JPH10272829A - Recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material which can be repeatedly printed especially through ink jet recording and is free from the deterioration of recording performance even when it is used a plural number of times in the case that a printout process is performed, not intended originally for preservation. SOLUTION: This recording material is composed of a solvent-absorbing resin which can swell finitely with the help of a substratially volatile solvent or a solvent-absorbing resin and a highly crystalline microparticle which has high affinity with the solvent. In addition, the material has a solvent receptive layer which shows a blushing phenomenon when receiving a solvent, although the blushing phenomenon is not seen when the solvent is not present. More preferably, a colored layer is to be provided at the lower part of the solvent- receptive layer. The solvent-absorbing resin is a substance insoluble in a solvent used for ink, for example, such as polyamide, polyacrylamide, polyvinylpyrrolidone or polyurethane. On the other hand, the highly crystalline microparticle is alumina hydroxide, smectite, mica or alumina hydrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reusable recording material mainly used for test printing and the like.

[0002]

2. Description of the Related Art With the spread of computers in recent years, various documents have been digitized, and with the spread of e-mails and the like, documents are often digitized and exchanged only on a CRT. Even a printed document is still output to a medium such as paper by various printers. In addition, when output is performed by a printer, it is often output without the purpose of preservation from the beginning for the purpose of trial printing or the like, and in reality, a large amount of waste of recording material such as paper is generated.

Therefore, it is conceivable to use ink which loses its color due to chemical treatment in order to use the recording material many times.

[0004]

However, such a chemical treatment is not preferable because components such as ink remain on the recording material and the recording performance gradually deteriorates.

Therefore, in the present invention, when an output is made without the purpose of preservation from the beginning, printing can be repeated many times, particularly by ink jet recording, and the recording performance does not deteriorate even if used many times. The purpose is to provide the material.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide a highly crystalline solvent-absorptive resin which can be finitely swelled by a substantially volatile solvent or which has a high solvent affinity with the solvent-absorptive resin. This is achieved by a recording material having a solvent receiving layer which is mainly composed of fine particles and is not turbid when no solvent is present, but becomes turbid when the solvent is received.

When printing is performed by ink jet recording using a substantially volatile solvent as an ink, the printed portion of the solvent receiving layer absorbs the solvent, swells and becomes cloudy, and the printed portion becomes recognizable. This is due to the difference in refractive index between the printed portion and the non-printed portion. If left after recording, the solvent evaporates, and the printed portion is not clouded again. There is no residue due to the previous printing, and ink jet recording can be performed under the same conditions as above.

Further, another preferred embodiment of the recording material of the present invention has a coloring layer below the solvent receiving layer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the recording material of the present invention will be described in detail.

[0010] The recording material of the present invention is mainly composed of a solvent-absorbing resin or a highly crystalline fine particle having a high solvent affinity which can be finitely swelled by a substantially volatile solvent. It has a solvent receiving layer which becomes cloudy when receiving a solvent.

Such a solvent-receiving layer may be provided on a support. If the solvent-receiving layer itself has properties such as thickness and mechanical strength suitable for ink jet recording, the support may be used. The solvent-accepting layer itself can be used as the ink jet recording material of the present invention without performing.

When a support for holding the solvent receiving layer is used for the recording material, for example, polyester, polyether sulfone, polycarbonate, polyethylene, polypropylene, poly (meth) acrylate, polyamide, polyvinyl chloride, acetylcellulose, A plastic film or sheet made of a material such as a copolymer of a monomer constituting the polymer and a copolymerizable monomer, paper, a glass plate, a metal sheet, or a sheet obtained by laminating a sheet of the above-mentioned material is used. It is possible. Above all, a film or sheet made of polyester is preferable in terms of heat resistance, mechanical strength, dimensional stability, cost, and the like.
The thickness may be any thickness as long as the recording material has sufficient mechanical strength necessary for ink-jet printing, and varies depending on the material, but is usually 20 to 100 μm, preferably 20 to 5 μm.
It is about 0 μm.

[0013] By the way, "swelling" generally means that a substance absorbs a solvent and swells. In the present invention, "swelling" continues to absorb the solvent, and includes infinite swelling in which the swelling spreads over the entire solvent. In other words, it means only finite swelling that stops when inflated to a certain size.

Specifically, the solvent-receiving layer of the recording material of the present invention comprises, as a first embodiment, a substantially volatile solvent, for example, an alcohol such as water, ethyl alcohol, methyl alcohol, glycerin, or ethylene glycol. It is mainly composed of a solvent-absorptive resin capable of finite swelling with such a glycol or the like.

