JPH05150663A - Decolorizing method and decolorizing device - Google Patents

Abstract

PURPOSE:To provide a decolorizing method and a decolorizing device by which the decolorizing speed of a toner image formed on a sheet body is drastically improved and the trace of the toner image which is decolorized on the sheet body is made inconspicuous. CONSTITUTION:The toner image by toner which can be photochemically decolorized on a recording paper 6 is ground by the grinding roller 38 of a working device 37 and the thickness of a toner layer is made thin. Thereafter, the toner which is heated at least to the temperature equal to or above the glass-transition temperature TG of the binding resin of the toner, ideally, temperature equal to or above the softening point of the binding resin and the temperature under the thermal separation temperature of the component of the toner by a heating roller 87 and is in a rubber elastic state or a melted state is irradiated with near infrared rays.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for erasing a toner image formed on a sheet body by using a photochemically erasable toner.

[0002]

2. Description of the Related Art In recent years, the reuse and recycling of used paper has been reviewed to protect nature, especially to protect forest resources and reduce waste in urban areas. As part of this, the reuse of used copy paper, printed matter, facsimile paper, etc. that has become unnecessary in the offices of companies is being studied.

However, since most of these papers are company confidential documents which are generally regarded as trade secrets, it is extremely difficult to collect and recycle these papers outside the company. Yes, and because the recorded and printed parts of printed matter, copies, etc. cannot be easily erased, they must be incinerated or crushed and discarded.
It was thought that such recycling of papers was practically impossible.

[0004]

Therefore, as a result of intensive studies in view of the above-mentioned conventional examples, the inventors of the present invention found a near-infrared erasable dye capable of absorbing near-infrared rays and erasing the color. Developed toner using dye,
Proposed in 77725. When electrostatic copying is performed using the toner, images, prints, etc. recorded on a sheet body such as copy paper can be erased only by irradiating with near-infrared rays, and electrostatic copy or printing can be performed again after erasing. Since it can be performed, it becomes possible to reuse the sheet body, and when discarding the used sheet body, recorded images, prints, etc. can be erased by irradiation of near infrared rays,
There are many advantages such as being able to collect and recycle sheet bodies inside a company without leaking confidential matters to the outside.

However, the erasing speed due to only the irradiation of near infrared rays is slow. For example, if an attempt is made to erase the toner image on the entire recording paper of size A4, Japanese Industrial Standard, at least 1.
It takes about several tens of seconds per sheet. That is, there is a problem that only a few sheets / minute can be erased.

Therefore, an object of the present invention is to solve the above-mentioned technical problems, to remarkably improve the decoloring speed of a toner image formed on a sheet body, and to be erased on the sheet body. It is to make the traces of the toner image inconspicuous.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a method of erasing a toner image formed by a photochemically erasable toner formed on a sheet body, in which the toner layer of the toner image is scraped off. A decolorizing method comprising a processing step of partially removing in the layer thickness direction by peeling, and a near infrared ray irradiation step of irradiating the toner image with near infrared rays.

Further, according to the present invention, in a decoloring device for decoloring a toner image formed by a photochemically decolorable toner formed on a sheet member, the toner layer of the toner image is scraped or peeled off. An erasing apparatus characterized by including a processing means for partially removing in the layer thickness direction and a near infrared ray irradiation means for irradiating the toner image with near infrared rays.

[0009]

According to the present invention, when a toner image formed by a photochemically decolorizable toner formed on a sheet is to be decolored, the toner of the toner image is scraped off or peeled off. Since the near-infrared rays are irradiated after being partially removed in the layer thickness direction, the decoloring reaction of the deep layer portion of the toner image is promoted. As a result, the decoloring speed of the toner image formed on the sheet body is significantly improved. Further, the traces of the decolorized toner image on the sheet body are inconspicuous because the toner is partially removed in the layer thickness direction and the layer thickness is thin.

The sheet body which can be recycled and used in the present invention is, for example, recording paper used for ordinary electrostatic photography, OHP film, magnetic card, plastic sheet for display board, and the like, electrostatic copying used for office and business. All possible papers,
When a sheet including a plastic film or the like is erased, the heat distortion temperature of the plastic film needs to be higher than the glass transition temperature of the toner to be used.

