JP2015004802A - Toner for electrostatic charge image development, electrostatic charge image developer, process cartridge, image forming method, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that can reduce toner contamination inside an image forming apparatus.SOLUTION: There is provided a toner for electrostatic charge image development that includes toner base particles containing a binder resin and an external additive, and contains, as the external additive, fatty acid metal salt particles having a water-soluble polymer attached to the surface. The toner for electrostatic charge image development is preferably a non-magnetic one-component toner, and the fatty acid metal salt is preferably a saturated fatty acid metal salt having a carbon number of 12 to 22.

Description

  The present invention relates to an electrostatic charge image developing 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 discloses a positively chargeable toner for electrostatic charge development in which metal soap particles are surface-treated with a silane compound and externally added to positively chargeable toner particles.
Patent Document 2 discloses a toner in which a fatty acid metal salt is externally added to a toner particle containing a binder resin and a colorant, and a weight-based average particle diameter D4 (μm) of the toner particle and a volume-based of the fatty acid metal salt. When the average particle diameter Dv (μm) is satisfied, the relationship of 0.02 ≦ Dv / D4 ≦ 0.20, 4.0 ≦ D4 ≦ 9.0, 0.15 ≦ Dv ≦ 0.90 is satisfied, and the toner particles A toner satisfying the relationship of + 20 ≦ Q1 ≦ + 150 and 15 ≦ | Q1−Q2 | ≦ 200, assuming that the charge amount Q1 (mC / kg) and the charge amount Q2 (mC / kg) of the fatty acid metal salt are disclosed. .
Patent Document 3 describes that (1) negatively chargeable hydrophobic silica fine particles having a BET specific surface area of 80 to 300 m ² / g on spherical toner base particles composed of at least a binder resin and a colorant, and (2) a BET specific surface area. Negatively chargeable hydrophobic spherical silica fine particles having a number average primary particle size of 80 to 150 nm and (3) hydrophobic titanium oxide fine particles having a number average primary particle size of 10 to 30 nm (5 to 40 m ² / g) 4) Disclosed is a negatively chargeable one-component toner externally treated with α-type alumina fine particles having a BET specific surface area of 4 to 15 m ² / g and (5) metal soap particles having a number average primary particle size of 1.5 μm or less.

JP 2004-206062 A JP 2010-160229 A JP 2007-147799 A

  An object of the present invention is to provide a toner for developing an electrostatic charge image that can reduce toner contamination in an image forming apparatus.

Said subject was solved by the means as described in <1>, <8>, <9>, <10> and <11> below. It is described below together with <2> to <7> which are preferred embodiments.
<1> An electrostatic charge comprising toner base particles containing a binder resin and an external additive, wherein the external additive contains fatty acid metal salt particles having a water-soluble polymer attached to the surface. Image developing toner,
<2> The electrostatic image developing toner according to <1>, which is a non-magnetic one-component toner,
<3> The electrostatic image developing toner according to <1> or <2>, wherein the fatty acid metal salt is a saturated fatty acid metal salt having 12 to 22 carbon atoms.
<4> The volume average particle diameter rt of the toner base particles is 3 to 10 μm, the volume average particle diameter ra of the fatty acid metal salt is 1 to 20 μm, and ra ≧ 0.3 rt, <1> to <3> The toner for developing an electrostatic charge image according to any one of 3),
<5> The water-soluble polymer may be any one of <1> to <4> selected from the group consisting of polyethyleneimine (PEI), polyallylamine (PAA), and PHMB (polyhexamethylene biguanide). The toner for developing an electrostatic image according to claim 1,
<6> The electrostatic image developing toner according to any one of <1> to <5>, further containing metal oxide particles as the external additive,
<7> The toner for developing an electrostatic charge image according to any one of <1> to <6>, which is for an image forming apparatus having a cleaning brush without having a cleaning blade,
<8> An electrostatic charge image developer comprising the electrostatic image developing toner according to any one of <1> to <7>,
<9> Development that is attached to and detached from the image forming apparatus, stores the electrostatic image developing toner according to any one of <1> to <7>, and holds and transports the electrostatic image developing toner. A process cartridge comprising means,
<10> 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 A transfer step of transferring the toner image onto the surface of the transfer member, a fixing step of fixing the toner image transferred to the surface of the transfer member, and a cleaning step of collecting residual toner remaining on the surface of the image carrier,
In the cleaning step, a brush in contact with the image carrier is used without using a blade, and the toner is the electrostatic image developing toner according to any one of <1> to <7>. An image forming method characterized by being,
<11> 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, and 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. A fixing unit, and a cleaning unit that cleans residual toner remaining on the surface of the image carrier, the brush having a contact with the image carrier as the cleaning unit, and having no cleaning blade, An image forming apparatus, wherein the toner is the electrostatic image developing toner according to any one of <1> to <7>.

