JP2024029931A - Multilayer body, security card, and passport - Google Patents

Abstract

To provide a multilayer body in which security is reinforced, and a security card and a passport.SOLUTION: A multilayer body includes a resin layer containing a laser marking agent, and a resin layer which has a thickness of 55-140 μm and contains a white pigment, and includes a resin region A having total light transmittance of 75-90% and a resin region B having total light transmittance of 50-74%, in a surface of a multilayer body, wherein the total area occupied by the resin region A and the resin region B to one surface of the multilayer body is 1-15%, and an L value in the resin region A is 93.8-95.2.SELECTED DRAWING: Figure 4

Description

The present invention relates to multilayer bodies, security cards, and passports.

2. Description of the Related Art Conventionally, cards using resin sheets or multilayer bodies containing resin sheets have begun to be used in ID cards, security cards such as non-contact IC cards, and passports such as e-passports.
Here, a multilayer body shown in FIG. 1 is known as an example of a security card. FIG. 1(A) shows each constituent layer of the multilayer body, and FIG. 1(B) is a schematic cross-sectional view of the multilayer body in the thickness direction. In FIG. 1, 10 is a multilayer body, 11 is an overlay layer (140 μm), and 12 and 13 are white core layers (white pigment layers). Moreover, an IC chip, an antenna, etc. are usually incorporated in or between the white core layers 12 and 13. By using the white core layers 12 and 13 having shielding properties, it is possible to make the IC chip, antenna, etc. invisible from the outside of the card. These layers (FIG. 1(A)) are joined together by, for example, hot pressing to form a multilayer body (FIG. 1(B)). Such a security card is described in, for example, Patent Document 1.

Furthermore, security cards with clear windows have also been considered in recent years. FIG. 2 shows an example of a security card (multilayer) having a clear window. Figure 2 (A) shows each constituent layer of a security card (multilayer body) with a clear window, and Figure 2 (B) is an image diagram of the security card (multilayer body) with a clear window in the process of being manufactured. 2(C) is a schematic cross-sectional view in the thickness direction of a security card (multilayer body) having a clear window. In FIG. 2, 20 indicates a security card (multilayer body), 21 indicates an overlay layer (transparent resin layer), 22 indicates a white core layer (white pigment layer), 23 indicates a transparent resin layer, and 24 indicates a clear window. ing. Here, the clear window 24 is provided on the security card for, for example, prevention of forgery and design, and is a transparent window portion introduced into a part of the card surface of the card. As a method for manufacturing a multilayer body having a clear window 24, when laminating each layer, an opening (a region where no white pigment layer exists) 25 is provided in the layer 22 containing a white pigment (see FIG. 2 (A). )), there is a method of joining each layer by heat pressing. Then, during hot pressing, a portion of the transparent resin of the overlay layer (transparent resin layer) 21 and the transparent resin layer 23 flows into the opening 25 (FIG. 2(B)), forming a clear window 24. (Figure 2(C)). Such a security card is described in, for example, Patent Document 2.

International Publication No. 2018/163889 International Publication No. 2022/038973

As mentioned above, multilayer bodies with enhanced security are known, but in recent years, there has been a demand for further enhancement of security. In particular, it would be beneficial if a function to further prevent counterfeiting was added to a multilayer body having a clear window while maintaining shielding properties. The present invention solves this problem and aims to provide a multilayer body, a security card, and a passport with further enhanced security.

Based on the above-mentioned problem, the present inventor conducted studies and found that security can be strengthened by further applying laser marking to the clear window. Specifically, we have found that the above problem can be solved by the following means.
<1> A resin layer containing a laser marking agent,
A multilayer body having a thickness of 55 to 140 μm and comprising a resin layer containing a white pigment,
The surface of the multilayer body includes a resin region A with a total light transmittance of 75 to 90% and a resin region B with a total light transmittance of 50 to 74%,
The total area occupied by the resin region A and the resin region B with respect to one surface of the multilayer body is 1 to 15%,
The L value in the resin region A is 93.8 to 95.2,
Multilayered body.
<2> The resin layer containing the white pigment has an opening, and when viewed from a direction perpendicular to the surface of the multilayer body, the resin region A and the resin region B are in the same area as the opening. The multilayer body according to <1>, wherein the resin region B is a laser marking image.
<3> The multilayer body according to <1> or <2>, wherein the resin layer containing the white pigment has a thickness of 60 to 110 μm.
<4> The multilayer body according to <1> or <2>, wherein the resin layer containing the white pigment has a thickness of 60 to 80 μm.
<5> The multilayer body according to any one of <1> to <4>, wherein the resin layer containing the white pigment contains titanium oxide in a proportion of 20 to 50% by mass of the resin layer.
<6> The multilayer body according to any one of <1> to <5>, further comprising a transparent resin layer.
<7> The multilayer body according to <6>, wherein the multilayer body has the resin layer containing the laser marking agent, the transparent resin layer, the resin layer containing the white pigment, and the transparent resin layer in the above order. body.
<8> The multilayer body includes the resin layer containing the laser marking agent, the transparent resin layer, the resin layer containing the white pigment, the transparent resin layer, the resin layer containing the white pigment, and the transparent resin layer. The multilayer body according to <6>, comprising:
<9> The multilayer body has two or more resin layers containing the laser marking agent, and in the cross-sectional direction of the multilayer body, the two resin layers containing the laser marking agent are perpendicular to the thickness direction of the cross section. The multilayer body according to any one of <1> to <8>, which is located symmetrically with respect to a central plane in the direction.
<10> There are two or more layers containing the laser marking agent, and two of the layers containing the laser marking agent are located at an interval of 300 μm or more and 600 μm or less in the thickness direction, <1> ~ The multilayer body according to any one of <9>.
<11><1> to <10>, including a resin region C other than the resin region A and resin region B in the thickness direction of the multilayer body, and the total light transmittance of the resin region C is 0.1 to 3%. The multilayer body according to any one of the above.
<12> The multilayer body according to <11>, wherein the resin region C occupies 85 to 99% of one surface of the multilayer body.
<13> The resin area B is a laser whose OD value according to ISO 5-4 is 0.45 to 0.70 after laser marking of the area where RGB is (0, 0, 0) in the original image. The multilayer body according to any one of <1> to <12>, which includes a marking image.
<14> The resin area B is a laser whose OD value according to ISO 5-4 is 0.15 to 0.25 after laser marking of the area where RGB in the original image is (180, 180, 180) The multilayer body according to any one of <1> to <13>, which includes a marking image.
<15> The resin area B is a laser whose OD value according to ISO 5-4 is 0.3 to 0.5 after laser marking of the area where RGB in the original image is (120, 120, 120). The multilayer body according to any one of <1> to <14>, including a marking image.
<16> The resin area B is a laser whose OD value according to ISO 5-4 is 0.45 to 0.70 after laser marking of the area where RGB is (0, 0, 0) in the original image. A marking image, a laser marking image with an OD value of 0.15 to 0.25 according to ISO 5-4 after laser marking processing of an area where RGB in the original image is (180, 180, 180), and the original Contains at least two of the laser marking images with an OD value of 0.3 to 0.5 according to ISO 5-4 after laser marking processing of an area where RGB is (120, 120, 120) in the image , the multilayer body according to any one of <1> to <12>.
<17> The multilayer body according to any one of <1> to <16>, wherein the laser marking agent contains a black pigment.
<18> The multilayer body according to any one of <1> to <17>, having a total thickness of 300 μm or more and 2.0 mm or less.
<19> The multilayer body according to any one of <1> to <17>, having a total thickness of 300 μm or more and 700 μm or less.
<20> At least one of the resin layers containing the white pigment has a thickness t of 55 μm or more and 100 μm or less, where T% is the total light transmittance of the resin layer containing the white pigment and t μm is the thickness. The multilayer body according to any one of <1> to <19>, wherein T*t, which is the product of t, is 250 or more and 750 or less.
<21> The multilayer body according to any one of <1> to <20>, wherein at least the outermost layer of the resin layer containing the white pigment contains an antistatic agent.
<22> The multilayer body according to any one of <1> to <21>, wherein the outermost layer of the resin layer containing the white pigment is fluorescently printed.
<23> Any one of <1> to <22>, wherein on the surface of the multilayer body, the area ratio of the resin region A to one surface of the multilayer body is 0.01% or more and less than 15%. Multilayer body as described.
<24> Any one of <1> to <23>, wherein on the surface of the multilayer body, the area ratio of the resin region B to one surface of the multilayer body is 0.01% or more and 10% or less. Multilayer body as described.
<24> The multilayer body according to any one of <1> to <23>, wherein at least one layer of the multilayer body contains a polycarbonate resin.
<26> The multilayer body according to any one of <1> to <25>, wherein the resin layer containing the white pigment contains a colorant other than the white pigment in a proportion of 5 to 150 ppm by mass.
<27> A security card comprising the multilayer body according to any one of <1> to <26>.
<28> A passport comprising the multilayer body according to any one of <1> to <26>.

