JP2003276367A - Sheet for hiding information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for hiding information which has a simple structure and is inexpensive, which can be used without using a release sheet, enables the view of the hidden information by separating an adhesive layer and a release agent layer from each other economically and entirely on the occasion of looking at the information after the sheet is used with these layers laid on each other and enables additional or secondary writing in the release agent layer. <P>SOLUTION: The sheet for hiding information is prepared by folding it up at a folding part provided in a prescribed part of a sheet base. The adhesive layer is provided on one of the folded surfaces, while the release agent layer being writable is provided on the other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information concealing sheet, and more specifically, it uses a surface superposed by folding or cutting as a concealing information carrying surface and has a writable peeling on the superposed surface. Releasable information transmission ticket with foldability, such as a folding sheet and a laminated sheet, which is provided with an agent layer, direct mail, postcard with reply with application form or request form, card, label, tag , A sheet for hiding information such as forms.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are explanatory views for explaining a conventional information hiding sheet. As shown in FIG. 3 (1), the conventional information hiding sheet 10 is a sheet in which information can be hidden by overlapping the folded-back portion 12 provided at a predetermined portion of the sheet base material 11 as a boundary. The release sheet 16 has the removable pressure-sensitive adhesive layer 13 provided on one of the overlapping surfaces, and the release sheet base material 15 has the removable release agent layer 14 provided on the removable pressure sensitive adhesive layer 13. Pasted through. Examples of the removable pressure-sensitive adhesive include an ordinary pressure-sensitive adhesive compounded with silicon or a surfactant to impart removability.

Next, the information 17 to be concealed is written on the other overlapping surface, as shown in FIG. 3 (2). Then, in order to conceal the information 17, the release sheet 16 is removed as shown in FIG. 3 (3), and as shown in FIG. It When the person who receives the information sees the concealed information 17, when the overlapping surface is peeled off at the folding portion 12, the overlapping surface on which the information 17 is written appears as shown in FIG. be able to.

In the conventional information hiding sheet 10 described above, additional information can be added on the superposed surface on which the information 17 is written, but the release sheet 16 is necessary to protect the adhesive surface, and the release sheet 16 is Since it is discarded after use, it becomes garbage and is not environmentally friendly. Therefore, it is conceivable to use the above-mentioned conventional information hiding sheet 10 without the release sheet 16, but if the use is made without the release sheet 16 and the overlapping surfaces are overlapped with the folded portion 12 as the boundary, the removability is improved. Adhesive is a sheet base material 1
There is a problem that the superposed surfaces cannot be economically and neatly peeled off due to transfer to the first side or due to the high progress of the removable pressure-sensitive adhesive. Therefore, the release sheet 16 is absolutely necessary.

FIG. 4 is an explanatory view for explaining another conventional information hiding sheet. As shown in FIG. 4 (1), the conventional information hiding sheet 10A is provided at a predetermined portion of the sheet base material 11. It is a sheet that is made to be able to conceal information by overlapping with the folded-back portion 12 as a boundary, and a transparent film 20, 21 pseudo-bonded with a permanent adhesive layer 18 and a pseudo-bonding surface 19 on one of the overlapping surfaces, The permanent adhesive layer 22 is provided in this order, and the release sheet 16 in which the release agent layer 14 is provided on the release sheet base material 15 is attached on the permanent adhesive layer 22 via the release agent layer 14. There is. Permanent adhesive layer 1
8 and 22 are formed by using a known permanent adhesive, and the pseudo-bonded transparent films 20 and 21 can be made of known materials such as polyethylene terephthalate, polypropylene, and polyester film. The transparent film 21 may be of the same type or of a different type, and the temperature may be 80 to 140 ° C. and the pressure may be 3 to 10 with a heat roller.
Overlap the films at 8kg / cm2 and press them together. The film surface may be subjected to surface treatment such as plasma treatment or corona discharge.

Next, the information 17 to be concealed is written on the other side of the overlapping surface as shown in FIG. 4 (2). Then, in order to conceal the information 17, as shown in FIG. 4 (3), the release sheet 16 is removed, and as shown in FIG. It When the recipient 17 sees the concealed information 17, the information 17 is seen through the transparent film 21 when peeled off at the pseudo adhesive surface 19 and opened with the folded portion 12 as a boundary as shown in FIG. 4 (5). be able to.

