JP2919220B2 - Copy paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive / copy paper which has a function of exposing only a portion irradiated with light and having a function of erasing after a predetermined time or after heat treatment, and which can be repeatedly copied.

[0002]

2. Description of the Related Art
2. Description of the Related Art Copiers (copiers) have been performing transfer by transferring toner onto paper. This is a mechanism in which light is irradiated to a copy source, the reflected light is detected by a photosensitive drum, toner adheres to the photosensitive drum, and the toner is further transferred to a copy destination sheet. In such a mechanism, the toner is semipermanently left on the paper in order to transfer the toner to the paper, and the recording performance is good. However, in recent years, the necessity of recycling has been highlighted from the viewpoint of environmental issues as well as recordability. Therefore, a temporary recording is possible, and there is a demand for a copy sheet that can be reused by erasing the recording.

On the other hand, the present inventors have proposed a transition metal oxide such as tungsten oxide (WO ₃ ) as an optical element material having the properties of photochromism and electrochromism and capable of producing a large-area display surface. And a gel composite membrane composed of a mixture of a water-soluble polymer and a water-soluble polymer. The present inventors have found that a paper impregnated with an aqueous solution comprising a mixture of a transition metal oxide and a water-soluble polymer substance meets the above-mentioned demand, and based on this finding, completed the present invention. I came to.

[0004]

Means for Solving the Problems That is, the present invention relates to WO
₃ , MoO ₃ , V ₂ O ₅ , Nb ₂ O ₅ , TiO ₂ , Rb
O ₂ , IrO ₃ , MnO ₂ , CoO ₃ , Fe ₂ O ₃ and
Met copy sheet containing Zn (WO ₄₎ a transition metal oxide selected from among ₂ and a mixture of water-soluble polymer
On one or both sides of the paper
The present invention provides a copy sheet that has been subjected to a glue processing .

Here, WO ₃ ,
MoO ₃ , V ₂ O ₅ , Nb ₂ O ₅ , TiO ₂ , Rb
O ₂ , IrO ₃ , MnO ₂ , CoO ₃ , Fe ₂ O ₃ and
Zn (WO ₄ ) ₂ , in particular WO ₃ , MoO ₃ ,
V ₂ O ₅ is preferred. In addition, as a water-soluble polymer substance,
For example, polyethylene glycol, polyvinyl alcohol, polyacrylamide, polyvinyl acetate, hydroxyethyl methacrylate and the like can be mentioned, and polyethylene glycol and polyvinyl alcohol are particularly preferable. In particular, polyethylene glycol having remarkable sensitization of photochromism is more preferable. The polyethylene glycol preferably has a molecular weight of about 5,000 to 100,000.

[0006] copy sheet of the present invention, which contains a mixture of such transition metal oxides and water-soluble polymer
And, as described further below, on one or both sides
Laminated with a minate film
is there. As such copy paper before lamination , specifically, for example, after applying and impregnating a mixed aqueous solution obtained by adding and mixing a water-soluble polymer substance to an aqueous solution of a transition metal oxide, or After the film is formed on the paper surface, it may be gelled. The paper thus obtained is made of amorphous tungsten oxide (WO
₃ ) shows exactly the same photochromism as that shown by ₃ ). Decoloring by heating is similar to amorphous tungsten oxide (WO ₃ ).

[0007] As described above, the copy paper of the present invention before the lamination process contains a mixture of a transition metal oxide and a water-soluble polymer substance in the paper by a sol-gel method. After applying and impregnating a mixed aqueous solution obtained by adding and mixing a water-soluble polymer substance to an aqueous solution of a product, or after forming a film on the surface of the paper, gelation can be performed. . Here, as the aqueous solution of the transition metal oxide, for example, an aqueous solution of a salt of the transition metal oxide such as sodium tungstate is subjected to ion exchange (Na ⁺
→ H ⁺ ) can be used. The concentration of the aqueous solution of the transition metal oxide is preferably from 0.3 to 2.0 mol / l, particularly preferably from 0.5 to 1.7 mol / l.

In this method, first, the water-soluble polymer substance is added to and mixed with the aqueous solution of the transition metal oxide to prepare a mixed aqueous solution. In this case, the mixing ratio of both is 0.5 to 100 parts by weight, preferably 5 to 50 parts by weight of the water-soluble polymer substance per 100 parts by weight of the aqueous solution of the transition metal oxide. As the amount of the water-soluble polymer increases, coloring and decoloring are completed in a short time. However, if the amount of the water-soluble polymer is too large, it becomes inhomogeneous.
Approximately 00 parts by weight.

