JP2000206727A - Recyclable material to be recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material to be recorded having satisfactory image removing performance and good paper passing performance at high humidity as a recyclable material to be recorded capable of removing a printing material such as a toner. SOLUTION: This recyclable material to be recorded consists essentially of a base material layer and a water-swellable surface layer with fine particles of 0.1-20 μm average particle diameter provided to the surface by electrostatic power or the van der Waals force between the material of the surface layer and the fine particles. A middle layer may be disposed between the base material layer and the surface layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material which can be removed from a recording material by forming an image with a copying machine, a printer or the like and which can be reused repeatedly. In particular, the present invention relates to a recording material suitable for a removing means by physical rubbing force such as a brushing method using an aqueous solvent such as water.

[0002]

2. Description of the Related Art Today, electrophotographic copying (so-called copying) techniques using toner have become widespread, and recording materials such as paper and OHP sheets have been used in large quantities. Printing materials printed or copied on such recording materials cannot be easily removed, and such technology has not been put to practical use. The fact is that it is.

It is obvious that this is not preferable for environmental protection and resource protection. Therefore, techniques for regenerating or recycling the recording material to be discarded are being actively studied. For example, in JP-A-6-222604, a swelling layer swelling with water is formed on the surface of a recording material, and the swelling layer is wetted with water and swelled to record on the recording material. A method for removing an image is disclosed.

In such a recyclable recording material, reusability is the most necessary characteristic.
At the same time, performance as a recording material is also required, so that it is necessary to be able to use repeatedly without deteriorating this performance. In order to achieve this requirement, it is necessary to adjust various physical properties.

For example, in Japanese Patent Application Laid-Open No. Hei 7-31523, the surface roughness is reduced to 1 by adding fine particles.
There is disclosed a technique of adjusting the thickness within a range of 30 μm to adjust the peeling characteristic. Japanese Patent Application Laid-Open No. 9-104197 discloses that a fusible resin powder is added for detecting the number of removals.

However, the water-swellable resin used for the above-mentioned recording material has a high adhesiveness, and particularly at a high humidity of 80% or more, the adhesion between the recording materials becomes large, and paper-passing properties, especially paper-feeding properties, are increased. Adversely affect To solve this problem, adding fine particles is an effective means. However, simply adjusting the surface roughness by adding the fine particles cannot improve the paper passing characteristics.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a sufficient image removing performance in a recyclable recording material capable of removing a printing material such as toner. It is an object of the present invention to provide a recording material having good paper passing characteristics under high humidity.

[0008]

The present invention relates to a recyclable recording material comprising at least a substrate layer and a water-swellable surface layer, wherein fine particles having an average particle size of 0.1 to 20 nm are formed on the surface of the surface layer. The present invention relates to a recyclable recording material, which is provided. In particular, the present invention relates to the above-mentioned recording material, wherein the application of the fine particles to the surface of the surface layer is performed by an electrostatic force or a van der Waals force between the surface layer material and the fine particles. The present invention also relates to the above-mentioned recording material, wherein an intermediate layer is provided between the base layer and the surface layer.

With the above construction, the recording material of the present invention can easily remove the printing material adhered to the surface thereof by a physical rubbing force such as a brushing method using an aqueous solvent such as water. In addition to being able to be reused, it is possible to prevent the recording materials from blocking each other due to the surface layer material and to maintain excellent paper-passing properties.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. FIG. 1 is a schematic cross-sectional view showing the configuration of an embodiment of the recording material of the present invention. FIG. 1 shows a recording material in which a surface layer 3 is laminated on a base material layer, and a printing material 4 is printed on the surface of the surface layer 3. Although FIG. 1 shows a configuration in which the surface layer is formed on one surface of the base material layer 1, a configuration in which the surface layer 3 is formed on both surfaces of the base material layer 1 may be used.

