WO2009110580A1 - Invisible-information-printed sheet - Google Patents

Abstract

An invisible-information-printed sheet which comprises a support and a printed part formed thereon using an ink for color development through scratching which comprises a dye precursor, an electron-accepting color developer, and a varnish. The invisible-information-printed sheet is characterized in that the support is a coated support having a pigment coating layer comprising a pigment and a binder and formed in an amount of 0.5-6.5 g/m² on the surface on the side where the printed part is to be formed using the ink for color development through scratching.

Description

 Specification

Title of invention

 Invisible information printing sheet Technical Field

[0001]

 The present invention relates to an invisible information printing sheet that visualizes invisible information that has been printed in advance by developing a color by physical or chemical action. Background art

 [0002]

 As an invisible information printing sheet, for example, a scratch lot application is known. They are generally invisible information printing sheets that print information such as letters, numbers, and other patterns that indicate a failure on a sheet of paper or the like, and that are covered with a concealing layer to make the information invisible. Specifically, after printing visible information, etc. on a sheet of paper, etc., and further printing information to be invisible, a release agent layer is provided to cover the information to be invisible, and a concealing silver color is provided thereon. It is used in such a way that invisible information appears by scraping it off with a coin or the like.

 However, there is a drawback that the scrap generated when removing the above scratch ink becomes garbage, and the use and place where it is used are limited. In addition, the color of the scratch ink is dark, and it tends to be dark and easily causes a design problem.

[0003]

In order to solve the above problems, it is possible to easily generate invisible information without using a concealing scratch ink, and to suppress the generation of scraps, and it contains colorless or light-colored electron-donating dye precursors and varnishes. It was obtained by mixing an electron-donating dye precursor ink base for scratch coloring and an electron-accepting head dye sink base for scratch coloring containing an electron-accepting developer and varnish separately with a dryer. Scrap that is characterized by Ink-coloring inks and invisible information printing sheets using them have been proposed (see, for example, Japanese Patent Publication No. 2000-0619). Invisible information before color development cannot be seen at all with normal size letters or numbers, but it can also handle larger letters and patterns, or further increase color density while maintaining invisibility. Is required.

[0004]

 In addition, the use of invisible information printing sheets includes authenticity determination. In this case, the color is developed by heat or by scratching (see, for example, Japanese Patent Application Laid-Open No. 2 0 06-2 9 0 9 75). It has been demanded. Summary of the Invention

Problems to be solved by the invention

[0005]

 Even invisible information such as large characters is not visible, and the invisible information printed part is difficult to develop by rubbing during normal handling, and invisible information can be easily visualized by simply rubbing with a nail, making invisible information visible It is to provide an invisible information printing sheet that is free from shavings and can produce a clear color image, especially when visualized. Means for solving the problem

[0006]

As a result of intensive studies by the present inventors, a printing portion using a color developing ink containing a colorless or light-colored electron-donating dye precursor, an electron-accepting developer, and a varnish is provided on the support. In the invisible information printing sheet, the support contains a pigment and a binder on the side on which the printing portion using the scratch coloring ink is provided, and the coating amount is 0.5 g / m ^{2 to} 6 It was found that the above-mentioned problems can be solved by using a coating support provided with a pigment coating layer of 5 g Zm ² .

[0007]

That is, the present invention (1) In an invisible information printing sheet in which a printing portion using a scratch coloring ink containing a dye precursor, an electron-accepting developer and a varnish is provided on a support, the support has a scratch coloring. Coating with a pigment coating layer containing pigment and binder on the side where the printing part using the ink sink is to be provided, and having a coating amount of 0.5 gZm ² to 6.5 _g m ² An invisible information printing sheet characterized by being a support,

(2) The invisible information printing sheet according to (1) above, wherein the coating amount of the pigment coating layer is 0.5 gZm ^{2 to} 6. O g / m ² .

 (3) In the pigment coating layer, the mass ratio of the pigment to the binder is 5 to 30 parts by mass of the binder with respect to 100 parts by mass of the pigment. The invisible according to any one of the above (1) and (2) Information printing sheet,

 (4) The pigment according to any one of the above (1) to (3), wherein the pigment is at least one selected from kaolin clay, calcined clay, light calcium carbonate, heavy calcium carbonate, aluminum hydroxide, and talc. Invisible information printing sheet,

 (5) The invisible information printing sheet according to any one of (1) to (4), wherein the Mohs hardness of the pigment is 3.5 or less,

 (6) The invisible information printing sheet according to any one of (1) to (5), wherein the pigment has an average particle diameter of 0.02 to 5 im.

 (7) The invisible information printing sheet according to any one of (1) to (6) above, wherein the smoothness smoothness of the coating support is 1.0 to 8 5.0 kPa, and

(8) The invisible information printing sheet according to any one of the above (1) to (7), wherein the basis weight of the base material for pigment coating is 40 to 450 g / m ² ,

Is to provide. The invention's effect

[0008]

The invisible information printing sheet of the present invention makes it possible to visualize invisible information clearly even by rubbing with a nail, hardly causes coloring stains due to rubbing during normal handling, no generation of shavings, and further coloring The invisibility in the previous state is also good. BEST MODE FOR CARRYING OUT THE INVENTION

[0009]

 Hereinafter, the invisible information printing sheet of the present invention will be described more specifically.

The present invention contains a colorless or light-colored electron-donating dye precursor (hereinafter abbreviated as a dye precursor), an electron-accepting developer (hereinafter abbreviated as a head colorant), and a varnish on a support. In the invisible information printing sheet provided with a printing portion using a scratch coloring ink, the support contains a pigment and a binder on the surface on which the printing portion using the scratch coloring ink is provided, An invisible information printing sheet, which is a coating support provided with a pigment coating layer having a coating amount of 0.5 g Zm ^{2 to} 6.5 g Zm ² .

