JPH08207435A - Pressure sensitive recording sheet having forgery preventing function - Google Patents

Abstract

PURPOSE: To obtain an excellent forgery preventing function by layering a top paper having a coupler layer which contains an electron donating coupler formed on a rear face of a support body, a middle paper having a self-coloring layer on the surface of the support body and a coupler layer on the rear face, and a bottom paper having a developer layer. CONSTITUTION: A top paper 11 has a coupler layer 12 which contains a black coupler-containing microcapsule 12a on its rear face. A middle paper 14 has a self-coloring layer 13 consisting of a developer layer 13c and a coupler layer 13b which contains a red coupler-containing microcapsule 13a on the surface and also has a coupler layer 15 which contains a red coupler-containing microcapsule 15a on the rear face. A bottom paper 17 has a developer layer 16 on the surface. The papers 11, 14, and 17 are superposed so as to form a pressure sensitive recording sheet. In this sheet, even when the middle sheet 14 is pulled out and an amount is written on the top paper 11, a black character is printed on the developer layer 16 not a red character, so that a forgery can be easily checked.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pressure-sensitive recording sheet which can be used for tampering prevention.

[0002]

2. Description of the Related Art A microcapsule layer composed of microcapsules containing an electron-donating color-developing agent (hereinafter sometimes simply referred to as "color-developing agent") and an electron-accepting developer (hereinafter "developing agent"). It is used to form a color-developed image by contacting a color developer layer containing (which may be said to be) and applying pressure to this to destroy the microcapsules and reacting the color developer with the color developer. The carbonless pressure-sensitive recording sheet has been known for a long time and is widely used.

A carbonless type recording sheet generally has a color former layer containing microcapsules containing a color former (hereinafter sometimes simply referred to as "color former layer") on the back surface of a support (generally paper). A structure in which two types of sheets, that is, a top sheet formed on a sheet and a developer layer containing a developer (hereinafter, also referred to as “developer layer”) are formed on the surface of a support, are combined. Or, it is used as a combination of the above three types of sheets, the upper paper, the developer layer formed on the surface of the support, and the color developer layer formed on the opposite back surface, and the lower paper. To be done. Therefore, the carbonless type recording sheet is generally used in the form of a receipt or an insurance premium collection sheet.

Such a form (pressure-sensitive recording sheet) is
While it is convenient that copying can be done easily, there is a problem that tampering can be done easily. Usually, such tampering is performed as specified for the input and the copy when the receipt form consisting of the upper paper (for input), the middle paper (receipt) and the lower paper (for copy) is taken as an example. To write the amount of money and write the amount of money on the receipt for the customer that exceeds the specified amount in response to the customer's request, or write the specified amount of money on the receipt for the customer, for input and copy In order to write the amount of money increased from the prescribed amount (for example, to settle the difference). In both cases, tampering can be done in the same way. That is, in order to tamper with a receipt such as the above-mentioned top paper (for input), middle paper (receipt) and bottom paper (for receipt), for example, the receipt should be received in advance so that it is not printed on the receipt. Take out the book, write the amount of money above the specified amount on the remaining input and copy forms, print the increased amount as a copy, and then remove it for the customer It can be done by writing the amount of money as specified in the receipt with a ballpoint pen or the like. Or, put plain paper between the input and the receipt so that it will not be printed on the receipt, write the amount of money above the specified amount from the top of the input and print the increased amount as a copy, and It is possible to write the prescribed amount of money on the receipt for the customer with a ballpoint pen or the like. It is also possible to fill in the numbers as they are and then add numbers for input and as a copy. It is possible to falsify forms such as insurance premium collection forms in the same manner as above.

Therefore, it is necessary to prevent tampering with the amount of money in the form of receipts and insurance bill collection slips.
Japanese Utility Model Laid-Open No. 62-43772 discloses a pressure-sensitive recording sheet (carbonless forms) having a falsification preventing function shown in FIG. That is, the color former layer 32 including the microcapsules 32a containing a blue color former on the back surface.
A support 31 (upper paper) having the above, a developer layer 33 on the front surface, and a color former layer 35 containing microcapsules 35a containing a violet color former (different from the color of the color former) on the back surface A body 34 (medium paper) and a support 37 (lower paper) having a color developer layer on the surface are stacked and bonded at the ends to form a form. In this pressure-sensitive recording sheet, since the colors of the color formers on the back surface of the upper paper and the back surface of the middle paper are different from each other, if they are used as they are, blue letters will appear on the developer layer 33 of the middle paper. Violet characters are recorded on the developer layer 36 of the lower sheet. Then, in order to falsify, pull out the medium paper and write the specified amount of money, give it to the customer as a receipt, and enter the amount of money different from the receipt from the upper paper on the form of the remaining upper paper and lower paper, The letters printed on the lower sheet are blue and the tampering is checked.

However, in the above pressure-sensitive recording sheet, when plain paper is sandwiched between the upper and middle sheets and the amount of money is written from above the upper sheet, the character printed on the lower sheet becomes violet and is tampered with. I don't know. that time,
Since nothing is printed on the receipt, which is the middle paper, it is possible to tamper with it by stacking another pressure-sensitive recording paper on top of this and writing a prescribed amount of money.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure-sensitive recording sheet having a falsification preventing function that cannot be falsified even if falsification is attempted by various conventionally known means. It is in.

[0008]

The present invention includes the following (1).
-(3): (1) Top paper on which a color former layer containing microcapsules containing an electron-donating color former is provided on the back surface of the support; (2) Electron-accepting color development on the surface of the support. Self-coloring layer containing an agent and a microcapsule containing an electron-donating color developer whose color obtained by the reaction with the color developer is different from the color obtained by the reaction with the color developer on the upper paper And a color developing agent layer containing microcapsules containing an electron donating color developing agent on its back surface; and (3) a developer layer containing an electron accepting developing agent on the surface. The lower sheet is a pressure-sensitive recording sheet having a tampering prevention function, which is formed by overlapping the front and back sides in this order.

