JP6281180B2 - Recording medium - Google Patents

Description

The present invention can erase images formed by electrophotographic methods, thermal transfer methods using hot melt inks and thermal sublimation dyes, inkjet methods using inkjet inks, etc., and does not require re-molding of the substrate. The present invention relates to a recording medium that can be reproduced in almost complete form and that can be easily processed on demand.
In the present invention, an image can be formed / erased on demand on a substrate whose surface is formed of a material other than a cellulosic fiber material, and a tag card (including an IC chip) for production management and inventory management. However, it can be advantageously applied to films such as OHP films, credit cards, members cards, traffic permits, admission permits, employee ID cards, and advertising billboards.

With recent OA, printer paper and copy paper have been used in large quantities. Along with this, a large amount of waste paper is generated from the office, and many of them are wasted.
The present applicant uses a recording medium in which a layer that dissolves and swells with a liquid is provided in the vicinity of the surface on which an image is formed, and the liquid containing water that greatly swells the swelling layer of the recording medium. A method of reproducing the recording medium by applying it to the recording medium and removing the image forming substance has been proposed (for example, Japanese Patent Application Laid-Open No. 7-13383 of Patent Document 1).
This method is excellent in that it can peel and regenerate images formed on commonly used paper, but the substrate itself has low water resistance and is durable for repeated reproduction. There is a problem.

In recent years, tag cards for production management and inventory management (including IC chips, the same applies below), OHP films, credit cards and members cards, traffic permits, admission, which use plastic film as the base material. Cards such as permits and employee ID cards have come to be used.
In these cards, in addition to magnetic information that can be read by a machine, image information that can be recognized by a person is often recorded, and images that can be recognized by a person when the information that can be read by the machine is rewritten. Information also needs to be rewritten, and reproduction of a recording medium using a plastic film as a base material involves a method of collecting the film, melting it once, and reusing it.

However, this method has the disadvantage that the energy efficiency for regeneration is poor, and the regenerated product becomes expensive or poor in quality as compared to using new raw materials.
In addition, many types of cards include personal information such as the user's address and name, and outsourcing to a company that performs the disposal or recycling process requires only a slight risk of compromising confidentiality. I can't.

In JP-A-64-69345 of Patent Document 2, a printing ink layer is removed by supplying a removing liquid such as methylene chloride to the printing surface of a prepaid card such as a telephone card and rubbing with a rotating brush. It is described to do.
However, the use of a chlorine-containing organic solvent such as methylene chloride is clearly an environmental and health problem. Even if it is not a halogenated organic solvent, it is preferable to avoid the use of an organic solvent for cleaning and removing unnecessary materials as much as possible from the viewpoint of environmental problems and economy.

  Japanese Patent Application Laid-Open No. 2003-30617 of Patent Document 3 and Japanese Patent Application Laid-Open No. 7-68978 of Patent Document 4 disclose a card mounted with an IC chip provided with a reversible thermosensitive recording layer. Although this card can rewrite the formed image, it uses a thermal recording material and cannot form a full-color image.

  Japanese Patent Application Laid-Open No. 2010-806 of Patent Document 5 describes a reversible thermosensitive recording material having both an ink receiving layer capable of ink jet recording and a thermosensitive recording layer. Although this recording material can form a full color image by ink jet recording, the full color image formed on the ink receiving layer cannot be rewritten.

In Japanese Patent No. 3313886 of Patent Document 6, a swelling layer having a high swelling property with respect to a highly polar liquid such as water or alcohol is provided on a base material mainly composed of materials other than cellulose fibers, and the swelling A recording medium is disclosed in which an image can be peeled off by a stress generated by a difference in swelling amount from an image formed on a layer.
Although this recording medium can rewrite full-color images, it is necessary to irradiate the substrate internally containing titanium oxide with a deep ultraviolet ray to make it hydrophilic, and since it swells with water or alcohol, it may be exposed to rain. Use in some fields is limited and ink jet recording is not possible.

Therefore, in view of the current state of the art, the present invention has water resistance at the time of use, and can completely erase an image formed at the time of erasing an image, so that it is not necessary to re-mold a water-resistant substrate. It is an object of the present invention to provide a recording medium that can be reproduced in almost complete form and that can perform ink jet recording and can form and erase a full color image.

The inventors of the present invention have disclosed that a release layer of a recording medium provided with a release layer and an image receiving layer on a water-resistant substrate contains a water-soluble resin, so that the release layer becomes water at room temperature (25 ° C.). Has not been easily dissolved, and can be used in the field, and it has been found that it can be dissolved in an image material removing solution (hot water) to remove an image.
That is, the said subject is solved by following (1)-(11) of this invention.
(1) “A recording medium having at least a base material, a release layer, and an image receiving layer, wherein the base material layer has water resistance, and the release layer is a water-soluble resin. Recording medium. "
(2) The recording medium according to claim 1, wherein the water-soluble resin is any one selected from the following (a) to (d).
(A) Aqueous polyester having an arylene group and an alkylene group and / or a polyoxyalkylene group in the main chain and pendant with a metal sulfonate group (b) Polyvinyl alcohol (c) The core is vinyl chloride and the shell is a water-soluble acrylic Aqueous core-shell type particles (d) starch ",
(3) “The recording medium according to (1) and (2), wherein the aqueous polyester is an aqueous polyester represented by the following general formula (1);