[0010]

The invisible information printed sheet of the present invention, as a support contains a pigment and a binder, coating E the amount ^{0. 5 g Zm 2 ~6.} 5 coating having a pigment coating layer is g Zm ² A support is used. The printed portion using the scratch coloring ink is provided on the surface on which the pigment coating layer is provided. When printing parts with scratch coloring ink are provided on both sides of the support, double-sided coating support with a pigment coating layer of 0.5 g Zm ^{2 to} 6.5 g / m ² on each side. When the body is used, the effect of the present invention is preferably obtained on both sides. Paper is readily available as a base material for pigment coating. Other preferred base materials include various woven fabrics, non-woven fabrics, synthetic resin films, synthetic resin laminated papers, synthetic papers, metal foils, vapor-deposited sheets, or composite sheets obtained by combining them together. Can be mentioned. The coating support or its substrate may contain a fluorescent whitening agent, an ultraviolet absorber, an antioxidant, etc. as necessary. As the ultraviolet absorber and the antioxidant, a scratch coloring ink, which will be described later, is used. Examples include those that may be included as needed.

In addition, when a printed part with scratch coloring ink is provided on one side of the support, on the opposite side, if necessary, a thermal recording layer, a dye precursor-encapsulated microcapsule containing layer for pressure-sensitive copying , Fixing layer for ink jet recording, magnetic recording layer, adhesive layer, resin coating layer, face A coating layer or the like may be provided.

[0011]

Further, in the present invention, when a coating support is used, the appearance and opacity are good, and the scratching property (ease of rubbing), the coloring property (coloring sensitivity) and the color density due to scratching are improved, and when handling. This is preferable because the coloring stain of the color is improved. However, there was a drawback that even the printed part before scratch coloring was visually obscured and the invisibility was slightly worse. In order to maintain the invisibility at a high level, it was necessary to sacrifice other advantages such as lowering the color density. However, by making the coating amount 6.5 g / m ² or less, preferably 6.0 gZm ² or less, not only the invisibility can be remarkably improved, but also the color density can be kept remarkably high. It was. Even if this upper limit value is slightly exceeded, the effect of the present invention is hardly obtained. On the other hand, if the coating amount is less than 0.5 gZm ² , the production of the coating support cannot be performed stably. If more stabilization is desired, it is preferably 2. O g / m ² or more, more preferably 2.5 gZm ² or more, and the above-described opacity and scratching properties of the coating support are also preferable. Kept. Therefore, in the present invention, the coating amount is limited to 0.5 g, m ^{2 to} 6.5 gZm ² , preferably 0.5 g Zm ² to 6.0 g / m, and more preferably 2. O g / m ^{2 to} 6.0 g, particularly preferably ^2.5 g / m ^{2 to} 6. O gZm. It is difficult to predict from the known knowledge of commercial printing coating supports, etc., that a coating support in such a narrow coating amount range is used for the invisible information printing sheet to increase the preferable effect.

[0012]

 In the pigment coating layer, the mass ratio of the pigment and the binder is 5 to 30 parts by mass, more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the pigment.

It was found preferable because (ease of rubbing), color developability (color development sensitivity) and color density due to scratches are improved, and color stains during handling are also improved. If the mass ratio of the binder is less than the preferred range, the coating layer may be peeled off by scratches and white powder may be generated. Also, part of the coating layer is peeled off during printing, causing problems such as blanket stains. On the other hand, when the mass ratio of the binder is larger than the preferable range, the adhesion state of the scratch coloring ink to the pigment coating layer may be deteriorated during printing. Especially, film formation on the surface If there is, there is a risk that the infiltration of the ink will worsen and the invisibility will decrease.

[0013]

 The pigments contained in the pigment coating layer include kaolin clay, diatomaceous earth, tanolec, calcined clay, light calcium carbonate, heavy calcium carbonate, precipitated calcium carbonate, light magnesium carbonate, heavy magnesium carbonate, chalk, oxidation Inorganic pigments such as zinc, aluminum oxide, aluminum hydroxide, magnesium hydroxide, titanium dioxide, barium sulfate, zinc sulfate, amorphous silica, amorphous calcium silicate, gas phase method silica, colloidal silica, and alumina And one or more selected from organic pigments such as melamine resin filler, urea-formalin resin filler, polyethylene powder, nylon powder, and starch. Usually, a white pigment is used, but a colored pigment may be used.

[0014]

 It is preferable that the Mohs hardness of the pigment contained in the pigment coating layer is low. If the Mohs hardness is 4 or less, more preferably 3.5 or less, it is preferable that the portions other than the invisible information printing portion are not darkened at the time of scratch coloring using a coin. In particular, at least one selected from kaolin clay, calcined clay, light calcium carbonate, heavy calcium carbonate, aluminum hydroxide, and talc is preferable from the balance of coating suitability, color developability, and invisibility. . However, pigments with a Mohs hardness of 4 or more may be used to leave a trace of scratches from coins.

 [0015]

Binders used in the pigment coating layer include starches, hydroxymethyl cellulose, methyl cellulose, ethyl cellulose, canoleoxy methino cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, soda alginate, polyvinyl Pyrrolidone, polyacrylamide, acrylic amide Z acrylate ester copolymer, acrylamide Z acrylate ester Z methacrylic acid terpolymer, polyacrylic acid alkali salt, polymaleic acid alkali salt A water-soluble binder such as an alkali salt of a styrene maleic anhydride copolymer, an alkali salt of an ethylene / maleic anhydride copolymer, an alkali salt of an isobutylene maleic anhydride copolymer, and a styrene Z butadiene copolymer, Acrylo Nitrilunobutadiene copolymer, Methyl acrylate / butadiene copolymer, Atalylonitrile / butadiene / styrene terpolymer, Polyacetate butyl acetate, Bierno acrylate acetate copolymer, Ethylene / vinyl acetate copolymer 1 type or more chosen from water-dispersible binders, such as a coalescence, a polyacrylic acid ester, a styrene Z acrylic acid ester copolymer, and a polyurethane.

