JP7651880B2 - Printed materials - Google Patents

Description

The present invention relates to a printed matter in which the image changes depending on the viewing angle.

Anti-counterfeiting technologies have been developed for valuable printed matter such as banknotes, passports, and securities. To make it easy to visually determine whether a printed matter has been counterfeited or copied, a known anti-counterfeiting technology combines halftone dots or lines that make up the valuable printed matter with unevenness formed by a base material or ink buildup, thereby changing the color or shape of the image depending on the observation angle.

As a printed matter having these anti-counterfeiting technologies, a printed matter in which the color of the image changes depending on the viewing angle has been disclosed (see, for example, Patent Document 1). The printed matter in Patent Document 1 is formed by applying a base layer on a substrate for forming a first image, arranging adjacent printed lines forming a second image and printed lines forming a third image on top of that, and further applying lines that shield the printed lines on top of that, so that the second image changes to the third image depending on the viewing angle.

Other printed matter has been disclosed in which the shape of the image changes with a change in the observation angle (see, for example, Patent Document 2). The printed matter of Patent Document 2 has a base material on which a plurality of first image lines are arranged, each having two levels of height and forming a first image, and a second image line is arranged between the first image lines, lower than the first image line. From the front, the second image is visible, and as the observation angle changes, the second image line is shielded by the first image line, allowing the first image to be viewed.

Furthermore, as another type of printed matter, a printed matter has been disclosed in which the shape of the image changes depending on the viewing angle (see, for example, Patent Document 3). By forming a multi-layered structure of raised printed lines, an image whose color and shape change depending on the viewing angle can be seen, and by providing different functional materials to each layer that makes up the formed body, the image can be seen in different environments that correspond to the provided functionality.

On the other hand, printing methods used in printing methods for forming patterns have been proposed according to the line width, linearity, thickness, line width accuracy, relative position accuracy, absolute position accuracy, surface smoothness, production speed, etc. of the pattern to be formed. These include flexographic printing, inkjet printing, gravure printing, screen printing, gravure offset printing, screen offset printing, pad printing, offset printing (lithographic printing), letterpress printing, rotary screen printing, letterpress reverse printing, dispenser printing, and electrostatic ejection inkjet printing.

Among these, the printing method in which the composition is first transferred or printed onto a blanket and then transferred from the blanket to the substrate is attracting attention because it allows for finer patterns, stabilizes the pattern shape, and allows for the transfer of a constant amount of printing composition.

In gravure offset printing, one such printing method, a printing composition is filled into the recesses of an intaglio plate, which have recesses formed corresponding to the desired pattern, using a doctor blade or the like, and then the printing composition is transferred to a blanket, and then transferred again from the blanket to the substrate to be printed, thereby forming a pattern on the substrate. Depending on the type of ink, the ink is cured as necessary by exposure to heat or UV light, for example, to form a conductive pattern, for example.

In screen offset printing, a printing composition is printed onto a blanket using a screen formed to correspond to the desired pattern, and then transferred from the blanket to a substrate to be printed, thereby forming a pattern on the substrate.

In pad printing, a printing composition is filled into the recesses of an intaglio plate, which has recesses formed corresponding to the desired pattern, and then the printing composition is transferred to a soft, hemispherical or boat-shaped blanket called a pad. The pad (blanket) is then pressed against the substrate to be printed, and the printing composition on the pad (blanket) is transferred again to the substrate, forming a pattern on the substrate.

JP 2010-247460 A JP 2011-42049 A Patent No. 5971593

The printed matter of Patent Document 1 is an anti-counterfeiting technology with excellent design, as images of different colors appear depending on the observation angle. However, in order to mask the printed lines when observed from the front, it is necessary to add masking lines to all adjacent printed lines, so the image visible from the front and the image visible as the observation angle changes are the same shape, and it is impossible to form a printed matter in which images of different shapes appear as the observation angle changes.

In addition, the print in Patent Document 2 allows the height of the image lines to be changed, making it possible for images of different shapes to appear depending on the observation angle, something that was not possible with Patent Document 1. However, because the image lines are formed using one type of monochrome ink, there is a demand for prints in which the color and shape of the image change depending on the observation angle.

Furthermore, Patent Documents 1 and 2 have made it possible to produce printed matter in which an image appears by simply changing the observation angle, which is a simple identification direction. However, in recent years, it has become possible to easily produce printed matter with raised lines formed thereon using inkjet printers, and so there is a demand for printed matter whose authenticity can be determined not only visually but also under multiple different environments or by machine reading.

Therefore, according to Patent Document 3, by combining a complex multi-layer structure with functional materials, it is possible to distinguish between genuine and counterfeit in different environments or by machine reading. However, there is a problem in that using materials with different functions to create a complex multi-layer structure requires complicated processes, making it difficult to accurately form the required image, and increasing manufacturing costs.

The present invention was made in consideration of these problems, and aims to provide a printed matter in which printed lines are formed in a simple manner and the image changes depending on the observation angle.

As a means for solving the above problems, a printed matter according to one aspect of the present invention is a printed matter having a printed portion made of a plurality of printed lines provided on at least a part of a substrate,
The plurality of printing lines are composed of two or more types of lines including at least a first line and a second line, the lines of each type are arranged alternately, and the first line and the second line, which are positioned so that the distance D between the center of the width W2 of the second line and the center of the width W1 of the adjacent first line is the shortest, satisfy the relationship of (Formula 1), and the shortest distance D is 115 μm or less.
4.3≦W1/W2≦10.3 (Formula 1)

The printed matter of the present invention is formed from multiple printed lines that satisfy the above-mentioned configuration, so the printed lines are not seen as single lines by the observer, but the image changes depending on the observation angle. This change in image can add a sense of luxury and interest. Furthermore, even if the printed matter is copied, the shape of the printed lines cannot be reproduced, making it difficult to counterfeit, and a high level of effectiveness in preventing counterfeit printing can be achieved.