The base material layer 1 may be one having water resistance and appropriate mechanical strength and flexibility, and is typically a transparent plastic film or a plastic film made opaque by adding inorganic fine particles. Is preferably used. The material of the plastic film is not particularly limited, but polyester, polycarbonate, polyimide, polymethyl methacrylate and the like are preferable in consideration of heat resistance and the like. Taking into account versatility, price, heat resistance, durability, etc., polyesters, especially polyethylene terephthalate (PET) and polyethylene naphthalate (PEN)
Is desirable. So-called synthetic paper, such as paper made of plastic fiber such as PET fiber or paper based on plastic, is also useful as the base layer. In addition, metal foil, paper with improved water resistance, and composite materials such as resin, paper, and metal can also be used. In short, any material can be used as long as it can maintain flatness through printing and removal of the printing material, and has water resistance and appropriate mechanical strength and flexibility.

If necessary, additives such as an antistatic agent, a colorant, and a biodegradability promoting additive can be added to the base material layer as long as the essential properties are not impaired. The surface of the base material layer can be activated by a discharge treatment or other conventional means in order to improve the laminating adhesion of a surface layer thereon or an intermediate layer described later, if necessary.
The thickness of the substrate layer is 30 to 200 μm, preferably 50 to 200 μm.
150 μm is suitable.

The surface layer 3 contains a water-swellable resin as a main component. Here, the term “water swelling” means that it swells but does not dissolve in water or an aqueous solvent. This can be produced by using a water-soluble resin as a base resin and crosslinking the base resin. The water-soluble resin which is the base resin of the water-swellable resin which is the main component constituting the surface layer of the present invention includes active hydrogen such as a hydroxyl group, an amino group, an amide group, a thiol group, a carboxyl group and a sulfonic acid group in a molecule. Water-soluble resin having a functional group having, for example, polyvinyl alcohol, methyl cellulose, polyacrylic acid, carboxymethyl cellulose,
Hydroxyethyl cellulose, polyvinyl pyrrolidone,
Polyacrylamide, diacetone acrylamide and the like can be used. Further, a copolymer component containing a component having a cationic group in these resins can also be used. Preferably, polyvinyl alcohol, methyl cellulose, or polyacrylic acid is used. Among them, polyvinyl alcohol having a large number of hydroxyl groups is preferable, and the degree of polymerization is 300 to 3000, preferably 5
It is preferably from 2000 to 2000, more preferably from 500 to 1700. When such a water-soluble resin is applied to a substrate or the like as a surface layer, an aqueous medium 10
2 to 30 parts by weight, preferably 5 to 10 parts by weight per 0 parts by weight
It is appropriate to use it by dissolving parts by weight.

To crosslink a water-soluble resin, a crosslinking agent and, if necessary, an initiator may be added to an aqueous solution of the resin.
Any crosslinking agent may be used as long as it has reactivity with a hydroxyl group, amide group, or carboxyl group present in the water-soluble resin molecule and can crosslink the water-soluble resin. For example, epoxy compounds, isocyanate compounds, glyoxals,
Examples include methylol compounds, melamine resins, dicarboxylic acids, aziridine compounds, dihydrazides and compounds having a double bond, such as diacrylate compounds and dimethacrylate compounds.

For example, epoxy compounds include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polydiglycidyl ether, sorbitan polydiglycidyl ether, polyglycerol polyglycidyl ether and the like. In addition to these, various epoxy compounds can be used.

As the isocyanate compound, those having two or more isocyanate groups in one molecule can be used. By using a compound having a plurality of isocyanate groups, the substrate layer and the surface layer can be more firmly bonded.

Examples of the isocyanate include 4,4-diphenylmethane diisocyanate, 4,4-methylenebiscyclohexyl isocyanate, and tris (p-
Isocyanate phenyl) thiophosphate, tris (p-isocyanate phenyl) methane, tolylene diisocyanate 3 adduct of trimethylolpropane, aliphatic polyisocyanates having a hydrophilic group in the molecule, and the like can be used.

