Sheet, label, and method for manufacturing the sheet

Abstract

We provide highly decorative sheets in which the appearance of the pattern drawn on the surface of the sheet changes depending on the viewing angle. [Solution] A sheet comprising a transparent resin layer and a reflective layer laminated with the resin layer and reflecting light transmitted through the resin layer, wherein the resin layer has a first surface which is the incident surface of visible light, and the first surface has a first pattern drawn by a plurality of first grooves, and the plurality of first grooves are linear grooves arranged parallel to each other.

Description

Technical Field

[0001] The present invention relates to a sheet, a label, and a method for manufacturing a sheet. More specifically, the present invention relates to a sheet in which the appearance of a pattern drawn on the surface of the sheet changes depending on the viewing direction or the direction in which light hits.

Background Art

[0002] Patent Document 1 discloses a laser engraving for simple identification having a first pattern and a second pattern formed in the first pattern on the surface of a metal material. The first pattern is a base pattern formed to include a rough surface having a predetermined surface roughness. The second pattern is an identification pattern formed to include parallel grooves aligned in a certain direction with a predetermined depth by laser engraving. The second pattern is visible when viewed from a specific direction or when light is applied from a specific direction.

[0003] Patent Document 2 discloses a method for manufacturing a shrink film with a hologram. This manufacturing method forms a hologram forming layer provided with a hologram uneven pattern on one side of a shrink film base material. In this manufacturing method, the hologram forming layer is formed as follows. An uncured hologram forming resin is applied to one side of the shrink film base material. The hologram uneven pattern provided on the uneven pattern forming sheet for hologram is pressed and transferred to the applied uncured hologram forming resin. The hologram forming resin to which the hologram uneven pattern has been transferred is cured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005]

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] To appeal to consumers, companies often enhance the design of their products by applying special processing to their labels or packaging, thereby making the products more attractive and promoting sales.

[0006] The present invention has been made in view of the above circumstances, and one of its objectives is to provide a highly aesthetic sheet in which the appearance of the pattern drawn on the surface of the sheet changes depending on the viewing angle. [Means for solving the problem]

[0007] (1) A sheet according to one aspect of the present invention comprises a transparent resin layer and a reflective layer laminated with the resin layer and reflecting light transmitted through the resin layer. The resin layer has a first surface which is the incident surface of visible light. The first surface has a first pattern drawn by a plurality of first grooves. The plurality of first grooves are linear grooves arranged parallel to each other.

[0008] The sheet described in (1) above changes the appearance of the first pattern depending on the direction from which a person views it or the direction from which light hits it. The sheet described in (1) above has high design appeal because the appearance of the first pattern changes depending on the viewing angle.

[0009] (2) In the sheet described in (1) above, the width of each of the plurality of first grooves may be 40 μm or more and 170 μm or less.

[0010] The sheet in (2) above makes the first pattern easier to see.

[0011] (3) In the sheet of (1) or (2) above, the depth of each of the plurality of first grooves may be less than the thickness of the resin layer.

[0012] In the sheet described in (3) above, the multiple first grooves do not penetrate the resin layer.

[0013] (4) In the sheet described in (3) above, the depth of each of the plurality of first grooves may be 5 μm or more and 50 μm or less.

[0014] In the sheet of (4) above, the first pattern is easy to see.

[0015] (5) In any of the sheets of (1) to (4) above, the interval between adjacent first grooves may be 300 μm or more and 600 μm or less.

[0016] When the interval between the first grooves is 300 μm or more, the adjacent first grooves are not too close, making it easy to draw the first pattern. When the interval between the first grooves is 600 μm or less, the adjacent first grooves are not too far apart, making it easy to visually recognize what is drawn as the first pattern.

[0017] (6) In any of the sheets of (1) to (5) above, the first pattern may include at least one of characters and patterns.

[0018] In the sheet of (6) above, the first pattern can be expressed by one or both of characters and patterns.

[0019] (7) In any of the sheets of (1) to (6) above, the resin layer may be a layer made of a transparent resin film.

[0020] The resin film is suitable for the resin layer.

[0021] (8) In the sheet of (7) above, the resin film may be formed of polyethylene terephthalate or polystyrene.

