JP6191274B2 - Non-magnetic one-component toner, electrostatic charge image developer, process cartridge, image forming method, and image forming apparatus - Google Patents

Description

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

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

  One development method using electrophotography is a one-component development method. 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 is a developer used for reversal development of an electrostatic latent image formed on a positively charged amorphous silicon photoconductor, and includes at least a positively charged toner, an aminosilane coupling agent, and First inorganic fine particles having a number average particle size in the range of 0.1 to 3 μm surface-treated with at least one surface treatment agent selected from amino silicone oils, and an average primary particle size subjected to hydrophobic treatment is 0. Disclosed is a developer containing second inorganic fine particles in a range of 0.005 to 0.02 μm.

  Patent Document 2 is a positively chargeable toner for non-magnetic one-component development composed of toner base particles containing a colorant and polyester as a binder resin and an external additive. Disclosed is a positively chargeable toner for nonmagnetic one-component development comprising positively chargeable silica having a particle size of 5 to 30 nm and negatively chargeable silica having an average particle size of 0.2 to 0.6 μm.

  Patent Document 3 discloses a recycling system characterized in that an external additive containing at least calcium carbonate or porous calcium phosphate as calcite crystals is attached to the surface of toner particles mainly composed of a binder resin and a colorant. Discloses a two-component toner for use in the present invention.

Japanese Patent Laid-Open No. 10-48888 JP 2008-058395 A JP 2002-287411 A

  In Patent Document 1, filling is prevented by using two types of inorganic particles having different particle diameters, but there is no provision on the toner base particle side, and the development rate of calcium carbonate decreases with the deterioration of the toner, and the influence of calcium carbonate. Expands.

  Patent Document 2 discloses that, among two types of silica having different particle diameters, surface treatment is performed on small-diameter silica particles with a positively-charged hydrophobizing agent, but the influence of calcium carbonate mixed in the toner is disclosed. Cannot be excluded.

  Patent Document 3 relates to a toner for a two-component developer. In a system in which the toner remaining on the surface of the photoreceptor is scraped off by a cleaning blade or the like and recovered in an unused developer, In order to prevent filming, a toner is disclosed in which calcium carbonate exhibiting calcite crystals or porous calcium phosphate is externally added to toner particles as an abrasive. However, although it is attached to the toner due to the characteristics (particle size / surface treatment) on the calcium carbonate side, there is no regulation that calcium carbonate is transferred as a toner image, and the calcium carbonate mixed in the toner is not regulated. The effect cannot be excluded.

  When the present inventors use a paper using calcium carbonate as a white additive for recording paper, the calcium carbonate is often not subjected to surface treatment. It has been found that in an image forming apparatus that is not transferred and does not have a cleaning system, calcium carbonate is mixed in the apparatus, and as its concentration increases, charging decreases. The present inventors have found that there is a similar problem when talc is used instead of calcium carbonate as a white additive.

  The problem to be solved by the present invention is that even when recording paper containing talc or calcium carbonate is used, talc or calcium carbonate mixed in the developing machine is discharged together with the toner to an output image, and a stable image is obtained over a long period of time. It is to provide a non-magnetic one-component toner that can be used.

Said subject was solved by the means as described in <1>, <7>, <8>, <9> or <10> below. It is listed below together with <2> to <6> which are preferred embodiments.
<1> a non-magnetic one-component toner containing toner base particles and at least two kinds of external additives and having a calcium carbonate discharge rate of 0.8 or more,
<2> The non-magnetic one-component toner according to <1>, wherein the toner base particle is a chemical toner having a volume average particle size of 3 to 10 μm and a shape factor SF1 of 110 to 135,
<3> The nonmagnetic one-component toner according to <1> or <2>, wherein the toner base particles are positively charged.
<4> The non-magnetic one-component toner according to any one of <1> to <3>, wherein the toner base particles have a polymer containing a nitrogen atom on a surface thereof.
<5> Any one of <1> to <4>, wherein the toner contains a small-diameter external additive and a large-diameter external additive, the surface of the large-diameter external additive is oil-treated, and has negative chargeability. The non-magnetic one-component toner according to one;
<6> The non-magnetic one-component toner according to any one of <1> to <5>, which is for an image forming apparatus having no cleaning blade,
<7> An electrostatic charge image developer comprising the non-magnetic one-component toner according to any one of <1> to <6>,
<8> Development that is detachable from the image forming apparatus, contains the nonmagnetic one-component toner according to any one of <1> to <6>, and holds and transports the nonmagnetic one-component toner A process cartridge comprising means,
<9> A latent image forming step of forming an electrostatic latent image on the surface of the image carrier, a developing step of developing the electrostatic latent image formed on the surface of the image carrier with toner to form a toner image, and the toner image And a fixing step for fixing the toner image transferred to the surface of the transfer medium, without a cleaning step using a cleaning blade, and the toner is <1> to <6>, the non-magnetic one-component toner according to any one of 6),
<10> An image holding member, a charging unit for charging the image holding member, an exposure unit for exposing the charged image holding member to form an electrostatic latent image on the surface of the image holding member, and the static by toner. A developing unit that develops the electrostatic latent image to form a toner image, a transfer unit that transfers the toner image from the image holding member to the surface of the transfer target, and a toner image transferred to the surface of the transfer target are fixed. An image holding member having no cleaning blade, and the toner is the non-magnetic one-component toner according to any one of <1> to <6>. Forming equipment.

According to the invention described in <1> above, even when a recording paper containing a large amount of calcium carbonate is used, calcium carbonate is discharged together with the toner, and stable generation in which charge reduction, fogging and unevenness are suppressed is suppressed. There is provided a non-magnetic one-component toner capable of continuously obtaining an image having an image quality over a long period of time.
According to the invention described in the above <2>, there is provided a non-magnetic one-component toner capable of obtaining a more stable image over a long period of time without supplying toner.
According to the invention described in the above <3>, a nonmagnetic one-component toner capable of obtaining a more stable image over a long period of time is provided.
According to the invention described in <4> above, the surface treatment with a polymer containing a nitrogen atom can improve the discharge rate of calcium carbonate under high temperature and high humidity in which calcium carbonate contamination increases, and therefore, further over a long period of time. There is provided a non-magnetic one-component toner capable of obtaining a stable image.
According to the invention described in <5> above, the tendency of calcium carbonate to be discharged is increased by the electrostatic and non-electrostatic action of the oil-treated large-diameter external additive. A non-magnetic one-component toner that can provide a stable image is provided.
According to the invention described in <6>, there is provided a non-magnetic one-component toner that can provide a stable image over a long period of time even when used in an image forming apparatus having no cleaning blade.
According to the invention described in <7> above, an electrostatic charge image developer capable of obtaining a stable image over a long period of time is provided.
According to the invention described in <8>, a process cartridge capable of obtaining a stable image over a long period of time is provided.
According to the invention described in <9>, there is provided an image forming method capable of obtaining a stable image over a long period of time.
According to the invention described in <10> above, an image forming apparatus capable of obtaining a stable image over a long period of time is 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.

