JPH06227183A - Pressure sensitive duplicate sheet for preventing alteration - Google Patents

Abstract

PURPOSE:To perform an efficacious preventive function against alteration effected by a desensitization component in particular by coloring at least one part of the area having a recorded image formed therein, with a decolorizable material in a pressure sensitive duplicate sheet employing a coloring agent and developer. CONSTITUTION:The pressure sensitive duplicate sheet 1 is composed of a transfer sheet 2 and a receiving sheet 5. The transfer sheet 2 is provided with a microcapsule layer 4 including a coloring agent A on the rear surface of a carrier 3. On the other hand, the receiving sheet 5 is provided with a developer layer 7 on the surface of another carrier 6. In this case, the receiving sheet 5 serves to color a part of the area 8 in a developer layer 7 with decolorizable material. Herein, as an entry 10 is executed on the surface of the transfer sheet 2 with a ball-point pen 9 or the like, the microcapsules 4 are broken by pressure of the pen, so that the coloring agent A is transferred to the developer layer 7 in order to obtain duplication. At this time, even a duplication image 11 in the coloring area 8 is erased by a desensitization component, since the coloring is also erased by the desensitization component, with the result that a trace of the original image remains therein.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to pressure sensitive copying sheets,
In particular, the present invention relates to a tampering-proof pressure-sensitive copy sheet that can easily detect tampering performed using a desensitizing component.

[0002]

2. Description of the Related Art Electron-donating color formers such as crystal violet lactone and benzoyl leuco methylene blue,
A pressure-sensitive copying sheet utilizing a color reaction of an electron-accepting color developer such as activated clay, a phenol-formaldehyde condensate, and a polyvalent metal salt of an aromatic carboxylic acid is well known. Such pressure-sensitive copying sheets are produced by phase separation method, interfacial polymerization method, in-sit
u Top paper (transfer sheet) coated with color-forming agent-encapsulated microcapsules prepared by a method such as polymerization, bottom paper (receptor sheet) coated with color-developing agent on the support, the above-mentioned color-forming agent-encapsulated microcapsules Medium papers (sheets having both the functions of a transfer sheet and a receiving sheet) in which a color developer and a color developer are applied to different surfaces of a support are appropriately combined for practical use.

Separately, a so-called self-coloring type pressure-sensitive copying sheet in which microcapsules containing a color-forming agent and a color-developing agent are laminated or mixed as a coating layer on the same surface of a support, and the self-coloring type pressure-sensitive copying sheet. There is a self-coloring type pressure-sensitive copying sheet set in which a color-forming agent-encapsulating microcapsule layer is provided on the back surface of the above, and the above lower paper and middle paper are appropriately combined.

However, while these pressure-sensitive copying sheets are convenient in that they can be easily copied, the copied image can be easily erased by using a desensitizing component, and other pressure-sensitive copying sheets having the same color tone can be used. Since the data can be added and used, tampering can be performed relatively easily, and various problems occur depending on the application.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive copying sheet which exhibits an excellent function of preventing tampering using a desensitizing component.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made a pressure-sensitive copying sheet using a color former and a developer with a material capable of erasing at least a part of a region where a recorded image is formed on the sheet. The inventors have found that the above objects can be achieved by coloring, and have completed the present invention.

[0007]

First, the tamperproof pressure-sensitive copying sheet of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a pressure-sensitive copy sheet 1 for tampering prevention according to the present invention. Microcapsule layer 4 containing color former A on the back surface of support 3
And a receiving sheet 5 in which a color developing layer 7 is provided on the surface of a support 6 and a color developing layer in a partial region 8 is colored with a decolorizable material. is there.

In this copy sheet 1, when the surface 10 of the transfer sheet 2 is filled with a ballpoint pen 9 or the like, the microcapsules are destroyed by the writing pressure, and the coloring agent A is transferred to the transfer sheet 2.
To the developer layer 7 of the receiving sheet 5 to obtain a copy. The copy image 11 of the area 8 colored with the erasable material of the receiving sheet 5 is erased partly by using a desensitizing component, and even if another transfer sheet is used for writing, the colored color is also reduced. The trace of the original image remains because it disappears due to the sense component.

