JPS621984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an ink composition for imparting a square pattern to prevent forgery on cash certificates such as stock certificates, checks, promissory notes, gift certificates, lottery tickets, commuter passes, train tickets, etc., or paper therefor. Regarding.

Conventionally, it has been widely practiced to add a squash pattern to the above-mentioned cash vouchers for the purpose of preventing forgery. One of the most common methods for this purpose is to
A method is known in which a pattern is attached to a dandy roll, a press roll, etc., and the paper thickness is made thinner (white watermark) or thicker (black watermark) to form a paper cut pattern (for example, Japanese Patent Publication No. 38-21801 is known). However, such methods have the following drawbacks: (1) The papermaking process becomes complicated and costs increase; (2) The paper thickness changes locally, which causes wrinkles when printing on sheets; Since a pattern is inserted, the positional relationship with the printed pattern during roll printing cannot be freely given. For this reason, when printing certain characters and symbols on checks, the quality of the print on the margin may deteriorate and cause misreading in automatic readers such as optical readers. d) Changes in paper thickness may cause feed failure to the automatic reader; e) The shape of the squash pattern is also subject to restrictions;
f) It has disadvantages such as being essentially suitable only for mass production.

On the other hand, there is also known a method of printing with a printing ink that uses boiled vegetable oil as the main material and blends non-boiled vegetable oil, animal oil, and mineral oil to create a squash pattern.
Publication No. 345). This method does not have the drawbacks of the above-mentioned method of adding a squash pattern by changing the paper thickness, and has the advantage that any shape can be freely selected, the production cost of the prototype is low, and a wide variety of products can be produced in small quantities. but,
Several problems have also been found in using the ink compositions described above. That is, (a) the squash pattern is not only created by simply printing the ink on the paper surface, but is created by penetrating the paper in the thickness direction, and since the above-mentioned ink composition is mainly composed of boiled vegetable oil, It takes a long time to penetrate the paper and dry. Particularly hard and dense paper has the disadvantage that a sufficient squeezing effect cannot be obtained.
b) If stored for a long period of time, it will turn yellow and become discolored due to moisture in the air and oxidation. C) Animal and vegetable oils that are not boiled will bleed between the paper fibers, causing the squash pattern to become unclear over time. d) The ink is highly oily throughout, and if you use a water-based pen, the oilyness of the markings will cause it to bleed, making it impossible to write on it. Therefore, considering this point, the shape of the squash pattern,
The size, position, etc. are restricted, and the effectiveness in preventing counterfeiting is halved.

An object of the present invention is to provide a method for imparting a squash pattern that improves the above-mentioned drawbacks. More specifically, the present invention is for use in a method of giving a scat pattern by printing, and for freely and clearly giving a scat pattern of any shape without causing bleeding or yellowing even after long-term storage. The purpose of the present invention is to provide a printing ink composition of the present invention. According to the present inventors, it has been discovered that such an object can be achieved by an ink composition containing a novel alkylbenzene-based solvent and a vehicle mainly composed of a resin soluble in the solvent. That is, the anti-counterfeiting ink composition of the present invention has the general formula (Here, R is an alkyl or alkylene group having 1 to 20 carbon atoms, X is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms, m is an integer of 0 to 5, and n is 1 or 2) It is characterized by containing an alkylbenzene solvent represented by the following and a resinous substance soluble in the solvent as main vehicles.

The above-mentioned alkylbenzene solvent is colorless and transparent and has excellent permeability and adhesion to paper fibers, so it provides an appropriate shaving effect, and is a stable substance with excellent chemical resistance such as acid resistance and alkali resistance, and excellent oxidation resistance. . In addition, it has solubility in a wide range of resinous substances, and the vehicle formed by dissolving the resinous substance penetrates and fixes between the fibers of paper, providing a stable squishing effect for a long period of time.

The present invention will be explained in more detail below.

The alkylbenzene solvent used in the present invention is represented by the above general formula, and includes an alkylbenzene with one benzene ring and a diarylalkane with two benzene rings.
Typical examples are trimethylbenzene, tetramethylbenzene, pentamethylbenzene, hexamethylbenzene, cymene, triethylbenzene,
Examples include butylbenzene, dodecylbenzene, diphenylthane, and the like.