[0022] Polyethylene terephthalate or polystyrene is suitable for forming grooves by laser processing.

[0023] (9) In any of the sheets of (1) to (8) above, the reflective layer may be a metal layer.

[0024] The metal layer is suitable for the reflective layer.

[0025] (10) In the sheet of (9) above, the metal layer may be formed of aluminum or an aluminum alloy.

[0026] Aluminum or an aluminum alloy has high corrosion resistance and is likely to maintain luster.

[0027] (11) In the sheet of any one of (1) to (10) above, the first surface may have a second pattern depicted by a plurality of second grooves. The plurality of second grooves are linear grooves arranged parallel to each other and intersect with the plurality of first grooves.

[0028] In the sheet of (11) above, the appearance of the second pattern changes depending on the direction in which a person looks or the direction in which light hits. In the sheet of (2) above, the appearances of the first pattern and the second pattern change depending on the viewing angle, so the design property is high.

[0029] (12) In the sheet of (11) above, the plurality of second grooves may be perpendicular to the plurality of first grooves.

[0030] In the sheet of (11) above, the difference in the appearances of the first pattern and the second pattern is large.

[0031] (13) In the sheet of (11) or (12) above, the width of each of the plurality of second grooves may be 40 μm or more and 170 μm or less.

[0032] In the sheet of (13) above, the second pattern is easy to see.

[0033] (14) In the sheet of any one of (11) to (13) above, the depth of each of the plurality of second grooves may be smaller than the thickness of the resin layer.

[0034] In the sheet of (14) above, the plurality of second grooves do not penetrate the resin layer.

[0035] (15) In the sheet of (14) above, the depth of each of the plurality of second grooves may be 5 μm or more and 50 μm or less.

[0036] The sheet in (15) above makes the second pattern easier to see.

[0037] (16) In any of the sheets described in (11) to (15) above, the spacing between adjacent second grooves may be 300 μm or more and 600 μm or less.

[0038] When the spacing between the second grooves is 300 μm or more, adjacent second grooves are not too close together, making it easier to draw the second pattern. When the spacing between the second grooves is 600 μm or less, adjacent second grooves are not too far apart, making it easier to visually identify what is being drawn as the second pattern.

[0039] (17) In any of the sheets described in (11) to (16) above, the second pattern may include at least one of characters and images.

[0040] The sheet described in (17) above can represent a second pattern using either or both text and / or images.

[0041] (18) A label according to one aspect of the present invention comprises any of the sheets described in (1) to (17) above, an adhesive layer provided on the side of the reflective layer opposite to the resin layer, and a separator bonded to the adhesive layer.

[0042] The label described in (18) above can be affixed to a surface such as a product.

[0043] (19) A method for manufacturing a sheet according to one aspect of the present invention comprises the steps of: preparing a material sheet having a transparent resin layer and a reflective layer that reflects light transmitted through the resin layer laminated together; and irradiating the first surface of the resin layer with a laser to draw a first pattern. The first pattern is formed by a plurality of first grooves arranged parallel to each other.

[0044] The sheet manufacturing method described in (19) above makes it easy to form fine first grooves on the first surface of the resin layer by laser processing.

[0045] (20) In the method for manufacturing the sheet described in (19) above, the method may further include a step of irradiating the first surface with a laser to draw a second pattern. The second pattern is formed by a plurality of second grooves arranged parallel to each other. The plurality of first grooves and the plurality of second grooves intersect.

[0046] The sheet manufacturing method described in (20) above makes it easy to form fine second grooves on the first surface of the resin layer by laser processing. [Brief explanation of the drawing]

[0047] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a sheet according to the embodiment. [Figure 2] Figure 2 is a schematic plan view showing an example of a sheet according to the embodiment. [Figure 3] Figure 3 is a schematic partial cross-sectional view with the line III-III shown in Figure 2 as the cutting line. [Figure 4] Figure 4 is a schematic perspective view showing the sheet from Figure 2 tilted with the axis along the length of the first groove as the axis of rotation. [Figure 5] Figure 5 is a schematic plan view showing another example of the sheet according to the embodiment. [Figure 6] Figure 6 is a schematic perspective view showing the sheet from Figure 5 tilted laterally, with the axis along the length of the second groove as the axis of rotation. [Figure 7] Figure 7 is a schematic cross-sectional view showing an example of a label according to the embodiment. [Modes for carrying out the invention]