According to the invention described in <1> above, the toner for developing an electrostatic charge image with less toner contamination of an image forming apparatus such as a toner jet in a process section and a conveyance path around the cartridge as compared with the case where the present configuration is not provided. Can be provided.
According to the invention described in <2> above, it is possible to provide a toner for developing an electrostatic charge image that is a non-magnetic one-component toner with less toner contamination in the image forming apparatus.
According to the invention described in <3> above, it is possible to provide a toner for developing an electrostatic image with less toner contamination in the image forming apparatus as compared with the case where the present configuration is not provided.
According to the invention described in <4> above, it is possible to provide a toner for developing an electrostatic image with less toner contamination in the image forming apparatus as compared with the case where the present configuration is not provided.
According to the invention described in <5> above, it is possible to provide a toner for developing an electrostatic image with less toner contamination in the image forming apparatus as compared with the case where the present configuration is not provided.
According to the invention described in <6> above, it is possible to provide a toner for developing an electrostatic charge image in which toner contamination in the image forming apparatus is particularly small as compared with the case where the present configuration is not provided.
According to the invention described in <7> above, it is possible to provide a toner for developing an electrostatic image with less toner contamination in the image forming apparatus as compared with the case where the present configuration is not provided.
According to the invention described in <8> above, it is possible to provide an electrostatic charge image developer with less toner contamination in the image forming apparatus as compared with the case where this configuration is not provided.
According to the invention described in <9> above, it is possible to provide a process cartridge with less toner contamination in the developing unit as compared with the case where the present configuration is not provided.
According to the invention described in <10> above, it is possible to provide an image forming method in which the toner contamination of the developing portion is less than when the present configuration is not provided.
According to the invention described in <11> above, it is possible to provide an image forming apparatus with less toner contamination in the developing unit as compared with the case where the present configuration is not provided.

1 is a schematic cross-sectional view showing an example of a tandem type image forming apparatus preferably used in the present embodiment. 1 is a schematic diagram illustrating an example of a developing device using a nonmagnetic one-component toner or a nonmagnetic one-component developer according to an exemplary embodiment.

The electrostatic image developing toner of the present embodiment (hereinafter also simply referred to as “toner”) includes toner base particles containing a binder resin and an external additive. It contains fatty acid metal salt particles having molecules attached to the surface.
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.

  The electrostatic image developing toner of the present exemplary embodiment is suitable as a non-magnetic one-component toner, and particularly suitable as a positively charged non-magnetic one-component toner. The non-magnetic one-component toner is preferably used for a non-magnetic one-component contact development method, and more preferably used for an image forming apparatus having a cleaning brush without a cleaning blade.

When printing (image formation) is performed for a long time, the ejection of toner may be recognized inside the image forming apparatus. This phenomenon is frequently observed in an image apparatus that does not have a blade for cleaning the toner remaining on the surface of the image holding member, and is remarkable in a high-temperature and high-humidity environment.
As a result of intensive studies, the present inventors have found that in the image forming apparatus that does not have the cleaning blade, when paper dust is mixed into the toner, the mixed paper powder generates dirt due to toner ejection due to poor layer formation. . It is presumed that such a problem becomes conspicuous under high temperature and high humidity because paper powder absorbs moisture so that the adsorptive power becomes high and is easily taken into the toner.
Further, the present inventors use a cleaning brush to remove paper dust from the image carrier, by attaching a water-soluble polymer to the surface of the external additive and supplying it to the brush. It has been found that the paper dust trapping force of the brush is improved, and that the use of fatty acid metal salt particles as the external additive improves the lubrication function of the brush and is removed from the external additive from the brush.

Patent Document 1 externally adds a fatty acid metal salt to a positively chargeable toner surface-treated with a silane compound for the purpose of recovering image density and obtaining an image free from fogging. The problem cannot be solved satisfactorily.
The numerical range of the weight average particle size of the toner particles and the fatty acid metal salt and the particle size ratio as described in Patent Document 2 are insufficient to solve the above problem.
Even if the metal soap that has not been surface-treated is ablated together with the plurality of external additives described in Patent Document 3, the above problem cannot be sufficiently solved.

As a result of intensive studies, the present inventor includes toner base particles containing a binder resin and an external additive, and the external additive contains fatty acid metal salt particles having a water-soluble polymer attached to the surface. By using the electrostatic charge image developing toner characterized by the above, based on the lubricating action of the fatty acid metal salt and the paper dust trapping property of the water-soluble polymer, the toner is prevented from being blown out and the stains in the image forming apparatus are improved. As a result, the present invention has been completed.
Hereinafter, the present invention will be described in more detail.

1. Toner for developing an electrostatic image The toner for developing an electrostatic image of this embodiment contains toner base particles containing a binder resin and an external additive.
1-1. Toner mother particles In the present embodiment, the toner mother particles contain at least a binder resin and, if necessary, a colorant, a release agent and the like.
Hereinafter, components constituting the toner base particles will be described.

(1) Binder Resin In the present embodiment, the toner base particles contain a binder. 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) is a styrene monomer and / or (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 a binder resin for toner base particles, a polyester resin is also preferably used.
The polyester resin is synthesized by polycondensation of a polycarboxylic acid, preferably a dicarboxylic acid component, and a polyol, preferably a diol component.
As the polyester resin, a linear polyester obtained by polycondensation of diol and dicarboxylic acid is preferable. In addition, as a polyester resin, a commercial item may be used and what was synthesize | combined may be used.
Polyester resins include crystalline polyester resins and non-crystalline polyester resins. In order to impart low-temperature fixability to the toner, it is preferable to use an amorphous polyester resin and a crystalline polyester resin in combination as the binder resin.

“Crystalline polyester resin” refers to a resin having a clear endothermic peak in differential scanning calorimetry (DSC). That is, in differential scanning calorimetry (DSC), it indicates that it has a clear endothermic peak. Specifically, the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C. Means. On the other hand, a resin in which the half-value width of the endothermic peak exceeds 6 ° C. or a resin in which no clear endothermic peak is observed is regarded as non-crystalline (non-crystalline). When the crystalline resin shows a plurality of melting peaks, the maximum peak is taken as the melting temperature.
Moreover, the glass transition temperature of an amorphous resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.

The polycarboxylic acid and polyol used for the synthesis of the crystalline polyester resin will be described.
The polycarboxylic acid component preferably contains an aliphatic dicarboxylic acid. For example, succinic 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, 1,10-undecanedicarboxylic acid Acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc., or lower alkyl esters thereof, An acid anhydride is mentioned. Further, it may contain a dicarboxylic acid component having an ethylenically unsaturated bond such as fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid.