The isocyanate used in the present embodiment, including these compounds, may be protected with phenol, sulfurous acid or the like.

Examples of the methylol compound include methylolated melamine such as dimethylolmelamine and trimethylolmelamine, dimethylolated urea, and melamine-formaldehyde resin. In addition to these, various methylol compounds can be used, and those having a moderately high molecular weight and those having a molecular chain having an appropriate length are preferable.From this viewpoint, among the methylol compounds exemplified above, melamine -Formaldehyde resins are preferred.

Examples of the aziridine compound include, for example, diphenylmethane-bis-4,4'-N, N'-diethylurea,
2-bishydroxymethylbutanol-tris- [3- (1-
Aziridinyl) propinate]. Further, an oxazoline group-containing polymer can also be used.

These cross-linking agents vary depending on the type of resin, cross-linking agent, molecular weight, reaction conditions, etc., and cannot be said unconditionally. However, 0.1 to 10 parts by weight based on 100 parts by weight of the water-soluble resin.
0 parts by weight, preferably 1 to 50 parts by weight may be added.
If the addition amount is too small, the film strength at the time of swelling may be insufficient, or the film may be dissolved. On the other hand, if the amount is too large, the resin molecular chains are more restrained and sufficient swelling property cannot be obtained, so that sufficient image removing characteristics cannot be obtained.

Fine particles may be incorporated in the surface layer in order to improve the writing characteristics. The fine particles added for such purpose have an average secondary particle size (secondary particle size) of 5 to 30 μm, preferably 10 to 20 μm. If the secondary particle size is smaller than 5 μm, it is difficult to obtain a writing effect, and if the secondary particle size exceeds 30 μm, a problem may occur in image quality and the like. The secondary particle size is
It refers to the particle size when an aggregate formed by aggregating individual particles is regarded as one particle. The addition amount of the fine particles is 0.1 to 50 parts by weight based on the total of the water-soluble resin and the crosslinking material, that is, 100 parts by weight of the water-swellable resin. Preferred fine particles that can be added, for example, silica, titanium oxide,
Examples include inorganic fine particles such as alumina, zinc oxide, and calcium carbonate, and resin fine particles such as acryl and styrene, but are not limited thereto.

The surface layer may be subjected to an antistatic treatment as needed to improve the paper passing property. The antistatic agent may be added to the material forming the surface layer, or after forming the surface layer, an antistatic agent dissolved or dispersed in a suitable solvent may be applied thereon. Antistatic agents that can be used for this purpose include, for example, cationic surfactants such as quaternary ammonium salts.

Further, a surfactant may be added to improve the coating performance of the resin solution constituting the surface layer. The surfactant used for this purpose is not particularly limited, such as anionic, cationic and nonionic. The addition amount is preferably from 0.1% to 20%, more preferably from 0.5% to 10%, based on the water-soluble resin.

As a method for forming the surface layer, a coating method in which a coating solution in which surface layer components are dissolved or dispersed is applied to a substrate can be used. The surface layer component comprises the above-mentioned water-soluble resin and crosslinking agent as essential components, and if necessary, comprises the above-mentioned initiator, surfactant, and further monomers, oligomers, and other additives. It can be dissolved or dispersed in a solvent such as a mixed liquid or an organic solvent to form a coating liquid. After applying the coating of the surface layer component on the substrate, the surface layer can be formed by heating the coating to 50 to 180 ° C, preferably 80 to 150 ° C. The film thickness of the resulting surface layer after drying is 0.
The thickness is 5 to 30 μm, preferably 5 to 20 μm. If the thickness of the surface layer is less than 0.5 μm, a sufficient amount of swelling cannot be obtained, and the removal of printing material becomes insufficient. If the thickness of the surface layer is more than 30 μm, the strength of the film becomes weak. The above problems arise.