The preferred embodiments of the pressure-sensitive recording sheet of the present invention are as follows. 1) The color formers used on the front and back sides of the support of the medium paper are both color formers which show the same color due to the reaction with the developer. 2) The color-developing agent of the upper paper is a color-developing agent that exhibits a black or blue color due to the reaction with the color-developing agent. 3) The color former used for the medium paper is a color former showing a color other than black and blue. 4) Medium paper is used as a receipt. 5) The lower sheet is used for checking. 6) The pressure-sensitive recording sheet having the tampering prevention function is a form in which the edges of each sheet are pasted. 7) The pressure-sensitive recording sheet having the tampering prevention function is a receipt document in which the edges of each sheet are glued. 8) The self-coloring layer is composed of a color-developing layer containing an electron-accepting color-developing agent and a micro-capsule containing an electron-donating color-developing agent and provided thereon.

The present invention also provides the following (1) to (4): (1) Top paper having a color former layer containing microcapsules containing an electron-donating color former on the back surface of a support; (2) Middle paper having a color developer layer containing an electron-accepting color developer on the surface of a support and a color developer layer containing microcapsules containing an electron-donating color developer on the back surface; 3) Electron-donating property on the surface of the support, wherein the color obtained by the reaction between the electron-accepting developer and the developer is different from the color obtained by the reaction between the color-developing agent of the upper paper and the developer. Medium paper having a self-coloring layer containing microcapsules containing a color former and a colorant layer containing microcapsules containing an electron donating colorant on the back surface; and (4) electron accepting on the surface A sheet of a lower sheet provided with a developer layer containing a sex developer, A pressure-sensitive recording sheet having a tampering prevention function, which is formed by stacking the front and back sides in contact with each other in this order.

The preferred embodiments of the pressure-sensitive recording sheet of the present invention are as follows. The color formers used on the front and back sides of the inner paper of 1) and (3) are color formers that exhibit the same color due to the reaction with the developer. 2) The color former of the upper paper and the middle paper of (2) is a color former showing a black or blue color. 3) The color former used for the inner paper of (3) is a color former showing colors other than black and blue. 4) The medium paper of (3) is used as a receipt. 5) The lower sheet is used for checking. 6) The medium paper of (2) is used as a copy. 7) The pressure-sensitive recording sheet having the tampering prevention function is a form in which the edges of each sheet are pasted. 8) The pressure-sensitive recording sheet having the tampering prevention function is a receipt document in which the edges of each sheet are glued. 9) The self-coloring layer is composed of a color-developing layer containing an electron-accepting color-developing agent and a micro-capsule containing an electron-donating color-developing agent and provided thereon.

The pressure-sensitive recording sheet having the tampering prevention function of the present invention has a basic structure composed of an upper sheet, one or more middle sheets and a lower sheet, and a sheet such as a receipt that may be tampered with. A single medium-sized sheet having a self-coloring layer including a color developer and microcapsules containing a color-developing agent different in color from the color-developing agent of the upper sheet.

The pressure-sensitive recording sheet having the tampering prevention function of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a cross section of a typical example of the pressure-sensitive recording sheet having the tampering prevention function of the present invention. In FIG. 1, a support 11 is provided on the back surface of which a color former layer 12 containing microcapsules 12a containing a black color former is provided.
(Upper paper), a self-developed developer consisting of a color developer layer 13c and a color developer layer 13b containing microcapsules 13a encapsulating a color developer of red color (color when developed is different from that of the upper paper). A support 14 (middle paper) provided with a color-forming layer 13 and a color-forming layer 15 containing microcapsules containing a red-color-forming colorant on the back surface, and a developer layer 16 on the surface The support 37 (lower sheet) is shown. These sheets are used with the front side and the back side in contact with each other, and the ends are adhered to each other. The self-coloring layer is a microcapsule 13a containing a color developer and a color developer.
It may be a layer consisting of one layer containing. In the pressure-sensitive recording sheet (form) having such a tampering prevention function, for example,
The upper form is used for input (or copy), the middle form is used for receipt, and the lower form is used for checking.

If the above pressure-sensitive recording sheet is used as it is, that is, when writing is performed on the surface of the upper paper, almost black (slightly reddish) is formed on the developer layer 13b of the middle paper (receipt). Character) is printed, and the developer layer 1 of the lower paper
A red character is printed on top of 6. Then, in order to write the amount of money different from the amount of the upper and lower sheets on the medium sheet, if the medium sheet is pulled out and the amount is written on the upper sheet (falsification A), the developer layer 16 of the lower sheet is used. Since black letters are printed on the top instead of red letters, tampering is checked. Even if the plain paper is sandwiched between the upper paper and the middle paper and the amount is written from above the upper paper (tampering B) for the same purpose, the developer layer 13b of the middle paper is not used. Since red letters are printed on the top rather than black, it cannot be tampered with. A combination of the color formers (in the color at the time of color formation) used for the color former layers of the upper and middle sheets, the color of the characters formed on each developer layer, and the case of falsification (the above falsification A or B) Table 1 to Table 3 show the color of the characters in the case of not doing (none).