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.
In this embodiment, a combination of preferred embodiments is a more preferred embodiment.

1. Non-magnetic one-component toner The non-magnetic one-component toner of the present embodiment (hereinafter also simply referred to as “toner”) contains toner base particles and at least two types of external additives, and discharge rate of calcium carbonate. Is 0.8 or more.
The nonmagnetic monocomponent toner of this embodiment is preferably used for nonmagnetic monocomponent contact development. Further, the non-magnetic one-component toner of this embodiment is preferably used for an image forming apparatus that does not have a cleaning blade, and more preferably for an image forming apparatus that does not have a cleaning blade that uses a non-magnetic one-component contact development method. used. The non-magnetic one-component toner of this embodiment is preferably used in an image forming apparatus using a simultaneous development cleaning system that does not use a cleaner. In any one of the above aspects, the effect of the present embodiment is more effectively exhibited.
Furthermore, the non-magnetic one-component toner of the present embodiment is preferably a chemical toner, and more preferably a chemical toner produced by an emulsion aggregation method.
This embodiment will be described in detail below.

Conventionally, in a so-called “cleaner-less system” that does not particularly use a cleaning blade, there is no cleaning blade for removing deposits on the surface of the image carrier (photoreceptor), so toners such as wax components and external additive components There is a problem that components, paper components, and the like adhere and accumulate.
In particular, when recording paper coated with calcium carbonate or the like as a pigment for improving whiteness, such as art paper, the adhesion state of the toner component depends on the output history, and there is a difference in the adhesion state of the toner to the photoreceptor surface. Arise. Such a difference in the adhesion state of the photoreceptor surface depends on the surface condition of the photoreceptor in order that the external additive on the toner surface keeps the adhesion force between the toner and the photoreceptor in an appropriate range when the toner is not deteriorated. The influence on the toner transferability is small, and the influence on the image quality is small.
As a result of intensive studies, the present inventors have found that the surface of the photosensitive member surface has been deteriorated in a state where the deterioration of the toner such as detachment, embedding, and deformation of the external additive has progressed due to mechanical stress caused by the developing device, or when there is no toner supply. It has been found that the transferability of the toner varies depending on the state of adhered matter, and in particular, when a halftone image is formed, it may appear as an increase in density unevenness or fog due to charge fluctuation.

  In the non-magnetic one-component toner containing toner base particles and at least two kinds of external additives, the present inventors made the following calcium carbonate discharge rate to be 0.8 or more, thereby stabilizing the toner for a long period of time. We found that an image can be obtained.

<Calcium carbonate discharge rate>
The calcium carbonate discharge rate (A) is determined as follows for the initial stage and the lapse of time.
・ Initial discharge rate (initial A) A _I
A toner to which 0.5% by weight of calcium carbonate (Softon 3200: manufactured by Shiraishi Calcium Co., Ltd.) is added is prepared, and an unfixed image having an image density of 100% is output. It was collected toner from an unfixed image, when the content ratio of the measured calcium carbonate by X-ray fluorescence analysis and X (wt%), the initial discharge rate A _I of calcium carbonate can be obtained from the following expression.
Initial discharge rate A _I = X / 0.5
・ Aging rate (A) A _A
Similarly, the time-dependent discharge rate A _{A of} calcium carbonate is similarly obtained as follows. That is, the time-dependent discharge rate A _A of calcium carbonate can be obtained as follows using the deteriorated toner after 3 hours of idling and using the same method as described above.
Aging rate A _A = X / 0.5

Calcium carbonate used as a paper filler is often not surface-treated and has low resistance. For this reason, even if it adheres to the photosensitive member, it is not transferred to the paper and does not have a cleaning system. If it is continuously used, calcium carbonate is mixed into the developing machine, and as its concentration increases, the charge decreases.
By setting the above-mentioned initial and time-dependent calcium discharge rates (respectively A _I and A _A ) to 0.8 or more, carbon dioxide mixed in the developing machine can be mixed even on paper containing a large amount of talc and calcium carbonate. Calcium was discharged to the output image together with the toner to obtain a toner capable of obtaining stable image quality over a long period of time.
In order to develop calcium carbonate and the like together with the toner, it is exemplified that the adhesion force between the large-diameter external additive and the calcium salt is increased among the two types of external additives having different particle diameters. In order to improve the adhesion of the surface of the large-diameter external additive, a method of treating the large-diameter external additive with a material having viscosity at room temperature can be exemplified. Various oils are used as the material for imparting viscosity, which will be described in detail later.

<Toner base particles>
The nonmagnetic one-component toner of this embodiment contains toner base particles and at least two kinds of external additives. The toner base particles contain a binder resin, and if necessary, a colorant, a release agent, and other additives.
Hereinafter, components constituting the toner base particles will be described.

(1) Binder Resin In the present embodiment, the toner base particles contain a binder resin. The binder resin refers to a resin that is blended to have the shape and function of toner base particles. The binder resin contained in the toner base particles is not particularly limited. For example, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic (Meth) acrylic acid esters such as n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile, Vinyl nitriles such as 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; Polyethylene such as ethylene, propylene and butadiene Homopolymer consisting of a monomer such as olefins, or copolymers obtained by combining two or more of these, even mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.
Among the binder resins, a styrene acrylic resin or a polyester resin is preferably used, and a polyester resin is more preferably used.

(1-1) Styrene acrylic resin Styrene resin, (meth) acrylic resin, styrene- (meth) acrylic copolymer resin (styrene acrylic resin) are, for example, styrene monomer and (meth) acrylic acid single monomer. The body can be obtained by a known method alone or in appropriate combination. “(Meth) acryl” is an expression including both “acryl” and “methacryl”.
When using a styrene resin, a (meth) acrylic resin or a copolymer resin thereof as a binder resin, the weight average molecular weight Mw is 20,000 or more and 100,000 or less, and the number average molecular weight Mn is 2,000 or more and 30,000 or less. It is preferable to use the thing of the range.

(1-2) Polyester resin As the binder resin, a polyester resin is also preferably used.
Examples of the polyester resin include known amorphous polyester resins.

  Examples of the polyester resin include a condensation polymer of a polyvalent carboxylic acid (polycarboxylic acid) and a polyhydric alcohol (polyol), and a linear polyester of a diol and a dicarboxylic acid is preferable. In addition, as a polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

In order to impart low temperature fixability to the toner, it is preferable to use a crystalline polyester resin as a part of the binder resin.
In this embodiment, “crystallinity” refers to having a clear endothermic peak in differential scanning calorimetry (DSC), and specifically, when measured at a heating rate of 10 ° C./min. It means that the half-value width of the endothermic peak is within 15 ° C. On the other hand, a resin having a half-value width of an endothermic peak exceeding 15 ° C. or a resin having no clear endothermic peak means amorphous.
The crystalline polyester resin is preferably composed of an aliphatic dicarboxylic acid and an aliphatic diol, and more preferably a linear dicarboxylic acid or a linear aliphatic diol having 4 to 20 carbon atoms in the main chain portion. The linear type is excellent in the crystallinity of the polyester resin and has an appropriate crystal melting point, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability. Further, when the carbon number is 4 or more, the ester bond concentration is low, the electric resistance is moderate, and the toner charging property is excellent. Further, when it is 20 or less, it is easy to obtain practical materials. The carbon number is more preferably 14 or less.

