JPH11296033A - Image holding and supporting body and recycling method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make easily recyclable a used copying paper and the like. SOLUTION: By this method, the image holding and supporting body on which an image consisting of a thermofusing or thermoplastic image forming material is formed is recycled by brining an image peeling body into heat- contact with it and peeling and eliminating the image from it. Then, a heat- contact is executed for two or more seconds. It is preferable that the critical surface tension of the surface of the image holding and supporting body is 20 mN/m to 30 mN/m, or >=40 mN/m and that of the surface of the image peeling body is 30 mN/m to 40 mN/m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reproducing used copy paper.

[0002]

2. Description of the Related Art Recently, with the development of OA, printer paper and copy paper have been used in large quantities. As a result, the problem of deteriorating the global environment due to the deforestation of forests, which are paper production resources, has been caused. Conventionally, the only solution to this problem has been to remove ink and the like on the paper once used, crush and re-make the paper, and recycle it into paper called waste paper. However, paper has recently been developed that can remove character images on paper that have been used once by cleaning, and can be reused for copying or printing.

[0003] For example, as described in JP-A-2-55195 and JP-A-4-64472, an erasable printed material (erasable) is obtained by releasing the surface of a sheet-like support with a silicone-based flame retardant. Media and device (eraser) for copying an image, erasing an image by copying after copying, heating and then contacting an endless sheet having a hot-melt resin
There is a disclosure.

However, such copying paper is
It becomes an image on the release agent, and the image fixability at the time of recopying is of course poor and there is a difficulty in use. However, when erasing is performed, unevenness in thickness due to the pattern of the image occurs, which causes unevenness in erasing.

[0005] In contrast to these methods, a method of obtaining a toner image copied on general copying paper, printing paper, or the like, which is currently used in large quantities, is to at least partially use a paper layer mainly composed of cellulose fibers. An image release liquid containing water is held on an image holding support formed and forming a hydrophobic image made of a heat-flexible ink (toner) on the paper-like layer, and in a state where the image release liquid is held, A method for regenerating an image-bearing support, in which the hydrophobic image is separated from the paper layer by bringing the hydrophobic image into contact with an image-separated body, has been proposed (JP-A-7-13383, etc.). Although Figure 4 shows an example of an apparatus for carrying out the method, with respect to 1 of the toner separation belt hits the supplying paper P, throughout the application roller R ₂ immersed in the image stripping solution 2, The image peeling liquid is applied to the surface of the paper P, supplied, transferred and separated via the heating rollers R ₁ and R ₃ , and regenerated through the finishing roller 4. However, various problems remain to implement it concretely. For example, when an image release liquid is immersed in an image holding support (copy paper), 1 g or more (normally 3 to 5 g / A4) is consumed per copy paper A4 size, so that a large amount of power is consumed for drying or wrinkles are generated. There is a problem that it easily occurs. Further, there is a problem that an application section for attaching the stripping liquid and a drying section for the liquid are required, and the apparatus becomes large in size and the cost increases.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an image-holding support having a surface suitable for a simpler process and a physical property of an image-separated body for separating a toner without using an image-separating liquid. Heading, longer heating contact time (2-
20 seconds), and
This realizes more effective reproduction of the image holding support.

[0007]

The present invention has the following constitution. The image-retaining support, on which an image formed of a thermofusible or thermoplastic image-forming substance is formed, is heated and melted to release and remove the image from the image-retaining support to remove the image. A method for reproducing an image holding support, which comprises reproducing a body. At this time, heating contact is performed for 2 seconds or more. The critical surface tension of the surface of the image holding support used in such a reproducing method is 20 mN / m or more and 30 m or more.
N / m or less, or 40 mN / m or more;
The critical surface tension of the surface of the image exfoliated body is 30 mN / m or more 4
0 mN / m or less.

Further, at least a part of the image holding support is composed of a paper layer mainly composed of cellulose fibers or a plastic film. Further, at least a part of the same treatment on both surfaces is made of a paper layer or a plastic film containing cellulose fibers as a main component. Further, the contact angle of the surface of the image holding support with a liquid having a value of 35 mN / m is 30 degrees or more or 5 degrees or more.
The contact angle with a liquid having a value of 0 mN / m is 30 degrees or less.