In General Formula (1), Ar represents a phenyl group or a naphthyl group, R represents a hydrocarbon group having 1 to 10 carbon atoms which may have a branch, or a polyoxyalkylene having 1 to 10 carbon atoms, M represents An alkali metal is represented, and m / n is 10/90 to 40/60. "
(4) “The recording medium according to (1) to (3) above, wherein the release layer has a thickness of 0.5 μm to 50 μm”;
(5) “The recording medium according to any one of (1) to (4), wherein the image receiving layer is water-permeable”;
(6) “The recording medium according to any one of (1) to (5) above, wherein the image receiving layer includes a polymer material having an amino group and a crosslinked structure” ,
(7) “The recording medium according to any one of (1) to (6), wherein the image receiving layer has a thickness of 1 μm to 120 μm”;
(8) “The recording medium according to any one of (1) to (7), wherein the base material is a resin”;
(9) "The recording medium according to any one of (1) to (8), wherein the base material is glass",
(10) “A recording medium reproducing apparatus according to any one of (1) to (9), including an image removing unit, a release layer coating unit, and an image receiving layer coating unit. And the image removing means has a nozzle head that ejects an image material removing liquid onto an image holding surface of a recording medium, and the liquid temperature of the image material removing liquid is 40 ° C. or higher and 100 ° C. or lower. Characterized recording medium playback device ",
(11) The image removing means includes means for brushing or wiping the surface of the recording medium after supplying the image material removing liquid to the image holding surface of the recording medium. The recording medium reproducing device described in 1.].

  As will be understood from the following detailed and specific description, according to the present invention, the image recorded on the surface of the recording medium can be completely erased, and the base material of the recording medium is re-molded. By reproducing in an almost complete form to the extent that it is not necessary, it is possible to provide a recording medium that can be acquired easily and can be easily used on-demand.

It is a figure which shows an example of the to-be-image-recorded medium in this invention. FIG. 3 is a schematic diagram illustrating a state where an image on an image recording medium in the present invention is removed. It is a figure which shows the example of the nozzle head of the to-be-recorded medium reproduction apparatus in this invention. It is a figure which shows the example of the image removal means of the to-be-recorded medium reproduction apparatus in this invention. It is a figure which shows an example of the storage layer of the to-be-image-recorded-medium reproducing | regenerating apparatus in this invention. It is a figure which shows an example of the to-be-image-recorded-medium reproducing | regenerating apparatus of this invention. It is a figure which shows the example of the reverse roll coating apparatus of the to-be-recorded medium reproduction apparatus in this invention. It is a figure which shows the example of the silk screen printing coating apparatus of the to-be-recorded medium reproduction apparatus in this invention.

The recording medium fee of the present invention will be described in detail.
The recording medium material of the present invention is a recording medium material having a base material, a release layer, and an image receiving layer, the base material is made of a material having water resistance, and the release layer is made of a water-soluble resin. It is what you have.

Hereinafter, further details will be described with reference to the drawings.
FIG. 1 is a diagram showing an example of an image recording medium 1 according to the present invention.
In this example, the image recording medium is provided with a release layer 2 of the present invention on a water-resistant substrate 3, and an image receiving layer 4 for receiving an image forming material 5 is provided on the release layer 2. . Part of the image forming material 5 in such an image recording medium adheres to the surface of the image receiving layer 4, the other part penetrates to the inside of the image receiving layer 4, and the other part of the image receiving material 5 It partially penetrates to the surface of the release layer 2 or the inside of the release layer 2 through the layer 4. In any case, the image forming material 5 present on the surface of the image receiving layer 4 may be the image forming material 5 that has penetrated to the inside of the image receiving layer 4 or the surface of the release layer 2 through the image receiving layer 4 or the release layer 2. The image forming material 5 partially penetrating into the inside of the film is difficult to remove, but according to the present invention, it can be completely removed.

<Peeling layer>
The release layer of the recording medium in the present invention is mainly composed of a water-soluble resin, takes a balance between water resistance and hydrophilicity, and does not easily peel off even when exposed to rain or the like due to outdoor use. At the time of reproduction, the image is quickly peeled off and the image can be removed.
In the release layer, in addition to the water-soluble resin, various subcomponents such as a filler, a surfactant, an antioxidant, a leveling agent, a thickener, an antifoaming agent and the like may be added if desired. Can be contained. The water-soluble resin used for the release layer of the recording medium material of the present invention itself has a film-forming property and is excellent in adhesion between the substrate and the ink receiving layer, but dissolves or swells when supplied with an image material removing solution. This reduces the adhesion to the substrate. Furthermore, the adhesion to the ink receiving layer is also significantly reduced, but this is not essential in the present invention.

(Water-soluble resin)
As the water-soluble resin, any water-soluble resin can be used as long as it has water resistance at the time of use and dissolves in warm water at the time of erasing an image and peels from the substrate. Examples of the water-soluble resin include aqueous polyester, polyvinyl alcohol, water-soluble acrylic, starch, and the like.
The water-soluble resin has both toughness and flexibility, and the solubility in water at a temperature 20 ° C. higher than normal temperature (20 ° C. to 25 ° C.) is 1.5 times or more the solubility in water at normal temperature.

  As the aqueous polyester, those containing an aqueous polyester having an arylene group, an alkylene group and / or a polyoxyalkylene group in the main chain and pendant with a metal sulfonate group can be used.

The aqueous polyester is preferably an aqueous polyester represented by the following general formula (1).

In General Formula (1), Ar represents a phenyl group or a naphthyl group, R represents a hydrocarbon group having 1 to 10 carbon atoms which may have a branch, or a polyoxyalkylene having 1 to 10 carbon atoms, M represents It represents an alkali metal, m and n are integers, and m / n is 10/90 to 40/60.

