JP2002174924A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a full color image excellent in color reproducibility as well as to satisfactorily fix supplied color toners on a recording medium with a non-contact heat fixing device even if the amount of an IR absorbent contained in the color toners is not increased when color toners having different colors are overlapped and supplied to the top of the recording medium to obtain a full color image. SOLUTION: When at least yellow, magenta and cyan toners are used as color toners, these color toners are supplied to the top of a recording medium 1 to form a full color toner image and this toner image is fixed on the recording medium with a non-contact heat fixing device to form a full color image, color toners containing an IR absorbent are used and the yellow toner is situated at the uppermost layer in a part where the yellow toner is supplied to the top of the recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a full-color toner image by supplying a color toner onto a recording medium.
The present invention relates to an image forming method for fixing a toner image on a recording medium by a non-contact heat fixing device to form a full-color image. It is characterized in that it is sufficiently fixed on a recording medium by a heat fixing device.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, various fixing devices have conventionally been used for fixing toner supplied on a recording medium to the recording medium. As one type, non-contact heat fixing devices such as an oven fixing device and a flash fixing device have been used.

In the non-contact heat fixing device as described above, the toner supplied onto the recording medium is irradiated with heat or infrared rays, thereby heating the toner and fixing the toner on the recording medium. .

Here, in the case of a black toner generally used in the past, carbon black or the like having high heat and infrared absorptivity is contained in the toner particles. Was sufficiently fixed on the recording medium.

However, in the case of a color toner having a color other than black, heat or infrared absorption is not sufficient, and the color toner can be sufficiently fixed on a recording medium by the above-described non-contact heat fixing device. It was difficult.

For this reason, conventionally, it has been customary to include an infrared absorber in the above color toner to enhance the heat and infrared absorption of the color toner and improve the fixability of the color toner to a recording medium. Is being done.

However, even if a color toner containing an infrared absorbing agent as described above is used, when a full-color image is obtained by supplying a plurality of color toners on a recording medium in a superposed manner, As a result, a large amount of color toner is supplied, and it is very difficult to sufficiently fix the supplied color toner on a recording medium by a non-contact heat fixing device.

For this reason, when a full-color image is obtained by supplying a plurality of color toners on a recording medium in an overlapping manner as described above, it is necessary to further increase the amount of the infrared absorber contained in the color toners. Needed.

However, when such a large amount of the infrared absorbent is contained in the color toner, the production cost of the toner is increased, and the color of the color toner is changed by the infrared absorbent. There is also a problem that color reproducibility in the obtained color image is deteriorated.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a full-color toner image is formed by supplying a color toner onto a recording medium, and the toner image is fixed on the recording medium by a non-contact heat fixing device. It is an object of the present invention to solve the various problems as described above in forming a.

That is, according to the present invention, when a full-color image is obtained by supplying a plurality of color toners in a superimposed manner on a recording medium, the amount of the infrared absorber contained in the color toners can be increased without increasing the amount. An object of the present invention is to provide a full-color image excellent in color reproducibility by sufficiently fixing a supplied color toner on a recording medium by a non-contact heat fixing device.

[0012]

According to a first image forming method of the present invention, at least a yellow toner, a magenta toner, and a cyan toner are used as color toners to solve the above-mentioned problems. A color toner is supplied onto a recording medium to form a full-color toner image, and the toner image is fixed on the recording medium by a non-contact heat fixing device to form a full-color image. In a portion where a yellow toner is supplied onto a recording medium using a color toner having an agent, the yellow toner is positioned at the uppermost layer.

As in the first image forming method, when a color toner having an infrared absorbing agent is used and the yellow toner is supplied to a portion of the recording medium where the yellow toner is supplied, Even without adding a large amount of infrared absorber to the yellow toner having low infrared absorption performance, the yellow toner can be sufficiently fixed on the recording medium by the non-contact heat fixing device, and the color of the yellow toner can be absorbed by the infrared absorption. The change by the agent is also reduced.

In the case where the above-mentioned yellow toner, magenta toner and cyan toner are supplied in a superposed manner on a recording medium, the yellow toner having a low infrared absorption performance can be used.
It is preferable to position the magenta toner and the cyan toner in order from the upper layer. In this case, even if the amount of the infrared absorber added to these color toners is not increased, these color toners can be sufficiently fixed on the recording medium by the non-contact heat fixing device. The color of the color toner is less changed by the infrared absorbing agent, and a full-color image with excellent color reproducibility can be obtained.

In the second image forming method according to the present invention, in order to solve the above-mentioned problems, a red toner, a green toner and a blue toner are used as color toners, and these color toners are used as recording media. To form a full-color toner image, and fix the toner image on a recording medium by a non-contact heating and fixing device to form a full-color image. Using
In the portion where the red toner is supplied on the recording medium, the red toner is positioned at the uppermost layer.

Then, as in the second image forming method, when the color toner having the infrared absorbing agent is used and the red toner is located on the uppermost layer in the portion where the red toner is supplied on the recording medium, Even without adding a large amount of infrared absorbent to red toner with low infrared absorption performance, this non-contact heating and fixing device enables the red toner to be sufficiently fixed on the recording medium, and the color of the red toner is absorbed by infrared light. The change by the agent is also reduced.

In the case where the above-described red toner, green toner and blue toner are supplied in a superposed manner on a recording medium, the red toner, the green toner and the blue toner having low infrared absorption performance are sequentially arranged from the upper layer. Preferably, it is located. In this case, even if the amount of the infrared absorber added to these color toners is not increased, these color toners can be sufficiently fixed on the recording medium by the non-contact heat fixing device. The color of the color toner is less changed by the infrared absorbing agent, and a full-color image with excellent color reproducibility can be obtained.

