JP7746777B2 - Laminate, card and booklet using laminate - Google Patents

Description

The present invention relates to a laminate that can be laser marked, and cards and booklets that use the laminate.

Technology has been known in the past in which a substrate is colored by irradiating it with laser light, thereby performing printing and other operations. When laser light is irradiated onto a color-forming layer, heat is generated by the energy of the laser light, and this heat can cause deformation or foaming in or near the printed portion of the color-forming layer or a laminate containing the color-forming layer.

In this regard, Patent Document 1 discloses a technique for adjusting the thickness of the color-forming layer, and Patent Document 2 discloses a technique for using a color-forming layer and adhesive layer in a card sheet that satisfy specified glass transition temperature conditions. These techniques, through their respective configurations, prevent deformation and foaming of the card sheet.

Patent Document 3 also describes a laser marking laminate comprising a base film, a color-forming layer that develops color when irradiated with laser light, and a reflective layer that reflects the laser light, provided on the side of the color-forming layer opposite the side that is irradiated with laser light, the reflective layer containing a scaly filler. By providing a layer containing a scaly filler in the color-forming layer that develops color when irradiated with laser light, the layer reflects the laser light, enabling the desired recording to be performed with laser light of an intensity that is unlikely to damage the base film.

Japanese Patent Application Laid-Open No. 2004-148642 Japanese Patent Application Laid-Open No. 2004-243685 Patent No. 6342042

When printing color on a card using laser light, it is preferable to provide as much contrast as possible with the background to make it easier to see, while also preventing deterioration in appearance quality due to foaming of the card material, etc.

The present disclosure has been made in light of these circumstances, and aims to provide a laminate that improves the visibility of the color pattern formed on the card by irradiating it with laser light, suppresses foaming of the card material, and improves appearance quality, as well as cards and booklets that use the laminate.

The laminate according to this embodiment comprises a substrate, an expansion-inhibiting layer provided on one side of the substrate, and a laser coloring layer provided on the side of the expansion-inhibiting layer opposite the substrate. The laser coloring layer is transparent to visible light, and the expansion-inhibiting layer contains a pearl pigment and a black or chromatic pigment.

Furthermore, in the laminate according to another embodiment of this invention, it is preferable that the black or chromatic pigment in the foam-inhibiting layer does not contain carbon black.

In addition, the laminate according to another embodiment of the present invention may further include a colored layer containing a black or chromatic pigment, and may be provided between the foaming suppression layer and the laser coloring layer, or on the side of the foaming suppression layer opposite the laser coloring layer.

Furthermore, in another embodiment of the laminate, it is preferable that the black or chromatic pigment in the colored layer does not contain carbon black.

Furthermore, in a laminate according to another embodiment of the present invention, the ratio of the weight of the pearl pigment particles in the expansion-inhibiting layer to the weight of the ink constituting the expansion-inhibiting layer after solidification may be 1 or less.

Furthermore, in a laminate according to another embodiment of the present invention, the height of the portion of the laser coloring layer irradiated with laser light relative to the surface not irradiated with laser light may be 100 μm or less.

In another embodiment of the laminate, the laminate may further include a second expansion-inhibiting layer provided on the other side of the substrate, a transparent layer that is transparent to visible light and provided on the side of the second expansion-inhibiting layer opposite the substrate, and a second colored layer that contains a chromatic or achromatic pigment; when irradiated with laser light in a predetermined pattern under predetermined conditions, the second colored layer is partially removed in a pattern corresponding to the predetermined pattern, and the underlying second expansion-inhibiting layer can be seen as the predetermined pattern through the transparent layer.

A card equipped with a laminate according to this embodiment may include any of the laminates described above.

A booklet including the laminate according to this embodiment may include any of the laminates described above.

This embodiment makes it possible to provide a laminate, as well as cards and booklets using the laminate, that improve the visibility of the color pattern formed on the card by irradiating it with laser light and suppress foaming of the card material, thereby improving the appearance quality.

1A and 1B are a plan view and a cross-sectional view illustrating the structure of a card that is a laminate of the first embodiment. 10A and 10B are cross-sectional views illustrating the structure of a card according to a modified example of the first embodiment. 10A and 10B are a schematic perspective view and a cross-sectional view illustrating the structure of a booklet, which is a stack of the second embodiment. FIG. 10 is a diagram showing the state of laser coloring on a card.

An example of a laminate according to the present disclosure will be described below with reference to the drawings, etc. However, the laminate according to the present disclosure is not limited to the embodiments and examples described below.

The figures shown below are schematic illustrations. Therefore, the size and shape of each part have been exaggerated as appropriate to make them easier to understand. Furthermore, hatching indicating the cross section of a component has been omitted as appropriate in each figure. The numerical values, such as dimensions, and material names of each component described in this specification are examples of an embodiment and are not limited to these, and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include substantially the same state in addition to their strict meaning.

1. First Embodiment A first embodiment, which is an example of an embodiment of a laminate of the present disclosure, will be described. FIG. 1( a) is a plan view of a card 1, which is one type of laminate of the present disclosure, viewed from a direction perpendicular to one of its surfaces. While this surface is conveniently referred to as the front surface 1p, in practice, either the front surface or the other surface of the card 1 may be referred to as the front or back surface. The card 1 has length and width dimensions, thickness, and shape conforming to ISO/IEC 7810, which are typically used as credit cards, cash cards, employee ID cards, etc. The laminate of the present disclosure primarily refers to a product formed by joining and integrating multiple resin layers, paper layers, etc., by heat fusion or adhesive, and exemplifies the laminate, which includes booklets such as passports and savings books, cards, and intermediate products such as laminated sheets for manufacturing these.