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

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

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

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

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

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

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

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

(2) Colorant The colorant is a colored material added to enable the toner image to be optically recognized by the naked eye or by a machine. As a colorant for forming a black and white image, a black pigment is preferably used. In order to form a full-color image, colorants exhibiting three primary colors of yellow, magenta and cyan are preferably used, and a black pigment may be used in combination.
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 and used for full color reproduction.

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

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

(3) Release agent The release agent is used to improve the separation between the heat-melted toner and the heat roller when the toner is heat-fixed, particularly when fixing with a heat roller.
In this embodiment, the toner base particles preferably contain a release agent.
Specific examples of the release agent include, for example, polyolefin wax such as polyethylene wax, polypropylene wax or ethylene-propylene copolymer, and ester wax, but polyglycerin wax, microcrystalline wax, paraffin wax, carnauba wax, Sazol wax, 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, Saturated alcohols such as carnauvir alcohol, ceryl alcohol, melyl alcohol, or long chain alkyl alcohols having a long chain alkyl group; such as sorbitol Monohydric alcohols; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide , Unsaturated fatty acid amides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N'-dioleyl adipic acid amide, N, N'-dioleyl sebacic acid amide; m-xylene bisstearic acid Aromatic bisamides such as amides and N, N'-distearylisophthalic acid amides; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (generally referred to as metal soap); fats Obtained by grafting to aromatic hydrocarbon wax using vinyl monomers such as styrene and acrylic acid; partially esterified products of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; obtained by hydrogenation of vegetable oil Examples include methyl ester compounds having a hydroxyl group.
Among these, polyolefin waxes are preferable, and specific examples include α-olefins such as ethylene and propylene, and homopolymers, copolymers, and copolymers of cyclic olefins such as cyclohexene and norbornene. .
As the polyolefin wax, polyethylene wax, polypropylene, or ethylene-propylene copolymer is more preferable, and polyethylene wax is particularly preferable. In the above embodiment, the charge retention is excellent, and the generation of white spots in the obtained image is further suppressed.

A mold release agent may be used individually by 1 type, or may use 2 or more types together.
The content of the release agent is preferably 1 to 20 parts by weight and more preferably 3 to 15% by weight with respect to 100 parts by weight of the toner base particles. Within the above range, both good fixing and image quality characteristics can be achieved.
As the release agent, various waxes are preferably used. For example, hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; fatty acid esters And ester waxes such as montanic acid ester.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the “melting peak temperature” described in the method for determining the melting temperature in JIS K-1987 “Method for measuring the transition temperature of plastics” from the DSC curve obtained by differential scanning calorimetry (DSC). .

  The content of the release agent is, for example, preferably 1% by mass to 20% by mass and more preferably 5% by mass to 15% by mass with respect to the entire toner particles.

-Other additives-
Examples of other additives include additives such as charge control agents and inorganic powders. In this embodiment, the toner base particles do not contain a magnetic material. The charge control agent will be described later.

<Characteristics of toner mother particles>
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be. Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is preferable that it is comprised by the comprised coating layer.

(Volume average particle diameter of toner base particles)
The volume average particle diameter of the toner base particles of the present embodiment is a median value of the cumulative volume distribution, preferably 3 to 10 μm, and more preferably 3.5 to 8.5 μm. This is because the surface area of the toner base particles is increased and the charging area is increased within the above numerical range, so that the decrease in charging due to calcium carbonate can be reduced.
A Coulter Multisizer-II type (manufactured by Beckman-Coulter) was used as a measuring device for the volume average particle diameter of the toner base particles, and ISOTON-II (manufactured by Beckman-Coulter) was used as the electrolyte.
As a measurement method, 1.0 mg of a measurement sample was added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant. This was added to 100 ml of the electrolytic solution to prepare an electrolytic solution in which the sample was suspended.
The electrolyte in which the sample was suspended was dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles of 1 to 30 μm was measured using the Coulter Multisizer-II type with an aperture diameter of 50 μm. Average distribution and number average distribution are obtained. The number of particles to be measured was 50,000.
The volume average particle size of the external additive is measured with a laser diffraction / scattering particle size distribution measuring device LS Coulter (Beckman-Coulter, particle size measuring device).

(Toner base particle shape factor SF1)
The shape factor SF1 of the toner base particles is preferably 110 or more and 145 or less, more preferably 110 or more and 135 or less, and still more preferably 110 or more and 130 or less.
Within the above numerical range, since the toner base particles are nearly spherical, the external additive, in particular, the large-diameter external additive is uniformly dispersed on the surface of the toner base particles, and the mixed calcium salt is easily discharged. Become.

The shape factor SF1 is obtained by the following formula (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image with an image analyzer, and is calculated as follows. That is, by capturing an optical microscope image of particles dispersed on the surface of a slide glass into a Luzex image analyzer using a video camera, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and obtaining the average value can get.

(Chemical toner)
In the present embodiment, the toner is preferably a chemical toner rather than a pulverized toner. The chemical toner is also called a polymerization toner, and includes an emulsion aggregation method, a suspension polymerization method, and a dissolution suspension method, and toner base particles produced by the emulsion aggregation method are preferable.
The emulsion aggregation method (EA method) is a method in which, in addition to emulsion polymerization resin particles obtained by an emulsion polymerization method, pigment particles and wax particles are aggregated in water and then combined to form toner mother particles. It is. The emulsion aggregation method is a method for producing toner base particles by applying a uniform and long-term shearing force in the aggregation step and the coalescence step, and is excellent in that the particle size and shape factor can be controlled. .
In addition, when resin and pigment particles are aggregated and united in water, a polyester resin has been used instead of a styrene acrylic resin in order to impart low temperature fixability and image strength. As the polyester resin in this case, those obtained mainly by condensation polymerization of dicarboxylic acids and dialcohols are preferable. The amorphous polyester resin is easily prepared as a resin particle dispersion by adjusting the acid value of the resin or emulsifying and dispersing it using an ionic surfactant or the like.

(Charge polarity)
In this embodiment, in order to control the charging property of the toner base particles, the surface of the toner base particles may be surface-treated. For this purpose, a charge control agent may be used for the toner base particles.
In particular, when the chargeability is not controlled, the toner base particles are often negatively charged.
In the present embodiment, the toner base particles are preferably positively charged rather than negatively charged.
As a method for performing the surface treatment so that the toner base particles are positively charged, it is preferable to use a charge control agent.
Examples of the charge control agent for positively charging the toner base particles include the following.
Examples of positively chargeable charge control agents include nigrosine dyes, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Onium salts such as phosphonium salts and their lake pigments; 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 A guanidine compound, an imidazole compound, an aminoacrylic resin, polyethyleneimine, and the like.
Examples of negatively chargeable charge control agents include trimethylethane dyes, metal complexes of salicylic acid, metal complexes of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes Heavy metal-containing acidic dyes such as 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 5% by weight with respect to the total weight of the toner base particles. When the addition amount is within the above range, good chargeability can be obtained.