A contact angle of the surface of the image peeling body with a liquid having a value of 50 mN / m is 30 degrees or more and 60 degrees or less. The method for regenerating the image holding support of the present invention using the image holding support and the image peeling body having the above-described features is capable of removing the toner only by the transfer and separation mechanism without using the conventional image peeling liquid or finishing roller. It turned out to be possible. In this case, it was also found that the use of a peeling method of peeling the toner by longer heating contact (2 to 20 seconds) was more effective.

More specifically, when the critical surface tension of the surface of the image holding support is 20 mN / m or more and 30 mN / m or less, the toner can be peeled without using an image peeling liquid. Was found. This is because the critical surface tension of the toner is from 30 mN / m to 35 mN / m. Therefore, when the image peeling member and the toner image holding support are brought into contact with each other by heating, the toner moves toward the image peeling member having a larger critical surface tension. It is considered to be transferred. Further, it was also found that the toner can be peeled off without using an image peeling liquid when the critical surface tension of the surface of the image holding support is 40 mN / m or more. In this case, it is presumed that, because the surface energy difference from the toner is large, the toner once adhered is peeled and transferred to the image peeling body having a surface energy closer to the toner.

Therefore, in order to satisfy this condition, the critical surface tension of the image peeling member needs to be 30 mN / m or more, preferably 35 mN / m or more. However, 40mN /
If it exceeds 30 m, the adhesion to the toner image is deteriorated.
A preferred range is from mN / m to 40 mN / m.
The critical surface tension is measured using a wetting index standard solution (manufactured by Wako Pure Chemical Industries, Ltd.) in accordance with JIS K6768, and the cosine (cos) of the contact angle A with respect to the surface tension of the solution on the image holding support or the image peeling body. .A) and plot c
os. A = 1, that is, the surface tension of the liquid corresponding to the contact angle A = 0 was defined as the critical surface tension (FIGS. 2 and 3).

It is sufficient that the critical surface tension is such that the image-holding support <the image-forming substance ≦ the image-peeled body. (FIG. 2) The surface of the image holding support having a critical surface tension of 20 mN / m or more and 30 mN / m or less is the surface of an image holding support such as paper or a plastic sheet, and the surface tension of the liquid is 30 mN / m or less. It is obtained by treating with an aqueous surfactant solution (1%) and drying. As the surfactant, various nonionic,
Anionic and cationic surfactants can be used,
The toner having particularly good releasability was a sodium dialkyl succinate system having an alkyl group having 5 or more carbon atoms. (Aerosol TR-70, O manufactured by Mitsui Cytec Co., Ltd.
T-100, MA-80, AY-100, etc.) Same series of aerosol 1M-100 and aerosol A-1
No. 96 is a surfactant whose surface tension of a 1% aqueous solution exceeds 30 mN / m, and the critical surface tension of an image holding support such as paper treated with the solution also exceeds 30 mN / m, so that toner releasability is not good. Was.

Further, the image holding support is manufactured by AMC manufactured by Nippon PMC.
By performing surface sizing using an S-202 alkyl ketene dimer, the critical surface tension of the surface is reduced to 30 m.
N / m or less was effective, but other olefinic and acrylic sizing agents also have a critical surface tension of 30 mN.
/ M, the toner releasability was not good.
Further, as a comparative example, examples of an image holding support having a critical surface tension of 30 mN / m or less include fluorine-based and silicone-based resins, but are less than 20 mN / m and have poor toner fixability during copying. I didn't get it.

When the image-holding support is paper or other liquid-absorbing material and the standard for critical surface tension is not clear, a contact angle with a standard solution of 35 mN / m can be used as an alternative characteristic. . In this case, if the contact angle is 30 degrees or more, the critical surface tension is 30 mN / m or more, and the contact angle is 3 mN / m or more.
If it is less than 0 degree, the critical surface tension is less than 30 mN / m, so that it can be used as a substitute property. In addition, it was found that even when the surface of the image holding support had a critical surface tension of 40 mN / m or more, it could be repeatedly used by the reproduction method of the present invention. That is, it is only necessary that the correlation between the critical surface tensions is such that the image forming substance ≦ the image peeled body <the image holding support (FIG. 3).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments will be described. Example 1 A 1% aqueous solution of sodium dioctylsuccinate (Aerosol OT100 manufactured by Mitsui Cytec Co., Ltd.) was applied on a 100-micron white polyester film (Lumirror E20 manufactured by Toray Industries Co., Ltd.) using the stripper application apparatus of FIG. Was applied to obtain a dried image holding support. (Both sides have a critical surface tension of 25 mN / m.) Copiers made by Ricoh Co., Ltd., Spiri6000, were used to make copies on this image holding support.

