Label production method

Abstract

To provide a method for producing a label that cannot be cleanly peeled off and is easily torn when removed from the object it is attached to.SOLUTION: A method for producing a label includes a first step where a substrate made of polypropylene is irradiated with an electron beam and a second step where an adhesive layer and a separator are applied to the first surface of the substrate to form a label. In the first step, if the substrate thickness is less than 50 μm, the electron beam is applied with a dose of 1200 kGy or more but less than 2400 kGy, using an acceleration voltage of at least 200 kV; on the other hand, if the substrate thickness is 50 μm or more, the irradiation is performed with a dose of at least 2400 kGy, also at an acceleration voltage of at least 200 kV.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a label.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a marking film in which a vinyl chloride film is irradiated with an electron beam of 3 to 10 Mrad and then an adhesive is applied to one surface of the vinyl chloride film. When the marking film obtained by this manufacturing method is attached to an object such as a plate and an external force is applied, only the portion where the external force is applied is cut off from the other portions and peeled off from the object. Hereinafter, the marking film will be referred to as a label.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When peeling off a label attached to an object, there is a demand for a label that can be discriminated, for example, as having been peeled off without permission because it is not cleanly peeled off but torn. If the label is cleanly peeled off from the object, there is a risk that the label may be reused, for example. Depending on how the external force is applied, the label described in Patent Document 1 may be cleanly peeled off from the object.

[0005] One object of the present invention is to provide a method for manufacturing a label that is likely to be torn rather than cleanly peeled off when peeled off from an object to which it is attached.

Means for Solving the Problems

[0006] (1) The method for manufacturing a label according to one aspect of the present invention includes a first step of irradiating a base material made of polypropylene with an electron beam, and a second step of forming a label by providing an adhesive layer and a separator on a first surface of the base material. In the first step, when the thickness of the base material is less than 50 μm, the electron beam is irradiated at a dose of 1200 kGy or more and less than 2400 kGy with an acceleration voltage of 200 kV or more. When the thickness of the base material is 50 μm or more, the electron beam is irradiated at a dose of 2400 kGy or more with an acceleration voltage of 200 kV or more.

[0007] In the case of the method for manufacturing a label as described in (1) above, it is possible to manufacture a label that is not cleanly peeled off but is easily torn when peeled off from the object to which it is attached. By adjusting the dose and acceleration voltage of the electron beam according to the thickness of the base material and irradiating the adjusted electron beam to the base material, the base material can be made vulnerable. The base material irradiated with the electron beam adjusted to a specific dose and acceleration voltage is easily torn without being cleanly peeled off from the object regardless of how the external force is applied.

[0008] The base material made of polypropylene is excellent in durability. Even if the base material made of polypropylene is irradiated with an electron beam adjusted to a specific dose and acceleration voltage and is made vulnerable, the state of being attached to the object is maintained. In the case of the method for manufacturing a label as described in (1) above, it is possible to manufacture a label that is not cleanly peeled off but is easily torn when peeled off from the object while maintaining the state of being attached to the object.

[0009] (2) In the method for manufacturing a label as described in (1) above, the second step may include a step of preparing a laminate in which the adhesive layer is laminated on a first surface of the separator, and a step of bonding the laminate to the base material such that the adhesive layer faces the first surface of the base material that has undergone the first step.

[0010] By preparing a laminate in which the adhesive layer is integrated with the separator and bonding this laminate to the base material, it is difficult for an external force that causes the base material to break to be applied to the base material during the manufacturing stage.

[0011] (3) In the method for manufacturing the label according to (1) above, in the second step, a laminate provided with the adhesive layer and the separator on the first surface of the base material before irradiation with the electron beam may be prepared, and in the first step, the laminate may be irradiated with the electron beam.

[0012] Since the electron beam is irradiated with the adhesive layer and the separator provided on the base material, it is less likely that the base material will be accidentally broken during the manufacturing process compared to the case where the adhesive layer and the separator are provided on the base material irradiated with the electron beam. The formation of the base material into a desired shape and dimensions is often performed after the adhesive layer and the separator are provided on the base material. When the electron beam is irradiated with the adhesive layer and the separator provided on the base material, the electron beam is irradiated onto a laminate having a desired shape and dimensions, and it is easy to miniaturize the electron beam irradiation device.

[0013] (4) In the method for manufacturing the label according to any one of (1) to (3) above, the thickness of the base material may be 30 μm or more and 60 μm or less.

[0014] A base material having a thickness of 30 μm or more is difficult to break and easy to handle during the manufacturing process. If the thickness is 60 μm or less, the base material can be easily weakened without excessively increasing at least one of the value of the electron beam dose or the acceleration voltage.

[0015] (5) In the method for manufacturing the label according to any one of (1) to (3) above, the average value of the tensile strength of the base material before irradiation with the electron beam may be 180 MPa or more. The average value of the tensile strength of the base material is the average value of the tensile strength along the flow direction of the raw material during the manufacture of the base material and the tensile strength along the width direction perpendicular to the flow direction.

[0016] If the average value of the tensile strength of the base material before irradiation with the electron beam is 180 MPa or more, the base material is less likely to break during the manufacturing stage.

[0017] (6) In the method for manufacturing any one of the labels (1) to (5) above, in the first step, when the thickness of the base material is less than 50 μm, the electron beam may be irradiated so that the average value of the tensile strength of the base material is 100 MPa or less.