The present invention has made it possible to provide a multilayer body, a security card, and a passport with further enhanced security.

FIG. 2 is a schematic cross-sectional view in the thickness direction showing an example of the layer structure of a conventional security card. FIG. 2 is a schematic cross-sectional view in the thickness direction showing an example of the layer configuration of a conventional security card (multilayer body) having a clear window. FIG. 1 is a schematic cross-sectional view in the thickness direction showing an example of the layer structure of the security card (multilayer body) of the present invention. FIG. 1 is a schematic diagram showing an example of the layer structure of a security card (multilayer body) of the present invention, viewed from a direction perpendicular to a plane. FIG. 1 is a schematic cross-sectional view in the thickness direction showing an example of the layer structure of a composite film using the multilayer body of the present invention.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "this embodiment") will be described in detail. Note that the present embodiment below is an illustration for explaining the present invention, and the present invention is not limited only to this embodiment.
In addition, in this specification, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.
In this specification, various physical property values and characteristic values are assumed to be at 23° C. unless otherwise stated.
In this specification, the term "process" is used not only to refer to an independent process, but also to include a process in which the intended effect of the process is achieved even if the process cannot be clearly distinguished from other processes. .
In this specification, the multilayer body is intended to include those in the form of a film or a sheet, respectively. The terms "film" and "sheet" respectively refer to a generally flat molded body that is thin relative to its length and width. Also, a flat part perpendicular to the thickness direction of a multilayer body is called a plane. The flat portion in this embodiment is intended to include, for example, a surface having irregularities as indicated by surface roughness Ra.
If the measurement methods, etc. explained in the standards shown in this specification differ from year to year, unless otherwise stated, they shall be based on the standards as of January 1, 2022.
Further, the scale of each member shown in the drawings is not accurate, and the present invention is not limited to this scale.

The multilayer body of the present embodiment includes a resin layer containing a laser marking agent (herein sometimes referred to as a "laser marking layer"), a resin layer having a thickness of 55 to 140 μm and containing a white pigment ( In this specification, the multilayer body includes a resin region A having a total light transmittance of 75 to 90% on the surface of the multilayer body, and a total light transmittance 50 to 74%, the total area occupied by resin region A and resin region B to one surface of the multilayer body is 1 to 15%, and the L value in resin region A is 93.8. ~95.2.
With such a configuration, a multilayer body with enhanced security functions can be obtained. That is, it is possible to have a laser marking image in the clear window area, for example, while maintaining the high shielding properties provided by the white pigment layer, and the anti-counterfeiting function can be enhanced.

Details of this embodiment will be described below with reference to the drawings. It goes without saying that this embodiment is not limited to the mode shown in the figures.
FIG. 3 is a schematic diagram showing an example of the layer structure of the multilayer body of this embodiment. FIG. 3(A) shows the structure of each layer of the multilayer body of this embodiment, and FIG. 3(B) shows a schematic cross-sectional view of the multilayer body in the thickness direction.
In FIG. 3, 30 is a multilayer body, 31 is an overlay layer (transparent resin layer), 32 is a white core layer (white pigment layer), 33 is a transparent core layer (transparent resin layer), and 34 is a clear window. , 35 indicates an opening (area where no white pigment layer exists), and 36 indicates a laser marking layer. When stacking each layer, there is a method in which an opening (region where no white pigment layer exists) 35 is provided in the white pigment layer 32 (FIG. 3(A)) and the layers are bonded by hot pressing. Then, during hot pressing, a portion of the transparent resin of the transparent core layer (transparent resin layer) 33 flows into the opening 35, forming a clear window 34 (FIG. 3(B)). In this embodiment, by reducing the thickness of the white pigment layer to 140 μm or less, the transparent resin can easily flow into the opening 35.
This embodiment further includes a laser marking layer 36. By including the laser marking layer, the security of the multilayer body can be further enhanced. In this embodiment, the laser marking layer has a total light transmittance of 75 to 90% before laser marking. Such high light transmittance is achieved by adjusting the amount of the laser marking agent. Therefore, although the clear window 34 in the multilayer body shown in FIG. 3 is located inside the laser marking layer 36 in the thickness direction, the area (resin area A). On the other hand, the portion of the laser marking layer 36 subjected to the laser marking process becomes a resin region B having a total light transmittance of 50 to 74% due to the presence of the laser marking image.
More specifically, this will be explained using FIG. 4. FIG. 4 is a diagram of the multilayer body shown in FIG. 3 viewed from a direction perpendicular to the surface (the direction of the black arrow in FIG. 3(B)). In FIG. 4, 30 indicates a multilayer body, 34 indicates a clear window, and 37 indicates a resin region B. Further, when viewed from a direction perpendicular to the surface, it is preferable that the area other than the resin area B in the clear window 34 is the resin area A. Moreover, in FIG. 4, it is preferable that the resin region C other than the resin region A and the resin region B has a low total light transmittance, as will be described in detail later. That is, the white pigment layer has an opening, and when viewed from a direction perpendicular to the surface of the multilayer body, resin region A and resin region B are located in the same region as the clear window 34, and resin region B is preferably a laser marking image. In this way, by providing the resin region B (laser marking image) in the same area as the clear window, the design and security tend to be further improved. That is, in a normal security card, designs (including photographic printing) are printed on the white pigment layer, and even if there is a clear window, it is not possible to print designs on the clear window. However, in this embodiment, by introducing a laser marking layer, a pattern can be introduced in the same area as the clear window. Furthermore, since the structure is complicated, security can be improved. Note that the resin region A and the resin region B may exist only in a part of the same region as the opening, or may exist in the entirety.