A feature of the present invention resides in that fine particles are provided on the surface of the surface layer. Since the fine particles are provided on the water-swellable surface layer, the printing material printed thereon can be easily removed to facilitate the recycling of the recording material, and the paper-passing property is improved. be able to.

The fine particles which can be used for this purpose have an average particle size of 0.1 to 20 μm, preferably 0.5 to 10 μm.
It is. If the average particle diameter is larger than 20 μm, the fine particles cannot be uniformly present on the surface layer, so that sufficient paper-passing property cannot be ensured. If the average particle diameter is smaller than 0.1 μm, the fine particles tend to aggregate. Problem arises. Application amount onto the surface of the inorganic fine particles 0.005~1g / m ^2, preferably from 0.01 to 0.5 g / m ^2. If the amount is more than 1 g / m ² , the light transmittance may be reduced, or a copier may be adversely affected,
On top of this, printing on it becomes defective. On the other hand, if it is less than 0.005 g / m ² , sufficient paper-passing property cannot be secured.

The type of fine particles that can be used for the above purpose is not particularly limited as long as the purpose of improving the paper-passing property can be achieved, and is not particularly limited, and silica, titanium oxide, alumina, zinc oxide, carbonate Examples thereof include inorganic fine particles such as calcium, resin fine particles such as polymethacrylic acid, polyester, and polyurethane, and organic fine particles such as an organic pigment.

In the recording material of the present invention, an intermediate layer may be formed between the base layer and the surface layer. The intermediate layer is provided for the purpose of bonding the surface layer more firmly to the base material layer.

FIG. 2 is a schematic sectional view of a recording material having an intermediate layer according to another embodiment of the present invention. 1 is a substrate layer,
2 is an intermediate layer and 3 is a surface layer. Note that in FIG.
2 shows a configuration in which the printing material 4 is printed on the surface of the printing medium. FIG. 2 shows a configuration in which the intermediate layer 2 and the surface layer 3 are formed on one surface of the base material layer 1, but a configuration in which the intermediate layer 2 and the surface layer 3 are formed on both surfaces is also included in the present invention.

The intermediate layer 2 is composed of a base resin having high adhesiveness to the base layer, more preferably a resin having high adhesiveness to both the base layer and the surface layer. May optionally include a compound (reactive compound) 5 having a functional group capable of chemically bonding to the surface layer constituting resin. As the base resin constituting the intermediate layer having high adhesiveness with the base material layer, urethane resin, acrylic resin, styrene resin, polyester resin, borocarbonate resin, acetic acid according to the type of the base layer constituent resin Vinyl resin, vinyl chloride resin and the like can be used as appropriate, preferably,
Examples include polymethyl methacrylate resin, polyester resin, polycarbonate resin, vinyl chloride resin, urethane resin, and the like.

The reactive compound optionally contained in the intermediate layer is not particularly limited as long as it has a functional group capable of chemically bonding to the resin constituting the surface layer. Examples thereof include isocyanate compounds, methylol compounds, aziridine compounds, and epoxy compounds. Compounds and the like can be used. When the resin constituting the surface layer is a resin having a hydroxyl group such as polyvinyl alcohol and methyl cellulose, an isocyanate compound, a methylol compound, and an epoxy compound are preferred.
When the resin constituting the surface layer is a resin having a carboxyl group such as polyacrylic acid, an isocyanate compound, an epoxy compound, and an aziridine compound are preferable.
In addition, these compounds can be similarly used as a crosslinking agent for the water-soluble resin constituting the surface layer.

Examples of the methylol compound include methylolated melamine such as dimethylolmelamine and trimethylolmelamine, dimethylolurea, and melamine-formaldehyde resin. In addition to these, various methylol compounds can be used, and those having a moderately long molecular chain are preferable. From this viewpoint, among the methylol compounds, a melamine-formaldehyde resin is preferable.

