JPH06175537A - Decoloring device - Google Patents

Abstract

PURPOSE:To provide a decoloring device which can efficiently decolor optically erasable toners, is short in decoloration time per sheet and is small in size and light in weight by radiation-heating the toners to the glass transition temp. of a binder resin thereof or above. CONSTITUTION:This decoloring device is constituted of a light source 40 for irradiating the toners fixed onto a sheet body with near IR rays and radiation- heating the toners by this radiation heat to the glass transition temp. of the binder resin thereof or above and a concave mirror 41 for condensing the light radiated from this light source 40 to the sheet body existing between guide members 23, 24. The thermal momentum of the molecules of the toners increases and the decoloring chemical reaction of the coloring matter existing in the toners is accelerated by heating the toners to the glass transition temp. of the binder resin thereof or above and, therefore, the time required for decoloring is drastically shortened as compared with the case photoirradiation is merely executed. The light source 40 is preferably, for example, a xenon flash lamp, or the like which can generate a large quantity of the near IR rays and radiation heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an erasing device for erasing a photochemically erasable toner fixed on a sheet.

[0002]

2. Description of the Related Art Recently, the reuse and recycling of used papers and plastics has been reviewed to protect the earth's resources. Regarding the reuse of documents in which highly confidential information is recorded, Since it is difficult to request an outside reclaimer, most of them are amortized or crushed.

[0003]

In order to solve such a problem, the color of ink or toner fixed on the recording medium is erased while maintaining the shape of the recording medium.
Toner that can be reproduced as a plain recording medium,
It is proposed in Japanese Patent Application No. 3-277725. When electrostatic copying is performed using such a toner, it is possible to erase the recorded image by irradiating near-infrared rays to the image recorded on a sheet body such as copy paper or the recorded image such as printing. Therefore, the recording medium can be easily reused.

However, there has been a problem that a decoloring device capable of decolorizing a photochemically decolorable toner efficiently and quickly has not been developed.

In order to solve the above-mentioned problems, an object of the present invention is to efficiently erase color of a photochemically erasable toner, to reduce the erasing time per sheet, and to make it lightweight and compact. It is to provide a color device.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a sheet body transporting means for transporting a sheet body on which a toner image formed of photochemically decolorizable toner is formed, and to the toner image.
An erasing device, comprising: a radiant heat at least a glass transition temperature of a binder resin of the toner and a light source for irradiating near infrared rays.

The present invention is also characterized in that the light source is a flash lamp.

[0008]

According to the present invention, the sheet body conveying means for conveying the sheet body on which the toner image formed by the photochemically decolorable toner is formed, and at least the binder resin of the toner for the toner image. By providing a light source for irradiating near-infrared rays at the same time as radiant heating above the glass transition temperature, it is possible to perform near-infrared ray irradiation processing and heating processing on the toner at the same time while conveying the sheet body, so that the entire erase Color processing time can be significantly reduced. Further, since the toner on the sheet body can be heated in a non-contact manner, the heating of the sheet body can be made uniform and wrinkles and curls of the sheet body can be prevented.

Further, since the light source is a flash lamp, extremely high energy can be irradiated in a short time, and the erasing process can be started immediately after energization of the apparatus. Further, the temperature of the toner rises faster than the sheet body due to the radiant heating for a short time, so that it is possible to suppress the application of extra energy to the sheet body.

[0010]

EXAMPLES First, the toner used in the present invention will be described. The toner is a photochemically decolorizable toner, in particular, a decoloring toner that decolorizes by absorbing near-infrared rays, and examples of a large number of composition examples and other components constituting the toner such as a sensitizer, The details of the decoloring action of the toner of each composition example and the like are described in Japanese Patent Application No. 3-277725. Therefore, in other embodiments, several examples of decolorizable toner will be shown. The present invention is not limited to the examples 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, for example, the following (Chemical formula 1) or (Chemical formula 2).

[0012]

[Chemical 1]

[0013]

[Chemical 2]

The styrene resin is widely used as a binder resin for toner. The above (Chemical formula 1) and (Chemical formula 2)
The dye represented by is one of the cyanine dyes and has a wavelength of 820 when coexisted with an organic boron ammonium salt.
Irradiation with near-infrared rays in the vicinity of nm absorbs the near-infrared rays to cause an irreversible reaction, and the blue color disappears to become colorless. As the organic boron ammonium salt, for example, tetrabutylammonium nbutyltriphenylboron shown in the following (Chemical Formula 3) is used.

[0015]

[Chemical 3]

Next, the erasing apparatus according to the present invention will be described. FIG. 1 (a) is a front view showing the configuration of an erasing apparatus 1 which is an embodiment of the present invention, and FIG. 1 (b) is a plan view thereof. The erasing apparatus 1 includes a sheet feeding cassette 30 for accommodating a sheet body made of paper or plastic on which the above-mentioned photochemically erasable toner is fixed, and a sheet feeding cassette 3.
A sheet feeding roller 11 for taking out the sheet body in 0, a conveying roller 12 for conveying the sheet body along a chain line in the drawing,
13, 14, 15 and a guide member 2 for guiding the sheet body
1, 22, 23, and 24 and the toner fixed on the sheet body are irradiated with near-infrared rays, and the radiant heat of the toner causes the binder resin of the toner to have a glass transition temperature or higher, for example, the above-mentioned styrene resin. In case of about 50 ℃
A light source 40 for radiant heating to 70 ° C. or higher, and a light source 40
A concave mirror 41 for condensing the light emitted from the sheet member on the sheet body located between the guide members 23 and 24;
Paper discharge tray 3 for receiving the sheets discharged from sheets 4 and 15
1 and a housing 10 that holds and stores them. By heating above the glass transition temperature of the binder resin of the toner, the thermal momentum of the molecules of the toner increases and the decolorization chemical reaction of the dye existing in the toner is accelerated, so it is possible to use only light irradiation. The time required for erasing is significantly shortened as compared with the case of performing.