[0011]

EXAMPLES Image formation on a recording sheet using the decolorizable toner used in the present invention is carried out by using, for example, an electrostatic copying machine. The toner used in this electrostatic copying machine is a photochemically decolorizable toner, and is a decoloring toner that is decolorized by absorbing near infrared rays. For details of a number of composition examples of such decoloring toner and the appearance of the decoloring action of the toner of each composition example, the above-mentioned Japanese Patent Application No. 3-27772.
5 are mentioned. Therefore, in the following examples, several examples of decolorizable toner will be shown. The present invention is not limited to the example of this embodiment, but includes a wide variety of modifications in accordance with the spirit of the present invention.

Such an erasable toner is, for example, constituted by dispersing a dye and an organic boron ammonium salt in a styrene resin. The dye is represented by the following chemical formula 1 or chemical formula 2, for example.

[0013]

[Chemical 1]

[0014]

[Chemical 2]

The styrene resin is widely used as a binder resin for toner. The dyes represented by the above chemical formulas 1 and 2 are one of cyanine dyes, and when coexisting with an organic boron ammonium salt, when they are irradiated with near infrared light having a wavelength of around 820 nm, they absorb near infrared light and become non-visible. A reversible reaction occurs and the blue color disappears and becomes colorless. As the organic boron ammonium salt, for example, tetrabutylammonium n-butyltriphenylboron represented by the following chemical formula 3 is used.

[0016]

[Chemical 3]

Decoloring of the toner image on the recording paper on which the toner image is formed by the decoloring toner formed as described above is performed as follows, for example.

In the examples below, the T shown in Table 1 below is used.
Four types of decoloring toners 1 to T4 were prepared and used.

[0019]

[Table 1]

In Table 1, symbols RE1 to RE2 are binder resins, for example, a styrene-acrylic resin is used, and RE1 is Hymer SBM-100 manufactured by Sanyo Chemical Industries, Ltd., which has a softening point. MP is 104 ℃,
The glass transition temperature TG is 60 ° C. RE2 is Hymer ST-125 manufactured by Sanyo Kasei Co., Ltd., and has a softening point MP of 125 ° C and a glass transition temperature TG of 50 ° C.

The symbols DY1 and DY2 are dyes, and DY1
Is the dye shown in Chemical Formula 1 above, and DY2 is the dye shown in Chemical Formula 2 above. The sensitizer in Table 1 is an organic boron ammonium salt, which is tetrabutylammonium n-butyltriphenylboron shown in Chemical formula 3 above. The example of the wax in Table 1 above is polypropylene wax manufactured by Sanyo Chemical Industries, Ltd.
50P was used.

The respective mixtures T1 to T4 in Table 1 were kneaded with a pressure mixer at a temperature of 120 ° C. for 15 minutes. Thereafter, the cooled solidified product was pulverized by a jet mill, and then a classifier was used to obtain a toner having a particle size of about 5 to 20 μm and an average particle size of about 10 μm. Next, 0.5 part by weight of silica-based fine powder was added as an external additive to 100 parts by weight of the toner, and mixed with a Henschel mixer. The silica-based fine powder adheres to the surface of the toner and has the function of aligning the charging polarity of the toner with the negative electrode, improving the charging ability of the toner and preventing the toner from aggregating and solidifying.

As the carrier mixed with the toner of this embodiment, Cu-Zn ferrite was used. Specifically, the product name FB-810 manufactured by Kanto Denka Kogyo Co., Ltd. was used. 95 parts by weight of this carrier and 5 parts by weight of the toner were put in a polypropylene container and mixed at 50 rpm for 30 minutes to obtain a developer. As the recording paper, a laser beam printer KX-P4420 manufactured by Kyushu Matsushita Electric Co., Ltd. was used, and a copy paper NoV602 manufactured by Fuji Xerox Co., Ltd., which was printed with “TONER” in a square character of about 4 mm. The thick layer of the toner image on the recording paper was about 35 μm.

Example of Decoloring Method An experiment on the decoloring method of the present invention was conducted as follows. A recording paper having a toner layer thickness of about 35 μm, which was printed using the above-described decolorizable toner, was taken out, and the toner image was shaved to a layer thickness of about 10 μm by an abrasive member such as so-called sand paper as described later, and then, Irradiation with near infrared rays was performed. At this time, the irradiation time of near infrared rays until the toner image on the recording paper was completely erased was examined.

As another experimental example, a heat roller heated to about 110 to 130 ° C. was pressed against the surface of the recording paper having the toner layer thickness of about 35 μm. As a result, the toner image was reversely transferred to the heat roller, and the toner layer thickness on the recording paper side was set to about 15 μm.