The method of mixing the aqueous solution of the transition metal oxide and the water-soluble polymer is not particularly limited, and may be a commonly used method, for example, using a stirrer or the like.
It may be performed for about 0 to 20 minutes. By adding the water-soluble polymer substance to the aqueous solution of the transition metal oxide as described above, the shrinkage during drying is suppressed (functioning as a binder), and when the aqueous solution of the transition metal oxide is used alone, In contrast, photochromism can be significantly sensitized.

[0010] The mixed aqueous solution thus prepared is
After coating and impregnating the paper, or forming a film on the paper surface, and then gelling, a copy paper before lamination can be obtained. The amount of application largely depends on the paper to be applied, impregnated, or formed into a film. However, the amount of application is preferably such that the softness of the paper is not impaired, and the higher the application, the better the coloring sensitivity. .

Here, the paper may be any paper generally used for writing or the like, and is not particularly limited. For example, examples of the writing paper include bond paper, fools, filter paper, bran paper, and medicine paper.

[0012] The copy paper before the laminating process is performed by applying the mixed aqueous solution prepared as described above to ordinary paper and impregnating it, or forming a film on the paper surface, and then drying at normal temperature or hot air drying. It can be manufactured by gelling. The copy paper thus obtained is
Copying and exposure can be performed only by light irradiation. Also,
The used copy paper is stored in a dark place for a predetermined period of time, or is subjected to a heat treatment using a hot-air dryer or the like, so that it can be erased and reused.

As the copy paper in the present invention, the impregnated paper thus obtained (a paper prepared by applying the mixed aqueous solution prepared as described above to paper and impregnating the paper, or forming a film on the paper surface). ) Is further laminated with a laminate film by a known method . In this case, not only one side but also a lamination processing from both sides may be used. The laminated film is not particularly limited, and examples thereof include polyethylene, polyethylene terephthalate, polycarbonate, syndiotactic polystyrene, polyether nitrile, and polyether ether ketone. Copy paper that has been subjected to such lamination processing can be overwritten with an oil-based pen or the like from above, and can be reused by wiping the overwritten characters with alcohol or the like.

[0014]

Next, the present invention will be described in detail with reference to examples. Example 1 (1) An aqueous solution of sodium tungstate was subjected to ion exchange (Na ⁺ → H ⁺ ) through an ion exchange resin to prepare an aqueous solution of tungstic acid. To this aqueous solution of tungstic acid, polyethylene glycol (PEG) (molecular weight: 20,000) was added to a concentration of 10% by weight to prepare a mixed aqueous solution. (2) The mixed aqueous solution obtained in the above (1) was applied and impregnated on filter paper, and then allowed to dry at room temperature to obtain copy paper A. (3) Copy paper A obtained by drying was subjected to laminating from both sides with a laminated laminate film of polyethylene terephthalate and low-density polyethylene (thickness: 90 μm) to obtain copy paper B. (4) Copy paper A obtained in (2) above and (3)
When the ultraviolet light reflected from the copy source was further inverted and illuminated for 1 minute on each of the copy paper B obtained in the above, the portions other than the characters (the portions where nothing was described) were exposed to blue, and the characters were Emerged. (5) After being exposed as described above, the color was erased by storing in a dark room for 12 hours, so that it could be reused.
Separately, the copy paper is heated at 80 ° C. for 1 hour using a hot air dryer.
The color was erased by the time treatment, and it could be reused.

[0015]

The copy paper of the present invention is colored (photochromism) by irradiation with light due to the action of a mixture (aqueous mixed solution) of a transition metal oxide and a water-soluble polymer substance contained therein. have. Therefore,
By irradiating the copy sheet of the present invention with light, it is possible to expose and copy only the portion irradiated with the light. In addition, the copy sheet of the present invention is stored in a dark place for a predetermined time or heat-treated at a predetermined temperature to erase the color. Therefore, copying can be repeated. Therefore, there is an advantage that the resource can be conserved without discarding the paper unnecessarily. Furthermore, since copying is performed using photochromism, the copying machine itself does not require a photosensitive drum or a fixing step, and the apparatus can be simplified. Ma
The copy paper of the present invention has been subjected to lamination processing.
, It is possible to overwrite with oily pen from above,
Moreover, by wiping the overwritten characters with alcohol etc.
And can be reused. Therefore, the copy sheet of the present invention can be effectively used as a new type of copy sheet and recording sheet.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-173189 (JP, A) JP-A-57-144546 (JP, A) JP-A-2-294633 (JP, A) JP-A-6-294633 242472 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03C 1/725

Claims (1)

(57) [Claims] 1. WO ₃ , MoO ₃ , V ₂ O ₅ , Nb ₂ O
₅ , TiO ₂ , RbO ₂ , IrO ₃ , MnO ₂ , CoO
_3, a copy sheet containing Fe ₂ O ₃ and Zn (WO ₄₎ <br/> transition metal oxide selected from among ₂ and a mixture of water-soluble polymer, of the paper side or Laminate on both sides
Copy paper made by laminating with film.