 [0016]

 In the case of a coating support, the glossiness can be adjusted widely. For example, when it is desired to reduce the glossiness, it can be achieved by using a pigment having a large average particle diameter in the pigment coating layer or increasing the pigment content ratio. However, if the average particle size of the pigment is too large, the surface on which the scratch coloring ink is printed becomes rough, and the printed information tends to be unclear. Conversely, when it is desired to increase the glossiness, it can be achieved by reducing the average particle size of the pigment, but it is difficult to obtain an extremely small average particle size. The average particle size of the preferred pigment is 0.02 to 5 / zm, more preferably 0.3 to 4 / zm.

 Also, the glossiness can be adjusted depending on the processing conditions by surface treatment of the pigment coating layer, for example, super calender, soft calender, etc.

 When invisibility is particularly important, it is preferable to reduce the smoothness of the coating support. Smoother smoothness of 1.0 k Pa or higher, more preferably 10 K. Pa or higher, especially 30. O K Pa or higher is preferable in terms of invisibility. In addition, smooth smoothness of 85.O k Pa or less, more preferably 80.O k Pa or less, and particularly 75.0 k Pa or less is preferable because of less printing unevenness. Smoother smoothness measurement may be performed on the coated support before printing, or after various printings to form an invisible information printed sheet. In the case of a double-sided coating support, the surface to be measured is the surface on which the scratch coloring ink is provided.

[0017]

In many cases, paper is used as the base material for pigment coating. There are no particular restrictions on the thickness or basis weight of the paper as the base material, but from the viewpoint of ease of handling, such as being hard to tear when wrinkled on the printed part using the scratch coloring ink, or not wrinkling, The basis weight is preferably 40 gZm ² or more, more preferably 60 gZm ² or more, and still more preferably 80 gZm ² or more. There is no particular upper limit to the basis weight, and paperboard may be used as the base material. Paperboard with a pigment coating layer For example, it is easy to obtain as white paperboard. However, when the invisible information printing sheet of the present invention is used in the form of a card or a package, the basis weight of the substrate is usually 4500 g / m ² or less, particularly 3500 g Zm ² or less, Furthermore, it is preferable that it is ² 50 g Zm ² or less because it is not bulky.

[0018]

 Wood pulp used for paper as a base material includes kraft pulp obtained from hardwood and softwood, alkali pulp, sulfite pulp, and other chemical pulp, semi-chemical pulp, semi-mechanical pulp, mechanical pulp, and the like. Waste paper pulp that has undergone dust removal and deinking processes can also be used. Using these, high-quality paper and medium-quality paper are manufactured and used by a paper machine, but some physical strength is required because they are rubbed with nails and coins.

[0019]

 If necessary, the paper as the base material may contain a filler, a sizing agent, a paper strength enhancer and the like. The filler is not particularly limited, and white pigments such as tanolec, clay, calcined clay, calcium carbonate, and amorphous silica can be used, and these can be used in combination.

[0020]

 Since a pigment coating layer is provided on paper as a base material, a sizing agent is usually not used in many cases. When used, the sizing agent is not particularly limited. For acidic paper and neutral paper mainly composed of neutral rosin, alkyl ketene dimer, alkenyl succinic anhydride or petroleum resin, which are generally used as internal sizing agents. These sizing agents can be used as appropriate.

[0021]

 The scratch coloring ink used in the present invention contains a dye precursor, a developer and a varnish. In order for the dye precursor and the developer to be substantially uncolored, it is more preferable that each of them be contained as a solid particle in the scratch coloring ink.

 The components contained in the scratch coloring ink will be described. The dye precursor contained in the scratch coloring ink used in the present invention is typically represented by a pressure-sensitive recording material or a heat-sensitive recording material, but is not particularly limited.

[0022]

As an example of a specific dye precursor, (1) Triarylmethane compounds or compounds having an indolyl group: 3, 3-bis (4 —dimethylaminophenyl) ― 6-dimethylaminophthalide (crystal violet tracton), 3, 3-bis (4-Dimethylaminophenyl) phthalide, 3- (4-Dimethylaminophenyl) 1 3- (1,2-Dimethylindole-3-yl) phthalide, 3- (4-Dimethylaminophenyl) 1 3 — (2—Methylindole 1- 3-yl) phthalide, 3—

(4-Dimethylaminophenyl) 1 3- (2-Phenylindole-3-yl) Phthalide, 3, 3-bis (1,2-Dimethylindole-3-yl) 15-Dimethyl Minophthalide, 3,3-bis (1,2-dimethylindole-3-yl) 1-6-dimethylaminophthalide, 3,3-bis (1-butyl-1,2-methylindole-3-yl ) Phthalide, 3, 3-bis

(9-Ethylcarbazol-3-yl) _ 5-Dimethylaminophthalide, 3,3-bis (2-phenylindiol-3-yl) 15-Dimethylaminophthalide, 3- (4 —Dimethylaminophenyl) 1 3— (1-Methylpyrrole 1 2-yl) 1 6-Dimethylaminophthalide, 3— (1-Ethyl 2 _Methylindole— 3—yl) 1 3— (2 —Ethoxy 1-4-1 dimethylaminophenyl) 1-azaphthalide, 3 -— (1-Ethyl 1-2-Methylindole 3-yl) 1- 3— (2-Ethoxy-1-4-ethynoleaminophenyl) 1-4 Azaphthalide, etc.

[0023]

 (2) Diphenylmethane compounds: 4, 4 'monobis (dimethylaminophenyl) benzhydrylbenzyl ether, N—black phenenoreleucoolamine, N—2, 4, 5—trick Enilleucooramine, etc.