In addition, in the multilayer body 30 shown in FIGS. 3 and 4, the area having the clear window 34 is arranged in order from the top of FIG. 33, clear window 34, transparent resin layer 33, clear window 34, transparent resin layer 33, laser marking layer 36, and transparent resin layer 31. That is, in the area of the clear window 34, layers with high light transmittance are laminated in the thickness direction. Therefore, the resin region A can achieve a high light transmittance, and the region where a laser marking image is formed on the laser marking layer 36 (for example, reference numeral 37 in FIG. 4) has a total light transmittance of 50 to 74%. This is a certain resin region B. By satisfying such total light transmittance, a laser marking image can be made clear.

As mentioned above, the total light transmittance of the resin region A is 75 to 90%, preferably 77% or more, more preferably 80% or more, and even more preferably 82% or more. , more preferably 85% or more, and even more preferably 87% or more. By making it more than the above-mentioned lower limit, the designability tends to be further improved.
As mentioned above, the total light transmittance of the resin region B is 50 to 74%, but may be 51% or more, or 52% or more. Further, the upper limit of the total light transmittance of the resin region B is preferably 72% or less, more preferably 68% or less, even more preferably 64% or less, and preferably 60% or less. More preferably, it is 58% or less. By setting it below the upper limit, the laser marking image tends to become clearer.

In this embodiment, the L value of the resin region A is 93.8 to 95.2. By setting the amount to be equal to or more than the lower limit, it tends to be possible to more effectively suppress blackening of the multilayer body and blackening of the laser marking image. By setting it below the upper limit, the laser marking image tends to become clearer. The L value of the resin region A is preferably 93.9 or more, more preferably 94.0 or more, and even more preferably 94.1 or more. The L value of the resin region A is preferably 95.1 or less, more preferably 95.0 or less.

In this embodiment, the total area occupied by resin region A and resin region B with respect to one surface of the multilayer body is 1 to 15%. That is, the total area of resin area A and resin area B is set to be 1 to 15% when the entire area of one surface of the multilayer body is 100%. The area of one surface of the multilayer body at this time is based on the area assuming that the surface of the multilayer body is a flat surface that does not take into account minute irregularities on the surface. By setting it to the above lower limit or more, a sufficient resin region B can be formed and a multilayer body with excellent security function can be obtained. On the other hand, by setting it below the upper limit value, a sufficient area for shielding IC chips and the like can be secured.
The total of resin region A and resin region B is preferably 14% or less, more preferably 12% or less, even more preferably 11% or less, with respect to one surface of the multilayer body. % or less is more preferable, and even more preferably 3% or less.
In the multilayer body of this embodiment, the number of resin regions A and resin regions B may be one, or two or more. When there are two or more resin regions A and/or resin regions B, it is preferable that the total thereof satisfies the above range. In addition, when there are two or more resin regions A and/or resin regions B, the area of each resin region A and resin region B is 10% or more and 99% or less of the total area of resin regions A and resin region B. It is preferable that there be. Moreover, the number of resin regions A and resin regions B in the multilayer body is preferably five or less, respectively.

In the multilayer body of this embodiment, the ratio of the area of the resin region A to one side of the multilayer body is preferably 0.01% or more and less than 15%. By setting the amount to be equal to or more than the lower limit, a laser marking image tends to be more easily formed. Further, by setting the amount to be less than or equal to the upper limit value, a clear window tends to be formed more favorably.
The area ratio of the resin region A is preferably 0.05% or more, more preferably 0.1% or more, even more preferably 0.5% or more, and 1.0% or more. It is more preferable that the amount is at least 1.2%, and even more preferably 1.2% or more. The area ratio of the resin region A is preferably 14% or less, more preferably 13% or less, even more preferably 10% or less, may be 5% or less, and 3% or less. It may be.
Further, in the surface of the multilayer body of this embodiment, it is preferable that the ratio of the area of the resin region B to one surface of the multilayer body is 0.01% or more and 10% or less. By setting it above the lower limit, the clarity of the laser marking image tends to be further improved. Further, by setting the amount to be less than or equal to the upper limit value, a clear window tends to be formed more favorably.
The area ratio of the resin region B is preferably 0.03% or more, more preferably 0.08% or more, even more preferably 0.1% or more, and even more preferably 0.2% or more. It is more preferable that the amount is at least 0.4%, and even more preferably 0.4% or more. By setting it above the lower limit, the clarity of the laser marking image tends to be further improved. Further, the area ratio of the resin region B is preferably 8% or less, more preferably 6% or less, even more preferably 4% or less, even more preferably 2% or less, It is even more preferable that it is 1% or less. By setting it below the upper limit value, a clear window tends to be formed better.

In this embodiment, as described above, the resin region B is usually a laser marking image formed by a laser marking process, but it is preferable that the resin region B includes at least one of the following laser marking images. .
(1) Laser marking image in which the OD value according to ISO 5-4 is 0.45 to 0.70 after laser marking processing of the area where RGB is (0,0,0) in the original image (2) The above The resin area B is a laser marking image (3 ) Laser marking image with an OD value of 0.30 to 0.50 in accordance with ISO 5-4 after laser marking processing of an area where RGB is (120, 120, 120) in the original image

In this embodiment, it is more preferable to have at least two of the laser marking images (1) to (3) above. With such a configuration, it is possible to mark a face image with clearer shadows, and a multilayer body with excellent authenticity determination performance and security can be obtained.
In this embodiment, the OD value (OD ₀ value) according to ISO 5-4 after laser marking processing of the area where RGB is (0, 0, 0) in the original image is 0.50 or more. is more preferable, and more preferably 0.65 or less.
In this embodiment, the OD value (OD ₁₈₀ value) according to ISO 5-4 after laser marking processing of the area where RGB is (180, 180, 180) in the original image is 0.17 or more. is more preferable, and more preferably 0.24 or less.
In this embodiment, the OD value (OD ₁₂₀ value) according to ISO 5-4 after laser marking processing of the area where RGB is (120, 120, 120) in the original image is 0.33 or more. is more preferable, and more preferably 0.45 or less.

In this embodiment, the OD value conforming to ISO 5-4 after laser marking processing of the area where RGB in the original image is (120, 120, 120) and the RGB in the original image are (0, 0, 0) The difference in OD values (OD ₀ value - OD ₁₂₀ value) according to ISO 5-4 after laser marking processing of the area is, for example, 0.13 or more, and it is 0.15 or more. It is preferably 0.16 or more, more preferably 0.17 or more, even more preferably 0.18 or more, and even more preferably 0.19 or more. By setting it above the lower limit, contrast is created in the laser marking image, and a multilayer body with better security can be obtained. Furthermore, the practical upper limit of the OD ₀ value - OD ₁₂₀ value is, for example, 0.30 or less.
A laser marking image satisfying the above OD value can be achieved, for example, by selecting an appropriate laser marking agent and adjusting the blending amount.