For ease of explanation, an XYZ Cartesian coordinate system is set for card 1. As shown in Figure 1(a), the Z axis is taken in the normal direction to the front of the card, and the X axis is taken in the direction along the long side of card 1. The Y axis is taken in the direction along the short side of card 1. The direction from back side 1q to front side 1p of card 1 along the Z axis is the +Z direction, and the opposite direction is the -Z direction. The direction along the Z axis is also simply referred to as the up-down direction. The direction from left to right along the X axis is the +X direction, and the opposite direction is the -X direction. The direction along the X axis is also simply referred to as the left-right direction. Furthermore, the direction from bottom to top of the paper along the Y axis is the +Y direction, and the opposite direction is the -Y direction.

Figure 1(b) is a plan view of card 1 in Figure 1(a) with the card 1 turned over and positioned so that the back surface 1q faces the front. Figure 1(c) is a cross-sectional view of card 1 in Figure 1(a) taken along line A-A along the Y axis, viewed from the +X direction.

(a) Card Structure As shown in FIG. 1(c), the card 1 is configured by laminating and integrating, in order from the back surface 1q side, i.e., the -Z direction side, a laser coloring layer 6, an expansion suppression layer 120, a core layer 5, a core layer 4, an expansion suppression layer 110, an oversheet layer 3, and a concealing coloring layer 2. Of these, the expansion suppression layer 120 is disposed over substantially the entire surface of the card 1 along the XY plane, while the expansion suppression layer 110 is disposed only in a portion of the corner of the card 1 along the XY plane, as shown by the area surrounded by the dashed line in FIG. 1(a). Therefore, the card 1 has an area where the core layer 4 and the oversheet layer 3 are directly bonded and an area where they are bonded via the expansion suppression layer 110. The oversheet layer 3 is also referred to as a transparent layer, and the core layers 4 and 5 are also referred to as substrates.

However, the configuration of the card 1 is not limited to this, and the expansion suppression layer 120 may be arranged on only a portion of the surface of the card 1 along the XY plane, or conversely, the expansion suppression layer 110 may be arranged over the entire surface of the card 1 along the XY plane. Also, a different layer may be arranged between adjacent layers.

As shown in Figures 1(a) and 1(b), when the surface 1p of the card 1 is viewed in plan, a concealing colored layer 2 that constitutes the leading edge of the card 1 on the +Z direction side is visible across the entire surface 1p. The concealing colored layer 2 is a printed layer formed, for example, from an ink with a silvery metallic luster that uses aluminum powder as a coloring pigment. Furthermore, when the surface 1p of the card 1 is viewed in plan, a first pattern 310, exemplified by a combination of alphanumeric characters "A1234," is visible at the corners on the -X direction side and the -Y direction side.

On the other hand, when the back surface 1q of the card 1 is viewed in plan, the foam suppression layer 120 inside the transparent laser coloring layer 6 that constitutes the leading edge of the card 1 on the -Z direction side is visible across the entire back surface 1q. The foam suppression layer 120 is a printed layer formed, for example, from an ink with a silvery metallic luster that contains a pearl pigment and a black or chromatic pigment, as described below. Furthermore, when viewed in plan on the back surface 1q of the card 1, a second pattern 320, exemplified by the combination of the numbers "1234 5678," is visible at the corners on the +X direction side and the -Y direction side.

As shown in Figure 1(c), the first pattern 310 is formed by irradiating the laser light such that the concealing color layer 2 on the front surface 1p is removed along a predetermined pattern, and the predetermined pattern formed by the color of the underlying foaming suppression layer 110 is visible through the transparent over-sheet layer 3. Furthermore, the second pattern 320 is formed by irradiating the laser light such that the transparent laser coloring layer 6 on the back surface 1q is partially colored, for example, black, along the predetermined pattern to form colored portions 61, which are visible from the outside.

Here, the second pattern 320 uses the color of the expansion-inhibiting layer 120, which is visible through the laser coloring layer 6, as its base color. The color of the colored portion 61, such as black, produced by the laser coloring layer 6 contrasts with the base color, making the second pattern 320 of the colored portion 61 easily visible. The color of the expansion-inhibiting layer 120 is a silver color with a metallic luster, which is often used, for example, as the color on the back of a credit card to give it a luxurious feel. Such a color can typically be formed by printing ink containing aluminum powder as a coloring pigment. Here, when the laser used is a YAG laser, as described below, the absorption rate of metallic aluminum is relatively high, making it easy to convert the energy of the laser light into heat. Therefore, a layer printed with ink containing aluminum powder as a coloring pigment is prone to foaming due to gas generated by heat, which can easily degrade the appearance quality of the card.

In contrast, the expansion-inhibiting layer 120 of this embodiment is composed of ink containing pearl pigment and black or chromatic pigment, rather than aluminum powder. Therefore, the color appearance of the expansion-inhibiting layer 120 has a luxurious metallic luster similar to that of ink using aluminum powder as a coloring pigment. Furthermore, the pearl pigment and black or chromatic pigment that make up the expansion-inhibiting layer 120 generate less heat when irradiated with laser light than aluminum powder, etc. This reduces the occurrence of appearance defects due to foaming in the expansion-inhibiting layer 120. As described above, a card 1 using the laminate of this embodiment improves the visibility of the color pattern formed on the card by irradiating it with laser light, and can suppress foaming in the card material, improving appearance quality. The configuration of the card 1 is described in detail below.

(i) Laser Coloring Layer The laser coloring layer 6 has the property that, when irradiated with laser light, the laser light energy is converted into heat, causing the member to carbonize and change color to black, brown, or the like. In this embodiment, the laser coloring layer 6 is normally transparent and, when irradiated with a YAG laser under predetermined conditions, partially changes color to black. However, the laser coloring layer 6 may also be opaque, and the color upon irradiation with laser light may be other than black. Note that a member being transparent or having transparency means that it is transparent to visible light to the extent that it can be visually or machine-read, but may also include, for example, a transmittance of 50% or more for visible light with a wavelength of 380 nm or more and 780 nm or less.