Since the information 17 is covered with the transparent film 21 which is permanently adhered by the permanent adhesive layer 22 in the conventional information hiding sheet 10A described above, additional information and secondary information cannot be entered, so that it is excellent in tamperproof property. On the other hand, on the other hand, it can be said that the application is limited because additional entry and secondary entry are not possible. Further, there is a problem that the release sheet 16 is required to protect the surface of the permanent adhesive layer 22, and the release sheet 16 is discarded after use and becomes dust, which is not environmentally friendly.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an information hiding sheet which can be used without a release sheet, wherein an adhesive layer is provided on one of the overlapping surfaces and the other is overlaid. After the release agent layer is provided on the surface and both are used in a superimposed manner, the hidden information can be seen economically and neatly when the hidden information is viewed, and the release agent layer is Additional entries and secondary entries are possible,
An object of the present invention is to provide an information hiding sheet that has a simple structure and is inexpensive.

[0009]

In order to solve the above problems, the information hiding sheet according to claim 1 of the present invention is overlapped with a folded portion provided at a predetermined portion of a sheet base material as a boundary,
A sheet for hiding information, characterized in that an adhesive layer is provided on one of the overlapping surfaces, and a release agent layer having writability is provided on the other overlapping surface.

The information hiding sheet according to claim 2 of the present invention is
The information hiding sheet according to claim 1, wherein the release agent is
The release agent is characterized in that a release agent powder is mixed with a vehicle containing a glycol solvent having a boiling point of 100 ° C. or higher as a main component.

The information hiding sheet according to claim 3 of the present invention is
The information hiding sheet according to claim 1, wherein the release agent is
For vehicles containing radiation-curing components as the main component,
It is a release agent containing porous fine particles.

The information hiding sheet according to claim 4 of the present invention is
The information hiding sheet according to claim 1, wherein the release agent is
For vehicles containing radiation-curing components as the main component,
It is characterized by being a release agent containing a release material powder.

The information concealing sheet of the present invention has a pressure-sensitive adhesive layer provided on one of the overlapping surfaces and a release agent layer having writability on the other overlapping surface, so that the structure is simple and inexpensive. It is also possible to use without a release sheet, and after using the pressure-sensitive adhesive layer and the release agent layer overlaid, it is economically and neatly peeled off when viewing hidden information. The information obtained can be viewed, and additionally, the release agent layer can be additionally filled or secondary filled.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the information concealing sheet of the present invention will be described below with reference to FIGS. Figure 1 (1)
1 is an explanatory plan view of the information hiding sheet 1 of the present invention, FIG.
(2) is a sectional explanatory view of the information hiding sheet 1 of the present invention shown in FIG. 1 (1). The information concealing sheet 1 of the present invention is a sheet for concealing information by overlapping the folded portion 3 provided at a predetermined portion of the sheet base material 2 as a boundary, and the adhesive layer 4 is provided on one of the overlapping surfaces. And the release agent layer 5 having writability is provided on the other overlapping surface. As shown in FIG. 1 (3), in the information concealing sheet 1 of the present invention, the adhesive does not transfer to the release agent layer 5 side even if it is overlapped with the folded-back portion 3 for a long period of time. When re-peeling, the overlapping surfaces can be peeled economically and cleanly as shown in FIG. Therefore, it is possible to say that the information hiding sheet 1 of the present invention is environmentally friendly, since it is possible to reduce the amount of dust without using the conventionally used release sheet.

Next, the information 6 to be hidden is written on the release agent layer 5 as shown in FIG. Then, in order to conceal the information 6, as shown in FIG. 1 (5), the overlapping surfaces are overlapped with each other with the folded-back portion 3 as a boundary, and the information is sent. When the person who receives the information sees the concealed information 6, it can be easily and cleanly peeled between the release agent layer 5 and the adhesive layer 4, and the information 6 written on the release agent layer 5 can be seen. Then, it is possible to easily make additional entries and secondary entries on the release agent layer 5,
After additional entry or secondary entry, as shown in FIG. 1 (5) again, the overlapping surfaces can be overlapped with each other at the folded-back portion 3, and the information can be shipped. Therefore, the information hiding sheet 1 of the present invention can be used. Can also be used as a postcard with a reply such as an application form or a request form.