The light source 40 is preferably one that can generate a large amount of near infrared rays and radiant heat, such as a xenon flash lamp. FIG. 2 is a graph showing a typical emission spectrum of a xenon flash lamp. Looking at FIG. 2, in the wavelength range of 800 nm to 1050 nm,
It is understood that the presence of high-power near-infrared rays showing a plurality of sharp peaks is suitable for the decoloring process of the toner. A characteristic of xenon flash lamps is that they can emit a flash of very high energy and a selective wavelength within a light emission time of about 2 msec or less, so that the emitted light can be efficiently collected. By doing so, extremely high light energy can be locally obtained. Therefore, the temperature of the toner rises to, for example, about 100 ° C. to 150 ° C. in an extremely short time.
Also, a sufficient amount of light can be obtained immediately after energization without preheating.

Next, this operation will be described. The sheet bodies accommodated in the sheet feeding cassette 30 are taken out one by one by the sheet feeding roller 11, guided by the guide members 21 and 22 along the one-dot chain line in the drawing, and further conveyed by the conveying rollers 12 and 1.
3 is delivered to the guide members 23 and 24. Light source 40
The side guide member 23 is composed of a plurality of linear members formed by bending such as wire so as not to interfere with the irradiation of light, and is arranged at predetermined intervals along the sheet conveying direction. Further, the guide member 23 may be a plate member made of, for example, glass or synthetic resin, which is permeable to radiant heat rays for heating the sheet body and near infrared rays for decoloring. Further, the guide member 2 on the opposite side of the light source 40
It is preferable that 4 is a plate-like member whose surface facing the sheet body is a light-reflecting mirror surface, which can improve the light-collecting efficiency on the sheet body. Then, while the sheet body is being conveyed, the light source 40 repeatedly emits light, so that the toner on the sheet body is irradiated with near-infrared rays and heated by radiant heat. At this time, when a white or colorless transparent sheet body is generally compared with a toner in which the above-mentioned pigment is dispersed, the light energy absorption efficiency per unit time is different, and as shown in FIG. The rate of temperature increase becomes large. Therefore, by using the heating method using radiant heat, the heating efficiency of the toner is improved and the sheet body can be prevented from being overheated. In order to obtain a uniform light intensity on the entire surface of the sheet body, it is preferable that a parabolic mirror is used as the concave mirror 41 and the light source 40 is arranged at the focal position of the parabolic mirror. Also,
By stopping the conveyance of the sheet body at the positions of the guide members 23 and 24 for a predetermined time and performing light irradiation, a sufficient amount of light is irradiated to the sheet body, and more reliable decoloring processing can be performed. The sheet body that has been subjected to the color erasing process by light irradiation is discharged to the paper discharge tray 31 by the transport rollers 14 and 15.

In this way, the sheet body once recorded with the toner is erased efficiently and quickly before being conveyed from the paper feed cassette 30 to the paper discharge tray 31. It should be noted that the sheet body that has not been erased even by one-time erase processing can be erased more reliably by returning it to the paper feed cassette 30 again and performing the erase processing many times.

[0020]

As described in detail above, according to the present invention,
Since it is possible to shorten the heating time and the light irradiation time to the sheet body, it is possible to perform the toner decoloring process efficiently and quickly, and to provide a small and lightweight decoloring device. it can. Furthermore, since wrinkles and curls of the sheet body can be prevented, the occurrence of troubles such as a paper jam during the transportation of the sheet body is reduced. Further, since excess energy is not applied to the sheet body, the load on the sheet body is reduced, and the number of reuses of the sheet body can be increased.

As described above, when the sheet body is reused by using the erasing apparatus according to the present invention, a large-scale facility is not required, and the reuse in each company can be easily carried out.

[Brief description of drawings]

FIG. 1 (a) is a front view showing a configuration of an erasing apparatus 1 which is an embodiment of the present invention, and FIG. 1 (b) is a plan view thereof.

FIG. 2 is a graph showing a typical emission spectrum of a xenon flash lamp.

FIG. 3 is a graph showing temperature rise curves of a sheet body and toner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decoloring apparatus 10 Housing 11 Paper feeding rollers 12, 13, 14, 15 Conveying rollers 21, 22, 23, 24 Guide member 30 Paper feeding cassette 31 Paper ejection tray 40 Light source 41 Concave mirror

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 sheet body conveying means for conveying a sheet body having a toner image formed of a photochemically decolorable toner, and at least the glass transition temperature of a binder resin of the toner with respect to the toner image. And a light source for irradiating near-infrared rays simultaneously with radiant heating. 2. The erasing device according to claim 1, wherein the light source is a flash lamp.