JP3451151B2 - Printing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method, and more particularly, to a printing method capable of changing the color development mode depending on the direction of the line of sight to be observed.

[0002]

2. Description of the Related Art Various improvements in printing technology have made it possible to express a variety of tones and gradations. In addition to general printed materials intended to faithfully reproduce original images, packages for product packaging are also available. The printing technique is also used in various forms for decorative purposes such as brochures, posters, display stands for stores, and graphic arts. There are several printing methods currently in practical use, such as letterpress printing, offset printing, gravure printing, and silk screen printing. In any printing method, the original image is faithfully reproduced so far. That is the central issue. Then, with the introduction of color scanners and computers, improvements in printing ink, improvements in the halftone dot method, etc., printing of color photographic images is almost satisfactory.

[0003]

However, since the conventional printing techniques aim to faithfully reproduce the original image, the decorative effect should be enhanced in the printed matter mainly for the above decorative purposes. Then, the pattern and color of the original picture itself, or a combination of them, must be given appeal. Moreover, when the original image is accompanied by a delicate color tone or gradation expression such as a color photographic image, process printing using three process colors of Y (cyan), M (magenta), C (cyan) and black is generally used. However, it is not possible to ignore the tendency that color misregistration easily occurs in the printing process or the sharpness decreases due to color mixture and superposition of printing inks, and there is a limit to enhancing appealing power only with the original image itself. It was

Further, in order to enhance the decorative effect, in addition to the process ink, a reflective ink that imparts luster such as gold, silver, and pearl, and orange, red, and other vivid colors that are difficult to achieve high saturation in halftone dot expression. It is also used to combine the special color inks. FIG. 11 shows an example in which a decorative sheet is printed on a transparent sheet used for packaging of products, for example, on the back surface of a transparent base film 2 made of OPP (Oriented Polypropylene).
After printing characters and image patterns with the red ink layer 3,
In order to enhance appeal, a gold ink layer 4 is solidly printed on the background color, and a white ink layer 5 is solidly printed as a back layer. The white ink layer 5 is the red ink layer 3
The color development of the gold or gold ink layer 4 is made clear, and the function of preventing the color development of the red ink layer 3 or the gold ink layer 4 from becoming muddy due to the surface reflection color of the packaged object is performed.

[0005] Gold ink contains high-brightness reflective particles (usually brass powder particles) in place of the pigment, and has a high specular reflectance as compared with general colored inks and gives a unique metallic luster. Decoratively has a high appeal. However, since the red ink layer 3 slightly transmits light, when the gold ink layer 4 is used in the above layer structure, the reflected light accompanied by coloring from the gold ink layer 4 passes through the red ink layer 3. The red ink layer 3 becomes turbid, and a clear red color is hard to appear.

The present invention has been made in view of the above background, and an object of the present invention is to provide a printing method capable of highly decorative printing which cannot be obtained only by a pattern or color combination of an original image.

[0007]

In order to achieve the above-mentioned object, the present invention provides a process ink (three primary color ink) for obtaining coloring by coloring a pigment, a special color ink, and further a normal coloring ink such as a black ink or a white ink. By the synergistic action of the layer and a layer of a reflective ink containing particles having high-brightness reflective property such as gold ink, silver ink, pearl ink, etc., more decorative printing is enabled. For this reason, in the method of the present invention, density gradation areas by halftone dot expression are given to the respective printing patterns of the colored ink and the reflective ink, and the ink layers are partially overlapped in these density gradation areas. Is done. Then, it is possible to express a unique color tone by utilizing the fact that the coloring ink has a light transmitting property even if it is slight. In addition,
The light-transmitting ink referred to here is not only an ink that is positively transparent, which is called a transparent ink in the printing field, but also a light-transmitting ink that has a light transmittance of, for example, about several percent or less. If present, it also includes ordinary process inks and coloring inks.

The present invention also provides a layer of a white ink having a high diffuse reflectance and a colored ink when the support itself has a high reflectivity or a layer having a high reflectivity is formed on the support. It can also be carried out in a form that utilizes a synergistic effect with the layer. To do this, give density gradation areas by halftone dot expression to the printing patterns of the colored ink and the white ink with high diffuse reflectance, and overlap these ink layers partially in these density gradation areas. Together, they are constructed so that some of the light reflected from the support or reflective layer can be seen through the layer of colored ink.