FIG. 2 (1) is a plan view of another information hiding sheet 1A of the present invention, and FIG. 2 (2) is a sectional view of the information hiding sheet 1A of the present invention. The information concealing sheet 1A of the present invention is a sheet for concealing information by overlapping the folded portion 3 provided at a predetermined portion of the sheet base material 2 as a boundary, and the adhesive layer 4 is provided on one of the overlapping surfaces. Is provided,
A release agent layer 5 having writability is provided on the other overlapping surface.

Then, the information 6 to be concealed is written on the release agent layer 5 as shown in FIG. Then, in order to conceal the information 6, as shown in FIG. 2C, the overlapping surfaces are overlapped with each other with the folded-back portion 3 as a boundary, and then the information 6 is shipped. When the person who receives the information sees the concealed information 6, it can be easily and cleanly peeled between the release agent layer 5 and the adhesive layer 4, and the information 6 written on the release agent layer 5 can be seen. Then, it is possible to easily make additional entries and secondary entries on the release agent layer 5,
After additional entry and secondary entry, as shown in FIG. 2 (3) again, since the overlapping surfaces can be overlapped with each other at the folded-back portion 3 as a boundary, the information hiding sheet 1A of the present invention can be sent. Can also be used as a postcard with a reply such as an application form or a request form.

The release agent used in the present invention is not particularly limited as long as it is a release agent excellent in writability. However, as a release agent used in the present invention, a vehicle containing a glycol solvent having a boiling point of 100 ° C. or higher as a main component, a release agent containing a release material powder, or a vehicle containing a radiation curing component as a main component On the other hand, a release agent containing porous fine particles or a vehicle containing a radiation-curable component as a main component is preferably used because the release agent containing the releaseable substance powder is excellent in writing properties and removability. it can.

The glycol solvent used in the present invention is a medium boiling point solvent or a high boiling point solvent (having a boiling point of 100 ° C. or higher), and specifically, for example, glycol (glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene). Glycol, propylene glycol, dipropylene glycol) and glycol derivatives (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate) , Diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether Chill ether acetate), etc., and the like, and these two or more thereof.

The peelable substance powder used in the present invention is not particularly limited. Specific examples of the peelable substance powder used in the present invention include fine powders such as tetrafluoroethylene resin such as KT-300M, KT-400H, and KTL.
-450, KTL-8F, KTL-4N, KTL-50
0F, KTL-350, KTL-610, KTL-8N
(Manufactured by Kitamura Co., Ltd.), a trefil F powder that is made into a powder while highly blending various silicone polymers with an inorganic carrier.
-201, F-202, F-204, F-250, F-
300 (manufactured by Toray Dow Corning Silicone Co., Ltd.), trefil R-900, R-902A, R-910 (manufactured by Toray Dow Corning Silicone Co., Ltd.), which is a fine powder of silicone resin, spherical or non-spherical Trefill E-500, E-505C, E-506, which are silicone rubber elastic bodies that are ultrafine particles in a fixed shape
C, E-600, E-601, E-604, E-850
(Manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The amount of the peelable substance powder used in the present invention is not particularly limited, but the peelable substance powder is added to 100 parts by mass of a vehicle containing a glycol solvent having a boiling point of 100 ° C. or more as a main component. It is desirable to mix 20 to 80 parts by mass, preferably 30 to 70 parts by mass, and more preferably 40 to 60 parts by mass of the body. If it is less than 20 parts by mass, the releasability may not be improved, and if it exceeds 80 parts by mass, the printing ink suitability may be deteriorated, and printing, writing,
All of them are not preferable because there is a risk that marking or the like may not be possible.

In the present invention, a vehicle containing a glycol-based solvent having a boiling point of 100 ° C. or higher as a main component and, if necessary, a binder resin may be used. Further, by adding a binder resin, the formed release agent layer becomes resistant to rubbing, and even if it is rubbed, the releasable substance powder does not separate, and the release agent layer does not peel off to the pressure-sensitive adhesive layer side, which is preferable.

