obtained, 0.6 parts of silica particles (trade name RA200H, manufactured by Nippon Aerosil Co., Ltd.) are added and mixed with a Henschel mixer, and the positively charged nonmagnetic one-component toner 6 is mixed. Got. The toner 6 thus obtained had a shape factor SF1 of 114 and a number average maximum length ML1 of 5.5 μm.

(Preparation of electrostatic charge image developer)
<Preparation of electrostatic charge image developer 1>
2.0 parts of specific resin particles 1 and 100 parts of non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 1.
At this time, ML2 / ML1 = 1.5.

<Preparation of electrostatic charge image developer 2>
0.08 part of the specific resin particles 1 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 2. At this time, ML2 / ML1 = 1.5.

<Preparation of electrostatic charge image developer 3>
0.15 part of the specific resin particles 1 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to prepare an electrostatic charge image developer 3. At this time, ML2 / ML1 = 1.5.

<Preparation of electrostatic image developer 4>
3.8 parts of specific resin particles 1 and 100 parts of non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 4. At this time, ML2 / ML1 = 1.5.

<Preparation of electrostatic charge image developer 5>
4.6 parts of specific resin particles 1 and 100 parts of non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 5. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 6>
2.0 parts of specific resin particles 1 and 100 parts of non-magnetic one-component toner 2 were mixed with a Henschel mixer to produce an electrostatic charge image developer 6. At this time, ML2 / ML1 = 1.2.

<Preparation of electrostatic charge image developer 7>
2.0 parts of the specific resin particles 2 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 7. At this time, ML2 / ML1 = 1.4.

<Preparation of electrostatic charge image developer 8>
2.5 parts of the specific resin particles 3 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 8. At this time, ML2 / ML1 = 2.6.

<Preparation of electrostatic image developer 9>
1.8 parts of the specific resin particles 4 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 9. At this time, ML2 / ML1 = 0.4.

<Preparation of Electrostatic Charge Image Developer 10>
2.6 parts of the specific resin particles 5 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 10. At this time, ML2 / ML1 = 3.2.

<Preparation of Electrostatic Charge Image Developer 11>
1.5 parts of the specific resin particles 6 and 100 parts of the non-magnetic one-component toner 3 were mixed with a Henschel mixer to produce an electrostatic charge image developer 11. At this time, ML2 / ML1 = 0.6.

<Preparation of Electrostatic Charge Image Developer 12>
2.9 parts of specific resin particles 7 and 100 parts of non-magnetic one-component toner 4 were mixed with a Henschel mixer to prepare an electrostatic charge image developer 12. At this time, ML2 / ML1 = 2.9.

<Preparation of Electrostatic Charge Image Developer 13>
2.0 parts of the specific resin particles 8 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 13. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 14>
2.0 parts of specific resin particles 9 and 100 parts of non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 14. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 15>
2.0 parts of the specific resin particles 10 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 15. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 16>
2.0 parts of the specific resin particles 11 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to prepare an electrostatic charge image developer 16. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 17>
2.0 parts of specific resin particles 1 and 100 parts of non-magnetic one-component toner 5 were mixed with a Henschel mixer to produce an electrostatic charge image developer 17. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 18>
1.6 parts of specific resin particles 12 and 100 parts of non-magnetic one-component toner 6 were mixed with a Henschel mixer to prepare an electrostatic charge image developer 18. At this time, ML2 / ML1 = 1.3.

<Preparation of Electrostatic Charge Image Developer 19>
An electrostatic charge image developer 19 was prepared without adding specific resin particles to the non-magnetic one-component toner 1.

<Preparation of Electrostatic Charge Image Developer 20>
5.4 parts of the specific resin particles 1 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to prepare an electrostatic charge image developer 20. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 21>
0.04 part of specific resin particles 1 and 100 parts of non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 21. At this time, ML2 / ML1 = 1.5.