In this embodiment, it is preferable to include a resin region C other than resin region A and resin region B in the thickness direction of the multilayer body. A preferable example of the resin region C is a case where all parts of one surface of the multilayer body other than the clear window are the resin region C, as shown in FIGS. 3 and 4. Moreover, the multilayer body of this embodiment may include portions other than the resin region A, the resin region B, and the resin region C on one surface of the multilayer body. For example, a multilayer body is exemplified by a multilayer body bordered with an inorganic material or the like.
In the multilayer body of this embodiment, the area occupied by the resin region C with respect to one side of the multilayer body is preferably 85 to 99%.
Furthermore, in this embodiment, it is preferable that the total area of resin region A, resin region B, and resin region C occupies 99% or more of one surface of the multilayer body.

It is also preferable that the resin region C has a total light transmittance of 0.1 to 3%. The total light transmittance of the resin region C is preferably 2.5% or less, more preferably 2% or less, even more preferably 1.6% or less, and 1.4% or less. It is more preferable that the amount is 1.3% or less, even more preferably 1.0% or less, and even more preferably 1.0% or less, whereby a multilayer body with even better shielding properties can be obtained. There is a tendency to The lower limit of the total light transmittance of the resin region C is ideally 0%, but may be 0.2% or more.

The resin constituting the clear window is the same as the transparent resin contained in the transparent resin layer described later, and the preferable range is also the same. Further, components other than the resin that may be included in the clear window are also the same as those included in the transparent resin layer.

Next, each layer will be explained.
The multilayer body of this embodiment includes a resin layer (laser marking layer) containing a laser marking agent. In this embodiment, by providing the laser marking layer, it becomes possible to provide the multilayer body with a laser marking image. The laser marking image usually constitutes the resin area B.
The type of laser marking agent contained in the laser marking layer is not particularly limited, but it is preferably a black pigment, and more preferably carbon black. Additionally, metal oxide laser marking agents can also be used. For details of the laser marking agent and the laser marking layer, in addition to the above, the description in JP-A-2020-075487 can be referred to, the contents of which are incorporated herein.
The content of the laser marking agent in the laser marking layer is preferably 0.0006% by mass or more, more preferably 0.0008% by mass or more, and even more preferably 0.0010% by mass or more. , more preferably 0.0013% by mass or more, and even more preferably 0.0018% by mass or more. By setting it above the lower limit, the sharpness of the laser marking image tends to be further improved. Further, the content of the laser marking agent in the laser marking layer is preferably 0.01% by mass or less, more preferably 0.008% by mass or less, and preferably 0.006% by mass or less. It is more preferably 0.004% by mass or less, even more preferably 0.003% by mass or less. By setting it below the above-mentioned upper limit, there is a tendency to suppress blackening of the multilayer body and black crushing of the laser marking image.
The laser marking layer may contain only one type of laser marking agent, or may contain two or more types of laser marking agents. When two or more types are included, it is preferable that the total amount falls within the above range.

The laser marking layer contains a resin in addition to the laser marking agent. The resin is usually a thermoplastic resin, including polycarbonate resin; polystyrene resin; acrylic resin; polyester resin (thermoplastic polyester resin); polyamide resin; polyolefin resin such as polyethylene resin, polypropylene resin, and cyclic cycloolefin resin; polyacetal resin; Examples include polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; polymethacrylate resin; and it is preferable that polycarbonate resin is included.
The content of the resin (preferably thermoplastic resin) contained in the laser marking layer is preferably 97% by mass or more, more preferably 98% by mass or more, and 99% by mass or more. It is even more preferable that there be. The upper limit of the content of the resin (preferably thermoplastic resin) contained in the laser marking layer is such that the total of the resin (preferably thermoplastic resin) and laser marking agent is 100% by mass.
The laser marking layer may contain only one type of resin (preferably a thermoplastic resin), or may contain two or more types of resin. When two or more types are included, it is preferable that the total amount falls within the above range.

In addition to the laser marking agent and resin, the laser marking layer may contain other components without departing from the spirit of the present invention. Specifically, stabilizers, mold release agents, flame retardants, ultraviolet absorbers, antistatic agents, antifogging agents, fluidity improvers, plasticizers, dispersants, antibacterial agents, etc. are exemplified, and stabilizers are included. is preferred. These may contain only one type, or may contain two or more types.

Although the thickness of the laser marking layer is not particularly limited, it is preferably 20 μm or more, and preferably 200 μm or less, for example.

Next, a resin layer containing a white pigment (white pigment layer) included in the multilayer body of this embodiment will be explained. In this embodiment, by including the white pigment layer, a multilayer body with excellent shielding properties can be obtained. Therefore, it becomes possible to incorporate an IC chip or the like inside the multilayer body so that it cannot be seen from the outside.
The type of white pigment is not particularly limited, but titanium oxide is preferred.
The content of the white pigment contained in the white pigment layer is preferably 20 to 50% by mass of the white pigment layer. By setting it to the above lower limit or more, a multilayer body with better shielding properties can be obtained. In addition, by setting the content to be less than or equal to the upper limit value, appearance defects due to agglomeration of titanium oxide tend to be more suppressed. The content of the white pigment contained in the white pigment layer is more preferably 23% by mass or more, even more preferably 25% by mass or more, and even more preferably 27% by mass or more. , more preferably 28% by mass or more. Further, the content of the white pigment contained in the white pigment layer is more preferably 45% by mass or less, even more preferably 40% by mass or less, even more preferably 38% by mass or less, and 35% by mass or less. % or less, and even more preferably 32% by mass or less.
The white pigment layer may contain only one type of white pigment, or may contain two or more types of white pigment. When two or more types are included, it is preferable that the total amount falls within the above range.

The white pigment layer contains a resin in addition to the white pigment. The resin is usually a thermoplastic resin, including polycarbonate resin; polystyrene resin; acrylic resin; polyester resin (thermoplastic polyester resin); polyamide resin; polyolefin resin such as polyethylene resin, polypropylene resin, and cyclic cycloolefin resin; polyacetal resin; Examples include polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; polymethacrylate resin; and it is preferable that polycarbonate resin is included.
The content of the resin (preferably thermoplastic resin) contained in the white pigment layer is preferably 50% by mass or more, more preferably 55% by mass or more, and 60% by mass or more. It is more preferably at least 62% by mass, even more preferably at least 65% by mass, even more preferably at least 68% by mass. By setting it to the above lower limit or more, even if the white pigment layer is made thin, high shielding properties can be achieved, and a clear window can be molded more easily. Further, the content of the white pigment contained in the white pigment layer is preferably 80% by mass or less, more preferably 73% by mass or less, and even more preferably 75% by mass or less. It is preferably 73% by mass or less, more preferably 72% by mass or less, and even more preferably 72% by mass or less. By setting it below the upper limit value, moldability tends to improve.
The white pigment layer may contain only one type of resin (preferably a thermoplastic resin), or may contain two or more types of resin. When two or more types are included, it is preferable that the total amount falls within the above range.

