JP2003231341A - Method for printing pearl tone printed matter, and pearl tone printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for performing pearl printing with a high brightness by flexographic printing, relief printing or offset printing and a pearl tone printed matter. <P>SOLUTION: In the method for printing the pearl tone printed matter with a pearl ink by the flexographic printing, the relief printing or the offset printing, the method for printing of the present invention is characterized by (1) using a printing plate which does not form a non-image area with a width of 0.5 mm or smaller between printing areas on a plate face of a pearl printing plate, (2) using a printing plate which only consists of a figure-like solid pattern with neither non-image area nor part bending at acute angle on the sides in parallel to the printing direction of the pattern and printing twice with the pearl ink, or (3) performing precise printing with an ordinary ink and then, performing printing with the pearl ink so as to cover the precisely printed part 4. The pearl tone printed matter is the printed matter printed by these methods. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a printing method relating to gift certificates, securities, cash vouchers such as stock certificates, cards such as credit cards and commuter tickets, and other commercial printed materials, and printed materials by the printing method. More specifically, the present invention relates to a technique for making a pattern crush and misregistration inconspicuous when the printed matter is printed using pearl ink.

[0002]

2. Description of the Related Art Printing inks containing pearl pigments have existed as inks for silk screen printing or gravure printing, and have a high anti-counterfeiting effect by preventing the copying of cash vouchers and cards. Since it is possible to impart the design property of, it has been conventionally used for these various printed materials. However, in recent years, there has been a demand for the practical application of pearl ink in flexographic printing, letterpress printing, and lithographic printing, which can further improve efficiency in terms of plate making work and printing speed.

The prior art of this pearl ink is disclosed in JP-A-7-
No. 34021 “Offset printing ink” and JP 2001-240786 A.
The issue is "Pearl ink for printing and pearl-like printed matter". Japanese Unexamined Patent Publication No. 7-34021 discloses a lithographic printing ink containing a pearlescent pigment. In the case of lithographic printing, the ink transfer is theoretically different from that of silk screen printing or gravure printing. It is stated that it is necessary to increase the brightness of the pearl printing pattern by a method of increasing the amount of ink transfer compared to general lithographic printing conditions due to the small amount, or by a method of printing the pattern multiple times. There is.
Further, it is explained that the offset printing ink containing the pearlescent pigment has a remarkable ink accumulation on the printing plate, and continuous printing of 10,000 sheets is almost impossible.

Further, Japanese Patent Laid-Open No. 2001-240786 proposes a pearl ink using a binder component having an unsaturated bond such as ultraviolet curability. The pearl ink enables high-speed rotary offset printing and printing on plastic sheets, which has been impossible in the past.

In relief printing including flexographic printing, the amount of ink transfer can be increased and the brightness of the pearl printing pattern can be made slightly higher than in lithographic printing. However, in order to further increase the brightness, it is necessary to use more printing conditions than the general printing conditions. It is also necessary to print with a large amount of ink.

When printing is performed with a larger amount of ink than the general printing conditions, the pearl ink adhering to the image area of the printing plate overflows to the non-image area due to the printing pressure, and as a result, Since the pattern formed on the base material such as paper becomes thick, it is necessary to devise the pattern so that the thickness is not noticeable. Particularly in letterpress printing including flexographic printing, excess ink is likely to be accumulated in the non-image area where the image area is in an acute angle, and the thickening of the pattern is remarkable in this area.

Further, in the case of a method of increasing the brightness by printing the same pattern a plurality of times so as not to spoil the appearance,
It is required that the patterns to be printed on top of each other are not misaligned. Although there are differences depending on the printing equipment used, it is difficult to completely suppress the misregistration. Especially, the misregistration is more likely to occur in the print flow direction than in the print width direction, and as a pattern, the misregistration in the print flow direction is conspicuous. It is necessary to devise ways to eliminate it.

[0008]

As described above, the present invention has not been frequently used in the past, and flexographic printing,
In pearl printing in letterpress printing and lithographic printing, the research was completed in order to increase the brightness of pearls and to make the crushing and misregistration of pictures less noticeable.

