JPH10264514A - Record sheet - Google Patents

Abstract

(57) [Abstract] [Problem] It has sufficient pressure-sensitive color developing property, abrasion resistance and impact resistance,
Provided is a recording sheet having anti-counterfeiting properties due to pressure-sensitive coloring. A 5 kgf is obtained by laminating a support, a thermoplastic resin layer, a self-coloring pressure-sensitive recording layer, and a cover sheet.
/ Rel ² when applying a surface pressure of 0.99
1.00 and a Yrel value of 0.81 when a linear pressure of 10 kg / cm is applied by a chilled roll. As a result, a recording sheet having a good balance of pressure-sensitive coloring property, abrasion resistance and impact resistance, and having a function of preventing forgery by pressure-sensitive coloring property can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet having anti-counterfeiting properties, and the basic anti-counterfeiting properties are given by pressure-sensitive coloring. further,
The present invention relates to a self-coloring type pressure-sensitive recording sheet which can be copied (copy) simply by using it with high quality paper and has not only printability as ordinary paper but also sufficient abrasion resistance. is there. Such a recording sheet can be used for slips, forms, recording paper, toys, communications, securities, cash vouchers, tickets, tickets, documents, stickers, lottery, labels, etc. It is a recording sheet having a preventive property.

[0002]

2. Description of the Related Art In recent years, with the remarkable development of color image forming techniques such as a color copy technique, an ink jet recording technique, and a thermal transfer recording technique, a beautiful multi-color or full-color image has been easily obtained.
However, it is true that such a situation also facilitates forgery of various kinds of cash vouchers and the like.

[0003] Due to the development of forgery methods in social life (particularly where color copying is largely owed), the targets are not only gold vouchers such as tickets and tickets, but also labels, price tags and documents. Not leak. In other words, besides cash vouchers such as admission tickets, tickets, stamps, stamps, bills, checks, certificates, etc., labels and manuals such as books, CDs, game software, etc. which are circulating in the world, price tags of products, lotteries of all kinds At present, voting tickets (e.g. betting tickets) and company stationery can be easily made by color copying.

[0004] For the purpose of preventing forgery, such recording paper for so-called cash vouchers is printed with a forgery-preventing tint block or with micro-characters to prevent forgery. With the development of image forming technology, printing has become a situation where even a layman can easily make a copy at a level that cannot be verified even at first glance.

On the other hand, the self-coloring pressure-sensitive recording system which is the basis of the present invention has been developed from so-called carbonless copying paper, and as a product form, it is also called a self-coloring pressure-sensitive recording sheet or a self-contained paper. ing. The structure is such that a microcapsule containing a colorless dye (hereinafter, referred to as a color forming agent) is provided on a support, and an electron accepting substance (hereinafter, referred to as an acid clay, a phenol resin, an organic acidic substance, etc.) And a method of providing a two-layer coating (including those in which the coating order is reversed), and microencapsulation of at least one of the two components. Manufacturing method by mixing uniformly and applying one layer (Japanese Patent Publication No. 47-1)
No. 6096).

Naturally, in the self-coloring pressure-sensitive recording sheet, since both the color former and the developer are present close to the surface of the support, and the color is developed by a little friction or pressure, abrasion resistance is imparted. is necessary. As a simple method of imparting abrasion resistance, there is a method in which wheat starch particles having a particle size larger than that of microcapsules are dispersed in the self-coloring pressure-sensitive recording layer so that color is not inadvertently formed by a slight pressure. However, the combined use of such a cushion material (stilt material) has limited its abrasion resistance effect.

Heretofore, for example, a method of providing a laminate layer by a vacuum adhesion method on a recording layer of a self-coloring pressure-sensitive recording sheet (Japanese Patent Publication No. 49-10857) or a recording method having a plastic layer by a melt lamination method Examples of a sheet (Japanese Utility Model Application Laid-Open No. 52-149709) and an example in which a release layer is provided on these protective layers, or a soluble polymer solution is applied on a self-coloring pressure-sensitive recording layer and dried to form a film. Methods and the like are known. However, according to these methods, remarkable color fogging is generated due to the destruction of the microcapsules, or the microcapsules are covered with the resin, the original self-coloring pressure-sensitive recording property is almost lost, and the color density and the color forming speed are reduced. In addition to the problem that the recordability is deteriorated, there is also a problem that the surface is made of plastic, resulting in poor printability and a problem that paper texture is lost.

[0008] Further, a polyolefin resin coating layer is provided on the recording layer of the self-coloring pressure-sensitive recording sheet, and an opaque coating sheet (destination display sheet) coated with a heat-sealable adhesive on the back surface is superposed thereon. Method of integrating by crimping (Japanese Utility Model Laid-Open No. 2-2173, Japanese Utility Model Application Laid-Open No. 3-1)
No. 16974) is disclosed. In addition, a method of integrating a self-coloring pressure-sensitive recording sheet and an opaque covering sheet with a thermoplastic resin (Japanese Patent Laid-Open No. 5-278175), and a method of forming a self-coloring pressure-sensitive recording sheet and an opaque covering sheet substantially in two layers A method of integrating with a thermoplastic resin layer (JP-A-5-307362) is disclosed. However, in these methods, although the printability of the surface and the texture of the paper are maintained, the purpose of this method is to conceal the self-coloring pressure-sensitive recording layer in a releasable manner. The color development was different from the original use of the self-coloring pressure-sensitive recording sheet in that it could not be read unless the opaque cover sheet was peeled off.