  On the other hand, the polyol component preferably contains an aliphatic diol, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane. Diol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanedi Examples include, but are not limited to, all, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and the like.

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, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability.

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

The polycarboxylic acid and polyol used for the synthesis of the amorphous polyester resin will be described.
As a raw material monomer for an amorphous polyester resin (also referred to as “amorphous polyester resin”), a dihydric or higher secondary alcohol and / or a divalent or higher aromatic carboxylic acid compound is preferable. Examples of the dihydric or higher secondary alcohol include a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol A, propylene glycol, 1,3-butanediol, and glycerol. In these, the propylene oxide adduct of bisphenol A and / or the ethylene oxide adduct of bisphenol A are preferable.
As the divalent or higher aromatic carboxylic acid compound, terephthalic acid, isophthalic acid, phthalic acid and trimellitic acid are preferable, and terephthalic acid and trimellitic acid are more preferable.

There are no particular limitations on the method for producing the polyester resin, regardless of crystallinity and non-crystallinity, and the polyester resin can be produced by a general polyester polymerization method in which a polyol component and a polycarboxylic acid component are reacted. Examples include polycondensation, transesterification, and the like. Further, it is preferable to use a polycondensation catalyst such as a metal catalyst or a Bronsted acid catalyst.
When the polyester resin directly polycondenses the polyol and the polycarboxylic acid, for example, the polyol and the polycarboxylic acid, a catalyst as necessary, a reaction vessel equipped with a thermometer, a stirrer, and a flow-down condenser When heated at 150 ° C. to 250 ° C. in the presence of an inert gas (nitrogen gas, etc.), continuously removes by-product low-molecular compounds out of the reaction system, and reaches a predetermined acid value The reaction is stopped by cooling, cooled, and the desired reactant is obtained.

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 slope.

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 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 may be used as the colorant, and may be arbitrarily selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, dispersibility in the toner, and the like.
The colorant may be a dye or a pigment, but is preferably a pigment from the viewpoint of light resistance and water resistance. The colorant is not limited to a colored colorant, and may be a white colorant or a colorant exhibiting a metallic color.

For example, in cyan toner, as the colorant, for example, C.I. I. Pigment Blue 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 13, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 17, 23, 60, 65, 73, 83, 180, C.I. I. Vat cyan 1, 3 and 20, etc., bitumen, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, first sky blue, indanthrene blue BC cyan pigment, C.I. I. Cyan dyes such as solvent cyan 79 and 162 are used.
In the magenta toner, as the colorant, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 70, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 185, 202, 206, 207, 209, 238, etc., pigment violet 19 magenta pigments, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 100, 109, 121, C . I. Disper thread 9, C.I. I. Basic Red 1, 2, 9, 9, 13, 14, 15, 17, 17, 18, 22, 23, 24, 27, 29, 32, 34, the same 35, 36, 37, 38, 39, 40, etc. Magenta dyes, etc., Bengala, Cadmium Red, Lead Tan, Mercury Sulfide, Cadmium, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red, Calcium Salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B and the like are used.
In the yellow toner, as the colorant, for example, C.I. I. Pigment Yellow 2, 3, 15, 15, 17, 74, 93, 97, 128, 155, 180, 185, 139, and the like are used.
In the black toner, as the colorant, for example, carbon black, activated carbon, titanium black, magnetic powder, Mn-containing nonmagnetic powder, or the like is used. Further, black toner may be obtained by mixing yellow, magenta, cyan, red, green, and blue pigments.
As the colorant, a surface-treated colorant or a pigment dispersant may be used. By selecting the type of the colorant, color toners such as yellow toner, magenta toner, cyan toner and black toner are prepared 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; sorbitol, etc. Polyhydric alcohols; Fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; Saturated fatty acids such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide Unsaturated fatty acid amides such as bisamides, ethylenebisoleic acid amide, hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; Aromatic bisamides such as acid amide and N, N′-distearylisophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (generally referred to as metal soap); Waxes grafted to aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; Partially esterified products of fatty acids such as behenic acid monoglyceride and polyhydric alcohols; Obtained by hydrogenation of vegetable oils and fats And methyl ester compounds having a hydroxyl group.

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.

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). .

(4) Other components In this embodiment, the toner base particles may contain other components in addition to the above components. Examples of other components include a charge control agent, inorganic particles, organic particles, a lubricant, Examples include abrasives.
<Charge control agent>
In this embodiment, a charge control agent may be added to the toner base particles in order to control the chargeability of the toner. For example, as a positively chargeable charge control agent, a nigrosine dye, a quaternary ammonium salt such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like, phosphonium which is an analog thereof Onium salts such as salts, and lake pigments thereof; triphenylmethane dyes; metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate; Examples thereof include guanidine compounds, imidazole compounds, aminoacrylic resins, and polyethyleneimine.
Examples of the negatively chargeable charge control agent include trimethylethane dyes, metal complex salts of salicylic acid, metal complex salts of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes, etc. Examples include heavy metal-containing acid dyes, calixarene type phenolic condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like.
These charge control agents may be used alone or in combination of two or more.

  The addition amount of the charge control agent is preferably 0.1 to 5% by weight with respect to the toner base particles. When the addition amount is within the above range, good chargeability can be obtained.

  Examples of other additives include additives such as inorganic powder. In this embodiment, the toner base particles preferably do not contain a magnetic material.

1-2. External Additive The toner for developing an electrostatic charge image according to the exemplary embodiment includes toner base particles and an external additive, and includes fatty acid metal salt particles having a water-soluble polymer attached to the surface as the external additive. Features.

