JP2013072969A - Image forming method, image forming apparatus, toner set for electrostatic charge image development, electrostatic charge image developer set, toner cartridge set and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method for achieving formation of a build-up image that gives a visually and tactually enhanced impression.SOLUTION: The image forming method includes a first image forming step of forming a chromatic toner image on a recording medium, a second image forming step of forming a transparent toner image with a transparent toner for electrostatic charge image development on the chromatic toner image on the recording medium, and a fixing step of fixing the chromatic toner image and the transparent toner image on the recording medium. The volume average particle diameter Dc of the chromatic toner for electrostatic charge image development and the volume average particle diameter Dt of the transparent toner for electrostatic charge image development satisfy the relationship of formulae (A1):18≤Dt≤30 and (A2):2.5≤Dt/Dc≤9. The aluminum content Alc of the chromatic toner for electrostatic charge image development and the aluminum content Alt of the transparent toner for electrostatic charge image development satisfy the relationship of formula (B1):1.2≤Alt/Alc≤4.0.

Description

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

  A method of visualizing image information through an electrostatic latent image by electrophotography or the like is currently used in various fields. In electrophotography, image information is formed as an electrostatic latent image on the surface of a latent image carrier (photoreceptor) by charging and exposure processes, and the toner image is developed on the surface of the photoreceptor using a developer containing toner. The toner image is visualized as an image through a transfer step of transferring the toner image to a recording medium (transfer object) such as paper and a fixing step of fixing the toner image on the surface of the recording medium.

  In this electrophotographic method, in addition to colored toner, transparent toner is used to correct the gloss difference in the image surface, control the gloss on the transfer paper surface, and correct the image density and toner adhesion amount. Attempts have been made (for example, Patent Documents 1 to 3).

In addition, for example, in order to reduce the adhesion between papers, a technique is also known in which a convex portion is formed at the end of a recording medium (transfer object) with a transparent toner (for example, Patent Document 4).
For example, a technique for forming a lens-shaped image using transparent toner is also known (for example, Patent Document 5).

JP 2002-236396 A JP 2005-99122 A JP 2005-274614 A JP-A-10-301339 Special table 2010-533318 gazette

  An object of the present invention is to provide an image forming method that realizes formation of a raised image that gives an impression that is visually and textured.

The above problem is solved by the following means. That is,
The invention according to claim 1
A first image forming step of forming a colored toner image on a recording medium with a colored toner for developing an electrostatic image including a binder resin, a colorant, and aluminum;
A second image forming step of forming a transparent toner image with a transparent toner for developing an electrostatic charge image containing a binder resin and aluminum on the colored toner image on the recording medium;
A fixing step of fixing the colored toner image and the transparent toner image on the recording medium;
Have
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. An image forming method to satisfy.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0

The invention according to claim 2
The image forming method according to claim 1, wherein the binder resin of the transparent toner for developing an electrostatic charge image is a polyester resin.

The invention according to claim 3
A colored toner image comprising a first developing device containing a first electrostatic image developer containing a colored toner for developing an electrostatic image comprising a binder resin, a colorant and aluminum. First image forming means for forming the image on a recording medium;
A second developing device containing a second electrostatic image developer having a transparent toner for developing an electrostatic charge image containing a binder resin and aluminum; and recording the transparent toner image by the transparent toner for developing an electrostatic charge image Second image forming means for forming on the colored toner image on the medium;
Fixing means for fixing the colored toner image and the transparent toner image on the recording medium;
With
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. An image forming apparatus that fills.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0

The invention according to claim 4
The image forming apparatus according to claim 3, wherein the binder resin of the transparent toner for developing an electrostatic charge image is a polyester resin.

The invention according to claim 5
A colored toner for developing an electrostatic charge image comprising a binder resin, a colorant and aluminum;
A transparent toner for developing an electrostatic image comprising a binder resin and aluminum;
Have
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. Toner set for developing electrostatic charge image.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0

The invention according to claim 6
6. The toner set for developing an electrostatic charge image according to claim 5, wherein the binder resin of the transparent toner for developing the electrostatic charge image is a polyester resin.

The invention according to claim 7 provides:
5. The electrostatic image developing toner according to claim 5, wherein the electrostatic image developing toner includes the colored toner for developing the electrostatic image, and the electrostatic image developing toner according to claim 5. An electrostatic charge image developer set comprising: a second electrostatic charge image developer including the electrostatic charge image developing transparent toner in the set.

The invention according to claim 8 provides:
5. The electrostatic image developing toner set according to claim 5, wherein the electrostatic toner image developing toner set contains the first toner cartridge containing the electrostatic image developing colored toner, and the electrostatic image developing toner set according to claim 5. A second toner cartridge containing the electrostatic toner for developing an electrostatic charge image,
A toner cartridge set that is detachable from the image forming apparatus.

The invention according to claim 9 is:
8. The first developing device containing the first electrostatic image developer in the electrostatic image developer set according to claim 7, and the second electrostatic charge in the electrostatic image developer set according to claim 7. A second developing device containing an image developer,
A process cartridge that is detachable from the image forming apparatus.

According to the first aspect of the present invention, compared with the case where the colored toner for developing an electrostatic image and the transparent toner for developing an electrostatic image do not satisfy the relationship of the above formulas (A1), (A2) and (A3), In addition, it is possible to provide an image forming method that realizes formation of a raised image that gives an impression that is aesthetically enhanced.
According to the second aspect of the present invention, compared to the case where the binder resin of the electrostatic toner for developing an electrostatic charge image is not a polyester resin, an image that realizes the formation of a raised image that gives a visually and texture-enhanced impression is realized. A forming method can be provided.

According to the third aspect of the present invention, the colored toner for developing an electrostatic image and the transparent toner for developing an electrostatic image do not visually satisfy the relationship of the above formulas (A1), (A2), and (A3). In addition, it is possible to provide an image forming apparatus that realizes formation of a raised image that gives an impression that is aesthetically enhanced.
According to the invention of claim 4, compared with the case where the binder resin of the transparent toner for developing an electrostatic charge image is not a polyester resin, an image that realizes formation of a raised image that gives a visually and texture-enhanced impression is realized. A forming apparatus can be provided.

According to the fifth aspect of the invention, the colored toner for developing an electrostatic image and the transparent toner for developing an electrostatic image do not visually satisfy the relationship of the above formulas (A1), (A2), and (A3). In addition, it is possible to provide a toner set for developing an electrostatic charge image that realizes formation of a raised image that gives an impression that is aesthetically enhanced.
According to the sixth aspect of the present invention, compared to the case where the binder resin of the transparent toner for developing an electrostatic charge image is not a polyester resin, the formation of a raised image that gives an impression that is visually and textured is realized. A toner set for developing a charge image can be provided.

  According to the seventh aspect of the present invention, the colored toner for developing an electrostatic image and the transparent toner for developing an electrostatic image do not visually satisfy the relationship of the above formulas (A1), (A2), and (A3). In addition, it is possible to provide an electrostatic charge image developer set that realizes formation of a raised image that gives an impression that is aesthetically enhanced.

  According to the inventions according to claims 8 and 9, compared to the case where the colored toner for developing an electrostatic image and the transparent toner for developing an electrostatic image do not satisfy the relationship of the above formulas (A1), (A2) and (A3), It is possible to provide a toner cartridge set and a process cartridge that realize formation of a raised image that gives an impression that is visually and textured.

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

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

(Toner set for electrostatic image development)
The electrostatic image developing toner set (hereinafter referred to as “toner set”) according to the present embodiment is a colored toner for electrostatic image development (hereinafter simply referred to as “colored toner”) containing a binder resin, a colorant, and aluminum. And a transparent toner for developing an electrostatic image containing a binder resin and aluminum (hereinafter simply referred to as “transparent toner”).
The colored toner is a toner used for a colored toner image and includes a colorant and exhibits a chromatic color.
On the other hand, a transparent toner is a toner used for a transparent toner image formed on a colored toner image for the purpose of forming a raised image. Specifically, a colorant does not include a colorant or includes a colorant. Is a colorless toner having a content of 0.01% by mass or less.