FIG. 1 is a plan view showing a printed matter according to one embodiment of the present invention. 2A and 2B are diagrams showing a printing unit according to a first embodiment of the present invention, in which FIG. 2A is a top view and FIG. 2B is a cross-sectional view taken along line IIa-IIa in FIG. 2A. 3A and 3B are diagrams showing a printing unit according to a second embodiment of the present invention, in which FIG. 3A is a top view and FIG. 3B is a cross-sectional view taken along line IIb-IIb in FIG. 4A and 4B are diagrams showing a part of a printing unit according to a second embodiment of the present invention, in which FIG. 4A is a top view and FIG. 4B is a cross-sectional view taken along line IIc-IIc in FIG. FIG. 5(a) is a diagram showing how the cross-sectional view taken along the cutting line IIb-IIb in FIG. 3(a) appears at a first observation angle (S1), a second observation angle (S2), and a third observation angle (S3), and FIG. 5(b) is a diagram showing examples of images viewed at each observation angle in the example printed line pattern shown in FIG. 4(a). FIG. 6(a) is a top view showing an alternating arrangement of first and second print lines of a printing unit according to a first embodiment of the present invention, and FIG. 6(b) is a cross-sectional view taken along line VIII-VIII in FIG. 6(a). Figure 7(a) is a top view showing the alternating arrangement of first, second and third lines of a printing section relating to the second embodiment of the present invention, and Figure 7(b) is a cross-sectional view showing the position of the cutting line VIV-VIV in Figure 7(a).

The present invention will be described in detail with reference to Figs. 1 to 7. The present invention relates to a printed matter having a printing section. Note that the present invention is not limited to the embodiments described below. Various changes or modifications can be made to the present invention based on the knowledge of those skilled in the art. Furthermore, embodiments to which such changes or modifications have been made are also included in the scope of the present invention.

First Embodiment
(Printed matter)
A first embodiment of the printed matter according to the present invention has a printed part on a substrate. Fig. 1 shows a plan view of a printed matter 500 of this embodiment, and Fig. 2 shows a plan view and a cross-sectional view of a printed part 100 taken along the line IIa-IIa. As shown in Fig. 1, the printed matter 500 of the present invention has, on a part of the surface of a substrate 103, a printed part 100 consisting of a plurality of printed lines which are parallel to each other and extend in one direction.

<Printing Department>
As shown in Fig. 2, the printing unit 100 includes printed lines 130 including at least two types of printed lines 130x and 130y formed on the substrate 103. The printed lines 130x and the printed lines 130y are arranged alternately. The pattern of the printed lines 130 only needs to include a plurality of lines arranged in at least one direction, and the number of lines is not limited. Each part constituting the printing unit 100 will be described in detail below.

[Printing substrate]
The printing substrate 103 may be paper, plastic film, glass plate, or metal, or may be any material that has been used for printing, but is not limited to these. In terms of print visibility, the printing substrate 103 is preferably plastic. The thickness of the printing substrate 103 may be, but is not limited to, 10 μm or more and 3 mm or less. The long side of the printing substrate 103 may be, but is not limited to, 3 cm or more and 3 m or less.

Examples of paper that can be used for the printing substrate 103 include various types of paper with excellent surface properties that are used for normal publication printing and advertising materials. For example, mirror coated paper, coated paper, art paper, and high-quality paper, but carton paper and cardboard used for packaging materials are also acceptable. Synthetic paper (product names include "Yupo (trademark)" and "Peach Coat (trademark)") is also preferred because it has little expansion and contraction.

The plastic film that can be used for the printing substrate 103 can be a thermoplastic plastic film. The thermoplastic plastic can also be a cast film. Examples of the plastic film include the following materials: polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene, polypropylene, and polymethylpentene; cellulose esters or derivatives thereof such as cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate (CAP), cellulose acetate phthalate, and cellulose nitrate; polyvinylidene chloride; polyvinyl alcohol; polyethylene vinyl alcohol; syndiotactic polystyrene; polycarbonate; polyether ketone; polyimide; polyether sulfone (PES); polyphenylene sulfide; polysulfones; polyetherimide; polyether ketone imide; polyarylate; acrylic resins such as polymethyl methacrylate (PMMA); and cycloolefin resins such as norbornene resin.

The glass plate that can be used for the printing substrate 103 can be a glass plate of soda-lime glass, barium-strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, or quartz glass. The metal that can be used for the printing substrate 103 can be, for example, copper, brass, aluminum, aluminum alloy, stainless steel, or steel. These metals are preferably rolled plates.

[Printed lines]
FIG. 2(a) shows a top view of a plurality of printed lines 130x (first lines) and a plurality of printed lines 130y (second lines) extending in one direction, and FIG. 2(b) shows a cross-sectional view along the cutting line IIa-IIa. The plurality of printed lines 130x have the same width, and the intervals between adjacent printed lines 130x are the same. The plurality of printed lines 130y have the same width, and the intervals between adjacent printed lines 130y are the same. Furthermore, the plurality of printed lines 130x and 130y are alternately arranged, and the intervals between adjacent 130x and 130y in the same direction, which is either the left or right direction in FIG. 2, are the same. For example, the interval between a certain printed line 130y and a printed line 130x located to the right of it in FIG. 2 are the same regardless of the printed line 130y.