In the third image forming method according to the present invention, in order to solve the above-mentioned problems, a color toner and a highly transparent stealth toner are used, and the color toner and the stealth toner are formed on a recording medium. To form a full-color toner image, and fixing the toner image on a recording medium by a non-contact heating and fixing device to form a full-color image. Has a second infrared absorbing agent, and the second infrared absorbing agent is an infrared-emitting fluorescent material. In a portion where the stealth toner is supplied onto the recording medium, the stealth toner is located in the uppermost layer. I did it.

Then, as in the third image forming method, a portion where the stealth toner is supplied onto the recording medium using the color toner having the first infrared absorber and the stealth toner having the second infrared absorber is used. In the case where the stealth toner is located at the uppermost layer, the stealth toner is sufficiently fixed on the recording medium by the non-contact heat fixing device without adding much infrared absorber to the stealth toner having low infrared absorption performance. In addition, the transparency of the stealth toner is prevented from being reduced by the infrared absorber.

Further, as described above, the first infrared absorbing agent added to the color toner is different from the second infrared absorbing agent added to the stealth toner, and an infrared light emitting fluorescent material is used as the second infrared absorbing agent. Then, only the second infrared absorber in the stealth toner can be detected by light in the infrared region, and various information can be written using the stealth toner without affecting the color image. .

In the above-described first to third image forming methods, when a black toner is further used, in a portion where the black toner is supplied onto a recording medium,
This black toner is positioned at the lowermost layer so as not to affect the above color toners and stealth toner.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming method according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings.

Here, in the color toner, stealth toner and black toner used in each of the following embodiments, known binder resins and various coloring agents generally used conventionally can be used.

Here, as the binder resin used for these toners, for example, styrene-acrylic resin,
A polyester-based resin, an epoxy-based resin, or the like can be used, but it is preferable to use a polyester-based resin from the viewpoint of durability and light-transmitting properties.

The colorant is appropriately selected and used in accordance with the color of the toner.

Here, in the yellow toner, for example, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 1
3, 14, 15, 16, 17, 23, 65, 73, 8
3,180, C.I. I. Yellow pigments such as Vat Yellow 1, 3, and 20; I. Solvent Yellow 79, 1
For example, a yellow dye such as 62 can be used.

In the magenta toner, for example, C.I. I. Pigment Red 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 21, 2
2, 23, 30, 31, 32, 37, 38, 39, 4,
0, 41, 48, 49, 50, 51, 52, 53, 5
4, 55, 57, 58, 60, 63, 64, 68, 8
1, 83, 87, 88, 89, 90, 112, 114,
122, 123, 163, 184, 202, 206, 2
Magenta pigments such as C.07, 209 and the like; I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 4
9, 81, 82, 83, 84, 100, 109, 12
1, C.I. I. Disperse Red 9, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17,
18, 22, 23, 24, 27, 29, 32, 34, 3
Magenta dyes such as 5, 36, 37, 38, 39, and 40 can be used.

In the cyan toner, for example, C.I. I. Pigment Blue 2, 3,
For example, cyan pigments such as 15, 16, and 17 can be used.

In the red toner, as a coloring agent, for example, red iron, cadmium red, leadtan, mercury sulfide, cadmium, permanent red 4R,
Risole Red, Pyrazolone Red, Watching Red, Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rotamine Lake B, Alizarin Lake, Brilliant Carmine 3B and the like can be used.

In the green toner, for example, chrome green, chromium oxide, pigment green B, micalite green lake, final yellow green G, and the like can be used as the colorant.

In the blue toner, as a coloring agent, for example, navy blue, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky blue, indaslen blue BC, etc. Can be used.

In the black toner, for example, carbon black, activated carbon, titanium black, magnetic powder and the like can be used as the colorant.

On the other hand, for a stealth toner having high transparency, the above-mentioned coloring agent is not used.

Further, a home appliance controlling agent or a wax may be added to each of the toners as required.

In producing each of the toners as described above, a generally used kneading-pulverizing method, a wet granulation method, or the like can be used.

Here, the wet granulation method includes a suspension polymerization method, an emulsion polymerization method, an emulsion polymerization association method, a soap-free emulsion polymerization method, a non-aqueous dispersion polymerization method, an in-situ polymerization method, an interfacial polymerization method, and an emulsion polymerization method. A dispersion granulation method or the like can be used.

As the infrared absorber to be added to the color toner, known infrared absorbers can be used, for example, cyanine compounds, merocyanine compounds, benzenethiol-based metal complexes, mercaptophenol-based metal complexes, aromatic Diamine-based metal complexes, diimonium compounds, aminium compounds, nickel complex compounds, phthalocyanine-based compounds, anthraquinone-based compounds, naphthalocyanine-based compounds, and the like can be used. : SIR-13
0, SIR132), bis (dithiobenzyl) nickel (MIR-101, manufactured by Midori Kagaku), bis [1,2-
Bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel (MIR-10 manufactured by Midori Kagaku)
2), tetra-n-butylammonium bis (cis-
1,2-diphenyl-1,2-ethylenedithiolate)
Nickel (manufactured by Midori Kagaku: MIR-1011), tetra-n-butylammonium bis [1,2-bis (p-
Methoxyphenyl) -1,2-ethylenedithiolate]
Nickel (manufactured by Midori Kagaku: MIR-1021), bis (4-tert-1,2-butyl-1,2-dithiophenolate) nickel-tetra-n-butylammonium (manufactured by Sumitomo Seika: BBDT-NI) ), A cyanine infrared absorbing agent (manufactured by Fuji Photo Film Co., Ltd .: IRF-106, IR)
F-107), an inorganic salt-based infrared absorber (NIR-AM1 manufactured by Teikoku Chemical Industry Co., Ltd.), an immonium compound (CIR-1080, CIR-1081 manufactured by Nippon Carlit Co., Ltd.), an aminium compound (CIR- manufactured by Nippon Carlit Co., Ltd.) 96
0, CIR-961), anthraquinone-based compound (Nippon Kayaku Co., Ltd .: IR-750), aminium-based compound (Nippon Kayaku Co., Ltd .: IRG-002, IRG-003), polymethine-based compound (Nippon Kayaku Co., Ltd.) : IR-820B), diimonium-based compound (manufactured by Nippon Kayaku Co., Ltd .: IRG-022, I)
RG-023), a dianine compound (manufactured by Nippon Kayaku Co., Ltd .: CY)
-2, CY-4, CY-9), soluble phthalocyanine (TX-305A, manufactured by Nippon Shokubai Co., Ltd.) and the like. Among these infrared absorbers, a dithiol-based nickel complex is preferable because of its high infrared absorption efficiency and light color.