In the toner set according to the present embodiment, the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm), and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm). And satisfying the relationship of the following formulas (A1) and (A2), the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%), and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%). ) Satisfies the relationship of the following formula (B1).
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0

In the toner set according to the present embodiment, the above configuration realizes formation of a raised image that gives an impression that is visually and textured.
The reason for this is not clear, but is thought to be due to the following reasons.

  First, in recent years, since an electrophotographic system capable of producing printed matter on demand has begun to be used in the commercial printing field, it is required to obtain an image that can provide a special effect that has been conventionally performed in the printing field. One of them is, for example, a technique called “lifting printing” in which a transparent resin layer having an image thickness of about 20 μm to 100 μm is formed on a colored image and a rising image that gives a visually and tactilely emphasized impression is printed.

  In boost printing, in order to visually and tactilely enhance a boosted image, it is important that the image has a step difference with respect to the image forming surface of the recording medium and that the gradient angle of the image step is large.

However, when an attempt is made to realize enveloping printing by forming a transparent toner image with a transparent toner on a color toner image with a color toner by an electrophotographic image forming method, It is difficult to carry a large amount of transparent toner, and as a result, the transparent toner-fixed image tends to be thin and it is difficult to make a step difference in the image.
Therefore, in this embodiment, a transparent toner having a larger particle diameter than that of the colored toner is used so as to satisfy the above formulas (A1) and (A2). As a result, a large amount of transparent toner can easily be placed on the colored toner image. When the toner is fixed in this state, a thick transparent toner fixed image is formed on the colored toner fixed image. In comparison, it is considered that a raised print image having a large step is obtained.

On the other hand, if transfer or fixing is performed in a state where a large amount of transparent toner is placed on a colored toner image, the edge of the image tends to collapse due to the pressure at the time of transfer or fixing, and the gradient angle of the step of the image is increased. It is likely to be lost.
Therefore, in the present embodiment, by adjusting the particle size difference (particle size ratio) between the color toner and the transparent toner so as to satisfy the above formulas (A1) and (A2), the pressure at the time of transfer or fixing is adjusted. It is considered that the collapse at the edge of the image is less likely to occur and the gradient angle of the image step is less likely to be lost.

In addition, when fixing is performed with a large amount of transparent toner on the color toner image, the transparent toner formed in the upper layer over the color toner is preferentially subjected to heat at the time of fixing, so it melts more than the color toner. It is considered that the viscosity becomes lower and the flow becomes easier, and as a result, the gradient angle of the step of the image is easily lost.
Therefore, in this embodiment, a transparent toner having a higher aluminum content than the colored toner is used so as to satisfy the above formula (B1). As a result, the degree of ionic cross-linking between the binder resin and aluminum in the toner is higher in the transparent toner than in the colored toner, so that fixing can be performed with a large amount of transparent toner on the colored toner image. Even if the transparent toner preferentially receives heat at the time of fixing, it is difficult for the melting to proceed and the flow due to the decrease in viscosity is suppressed, and as a result, the gradient angle of the image step is unlikely to be lost.

From the above, with the toner set according to the present embodiment, it is considered that formation of a raised image that gives an impression that is visually and textured is realized.
In the toner set according to the present embodiment, the color toner fixed image and the transparent toner fixing are adjusted by adjusting the aluminum content difference (content ratio) between the color toner and the transparent toner so as to satisfy the above formula (B1). It is considered that the difference in glossiness from the image is reduced, and a natural raised print image can be formed.

  In particular, in the toner set according to the present embodiment, by adopting a polyester resin as a binder resin for the transparent toner, it is easy to form a strong ion cross-linked body with aluminum as compared with other resins. Even when preferentially receiving the heat of the time, it is difficult for the melting to proceed and the flow due to the decrease in viscosity is suppressed, and as a result, the gradient angle of the image step is unlikely to be lost. Formation of a raised image which gives an impression that is emphasized in an easy manner.

Hereinafter, the toner set according to the exemplary embodiment will be described in detail.
The toner set according to the present embodiment satisfies the relationship of the following formula (A1), but preferably satisfies the relationship of the following formula (A1-2), and more preferably satisfies the relationship of the following formula (A1-3). .
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A1-2): 20 ≦ Dt ≦ 29
Formula (A1-3): 22 ≦ Dt ≦ 28

The toner set according to the present embodiment satisfies the relationship of the following formula (A2), but preferably satisfies the relationship of the following formula (A2-2), and more preferably satisfies the relationship of the following formula (A2-3). .
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (A2-2): 3.0 ≦ Dt / Dc ≦ 8.0
Formula (A2-3): 3.5 ≦ Dt / Dc ≦ 7.0

The toner set according to the exemplary embodiment preferably satisfies the relationship of the following formula (A3), preferably satisfies the relationship of the following formula (A3-2), and more preferably satisfies the relationship of the following formula (A3-3). Is good.
Formula (A3): 3 ≦ Dc ≦ 10
Formula (A3-2): 3.2 ≦ Dc ≦ 9
Formula (A3-3): 3.4 ≦ Dc ≦ 8

  In the toner set according to the present embodiment, a large amount of transparent toner is formed on the color toner image by satisfying the relations of the above expressions (A1) and (A2), and preferably satisfying the relation of the above relational expression (A3). It becomes easy to be placed, and the collapse at the edge of the image hardly occurs due to the pressure at the time of transfer or fixing.

Here, the volume average particle diameter of each toner is a value measured as the volume average particle diameter of toner particles using a Multisizer II (manufactured by Beckman-Coulter) measuring device. As the electrolytic solution, ISOTON-II (manufactured by Beckman Coulter, Inc.) is used.
For the measured particle size distribution, a cumulative distribution is drawn from the smaller diameter side with respect to the divided particle size range (channel), the particle size that is 16% cumulative with respect to the volume is D16v, and the cumulative particle size is 16% with respect to the number. The particle size is D16p, the particle size is 50% cumulative with respect to the volume is D50v, the particle size is 50% cumulative with respect to the number is D50p, the particle size is 84% cumulative with respect to the volume is D84v, and the particle size is 84% cumulative. The particle size is defined as D84p.
And volume average particle diameter refers to D50v.

On the other hand, the toner set according to the present embodiment satisfies the relationship of the following formula (B1), but preferably satisfies the relationship of the following formula (B1-2), and more preferably satisfies the relationship of the following formula (B1-3). Is good.
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0
Formula (B1-2): 1.5 ≦ Alt / Alc ≦ 3.5
Formula (B1-3): 1.8 ≦ Alt / Alc ≦ 3.0

Further, the toner set according to the present embodiment preferably satisfies the relationship of the following formula (B2), preferably the relationship of the following formula (B2-2), more preferably the relationship of the following formula (B2-3). It is good to satisfy.
Formula (B2): 0.003 ≦ Alc ≦ 0.01
Formula (B2-2): 0.004 ≦ Alc ≦ 0.009
Formula (B2-3): 0.005 ≦ Alc ≦ 0.008

Further, the toner set according to the present embodiment preferably satisfies the relationship of the following formula (B3), preferably the relationship of the following formula (B3-2), more preferably the relationship of the following formula (B3-3). It is good to satisfy.
Formula (B3): 0.004 ≦ Alt ≦ 0.04
Formula (B3-2): 0.006 ≦ Alt ≦ 0.035
Formula (B3-3): 0.008 ≦ Alt ≦ 0.03

  In the toner set according to the present embodiment, the transparent toner gives priority to heat at the time of fixing by satisfying the relationship of the above formula (B1), preferably further satisfying the relationships of the above formulas (B2) and (B3). In this case, melting is difficult to proceed, flow due to a decrease in viscosity is suppressed, and the difference in gloss between the colored toner fixed image and the transparent toner fixed image is reduced.

Here, the aluminum content of each toner is the amount of aluminum relative to the total constituent atomic weight of the toner by fluorescent X-rays, and is a value measured as follows.
First, a sample is obtained by pre-processing the toner 6g by compression molding under a pressure condition of 10 tons for 1 minute with a pressure molding machine. Thereafter, the composition ratio of the target metal element (aluminum) in all the elements in the total element analysis method using a scanning X-ray fluorescence analyzer “ZSX Primus II” manufactured by Rigaku Co., Ltd. atom%).
Measurement conditions are a tube voltage of 60 KV, a tube current of 50 mA, and a measurement time of 40 deg / min.