 [0024]

(3) Xanthene compounds: Rhodamine B anilinolactam, Rhodamine B—p-chloroanilinolactam, 3-jetylamino-7-dibenzylaminofluorane, 3-jetylamino _7-octylaminofluorane, 3-jetylamino 7-Phenylfluorane, 3-Detylamino-1, 7-Black fluoran, 3-Detylamino-6-Black, 7-Methylfluorane, 3-Detylamino-1, 7- (3,4-Dichloroanilino) fluorane, 3-Jetylamino 1 7- (2-Chloroanilino) fluorane, 3-Jetylami 1-6-methyl-7-ayurinofluorane, 3-dibutylamino 6-methyl-7-anilinofluorane, 3-dipentylamino-1, 6-methyl-1-7-anilinofluorane, 3- (N-ethyl) 1-N-p-tolyl) Amino-6-methyl-1-7-anilinofluorane, 3-piperidino-1-6-methyl-1-7-anilinofluorane, 3-- (N-ethyl-N-p-tolyl) amino 1-6-Methinoleol 7-Phenenolenoleolane, 3-Gethinoreamino-7- (4-Nitrore dilino) fluorane, 3-Dibutylamino-6-methyl-7-anilinofluorane, 3- (N-methyl-1-N-propyl) amino-6-methyl-7-anilinofluorane, 3— (N-ethyl-1-N-isoamyl) amino-6-methyl-1-7-anilinofluorane, 3-— (N — Methyl 1-N-cyclohexyl) Amino 1 6— Tilu 7-anilinofluorane, 3— (N—ethyl-1-N-tetrahydrofurofololefuryl) amino-6-methyl-7-anilinofluorane, 3,6-dimethoxyfunoleolane, 3-cyclohexinoleamino 1 6 —Chlorofunoleolane, etc.

[0025]

 (4) Thiazine compounds: Benzylleucomethylene Blue, 4-Nitrobenzoyl Methyl Blue, etc.

 [0026]

 (5) Spiro compounds and other compounds: 3-methylspirodinaphthopyran, 3-ethylspirodinaphthoviran, 3,3'-dichlorospirodinaphthoviran, 3-benzil spirodinaphthoviran, 3 —Methylnaphtho (3-methoxybenzo) spiropyran, 3-propylspirobenzopyran, 2,6-diphenyl 4- (4-dimethylaminophenyl) —pyridine, 2, 2-bis (4— (2— ( 4--Jetylaminophenyl) Quinazolyl) Oxyphenyl) Propane, 4—Black N- (4— (N— (4-Methylbenzyl) 1 N— Methylamino) Benzylidene) Anilin, 1 1 (2-Quinolyl) 1) 2- (3-Methoxy-4-dodecyloxyphenyl) ethene. These dye precursors can be used alone or in admixture of two or more as required. A xanthene compound is preferable from the viewpoint of discoloration prevention and color development sensitivity of the scratch coloring ink, and a triaryl methane compound or a compound having an indolyl group is also preferable because the color hue is vivid.

[0027] The developer contained in the scratch coloring ink used in the present invention is typically represented by an acidic substance used in a pressure-sensitive recording material or a heat-sensitive recording material, but is not limited thereto. For example, phenol derivatives, aromatic carboxylic acid derivatives, N, Ν'-diaryl thiourea derivatives, arylsulfonylurea derivatives, sulfonamide derivatives, polyvalent metal salts such as zinc salts of organic compounds, benzenesulfonamide derivatives, etc. Can be mentioned.

[0028]

 Specific examples include 4,4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenenolesnorephone, 4-hydroxyl-4'-isopropoxydiphenenolesnolephone, 4 -Hydroxy 1 4 '1 Penzinoreoxydiphenenolesnorephone, 4-Hydroxy 1 4' —Propoxydiphenylnerephone, Bis (3-Alinole 1-Hydroxyphenenole) Snorephone, 3, 4 Examples include diphenylsulfone compounds such as 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-benzenesulfonoxydiphenylsulfone, and 2,4-di (phenylsulfonyl) phenol. .

[0029]

Other specific examples include: 4-phenylphenol, 4-hydroxyacetophenone, 1,1-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) pentane, 1, 1-bis (4-hydroxyphenyl) hexane, 1, 1-bis (4-hydroxyphenyl) ^ cyclohexane, 2, 2-bis (4-hydroxyphenyl) propan, 2 , 2_bis (4-hydroxyphenenyl) hexane, 1, 1-bis (4-hydroxyphenenyl) 1 2-ethylhexyl, 2, 2-bis (3-chlorodiphenyl 4-hydroxyphenyl) Le) Puronoヽ⁰ emissions, 1, 1- bis (4-arsenate Dorokishifueniru) Single 1 one Fueniruetan, 1, 3 - bis [2- (4-arsenate Dorokishifueniru) one 2-propyl] benzene, 1, 3-bis [ 2 1 (3,4-dihydroxyphenyl) 1-Propyl] benzene, 1, 4-bis (2- (4-Hydroxyphenyl) 1-Propylbenzene, 4, 4'-Hydroxydiphenyl ethereol,

[0030]

3, 3 '-Dicrocus 4, 4'-Hydroxydiphenyl sulphide, 2, 2-bis (4 —Hydroxyphenyl) methyl acetate, 2,2-bis (4-hydroxyphenyl) butylacetate, 4, 4'-thiobis (2-tert-butyl-5-methylphenol),

 [0031]

 N- (2-hydroxyphenyl) benzenesulfonamide, N— (2-hydroxyphenoxy 2- / l) 1 p-tonoleens norephone amide, N— (2, 4-dihydroxyphenyl) benzene sulfonamide, N— (2,4-Dihydroxyphenyl) 1-p-toluenesulfonamide, N— (2-Hydroxynaphthyl) benzenesulfonamide, N— (2-Hydroxynaphthyl) 1-p-toluenesulfonamide, N— (2-Hydroxyphenyl) 1-Naphthalenesulfonamide, N— (2-Hydroxyphenyl) 1-2-Naphthalenesulfonamide, N- (2-Hydroxynaphthyl) 1-Naphthalenesulfonamide, N — (2-Hydroxynaphthyl) 1 2-Naphthalenesulfonamide, N— (2-Hydroxyphenyl) _p—Chlorobenzenesulfonamide, N— ( 2-Hydroxyphenyl) One p-Methoxybenzene snorephoneamide, N— (2-Hydroxyphene nitrile) One p-Alinole benzene snorephone amide, N- (2-Hydroxyphenyl) One p— Phenylolene senolephone amide, 4, 4 '— Bis (2-hydroxyphenylaminosulfonyl) diphenylmethane, N— (2-Hydroxyphenyl), N-methylolene senolephone amide, N— (2-Hydroxyphenyl) 1 N—Methyl _ p— Toluenesulfonamide, N— (2—Hydroxyphenyl) N— Benzinore p— Tonorrecens norephone amide, N— (2— (Hydroxyphene / Le) 1 N-ary. P-tonoreens norehon amide, N— (2-Hydroxyfenenole) 1 N-Phenolenobenzene sulphide amide,