[0009]

The first of the gist of the present invention for solving the above-mentioned problems is a method for printing a pearl tone printed matter by using a pearl ink by flexographic printing, letterpress printing or offset printing. Using a printing plate comprising a pattern in which the plate surface of the plate does not have a non-image area such that the width between the image areas is less than 0.5 mm,
A method for printing a pearl-like printed matter, characterized by printing,
The second aspect of the present invention is a method of printing a pearl-like printed matter using a pearl ink by flexographic printing, letterpress printing, or offset printing, in which the plate surface of the pearl printing plate does not include a non-image area. Pearl tone characterized by printing the pearl ink twice using two printing plates each having a solid pattern and having only a pattern having no acute-angled portion on the side parallel to the printing direction of the pattern. There is a method of printing printed matter.

A third aspect of the present invention is a method for printing a pearl tone printed matter by using a pearl ink by flexographic printing, letterpress printing or offset printing.
After performing fine printing with general ink by either letterpress printing or offset printing, it is possible to perform printing with pearl ink by flexographic printing, letterpress printing, or offset printing so as to cover the fine printing portion. The printing method of the pearl-like printed matter is characterized. With such a printing method, a printed matter in which the misregistration is inconspicuous can be obtained.

A fourth gist of the present invention is a pearl-like printed matter in which a pearl ink is printed by flexographic printing, letterpress printing or offset printing, and the plate surface of the pearl printing plate used for printing the printed matter has an image area portion. The width between the line and the image area is 0.
A pearl-like printed matter characterized by being printed using a printing plate comprising a pattern having a non-image area of less than 5 mm. A fifth aspect of the present invention is flexographic printing, letterpress printing, It is a pearl-like print that is printed with pearl ink by offset printing, and the plate surface of the pearl printing plate used for printing the print is a solid pattern in the shape of a figure that does not include non-image areas, and A pearl-like printed matter, which is a printed matter obtained by printing a pearl ink twice using two printing plates each having a pattern having no acute-angled portions on parallel sides. The sixth gist of the present invention is flexographic printing,
A pearl-like printed material in which a pearl ink is printed by letterpress printing or offset printing, and the printed matter is subjected to fine printing with general ink by flexographic printing, letterpress printing, or offset printing, and then covers the fine printed portion. In this way, printing with pearl ink flexo printing,
A pearl-like printed matter, which is a printed matter printed by either letterpress printing or offset printing.
Since it is such a printed matter, it is a pearl-like printed matter with no noticeable misregistration and a high anti-counterfeiting effect.

In the printing method of the pearl-tone printed matter and the pearl-tone printed matter, any one of ultraviolet curing type ink, oxidation polymerization type ink, evaporation drying type ink, permeation drying type ink and heat set type ink is used as the pearl ink. Can be one.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, as a result of trying various methods for realizing high-brightness pearl printing by letterpress printing including flexographic printing and offset printing, a remarkable effect is recognized by the following method. Therefore, the embodiments will be sequentially described.

(1) Do not provide a non-drawing portion that enters an acute angle in the drawing portion. In the section of the prior art, particularly in letterpress printing including flexographic printing, excess ink is likely to accumulate in the non-image area that enters the image area at an acute angle, and the thickening of the pattern is remarkable in this area. Having described, this phenomenon will be described based on the drawings. FIG. 1 is a diagram showing an example of a non-drawing portion that enters into the drawing portion in an acute angle shape. FIG. 1A shows the state of characters printed immediately after the start of printing, and FIG. 1B shows the state of characters after a considerable amount of printing time has elapsed from the start of printing. Figure 1
In the bold “N” in the Gothic type, the non-image area 2 having a sharp tip is included in the image area 1. Immediately after the start of printing, since the plate surface of the rubber relief plate (a plastic material having high solvent resistance is also used) is clean, sharp characters as shown in FIG. 1A are reproduced. However, if the same number of plates are printed, the ink will accumulate on the plate (clogging).
Occurs (the tip of the arrow), and the printed characters also gradually change as shown in FIG. For this reason, the quality deviation can be easily confirmed even within the same manufacturing lot. The same phenomenon occurs in metal letterpress and offset printing. This phenomenon is particularly noticeable in a character or the like having a non-drawing portion 2 that enters the drawing portion 1 at an acute angle.