The binder resin used in the present invention is not particularly limited as long as it can be used together with the glycol solvent. Specifically, for example, albumin, gelatin, casein, starch, gum arabic, natural resins such as sodium alginate, carboxymethyl cellulose, cellulose derivatives such as hydroxyethyl cellulose, polyamide, polyacrylamide, polyhydroxyethyl methacrylate, polyphenylacetoacetal, Polyethyleneimine, polyvinylpyrrolidone, polyvinylpyridium halide, melamine resin, polyurethane, polyvinyl alcohol and its derivatives, synthetic resins such as polyester, sodium polyacrylate, acrylic acid ester copolymer, dimethylamine epichlorohydrin polycondensate, acrylamide Diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dimethyl
A cationic resin such as a compound containing diallyl ammonium chloride as a main component or a mixture of two or more kinds thereof, electron beam curable ink, ultraviolet curable ink, sulfonic acid group, carboxyl group, sulfate ester group,
Examples thereof include rosin-modified maleic acid and rosin-modified phenol resin having an anionic group such as a phosphate group.

The other release agent used in the present invention is prepared by incorporating porous fine particles into a vehicle mainly containing a radiation-curable component. The radiation-curable component used in the present invention is not particularly limited as long as it is a component that can be cured by radiation such as ultraviolet rays, electron beams, X-rays, β-rays, γ-rays, and among these, UV-curable and / or electron beam-curable Can be preferably used. The radiation-curable component used in the present invention can be arbitrarily selected from known photopolymerizable monomers and / or photopolymerizable oligomers. Examples of such a photopolymerizable monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid or esters thereof, such as alkyl-, cycloalkyl-, halogenated alkyl-, alkoxyalkyl-, hydroxyalkyl-, aminoalkyl-. , Tetrahydrofurfuryl-,
Allyl-, glycidyl-, benzyl-, phenoxy-acrylates and methacrylates, alkylene glycols, polyoxyalkylene glycol mono- or diacrylates and methacrylates, trimethylolpropane triacrylate and methacrylates, pentaerythritol tetraacrylates and methacrylates, acrylamides, methacryls, etc. Amides or their derivatives, such as acrylamide and methacrylamide, mono- or di-substituted with alkyl or hydroxyalkyl groups, diacetone acrylamide and methacrylamide, N, N'-
Alkylene bis acrylamide and methacrylamide, etc., allyl compounds, such as allyl alcohol, allyl isocyanate, diallyl phthalate, triallyl isocyanurate, maleic acid, maleic anhydride, fumaric acid or its esters, such as alkyl, halogenated alkyl, alkoxyalkyl Other unsaturated compounds such as mono- or dimaleate and fumarate are used, eg styrene, vinyltoluene, divinylbenzene, N-vinylcarbazole, N-vinylpyrrolidone.

In the case where the curing shrinkage is an obstacle, for example, isobornyl acrylate or methacrylate, norbornyl acrylate or methacrylate, dicyclopentenoxyethyl acrylate or methacrylate, dicyclopentenoxypropyl acrylate or Acrylic acid ester or methacrylic acid ester of diethylene glycol dicyclopentenyl monoether such as methacrylate, polyoxyethylene or polypropylene glycol dicyclopentenyl monoether acrylic acid ester or methacrylic acid ester, such as dicyclopentenyl cinnamate, dicyclopentenoxy Ethyl cinnamate, dicyclopentenoxyethyl monofumarate or difumarate such as 3,9-bis (1,1
-Bismethyl-2-oxyethyl) -spiro [5,5]
Undecane, 3,9-bis (1,1-bismethyl-2-
Oxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9-bis (2-oxyethyl) -spiro [5,5] undecane, 3,9-bis (2-oxyethyl) Mono-, diacrylate or mono-, dimethacrylate such as -2,4,8,10-tetraoxaspiro [5,5] undecane, or mono-, ethylene oxide or propylene oxide addition polymer of these spiroglycols, Diacrylate, mono- or dimethacrylate, or methyl ether of the monoacrylate or methacrylate, 1-azabicyclo [2,2,2] -3-octenyl acrylate or methacrylate, bicyclo [2,2,1] -5 -Heptene-2,3-dicarboxyl monoallyl ester, such as dicyclopenta Enyl acrylate or methacrylate, it can be used a photopolymerizable monomer, such as dicyclopentadienyl oxyethyl acrylate or methacrylate, dihydrodicyclopentadienyl acrylate or methacrylate. These photopolymerizable monomers may be used alone or in combination of two or more.