When an infrared absorbing agent is added to the stealth toner, an infrared-emitting fluorescent material that emits fluorescence when excited by infrared light is used as the infrared absorbing agent. When such a material is used as an infrared absorbent, when the obtained color image is irradiated with infrared light, only the portion formed by the stealth toner in the color image emits fluorescence and can be detected.

When adding the above-mentioned infrared absorbent to the color toner or the stealth toner, the infrared absorbent is dispersed and added to the inside of the color toner or the stealth toner, or the infrared absorbent is added to the color toner or the stealth toner. It can be fixed to the surface of the toner.

Here, if the infrared absorbing agent is fixed to the surface of the color toner or the stealth toner, the infrared absorbing agent efficiently absorbs the infrared light on the surface of the color toner or the stealth toner, so that the color toner or the stealth toner can be used. The infrared absorption efficiency is improved, and even when the amount of the infrared absorbent added to the color toner or the stealth toner is reduced, the color toner or the stealth toner can be sufficiently fixed on the recording medium by the non-contact heat fixing device.
Further, since the amount of the infrared absorbing agent can be reduced in this manner, the manufacturing cost of these toners is reduced, and the deterioration of characteristics such as charging performance of these toners is suppressed. The change of the color of the color toner and the decrease in the transparency of the stealth toner due to the agent are also suppressed, and a color image with excellent color reproducibility can be obtained.

When the infrared absorbing agent is fixed to the surface of the color toner or the stealth toner as described above, the infrared absorbing agent is fixed to the surface of the toner particles by using, for example, a surface modifying device. Alternatively, when the toner is granulated by a wet granulation method, an infrared absorbing agent can be fixed to the surface of the toner particles.

Examples of the above-mentioned surface reforming apparatus include a surffusing system (manufactured by Nippon Pneumatic Industries Ltd.), a hybridization system (manufactured by Nara Machinery Co., Ltd.), a Kryptron Cosmo series (manufactured by Kawasaki Heavy Industries, Ltd.), Applying dry mechanochemical method such as Inomaizer System (Hosokawa Micron) and other surface reforming equipment that gives impact in high-speed airflow, Mechano Fusion System (Hosokawa Micron) and Mechanomill (Okada Seiko) It is possible to use a suitable combination of a surface modification device, a surface modification device using a wet coating method of Dispercoat (manufactured by Nisshin Engineering Co., Ltd.) and a coatmizer (manufactured by Freund Corporation).

Here, each toner used in the present invention has a volume average particle diameter Dv in the range of 3 to 9 μm, preferably 4 to 8 μm, and the volume average particle diameter Dv with respect to the number average particle diameter Dp. Ratio (Dv / Dp) is 1.0 to
It is preferable to be within the range of 1.25. By using such a toner having a small particle diameter and a uniform particle diameter, variations in the charging performance of the toner are suppressed, fog in a formed image is reduced, and the fixing property of the toner is improved. Can be done. In addition, fine line reproducibility and dot reproducibility in an image to be formed can be improved.

The average circularity of each toner is set to 0.955.
Above, preferably 0.960 or more, the standard deviation of the circularity is 0.040 or less, preferably 0.038 or less,
Since each toner can be superimposed on the recording medium in a dense state, the layer thickness of the toner on the recording medium can be reduced, and the fixing property can be improved. Further, by aligning the shapes of the toners in this way, the fog, fine line reproducibility, and dot reproducibility of the formed image are improved.

(Embodiment 1) In Embodiment 1, as a toner, a black toner, a color toner including a cyan toner, a magenta toner, and a yellow toner to which an infrared absorber is added, and an infrared absorber in the above color toner And a stealth toner to which a second infrared absorbing agent having a different infrared absorbing region is added.

In Embodiment 1, FIG.
The recording medium 1 wound into a roll is fed by each feed roller 2 using a full-color image forming apparatus shown in FIG.
From the upstream side to the downstream side in the feeding direction of the recording medium 1,
A first image forming unit 10Bk for supplying the black toner to the recording medium 1, and a second image forming unit 10C for supplying the cyan toner to the recording medium 1.
And a third for supplying the above-mentioned magenta toner to the recording medium 1.
Image forming unit 10M, and a fourth image forming unit 10 that supplies the yellow toner to the recording medium 1.
Y and a fifth image forming unit 10S for supplying the stealth toner to the recording medium 1 are provided in this order.

The first to fifth image forming units 10Bk, 10C, 10M, 10 are placed on one side of the recording medium 1 fed by the feed roller 2 as described above.
Each of the toners is supplied to an appropriate position from Y and 10S to continuously form a full-color toner image on one side of the recording medium 1.

In this way, black toner, cyan toner, magenta toner, yellow toner, and stealth toner are supplied on the recording medium 1 in this order.
In the portion where the stealth toner is supplied, the stealth toner is located in the uppermost layer, and in the portion where the stealth toner is not supplied and the yellow toner is supplied,
The yellow toner is located at the uppermost layer.

Then, the recording medium 1 on which a full-color toner image is continuously formed on one side as described above is guided by a feed roller 2 to a flash fixing device 20 using a flash lamp such as a xenon lamp. From 20, an infrared ray is applied to the full-color toner image formed on one surface of the recording medium 1, and the infrared ray fixes the full-color toner image on the recording medium 1.

