JP4400335B2 - Developing toner and developing toner discrimination method - Google Patents

Description

  The present invention relates to a developing toner used for developing an electrostatic latent image formed mainly by an electrophotographic method or an electrostatic recording method, and a method for determining the same.

In recent years, there has been a strong demand for high resolution and high image quality in image forming apparatuses such as electrophotographic systems and electrostatic recording systems, and therefore development of developing toners for developing the formed electrostatic latent images (electrostatic images). Is also progressing.
In general, each manufacturer's image forming apparatus is premised on the use of development toner (hereinafter referred to as “regular toner”) developed by the manufacturer, so that the reproduced image is optimal and the internal mechanism and various images are optimized. The formation conditions (charging charger voltage, developing bias, transfer voltage, fixing temperature, etc.) are designed.

However, recently, a situation has arisen in which other vendors manufacture and sell inexpensive toners (hereinafter referred to as “imitation toners”) that are not regular toners. If such a counterfeit toner is used, the color developability and the fixing property are deteriorated, and it is difficult not only to reproduce the optimum image quality guaranteed by the manufacturer, but in the worst case, it may cause a failure of the image forming apparatus. Absent.
For this reason, there is a strong demand for accurately discriminating between regular toner and counterfeit toner.

In general, as a method for imparting distinguishability to a developing toner, for example, Patent Document 1 and Patent Document 2 disclose a configuration in which a fluorescent substance is added to a developing toner.
Japanese Patent Laid-Open No. 11-138974 JP 2002-72542 A

Certainly, if a fluorescent substance is added to the toner, the toner can be discriminated with the naked eye. However, due to the addition, there arises a problem that the color tone of the copied image and the original is different and the reproducibility is remarkably deteriorated.
The present invention has been made in view of such circumstances, and provides a developing toner and a toner discriminating method that can discriminate regular toner by a simple method without impairing the reproducibility of a formed image. For the purpose.

In order to achieve the above object, a developing toner according to the present invention is a developing toner comprising toner particles comprising core particles containing at least a binder resin and coating layers covering the core particles, An infrared light emitting material is contained only in the coating layer .

The developing toner according to the present invention includes an infrared light emitting material in the toner particle coating layer. Therefore, it is easy to use a normal toner by detecting light in the near infrared to infrared region with an infrared light receiving element. It can be determined whether or not there is.
Further, the substance added to enable discrimination is an infrared light emitting material that emits light in the near infrared to infrared region, and the light in the region is not perceived by vision. Therefore, according to the developing toner according to the present invention, the quality of the reproduced image is not impaired.

Furthermore, since by containing an infrared light-emitting material only to the covering layer, while the so that can measure the light emitted from the infrared light emitting material from the outside effectively, infrared it needs to determine the toner luminescent material The addition amount of can be reduced. Further, the infrared light emitting material is less likely to be detached from the toner particles during use or storage as compared with the case where the infrared light emitting material is externally added around the toner particles.

The infrared light emitting material is preferably contained in the range of 0.01% by weight to 1.0% by weight with respect to the total amount of toner. This is because if it is less than 0.01% by weight, it becomes difficult to identify, and if it exceeds 1.0% by weight, the color may be impaired.
Here, the toner particles may be obtained by aggregating a plurality of resin fine particles and heat-sealing them. As a result, toner particles having a uniform size and a sharp particle size distribution can be obtained.

Furthermore, the developing toner discriminating method according to the present invention detects near-infrared to infrared light emitted from the developing toner contained in the agitation tank of the developing device, thereby detecting the developing toner. Is characterized by determining whether or not the toner is a developing toner containing the infrared light emitting material described above.

  If an infrared light emitting material is added to the regular toner, the regular toner and the counterfeit toner can be easily distinguished by the above-described discrimination method.

Hereinafter, the developing toner and the method for determining the developing toner according to the present invention will be described in detail based on the embodiments.
<First Embodiment>
1. Configuration of Developing Toner FIG. 1 is a schematic cross-sectional view showing the structure of particles of an electrostatic charge developing toner (hereinafter simply referred to as “toner”) according to the present embodiment.

As shown in FIG. 1, the toner particles 1 in the present embodiment are substantially composed of core particles 10 made of a binder resin and a color material, a capsule layer (coating layer) 20 that covers the core particles 10, and the capsule layer 20. It is comprised from the infrared luminescent material 30 distributed uniformly.
As the color material used as the raw material of the core particle 10, a known pigment conventionally used for coloring for a full color toner can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, duPont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green, oxalate, lamp black, rose pengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 184, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Solvent Yellow 162, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 3, C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 17, C.I. I. Pigment red 22, C.I. I. Pigment red 23, C.I. I. Pigment Blue 16 or the like can be used. Furthermore, nigrosine dye, iron black, etc. can be used.