[0032]

4-Hydroxyhydroxyphthalate, 4-Hydroxybenzyl benzoate, 4-Hydroxymethyl benzoate, Benzyl gallate, Stearyl gallate, N, N'-Diphenylthiourine, 4, 4'-Bis [3 — (4-Methylphenylsulfonyl) ureido] Diphenylmethan, N— (4-Methylphenylsulfonyl) — N ′ — Phenylurea, salicylanilide, 5-hydroxy-salicylanilide, salicylic acid, 3, 5-di- t-Butylsalicylic acid, 3, 5 —Di-α-methylbenzylsalicylic acid, 4— [2 '— (4-Methoxyphenoxy) ethyl Oxy] salicylic acid, 3- (octyloxycarbonylamino) salicylic acid or metal salts of these salicylic acid derivatives, N- (4-hydroxyphenyl) 1-p-toluenesulfonamide, N- (4-hydroxyphenyl) ) Benzenesulfonamide, N— (4-Hydroxyphenyl) 1 1 Naphthalenesulfonamide, N— (4-Hydroxyphenyl) 1 2-Naphthalenesulfonamide, N— (4-Hydroxynaphthyl) 1 p—Toluene sulphonamide, N— (4-Hydroxynaphthyl) benzenesulfonamide, N— (4-Hydroxynaphthyl) — 1—Naphthalenesulfonamide, N— (4-Hydroxynaphthyl) ) 1-Naphthalene norephone amide, N— (3-Hydroxyphenone) _ p—Tonoreens norehon amide, N— (3-Hide Kishifue two Norre) benzenesulfonic ^ Hon'ami de, N-(3- arsenate Dorokishifu Eniru) one 1-naphthalenesulfonic Ami de, N-(3- arsenate Dorokishifueniru) such as a single 2-naphthoquinone dripping down sulfonamidyl de like. In particular, diphenylsulfone compounds are preferred from the viewpoint of discoloration prevention and color development sensitivity of the scratch coloring ink.

[0033]

 The varnish contained in the scratch coloring ink used in the present invention contains a binder resin and, if necessary, an oil, a solvent and the like.

[0034]

 Specific examples of the binder resin contained in the varnish include, for example, natural resins such as rosin, natural resin derivatives such as cured rosin and rosin ester, alkyd resin, polyamide resin, acrylic resin, polychlorinated butyl, and polyacetic acid. Starting from unsaturated hydrocarbons such as vinyl, styrene resin, epoxy resin, cellulose derivative, phenol resin, rosin-modified phenol resin, xylene resin, melamine resin, urea resin, ketone resin, rosin-modified maleic acid resin, and olefin Examples include synthetic resins such as petroleum resins.

[0035]

 Specific examples of oils contained in the varnish as needed include vegetable oils such as Amani oil, rapeseed oil, pear oil, olive oil, soybean oil, tung oil, etc., and vegetable oils obtained by reprocessing them, Spindle oil Mineral oils such as machine oil and mobile oil.

In the present invention, the non-volatile organic liquid is called oil and the volatile organic liquid is called solvent. [0036]

Specific examples of the solvent contained in the varnish as necessary include, for example, aromatic solvents such as toluene and xylene, ester solvents such as ethyl acetate and isopropyl acetate, ketone solvents such as acetone and methylethyl ketone, methyl Examples thereof include alcohol solvents such as alcohol, isopropyl alcohol and _n- propyl alcohol, aliphatic hydrocarbons such as n-hexane, n-heptane and cyclohexane, and glycol solvents such as ethylene glycol and diethylene glycol.

 Petroleum solvents with an aromatic content of 1% by mass or less, mainly composed of paraffin and naphthenic compounds, are non-volatile, but they are contained as necessary, as with volatile solvents.

[0037]

 The scratch coloring ink used in the present invention may further contain various auxiliary agents. For example, dryers such as cobalt naphthenate and manganese octylate as drying accelerators, chelating agents commonly called aluminum chelates, adjusting agents such as petroleum-based solvents and varnishes that adjust the viscosity of the ink, and slip after printing Sensitizers such as waxes, surfactants, organic and inorganic fine particles, fatty acid amides, aliphatic urea compounds, ether compounds, ester compounds, biphenyl derivatives, etc., well known for heat-sensitive recording materials You may make it contain in order to raise a density | concentration.

[0038]

In the scratch coloring ink used in the present invention, the mass ratio (% by mass) of the developer to the dye precursor is preferably from 50 to 100% by mass from the viewpoint of stains and color developability of the printed part. ˜50% by weight is particularly preferred. Also, if the dye precursor and the developer are simultaneously added to the vehicle (varnish) in a predetermined ratio and kneaded, the dye precursor may develop color and cause ink coloring. It is preferable to sufficiently mix the ink in a predetermined ratio with an agitator or the like after ink conversion because it can reduce ink coloring due to contact between the dye precursor and the developer, etc., so that the printed portion is invisible. The type of vehicle (varnish) and the varnish content in the ink for scratch coloring vary depending on the printing method; preferably 10 to 90% by mass, more preferably 60 to 85% by mass of the scratch coloring ink. More preferably, it is appropriately selected in the range of 65 to 85% by mass. In addition, when the individual components are kneaded separately during the production of scratch coloring inks, these are called ink bases.