(1) Fatty acid metal salt The fatty acid metal salt is an alkaline earth metal salt (IIA) or 12 group (IIB) metal salt of a saturated monocarboxylic acid, such as IIA metal salt (Ca, Mg, etc.) and IIB metal salt ( Zn, Cd, etc.) are preferable, and a calcium salt, magnesium salt or zinc salt of a saturated monocarboxylic acid having 12 to 22 carbon atoms is preferable, and zinc oleate, zinc stearate, and zinc behenate are more preferably exemplified. Zinc stearate is particularly preferred.
The fatty acid metal salt preferably has a volume average particle diameter approximately equal to the volume average particle diameter of the toner base particles.
Here, the volume average particle diameter of the toner base particles and the fatty acid metal salt particles is obtained as a 50% diameter (D50v) in the cumulative frequency of the volume particle diameter measured by a laser diffraction / scattering particle size distribution measuring apparatus.
Specifically, the volume average particle size ra of the fatty acid metal salt is preferably 1 to 20 μm, more preferably 2.5 to 18 μm, and particularly preferably 5 to 15 μm.
The toner mother particles preferably have a volume average particle size rt of 3 to 10 μm, and the fatty acid metal salt preferably has a volume average particle size ra of 1 to 20 μm, and satisfies the relational expression of ra ≧ 0.3 rt. It is more preferable that the relational expression of 2rt ≧ ra ≧ 0.8rt is satisfied.

The reason why the volume average particle size ra of the fatty acid metal salt particles is preferably 0.3 rt or more and 2 rt or less is estimated as follows. That is, when the ra becomes large enough to satisfy the relational expression of ra ≧ 0.3 rt with respect to the volume average particle diameter rt of the toner base particles, the fatty acid metal salt particles are easily released from the toner base particles, and the cleaning brush Therefore, it is considered that the residual toner can be easily collected by the lubrication function, and the toner contamination can be reduced. Further, when the fatty acid metal salt particles exceed 2 rt, it is presumed that the toner stain inhibiting action is also reduced because the external addition action is reduced.
The reason why the water-soluble polymer adhering to the surface of the fatty acid metal salt particles is particularly preferably a synthetic polymer containing a specific amino group such as polyethyleneimine is that it is positively charged with respect to the fatty acid metal salt particles. This is considered to be given.

From the electrostatic charge image developing toner, the toner base particles and the fatty acid metal salt particles are separated based on the specific gravity difference, if necessary, and the particle size is measured.
As an example of the separation method, a toner is mixed in a 5% aqueous solution of a surfactant as a dispersant so that the ratio of the toner and the aqueous solution is about 5: 100, and the dispersion treatment is performed for 1 minute with an ultrasonic disperser. And then centrifuging to settle the toner, and then removing the supernatant. This is added to 100 ml of ISOTON-II (manufactured by Beckman-Coulter), which is an electrolytic solution, to prepare an electrolytic solution in which the sample is suspended.
The electrolyte in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and a particle size distribution of 1 to 30 μm particles using a 50 μm aperture as an aperture diameter is obtained by Coulter Multisizer II (manufactured by Beckman-Coulter). Measure volume average distribution and number average distribution. The number of particles to be measured is 50,000.

A method for producing fatty acid metal salt particles will be described by taking as an example a method for producing zinc stearate particles to which a water-soluble polymer is adhered.
Zinc hydroxide is added little by little to a mixture obtained by adding stearic acid to ethanol and mixing under heating, and mixing with stirring. Thereafter, the mixture is cooled to room temperature, the product is filtered off, ethanol and the reaction residue are removed, and the resulting solid product is dried in a heated vacuum dryer. It is taken out from the dryer and allowed to cool to obtain a solid material of zinc stearate. Since the obtained solid matter has a large particle size, a powder having a volume average particle size of 0.4 to 20 μm is selected by selecting an appropriate number of rotations with a small pulverizer (sample mill) and pulverizing for a necessary time. Shaped zinc stearate particles are obtained.

  By adjusting the rotation speed and time of the sample mill, zinc stearate having a target particle diameter can be obtained.

  Zinc laurate and zinc behenate particles can be obtained in the same manner. Details will be described in Examples. Also, fatty acid magnesium particles can be obtained by using magnesium hydroxide instead of zinc hydroxide.

  As described above, the fatty acid metal salt has a volume average particle diameter ra of preferably 1 to 20 μm, more preferably 2.5 to 18 μm, and particularly preferably 5 to 15 μm.

(2) Water-soluble polymer The above-mentioned “water-soluble polymer” means a polymer in which 1 g or more of the polymer dissolves in 100 g of water at room temperature of 25 ° C., preferably 5 g or more.
The water-soluble polymer is preferably a synthetic polymer containing a primary amino group, a secondary amino group, and a tertiary amino group. Examples of these polyamine-based water-soluble polymers include polyallylamines, polyethyleneimine Polyaminopropyl biguanide (polyhexamethylene biguanide) is preferred, polyallylamines and polyethyleneimines are more preferred, and polyethyleneimine is particularly preferred. Further, these polyamine-based water-soluble polymers preferably have a weight average molecular weight of 10,000 or more, more preferably 1 to 200,000.
These water-soluble polymers are used by being attached to the surface of the fatty acid metal salt particles, and may be used alone or in combination of two or more.
The polyamine-based water-soluble polymer may form a salt at least partially, and examples thereof include adducts of protonic acids. For example, the pH of the aqueous solution of polyethyleneimine may be adjusted with dilute nitric acid so that the pH is in the range of 5 to 7, and after this pH range is maintained, it may adhere to the surface of the fatty acid metal salt particles.
The method for attaching the water-soluble polymer to the surface of the fatty acid metal salt particle is not particularly limited. A simple method is to immerse the fatty acid metal salt particles in an aqueous solution of a water-soluble polymer and then lift and remove the moisture from the adhered solution and dry. The adhesion state of the water-soluble polymer is not particularly limited, and may be a state where the surface of the fatty acid metal salt particle is completely or partially covered, or may be present discontinuously on the particle surface.
The amount of the water-soluble polymer attached to the surface of the fatty acid metal salt particles is preferably 0.1 to 20% by weight and more preferably 1 to 10% by weight with respect to the fatty acid metal salt.
The blending amount of the fatty acid metal salt particles having the water-soluble polymer adhered to the surface thereof with respect to the toner base particles is preferably 0.01 to 10% by weight, and more preferably 0.05 to 5% by weight.