Therefore, the first embodiment of the present invention resides in that the printing surface or the printing plate surface is not provided with an acute non-image area. Specifically, the acute angle non-image area means that a non-image area having a width of less than 0.5 mm does not enter the image area. It is a numerical value found empirically that it is inconspicuous if it is 0.5 mm or more, but it is because if it is more than that interval, change of appearance due to ink accumulation can hardly be confirmed. On the contrary, if this value is set to 2.0 mm or 3.0 mm, a necessary portion becomes an obtuse angle, and a printed matter having no sharpness is obtained although it varies depending on the observation distance. Not provided on the printing plate means not using characters or patterns that form such a plate.

FIG. 2 is a diagram showing an example of the improved pattern. It is a bold letter "N" in the Gothic type, but in the portions (two places) indicated by the arrows, the image area 1a and the image area 1b are formed.
The shape is processed into an arc shape so that the distance between and is at least 0.5 mm or more, and no non-image area portion that enters into an acute angle shape is provided in the image area portions 1a and 1b. In the case of letters, it is also possible to use letters of such a typeface. As described above, when the non-image area has a width of 0.5 mm or more, even if the continuous printing is performed, the thickening of the characters and the pattern due to the accumulation of the pearl ink does not occur or becomes inconspicuous, and the quality fluctuation in the manufacturing lot is eliminated.

(2) As a design, devise to use a design in which misregistration in the printing flow direction is inconspicuous. In the second embodiment of the present invention, when the patterns are printed several times in order to increase the brightness of the pearl printing, the patterns to be printed do not appear to be misregistered so as not to spoil the appearance. Is to FIG. 3 is a diagram showing a pattern to be printed in an overlapping manner, and is an example of a pattern in which misregistration is not noticeable. FIG. 3A shows a case where the registrations are the same after two overprints, and FIG. 3B shows a case where the registrations are misaligned after the two overprints. 3 (A) and 3 (B) may look the same as each other, the patterns of FIG. 3 (B) are both different from the pattern of FIG. 3 (A) in the direction of arrow Y (printing paper). The direction of travel is not correct. This is because it is necessary to increase the printing brightness in pearl printing as described above, so two printing plates with the same pattern are used to perform overprinting twice, but in that case misregistration occurs. ing. That is, even if there is misregistration, such an image is inconspicuous because the ink is the same pearl ink.

FIG. 4 is a diagram showing a pattern to be printed in an overlapping manner, which is an example of a pattern with a noticeable misregistration. FIG. 4A shows a case where the registrations are the same after two overprints, and FIG.
The figure shows the case where the registration is misaligned during overprinting. Figure 4
Also in (B), the degree of deviation is the same as in the case of FIG. Figure 4
Even if a glance is made between (A) and FIG. 4 (B), it is clear that misregistration occurs in FIG. 4 (B). In addition to characters, the figures shown in FIGS. 4B and 4G also show significant misregistration. This is because the misregistration becomes clear when an acute-angled shape is projected so as to be orthogonal to the running direction of the printing paper (direction of arrow Y). Such a state of the characters (h) and (i) is also expressed as the pattern being crushed.

Let us consider what is different between the patterns in FIGS. 3 and 4. The design of FIG. 3 is the first design, and the design of FIG. 4 is the second design. (1) The first pattern is an acute angle part (angle part less than 90 degrees)
The second design is a graphic or a character having an acute angle portion, although the graphic does not have. (2) The first pattern has no non-image area in the pattern, and the second pattern exists. (3) The first pattern is solid printing, and the second pattern is not solid printing. (4) The first pattern is a straight line (a curved line may be a gentle curve) whose side portion is substantially parallel to the arrow (Y) direction, and the second pattern has irregularities in that part. To express these in one word, the first picture is that "the figure is a solid pattern that does not include a non-image area, and the sides parallel to the printing flow direction are substantially linear." become.