In addition to the white pigment and resin, the white pigment layer may contain other components without departing from the spirit of the present invention. Specifically, stabilizers, mold release agents, flame retardants, ultraviolet absorbers, antistatic agents, antifogging agents, fluidity improvers, plasticizers, dispersants, antibacterial agents, etc. are exemplified, and stabilizers and/or Preferably, an antistatic agent is included. These may contain only one type, or may contain two or more types.
In this embodiment, it is preferable that the white pigment layer contains an antistatic agent. In particular, it is preferred that at least the outermost layer of the white pigment layer contains an antistatic agent. Including an antistatic agent tends to further improve the antistatic properties of the multilayer body.
The content of the antistatic agent in the white pigment layer is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and 2% by mass or less. The content is preferably 1% by mass or less, and more preferably 1% by mass or less.
The white pigment layer in this embodiment may contain only one type of antistatic agent, or may contain two or more types of antistatic agent. When two or more types are included, it is preferable that the total amount falls within the above range.

It is also preferable that the white pigment layer contains a colorant other than the white pigment in a proportion of 5 to 150 ppm by mass. By including other colorants, it is possible to impart some color to the multilayer body, and the appearance (design) of the multilayer body tends to be improved. Moreover, the light shielding performance of the multilayer body can be further improved.
The white pigment layer in this embodiment may contain only one type of other colorant, or may contain two or more types of other colorants. When two or more types are included, it is preferable that the total amount falls within the above range.
Other colorants include inorganic pigments, organic pigments, organic dyes, and the like.
Inorganic pigments include, for example, sulfide pigments such as carbon black, cadmium red, and cadmium yellow; silicate pigments such as ultramarine; zinc white, Bengara, chromium oxide, iron black, titanium yellow, and zinc-iron brown. , titanium cobalt green, cobalt green, cobalt blue, copper-chromium black, copper-iron black, and other oxide pigments; yellow, molybdate orange, and other chromic acid pigments; dark blue and other ferrocyanic pigments. Examples include.
Examples of organic pigments and organic dyes include phthalocyanine dyes or pigments such as copper phthalocyanine blue and copper phthalocyanine green; azo dyes or pigments such as nickel azo yellow; thioindigo, perinone, perylene, quinacridone, and dioxazine dyes. , isoindolinone-based, and quinophthalone-based dyes or pigments; anthraquinone-based, heterocyclic-based, and methyl-based dyes or pigments.

Specific examples of the other colorants include colorants having maximum absorption in the wavelength range of 450 to 650 nm. By incorporating a colorant with maximum absorption in the wavelength range of 450 to 650 nm, which effectively absorbs light around 550 nm, a wavelength that humans can sensitively perceive, the shielding properties of the multilayer body can be effectively improved. can be improved.
Furthermore, there is also an embodiment in which the other coloring agent is a dye. Examples of dyes include colorants having maximum absorption in the wavelength range of 450 to 650 nm.
Moreover, the above-mentioned carbon black is also mentioned as a specific example of the other coloring agent. By blending carbon black, the light shielding performance of the multilayer body can be further improved.

When the white pigment layer contains another colorant, the content thereof is preferably 5 ppm or more by mass, more preferably 7 ppm or more by mass, and 10 ppm or more by mass in the white pigment layer. It is more preferably 15 mass ppm or more, and even more preferably 20 mass ppm or more. The upper limit of the content of the other colorant in the white pigment layer is preferably 150 mass ppm or less, more preferably 120 mass ppm or less, even more preferably 100 mass ppm or less, More preferably, it is 80 mass ppm or less. By setting it within such a range, the appearance of the obtained white pigment layer tends to be further improved, and the light shielding performance tends to be further improved.
The white pigment layer of this embodiment may contain only one type of other colorant, or may contain two or more types of other colorants. When two or more types are included, it is preferable that the total amount falls within the above range.

In this embodiment, it is preferable that fluorescent printing is applied to the outermost layer of the white pigment layer.

In this embodiment, the thickness of the white pigment layer is 55 to 140 μm. By keeping the above upper and lower limits below, a clear window tends to be more easily molded. By making it equal to or more than the lower limit value, the shielding properties of the multilayer body can be achieved. The thickness of the white pigment layer is more preferably 60 μm or more, even more preferably 65 μm or more, and even more preferably 70 μm or more. Further, the thickness of the white pigment layer is more preferably 120 μm or less, even more preferably 100 μm or less, even more preferably 90 μm or less, and even more preferably 80 μm or less.
The thickness of the white pigment layer is preferably the same as or thinner than the thickness of the adjacent transparent resin layer.
In this embodiment, the white pigment layer preferably has T*t of 250 or more, more preferably 265 or more, where the total light transmittance of the white pigment layer is T% and the thickness is tμm. It is preferably 280 or more, even more preferably 295 or more, and even more preferably 310 or more. When the amount is equal to or more than the lower limit, the light shielding properties and moldability of the obtained multilayer body tend to be improved in a well-balanced manner. Further, the upper limit value is preferably 750 or less, more preferably 700 or less, even more preferably 650 or less, even more preferably 600 or less, and even more preferably 550 or less. Preferably, it may be 500 or less, 450 or less, 420 or less, 405 or less, 400 or less, 380 or less, 350 or less, 340 or less, or 335 or less. When the amount is below the upper limit, the light shielding properties and moldability of the obtained multilayer body tend to be improved in a better balance.
In this embodiment, in particular, the thickness t is 55 μm or more and 100 μm or less, and when the total light transmittance of the white pigment layer is T% and the thickness is t μm, T*t, which is the product of T and t, is 250 or more. It is preferably 750 or less.

Next, the transparent resin layer will be explained. The transparent resin layer in this embodiment is preferably used as an overlay layer and a transparent core layer, as will be described in detail later.
The transparent resin layer contains resin. The resin is usually a thermoplastic resin, including polycarbonate resin; polystyrene resin; acrylic resin; polyester resin (thermoplastic polyester resin); polyamide resin; polyolefin resin such as polyethylene resin, polypropylene resin, and cyclic cycloolefin resin; polyacetal resin; Examples include polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; polymethacrylate resin; and it is preferable that polycarbonate resin is included.
The content of the resin (preferably thermoplastic resin) contained in the transparent resin layer is preferably 97% by mass or more, more preferably 98% by mass or more, and 99% by mass or more. It is even more preferable that there be. By setting it to the above lower limit or more, transparency and clear window moldability tend to be further improved. The upper limit of the content of the resin (preferably thermoplastic resin) contained in the transparent resin layer is 100% by mass or less of the transparent resin layer.
The transparent resin layer may contain only one type of resin (preferably thermoplastic resin), or may contain two or more types of resin. When two or more types are included, it is preferable that the total amount falls within the above range.