FIG. 3(a) shows a top view of a plurality of printed lines 130x, a plurality of printed lines 130y, and a plurality of printed lines 130z (referred to as third image lines) extending in one direction, and FIG. 3(b) shows a cross-sectional view taken along line IIb-IIb. The plurality of printed lines 130x have the same width, and the intervals between adjacent printed lines 130x are the same. The plurality of printed lines 130y have the same width, and the intervals between adjacent printed lines 130y are the same. Furthermore, the plurality of printed lines 130z have the same width, and the intervals between adjacent printed lines 130z are the same. Here, the printed lines 130x of the first image lines, the printed lines 130y of the second image lines, and the printed lines 130z of the third image lines alternate, i.e.,
They are arranged in the order of 130x, 130y, 130z, 130x, 130y, etc.
The printing unit 100 may have an area consisting of the printed lines 130x of the first object line and the printed lines 130y of the second object line, or may have an area consisting of the printed lines 130x of the first element, the printed lines 130y of the second object line and the printed lines 130z of the third object line, or may have both. Note that the terms "first object line,""second object line" and "third object line" are used merely for the purpose of distinction, and which are the first object line, the second object line and the third object line are optional.

Figure 4(a) shows a top view of an example of a printed line pattern composed of the printed lines 130x, 130y, and 130z shown in Figure 3(a). That is, the printed lines 130y of the second line and the third line 130z are arranged in the gaps between the printed lines 130x of the first line, and one printed line 130y of the second line and one printed line 130z of the third line are positioned in order relative to one printed line 130x of the first line. In the line length direction of the printed line 130x of the first line, the printed lines 130y of the second line and the printed lines 130z of the third line change their lengths according to the image to be displayed. A cross-sectional view at the cutting line IIc-IIc is shown in Figure 4(b). Depending on the position of the cutting line, only the printed line 130x of the first line may be positioned, and the printed lines 130y of the second line and the printed lines 130z of the third line may or may not be positioned.

The difference in the appearance of the image when the pattern of printed lines as shown in FIG. 3(a) is observed from the top side is explained with reference to FIG. 5(a). The image seen from the first observation angle (S1), which is the observation angle from the front, the second observation angle (S2) tilted in one direction from the front, and the third observation angle (S3) tilted in the other direction from the front, differ. The image seen from the first observation angle (S1) is formed from both the printed lines 130y of the second image line and the printed lines 130z of the third image line. The image seen from the second observation angle (S2) is hidden by the printed lines 130x of the first image line, and the printed lines 130z of the third image line cannot be seen, so the pattern formed from the printed lines 130y of the second image line is visible. Additionally, in the image viewed from the third observation angle (S3), the pattern formed by the printed lines 130z of the third image line is visible because the printed lines 130y of the second image line are hidden by the printed lines 130x of the first image line and cannot be seen.

Figure 5(b) shows the images seen at each observation angle for the example printed line pattern shown in Figure 4(a). The image seen from the second observation angle (S2) is an "O" pattern, the image seen from the third observation angle (S3) is an "E" pattern, and the image seen from the first observation angle (S1) is a combination of these and seen as a "sun" pattern. Note that the pattern of the printed lines 130x of the first image line looks the same regardless of the observation angle, and does not particularly attract the observer's attention when the observation angle is changed, so it has been omitted from Figure 5(b).

Next, the printing line 130 will be described in detail with reference to FIG. 6. FIG. 6(a) is a perspective view showing an example of the configuration of the top surface shape of the printing unit 100 and the position of the cutting line VIII-VIII. FIG. 6(b) is a cross-sectional view showing a part of a cross section along the cutting line VIII-VIII in the printing unit of FIG. 6(a).

The cross-sectional shape of the printed line 130 (130x, 130y) formed on the substrate 103 is convex as shown in FIG. 6(b), the lower surface that contacts the substrate 103 is linear, and the line connecting the contact point with the substrate 103 and the upper surface portion is a gently curved convex shape.
Here, the width of printed line 130xa, which is the printed line 130x of the first image line on the substrate 103 (the distance between the two points at which printed line 130xa contacts substrate 103 in FIG. 6(b)), is defined as W1a, and the width of printed line 130xb (the distance between the two points at which printed line 130xb contacts substrate 103 in FIG. 6(b)) is defined as W1b. Also, the height of printed line 130x of the first image line from substrate 103 (the distance between the highest point of printed line 130x of the first image line and the surface of substrate 103 in FIG. 6(b)) is defined as H1.

The width of one printed line, printed line 130ya (the distance between the two points where printed line 130ya contacts substrate 103 in FIG. 6(b)) is defined as W2, and the height of printed line 130ya from substrate 103 (the distance between the highest point of printed line 130ya and the surface of substrate 103 in FIG. 6(b)) is defined as H2. Of the distance between the center of width of printed line 130xa and the center of width of printed line 130ya, and the distance between the center of width of printed line 130xb and the center of width of printed line 130ya, the shortest is defined as D2, and the longer is defined as D2x.