The recording paper on which the toner image was reversely transferred to the heat roller was immediately irradiated with near infrared rays, and the irradiation time until complete erasing was examined. The thickness of the toner layer on the recording paper was measured by cutting the recording paper together with the toner layer and observing the cut surface with a microscope. These experiments relating to the erasing method of the present invention were carried out by installing the experimental apparatus shown in FIGS. 1 and 2 in a dark room.

FIG. 1 is a schematic diagram of an experimental apparatus 30 used for performing such measurement. This measurement was performed by installing the experimental apparatus 30 shown in the figure in a dark room. In this structure, a cylindrical heat insulating cover 53 having an upper opening is mounted on the heater 33 in an airtight manner, and the transparent heat resistant glass 5 is provided in the opening of the heat insulating cover 53.
Fix 4 airtightly. As a result, an internal space 55 that is airtight to the outside is formed. The recording paper 6 on which the toner image formed by the photochemically decolorizable toner is formed is mounted on the support plate 52 made of a heat insulating material and disposed on the heater 33, and the abrasive material 31 such as sandpaper is A processing member 36 in which the cylindrical body 32 mounted on the outer periphery is held by a holding piece 34.
Holds the holding piece 3 in order to polish and remove the toner layer on the recording paper 6.
It is configured to be able to reciprocate in the arrow direction on the recording paper 6 while being held by 4. After this processing, the heater 33 heats the recording paper 6. A light source 35 such as a halogen lamp is arranged above the recording paper 6.

That is, in this construction, the heater 33 heats the air in the internal space 55, and the heated air heats the recording paper 6. Temperature of recording paper 6, that is, internal space 55
The temperature is measured by a thermometer 56 that penetrates the heat insulating cover 53 and projects into the internal space 55.

The procedure for decoloring the toner on the recording paper 6 by using the configuration shown in FIG.
Polish the top toner. Next, the heater 33 heats the air in the internal space 55 to bring the temperature of the internal space 55 measured by the thermometer 56 to a predetermined temperature. Internal space 55
When the temperature reaches a predetermined temperature, the state is maintained as it is for about 5 minutes, and thereafter, near-infrared rays are irradiated by the light source 35. As the light source 35, an aluminum coat type halogen lamp that generates near infrared rays is used.
Irradiation was performed at the rating of.

FIG. 2 is an enlarged sectional view of an experimental apparatus 30a which realizes the second embodiment of the erasing method of the present invention. The experimental device 30a is similar to the experimental device 30 of FIG. 1, and the same reference numerals are given to corresponding parts. The experimental apparatus 30a is characterized in that, in the experimental apparatus 30, the processing member 36 is configured as a metal reverse transfer roller 43 having a heat source 45 such as a lamp or a heater built therein, and the reverse transfer roller 43 is a holding piece 34. While being held, the toner image on the recording paper 6 is melted by the heat from the heat source 45. The term "reverse transfer" as used herein means that the toner layer transferred onto the recording paper 6 is heated to a temperature equal to or higher than the glass transition temperature TG so that it has at least rubber elasticity, preferably a melted state, and is transferred to a belt or a roller. It is a process of transferring the toner in such a state.

When the reverse transfer roller 43 is rotated on the recording paper 6, the melted toner 75 adheres to the surface of the reverse transfer roller 43 forming a reverse transfer layer 46. In this way, the toner 75 on the recording paper 6 can be peeled off and removed, and the toner layer thickness can be reduced prior to the irradiation of near infrared rays.

The erasing processing procedure using the experimental apparatus 30a is almost the same as that using the experimental apparatus 30, and the toner 75 is reversely transferred by the reverse transfer roller 43, that is, the recording paper 6 is used.
After peeling off and removing the surface layer portion of the toner layer from above, the heat treatment by the heater 33 and the light source 35 as described above are performed.
Near-infrared irradiation processing is performed.

Also according to the embodiment of such a decoloring method,
It is possible to achieve the same effects as those described in the above embodiment.

Table 2 shows the results of such measurement. In this experimental example, 10 observers were prepared for the determination of the erasing completion, and the shortest time when 6 out of 10 judged that the erasing was completed is the erasing completion, and this shortest time is necessary for the erasing. Irradiation time. The softening point MP of the toner is measured by the Japanese Industrial Standard JIS K-2207 (1990) ring and ball method, and the glass transition temperature is measured by a thermal analyzer (DSC) according to the American standard ASTM D3418-82. The measurement method is as follows.