  Examples of the binder resin include acrylic resins, styrene resins, styrene-acrylic resins, polyester resins, and those obtained by introducing silicon or fluorine into these resins. Examples of acrylic resin monomers include acrylic esters, methacrylic acids, their methyl esters, ethyl esters, n-butyl esters, 2-ethylhexyl esters and other alkyl esters that may be branched. Examples of styrene resin monomers include styrene, methylstyrene (o-, m-, p-isomer), p-ethylstyrene, p-methoxystyrene, and the like.

The infrared light emitting material 30 gives light in the infrared to near-infrared region (hereinafter referred to simply as “infrared light” in the present specification) rather than the conventional developing toner material as described above by applying energy such as heat and friction. For example, a phosphorescent lanthanide-based near-infrared light emitting complex represented by the following chemical formula [Ln (DBM) ₃ bath (Ln: Nd, Yb, Er) ] Can be used.

ここで、赤外発光材料３０の添加量は、トナー全重量に対して０．０１重量％から１．０重量％程度とする。０．０１重量％より少ないと他の現像用トナーとの識別が困難になるからであり、また、１．０重量％より多いと、色材の色味が損なわれるおそれがあるからである。

Here, the addition amount of the infrared light emitting material 30 is about 0.01 wt% to 1.0 wt% with respect to the total weight of the toner. This is because if it is less than 0.01% by weight, it is difficult to distinguish it from other developing toners. If it is more than 1.0% by weight, the color of the coloring material may be impaired.

The capsule layer 20 is formed of a known shell agent. Although FIG. 1 illustrates a case where the capsule layer is a single layer, the toner particles 1 may have a structure having a plurality of capsule layers.
In the toner particles 1, the infrared light emitting material 30 is distributed in the capsule layer 20. By including the infrared light emitting material 30 in the capsule layer 20 closer to the surface in this way, the infrared light emitted from the infrared light emitting material 30 is not shielded by the color material or the binder resin in the core particle 10. There is an advantage that the amount of the infrared light emitting material 30 necessary for detection can be reduced. Furthermore, it is possible to prevent the infrared light emitting material 30 from being detached from the toner particles during use or storage.

As described above, the toner particles 1 are preferably formed by a capsule structure, but the configuration of the toner particles 1 may be a type as shown in FIGS.
That is, a configuration in which the infrared light emitting material 30 is externally added to the surface of the core particle 10 as shown in FIG. Further, as shown in FIG. 2B, an infrared light emitting material 30 may be added to the core particle 10.

Alternatively, the toner particles 1 may be formed in a capsule structure, and the infrared light emitting material 30 may be provided on both the capsule layer 20 and the core particle 10.
If necessary, the toner particles 1 may be added with additives such as a charge control agent, a release agent, and a magnetic material, and external additives such as a fluidity improver.
Examples of the external additive include silicon oxide, aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, silicon nitride, silicon carbide, calcium sulfate, barium sulfate, and calcium carbonate.

  Various waxes can be used as the release agent. As the wax, waxes known in the field of electrostatic charge image developing toners can be used. For example, polyolefin waxes such as polyethylene wax and polypropylene wax, natural waxes such as carnauba wax and rice wax, montan wax, Fischer-Tropsch Examples thereof include wax and paraffin wax.

As described above, since the toner particle 1 has the infrared light emitting material 30, it emits infrared light. Therefore, by adopting toner particles 1 as regular toner and determining whether or not near infrared or infrared light is emitted in a dark place, it is determined whether a certain toner is regular toner or imitation toner. can do.
Here, the light used for discrimination in the toner particles 1 is infrared light and is not recognized by human eyes. Therefore, the toner according to the present embodiment has an advantage that the image quality of the printed matter is not deteriorated unlike the toner containing the fluorescent material described in the section of the prior art.

2. 1. Toner Production Method The toner particles 1 shown in FIG. 1 are formed by agglomerating a plurality of resin fine particles including a colorant and a binder resin by, for example, an emulsion polymerization agglomeration method, and heat-fusing to form particles. Manufactured. At this time, the resin fine particles containing the color material and the resin fine particles not containing the color material may be aggregated. The particles obtained by heating and melting the agglomerates in this manner are used as the core particles 10, and then the core particles 10 are coated with a shell agent containing an infrared light emitting material to form a capsule layer. The toner particles 1 having the structure shown in FIG.

By adopting such a manufacturing method, there is an advantage that the particle size and shape can be easily controlled, the size can be easily made uniform, and the particle size distribution can be sharpened. A toner containing an infrared light emitting material homogeneously can be easily obtained.
The toner particles 1 may be produced by a wet method such as a suspension polymerization method, an emulsion dispersion method, an interfacial polymerization method, or an emulsion polymerization method in addition to the emulsion polymerization aggregation method. Moreover, it is also possible to manufacture by a dry method through kneading, pulverization, and classification steps.

  In short, for the formation of the core particles and the capsule layer in the toner particles, a known production method used in the conventional developing toner can be used (for example, JP-A-2001-255703 for the emulsion polymerization aggregation method). JP, 2003-316064, JP 6-250439, JP 63-282752), and in this embodiment, infrared is contained in the shell agent for forming the capsule layer 30. There is a great feature in that particles of the luminescent material are mixed.