FIG. 2 shows another embodiment of the present invention.
A transfer sheet 2 provided with a microcapsule layer 4 containing a color former A on the back surface of the support 3, and a microcapsule layer 12 containing a color former B by printing, and a support 6
Is a combination of a receiving sheet 5 in which a color-developing layer 7 is provided on the surface of and the color-developing layer in a partial region 8 is colored with a decolorizable material, and has the same function as in FIG. Since the color tone of the copied image 11 is different from that of a general-purpose transfer sheet,
It is difficult to tamper with.

As described above, the present invention is characterized in that at least a part of the area of the recording sheet on which the recorded image is formed is colored with a decolorizable material.

Examples of the color former used in the present invention include the following electron-donating color formers known in the field of pressure-sensitive copying sheets. Triallylmethane compounds such as 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide and 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide Dye, 4,4'-bis-dimethylaminobenzhydrylbenzyl ether, N-2,
Diphenylmethane dyes such as 4,5-trichlorophenyl leuco auramine, thiazine dyes such as benzoyl leuco methylene blue, p-nitrobenzoyl leuco methylene blue, spiro such as 3-phenyl-spiro-dinaphthopyran, 3-propyl-spiro-dibenzopyran -Based dyes, lactam-based dyes such as rhodamine-B-anilinolactam, rhodamine (o-chloroanilino) lactam, 3- (N-ethyl-p-toluidino) -7-methylfluorane, 3-piperidino-methyl-7- Fluoran-based dyes such as phenylaminofluorane and mixtures thereof.

In the case of encapsulating the color former, these are usually dissolved in an oily substance and used as a core substance. Examples of the oily substance include those described below which are well known in the field of pressure-sensitive copying sheets. The substance is exemplified. Vegetable oil such as cottonseed oil, kerosene, paraffin, naphthene oil, mineral oil such as chlorinated paraffin, alkylated biphenyl, alkylated terphenyl, alkylated naphthalene, diarylethane, triarylmethane, aromatic carbonization such as diphenylalkane Hydrogen, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, dioctyl phthalate, diethyl adipate, di-n adipate
-Esters such as propyl, di-n-butyl adipate, dioctyl adipate, and mixtures thereof.

The blending amount of the color former with respect to the oily substance cannot be determined unconditionally depending on the solubility of the colorant into the oily substance or the coloring ability, but it is 1 to 200 parts by weight per 100 parts by weight of the oily substance. , And more preferably 2 to 100 parts by weight.

The microcapsules used in the present invention are
A conventionally known coacervation method (for example, US Pat. No. 2
No. 8000457, No. 2800458 and the like), interfacial polymerization method (for example, Japanese Examined Patent Publication No. 38-19574).
No. 42, No. 42-446, No. 42-771, No. 49-45133, etc.), in-situ
Polymerization method (for example, Japanese Patent Publication No. 36-9168, Japanese Patent Publication No. 51-
No. 9079 and Japanese Patent Publication No. 53-84881).

The microcapsule layer is provided by printing or coating an aqueous or non-aqueous capsule ink or coating liquid. In the case of an aqueous system, it is prepared by adding a binder, a capsule protector (stilt agent), a surfactant, an antifoaming agent, a pigment, a preservative, an ultraviolet absorber, etc. to an aqueous capsule dispersion liquid, if necessary. To be done. On the other hand, in the case of a non-aqueous system, a binder, a capsule protector (stilt agent), a surfactant, a pigment, an ultraviolet absorber, a release agent, a photopolymerization initiator, a sensitizer and Various auxiliaries such as a sensitizer, a wax, a drier, a thickener and a gelling agent are added to prepare an evaporative drying type, an ultraviolet curing type, an oxidative polymerization type and the like.

The mixing ratio of each material to the ink or the coating liquid is appropriately determined in consideration of the suitability for printing or coating and the performance of the sheet to be obtained. Usually, it is set in the range of 10 to 50 parts by weight with respect to 100 parts by weight of the ink or the coating liquid.

Examples of the water-based binder used for preparing the capsule ink or the coating liquid include a water-soluble binder and a latex-based binder. As the water-soluble binder, for example, proteins such as gelatin, albumin, casein, cereal starch, pregelatinized starch, oxidized starch, etherified starch, starch such as esterified starch, carboxymethyl cellulose, cellulose such as hydroxyethyl cellulose, Water-soluble natural polymer compounds such as agar, sodium alginate, and polysaccharides such as arabic gum, and water-soluble synthetic polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, maleic acid copolymers and the like. Examples of the latex binder such as a mixture include styrene-butadiene latex, acrylonitrile-butadiene latex, acrylic ester latex, vinyl acetate latex, methyl methacrylate-butadiene latex and the like. These carboxy-modified (e.g., acrylic acid) latex and mixtures thereof.