[0035]

[Table 2]

The following can be seen from Table 2. That is, as in Examples 1, 2, 4, 5, 5, 7, 8, 10, and 11, the recording paper 6 on which the toner layer has a layer thickness of about 35 μm and which is subjected to decoloring processing.
When the thickness of the toner layer is reduced to about 10 μm by polishing, the irradiation time of near infrared rays required for complete decoloring is
The time is remarkably shortened as compared with the original toner layer having a thickness of about 35 μm. Similarly, when the toner layer thickness on the recording paper 6 is thinned by the above-described reverse transfer process as in Examples 3, 6, 9 and 12, the irradiation time of the near infrared rays required for complete erasing is the same as the original one. As compared with the toner layer having a thickness of about 35 μm, the time can be remarkably shortened.

Further, when comparing the inconspicuousness of the toner printing portion on the recording paper 6 after the color erasing processing with the toner layer thickness of about 35 μm and the toner layer thickness of about 10 to 15 μm, the toner layer It can be seen that the film having a thickness of about 10 to 15 μm is less noticeable. This inconspicuousness is evaluated by, for example, visually observing the toner-printed portion after the color erasing process, and it is not possible to clearly recognize the protrusion of the toner layer on the recording paper 6. Those that were not clearly recognized were rated as “◯”.

Therefore, in order to make the toner-printed portion after color erasing inconspicuous, the toner layer on the recording paper 6 is abraded so as to be partially removed in at least the layer thickness direction, or by the above-mentioned reverse transfer or the like. It is understood that the toner layer may be thinly removed by partially removing it in the layer thickness direction.

Therefore, in this embodiment, when erasing the toner image with the erasing toner, the toner layer on the recording paper is partially removed in the layer thickness direction and thinned before irradiating with near infrared rays, and then, Irradiate near infrared rays. As a result, the erasing speed in the deep portion of the toner layer is improved. Further, since the toner layer on the recording paper is erased in a state where the toner layer is thin, the toner layer after the erase can be made extremely inconspicuous on the recording paper.

The erasing method of the present invention is not limited to the example in which the toner layer having the layer thickness of 35 μm on the recording paper 6 is thinned to the layer thickness of about 10 μm as in the above-mentioned embodiment. That is, according to the present invention, regardless of the layer thickness of the toner layer on the recording paper 6, the surface layer portion is removed by scraping or peeling the toner layer, and the near infrared ray is applied to the thinned toner layer. It includes a wide variety of modified examples of irradiating.

(Embodiment of Decoloring Apparatus) FIG. 3 is a sectional view of a decoloring apparatus 60 according to an embodiment of the present invention, and FIG. 4 is an enlarged sectional view of the decoloring apparatus 60. The erasing device 60 includes a tray 83 on which the recording papers 6 to be erased are stacked. The recording papers 6 on the tray 83 are taken out by a paper feed roller 84 and supplied to the endless belt 64 side by a registration roller 85. The processing device 37 is arranged on the upstream side of the endless belt 64 in the conveyance direction A1 of the recording paper 6. The processing device 37 is
The duct 40 is provided so as to cover the endless belt 64 over the entire length in the width direction and is opened downward. The duct 40 is driven to rotate about a rotation axis parallel to the width direction of the endless belt 64 and has a rough outer peripheral surface. A polishing roller 38, which is processed or sandpaper is fixed to the recording paper 6, is arranged at a position for polishing the toner layer 75 on the recording paper 6 to have a layer thickness of about 10 μm, and is rotationally driven in the arrow A2 direction.

In the duct 40, the polishing roller 3
In order to remove the toner adhering to the polishing roller 38, a cleaning brush 39 formed by implanting electrically insulating fibers on a cylindrical member is arranged at a position where it slides on the outer surface of the roller 8. The air in the duct 40 is sucked from the outside and set to a negative pressure. That is, the toner removed from the surface of the polishing roller 38 by the cleaning brush 39 is drawn to the outside by the suction action and is collected by a dust collecting device (not shown). Further, the endless belt 6 is formed between the polishing roller 38 and the polishing roller 38.
The support member 41 is arranged at a position where the recording paper 4 and the recording paper 6 are clamped.