The laser coloring layer 6 is constructed by adding a specific coloring agent to a base material. A wide variety of plastic sheets can be used as the material, including the following single films or composite films: polyethylene terephthalate (PET), PET-G (terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer), polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polycarbonate, polyamide, polyimide, cellulose diacetate, cellulose triacetate, polystyrene, ABS, polyacrylic ester, polypropylene, polyethylene, polyurethane, etc.

The color former added to the component is a metal oxide that absorbs a specific laser beam and generates heat. Examples of metals that form black oxides include copper, iron, nickel, manganese, titanium, lead, chromium, cobalt, tin, thallium, vanadium, niobium, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, osmium, iridium, bismuth, palladium, silver, platinum, and gold. In addition to these color formers, carbon black, which has high heat absorption properties, and light absorbers that absorb laser beams of a specific wavelength may also be added. This configuration carbonizes the periphery of the component, potentially resulting in a more visible color. Examples of light absorbers include cyanine dyes, polymethine dyes, anthraquinone dyes, phthalocyanine dyes, and naphthalocyanine dyes, which have absorption peaks in the wavelength range of the laser used.

There are no particular restrictions on the thickness of the laser coloring layer 6, but it can be, for example, 0.01 mm or more and 0.2 mm or less, and preferably 0.05 mm or more and 0.1 mm or less.

In this embodiment, a magnetic stripe 220 is embedded by thermal transfer on the surface of the laser coloring layer 6 that is exposed to the outside, i.e., the surface opposite the core layer 5. Magnetic data specified in, for example, ISO/IEC 7811-2, ISO/IEC 7811-6, or JIS X6302-2 Annex JA is recorded on the magnetic stripe 220 so that it can be read and written by a compatible magnetic reader.

(ii) Core Layer: A wide variety of plastic sheets, typically white or colored, can be used for the core layers 4 and 5, including those exemplified above as the laser coloring layer 6. The thickness of the core layers 4 and 5 is not particularly limited, but can be, for example, 0.05 mm or more and 0.5 mm or less, and preferably 0.15 mm or more and 0.3 mm or less. The thicknesses of the core layers 4 and 5 can be approximately the same, taking into account the symmetry of each layer along the thickness direction of the card 1, but may also be different. Having the core layers 4 and 5 have approximately the same thickness can suppress warping during the process of integrating the laminated body by heat pressing or the like, or subsequent changes over time.

(iii) Over-sheet Layer The over-sheet layer 3 can be made of a wide variety of typically transparent plastic sheets, including those exemplified above as the components of the laser coloring layer 6. The thickness of the laser coloring layer 6 is not particularly limited, but can be, for example, 0.01 mm or more and 0.2 mm or less, and preferably 0.05 mm or more and 0.1 mm or less. Similarly to the core layers 4 and 5, the laser coloring layer 6 and the over-sheet layer 3 can have substantially the same thickness, but they may also have different thicknesses. By ensuring that the core layers 4 and 5, as well as the laser coloring layer 6 and the over-sheet layer 3, have substantially the same thickness, warping can be suppressed during the process of integrating the laminate by heat pressing or the like, or due to subsequent changes over time.

In this embodiment, the magnetic stripe 210 is embedded by thermal transfer on the outward-facing surface of the over-sheet layer 3, i.e., the surface opposite the core layer 4. Magnetic data specified in, for example, ISO/IEC 7811-2, ISO/IEC 7811-6, or JIS X 6302-2 Annex JA is recorded on the magnetic stripe 210 so that it can be read and written by a compatible magnetic reader. On the surface of the over-sheet layer 3 on which the magnetic stripe 210 is formed, i.e., the surface further in the +Z direction of the over-sheet layer 3, a concealing colored layer 2, which is a printed layer that conceals the magnetic stripe 210 to make it less visible, is formed over the entire surface.

1(c), the expansion suppression layers 120 and 110 of this embodiment are respectively disposed between the laser coloring layer 6 and the core layer 5, and between the core layer 4 and the over-sheet layer 3. In particular, the expansion suppression layer 120 adjacent to the laser coloring layer 6 is formed by printing or the like over substantially the entire surface of the core layer 5 opposite to the core layer 4.

The foam-inhibiting layer 120 is a printed layer containing a pearl pigment and a black or chromatic pigment. Pearl pigments are thin-plate mica particles coated with titanium dioxide or similar, and have the property of making colors with varying luster visible depending on the viewing angle by utilizing the multilayer reflection and interference phenomena of the mica thin film. Inks containing pearl pigments are used in a variety of applications as special prints that exhibit the luster, metallic finish, and iridescent colors of natural pearls. A printed layer containing such pearl pigments can be formed, for example, as a solid printed layer with uniform density across substantially the entire surface of core layer 5 opposite core layer 4.

On the other hand, general chromatic pigments refer to pigments that exhibit chromatic colors such as the well-known cyan, magenta, and yellow. Black or chromatic pigments refer to achromatic black pigments or general chromatic pigments, excluding white. By mixing appropriate amounts of each of these pigments and dispersing them in varnish to prepare an ink, it is possible to obtain an ink of the desired color.

The expansion-inhibiting layer 120 may be formed as a printed layer of uniform density over substantially the entire surface of the core layer 5 opposite the core layer 4, using an ink synthesized by mixing an ink made by mixing black or chromatic pigments with the ink containing the pearl pigment described above. Alternatively, a layer made of a printed layer of the ink containing the pearl pigment described above may be referred to as the first expansion-inhibiting layer, and a layer made of a printed layer of an ink containing black or chromatic pigments, or an ink made by mixing these, may be referred to as the second expansion-inhibiting layer. In this case, the expansion-inhibiting layer 120 may be formed by laminating the second expansion-inhibiting layer on top of the first expansion-inhibiting layer. There is no restriction on the order of the first and second expansion-inhibiting layers in the thickness direction, but it is preferable to form the first expansion-inhibiting layer between the core layer 5 and the second expansion-inhibiting layer.