(3) Other External Additives In the present embodiment, the above fatty acid metal salt particles may be added as external additives, and other external additives may be further used in combination. Examples of other external additives include inorganic particles and organic particles.
Inorganic particles are generally used for the purpose of improving fluidity, and metal oxide particles are preferable, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, bengara, Chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, and zirconium oxide are more preferable. Among these, silica particles and titanium oxide particles are preferable, and hydrophobically treated particles are particularly preferable.
The volume average particle diameter of the metal oxide particles is preferably 1 nm or more and 200 nm or less, more preferably 10 to 180 nm, and still more preferably 10 to 120 nm.
The external addition amount of the metal oxide particles is preferably in the range of 0.01 to 20 parts by weight with respect to 100 parts by weight of the toner base particles. The amount is more preferably 0.1 to 10 parts by weight, and still more preferably 0.1 to 5 parts by weight.

<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.

<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 an emulsion aggregation method as the electrostatic image developing toner in this embodiment.

(Chemical toner)
In this embodiment, the toner may be a pulverized toner or a chemical toner, but is preferably a chemical toner. The chemical toner is also called a polymerized toner, and includes the above-described emulsion aggregation method, suspension polymerization method, and 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 mother particles by applying a uniform and long-time shear force in the aggregation step and the coalescence step, and is excellent in that the particle size and shape factor can be controlled. Yes.
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. When a polyester resin, particularly an amorphous polyester resin, is blended in a large amount, a resin particle dispersion can be easily prepared 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, the above 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 the above charge control agent.

  A method for externally adding the fatty acid metal salt particles to the toner base particles is not particularly limited, and a known method can be used. Specifically, for example, a method of externally adding to the toner base particles by a dry method using a mixer such as a V blender or a Henschel mixer can be mentioned.

2. Electrostatic Image Developer The electrostatic image developer of this embodiment contains at least the electrostatic image developing toner of this embodiment. If necessary, other known components may be contained.
The electrostatic charge image developer of the present embodiment is preferably a non-magnetic one-component developer, and can be suitably used as an electrostatic charge image developer by a non-magnetic one-component contact development method. It is preferably used for an image forming apparatus using the (development simultaneous cleaning) method, and particularly preferably used for an image forming apparatus having a cleaning brush without a cleaning blade.
The electrostatic charge image developer according to the exemplary embodiment (hereinafter sometimes simply referred to as “developer”) is not particularly limited as long as it includes the toner according to the exemplary embodiment, and is a one-component developer or a two-component developer. Any developer may be used.

(1) Two-component developer When used as a two-component developer, a toner and a carrier are mixed and used.
The carrier that can be used for the two-component developer is not particularly limited. For example, a magnetic metal such as iron oxide, nickel, or cobalt, a magnetic oxide such as ferrite or magnetite, or a resin having a resin coating layer on the surface of the core material. Examples thereof include a coat carrier and a magnetic dispersion type carrier. The carrier may be a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin.

Examples of the coating resin / matrix resin used for the carrier include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene. Examples include, but are not limited to, acrylic acid copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, and epoxy resins.
Examples of the conductive material include metals such as gold, silver, and copper, and carbon black, as well as titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black. It is not limited.

Examples of the carrier core material include magnetic metals such as iron, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to use the carrier for the magnetic brush method, a magnetic material is used. It may be.
Examples of the volume average particle size of the core material of the carrier include a range of 10 μm to 500 μm, and preferably 30 μm to 100 μm.
Examples of the method of coating the surface of the carrier core material with a resin include a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in a solvent. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include, for example, an immersion method in which a carrier core material is immersed in a coating layer forming solution, a spray method in which a coating layer forming solution is sprayed on the surface of the carrier core material, and a carrier core material. Examples include a fluidized bed method in which a coating layer forming solution is sprayed in a state of being floated by flowing air, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and the solvent is removed. .

  Examples of the mixing ratio (weight ratio) of the toner and the carrier in the two-component developer include a range of toner: carrier = 1: 100 to 30: 100, and a range of 3: 100 to 20: 100. May be.

(2) One-component developer The developer according to this embodiment may be a one-component developer. In the case of a one-component developer, it may be a magnetic one-component developer containing magnetic metal particles, or a non-magnetic one-component developer containing no magnetic metal particles.
In the present embodiment, a non-magnetic one-component developer, in which deterioration of charge maintenance due to paper powder mixing is particularly problematic, is suitable. In the case of a non-magnetic one-component developer, the electrostatic image developing toner of this embodiment can be used as a developer (non-magnetic one-component developer) as it is.