  Next, components of the color toner and the transparent toner will be described in detail.

  The colored toner includes, for example, colored toner particles and, if necessary, an external additive. The colored toner particles include, for example, at least a binder resin, a colorant, aluminum, and, if necessary, other additives such as a release agent.

  On the other hand, the transparent toner includes, for example, transparent toner particles and, if necessary, an external additive. The transparent toner particles include at least a binder resin, aluminum, and, if necessary, other additives such as a release agent.

  The colored toner and the transparent toner may have the same configuration except for the presence or absence of the colorant, the content thereof, the particle size, and the aluminum content. Therefore, the colored toner and the transparent toner are hereinafter referred to as “toner”. Will be described.

The binder resin will be described.
The binder resin is not particularly limited. For example, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, acrylic Esters having vinyl groups such as lauryl acid, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; single quantities of polyolefins such as ethylene, propylene and butadiene Homopolymer consisting of, or copolymers obtained by combining two or more of these, more mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.

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

  When using a styrene resin, a (meth) acrylic resin or a copolymer resin thereof as a binder resin, the weight average molecular weight Mw is 20,000 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 desirable to use the thing of the range. On the other hand, when a polyester resin is used as the binder resin, a resin having a weight average molecular weight Mw of 5,000 or more and 40,000 or less and a number average molecular weight Mn of 2,000 or more and 10,000 or less may be used. desirable.

The colorant will be described.
The colorant is selected from known colorants according to the intended toner color.
Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like. 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. And cyan dyes such as solvent cyan 79 and 162.

  Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds, perylene compounds, and the like. 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, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 202, 206, 207, and 209, 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 Examples include salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B.

  Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds, and the like. I. And CI pigment yellow 2, 3, 15, 16, 17, 97, 180, 185, 139 and the like.

  Examples of the black colorant include carbon black (acetylene black, furnace black, thermal black, channel black, ketjen black), copper oxide, manganese dioxide, aniline black, titanium black, activated carbon, nonmagnetic ferrite, and magnetite. .

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.

  As content of a coloring agent, the range of 1 to 30 mass parts is desirable with respect to 100 mass parts of binder resin.

Aluminum will be described.
Examples of the aluminum supply source (compound to be added to the toner as an additive) include an aggregating agent that is added when toner particles are produced by an agglomeration and coalescence method.
Examples of the aggregating agent containing aluminum include aluminum chloride, aluminum sulfate, polyaluminum chloride, and polyaluminum hydroxide. In addition, you may add these flocculants as a mere additive instead of a flocculant use.

  The content of aluminum is adjusted so as to satisfy the above formula (B1).

The release agent will be described.
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters. Wax; and the like, but is not limited thereto.

  The melting temperature of the release agent is preferably 50 ° C. or higher and more preferably 60 ° C. or higher from the viewpoint of storage stability. Further, from the viewpoint of offset resistance, the temperature is desirably 110 ° C. or less, and more desirably 100 ° C. or less.

  The content of the release agent is preferably 1 part by mass or more and 15 parts by mass or less, more preferably 2 parts by mass or more and 12 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. Even more desirable.

Other additives will be described.
Examples of other internal additives include magnetic materials, charge control agents, inorganic powders, and the like.

The characteristics of the toner particles will be described.
The toner particles may have a single layer structure or a structure (so-called core / shell structure) constituted by a core part and a coating layer covering the core part.

The external additive will be described.
Examples of the external additive include inorganic particles. Specifically, for example, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO. , CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO · SiO ₂ , K ₂ O · (TiO ₂ ) _n , Al ₂ O ₃ · 2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like. Can be mentioned.

The surface of the external additive may be hydrophobized. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually about 1 part by mass or more and about 10 parts by mass with respect to 100 parts by mass of the inorganic particles, for example.

  The external addition amount of the external additive is preferably 0.5 parts by mass or more and 2.5 parts by mass or less with respect to 100 parts by mass of the toner particles.

Hereinafter, a method for producing a colored toner will be described.
First, colored toner particles may be produced by a dry process (for example, a kneading and pulverizing process), a wet process (for example, an aggregation coalescence method, a suspension polymerization method, a solution suspension granulation method, a solution suspension method, a solution emulsion aggregation method Etc.). There is no restriction | limiting in particular in these manufacturing methods, A well-known manufacturing method is employ | adopted.
Among these, it is preferable to obtain colored toner particles by an aggregation and coalescence method.

Specifically, it is as follows.
In the following description, a method for obtaining colored toner particles containing a colorant and a release agent will be described. The colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.
Further, although a method for obtaining colored toner particles to which an aggregating agent is applied as an aluminum supply source will be described, the present invention is not limited to this.

-Preparation step of resin particle dispersion-
First, together with a resin particle dispersion in which polyester resin particles are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent dispersion in which release agent particles are dispersed are prepared.

  Here, the resin particle dispersion is prepared, for example, by dispersing polyester resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

The surfactant is not particularly limited. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; amine salt type, quaternary ammonium salt type Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

Examples of a method for dispersing polyester resin particles in a dispersion medium in a resin particle dispersion include general dispersion methods such as a rotary shearing homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles used, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the aqueous medium. (W phase) is added to convert the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase and disperse the resin in an aqueous medium in the form of particles. It is.

Examples of the volume average particle diameter of the polyester resin particles dispersed in the resin particle dispersion include a range of 0.01 μm or more and 1 μm or less, and may be 0.08 μm or more and 0.8 μm or less, or 0.1 μm or more. It may be 0.6 μm.
The volume average particle diameter of the resin particles is measured with a laser diffraction particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.). Hereinafter, unless otherwise specified, the volume average particle diameter of the particles is measured in the same manner.

  Examples of the content of the polyester resin particles contained in the resin particle dispersion include 5% by mass to 50% by mass, and may be 10% by mass to 40% by mass.

  In addition, similarly to resin particle dispersion, for example, a colorant dispersion and a release agent dispersion are also prepared. In other words, regarding the volume average particle size of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant dispersion and the release agent dispersed in the release agent dispersion are used. The same applies to the mold agent particles.

-Aggregated particle formation process-
Next, the colorant particle dispersion and the release agent dispersion are mixed together with the resin particle dispersion.
The polyester resin particles, the colorant particles, and the release agent particles are hetero-aggregated in the mixed dispersion, and the polyester resin particles, the colorant particles, and the release agent have a diameter close to that of the target colored toner particles. Agglomerated particles including particles are formed.

Specifically, for example, a flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Thereafter, the polyester resin particles are heated to a glass transition temperature (specifically, for example, a glass transition temperature of the polyester resin particles of −30 ° C. or higher and a glass transition temperature of −10 ° C. or lower), and the particles dispersed in the mixed dispersion liquid. Are aggregated to form aggregated particles.
In the agglomerated particle forming step, for example, the aggregating agent is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, the pH is 2 or more and 5 or less). ), And after adding a dispersion stabilizer as necessary, the heating may be performed.

Examples of the flocculant include surfactants having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, for example, inorganic metal salts and divalent or higher-valent metal complexes. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
Examples of the addition amount of the chelating agent include a range of 0.01 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the polyester resin particles, and 0.1 parts by mass or more and less than 3.0 parts by mass. It may be.

-Fusion / unification process-
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated to, for example, a glass transition temperature or higher of the polyester resin particles (for example, a temperature of 10 to 30 ° C. higher than the glass transition temperature of the polyester resin particles), The aggregated particles are fused and united to form colored toner particles.

Through the above steps, colored toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion liquid in which the aggregated particles are dispersed, the aggregated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the aggregated particles. A process of aggregating to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles. The colored toner particles may be manufactured through a step of forming colored toner particles having a core / shell structure.

Here, after completion of the fusion / unification process, the colored toner particles formed in the solution are dried through a known washing process, solid-liquid separation process, and drying process to obtain colored toner particles.
In the washing step, it is desirable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably used from the viewpoint of productivity. Furthermore, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used.