Examples of the epoxy compound include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, and glycerin polyglycidyl ether. In addition to these, various epoxy compounds can be used.

As the isocyanate compound, those having two or more isocyanate groups in one molecule can be used. By using a compound having a plurality of isocyanate groups, the base layer and the surface layer can be more firmly bonded. Such isocyanates include 4,4′-diphenylmethane diisocyanate,
4,4′-methylenebiscyclohexyl isocyanate,
Tris (p-isocyanatephenyl) methane, trimethylolpropane tolylene diisocyanate 3 adduct,
An aliphatic polyisocyanate having an intramolecular hydrophilic group can be used.

The isocyanate used in the present embodiment may be protected with phenol, sulfurous acid or the like.

As the aziridine compound, for example, diphenylmethane-bis-4,4′-N, N′-diethyl urea,
2'-bishydroxymethylbutanol-tris- [3- (1
-Aziridinyl) propionate] can be used. Further, an oxazoline group-containing polymer can also be used.

The above-mentioned reactive compound is more preferably a solid or wax at room temperature or a viscous liquid at room temperature. If the reactive compound is solid or waxy at room temperature or a viscous liquid at room temperature, it does not evaporate due to drying during the formation of the intermediate layer, and since the surface is not sticky after drying, the surface layer is coated. There is an advantage that it becomes easy. Further, when a reactive compound that is soluble in or has affinity for water is used, there is no need to use an organic solvent to apply and form the intermediate layer, and the organic solvent remains in the intermediate layer. Can be prevented.

To coat the intermediate layer 2 on the base material layer 1, the intermediate layer base resin and, if desired, the above-mentioned reactive compound are mixed with a suitable solvent such as tetrahydrofuran (THF), dioxane, acetone, ethyl acetate, methyl ethyl ketone (MEK). For example, a solvent coating method in which a solution dissolved in such as is applied and then dried to form a coating film, or a solvent-free coating method without a solvent can be applied. A solution in which a resin such as a water-soluble or hydrophilic polyurethane or polyester is dissolved or dispersed in water can also be used.Such aqueous resin solutions and resin emulsions are commercially available. In particular, there is an advantage that a coating film can be formed without using a non-aqueous organic solvent. For this reason, safety at the time of manufacture can be improved. In addition, it is possible to prevent a problem such as generation of gas of a residual solvent from the inside due to heating of the recording material due to paper passing through a copying machine or the like. When an aqueous solvent is used, the addition of a surfactant makes it easier to apply the intermediate layer. If the intermediate layer and the surface layer are formed using an aqueous solvent, it is possible to manufacture a recording material without using a non-aqueous organic solvent, and to ensure the safety and residual non-aqueous organic solvent in the recording material. Problems can be prevented.

The intermediate layer has a thickness of about 0.5 μm to about 20 μm, preferably about 0.5 μm to about 10 μm, and more preferably about 0.5 μm to about 20 μm, by the wet coating method or the melt coating method.
It is formed to have a thickness of about 6 μm. If the thickness is less than 0.5 μm, coating unevenness is likely to occur, and uncoated portions are easily formed, resulting in non-uniform transparency. On the other hand, if it exceeds 20 μm, problems may occur in the strength, heat resistance and the like of the recording material.

When an intermediate layer is used, the surface of the intermediate layer formed on the substrate may be subjected to a corona discharge treatment.

When paper or a fibrous material is used as the substrate layer, the substrate may be immersed in a coating solution for forming the intermediate layer to fill the intermediate layer material between the fibers constituting the substrate. .

The recording material obtained as described above can be suitably applied to a method of removing the recording material through a process of swelling the surface layer → physical rubbing by brushing or the like → drying process, and is recyclable.

A method for removing a printing material from a recording material having a printing material such as a toner printed on the surface thereof will be described below. The method includes a step of supplying a recording material on which a printing material is printed to a solvent capable of swelling the surface layer, and scraping the recording material from the swollen recording material surface with a physical force. Hereinafter, a more detailed description will be given with reference to the drawings.