3. Process Cartridge, Image Forming Method, and Image Forming Apparatus An image forming method according to the present embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of an image carrier, a developer layer on a developing roll, and the image A developing process for developing the electrostatic latent image by contacting the holding body to form a toner image, a transferring process for transferring the toner image to the transfer target, and a fixing process for fixing the toner image on the transfer target And cleaning the residual toner remaining on the surface of the image carrier with a brush instead of a blade, wherein the toner is an electrostatic charge image developing toner of the present embodiment or the developer is a static of the present embodiment. It is a charge image developer.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that forms an electrostatic latent image on the charged surface of the image carrier, A developing unit that develops the electrostatic latent image as a toner image with a developer containing toner; a transfer unit that transfers the toner image formed on the surface of the image holding member to the surface of the transfer target; A fixing unit that fixes the toner image transferred to the surface of the transfer member; and a cleaning unit that cleans residual toner remaining on the surface of the image holding member. The cleaning unit is brought into contact with the image holding member. The toner is an electrostatic charge developing toner according to this embodiment, or the developer is an electrostatic charge image developer according to this embodiment.

  Each process and each means are general per se, and are described in, for example, Japanese Patent Application Laid-Open No. 2012-203369. Note that the image forming method of the present embodiment can be carried out using a known image forming apparatus such as a copying machine or a facsimile machine.

The latent image forming step is a step of forming an electrostatic latent image on an image carrier (photoconductor).
The developing step is a step of developing the electrostatic latent image with a developer layer on a developer holding member to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developing toner of this embodiment.
The transfer step is a step of transferring the toner image onto a transfer target. Examples of the transfer medium in the transfer process include an intermediate transfer medium and a recording medium such as paper.
In the fixing step, for example, there is a method of forming a copy image by fixing the toner image transferred onto the transfer paper by a heating roller fixing device in which the temperature of the heating roller is set to a constant temperature.
As the recording medium, known media can be used, for example, paper used for electrophotographic copying machines, printers, OHP sheets, etc. For example, the surface of plain paper is made of resin, etc. Coated coated paper, art paper for printing, and the like can be suitably used.
The cleaning process of this embodiment does not have a cleaning blade for removing the electrostatic charge image developer remaining on the image carrier, but uses a cleaning brush in contact with the image carrier.

In the image forming method of the present embodiment, a brush cleaning process in which the pressure on each individual toner is small is used as the residual toner cleaning process on the image carrier.
The brush cleaning process is preferable because the residual toner does not adhere to the image carrier because the pressure on the residual toner is small. For this reason, unlike the case where blade cleaning is used, there is no concern that residual toner will flow due to the stress from the cleaning blade and adhere to the photoreceptor, so-called filming or the like.
The brush cleaning means used in the present embodiment is a toner removing member having a brush member, and takes a form according to the purpose, such as a fixed brush such as a brush, or a rotating brush used by rotating fibers arranged in a cylindrical shape. be able to. In addition, a conductive brush used by applying a voltage using conductive fibers can also be used.
Brush fibers include natural cellulose fibers, regenerated cellulose fibers such as rayon, nylon fibers, polypropylene fibers, polyester fibers, polyurethane fibers, polyolefin fibers, acrylic fibers, polyamide fibers, polyamideimide fibers, polyetheramide fibers, polyphenylene sulfide fibers, Examples thereof include polybenzimidazole fiber and polyvinyl fiber.

  The image forming method of the present embodiment may further include a recycling step. The recycling step is a step of transferring the electrostatic image developing toner collected in the cleaning step to the 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 cleaning process using a blade may be omitted, and the present invention may be applied to a recycling system that collects toner simultaneously with development.

Note that the image forming apparatus according to the present exemplary embodiment includes at least the image holding member, the charging unit, the exposure unit, the developing unit, the transfer unit, the fixing unit, and the cleaning unit as described above. Although it does not specifically limit, The static elimination means etc. may be included as needed.
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 forming apparatus according to the present exemplary embodiment may include units and apparatuses 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 that has passed 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 near 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.

  Note that one end of the toner layer regulating member 58 is fixed to the opening of the housing 62 so as to close the opening of the housing 62. Further, the side opposite to the side where the toner layer regulating member 58 is attached (the upper side of the opening) (the lower side of the opening) of the casing 62 covers the lower side of the developing roll 52 and the developer scraping member 56. It is configured as follows. Here, the developer (electrostatic image developer) 64 is disposed so as to be deposited on the lower side of the casing 62, and a space between the lower side of the developing roll 52 and the lower side of the opening of the casing 62. Are deposited so as to cover the toner 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, an external additive recovery agent is present on the developing roll 52 that is in contact with the image carrier 1, and the external additive is brought into contact with the image carrier by contacting the external additive recovery agent and the external additive. 1 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.

Example 1
(Preparation of toner base particles)
<Preparation of various dispersions>
<Preparation of Colorant Dispersion (1)>
<Preparation of black pigment dispersion>
Black pigment (# 25, manufactured by Mitsubishi Chemical Corporation, 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 are mixed, 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 did. The pigment concentration of the dispersion was 23%.

<Preparation of polyester resin particle dispersion (1)>
-Dimethyl adipate: 74 parts-Dimethyl terephthalate: 192 parts-Bisphenol A ethylene oxide 2-mole adduct: 216 parts-Ethylene glycol: 38 parts-Tetrabutoxy titanate (catalyst): 0.037 parts

The above components were placed in a heat-dried two-necked flask, and nitrogen gas was introduced into the container, and the temperature was raised while stirring in an inert atmosphere. Then, a copolycondensation reaction was performed at 160 ° C. for 7 hours, and then gradually until 10 Torr. The temperature was raised to 220 ° C. while reducing the pressure to 4 hours. The pressure was returned to normal pressure, 9 parts of trimellitic anhydride was added, the pressure was gradually reduced to 10 Torr, and the pressure was maintained at 220 ° C. for 1 hour to synthesize polyester resin (1).
It was 65 degreeC when the glass transition temperature of the obtained polyester resin (1) was measured using the differential scanning calorimeter (DSC). When the molecular weight of the obtained polyester resin (1) was measured using GPC, the weight average molecular weight (Mw) was 12,000 and the number average molecular weight (Mn) was 4,000.