  The colored toner is produced, for example, by adding an external additive to the obtained dried colored toner particles and mixing them. Mixing is preferably performed by, for example, a V blender, a Henshur mixer, a ladyge mixer or the like. Furthermore, if necessary, coarse particles of colored toner may be removed using a vibration classifier, a wind classifier, or the like.

Next, a transparent toner manufacturing method will be described.
First, the transparent toner particles are preferably manufactured in an aqueous medium because aluminum is easily introduced into the binder resin. Among these, a method for producing a transparent toner is preferably a production method using an aggregation and coalescence method because of excellent controllability of particle size and shape, environmental load and safety.
Hereinafter, a case where the aggregation coalescence method is used as a method for producing transparent toner particles will be described.

  Transparent toner particles obtained by the aggregation coalescence method are prepared by adding a flocculant containing divalent or higher metal ions to a raw material dispersion containing at least a resin particle dispersion in which binder resin particles are dispersed, and heating the raw material dispersion. Agglomeration step for forming aggregated particles therein, a cooling step for cooling the raw material dispersion in which the aggregated particles are formed, a stop step for stopping the growth of the cooled aggregated particles, and the growth of the particle size is stopped by the stop step The agglomerated particles are preferably manufactured through a fusion process in which the aggregated particles are fused by heating.

-Preparation step of resin particle dispersion-
First, in the same manner as in the production of colored toner particles, the resin particle dispersion process is performed in the production of transparent toner particles. However, unlike colored toner particles, it is not necessary to prepare a colorant particle dispersion.

-Aggregated particle formation process-
Next, a flocculant is added to the mixed dispersion obtained by mixing the resin particle dispersion and the release agent fine particle dispersion, and the mixture is heated at a temperature near the glass transition temperature of the binder resin. Then, agglomerated particles are formed by agglomerating particles composed of the respective components.
Aggregated particles are formed, for example, by adding an aggregating agent at room temperature while stirring with a rotary shearing homogenizer.
As the flocculant, a compound having a valence of 2 or more is preferable. Specific examples of the compound include calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, and metal salts such as, and And inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide.
However, considering the stability of aggregated particles by introducing aluminum into the binder resin, the stability of the aggregated particles, the stability of the coagulant against heat and aging, and removal during washing, the coagulant is particularly an aluminum-based aggregate. The agent is good.
Specific examples of the aluminum flocculant include metal salts of inorganic acids such as aluminum chloride, aluminum sulfate, and aluminum nitrate, and inorganic metal salt polymers such as polyaluminum chloride.

The addition amount of these flocculants varies depending on the valence of the charge, but both are small amounts, in the case of monovalent, about 3% by weight or less of the whole aggregate system, in the case of divalent, about 1% by weight or less, In the case of trivalent, it is about 0.5% by weight or less. Since it is desirable that the amount of the flocculant is small, it is desirable to use a compound having a large valence.
The heating temperature in the agglomeration process varies depending on the amount of release agent added, the amount of aggregating agent, etc., and thus cannot be determined unconditionally, but it is necessary to grow the particle size larger than that of a color toner. It is desirable to raise the glass transition temperature to the same level as or slightly above the glass transition temperature. As a rough guide, a range of 0 ° C. or higher and + 10 ° C. or lower is preferable based on the glass transition temperature of the binder resin.

-Cooling process-
Next, when the particle size of the aggregated particles has grown to a predetermined range, it is desirable to cool the aggregated particle dispersion (raw material dispersion containing aggregated particles).
Although the growth of the particle size of the aggregated particles is stopped by a stop step described later, if the stop step is performed without the cooling step, the aggregated particles may be dispersed and the target particle size may not be obtained. This is thought to be because the molecular motion of the binder resin is intense when the temperature is equal to or higher than the glass transition temperature, and the kinetic energy of the molecule becomes larger when the cohesive force due to the flocculant stops working. It is done.
As a standard of the temperature after cooling in the cooling step, it is desirable that the temperature is in the range of −20 ° C. to −10 ° C. based on the glass transition temperature of the binder resin. The cooling rate varies depending on the type / amount of the binder resin, but is generally −1 ° C./min or more.

-Stop process-
It is preferable to have a stopping step of adding an organometallic sequestering agent to the aggregated particles obtained by the cooling step to stop the aggregation of the aggregated particles. In the stopping step, by adding an organometallic sequestering agent to the aggregated particles, the function of the metal ions can be sequestered and the growth of the aggregated particle size can be stopped quickly, as well as necessary for the toner of the present invention. Aluminum can be left in the toner.
This is presumed as follows. That is, the aggregated particles of the present invention have a larger particle size than the aggregated particles in the toner that is usually used, and are aggregated at a temperature exceeding the glass transition temperature of the binder resin in the aggregation step. The entanglement of internal molecules is increasing. When an organic metal ion sequestering agent is added thereto, it does not sufficiently act on the inside of the aggregated particles depending on the molecular size of them, and acts preferentially on the surface. As a result, aluminum tends to remain inside while stopping the particle size growth of the aggregated particles.

Examples of organometallic sequestering agents include ethylenediaminetetraacetic acid (EDTA), gluconal, sodium gluconate, potassium citrate and sodium citrate, nitrotriacetate (NTA) salt, GLDA (commercially available L glutamic acid N, N Acetic acid), humic acid and fulvic acid, maltol and ethyl maltol, petaacetic acid and tetraacetic acid, COOH and OH, and many water soluble polymers (polyelectrolytes), especially EDTA and its Na Suitable examples include alkali metal salts such as salts.
The amount of the organic metal ion sequestering agent varies depending on the material type, but is generally from 0.01% to 5.00%, preferably from 0.10% to 3.00% with respect to the mass of the toner particles. is there. If it is less than 0.01%, the function as a sequestering agent may be insufficient. If it exceeds 5%, problems such as dispersion of aggregated particles and insufficient amount of aluminum in the binder resin occur. There is a case.

-Fusion / unification process-
Next, as in the production of the colored toner particles, the aggregated particle dispersion in which the aggregated particles are dispersed is, for example, not less than the glass transition temperature of the polyester resin particles (for example, 10 to 30 from the glass transition temperature of the polyester resin particles). To a temperature higher than 0 ° C.), the aggregated particles are fused and united to form transparent toner particles.

Transparent toner particles are obtained through the above steps.
Similar to the production of colored toner particles, in the production of transparent toner particles, colored toner particles in a dried state are obtained through a known washing step, solid-liquid separation step, and drying step. Also, transparent toner particles having a core / shell structure may be manufactured.

  Then, in the same manner as in the production of the colored toner, an external additive is added to the obtained transparent toner particles to obtain a transparent toner.

(Static charge image developer set)
The electrostatic charge image developer set according to the present embodiment includes a first electrostatic charge image developer including a colored toner and a second electrostatic charge image developer including a transparent toner in the toner set according to the present embodiment. It is what you have.
Each electrostatic image developer may be a one-component developer containing only toner, or may be a two-component developer mixed with the toner and a carrier.

  There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. Examples of the carrier include a resin-coated carrier, a magnetic dispersion carrier, a resin dispersion carrier, and the like.

  The mixing ratio (mass ratio) of toner and carrier in the two-component developer is preferably in the range of toner: carrier = 1: 100 to 30: 100, and more preferably in the range of 3: 100 to 20: 100.

(Image forming method, image forming apparatus, toner cartridge, process cartridge)
The image forming method according to the present embodiment includes a first image forming step of forming a colored toner image with a colored toner in the toner set according to the present embodiment on a recording medium, and a transparent toner of the toner set according to the present embodiment. And a second image forming step for forming the transparent toner image on the color toner image on the recording medium, and a fixing step for fixing the color toner image and the transparent toner image on the recording medium.

  Then, the image forming apparatus according to the present embodiment that realizes the image forming method according to the present embodiment includes the first development in which the first electrostatic charge image developer having colored toner is contained in the toner set according to the present embodiment. A first image forming means for forming a colored toner image on the recording medium, and a second electrostatic charge image developer having a transparent toner in the toner set according to the present embodiment. A second image forming unit including a second developing device housed therein, and forming a transparent toner image with a transparent toner for developing an electrostatic charge image on the colored toner image on the recording medium; and the colored toner image and the transparent toner on the recording medium Fixing means for fixing an image.