Since the reflective ink layer and the layer having high reflectivity contain coarse particles, the reflected light having a metallic luster from the surface thereof becomes shaded depending on the direction of observation. When the layer of colored ink is illuminated by reflected light accompanied by such a shade in the density gradation area represented by halftone dots, the color of the layer of colored ink changes subtly depending on the direction of observation. The decorative effect of will be obtained.

[0010]

FIG. 4 shows an example of a packaging form of an audio cassette, in which a packaging sheet 5 is covered so as to cover the entire surface of the audio cassette. A transparent OPP (stretched polypropylene) film is used for the packaging sheet 5, and characters for displaying a product name and a manufacturer name, design figures for decoration, patterns, etc. are printed by gravure printing on the back surface thereof. . In addition to gravure printing, other printing methods such as letterpress printing, flexo printing, and silk screen printing may be used for these printings.

As is well known, when printing with a plurality of colors, a printing plate is prepared for each color of printing ink, and these plates are sequentially used to perform printing for each color. In the illustrated example, for example, the character 6a is black, the character 6b is yellow, the figure 6c is red, the photographic image 7 is dark purple and black, and the background 8 is gold. Although the photographic image 7 partially overlaps the character 6a, this overlapping portion of the character 6a is designed to be supplemented by the printing of the photographic image 7 and is not visible in the black printing plate. There is. The present invention is characterized by the method of printing the photographic image 7 and the background 8.
Hereinafter, these printing methods will be described.

Unlike the characters 6a and 6b or the graphic 6c, the photographic image 7 has an area having a gradation in density (density gradation area). FIG. 3 schematically shows the print pattern of the photographic image 7, and in the periphery of the shaded image portion, the portion shown by the broken line is gradually lower in density. As is well known, such a density gradation area is expressed by halftone dots, and is printed by changing the size and distribution density of halftone dots. Therefore, when printing the photographic image 7, a plate having a plate mold completely corresponding to the printing pattern of FIG. 3 is used.

FIG. 2 schematically shows the printing pattern of the background 8 and coincides with the plate type of the plate for printing this. In the figure,
The white portion represents an area printed by another printing plate.
Generally, the background 8 is printed by solid printing as described with reference to FIG. 11. However, in the present invention, the portion overlapping with the photographic image 7 is blank. A part that becomes an image is provided. Then, the portion of the photographic image 7 that overlaps with the density gradation range is
As indicated by the broken line in the figure, the density gradation range is also expressed by halftone dots. As a matter of course, the halftone dot portion of the background 8 where the density gradation region is printed has a reverse dot distribution pattern to the halftone dot portion where the density gradation region of the photographic image 7 is printed.

FIG. 1 shows a state in which a photographic image 7 and a background 8 are sequentially printed, and in particular, each density gradation area portion is enlarged and shown. A photographic image 7 is printed on the back surface of the support 10 made of a transparent OPP (stretched polypropylene) film by the image printing pattern shown in FIG.
As a result, a dark purple colored ink layer 11 is formed on the back surface of the support 10 as shown in FIG. In the density gradation area, since the halftone dot is expressed, the colored ink is not applied to the portion without the halftone dot, and the bare portion 12 is left.

Next, the characters 6a, 6b and the figure 6c are sequentially printed by the coloring inks of other colors within a range not overlapping the photographic image 7. Subsequently, the background 8 is printed using the gold ink according to the background printing pattern shown in FIG.
Since the background print pattern has a negative image relationship with the image print pattern in the portion overlapping the photographic image 7, printing is not performed in the portion to which the colored ink layer 11 is applied,
Printing is performed on the portion that has become the blank portion 12. But,
In the overlapping portions of the density gradation areas, since the respective print patterns are expressed by fine halftone dots, the gold ink layer 13 does not always completely match the blank portion 12, and as shown in FIG. In addition, the golden ink layer 13 partially overlaps with the edge portion of the colored ink layer 11.

The state shown in FIG. 1 represents a state in which the halftone dots expressing the density gradation area of the background print pattern are slightly larger than the blank areas 12 of the image print pattern. However, even if they match,
When the print patterns are slightly displaced, the gold ink layer 13 also partially overlaps the edge portion of the colored ink layer 11. Since the present invention positively utilizes this overlap, the halftone dots in the density gradation area of the background print pattern are made larger in advance as shown in the figure, and the printing plate is used when performing each printing. You may make it shift.

Further, as shown in the figure, a white ink layer 14 is solidly printed as a back layer. White ink layer 1
4 is performed on the entire back surface of the support 10 and has the function of making the color development of each layer of the color ink already printed clear and preventing the color development from the color ink layer 11 from becoming turbid by the color of the audio cassette. .