The water-based polyester is imparted with excellent hydrophilicity by a metal sulfonate group, and exhibits excellent adhesion to resin materials such as polyester, vinyl chloride and polycarbonate, and metal materials such as an aluminum plate and a steel plate.
Moreover, since it is saturated polyester which does not have a double bond, it is excellent in a weather resistance.
If the content of the metal sulfonate group is too small, the water solubility of the resulting polyester resin will be insufficient, making it difficult to peel off during regeneration, and conversely if too much, the water resistance of the aqueous polyester resin will be insufficient. Therefore, m / n is 10/90 to 40/60, preferably 15/85 to 35/65, and more preferably 20/80 to 30/70.

The molecular weight of the aqueous polyester is preferably 10,000 to 30,000. If the molecular weight is less than 10,000, the mechanical strength may decrease.

The aqueous polyester is obtained by using a dicarboxylic acid component, a diol component, and a water-solubility-imparting component having a metal sulfonate group as raw materials, and subjecting them to a condensation reaction.
In addition, the dicarboxylic acid component and the glycol component in the case where the raw material of the aqueous polyester resin is separated from the dicarboxylic acid component, the glycol component, and the water solubility imparting component having a metal sulfonate group include those corresponding to the water solubility imparting component. It is.

  The dicarboxylic acid component is selected from dicarboxylic acid derivatives such as anhydrides, esters, acid chlorides, halides, etc., which react with glycol components described later to form esters (ester-forming derivatives of dicarboxylic acids). Consisting of one or more compounds.

Examples of the dicarboxylic component include dicarboxylic acids such as aromatic dicarboxylic acids and aliphatic dicarboxylic acids. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, diphenic acid, naphthalic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6. -Naphthalene dicarboxylic acid etc. can be mentioned.
Examples of the aliphatic dicarboxylic acid include linear, branched and alicyclic oxalic acid, malonic acid, succinic acid, maleic acid, itaconic acid, glutaric acid, adipic acid, pimelic acid, 2,2-dimethylglutaric acid, Examples include suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, diglycolic acid, thiodipropionic acid, and the like.

These dicarboxylic acid components and ester-forming derivatives thereof may be used alone or in combination of two or more. Among these dicarboxylic acids and ester-forming derivatives thereof, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are easy to react, weather resistance of the resulting resin, durability, etc. Are preferably used.
In particular, it is preferable to use only aromatic dicarboxylic acids as the dicarboxylic acid component that does not correspond to the water-solubilizing component.

  Examples of the glycol component include polyethylene glycol such as ethylene glycol and diethylene glycol, triethylene glycol, tetraethylene glycol, and pentaethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and the like. , Neopentyl glycol, 1,6-hexane glycol, 2,7-dimethyl-4,7-octanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-2-butyl-1,3- Examples thereof include aliphatic diols such as propanediol, 2,2,4-trimethyl-1,6-hexanediol, and 3-methyl-1,5-pentanediol.

  These glycols are used individually by 1 type, or multiple types are used together. Among these glycols and ester-forming derivatives thereof, ethylene glycol, diethylene glycol, and butanediols such as 1,4-butanediol are preferably used from the viewpoint of easy reaction and durability of the resulting resin. Is done.

  The water solubility-imparting component having a metal sulfonate group reacts with at least one of dicarboxylic acid, glycol, and ester-forming derivatives thereof in the raw material of the aqueous polyester resin to constitute a part of the skeleton structure of the aqueous polyester resin. To do. Also, at this time, by introducing an ionic polar group having a metal sulfonate group into the skeleton of the aqueous polyester resin, the aqueous polyester resin is given hydrophilicity, and the aqueous polyester resin can be dispersed or dissolved in an aqueous solvent. It is what.

  Examples of the water solubility-imparting component having a metal sulfonate group include dicarboxylic acids having a metal sulfonate group, and ester-forming derivatives thereof.

  Among these water-solubilizing components, dicarboxylic acids having a metal sulfonate group and ester-forming derivatives thereof (hereinafter collectively referred to as dicarboxylic acids having a metal sulfonate group, etc.) include, for example, 5-sulfoisophthalic acid, 2-sulfo Examples include alkali metal salts such as isophthalic acid, 4-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfonaphthalene-2,6-dicarboxylic acid, and ester-forming derivatives thereof such as esters, acid chlorides and halides. In order to impart good water dispersibility or water solubility to the aqueous polyester resin, the alkali metal is preferably sodium, potassium or lithium.

When a dicarboxylic acid having a metal sulfonate group or the like is used as a water solubility-imparting component, the metal sulfonate group effectively remains in the aqueous polyester resin and excellent hydrophilicity is imparted.
In particular, when 5-sodium sulfoisophthalic acid or an ester thereof (for example, sodium 5-sulfonate dimethylisophthalic acid) is used as a water-solubilizing component, the sodium sulfonate group effectively remains in the aqueous polyester resin and has excellent hydrophilicity. Sex is imparted.

Regarding the adjustment of water resistance and hydrophilicity of the aqueous polyester, as disclosed in JP-A-8-295792, JP-A-2004-331830, JP-A-2009-275186, etc. It can be adjusted by the content.

  In addition, as such an aqueous polyester, a commercially available product may be used. For example, a copolymer made of terephthalic acid, ethylene glycol, and 5-sodium sulfoisophthalic acid commercially available from Kyoyo Chemical Industry Co., Ltd. -221 "," Plus Coat Z-446 "," Plus Coat Z-561 ", etc.).

As the polyvinyl alcohol, partially saponified polyvinyl alcohol can be used. Since the completely saponified product is easily crystallized and hardly soluble in water, image erasure becomes difficult.
The degree of saponification of the partially saponified polyvinyl alcohol is preferably 70 or more and 90 or less. If the degree of saponification is less than 70, the water resistance may be lowered, and if it exceeds 90, image erasure becomes difficult.