When forming a first expansion-suppressing layer between the core layer 5 and the second expansion-suppressing layer, inks containing black or chromatic cyan, magenta, and yellow pigments may be printed sequentially on top of a printed layer of ink containing a pearl pigment so that each ink forms a halftone dot of a predetermined size. When printing inks containing black or chromatic cyan, magenta, and yellow pigments, printing them to form halftone dots makes it easier to adjust the color of the ink composite. Furthermore, the dot area ratio of each ink containing black or yellow, magenta, and cyan chromatic pigments in the second expansion-suppressing layer may each be 60% or less. By keeping the dot area ratio within this range, the desired color of the expansion-suppressing layer 120 can be obtained. Furthermore, adhesion between the core layer 5 and the laser coloring layer 6 can be ensured during lamination by thermal fusion, and a moderate metallic luster can be achieved by the first expansion-suppressing layer.

Note that dot area ratio is the ratio of dot area per unit area in halftone gradation, expressed as a percentage (see "Printing Glossary" (First Edition, Japan Federation of Printing Industries)).

As a result, the presence of the printed layer of ink containing pearl pigment allows the expansion-inhibiting layer 120 to be seen with a metallic luster across its entire surface. Furthermore, the presence of the printed layer of ink containing black or chromatic pigments allows the expansion-inhibiting layer 120 to be seen with a grayish color. Therefore, the expansion-inhibiting layer 120 can be seen as a luxurious, glossy silvery color, similar to printing with ink that uses aluminum powder as a pigment.

It is generally known that metallic aluminum has a peak absorption rate of approximately 15% when the wavelength of the laser light is in the range of approximately 700 nm or more and 900 nm or less. On the other hand, when a YAG laser is used, the wavelength of the laser light is 1064 nm, which is close to the wavelength at which metallic aluminum has a peak absorption rate and shows a relatively high absorption rate. For this reason, if a printed layer made of ink containing aluminum powder as a pigment is placed on the surface of the laser coloring layer 6 opposite the laser light incident side, i.e., the surface on the +Z direction side, the aluminum powder will heat up, increasing the likelihood that the air inside will expand and foam.

However, the pearl pigment contained in the expansion-inhibiting layer 120 of this embodiment, and the black or chromatic cyan, magenta, and yellow pigments that do not contain carbon black, have a relatively low absorption rate for YAG laser light compared to aluminum powder. Furthermore, the pearl pigment contained in the expansion-inhibiting layer 120 is made by coating lamellar mica particles with titanium dioxide or the like, and it is believed that the white titanium dioxide easily reflects laser light. Therefore, it is believed that the degree of foaming in the expansion-inhibiting layer 120 when laser light is irradiated onto the laser coloring layer 6 is relatively small compared to a printed layer made of ink that uses aluminum powder as a pigment. This effectively prevents deterioration in the visibility of the second pattern 320 colored by the laser light and the appearance quality of the card 1.

For example, Figure 4(a) shows card 1b, positioned so that its back side is visible as the front. On the back side of card 1b, a signature panel 230 and a second pattern 321, which is the card's unique information, are formed by irradiating it with laser light. Second pattern 321 is a combination of numbers, such as "4000 1234 5678 9012." The layer structure of card 1b is generally the same as that of card 1, except for the signature panel 230. That is, the layer structure of the cross section of the area where second pattern 321 is formed is the same as the structure on the -Z direction side of the cross-sectional view in Figure 1(c). A laser coloring layer 6b corresponding to laser coloring layer 6 is disposed on the outermost surface of card 1b in Figure 4(a), and a foaming suppression layer 121 corresponding to foaming suppression layer 120 is disposed on the back side.

Here, cards 1b were produced in two cases: one in which the foam-inhibiting layer 121 was composed of ink containing pearl pigment and chromatic pigment, as in this embodiment, and the other in which the foam-inhibiting layer 121 was composed of ink containing aluminum powder as a pigment instead of pearl pigment and not containing chromatic pigment. Then, for both cases, laser light was irradiated using a YAG laser under the same conditions to draw a second pattern 321. Figure 4(b) shows an enlarged image of the "1234" portion, which is part 322 of the second pattern 321, when laser light was irradiated under the former conditions. Figure 4(c) shows a similar enlarged image when laser light was irradiated under the latter conditions.

As a result, the sample irradiated with laser light under the latter conditions had multiple foamed areas 510, where parts of the black numbers had foamed and turned white, as shown in Figure 4(c), degrading the appearance quality. Furthermore, when the area containing the foamed areas 510 was touched with a finger, a protruding bump was felt. In contrast, the sample irradiated with laser light under the former conditions had a clearly visible black number print, no foaming as in the latter conditions, and had good appearance quality, as shown in Figure 4(b).

In the foamed portion 510 shown in Figure 4(c), where a portion of the black number print has foamed and turned white, the height of the foamed portion 510 irradiated with laser light relative to the surface of the laser coloring layer that was not irradiated with laser light exceeded 100 μm. In contrast, in the case of the product with a good appearance shown in Figure 4(b), the height of the portion of the laser coloring layer irradiated with laser light relative to the surface that was not irradiated with laser light was 0.5 μm or more and 50 μm or less.

Here, we increased the power of the laser irradiation to investigate the limit for maintaining a good appearance, and found that if the protrusion height was 100 μm or less, there were few problems with appearance. Thus, when the protrusion height of the laser coloring layer in the irradiated portion relative to the non-irradiated surface is 100 μm or less, not only does the appearance remain good, but it also feels smooth to the touch, reducing the discomfort felt when touched. The protrusion height of the laser coloring layer in the irradiated portion relative to the non-irradiated surface can be measured by replacing the magnetic stripe with a foam layer in accordance with the test method for protrusion height of magnetic stripes in ISO/IEC 10373-2, 5.2.3.2.