In the present embodiment, it is preferable to use a high-molecular charge control agent rather than a low-molecular charge control agent, and the molecular weight is more preferably 10,000 or more in weight average molecular weight. The polymer charge control agent is preferably water-soluble for uniform surface treatment. Here, “water-soluble” means that 1.0 g or more is dissolved in 100 ml of water at room temperature. The polymer charge control agent is preferably a polymer containing a nitrogen atom, and particularly preferably a polyamine polymer. As the polyamine-based charge control agent, polyallylamines, polyethyleneimines, and polyaminopropyl biguanides (polyhexanides) are preferable, polyethyleneimines are more preferable, and polyethyleneimine is particularly preferable.
These charge control agents are used by adhering to or reacting with the surface of the toner base particles, and may be used alone or in combination of two or more.
The amino group and biguanide group in the polyallylamines, polyethyleneimines, and polyaminopropyl biguanide may form a salt at least partially.
The amino group in the polyallylamines may be a primary amino group, a secondary amino group, and / or a tertiary amino group, and may form a salt.
Examples of polyallylamines include polyallylamine, allylamine salt polymer, methyldiallylamine salt polymer, diallyldimethylammonium chloride polymer, polydiallylamine, diallylamine salt polymer, and the like. Salts are formed with inorganic acids such as nitric acid.
In addition, examples of commercially available polyallylamines include PAA series and PAS series manufactured by Nitto Bo Medical Co., Ltd.

Further, as a surface treatment method of toner mother particles with polyallylamines, polyaminopropyl biguanides, etc., polyallylamines, polyaminopropyl biguanides, etc. are added to a dispersion containing toner mother particles, and the pH of the dispersion is diluted with dilute nitric acid. A method of adjusting the pH to be in the range of 5 to 7, maintaining this pH range, and performing surface treatment is preferred.
The addition amount of polyallylamines and polyaminopropyl biguanide is preferably 0.01 to 10% by weight, more preferably 0.02 to 2% by weight, based on the total weight of the toner base particles. More preferably, it is 05 to 0.1% by weight. When the amount is within the above range, a positive charge amount is increased, and a toner having excellent positive charge stability can be easily obtained.

In this embodiment, when used as a charge control agent containing nitrogen atoms, the weight fraction of nitrogen atoms on the surface of the toner base particles is preferably in a specific numerical range.
That is, in this embodiment, the content of nitrogen atoms on the surface of the toner particles, as measured by X-ray photoelectron spectroscopy, is preferably 0.8 atomic% or more and 5.0 atomic% or less, and from the surface of the toner particles. The nitrogen atom content within 10 nm is preferably 0.4 atomic% or less.

  In this embodiment, the content of nitrogen atoms on the toner particle mother surface is measured by X-ray photoelectron spectroscopy. In the present exemplary embodiment, the content of nitrogen atoms on the toner particle surface is more preferably 0.8 atomic% or more and 4.5 atomic% or less, and particularly preferably 0.9 atomic% or more and 4.0 atomic% or less. preferable. By setting the surface nitrogen amount within the above range, even when the relative humidity drops more rapidly, the change in humidity near the surface of the toner particles is suppressed, and continuous printing under high humidity conditions is possible. In addition, the formation of a good solid image is maintained.

(Nitrogen atomic weight fraction on toner mother particle surface)
In this embodiment, it is preferable that nitrogen atoms exist on the outermost surface of the toner base particles and do not exist as much as possible inside the toner particles. This is because the charge amount of the toner is determined on the outermost surface of the toner, and the nitrogen present in the depth direction of the toner particles and the moisture adsorbed on the nitrogen do not contribute to the charging, but the moisture present in the depth direction is once This is because it is difficult to dehydrate once adsorbed. Therefore, after the toner is left in a high humidity environment for a long period of time, the electrical characteristics are deteriorated. In particular, with black toner, the fog deterioration may be remarkable.
In this embodiment, the content of nitrogen atoms within 10 nm from the surface of the toner particles is 0.4 atomic% or less, and the transferability is lowered even after the toner is left in a high humidity environment for a long time. It is preferable for forming a good image without causing fogging or the like. It is more preferable that the content of nitrogen atoms within 10 nm from the surface of the toner particles is 0.3 atomic% or less because a better image is formed.

In the present embodiment, the measurement conditions of the X-ray photoelectron spectroscopy performed for the content of nitrogen atoms are as follows.
Equipment used: Physical Electronics Industries, Inc. 1600S type X-ray photoelectron spectrometer manufactured by company ・ Measurement conditions: X-ray source MgKα (400 W)
-Spectral region: 800 μm in diameter

In the present embodiment, the method for removing the surface layer of the toner particles is not particularly limited, and any method can be applied as long as the method removes a thickness of 10 nm from the surface of the toner particles without modifying the toner material.
In this embodiment, for example, the content of nitrogen atoms in the interior of 10 nm from the surface of the toner particles was confirmed by etching the surface of the toner particles using an Ar etching method and measuring the amount of surface nitrogen each time. As Ar etching conditions, for example, Ar gas: 3.0 × 10 ⁻² Pa and acceleration voltage: 400 V were performed for 80 seconds.

In this embodiment, the nitrogen atom content is a value for the toner base particles, and is the nitrogen atom content in a state where the external additive added to the toner base particles is removed.
In the present embodiment, examples of a method for separating the external additive from the toner into toner mother particles include the following methods.
The externally added toner is dispersed in an aqueous solution of 0.2% by mass of polyoxyethylene (10) octylphenyl ether so as to be 10% by mass, and ultrasonic vibration (frequency 20 kHz, output 30 W) is maintained at a temperature of 30 ° C. or lower. ) Is allowed to act for 60 minutes to release the external additive. The toner base particles from which the external additive has been removed can be obtained by filtering and washing the toner base particles from the dispersion.

<External additive>
The toner of the present embodiment contains at least two types of external additives in addition to the toner base particles, and these external additives may be the same material or different materials, but the average particle diameter may be different. preferable.
The external additive refers to an inorganic powder or a resin powder that is added to the toner base particles in order to improve the long-term storage property, fluidity, developability, transferability, and cleaning properties of the toner.
Examples of the inorganic powder include silica, alumina, titania, zinc oxide, and cerium oxide. Examples of the resin powder include PMMA, nylon, melamine, benzoguanamine, fluorinated spherical particles, vinylidene chloride, and fatty acid metal salts. An example is powder. The total addition amount of these external additives is preferably in the range of 0.5% by mass or more and 10% by mass or less, and more preferably in the range of 2% by mass or more and 8% by mass or less with respect to the toner base particles. preferable.