The heating unit 59 arranged downstream of the processing device 37 in the conveying direction A1 of the recording paper 6 has a heat insulating wall 61 made of a heat insulating material, and a heating roller 59 is provided on a lower portion of the heat insulating wall 61 to hang a pair of rollers 62, 63. An endless belt 64 to be passed is provided.
A pressing roller 86 is arranged between the pair of rollers 62 and 63 in a space surrounded by the endless belt 64,
A heating roller 87 is arranged on the opposite side of the endless belt 64 from the pressing roller 86. As a result, the recording paper 6 sandwiched between the rollers 86 and 87 is heated at least to the glass transition temperature TG or higher of the binder resin used for the toner, preferably to the melting point MP or higher, and at least in the rubber elastic state. Toner is spread.

Conveying rollers 88 and 89 are disposed above the rollers 62 and 63, respectively, and the recording paper 6 is conveyed while being sandwiched between the recording paper 6 and the endless belt 64. A light source 35 is disposed inside the heat insulating wall 61, and a fan 90 is provided above the light source 35. The light source 35 irradiates near infrared rays while pressing the recording paper 6 on the endless belt 64 against the endless belt 64. It The color-erased recording papers 6 are stacked on the tray 91.

Even with such an embodiment, the same effects as those described in the embodiment of the erasing method can be achieved.

FIG. 5 is a sectional view of an erasing device 60a according to another embodiment. This embodiment is similar to the embodiment shown in FIG. 3, and the corresponding parts are designated by the same reference numerals. In the erasing device 60b, the processing device 37a arranged on the upstream side of the endless belt 64 in the conveyance direction of the recording paper 6 is provided with a duct 40 that opens downward and covers the endless belt 64 over the entire length in the width direction. In the duct 40, the electrically insulating fiber is planted on the cylindrical member for removing the toner on the recording paper 6, which is driven to rotate in the direction of arrow A2 about the rotation axis parallel to the width direction of the endless belt 64. Toner removal brush 4
2 is placed. The air in the duct 40 is sucked from the outside and set to a negative pressure. That is, the toner removed by the toner removing brush 42 from the surface of the recording paper 6 is drawn to the outside by the suction action and is collected by a dust collecting device (not shown).

The embodiment having such a configuration can also achieve the same effect as that of the above embodiment.

FIG. 6 shows an erasing device 60b of another embodiment.
FIG. This embodiment is similar to the embodiment shown in FIG. 3, and the corresponding parts are designated by the same reference numerals. In the erasing device 60b, a pair of endless belts 64a and 64b are provided on the downstream side of the registration roller 85 and two pairs of rollers 6 are provided.
2a, 63a; 62b, 63b, respectively. A heater 65 is disposed between the pair of rollers 62a and 63a in a space surrounded by the endless belt 64a, and the roller 62 is disposed inside the endless belt 64b.
A plurality of pressing rollers 92 that press the endless belt 64b against the heater 65 via the endless belt 64a are arranged between b and 63b. A fan 68 is provided above the endless belt 64a to cool and solidify the molten toner adhering to the endless belt 64a.

The recording paper 6 is attached to the endless belt 64a.
Since the upper toner image has rubber elasticity or is melted by being heated by the heater 65, a brush-like cleaning member 93 that is rotationally driven is arranged and cleaned in order to remove the toner attached to the endless belt 64a. The waste toner removed by the member 93 is stored in the storage tank 94. Further, a peeling claw 95 for contacting the end of the endless belt 64a with the roller 63a from outside and peeling the recording paper 6 from the endless belt 64a is provided.

An irradiation unit 70 for irradiating the recording paper 6 with the light including the near infrared rays is provided on the downstream side of the endless belts 64a and 64b along the conveying direction A1 of the recording paper 6. In the irradiation unit 70, the light source 72 is arranged in the heat insulating wall 61. A mounting table 71 is arranged below the light source 72, and a pair of fixing rollers 73 is arranged on the downstream side of the mounting table 71 in the transport direction A1 so that the decolored toner remaining on the recording paper 6 is removed. The recording paper 6 is pinched by the pair of fixing rollers 73 and stretched over the entire width of the recording paper 6 to make the surface of the recording paper 6 relatively smooth. A pair of discharge rollers 74 is arranged on the downstream side of the fixing roller 73 in the conveying direction, and the recording paper 6 whose toner image has been erased is discharged to the outside of the erasing device 60 and stored in the tray 91.

With such an embodiment, the same effect as that of the above-mentioned embodiment can be achieved.