However, since the above is premised on that the misregistration does not occur in the width direction, from the viewpoint of safety considering that the misregistration may occur also in the width direction,
It is considered that it may be expressed as "a pattern that does not include a non-image area and is a solid pattern that does not have a portion that bends at an acute angle on its peripheral side". Therefore, it is a good idea to use such a pattern for pearl printing in order to make the misregistration inconspicuous. As shown in FIG. 3, patterns satisfying the above conditions are limited to particular shapes such as rectangles, polygons, rounded polygons, and ellipses. Generally, the pattern is not for the purpose of transmitting information but for improving the design and preventing copying. Therefore, it is not necessary to use many characters, and the purpose can be achieved by using the pattern as described above.

(3) As a picture pattern, ordinary fine printing is performed and then pearl printing is overprinted. The third embodiment of the present invention is to take into consideration that, when performing pearl printing, it is possible to overprint an ordinary fine pattern for use. FIG. 5 is a diagram for explaining the third embodiment. In the third embodiment, first of all, the fine print portion 4 is provided by general ink (printing ink other than pearl ink) by offset printing (lithographic printing) or the like. The fine print does not mean a print including an extremely precise pattern, but it is a normal print including a fine readable character, a logo, and a pattern. After this printing, the pearl printing portion 3 is provided by flexographic printing using pearl ink, letterpress printing, or offset printing. For the pearl printing portion 3, a transparent ink is used so that the offset printing on the lower side can be observed.

By adopting such a print pattern construction, it is possible to have a fine pattern and character information even though it is a pearl tone print, and to maintain a copy prevention function by pearl ink and a high designability. In addition, since the fine print portion is on the lower surface of the pearl print portion, there is an effect that it is difficult to modify. It should be noted that the reason why the pearl-like printed matter has a high copy preventing function is that it is based on the light interference of the pearl pigment. Due to the difference.

By the way, in flexographic printing, letterpress printing and offset printing using such pearl ink, various inks developed for pearl printing can be selected and used. Pearl inks can be classified into ultraviolet curing type inks, oxidation polymerization type inks, evaporation drying type inks, permeation drying type inks, and heat set type inks, mainly based on the ink dry form. Each has the following features.

(1) Ultraviolet curable ink This type of ink is an ink that is cured by irradiation with ultraviolet rays, which is a type of electromagnetic wave, and is used for business foams, general packaging materials, printed circuit boards, various coatings and the like. Suitable for drying prints that cannot be heated. Sensitizer is mixed with polyfunctional monomer and acrylate oligomer,
When irradiated with ultraviolet rays, the sensitizer forms radicals to cause a chain reaction of oligomers and monomers. It is said that the difference in the ultraviolet absorption of the pigment affects the curing speed, and it is necessary to adjust the amount and combination of the sensitizers.

As an ultraviolet curable ink for high speed off-wheel printing, Japanese Patent Laid-Open No. 2001-240786 discloses "at least,
(A) Binder component 25 comprising one or more kinds of monomers or oligomers having one or more unsaturated bonds
A pearl ink for printing, comprising a composition containing 95 parts by weight and (b) 5 to 60 parts by weight of a pearl pigment. Is proposed. Based on the technology of this application, a printed matter having a sufficient pearl luster and a cured film is obtained by a printing ink using an oligoester acrylate or a polyol acrylate as a binder. The ink can be printed on any material such as paper or plastic.

In this case, the printing itself is carried out in the same manner as the usual printing, and after printing, the electron beam irradiator or the ultraviolet irradiator installed beforehand on the discharge side is immediately irradiated with the electron beam or the ultraviolet ray, A pearl print can be obtained by curing the ink coating film. After printing,
Since the ink has already been hardened, the ink will stick even if the printed materials are stacked or wound up, whether it is printed on a sheet-fed printing press on plastic or on a high-speed rotary press on paper or plastic film. There is no such thing. In the case of printing on a plastic card or a plastic sheet, ultraviolet ray or electron beam curable ink is often used.