As a method for imparting good abrasion resistance without impairing the color developing property of the self-coloring pressure-sensitive recording sheet, an opaque support provided with a self-coloring pressure-sensitive recording layer and a transparent paper are prepared by using a polyolefin resin layer. (Japanese Unexamined Patent Publication No.
No. 52938). However,
In the case of this method, although it has a function of preventing forgery, it has been difficult to use the self-coloring pressure-sensitive recording layer unnecessarily conspicuous due to slight breakage or the like, and it is easy to curl.

[0010]

An object of the present invention is to provide a recording sheet provided with anti-counterfeiting properties, which can easily be authenticated by employing a self-coloring pressure-sensitive recording system. Is to provide. In this case, the self-coloring pressure-sensitive recording layer has sufficient pressure-sensitive color-forming properties, abrasion resistance and impact resistance, and has printability and paper texture comparable to ordinary general paper. It is to provide.

[0011]

Means for Solving the Problems The present inventors have considered the application of a self-coloring pressure-sensitive recording system as a means for imparting simple authenticity judgment. That is, it was thought that if a sheet that self-pressure-colored was used as a printing sheet such as a cash voucher, the authenticity could be easily determined based on the presence or absence of coloration during pressurization.

However, in adopting the self-coloring pressure-sensitive recording system, printability as a recording sheet and pressure-sensitive coloring at a practical level must not be impaired, and unnecessary color stains during handling must be avoided.

In view of the above, as a result of earnest research, the following invention has been attained.

At least one of a support, a thermoplastic resin layer, a color former or a developer is microencapsulated, and each of them is laminated or mixed alone to form a single self-coloring pressure-sensitive recording layer (hereinafter simply referred to as self-coloring). Pressure-sensitive recording layer),
When a surface pressure of 5 kgf / cm ² is applied, the Yrel value represented by the following equation 1 is 0.
99-1.00, and 10 kg / cm with chilled roll
A self-coloring type pressure-sensitive recording sheet characterized in that the Yrel value represented by the following formula 1 when the linear pressure is applied is less than 0.81.

(Equation 1) Yrel = Yf / Yi Yrel: ratio of Y value of sheet pressing portion before and after pressing Yf: Y value of sheet pressing portion after pressing Yi: Y of sheet before pressing Value Here, the Y value means the Y value of the tristimulus values X, Y, and Z of the object color in the CIE (XYZ) color system.

A forgery prevention sheet using the recording sheet, wherein forgery prevention or forgery detection can be performed by pressure-sensitive coloring.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below.
The configuration of the recording sheet of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of a recording sheet of the present invention. The recording sheet of the present invention is formed by laminating a thermoplastic resin layer 2, a self-coloring pressure-sensitive recording layer 3, and a cover sheet 4 on a support 1. The surface of the support 1 that is not in contact with the thermoplastic resin layer 2 and the cover sheet 4
The surface not in contact with the self-coloring pressure-sensitive recording layer 3 has printability. The thermoplastic resin layer 2 functions as an adhesive layer between the support 1 and the self-coloring pressure-sensitive recording layer 3. Self-coloring pressure-sensitive recording layer 3
Acts as a layer having a forgery prevention function or a forgery detection function due to its pressure-sensitive coloring property. The self-coloring pressure-sensitive recording layer 3
It is important not to be located in the outermost layer in the structure in order to provide excellent abrasion resistance.

Further, it is important that the recording sheet of the present invention has a controlled coloring property when a constant pressure is applied. That is, when the surface pressure of 5 kgf / cm ² is applied, the Yrel value represented by the following formula 1 is 0.99 to 1.00, and when the linear pressure of 10 kg / cm is applied by a chilled roll, the following formula 1 is applied. Is characterized in that the Yrel value indicated by is less than 0.81.

(Equation 1) Yrel = Yf / Yi Yrel: ratio of Y value of sheet pressing portion before and after pressing Yf: Y value of sheet pressing portion after pressing Yi: Y of sheet before pressing Value Here, the Y value means the Y value of the tristimulus values X, Y, and Z of the object color in the CIE (XYZ) color system.

Here, the term "applying a surface pressure" refers to an operation of applying a force of 5 kgf / cm ² for 1 minute on a smooth surface having a constant area in a direction perpendicular to the sample from above the sample which is allowed to stand on a smooth table. Means Applying a linear pressure means an operation of passing a sample between two chilled rolls and applying a linear pressure of 10 kg / cm at a speed of 3 m / min.

Since the Y value of the CIE (XYZ) color system is an index of the optical density, the ratio (Yrel) of the Y value before and after color development is obtained.
Value) can be used as an index of the color density of the self-coloring pressure-sensitive recording layer. The larger the Yrel value, the smaller the change in optical density before and after pressurization.
Only when the Yrel value is in an appropriate range, it is possible to achieve both a practical level of self-pressure-sensitive color development for the purpose of preventing forgery, and excellent abrasion resistance and unnecessary color development at the time of handling. The appropriate range of the specific Yrel value is 5 kgf /
When the surface pressure of ² cm ² is applied, the Yrel value is 0.99-1.
00 and a Yrel value of less than 0.81 when a linear pressure of 10 kg / cm is applied by a chilled roll. 5kgf /
If the Yrel value when a surface pressure of cm ² is applied is smaller than 0.99, the abrasion resistance is inferior, and a slight impact during handling may cause unnecessary coloring of the self-coloring pressure-sensitive recording layer. It is theoretically impossible for the Yrel value to exceed 1.00. When the Yrel value when applying a linear pressure of 10 kg / cm with a chilled roll is 0.81 or more,
Self-color-forming property The color-forming property of the pressure-sensitive recording layer is insufficient, and the forgery preventing property (forgery detecting property) is insufficient.