As the photopolymerizable oligomer, acrylic acid ester of epoxy resin, for example, diglycidyl ether diacrylate of bisphenol A, reaction product of epoxy resin with acrylic acid and methyltetrahydrophthalic anhydride, epoxy resin with 2-hydroxyl Epoxy resin prepolymers such as reaction products with ethyl acrylate, reaction products with diglycidyl ether of epoxy resin and diallylamine, ring-opening copolymerized esters of glycidyl diacrylate and phthalic anhydride, methacrylic acid dimers Unsaturated polyester prepolymers such as esters of carboxylic acid and polyol, polyesters obtained from acrylic acid, phthalic anhydride and propylene oxide, reaction products of polyethylene glycol, maleic anhydride and glycidyl methacrylate, etc. , A reaction product of polyvinyl alcohol and N-methylolacrylamide, a polyvinyl alcohol-based prepolymer such as one obtained by esterifying polyvinyl alcohol with succinic anhydride and then adding glycidyl methacrylate, and pyromellitic dianhydride. A polyamide prepolymer such as a prepolymer obtained by reacting a diallyl esterified product with p, p'-diaminodiphenyl, a reaction product of an ethylene-maleic anhydride copolymer and allylamine, methyl vinyl ether-maleic anhydride A reaction product of an acid copolymer and 2-hydroxyethyl acrylate, a polyacrylic acid such as a product obtained by further reacting it with glycidyl methacrylate, or a maleic acid copolymer-based prepolymer, etc. Linked alkylene segments, or saturated polyester segment or both, and the like urethane prepolymer having an acryloyl group or a methacryloyl group at both ends. It is suitable that these photopolymerizable oligomers have a weight average molecular weight of about 2,000 to 30,000.

The photopolymerization initiator used in the present invention includes a thermal decomposition type radical polymerization initiator such as a peroxide or an azo compound which is decomposed by heat to generate a radical [eg, benzoyl peroxide, azobisisobutyronitrile. , Cumene hydroperoxide, tert-butyl hydroperoxide, persulfates (potassium salts, ammonium salts), redox-based catalysts that increase the rate of radical generation by adding a reducing agent, etc. Benzoin alkyl ethers such as benzoin ethyl ether, benzoin-n-propyl ether, benzoin-isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, benzophenone, benzyl, diacetyl, diphenyl sulfide, ether Singh, thionine, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone. These photopolymerization initiators may be used alone or in combination of two or more. The content thereof is preferably selected in the range of 5 to 15 parts by mass per 100 parts by mass of the radiation curing component.

The porous fine particles used in the present invention are not particularly limited. Specific examples of the porous fine particles used in the present invention include, for example, silica fine particles, Mizukasil P.
-526, P-801, P-527, P-603, P8
32, P-73, P-78A, P-78F, P-87,
P-705, P-707, P-707D (manufactured by Mizusawa Chemical Co., Ltd.), Nipsil E200, E220, SS-10.
F, SS-15, SS-50 (manufactured by Nippon Silica Industry Co., Ltd.),
For calcium carbonate fine particles such as SYLYSIA 730 and 310 (manufactured by Fuji Silysia Chemical Ltd.), Brillia
nt-15, Brilliant-S15, Unibu
r-70, PZ, PX, Tunex E, Vigot-1
0, Vigoto-15, Unifant-15FR,
Brilliant-1500, Homocal D, Gelton 50 (manufactured by Shiraishi Industry Co., Ltd.) and Satin White SW, SW-B, S are used as fine particles of calcium sulfo-aluminate.
W-BL (manufactured by Shiraishi Kogyo Co., Ltd.) and alumina fine particles are AL-41G, AL-41, AL-42, AL-4.
3, AL-44, AL-41E, AL-42E, AL-
M41, AL-M42, AL-M43, AL-M44,
AL-S43, AM-21, AM-22, AM-25,
AM-27 (manufactured by Sumitomo Chemical Co., Ltd.), aluminum oxide C (manufactured by Nippon Aerosil Co., Ltd.) and the like, and titanium dioxide fine particles include titanium dioxide T805 and P25 (manufactured by Nippon Aerosil Co., Ltd.). These may be used alone or in combination of two or more.