[0016]

[Table 1] Table 1 ──────────────────────────────────── Top paper Black Blue Black Blue Blue Coloring agent ──────────────────────────────────── Medium paper Red Red Green Green Coloring agent ────── ────────────────────────────── Tampering None / A / B None / A / B None / A / B None / A / B ──────────────────────────────────── Medium paper Black ／ － ／ Red Blue Purple ／ － ／ Red Black /-/ Green green blue /-/ green developer layer ──────────────────────────────────── Below Paper Red / Black / Red Red / Blue / Red Green / Black / Green Green / Blue / Green Developer layer ────────────────────────── ───────────

[0017]

[Table 2] Table 2 ──────────────────────────────────── Top paper Black Blue Black Blue Blue Coloring agent ──────────────────────────────────── Medium paper Purple Purple Brown Brown Coloring agent ────── ────────────────────────────── Tampering None / A / B None / A / B None / A / B None / A / B ──────────────────────────────────── Medium paper Black /-/ Purple Blue /-/ Purple Black /-/ Brown Black /-/ Brown Developer layer ──────────────────────────────────── Below Paper Purple / Black / Purple Purple / Blue / Purple Brown / Black / Brown Brown / Blue / Brown Developer layer ────────────────────────── ───────────

[0018]

[Table 3] Table 3 ──────────────────────────────────── Top paper Black Blue Coloring agent ── ────────────────────────────────── Medium paper Orange orange Coloring agent ────────── ────────────────────────── No tampering / A / B nothing / A / B ───────────── ─────────────────────── Medium paper Black / − / Orange Black / − / Orange Developer layer ─────────── ───────────────────────── Bottom paper Orange / Black / Orange Orange / Blue / Orange Developer layer ───────── ────────────────────────────

Further, using the pressure-sensitive recording sheet of the present invention, once writing is performed as it is, and only the receipt is peeled off except for the medium paper (receipt), and then a letter is written on the receipt. When added, the pressure-sensitive recording sheet of the present invention cannot perform such tampering, because the person who knows that tampering cannot be tampered with because the color develops red instead of black. In the middle paper, the color of the color former in the color former 13b and the color of the color former 1
Even if it is different from the color of the color former of No. 5 at the time of color development, if it is different from the color of the color former of the upper sheet at the time of color development, the above-described tampering prevention effect of the present invention can be obtained.

FIG. 2 is a diagram schematically showing a cross section of another representative example of the pressure-sensitive recording sheet having the tampering prevention function of the present invention. In FIG. 2, a support 21 (upper sheet) is provided with a color former layer 22 containing microcapsules 22a containing a black color former on the back surface, a developer layer 23 is provided on the front surface, and a black color is formed on the back surface. Microcapsules 25 containing the color former
On the surface of the support 24 (medium paper A) provided with the color-developing layer 25 containing a, a developer layer 26c and a color-developing agent of red color (color at the time of coloring is different from the color-developing agent of the upper paper) are provided. A support 27 is provided with a self-coloring layer 26 including a color-forming agent layer 26b including microcapsules 26a included therein, and a color-forming agent layer 28 including microcapsules 28a including red-coloring color-forming agent included on the back surface. The middle sheet of paper B) and the support 20 (lower sheet) provided with the color developer layer 29 on the surface are shown. These sheets are used by stacking them so that the front and back are in contact with each other and then glued at the edges. The self-coloring layer may be a layer composed of one layer containing microcapsules containing a color developer and a color developer. In the pressure-sensitive recording sheet (form) having such a tampering prevention function, for example, the upper sheet is for input, the inner sheet A is for copy, the inner sheet B is for receipt,
Then, the lower sheet is used for checking. Medium paper A
Can be increased to a desired number, and
The number of sheets can be increased to a desired number by combining and the medium sheet B.

The pressure-sensitive recording sheet shown in FIG.
When the middle paper A is added to the configuration of the pressure-sensitive recording sheet of FIG. 1, and the middle paper A is considered as the upper paper of FIG. 1, the same function is exhibited. That is, if it is used as it is, black characters are printed on the developer layer 23 of the middle paper A (reservation), and almost black (slightly) on the developer layer 26c of the middle paper B (receipt). Characters (reddish) are printed, and red characters are printed on the developer layer 29 of the lower sheet. However, when the middle paper A is removed (tampering A), black characters, not red, are printed on the developer layer 29 of the lower paper, and tampering is checked. When plain paper is sandwiched between the middle paper A and the middle paper B (tampering B), red characters, not almost black, are printed on the developer layer 27b of the middle paper. It is impossible.

The support may be any support conventionally used as a support for pressure-sensitive recording sheets, for example, high-quality paper, medium-quality paper, waste paper, machine-coated paper, art. Examples thereof include paper, cast coated paper, synthetic paper, resin coated paper, plastic film and the like. The microcapsule layer of the color-forming agent-containing layer in the pressure-sensitive recording sheet of the present invention can be formed in the same manner as the conventional microcapsule layer of the pressure-sensitive recording sheet. For example, a color-forming agent is dissolved in a suitable solvent to form microcapsules, a coating liquid for forming a microcapsule layer is prepared together with a binder, a capsule protective agent, etc., coated on a support, and dried to form a microcapsule layer. To do. Also,
The self-coloring layer can be obtained by forming the above-mentioned microcapsule layer on a support and then forming a developer layer described below on the microcapsule layer.

The color former contained in the microcapsule layer needs to be relatively changed as described above depending on the color former layer used, but a conventional color former can be used. For example, triphenylmethanephthalide compound, fluorane compound, phenothiazine compound,
Various compounds such as indolyl phthalide compounds, leuco auramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, fluorene compounds can be mentioned.

Among these color formers, the blue color formers which form a blue color image by reaction with a color developer include:
For example, crystal violet lactone, 3,6-bis-diphenylaminofluorane, 3- [4- (diethylamino) -2-ethoxyphenyl] -3- (2-methyl-1-octyl-3-indolyl) -phthalide, 3-
[4- (diethylamino) -2-ethoxyphenyl]-
3- (2-methyl-1-octyl-3-indolyl)-
4-azaphthalide, 3- [4- (diethylamino) -2
-Ethoxyphenyl] -3- (2-methyl-1-ethyl-3-indolyl) -4-azaphthalide, 3- [1,1
-Bis (4-diethylaminophenyl) ethylene-2-
Illy] -6-dimethylaminophthalide and the like.