When the full-color toner image is fixed on the recording medium 1 by irradiating infrared rays from the flash fixing device 20, the infrared rays are emitted in the order of stealth toner, yellow toner, magenta toner, cyan toner, and black toner. The intensity of the irradiated infrared rays decreases in the order of stealth toner, yellow toner, magenta toner, cyan toner, and black toner. become. For this reason, even if the amount of the infrared absorbing agent added to the stealth toner or the like having low infrared absorbing performance is reduced, these toners can be sufficiently fixed on the recording medium 1 by the flash fixing device 20, and The transparency and color of the toner hardly change due to the infrared absorbing agent, and a full-color image excellent in color reproducibility can be obtained.

Here, when the full-color toner image is fixed on the recording medium 1 by the flash fixing device 20 using the flash lamp as described above, the full-color toner image can be sufficiently formed on the recording medium 1 while reducing power consumption. It is preferable that the emission energy of the above-mentioned flash lamp be in the range of 3.0 to 7.0 J / cm ² in order to fix the toner.

In the embodiment shown in FIG. 1, a black toner, a cyan toner, a magenta toner, a yellow toner, and a stealth toner are supplied to the recording medium 1 on one side of the recording medium 1 fed by the feed roller 2. 1
To the fifth image forming units 10Bk, 10C, 10
Although only M, 10Y, and 10S are provided,
As shown in FIG. 2, the first to fifth image forming units 10Bk, 10C, 10M, 10Y, and 10 are respectively provided on both sides of the recording medium 1 fed by the feed roller 2.
S, a full-color toner image is continuously formed on both sides of the recording medium 1, and the above-mentioned flash fixing device 20 using a flash lamp is provided on both sides of the recording medium 1. It is also possible to irradiate the full-color toner images formed on both sides of the recording medium 1 with infrared rays, and to fix the full-color toner images on both sides of the recording medium 1 with the infrared rays.

(Embodiment 2) In Embodiment 2, as a toner, a black toner, a color toner composed of a blue toner, a green toner, and a red toner to which an infrared absorber is added, and an infrared absorber in the above color toner And a stealth toner to which a second infrared absorbing agent having a different infrared absorbing region is added.

In Embodiment 2, FIG.
The recording medium 1 wound into a roll is fed by each feed roller 2 using a full-color image forming apparatus shown in FIG.
From the upstream side to the downstream side in the feeding direction of the recording medium 1,
A first image forming unit 10Bk for supplying the black toner to the recording medium 1 and a second image forming unit 10B for supplying the blue toner to the recording medium 1
And a third for supplying the green toner to the recording medium 1.
Image forming unit 10G, and a fourth image forming unit 10R that supplies the red toner to the recording medium 1.
And a fifth for supplying the above-mentioned stealth toner to the recording medium 1.
And the image forming unit 10S.

The first to fifth image forming units 10Bk, 10B, 10G, 10 are placed on one side of the recording medium 1 fed by the feed roller 2 as described above.
Each of the toners is supplied to an appropriate position from R and 10S to continuously form a full-color toner image on one side of the recording medium 1.

In this manner, black toner, blue toner, green toner, red toner, and stealth toner are supplied on the recording medium 1 in this order, and the stealth toner is supplied to the portion where the stealth toner is supplied. Is located in the uppermost layer, and in a portion where the stealth toner is not supplied and the red toner is supplied, the red toner is located in the uppermost layer.

Then, the recording medium 1 on which the full-color toner image is continuously formed on one side as described above is guided by a feed roller 2 to a flash fixing device 20 using a flash lamp such as a xenon lamp. From 20, an infrared ray is applied to the full-color toner image formed on one surface of the recording medium 1, and the infrared ray fixes the full-color toner image on the recording medium 1.

When a full-color toner image is fixed on the recording medium 1 by irradiating infrared rays from the flash fixing device 20, the infrared rays are emitted in the order of stealth toner, red toner, green toner, blue toner, and black toner. The intensity of the irradiated infrared rays decreases in the order of stealth toner, red toner, green toner, blue toner, and black toner, and the strong infrared rays are irradiated to the toner having low infrared absorption performance. become. For this reason, even if the amount of the infrared absorbing agent added to the stealth toner or the like having low infrared absorbing performance is reduced, these toners can be sufficiently fixed on the recording medium 1 by the flash fixing device 20, and The transparency and color of the toner hardly change due to the infrared absorbing agent, and a full-color image excellent in color reproducibility can be obtained.

Here, when the full-color toner image is fixed on the recording medium 1 by the flash fixing device 20 using the flash lamp as described above, the full-color toner image can be sufficiently formed on the recording medium 1 while reducing power consumption. It is preferable that the emission energy of the above-mentioned flash lamp be in the range of 3.0 to 7.0 J / cm ² in order to fix the toner.

In the embodiment shown in FIG. 3, black toner, blue toner, green toner, red toner and stealth toner are supplied to the recording medium 1 on one side of the recording medium 1 fed by the feed roller 2. 1 to
Fifth image forming units 10Bk, 10B, 10
G, 10R and 10S are only provided,
As shown in FIG. 4, the first to fifth image forming units 10Bk, 10B, 10G, 10R, and 10 are provided on both sides of the recording medium 1 fed by the feed roller 2, respectively.
S, a full-color toner image is continuously formed on both sides of the recording medium 1, and the above-mentioned flash fixing device 20 using a flash lamp is provided on both sides of the recording medium 1. It is also possible to irradiate the full-color toner images formed on both sides of the recording medium 1 with infrared rays, and to fix the full-color toner images on both sides of the recording medium 1 with the infrared rays.

[0061]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an image forming method according to an embodiment of the present invention will be described in detail, and when a full-color image is obtained by the image forming method according to the embodiment of the present invention, a xenon lamp or the like is used. The fact that the full-color toner image can be sufficiently fixed on the recording medium by the flash fixing device will be described with reference to comparative examples.

Here, in the following Examples and Comparative Examples, the respective toners produced as described below were used.