FIG. 3 is a process flow chart for explaining an example of a printing material removing method. In FIG. 3, the recording material 1
No. 00 has an intermediate adhesive layer and a surface layer formed on both surfaces thereof. A printing material 4 such as toner is printed on the surface of the recording material. As a printing material, a toner used for electrophotography is preferably used. In addition, a recording material used for an ink-jet method, a thermal transfer method, a printing method, and the like using a hot melt ink, and other oil-based paint agents For example, a type that forms a film-like image by adhering to the surface of a recording material such as a recording medium can be used. The recording material is conveyed from right to left in the drawing.

First, a surface swelling solvent is supplied to the surface of the recording material on which the printing material 4 has been printed from the solvent supply device 11. As the solvent capable of swelling the surface layer, various solvents such as an aqueous solvent, that is, water, a mixed solvent of water and a water-soluble organic solvent, or an aqueous organic solvent can be used.
Also, a desired additive such as a surfactant may be added. As described above, the present embodiment has a great advantage in that the printing material can be removed using water. In the following description, the case where water is used will be described.

As shown in FIG. 3, the water may be supplied by showering water from the shower device 11 onto the surface layer, or immersed in water (not shown). In order for water to penetrate into the surface layer of the recording material, it is preferable to contact the recording material for about 15 to 150 seconds. The longer the contact time, the more water can penetrate, but the longer the treatment time. When water penetrates into the surface of the recording material, the surface swells (the swollen surface is shown as 13), and the adhesive force between the printing material 4 and the surface decreases. At this time, the water temperature is 15 ° C
~ 45 ° C is appropriate. If the temperature is too high, the evaporation of water increases, and if the temperature is too low, a sufficient cleaning effect may not be obtained.

After the water has sufficiently penetrated into the surface layer of the recording material, the recording material is further transported to the printing material removal area, and the brush 1
Called 4 The brush 14 is rotating, and the printing material 4 on the recording material 100 is removed by the brush. In the present invention, in addition to the brush, other means capable of applying a physical or mechanical force to the surface and rubbing or scraping the surface, such as a blade, a cloth, etc. Good. In FIG.
Although the brush 14 is arranged in the liquid, it may be arranged outside the liquid. The length and thickness of the bristles of the brush 14 are not particularly limited. For example, the length is about 5 to 20 mm, and the thickness is 10 to
It can be about 60 μm. The material is not particularly limited, but nylon or the like having excellent wear resistance is suitable.

The paper passing speed, that is, the recording material is the brush 14
May be determined in consideration of the balance between productivity and cleaning performance, and may be, for example, 0.5 cm / sec to 5 cm / sec. The rotation speed of the brush is preferably 5 times or more, more preferably 10 times or more the transport speed. The brush may be rotated in any direction.

After the printing material 4 is removed, the recording material is conveyed to a shower area, and a cleaning shower 15 is applied to the surface of the recording material to wash away the printing material remaining on the surface of the recording material. As the liquid used for the cleaning shower 15, the same aqueous solvent as used for swelling the surface layer can be used. Water is particularly preferred as the aqueous solvent.

After being subjected to the cleaning shower 15, the recording material is further transported to the drying area, and
And dried. The drying method may be a contact type such as a heat roller, but a non-contact type such as a far-infrared lamp is more preferable in that the surface of the recording material is not damaged.

FIG. 4 is a view showing an embodiment of a cleaning apparatus to which the above-described cleaning method can be applied.
The apparatus shown in FIG. 4 includes a cleaning tank 22 for storing a liquid 30 for swelling a recording material in a casing 23. The cleaning tank 22 is connected to a pump 20 having a filter for removing printing material accumulated in the liquid in the tank, and the swelling shower 11 and the cleaning shower are connected to the pump 20 via a pipe 31. 15 are connected.