Examples of the red color-forming color agent which forms a red color image by reaction with a color developing agent include 2-chloro-3.
-Methyl-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 1,2-benzo-6-N-ethyl-N-isoamylaminofluorane,
2-methyl-6-N-ethyl-N-tolylaminofluorane, 2-chloro-6-diethylaminofluorane,
1,2-benzo-6-dibutylaminofluorane, 3,
3-bis (1-octyl-2-methylindole-3-
Yl) phthalide, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1
-Butyl-2-methylindol-3-yl) phthalide, rhodamine-β- (γ-nitroanilino) lactam and the like can be mentioned.

Examples of green color-forming color formers which form a green color image by reaction with a color developer include 2-dibenzylamino-6-diethylaminofluorane and 2-anilino-6-N-ethyl-N. -Hexylaminofluorane, 2
-Octylamino-6-diethylaminofluorane, 2
Examples thereof include-(N-methyl) anilino-6-N-ethyl-N-tolylaminofluorane and 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide.

Examples of the orange color-developing agent which forms an orange color image by reaction with the color developing agent include 2-methyl-6.
-Diethylaminofluorane, 3-chloro-6-N-cyclohexylaminofluorane, 2-t-butyl-6-
Examples thereof include diethylaminofluorane, 1,3-dimethyl-6-diethylaminofluorane and 1,3-dimethyl-6-dibutylaminofluorane.

Examples of the brown color-forming color forming agent which forms a brown color image by reaction with a color developing agent include 2- (2-methylphenylamino) -6-diethylaminofluorane.
2-isobutyl-6-diethylaminofluorane, 2-
Isoamylamino-6-diethylaminofluorane, 2
Mention may be made of -phenoxyethylamino-6-diethylaminofluorane and 2-butoxyethylamino-6-diethylaminofluorane.

Examples of the black color-forming color-forming agent which produces a black color-developed image by reaction with a color-developing agent include 2-anilino-3-
Methyl-6-N-methyl-N-isopropylaminofluorane, 2-anilino-3-methyl-6-N-methyl-
N-pentylaminofluorane, 2-anilino-3-methyl-6-N-methyl-N-cyclohexylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl- 6-dibutylaminofluorane, 2-anilino-3-chloro-6-
Dimethylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane,
2-anilino-3-methyl-6-N-methyl-N-isoamylaminofluorane, 2-anilino-3-chloro-
6-diethylaminofluorane, 2-anilino-3-chloro-6-N-methyl-N-ethylaminofluorane,
2-anilino-3-chloro-6-N-methyl-N-isopropylaminofluorane, 2-anilino-3-chloro-6-N-3-methyl-6-dimethylaminofluorane, 2- (p-methylanilino ) -3-Methyl-6-diethylaminofluorane, 2- (p-methylanilino)
-3-Methyl-6-N-methyl-N-ethylaminofluorane, 2- (p-methylanilino) -3-methyl-6
-N-methyl-N-isopropylaminofluorane, 2
-(P-methylanilino) -3-methyl-6-N-methyl-N-pentylaminofluorane, 2- (p-methylanilino) -3-methyl-6-N-methyl-N-cyclohexylaminofluorane, 2 -(P-methylanilino) -3-methyl-6-N-ethyl-N-pentylaminofluorane, 2- (p-methylanilino) -3-chloro-6-dimethylaminofluorane, 2- (p-methylanilino) -3-Chloro-6-diethylaminofluorane and 2- (p-methylanilino) -3-chloro-6-
Mention may be made of N-methyl-N-ethylaminofluorane.

As the solvent, natural or synthetic oils can be used alone or in combination. Examples of such solvents include vegetable oil, kerosene, paraffin, naphthene oil, alkylated biphenyl, alkylated terphenyl,
Examples thereof include chlorinated paraffin, alkylated naphthalene, diarylalkane, and phthalic acid ester.

The microcapsules containing the color former can be produced by any method known per se, for example, interfacial polymerization method, internal polymerization method, phase separation method, external polymerization method, coacervation method and the like. it can. In addition, a water-soluble binder, a latex-based binder or the like can be used as the binder, and cellulose powder, starch particles, talc or the like can be used as the capsule protecting agent. The color former layer containing microcapsules can be formed on the support by a method known per se.

The final coating amount of the color former in the microcapsule layer is 0.03 to 0.30 g / m ² , preferably 0.0.
5 to 0.20 g / m ² is suitable.

The color developer contained in the color developing layer for contacting with the color developing agent-containing layer of the pressure-sensitive recording sheet of the present invention includes acid clay, activated clay, attapulgite, zeolite, bentonite, kaolin. Examples thereof include clay substances, metal salts of aromatic carboxylic acids, phenol formaldehyde resins and the like. Of these, aromatic carboxylic acid metal salts are preferable. Specific preferred examples of the metal salt of aromatic carboxylic acid include 3,5-di-t-butylsalicylic acid,
3,5-di-t-octylsalicylic acid, 3,5-di-t
-Nonylsalicylic acid, 3,5-di-t-dodecylsalicylic acid, 3-methyl-5-t-dodecylsalicylic acid, 3-
t-dodecylsalicylic acid, 5-t-dodecylsalicylic acid, 5-cyclohexylsalicylic acid, 3,5-bis (α, α-dimethylbenzyl) salicylic acid, 3-methyl-5- (α-methylbenzyl) salicylic acid, 3- (α ，
α-Dimethylbenzyl) -5-methylsalicylic acid, 3-
(Α, α-Dimethylbenzyl) -6-methylsalicylic acid, 3- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -6-ethylsalicylic acid , 3-phenyl-5
(Α, α-Dimethylbenzyl) salicylic acid, carboxy-modified terpene phenolic resin, zinc salt, nickel salt, such as salicylic acid resin which is a reaction product of 3,5-bis (α-methylbenzyl) salicylic acid and benzyl chloride,
Aluminum salts, calcium salts and the like can be mentioned.