It is preferable that the inks containing black or the chromatic pigments of yellow, magenta, and cyan for the first expansion-inhibiting layer as well as the second expansion-inhibiting layer be carbonless inks. If the color of the expansion-inhibiting layer 120 is desired to be achromatic black or gray, it is preferable to achieve this color by combining yellow, magenta, and cyan pigments without using carbon black, which is a black pigment, or to use a black pigment other than carbon black. This is because carbon materials have the property of absorbing laser light of a certain wavelength, such as a YAG laser, and irradiating the laser coloring layer 6 with laser light may heat the carbon material and cause the surrounding resin to foam.

The foam-inhibiting layer 120 can be formed using known printing or coating methods, such as offset printing, silk printing, letterpress printing, gravure printing, flexographic printing, inkjet printing, electrostatic printing, and thermal transfer from an ink ribbon. When printing inks containing black or chromatic cyan, magenta, and yellow pigments, as described above, sequentially on top of a printed layer of ink containing pearlescent pigment formed at uniform concentrations so that each ink forms halftone dots of a predetermined size, it is preferable to do this as follows: That is, the printing of the ink containing pearlescent pigment, which constitutes the first foam-inhibiting layer, is performed by silk screen printing, and the printing of the ink containing black or chromatic pigment, which constitutes the second foam-inhibiting layer, is performed by offset printing.

There are no particular restrictions on the film thickness of the expansion-inhibiting layer 120. For example, the film thickness of a printed layer of ink containing a pearl pigment can be 1 μm or more and 10 μm or less. Furthermore, the film thickness of a printed layer of ink containing black or chromatic pigments such as cyan, magenta, and yellow can be 0.5 μm or more and 5 μm or less. The average particle diameter of the pearl pigment particles is preferably 2 μm or more and 30 μm or less. By keeping the average particle diameter within this range, the pearl pigment can be evenly dispersed in the vehicle during printing, achieving a stable metallic luster across the entire printed surface. Furthermore, the average thickness of the pearl pigment is preferably 0.05 μm or more and 1.05 μm or less. By keeping the average thickness of the pearl pigment within this range, the pearl pigment can be evenly dispersed in the vehicle during printing, while appropriately adjusting the strength of the concealing effect of the base color.

The ratio of the weight of the pearl pigment particles in the expansion-inhibiting layer 120 to the weight of the ink that constitutes the expansion-inhibiting layer 120 after solidification may be 1 or less. In other words, the value obtained by dividing the weight of the pearl pigment particles by the weight of the solidified ink may be 1 or less. By setting this ratio to 1 or less and limiting the amount of pearl pigment particles to a predetermined ratio, it is possible to prevent the expansion-inhibiting layer 120 containing the pearl pigment from peeling off from other layers and to achieve stronger adhesion to those other layers.

The average particle size of the pearl pigment refers to the particle size at 50% of the volumetric cumulative value of the particle size distribution measured using a particle size distribution analyzer based on the laser diffraction and scattering method specified in JIS Z8825. The average thickness of the pearl pigment refers to the arithmetic mean of the difference from a reference plane measured using an atomic force microscope.

The expansion suppression layer 110, which is disposed between the core layer 4 and the oversheet layer 3, may have the same configuration as the expansion suppression layer 120 described above, or it may have a different configuration. When the expansion suppression layer 110 has the same configuration as the expansion suppression layer 120, the following effects are achieved. First, the expansion suppression layer 110 is formed, for example, by printing on the surface of the core layer 4 opposite the core layer 5. Here, because the expansion suppression layer 110 and the expansion suppression layer 120 are made of ink with the same configuration, the work of forming the expansion suppression layers 120 and 110 on the core layer 4 and core layer 5 can be carried out consecutively without changing the ink configuration of the printing press.

In addition, in this embodiment, as shown in FIG. 1(a), the formation area of the expansion-inhibiting layer 110 is not substantially the entire surface of the core layer 4, but only a partial area in the XY plane. However, by forming the expansion-inhibiting layer 110 substantially the entire surface of the core layer 4, as with the formation area of the expansion-inhibiting layer 120, the core layers 4 and 5 can be printed continuously using the same ink and printing plate configuration. This significantly reduces the workload of the printing process in the manufacture of the card 1.

As described above, the first pattern 310 is formed by irradiating the concealing color layer 2 on the front surface 1p with laser light, removing the concealing color layer 2 along a predetermined pattern, and the predetermined pattern formed with the color of the underlying expansion-inhibiting layer 110 is visible through the transparent over-sheet layer 3. Because the over-sheet layer 3 is disposed between the concealing color layer 2 and the expansion-inhibiting layer 110, the degree of heat generation in the expansion-inhibiting layer 110 due to irradiation with laser light is less than the degree of heat generation in the expansion-inhibiting layer 120 due to irradiation of the laser coloring layer 6 on the back surface 1q with laser light. However, if the expansion-inhibiting layer 110 has the same configuration as the expansion-inhibiting layer 120, foaming in the expansion-inhibiting layer 110 is inhibited, just like the expansion-inhibiting layer 120, and deterioration in the visibility of the first pattern 310 and the appearance quality of the card 1 is suppressed.

Furthermore, the first pattern 310 is visually recognized as a predetermined pattern formed in the color of the expansion-inhibiting layer 110, with the color of the concealing color layer 2 as the background color. Therefore, by appropriately selecting the background color, it is easy to ensure sufficient contrast while making the color of the concealing color layer 2 a glossy silver-like color with a luxurious feel. Therefore, highly designed patterns in colors other than the black and brown that are produced when using a typical laser coloring agent can be easily formed by irradiating with laser light, regardless of the type of laser coloring agent, etc.