The specific means for controlling the Yrel value within the above range is not particularly limited. For example, the self-coloring pressure-sensitive recording layer for controlling the thickness, density, and opacity of the covering sheet may be used. Controlling the coloring properties of the self-coloring pressure-sensitive recording layer by the coating liquid composition to be formed, controlling the cushioning property of the recording sheet of the present invention by the thickness and density of the support and the thermoplastic resin layer, or a combination of these methods And the like.

The support and the cover sheet used in the present invention are not particularly limited as long as they are generally used as printing papers or printing sheets. Fine paper, art paper, cast paper, coated paper, etc. Normal natural pulp paper such as paper can be used, wood pulp, synthetic pulp,
Raw materials usually used in papermaking, such as fillers, sizing agents, ultraviolet absorbers, antioxidants, pigments, paper strength agents, and dyes, can be used as needed. Polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyethylene, polypropylene, polyvinyl alcohol, ethylene / vinyl alcohol copolymer, ethylene / vinyl acetate copolymer, and fat. Aromatic or aromatic polyamide (nylon or aramid), polyimide, polycarbonate, polyurethane, fluororesin, polyacrylonitrile, TPX, polybutene, polyarylate, polyetheretherketone, polysulfone, polyethersulfone, polyetherimide, polyphenylenesulfide, Polyphenylene ether, polyacetal, cellophane, ionomer, or copolymerization, coextrusion, coating, Synthetic resin film complexed by a technique such as command,
Alternatively, non-woven fabric or woven fabric made of synthetic fiber, natural fiber, pulp fiber, glass fiber, etc., synthetic paper, synthetic resin on one side of paper,
Alternatively, a laminated paper laminated on both sides, a metal foil, or a composite sheet combining these can be used according to the purpose. Synthetic resins can be made opaque with inorganic or organic pigments. These materials may be white or colored.

In order to obtain the recording sheet of the present invention, a single layer of a color former or a developer, at least one of which is microencapsulated, is typically laminated or mixed on one side of the cover sheet. It can be produced by combining the step of providing a self-coloring pressure-sensitive recording layer, the step of integrating a support sheet provided with the self-coloring pressure-sensitive recording layer and a support with a thermoplastic resin layer, and particularly, It does not limit the details of the steps or the combination order.

As the thermoplastic resin used for the recording sheet of the present invention, generally, any thermoplastic resin used for thermoplastic resin coating or thermoplastic resin lamination can be used without limitation. For example, polyethylene (low density, medium density) , High density, linear low density polyethylene), polypropylene, polytrimethylpentene, polybutene, polyester, polystyrene, polyamide, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene acrylic acid copolymer, ethylene methyl acrylate Copolymer, ethylene vinyl alcohol copolymer,
General-purpose melt-extruded resins such as ethylene methacrylic acid copolymers and salts thereof, vinyl chloride, and vinylidene chloride can be used alone or in combination.

The method of mixing the thermoplastic resin is not particularly limited, and any method can be used. For example, extruders for kneading machines, heated kneading rolls, Banbury mixers,
Using a kneader or the like, add a predetermined amount of thermoplastic resin, and if necessary, various additives (release agent, slip agent, pigment, antioxidant, neutralizing agent, ultraviolet absorber, etc.), melt and mix. A method of pulverizing and pulverizing the mixture, a method of directly extruding and extruding a so-called simple blend into an extruder, or a method of copolymerizing other components during polymerization of one thermoplastic resin. For example, a method using the obtained mixed resin can be used. Since the thermoplastic resin comes into direct contact with the self-coloring pressure-sensitive recording layer, it is necessary to use the thermoplastic resin in consideration of the effects of the plasticizer, dispersant, antioxidant and the like in the resin.

In order to integrate the support and the coated sheet having the self-coloring pressure-sensitive recording layer with the thermoplastic resin layer, a general melt extrusion die, a T die, or a multilayer simultaneous extrusion die can be used. As a pretreatment for the melt extrusion, a known treatment for improving adhesion such as a corona treatment or a frame treatment may be performed on the coated sheet or the support having the self-coloring pressure-sensitive recording layer. Further, on the back surface of the recording sheet of the present invention, a back coat layer such as an anti-curl, anti-static, pigment coat layer or a water-resistant layer can be provided, and the back coat layer has an antistatic agent, a hydrophilic binder, a latex , A hardening agent, a pigment, a surfactant, a pressure-sensitive adhesive, and the like can be appropriately combined.

Application amount of thermoplastic resin (lamination amount)
Is preferably within a certain range because it affects the color developing property of the pressure-sensitive recording layer and the adhesiveness to transparent paper. For the purpose of sufficiently maintaining the adhesive strength between the transparent paper and the support, a coating amount of 8 to 40 g / m ² is preferable, and an excessive decrease in color development due to the cushioning property of the thermoplastic resin is suppressed, and practically sufficient self-coloration is achieved. In order to secure the coloring of the sensitized pressure-sensitive recording layer, a method of suppressing the coating amount to at most 30 g / m ² or less is more preferable. When the basis weight of the transparent paper exceeds a certain range, the coloring property sufficient for reading is impaired. In addition, the thermoplastic resin layer is 8 g /
If it is less than m ^2, the adhesiveness of the coated sheet provided with the self-coloring pressure-sensitive recording layer will be insufficient.