The above-mentioned aromatic carboxylic acid metal salt can be mechanically dispersed in an aqueous system or dissolved in an organic solvent before use.

When the aromatic carboxylic acid metal salt is mechanically dispersed, it can be treated with a ball mill, an art writer, a sand grinder or the like to prepare a dispersion liquid.

As the organic solvent for dissolving the metal salt of aromatic carboxylic acid, diisopropylnaphthalene, 1-phenyl-1-xylylethane, 1-phenyl-1-isopropylphenylethane, 1-phenyl-1-ethylphenylethane, toluene, Examples thereof include xylene, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, ethyl acetate, butyl acetate, amyl acetate, methylene chloride, butanol, paraffin and kerosene.

A solution prepared by dissolving an aromatic carboxylic acid metal salt in the above organic solvent is added to the dispersion-containing water in an amount of 5 to 120% by weight, preferably 50 to 100% by weight, and emulsified and dispersed. Subsequently, the emulsified dispersion may be heated to remove the organic solvent. The aromatic carboxylic acid metal salt is generally used by dissolving it in an organic solvent in an amount of 10 to 200% by weight.

As the dispersant, an ionic or nonionic surfactant or a water-soluble polymer compound can be used. Examples of the surfactant include alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkyl sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyhydric alcohol fatty acid partial ester and the like. . Examples of the water-soluble polymer compound include polyvinyl alcohol, modified polyvinyl alcohol, polyacrylamide, sodium polyacrylate, polyvinyl ether, sodium polystyrene sulfonate, and maleic anhydride copolymer.

The coating liquid for forming the above-mentioned color developer layer contains, as a binder, a styrene-butadiene copolymer latex, a vinyl acetate latex, an acrylate latex, polyvinyl alcohol, polyacrylic acid, maleic anhydride. -Styrene-copolymers, starch, casein, acacia, gelatin, carboxymethylcellulose, methylcellulose and other synthetic or natural polymer substances may be added.

The final coating amount of the color developer applied to the support is
^{0.1g / m 2 ~3.0g / m 2} , preferably 0.2g
/ M ^{2 to} 1.0 g / m ² is suitable.

[0041]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Embodiment 1] A pressure-sensitive recording sheet having a tampering prevention function (composed of an upper sheet, middle sheets (A) and (B), and a lower sheet shown in FIG. 2).
(Preparation of top paper) [Preparation of microcapsule dispersion containing black color-developing agent] 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane 5.0 g, benzoyl leuco 1.0 g of methylene blue and 2.0 g of 2-dibenzylamino-6-diethylaminofluorane were dissolved in 100 g of diisopropylnaphthalene. To the obtained oily liquid, 10 g of carbodiimide-modified diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "Millionate MTL"), isocyanurate of hexamethylene diisocyanate (Nippon Polyurethane Co., Ltd.)
Made by the trade name "Coronate EH") and ethylenediamine butylene oxide adduct (addition mole number of butylene oxide to ethylenediamine 16.8 mol,
A primary solution was prepared by dissolving 3.0 g of a molecular weight of 1267).

Next, in 140 g of water, 10 parts of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "PVA-205")
g and 5 g of carboxymethyl cellulose were dissolved to prepare a secondary solution. While vigorously stirring the secondary solution, the primary solution was poured into the secondary solution to form an oil-in-water emulsion. Agitation was weakened when the average oil droplet size reached 7.0 μm, and then water of 20 ° C. was added to the emulsion.
After the addition of 00 g, the system temperature was gradually raised to 65 ° C. and maintained at this temperature for 90 minutes to prepare a microcapsule dispersion.

[Preparation of Coating Solution for Forming Black Color-Developing Coloring Agent Layer]
80 g of a 15 wt% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name “PVA-217E”), 30 g of carboxy-modified SBR latex as a solid content, and 60 g of starch particles (average particle size 15 μm). Was added. Then add water to bring the solids concentration to 20.
The coating liquid for forming a colorant layer containing the colorant-encapsulating microcapsules was prepared by adjusting the content to the weight percent.

An OCR basis weight of 60 g / m ^{2 On} one surface of the base paper, the above-mentioned coloring agent layer forming coating solution was applied using an air knife coating machine so that the solid content coating amount was 4.0 g / m ^2. And then the coating film is dried to form a color former layer.
No. 21 and No. 22 above, and an upper paper (a pressure-sensitive recording sheet) containing a black color-forming agent was manufactured.

(Preparation of Medium Paper (A)) [Preparation of Coating Solution A for Forming Developer Layer] 15 g of zinc 3,5-di-α-methylbenzylsalicylate, calcium carbonate 1
Dispersion A was prepared by dispersing 20 g, activated clay 30 g, zinc oxide 20 g, sodium hexametaphosphate 1 g, and water 200 g so that the average particle diameter was 3 μm using a sand grinder. Then 400 g of this dispersion
In addition, 100 g of a 10 wt% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "PVA-203") and polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "P").
100 g of a 10% by weight aqueous solution of VA-117 ") was added and water was adjusted so that the solid content concentration was 20% by weight to prepare a coating liquid A for forming a developer layer.