(b) Method for Manufacturing the Card Next, an example of a method for manufacturing the card 1 using the above-mentioned members will be described.

First, the components that will form each layer of the card 1 laminate are prepared. That is, each layer is prepared so that, when viewed from the -Z direction, the laser coloring layer 6, core layer 5, core layer 4, and oversheet layer 3 can be stacked in this order. These layer components are typically prepared in a large format, not for a single card, with multiple cards arranged lengthwise and widthwise, and are processed into a multi-faceted laminate or laminate sheet. That is, each layer has an area, when viewed in a plan view in the thickness direction, that allows multiple cards to be arranged without overlapping. The large-format multi-faceted laminate is then punched into individual card shapes to obtain the card 1, which is a card-shaped laminate.

Here, the aforementioned predetermined foam suppression layer 120 is formed in advance on the surface of the core layer 5 facing the laser coloring layer 6 by offset printing, silk printing, letterpress printing, gravure printing, flexographic printing, inkjet printing, electrostatic printing, thermal transfer from an ink ribbon, or the like. In addition, if necessary, a magnetic stripe 220 is thermally transferred onto the surface of the foam layer 6 facing in the -Z direction.

The foaming suppression layer 110 described above is also formed on the surface of the core layer 4 facing the over-sheet layer 3 by the printing method described above. If necessary, a magnetic stripe 210 is thermally transferred onto the surface of the over-sheet layer 3 facing the +Z direction. Furthermore, a concealing color layer 2 is formed by printing or the like on the surface of the over-sheet layer 3 opposite the core layer 4, i.e., the surface facing the +Z direction, to conceal the magnetic stripe 210, making it less visible and improving the design. This concealing color layer 2 may be printed directly onto the over-sheet layer 3 with the magnetic stripe 210 before lamination.

Alternatively, a predetermined pattern can be formed in advance on a PET film with a high softening point using offset printing or silk printing, and then thermally transferred to the over-sheet layer 3 with the magnetic stripe 210 either before or after lamination. This makes it easy to form a relatively thick printed layer on the over-sheet layer 3, thereby improving the concealment of the magnetic stripe 210.

The laminate of large sheets obtained as described above is punched out using a punching machine to form cards 1 that meet the ISO/IEC 7810 card size. For punching, a punching die combining a convex male blade and a mating concave or through-hole female blade may be used, or a Thomson blade or Vickers blade with a peripheral blade and a hollow interior may be used as the punching die. In this way, card 1 is completed before the first pattern 310 and second pattern 320 are formed, prior to irradiation with laser light.

Next, a first pattern 310 of a combination of alphanumeric characters, exemplified by "A1234," and a second pattern 320 of a combination of numbers, exemplified by "1234 5678," are formed on the front surface 1p and back surface 1q of the card 1. The first pattern 310 and the second pattern 320 are formed by irradiating a designated area of the card 1 with a laser beam of a predetermined wavelength while drawing a predetermined pattern in an issuing machine or the like equipped with a laser marking function. Examples of the type of laser beam include a YAG laser, a _YVO4 laser, a _CO2 laser, and a fiber laser, with the use of a YAG laser, a _YVO4 laser, or a fiber laser being particularly preferable.

For the surface 1p of the card 1, the issuing machine's laser beam is focused on the concealing color layer 2 in the thickness direction of the card 1, and the laser beam is applied to remove portions of the concealing color layer 2 corresponding to the predetermined pattern along the path traced by the laser beam. The concealing color layer 2 is removed when the concealing color layer 2 is heated by the energy of the laser beam and partially detaches or evaporates from the over-sheet layer 3. As a result, in the region of the predetermined pattern from which the concealing color layer 2 has been removed, the foam-inhibiting layer 110 located further below it can be seen through the over-sheet layer 3 located below, i.e., on the -Z direction side. Therefore, in this region, the foam-inhibiting layer 110 formed in the predetermined pattern can be seen as the first pattern 310 against the background of the concealing color layer 2.

On the other hand, for the back surface 1q of the card 1, the issuing machine's laser beam is focused at a predetermined position on the laser coloring layer 6 in the thickness direction of the card 1 and the laser beam is irradiated. The portion of the laser coloring layer 6 corresponding to the predetermined pattern develops a color, such as black, along the trajectory of the laser beam. The color development of the laser coloring layer 6 occurs when the resin surrounding the coloring agent contained in the laser coloring layer 6 is heated by the energy of the laser beam and discolors. As a result, a second pattern 320 is visible in the area of the predetermined pattern drawn on the laser coloring layer 6 due to the color development. Furthermore, the foaming suppression layer 120, located above the second pattern 320, i.e., on the +Z direction side, is visible as a background to the second pattern 320. This completes the card 1 on which the first pattern 310 and second pattern 320 are formed by irradiating the laser beam.

The first pattern 310 and the second pattern 320 formed by irradiating the front surface 1p and the back surface 1q of the card 1 with laser light are illustrated as alphanumeric characters or a combination of numbers. However, the first pattern 310 and the second pattern 320 are not limited to this and may be, for example, any combination of letters, alphanumeric characters, Roman numerals, symbols, patterns, photographs, illustrations, foreign language characters, figures, etc. Furthermore, the expansion-inhibiting layers 110 and 120 are illustrated as having a metallic luster and a silvery color, formed by a printed layer containing a pearl pigment and a black or chromatic pigment. However, the expansion-inhibiting layers 110 and 120 are not limited to this and may, for example, be colored with a black or chromatic pigment to form an overall orange color, resulting in a metallic luster and a gold-like color.

(c) Regarding the Card of the First Embodiment As described above, the card 1, which is a laminate according to the first embodiment, comprises a core layer 5 that is a substrate, an expansion suppression layer 120 provided on one surface side of the substrate, that is, the surface side in the -Z direction, and a laser coloring layer 6 provided on the surface side opposite the substrate of the expansion suppression layer 120. The laser coloring layer 6 is transparent to visible light, and the expansion suppression layer 120 contains a pearl pigment and a black or chromatic pigment.