In this embodiment, the arithmetic mean W1 (W1 = (W1a + W1b) / 2) of the widths W1a and W1b of the printing lines 130x and 130y (in the above explanation, 130xa, 130xb, and 130ya were used as examples, but either one is acceptable) and the width W2 must satisfy the following formula (Formula 1).
4.3≦W1/W2≦10.3 (Formula 1)

In FIG. 6, the width W1 of the printed line 130x is preferably 20 μm or more and 200 μm or less. If it is less than 20 μm, the formation of the height of the printed line is not stable, which is not preferable. If it is more than 200 μm, the printed lines 130x are easily visible one by one, which is not preferable. The width W2 of the printed line 130y is preferably 3.5 μm or more and 30 μm or less. If it is less than 3.5 μm, the printed lines are difficult to see, which is not preferable. If it is more than 30 μm, the width of the printed line 130x needs to be increased, which makes the printed line 130x easily visible, which is not preferable. It is preferable that the shortest distance D2 between the printed line 130y and the adjacent printed lines 130xa and 130xb is 115 μm or less. If it is greater than 115 μm, the distance between the printing lines 130y and 130x that causes the image change will be large, and the change will be difficult to see even if the viewing angle is changed significantly, which is not preferable.

The height H1 of the printed line 130x is preferably 2.0 μm or more and 10.0 μm or less. If it is less than 2.0 μm, it is not preferable because it is difficult to conceal the printed line 130y. If it is more than 10.0 μm, it is not preferable because the unevenness of the printed line 130x is visible regardless of the observation angle. The height H2 of the printed line 130y is preferably 0.5 μm or more and 2.5 μm or less. If it is less than 0.5 μm, the particles contained in the printed line 130y are not sufficiently dispersed, and minute unevenness occurs on the surface and ends of the printed line 130y, making the printed line unclear, which is not preferable. If it is more than 2.5 μm, it is not preferable because it is difficult to conceal the printed line 130x.

As described above, by setting the values of W, D, and H, it is possible to make the image appear to change depending on the observation angle when the printing unit 100 has printing lines 130x and 130y (see Figure 2), as in the printout in Figure 1, for example.

In this embodiment, the printed line 130x is preferably colorless, white, or the same color as the substrate, which has transparency. It is preferable to use any of these colors because it makes the printed line 130y easier to see. Colorless and transparent means a property of being transparent to light. The transparent material according to this embodiment preferably transmits light from the ultraviolet region to the infrared region. In terms of wavelength region, it is preferable that the average transmittance is 50% or more in the wavelength region from 380 nm to 800 nm. If the printed line 130x is a colorless, transparent printed line having transparency and has a convex shape consisting of a gentle curve connecting the contact point with the substrate 103 and the upper surface portion, the color of the substrate is visible when observed from the front of the printed matter (the (S1) direction in FIG. 5(a)), and when observed from a first viewing angle, a light refraction effect is obtained due to the convex shape of the printed line and the refractive index of the resin or the like that constitutes the printed line, and the printed line 130y adjacent to the printed line 130x is not visible. Also, when observed from a second viewing angle, the printed line 130y is visible. That is, the printed lines 130x are difficult to see and have concealment properties.
Moreover, in terms of the wavelength region, white is preferably a color that does not have a maximum point in the wavelength range of 380 nm to 800 nm and has an average reflectance of 50% or more. Moreover, the color that is the same as the substrate is preferably a color that is equivalent in brightness to the substrate and is difficult to distinguish from the surface color of the substrate. Specifically, the ΔE* value, which is the color difference between the substrate and the printed line in the CIE L*a*b* color space, can be 4 or less, preferably 1 or less. When the printed line 130x is white, the reflected white color is visible when observed from the front of the printed matter (the (S1) direction in FIG. 5(a)), the reflected white color is visible and conceals the printed line 130y when observed from a first viewing angle, and the printed line 130y is visible when observed from a second viewing angle. That is, the color of the image to be viewed can be accentuated, and the brightness of the entire printed matter can be maintained.

[Ink]
The inks used to form the printing lines according to the present invention can be the four basic process ink colors (yellow, red, indigo, and black), but a wide variety of inks made by combining pigments, varnishes, and additives, so-called special colors, can also be used.
The raw materials that make up printing ink include colorants (pigments and dyes), vehicles (oils, resins, solvents, plasticizers), and additives (wax, dryers, surfactants, gelling agents, stabilizers, defoamers, etc.). Printing ink can be a mixture of these.
The size of the solid material contained in the ink needs only to be smaller than the width and height of the printed line, and is preferably equal to or less than half the height of the printed line to be formed. When the solid material is contained in the printed line formed, the effect of the printed line shape is obtained.
The solid content ratio in the ink is preferably 50% or more, and more preferably 70% or more. If the solid content ratio is high, the fluidity is suppressed when forming the printed line, and the shape of the printed line can be maintained. The upper limit of the solid content is not particularly limited, but can be 99% or less, or even 90% or less.

The color developer for the ink may be disazo yellow, brilliant carmine, phthalocyanine blue, etc., but is not limited to these, and any organic or inorganic pigment known in the printing field and used in process printing may be used as appropriate.
The pigments can be inorganic, organic or a mixture thereof. Inorganic pigments can be metal particles, oxides, hydroxides, sulfides, selenides, ferrocyanides, chromates, sulfates, carbonates, silicates, phosphates, carbon, or other particles, either alone or in admixture. Oxides can be titanium dioxide, zinc oxide, or black iron oxide.

The organic pigments can be carbon compounds, nitroso-based, nitro-based, azo-based, lake-based, phthalocyanine-based, or condensed polycyclic materials. They can also be phosphorescent or afterglow pigments, or metal oxides or quantum dots that emit light in response to light of a specific wavelength, such as ultraviolet or infrared. One of these pigments can be used, or multiple pigments can be mixed together.