  Polyvinyl alcohol preferably has a degree of polymerization of 400 or more and 4000 or less, and a viscosity at a concentration of 4% and 20 ° C. of 4 mPa · s or more and 40 mPa · s or less. If the degree of polymerization is less than 400 or less than 4 mPa · s, the water resistance may be lowered, and if the degree of polymerization exceeds 4000 or exceeds 40 mPa · s, image erasure may be difficult.

  The saponification degree is represented by [m / (m + n)] × 100 in the following general formula (2), and the polymerization degree is represented by m + n.

In general formula (2), n and m represent integers.

The partially saponified polyvinyl alcohol may saponify polyvinyl acetate obtained by polymerizing vinyl acetate, but uses GOHSENOL GH-17, KH-17, NK-05R, etc. manufactured by Nippon Synthetic Chemical Industry Co., Ltd. be able to. Further, it may be a modified polyvinyl alcohol having a modifying group such as a polyoxylene group. Examples of the polyvinyl alcohol having the modifying group include Ecomaty WO-320R manufactured by Nippon Synthetic Chemical Industry Co., Ltd.

The aqueous core / shell type particles are preferably resins having a core / shell type particle structure having a different composition between the core of the particle and the outer shell (shell). More preferably, the resin is a water-soluble acrylic.
Such a core / shell type water-soluble acrylic resin may be produced by the method described in JP-T-2005-522578, and also used by Starlight PMC Co., Ltd .: Hiros-X: BE-7650. May be.

As the starch, a conventionally known starch can be used, but it is preferable to use a starch that balances water resistance and hydrophilicity.

In addition to the water-soluble polyester represented by the general formula (1), the water-soluble resin such as polyvinyl alcohol, water-based core / shell type particles, and starch, the release layer of the present invention is within the range not departing from the object of the present invention. Alternatively, one or more other water-soluble resins can be used in combination.
Examples of water-soluble resins that can be used in combination include polyvinylpyrrolidone, polyethylene oxide, sodium polyacrylate, sodium alginate, agar, polysaccharides (cellulose-based derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium carboxymethylcellulose, etc.) ), Protein (gelatin, glue, etc.) and the like.
The content of the water-soluble resin that can be used in combination is less than 30 parts per 100 parts of the aqueous polyester, polyvinyl alcohol, aqueous core-shell type particles, or starch.

A small amount (10% or less, preferably 7% or less) of a surfactant may be added to the aqueous coating liquid for forming the release layer in order to increase wettability and water permeability (of course, 7% or less). You do not have to use it). As the surfactant, various surfactants such as anionic and nonionic surfactants can be used, and there is no particular limitation, but a fluorine-based surfactant that can improve wettability and water permeability in a small amount is preferable. Further, an antifoaming agent or a thickener may be added in order to improve the coating property and coating quality.

  In addition, the release layer receives ink that could not be accommodated in the image receiving layer, and further prevented silica, titanium oxide, alumina, Inorganic fine particles such as zinc oxide and calcium carbonate and resin fine particles such as acrylic and styrene may be added.

When such inorganic fine particles are added, 1 to 50 parts by weight, preferably 1 to 20 parts by weight can be added to 100 parts by weight of the water-soluble resin. The average particle size (secondary particle size) of secondary particles of these fine particles is preferably 5 μm or more and 30 μm or less. If the thickness is 5 μm or less, the effect is difficult to be obtained, and if it exceeds 30 μm, there is a possibility that a problem may occur in image quality. The secondary particle size refers to the particle size when an aggregate formed by aggregation of individual particles is regarded as one particle. The secondary particle size can be measured by microscopic observation or the like.

In order to coat the release layer on the substrate, a solvent coating method, a melt coating method, or the like in which a release layer coating solution containing the above water-soluble resin or a solution obtained by dissolving this in water or an appropriate aqueous solvent is applied and dried. It can be carried out.

The thickness of the release layer varies depending on the coating method and the application method, but the release layer is formed so that the thickness is 0.5 μm to 50 μm, preferably 1 to 40 μm, more preferably 5 to 30 μm. If the thickness is less than 0.5 μm, uneven coating tends to occur and an uncoated portion is likely to be formed. If it exceeds 50 μm, there is a risk of problems in the strength and heat resistance of the recording medium.

<Image receiving layer>
The image receiving layer of the recording medium in the present invention may be used as long as it has water permeability and water resistance, such as a porous material, regardless of hydrophilicity or hydrophobicity. it can. Further, it is preferably white for image formation.

The image receiving layer in the present invention preferably contains a polymer material having an amino group and a crosslinked structure.
The polymer material has high hydrophilicity due to amino groups, high ink absorbability, excellent affinity with the water-soluble resin, and excellent water resistance due to a crosslinked structure. The image receiving layer containing the polymer material preferably receives the ink droplets sent from the ink jet recording head without beading or bleeding, and forms an image, thereby removing the image material (for example, the colorant of the ink jet ink). Thus, it has appropriate water permeability to the release layer, which is the lower layer, and is excellent in water resistance.

The polymer material heats the protein by adding a crosslinking agent such as isocyanate to a resin material having an amino group, for example, an aqueous solution or an aqueous emulsion of polyester, polycarbonate, polyurethane, or the like having an amino group, and then crosslinking the protein. Can be formed. Commercially available ink acceptors may also be used, such as Pateracol EG-4X (manufactured by DIC), Pateracol IJ-70 (manufactured by DIC), WR-454 (manufactured by Idemitsu Technofine). be able to.