When the back surface 1q of the card 1 is viewed in plan, the foam suppression layer 120 inside the transparent laser coloring layer 6 that forms the leading edge of the card 1 in the -Z direction is visible through the layer. The foam suppression layer 120 is a printed layer formed from an ink that contains a pearl pigment and a chromatic pigment and has a metallic luster, such as a silver color. Furthermore, when the back surface 1q of the card 1 is viewed in plan, the foam suppression layer 120 is visible as a background, and the second pattern 320 is formed when part of the laser coloring layer 6 is colored black or the like by the irradiation of the laser light.

The color of the expansion-inhibiting layer 120, which forms the background of the second pattern 320, can be, for example, a silvery color with a metallic luster to give it a luxurious feel. Furthermore, the expansion-inhibiting layer 120 is composed of a printed layer containing a pearl pigment and a black or chromatic pigment. Therefore, even if the energy of the laser light irradiated onto the laser coloring layer 6 reaches the adjacent expansion-inhibiting layer 120 above, the energy is absorbed and the degree of heat generation is reduced compared to when ink containing aluminum powder as a coloring pigment is printed. Therefore, the card 1 of this embodiment improves the visibility of the coloring pattern formed on the card by irradiation with laser light, and can suppress foaming of the card material, improving the appearance quality.

2. Modifications of the First Embodiment Next, a modification of the first embodiment of the laminate of the present disclosure will be described. FIG. 2 is a cross-sectional view similar to FIG. 1(c) of a card 1a, which is a type of laminate according to the modification, cut along a line similar to line A-A along the Y axis in FIG. 1(a), as viewed from the +X direction. The card 1a according to the modification differs from the configuration of the card 1 according to the first embodiment in that it further includes a colored layer 7 between the laser coloring layer 6 and the expansion suppression layer 120. The colored layer 7 is composed of ink or the like containing a colored pigment formed by any printing method or the like, and may contain a pigment such as black, cyan, magenta, or yellow, which is also contained in the expansion suppression layer 120, or may contain a pigment of another special color.

The colored layer 7 has a moderate degree of visible light transparency or is formed as halftone dots, allowing for fine adjustment of the color visible from the outside while preserving the color and gloss of the underlying expansion suppression layer 120. In other words, by providing the colored layer 7, the background color of the second pattern 320 can be changed, further enhancing the design while taking advantage of the glossy color of the pearl pigment, etc., of the expansion suppression layer 120.

The colored layer 7 is formed as follows. That is, in the manufacturing method of the card 1 described above, the predetermined expansion-inhibiting layer 120 described above is first formed on the surface of the core layer 5 facing the laser coloring layer 6 by offset printing, silk printing, letterpress printing, gravure printing, flexographic printing, inkjet printing, electrostatic printing, thermal transfer from an ink ribbon, or the like. Furthermore, the colored layer 7 is formed on the surface of the core layer 5 facing the -Z direction of the expansion-inhibiting layer 120 by a printing method similar to that described above. The colored layer 7 may be formed as a single-color printed layer, or as a laminate of multiple-color printed layers.

Such a colored layer 7 may have a dot area ratio of 60% or less for each ink containing a black or chromatic pigment, for example. By keeping the dot area ratio within the above range, the desired gloss and color of the expansion-inhibiting layer 120 can be maintained while the coloring effect of the colored layer 7 can change the background color of the second pattern 320, resulting in a card 1a with a highly decorative design. Furthermore, adhesion between the core layer 5 and the laser coloring layer 6 can be ensured when they are laminated by thermal adhesion. There are no particular restrictions on the film thickness of the colored layer 7, but it can be, for example, 0.5 μm or more and 5 μm or less.

Furthermore, it is preferable that the black or chromatic pigments that make up the colored layer 7 do not contain carbon black. This, as with the foaming-inhibiting layer 120 described above, can suppress foaming in the colored layer 7 when the laser coloring layer 6 is irradiated with laser light, effectively preventing deterioration in the visibility of the second pattern 320 and the appearance quality of the card 1.

In the card 1a of this modified example, the colored layer 7 is provided between the expansion-inhibiting layer 120 and the laser-coloring layer 6, but this is not limited thereto. For example, the colored layer 7 may be provided on the side of the expansion-inhibiting layer 120 opposite the laser-coloring layer 6, i.e., between the expansion-inhibiting layer 120 and the core layer 5. In this case, the color of the colored layer 7 can be combined from behind while retaining the color and gloss of the expansion-inhibiting layer 120, allowing fine adjustments to the color visible from the outside while emphasizing the color and gloss of the expansion-inhibiting layer 120.

3. Second Embodiment Next, a second embodiment of the laminate of the present disclosure will be described. Fig. 3(a) is a schematic perspective view illustrating a booklet 10, which is one type of laminate according to the second embodiment. Fig. 3(b) is a cross-sectional view of a data page 410 included in the booklet 10 of Fig. 3(a) taken along line B-B along the Y axis parallel to the main surface of the data page 410, as viewed from the +X direction.

The booklet 10 refers to a booklet-like object, such as a passport or savings passbook, in which multiple pages are bound together at one end. In this embodiment, the booklet 10 is a passport. The booklet 10 has a substantially rectangular front cover 420 and back cover 430, with one or more pages sandwiched and bound between the front cover 420 and back cover 430, and is configured to prevent individual pages from being removed fraudulently or inadvertently.

These pages include a data page 410 containing the passport owner's qualifications and other information. The data page 410 may display various information verifying the passport owner's qualifications, such as the owner's photograph, name, date of birth, passport number, and expiration date. In the booklet 10 of the present disclosure, as shown in FIG. 3(a), when the data page 410 is viewed from the outside, a third pattern 330 formed by irradiation with laser light and colored, for example, black, can be seen against the foam suppression layer 130, which has a glossy silver-colored background, for example. The third pattern 330 is a combination of alphanumeric characters, such as "ABCD 1234."