The dark purple colored ink used for printing the photographic image 7 transmits about 10% of light. Further, the gold-colored ink used for printing the background 8 contains brass powder as high-brightness reflective particles, unlike ordinary colored inks that use pigments for coloring, and the metal powder is formed by regular reflection of brass powder. Gives luster. Other examples of such reflective inks include silver inks and pearl inks that give pearly luster. In each case, fine particles that cause specular reflection are randomly mixed in the binder contained in the inks. Therefore, the support 10
When the angle of the light incident from the surface of the light changes, the strong and weak directions of the scattered reflected light change finely and subtly to give a unique glossy feeling.

Therefore, in the case of FIG. 1, the golden ink layer 1
Reflected light from a portion of 3 overlapping with the colored ink layer 11 partially passes through the colored ink layer 11 and is emitted to the surface of the support body 10. When the direction, or the direction of the line of sight when observed from the surface of the support 10, changes, the intensity of the reflected light that passes through the colored ink layer 11 changes subtly. Therefore, the coloring density and the coloring intensity of the colored ink layer 11 change in the density gradation range, and the color tone exhibited by the colored ink layer 11 changes slightly because the reflected light is gold.

As described above, by changing the color tone and the density of the photographic image 7 when the incident direction of light or the viewing direction of observation is changed, a unique appealing power that cannot be obtained by the conventional decorative printing. In addition, since the gold-colored ink layer 13 is blank in the area where there is no density gradation, and the white ink layer 14 is formed instead, the coloration from the colored ink layer 11 becomes turbid. There is no such thing.
Therefore, the photographic image 4 itself becomes clear and is observed in the density gradation range with a slight change in the coloring mode, so that the purchaser can be alerted and, in turn, can be motivated to purchase. .

In the above-described embodiment, the colored ink layer 11 is formed on the back surface of the transparent support 10 by the image print pattern of FIG. 3, and the gold ink layer 13 is formed thereon by the background print pattern of FIG. Although the desired effect is obtained by forming and forming the overlapping contradictory density gradation regions, the present invention can be implemented in the form shown in FIG. In the embodiment of FIG. 5, the colored ink layer 11 is first formed on the back surface of the transparent support 10 by the image printing pattern of FIG. 3, and then the colored ink layer 11 is partially exposed particularly in the density gradation region. The white ink layer 14 is printed in such a printing pattern. The print pattern of the white ink layer 14 is almost the same as the image print pattern of FIG. 3, and the size of the halftone dots expressing the density gradation range is slightly smaller. It is also possible to use exactly the same plate, and in this case, the plate of the white ink layer 14 may be slightly shifted with respect to the plate of the colored ink layer 11 for printing.

After the color ink layer 11 and the white ink layer 14 are printed in this manner, the gold ink layer 13 is solidly printed so as to cover them. As a result, the portion of the colored ink layer 11 exposed from the white ink layer 14 is covered with the golden ink layer 13, and a part of the reflected light from the golden ink layer 13 passes through the colored ink layer 11 and the support 1
It will be observed from the 0 surface. Therefore, the color tone changes depending on the direction of observation, and the same effect as that of the above-described embodiment is obtained. In the case of this embodiment, the golden ink layer 13 depends on the density gradation range of the white ink layer 14.
Since the density gradation range is given to, the gold ink layer 13
May be formed by solid printing on the entire surface, or instead of printing, a metal thin film may be deposited so as to cover the entire back surface of the support 10 or a metal foil sheet having a golden luster may be attached. In addition, in the portion where the white ink layer 14 is formed, almost no reflected light from the gold ink layer 13 passes through the surface of the support 10, so that a negative image is formed in the image print pattern of the white ink layer 14. The gold ink layer 13 may be printed with the following print pattern.

When the support 10 is transparent, the embodiment of FIG. 6 can be further adopted. In this embodiment, in order to provide the reflective layer on the entire back surface of the transparent support 10, the metal thin film layer 15 having high reflectivity is formed by vapor deposition. Instead of vapor deposition, a metal thin film may be attached, or solid printing may be performed on the entire surface with a reflective ink having a metallic luster.

A photographic image 7 is printed on the surface of the support 10 with the dark purple coloring ink in the image printing pattern of FIG. 3, but in order to make the coloring of the coloring ink vivid,
First, white ink is used to perform printing with a print pattern substantially similar to the image print pattern of FIG. Next, the colored ink layer 11 is printed with the image printing pattern of FIG. 3 using the colored ink, but these printing patterns are slightly different, especially in the halftone dot expression portion, as in the embodiment of FIG. Therefore, the edge portion of the colored ink layer 11 comes to protrude from the white ink layer 14. Of course, even when the same printing plate is used, the colored ink layer 11 can be partially protruded from the white ink layer 14 by positively shifting the printing pattern.