[0048] Specific examples of sheets according to embodiments of the present invention will be described with reference to the drawings. Identical reference numerals in the drawings indicate the same or corresponding parts. The sizes and proportions of the components shown in each drawing are represented for the purpose of clarifying the explanation and do not necessarily represent the actual dimensions and proportions. However, the present invention is not limited to these examples, and is intended to include all modifications within the meaning and scope of the claims as shown, and equivalents thereof.

[0049] <Sheet> The sheet 1 of the embodiment will be described with reference to Figures 1 to 6. As shown in Figure 1, the sheet 1 comprises a resin layer 2 and a reflective layer 3. In this example, the sheet 1 has the resin layer 2 and the reflective layer 3 laminated in contact with each other, and there is no other layer between the resin layer 2 and the reflective layer 3. Unlike this example, another layer may be placed between the resin layer 2 and the reflective layer 3. That is, the resin layer 2 and the reflective layer 3 may be laminated with another layer in between. This other layer may be, for example, an adhesive layer (not shown) that bonds the resin layer 2 and the reflective layer 3. One of the features of the sheet 1 is that, as shown in Figure 2, a first pattern 21 is drawn on the first surface 2a of the resin layer 2 by a plurality of first grooves 21g.

[0050] The shape of Sheet 1 shown in Figure 2 is rectangular. The shape of Sheet 1 can be arbitrarily selected. Sheet 1 may be circular or elliptical, or it may be a polygon such as a triangle, square, or hexagon.

[0051] ≪Resin layer≫ As shown in Figure 1, the resin layer 2 has a first surface 2a and a second surface 2b. The first surface 2a and the second surface 2b are surfaces facing opposite directions in the direction along the thickness of the resin layer 2. The first surface 2a is the surface of the resin layer 2, and the second surface 2b is the back surface of the resin layer 2. The first surface 2a is the incident surface for visible light. The first surface 2a has a first pattern 21, which will be described later.

[0052] The resin layer 2 is transparent. Transparency means that it transmits visible light and is visible through it. Visible light incident from the first surface 2a is transmitted through the resin layer 2. The resin layer 2 may be colorless and transparent, or it may be colored and transparent. The resin layer 2 is, for example, a layer made of a transparent resin film. The resin film is made of, for example, polyethylene terephthalate (PET) or polystyrene (PS). Here, "made of" means that it is made of only the material in question. In this example, the resin layer 2 is a colorless and transparent PET film.

[0053] The thickness of the resin layer 2 is, for example, 40 μm to 100 μm. If the thickness of the resin layer 2 is 40 μm or more, it is easy to form the first groove 21g and the second groove 22g described later in the resin layer 2. If the thickness of the resin layer 2 is 100 μm or less, the resin layer 2 is easily transparent to visible light.

[0054] ≪Reflection layer≫ The reflective layer 3 reflects light that has passed through the resin layer 2. In this example, the reflective layer 3 is laminated in direct contact with the second surface 2b of the resin layer 2. The reflective layer 3 is, for example, a metal layer formed from a metal. The reflective layer 3 may be a metal vapor-deposited film or a metal foil. If the reflective layer 3 is a metal vapor-deposited film, it may be vapor-deposited directly onto the second surface 2b of the resin layer 2. If the reflective layer 3 is a metal foil, it may be attached to the second surface 2b of the resin layer 2 with an adhesive. This adhesive is transparent and transmits visible light. The metal layer that is the reflective layer 3 is formed from, for example, aluminum, tin, silver, or an alloy of any of these. Among these, aluminum or an aluminum alloy is preferred. In this example, the reflective layer 3 is a vapor-deposited film of aluminum.