A basis weight of 30 g / m ^{2 On} one surface of the base paper, the coating liquid for forming the black color-developing layer was applied in a solid content of 4.0 g / m ^2.
As will become m ^2, it was coated using an air knife coater so that the solid coating amount of the developer layer forming coating solution A on the other surface (back surface) is 4.5 g / m ² Then, the coating film was dried to manufacture a medium paper (A) containing a black color-developing agent corresponding to 23, 24 and 25 in FIG.

(Preparation of Medium Paper (B)) [Preparation of Microcapsule Dispersion Liquid a Containing Red Coloring Agent]
2.0 g of 2-methyl-6-N-ethyl-N-tolylaminofluorane as a color former and 3,3-bis (1-octyl-2-methylindol-3-yl) phthalide 4.0
g was dissolved in 90 g of 1-phenyl-1-xylylethane. IP was added to the obtained oily liquid as a paraffinic solvent.
Solvent 1016 (manufactured by Idemitsu Petrochemical Co., Ltd.) 30 g,
Carbodiimide-modified diphenylmethane diisocyanate (manufactured by Mitsui Toatsu Chemicals, Inc., trade name "MDI-LT") 8 g as a polyvalent isocyanate and hexamethylene diisocyanate biuret (manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name "Sumjour N3200") A primary solution was prepared by dissolving 8 g.

Next, to 140 g of water, polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "PVA-205") 10 was added.
g and 5 g of carboxymethyl cellulose were dissolved to prepare a secondary solution. While vigorously stirring the secondary solution, the primary solution was poured into the secondary solution to form an oil-in-water emulsion. When the average oil droplet size reached 8.0 μm, the stirring was weakened, and then water of 20 ° C. was added to the emulsion.
After adding 00 g and diethylenetriamine 1.6 g,
The system temperature is gradually raised to 90 ° C., and at this temperature 6
The microcapsule dispersion liquid a was prepared by maintaining it for 0 minutes.

[Preparation of coating liquid a for forming red color-developing layer]
The microcapsule dispersion liquid thus obtained is used as 25
After cooling to 0 ° C., 80 g of a 15 wt% aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd., trade name “PVA-205”), 15 g of carboxy-modified SBR latex as a solid content, and starch particles (average particle diameter 15 μm) were added. 60 g was added. Then add water to bring the solids concentration to 20.
The coating liquid a for forming a color-forming agent layer containing red color-developing agent-containing microcapsules was prepared by adjusting the content to 1% by weight and further adding 1 g of dodecylbenzenesulfonate as a surfactant.

[Preparation of coating liquid b for forming red color-developing agent layer]
To the microcapsule dispersion a, 120 g of a 15 wt% aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd., trade name "PVA-205"), 15 g of carboxy-modified SBR latex as a solid content, starch particles (average particle diameter 16 μm) 60 g was added. Then, water was added to adjust the solid content concentration to 20% by weight, and 1 g of dodecylbenzene sulfonate (Daiichi Kogyo Seiyaku Co., Ltd., trade name "Neogen T") was added as a surfactant to give a red color. A coating solution b for forming a color former layer containing microcapsules containing a color former was prepared.

[Preparation of coating liquid B for forming developer layer] 3, 5
100 g of zinc di-α-methylbenzylsalicylate was added to 80 g of xylene and dissolved. This xylene solution was added to 120 g of a 4 wt% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "PVA-205"), and 4 g of a 10 wt% aqueous solution of polyoxyethylene sorbitan oleate was added as a surfactant. The obtained mixture was dispersed by a homogenizer to prepare an emulsion dispersion liquid having an emulsion having an average particle size of 1.0 μm.

Next, 180 g of water was added to this emulsified dispersion, which was then heated to azeotrope xylene with water to remove it from the emulsified dispersion, and the solid content concentration was adjusted to 30% by weight. To obtain a color developer dispersion.

Separately, 120 g of calcium carbonate, 20 g of zinc oxide, 1 g of sodium hexametaphosphate and 200 of water.
g was atomized by a sand mill to obtain an inorganic pigment dispersion liquid. 48% to 300 g of the obtained inorganic pigment dispersion liquid
Add 20 g of styrene / butadiene rubber latex,
Then, 15 g of the developer dispersion obtained above is added and water is adjusted so that the solid content concentration is 27% by weight, and dodecylbenzene sulfonate as a surfactant is further added to 0.1.
8 g was added to prepare a coating liquid B for forming a developer layer.

A coating amount b of solid content of 4.0 g of the coating solution b for forming the red color-developing layer is applied to one surface of the base paper having a basis weight of 50 g / m ^2.
/ M ² and the developer B-forming coating liquid B to be applied thereon so as to give a solid coating amount of 6.0 g / m ² by the simultaneous multilayer curtain coating method, and then It dried at 80 degreeC and formed the self-coloring layer corresponding to 26 (26c and 26b) of FIG. The other side (back side)
The coating liquid a for forming the red color-developing agent layer is applied to the above by a curtain coating method so that the solid content coating amount becomes 4.0 g / m ² , and the coating film is dried to correspond to 28 in FIG. A red color developing agent layer was formed. Thus, 26, 27 and 28 of FIG.
A medium paper (B) containing a red color-developing agent corresponding to the above was produced.

(Preparation of lower paper) Basis weight 40 g / m ^{2 On} one surface of the base paper, the developer A for forming the developer layer was coated with air so that the coating amount of solid content was 4.5 g / m ^2. Apply using a knife applicator, dry the coating,
A black-colored bottom paper (pressure-sensitive recording sheet) corresponding to 0 was manufactured.