As such a solvent-absorbing resin, a substance which does not dissolve in the solvent used for the ink, for example, polyamide,
Polyacrylamide, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyridylium halide, melamine resin, polyurethane, polyethylene vinyl alcohol, polyvinyl alcohol, polyvinyl acetal, polyester, acrylic resin, synthetic polymers such as sodium polyacrylate, gelatin, starch, cellulose Natural polymers such as casein, chitin and chitosan, and highly absorbent resins such as polyethylene oxide and its crosslinked products and copolymers can be used.

Further, the solvent receiving layer of the recording material of the present invention comprises:
As a second embodiment, the above-described solvent-absorbing resin and a high affinity for the solvent may be mainly composed of high crystalline fine particles, such a high affinity for the solvent high crystalline fine particles, Examples thereof include alumina hydroxide, alumina hydrate, smectite, mica, and (highly water-absorbing, highly oil-absorbing) polymer fine particles. In this case, the mixing ratio of the solvent absorbing resin and the fine particles is preferably in the range of 100: 10 to 100: 600. In particular, the primary particle size of alumina hydrate is 200
When a resin having a thickness of Å or less is used, it is preferably at least one-fold that of the resin as long as it can be retained as a film, and it is most preferable to control the central pore radius to 100 Å or less in terms of solvent absorbability and swellability.

By forming the solvent receiving layer mainly from such a resin, when printing is carried out by ink jet recording using a substantially volatile solvent such as water or alcohol as an ink, the printed portion of the solvent receiving layer is formed. The solvent becomes turbid due to absorption and swelling, and the non-printed portion can be recognized.

After the recording, the solvent is evaporated by leaving the recording, and the printed portion is not clouded again, and there is no residue due to the previous printing, and the ink jet recording can be performed again.

Although the thickness of the solvent receiving layer is not particularly limited,
In the case of also serving as a support, 25 to 20 in consideration of transportability
It is about 0 μm, and when it is formed as a coating film on a support, it is about 1 to 30 μm. 1 to form as a coating
When the thickness exceeds 30 μm, the solvent receiving layer receives the solvent and does not easily become cloudy even when the solvent is received, and the printed portion is difficult to visually recognize. On the other hand, when the thickness is less than 1 μm, the solvent reception in the printed portion becomes insufficient, and the non-printed portion becomes insufficient. This is because a difference in the refractive index from the above hardly occurs.

The solvent receiving layer may contain a leveling agent, an ultraviolet absorber, an antioxidant and other additives to such an extent that the solvent absorbability after the formation of the coating film is not impaired. Further, a porous pigment as an anti-blocking agent may be added to the extent that the solvent absorbability is not impaired, but the addition ratio of the solvent-absorbent resin and the pigment in this case is at most 100 parts by weight of the resin. Up to 5 parts by weight is preferred. Depending on the type, addition of more than this results in the pigment helping the solvent absorption performance, so that it becomes less turbid when swelled, or the addition of the pigment increases the whiteness of the entire recording material, causing This is because the difference in the refractive index between the print portion and the other portions is too small.

When the above-mentioned solvent-accepting layer is formed as a coating film on a support, the above-mentioned resin may be used alone or as a mixture, and if necessary, an additive may be added to propylene glycol monomethyl ether; Organic solvents such as methylene glycol monomethyl ether, ethyl alcohol, methyl alcohol, isopropyl alcohol, etc., are dissolved or dispersed in a suitable solvent such as water to prepare a coating solution, for example, roll coating, bar coating, air knife coating, It can be manufactured by coating and drying on a support by a known method such as a spray coating method, and when the recording material is constituted by the solvent receiving layer itself, a recording material having a predetermined thickness should be manufactured using a film forming machine or the like. Can be.

Further, a colored layer may be provided below the solvent receiving layer. When the solvent receiving layer is provided on the support, a colored layer can be provided on the support opposite to the side on which the solvent receiving layer is provided, or a colored layer can be provided between the solvent receiving layer and the support. When not used, a colored layer can be provided on the side opposite to the printing surface of the solvent receiving layer. By providing a colored layer, when the solvent receiving layer receives the solvent and becomes cloudy, the colored layer becomes invisible through the solvent receiving layer and the support, and is printed by the color contrast of the solvent receiving layer and the colored layer in the clouded printed portion. The department will be more clearly recognized.

For such a colored layer, use is made of the above-mentioned materials suitable for the support, and pigments and
It can be composed of a compound containing a dye or the like, or a material coated with a paint containing a pigment, a dye, etc.
It can be laminated on a support or the like by a known method such as using an adhesive or thermocompression bonding. The thickness of the coloring layer is not particularly limited, either. When a support having the above thickness is used, the thickness can be about 1 to 30 μm, more preferably about 5 to 20 μm.