FIG. 7 shows a decoloring device 60c of still another embodiment.
8 is an enlarged cross-sectional view of the erasing device 60c. This embodiment is similar to the embodiment shown in FIG.
Corresponding parts are designated by the same reference numerals. Decoloring device 60
In c, the recording paper 6 is conveyed in the conveying direction A of the endless belt 64.
1 The processing device 37c disposed on the upstream side includes the duct 40 that opens downward and covers the endless belt 64 over the entire length in the width direction, and the inside of the duct 40 rotates parallel to the width direction of the endless belt 64. A reverse transfer roller 43, which is rotationally driven in the arrow A2 direction around the axis, is arranged. The reverse transfer roller 43 has a built-in heater 44, and is formed in a cylindrical shape from a material to which the toner of the present invention is relatively attached in order to peel off the toner on the recording paper 6 and perform the reverse transfer as described above. .. Inside the duct 40, at a position where it comes into sliding contact with the reverse transfer roller 43,
In order to remove the toner on the reverse transfer roller 43, a cleaning brush 39 in which electric insulating fibers are planted is arranged. The air in the duct 40 is sucked from the outside and set to a negative pressure. That is, the cleaning brush 39
The toner removed from the surface of the recording paper 6 is pulled out by the suction action and is collected by a dust collecting device (not shown).

Even in such an embodiment, the same effects as those described in the above embodiments can be achieved. Further, an application example in which the configuration of each of the embodiments shown in FIGS. 3 to 8 is incorporated in an electrostatic copying machine or the like and used as an erasing means is also included in the embodiments of the present invention.

The method and apparatus of the present invention are not limited to the toner contained in the developer of the electrostatic copying machine as in the above embodiment, but the dyes shown in Chemical formula 1 or Chemical formula 2,
Alternatively, it can be applied to a erasable ink for printing, stamping or writing which contains a wide range of other dyes.

[0055]

As described above, according to the present invention, when the toner image formed by the photochemically decolorizable toner formed on the sheet is to be decolored, the toner of the toner image is scraped off. Since the near-infrared rays are irradiated after being partially removed in the layer thickness direction by peeling or the like, the decoloring reaction of the deep layer portion of the toner image is promoted. As a result, the decoloring speed of the toner image formed on the sheet body is significantly improved. Further, the traces of the decolorized toner image on the sheet body are inconspicuous because the toner is partially removed in the layer thickness direction and the layer thickness is thin.

[Brief description of drawings]

FIG. 1 is a sectional view of an experimental apparatus 30 relating to a first erasing method.

FIG. 2 is a sectional view of an experimental apparatus 30a relating to a second erasing method.

FIG. 3 is a system diagram of an erasing device 60 according to an embodiment of the present invention.

FIG. 4 is an enlarged sectional view of the present embodiment.

FIG. 5 is a system diagram of an erasing device 60a according to another embodiment.

FIG. 6 is a system diagram of an erasing device 60b according to another embodiment.

FIG. 7 is a system diagram of an erasing device 60c according to another embodiment.

FIG. 8 is an enlarged sectional view of the erasing device 60c.

[Explanation of symbols]

 6 Recording Paper 35, 72 Light Source 33, 65 Heater 37, 37a, 37b, 37c Processing Device 38 Polishing Roller 43 Reverse Transfer Roller 59 Heating Unit 60, 60a, 60b, 60c Decoloring Device 64, 64a, 64b Endless Belt 68, 90 fan 70 irradiation unit 75 toner 87 heating roller

Front page continuation (72) Inventor Katsumi Murofushi 5-1, Ogimachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Denko KK Chemicals Research Laboratory (72) Kiichi Hosoda 5-1, Ogimachi, Kawasaki-ku, Kanagawa Prefecture Showa Denko Chemicals Laboratory Co., Ltd.

Claims (2)

[Claims] 1. A erasing method for erasing a toner image formed by a photochemically erasable toner formed on a sheet body, wherein the toner layer of the toner image is scraped or peeled off.
A decolorizing method comprising a processing step of partially removing in the layer thickness direction and a near infrared ray irradiation step of irradiating the toner image with near infrared rays. 2. A erasing device for erasing a toner image formed by a photochemically erasable toner formed on a sheet member, wherein the toner layer of the toner image is scraped or peeled off.
An erasing device comprising: a processing means for partially removing in the layer thickness direction; and a near-infrared irradiation means for irradiating the toner image with near-infrared rays.