The image receiving layer in the invention may further contain a water-soluble resin, a fine particle filler for absorbing ink, and various auxiliary agents as desired.

Examples of the water-soluble resin include polyvinyl alcohol, starch and starch derivatives, methyl cellulose, polyacrylic acid, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, polyacrylamide, and diacetone acrylamide.
When the water-soluble resin is used in combination, the content of the water-soluble resin is less than 300 parts per 100 parts of the water-insoluble polymer material. When the content of water-soluble resin increases, water resistance decreases.

As the fine particle filler, known ones such as natural silica, calcium carbonate, alumina, pseudoboehmite, colloidal alumina, and alumina hydrate are used. Particularly preferred are alumina hydrate, silica, colloidal silica and the like. Synthetic silica, calcium carbonate, barium sulfate, calcium sulfate, titanium oxide, zinc oxide, zinc carbonate, satin white, diatomaceous earth, calcium silicate, colloidal silica, aluminum silicate, magnesium silicate, alumina and other inorganic pigments, plastic pigment, urea resin Examples thereof include organic pigments such as pigments and melamine resin pigments, and organic / inorganic composite pigments. These fine particles are formed in a void shape in the ink image receiving layer, adsorb ink colorants, and prevent ink bleeding.

The particle diameter of the fine particle filler is not particularly limited, but the average particle diameter is 1 to 18 μm, preferably 2 to 10 μm, based on the image quality and the texture of the surface of the recording medium material. The average particle diameter can be measured by Coulter counter model TA-II (manufactured by Coulter Electronics).
The addition amount of the fine particle filler is preferably 50 parts or less, preferably 30 parts or less, more preferably 25 parts or less per 100 parts of the binder resin.

The thickness of the image receiving layer of the present invention is preferably relatively thick for sufficient ink absorption by the image receiving layer and for improved durability, and is 1 to 120 μm, preferably 10 to 60 μm, More preferably, it is 20-40 micrometers.
If the thickness is less than 1 μm, the ink absorption action may decrease, and the effect of improving the environmental resistance such as water resistance, abrasion resistance and weather resistance when formed into a film may not be sufficient. This is not preferable.

<Base material>
As described above, the recording medium material in the present invention has a release layer on at least one surface on a substrate (support), and an image receiving layer on the release layer. The base material has water resistance that does not change due to the supply of the image material removing liquid.
For example, in the case of a support in which an IC chip is embedded, it is preferable that the performance is not impaired even when the image material removing liquid is supplied.

The substrate can be used as long as it is water-resistant, and can be used as a film or resin-coated paper, for example, polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polycarbonate, polyamide, polyamideimide. , Polysulfone, Polyphenylenesulfone, Cellulose Acetate, Polyethylene, Polyurethane, ABS, Polystyrene, Fluororesin film, Art paper, Resin coated or Cast coated plain paper, Fine paper, Glassine paper Paper, baryta paper, non-woven paper, etc. can be used. Moreover, although the base material whose surface is a metal, ceramics, or glass may be sufficient, it is preferable that a surface has a hydrophilic group from an adhesive viewpoint with the said peeling layer.

  Although the thickness of a base material changes with uses, etc., it is preferable that they are 30 micrometers-1500 micrometers, and it is more preferable that they are 60 micrometers-800 micrometers. The thickness varies depending on the purpose of use, sheet size, material, and the like. For example, in the case of an adhesive label or the like, the thickness may be relatively thin. On the contrary, in the case of a support in which an IC chip is embedded, the thickness is generally 600 μm to 800 μm. . In the case of a certain sort of magnetic card, there is a tendency to become thicker, but in any case, if it is less than 30 μm, there is no strength or so-called stiffness, and there are many cases where wrinkles are generated or conveyance accuracy in an inkjet printing machine is lacking, When the thickness exceeds 1500 μm, there are many cases where troubles occur in the transportability of the machine.

<Image material removal liquid and removal treatment>
The image material removing liquid in the present invention can be water or an aqueous liquid containing a small amount (10% or less, preferably 5% or less) of a surfactant in water. Such an image material removing solution is heated to 35 ° C. or more and 100 ° C. In terms of image removability, a higher temperature is preferable, but 40 ° C. to 60 ° C. is preferable in terms of a balance with energy consumption for maintaining the temperature of hot water.

Such an image material removing liquid can be applied to the surface of a recording medium in various application modes such as dip coating, roll coating, spray coating, transfer coating, spray nozzle coating, and flow-down coating. When the removal liquid is water, it can be ejected in the form of water vapor to expose the surface of the recording medium material.
Then, if necessary, at the same time as the removal liquid is applied, the surface of the recording medium to which the image material removal liquid is applied is wiped off with an wiping means such as a wiping cloth or a brush. It may be provided.
Thus, the recording medium of the present invention can be suitably used for a method for removing a recording material that has undergone a drying process by dissolving / removing the release layer → (physical rubbing by brushing or the like if necessary) → drying process. .

In the present invention, since the image removing solution penetrates to the release layer through the surface image-receiving layer, the release layer dissolves and the layer having the image material can be completely removed. Regardless of the force, as schematically shown in FIG. 2, the recording medium can be recovered without damaging the substrate.

FIG. 3 shows an example of an image erasing apparatus suitable for carrying out the image erasing method for a recording medium charge according to the present invention.
The recording medium image erasing apparatus of the present invention has a nozzle head 65 that jets and jets an image material removing liquid 6 made of water or an aqueous liquid onto the image holding surface of the recording medium.
The pressurizing pressure of the image material removing liquid is preferably 0.3 MPa to 15 MPa, and more preferably 0.3 MPa to 3 MPa.