This copy was taken in the apparatus shown in FIG. 1 using a polyetheretherketone film (PEEK manufactured by Mitsui Toatsu Co., Ltd.) (critical surface tension: 34 mN / m) as an image peeling body, at a peeling speed of 20 mm / sec, and at a peeling temperature of 100 ° C. As a result, copy-reproduced paper having almost no residual image and no wrinkles was obtained. Using this recycled paper, 50 times of copying and reproducing were obtained with the quality that can be practically used.

Example 2 A commercially available coated paper (A2 coated paper,
30 g / m ² coated on both sides on a high-quality paper and subjected to a super calender treatment) 50 parts by weight of a copolymer of sodium polyacrylate and polyvinyl alcohol (Sumikagel L-5H manufactured by Sumitomo Chemical Co., Ltd.) and an epoxy crosslinking agent 0.5
Parts of isopropyl alcohol and 49.5 parts by weight of isopropyl alcohol, dried at 100 ° C. for 5 hours, and coated on both sides with a surface treatment layer having a dry weight of 2.0 g / m ² per side (image holding support) )Obtained.

(Critical surface tension: 45 mN / m) A copying machine, Spiri7000, manufactured by Ricoh Co., Ltd.
Was copied. Using a polyester film (Lumirror E20 manufactured by Toray Co., Ltd.) (critical surface tension: 36 mN / m) as an image exfoliating body in the apparatus shown in FIG. Copy reproduction paper having almost no residual toner and no wrinkles was obtained. Using this recycled paper, a quality was obtained in which copying and reproducing 50 times repeatedly were practically used.

Comparative Example 1 When the 100-micron white polyester film (Lumirror E20 manufactured by Toray Industries, Inc.) used in Example 1 was used as it was as an image holding support, the peeling rate of the toner was about 50%, and the toner could not be used repeatedly. Table 1 shows other examples and comparative examples together with examples 1 and 2 and comparative example 1.

[0020]

[Table 1]

[0021]

According to the present invention, by controlling the physical properties of the surfaces of the image holding support and the image peeling body,
By taking a long heating contact time, the image holding support can be effectively regenerated without using an image peeling liquid or a finishing roller.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus suitable for implementing the present invention.

FIG. 2 is a graph showing a critical surface tension of a surface of an image holding support.

FIG. 3 is the same as FIG. 2;

FIG. 4 is an explanatory diagram of an apparatus suitable for implementing a conventional method.

Claims (11)

[Claims] 1. An image exfoliating body is brought into heat contact with an image holding support on which an image formed of a thermofusible or thermoplastic image forming substance is formed, whereby the image is exfoliated and removed from the image holding support. A method for reproducing the image holding support by regenerating the image holding support. 2. The method for regenerating an image holding support according to claim 1, wherein the image holding support is brought into contact with the image peeling member by heating for 2 seconds or more. 3. The critical surface tension of the surface of the image holding support used in the reproducing method according to claim 1 or 20 mN /.
m and 30 mN / m or less. 4. A critical surface tension of the surface of the image holding support used in the reproduction method according to claim 1 or 40 mN /.
m or more. 5. An image-separated body, wherein the surface of the image-separated body used in the reproduction method according to claim 1 or 2 has a critical surface tension of 30 mN / m or more and 40 mN / m or less. 6. An image holding support, characterized in that at least a part of the image holding support used in the reproduction method according to claim 1 or 2 is made of a paper layer mainly composed of cellulose fibers. 7. An image holding support, wherein the image holding support used in the reproduction method according to claim 1 is made of a plastic film. 8. The image holding support used in the reproducing method according to claim 1 or 2, wherein at least a part of the image holding support is made of a paper layer or a plastic film containing cellulose fibers as a main component and having the same treatment on both sides. An image holding support, characterized in that: 9. A surface of the image holding support used in the reproducing method according to claim 1 or 2, wherein a contact angle with a liquid having a value of 35 mN / m is 30 degrees or more. Image holding support. 10. A surface of the image holding support used in the reproducing method according to claim 1 or 2, wherein a contact angle with a liquid having a value of 50 mN / m is 30 degrees or less. Image holding support. 11. The surface of an image peeling body used in the reproducing method according to claim 1 or 2, wherein a contact angle with a liquid having a value of 50 mN / m is 30 degrees or more and 60 degrees or less. Image exfoliated body.