Upper paper and middle paper (A) obtained in Example 1
(B) and the lower sheet were stacked in this order to prepare a pressure-sensitive recording sheet having a tampering prevention function, and the following tampering test was conducted. (Falsification test) 1) No tampering A number was written with a black ballpoint pen on the top sheet of the tamperproof pressure-sensitive recording sheet (the surface without the developer layer). 2) Falsification A The middle sheet (B) of the tamperproof pressure-sensitive recording sheet was pulled out, and a number was written with a black ballpoint pen on the top sheet. After that, a black ballpoint pen was used to write on the self-coloring layer of the medium paper (B). 3) Tampering B Plain paper was sandwiched between the middle papers (A) and (B) for tampering prevention pressure-sensitive recording sheet, and a number was written on the upper paper with a black ballpoint pen.

(Results) 1) The colors of the numbers on the surfaces of the medium paper (A), the medium paper (B) and the lower paper were black, black (reddish) and red, respectively. 2) The numbers of the numbers on the surfaces of the medium paper (A) and the lower paper were both black. Unlike the case where the color of the lower paper was not tampered with, the tampering was easy to see. 3) The colors of the numbers on the surfaces of the middle paper (A), the middle paper (B) and the lower paper are black, red and black, respectively. The middle paper (B) was already printed in a different red color from that when it was not tampered with and could not be tampered with.

[Example 2] Preparation of pressure-sensitive recording sheet having tampering prevention function (composed of upper sheet, middle sheet and lower sheet shown in Fig. 1) (Preparation of upper sheet) [Microcapsules containing blue color former] Preparation of Dispersion] 5 g of a partial sodium salt of polyvinyl sulfonic acid (manufactured by National Starch Co., Ltd., VERSA, TL500; average molecular weight 500000) was added to 95 g of hot water at about 80 ° C. with stirring and dissolved, followed by cooling. did. The pH of the aqueous solution is 2
Was adjusted to pH 4.0 by adding a 20% by weight sodium hydroxide aqueous solution to obtain a 5% by weight aqueous solution of a partial sodium salt of polyvinylsulfonic acid. Crystal Violet Lactone 4g and 3-
(4-diethylamino-2-ethoxyphenyl) -3-
(2-Methyl-1-octyl-3-indolinyl) -4
-Azaphthalide 2 g, diisopropyl naphthalene 94
This oily liquid was dissolved in 100 g and was emulsified and dispersed in 100 g of a 5% by weight aqueous solution of a partial sodium salt of polyvinyl sulfonic acid to prepare an emulsion having a particle size of 5.0 μm in average diameter.

Separately, 6 g of melamine and 11 g of 37% by weight aqueous formaldehyde solution were heated and stirred at 60 ° C. for 30 minutes to obtain transparent melamine, formaldehyde and melamine /
A mixed aqueous solution of the formaldehyde initial condensate (initial condensate solution) was obtained. The pH of this aqueous solution was 6-8. This initial condensate solution was added to the emulsion and mixed, and while stirring, the pH was adjusted to 6.0 with a 3.6 wt% hydrochloric acid solution, the liquid temperature was raised to 65 ° C., and stirring was continued for 360 minutes. To form a capsule, and a capsule dispersion liquid was obtained.

[Preparation of coating solution for forming blue color developing agent layer] This capsule dispersion was cooled to room temperature and adjusted to pH 9.0 with a 20% by weight aqueous sodium hydroxide solution. In this capsule liquid, 10% by weight of polyvinyl alcohol 200
g, carboxy-modified SBR latex as solid content 2
0 g and 50 g of starch particles (average particle size 20 μm) were added. Then, water was added to adjust the solid content concentration to 20% by weight to prepare a coating solution for forming a color former layer containing microcapsules containing a blue color former.

Basis weight 40 g / m ^{2 On} one surface of the base paper, the above coating liquid for forming the color-forming agent was applied at a solid content of 4.0 g / m 2.
Apply using an air knife coating machine so that it becomes ² ,
The coating film was dried to produce an upper paper (pressure-sensitive recording sheet) containing a blue color-developing agent corresponding to 11 and 12 in FIG.

(Preparation of Medium Paper) [Preparation of Coating Solution a for Forming Green Color-Developing Agent Layer] In the preparation of the red color-developing agent-containing microcapsule dispersion a of Example 1, 2-methyl-6- Instead of 2.0 g of N-ethyl-N-tolylaminofluorane and 4.0 g of 3,3-bis (1-octyl-2-methylindol-3-yl) phthalide, 2-dibenzylamino-6- 5.0 g of diethylaminofluorane and 2-anilino-6-
A green color-forming colorant-encapsulating microcapsule dispersion a was prepared in the same manner as in Example, except that 3.0 g of N-ethyl-N-hexylaminofluorane was used, and then, similarly, coating for forming a green color-forming colorant layer was performed. Liquid a was prepared.

[Preparation of coating solution b for forming green color-forming color developer layer]
Microcapsule dispersion liquid b containing the red color-forming agent of Example 1
In the preparation of, 2-methyl-6-N-ethyl-N-tolylaminofluorane (2.0 g) and 3,3-
5.0 g of 2-dibenzylamino-6-diethylaminofluorane and 2-anilino-6-N-ethyl-N instead of 4.0 g of bis (1-octyl-2-methylindol-3-yl) phthalide. -Preparation of a green color-forming colorant-containing microcapsule dispersion b in the same manner as in Example 1 except that 3.0 g of hexylaminofluorane was used, and then a coating solution b for forming a green color-forming colorant layer was similarly prepared. did.