Further, as shown in FIG. 4, there may be provided a scrubbing means and a dewatering means for scrubbing the image holding surface of the recording medium material, and before the image material removing liquid 6 is supplied under pressure by the nozzle head 65. In addition, a dissolving / swelling step of immersing the recording medium in the storage tank 52 storing the image material removing liquid shown in FIG. 5 may be provided.

In the image erasing apparatus 50 shown in FIG. 4, the recording medium material is conveyed into the apparatus by the conveying roller pair 51, and the image material is removed from the nozzle head 65 at the image material removing liquid application site as shown in FIG. The liquid 6 is jetted under pressure, an image material removing liquid is applied to the surface of the image receiving layer having the image material, and the release layer is dissolved and swollen.
Next, the recording medium material is guided to a scrubbing process, brushed by a brush roller 58 provided between the two holding roller pairs 56, the swollen release layer collapses, and the image material from the nozzle head 65 again. The removal liquid is washed by pressure jetting, and after the release layer is completely removed, it is dehydrated by the dewatering roller 60.
Note that the wiping process may be wiping with a woven cloth or the like instead of brushing.

<Recording medium playback processing>
FIG. 6 shows a reproducing apparatus 121 for reproducing the recording medium of the present invention.
The reproduction apparatus 121 includes a step 122 for recoating the release layer 2 on the substrate 3 of the recording medium from which the release layer 2 and the image receiving layer 4 have been removed by the erasing apparatus 50 shown in FIG. And the step 123 of regenerating and coating the image receiving layer 4 in which the image forming material 5 is permeated.

An example of a reverse roll coating apparatus used in the release layer coating 122 step and the receiving layer coating 123 step is shown in FIG.
The base material 3 is held by the transport device 83 and transported at a constant speed. A plurality of holes are formed in the transport device 83, and air is sucked out by a fan 84 below the transport device 83, thereby adsorbing the base material 3 in the downward arrow direction shown in FIG. 5. In this state, the transport device 83 is moved horizontally in the direction of the right arrow in FIG.
When the transport device 83 moves horizontally with the substrate 3 sucked and held, the coating roll 80 in FIG. 7 is rotated in the direction of the arrow of the coating roll 80 in FIG. Then, the upper surface of the substrate 3 and the coating roll 80 are conveyed while being in contact with each other. At that time, the material of the release layer 2 or the image receiving layer 4 adhering to the surface of the coating roll 80 is transferred to the substrate.
In the present invention, butylene rubber having a rubber hardness of 30 ° is used as the coating roll 80, but the invention is not limited to this.
When the applicator roll 80 is in contact with the metering roll 81 as shown in FIG. 5 and a constant amount of the material of the release layer 2 or the receiving layer 4 is always stored at the contact location, and the metering roll 81 rotates in the direction shown in FIG. The metal doctor 82 adheres the material of the release layer 2 and the receiving layer 4 to the surface of the measuring roll 81 with a constant thickness, and the material is transferred to the coating roll 80. The measuring roll 81 is a metal roller having a surface with a grid-like groove, and is configured to always store a certain amount of the material of the release layer 2 or the receiving layer 4. As shown in FIG. 4, on the downstream side after applying the release layer 2 or the receiving layer 4, each material is provided with a drying process in which warm air is applied to dry and fix the material, and the substrate 3 is conveyed. The material of the release layer 2 and the receiving layer 4 is dried and fixed while being allowed to flow.

Moreover, you may use a silk screen printing coating apparatus for the peeling layer coating 122 process and the receiving layer coating 123 process.
An example of a silk screen printing coating apparatus is shown in FIG.
Similar to the reverse roll coating apparatus, the silk screen printing coating apparatus holds the base material 3 by the transport device 83 and transports the base material 3 at a constant speed. A plurality of holes are formed in the transport device 83, and air is sucked out by a fan 84 below the transport device 83, thereby adsorbing the base material 3 in the downward arrow direction shown in FIG. 5. In this state, the driving device (not shown) causes the conveying device 83 to move horizontally in the direction of the right arrow in FIG. 5 and to come directly under the silk screen printing plate 90.
At this time, the conveyance device 83 moves upward in a state where the substrate 3 is sucked and held, and the substrate 3 comes into contact with the silk screen printing plate 90.
In this state, the material of the release layer 2 and the image receiving layer 4 replenished on the silk screen printing plate 90 is thinly extended by moving the squeegee 91 in the horizontal arrow direction of FIG. 8 on the silk screen printing plate 90. The material of the release layer 2 and the receiving layer 4 passes through the stitches of the silkscreen printing plate 90 and is coated on the substrate 3 with a constant thickness. A thickener may be added to the coating material.
As shown in FIG. 4, on the downstream side after applying the release layer 2 or the receiving layer 4, each material is provided with a drying process in which warm air is applied to dry and fix the material, and the substrate 3 is conveyed. The material of the release layer 2 and the receiving layer 4 is dried and fixed while being allowed to flow.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example.