(Two kinds of external additives)
In the exemplary embodiment, the toner preferably contains a small-diameter external additive and a large-diameter external additive.
These external additives having different particle diameters are selected from the same or different materials. The small and large external additives are preferably inorganic oxide particles, more preferably selected from silica, alumina, cerium oxide, or titanium oxide, and are silica, alumina, or cerium oxide. Is more preferable, and silica is particularly preferable. Both the small diameter and large diameter external additives are preferably silica.
The external additive having a small diameter preferably has a particle diameter range of 5 to 30 nm, more preferably 5 to 20 nm, in which 50% of the total weight of the particles is contained. The large-diameter external additive preferably has a particle size range of 32 to 300 nm, more preferably 32 to 100 nm.
By combining this particle size range, the small-diameter external additive is stably disposed on the surface of the base particle, so that stable chargeability can be obtained against structural changes, and the oil-treated large-diameter external additive Is disposed on the outermost surface of the toner, so that the discharge rate of calcium carbonate is maintained within a desired range.
The addition ratio of the large-diameter external additive and the small-diameter external additive can be arbitrarily selected, but the external additive amount of the large-diameter external additive and the weight ratio of the small-diameter external additive should be 1: 3 to 3: 1. preferable.

(Oil treatment)
The large-sized external additive is preferably oil-treated and preferably negatively charged.
The type of oil used for the oil treatment of the large-diameter external additive is not particularly limited, but is preferably an inert oil having a kinematic viscosity at room temperature of about 100 centistokes (cs), and is easily available. In view of ease of treatment, an inert silicone oil is more preferable.
Examples of the silicone oil include dimethyl silicone oil, methyl hydrogen silicone oil, and methylphenyl silicone oil. Dimethyl silicone oil (polydimethylsiloxane (hereinafter also referred to as PDMS)) is preferable, and polydimethylsiloxane (PDMS) is more preferable. preferable.

A surface treatment method using a silicone oil as a large-diameter external additive may be appropriately selected from known methods. For example, a silicone oil or a solution containing silicone oil is sprayed onto particles suspended in a gas phase. Examples thereof include a dry method such as a spray drying method, or a wet method in which particles are immersed in a solution containing silicone oil and dried. Among these, the spray drying method is preferable from the viewpoint of controlling the surface treatment amount of the silicone oil.
After the surface treatment, it is also preferable to adjust the excessively treated silicone oil to an appropriate amount range by immersing it again in a solvent such as ethanol and drying the solvent.
The treatment amount of the silicone oil is preferably 5 to 30 parts by weight, more preferably 10 to 30 parts by weight with respect to 100 parts by weight of the large-diameter external additive from the viewpoint of calcium carbonate discharge rate. 10 to 20 parts by weight is more preferable. The treatment amount of the silicone oil is measured by dispersing particles surface-treated with the silicone oil in a good solvent for the silicone oil (for example, toluene, xylene, etc.) and eluting the silicone oil.

As described above, the large-diameter external additive preferably has negative chargeability.
The negatively charged particles such as silica may be used as they are without changing the charging characteristics, or the charging characteristics may be further clarified by a negatively charged charge control agent. When used in combination with positively chargeable mother particles, the agent reduces the discharge rate of calcium carbonate, especially by the electrostatic interaction between the two and the non-electrostatic interaction between the large-diameter external additive and calcium carbonate. Improve.
The chargeability of the small-diameter external additive is not particularly limited, but it is preferable to have a positive chargeability like the toner base particles.
In addition, in this embodiment, the combination of preferable forms is a more preferable form.

<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 manufacturing method may be performed in which the toner particles obtained by the above method are used as a core, and agglomerated particles are further adhered and heated and fused to form a core-shell structure.
As already described, it is preferable to use toner base particles produced by the emulsion aggregation method for the nonmagnetic one-component toner of this embodiment.

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

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

3. Process Cartridge, Image Forming Method, and Image Forming Apparatus An image forming method of the present embodiment includes a latent image forming step for forming an electrostatic latent image on the surface of an image carrier, and an electrostatic latent image formed on the surface of the image carrier. A developing step of developing with toner to form a toner image, a transfer step of transferring the toner image to the surface of the transfer target, and a fixing step of fixing the toner image transferred to the surface of the transfer target; A cleaning process using a blade is not included, and the toner is the non-magnetic one-component toner of the present 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 toner to form a toner image; a transfer unit that transfers the toner image from the image holding member to the surface of the transfer target; and a surface of the transfer target. Fixing means for fixing the transferred toner image, the image carrier does not have a cleaning blade, and the toner is the non-magnetic one-component toner 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 coated with resin, etc. Coated paper, art paper for printing, and the like can be suitably used.
The image forming method of the present embodiment may have a cleaning step for removing the electrostatic charge image developer remaining on the image carrier, but the blade is not used in the cleaning step and contacts the image carrier. It is preferable that it is the process of using the brush which was made to use.
The image forming apparatus according to the present exemplary embodiment may include a cleaning unit that removes the electrostatic image developer remaining on the image carrier, but does not use a cleaning blade and contacts the image carrier. It is preferable to have a cleaning brush.

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

The image forming apparatus of the present embodiment includes an image carrier, a charging unit that charges the image carrier, and an exposure unit that exposes the charged image carrier to form an electrostatic latent image on the image carrier. And developing means for developing the electrostatic latent image with a developer containing toner to form a toner image, and transfer means for transferring the toner image from the image holding member to a transfer target, The developer containing the toner preferably contains the electrostatic image developing toner of this embodiment.
The image forming apparatus of the present exemplary embodiment is not particularly limited as long as it includes at least the image carrier, the charging unit, the exposure unit, the developing unit, the transfer unit, and the fixing unit as described above. In addition, it may include a static elimination means or the like as necessary.
In the transfer unit, the transfer may be performed twice or more using an intermediate transfer member. Examples of the transfer medium in the transfer unit include an intermediate transfer medium and a recording medium such as paper.

  The image carrier and each of the above-described units can preferably use the configurations described in the respective steps of the image forming method. As each of the above-described means, a known means in the image forming apparatus can be used. In addition, the image forming apparatus according to the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus according to the present embodiment may simultaneously perform a plurality of the above-described means.

An example of an image forming apparatus that develops using a non-magnetic one-component developer will be described below with reference to FIGS.
FIG. 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.
The developing devices 4Y, 4M, 4C, and 4K can be performed using a general developing device that develops by contacting non-magnetic one-component toner or non-magnetic one-component developer described later (developing step). Such a developing device is not particularly limited as long as non-magnetic one-component toner or non-magnetic one-component developer is used, and a known one can be appropriately selected according to the purpose. In the primary transfer process, a primary transfer bias having a polarity opposite to that of the toner on the image carrier is applied to the primary transfer rolls 5Y, 5M, 5C, and 5K, whereby each color is transferred from the image carrier to the intermediate transfer belt 20. The toner is sequentially primary transferred.

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

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

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

  When developing, first, the developer 64 in the housing 62 is supplied from the agitator 60 to the surface of the developing roll 52 by the developer scraping member 56. Next, the developer 64 attached to the surface of the developing roll 52 is attached by the toner layer regulating member 58 so as to form a toner layer having a uniform thickness on the surface of the developing roll 52. At this time, the non-magnetic one-component toner and the external additive collecting agent 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.