The toner particles shown in FIG. 2A can be manufactured by attaching a particulate infrared light emitting material 30 around the core particles 10 by a known external addition process. The toner particles shown in (2) can be produced by mixing the infrared light emitting material 30 into the material of the conventional core particle 10.
3. Toner discriminating method To discriminate the toner manufactured as described above, it is desirable to perform measurement in a state where outside light is blocked, for example, in a dark place, in order to avoid erroneous detection.

FIG. 3 is a schematic diagram showing a configuration for discriminating regular toner in a developing device in an electrophotographic image forming apparatus as an example.
As shown in the figure, the developing device 40 includes a toner hopper 41, a toner supply roller 42, a stirring tank 43, a developing roller 44, a photosensitive drum 45, and an infrared light receiving element capable of detecting infrared light. 50. Normally, an agitation roller for agitating and charging the toner supplied from the toner hopper 41 by friction is provided in the agitation tank 43, but the illustration is omitted here for the sake of simplicity. ing.

The infrared light receiving element 50 is made of, for example, a photodiode, and is disposed on the inner upper surface (position A) of the stirring tank 43 with its light receiving surface facing downward.
Based on the detection signal from the infrared light receiving element 50, it can be determined whether the toner used in the developing device 40 is regular toner or imitation toner. Specifically, when the toner present in the stirring tank 43 is a regular toner, infrared light is emitted from the infrared light emitting material by stirring or the like, and the infrared light receiving element 50 receives the infrared light and receives the infrared light. A detection voltage having a magnitude corresponding to the amount of received light is output. This output value is compared with a predetermined threshold value set in advance by a comparator in a detection circuit (not shown). For example, when the output value exceeds the threshold value, it is determined that the toner is normal toner, and If the output value is less than the threshold value, it is determined that the toner is a counterfeit toner.

  The determination result can be notified to the user by displaying a predetermined message on a liquid crystal display panel provided on an operation panel of a normal image forming apparatus, for example. Normally, it is sufficient to display only when it is determined that the toner is a counterfeit toner. In this case, for example, a message “Your toner is not regular toner” is displayed on the liquid crystal display panel. Moreover, instead of displaying such a message, or together with this, a warning lamp may be blinked or a warning sound may be sounded.

In addition to the position A, the infrared light receiving element 50 can be disposed at a position B or a position C indicated by a broken line (the light receiving surface of the infrared light receiving element is the stirring tank 43 or the toner hopper 41, respectively). It faces the toner inside through an opening (not shown) provided on the surface). However, if the detector is disposed at a position that is always in contact with the toner, such as positions B and C, the toner may adhere to the light receiving surface of the infrared light receiving element 50 and the detection accuracy may be reduced. Also, it is desirable to arrange at a position where it is difficult to come into contact with the toner, such as the position A.

In the determination method shown in FIG. 3, the determination is made with respect to the toner existing in the developing device 40. However, the normal toner is determined by measuring the amount of infrared light emission of the recorded matter printed on the transfer paper as follows. May be performed.
Specifically, as shown in the schematic diagram of FIG. 4, an infrared light receiving element 50 is arranged on the recording surface side of a recorded material thermally transferred by a fixing device after the toner image 70 is transferred to the transfer paper 60. The amount of infrared light emitted from the toner image 70 is detected, and when the detected value is equal to or greater than a predetermined threshold value, it is determined as normal toner, and otherwise, it is determined as imitation toner. can do.

Note that the threshold value for determining whether or not the toner is regular toner in each of the determination methods described above can be easily obtained through experiments or the like in advance. In addition, it is not always necessary to install a detection device in the image forming apparatus for discrimination, and any configuration can be used as long as it can detect infrared light from toner or toner recorded matter in a dark place. May be.
<Second Embodiment>
The second embodiment relates to a black toner for development. In the first embodiment, an infrared light emitting material is added to the toner. However, the present embodiment is characterized in that an infrared reflective material is added.
1. Configuration of Toner FIG. 5 is a schematic cross-sectional view showing the structure of particles of a developing black toner (hereinafter simply referred to as “black toner”) in the electrophotographic image forming apparatus according to the present embodiment.

The black toner 2 according to the second embodiment includes a core particle 10, a capsule layer (coating layer) 20 that covers the core particle 10, and an infrared reflective material 32 that is distributed in the capsule layer 20. Yes.
The core particle 10 is composed of a binder resin and a black colorant (coloring material) that does not exhibit reflection characteristics in the near infrared to infrared region.

As in the first embodiment shown in FIG. 1, the core particle 10 is covered with a capsule layer 20, and the capsule layer 20 has infrared characteristics that reflect light in the near infrared to infrared region. The reflective material 32 is distributed substantially uniformly.
As the binder resin, the same binder resin as in the first embodiment can be used.