[0055] The thickness of the reflective layer 3 is not particularly limited. If the reflective layer 3 is a metal vapor-deposited film, the thickness of the reflective layer 3 is, for example, 0.005 μm or more and 0.07 μm or less. If the reflective layer 3 is a metal foil, the thickness of the reflective layer 3 is, for example, 5 μm or more and 10 μm or less.

[0056] [Pattern 1] The first pattern 21 is formed by a plurality of first grooves 21g formed on the first surface 2a of the resin layer 2, as shown in Figure 2. The first pattern 21 includes at least one of letters and / or images. That is, the first pattern 21 may consist only of letters, only of images, or a combination of letters and images. The first pattern 21 shown in Figure 2 is an image of the sun. The first pattern 21 can be arbitrarily selected.

[0057] <1st groove> The multiple first grooves 21g are linear grooves arranged parallel to each other. In this example, the multiple first grooves 21g extend along the lateral direction of the resin layer 2. In this example, the multiple first grooves 21g are arranged at equal intervals in the vertical direction. In Figure 2, the lateral direction is the left-right direction, and the vertical direction is the up-down direction. The orientation of the first grooves 21g can be arbitrarily selected. In this example, the first grooves 21g are formed by laser processing. The method for forming the first grooves 21g is not limited to any method that can form multiple grooves having the width, depth, and spacing described later. As for the method of forming the grooves, for example, mechanical methods such as cutting or grinding, chemical methods such as etching, and optical methods such as photolithography or laser can be used. This is also true for the second grooves 22g described later.

[0058] Referring to Figure 3, the cross-sectional shape of the first groove 21g, as well as its width w, depth d, and spacing p, will be described.

[0059] Figure 3 shows the cross-sectional shape of the first groove 21g, with the cutting plane perpendicular to the direction along the length of the groove. The first groove 21g, formed by laser processing, is most concave in the center and raised on both sides because the first surface 2a of the resin layer 2 irradiated with the laser melts. This is because the energy density of a laser spot is usually highest in the center and decreases as it approaches the outer edge. The cross-sectional shape of the first groove 21g is V-shaped, gradually narrowing from the first surface 2a to the second surface 2b. The first groove 21g does not reach the second surface 2b. In other words, the first groove 21g does not penetrate the resin layer 2.

[0060] "width" The width w of the first groove 21g is, for example, between 40 μm and 170 μm. The width w is the horizontal distance between the vertices of the raised parts on both sides of the first groove 21g. The horizontal distance is the distance parallel to the first surface 2a. The first pattern 21 is easily visible when the width w is between 40 μm and 170 μm. The width w may also be between 60 μm and 160 μm, or even between 90 μm and 150 μm.

[0061] Depth The depth d of the first groove 21g is, for example, between 5 μm and 50 μm. The depth d is the vertical distance from the deepest point of the first groove 21g to the vertices of the raised portions on both sides of the first groove 21g. The vertical distance is the distance perpendicular to the first surface 2a. If the heights of the vertices of the raised portions on both sides are different, the average height is taken. The first pattern 21 is easily visible when the depth d is between 5 μm and 50 μm. The depth d may also be between 10 μm and 45 μm, or even between 15 μm and 40 μm.

[0062] The depth d is, for example, 10% or more and less than 100% of the thickness t of the resin layer 2. The depth d may also be 20% or more and 90% or less of the thickness t of the resin layer 2, or even 30% or more and 80% or less.

[0063] The appearance of the first pattern 21 mainly depends on the width w and depth d of the first groove 21g. Preferably, the first groove 21g has a width w of 40 μm or more and 170 μm or less, and a depth d of 5 μm or more and 50 μm or less.

[0064] "interval" The spacing p between adjacent first grooves 21g can be any range greater than the width w. A spacing p greater than the width w makes it less likely for adjacent first grooves 21g to interfere with each other, thus facilitating the formation of the first grooves 21g. For example, the spacing p is between 300 μm and 600 μm. The spacing p is the horizontal distance between the centers of adjacent first grooves 21g. A spacing p of 300 μm or more ensures that adjacent first grooves 21g are not too close together, making it easier to draw the first pattern 21. A spacing p of 600 μm or less ensures that adjacent first grooves 21g are not too far apart, making it easier to visually identify what is being drawn as the first pattern 21. The spacing p may also be between 400 μm and 500 μm.