Also in this embodiment, the white ink layer 1
In the portion overlapping with 4, the deep purple coloration of the colored ink layer 11 is clearly observed. Further, since the colored ink layer 11 protruding from the white ink layer 14 is illuminated from the back side by the light reflected by the metal thin film layer 15 and transmitted through the support 10, this portion is dark purple and metallic gloss. It comes to be observed in a mixed color tone. Then, the background color due to the metal thin film layer 15 is observed from a portion where neither the white ink layer 14 nor the colored ink layer 11 is printed.

Since the reflected light with a metallic luster color from the metal thin film layer 15 is uneven depending on the observation direction, the colored ink layer 11 protruding from the white ink layer 14 has a coloring intensity and a color tone depending on the observation direction. Subtly changes.
Further, in particular, in the density gradation range expressed by halftone dots, the reflected light from the metal thin film layer 15 also becomes a background color, so that the influence on the colored ink layer 11 is large, and similar to the above-described embodiment.
You can get a novel decoration effect. In addition, in order to protect the colored ink layer 11, the entire surface side may be covered with a transparent layer.

In the embodiment shown in FIG. 7, the metal thin film layer 15 is formed on the back surface of the support 10, and the front surface is first printed with white ink having a high diffuse reflectance in the background printing pattern shown in FIG. The density gradation range of the background print pattern is
Like the above-described embodiment, the white ink layer 14 is represented by halftone dots, and the white ink layer 14 is formed discretely in the density gradation range. However, the size of the halftone dots is larger than the size corresponding to the original density gradation. Is adjusted to. On top of that, the photographic image 7 is printed in the image printing pattern of FIG. As a result, the colored ink layer 11 partially overlaps the white ink layer 14 at the edge portion.

In this embodiment, the background color is white due to the white ink layer 14, but in the density gradation area of the photographic image 7, the light diffused and reflected by the white ink layer 14 and the metal thin film layer 15 are reflected. Both the reflected light and the reflected light come to be observed through the colored ink layer 11. The reflected light from the white ink layer 14 hardly affects the color tone of the colored ink layer 11, while the metal thin film layer 15
The reflected light from is accompanied by a metallic luster color and is lower than the photographic image 4 by the thickness of the support 10, so that the photographic image 4 formed by the colored ink layer 11 is swung in the direction of the line of sight. Causes slight changes in color tone and color density. A transparent protective layer may be provided so as to cover the colored ink layer 11 and the white ink layer 14.

Further, as shown in FIG. 8, the colored ink layer 11 having the image print pattern of FIG. 3 and the white ink layer 14 having the background print pattern of FIG. 2 are printed on the back surface of the transparent support 10. Further, the metal thin film layer 15 may be vapor-deposited or laminated so as to cover these entire surfaces. In this case,
In the portion overlapping with the white ink layer 14, the colored ink layer 11
Performs a normal color development, and the portion overlapping with the metal thin film layer 15 is illuminated with a metallic luster color to change the color tone, and the same decorative effect can be obtained.

Furthermore, the present invention can be carried out not only on transparent supports but also on opaque supports.
In the embodiment shown in FIG. 9, the background printing pattern shown in FIG. 2 is printed using gold ink on the surface of the opaque support 20 having a white surface, and the colored ink of FIG. The image is printed with an image print pattern. The colored ink layer 11 and the golden ink layer 13 partially overlap each other in the density gradation range, and the color development of the colored ink layer 11 is observed by changing the line-of-sight direction as in the embodiment of FIG. Like

In the embodiment shown in FIG. 10, the metallic thin film layer 15 described above imparts a metallic luster to the surface of the support 20, and the white ink layer 14 is formed on the surface of the substrate 20 with a printing pattern substantially the same as the image printing pattern of FIG. Is printed, and the colored ink layer 11 is further formed thereon by printing with the image printing pattern of FIG. Then, the size of the halftone dots of the colored ink layer 11 is made relatively large with respect to the size of the halftone dots of the white ink layer 14 so that these layers do not completely match in the density gradation range. According to this, the metallic luster of the metal thin film layer 15 becomes the background color, and a part of the reflected light reaches the surface through the colored ink layer 11 at the edge portion of the white ink layer 14, which is the same as the previous embodiments. The same decorative effect can be obtained. In order to give the surface of the support 20 a metallic luster, the gold ink layer 13 can be solid-printed as described above. For a support such as an aluminum sheet having a metallic luster itself or a support having an aluminum sheet laminated on the surface, the white ink layer 14 and the colored ink layer 11 are formed on the surface. And may be printed sequentially.