The self-coloring pressure-sensitive recording layer that can be used in the present invention is not particularly limited, and a conventionally known layer can be used. For example, a method of microencapsulation, a wall material of a microcapsule, a color former or an oil dissolving a color former, or a developer, an adhesive resin (binder), a microcapsule protective agent, or the like is used.

Examples of the microencapsulation method include coacervation method (US Pat. No. 2,800,458), interfacial polymerization method (JP-B-47-1763, etc.), and in-situ polymerization method (JP-A-51-9079). Gazettes) can be used.

As the wall material of the microcapsules, polyurethane, polyurea, epoxy resin, urea / formalin resin, melamine / formalin resin and the like can be used.

The color former and the developer used in the present invention are not particularly limited as long as they are generally used in pressure-sensitive recording materials. For example, as a color former for pressure-sensitive recording, triallylmethane compounds, diarylmethane compounds, xanthene compounds, thiazine compounds, spiropyran compounds, diphenylmethane dyes, spiro dyes, lactam dyes, fluoran dyes Etc. can be used.

Specifically, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- ( p-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3 , 3-Bis (1,2-dimethylindole-3
-Yl) -5-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -6-dimethylaminophthalide, 3,3-bis (2-phenylindo-
Ru-3-yl) -6-dimethylaminophthalide, 3-p
-Dimethylaminophenyl-3- (1-methylpyrrol-3-yl) -6-dimethylaminophthalide, 3-p-
Dimethylaminophenyl-3- (1-methylpyrrole-
2- (yl) -6-dimethylaminophthalide 3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2- Phenylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindole-
3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazole-3- Yl) -5-dimethylaminophthalide,
3,3-bis (2-phenylindol-3-yl)-
Triallylmethane dyes such as 5-dimethylaminophthalide.

4,4'-bis-dimethylaminophenylbenzhydryl benzyl ether, 4,4'-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenylleucouramine, N-2,4, Diphenylmethane dyes such as 5-trichlorophenylleuco auramine.

Thiazine dyes such as benzoyl leucomethylene blue and p-nitrobenzoyl leucomethylene blue;

3-methyl-spiro-dinaphthopyran, 3
-Ethyl-spiro-dinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran,
3-propylspirobenzopyran, 3-methylnaphtho-
Spiro dyes such as (3-methoxybenzo) spiropyran, 3-methyl-naphtho (6'-methoxybenzo) spiropyran, and 3-propyl-spiro-dibenzopyran.

Rhodamine-B-anilinolactam,
Lactam dyes such as damine (p-nitroanilino) lactam and rhodamine (o-chloroanilino) lactam.

Rhodamine B anilinolactam, rhodamine Bp-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-dimethylamino-7-dibenzylaminofluoran, 3-diethylamino-7- Octylaminofluoran, 3-diethylamino-7-phenylfluoran, 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-7-
N-diethylaminofluoran, 3-diethylamino-
7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 3-diethylamino-6-methyl-
7-chlorofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-
Methylfluoran, 3-diethylamino-7- (3,4
-Dichloroanilino) fluoran, 3-diethylamino-7- (2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-
Diethylamino-6-methyl-7-phenylaminofluoran, 3-diethylamino-6,7-dimethylfluoran, 3- (N-ethyl-N-tolyl) amino-6-methyl-7-anilinofluoran, 3 -Piperidino-6
Methyl-7-anilinofluoran, 3- (N-ethyl-
N-tolyl) amino-6-methyl-7-phenethylfluoran, 3-diethylamino-7- (4-nitroanilino) fluoran, 3-dibutylamino-6-methyl-7
-Anilinofluoran, 3- (N-methyl-N-propyl) amino-6-methyl-7-anilinofluoran, 3
-(N-ethyl-p-toluidino) -7-methylfluoran, 3- (N-ethyl-p-toluidino) -6-methyl-7-phenylaminofluoran, 3- (N-ethyl-p-toluidino) ) -6-Methyl-7- (p-toluidino) fluoran, 3-diethylamino-7- (2-carbomethoxy-phenylamino) fluoran, 3-diethylamino-7-N-acetyl-N-methylaminofluoran, 3 -(N-ethyl-N-isoamyl) amino-6
-Methyl-7-anilinofluoran, 3-diethylamino-7-N-chloroethyl-N-methylaminofluoran, 3-diethylamino-7-methyl-N-benzylaminofluoran, 3-diethylamino-7-N- Methylaminofluoran, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluoran,
3- (N-ethyl-N-iso-amylamino) -6-methyl-7-phenylaminofluoran, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-phenylaminofluoran, -(N-ethyl-N-tetrahydrofuryl) amino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-phenylaminofluoran, 3-pyrrolidino-6-methyl-7-
Phenylaminofluoran, 3-diethylamino-6-
Methyl-7-xylidinofluoran, 3-diethylamino-7- (o-chlorophenylamino) fluoran, 3
-Dibutylamino-7- (o-chlorophenylamino)
Fluorane dyes such as fluorane and 3-pyrrolidino-6-methyl-7-p-butylphenylaminofluoran.