[0065] The appearance of the first pattern 21 changes depending on the direction from which a person is looking or the direction from which light is hitting it. This is because the light incident from the first surface 2a and the light reflected by the reflective layer 3 are refracted in the first groove 21g, creating an optical path difference, which causes a change in brightness. The first pattern 21 is easiest to see when the line of sight is perpendicular to the axis along the length of the first groove 21g. When the sheet 1 is tilted with the axis of the first groove 21g as the axis of rotation, that is, when the sheet 1 is tilted vertically as shown in Figure 4, the first pattern 21 becomes easier or harder to see depending on the viewing angle.

[0066] [Pattern 2] The first surface 2a may have a second pattern 22 in addition to the first pattern 21 described above, as shown in Figure 5. The second pattern 22 is drawn by a plurality of second grooves 22g formed on the first surface 2a of the resin layer 2. The second pattern 22 is drawn so as to overlap with the first pattern 21. The second pattern 22 includes at least one of letters and / or pictures. The second pattern 22 shown in Figure 5 is a picture of the moon. The second pattern 22 can be arbitrarily selected. The second pattern 22 differs from the first pattern 21 in at least one of the letters, pictures, and size.

[0067] <Second groove> The multiple second grooves 22g are linear grooves arranged parallel to each other and intersect with the multiple first grooves 21g. In this example, the multiple second grooves 22g extend along the longitudinal direction of the resin layer 2. That is, the multiple second grooves 22g are perpendicular to the multiple first grooves 21g. In this example, the multiple second grooves 22g are arranged at equal intervals in the lateral direction. The orientation of the second grooves 22g, that is, the angle of intersection with the first grooves 21g, can be arbitrarily selected as long as they intersect with the multiple first grooves 21g. In this example, the second grooves 22g are formed by laser processing.

[0068] The cross-sectional shape perpendicular to the direction along the length of the second groove 22g is substantially the same as the cross-sectional shape of the first groove 21g shown in Figure 3. In other words, although not shown, the cross-sectional shape of the second groove 22g is also V-shaped, gradually narrowing in width from the first surface 2a to the second surface 2b. The second groove 22g does not reach the second surface 2b. Furthermore, the width, depth, and spacing of the second groove 22g are the same as the width w, depth d, and spacing p of the first groove 21g described above. The width, depth, and spacing of the first groove 21g and the width, depth, and spacing of the second groove 22g may be the same or different, respectively.

[0069] As shown in Figure 5, when sheet 1 is viewed from a direction perpendicular to the first surface 2a, the first pattern 21 and the second pattern 22 appear to overlap. The appearance of the second pattern 22 changes depending on the direction from which the person is looking or the direction from which light is hitting it, based on the same principle as the appearance of the first pattern 21 described above. The second pattern 22 is easier to see when the line of sight is perpendicular to the axis along the length of the second groove 22g. When sheet 1 is tilted with the axis of the second groove 22g as the axis of rotation, that is, when sheet 1 is tilted laterally as shown in Figure 6, the second pattern 22 becomes easier or harder to see depending on the viewing angle.

[0070] <Method of manufacturing the sheet> Sheet 1 can be manufactured by the sheet manufacturing method according to the embodiment. The sheet manufacturing method comprises a preparation step and a first processing step. Each step will be described in detail below.

[0071] ≪Preparation process≫ The preparation step involves preparing the material sheet that will be used as the material for sheet 1 as described above. The material sheet is, for example, a laminated resin layer 2 and a reflective layer 3, as shown in Figure 1. The specifications of the resin layer and reflective layer of the material sheet are the same as those of the resin layer 2 and reflective layer 3 described above, so their explanation will be omitted.

[0072] ≪First processing step≫ The first processing step is a process of creating a pattern by forming multiple grooves on the surface of the resin layer of the material sheet using laser processing. In the first processing step, as shown in Figure 2, a laser is irradiated onto the first surface 2a of the resin layer 2 to draw the first pattern 21. The first pattern 21 is formed by a plurality of first grooves 21g arranged parallel to each other. The first processing step produces a sheet 1 with the first pattern 21 drawn on the first surface 2a of the resin layer 2, as shown in Figure 2. The conditions for laser processing to form the first grooves 21g are described below.