Example 1
An aqueous polyester (terephthalic acid, ethylene glycol, 5-sodium sulfoisophthalic acid) is used on the upper surface of a PET sheet (thickness 0.125 mm, laminated surface roughness Rmax 0.9 mμ, whiteness 100%, total light transmittance 12%). Copolymer: Shore altitude 73, pencil altitude 2H, melting point 47 ° C., softening point 137 ° C., molecular weight about 14,000: plus coat Z-221: manufactured by Kyoyo Chemical Co., Ltd.) 20% by weight, isopropyl alcohol 39.5% by weight, A release layer coating solution mixed at a ratio of 39.5% by weight of water and 1% by weight of a fluorosurfactant was applied to a thickness of 5 μm with a wire bar, dried at 60 ° C. for 2 minutes, and the film thickness after drying Formed a release layer of 1 μm.
On the release layer, an image receiving agent containing polyester, yellowing type polyurethane and protein (viscosity 1200 ± 500 m · Pas, WR-454: manufactured by Idemitsu Fine Techno Co., Ltd.) 42% by weight, isopropyl alcohol 29% by weight, water 29 The image receiving layer coating solution mixed at a ratio of% by weight is applied with a wire bar to a thickness of 47.6 μm and dried at 60 ° C. for 2 minutes to form an image receiving layer with a thickness of 20 μm after drying, A recording medium 1 was obtained.

(Example 2)
A recording medium 2 was obtained in the same manner as in Example 1 except that the PET sheet of Example 1 was replaced with a polycarbonate sheet (thickness 0.25 mm, Rmax 0.9 mμ on the laminated surface, transparent total light transmittance 89.6%). .

(Example 3)
A recording medium 3 was obtained in the same manner as in Example 1 except that the PET sheet of Example 1 was replaced with a glass plate (thickness 1 mm).

Example 4
An image receiving agent containing a polyol, an aliphatic isocyanate, and a self-emulsifying type urethane resin (viscosity 1036 m · Pa, Pateracol: EG-4X: manufactured by DIC Corporation) is applied to a thickness of 121 μm with a wire bar, and 120 ° C. The recording medium 4 was obtained in the same manner as in Example 1 except that the image receiving layer having a thickness of 20 μm after drying was formed.

(Example 5)
On the recording media 1 to 4, a solid image was formed on the entire surface using a GELJET viscous ink of a high viscosity pigment ink by a Ricoh inkjet printer GX 3300.
When the image was removed by spraying 40 ° C. warm water at a pressure of 0.5 MPa for 10 minutes onto the printing surface of the recording media 1 to 4, the release layer of the recording media 1 to 4 was dissolved in the warm water, and the image receiving layer Became a collapsed state, peeled off from the base material, and removed together with the hot water by the hot water jet pressure, leaving only the base material.
The evaluation of image removal was performed by visually confirming that no ink remained on the recording medium after washing, and measuring the thickness of the recording medium after washing, and the thickness was equal to or less than the thickness of the base material + 1 μm. Was confirmed.

(Example 6)
When the image was removed by spraying 60 ° C. hot water at a pressure of 0.5 MPa for 1 minute on the printing surface of the recording medium 1, the release layer of the recording medium 1 was dissolved in the hot water, and the image receiving layer was in a collapsed state. Thus, it was peeled off from the base material and removed together with the hot water by the hot water jet pressure, and only the base material was obtained.

(Example 7)
When the image was removed by spraying 100 ° C. water vapor at a pressure of 0.5 MPa for 1 minute on the printing surface of the recording medium 1, the release layer of the recording medium 1 was dissolved in warm water, and the image receiving layer was in a collapsed state. Thus, it was peeled off from the base material and removed together with the hot water by the hot water jet pressure, and only the base material was obtained.

(Example 8)
When hot water of 25 ° C. was jetted onto the printing surface of the recording medium 1, it was necessary to jet it at a pressure of 3 MPa for 10 minutes in order to remove the image.

Example 9
An image was formed on the recording medium 1 with imagio toner type 29W black using imagio MP W4000 manufactured by Ricoh.
When the image was removed by spraying 40 ° C. warm water at a pressure of 0.5 MPa for 10 minutes onto the printing surface of the recording medium 1, the release layer of the recording medium 1 was dissolved in the warm water, and the image receiving layer was in a collapsed state. Then, it was peeled from the base material and removed together with the hot water by the hot water jet pressure, and only the base material was obtained.

(Example 10)
The recording medium 1 was written with an alcohol oil-based dye (ZEBRA Mackey ultrafine pen).
When the image was removed by spraying 40 ° C. warm water at a pressure of 0.5 MPa for 10 minutes onto the printing surface of the recording medium 1, the release layer of the recording medium 1 was dissolved in the warm water, and the image receiving layer was in a collapsed state. Then, it was peeled from the base material and removed together with the hot water by the hot water jet pressure, and only the base material was obtained.

( Reference Example 11)
Peeling layer coating liquid of polyvinyl alcohol solution (polyvinyl obtained by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate resin of Example 1: degree of saponification 71.0~75.0mol%, 4.5~ The recording medium 5 was prepared in the same manner as in Example 1 except that 5.5 mPa · s: Gohsenol NK-05R: Nippon Synthetic Chemical Industry Co., Ltd .: 10 wt%, 90 wt% water). Furthermore, when the image formation and image removal steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 5 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 12)
Polyvinyl alcohol of the release layer coating solution of Reference Example 11, Gosenol KH-17 (degree of saponification 78.5~81.5mol%, 32~38mPa · s: Nippon Synthetic Chemical Industry Co., Ltd.), except substituting the, reference A recording medium 6 was prepared in the same manner as in Example 11. Further, when the image forming and image removing steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 6 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 13)
Polyvinyl alcohol of the release layer coating solution of Reference Example 11, Gosenol GH-17 (degree of saponification 86.5~89.0mol%, 27~33mPa · s: Nippon Synthetic Chemical Industry Co., Ltd.), except substituting the, reference A recording medium 7 was prepared in the same manner as in Example 11. Further, when the image forming and image removing steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 7 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 14)
Polyvinyl alcohol of the release layer coating liquid of Reference Example 12 was modified polyvinyl alcohol: Ecomati WO-320R (degree of saponification: 86.5-89.5 mol%, 6.0-8.0 mPa · s: Nippon Synthetic Chemical Industry Co., Ltd.) A recording medium 8 was prepared in the same manner as in Reference Example 11 except that the product was changed to (manufactured). Further, when the image forming and image removing steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 8 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 15)
Except for changing the peeling layer coating solution of Example 1 to a vinyl-acrylic resin core-shell type emulsion: Hiros-X · BE-7650 (manufactured by Seiko PMC Co., Ltd., production method is based on Patent 3225105 Special Table 2005-522578), A recording medium 9 was prepared in the same manner as in Example 1. Further, when the image formation and image removal steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 9 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 16)
The same procedure as in Example 1 was followed except that the release layer coating solution of Example 1 was replaced with an aqueous starch solution (starch: soluble starch: 30% by weight + glycerin: 1% by weight + water mixed at a ratio of 69% by weight). A recording medium 10 was prepared. Further, when the image forming and image removing steps were performed on the coated surface of the recording medium in the same manner as in Examples 5 to 10 except that the recording medium 10 was used, the same results as in Examples 5 to 10 were obtained. It was.