As oils for dissolving the color former in the pressure-sensitive recording layer, aromatic synthetic oils such as diarylalkanes, alkylnaphthalenes, alkylated biphenyls, hydrogenated terphenyls, kerosene, naphtha, paraffin oils, chlorinated paraffins And vegetable oils such as cottonseed oil, coconut oil, soybean oil, and linseed oil.

As the protective agent for the microcapsules, cellulose powder, starch particles, talc, calcined kaolin, calcium carbonate and the like can be used.

Examples of the developer for pressure-sensitive recording include clays (for example, activated clay, acid clay, attapulgite, bentonite, colloidal silica, aluminum silicate, etc.)
Organic acids (eg, aromatic carboxy compounds such as salicylic acid or metal salts thereof), mixtures of organic acids and metal compounds, acidic polymers (eg, phenol / formaldehyde resin, salicylic acid resin or zinc, magnesium, Aluminum, calcium, titanium, manganese, tin, nickel, etc.).

As the adhesive resin (binder) used for the self-coloring pressure-sensitive recording layer, a known water-based adhesive polymer (that is, a water-soluble or emulsion or latex form) can be used. They can be used alone or as a mixture, but are not limited thereto.

Starches such as starch, oxidized starch, esterified starch, hydroxyethylated starch, acetylated starch, cationized starch, dextrin, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, casein, gelatin and the like Protein, agar, xanthan gum, pullulan, chitosan, star gum, guar gum, gum arabic, tragacanth gum, natural polymer polysaccharides such as alginic acid derivatives, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyrrolidone, polyacrylic acid,
Polyacrylates such as sodium polyacrylate, polyacrylates, polyacrylamide, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, isobutylene / maleic anhydride copolymer Copolymer, styrene / maleic anhydride copolymer and its alkali salt, ethylene / maleic anhydride copolymer alkali salt, styrene / acrylic acid copolymer, polyvinyl acetate, polyurethane, styrene / butadiene copolymer, acrylonitrile / Butadiene copolymer, methyl acrylate / butadiene copolymer,
Vinyl acetate / acrylic acid (ester) copolymer, acrylonitrile / butadiene / acrylic acid copolymer, ethylene / vinyl acetate copolymer, vinylidene chloride, polychloroprene, organopolysiloxane, polyethylene, etc.

Pigments used in the self-coloring pressure-sensitive recording layer include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, calcium sulfate, magnesium carbonate, titanium oxide, zinc oxide, zinc hydroxide, silicon oxide,
Examples include, but are not limited to, aluminum hydroxide, urea-formalin resin, melamine-formalin resin, and the like.

Further, as a constitution of the present invention, in order to obtain a high color density, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, silicate are disposed between the covering sheet and the self-coloring pressure-sensitive recording layer. Magnesium, lead sulfate, lead white, zinc white, zinc sulfide, satin white, titanium oxide,
Inorganic pigments such as antimony oxide, mica, bentonite, calcium silicate, gypsum, aluminum hydroxide, or polystyrene, polyvinyl toluene, styrene / divinylbenzene copolymer, polymethyl methacrylate, urea /
There is no problem with providing an anchor layer containing a finely divided organic pigment such as a formaldehyde polymer or polyethylene, or dispersing in the self-coloring pressure-sensitive recording layer.

Other auxiliary agents include metal salts of higher fatty acids such as zinc stearate and calcium stearate;
Waxes such as paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, and caster wax; dispersants such as sodium dioctyl sulfosuccinate and sulfonic acid-modified polyvinyl alcohol; and ultraviolet absorbers such as benzophenone and benzotriazole, In addition, a surfactant, a fluorescent dye, an antistatic agent, a thickener, a preservative, an antioxidant, an antifoaming agent, a release agent, a lubricant, a blocking resistance improver, a tackifier, etc.
It is added to the self-coloring pressure-sensitive recording layer, the thermoplastic resin layer, and the cover sheet as needed.

In the present invention, the method of applying the self-coloring pressure-sensitive recording layer includes a gravure coater, a gravure offset coater, a bar coater, a roll coater, an air knife coater, a U comma coater, an AKKU coater, a smoothing coater, a microgravure coater, and a reverse coater. Roll coater, 4 or 5 (multistage) roll coater, curtain coater, blade coater, dip coater, drop curtain coater, slide coater, lip coater, die coater, squeeze coater, short dwell coater, size press,
Various devices such as sprays can be used on-machine or off-machine.

The method for printing and recording on the recording sheet of the present invention is not limited by writing, printing, impact printing, electrophotography, thermal transfer, ink ribbon, ink jet, pressure sensitivity, laser printing, label bonding, and the like. . However, recording on the self-coloring pressure-sensitive recording layer after being integrated with the cover sheet is limited to a recording method involving color development by pressure. When recording on the self-coloring pressure-sensitive recording layer, it is possible to use an impact printer or a typewriter, or if it is necessary to record a large amount of the same information, it is also possible to record by letterpress printing is there. Also,
Recording with a ballpoint pen, iron brush, etc. is also possible.

On the front or back surface of the recording sheet of the present invention,
As long as it satisfies the specified Yrel value range, a pigment coating layer for improving writability and printability, a thermal transfer image receiving layer, an ink jet ink receiving layer, a thermosensitive recording layer, a reversible thermosensitive recording layer, a photosensitive recording layer, a magnetic recording layer, Various recording layers such as a recording layer can be provided.