(Yellow toner Y1) Yellow toner Y
In the production of No. 1, a polyester resin obtained as described below was used.

First, polyoxypropylene (2.2)-
2,2-bis (4-hydroxyphenyl) propane;
Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane and terephthalic acid were mixed at a molar ratio of 3: 7: 9, and these were used as polymerization initiators. Along with dibutyltin oxide, the mixture was placed in a four-neck glass flask equipped with a hygrometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube.

Then, the four-necked flask was set in a mantle heater, and heated and agitated while introducing nitrogen into the flask from the above-described nitrogen introduction tube to cause a reaction.
During the reaction, the reaction state was tracked while measuring the acid value, and the reaction was terminated when the acid value reached a predetermined value.
This was cooled to obtain a polyester resin.

The physical properties of the polyester resin thus obtained were such that the number average molecular weight (Mn) was 3,300 and the weight average molecular weight (Mw) / number average molecular weight (Mn) was 4.
2. The glass transition temperature (Tg) is 68.5 ° C and the softening point (T
m) was 110.3 ° C., the acid value was 3.3 KOH mg / g and the hydroxyl value was 28.1 KOH mg / g. Here, as for the glass transition temperature (Tg), a differential scanning calorimeter (manufactured by Seiko Instruments Inc .: DSC-200) was used, alumina was used as a reference, and a 10 mg sample was heated at a rate of 10 ° C.
/ Min at a temperature of 20 to 120 ° C., and the shoulder value of the main endothermic peak was taken as the glass transition point. The softening point (Tm) was measured using a flow tester (CFT-500, manufactured by Shimadzu Corporation).
mm, a 1mm long die, pressure 20kg /
cm ^2, the temperature corresponding to 1/2 of the height of the flow ending point from the flow starting point for a sample of 1 cm ² were melted runoff under the conditions of heating rate 6 ° C. / min and the softening point. Concerning the acid value, a 10 mg sample was dissolved in 50 ml of toluene, and the consumption of the N / 10 potassium hydroxide / alcohol solution, which had been evaluated in advance, was determined using a mixed indicator of 0.1% promthymol blue and phenol red. It was calculated from the amount.
The hydroxyl value was indicated by mg of potassium hydroxide required to treat the weighed sample with acetic anhydride, hydrolyze the obtained acetyl compound, and neutralize liberated acetic acid.

In using the polyester resin obtained as described above, the polyester resin was roughly pulverized so that the particle size became 1 mm or less.

The polyester resin and C.I. I. Pigment Yellow 180 (manufactured by Clearant) in a pressure kneader at a weight ratio of 7: 3, and kneaded at 120 ° C. for 1 hour.
This was cooled and then coarsely pulverized with a hammer mill to obtain a pigment masterbatch having a yellow colorant content of 30% by weight.

Next, the polyester resin 100
The C.I. I. The above-mentioned polyester resin and pigment master batch were sufficiently mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds so that Pigment Yellow 180 became 7 parts by weight.

The mixture was melted and kneaded by a twin screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.). The kneaded product was rolled to a thickness of 2 mm by a press roller, cooled by a cooling belt, and then cooled. Was coarsely pulverized by a feather mill. Thereafter, this is pulverized by a mechanical pulverizer (KTM, manufactured by Kawasaki Heavy Industries, Ltd.) and further pulverized by a jet pulverizer (IDS, manufactured by Nippon Pneumatic Industries, Ltd.). (ATP classifier 100ATP) to obtain yellow toner particles.

The yellow toner particles thus obtained have a volume average particle size of 7.2 μm and an average circularity of 0.9 μm.
54, the standard deviation of the circularity was 0.041.

Next, the yellow toner particles 100
0.5 parts by weight of a dithiol-based nickel complex (manufactured by Mitsui Chemicals, Inc .: SIR-130) and 0.5 parts by weight of hydrophobic silica (manufactured by Wacker Inc .: H2000) are used as the infrared absorber. After mixing these at a peripheral speed of 40 m / sec for 60 seconds using a Henschel mixer, a hybridization system (Nara Machinery Co., Ltd .:
(NHS-0 type) at 16400 rpm for 3 minutes, and the surface of the toner particles was fixed with an infrared absorbent.

Next, 0.2 parts by weight of hydrophobic silica (W2000: H2000) and titanium oxide (Titanium Industries: After adding 0.5 parts by weight of STT30A) and 1.0 part by weight of strontium titanate having an average particle size of 0.2 μm, and mixing them with a Henschel mixer at a peripheral speed of 40 m / sec for 60 seconds, Sieve through sieve with openings of 90 μm, yellow toner Y1
I got

The yellow toner Y1 has a volume average particle diameter Dv of 7.3 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.24, and an average circularity of 0. 962, the standard deviation of the circularity (roundness SD) was 0.036.

Here, the volume average particle diameter Dv and the number average particle diameter Dp were measured using a Coulter Multisizer II (manufactured by Coulter Counter) using a 50 μm aperture tube.

The average circularity and the standard deviation of the circularity (circularity SD) were determined by using a flow-type particle image analyzer (FPIA-2000, manufactured by Sysmec Corporation) using a water dispersion system. The length and the perimeter of a circle equal to the projected area of the toner particles are determined, the circularity is calculated by the following equation, and based on this, the average circularity and the standard deviation of the circularity (circularity SD) are determined. Was.

Circularity = perimeter of a circle equal to the projected area of toner particles / perimeter of projected image of toner particles

(Cyan Toner C1) In producing the cyan toner C1, the same polyester resin as in the case of the above-mentioned yellow toner Y1 is used, and this polyester resin and C.I. I. Pigment Blue 1
5-3 (manufactured by Dainippon Ink and Chemicals) was charged into a pressure kneader at a weight ratio of 7: 3, kneaded at 120 ° C. for 1 hour, cooled, and then coarsely pulverized with a hammer mill. Thus, a pigment master batch having a cyan colorant content of 30 wt% was obtained.