[0039]

 Preparation of the varnish in the scratch coloring ink used in the present invention may be performed by a conventionally known method. For example, a binder resin and, if necessary, components such as oil to be contained as necessary are heated and dissolved, and then as necessary. Obtained by adding a solvent, an aluminum chelating agent, and the like.

[0040]

 Next, a description will be given of a method for obtaining an invisible information print sheet. Ordinary printing may be performed on the invisible information printing sheet of the present invention. In this case, various printing inks can be used. However, it is also possible to use a coloring hue of the scratch coloring ink or a hue different from the hue of the support surface. If the color of the surface of the support is white and the color of the scratch coloring ink is black or blue, an ink having a high brightness such as yellow or orange is preferred.

[0041]

 To print the invisible information of the invisible information printing sheet of the present invention, it is produced using various printing methods such as offset printing, gravure printing, letterpress printing, etc., using the scratch coloring ink used in the present invention. From the viewpoint of accuracy and printability, it is particularly preferable to produce by offset printing. In the case of offset printing, the printing conditions may be the same as those for normal offset printing ink, and either a method using a dampening liquid or a method using a waterless lithographic plate may be used. The amount of printing of the scratch coloring ink is not particularly limited. Example

[0042]

 Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.

[0043]

 (Production example)

The following are examples of making varnish, each ink base, and scratch coloring ink. [0044]

 (Production of varnish)

 Amano oil 20 parts by weight as vegetable oil, rosin-modified phenol resin (mass average molecular weight 600 00, acid value 20 mg KOH g) 50 parts by weight, spindle oil 20 parts by weight, and heated at about 200 ° C for about 1 hour After dissolving the resin in this manner, 10 parts by weight of spindle oil and 1 part by weight of an anoleminum chelate agent were added and heated at about 180 ° C. for about 1 hour to prepare a varnish.

[0045]

 (Preparation of scratch-coloring dye precursor ink base (a))

 50 parts by weight of the above varnish, 3-dibutylamino-6-methyl-7-anilinofluorane 30 parts by weight, 5 parts by weight of spindle oil are kneaded in a three-roll mill, and 10 parts by weight of the above varnish, spindle Scratch coloring dye precursor ink base by adding 10 parts by mass of oil

(a) was produced.

[0046]

 (Preparation of color developer ink base for scratch coloring (b))

 50 parts by mass of the above varnish, 4-hydroxyl-4′-isopropoxydiphenylsulfone 30 parts by mass, spindle oil 5 parts by mass in a three-roll mill, the above varnish 10 parts by mass, spindle oil 10 Scratch color developing developer ink base (b) was prepared by adding parts by mass.

[0047]

 (Production of scratch coloring ink)

 The above two types of ink bases (a) and (b) are mixed at a mass ratio of 1: 2, respectively, and 0.2% by mass of the manganese naphthenate of the dryer is added to the total of the ink bases, and the mixture is thoroughly stirred. Scratch coloring ink was produced by qualification.

[0048]

 (Printing condition 1)

 The conditions for obtaining the invisible information printing sheet were determined under the following conditions.

Printing speed 1 50 m / min Supports Supports of Examples and Comparative Examples

 Humidifying liquid 5% by mass I P A— 0.2% by mass S EVENS TAR (manufactured by Dainichi Seika Kogyo)

 Used printing plate HPF 0.24mm (Fuji Film)

 Halftone line number, halftone dot angle, halftone dot shape (printing dot ratio is 50%)

 100 lines, 45 degrees, round

 Scratch coloring ink pattern

 Patterns described in each example and each comparative example

 Ink film thickness 1.4 zm

 Printing machine MVF-18D (Miyakoshi)

 [0049]

 (Example 1)

 (Preparation of coating support)

Using a pigment coating layer coating solution (A) having the following composition, roll rolls are coated on one side of a high-quality paper with a basis weight of 80 g / m ^{2 so} that the coating amount is 0.5 g / m ^{2 in the} dry state. The coating support was obtained by drying and coating with a coating calender. The smoother smoothness was adjusted to 85. O k Pa.

 Composition of pigment coating layer coating solution (A)

 Kaolin clay (average particle size 1.5 / im) 30 parts by mass

 Light calcium carbonate (average particle size 1.8 μιη) 70 parts by mass

 Phosphoric esterified starch 5 parts by mass

 10 parts by mass of styrene / butadiene latex

 (Preparation of pigment dispersion, coating liquid, and adjustment of coating liquid concentration were in accordance with standard methods.)

 (Production of invisible information printing sheet)

Using the scratch coloring ink obtained in the above preparation example on the coating layer surface of the resulting coating support, 1-digit Chinese numerals from 1 to 9 so that the ink film thickness is 0.6 m (24 Point, Gothic.) And triangle, square and circle geometric patterns (triangle, square and circle inside are also printed with ink. For example, in the case of a circle, the black design was designed to make the black circle visible by scratching, and offset printing was performed under the above printing condition 1 to obtain an invisible information printed sheet. The smoothness smoothness of the invisible information printed sheet was 8 5. O k Pa, which was not changed from before printing.

[0050]

 (Example 2)

An invisible information printed sheet was obtained in the same manner as in Example 1 except that the coating amount of the pigment coating layer was changed to 1.0 g / m ² in a dry state. The smoothness of the coated support was adjusted to 80.O k Pa.

[0051]

 (Example 3)

An invisible information printed sheet was obtained in the same manner as in Example 1 except that the coating amount of the pigment coating layer was changed to 2.0 g / m ² in a dry state. The smoothness and smoothness of the coating support was adjusted to 77.5 kPa.

[0052]

 (Example 4)

An invisible information printed sheet was obtained in the same manner as in Example 1 except that the coating amount of the pigment coating layer was changed to 3.0 gZm ² in a dry state. The smoothness of the coated support was adjusted to 1 8. O k Pa.