These alkylbenzene solvents are
It is preferable to use it at a ratio of 40 to 99% (weight %, the same applies hereinafter). Other solvents can be used in combination, but these solvents have a 50%
% or less. Among the alkylbenzene-based solvents mentioned above, those having a boiling point in the range of 150°C to 400°C are particularly preferred from the viewpoint of printability and screening effect. If a large amount of low boiling point solvent is contained, it is not preferable because the squashing effect will be reduced during long-term storage. The viscosity of the composition is adjusted by adding a resinous substance, which will be described later, but since the solvent itself has an appropriate viscosity, it has a relatively low viscosity and good permeability, and alkylbenzene and a relatively viscous, squishy pattern. It is particularly preferable to use diarylalkane, which has the effect of suppressing bleeding, in combination.

Resin-like substances are added to preserve the squashing effect for a long period of time by fixing to paper fibers and retaining the solvent, as well as to prevent bleeding by suppressing the infiltration and diffusion of the solvent into the paper. and is arbitrarily selected from relatively transparent resinous substances that are soluble in alkylbenzene solvents. This resinous substance can generally be selected from natural resins, synthetic resins, synthetic rubbers, and celluloses, and may be solid or viscous liquid at room temperature. Typical examples include natural resins such as pine resin, hardened rosin obtained by saponifying pine resin with calcium, hydrogenated rosin, and ester gum, and residual oil obtained by extracting B, T, and X from the cracked oil of naphtha decomposition. Distillates between 150 and 250°C (C ₉ − such as vinyltoluene and alkylindene)
petroleum resins, alicyclic saturated hydrocarbon resins, styrene copolymer resins, ketone resins, phthalic acid resins, phenolic resins, maleic acid resins, alkyd resins, etc. obtained by polymerizing _C11 aromatic saturated compounds). Examples include synthetic resins, synthetic rubbers such as polybutadiene, cyclized rubber, and polybutene, celluloses such as ethyl cellulose, hydroxyethyl cellulose, and cellulose acetate butyrate, and castor oil, tung oil, linseed oil, soybean oil, modified alkyd resins, and polyterpene resins. Among them, petroleum resins, alicyclic saturated hydrocarbon resins, styrene copolymer resins, polyterpene resins and the like are most effectively used as they have little coloring property, have good adhesion to paper, and provide a stable squishing effect.

These resinous substances are present in the vehicle at 1 to 60%,
It is preferably used in a range of 5 to 40%. 1%
If the amount is less, the above-mentioned effect of addition will be poor, and if it is in excess, the permeability will be extremely inhibited and drying will be delayed, making it impossible to provide a stable squash pattern. From the viewpoint of preventing bleeding and printing suitability, the ink composition preferably has a viscosity in the range of 1 to 2000 poise at room temperature (25° C.).

The above resinous substance is heated at room temperature or 80 to 130℃.
The vehicle is prepared by dissolving in the alkylbenzene under heating to a temperature of about 100 ml.

The vehicle thus obtained can be used by itself as the ink composition of the present invention, and can be printed to give a white squash pattern. However, in order to further improve the anti-counterfeiting effect of the above-mentioned coupons, a coloring agent for erasing ink or a fluorescent whitening agent may be further added to the ink composition of the present invention.

A two-component ink eraser that uses a combination of two solutions, an oxalic acid aqueous solution and a sodium hypochlorite aqueous solution, is usually used as an ink eraser, but examples of coloring agents that develop color by reacting with such an ink eraser include: Thiazole compounds such as 2-aminobenzothiazole, 2-amino-6ethoxybenzothiazole, 2-aminodichlorobenzothiazole, 2-amino-6-methoxybenzothiazole and their sulfates, dichlorobenzine and its sulfates, etc. Benzidine compounds, diphenylamine, p, p'-
Diaminodiphenylmethane, o-tolidine, o-
Examples include phenylamine compounds such as deanisidine and salts thereof. These color formers react with sodium hypochlorite during the above-mentioned ink erasing process to develop color. Even if an attempt is made to correct the letters and numbers written on the markings provided by the ink composition containing these coloring agents by erasing the ink, the markings will produce color and cannot be forged or altered. Therefore, adding a coloring agent in this way can improve the effect of preventing counterfeiting or tampering, since the squash pattern is permeable to the paper and cannot be removed by surface friction with a knife or eraser. These coloring agents are contained in the ink composition in an amount of 5 to 20%.
Used in the range of %.