An oil-soluble binder can be used as the binder used in the non-aqueous capsule ink or the coating liquid. As the oil-soluble binder, for example, rosin, (gum rosin, wood rosin, tall oil rosin), natural resin such as cerax, copearl, dalman, gilsonite, zein, cured rosin, ester gum and other rosin ester, maleic acid resin, fumar Acid resin, Duplex rosin, Polymerized rosin, Rosin-modified phenol resin, Methylcellulose, Ethylcellulose, Hydroxypropylcellulose, Ethylhydroxyethylcellulose, Cellulose acetate propionate, Cellulose acetate butyrate, Semi-synthetic resin such as Nitrocellulose, Phenolic resin, Xylene resin , Urea resin, melamine resin, ketone resin, coumarone / indene resin, petroleum resin, terpene resin, cyclized rubber, chlorinated rubber, alkyd resin, polyamide resin, acrylic resin Polyvinyl chloride, vinyl chloride,
Examples thereof include acetic acid copolymer, polyvinyl acetate, polyvinyl butyral (butyral resin), polyvinyl pyrrolidone, chlorinated polypropylene resin, epoxy resin, synthetic resin such as polyurethane, and mixtures thereof.

These binders are selected according to the type of medium to be used, and the method of use can be appropriately selected from the methods disclosed in, for example, printing ink technology CMC version.

As the non-aqueous medium used when preparing the non-aqueous ink or coating liquid, there are low-boiling medium, high-boiling medium, ethylenically unsaturated compound, oils, waxes and the like known in the printing industry. It can be used as appropriate. Specific examples include benzene, toluene, xylene, cyclohexane,
Hexane, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, n-hexanol, cyclohexanol, 2-
Ethylhexyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, dienelene glycol monobutyl ether, diethylene glycol monobutyl acetate, ethylene glycol diacrylate, ethylene glycol dimethacrylate. , Polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, polypropylene glycol diacrylate, propylene glycol dimethacrylate,
1,2-butanediol diacrylate, 1.2-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4
-Butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, glycerol dimethacrylate, glycerol methacrylate acrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, Pentaerythritol triacrylate, pentaerythritol tetraacrylate, reaction product of epoxy resin and acrylic acid, condensation product of maleic acid and diethylene glycol and acrylic acid, carnauba wax, microcrystalline wax, stearic acid, vegetable oil (linseed oil, sunflower oil, etc.) Dry oil, semi-dry oil such as soybean oil,
Dehydrated castor oil, polymerized oil, maleated oil, vinylized oil, urethane oil), mineral oil (machine oil, spindle oil) and mixtures thereof may be mentioned.

The coating amount of the capsule ink or the coating liquid on the support is not limited to this, but it is 1 to 15 g / m ² , more preferably ² from the viewpoint of color developability and economy.
10 to 10 g / m ² .

Examples of the color developing agent include the following electron-accepting color developing agents known in the field of pressure-sensitive copying sheets. Clays such as acid clay, activated clay, attapulgite, zeolite, bentonite, phenolic resins, polyvalent metal salts of various aromatic carboxylic acids as described in JP-B-51-25174, JP-A-54-
Organic developer such as zinc salt of 2,2'-bisphenol sulfone compound as described in 106316 and mixtures thereof.

For forming the color developing layer of the present invention, an aqueous or non-aqueous color developing ink or coating liquid is used. In the case of an aqueous system, in addition to the usual color developer and binder, if necessary, pigments, oil capsules, UV absorbers, antioxidants,
It is prepared by adding a fluorescent dye, a surfactant, a dispersant, a preservative, an antifoaming agent and the like. In the case of a non-aqueous system, usually a color developer,
In addition to the binder, various auxiliaries such as pigments, oil capsules, surfactants, ultraviolet absorbers, photopolymerization initiators, sensitizers, waxes, dryers, thickeners, gelling agents, etc. are added if necessary. , Evaporative drying type, ultraviolet curing type, oxidative polymerization type and the like. The developer can be used by dissolving or dispersing it in an oily substance and then encapsulating it in microcapsules.