[0053]

 (Example 5)

An invisible information printed sheet was obtained in the same manner as in Example 1 except that the coating amount of the pigment coating layer was changed to 5.0 gZm ² in a dry state. The smoothness of the coated support was adjusted to 7 3 · O k Pa.

[0054]

 (Example 6)

Invisible information printing sheet as in Example 1, except that the roll coater used in Example 1 was changed to a blade coater and the coating amount of the pigment coating layer was changed to 6.0 gm ² in the dry state. The Obtained. The smoothness of the coated support was adjusted to 30.O k Pa.

[0055]

 (Example 7)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 6.5 g / m ² in a dry state. The smoothness of the coated support was adjusted to 23.O k Pa.

[0056]

 (Comparative Example 1)

 An invisible information printed sheet was obtained in the same manner as in Example 1 except that the high-quality paper of the base material was used as it was as the support without providing the pigment coating layer in Example 1. The smooth smoothness of the high-quality paper as the support was 90.O k Pa.

[0057]

 (Comparative Example 2)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 7.0 g / m ² in a dry state. The smoothness and smoothness of the coated support was adjusted to 1 8. O k Pa.

[0058]

 (Comparative Example 3)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 10.0 gZm ² in a dry state. The smooth smoothness of the coated support was adjusted to 1 3. O k Pa.

[0059]

 (Comparative Example 4)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 13.0 gZm ² in a dry state. The smooth smoothness of the coated support was adjusted to 1 1. O k Pa.

[0060] (Comparative Example 5)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 16.0 gZm ² in a dry state. The smoothing smoothness of the coating support was adjusted to 5.5 kPa.

[0061]

 (Comparative Example 6)

An invisible information printed sheet was obtained in the same manner as in Example 6 except that the coating amount of the pigment coating layer was changed to 19.0 g / m ² in a dry state. The smoothing smoothness of the coating support was adjusted to 0.9 kPa.

[0062]

 (Examples 8 to 1 3)

 An invisible information printed sheet was obtained in the same manner as in Example 5 except that the basis weight of the high-quality paper as the base material used in Example 5 was changed as follows. The fine paper basis weight as a base material of each Example is shown below. The smoothing smoothness of the coating support used in Examples 8 to 13 was 1 0.5 k.

Adjusted to become Pa.

 Example Basis weight of base paper

 Example 8 60

 Example 9 1 00

 Example 1 0 1 20

 Example 1 1 1 50

 Example 1 2 1 80

 Example 1 3 200

 [0063]

 (Example 14)

 The pigment coating layer coating solution (A) used in Example 5 was mixed with a pigment coating layer coating solution having the following composition (B) Kaolin clay (average particle diameter 1.5 μππι) 30 parts by mass

Light calcium carbonate (average particle size 1. 8 μ πι) 70 parts by mass Phosphate esterified starch 1. 7 parts by mass Styrene-butadiene-based latex An invisible information printing sheet was obtained in the same manner as in Example 5 except that the content was changed to 3.3 parts by mass.

[0064]

 (Example 15)

 The pigment coating layer coating solution (A) used in Example 5 was mixed with the pigment coating layer coating solution having the following composition (C) Kaolin clay (average particle size 1.5 μπι) 30 parts by weight light calcium carbonate ( (Average particle size 1.8 / m) 70 parts by mass Phosphate-esterified starch 3.4 parts by weight Styrene Butadiene latex Except for changing to 6.6 parts by weight, an invisible information printing sheet was obtained in the same manner as in Example 5. It was.

[0065]

 (Example 16)

 The pigment coating layer coating solution (A) used in Example 5 was converted into a pigment coating layer coating solution having the following composition (D) Kaolin clay (average particle size 1.5 / m) 30 parts by weight Light calcium carbonate (Average particle size 1.8 Aim) 70 parts by weight Phosphate esterified starch 6.8 parts by weight Styrene / butadiene latex 1 3.2 parts by weight Invisible information printing in the same manner as in Example 5 A sheet was obtained.

[0066]

 (Example 1 7)

The pigment coating layer coating solution (A) used in Example 5 was mixed with the pigment coating layer coating solution (E) kaolin clay (average particle size 1.5 / zm) 30 parts by weight of light calcium carbonate. (Average particle diameter 1.8 μπι) 70 parts by mass Phosphate esterified starch 10 parts by mass Styrene-butadiene latex was obtained in the same manner as in Example 5 to obtain an invisible information printed sheet except that the content was changed to 20 parts by mass. [0067]

 (Example 1 8)

 The pigment coating layer coating solution (A) used in Example 5 was replaced with a pigment coating layer coating solution (F) kaolin clay (average particle size 1.5 / zm) 15 parts by mass

 Firing cradle (average particle size 1 · 5 μm) 1 5 parts by mass

 Light calcium carbonate (average particle size 1.8 μm) 20 parts by mass

 Heavy calcium carbonate (average particle size 1. 8 μ τη) 20 parts by mass

 Talc (average particle size 1 · 8 μm) 20 parts by mass

 Aluminum hydroxide (average particle size 1.0 μm) 10 parts by mass

 Phosphate esterified starch 10 parts by mass

 Styrene Butagen-based latex 20 parts by mass

An invisible information printed sheet was obtained in the same manner as in Example 5 except that

[0068]

 (Example 1 9)

An invisible information printed sheet was obtained in the same manner as in Example 1 except that the coating support used in Example 1 was replaced with the product name Pearl Soft® manufactured by Mitsubishi Paper Industries. The base material of this support is medium paper. The coating amount in terms of one side was 5.0 gZm ² and the substrate basis weight was 1 1 7.9 g / m ² . The smoother smoothness of the surface used for printing was 73.6 kPa.

[0069]

 (Evaluation 1 Evaluation of invisibility of printed parts)

 The printed portions of the invisible information printed sheets obtained in Examples 1 to 19 and Comparative Examples 1 to 6 were evaluated in the following three stages by visual observation.

 ○ can not read the information at all.

 Δ indicates that the information cannot be read but the print portion exists.

 X is information visible.