The amount of the porous fine particles used in the present invention is not particularly limited, but 20 to 80 parts by weight of the porous fine particles, preferably 100 parts by weight of the vehicle containing the radiation curing component as a main component, is preferable. Is 30 to 70 parts by mass,
More preferably, it is desirable to add 40 to 60 parts by mass. If it is less than 20 parts by mass, the releasability and printability may not be improved, and if it exceeds 80 parts by mass, the suitability for printing ink may be deteriorated, and thus both are not preferable.

Another release agent used in the present invention is prepared by blending the release material powder with a vehicle mainly containing the radiation-curable component. The compounding amount of the peelable substance powder is not particularly limited, but 10 to 80 parts by mass, preferably 20 to 10 parts by mass of the peelable substance powder to 100 parts by mass of the vehicle containing the radiation curing component as a main component. 7
It is desirable to add 0 parts by mass, more preferably 40 to 60 parts by mass. If it is less than 10 parts by mass, the releasability may not be improved, and if it exceeds 80 parts by mass, the suitability for printing ink may be deteriorated, and printing, writing, marking, etc. may not be possible.

The release agent used in the present invention may further include, if desired, an additive component commonly used, for example, a mildew-proofing agent,
Antibacterial agents, antiseptics, tackifiers, viscosity modifiers, antioxidants, defoamers, various stabilizers, colorants, coatability improvers and the like can be contained.

The release agent used in the present invention is, for example, a gravure coater, flexo, air knife coater, bar coater, blade coater, river roll coater, kiss roll coater, cast coater. A release agent layer can be formed by applying a predetermined portion on the surface of the base material by a coating means such as a coater or a coater coater, and drying and curing it as necessary. The release agent used in the present invention may be diluted with a solvent or the like having an optimum concentration suitable for each coater.

As the base material used in the present invention, synthetic paper, or synthetic film or sheet of polyethylene, polyethylene terephthalate having transparency, polypropylene, vinyl chloride, etc. may be used in addition to ordinary high quality paper. it can. When these synthetic films or sheets are used, it is preferable that the surface of the substrate is subjected to surface treatment such as matte treatment or corona treatment.

The pressure-sensitive adhesive used in the present invention is not particularly limited, and known pressure-sensitive adhesives can be used. Specifically, for example, natural rubber-based adhesives, synthetic rubber-based adhesives, tackifiers (rosin and rosin derivatives, polyterbene resins, terpene phenol resins, petroleum resins) and softeners (liquid polybutene) for natural rubber and synthetic rubber. , Rubber oil mixed with known additives such as mineral oil, liquid polyisobutylene, liquid polyacrylic acid ester) and anti-aging agent, multiple acrylic acid esters with different glass transition temperatures and other functional monomers Examples thereof include polymerized acrylic type, silicone type composed of silicone rubber and resin, polyether or polyurethane type pressure sensitive adhesives, or pressure sensitive adhesives made of a combination thereof.

Examples of acrylic adhesives include, for example:
(Meth) acrylic monomers such as acrylic acid ester, methacrylic acid ester, hydroxylethyl acrylate and hydroxylethyl methacrylate, amide monomers such as acrylonitrile, acrylamide and methacrylamide, and amide monomers thereof. N-alkoxy-substituted products, N-methylol-substituted products, styrene-based monomers such as styrene, vinyltoluene, α-methylstyrene and divinylbenzene, diallyl phthalate, allyl glycidyl ether, triallyl isocyanurate. One or more of an allyl monomer such as G., a vinyl acetate, a monomer having a polymerizable double bond such as N-vinylpyrrolidone, and the like;
Acrylic acid having a carboxyl group, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid,
Other examples include copolymers with one or more unsaturated carboxylic acids. Among the above acrylic pressure-sensitive adhesives, 3 to 4 components of 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene, vinyl acetate, N-vinylpyrrolidone, etc. are used together. A polymerized acrylic adhesive can be preferably used.

The pressure-sensitive adhesive used in the present invention may further contain an antioxidant, a fungicide, a preservative, a dispersant, and a pH, if necessary.
Modifiers, stabilizers, plasticizers, defoamers and other desired additives can be added. These pressure-sensitive adhesives include not only a solution type dissolved in a solution but also an aqueous emulsion type, and any of them can be used.