Then, the above-mentioned polyester resin 100
The C.I. I. Pigment Blue 15-3 in a proportion of 5 parts by weight, the polyester resin and the pigment masterbatch are sufficiently mixed by a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds. Yellow toner Y1
In the same manner as in the above case, a cyan toner C1 having a dithiol-based nickel complex (SIR-130, manufactured by Mitsui Chemicals, Inc.) fixed on the surface thereof was obtained.

The cyan toner C1 has a volume average particle diameter Dv of 7.2 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.23, and an average circularity of 0.2. 961, the standard deviation of circularity (circularity SD) was 0.036.

(Magenta Toner M1) Magenta Toner M
In producing the yellow toner Y1
The same polyester-based resin as in the case of the above was used, and this polyester-based resin and C.I. I. Pigment Red 184 (manufactured by Dainippon Ink) in a pressure kneader at a weight ratio of 7: 3, kneaded at 120 ° C. for 1 hour, cooled, and then coarsely pulverized by a hammer mill. Thus, a pigment masterbatch having a magenta colorant content of 30 wt% was obtained.

The above polyester resin 100
The magenta colorant C.P. I. Pigment Red 184 in a ratio of 4.5 parts by weight, the above-mentioned polyester resin and pigment masterbatch are sufficiently mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds, and thereafter, In the same manner as in the case of the yellow toner Y1, a magenta toner M1 having a dithiol-based nickel complex (SIR-130, manufactured by Mitsui Chemicals, Inc.) fixed on the surface thereof was obtained.

The magenta toner M1 has a volume average particle diameter Dv of 7.2 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.24, and an average circularity of 0.2. 962, the standard deviation of the circularity (roundness SD) was 0.036.

(Red Toner R1) In producing the red toner R1, the same polyester resin as in the case of the above-mentioned yellow toner Y1 is used, and this polyester resin and C.I. I. Pigment Red 4
8-1 (manufactured by Dainippon Ink and Chemicals) was charged into a pressure kneader at a weight ratio of 7: 3, kneaded at 120 ° C. for 1 hour, cooled, and then coarsely ground with a hammer mill. Thus, a pigment master batch having a red colorant content of 30 wt% was obtained.

The above polyester resin 100
The C.I. I. Pigment Red 48-1 in a proportion of 5 parts by weight, the above-mentioned polyester resin and pigment master batch are sufficiently mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds, and thereafter, Yellow toner Y1
In the same manner as in the above case, a red toner R1 having a dithiol-based nickel complex (SIR-130, manufactured by Mitsui Chemicals, Inc.) fixed on the surface thereof was obtained.

The red toner R1 has a volume average particle diameter Dv of 7.1 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.24, and an average circularity of 0. 962, the standard deviation of circularity (roundness SD) was 0.035.

(Green Toner G1) Green Toner G
In producing the yellow toner Y1
Using the same polyester resin as in the case of the above, a pressure kneader was used so that the weight ratio of this polyester resin and Lionol Green 8920 (manufactured by Toyo Ink Co., Ltd.) as a green colorant was 7: 3. After kneading at 120 ° C. for 1 hour, the mixture was cooled and then coarsely pulverized with a hammer mill to obtain a pigment master batch having a green colorant content of 30 wt%.

The above polyester resin 100
Green colorant Lionol Gre
The polyester resin and the pigment masterbatch were sufficiently mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds so that the amount of en8920 was 5 parts by weight.
In the same manner as in the case of No. 1, a green toner G1 having a dithiol-based nickel complex (SIR-130 manufactured by Mitsui Chemicals, Inc.) as an infrared absorber fixed to the surface was obtained.

The green toner G1 has a volume average particle diameter Dv of 7.2 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.23, and an average circularity of 0. 961, the standard deviation of the circularity (roundness SD) was 0.035.

(Blue Toner B1) In producing the blue toner B1, the same polyester resin as in the case of the above-mentioned yellow toner Y1 was used, and this polyester resin and C.I. I. Pigment Blue 1
5-3 (manufactured by Dainippon Ink and Chemicals) was charged into a pressure kneader at a weight ratio of 7: 3, kneaded at 120 ° C. for 1 hour, cooled, and then coarsely pulverized with a hammer mill. Thus, a pigment master batch having a blue colorant content of 30 wt% was obtained.

Then, the above-mentioned polyester resin 100
The C.I. I. Pigment Blue 15-3 in a proportion of 5 parts by weight, the polyester resin and the pigment masterbatch are sufficiently mixed by a Henschel mixer at a peripheral speed of 40 m / sec for 180 seconds. Yellow toner Y1
In the same manner as in the above case, a blue toner B1 having a dithiol-based nickel complex (manufactured by Mitsui Chemicals, Inc .: SIR-130) as an infrared absorber fixed to the surface was obtained.

The blue toner B1 had a volume average particle diameter Dv of 7.1 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.23, and an average circularity of 0.1. 962, the standard deviation of the circularity (roundness SD) was 0.036.

(Stealth toner S1) Stealth toner S
In producing the yellow toner Y1
In the production of, while not adding a colorant,
Y as an infrared absorber with respect to 100 parts by weight of toner particles
A stealth toner S1 was obtained in the same manner as in the case of the yellow toner Y1, except that 1 part by weight of a white infrared light-emitting fluorescent material composed of b _0.3 Y _2.7 Al ₅ O ₁₂ was added.

The stealth toner S1 has a volume average particle diameter Dv of 7.1 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.23, and an average circularity of 0.1. 962, the standard deviation of the circularity (roundness SD) was 0.036.