The liquid in the cleaning tank 22 is supplied to the pump 20.
After being purified by the internal filter, it is sent to showers 11 and 15 through a pipe 31, and is used as a liquid for swelling the recording material in the shower 11 and as a cleaning liquid in the cleaning shower 15.

The recording material is introduced into the apparatus by the paper feed roller 21 and sprayed with a swelling liquid by the shower 11, and then passes through the guide 26 and the transport roller 24 and is immersed in the liquid 30 in the cleaning tank 22. You. And
After standing still for a predetermined time, the conveying roller 24 and the guide 28
Is sent to the opposite portion of the brush 14 to remove the printing material.

Thereafter, the recording material passes through the guide 29, the conveying roller 25, and the guide 27, is sprayed with a cleaning liquid by the cleaning shower 15, finally dried by the drying roller 17, and discharged out of the apparatus. .

[0056]

The present invention will be described in more detail with reference to the following examples. Example 1 A 100 μm-thick polyethylene terephthalate (PET) sheet was used as a substrate layer. Melamine-formaldehyde resin (“SUMIREZ 61”) was added to 100 g of a water-dispersible urethane resin solution (“HUX-232”, manufactured by Asahi Denka Co., Ltd.).
3 ", manufactured by Sumitomo Chemical Co., Ltd.) and 5 g of polyoxyethylene nonylphenyl ether (" Nonipol ", manufactured by Sanyo Chemical Industries, Ltd.)
0.1 g was added, and the mixture was stirred for 5 minutes to prepare an intermediate layer resin solution. This intermediate layer resin solution was applied on the above-mentioned base material layer using a bar coater, and dried at 120 ° C. for 5 minutes to form an intermediate layer having a thickness of 6 μm. Next, 16 g of polyvinyl alcohol ("CM-318", manufactured by Kuraray Co., Ltd.)
Was dissolved in 184 g of water to prepare a resin aqueous solution. To this aqueous resin solution, 0.7 g of a melamine-formaldehyde resin (“SUMIREZE 613”), 0.6 g of ammonium chloride, and 0.2 g of polyoxyethylene nonylphenyl ether as a surfactant were added, and the mixture was stirred to form a resin solution for a surface layer. Prepared. The obtained solution was applied on the intermediate layer formed above using a bar coater, and heated at 120 ° C. for 2 hours to form a surface layer having a thickness of 8 μm, thereby obtaining a three-layer laminated sheet. . This sheet was immersed in a dispersion of fine silica powder having an average particle size of 5 μm in water at a concentration of 0.01% by weight. This was dried to obtain a recording material having about 0.02 g / m ² of silica fine powder on the surface layer.

Example 2 "Minolta EP paper" (manufactured by Minolta) having a thickness of 100 μm was used as a base material layer. 100 g of a water-dispersible urethane resin solution “HUX-232”, 5 g of a melamine-formaldehyde resin “SUMIREZ 613” and 0.1 g of polyoxyethylene nonylphenyl ether “Nonipol” 0.1
g was added and the mixture was stirred for 5 minutes to prepare an intermediate layer resin solution. This intermediate layer resin solution is coated on the substrate layer with a bar.
It was applied using a coater and dried at 120 ° C. for 5 minutes to form an intermediate layer having a thickness of 5 μm. Next, 16 g of polyvinyl alcohol ("KL-318", manufactured by Kuraray Co., Ltd.) was added to water 18
The resultant was dissolved in 4 g to prepare an aqueous resin solution. Glycerin polyglycidyl ether (“EX-31
3 ", manufactured by Nagase Kasei Co., Ltd.) 3 g and potassium hydroxide 0.2 g,
0.2 g of polyoxyethylene dodecyl phenyl ether as a surfactant, and alumina having an average particle size of 2 μm
g was added and stirred for 5 minutes to prepare a surface layer resin solution.
The obtained solution was applied on the intermediate layer formed above using a bar coater, and heated at 140 ° C. for 2 hours to obtain a thickness of 10 μm.
m was formed to obtain a three-layer laminated sheet. 0.2% by weight of alumina fine particles having an average particle size of 2 μm were added to this sheet.
A dispersion dispersed in water at a concentration was applied with a bar coater. As a result, a recording material to which 0.05 g / m ^{2 of} fine particles was applied was obtained.