The dyes can be acid dyes, basic dyes, solvent dyes, or disperse dyes.
In addition, pigments or dyes intended for these colors may be mixed with conductive polymers such as metal fine particles, conductive metal oxide fine particles, metal nanowires, metal chlorides, conductive polyaniline, conductive polypropylene, and conductive polythiophene (a complex of polyethylenedioxythiophene and polystyrene sulfonic acid) for the purpose of conductivity, and used as conductive inks.

The oil of the vehicle may be a vegetable oil, a processed oil, a mineral oil, either alone or in combination.The resin may be a natural resin, a derivative of a natural product, a synthetic resin, or in combination.
The vehicle oil may also be a curable compound (curable resin) that hardens to a solid. The curable compound may be a relatively low molecular weight curable compound (curable resin) such as an epoxy resin or a polyfunctional acrylic monomer (oligomer). A mixture thereof may also be used. The vehicle oil may not contain a curable functional group. Such vehicle oil may be polyester, polycarbonate, polyvinyl chloride, a copolymer of vinyl chloride and other unsaturated double bond-containing monomers, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, homopolymer of (meth)acrylic acid ester, copolymer of (meth)acrylic acid ester and other unsaturated double bond-containing monomers, polystyrene, copolymer of styrene and other unsaturated double bond-containing monomers, ketone-formaldehyde condensate or hydrogenated product thereof, epoxy resin, phenoxy resin, polyvinyl acetal or copolymer thereof, polyurethane, polyurea, polyamide, etc. These may be used alone or in combination of two or more. Further, the resin (polymer) may have a curable functional group at the side chain or end of the resin (polymer). These may be used alone or in combination of two or more kinds, including those with or without functional groups.

The curable compound (curable resin) contained in the binder resin preferably has a functional group. Particularly preferred are polyhydric alcohols having a hydroxyl group as a functional group, epoxy resins (glycidyl compounds) having an epoxy group (glycidyl group), polycarboxylic acids having a carboxyl group, and (meth)acrylate monomers or oligomers having a (meth)acrylic group.

〔solvent〕
The solvent that can be used in the present embodiment is not particularly limited, and examples thereof include diol solvents such as 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, tripropylene glycol, triethylene glycol, 1,2-hexanediol, 1.3 butylene glycol, 1,3-propanediol, dipropylene glycol, and 2-butene-1,4-diol. Further, polyhydric alcohols such as glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, ethylene glycol, diethylene glycol, 1,2-butanediol, propylene glycol, and 2-methylpentane-2,4-diol; monohydric alcohols such as butyl triglycol, isobutyl diglycol, 2-butoxyethanol, 3-methoxy-3-methylbutanol, 2-(2-methoxyethoxy)ethanol, and 2-(2-hexyloxyethoxy)ethanol; tripropylene glycol-n-butyl ether, butyl carbitol, diethylene glycol monomethyl ether, and tripropylene glycol monomethyl ether; Examples of the glycol ethers include ethylene glycol methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, ethylene glycol monohexyl ether, dipropylene glycol methyl ether, propylene glycol diacetate, 1,4-butanediol divinyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, and the like; glycol ethers, glycol esters, terpene solvents, hydrocarbon solvents, and alcohol solvents. Further, for example, saturated or unsaturated aliphatic hydrocarbon compounds such as tetradecane, octadecane, heptamethylnonane, tetramethylpentadecane, hexane, heptane, octane, nonane, decane, tridecane, methylpentane, normal paraffin, and isoparaffin; cyclic hydrocarbon compounds such as toluene and xylene; alicyclic hydrocarbon compounds such as limonene, dipentene, terpinene, terpinene (also called terpinene), nesol, sinene, orange flavor, terpinolene, terpinolene (also called terpinolene), phellandrene, menthadiene, terebene, dihydrocymene, mosulene, isoterpinene, isoterpinene (also called isoterpinene), chrytomene, cautusine, cajepten, eulimene, pinene, terebin, menthane, pinane, terpene, cyclohexane; aliphatic alcohols such as saturated or unsaturated aliphatic alcohols having 6 to 30 carbon atoms, such as 1-octanol, 2-octanol, 3-octanol, etc.), decanol (1-decanol, etc.), lauryl alcohol, tetradecyl alcohol, cetyl alcohol, 2-ethyl-1-hexanol, octadecyl alcohol, hexadecenol, oleyl alcohol, etc.; cyclic alcohols such as cresol, eugenol, etc.; cycloalkanols such as cyclohexanol, etc.; terpene alcohols (monoterpene alcohols, etc.) such as terpineol (including terpineol, α, β, γ isomers, or any mixture thereof), dihydroterpineol, etc.; and cyclic alcohols such as dihydroterpineol, myrtenol, sobrerol, menthol, carveol, perillyl alcohol, pinocarveol, sobrerol, verbenol, etc.
For quick-drying inks, it is possible to use solvents with low boiling points (MEK, ethanol, acetone, etc.) that dry at room temperature, and for water-based inks, it is possible to use water (purified water).

The printed matter of this embodiment is preferably formed by a printing method.

In this embodiment, a known method can be used as the printing method, and among them, intaglio printing represented by gravure printing is preferred, and gravure offset printing is particularly preferred. The printing device used can also be a known one, and for example, in the case of intaglio printing represented by gravure printing, a metal intaglio plate having grooves on the surface that serve as the mold for fine lines can be used.