(2) Oxidation-polymerizable ink This type of ink forms a film by solidification and insolubilization of a vehicle by oxidative polymerization, and inks containing a dry oil varnish, a dry alkyd, etc. fall into this category. Examples are general planographic ink and letterpress ink. Planographic ink
There are so-called quick set inks containing some high boiling point petroleum as topographic inks, but the final drying of these is also due to oxidative polymerization. This type of ink can be applied to offset printing, but is preferably used for sheet-fed printing and rotary printing at a relatively low speed.

(3) Evaporative Drying Ink This type of ink forms a film of solid resin due to the evaporation of the solvent in the vehicle, and it corresponds to certain types of gravure, flexo and silk screen inks. It has the property of drying quickly at room temperature. In the present invention, it can be suitably used for flexographic paper printing using an alcohol solvent. (4) Permeation dry type ink This type of ink is an ink that sticks and dries when the low-viscosity component of the ink permeates the material to be printed. The ink printed on paper permeates by the printing pressure, and After printing, it gradually penetrates and sets. In this type of ink, the low-viscosity component of the vehicle penetrates into the paper after printing, and the pigment is fixed in the fiber gap by a fixing component or the like. Therefore, it is often used for printing on medium-quality paper, rough paper, etc., which is porous and has high permeability. (5) Heat-set type ink This type of ink is an ink that softens when heated and solidifies when cooled. It is used for relatively high speed printing of planographic printing and letterpress printing. Waxes, vegetable oils, mineral oils, petroleum-based solvents are used as vehicles. This type of ink is often used for printing pressure-sensitive copy layers of shipping slips.

As the pearl ink, there are used various types of ink binders as described above, in which fine flakes (flakes) are coated on the outside with a metal oxide or a mixture of metal oxides. The fine flakes include mica, talc, kaolin, bismuth oxychloride, or glass flakes, SiO ₂ flakes, or synthetic ceramic flakes. Examples of metal oxide coating the outside of these fine flakes Is TiO ₂ , Fe ₂
There are O ₃ , SnO ₂ , CrO ₃ , and ZnO. Among these combinations, mica, glass flakes, or SiO
₂ flakes with TiO ₂ coating and / or Fe ₂ O ₃
Coated ones are preferred. The size of the individual flakes of the pearl pigment is 1 to 100 μm.

The printing substrate used for pearl printing is
High-quality paper, medium-quality paper, and OC that have been conventionally used for printing
R paper, MICR paper, carbonless paper, thermal paper, coated paper,
Various plastic films, plastic sheets, etc. can be used.

[0031]

Embodiments Embodiments of the present invention will be described with reference to FIG. An ultraviolet curable ink having the composition shown below was prepared using a commercially available pearl pigment, and printing was performed on a high-quality paper (64 g / m ² ) using an offset printing machine. Printing is shown in Figure 5.
3 was printed using a normal offset printing ink, and then two pearl plates having a rectangular pattern shown in FIG. 3 (A) were produced, and the printing was performed twice by registering them. <Ultraviolet curable ink> Pearl pigment (Merck & Co., TiO ₂ coated mica, trade name “Iriodin”) 20 parts by weight Oligoester acrylate 68 parts by weight Ethylene oxide modified bisphenol A diacrylate 10 parts by weight Aromatic photopolymerization start 2 parts by weight of agent (ink viscosity: 1.5 × 10 ⁴ cP)

The pearl print thus obtained exhibited a pearly color tone with high brightness, and sufficient pearl luster was obtained. Moreover, the printing register of the pearl printing unit 3 is 1 mm in the running direction of the printing paper.
Even if it deviated to some extent, it did not become a remarkable defective state. The fine print portion 4 under the pearl print was also sufficiently visible, and when copied, it became difficult to see.

Since the present invention has the features described above, important documents such as gift certificates, stock certificates, admission tickets, boarding tickets, tickets, and certificates, as well as cash cards, credit cards, commuter tickets, and ID cards. It can be used for various printed matters such as cards and the like, which are required to have a copy protection function and design, and various printed matters such as packaging materials, commercial printed matters, and book publications.