In the image forming apparatus according to the present embodiment, as these first and second image forming units, for example, a latent image holding member and an electrostatic charge image developer are accommodated, and the electrostatic image formed on the latent image holding member, respectively. Each developing device that develops the electrostatic latent image as each toner image (colored toner image, transparent toner image), a transfer device that transfers the toner image formed on the latent image holding member to the transfer target, and a latent image if necessary And other devices such as a cleaning device for cleaning the transfer residue of the image carrier.
The first image forming means accommodates, as a developing device, a first electrostatic image developer having colored toner, and develops the electrostatic latent image formed on the latent image holding member as a colored toner image. A developing device is provided. On the other hand, the second image forming means contains a second electrostatic charge image developer having transparent toner as a developing device, and develops the electrostatic latent image formed on the latent image holding member as a transparent toner image. A developing device is provided.
For example, the first and second image forming units may share an image carrier, a transfer device, a cleaning device, and the like.

  The image forming apparatus according to the present embodiment includes, for example, an image forming apparatus that sequentially repeats primary transfer of each toner image held on a latent image holding body to an intermediate transfer body, and a plurality of latent images including developing means for each color. It may be a tandem type image forming apparatus or the like in which the image holding member is arranged in series on the intermediate transfer member.

In the image forming apparatus according to the present embodiment, for example, a part including a developing unit that stores the electrostatic latent image developer according to the present embodiment has a cartridge structure (process cartridge) that is detachable from the image forming apparatus. In addition, a cartridge structure (toner cartridge) in which the portion for storing the electrostatic latent image developing white toner according to the present embodiment as a replenishing toner to be supplied to the developing means is detachable from the image forming apparatus. May be.
That is, the image forming apparatus includes a first toner cartridge that stores colored toner in the toner set according to the present embodiment, and a second toner cartridge that stores transparent toner in the toner set according to the present embodiment. The toner cartridge set to be detached may be provided in the image forming apparatus according to the present embodiment.
In addition, the first developing device that accommodates the first electrostatic image developer in the electrostatic image developer set according to the present embodiment, and the second electrostatic image development in the electrostatic image developer set according to the present embodiment. The image forming apparatus according to the present embodiment may include a process cartridge that includes a second developing device that contains an agent and is detachable from the image forming apparatus.

The image forming apparatus according to the present embodiment will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 has a tandem configuration in which a plurality of photosensitive members as latent image holding members, that is, a plurality of image forming units (image forming means) are provided. That is, the image forming apparatus shown in FIG. 1 includes four image forming units 50Y, 50M, 50C, and 50K that form images of yellow, magenta, cyan, and black, respectively, and an image forming unit 50T that forms a transparent image. Are arranged in parallel (tandem) at intervals.

Here, each of the image forming units 50Y, 50M, 50C, 50K, and 50T has the same configuration except for the color of the toner in the stored developer. The unit 50Y will be described as a representative.
It should be noted that reference numerals with magenta (M), cyan (C), black (K), and transparency (T) are attached to the same parts as the image forming unit 50Y instead of yellow (Y). Description of the image forming units 50M, 50C, 50K, and 50T is omitted.

  The yellow image forming unit 50Y includes a photoconductor 11Y as a latent image holding member, and this photoconductor 11Y is rotationally driven at a predetermined process speed by a driving unit (not shown) along the direction of an arrow A shown in the drawing. It has come to be. As the photoreceptor 11Y, for example, an organic photoreceptor having sensitivity in the infrared region is used.

  A charging roll (charging means) 18Y is provided above the photoconductor 11Y. A predetermined voltage is applied to the charging roll 18Y by a power source (not shown), and the surface of the photoconductor 11Y is predetermined. Charged to a certain potential.

  Around the photoreceptor 11Y, an exposure device (latent image forming means) 19Y that exposes the surface of the photoreceptor 11Y to form an electrostatic latent image is disposed downstream of the charging roll 18Y in the rotation direction of the photoreceptor 11Y. Has been. Here, as the exposure device 19Y, an LED array that can be miniaturized is used because of space, but the present invention is not limited to this, and other latent image forming means using a laser beam or the like may be used. Of course there is no problem.

  Further, a developing device (developing unit) 20Y including a developer holding body that holds a yellow developer is disposed around the photoconductor 11Y on the downstream side in the rotation direction of the photoconductor 11Y with respect to the exposure device 19Y. The electrostatic latent image formed on the surface of the photoreceptor 11Y is visualized with yellow toner, and a toner image is formed on the surface of the photoreceptor 11Y.

  Below the photoconductor 11Y, an intermediate transfer belt (intermediate transfer body) 33 that primarily transfers a toner image formed on the surface of the photoconductor 11Y extends below the five photoconductors 11T, 11Y, 11M, 11C, and 11K. Are arranged as follows. The intermediate transfer belt 33 is pressed against the surface of the photoreceptor 11Y by the primary transfer roll 17Y. Further, the intermediate transfer belt 33 is stretched by three rolls of a drive roll 12, a support roll 13, and a bias roll 14, and is rotated in the direction of arrow B at a moving speed equal to the process speed of the photoconductor 11Y. It has become. On the surface of the intermediate transfer belt 33, the transparent toner image is primarily transferred prior to the yellow toner image primarily transferred as described above, and then the yellow toner image is primarily transferred, and then each color of magenta, cyan, and black is further transferred. The toner images are sequentially primary-transferred and stacked.

  Further, around the photoreceptor 11Y, the toner remaining on the surface of the photoreceptor 11Y and the retransferred toner are cleaned downstream of the primary transfer roll 17Y in the rotation direction (arrow A direction) of the photoreceptor 11Y. A cleaning device 15Y is arranged. The cleaning blade in the cleaning device 15Y is attached so as to be in pressure contact with the surface of the photoreceptor 11Y in the counter direction.

  A secondary transfer roll (secondary transfer unit) 34 is pressed against the bias roll 14 that stretches the intermediate transfer belt 33 via the intermediate transfer belt 33. The toner image that is primarily transferred and laminated on the surface of the intermediate transfer belt 33 is applied to the surface of the recording paper (transfer object) P fed from a paper cassette (not shown) at the pressure contact portion between the bias roll 14 and the secondary transfer roll 34. , Electrostatically transferred. At this time, the toner image transferred and laminated on the intermediate transfer belt 33 has the transparent toner image at the bottom (position in contact with the intermediate transfer belt 33). The transparent toner image is at the top.

  Also, downstream of the secondary transfer roll 34, a fixing device (fixing means) for fixing the toner image transferred on the recording paper P onto the surface of the recording paper P by heat and pressure to form a permanent image. 35 is arranged.

  As the fixing device used in this embodiment, for example, a low surface energy material typified by a fluororesin component or a silicone resin is used on the surface, a fixing belt having a belt shape, and a fluororesin component or the like on the surface. Using a low surface energy material typified by a silicone resin, a cylindrical fixing roll can be mentioned.

  Next, the operation of each of the image forming units 50T, 50Y, 50M, 50C, and 50K that forms images of each color of transparent, yellow, magenta, cyan, and black will be described. Since the operations of the image forming units 50T, 50Y, 50M, 50C, and 50K are the same, the operation of the yellow image forming unit 50Y will be described as a representative example.

  In the yellow developing unit 50Y, the photoreceptor 11Y rotates in the direction of arrow A at a predetermined process speed. The surface of the photoconductor 11Y is negatively charged to a predetermined potential by the charging roll 18Y. Thereafter, the surface of the photoreceptor 11Y is exposed by the exposure device 19Y, and an electrostatic latent image corresponding to the image information is formed. Subsequently, the negatively charged toner is reversely developed by the developing device 20Y, and the electrostatic latent image formed on the surface of the photoconductor 11Y is visualized on the surface of the photoconductor 11Y to form a toner image. Thereafter, the toner image on the surface of the photoreceptor 11Y is primarily transferred onto the surface of the intermediate transfer belt 33 by the primary transfer roll 17Y. After the primary transfer, transfer residual components such as toner remaining on the surface of the photoreceptor 11Y are scraped off and cleaned by the cleaning blade of the cleaning device 15Y to prepare for the next image forming process.