In addition to the resin, the transparent resin layer may contain other components without departing from the spirit of the present invention. Specifically, stabilizers, mold release agents, flame retardants, ultraviolet absorbers, antistatic agents, antifogging agents, fluidity improvers, antiblocking agents, plasticizers, dispersants, antibacterial agents, etc. It is preferable to include an agent. These may contain only one type, or may contain two or more types.
It is preferable that the transparent resin layer substantially contains neither a laser marking agent nor a white pigment. Regarding the laser marking agent, "substantially not containing" means that the content of the laser marking agent contained in the transparent resin layer is less than the content of the laser marking agent contained in the laser marking layer. The content of the laser marking agent contained in the laser marking agent is 10% by mass or less (preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less). In addition, "substantially free of white pigment" means that the content of white pigment contained in the transparent resin layer is less than the content of white pigment contained in the white pigment layer, and the content of white pigment contained in the white pigment layer is The content of the white pigment is 10% by mass or less (preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less).

The total light transmittance of the transparent resin layer is preferably in the same range as the resin region A.
Although the thickness of the transparent resin layer is not particularly limited, it is preferably 20 μm or more, and preferably 200 μm or less, for example.

Next, a preferred layer structure of the multilayer body of this embodiment will be explained.
The multilayer body of this embodiment includes a laser marking layer and a white pigment layer. In the present embodiment, the laser marking layer is usually located outside (closer to the surface) than the white pigment layer. Further, as shown in FIG. 4, the multilayer body of this embodiment has a resin region A and a resin region B when viewed from the surface, but the white pigment layer preferably has an opening, and the multilayer body When viewed from a direction perpendicular to the surface, resin region A and resin region B are located in the same area as the opening. Examples of embodiments in which resin region A and resin region B are located in the same region as the opening include embodiments in which resin region A and part of resin region B are located in the same region as the opening, and embodiments in which resin region A and part of resin region B are located in the same region as the opening. This includes an embodiment in which resin region A and resin region B are located in a part of the same region. Furthermore, it is preferable that the multilayer body of this embodiment has a transparent resin layer. A preferred embodiment of the transparent resin layer is that it is adjacent to a white pigment layer with openings. Because the transparent resin layer and the white pigment layer are adjacent to each other, the transparent resin of the transparent resin layer can can easily flow in, and a clear window (for example, reference numeral 34 in FIG. 3(B)) can be easily formed. Another preferred embodiment of the transparent resin layer is that it is located outside the laser marking layer, adjacent to the laser marking layer, and outside the laser marking layer. The multilayer body of this embodiment preferably has both a transparent resin layer adjacent to the white pigment layer having an opening and a transparent resin layer adjacent to the laser marking layer and located outside the laser marking layer. . Moreover, as described above, it is preferable that the opening is filled with a part of the material constituting the transparent resin layer, thereby forming a clear window of the multilayer body.
Further, the multilayer body of this embodiment can also be used as a composite body having a film having a total light transmittance of less than 75% on one side thereof. FIG. 5 is a schematic cross-sectional view showing the layer structure of the composite body 50, in which a film 38 with low total light transmittance is provided on one side of the multilayer body 30 of this embodiment. With such a configuration, when the composite film 50 is used as a security card, the clear window 34 is visible when viewed from one side, and the clear window 34 is not visible when viewed from the other side. It is also possible to do this. In the embodiment shown in FIG. 5, the multilayer body 30 includes an overlay layer (transparent resin layer) 31, a laser marking layer 36, a transparent resin layer 33, a white core layer (white pigment layer) 32, a transparent resin layer 33, and a white core. Although it is composed of a layer (white pigment layer) 32 and a transparent resin layer 33, it goes without saying that other layer configurations may be used.

More specifically, the multilayer body of this embodiment preferably has a laser marking layer, a transparent resin layer, a white pigment layer, and a transparent resin layer in the above order. Here, each layer may or may not be adjacent to each other in the thickness direction, but it is preferable that the transparent resin layer and the white pigment layer are adjacent to each other. Moreover, it is more preferable that all the layers are in contact with each other.
The multilayer body of this embodiment may further have other layers.
The multilayer body of this embodiment more preferably has a laser marking layer, a transparent resin layer, a white pigment layer, a transparent resin layer, a white pigment layer, and a transparent resin layer in the above order.

More preferably, the multilayer body of this embodiment has two or more laser marking layers, and in the cross-sectional direction of the multilayer body, the two laser marking layers are based on a center plane in a direction perpendicular to the thickness direction of the cross section. It is preferable that they are located symmetrically. Being symmetrically located with respect to the central plane in the direction perpendicular to the thickness direction of the cross section means, for example, in FIG. 3(B), the central plane in the thickness direction is represented by XX. This means that the cross section in the thickness direction is symmetrical with respect to this plane.
Here, it is preferable that there are two or more laser marking layers, and two of the laser marking layers are located at an interval of 300 μm or more and 600 μm or less in the thickness direction. In FIG. 3, the layers located between the two laser marking layers 36 and 36 (transparent resin layer 33, white core layer (white pigment layer) 32, transparent resin layer 33, white core layer (white pigment layer) 32. The total thickness of the transparent resin layer 33) is preferably 300 μm or more and 600 μm or less. The lower limit of the interval is more preferably 350 μm or more, and more preferably 380 μm or more. By setting it above the lower limit value, it tends to be easier to introduce an IC chip or an antenna. Further, the upper limit of the interval is more preferably 550 μm or less, even more preferably 520 μm or less, even more preferably 500 μm or less, even more preferably 480 μm or less, and even more preferably 450 μm or less. It's okay. By setting it below the upper limit value, card accommodating properties tend to be further improved.

A particularly preferable layer structure of the multilayer body of this embodiment is the structure shown in FIG. (white pigment layer) 32, transparent resin layer 33, white core layer (white pigment layer) 32, transparent resin layer 33, laser marking layer 36, and overlay layer (transparent resin layer) 31.
Of course, the multilayer body of this embodiment is not limited to the layer configuration shown in FIG. 3. It goes without saying that the multilayer body shown in FIG. 3 may also include other layers without departing from the spirit of the present invention.

In the multilayer body of this embodiment, it is preferable that at least one layer contains a polycarbonate resin, and it is more preferable that the laser marking layer, the white pigment layer, and the transparent resin layer each contain a polycarbonate resin. When each layer contains a polycarbonate resin, the adhesion between the layers can be further improved.

The thickness of the multilayer body of this embodiment can be determined as appropriate depending on the application, but the total thickness is preferably 300 μm or more, more preferably 400 μm or more. By setting it above the lower limit value, it tends to be easier to introduce an IC chip or an antenna. Further, the upper limit of the total thickness is preferably 2.0 mm or less, more preferably 1.0 mm or less, and may be 700 μm or less. By setting it below the upper limit value, card accommodating properties tend to be further improved. In this embodiment, by adjusting the thickness of the white pigment layer and the proportion of the white pigment in the white pigment layer, good shielding performance can be achieved even if the total thickness of the multilayer body is as thin as 700 μm or less.

In addition to heat-pressing each constituent layer as described above, the method for manufacturing the multilayer body of this embodiment includes increasing the adhesiveness between each layer using an adhesive or the like within the scope of the present embodiment. It's okay. Alternatively, each layer can be coextruded into a sheet.