Carbon black is preferably used as the black colorant. Nigrosine dye, iron black, and the like also have a weak reflection in the near infrared to infrared region, and therefore can be used as a black colorant.
The infrared reflecting material 32 means a material having a relatively large amount of reflected light in the near infrared to infrared region. In the present embodiment, the black colorant such as carbon black, nigrosine dye, and iron black is a material having a reflection property in the near infrared to infrared region, specifically, other than the black colorant. These known pigments and dyes can be used, and resin fine particles colored with the pigments and dyes may be used.

In order not to impair the color, the infrared reflective material 32 is contained in a smaller weight than the black colorant. Preferably, it is added so that the weight is less than half of the black colorant, more preferably less than 1/3 of the black colorant. Further, it is preferably about 0.01% to 0.8% by weight with respect to the total toner weight.
The capsule layer 20 is formed of a shell agent similar to the shell agent in the first embodiment.

Carbon black, which is widely used as a black colorant, has a property that the reflectance in the near infrared to infrared region is very low. Therefore, even when a general black toner is irradiated with infrared light, the infrared light is hardly reflected.
However, the black toner particles 2 according to the present embodiment are strongly reflected when irradiated with infrared light because the infrared reflective material 32 is added to the capsule layer 20. Therefore, it is possible to determine whether or not a certain toner is a regular toner by using a black toner as the regular toner and detecting the amount of reflected infrared light.

Moreover, since it is reflected in the infrared light region, it is not recognized by the human eye, the image quality of the printed matter is not deteriorated, and the content of the infrared reflecting material 32 is less than that of the black toner. Therefore, the color of the printed toner image is not easily impaired.
The black toner particles 2 are preferably of a capsule type in which the core particles 10 are covered with a capsule layer 20 as shown in FIG. By including the infrared reflective material 32 in the capsule layer 20, the shielding of the reflective agent by the binder resin or the like is prevented, the detection of the infrared reflected light is facilitated, and the infrared reflective material necessary for the determination is made. This is because the amount can be reduced.

However, it is not necessarily limited to the capsule type, and the infrared reflective material 32 may be externally added to the surface of the core agent 10 as in FIG. 2A in the first embodiment. In addition, as in the case of FIG. 2B, the toner can be discriminated also by a configuration in which the infrared reflecting material 32 is added into the core agent 10.
2. Black toner particle production method The black toner particle 2 is agglomerated with a plurality of resin fine particles containing a black colorant and a binder resin by, for example, an emulsion polymerization aggregation method in the same manner as the toner particle 1 according to the first embodiment. The core particles 10 are formed by wearing. At this time, the resin fine particles containing the color material and the resin fine particles not containing the color material may be aggregated. Subsequently, the black toner particles 2 having the structure shown in FIG. 5 can be obtained by coating the core particles 10 with a shell agent containing an infrared reflective material.

The black toner particles 2 can be produced by a wet method such as a suspension polymerization method, an emulsion dispersion method, an interfacial polymerization method, or an emulsion polymerization method in addition to the emulsion polymerization aggregation method. Moreover, it can also be produced by a dry method through kneading, pulverization and classification steps.
3. Next, a black toner discrimination method according to the present embodiment will be described in detail. Also in the present embodiment, it is desirable to perform toner determination in a dark place in order to avoid the influence of external light.

FIG. 6 is a schematic diagram showing a configuration in the case where regular black toner is discriminated in the developing device of the image forming apparatus.
The configuration of the developing device 40 is basically the same as that described with reference to FIG. 3, but in this embodiment, the infrared ray is reflected on the upper surface of the stirring tank 43 in order to detect the amount of reflected infrared light of the black toner. In addition to the light receiving element 50, an infrared light emitting element 52 that emits infrared light is disposed.

As the infrared light emitting element 52, for example, an infrared light emitting diode that emits light having an intensity (output) of about 10 μW to 1 mW and a wavelength of 900 to 1100 nm is used.
When the infrared light is emitted from the infrared light emitting element 52 to the black toner in the stirring tank 43 and the infrared light receiving element 50 detects the amount of reflected infrared light, the detected amount is equal to or greater than a predetermined threshold value. The toner is determined to be a regular toner, and if not, it is determined to be a counterfeit toner. The determination result is notified to the user by a display or an alarm sound in the same manner as described in the first embodiment.

  Further, along the circumferential surface of the photosensitive drum 45, an infrared light emitting element 53 and infrared light receiving elements 54 and 55 are arranged as shown in the figure, and the black toner is discriminated from the detection values of the infrared light receiving elements 54 and 55. You may do it. Specifically, the infrared light receiving element 55 directly detects the amount of infrared light emitted from the infrared light emitting element 53, and the infrared light receiving element 54 detects infrared reflected light from the surface of the photosensitive drum 45. When the relative ratio of the amount of reflected infrared light to the amount of emitted infrared light is determined to be equal to or greater than a predetermined threshold, the black toner can be determined to be a regular toner. In this case, the control unit in the image forming apparatus is configured to perform print control so that, for example, a black solid image is formed at the detection position of the photosensitive drum 45 when the toner discrimination mode is set. Just keep it.