(Black Toner Bk1) In producing the black toner Bk1, the same polyester resin as used in the case of the yellow toner Y1 was used, and carbon black (manufactured by Cabot Corp .: Mogar) was used for 100 parts by weight of the polyester resin. L) in an amount of 8 parts by weight, and a boron salicylate complex of a charge controlling agent (manufactured by Nippon Carlit Co .: LR
151) to 1 part by weight, melt-knead them with a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.), roll the kneaded material to a thickness of 2 mm with a press roller, and cool with a cooling belt After that, this was roughly pulverized by a feather mill.

Thereafter, this was pulverized by a mechanical pulverizer (KTM, manufactured by Kawasaki Heavy Industries, Ltd.) and further pulverized by a jet pulverizer (IDS, manufactured by Nippon Pneumatic Industries, Ltd.), followed by a rotor classifier (manufactured by Hosokawa Micron). : Using a T-plex classifier 100ATP) to obtain black toner particles having a volume average particle size of 7.2 μm, an average circularity of 0.954, and a standard deviation of circularity of 0.041. Was.

Next, the black toner particles 100
Hydrophobic silica (W20: H20)
00) was added at a rate of 0.5 parts by weight, mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 60 seconds, and then mixed with a hybridization system (manufactured by Nara Machinery Co., Ltd., NHS-0) at 16400 rpm at 3400 rpm. Minutes.

Then, based on 100 parts by weight of the toner particles, 0.2 parts by weight of hydrophobic silica (H2000, manufactured by Wacker Inc.) and titanium oxide (STT3, manufactured by Titanium Industry Co., Ltd.)
0A) in an amount of 0.5 part by weight and strontium titanate having an average particle size of 0.2 μm in an amount of 1.0 part by weight, and these were added at a peripheral speed of 40 m / sec by a Henschel mixer.
After mixing for 0 seconds, sieve through a sieve with openings of 90 μm,
A black toner Bk1 was obtained.

The black toner Bk1 has a volume average particle diameter Dv of 7.3 μm, a ratio of the volume average particle diameter Dv to the number average particle diameter Dp (Dv / Dp) of 1.24, and an average circularity of 0.3. 961, standard deviation of circularity (roundness SD)
Was 0.038.

Further, as a carrier to be mixed with each of the above toners, a binder type carrier produced as follows was used.

Here, in order to obtain a binder type carrier, a polyester resin (manufactured by Kao Corporation: NE-11)
10), 100 parts by weight of magnetic particles (manufactured by Toda Kogyo Co., Ltd .: magnetite EPT-1000), and 2 parts by weight of carbon black (Cabot Co., Ltd .: Mogal L). The mixture was melt-kneaded with a twin-screw extruder in which the temperature of the cylinder was set to 180 ° C and the temperature of the cylinder head was set to 170 ° C.

After cooling the kneaded product, the mixture was roughly pulverized by a hammer mill, finely pulverized by a jet pulverizer, and classified to obtain a binder type carrier having a volume average particle size of 40 μm. The volume average particle size of the binder-type carrier was measured using a Coulter Multisizer II (manufactured by Coulter Counter) using a 150 μm aperture tube.

Then, each developer is prepared by mixing each of the toner and the binder type carrier so that the weight ratio of each toner becomes 7% by weight, and each of the thus prepared developers is mixed for 30 minutes. After that, each developer was supplied to each image forming unit shown in FIG. 1 and FIG. 3 to form a full-color image.

Here, as shown in Table 1 below, in each example, each toner is supplied onto the recording medium in the order shown in the first and second embodiments, while in each comparative example, By replacing each image forming unit, the order of each toner to be supplied onto the recording medium is changed so that each toner is supplied onto the recording medium. In the case of Comparative Examples 1, 2 and 5, the total amount of toner adhered was 12 g / m ^2, and in the case of Example 2 and Comparative Examples 3 and 4 in which five types of toners were superposed, the total amount of toner was Adhesion amount is 1
An image is formed on the recording medium 1 so as to be 5 g / m ^2, and each toner image thus formed is irradiated with about 4 J / cm ² of infrared light from the above-mentioned flash fixing device, thereby making each toner image The image was fixed on a recording medium, and each image was formed on the recording medium.

For each of the images thus formed on the recording medium, the fixability of the toner and the color reproducibility, fog, dot reproducibility and fine line reproducibility of the image were examined. The results were shown in Table 1 below. It was shown to.

Here, regarding the toner fixing property, the image density Io before rubbing the obtained image with a sand eraser was used.
And the image density Is obtained after rubbing, and the fixing strength is calculated by the following formula. When the fixing strength is 90% or more, the mark is indicated by ◎.
% For less than 70% or more and × for less than 70%
Indicated by

Fixing strength = (Is / Io) × 100

Regarding the color reproducibility, black toner is not used in the above-described full-color image forming apparatus. Other than that, as shown in Table 1, each toner is supplied to the recording medium in the order shown in the table. When the toner was sufficiently mixed and the color reproducibility of the image was good,
△ indicates a case where the color mixture was somewhat insufficient but there was no practical problem, and a cross indicates a case where the color mixture of each toner was insufficient and the desired color reproduction was not performed and had a practical problem.

Regarding the fog, dot reproducibility and fine line reproducibility, the case where the image quality is excellent is indicated by “○”, the case where the image quality is at a level which does not cause a practical problem is indicated by “△”, and the case where the image problem occurs is indicated by “×”. .

[0110]

[Table 1]

As a result, as shown in the first embodiment, when supplying the toner to the recording medium, the toner is supplied in the order of black toner, cyan toner, magenta toner, yellow toner, and stealth toner. The order of the toner to be supplied to the recording medium is different from that of the second embodiment in which the toner is located at the uppermost layer and that of the first embodiment in which the yellow toner is located at the uppermost layer without supplying the stealth toner. As compared with those of Comparative Examples 1 and 2 in which the toner is changed, each toner is sufficiently fixed on the recording medium by the flash fixing device, and there is a practical problem in terms of fog, dot reproducibility, and fine line reproducibility. No image was obtained, and color reproducibility was not deteriorated in the formed image.