In this embodiment, it is preferable to further include a cleaning step of recovering the external additive of the image carrier to the developing device via the developing roll. Referring to FIG. 2, in this embodiment, an external additive (not shown) remaining on the image carrier 1 after the transfer process is transferred to the developing roller 52 by the contact between the image carrier 1 and the developing roller 52. And is preferably collected by the developing device 4. As a result, the transfer residual toner on the image carrier is cleaned without separately providing an image carrier cleaning means or a cleaning step. At this time, the external additive recovery agent is present on the roll 52 that is in contact with the image carrier 1, and the external additive is brought into contact with the image carrier 1 by contacting the external additive recovery agent and the external additive. To the surface of the external additive recovery agent, whereby the external additive is recovered by the developing device 4 together with the external additive recovery agent.
In the above cleaning step, it is preferable that the transfer residual toner on the photoreceptor is also collected by the developing device via the developing roll.

In 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.

  Hereinafter, the present embodiment will be specifically described with reference to examples, but the present embodiment is not limited to the following examples. Unless otherwise specified, “part” and “%” are based on weight.

<Preparation of crystalline polyester resin particle dispersion>
1,10-decanedicarboxylic acid 33 parts 1,4-butanediol 25 parts dimethyl sulfoxide 30 parts ethylene glycol 5 parts dibutyltin oxide 0.5 parts All of the above reagents are manufactured by Wako Pure Chemical Industries, Ltd.

  After putting the said composition in the dry 3 necked flask, the air in a container was made into inert atmosphere with nitrogen gas by pressure reduction operation, and it stirred at 185 degreeC by mechanical stirring for 8 hours. Dimethyl sulfoxide is distilled off under reduced pressure, and then the temperature is gradually raised to 210 ° C. under reduced pressure, followed by stirring for 2 hours. When a viscous state is reached, the reaction is stopped and the crystalline polyester resin is stopped. Was synthesized.

  Prepare 170 parts by mass of crystalline polyester resin, 150 parts by mass of ethyl acetate, and 0.05 parts by mass of aqueous sodium hydroxide (0.5N), put them in a 500 ml separable flask, and heat at 70 ° C. The mixture was stirred with a three-one motor (manufactured by Shinto Kagaku Co., Ltd.) to prepare a crystalline resin mixed solution. While stirring this crystalline resin mixed solution, 500 parts of an aqueous sodium hydroxide solution (0.05 N) was gradually added to carry out phase inversion emulsification. The transferred emulsion was transferred to a vat and stirred for 48 hours while stirring in a well-ventilated place to remove the solvent, thereby preparing a crystalline polyester resin particle dispersion in which crystalline polyester resin particles were dispersed.

<Preparation of amorphous polyester resin particle dispersion>
An acid component composed of 80 mol% terephthalic acid and 10 mol% fumaric acid and an alcohol component composed of 45 mol% bisphenol A ethylene oxide 2 mol adduct and 45 mol% bisphenol A propylene oxide 2 mol adduct in a molar ratio of 1: 1. , Put in a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, rectification tower, took 2 hours in a nitrogen atmosphere, raised to 80 ° C., and confirmed that the reaction system was uniformly stirred . Thereafter, 0.5 part of dibutyltin oxide was added to 100 parts of the mixture, and the temperature was raised to 210 ° C. over 2 hours from the same temperature while distilling off the generated water. To obtain an amorphous polyester resin.
Subsequently, the obtained amorphous polyester resin was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. In a separately prepared aqueous medium tank, 0.37% diluted aqueous ammonia obtained by diluting reagent ammonia water with ion exchange water is put, and heated at 95 ° C. with a heat exchanger at a rate of 0.1 liters per minute, The amorphous polyester resin melt was transferred to Cavitron CD1010 (manufactured by Eurotech). The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² . Then, after adjusting the pH of the system to 8.5 with 0.5 mol / l sodium hydroxide aqueous solution and treating at 45 ° C. for 5 hours, the pH is adjusted to 7.5 with nitric acid aqueous solution, and the solid content is further adjusted. Thus, an amorphous polyester resin particle dispersion was obtained.

<Preparation of styrene acrylic resin dispersion>
A mixture of 280 parts of styrene, 120 parts of n-butyl acrylate, 8 parts of acrylic acid, 6 parts of dodecanethiol and 2 parts of carbon tetrabromide was dissolved in an anionic surfactant (Neogen SC: Daiichi Kogyo Seiyaku Co., Ltd. ) Produced) Emulsion polymerization was carried out in a flask in which 10 parts were dissolved in 550 parts of ion-exchanged water. After carrying out nitrogen substitution, the contents in the flask were stirred and heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours. Styrene having a volume average particle size of 150 nm and a solid content concentration of 35% An acrylic resin dispersion was obtained. When the obtained styrene acrylic resin dispersion was dried, the weight average molecular weight was 31,500 and the glass transition temperature was 53 ° C.

<Preparation of release agent dispersion>
・ 45 parts of paraffin wax HNP9 (melting temperature: 74 ° C., manufactured by Nippon Seiwa Co., Ltd., specific gravity: 0.925 g / cm ³ ) 5 parts of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 200 parts or more of ion-exchanged water The above materials were heated to 95 ° C. and dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax T50), then dispersed with a pressure discharge type gorin homogenizer (Gorin), and volume averaged. A release agent dispersion having a particle size of 0.21 μm (release agent concentration: 20%) was prepared.

<Preparation of black pigment dispersion>
・ Black pigment (# 25, Mitsubishi Chemical Co., Ltd., primary particle size 0.047 μm) 100 parts ・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 15 parts ・ Ion-exchanged water 400 parts or more Were mixed and dissolved, and dispersed for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to prepare a black pigment dispersion having a volume average particle size of 0.35 μm. The pigment concentration of the dispersion was 23%.

<Preparation of toner mother particle 1>
A crystalline polyester resin particle dispersion and an amorphous polyester resin particle dispersion are mixed at a solid content ratio of 15:85, and 100 parts of this mixed resin particle dispersion and 10 parts of a black pigment dispersion are separated. 10 parts of the mold dispersion, 5 parts of polyaluminum hydroxide (manufactured by Asada Chemical Co., Ltd., Paho2S) and 600 parts of ion-exchanged water were homogenized in a round stainless steel flask (Ultra Turrax T50: IKA). And the mixture was dispersed and then heated to 45 ° C. while stirring the inside of the flask in a heating oil bath. After maintaining at 45 ° C. for 30 minutes, it was confirmed that aggregated particles having a D50v of 6.0 μm were produced. Further, the temperature of the heating oil bath was raised and maintained at 50 ° C. for 2 hours, and D50v was 6.2 μm. Thereafter, 20 parts of the amorphous polyester resin particle dispersion was added to the dispersion containing the aggregated particles, and then the temperature of the heating oil bath was raised to 60 ° C. and held for 30 minutes. After adding 1N sodium hydroxide to the dispersion containing the aggregated particles and adjusting the pH of the system to 8.2, the stainless steel flask is sealed, and heated to 85 ° C. while continuing stirring using a magnetic seal. Hold for 3 hours.