The offset roll can be a metal cylinder with the surface covered with a blanket material. Examples of the blanket material include elastic materials such as silicone resin, fluororesin, urethane resin, synthetic rubber, and natural rubber. Among these, silicone resin is particularly preferred because it has high durability and oil resistance, sufficient elasticity, and moderate stiffness, making it particularly suitable for gravure offset printing on hard substrates.

Gravure offset printing is also called intaglio offset printing.
In gravure offset printing, a gravure plate (intaglio) having recesses corresponding to the conductive pattern, a doctor blade for filling the recesses of the gravure plate (intaglio) with a printing composition, and a blanket having a surface made of, for example, silicone rubber are used. The intaglio used in gravure offset printing may have a different shape from the normal intaglio used in general-purpose gravure printing. Hereinafter, the "gravure plate or intaglio" used in gravure offset printing may be abbreviated to "gravure plate (intaglio)".

The printing composition is first transferred to the blanket from the recesses of the gravure plate (intaglio plate). A substrate is then placed opposite the blanket, and the two are pressed together to transfer the pattern on the blanket back onto the substrate, forming a print pattern.

This printing method allows the shape of the printed pattern to be freely set by changing the shape of the recesses, making it possible to precisely form printed patterns ranging from fine printed line patterns to large area patterns.

As the gravure plate (intaglio plate), a known one can be used.
The gravure plate (intaglio plate), blanket, and substrate may each be flat (sheet-shaped) or cylindrical. The blanket may be pressed against the substrate to continuously transfer the pattern on the blanket to the substrate.

When printing on multiple substrates using one blanket, it is also preferable to include a step of drying the blanket that has absorbed the solvent after printing. This drying step may be performed after each printing cycle, or may be performed at intervals after every 5 to 20 printing cycles.

The blanket is preferably made of silicone rubber. A sheet having a silicone rubber layer on its surface is preferred. It is preferably used wrapped around a rigid cylinder called a blanket cylinder. For example, a silicone blanket in which a silicone rubber layer is formed on a plastic film such as a polyester film can be used wrapped around a blanket cylinder.

[Method of manufacturing printed matter]
Next, a method for producing a printed matter according to one embodiment of the present invention will be described.
The method for producing a printed matter according to the present embodiment includes a step of forming a printed part on a substrate. A substrate formed of an appropriate material is selected. Next, the step of forming a printed part can be performed using a technique of gravure offset printing. In the gravure offset printing method, ink is supplied onto a metal intaglio plate on whose surface grooves that serve as a mold for fine lines have been adjusted to a predetermined width and depth, excess ink is removed by a doctor blade, and the ink filled in the grooves is transferred to the surface of a blanket material of an offset roll, the surface of which is a metal cylinder covered with a blanket material made of silicone resin, and then the ink is transferred to the surface of the substrate that has been transported, thereby performing printing. The substrate to which the desired shape has been transferred is heated and cured by hot air or infrared rays, cured by light irradiation, or left to stand for several days to be cured, thereby forming a printed part having the desired shape.

Second Embodiment
Fig. 7A is a cross-sectional perspective view showing a printing unit according to a second embodiment of the present invention. This embodiment is a cross-sectional perspective view showing another example of the upper surface shape of the printing unit 100 and the position of the cutting line VIV-VIV. Fig. 7B is a cross-sectional view showing a part of a cross section taken along the cutting line VIV-VIV in the printing unit in Fig. 7A.

As in the first embodiment, the cross-sectional shape of the printed line 130 (130x, 130y, 130z) formed on the substrate 103 is convex as shown in FIG. 7(b), the lower surface that contacts the substrate 103 is straight, and the line connecting the contact point with the substrate 103 and the upper surface portion is convex and gently curved as shown in FIG.
As in the first embodiment, the width of the printed line 130x on the substrate 103 is defined as W1a and W1b, and the height from the substrate 103 is defined as H1. The width of the printed line 130ya, which is one printed line, is defined as W2, and the height from the substrate 103 is defined as H2. The width of the printed line 130za, which is one printed line (the distance between the points at both ends where the printed line 130za contacts the substrate 103 in FIG. 7B) is defined as W3, and the height from the substrate 103 (the distance between the highest point of the printed line 130za and the surface of the substrate 103 in FIG. 7B) is defined as H3. Of the distance between the center of the width of the printed line 130xa and the center of the width of the printed line 130ya, and the distance between the center of the width of the printed line 130xb and the center of the width of the printed line 130ya, the shortest one is defined as D2, and the longer one is defined as D2x. In addition, the shortest distance between the center of the width of the printed line 130xa and the center of the width of the printed line 130za and the distance between the center of the width of the printed line 130xb and the center of the width of the printed line 130za are defined as D3 and the longer distance is defined as D3x. In this case, as in the above-mentioned embodiment, it is preferable that the distances D2 and D3 are 115 μm or less. If it is larger than 115 μm, the distance between the printed lines 130y and 130z and the printed line 130x that cause image changes is large, and it is not preferable because the change is difficult to visually recognize even if the viewing angle is changed greatly.