  The above operations are performed by the image forming units 50T, 50Y, 50M, 50C, and 50K, and the toner images visualized on the surfaces of the photoreceptors 11T, 11Y, 11M, 11C, and 11K are successively transferred to the intermediate transfer belt. 33 is transferred onto the surface. In the color mode, each color toner image is transferred in the order of transparent, yellow, magenta, cyan, and black. In the two-color and three-color modes, only the toner image of the required color is used in this order. Or, multiple transfer is performed. Thereafter, the toner image that has been single-transferred or multiple-transferred onto the surface of the intermediate transfer belt 33 is secondarily transferred onto the surface of the recording paper P conveyed from a paper cassette (not shown) by the secondary transfer roll 34, and then the fixing device 35. It is fixed by heating and pressurizing. The toner remaining on the surface of the intermediate transfer belt 33 after the secondary transfer is cleaned by the belt cleaner 16 constituted by a cleaning blade for the intermediate transfer belt 33.

  In the yellow image forming unit 50Y, the developing device 20Y including a developer holding body for holding the yellow electrostatic latent image developer, the photoconductor 11Y, the charging roll 18Y, and the cleaning device 15Y are integrated into an image. It is configured as a process cartridge that is detachable from the forming apparatus main body. The image forming units 50K, 50C, 50M, and 50T are also configured as process cartridges in the same manner as the image forming unit 50Y.

  The toner cartridges 40Y, 40M, 40C, 40K, and 40T are cartridges that store toner of each color and are attached to and detached from the image forming apparatus, and are connected to a developing device corresponding to each color by a toner supply pipe (not shown). ing. When the toner stored in each toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to these Examples at all. The “part” means “part by mass” unless otherwise specified.

[Synthesis of polyester resin]
(Polyester resin (1))
In a heat-dried two-necked flask, 80 mol parts of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 10 mol parts of ethylene glycol, 10 mol parts of cyclohexanediol, and terephthalic acid After 80 parts by mole, 10 parts by mole of isophthalic acid, and 10 parts by mole of n-dodecenyl succinic acid, dibutyltin oxide is added as a catalyst, nitrogen gas is introduced into the container, and the temperature is raised in an inert atmosphere. The polyester resin (1) was synthesized by carrying out a copolycondensation reaction at 150 to 230 ° C. for about 12 hours and then gradually reducing the pressure at 210 to 250 ° C.

The weight average molecular weight (Mw) of the obtained polyester resin (1) was 17,200. Moreover, the acid value of the polyester resin (1) was 12.4 mgKOH / g.
Furthermore, the glass transition temperature of the polyester resin (1) was measured using a differential scanning calorimeter (DSC) and obtained by analyzing it according to JIS standards (see JIS K-7121).
As a result, a stepwise endothermic change was observed without showing a clear peak. The glass transition temperature (Tg) at the midpoint of the stepwise endothermic change was 59 ° C.

[Preparation of polyester resin dispersion]
(Polyester resin dispersion (A1))
-Polyester resin (1) 100 parts by mass-Ethyl acetate 70 parts by mass-Isopropyl alcohol 15 parts by mass

  A mixed solvent of ethyl acetate and isopropyl alcohol was added to a 5 L separable flask, and the resin was gradually added thereto, stirred with a three-one motor, and completely dissolved to obtain an oil phase.

  To this stirred oil phase, a 10% by mass aqueous ammonia solution is gradually dropped with a dropper so that the total amount becomes 3.5 parts by mass, and further 230 parts by mass of ion-exchanged water is gradually added dropwise at a rate of 10 ml / min. Then, phase inversion emulsification was performed, and the solvent was removed while reducing the pressure with an evaporator to obtain a “polyester resin dispersion (A1)” containing “polyester resin (1)”. The volume average particle diameter of the resin particles dispersed in this dispersion was 182 nm. The resin particle concentration of the dispersion was adjusted to 20% by mass with ion exchange water.

[Preparation of colorant dispersion]
(Colorant dispersion (B1))
Cyan pigment 1000 parts by mass (manufactured by Dainichi Seika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine))
-15 parts by weight of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R)-9000 parts by weight of ion-exchanged water are mixed and dissolved, and a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) ) For about 1 hour to prepare a colorant dispersion liquid in which a colorant (pigment) is dispersed. The volume average particle size of the colorant (pigment) particles in the colorant dispersion was 0.16 μm, and the solid content concentration was 20%.

[Preparation of release agent dispersion]
(Releasing agent dispersion (C1))
Paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point: 75 ° C.): 50 parts by mass Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 0.5 parts by mass -Ion-exchanged water: 200 parts by mass or more were mixed, heated to 95 ° C, and dispersed using a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, a dispersion treatment (solid content concentration: 20%) in which the release agent was dispersed was prepared by dispersing with a Manton Gorin high-pressure homogenizer (Gorin). The volume average particle size of the release agent particles was 0.23 μm.

[Production of colored toner]
(Colored toner (C1))
Polyester resin dispersion (A1) 267 parts by weight Colorant dispersion (B2) 25 parts by weight Release agent dispersion (C1) 40 parts by weight Anionic surfactant (TeycaPower) 2.0 parts by weight Was placed in a 2 L cylindrical stainless steel container, and using a homogenizer (manufactured by IKA, Ultra Lalux T50), the homogenizer was rotated at 4000 rpm and dispersed and mixed for 10 minutes while applying a shearing force. Next, 1.75 parts by mass of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5000 rpm for 15 minutes and mixed to obtain a raw material dispersion.

  Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 42 ° C. At this time, the pH of the raw material dispersion was adjusted to a range of 3.2 or more and 3.8 or less using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The raw material dispersion was kept in the above pH range and allowed to stand for about 2 hours to form aggregated particles. The volume average particle diameter of the aggregated particles was 4.9 μm.

Next, 100 parts by mass of the polyester resin dispersion (A1) was additionally added to the raw material dispersion, and the resin particles of the polyester resin (1) were adhered to the surface of the aggregated particles. Further, the temperature of the raw material dispersion was raised to 44 ° C., and aggregated particles were prepared while confirming the size and form of the particles using an optical microscope and Multisizer II. Thereafter, ethylenediaminetetraacetic acid / 4Na salt tetrahydrate was added at 2.0% of the solid content (toner mother particle content) in the slurry, and then the pH of the system was adjusted to 7.5 with a 1 Mol / L sodium hydroxide aqueous solution. After that, the mixture was heated to 85 ° C. while continuing the stirring, and left at 85 ° C. with stirring for 3 hours. Thereafter, a multi-tube heat exchanger was used (the heat medium was 5 ° C. cold water), and the flow rate was adjusted so as to obtain a cooling rate of 30 ° C./min.
Toner particles were formed in the obtained raw material dispersion.

Next, the raw material dispersion was filtered, and the obtained toner particles after solid-liquid separation were dispersed in ion-exchanged water at 30 ° C., which is 20 times the solid content of the toner particles, and washed with water.
Then, this washing with water was repeated 10 times, followed by drying and classification in a cyclone collection using a loop type airflow dryer to obtain colored toner particles (C1).

Next, 1.5 parts by mass of fumed silica (volume average particle diameter 140 nm, HMDS treatment) was added to 100 parts by mass of the obtained colored toner particles (1), and a tip speed of the stirring blade was measured using a 20 L Henschel mixer. Blending was carried out at 10 m / s for 20 minutes and externally added. Furthermore, 1.3 parts by mass of titanium oxide particles (volume average particle diameter 20 nm) was added, and blended for 15 minutes at a stirring blade tip peripheral speed of 55 m / s using a 20 L Henschel mixer and externally added.
Thereafter, coarse particles were removed using a sieve having an opening of 45 μm, and a colored toner (C1) was produced.