The amount of the developer and the binder to be added to the ink or the coating liquid is usually 5 to 90 parts by weight of the developer and 10 to 100 parts by weight of the ink (coating liquid) (solid content).
It is 50 parts by weight. Further, the coating amount of the color developing ink or the coating liquid on the support is not limited to this, but from the viewpoint of color developability and economical efficiency, it is 0.5 to 15 g / m ² , more preferably 1 to 8 g. / M ² .

Examples of the pigment used for preparing the color developing ink or the coating liquid include silica, colloidal silica, zeolite, bentonite, kaolin, calcined kaolin, calcium phosphate, calcium carbonate, magnesium carbonate, calcium sulfate, aluminum hydroxide, zinc oxide, Inorganic and organic pigments known in the art, such as titanium oxide, melamine resin particles, urea resin particles, and polystyrene resin particles, and mixtures thereof can be mentioned.

As the binder, a water-soluble binder or a latex binder as described above is used in the case of an aqueous ink (coating liquid), and a binder as described above is used in the case of a non-aqueous ink (coating liquid). A non-aqueous binder is used. As the medium used when preparing the non-aqueous ink or the coating liquid, the above-mentioned non-aqueous medium is used.

To prepare the ink or coating solution, a stirrer, a ball mill, a sand grinder or the like is usually used.

The decolorizable coloring material used in the present invention is not particularly limited, but a substance produced by a reaction of the above-mentioned color former and a color developer is usually used. Coloring with a decolorizable material is performed by, for example, adding a decolorizable coloring material to the above-mentioned color developer coating liquid and coating the entire surface on a support, converting the decolorizable coloring material into an ink, and coating the entire surface on the support. Print on the coated developer layer, print ink containing decolorizable coloring material and developer on the support, ink containing decolorizable coloring material and developer on the support It is carried out by a method such as printing on the developer layer coated on the entire surface.Other than that, instead of the decolorizable coloring material, a coloring agent is made into an ink and printed, and the developer in the already-developed developer layer is printed. It may also be reacted with a colorant to form a colored material.

The tampering prevention system of the present invention can be used in combination with an already known tampering prevention system.
A transfer sheet whose front or back surface is self-coloring
A releasable developer ink is printed on the developer layer of the receiving sheet as described in Japanese Patent Application No. 63-48099 (In this case, an ink obtained by adding a decolorizable coloring material to the releasable developer ink is also used. Can be).

The printing or coating in the present invention is usually a printing machine having a printing unit such as offset, letterpress, flexo and gravure, or a coating having a coater head such as air knife, bar, blade, lip, curtain, roll and gravure. It is done on a machine.

[0031]

EXAMPLES In order to further clarify the effects of the present invention, examples will be given below, but the present invention is not limited to these examples. Parts and% in the examples represent parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 [Preparation of Transfer Sheet] 105 parts of internal phase oil obtained by heating and dissolving 5 parts of crystal violet lactone in 100 parts of diisopropyl naphthalene was added to aromatic polyisocyanate (trade name: Coronate-L, Nippon Polyurethane). (Manufactured by Mfg. Co., Ltd.) 15 parts are dissolved, and this is a 2% aqueous solution of polyvinyl alcohol 6
After adding to 100 parts and emulsifying to make the average particle size 8.0 μm, this system was reacted at 80 ° C. for 4 hours to obtain a capsule dispersion liquid. To this dispersion, 50 parts of starch particles and 20 parts of carboxy-modified styrene / butadiene copolymer latex (solid content) were added and diluted to a concentration of 18% to obtain a microcapsule coating liquid. 40 g of the obtained capsule coating liquid
/ M ² of base paper with air knife coater and solid content of 3.0
A transfer sheet was obtained by smearing so as to be g / m ² .

Preparation of decolorizable red ink 1 part of 3,3-bis (2-methyl-1-octyl-3-indolyl) phthalide and 3,5-di- (α-methylbenzyl) salicylic acid zinc salt 1 Parts were dissolved in 100 parts of xylene to obtain decolorizable red ink.

[Preparation of Receiving Sheet] 65 parts of light calcium carbonate, 20 parts of zinc oxide, a mixture of 3,5-di- (α-methylbenzyl) salicylic acid zinc salt and an α-methylstyrene / styrene copolymer. (Blend ratio 80/20) 15 parts,
Polyvinyl alcohol aqueous solution 5 parts (solid content) and water 30
40 g of a developer coating liquid prepared by adding 20 parts (solid content) of carboxy-modified styrene / butadiene copolymer latex to a dispersion liquid obtained by crushing 0 part by a ball mill for 24 hours.
/ M ² of base paper was smeared with an air knife coater so that the dry weight was 5 g / m ² . Then, the decolorizable red ink was applied on the developer layer of the sheet in an amount of 0.2 g /
Partially flexographically printed so as to be m ² , a receiving sheet having a red region was obtained.