As shown in Figure 3(b), the data page 410 included in the booklet 10 is constructed by laminating and integrating the core layer 5a, expansion suppression layer 130, and laser coloring layer 6a in this order from the -Z direction side. The expansion suppression layer 130 is arranged only in a roughly rectangular area of the data page 410 along the XY plane, as shown by the area surrounded by the dashed line in Figure 3(a). Therefore, the data page 410 has areas where the core layer 5a and laser coloring layer 6a are directly bonded, and areas where they are bonded via the expansion suppression layer 130.

The arrangement and detailed component configuration of the core layer 5a, expansion suppression layer 130, and laser coloring layer 6a of the data page 410 correspond to those of the core layer 5a, expansion suppression layer 120, and laser coloring layer 6 of the card 1 of the first embodiment. Therefore, this embodiment also has the same effects as those described in the first embodiment. That is, the booklet 10, which is a laminate of this embodiment, includes a data page 410. The data page 410 includes a core layer 5a that serves as a substrate, an expansion suppression layer 130 provided on one side of the substrate, and a laser coloring layer 6a provided on the side of the expansion suppression layer 130 opposite the substrate. The laser coloring layer 6a is transparent to visible light, and the expansion suppression layer 130 contains a pearl pigment and a black or chromatic pigment.

When the +Z direction surface of the data page 410 of the booklet 10 is viewed in plan, the foam suppression layer 130 inside the transparent laser coloring layer 6a that constitutes the leading edge of the data page 410 in the +Z direction is visible through the transparent laser coloring layer 6a. The foam suppression layer 130 is a printed layer formed from an ink with a metallic luster, such as a silver color, that contains a pearl pigment and a black or chromatic pigment. Furthermore, when viewed in plan from the +Z direction of the data page 410, a third pattern 330 formed by the coloring of a portion of the laser coloring layer 6a due to the irradiation of laser light is visible against the foam suppression layer 130 as a background. The third pattern 330 uses the color of the foam suppression layer 130, which is visible through the laser coloring layer 6a, as a base color. The color, such as black, of the colored portion 62 colored by the laser coloring layer 6a contrasts with the base color, making the third pattern 330 of the colored portion 62 easily visible. The color of the expansion suppression layer 130 is, for example, a silver color with a metallic luster.

The expansion-inhibiting layer 130 is composed of a printed layer containing a pearl pigment and a black or chromatic pigment. Therefore, even if the energy of the laser light irradiated onto the laser coloring layer 6a reaches the adjacent expansion-inhibiting layer 130 above, the degree to which the energy is absorbed and heat generated as a result is lower than when printed with ink containing aluminum powder as a coloring pigment. Therefore, the booklet 10 of this embodiment improves the visibility of the coloring pattern formed on the card by irradiation with the laser light, and suppresses foaming of the card material, improving the appearance quality.

In addition, the IC card of the present disclosure can be configured as a different embodiment by combining some or all aspects of the first embodiment and its variations, and the second embodiment, as long as no contradictions arise, and these are naturally included in the present disclosure.

1, 1a, 1b Card 1p Front surface 1q Back surface 2 Concealing color layer 3 Oversheet layer 4, 5, 5a Core layer 6, 6a, 6b Laser coloring layer 7 Coloring layer 10 Booklet body 21 Removable portion 61, 62 Coloring portion 110, 120, 121, 130 Foaming suppressing layer 210, 220 Magnetic stripe 230 Sign panel 310 First pattern 320, 321 Second pattern 322 Part 330 Third pattern 410 Data page 420 Cover 430 Back cover 510 Foaming portion

Claims (8)

A substrate;
an expansion suppression layer provided on one surface of the substrate;
a laser coloring layer provided on the surface of the expansion suppression layer opposite to the substrate,
the laser coloring layer is transparent to visible light;
the foaming suppression layer contains a pearl pigment and a black or chromatic pigment,
a second expansion suppression layer provided on the other surface of the substrate;
a transparent layer that is transparent to visible light and is provided on the surface of the second expansion suppression layer opposite to the substrate;
a first color layer containing a chromatic or achromatic pigment;
A laminate in which, when irradiated with laser light in a predetermined pattern under predetermined conditions, the first colored layer is partially removed in a pattern corresponding to the predetermined pattern, and the underlying second foaming suppression layer can be seen as the predetermined pattern through the transparent layer . A substrate;
an expansion suppression layer provided on one surface of the substrate;
a laser coloring layer provided on the surface of the expansion suppression layer opposite to the substrate,
the laser coloring layer is transparent to visible light;
the foaming suppression layer contains a pearl pigment and a black or chromatic pigment,
Further comprising a second color layer;
The second colored layer contains a black or chromatic pigment and is provided between the foaming suppression layer and the laser coloring layer or on the side of the foaming suppression layer opposite the laser coloring layer, and the dot area ratio of each ink containing the black or chromatic pigment is 60% or less . 3. The laminate according to claim 1, wherein the black or chromatic pigment in the expansion-inhibiting layer does not contain carbon black. The laminate according to claim 2 , wherein the black or chromatic pigment of the second color layer does not include carbon black. The laminate described in any one of claims 1 to 4, wherein the ratio of the weight of the pearl pigment particles in the expansion-inhibiting layer to the weight of the ink constituting the expansion-inhibiting layer after solidification is 1 or less. A laminate according to any one of claims 1 to 5, wherein the height of the portion of the laser coloring layer irradiated with laser light relative to the surface not irradiated with laser light is 100 μm or less. A card comprising the laminate according to any one of claims 1 to 6 . A booklet comprising the laminate according to claim 2 or 4 .