The recording sheet of the present invention can be used as a series of copy sheets in combination with other pressure-sensitive recording sheets, back carbon copy sheets, adhesive sheets, printing sheets, transparent films and the like. Part of the pressure-bonded sheet of the present invention, or processing such as die cut to the whole, separation of a part of the support,
Processing of perforations, printer feed holes (sprocket holes), etc. may be performed at all.

The recording sheet of the present invention is capable of forming a self-coloring pressure-sensitive recording layer by pressurizing, and the color is formed on the upper cover sheet or the recording sheet provided as necessary. It is possible to read through layers or printed layers. Confirmation of the presence or absence of color development in the self-coloring pressure-sensitive recording layer is effective in preventing forgery for the purpose of verifying authenticity.

In the recording sheet of the present invention, since the self-coloring pressure-sensitive recording layer is protected inside the transparent paper, careless friction may occur during general handling or recording by another recording method. Also, there is no need to worry about coloring stains due to some bending or bending, not only high abrasion resistance, but also weather resistance of recording,
Excellent water resistance, oil resistance, etc., excellent printability and handleability,
Double feeding due to the unique electrification of laminated paper does not occur, making it easy to handle.

Also, it can be used in combination with various other known forgery prevention means such as micro letter printing, magnetic recording, a method using a hologram, a method using an ultraviolet light-emitting ink, etc. By combining with means, it is possible to achieve a higher degree of forgery prevention.

[0052]

Next, the present invention will be described in more detail by way of examples. Note that all parts and percentages shown below are based on weight. The value indicating the amount of smear is the amount of smear after drying unless otherwise specified.

<Preparation Example 1: Self-color-forming pressure-sensitive coating liquid> A microcapsule containing a color-forming agent used for pressure-sensitive recording was prepared as follows. First, 6 parts of crystal violet lactone was heated and dissolved in 114 parts of Hisol SAS N-296 (manufactured by Nippon Petrochemical Co., Ltd.) to obtain an internal phase oil. 12 parts of melamine and 28 parts of 37% formalin were heated together with 70 parts of water to obtain a melamine-formalin initial polycondensate.
Next, the internal phase oil was emulsified in 150 parts of a 6% aqueous solution of styrene / maleic anhydride copolymer, and the above-mentioned melamine-formalin polycondensate was added to this emulsion, and the liquid temperature was raised to 70 ° C.
For 3 hours to obtain a dispersion of microcapsules containing a color former having a melamine-formalin resin film. The average particle size of the obtained microcapsules was about 6 μm.

The coating solution for the self-coloring pressure-sensitive recording layer was prepared according to the following formulation. Microcapsules containing a color former 100 parts Developer (PR26298 manufactured by Sumitomo Durez Co., Ltd.) 50 parts Starch particles 230 parts Calcined kaolin 20 parts Polyvinyl alcohol 53 parts Calcium carbonate 40 parts Solid content concentration 24%

<Preparation Example 2: Self-color-forming pressure-sensitive coating liquid> After preparing a microcapsule containing a color-forming agent in the same manner as in Preparation Example 1, a coating liquid for a self-color-forming pressure-sensitive recording layer was prepared according to the following formulation. . Microcapsules containing a color former 80 parts Developer (PR26298 manufactured by Sumitomo Durez Co., Ltd.) 50 parts Starch particles 250 parts Calcined kaolin 10 parts Polyvinyl alcohol 58 parts Calcium carbonate 25 parts Solid content concentration 24% The formulation of Preparation Example 2 Was designed to have a lower pressure-sensitive coloring sensitivity than the formulation of Preparation Example 1.

Example 1 As a covering sheet, tracing paper (50 g / m
² ) using the self-coloring pressure-sensitive coating liquid of the formulation of Preparation Example 1
Coating and drying were performed so that the dry coating amount was 5 g / m ² to obtain a coated sheet having a self-coloring pressure-sensitive recording layer. next,
A2 coated paper (105 g / m ² ) was used as a support,
The support and the coated sheet having the self-coloring pressure-sensitive recording layer were subjected to corona treatment, and then integrated by melt extrusion so that the self-coloring pressure-sensitive recording layer was in contact with the thermoplastic resin layer. As the thermoplastic resin, low-density polyethylene (density 0.924) was used, and the weight of the thermoplastic resin layer was 15 g / m ² . Subsequently, a coating liquid having the following composition was applied and dried on the tracing paper surface of the integrated sheet so that the dry coating amount was 8 g / m ² , to obtain a target recording sheet. Primary kaolin 70 parts Calcium carbonate 20 parts Silica 10 parts Phosphated ester starch 10 parts Styrene / butadiene copolymer latex 5 parts Solids concentration 35% Yrel value when a surface pressure of 5 kgf / cm ² is applied is 0.
99, the Yrel value was 0.57 when a linear pressure of 10 kg / cm was applied with a chilled roll.

Example 2 As a covering sheet, tracing paper (95 g / m
² ) using the self-coloring pressure-sensitive coating liquid of the formulation of Preparation Example 2
Coating and drying were performed so that the dry coating amount was 3 g / m ² to obtain a coated sheet having a self-coloring pressure-sensitive recording layer. next,
A2 coated paper (105 g / m ² ) was used as a support,
The support and the coated sheet having the self-coloring pressure-sensitive recording layer were subjected to a corona treatment, and then integrated with a thermoplastic resin in the same manner as in Example 1 to obtain a target recording sheet. The Yrel value when applying a surface pressure of 5 kgf / cm ² was 0.99, and the Yrel value when applying a linear pressure of 10 kg / cm with a chilled roll was 0.56.