  Next, the obtained polyester resin (1): 160 parts, ethyl acetate: 233 parts, and sodium hydroxide aqueous solution (0.3N): 0.1 part were put into a separable flask and heated at 70 ° C. A resin mixed solution was prepared by stirring with a motor (manufactured by Shinto Kagaku Co., Ltd.). While further stirring this resin mixture, 373 parts of ion-exchanged water was gradually added, phase-inversion emulsification and solvent removal were carried out to obtain a polyester resin particle dispersion (1) (solid content concentration: 30%). The volume average particle diameter of the resin particles in the dispersion was 160 nm.

<Preparation of polyester resin particle dispersion (2)>
-Bisphenol A ethylene oxide 2-mole adduct: 114 parts-Bisphenol A propylene oxide 2-mole adduct: 84 parts-Fumaric acid dimethyl ester: 75 parts-Dodecenyl succinic acid: 19.5 parts-Trimellitic acid: 7.5 parts

The above components were put into a flask equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectifying tower. After 1 hour, the temperature was raised to 190 ° C., and the reaction system was stirred, and then dibutyltin oxide 3.0 Department was put in. Further, 6 hours were required while distilling off the generated water, the temperature was raised from 190 ° C. to 240 ° C., and the dehydration condensation reaction was continued at 240 ° C. for another 2 hours to synthesize polyester resin (2).
The obtained polyester resin (2) had a glass transition temperature of 57 ° C., an acid value of 15.0 mgKOH / g, a weight average molecular weight (Mw) of 58,000, and a number average molecular weight (Mn) of 5,600.

  Next, the obtained polyester resin (2): 160 parts, ethyl acetate: 233 parts, and sodium hydroxide aqueous solution (0.3N): 0.1 part were put into a separable flask and heated at 70 ° C. A resin mixed solution was prepared by stirring with a motor (manufactured by Shinto Kagaku Co., Ltd.). While further stirring this resin mixture, 373 parts of ion-exchanged water was gradually added to effect phase inversion emulsification and solvent removal to obtain a polyester resin particle dispersion (2) (solid content concentration: 30%). The volume average particle diameter of the resin particles in the dispersion was 180 nm.

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

<Production of toner>
Ion-exchanged water: 1,000 parts by weight Polyester resin particle dispersion (1): 100 parts by weight Polyester resin particle dispersion (2): 100 parts by weight Release agent dispersion (1): 30 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd. Neogen RK, 20% by weight): 5 parts by weight The above components are put into a reaction vessel equipped with a thermometer, pH meter, and stirrer, and the temperature is controlled from the outside with a mantle heater. However, it was kept for 30 minutes at a temperature of 30 ° C. and a stirring rotational speed of 150 rpm.
15 parts by weight of the colorant dispersion (1) (20% by weight of the total toner) was added and held for 5 minutes. The 1.0 wt% nitric acid aqueous solution was added as it was, and the pH in the aggregation process was adjusted to 3.0.

While dispersing with a homogenizer (manufactured by IKA Japan: Ultra Tarax T50), 0.4 parts by weight of polyaluminum chloride was added, the temperature was raised to 50 ° C. while stirring, and the particle size was measured. The diameter was 5.5 μm. Thereafter, 110 parts by weight of the polyester resin particle dispersion (1) and 73 parts by weight of the polyester resin particle dispersion (2) were additionally added.
Thereafter, the pH was adjusted to 9.0 using a 5% by weight aqueous sodium hydroxide solution, the temperature was raised to 90 ° C. at a rate of temperature increase of 0.05 ° C./min, held at 90 ° C. for 3 hours, and then cooled. Filtration, further redispersion with ion-exchanged water, filtration, washing repeatedly until the electrical conductivity of the filtrate is 20 μS / cm or less, and then vacuum drying in an oven at 40 ° C. for 5 hours, Toner particles were obtained. The obtained toner base particles 1 had a volume average particle diameter of 7.0 μm. The volume average particle diameter of the toner base particles 2 obtained by the same method as described above was 5.0 μm, except that the holding time at 90 ° C. was 2 hours.

The obtained wet cake-like toner base particles were redispersed in ion-exchanged water so that the solid content concentration was 10%. While stirring, a 1% aqueous solution of a charge control agent Bontron P-51 (manufactured by Orient Chemical Co., Ltd.) corresponding to 0.035% of the solid weight of the toner base particles was added over 5 minutes. After stirring, the dispersion was filtered, washed with ion-exchanged water, and then dried using a vacuum dryer to obtain positively charged toner mother particles 1.
Except that the charge adjusting agent is Bontron S-22, the charge is adjusted in the same manner as the toner base particles 1 to obtain negatively chargeable toner base particles 3.

<Zinc stearate particles 1 with polyethyleneimine adhering to the surface>
1,422 parts of stearic acid was added to 10,000 parts of ethanol, and 507 parts of zinc hydroxide was added little by little to the mixture mixed at 75 ° C. After stirring, the mixture was stirred for 1 hour. Thereafter, the mixture was cooled to 20 ° C., the product was filtered off to remove ethanol and reaction residues, and the taken out solid product was dried at 150 ° C. for 3 hours in a heating type vacuum dryer. After taking out from the dryer and allowing to cool, a solid body of zinc stearate was obtained. Since the obtained solid has a large particle size, it is pulverized for 60 seconds at 6,000 rpm using SK-M10 (manufactured by Kyoritsu Riko Co., Ltd.) as a small pulverizer (sample mill), and the volume average particle size Zinc stearate particles 1 having a diameter of 6 μm were obtained.
The rotation speed and time of the sample mill were adjusted to obtain zinc stearate particles having a particle size as shown in Table 1.