[0073] [Types of lasers] The laser used is, for example, a CO2 (carbon dioxide) laser. CO2 lasers are suitable for processing resins. With a CO2 laser, it is easy to form the first groove 21g on the first surface of the resin layer 2 formed from PET or PS.

[0074] [Laser irradiation conditions] The width and depth of the multiple first grooves 21g are largely determined by the laser irradiation conditions. The main irradiation conditions for the main laser include, for example, power output and scanning speed.

[0075] <output> The laser output is, for example, between 3W and 25W. Higher output tends to result in wider and deeper grooves. Conversely, lower output tends to result in narrower and shallower grooves. An output of 3W to 25W makes it easier to form the first groove 21g, whose width and depth satisfy the above range. An output of 5W to 21W is also acceptable.

[0076] <Scanning speed> The laser scanning speed is, for example, between 500 mm / second and 3500 mm / second. A slower scanning speed tends to result in a longer laser irradiation time, a wider groove, and a deeper groove. Conversely, a faster scanning speed tends to result in a shorter laser irradiation time, a narrower groove, and a shallower groove. A scanning speed of 500 mm / second to 3500 mm / second makes it easier to form the first groove 21g whose width and depth meet the above ranges. A scanning speed of 1000 mm / second to 3000 mm / second is also acceptable.

[0077] The laser output and scanning speed can be appropriately selected so that the width and depth of the first groove 21g are within a predetermined range.

[0078] <Focal length> A laser beam is focused to a focal point by a focusing lens. The focal length is the distance from the principal point of the focusing lens to the focal point. At the focal point, the laser spot diameter is smallest and the energy density is maximum. If the laser irradiation point deviates from the focal length, the energy density tends to decrease, the groove width becomes narrower, and the groove depth tends to decrease.

[0079] <Pitch interval> The spacing between adjacent first grooves 21g is determined by the laser pitch. The larger the laser pitch, the wider the spacing between adjacent first grooves 21g. The smaller the laser pitch, the narrower the spacing between adjacent first grooves 21g. The laser pitch is, for example, between 300 μm and 600 μm, and also between 400 μm and 500 μm.

[0080] ≪Second processing step≫ The method for manufacturing the sheet may include a second processing step after the first processing step. The second processing step, like the first processing step, is a step in which a pattern is drawn by forming multiple grooves on the surface of the resin layer of the material sheet using laser processing. However, in the second processing step, as shown in Figure 5, a laser is irradiated onto the first surface 2a of the resin layer 2 to draw a second pattern 22. The second pattern 22 is formed by a plurality of second grooves 22g arranged parallel to each other. The plurality of first grooves 21g of the first pattern 21 and the plurality of second grooves 22g of the second pattern 22 intersect. The second processing step makes it possible to manufacture a sheet 1 in which the second pattern 22 is drawn on the first surface 2a of the resin layer 2 so as shown in Figure 5, with the second pattern 22 overlapping the first pattern 21.

[0081] The laser processing conditions for forming multiple second grooves 22g can be the same as those for forming the first grooves 21g described above. If the laser irradiation conditions are within the above range, it is easy to form second grooves 22g whose width and depth satisfy the above range. The laser irradiation conditions may be different for the first grooves 21g and the second grooves 22g.

[0082] In this example, a material sheet with a resin layer and a reflective layer laminated together is prepared in the preparation step, but a material sheet having only a resin layer may also be prepared. In this case, a pattern can be drawn on the resin layer by laser processing, and then the reflective layer can be laminated onto the resin layer by vapor deposition or bonding.

[0083] <label> The label 10 of the embodiment will be described with reference to Figure 7. As shown in Figure 7, the label 10 comprises the sheet 1, adhesive layer 4, and separator 5 described above.

[0084] ≪Adhesive layer≫ The adhesive layer 4 is provided on the side of the reflective layer 3 opposite to the resin layer 2. The adhesive layer 4 is formed of an adhesive. The adhesive is, for example, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a polyester adhesive, or a rubber adhesive.