Example 3 A typewriter paper (38 g /
m ² ), applying and drying the self-coloring pressure-sensitive coating liquid having the composition of Preparation Example 1 so that the dry coating amount is 5 g / m ² , to form a coated sheet having a self-coloring pressure-sensitive recording layer. Obtained. Next, using A2 coated paper (105 g / m ² ) as a support, the support and the covering sheet having the self-coloring pressure-sensitive recording layer were subjected to corona treatment, and then the same as in Example 1. The target recording sheet was obtained by integrating using a thermoplastic resin. Yre when applying a surface pressure of 5 kgf / cm ²
The l value was 1.00, and the Yrel value when a linear pressure of 10 kg / cm was applied with a chilled roll was 0.69.

Example 4 A high-quality paper (52 g / m ² ) was used as a covering sheet, and a self-coloring pressure-sensitive coating liquid having the composition of Preparation Example 1 was applied at a dry coating amount of 7%.
g / m ² and dried to obtain a coated sheet having a self-coloring pressure-sensitive recording layer. Next, A as a support
Using 2-coated paper (105 g / m ² ), the support and the above-mentioned coated sheet having a self-coloring pressure-sensitive recording layer were subjected to corona treatment, and then a thermoplastic resin was used in the same manner as in Example 1. Then, the desired recording sheet was obtained. 5kgf
/ Yrel value when multiplied by the surface pressure of cm ² is 1.00, Yr when multiplied by the linear pressure of 10kg / cm at chilled roll
The el value was 0.80.

Comparative Example 1 A2 coated paper (105 g / m ² ) was used as it was as recording paper. Yre when applying a surface pressure of 5 kgf / cm ²
The l value and the Yrel value when a linear pressure of 10 kg / cm was applied with a chilled roll were both 1.00.

Comparative Example 2 A commercially available self-coloring pressure-sensitive recording paper (Diaself Super N50 manufactured by Mitsubishi Paper Mills) was used as it was as a recording paper. 5k
The Yrel value when applying a surface pressure of gf / cm ² is 0.9.
8. The Yrel value when a linear pressure of 10 kg / cm was applied by a chilled roll was 0.52.

Comparative Example 3 Tracing paper (50 g / m
² ) using the self-coloring pressure-sensitive coating liquid of the formulation of Preparation Example 1
Coating and drying were performed so that the dry coating amount was 6 g / m ² to obtain a coated sheet having a self-coloring pressure-sensitive recording layer. next,
A2 coated paper (105 g / m ² ) was used as a support,
The support and the covering sheet having the self-coloring pressure-sensitive recording layer were subjected to corona treatment, and then integrated with a thermoplastic resin in the same manner as in Example 1 to obtain a recording sheet. 5k
The Yrel value when applying a surface pressure of gf / cm ² is 0.9.
8. The Yrel value was 0.57 when a linear pressure of 10 kg / cm was applied by a chilled roll.

Comparative Example 4 A recording sheet was obtained in the same manner as in Example 3 except that the composition of the self-coloring pressure-sensitive coating solution was changed from Preparation Example 1 to Preparation Example 2. The Yrel value when applying a surface pressure of 5 kgf / cm ² was 1.00, and the Yrel value when applying a linear pressure of 10 kg / cm with a chilled roll was 0.83.

COMPARATIVE EXAMPLE 5 The coated sheet was changed from a high quality paper of 52 g / m ² to a high quality paper of 105 g / m ^2.
It was replaced m ^2, thereby obtaining the recording sheet in the same manner as in Example 4. Yrel when applying a surface pressure of 5 kgf / cm ²
The value was 1.00, and the Yrel value when a linear pressure of 10 kg / cm was applied with a chilled roll was 0.95.

The recording sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were evaluated by the following methods. Table 1 shows the results
It was shown to.

<Measurement of Yrel value> The surface pressure and the Y value before and after applying the linear pressure were measured, and the
Values were calculated. For surface pressing, a heat seal tester manufactured by Tester Sangyo (5 kg / m ² , 1 minute) was used, and for linear pressing, a Yuri roll machine calendar (10 kg / m, 3 m / min) was used. For the measurement of the Y value, a color difference meter manufactured by Nippon Denshoku was used.

<Pressure-sensitive color development> An electric type writer (Olivetti LETTERA 39E) in which an ink ribbon is not attached to the recording sheets obtained in Examples and Comparative Examples.
C) was used to print 100 characters. The percentage of characters that are difficult to read due to poor coloring, blurring, discontinuity, etc., is shown as a printing failure rate (%; the smaller the value, the better).

<Scratch Resistance> The recording surface (coated sheet side) of the recording sheet obtained in each of Examples and Comparative Examples was strongly rubbed five times with a plastic eraser, and the degree of rubbing stain was evaluated by measuring the optical density difference before and after rubbing. (The smaller the difference, the better). Optical density was measured using a Macbeth RD918 reflection densitometer.

<Impact Resistance> A steel ball was allowed to fall freely from above the recording sheets obtained in the examples and comparative examples, and the drop starting height at which color stain due to impact was recognized on the recording sheets was measured. The higher the drop starting height is, the better the impact resistance is. When the drop starting height is 100 mm or more, it is excellent, 70 m
good if m or more and less than 100 mm, 40 mm or more and 70 m
The case where it was less than m was judged to be inferior when it was less than 40 mm.