Although the above description is based on the illustrated embodiment, the type of printing ink used in the present invention is not limited to the above. As the colored ink, various colors including white and black can be selected as long as it has optical transparency, and as the reflective ink, in addition to gold ink,
Any material containing particles having high-luminance reflectivity, such as silver ink or pearl ink, may be used. Of course, not only OPP but also plastics such as PET (polyethylene terephthalate) and various materials such as paper can be used as the support.

[0033]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a layer of a colored ink having a light transmitting property and a layer of a reflective ink containing particles having high-brightness reflectivity or a metal thin film are used for synergistic effect. It is possible to change the color development of the printed image according to the change of the direction of light or the direction of the line of sight, and it is possible to obtain a unique decorative effect that cannot be obtained by the conventional printing.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a process of a printing method of the present invention.

FIG. 2 is a schematic view of a background print pattern.

FIG. 3 is a schematic diagram of an image print pattern.

FIG. 4 is a perspective view showing an appearance of a package.

FIG. 5 is a schematic view showing another embodiment of the present invention.

FIG. 6 is a schematic view showing still another embodiment of the present invention.

FIG. 7 is a schematic view showing another embodiment of the present invention.

FIG. 8 is a schematic view showing still another embodiment of the present invention.

FIG. 9 is a schematic view showing another embodiment of the present invention.

FIG. 10 is a schematic view showing another embodiment of the present invention.

FIG. 11 is an explanatory diagram showing an example of a conventional printing method.

[Explanation of symbols]

10, 20 support 11 Colored ink layer 13 Gold ink layer 14 White ink layer 15 Metal thin film layer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 61-100488 (JP, A) JP 7-125403 (JP, A) JP 55-39343 (JP, A) JP 2- 127078 (JP, A) JP 53-44213 (JP, A) JP 63-71385 (JP, A) Actually open 63-7565 (JP, U) Actual flat 6-32048 (JP, U) Actual opening 55-113267 (JP, U) Actual opening 5-85666 (JP, U) Actual opening 3-36872 (JP, U) Actual opening 59-137075 (JP, U) Actual opening 1-31507 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 3/00

Claims (5)

(57) [Claims] 1. A high-brightness reflective particle after printing on the back surface of a transparent support with a first pattern having a density gradation range by halftone dot expression using a colored ink having light transmittance. Printing is performed using a reflective ink containing the ink, and a second pattern having a density gradation area opposite to the density gradation area of the first pattern is printed, and the respective ink layers are formed in the respective density gradation areas. A printing method characterized by partial overlapping. 2. A transparent support is printed on the back surface thereof with a first pattern having a density gradation region by halftone dot expression using a colored ink having a light-transmitting property, and then a white color having a diffuse reflection property. Printing with a second pattern that uses ink and has a density gradation area that is substantially the same as the density gradation area of the first pattern, and at least partially exposes the colored ink layer in the density gradation area of the first pattern And further covering at least the layer of the colored ink exposed from the layer of the white ink with a reflective layer which gives a metallic luster. 3. A colored ink having a light-transmitting property, which is printed on the surface of a transparent support with a first pattern having a density gradation region by halftone dot expression using a white ink having a diffuse reflection property. Has a density gradation area substantially the same as the density gradation area of the first pattern, and at least partially protrudes the colored ink layer from the white ink layer in the density gradation area of the first pattern. A printing method comprising: performing printing with the second pattern, and forming a reflective layer that imparts metallic luster on the back surface of the support before or after performing the printing. 4. The surface of the support is printed with a first pattern having a density gradation area by halftone dot expression using a reflective ink containing high-brightness reflective particles, and then the light-transmitting property is obtained. Printing is performed with a second pattern having a density gradation area that is opposite to the density gradation area of the first pattern by using a colored ink having A printing method characterized by superimposing them physically. 5. The surface of a support having a metallic luster is printed with a first pattern having a density gradation range by halftone dot expression using a white ink having a diffuse reflection property, and then the light transmission property is obtained. Having a density gradation area substantially the same as the density gradation area of the first pattern, and at least partially forming the color ink layer from the white ink layer in the density gradation area of the first pattern. A printing method characterized in that printing is performed with a second pattern that is projected.