As described in the second embodiment, when supplying the toner to the recording medium, the black toner,
In the third embodiment, the toner is supplied in the order of blue toner, green toner, red toner, and stealth toner, and the red toner is positioned at the uppermost layer without supplying the stealth toner. As compared with the toner of Comparative Example 3 in which the order of the toners to be changed is changed, the respective toners are sufficiently fixed on the recording medium by the flash fixing device, and are practical in terms of fog, dot reproducibility, and fine line reproducibility. An image without the above problems was obtained, and the color reproducibility of the formed image did not deteriorate.

In the above Comparative Examples 1, 3, and 5, the fixability of the toner to the recording medium was poor, and the toner was peeled off from the recording medium only by rubbing with a hand. Sex evaluation was not performed.

[0114]

As described in detail above, in the first image forming method of the present invention, when a full-color image is formed using at least a yellow toner, a magenta toner, and a cyan toner having an infrared absorbing agent, the yellow image is formed. In the portion where the toner is supplied, this yellow toner is positioned at the uppermost layer. Therefore, the yellow toner having a low infrared absorption performance can be supplied to the non-contact heat fixing device without adding much infrared absorbent to the yellow toner. As a result, the toner is sufficiently fixed on the recording medium, the color of the yellow toner is hardly changed by the infrared absorbing agent, and a full-color image having sufficient fixability and excellent color reproducibility is obtained. Became.

In the second image forming method according to the present invention, when a full-color image is formed by using a red toner, a green toner and a blue toner having an infrared absorbing agent, a portion where the red toner is supplied is Since the red toner is positioned at the uppermost layer, the red toner having a low infrared absorption performance can be sufficiently fixed on a recording medium by a non-contact heat fixing device without adding a large amount of an infrared absorbent to the red toner. As a result, the color of the red toner is hardly changed by the infrared absorbing agent, and a full-color image having sufficient fixability and excellent color reproducibility can be obtained.

Further, in the third image forming method of the present invention, a full-color image is formed by using a color toner having a first infrared absorber and a highly transparent stealth toner having a second infrared absorber. In the part where the stealth toner was supplied, the stealth toner was positioned at the uppermost layer, so that the stealth toner was not in contact with the stealth toner having low infrared absorption performance without adding much infrared absorber. The heat is fixed sufficiently on the recording medium by the heat fixing device,
Transparency of the stealth toner is hardly reduced by the infrared absorbing agent, and a full-color image having sufficient fixability and excellent color reproducibility can be obtained.

In the third image forming method, the first infrared absorber added to the color toner and the second infrared absorber added to the stealth toner are different, and the second infrared absorber is used as the second infrared absorber. Since the light emitting fluorescent material is used, the second infrared absorbing agent of the stealth toner is sensed by light in a specific infrared region, and various information can be written using the stealth toner without affecting the color image. It became so.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an example of a full-color image forming apparatus used to execute an image forming method according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing another example of a full-color image forming apparatus used for performing the image forming method according to the first embodiment.

FIG. 3 is a schematic explanatory view showing an example of a full-color image forming apparatus used to execute an image forming method according to a second embodiment of the present invention.

FIG. 4 is a schematic explanatory view showing another example of a full-color image forming apparatus used to execute the image forming method according to the second embodiment.

[Explanation of symbols]

1 Recording media 10Bk, 10C, 10M, 10Y, 10S, 10B,
10G, 10R Image forming unit 20 Flash fixing device

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) G03G 15/20 108 G03G 9/08 361 F term (reference) 2H005 AA06 AA15 AA21 CA21 EA05 EA10 FB03 2H030 AB02 AD01 AD04 AD05 2H033 AA02 AA11 BA25 BA58 BC09

Claims (8)

[Claims] 1. A color toner comprising at least a yellow toner, a magenta toner, and a cyan toner, supplying these color toners on a recording medium to form a full-color toner image, and fixing the toner image by non-contact heating. In an image forming method in which a full-color image is formed by fixing on a recording medium by an apparatus, a color toner having an infrared absorbing agent is used as the color toner, and in a portion where the yellow toner is supplied on the recording medium, An image forming method, wherein the yellow toner is positioned at the uppermost layer. 2. A full-color toner image is formed by using a red toner, a green toner, and a blue toner as color toners and supplying these color toners onto a recording medium. In the image forming method for forming a full-color image by fixing on a recording medium, a color toner having an infrared absorber is used as the color toner, and the red toner is supplied to a portion where the red toner is supplied on the recording medium. An image forming method, wherein the toner is positioned at the uppermost layer. 3. A full-color toner image is formed by supplying a color toner and a stealth toner onto a recording medium using a color toner and a highly transparent stealth toner, and the toner image is formed by a non-contact heat fixing device. In the image forming method of forming a full-color image by fixing on a recording medium, the color toner has a first infrared absorber and the stealth toner has a second infrared absorber,
The second infrared absorber is an infrared-emitting fluorescent material, and in a portion where the stealth toner is supplied on the recording medium,
An image forming method, wherein the stealth toner is located at the uppermost layer. 4. The image forming method according to claim 1, wherein a black toner is further used, and in a portion where the black toner is supplied onto a recording medium, the black toner is formed in a lowermost layer. An image forming method, comprising: 5. The image forming method according to claim 1, wherein a volume average particle diameter D of each of the toners.
v is in the range of 3 to 9 μm, and the ratio (Dv / Dp) of the volume average particle diameter Dv to the number average particle diameter Dp is 1.0 to 1.25.
An image forming method. 6. The image forming method according to claim 1, wherein the average circularity of each toner is 0.955 or more and the standard deviation of the circularity is 0.040 or less. An image forming method comprising: 7. The image forming method according to claim 1, wherein said non-contact heat fixing device is a flash fixing device using a flash lamp. 8. The image forming method according to claim 7, wherein said flash lamp has an emission energy of 3.0.
An image forming method characterized by being in a range of from 7.0 J / cm ^{2 to} 7.0 J / cm ² .