<Anti-counterfeiting property> A dot impact printer in which a color image is provided on the recording surface (covered sheet side) of the recording sheet obtained in each of Examples and Comparative Examples using a color copier and no ink ribbon is attached. Printing was performed by using. If the color image and the pressure-sensitive coloring overlap, the pressure-sensitive coloring can be read, and the anti-counterfeiting evaluation is excellent.If the color image and the pressure-sensitive coloring overlap, the pressure-sensitive coloring cannot be read in that part, Good when the pressure-sensitive coloring is clearly readable in the part where there is no color image, and when the pressure-sensitive coloring is slightly lighter but the part without the color image can be confirmed to be pressure-sensitive coloring. The case where it could not be confirmed was judged as poor, and the case where it could not be confirmed at all was judged as unacceptable.

<Copyability> One sheet of high-quality paper is sandwiched between the covering sheets of the recording sheets obtained in the examples and comparative examples, and a dot impact printer (OKI MICRO) is placed on the sheet.
LINE 5320SV) to print 100 characters. The percentage of characters that are difficult to read due to poor coloring, blurring, discontinuity, etc., is calculated as the copy failure rate (%; the smaller the value, the better)
As shown.

[0072]

[Table 1]

Evaluation: The recording sheets obtained in Examples 1 to 4 had a Yrel value of 0.99 to 1.00 when a surface pressure of 5 kgf / cm ² was applied, and a chilled roll of 10 kg / cm ^2.
The Yrel value is less than 0.81 when a linear pressure of 1 cm is applied, and has a good balance of pressure-sensitive color development, copyability, abrasion resistance, impact resistance, and forgery prevention. Therefore, it can be used as a self-coloring type pressure-sensitive recording sheet,
Utilization of pressure-sensitive coloring allows easy determination of authenticity. Also, the risk of unnecessarily developing color during handling is quite small.

On the other hand, Comparative Example 1 does not have a pressure-sensitive color-developing property, copying property, and anti-counterfeit property because it does not have a self-coloring pressure-sensitive recording layer. Further, Comparative Example 2 is a normal self-coloring pressure-sensitive recording paper itself, and thus is inferior in abrasion resistance and impact resistance.

Comparative Example 3 has a Yrel value of less than 0.99 when a surface pressure is applied, and is inferior in abrasion resistance and impact resistance as in Comparative Example 2. In Comparative Example 4, Yr when a linear pressure was applied
The el value was 0.81 or more, and the pressure-sensitive coloring property and copyability were poor, and the impact resistance was also poor. Comparative Example 5 also had a Yrel value of 0.95 when a linear pressure was applied, and 0.85.
It was not less than 1, and the pressure-sensitive coloring property and the copying property were considerably inferior, and the anti-counterfeiting property was also inferior.

[0076]

The recording sheet of the present invention comprises a support, a thermoplastic resin layer, a self-coloring pressure-sensitive recording layer, and a cover sheet, which are laminated to each other when a surface pressure and a linear pressure are applied.
By defining the l-value (color-forming property), the balance between pressure-sensitive coloring property and abrasion resistance (impact resistance) is excellent. By performing pressure printing on the recording sheet of the present invention, the self-coloring pressure-sensitive recording layer can be colored, and the coloring can be confirmed through the cover sheet. The self-coloring pressure-sensitive recording layer is protected inside the support and the cover sheet, and there is little fear of color stain due to careless friction or impact. Further, the recording sheet of the present invention can be used as forgery prevention paper. Documents, tickets, cash vouchers, etc. are usually
Regardless of whether it is a genuine or forged ticket, it does not have pressure-sensitive coloring properties, and it is difficult to judge authenticity if elaborate forgery is performed.However, printing the recording sheet of the present invention on documents, tickets, bills, etc. By using it as a base paper, counterfeiting can be easily detected by printing a part with pressure-sensitive color after printing. Further, the recording sheet of the present invention is not only a recording sheet for preventing forgery,
It can be used for many purposes such as continuous slips, pasted slips, labels, general-purpose recording paper, tickets, and dust-free recording paper, and is of great industrial significance.

[Brief description of the drawings]

FIG. 1 is a sectional view of a recording sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support body 2 Thermoplastic resin layer 3 Self-coloring pressure-sensitive recording layer 4 Covering sheet 5 Recording sheet of this invention

Claims (2)

[Claims] At least one of a support, a thermoplastic resin layer, a color former or a color developer is microencapsulated, and each of them is laminated or mixed alone to form a single-layer self-coloring pressure-sensitive recording layer, a coating sheet, 5k
The Yrel value shown by the following formula 1 when a surface pressure of gf / cm ² is applied is 0.99 to 1.00, and the Yrel value is shown by the following formula 1 when a linear pressure of 10 kg / cm is applied by a chilled roll. A self-coloring type pressure-sensitive recording sheet having a Yrel value of less than 0.81. (Equation 1) Yrel = Yf / Yi Yrel: ratio of Y value of sheet pressing portion before and after pressing Yf: Y value of sheet pressing portion after pressing Yi: Y of sheet before pressing Value Here, the Y value means the Y value of the tristimulus values X, Y, and Z of the object color in the CIE (XYZ) color system. 2. A forgery prevention sheet using the self-coloring type pressure-sensitive recording sheet according to claim 1, wherein forgery prevention or forgery detection can be performed by pressure-sensitive coloring.