  According to the detection method of this example, the light emission amount of the infrared light emitting element 53 is detected, and toner discrimination is performed while comparing with the light emission amount. Therefore, even if the light emission amount of the infrared light emitting element 53 changes over time. There is an advantage that accurate toner discrimination is possible. However, if a light source having a stable light emission amount is used, the infrared light receiving element 55 is not necessarily required, and thus such a configuration is not essential.

FIG. 7 is a schematic diagram showing a configuration for determining whether or not the used toner is a regular toner for the recorded matter after the toner image is fixed on the transfer paper.
As shown in the figure, in the recorded matter printed on the transfer paper 60, the infrared light emitting element 53 irradiates the portion where the toner image 70 exists with the infrared light, and the infrared reflected light from the toner image 70 is received by the infrared light. In addition to detection by the element 54, the infrared light receiving element 55 can directly detect the amount of infrared light emitted from the infrared light emitting element 53, and toner discrimination can be performed in the same manner as described above from both detection values. Also in this example, the infrared light receiving element 55 is not necessarily essential.

  Also in the determination method according to the present embodiment, each threshold value for determining whether or not the toner is a regular toner can be easily obtained in advance by an experiment or the like. In addition, it is not always necessary to install a detection device in the image forming apparatus, and in the dark place, infrared light is irradiated toward the toner or the recorded toner and the reflected infrared light is detected. Any configuration is possible as long as it is such.

Hereinafter, the developing toner and the determination method thereof according to the first and second embodiments will be described in detail with specific examples. However, the present invention is not limited to these examples. It is not a thing. In the following description, the number of parts represents part by weight.
(1) Preparation of pigment dispersion and the like <Preparation of pigment dispersion A>
25 parts of carbon black M-4750 manufactured by Cabot Co. is dispersed in 180 parts of pure water in a DCP mill using 10 parts of a sodium dodecylbenzenesulfonate dispersant, and a black pigment dispersion A having a solid content concentration of about 12 wt%. Got.

<Preparation of pigment dispersion B>
A magenta pigment dispersion B having a solid content concentration of about 12 wt% was obtained by the same procedure as the preparation of the pigment dispersion A, except that magenta pigment 527E manufactured by Fuji Color Co., Ltd. was used instead of carbon black.
<Preparation of pigment dispersion C>
Same as Preparation of Pigment Dispersion A, except that 20 parts of Carbon Black M-4750 from Cabot and 5 parts of Magenta Pigment 527E from Fuji Dye Co. were used instead of using carbon black alone. A dark black pigment dispersion C having a solid concentration of about 12 wt% was obtained by the procedure.

<Preparation of core agent A>
In a three-separable flask equipped with 450 parts of pure water and 0.56 parts of sodium dodecyl sulfate at 80 ° C. under a nitrogen flow and equipped with a Dimroth etc. to which 120 parts of a 1 wt% potassium persulfate aqueous solution was added, A mixture of 117 parts of styrene, 41 parts of butyl acrylate, 14 parts of methacrylic acid and 3 parts of n-octyl mercaptan was added dropwise over 1.5 hours using a branching dropping funnel, and the stirring was continued for 2 hours. After the reaction, the liquid was returned to room temperature to obtain milky white core agent A. The weight average molecular weight Mw of the polymer was 58,000, the glass transition temperature Tg was 52 ° C., the softening temperature Tm was 108 ° C., and the average particle size was 150 nm (measured by ELS-800 manufactured by Otsuka Electronics).

<Preparation of core agent B>
100 parts of the core agent A and 1 part of the infrared light-emitting material represented by the above [Chemical Formula 1] were dispersed and heated together to color the solid content, thereby obtaining the core agent B.
<Preparation of shell agent A>
400 parts of pure water and 0.4 parts of sodium dodecyl sulfate were stirred and mixed at 80 ° C. under a nitrogen flow, and branched into a three-necked separable flask equipped with a Dimroth etc. to which 100 parts of 1 wt% potassium persulfate aqueous solution was added. A mixture of 90 parts of styrene, 7 parts of butyl acrylate, 3 parts of methacrylic acid, and 0.6 part of n-octyl mercaptan was added dropwise over 1 hour using a dropping funnel, and the stirring was continued for 2 hours. After the reaction, the liquid was returned to room temperature to obtain a milky white dispersion. Next, 7 parts of an infrared light-emitting material represented by [Chemical Formula 1] was added to this dispersion, and the mixture was stirred, mixed, and heated to obtain shell agent A.

<Preparation of shell agent B>
Shell agent B was obtained in the same procedure as the preparation of shell agent A, except that the monomer used was 81 parts of styrene, 18 parts of butyl acrylate, and 1 part of methacrylic acid.
<Preparation of shell agent C>
7 parts of an infrared light emitting material represented by the above [Chemical Formula 1] was added to a polyester fine particle dispersion (Toyobo Co., Ltd. Vylonal MD-1200), and a shell agent C was obtained by stirring and mixing and heating.