In this embodiment, the arithmetic mean W1 (W1 = (W1a + W1b) / 2) of the widths W1a and W1b of the printing lines 130x, 130y, and 130z (in the above explanation, 130xa, 130xb, 130ya, and 130za have been used as examples, but any of them may be used) and the widths W2 and W3 must satisfy the following mathematical formulas (Formula 1) and (Formula 2).
4.3≦W1/W2≦10.3 (Formula 1)
4.3≦W1/W3≦10.3 (Formula 2)

Examples that embody the above-mentioned embodiments will be described below, along with comparative examples for comparison. In the following examples, observations were performed using a laser microscope to measure the width, height, and spacing of the printed portion 130. Specifically, at 10 randomly selected locations, images of each selected printed portion were obtained, and then the width W, height H, and length shown in Figures 6 and 7 were determined. The arithmetic mean value of the measurements at the 10 locations was taken as the characteristic value of the printed line that constitutes the printed portion 100.

Example 1
A coated paper having dimensions of 200 mm×200 mm and a thickness of 130 μm was cut out to prepare a substrate 103 .
Next, white and red printing was performed on the substrate 103 by gravure offset printing to form a plurality of white printed lines and red printed lines extending parallel to one direction as shown in Fig. 6(a), thereby obtaining a printed matter 500 including a printed portion 100. As shown in Fig. 6(b), the bottom surface of the printed line 130 was flat in contact with the substrate 103, and the top surface was convex.
In plan view, the printed line 130x obtained as described above had a width W1 of 50.4 μm, a height H1 obtained by arithmetically averaging the height H1a of the printed line 130xa and the height H1b of the printed line 130xb was 3.0 μm, and the printed line 130y had a width W2 of 5.1 μm, a height H2 of 0.6 μm, and the shortest distance D2 from 130x was 29.8 μm.

Next, W1/W2 was calculated from the values of W1 and W2, which was 9.9.

Next, the procedure of Example 1 was repeated, except for changing the concave plate used to form the printing lines, to obtain printed matter 500 including the printed portion 100 of Examples 2 to 8.

Example 2
In Example 2, the printed line 130x had a width W1 of 20.5 μm and a height H1 of 2.0 μm, the printed line 130y had a width W2 of 3.5 μm and a height H2 of 0.5 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 14.0 μm. W1/W2 was 5.8.

Example 3
In Example 3, the printed line 130x had a width W1 of 20.3 μm and a height H1 of 3.3 μm, the printed line 130y had a width W2 of 5.2 μm and a height H2 of 0.6 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 14.7 μm. W1/W2 was 3.9.

Example 4
In Example 4, the printed line 130x had a width W1 of 80.3 μm and a height H1 of 5.2 μm, the printed line 130y had a width W2 of 13.1 μm and a height H2 of 1.1 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 48.7 μm. W1/W2 was 6.1.

Example 5
In Example 5, the printed line 130x had a width W1 of 150.6 μm and a height H1 of 10.0 μm, the printed line 130y had a width W2 of 20.2 μm and a height H2 of 1.8 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 87.5 μm. W1/W2 was 7.5.

Example 6
In Example 6, the printed line 130x had a width W1 of 45.0 μm and a height H1 of 3.0 μm, the printed line 130y had a width W2 of 5.2 μm and a height H2 of 0.6 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 28.2 μm. W1/W2 was 8.7.

Example 7
In Example 7, the printed line 130x had a width W1 of 70.4 μm and a height H1 of 3.5 μm, the printed line 130y had a width W2 of 15.3 μm and a height H2 of 1.2 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 44.8 μm. W1/W2 was 4.6.

Example 8
In Example 8, the printed line 130x had a width W1 of 200.2 μm and a height H1 of 5.0 μm, the printed line 130y had a width W2 of 26.0 μm and a height H2 of 2.0 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 115.0 μm. W1/W2 was 7.7.

Next, the procedure of Example 1 was repeated, except that the intaglio plate used to form the printed lines was changed, and three types of intaglio plates were used, to obtain printed matter 500 including printed portion 100 of Examples 9 to 11. As shown in Figure 7(a), multiple white printed lines, red printed lines, and indigo printed lines extending parallel to one direction were formed, thereby obtaining printed matter 500 including printed portion 100. As shown in Figure 7(b), the bottom surface of printed line 130 was flat in contact with substrate 103, and the top surface was convex.

<Example 9>
In Example 9, the printed line 130x had a width W1 of 50.4 μm and a height H1 of 3.0 μm, the printed line 130y had a width W2 of 4.9 μm and a height H2 of 0.6 μm, and the shortest distance D2 from 130x was 29.7 μm, and the printed line 130z had a width W3 of 4.9 μm and a height H3 of 0.5 μm, and the distance D3 from 130x was 29.7 μm. W1/W2 was 10.3, and W1/W3 was 10.3.

Example 10
In Example 10, the printed line 130x had a width W1 of 20.4 μm and a height H1 of 2.3 μm, the printed line 130y had a width W2 of 3.7 μm and a height H2 of 0.5 μm, and the shortest distance D2 from 130x was 14.0 μm, and the printed line 130z had a width W3 of 3.5 μm and a height H3 of 0.5 μm, and the distance D3 from 130x was 13.9 μm. W1/W2 was 5.5, and W1/W3 was 5.8.

Example 11
In Example 11, the printed line 130x had a width W1 of 85.1 μm and a height H1 of 5.2 μm, the printed line 130y had a width W2 of 20.0 μm and a height H2 of 2.5 μm, and the shortest distance D2 from 130x was 54.5 μm, and the printed line 130z had a width W3 of 20.0 μm and a height H3 of 1.9 μm, and the distance D3 from 130x was 54.5 μm. W1/W2 was 4.3, and W1/W3 was 4.3.