Examples of optical brighteners include stilbene brighteners such as diaminostilbensulfonic acid and distilbenzene, diaminodiphenyl brighteners such as benzidine, benzidine sulfonic acid, and diaminofluorene, and imidazole brighteners such as imidazolone and triazole. Whitening agents and other optical brighteners such as thiazole type, oxazole type, coumarin type, carbostyryl type, naphthalimide type, pyrazolone type, and dihydropyridine type can be used. When these fluorescent brighteners are added to the ink composition, there is an advantage that the squash pattern becomes fluorescent and can be detected quickly when irradiated with an ultraviolet lamp, although it is not visible under daylight. The optical brightener is used by adding about 0.01 to 0.1% to the ink composition. If used in excess, the squash pattern will fluoresce even in daylight, which is undesirable.

Additives that are added to ordinary printing ink compositions can be optionally added to the ink composition of the present invention. Examples include waxes such as paraffin wax for imparting wear resistance;
Plasticizers such as phthalate ester, sebacate ester, citric acid ester, and polyethylene glycol to impart flexibility to the film; calcium carbonate, magnesium carbonate, and sedimentation properties to improve ink coverage and printing transfer properties. barium sulfate, alumina, white carbon, kaolin, clay,
These include inorganic fillers such as bentonite, anionic, cationic, and nonionic surfactants as dispersion stabilizers, and the like. These are 1 to 10 in the ink composition.
It can be added within a range of %.

Usually, dyes and pigments other than white are not added to the ink composition of the present invention. However, it is also possible to obtain an ink composition for providing a colored pattern by adding, for example, 0.05 to 10% of colored dyes or pigments.

In order to obtain an ink composition by adding the above-mentioned ink-erasing coloring agent, optical brightener, and other optional additives, the mixture of these additives and the above-mentioned vehicle is processed using a conventional machine such as a three-roll mill, a ball mill, or a sand grinder. Dispersion and mixing can be carried out using a disperser. The ink composition prepared in this way is
By finely adjusting the viscosity and drying speed as necessary, it is possible to print on any paper using printing methods such as letterpress, flexography, and gravure.

As described above, according to the present invention, there is provided a special vehicle anti-counterfeiting ink composition, which can easily print a scarf pattern, and the resulting scarf pattern is stable for a long period of time and has a yellow color. Effects such as no discoloration can be obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples. In the examples, "parts" indicate "parts by weight."

Example 1 (Composition) 1 Diphenylethane (Nippon Oil Hysol)
SASLH) 35 parts 2 Dodecylbenzene (Alkylbenzene 253 manufactured by Mitsubishi Yuka) 25 parts 3 Styrene copolymer resin (Picotex 120 manufactured by Etsu Oil) 40 parts Total 100 parts Mix the above components 1, 2, and 3 and heat to 130°C A transparent ink composition was obtained by stirring and dissolving with a desolver.

Using this ink composition, a square pattern was printed at a rate of 5 g/m ² on check paper (manufactured by Tokushu Paper Co., Ltd., plain MICR paper 106 g/m ² ) using a letterpress printing method.

The check paper had an extremely transparent white check pattern.

Example 2 (Composition) 1 Diphenylethane (Nippon Oil Hysol)
SASLH) 40 parts 2 Dodecylbenzene (Mitsubishi Yuka Co., Ltd. Alkylbenzene 253) 23 parts 3 Alicyclic saturated hydrocarbon resin (Arakawa Chemical Co., Ltd. Alcon p.115) 37 parts Total 100 parts Combined with the above components 1, 2, and 3. A transparent ink composition was obtained by heating to 120°C and stirring with a desolver to dissolve.

Using this ink composition, a square mark pattern was printed on check paper by letterpress printing in the same manner as in Example 1, and a good white square mark pattern was obtained.

Example 3 (Composition) 1 Diphenylethane (Nippon Oil Hysol)
SASLH) 40 parts 2 Dodecylbenzene (Alkylbenzene 253 manufactured by Mitsubishi Yuka) 23 parts 3 Alicyclic saturated hydrocarbon resin (Alcon p.115 manufactured by Arakawa Chemical Industries) 37 parts 4 Fluorescent brightener (Ubitex manufactured by Ciba Geigy)
OB) 0.07 parts Total: 100.07 parts Blend the above components 1, 2, and 3, heat to 120°C, stir with a desolver, and dissolve. Further, component 4 was added and stirring was continued to obtain a transparent ink composition.