<Preparation of shell agent D>
400 parts of pure water and 0.4 parts of sodium dodecyl sulfate were stirred and mixed at 80 ° C. under a nitrogen flow, and branched into a three-separable flask equipped with a gym load or the like to which 100 parts of a 1 wt% potassium persulfate aqueous solution was added. A mixture of 90 parts of styrene, 7 parts of butyl acrylate, 3 parts of methacrylic acid, and 0.6 part of n-octyl mercaptan was added dropwise over 1 hour using a dropping funnel, and the stirring was continued for 2 hours. After the reaction, the liquid was returned to room temperature to obtain milky white shell agent D.

<Preparation of shell agent E>
In the process of preparing the shell agent A, after obtaining a milky white dispersion, 60 parts of pigment dispersion B is added instead of the infrared light-emitting material represented by [Chemical Formula 1], and both are stirred, mixed, and heated. Shell agent E was obtained.
(2) Manufacture of experimental toner Next, toners for development up to the following experimental examples 1 to 10 are manufactured by combining the above prepared pigment dispersions A to C, core agents A and B, and shell agents A to D. did.

<Experimental example 1>
24 parts of Pigment Dispersion A, 240 parts of Core Agent A, 5 parts of Anionic Surfactant (Neogen SC; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and distilled water 240 parts were added and mixed with stirring, and the pH of the mixed solution was adjusted to 10.0 with an aqueous NaOH solution.

Further, 40 parts of a 50 wt% MgCl ₂ aqueous solution was added dropwise over 10 minutes, the temperature was raised to 80 ° C. for 30 minutes, the temperature was further raised to 88 ° C. and held for 30 minutes. At this time, the average particle size of the resin particles in the mixed dispersion was 4.5 μm.
Next, after the liquid temperature was lowered to 75 ° C., 48 parts of shell agent A was added, the temperature was raised to 83 ° C. and held for 1.5 hours. Further, 120 parts of a 20 wt% NaCl aqueous solution was added, and then the temperature was raised to 92 ° C. and held for 1 hour. After cooling to room temperature, filtration was performed, and washing by resuspension treatment with solid water in pure water was repeated several times, followed by drying.

  To 100 parts of the obtained particles, 0.5 part of hydrophobic silica (H-2000; manufactured by Clariant), 1.0 part of titanium oxide (STT30A: manufactured by Titanium Industry Co., Ltd.), and strontium titanate (average particle size of 0. 2 μm) 1.0 part was added, and the mixture was mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 60 seconds, and then passed through a sieve having an opening of 90 μm. Thus, a black toner (Experimental Example 1) containing an infrared light emitting material was obtained.

<Experimental example 2>
A magenta toner containing an infrared light emitting material (Experimental Example 2) in the same procedure as in Experimental Example 1 except that Pigment Dispersion B was used instead of Pigment Dispersion A and Shell Agent B was used instead of Shell Agent A Got.
<Experimental example 3>
A black toner containing an infrared light emitting material (Experimental Example 3) was prepared in the same procedure as in Experimental Example 1 except that Pigment Dispersion C was used instead of Pigment Dispersion A, and Shell Agent B was used instead of Shelling Agent A. Obtained.

<Experimental example 4>
A black toner (Experimental Example 4) containing an infrared light emitting material was obtained in the same procedure as in Experimental Example 1 except that Shell Agent C was used instead of Shelling Agent A.
<Experimental example 5>
A black toner (Experimental Example 5) containing an infrared light emitting material was obtained in the same procedure as in Experimental Example 1 except that the core agent B was used instead of the core agent A and the shell agent D was used instead of the shell agent A. .

<Experimental example 6>
A black toner (Experimental Example 6) containing an infrared light emitting material was obtained by the same procedure as in Experimental Example 1 except that the core agent B was used instead of the core agent A.
<Experimental example 7>
A black toner (Experimental Example 7) containing an infrared reflective material was obtained in the same procedure as in Experimental Example 1, except that Shell Agent E was used instead of Shell Agent A.

<Experimental Example 8>
A black toner containing an infrared reflective material (Experimental Example 8) was prepared in the same procedure as in Experimental Example 1 except that Pigment Dispersion C was used instead of Pigment Dispersion A, and Shell Agent E was used instead of Shell Agent A. Obtained.
<Experimental Example 9>
A dispersion of resin particles having an average particle diameter of 4.5 μm was prepared in the same procedure as in Experimental Example 1 except that Pigment Dispersion C was used instead of Pigment Dispersion A. Next, after the liquid temperature was lowered to 75 ° C., 48 parts of shell agent E was added, the temperature was raised to 83 ° C. and held for 1.5 hours. Further, after cooling to 75 ° C., 48 parts of shell agent D was added, the temperature was raised to 83 ° C. and held for 1.5 hours. Further, 120 parts of a 20 wt% NaCl aqueous solution was added, and then the temperature was raised to 92 ° C. and held for 1 hour. After cooling to room temperature, filtration was performed, and washing by resuspension treatment with solid content in pure water was repeated several times, followed by drying.