The basis weight 60 g / m ^{2 On} one surface of the base paper, the coating liquid b for forming the green color-developing agent layer has a solid content of 4.5 g.
/ M ² and the developer-containing coating liquid B of Example 1 applied on the solid content coating amount of 5.5 g / m 2.
² was applied by the simultaneous multilayer curtain coating method and then dried at 100 ° C. to form a self-coloring layer corresponding to 13 (13c and 13b) in FIG. On the other surface (rear surface), the green color-forming colorant layer-forming coating liquid a was applied by a curtain coating method so that the solid content coating amount was 4.0 g / m ² , and the coating film was dried, A green color developing agent layer corresponding to 15 in FIG. 1 was formed. Thus, 13 and 1 in FIG.
Medium papers containing green color formers corresponding to 4 and 15 were produced.

(Preparation of lower paper) Basis weight 40 g / m ^{2 On} one surface of the base paper, the above-mentioned developer-containing coating liquid A was coated with an air knife so that the solid coating amount was 4.5 g / m ^2. It was applied using a machine, and the coating film was dried to produce a black colored bottom paper (pressure-sensitive recording sheet) corresponding to 29 and 20 in FIG.

The upper sheet, the middle sheet and the lower sheet obtained in Example 2 were stacked in this order to prepare a tamperproof pressure-sensitive recording sheet, and the following tampering test was conducted. (Falsification test) 1) No tampering A number was written with a blue ballpoint pen on the top sheet of the tamperproof pressure-sensitive recording sheet (the surface without the developer layer). 2) Tampering A The inside of the pressure-sensitive recording sheet for tampering prevention was pulled out, and a number was written with a blue ballpoint pen on the top sheet. After that, a blue ballpoint pen was used to write on the self-coloring layer of the medium paper. 3) Falsification B Plain paper was sandwiched between the upper and middle sheets of the pressure-sensitive recording sheet for tampering prevention, and a number was written on the upper sheet with a blue ballpoint pen.

(Results) 1) The numbers of the numbers on the surfaces of the middle and lower sheets are blue green and green, respectively. 2) The color of the numbers on the surface of the lower sheet was blue. Unlike the case where the color of the lower paper was not tampered with, the tampering was easy to see. 3) The numbers of the numbers on the surfaces of the medium and lower sheets were both green. The medium paper was already printed in a different green color than when it was not tampered with, so it could not be tampered with.

[0069]

The pressure-sensitive recording sheet for tampering prevention according to the present invention exhibits an excellent effect that tampering is impossible even if tampering is attempted by various conventional means. For example,
A tamper-proof pressure-sensitive recording sheet that cannot be tampered with even if you insert plain paper between the paper on which you do not want to write a form and the paper on which you do not want to write a form is there.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a cross section of a representative example of a pressure-sensitive recording sheet having a tampering prevention function of the present invention.

FIG. 2 is a diagram schematically showing a cross section of another representative example of the pressure-sensitive recording sheet having the tampering prevention function of the present invention.

FIG. 3 is a diagram schematically showing a cross section of a typical example of a conventional pressure-sensitive recording sheet having a tampering prevention function.

[Explanation of symbols]

11, 14, 17, 21, 24, 27, 20, 31, 3
4, 37 Supports 12, 13b, 15, 22, 25, 26b, 28, 3
2, 35 color former layers 12a, 13a, 15a, 22a, 25a, 26a, 2
8a, 32a, 35a Coloring agent-containing microcapsules 13c, 16, 23, 26c, 29, 33, 36 Developer layer 13, 26 Self-coloring layer

Claims (6)

[Claims] 1. The following (1) to (3): (1) Top paper provided with a color former layer containing microcapsules containing an electron donating color former on the back surface of a support; (2) Support On the surface of the body, an electron-accepting color developing agent and an electron-donating color developing agent whose color obtained by the reaction with the color developing agent is different from the color obtained by the reaction between the color developing agent of the upper paper and the color developing agent. Medium paper provided with a self-coloring layer containing microcapsules to be encapsulated and a color former layer containing microcapsules containing an electron donating colorant on the back surface; and (3) Electron-accepting color development on the surface A pressure-sensitive recording sheet having a tampering prevention function, which is formed by stacking sheets of a lower sheet on which a developer layer containing an agent is provided so that the front and back sides of each sheet come into contact with each other in this order. 2. The pressure-sensitive recording sheet having the tampering prevention function according to claim 1, wherein the color formers on the front and back surfaces of the support of the middle paper are color formers exhibiting the same color. 3. The coloring agent of the upper paper is a coloring agent showing black or blue coloring, and the coloring agents of the front and back surfaces of the middle paper are coloring agents showing coloring other than black and blue. A pressure-sensitive recording sheet having the tampering prevention function described in. 4. The following (1) to (4): (1) Top paper on which a color former layer containing microcapsules containing an electron-donating color former is provided on the back surface of a support; (2) Support Medium paper having a developer layer containing an electron-accepting developer on the surface of the body and a color-developing layer containing microcapsules containing an electron-donating color developer on the back surface; (3) Support The surface of the sheet contains an electron-accepting color developer and an electron-donating color developer whose color obtained by the reaction with the color developer is different from the color obtained by the reaction between the color developing agent on the upper paper and the color developing agent. (4) An electron-accepting color developer on the front surface of which is provided a self-coloring layer containing microcapsules and a colorant layer containing microcapsules containing an electron-donating colorant on its back surface; The lower sheet provided with the developer layer containing Pressure-sensitive recording sheet having a tamper-proof comprising superimposed in contact. 5. The pressure-sensitive recording sheet having a tampering prevention function according to claim 4, wherein the color formers on the front surface and the back surface of the support of the inner medium paper (3) are color formers exhibiting the same color. 6. The coloring agent for the upper paper and the middle paper of (2),
5. A tampering preventive function according to claim 4, which is a color former exhibiting black or blue color, and (3) the color former on the front surface and the back surface of the middle paper is a color former exhibiting a color other than black and blue. Pressure-sensitive recording sheet.