[0085] ≪Separator≫ The separator 5 is bonded to the adhesive layer 4. The separator 5 is in contact with the adhesive layer 4. The separator 5 is peeled off when the label 10 is attached to an object such as a product. The separator is, for example, laminated paper or a resin film. Laminated paper is made by laminating a resin film onto the surface of a paper base material. The paper base material of laminated paper is, for example, fine paper, kraft paper, or glassine paper. The material of the resin film is, for example, polypropylene (PP), polyethylene (PE), polyamide (PA), or polyester (PEs). PEs includes PET. The surface of the separator 5 in contact with the adhesive layer 4 may be coated with a release agent. The release agent is, for example, a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl-based release agent.

[0086] [Test Example 1] A sheet was manufactured in which a first pattern and a second pattern were drawn on the first surface of a resin layer. In Test Example 1, multiple first grooves and multiple second grooves were formed by changing the laser irradiation conditions, and the appearance of the first and second patterns was examined.

[0087] A material sheet was prepared in which a PET film, which serves as the resin layer, has a vapor-deposited aluminum film, which serves as the reflective layer, formed on its back surface. The thickness of the PET film is 50 μm. The thickness of the vapor-deposited aluminum film is 0.01 μm. By irradiating the surface of this resin layer with a laser, multiple first grooves were formed to create a first pattern, and then multiple second grooves were formed to create a second pattern. The laser processing conditions for forming multiple first grooves and for forming multiple second grooves were the same.

[0088] The laser processing machine used was the Panasonic Industries LP-430U CO2 laser marker. The focal length of this laser marker is 185 mm. The distance from the focusing lens to the resin layer to be processed was set to 185 mm to match the focal length. The laser spot diameter is 180 μm. The laser output was varied from 3 W to 21 W. The laser scanning speed was varied from 500 mm / second to 3000 mm / second. The laser pitch spacing was set to 0.5 mm. The spacing between the first groove (21g) and the second groove (22g) was substantially the same as the laser pitch spacing, approximately 500 μm.

[0089] For each sheet sample manufactured under the laser irradiation conditions shown in Table 1, six evaluators evaluated the appearance of the first and second patterns when the sheet was tilted vertically and horizontally and the viewing angle was changed. The evaluation criteria were based on the following five levels. Rating 5. When the viewing angle is changed, both patterns are clearly visible, and the appearance does not change, or hardly changes at all. Rating 4. Changing the viewing angle makes one pattern easier to see, but the other pattern is still mostly visible. Rating 3. When the viewing angle is changed, one pattern becomes clearly visible, while the other pattern is invisible or almost invisible. The appearance of both patterns changes. Rating 2. Neither pattern is clearly visible, even when viewed from different angles. Rating 1. Neither pattern is clearly visible, even when viewed from different angles.

[0090] The evaluation method was as follows: Points were assigned to each of the five evaluation levels. A rating of 3 was assigned 3 points. Ratings 4 and 2 were each assigned 2 points. Ratings 5 ​​and 1 were each assigned 1 point. For each sample, the total score was calculated by adding the product of the number of people and their scores for each rating level, and this total score was divided by the total number of people to find the average rating. A rating closer to 3 indicates a better performance.

[0091] Table 1 shows the evaluation results for each sample. In Table 1, the average score for each sample is listed in the upper row, and the evaluation based on the average score is shown in the lower row. For evaluation based on the average score, an average score of 2 or less is designated as "C", an average score greater than 2 but less than 2.2 is designated as "B", and an average score of 2.2 or greater is designated as "A". For example, the average score for the sample with an output of 3W and a scanning speed of 500mm / sec was 2.67 points, resulting in an evaluation of A. However, each sample with an output of 3W and a scanning speed of 1000mm / sec or more, and each sample with an output of 6W and a scanning speed of 2500mm / sec or more, were excluded from evaluation because no grooves were formed on the surface of the resin layer, and neither pattern was visible. Furthermore, each sample with an output of 9W or more and a scanning speed of 500 mm / second, and each sample with an output of 15W or more and a scanning speed of 1000 mm / second, were excluded from evaluation with a rating of "Y" because the grooves penetrated the resin layer and the resin layer was severely damaged.