<Application>
Next, the application of the multilayer body of this embodiment will be described. The multilayer body of this embodiment is preferably used as a security card or passport containing these.
Examples of the security card in this embodiment include an identification card (ID card), a driver's license, a bank card, a credit card, an insurance card, and other identification cards.
An example of the passport in this embodiment is an e-passport.

In addition, in this embodiment, the descriptions in paragraphs 0048 to 0059 of JP2016-108424A and paragraphs 0075 to 0088 of JP2015-168728A are taken into consideration without departing from the spirit of the present invention. and the contents thereof are incorporated herein.

The present invention will be explained in more detail with reference to Examples below. The materials, usage amounts, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.
If the measuring equipment used in the examples is difficult to obtain due to discontinuation or the like, measurements can be made using other equipment with equivalent performance.

1. Raw material <polycarbonate resin>
E-2000N: Bisphenol A type polycarbonate resin, Iupilon (registered trademark), manufactured by Mitsubishi Engineering Plastics S-3000F: Bisphenol A type polycarbonate resin, Iupilon (registered trademark), manufactured by Mitsubishi Engineering Plastics

<Titanium oxide>
PFC317: Manufactured by Ishihara Sangyo Co., Ltd., rutile type titanium oxide, average primary particle size 0.24 μm

<Antistatic agent>
Trihexyltetradecylphosphonium bis(trifluoromethanesulfonyl)amide: manufactured by MERCK, CAS number 460092-03-9

<Other colorants>
Carbon black M#280: Manufactured by Cabot Corporation, MONARCH280
Carbon black M#800: Manufactured by Cabot Corporation, MONARCH800
Dye 1: Macrolex Red5B, Colorant Dye 2: Macrolex Violet3R, Colorant Dye 3: Diaresin Green C, Colorant

<Antioxidant>
AS2112: manufactured by ADEKA, tris(2,4-di-tert-butylphenyl) phosphite

2. Examples 1 to 6, Comparative Examples 1 to 7
<Manufacture of resin pellets>
Regarding the pellets for the transparent resin layer, the pellets for the laser marking layer, and the pellets for the white pigment layer, each component was blended in a tumbler to have the composition shown in Table 3 or Table 4, and then , TEX30α) from the base and melt-kneaded at a cylinder temperature of 240°C to produce each pellet.
In addition, in Table 3 and Table 4, the content of each component is shown in parts by mass. However, the dye in the white pigment layer is expressed in mass ppm.

<Manufacture of each resin layer>
Each resin layer was manufactured by the following method using each pellet obtained above.
The pellets were processed using a T-die melt film forming extruder consisting of a twin-screw extruder with a barrel diameter of 32 mm and a screw L/D (length/diameter) of 31.5, at a discharge rate of 20 kg/h and a screw rotation speed of 200 rpm. In addition, a resin sheet with a width of 300 mm was molded. The cylinder/T-die temperature was 240°C, and the extruded molten sheet was passed through a first cooling roll made of silicone rubber with a diameter of 250 mm and a ten-point average roughness Rzjis (JIS B0601:2013) of 21 μm. The sample was nipped with a second metal cooling roll having a diameter of 250 mm and embossed with a diameter of 18 μm according to JIS B0601:2013. Next, the sheet with the embossed pattern formed on its surface was further passed through a third cooling roll made of metal with a mirror surface, and was taken up with a take-up roll to form a resin sheet having the thickness shown in Table 1 (average thickness). . At this time, the temperature of the first cooling roll was set to 50°C, the temperature of the second cooling roll was set to 100°C, and the temperature of the third cooling roll was set to 100°C.

<Manufacture of multilayer body>
The resin sheets obtained above were stacked and laminated so as to have the layer structure shown in Table 3 or Table 4 (any of layer structures A to D) to produce a multilayer body. The layer configurations A to D are shown in Table 1 below.
For heating and pressurizing during lamination, steps 1 to 5 shown in Table 2 were performed. For lamination, a tabletop card laminator OLA6E manufactured by OASYS was used.

<Laser marking process>
Laser marking was performed on the multilayer body obtained above to create a laser marking image. Laser marking was performed using Easy MARKIV E10 manufactured by Rofin Corporation under the following laser conditions.
Output 35A, frequency 15kHz, speed 100mm/s, line width 0.020mm, pulse width 10.0μs
When performing laser marking, Iupilon Film SW-2000M1 (thickness: 100 μm), a film for ID cards manufactured by Mitsubishi Gas Chemical Co., Ltd., was placed under the multilayer body as an underlay. After performing laser marking, dirt adhering to the multilayer body was thoroughly wiped off with a cloth.
For the original images to be laser marked, we used Microsoft's graphic software Microsoft Paint to create an image with RGB of (0,0,0), an image with RGB of (180,180,180), and an image with RGB of (120). , 120, 120) was created in monochrome bitmap file format.

<Measurement of area of resin regions A, B, and C>
The ratio (%) of each resin area to the surface of the multilayer body (total area on one side) of resin area A, resin area B, and resin area C is determined by photographing the multilayer body and using image processing software WinROOF2013 manufactured by Mitani Shoji Co., Ltd. Calculated using

<Measurement of total light transmittance>
The total light transmittance of each constituent layer of the multilayer body was measured before the lamination.
Specifically, the total light transmittance of each layer was measured in accordance with ISO-13468-1 (measurement conditions: D65 light source, 10° field of view).
For the measurement, a haze meter HM-150 manufactured by Murakami Color Research Institute was used.
The unit of total light transmittance is expressed in %.
Further, for the white pigment layer, total light transmittance T×thickness t (T*t) was calculated.

<L value>
The L value of resin region A was measured in accordance with JIS Z 8781-4.
For the measurement, a spectrocolorimeter SD 7000 manufactured by Nippon Denshoku Kogyo Co., Ltd. was used.

<OD value of laser marking image>
A laser marking image of an area where RGB in the original image in resin area B is (0, 0, 0), a laser marking image of an area where RGB in the original image is (180, 180, 180), and a laser marking image of an area where RGB in the original image is ( The OD values in the laser marking images of the areas (120, 120, 120) were each measured in accordance with ISO 5-4.
In addition, the OD ₀ value of the laser marking image in the area where RGB is (0, 0, 0) in the original image and the OD ₁₂₀ value in the laser marking image in the area where RGB is (120, 120, 120) in the original image. The difference (D ₀ value - OD ₁₂₀ value) was calculated.
When measuring the OD value, a 504 spectrodensitometer manufactured by X-Rite was used.

<Appearance of clear window>
The appearance of the clear window of the obtained multilayer body was visually evaluated. Five experts made the judgment, and a majority vote was taken.
A: Good B: Not good (dents, bubbles, etc.)

<Appearance of laser marking image (LM image) on clear window surface>
The appearance of the laser marking image on the clear window surface of the obtained multilayer body was visually evaluated. Five experts made the judgment, and a majority vote was taken.
A: Good B: Not good (colors blown out, black spots, etc.)