(Colored toner (C2))
A colored toner (C2) was obtained in the same manner as the colored toner (C1) except that in the production of the colored toner C1, the growth time of the aggregated particles at 42 ° C. was changed from 2 hours to 3 hours.

(Colored toner (C3))
In the production of the color toner C1, the color toner is the same as the color toner (C1) except that the rotation speed of the homogenizer after dropping the flocculant is changed to 6000 rpm and the growth promoting temperature of the aggregated particles is changed from 42 ° C. to 35 ° C. (C3) was obtained.

(Colored toner (C4))
A colored toner (C4) was obtained in the same manner as the colored toner (C1) except that in the production of the colored toner C1, the growth promotion temperature of the aggregated particles was changed from 42 ° C. to 46 ° C.

(Colored toner (C5))
A colored toner (C5) was obtained in the same manner as the colored toner (C3) except that in the production of the colored toner C3, the growth promotion temperature of the aggregated particles was changed from 35 ° C. to 38 ° C.

(Colored toner (C6))
A colored toner (C6) was obtained in the same manner as the colored toner (C1) except that in the production of the colored toner C1, the growth time of the aggregated particles at 42 ° C. was changed from 2 hours to 2 hours and 50 minutes.

(Colored toner (C7))
A colored toner (C7) was obtained in the same manner as the colored toner (C3) except that in the production of the colored toner C3, the growth promotion temperature of the aggregated particles was changed from 35 ° C. to 34.5 ° C.

(Colored toner (C8))
A colored toner (C8) was obtained in the same manner as the colored toner (C1) except that in the production of the colored toner C1, the growth promotion temperature of the aggregated particles was changed from 42 ° C. to 47 ° C.

(Colored toner (C9))
A colored toner (C9) was obtained in the same manner as the colored toner (C3), except that in the production of the colored toner C3, the growth promotion temperature of the aggregated particles was changed from 35 ° C. to 38.5 ° C.

  The characteristics of the obtained color toner are listed in Table 1.

[Preparation of transparent toner]
(Transparent toner (T1))
Polyester resin dispersion (A1) 293 parts by weight Release agent dispersion (C1) 40 parts by weight Anionic surfactant (TeycaPower) 2.0 parts by weight The above raw materials are placed in a 2 L cylindrical stainless steel container and homogenizer ( Using an Ultra Larax T50, manufactured by IKA, the homogenizer was rotated at 4000 rpm and dispersed and mixed for 10 minutes while applying a shearing force. Next, 1.75 parts by mass of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5000 rpm for 15 minutes and mixed to obtain a raw material dispersion.
Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 62 ° C. At this time, the pH of the raw material dispersion was adjusted to a range of 3.2 or more and 3.8 or less using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The raw material dispersion was kept in the above pH range and allowed to stand for about 1 hour to form aggregated particles. The volume average particle diameter of the aggregated particles was 22.0 μm.

Next, 30 parts by mass of the polyester resin dispersion (A1) was additionally added to the raw material dispersion, and the resin particles of the polyester resin (1) were adhered to the surface of the aggregated particles. Furthermore, the raw material dispersion was cooled to 45 ° C. at a cooling rate of 1 ° C./min by air cooling, and aggregated particles were prepared using an optical microscope and Multisizer II while confirming the size and form of the particles. Thereafter, ethylenediaminetetraacetic acid / 4Na salt tetrahydrate was added at 2.0% of the solid content (toner mother particle content) in the slurry, and then the pH of the system was adjusted to 7.5 with a 1 Mol / L sodium hydroxide aqueous solution. After that, the mixture was heated to 85 ° C. while continuing the stirring, and left at 85 ° C. with stirring for 3 hours. Thereafter, a multi-tube heat exchanger was used (the heat medium was 5 ° C. cold water), and the flow rate was adjusted so as to obtain a cooling rate of 30 ° C./min.
Toner particles were formed in the obtained raw material dispersion.

Next, the raw material dispersion was filtered, and the obtained toner particles after solid-liquid separation were dispersed in ion-exchanged water at 30 ° C., which is 20 times the solid content of the toner particles, and washed with water.
Then, this washing with water was repeated 10 times, followed by drying and classification in a cyclone collection using a loop type airflow dryer to obtain transparent toner particles (T1).

Next, 0.4 parts by mass of fumed silica (volume average particle diameter 140 nm, HMDS treatment) was added to 100 parts by mass of the obtained transparent toner particles (T1), and the tip speed of the stirring blade tip was measured using a 20 L Henschel mixer. Blending was carried out at 10 m / s for 20 minutes and externally added. Further, 0.2 parts by mass of titanium oxide particles (volume average particle diameter 20 nm) was added, and the mixture was externally added by blending for 15 minutes at a stirring blade tip peripheral speed of 55 m / s using a 20 L Henschel mixer.
Thereafter, coarse particles were removed using a sieve having an aperture of 106 μm to produce a transparent toner (T1).

(Transparent toner (T2))
A transparent toner (T2) was obtained in the same manner as the transparent toner (T1) except that in the production of the transparent toner T1, the growth promotion temperature of the aggregated particles was changed from 62 ° C. to 60 ° C.

(Transparent toner (T3))
A transparent toner (T3) was obtained in the same manner as the transparent toner (T1) except that in the production of the transparent toner T1, the growth promotion temperature of the aggregated particles was changed from 62 ° C. to 65 ° C.

(Transparent toner (T4))
In the production of the transparent toner T1, the transparent toner (T4) was prepared in the same manner as the transparent toner (T1) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 3.5%. Obtained.

(Transparent toner (T5))
In the production of the transparent toner T1, the transparent toner (T5) was prepared in the same manner as the transparent toner (T1) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 1.0%. Obtained.

(Transparent toner (T6))
In the production of the transparent toner T2, the transparent toner (T6) was prepared in the same manner as the transparent toner (T2) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 3.5%. Obtained.

(Transparent toner (T7))
In the production of the transparent toner T2, the transparent toner (T7) was prepared in the same manner as the transparent toner (T2) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 1.0%. Obtained.

(Transparent toner (T8))
In the production of the transparent toner T3, the transparent toner (T8) was prepared in the same manner as the transparent toner (T3) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 3.5%. Obtained.

(Transparent toner (T9))
In the production of the transparent toner T3, the transparent toner (T9) was prepared in the same manner as the transparent toner (T3) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 1.0%. Obtained.
(Transparent toner (T10))
A transparent toner (T10) was obtained in the same manner as the transparent toner (T1) except that in the production of the transparent toner T1, the growth promotion temperature of the aggregated particles was changed from 62 ° C. to 58.5 ° C.

(Transparent toner (T11))
A transparent toner (T11) was obtained in the same manner as the transparent toner (T1) except that in the production of the transparent toner T1, the growth promotion temperature of the aggregated particles was changed from 62 ° C. to 67 ° C.

(Transparent toner (T12))
In the production of the transparent toner T10, the transparent toner (T12) was prepared in the same manner as the transparent toner (T10) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 4.0%. Obtained.

(Transparent toner (T13))
In the production of the transparent toner T11, the transparent toner (T13) was prepared in the same manner as the transparent toner (T11) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 4.0%. Obtained.

(Transparent toner (T14))
In the production of the transparent toner T10, the transparent toner (T14) was prepared in the same manner as the transparent toner (T10) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 0.5%. Obtained.

(Transparent toner (T15))
In the production of the transparent toner T11, the transparent toner (T15) was prepared in the same manner as the transparent toner (T11) except that the addition amount of ethylenediaminetetraacetic acid / 4Na salt hydrate was changed from 2.0% to 0.5%. Obtained.

(Transparent toner (T16))
-Styrene: 280 parts by mass-n-butyl acrylate: 120 parts by mass-Acrylic acid: 5 parts by mass-Dodecanethiol: 8 parts by mass The components of the above composition were mixed and dissolved into a nonionic surfactant (Sanyo Kasei) Co., Ltd .: Nonipol 400) 7 parts by mass and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 11 parts by mass were dissolved in 500 parts by mass of ion-exchanged water and dispersed in a flask. While emulsifying and slowly mixing for 10 minutes, 50 parts by mass of a solution prepared by dissolving 3 parts by mass of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) in ion-exchanged water was added thereto. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. Thereafter, the reaction solution was cooled to room temperature to prepare a styrene acrylic resin dispersion (1) in which resin particles having a glass transition point of 61 ° C. and a weight average molecular weight of 15000 were dispersed.