  To 100 parts of the obtained particles, 0.5 part of hydrophobic silica (H-2000; manufactured by Clariant), 1.0 part of titanium oxide (STT30A: manufactured by Titanium Industry Co., Ltd.), and strontium titanate (average particle size of 0. 2 μm) 1.0 part was added, and the mixture was mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 60 seconds, and then passed through a sieve having an opening of 90 μm. Thus, a black toner (Experimental Example 9) containing an infrared reflective material was obtained.

<Experimental example 10>
A toner (Experimental Example 10) containing no infrared light emitting material and no infrared reflective material was obtained in the same procedure as in Experimental Example 1 except that Shell Agent D was used instead of Shell Agent A.
(3) Evaluation (Measurement 1)
For the toners of Experimental Examples 1 to 6, and 10, in the dark, the intensity of light in the near infrared to infrared region generated from the toner was measured with an infrared light receiving element. The evaluation criteria are positive (◯) when the measured value of the toner of Experimental Example 1 is 1, and a relative value of 0.2 or more is positive (◯), 0.05 or more and less than 0.2 is Δ, and less than 0.05 is Negative (×).

(Measurement 2)
In addition, these toners are set in a commercially available electrophotographic printer (Magicolor 2300DL manufactured by Minolta Co., Ltd.), a solid image is printed on paper, and the intensity of light in the near infrared to infrared region generated from this printed matter in the dark is changed to infrared. Measured with a light receiving element. Evaluation criteria were the same as those in Measurement 1.

(Measurement 3)
On the other hand, the toners of Experimental Examples 7 to 10 are irradiated with infrared light having a distribution in the wavelength region of 900 to 1100 nm in the dark, and the spectral characteristics of the light in the infrared region reflected from the toner are infrared. Measured with a light receiving element. Evaluation criteria are positive (◯) when there is a region having a reflectance of 10% or more, Δ when the reflectance is 5% or more and less than 10%, and negative (×) when the reflectance is less than 5%. .

(Measurement 4)
In addition, these toners are set in a commercially available electrophotographic printer (Magicolor 2300DL manufactured by Minolta Co., Ltd.), and a solid image is printed on the paper. The red color having a distribution in the wavelength range of 900 to 1100 nm in the dark is applied to the printed matter. Spectral characteristics of light in the infrared region that was irradiated with external light and reflected from the printed material were measured with an infrared light receiving element. Evaluation criteria were the same as those in Measurement 3.

  The measurement results of (Measurement 1) to (Measurement 4) are shown in Table 1 below.

＜赤外発光材料を添加した場合（実験例１〜６）の評価＞
同表１に示すように赤外発光材料をカプセル層に添加したトナー（第１シェル剤としてシェル剤Ａ，Ｂ，Ｃを使用したもの：実験例１〜実験例４、６）においては、赤外発光量の測定１，２の双方において、陽性（○）と判定された。

<Evaluation when Infrared Luminescent Material is Added (Experimental Examples 1 to 6)>
As shown in Table 1, in the toner in which an infrared light emitting material is added to the capsule layer (using the shell agents A, B, and C as the first shell agent: Experimental Examples 1 to 4, 6), red It was determined to be positive (◯) in both measurements 1 and 2 of the external light emission amount.

  Further, in Experimental Example 5 (using the core agent B) in which the infrared light emitting material was added only to the core particles without being added to the capsule layer, negative (×) in measurement 1 and positive (◯) in measurement 2. It was judged. This is because, in measurement 1, since the measurement target is the toner before fixing, it is difficult to detect infrared light from the infrared light emitting material in the core particles from the outside. In measurement 2, the measurement target is fixed. This is considered to be because it is a later toner and is thermocompression bonded to expose the internal infrared light emitting material to the outside.

On the other hand, when neither the core particle nor the capsule layer contains an infrared light emitting material (Experimental example 10), both the measurements 1 and 2 were judged negative (x).
Therefore, by adding an infrared light emitting material to the capsule layer as a normal toner, it can be determined as a normal toner when it is determined to be positive in at least one of measurement methods 1 and 2. Further, when an infrared light emitting material is not added to the capsule layer as the regular toner but only to the core particles, the regular toner and the counterfeit toner can be distinguished by adopting the measurement method of measurement 2.