◯ and are practical levels.

[0070] (Evaluation 2 Readability evaluation of printed parts)

 The printed portions of the invisible information printed sheets obtained in Examples 1 to 19 and Comparative Examples 1 to 6 were rubbed with nails, and the readability was evaluated in the following three stages.

 ○ is easy to read information.

 Δ indicates that the information can be read but is slightly unclear.

 X cannot read information.

○ and △ are practical levels.

[0071]

 (Evaluation 3 Ink flow evaluation of invisible information printing sheet)

 The printed portions of the invisible information printed sheets obtained in Examples 1 to 19 and Comparative Examples 1 to 6 and the unprinted portions around them were rubbed with 10 yen coins, and the following items were evaluated.

 〇 No colored ink flowed around the information.

 In △, colored ink flowed around the information, but there was no problem in reading the information.

 In X, colored ink flowed around the information, and troubles were observed in reading the information.

[0072]

 (Evaluation 4 Gloss change evaluation of invisible information printed sheet)

 The printed portion of the invisible information printing sheet obtained in Examples 1 to 19 and Comparative Examples 1 to 6 and the exposed portion of the support on the periphery thereof were rubbed with 10 yen coins, and the following items were evaluated.

 O was not noticeable because there was little or no change in gloss even when the exposed part of the support was rubbed.

In Δ, a change in gloss was observed when the exposed portion of the support was rubbed, but there was no problem in reading information.

 X was found to be difficult to read due to gloss changes when the exposed part of the support was rubbed.

 [0073]

 (Evaluation 5 Blackness evaluation of invisible information printed sheet)

 The printed portion of the invisible information printing sheet obtained in Examples 1 to 19 and Comparative Examples 1 to 6 and the exposed portion of the support on the periphery thereof were rubbed with 10 yen coins, and the following items were evaluated.

 ◯ was not noticeable even if the exposed part of the support was rubbed.

In Δ, darkening was observed when the exposed portion of the support was rubbed, but information reading was not hindered. When X was rubbed on the exposed part of the support, darkening of the information was observed.

In all of the above ink flow, gloss change, and darkening evaluation, ○ or Δ is a practical level. If any of Evaluations 3-5 is X, there is a problem in reading the information, so X was assigned for all Evaluations 3-5.

[0074]

 (Evaluation 6: Scratch strength evaluation of invisible information printed sheet)

 The printed portion of the invisible information printing sheet obtained in Examples 1 to 19 and Comparative Examples 1 to 6 and the exposed portion of the support on the periphery thereof were rubbed with 100 yen coins, and the following items were evaluated.

 ○: The sheet was not torn or the surface was not scratched even when rubbed strongly.

 △: If the sheet was rubbed strongly, the sheet was partially broken or the surface was fuzzy, but there was no problem in reading.

 When X was rubbed hard, the sheet was torn and the surface was scratched. There is a problem in reading.

In all scratch strength evaluations, ○ or Δ is a practical level.

 [0075]

The evaluation results are summarized in Table 1.

[0076]

 table 1

 Details of coating liquids (A), (B), (C), (D), (E), and (F) can be found in the texts of Examples 1, 14, 15, 16, 17, and 18, respectively. See

[0077]

(Reference printing conditions) On the supports used in Examples 1 to 19 and Comparative Examples 1 to 6, 2 were adopted in Example 1 respectively. Printing was carried out in the same manner as in Example 1 except that 4 points, instead of Gothic, 1 2 points, Gothic was used as a reference printing condition. As a result, there was no difference in invisibility and visibility between each example and each comparative example.

[0078]

 (Reference Printing test with printing ink)

 Except that SCRSOYTF ink (manufactured by Toyo Ink Manufacturing Co., Ltd.) was used as a commercially available black ink for offset printing on the supports used in Examples 1 to 19 and Comparative Examples 1 to 6, instead of scratch coloring ink. Printing was performed in the same manner as in printing condition 1. As a result, each of Examples and Comparative Examples 2 to 6 using a coated support had better appearance than Comparative Example 1 using fine paper as the support, and the appearance was better as the coating amount was larger. It was a trend. Industrial applicability

[0079]

 The invisible information printing sheet of the present invention can visualize invisible information without using special tools (coins, etc.) and has a good appearance. As an example of use, it does not stain children's hands and does not generate scraps, so it is particularly effective for use in vehicles and restaurants that handle food and drinks.

Claims

The scope of the claims [Claim 1] In an invisible information printing sheet in which a printing portion using a scratch coloring ink containing a dye precursor, an electron-accepting developer and a varnish is provided on a support, the support includes: , the surface on the side provided with printed portions using the scratch color ink contains a pigment and a binder, the coating amount is provided 0. 5 gZm ² ~6. pigment coating layer is 5 gZm ² coating An invisible information printing sheet characterized by being a work support. 2. The invisible information printing sheet according to claim 1, wherein the coating amount of the pigment coating layer is from 0.5 gZm ^{2 to} 6.0 g / m ² . 3. The invisible information printing according to claim 1, wherein in the pigment coating layer, the mass ratio of the pigment and the binder is 5 to 30 parts by mass of the binder with respect to 100 parts by mass of the pigment. Sheet. 4. The invisible pigment according to any one of claims 1 to 3, wherein the pigment is at least one selected from kaolin clay, calcined clay, light calcium carbonate, heavy calcium carbonate, aluminum hydroxide, and talc. Information printing sheet. 5. The invisible information printing sheet according to any one of claims 1 to 4, wherein the Mo hardness of the pigment is 3.5 or less. 6. The invisible information printing sheet according to any one of claims 1 to 5, wherein the pigment has an average particle diameter of 0.02 to 5 μπι. [Claim 7] The invisible information printing sheet according to any one of claims 1 to 6, wherein the smoothness of the coated support is 1.0 to 85. Claim 8. The basis weight of the substrate for pigment coating is 40-4508 ^ 1 ² Dearu, invisible information printed sheet according to any Re Izu of claims 1-7.