[Evaluation] The transfer sheet and the receiving sheet were overlaid and printed with a typewriter to obtain a copy image in the red region of the receiving sheet. Then, after the copy image was erased with the desensitizing component, the copy image was tampered with using a blue color transfer sheet.
Since stains due to desensitization occurred in the red area, the action could be easily confirmed.

Example 2 (Preparation of green color-forming capsule ink) 25 parts of green dye 3-diethylamino-7-dibenzylaminofluorane and 100 parts of alkyldiphenylethane (trade name: Hisol S
AS-296, manufactured by Nippon Petrochemical Co., Ltd.) was heated and dissolved to obtain an internal phase oil. The pH was adjusted to 6 by adding 20% caustic soda aqueous solution to 200 parts of 3.0% aqueous solution of ethylene-maleic anhydride copolymer (trade name: EMA-31, manufactured by Monsanto).
After emulsifying this internal phase oil in a liquid of 0, the system was heated to 55 ° C.
The temperature was raised to.

Separately, 45% 37% aqueous formaldehyde solution
15 parts of melamine was added to each part and reacted at 60 ° C. for 15 minutes to prepare an aqueous prepolymer solution. This prepolymer aqueous solution was added dropwise to the emulsion, and after stirring, the mixture was heated to 80 ° C. and kept at that temperature for 1 hour, and then pH was adjusted with 0.2N hydrochloric acid.
Was lowered to 3.5 and kept for 3 hours, and then allowed to cool to obtain a capsule dispersion liquid having an average particle diameter of 6.5 μm.

Next, this dispersion was filtered and washed with ethanol, and then the capsule was redispersed in a mixed medium of 330 parts of ethanol and 165 parts of n-propanol, to which 10 parts of pulp powder and ethyl cellulose (ethyl cellulose No. 14) were added. , Manufactured by Hercules Co., Ltd.) to obtain a flexo type capsule ink.

[Preparation of Transfer Sheet] On the capsule surface of the transfer sheet obtained in the same manner as in Example 1, the above green color-forming capsule ink was printed so that the ink build-up was 4.5 g / m ^2. A transfer sheet was obtained by spot printing so that the spots overlap the red region of the receiving sheet.

[Evaluation] The transfer sheet and the receiving sheet were overlaid and printed with a typewriter to obtain a copy image in the red region of the receiving sheet. Next, after the copy image was erased with the desensitizing component, the copy image was tampered with by using a general-purpose blue color transfer sheet, but because the stain due to desensitization occurred in the red area, that action was taken. It was easy to confirm. Further, it has been more clearly found that the image has been tampered with because the coloring color tone is different.

[0041]

As is clear from the above evaluations, the tamper-proof pressure-sensitive copy sheet of the present invention is a copy sheet having extremely excellent tamper-proof property.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a tamperproof pressure-sensitive copy sheet of the present invention.

FIG. 2 is a sectional view showing the structure of a tampering prevention pressure-sensitive copy sheet of the present invention.

[Explanation of symbols]

 1: Tamper-proof pressure-sensitive copy sheet of the present invention 2: Transfer sheet 3: Support 4: Microcapsule layer containing color former A 5: Receiving sheet 6: Support 7: Developer layer 8: Decolorable material Colored area 9: Writing instrument 10: Entry image 11: Copy image 12: Coloring agent B-containing microcapsule layer

Claims (2)

[Claims] 1. A tamper-proof sheet comprising a pressure-sensitive copying sheet using a color former and a color developer, wherein at least a part of a region of the sheet on which a recorded image is formed is colored with an erasable material. Pressure sensitive copy sheet. 2. A pressure-sensitive copy comprising a transfer sheet having a color-forming agent-encapsulating microcapsule layer provided on the back surface of a support, and a receiving sheet having a color-developing layer that reacts with the color-forming agent to form a color on the support surface. The tamperproof pressure-sensitive copy sheet according to claim 1, wherein the receiving sheet is colored with a decolorizable material.