The recording material of the present invention obtained as described above can be printed with a solvent receiving layer as a printing surface by a usual ink jet printer. However, printing is performed using ink substantially consisting only of a volatile solvent so that the recording material can be used many times. Such volatile solvents include, for example, water, ethyl alcohol,
Alcohols such as methyl alcohol, glycerin, etc.
Glycols such as ethylene glycol are exemplified, but not limited thereto. Also, additives such as preservatives may be added to the solvent used as the ink,
Even if the solvent evaporates, the additive that remains in the solvent receiving layer gradually reduces the recording performance of the recording material of the present invention,
It is not preferable to add a large amount.

By performing ink-jet printing using such a solvent as an ink, the printed portion of the solvent-receiving layer of the recording material of the present invention becomes cloudy and can be distinguished from the surrounding non-printed portion which is not cloudy, and the printing state is confirmed. be able to. After printing, the recording material of the present invention returns to the same non-cloudy state as before printing by drying quickly at a speed depending on the type of solvent used, the ambient temperature, and the like. It can be performed.

The storage period of the printed portion can be appropriately adjusted by adding a small amount of a solvent having a low volatilization rate such as cellosolve or anone to the above solvent.

[0027]

The present invention will be described in more detail with reference to the following Examples, in which "parts" and "%" are by weight unless otherwise specified.

Example 1 A polyethylene oxide copolymer (Aqua Coke: Sumitomo Seika Co., Ltd.) insoluble in water alone was coated on a 75 μm thick transparent polyester film (Lumilar Q-81: Toray Industries, Inc.) with cyclohexanone.
It was adjusted to 0%, applied and dried by a Meyer bar coater method to form a 5 μm-thick solvent receiving layer, thereby obtaining a recording material.

When an image was recorded on the recording layer of this recording material using an ink jet printer (BJC410J: Canon Inc.) using water instead of ordinary ink, the printed portion became cloudy after printing and characters could be clearly identified. . Furthermore, if left for one day, the water dries and the printed portion cannot be identified, and can be reused.

Example 2 An ethylene vinyl alcohol copolymer resin (Soarnol: Nippon Synthetic Chemical Industry Co., Ltd.) was melt-added to a polyethylene oxide copolymer (Aqua Coke: Sumitomo Seika Co., Ltd.) to form a film. Depending on the machine, thickness 1
A recording material was obtained by forming a film also serving as a solvent receiving layer of 00 μm.

When recording was performed on the recording layer of this recording material in the same manner as in Example 1, the same results were obtained. If the recording material was left for one day, the water dried and the printed portion could not be identified, and the recording material could be reused. Was.

Example 3 On the film of Example 1, 500% of alumina sol (Kawaken Fine Chemical Co., Ltd.) was added to polyvinyl alcohol (Gohsenol KH-17: Nippon Synthetic Chemical Industry Co., Ltd.) to prepare a 10% solution. The coating was dried by a Meyer bar coater method to form a solvent receiving layer having a thickness of 5 μm, thereby obtaining a recording material.

When recording was performed on the recording layer of this recording material in the same manner as in Example 1, the same result was obtained. If the recording layer was left for one day, the water dried so that the printed portion could not be identified and could be reused. Was.

[Comparative Example 1] Polyvinyl alcohol (Gohsenol KH-17: Nippon Synthetic Chemical Industry Co., Ltd.) was adjusted to 10% on the film of Example 1, applied and dried by a Meyer bar coater method, and dried to a thickness of 5 μm. A solvent receiving layer was formed to obtain a recording material.

When recording was performed on the recording layer of this recording material in the same manner as in Example 1, no printed portion could be confirmed.

[0036]

The recording material of the present invention can be repeatedly printed by ink jet recording, and the printed state can be confirmed, so that the use of disposable recording material such as paper can be greatly reduced.

Claims (3)

[Claims] 1. A solvent-absorbing resin mainly composed of a solvent-absorbing resin capable of finitely swelling with a substantially volatile solvent and having a solvent receiving layer which is not turbid when no solvent is present but becomes turbid when a solvent is received. Recording material. 2. It is mainly composed of a solvent-absorbing resin capable of finite swelling with a substantially volatile solvent and highly crystalline fine particles having high solvent affinity, and is not cloudy when no solvent is present. A recording material having a solvent receiving layer that becomes cloudy when receiving a solvent. 3. The recording material according to claim 1, further comprising a coloring layer below the solvent receiving layer.