<Achieving both clear window appearance and laser marking image appearance>
The following evaluation was made based on the appearance of the clear window and the appearance of the laser marking image.
A: Both the clear window appearance and LM are rated A. B: One of the clear window appearance and LM is rated B. C: Both the clear window appearance and LM are rated B.

As is clear from the above results, the multilayer body of the present embodiment had excellent clear window appearance, excellent shielding properties, and also excellent laser marking appearance on the clear window surface (Examples 1 to 6).
On the other hand, in the multilayer body of Comparative Example 1, the content of black pigment in the laser marking layer was small, the L value was outside the range of the present invention, and the appearance of the laser marking (LM) image on the clear window surface was poor. It was clear.
In addition, in the multilayer body of Comparative Example 2, the content of black pigment in the laser marking layer was large, the L value was outside the range of the present invention, and the appearance of the LM image on the clear window surface was crushed.
Further, in the multilayer body of Comparative Example 3, although the total area occupied by resin region A and resin region B exceeded 15%, a dent occurred in the appearance of the clear window.
Further, in the multilayer body of Comparative Example 4, although the total area occupied by resin region A and resin region B was less than 1%, the appearance of the LM image on the clear window surface was minute.
Furthermore, in the multilayer body of Comparative Example 5, a clear window in which resin region A and resin region B were not present was not produced, and an LM image could not be produced.
Furthermore, although the multilayer body of Comparative Example 6 had a thick white pigment layer, air bubbles were generated in the clear window.
Further, in the multilayer body of Comparative Example 7, the thickness of the white pigment layer was small, and the shielding property was insufficient considering that a chip or the like was incorporated therein.

10, 20, 30 multilayer body (security card)
11, 21, 31 Overlay layer (transparent resin layer)
12, 22, 32 White core layer (white pigment layer)
13 Core layer 23, 33 Transparent resin layer 24, 34 Clear window 25, 35 Opening (area where white pigment layer does not exist)
36 Laser marking layer 38 Film with low total light transmittance 50 Composite film

Claims (28)

a resin layer containing a laser marking agent;
A multilayer body having a thickness of 55 to 140 μm and comprising a resin layer containing a white pigment,
The surface of the multilayer body includes a resin region A with a total light transmittance of 75 to 90% and a resin region B with a total light transmittance of 50 to 74%,
The total area occupied by the resin region A and the resin region B with respect to one surface of the multilayer body is 1 to 15%,
The L value in the resin region A is 93.8 to 95.2,
Multilayered body. The resin layer containing the white pigment has an opening, and the resin region A and the resin region B are located in the same area as the opening when viewed from a direction perpendicular to the surface of the multilayer body. The multilayer body according to claim 1, wherein the resin region B is a laser marking image. The multilayer body according to claim 1 or 2, wherein the resin layer containing the white pigment has a thickness of 60 to 100 μm. The multilayer body according to claim 1 or 2, wherein the resin layer containing the white pigment has a thickness of 60 to 80 μm. The multilayer body according to claim 1 or 2, wherein the resin layer containing the white pigment contains titanium oxide in an amount of 20 to 50% by mass of the resin layer. The multilayer body according to claim 1 or 2, further comprising a transparent resin layer. The multilayer body according to claim 6, wherein the multilayer body includes a resin layer containing the laser marking agent, the transparent resin layer, a resin layer containing the white pigment, and the transparent resin layer in the above order. The multilayer body includes the resin layer containing the laser marking agent, the transparent resin layer, the resin layer containing the white pigment, the transparent resin layer, the resin layer containing the white pigment, and the transparent resin layer in the above order. 7. The multilayer body according to claim 6. The multilayer body has two or more resin layers containing the laser marking agent, and in the cross-sectional direction of the multilayer body, the two resin layers containing the laser marking agent are located at the center in the direction perpendicular to the thickness direction of the cross section. The multilayer body according to claim 1 or 2, wherein the multilayer body is located symmetrically with respect to a plane. According to claim 1 or 2, there are two or more layers containing the laser marking agent, and two of the layers containing the laser marking agent are located at an interval of 300 μm or more and 600 μm or less in the thickness direction. Multilayer body as described. The multilayer body according to claim 1 or 2, wherein the multilayer body includes a resin region C other than the resin region A and the resin region B in the thickness direction of the multilayer body, and the total light transmittance of the resin region C is 0.1 to 3%. . The multilayer body according to claim 11, wherein the resin region C occupies 85 to 99% of one surface of the multilayer body. The resin area B is a laser marking image in which the OD value according to ISO 5-4 is 0.45 to 0.70 after laser marking processing of the area where RGB is (0, 0, 0) in the original image. The multilayer body according to claim 1 or 2, comprising: The resin area B is a laser marking image in which the OD value according to ISO 5-4 is 0.15 to 0.25 after laser marking processing of the area where RGB in the original image is (180, 180, 180). The multilayer body according to claim 1 or 2, comprising: The resin area B is a laser marking image in which the OD value according to ISO 5-4 is 0.3 to 0.5 after laser marking processing of the area where RGB in the original image is (120, 120, 120). The multilayer body according to claim 1 or 2, comprising: A laser marking image in which the resin area B has an OD value of 0.45 to 0.70 according to ISO 5-4 after laser marking processing of the area where RGB is (0, 0, 0) in the original image, A laser marking image with an OD value of 0.15 to 0.25 according to ISO 5-4 after laser marking processing of an area where RGB in the original image is (180, 180, 180), and RGB in the original image A claim comprising at least two laser marking images having an OD value of 0.3 to 0.5 according to ISO 5-4 after laser marking processing of a region where is (120, 120, 120). 3. The multilayer body according to 1 or 2. 3. A multilayer body according to claim 1 or 2, wherein the laser marking agent comprises a black pigment. The multilayer body according to claim 1 or 2, having a total thickness of 300 μm or more and 2.0 mm or less. The multilayer body according to claim 1 or 2, having a total thickness of 300 μm or more and 700 μm or less. At least one of the resin layers containing the white pigment has a thickness t of 55 μm or more and 100 μm or less, and when the total light transmittance of the resin layer containing the white pigment is T% and the thickness is t μm, the product of T and t is The multilayer body according to claim 1 or 2, wherein T*t is 250 or more and 750 or less. The multilayer body according to claim 1 or 2, wherein at least the outermost layer of the resin layers containing the white pigment contains an antistatic agent. The multilayer body according to claim 1 or 2, wherein the outermost layer of the resin layer containing the white pigment is fluorescent printed. The multilayer body according to claim 1 or 2, wherein, on the surface of the multilayer body, the ratio of the area of the resin region A to one surface of the multilayer body is 0.01% or more and less than 15%. The multilayer body according to claim 1 or 2, wherein, on the surface of the multilayer body, the ratio of the area of the resin region B to one surface of the multilayer body is 0.01% or more and 10% or less. The multilayer body according to claim 1 or 2, wherein at least one layer of the multilayer body contains a polycarbonate resin. The multilayer body according to claim 1 or 2, wherein the resin layer containing the white pigment contains a colorant other than the white pigment in a proportion of 5 to 150 ppm by mass. A security card comprising the multilayer body according to claim 1 or 2. A passport comprising the multilayer body according to claim 1 or 2.

Images