  After cooling with ice water at 10 ° C./min, the toner particles are filtered off and washed with ion exchange water at 25 ° C. five times. The resulting wet cake-like toner mother particles have a solid content concentration of It was redispersed in ion-exchanged water so as to be 10%. While stirring, a 1% aqueous solution of polyethyleneimine (PEI) 70000 (manufactured by Junsei Chemical Co., Ltd.) corresponding to 0.035% of the solid weight of the toner base particles was added over 5 minutes. After the addition, the pH was adjusted to 6.5 ± 0.5 with 1N nitric acid, and the mixture was stirred at room temperature for 2 hours. After stirring, the dispersion was filtered, washed with ion-exchanged water, and then dried using a vacuum dryer to obtain toner base particles 1.

<Preparation of toner mother particles 2>
Toner base particles 2 were obtained in the same manner as toner base particles 1 except that 6 parts of polyaluminum hydroxide used in the preparation of toner base particles 1 was heated to 50 ° C. while stirring the flask in a heating oil bath. It was.

<Preparation of toner mother particle 3>
Toner base particles 3 were obtained in the same manner as toner base particles 1 except that 8 parts of polyaluminum hydroxide used in the preparation of toner base particles 1 was heated to 53 ° C. while stirring the flask in a heating oil bath. It was.

<Preparation of toner mother particles 4>
Toner base particles 4 were obtained in the same manner as toner base particles 1 except that the conditions for preparation of toner base particles 1 were maintained at 85 ° C. for 3 hours at 75 ° C. for 2 hours.

<Preparation of toner mother particles 5>
Toner base particles 5 were obtained in the same manner as toner base particles 1 except that the conditions for preparation of toner base particles 1 were maintained at 85 ° C. for 3 hours at 72 ° C. for 1.5 hours.

<Preparation of toner mother particles 6>
Toner base particles 6 were obtained in the same manner as toner base particles 1 except that the conditions for preparing toner base particles 1 at 85 ° C. for 3 hours were changed to 70 ° C. for 1.3 hours.

<Preparation of toner mother particles 7>
-Styrene acrylic resin dispersion 157 parts-Release agent dispersion 45 parts-Black pigment dispersion 26 parts The above materials are placed in a round stainless steel flask and mixed with a homogenizer (IKA: Ultra Turrax T50). Distributed. Next, a 0.8% aqueous solution of aluminum sulfate was added as a flocculant thereto, and the dispersion operation was continued with an ultra turrax.
After installing a stirrer and a mantle heater and adjusting the rotation speed of the stirrer so that the slurry is sufficiently stirred, the temperature was raised to 40 ° C. at 0.5 ° C./min, and held at 40 ° C. for 15 minutes, The particle size was measured every 10 minutes while raising the temperature at 0.05 ° C./min. When the desired volume average particle size was obtained, 85 parts of an additional styrene acrylic resin dispersion was added over 3 minutes. . After holding for 30 minutes, the pH was adjusted to 7.0 using a 5% aqueous sodium hydroxide solution. Thereafter, while adjusting the pH to 7.0 every 5 ° C., the temperature was raised to 96 ° C. at a temperature rising rate of 1 ° C./min, and kept at 96 ° C. for 4 hours. Thereafter, the mixture was allowed to stand at 25 ° C., filtered, washed 7 times with ion-exchanged water, and then treated with polyethyleneimine in the same manner as toner base particles 1 to obtain toner base particles 7.

<Preparation of toner mother particles 8>
Similar to toner base particle 1 except that polyhexamethylene biguanide (PHMB) (BG-1, molecular weight 5,000, manufactured by Sanyo Chemical Co., Ltd.) was used instead of polyethyleneimine in the preparation of toner base particle 1. Thus, toner mother particles 8 were obtained.

<Preparation of toner mother particles 9>
In the same manner as toner mother particle 1 except that amino-modified silicone oil (amino oil) (X-22-161B, manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of polyethyleneimine in the preparation of toner mother particle 1. Toner mother particles 9 were obtained. The amino oil treatment was carried out after drying, not in a wet state after washing.

<Preparation of toner mother particle 10>
Toner base except that polyallylamine (PAA) (hydrochloride polymer (PAA-HCL-10L, molecular weight 150,000, manufactured by Nittobo Medical Co., Ltd.) was used instead of polyethyleneimine in the preparation of toner base particles 1 Toner base particles 10 were obtained in the same manner as for particles 1.

<Preparation of toner mother particle 11>
The toner base particles 11 were those which were not subjected to the polyethyleneimine treatment in the production of the toner base particles 1.

  Table 1 shows the values of the volume average particle diameter (μm) and the shape factor SF1 of the toner base particles 1 to 11.

<Preparation of external additive 1>
100 parts of Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd./7 nm) were placed in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and 20 parts of cyclic silazane was added dropwise and reacted for 2 hours. Thereafter, the external additive 1 was cooled and subjected to a hydrophobic treatment.

<Preparation of external additive 2>
100 parts of Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd./7 nm) were placed in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and 10 parts of cyclic silazane was added dropwise and reacted for 2 hours. Thereafter, 10 parts of KF-96 (polydimethylsiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise, reacted for 1 hour, cooled, and a hydrophobically treated external additive 2 was obtained.

<Preparation of external additive 3>
100 parts of OX50 (Nippon Aerosil Co., Ltd./40 nm) powder was put into a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and then KF-96 (polydimethylsiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) was added. 15 parts of the mixture was added dropwise, reacted for 1 hour, cooled, and a hydrophobically treated external additive 3 was obtained.

<Preparation of external additive 4>
100 parts of OX50 (manufactured by Nippon Aerosil Co., Ltd./40 nm) powder was put into a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and then 15 parts of hexamethyldisilazane was added dropwise and reacted for 2 hours. Thereafter, the external additive 4 was cooled and subjected to hydrophobic treatment.

<Preparation of external additive 5>
100 parts of OX50 (manufactured by Nippon Aerosil Co., Ltd./40 nm) powder was placed in a mixer and stirred at 200 rpm while heating to 200 ° C. in a nitrogen atmosphere, and 10 parts of aminosilane was added dropwise and reacted for 2 hours. Thereafter, 15 parts of KF-96 (polydimethylsiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise, reacted for 1 hour, cooled, and a hydrophobically treated external additive 5 was obtained.

<Examples 1-13 and Comparative Examples 1-3>
Toners were prepared according to the combinations shown in Table 1 and evaluated. The external additive shown in Table 1 was added to 100 parts by weight of the toner base particles, and the mixing conditions were as follows: the external speed was mixed with a Henschel mixer at a peripheral speed of 30 m / s for 3 minutes. Got.

(Measurement method of volume average particle diameter of toner base particles)
Various average particle diameters and various particle size distribution indexes of toner particles are measured using Coulter Multisizer II (manufactured by Beckman-Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Beckman-Coulter).
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm is obtained using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
A cumulative distribution is drawn from the smaller diameter side to the particle size range (channel) divided based on the measured particle size distribution, and the particle size at 50% cumulative is defined as the volume average particle size D50v. .