( Reference Example 17)
Recording medium 11 was recorded in the same manner as in Example 1 except that the peeling layer coating solution of Example 1 was replaced with a 10% by weight aqueous solution of dextrin (manufactured by Kanto Chemical Co., Ltd.) and the drying conditions were dried at 45 ° C. for 2 minutes. Was made.

( Reference Example 18)
When the image is removed by spraying 60 ° C. warm water at a pressure of 0.5 MPa for 1 minute on the printing surface of the recording medium 11, the release layer of the recording medium 11 is dissolved in the warm water, and the image receiving layer is in a collapsed state. Thus, it was peeled off from the base material and removed together with the hot water by the hot water jet pressure, and only the base material was obtained.

(Comparative Example 1)
The release layer of Example 1 was applied with a water-resistant polyester (m of the general formula (1) is less than 10, molecular weight 23000, plus coat RZ-570: manufactured by Kyoyo Chemical Co., Ltd.), and a thickness of 5 μm was applied with a wire bar. A recording medium 12 was obtained in the same manner as in Example 1 except that the film was dried at 80 ° C. for 2 minutes and a release layer having a thickness of 1 μm after drying was formed.
A full solid image was formed on the recording medium 12 using a GELJET viscous ink of a high viscosity pigment ink by a Ricoh inkjet printer GX 3300.
Using the image erasing apparatus shown in FIG. 3, hot water at 40 ° C. was jetted at a pressure of 0.5 MPa for 10 minutes.
The release layer of the recording medium 12 did not dissolve in warm water, and only a part of the image receiving layer was removed by the jet pressure of the hot water, but a part of the release layer and the image receiving layer did not peel off. Printing material remained. Further, when the thickness of the recording medium after washing was measured, a portion more than the thickness of the base material + intermediate layer was measured.

DESCRIPTION OF SYMBOLS 1 Recording medium 2 Release layer 3 Base material 4 Image receiving layer 5 Image forming material 6 Image material removal liquid 50 Image erasing apparatus 51 Conveying roller pair 52 Reservoir 56 Holding roller pair 58 Brush roller 60 Dehydrating roller 65 Nozzle head
80 Coating roll 81 Metering roll 82 Doctor 83 Conveying device 84 Fan 90 Plate 91 Squeegee 121 Reproducing device 122 Peeling layer coating 123 Image receiving layer coating

JP-A-7-13383 JP-A 64-69345 JP 2003-30617 A JP 7-68978 A JP 2010-806 JP Japanese Patent No. 3313886

Claims (11)

At least a base material, a release layer, a recording medium having an image-receiving layer, the base layer are those having water resistance, the release layer, Ri-soluble resin der,
The recording medium in which the water-soluble resin is a main chain having an arylene group and an alkylene group and / or a polyoxyalkylene group, wherein the aqueous polyester der Rukoto the metal sulfonate group is pendant. The solubility of water-soluble resin in water having a temperature 20 ° C higher than 20 ° C to 25 ° C is 1.5 times or more of the solubility in water at 20 ° C to 25 ° C. Recording medium. The recording medium according to claim 1, wherein the aqueous polyester is an aqueous polyester represented by the following general formula (1).
In General Formula (1), Ar represents a phenyl group or a naphthyl group, R represents a hydrocarbon group having 1 to 10 carbon atoms which may have a branch, or a polyoxyalkylene having 1 to 10 carbon atoms, M represents An alkali metal is represented, and m / n is 10/90 to 40/60.   The recording medium according to claim 1, wherein the release layer has a thickness of 0.5 μm to 50 μm.   The recording medium according to claim 1, wherein the image receiving layer is water permeable.   6. The recording medium according to claim 1, wherein the image receiving layer includes a polymer material having an amino group and having a crosslinked structure.   The recording medium according to claim 1, wherein the image receiving layer has a thickness of 1 μm to 120 μm.   The recording medium according to claim 1, wherein the base material is a resin. The recording medium according to any one of claims 1 to 7, wherein the substrate is glass. A reproducing apparatus for a recording medium according to 請 Motomeko 1 to 9 either, image removing unit, the peeling layer coating unit and, is one having an image-receiving layer coating unit, the image removal device Has a nozzle head that ejects an image material removing liquid onto the image holding surface of the recording medium, and the temperature of the image material removing liquid is 40 ° C. or higher and 100 ° C. or lower. Playback device.   The recorded image according to claim 10, wherein the image removing means includes means for brushing or wiping the surface of the recording medium after supplying the image material removing liquid to the image holding surface of the recording medium. Medium playback device.