<Surface adhesion of water-soluble polymer>
5 g of the obtained fatty acid metal salt particles were dispersed in 400 ml of an aqueous solution and adjusted to pH8. Next, a solution in which 0.05 g of polyethyleneimine (PEI) (Epomin manufactured by Nippon Shokubai Co., Ltd.) was dissolved in a 50 ml aqueous solution was appropriately stirred and then solids were filtered off and washed with ionized water. A solid was obtained. Thereafter, it was dried using a freeze-type vacuum dryer to obtain zinc stearate particles 1a having polyethyleneimine adhered to the surface.

The zinc stearate particles 1b with PHMB attached to the surface were prepared in the same manner as above except that PHMB (polyhexamethylene biguanide) (BG-1 manufactured by Sanyo Chemical Co., Ltd.) was used instead of PEI as the water-soluble polymer. Obtained.
Furthermore, zinc stearate particles 1c having P-70 adhered to the surface were obtained by the same method as above except that the water-soluble polymer was modified polyamide (AQ nylon; P-70 manufactured by Toray Industries, Inc.).

(Zinc laurate)
Zinc laurate particles produced in the same manner as the zinc stearate particles 1 to which the water-soluble polymer was adhered except that lauric acid was used instead of stearic acid were obtained.

(Zinc behenate)
Similarly, behenic acid was used to obtain zinc behenate particles.

(Magnesium stearate)
Magnesium stearate particles produced in the same manner as the zinc stearate particles 1 to which the water-soluble polymer was adhered except for using magnesium hydroxide instead of zinc hydroxide were obtained.

<Method for adjusting toner 1>
To 100 parts by weight of toner base particles, 1.0 part by weight of zinc stearate particles 1 and 2.0 parts by weight of hydrophobic silica (TG7120 manufactured by Cabot Corporation) as metal oxide particles and hydrophobic titanium oxide (Japan) 1.0 part by weight of Aerosil Co., Ltd., T805) was mixed and blended at 10,000 rpm for 30 seconds using a sample mill. Thereafter, toner 1 was prepared by sieving with a vibrating sieve having an opening of 45 μm.

<Developer>
The carrier was prepared by coating a 50 μm Mn—Sr core with 1.5% solid content of a silicone resin (manufactured by Toray-Dow Corning, SR2411) and using it in a two-component system.

(Examples 2 to 15 and Comparative Examples 1 and 2)
Separately, as shown in Table 1, toners 2 to 12 and comparative toners 13 and 14 were prepared by changing toner base particles and external additives.

(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 or more and 50 mg or less of a measurement sample was added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added into the electrolyte solution in a range of 100 ml to 150 ml.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size of particles having a particle size in the range of 2 μm to 60 μm using a Coulter Multisizer II with an aperture diameter of 100 μm. Measure the distribution. 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. .

(Toner dirt evaluation)
The evaluation of stains in the image forming apparatus was carried out by remodeling DocuPrint P300d manufactured by Fuji Xerox Co., Ltd., which employs a non-magnetic one-component contact development method and a simultaneous development cleaning method. Evaluation is performed to check for toner blowout and contamination in the process area and transport path around the cartridge after printing 1,000 sheets of XC4200 paper (manufactured by Xerox) on paper in a humid environment (28 ° C, 85%). It was.

<Toner stain determination>
A: No problem B: No problem C: Slight dirt is observed D: It is determined that there is a problem due to the occurrence of dirt.

  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 (11)

Including toner base particles containing a binder resin and an external additive,
A toner for developing an electrostatic image, wherein the external additive contains fatty acid metal salt particles having a water-soluble polymer adhering to the surface thereof.   The electrostatic image developing toner according to claim 1, which is a non-magnetic one-component toner.   The toner for developing an electrostatic charge image according to claim 1, wherein the fatty acid metal salt is a saturated fatty acid metal salt having 12 to 22 carbon atoms.   4. The volume average particle size rt of the toner base particles is 3 to 10 μm, the volume average particle size ra of the fatty acid metal salt is 1 to 20 μm, and ra ≧ 0.3 rt. Item 2. The toner for developing an electrostatic charge image according to Item 1.   The electrostatic charge image developing toner according to claim 1, wherein the water-soluble polymer is selected from the group consisting of polyethyleneimine, polyallylamine (PAA), and PHMB (polyhexamethylene biguanide). .   The electrostatic image developing toner according to claim 1, further comprising metal oxide particles as the external additive.   The electrostatic image developing toner according to claim 1, which is for an image forming apparatus having a cleaning brush without a cleaning blade. An electrostatic image developer comprising the electrostatic image developing toner according to claim 1. A developing unit that is detachably attached to the image forming apparatus, contains the electrostatic image developing toner according to claim 1, and holds and conveys the electrostatic image developing 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;
A fixing step of fixing the toner image transferred to the surface of the transfer target; and
A cleaning step of collecting residual toner remaining on the surface of the image carrier,
In the cleaning process, a blade that is in contact with the image carrier is used without using a blade,
An image forming method, wherein the toner is the electrostatic image developing 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;
Cleaning means for cleaning residual toner remaining on the surface of the image carrier,
Having a brush in contact with the image carrier as the cleaning means, without a cleaning blade,
An image forming apparatus, wherein the toner is the electrostatic image developing toner according to claim 1.

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