[0034]

As described above, in the printing method according to the first aspect of the present invention, the thickening of the pattern due to the accumulation of the pearl ink on the printing plate is not conspicuous, so that highly accurate printing can be continuously performed. You can In the printing method according to the second aspect of the present invention, since the misregistration of the printed matter is inconspicuous, the printing loss can be reduced and the printing efficiency can be improved. In the printing method according to the third aspect of the present invention, it is possible to easily print a fine pattern and a pattern in which pearl printing is synchronized. The pearl-like printed matter according to claims 5 to 7 of the present invention can exhibit effects such as forgery prevention while maintaining excellent print quality.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a non-drawing portion that enters an acute angle into the drawing portion.

FIG. 2 is a diagram showing an example of an improved pattern.

FIG. 3 is a diagram showing a pattern to be printed in an overlapping manner, which is an example of a pattern in which misregistration is not noticeable.

FIG. 4 is a diagram showing a pattern to be printed in an overlapping manner, which is an example of a pattern in which misregistration is noticeable.

FIG. 5 is a diagram illustrating a third embodiment.

[Explanation of symbols]

1 Drawing part 2 Non-image area 3 Pearl Printing Department 4 Detailed printing by lithographic printing

Claims (8)

[Claims] 1. A method for printing a pearl-tone print using a pearl ink by flexographic printing, letterpress printing, or offset printing, wherein the plate surface of the pearl printing plate has a width of 0. A method for printing a pearl-like printed matter, which comprises printing using a printing plate comprising a pattern having a non-image area of less than 5 mm. 2. A method for printing a pearlescent print using a pearl ink by flexographic printing, letterpress printing or offset printing, wherein the plate surface of the pearl printing plate is a solid pattern in a figure shape that does not include non-image areas. A method for printing a pearl-like printed material, comprising: printing twice a pearl ink, using two printing plates consisting only of a pattern having no acute-angled portions on the sides parallel to the printing direction of the pattern. 3. A method for printing a pearl-like printed matter with a pearl ink by flexographic printing, letterpress printing, or offset printing, after performing fine printing with a general ink by any one of flexographic printing, letterpress printing, and offset printing. A method for printing a pearl-like printed matter, characterized in that printing with a pearl ink is performed by flexographic printing, letterpress printing, or offset printing so as to cover the fine print portion. 4. The pearl ink uses one of an ultraviolet curable ink, an oxidative polymerization type ink, an evaporation drying type ink, a penetration drying type ink and a heat set type ink. A method for printing a pearl-like printed matter according to claim 3. 5. A pearl-tone printed material obtained by printing a pearl ink by flexographic printing, relief printing, or offset printing, wherein the plate surface of the pearl printing plate used for printing the printed material is
A pearl print, which is printed using a printing plate having a pattern having no non-image area having a width of less than 0.5 mm between the image areas. 6. A pearl-tone printed material obtained by printing a pearl ink by flexographic printing, letterpress printing, or offset printing, wherein the plate surface of the pearl printing plate used for printing the printed material is
To print the pearl ink twice using two printing plates that are solid patterns in the shape of a figure that do not include non-image areas and that do not have a portion that bends at an acute angle on the side parallel to the printing direction of the pattern. A pearl-like printed matter, which is a printed matter obtained by. 7. A pearlescent print obtained by printing a pearl ink by flexographic printing, letterpress printing or offset printing, wherein the printed matter is finely printed with general ink by any one of flexographic printing, letterpress printing and offset printing. After that, a pearl-like printed matter, which is a printed matter obtained by performing flexographic printing, letterpress printing, or offset printing by printing with a pearl ink so as to cover the finely printed portion. 8. The pearl ink is one using any one of an ultraviolet curable ink, an oxidative polymerization type ink, an evaporation drying type ink, a penetration drying type ink and a heat set type ink. The pearl-like printed matter according to claim 7.