Next, the procedure of Example 1 was repeated, except that the concave plate used to form the printed lines was changed, to obtain printed matter 500 including printed portions 100 of Comparative Examples 1 to 4.

<Comparative Example 1>
In Comparative Example 1, the printed line 130x had a width W1 of 18.8 μm and a height H1 of 1.9 μm, the printed line 130y had a width W2 of 10.0 μm and a height H2 of 0.9 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 16.5 μm. W1/W2 was 1.9.

<Comparative Example 2>
In Comparative Example 2, the printed line 130x had a width W1 of 30.5 μm and a height H1 of 1.0 μm, the printed line 130y had a width W2 of 2.0 μm and a height H2 of 0.4 μm, and the shortest distance D2 from 130x was 17.5 μm. W1/W2 was 15.3.

<Comparative Example 3>
In Comparative Example 3, the printed line 130x had a width W1 of 511.5 μm and a height H1 of 4.2 μm, the printed line 130y had a width W2 of 5.0 μm and a height H2 of 2.0 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 261.0 μm. W1/W2 was 102.3.

<Comparative Example 4>
In Comparative Example 4, the printed line 130x had a width W1 of 301.5 μm and a height H1 of 20.0 μm, the printed line 130y had a width W2 of 35.0 μm and a height H2 of 2.7 μm, and the shortest distance D2 between the printed line 130x and the printed line 130y was 171.5 μm. W1/W2 was 8.6.

<Evaluation>
The printed matter of Examples 1 to 11 and Comparative Examples 1 to 4 was placed under a white light source, and the printed matter was rotated 90 degrees relative to the length direction of the printed lines from a position 30 cm away from the printed surface, tilted to the front, which is the perpendicular direction of the substrate, and in one direction different by 90 degrees from the length direction of the printed lines, and then tilted to the other direction, which is the opposite direction, and visual evaluation was performed for each. When the individual printed lines were not visible and the directionality could not be recognized, that is, when the printed part looked flat, it was judged as (◯), when the direction of the printed lines was recognized (△), and when each printed line was visible (X).
A comprehensive judgment was made based on the judgment regarding whether or not the above-mentioned printed lines were visible, as well as the judgment regarding whether or not the color image changed in appearance from light purple when viewed from the front, to red when tilted in one direction, and to indigo when tilted in the other direction, as shown in Table 1.
That is, when the line was not visible (◯) or changed (◯), the overall judgment was ◎. As shown in Table 1 below, when the direction of the line was recognizable (△) and changed (◯), the overall judgment was ◯. When the line was not visible (◯) or did not change (×), the overall judgment was ×, and when the line was visible (×) or did not change (×), the overall judgment was XX.

The characteristic values and evaluation results of Examples 1 to 11 and Comparative Examples 1 to 4 are summarized in Table 2.

As shown in Table 2, the printed matter of Examples 1 to 11, which has printed lines with appropriate shapes that satisfy (Equation 1) and (Equation 2), had no visible printed lines, but the color of the image changed when observed continuously while changing the angle. As described above, it was confirmed that the printed matter has high color change performance that is angle-dependent. This is presumably because printed lines with good shapes were formed.

On the other hand, in the printed matter of Comparative Example 1, the individual printed lines were not visible, but the image did not change even when the viewing angle was changed, and it was defective. This is presumably because the printed line of the first line was small in size, and the printed line of the second line and the printed line of the third line were not concealed.

In the printed matter of Comparative Example 2, the individual printed lines were not visible, but the printed lines were unclear and the image did not change even when the viewing angle was changed, making it a defective product. It is presumed that the image was not displayed sufficiently and was not visible due to the small line width and low height of the printed lines.

The printed matter of Comparative Example 3 was defective because each of the printed lines was visible and the image did not change. It is presumed that the width of the first image was large, and each of the printed lines was visible. In addition, it is presumed that the proportion of the printed lines of the first image was large and the number of printed lines of the second image was relatively small, and therefore the area of the displayed color was small and not visible.

In the printed matter of Comparative Example 4, each printed line was visible, but the color of the image changed when the viewing angle was changed. It is presumed that the width of the second image line was large, and each printed line was visible.

100 Printing section 103 Substrate 130 Printing lines 130x, 130y, 130z Printing lines 130xa, 130xb, 130xc Printing lines of first image line 130ya, 130yb, 130yc Printing lines of second image line 130za, 130zb, 130zc Printing lines of third image line 500 Printed matter

Claims (4)

a printed matter having a printed portion consisting of a plurality of printed lines provided on at least a portion of a substrate, the plurality of printed lines consisting of two or more types of printed lines including at least a first image line and a second image line, the image lines of each type being alternately arranged, the first image line and the second image line which are positioned so that a distance D between a center of a width W2 of the second image line and a center of a width W1 of an adjacent first image line is shortest, satisfying the relationship of (Equation 1), and the shortest distance D is 115 μm or less, a height H1 of the first image line of the plurality of printed lines being within a range of 2.5 to 10.0 μm, and a height H2 of the second image line being within a range of 0.5 to 2.0 μm .
4.3≦W1/W2≦10.3 (Formula 1) The printed matter according to claim 1, characterized in that the width W1 of the first lines of the plurality of printing lines is within the range of 20 to 200 μm, and the width W2 of the second lines is within the range of 3.5 to 30 μm. 3. The printed matter according to claim 1 , wherein the first image line is transparent and colorless, white, or the same color as the base material. 4. The printed matter according to claim 1 , wherein the plurality of printing lines are formed by a gravure offset printing method.