<Preparation of Electrostatic Charge Image Developer 22>
2.0 parts of the specific resin particles 13 and 100 parts of the non-magnetic one-component toner 1 were mixed with a Henschel mixer to produce an electrostatic charge image developer 22. At this time, ML2 / ML1 = 1.5.

(Evaluation method)
<Image scattering evaluation>
The evaluation was performed by using DocuPrint P300d manufactured by Fuji Xerox Co., Ltd., which employs a non-magnetic one-component contact development method and a simultaneous development cleaning method, so that the process speed is variable.
The above-mentioned modified machine continuously printed 500 sheets of A4 images having an image density of 1% in a high humidity environment at a temperature of 25 ° C. and a humidity of 80%. Further, a thin line pattern was output immediately after printing 5,500 sheets of the same image, and image scattering after 6,000 sheets was evaluated according to the following criteria. If the evaluation is 1 to 3, there is no practical problem.
1: The scattering is not recognized at all visually, and a very good line image is obtained.
2: Slight scattering is perceived, but is sufficiently acceptable, and a good line image is obtained.
3: The scattering is slightly recognized but at an acceptable level.
4: Scattering is clearly recognized visually.

<Evaluation of fixability (fixing strength)>
With respect to the solid images after printing 500 sheets of A4 images with an image density of 1% and after printing 6,000 sheets, the presence or absence of image defects at the fold portions when the images were folded was visually evaluated according to the following criteria. The paper used was C2 paper manufactured by Fuji Xerox Co., Ltd. If the evaluation is 1 or 2, there is no practical problem.
1: Image defect is hardly recognized.
2: Image defects are slightly recognized but at an acceptable level.
3: Image defect is clearly recognized visually.
Table 1 shows the evaluation results of the developers 1 to 22.

  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 transport 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

Claims (8)

Toner base particles containing at least a binder resin and a colorant, a non-magnetic one-component toner containing an external additive, and
Contains resin particles with inorganic particles attached,
The inorganic particles have oil on the surface;
Containing 0.05 to 5.0 parts by weight of resin particles with inorganic particles attached to 100 parts by weight of the non-magnetic one-component toner,
The shape factor SF1 of the non-magnetic one-component toner is 126 or less, and the shape factor SF1 of the resin particles to which inorganic particles are attached is 134 or more and 180 or less,
An electrostatic charge image developer that satisfies the following formula (1), where ML1 is the number average maximum length of non-magnetic one-component toner and ML2 is the number average maximum length of resin particles to which inorganic particles are adhered.
0.5 ≦ ML2 / ML1 ≦ 3.0 (1)   The electrostatic charge image developer according to claim 1, wherein the number average maximum length (ML2) of the resin particles to which the inorganic particles are attached is 2 μm or more and 30 μm or less.   The electrostatic image developer according to claim 1, wherein the inorganic particles are silicone oil-treated silica particles having a number average particle diameter of 5 nm to 30 nm.   The electrostatic image developer according to claim 1, wherein the non-magnetic one-component toner has a positive charging property.   An electrostatic latent image formed on the surface of an image carrier, which is attached to and detached from an image forming apparatus and accommodates the electrostatic charge image developer according to claim 1, and the electrostatic charge image developer. A process cartridge comprising developing means for developing a toner image by developing a toner image. A latent image forming step of forming an electrostatic latent image on the surface of the image carrier;
A developing step of forming a developer layer on a developing roll and developing the electrostatic latent image in contact with the image carrier to form a toner image;
A transfer step of transferring the toner image to a transfer target;
A fixing step of fixing the toner image on the transfer body,
The image forming method according to claim 1, wherein the developer is the electrostatic charge image developer according to claim 1.   The image forming method according to claim 6, further comprising a cleaning step of collecting the external additive and / or residual toner on the image holding member in a developing device via a developing roll. 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 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, wherein the developer is the electrostatic charge image developer according to claim 1.

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