<Evaluation when Infrared Reflective Material is Added (Experimental Examples 7 to 9)>
As shown in Table 1, in Examples 7 and 8 in which black toner (shell agent E as a shell agent) in which a capsule layer is formed into one layer and an infrared reflecting material is added to this layer is used, the amount of infrared reflection It was determined as positive (◯) in both measurements 3 and 4.
In addition, the capsule layer was made into two layers, and an infrared reflective material was added to the first layer (inner layer), but no infrared light emitting material was added to the second layer (outer layer). With regard to the use of shell agent D as the second shell agent, it was determined to be negative (×) in measurement 3 and positive (◯) in measurement 4. In the case of measurement 3, since the measurement object is the toner before fixing, the infrared light irradiated from the infrared light emitting element is difficult to reach the infrared reflective material in the first layer. This is because most of the infrared light reflected by the first layer is absorbed by the second layer, and in the case of measurement 4, the measurement object is the toner after fixing, and it is thermocompression bonded to the inside. This is considered to be because the infrared reflective material is exposed to the outside and the amount of reflected infrared light increases accordingly.

On the other hand, in the case where neither the core particle nor the capsule layer contains an infrared reflective material (Experimental Example 10), the measurements 3 and 4 were both negative (x).
Therefore, if a normal toner having at least the outermost capsule layer added with an infrared reflecting material is used, it can be determined as a normal toner when it is determined to be positive in at least one of the measurement methods 3 and 4. . In addition, as a regular toner, when an infrared reflective material is included in a portion other than the outermost layer of the capsule layer (when there are a plurality of capsule layers, an infrared reflective material is added to the inner capsule layer and / or core particles) In the case of a single capsule layer, when an infrared reflective material is added only to the core particles), it is possible to distinguish between regular toner and counterfeit toner by employing the measurement method of measurement 4.

As described above, the regular toner and the counterfeit toner can be discriminated by adopting any one of Experimental Examples 1 to 9 as the regular toner. Of course, Experimental Examples 1 to 9 are examples that can be used as regular toners, and regular toners are not limited to these.
As described above, in the experimental example of this embodiment, only the case of the toner having the capsule layer has been described. However, the external addition type toner (see FIG. 2A) and the internal addition type toner (see FIG. 2B). Is understood that it can be determined according to the case where an infrared light emitting material or an infrared reflecting material is added to the outermost layer of the capsule layer.

As described above, in the present invention, an infrared light emitting material or an infrared reflecting material is used as an additive for the regular toner, and the light emitted or reflected by these materials is recognized by the human eye. It will never be done. Actually, in the above Experimental Examples 1 to 9, the image quality was not impaired when printing.
<Others>
(1) In each of the above embodiments, the light emission amount or reflected light amount of light in the near infrared to infrared region is simply measured to determine whether the toner is regular toner or imitation toner. If it is used to detect even the wavelength region within the infrared or near infrared region, it will be possible to make discrimination with higher accuracy.

That is, if a material that emits or reflects infrared light of a specific wavelength or near-infrared light is added to the toner, and it is determined that the toner is a regular toner when light in that wavelength range is measured, Even if a manufacturer of the present invention mixes an appropriate infrared light emitting material or infrared reflecting material into the toner, it is possible to accurately distinguish between regular toner and imitation toner.
(2) In the first embodiment, a colored color material is mixed in the core particles. However, a transparent toner may be used without necessarily using a colored color material.

  The present invention is suitable as a developing toner capable of discriminating between a regular toner and a counterfeit toner without impairing the image quality upon printing.

FIG. 3 is a schematic cross-sectional view showing the structure of the developing toner particles according to the first embodiment. (A), (b) is a schematic sectional drawing which shows another structure of the particle | grains of the developing toner which concerns on 1st Embodiment, respectively. FIG. 3 is a schematic diagram illustrating a method for discriminating developing toner according to the first embodiment in the developing device. FIG. 5 is a schematic diagram illustrating a method for determining whether or not the toner used for printing is the developing toner according to the first embodiment. It is a schematic sectional drawing which shows the structure of the particle | grains of the black toner for image development concerning 2nd Embodiment. FIG. 10 is a schematic diagram illustrating a method for determining a developing black toner according to a second embodiment in a developing device. FIG. 6 is a schematic diagram illustrating a method for determining whether or not a toner used for printing is a developing toner according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toner particle 2 Black toner particle 10 Core particle 20 Capsule layer 30 Infrared luminescent material 32 Infrared reflective material 40 Developing device 41 Toner hopper 42 Toner supply roller 43 Stirrer tank 44 Developing roller 45 Photosensitive drum 50, 54, 55 Infrared light reception Elements 52 and 53 Infrared light emitting element 60 Transfer paper 70 Toner image

Claims (4)

A developing toner comprising toner particles comprising at least core particles containing a binder resin and a coating layer covering the core particles,
A developing toner comprising an infrared light emitting material only in the coating layer . The developing toner according to claim 1, wherein the infrared light emitting material is contained in a range of 0.01 wt% to 1.0 wt% with respect to the total amount of the toner. The toner particles, developing toner according to claim 1 or 2, wherein the aggregate a plurality of resin particles, is obtained by heat sealing. The developing toner according to any one of claims 1 to 3 , wherein the developing toner is detected by detecting light in a near-infrared to infrared region emitted from the developing toner stored in a stirring tank of the developing device. A developing toner discriminating method comprising discriminating whether the toner is a developing toner.

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