[0092] The width and depth of the grooves were measured in each sample. The measurement of groove width and depth was performed as follows: The width and depth of three first grooves were measured, and the average values ​​were calculated. Table 2 shows the average values ​​of width w and depth d for each sample that received an evaluation of A, B, or C.

[0093] [Table 1]

[0094] [Table 2]

[0095] Although there was some variation in evaluation among evaluators, samples with a groove width w of approximately 40 μm to 170 μm and a groove depth d of approximately 5 μm to 50 μm received an A or B rating, indicating good quality. In particular, samples with a groove width w of approximately 60 μm to 160 μm and a groove depth d of approximately 10 μm to 40 μm almost all received an A rating, indicating very good quality. [Explanation of Symbols]

[0096] 1 sheet 10 labels 2 resin layers 2a 1st side, 2b 2nd side 21g, 1st groove, 21, 1st pattern 22g, 2nd groove, 22, 2nd pattern 3 reflective layer 4 Adhesive layer 5 Separators d depth, w width, p spacing t thickness

Claims

1. A transparent resin layer, The system comprises a resin layer and a reflective layer laminated thereto that reflects light transmitted through the resin layer, The resin layer has a first surface which is the surface on which visible light is incident. The first surface has a first pattern drawn by a plurality of first grooves, The plurality of first grooves are linear grooves arranged parallel to each other. Seat.

2. The sheet according to claim 1, wherein the width of each of the plurality of first grooves is 40 μm or more and 170 μm or less.

3. The sheet according to claim 1 or claim 2, wherein the depth of each of the plurality of first grooves is less than the thickness of the resin layer.

4. The sheet according to claim 3, wherein the depth of each of the plurality of first grooves is 5 μm or more and 50 μm or less.

5. The sheet according to claim 1 or claim 2, wherein the spacing between adjacent first grooves is 300 μm or more and 600 μm or less.

6. The sheet according to claim 1 or claim 2, wherein the first pattern includes at least one of characters and an image.

7. The sheet according to claim 1 or claim 2, wherein the resin layer is a layer made of a transparent resin film.

8. The sheet according to claim 7, wherein the resin film is formed from polyethylene terephthalate or polystyrene.

9. The sheet according to claim 1 or claim 2, wherein the reflective layer is a metal layer.

10. The sheet according to claim 9, wherein the metal layer is formed from aluminum or an aluminum alloy.

11. The first surface has a second pattern drawn by a plurality of second grooves, The sheet according to claim 1, wherein the plurality of second grooves are linear grooves arranged parallel to each other and intersect with the plurality of first grooves.

12. The sheet according to claim 11, wherein the plurality of second grooves are perpendicular to the plurality of first grooves.

13. The sheet according to claim 11 or claim 12, wherein the width of each of the plurality of second grooves is 40 μm or more and 170 μm or less.

14. The sheet according to claim 11 or claim 12, wherein the depth of each of the plurality of second grooves is less than the thickness of the resin layer.

15. The sheet according to claim 14, wherein the depth of each of the plurality of second grooves is 5 μm or more and 50 μm or less.

16. The sheet according to claim 11 or claim 12, wherein the spacing between adjacent second grooves is 300 μm or more and 600 μm or less.

17. The sheet according to claim 11 or claim 12, wherein the second pattern includes at least one of characters and an image.

18. A sheet according to claim 1 or claim 2, An adhesive layer provided on the side of the reflective layer opposite to the resin layer, A separator bonded to the adhesive layer, label.

19. A step of preparing a material sheet in which a transparent resin layer and a reflective layer that reflects light transmitted through the resin layer are laminated, The process includes irradiating the first surface of the resin layer with a laser to draw a first pattern, The first pattern is formed by a plurality of first grooves arranged parallel to each other. A method for manufacturing a sheet.

20. Furthermore, the process includes a step of irradiating the first surface with a laser to draw a second pattern, The second pattern is formed by a plurality of second grooves arranged parallel to each other, The method for manufacturing a sheet according to claim 19, wherein the plurality of first grooves and the plurality of second grooves intersect.

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