Using this ink composition, a square mark pattern was printed on check paper by letterpress printing in the same manner as in Example 1, and a good white square mark pattern was obtained. Furthermore, when the surface of the paper was irradiated with ultraviolet rays in a dark place, the squash pattern part became fluorescent and appeared to be raised, and the part rubbed with an eraser or the like became unevenly colored, and the corrected part was quickly detected.

Example 4 (Composition) 1 Diphenylethane (Nippon Oil Hysol)
SASLH) 60 parts 2 Dodecylbenzene (Mitsubishi Yuka Co., Ltd. Alkylbenzene 253) 10 parts 3 Alicyclic saturated hydrocarbon resin (Arakawa Chemical Co., Ltd. Alcon p.115) 15 parts 4 2-Aminobenzothiazole (Tokyo Kasei Reagent) 15 parts 100.0 parts in total Components 1, 2, and 3 above were blended, heated to 120°C, stirred with a desolver, and dissolved to obtain a transparent vehicle.

Component 4) was added to this vehicle and kneaded using three rolls to obtain a milky white ink composition with a viscosity of 150 poise.

Using this ink composition, a square mark pattern was printed on check paper by letterpress printing in the same manner as in Example 1, and a good white square mark pattern was obtained.

When an ink eraser (an oxalic acid-sodium hypochlorite two-component ink eraser) was brought into contact with this square patterned area, the contact area immediately turned brown.

Example 5 (Composition) 1 Diphenylethane (Nippon Oil Hysol)
SASLH) 60 parts 2 Dodecylbenzene (Mitsubishi Yuka Co., Ltd. Alkylbenzene 253) 10 parts 3 Alicyclic saturated hydrocarbon resin (Arakawa Chemical Co., Ltd. Alcon p.115) 15 parts 4 2-Amino-benzothiazole (Tokyo Kasei Reagent) 15 Part 5 Fluorescent brightener (Ubitex manufactured by Ciba Geigy)
OB) 0.05 part Total 100.05 parts The above components 1), 2), and 3) were blended, heated to 120°C, and stirred with a desolver to dissolve, thereby obtaining a transparent vehicle.

Components 4) and 5) were added to this vehicle and kneaded using two rolls to obtain a milky white ink composition.

Using this composition, a square mark pattern was printed on check paper by letterpress printing in the same manner as in Example 1, and a good white square mark pattern was obtained.

When an ink eraser was brought into contact with this squash-patterned area, the contact area immediately turned brown.

Furthermore, when the paper surface was irradiated with ultraviolet rays in a dark place, the square pattern part became fluorescent and appeared to be floating.

Example 6 (Composition) (1) Dodecylbenzene (Alkylbenzene 253 manufactured by Mitsubishi Yuka) 54 parts (2) Hydrogenated alicyclic hydrocarbon resin (Escorets 5300 manufactured by Exxon Chemical) 35 parts Total 89 parts Above components (1), (2) is blended, heated to 120°C, stirred with a desolver, and dissolved to form a transparent ink composition.

This is rapidly cooled and kneaded using three rolls to obtain a milky white ink composition. When this ink composition was used to print a square mark pattern on check paper by letterpress printing in the same manner as in Example 1, a good white square mark pattern was obtained.

Example 7 (Composition) (1) Diphenylethane (Nippon Oil Hysol)
SAS-LH) 90 parts (2) Hydrogenated alicyclic hydrocarbon resin (Exxon Chemical Escorets 5300) 10 parts Total 100 parts Combine the above components (1) and (2), heat to 120℃ and use a desolver. When stirred and dissolved, a transparent ink composition is obtained.

This is rapidly cooled and kneaded using three rolls to obtain a milky white ink composition.

When this ink composition was used to print a square pattern on check paper by letterpress method in the same manner as in Example 1, a good square pattern was obtained.

Claims (1)

[Claims] 1. General formula (Here, R is an alkyl or alkylene group having 1 to 20 carbon atoms, X is an alkyl group, m is an integer of 0 to 5, and n is 1 or 2), and has a boiling point of 150
A printing ink composition for printing a square pattern, characterized in that it contains as a main vehicle an alkylbenzene-based solvent at a temperature of 0.degree. C. to 400.degree. C. and a resinous substance soluble in the solvent.