The pressure-sensitive adhesive used in the present invention may be, for example, a gravure coater, flexo, air knife coater, bar coater, blade coater, river roll coater, kiss roll coater, cast coater. A pressure-sensitive adhesive layer can be formed by applying a predetermined portion on the surface of the base material with a coating means such as a coater or a coater and drying it as necessary. The pressure-sensitive adhesive used in the present invention may be diluted with an optimal solvent or the like to a concentration suitable for each coater.

The above description of the embodiments is for explaining the present invention and does not limit the invention described in the claims or reduce the scope thereof. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

[0039]

The sheet for hiding information according to claim 1 of the present invention is a sheet for hiding information by overlapping the folded portion provided at a predetermined portion of the sheet base material as a boundary.
Since the pressure-sensitive adhesive layer is provided on one of the superposed surfaces and the release agent layer having writability is provided on the other superposed surface, the constitution is simple and inexpensive, and the conventional release sheet is used. It can be used without using, and after using the pressure-sensitive adhesive layer and the release agent layer on top of each other, you can economically and neatly peel off the hidden information to see the hidden information. In addition, the peeling agent layer can be additionally filled or secondary filled, and the peelable information transfer ticket having the confidentiality such as a folding sheet or a superposing sheet,
It has a remarkable effect that it can be widely used as a direct mail, a postcard with a reply such as an application form and a request form, a card, a label, a tag, and a form.

The information hiding sheet according to claim 2 of the present invention is the information hiding sheet according to claim 1, wherein the release agent is a vehicle containing a glycol solvent having a boiling point of 100 ° C. or higher as a main component. Since it is a release agent containing a release material powder, it exhibits the same effect as that of the information masking sheet according to claim 1, and the release agent is excellent in printability and does not particularly dry after coating and coating. However, since a release agent layer having excellent printability, writing property, imprintability, removability, etc. can be easily formed, a special drying device is not required, and the further remarkable effect of further cost reduction can be achieved.

The information hiding sheet according to claim 3 of the present invention is the same as the information hiding sheet according to claim 1, wherein the release agent contains porous fine particles in a vehicle containing a radiation-curable component as a main component. Since the release agent has the same effect as the information concealing sheet according to claim 1, the release agent has excellent printability, and after application and coating, it is cured by irradiation with radiation such as ultraviolet rays and electron beams. Printability, writing ability,
A further remarkable effect is that a release agent layer having excellent imprintability, adhesion to a substrate, removability from the pressure-sensitive adhesive layer, and the like can be easily formed.

The information hiding sheet according to claim 4 of the present invention is the information hiding sheet according to claim 1, wherein the release agent is a release material powder for a vehicle containing a radiation curing component as a main component. Since the release agent has the same effect as that of the information masking sheet according to claim 1, the release agent has excellent printability, and is irradiated with radiation such as ultraviolet rays and electron beams after coating and coating. Further, it has a further remarkable effect that it can be easily cured to form a release agent layer excellent in printability, writability, imprintability, adhesiveness with a substrate, removability from an adhesive layer, and the like.

[Brief description of drawings]

FIG. 1 (1) to (5) are explanatory views illustrating an embodiment of an information hiding sheet of the present invention.

2 (1) to (3) are explanatory views for explaining another information hiding sheet of the present invention.

3 (1) to (4) are explanatory views illustrating an example of a conventional information hiding sheet.

4 (1) to (5) are explanatory views for explaining another conventional information hiding sheet.

[Explanation of symbols]

1, 1A Information hiding sheet of the present invention 2 sheet base materials 3 Folding part 4 Adhesive layer 5 Release agent layer 6 information

Continued front page    F term (reference) 2C005 HA30 HB20 JA09 JA10 KA03                       KA38 KB02

Claims (4)

[Claims] 1. A sheet for hiding information by superimposing a folded-back portion provided on a predetermined portion of a sheet base material as a boundary, wherein an adhesive layer is provided on one of the superposed surfaces.
An information concealing sheet comprising a release agent layer having writability provided on the other overlapping surface. 2. The release agent according to claim 1, wherein the release agent is a vehicle containing a glycol solvent as a main component having a boiling point of 100.degree. Concealment sheet. 3. The information hiding sheet according to claim 1, wherein the release agent is a release agent in which porous fine particles are mixed with a vehicle containing a radiation curing component as a main component. 4. The information hiding sheet according to claim 1, wherein the release agent is a release agent in which a release material powder is mixed with a vehicle containing a radiation-curable component as a main component.