COMPARATIVE EXAMPLE 1 The three-layer sheet before alumina application obtained in Example 2 was used as a recording material.

The recording materials obtained in Examples 1 and 2 and Comparative Example 1 were evaluated for recyclability by the following method. Evaluation of Image Removability An image was formed on the obtained recording material using a commercially available laser beam printer (“LP-1700”, manufactured by Epson Corporation). The recording material on which the image was formed was subjected to image removal (ink removal) using the apparatus shown in FIG. Table 1 shows the results of the image removal. In the table, the degree of image removal was evaluated by the toner removal rate when the time from water showering to brushing was 3 minutes. [Judgment Criteria] ト ナ ー: Toner removal rate of 95% or more, ：: Toner removal rate of 80% or more and less than 95%, ×: Toner removal rate of less than 80%.

The operating conditions of the apparatus shown in FIG. 4 are as follows. The swelling time was changed by adjusting the paper passing speed.・ Use a brush roller with a core bar diameter of 12 mm having nylon brush bristles with a hair length of 10 mm and a thickness of 30 μm ・ Water temperature in the tank 30 ° C. ・ Brush rotation tip speed / paper passing speed = 30 ・ Paper passing speed 1 cm / sec. ・ The temperature of the heat roller is 110 ° C.

Evaluation of Paper-passing Property Under an environment of 25 ° C. and 85% RH, “EP” manufactured by Minolta Co., Ltd.
-1082 "100 sheets of recording material were set in a cassette of a copying machine, and continuous copying was performed. The paper-passing property was evaluated by the number of occurrences of paper-pass failure during continuous copying. [Judgment Criteria] A: Less than 3 paper passing failures, x: 3 or more paper passing failures.

Evaluation of Recyclability The degree of image removal after the copying → toner removal process was repeated five times was evaluated.

[0063]

[Table 1]

[0064]

According to the recording material of the present invention, the printing material printed thereon can be easily removed and reused, and the problem of surface sticking which has been a disadvantage of the prior art can be solved. Also, it is excellent in paper passing property.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a recording material of the present invention.

FIG. 2 is a schematic sectional view showing another embodiment of the recording material of the present invention.

FIG. 3 is a process flow chart for explaining a method for removing a recording material.

FIG. 4

FIG. 5 is a diagram showing another example of a cleaning device that can be used for recycling a recording material of the present invention.

FIG. 6 is a diagram showing still another example of a cleaning device that can be used for recycling a recording material of the present invention.

[Explanation of symbols]

1: base material layer, 2: intermediate layer, 3: surface layer,
4: printing material, 11: shower device, 12: middle layer + surface layer, 13: swollen surface layer, 14: brush, 1
5: Cleaning shower, 16: Dryer, 100: Recording material.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Fujiwara 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 2H034 FA00

Claims (4)

[Claims] 1. A recyclable recording material comprising at least a substrate layer and a water-swellable surface layer, wherein fine particles having an average particle size of 0.1 to 20 μm are uniformly provided on the surface of the surface layer. Characteristic recyclable recording material. 2. The recording material according to claim 1, wherein the fine particles are provided on the surface of the surface layer by electrostatic force or Van der Waals force between the surface layer material and the fine particles. 3. The recording material according to claim 1, wherein the amount of the inorganic fine particles applied on the surface of the surface layer is 0.005 to 1 g / m ² . 4. The recording material according to claim 1, wherein an intermediate layer is provided between the base layer and the surface layer.