(Shape factor measurement method)
The shape factor SF1 is obtained by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, by capturing an optical microscope image of particles dispersed on the surface of a slide glass into a Luzex image analyzer using a video camera, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and obtaining the average value can get.

(Evaluation of chargeability of toner base particles and external additives)
The polarities of the toner base particles and the external additive were evaluated as follows.
The polarity of the toner base particles was evaluated as follows. 6 parts by mass of toner and 100 parts by mass of a standard carrier (N-01 / N-02 / P-01 / P02) in which a charge train of the Japan Imaging Society distribution is clearly specified are stirred for 10 minutes with a ball mill, and then the charge is measured. . The relationship between the charge train of each carrier and the charge when the carrier is used is linearly regressed, and the case where the charge at the point where the carrier charge train becomes 0 is greater than 0 and the case where it is less than 0 is evaluated as the negative polarity. did.
The polarity of the external additive was determined by externally adding an amount such that the coverage was 100% to the toner base particles, and performing the same evaluation as described above.
The amount C (%) of the external additive added to the toner was calculated by the following formula using Dt (toner particle size), ρt (toner specific gravity), Da (external additive specific gravity), and ρa (external additive specific gravity).
C = 100 × (2 × 3 ^1/2 × Dt × ρt) / (3 × Da × ρa)
Table 1 shows the amount of additive added as “Cov (%)”.

(Evaluation of calcium carbonate discharge rate A)
Although the initial discharge rate A _I and the discharge rate A _{A with} time were repeated, they were measured as follows.
・ Initial discharge rate (initial A) A _I
A toner to which 0.5% by weight of calcium carbonate (Softon 3200: manufactured by Shiraishi Calcium Co., Ltd.) is added is prepared, and an unfixed image having an image density of 100% is output. It was collected toner from an unfixed image, when the content ratio of the measured calcium carbonate by X-ray fluorescence analysis and X (wt%), the initial discharge rate A _I of calcium carbonate can be obtained from the following expression.
Initial discharge rate A _I = X / 0.5
・ Aging rate (A) A _A
Similarly, the time-dependent discharge rate A _{A of} calcium carbonate is similarly obtained as follows. That is, the time-dependent discharge rate A _A of calcium carbonate can be obtained as follows using the deteriorated toner after 3 hours of idling and using the same method as described above.
Aging rate A _A = X / 0.5
The measurement conditions for fluorescent X-rays are as follows.
The calcium carbonate content in the toner was measured by the following method. That is, using a fluorescent X-ray analyzer (XRF-1500, manufactured by Shimadzu Corporation), 0.3 g of toner as a sample was molded into a cylindrical shape with a diameter of 10 mm, a tube voltage of 40 kV, a tube current of 70 mA, and measurement. A mass-based composition ratio was calculated in consideration of the element mass from the calcium net strength obtained by analyzing all elements under the conditions of an area of 10 mmφ and a measurement time of 15 minutes, and the amount of calcium was determined.

(Actual machine evaluation)
Evaluation was performed at an image density of 10% using DocuPrintP300d manufactured by FujiXerox, using 4200 paper manufactured by Xerox Business under an environment of 30 ° C./80% RH.
Targeting 12,000 sheets, images were checked every 1,000 sheets, and the stage where severe image defects occurred was defined as the final life. Further, although not a serious image defect, the number of occurrences of slight toner scattering in the background portion was defined as the toner scattering life, and both were evaluated. When there was no problem with 1200 sheets, “> 12” was described, and no further processing was performed.
Needless to say, it is better to have a large number of images that do not cause image defects, but it can be said that there is no problem in the final life of 9,000 or more, more preferably 10,000 or more, and even more preferably 11,000 or more. It is.
The obtained results are shown in Table 1 together with the toner formulation.
Abbreviations in the table are as follows: For the binder resin, PES represents a polyester resin, and St represents a styrene acrylic resin.

  1, 1Y, 1M, 1C, 1K: electrophotographic photosensitive member (image carrier), 2Y, 2M, 2C, 2K: charging roll, 3: exposure device, 4, 4Y, 4M, 4C, 4K: developing device, 5Y , 5M, 5C, 5K: primary transfer roll, 20: intermediate transfer belt, 22: drive roll, 24: backup roll, 26: secondary transfer roll, 28: fixing roll, 30: cleaning unit, 32: transfer roll, 40: tray (recording medium tray), 50: housing, 52: developing roll, 54: bias power source, 56: developer scraping member, 58: toner layer regulating member, 60: agitator, 62: housing, 64: Developer, 100: Image forming apparatus

Claims (10)

Toner base particles , small-diameter external additive, and 15-30 parts by weight of silicone oil on the surface with respect to 100 parts by weight of large-diameter external additive, and a large-diameter external additive having negative chargeability And
A non-magnetic one-component toner having a calcium carbonate discharge rate of 0.8 or more determined by the following method .
The calcium carbonate discharge rate is determined as follows.
A toner is prepared by adding 0.5% by weight of calcium carbonate to the non-magnetic one-component toner, and an unfixed image having an image density of 100% is output. When toner is collected from an unfixed image and the content of calcium carbonate measured by fluorescent X-ray analysis is X (% by weight), the discharge rate A of calcium carbonate can be obtained by the following equation.
Emission rate A = X / 0.5   2. The nonmagnetic one-component toner according to claim 1, wherein the toner base particle is a chemical toner having a volume average particle diameter of 3 to 10 μm and a shape factor SF <b> 1 of 110 to 135. 3.   The nonmagnetic one-component toner according to claim 1, wherein the toner base particles are positively charged.   The non-magnetic one-component toner according to claim 1, wherein the toner base particles have a polymer containing a nitrogen atom on the surface thereof.   The non-magnetic one-component toner according to claim 1, wherein the small-diameter external additive has a positive charging property.   The nonmagnetic one-component toner according to any one of claims 1 to 5, which is for an image forming apparatus having no cleaning blade. An electrostatic charge image developer comprising the non-magnetic one-component toner according to claim 1. 7. A developing unit that is detachable from the image forming apparatus, contains the nonmagnetic one-component toner according to claim 1, and holds and conveys the nonmagnetic one-component toner. Characteristic process cartridge. A latent image forming step for forming an electrostatic latent image on the surface of the image carrier;
A developing step of developing the electrostatic latent image formed on the surface of the image carrier with toner to form a toner image;
A transfer step of transferring the toner image onto the surface of the transfer target; and
A fixing step of fixing the toner image transferred to the surface of the transfer target,
Does not include a cleaning process with a cleaning blade,
The image forming method, wherein the toner is the non-magnetic one-component toner according to claim 1. An image carrier,
Charging means for charging the image carrier;
Exposure means for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier;
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image from the image carrier to the surface of the transfer target;
Fixing means for fixing the toner image transferred to the surface of the transfer target,
The image carrier does not have a cleaning blade,
An image forming apparatus, wherein the toner is the non-magnetic one-component toner according to claim 1.

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