  A transparent toner (T16) was obtained in the same manner as the transparent toner (T1) except that the polyester resin dispersion (1) was changed to the styrene acrylic resin dispersion (1) in the production of the transparent toner T1.

  The characteristics of the obtained transparent toner are listed in Table 1.

[Examples 1 to 16, Comparative Examples 1 to 12]
According to Table 1, a toner set in which a colored toner and a transparent toner are combined is used as each example and each comparative example.
Table 1 shows the relationship between the volume average particle diameter and the aluminum content of each toner in the toner set of each example.

[Evaluation]
-Production of developer set-
Into a V blender, 92 parts by mass of the following carrier (1) is added to 8 parts by mass of each colored toner in the toner set of each example, and 92 parts by mass of the following carrier (2) is added to 8 parts by mass of each transparent toner. The mixture was stirred for 20 minutes, and then sieved with a mesh having a pore size of 212 μm to prepare each developer, and a developer set was prepared.

-Production of carrier (1)-
Ferrite particles (average particle size; 35 μm) 100 parts by mass Toluene 14 parts by mass Methyl methacrylate-perfluorooctylethyl methacrylate copolymer (copolymerization ratio 8: 2), Mw 76000 1.6 parts by mass Using a sand mill These were dispersed with stirring with a stirrer for 10 minutes to prepare a coating layer forming solution. Next, this coating layer forming solution and ferrite particles (35 μm) are put in a vacuum degassing type kneader and stirred at a temperature of 60 ° C. for 30 minutes, and then the pressure is reduced to distill off toluene, thereby forming a resin coating layer. Carrier (1) was obtained.

-Production of carrier (2)-
Ferrite particles (average particle size: 100 μm) 100 parts by mass Toluene 14 parts by mass Methyl methacrylate-perfluorooctylethyl methacrylate copolymer (copolymerization ratio 8: 2), Mw 76000 0.4 parts by mass Using a sand mill These were dispersed with stirring with a stirrer for 10 minutes to prepare a coating layer forming solution. Next, this coating layer forming solution and ferrite particles (100 μm) are put into a vacuum degassing type kneader and stirred at a temperature of 60 ° C. for 30 minutes, and then the pressure is reduced to distill off toluene to form a resin coating layer. Carrier (2) was obtained.

-Actual machine evaluation-
“Color 1000 Press” remodeling machine manufactured by Fuji Xerox Co., Ltd. (modified even if there is no developer in the developing machine so that it can be output if there is only one developer in the developing machine) The developer of the obtained developer set was placed in a developer for each color, and each toner of the obtained toner set was placed in a toner cartridge for each color.
Then, using this image forming apparatus, a solid image of only 5 × 5 cm of solid color toner and a solid image of transparent toner are formed on the solid image of colored toner, and then fixed, and then on the colored toner fixed image. A raised image on which a transparent toner fixed image was formed was formed.

-Measurement of image step, step gradient angle, and gross difference-
The obtained raised image was scanned with a surface roughness meter (Surfcom) from the non-image portion to the image portion to produce a height profile (vertical magnification 500 times, lateral magnification 20 times).
When the height of the non-image portion is zero, the point where the image height is 3 μm is X1, and when the point where the image height is the maximum is X2, the difference in height between X2 and X1 is As the step of the image, the gradient obtained from the moving distance and height of X2 and X1 was calculated as the gradient angle of the step. Further, with a portable gloss meter manufactured by Toyo Seiki Seisakusho Co., Ltd., the 60 ° gloss of the solid image portion of the colored toner and the raised image portion of the transparent toner was measured, and the gross difference was obtained. Note that the step of the image, the gradient angle of the step, and the gloss difference were measured at five locations per image, and the average value of the three points excluding the maximum and minimum values was used as the value.

~ Image steps ~
A: 25 μm or more ○: 21 μm or more and less than 25 μm Δ: 15 μm or more and less than 21 μm x: Less than 15 μm

~ Slope angle of steps ~
◎: 65 ° or more ○: 50 ° or more and less than 65 ° Δ: 40 ° or more and less than 50 ° x: less than 40 °

~ Gloss difference ~
◎: Less than 10 ○: 10 or more and less than 15 Δ: 15 or more and less than 25 x: 25 or more

  From the above results, it can be seen that, in this embodiment, a raised image having a higher image step and a larger step gradient angle is formed as compared with the comparative example.

DESCRIPTION OF SYMBOLS 11 Photoconductor 12 Drive roll 13 Support roll 14 Bias roll 15 Cleaning apparatus 16 Belt cleaner 17 Primary transfer roll 18 Charging roll 19 Exposure apparatus 20 Developing apparatus 34 Secondary transfer roll 35 Fixing device 40 Toner cartridge 50 Image forming unit P Recording paper

Claims (9)

A first image forming step of forming a colored toner image on a recording medium with a colored toner for developing an electrostatic image including a binder resin, a colorant, and aluminum;
A second image forming step of forming a transparent toner image with a transparent toner for developing an electrostatic charge image containing a binder resin and aluminum on the colored toner image on the recording medium;
A fixing step of fixing the colored toner image and the transparent toner image on the recording medium;
Have
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. An image forming method to satisfy.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0   The image forming method according to claim 1, wherein the binder resin of the transparent toner for developing an electrostatic charge image is a polyester resin. A colored toner image comprising a first developing device containing a first electrostatic image developer containing a colored toner for developing an electrostatic image comprising a binder resin, a colorant and aluminum. First image forming means for forming the image on a recording medium;
A second developing device containing a second electrostatic image developer having a transparent toner for developing an electrostatic charge image containing a binder resin and aluminum; and recording the transparent toner image by the transparent toner for developing an electrostatic charge image Second image forming means for forming on the colored toner image on the medium;
Fixing means for fixing the colored toner image and the transparent toner image on the recording medium;
With
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. An image forming apparatus that fills.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0   The image forming apparatus according to claim 3, wherein the binder resin of the transparent toner for developing an electrostatic charge image is a polyester resin. A colored toner for developing an electrostatic charge image comprising a binder resin, a colorant and aluminum;
A transparent toner for developing an electrostatic image comprising a binder resin and aluminum;
Have
When the volume average particle diameter of the colored toner for developing an electrostatic image is Dc (μm) and the volume average particle diameter of the transparent toner for developing an electrostatic image is Dt (μm), the following formulas (A1) and (A2) )
When the aluminum content of the colored toner for developing an electrostatic image is Alc (atom%) and the aluminum content of the transparent toner for developing an electrostatic image is Alt (atom%), the relationship of the following formula (B1) is established. Toner set for developing electrostatic charge image.
Formula (A1): 18 ≦ Dt ≦ 30
Formula (A2): 2.5 ≦ Dt / Dc ≦ 9
Formula (B1): 1.2 ≦ Alt / Alc ≦ 4.0   6. The toner set for developing an electrostatic charge image according to claim 5, wherein the binder resin of the transparent toner for developing the electrostatic charge image is a polyester resin.   5. The electrostatic image developing toner according to claim 5, wherein the electrostatic image developing toner includes the colored toner for developing the electrostatic image, and the electrostatic image developing toner according to claim 5. An electrostatic charge image developer set comprising: a second electrostatic charge image developer including the electrostatic charge image developing transparent toner in the set. 5. The electrostatic image developing toner set according to claim 5, wherein the electrostatic toner image developing toner set contains the first toner cartridge containing the electrostatic image developing colored toner, and the electrostatic image developing toner set according to claim 5. A second toner cartridge containing the electrostatic toner for developing an electrostatic charge image,
A toner cartridge set that is detachable from the image forming apparatus. 8. The first developing device containing the first electrostatic image developer in the electrostatic image developer set according to claim 7, and the second electrostatic charge in the electrostatic image developer set according to claim 7. A second developing device containing an image developer,
A process cartridge that is detachable from the image forming apparatus.