[0018] When the thickness of the base material is less than 50 μm, by irradiating the base material with an electron beam adjusted to a specific dose and acceleration voltage, the average value of the tensile strength of the base material can be made 100 MPa or less. If the average value of the tensile strength of the base material can be made 100 MPa or less, when the thickness of the base material is less than 50 μm, it is possible to manufacture a label that is easily torn rather than cleanly peeled off when peeled from the object to which it is attached.

[0019] (7) In the method for manufacturing any one of the labels (1) to (5) above, in the first step, when the thickness of the base material is 50 μm or more, the electron beam may be irradiated so that the average value of the tensile strength of the base material is 50 MPa or less.

[0020] When the thickness of the base material is 50 μm or more, by irradiating the base material with an electron beam adjusted to a specific dose and acceleration voltage, the average value of the tensile strength of the base material can be made 50 MPa or less. If the average value of the tensile strength of the base material can be made 50 MPa or less, when the thickness of the base material is 50 μm or more, it is possible to manufacture a label that is easily torn rather than cleanly peeled off when peeled from the object to which it is attached.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0022] Hereinafter, a specific example of the method for manufacturing the label of the present invention will be described with reference to the drawings. The same reference numerals in the drawings denote the same or corresponding parts. The sizes of the members shown in each drawing are represented for the purpose of clarifying the description and do not necessarily represent the actual dimensions. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0023] [Embodiment] With reference to FIGS. 1 to 3, the method for manufacturing the label of the embodiment will be described. The method for manufacturing the label includes a first step of irradiating an electron beam 8 onto a base material 2, and a second step of forming a label 1 by providing an adhesive layer 3 and a separator 4 on the base material 2. One of the features of the method for manufacturing the label of the embodiment is that in the first step, the dose and acceleration voltage of the electron beam 8 are adjusted according to the thickness 2T of the base material 2, and the adjusted electron beam 8 is irradiated onto the base material 2.

[0024] <First Step> In the first step, as shown in FIG. 1, an electron beam 8 is irradiated onto a base material 2 made of polypropylene. The base material 2 is embrittled by the irradiation of the electron beam 8. In FIG. 1, for the sake of convenience of explanation, a cross-section of the base material 2 cut along the thickness direction is shown. In FIG. 1, the irradiation direction of the electron beam 8 is indicated by a white arrow for easy understanding.

[0025] ≪Base Material≫ The base material 2 is a resin film made of polypropylene. The base material 2 has a first surface 21 and a second surface 22. An adhesive layer 3 and a separator 4 are provided on the first surface 21 of the base material 2 in the second step described later.

[0026] The base material 2 made of polypropylene is excellent in durability. The polypropylene is, for example, biaxially stretched polypropylene. The base material 2 made of biaxially stretched polypropylene is manufactured by using polypropylene as a raw material and stretching it in two directions, namely, the machine direction MD of the raw material flow and the transverse direction TD orthogonal to the machine direction MD. The machine direction MD is generally the direction in which the base material 2 is conveyed during the manufacture of the base material 2. The transverse direction TD is the direction orthogonal to the above-mentioned machine direction MD. Although the machine direction MD and the transverse direction TD shown in FIGS. 1 and 2 are indicated by single arrows, the opposite directions of the arrows are also similarly referred to as the machine direction MD and the transverse direction TD. The base material 2 made of biaxially stretched polypropylene is excellent not only in durability but also in transparency. The base material 2 made of biaxially stretched polypropylene is also excellent in printability. The base material 2 in this example is colorless and transparent. The base material 2 may be an unstretched film or a uniaxially stretched film.

[0027] The thickness 2T of the base material 2 is, for example, 30 μm or more and 60 μm or less. If the thickness 2T is 30 μm or more, the base material 2 is less likely to be torn during the manufacturing process and is easy to handle. If the thickness 2T is 60 μm or less, the base material 2 can be easily embrittled without excessively increasing at least one of the dose or the acceleration voltage of the electron beam 8 described later. The thickness 2T of the base material 2 may be 40 μm or more and 50 μm or less. The thickness 2T is the distance between the first surface 21 and the second surface 22.

[0028] The planar shape of the base material 2 is not particularly limited. The planar shape of the base material 2 shown in FIG. 2 is rectangular. The rectangular shape includes a square shape and a rectangular shape. Here, the rectangular shape means that the shape surrounded by four sides is substantially rectangular. The rectangular shape in this example does not have to be a rectangle in the geometric sense, and includes a range that can be regarded as substantially rectangular, including shapes in which the corners are planed or rounded. The planar shape of the base material 2 may be a polygon other than a rectangular shape, a circular shape, or an elongated shape having a length longer than the width. The circular shape includes a perfect circle and an ellipse.

[0029] When the planar shape of the base material 2 is rectangular, as shown in FIG. 2, the flow direction MD and the width direction TD are directions along either the vertical side or the horizontal side. In the rectangular base material 2, if the horizontal side is the flow direction MD, the vertical side is the width direction TD. If the horizontal side is the width direction TD, the vertical side is the flow direction MD.

[0030] The size of the base material 2, in this example, the lengths of the vertical side and the horizontal side are not particularly limited.

[0031] The base material 2 does not have an auxiliary part for making it easy to tear when peeling off the label 1 provided with the base material 2 from the object. The auxiliary part is, for example, a perforation line, a half-cut line, and a cut provided on the side of the base material 2.

[0032] The base material 2 may have a printing layer (not shown). The printing layer may be provided on either the first surface 21 or the second surface 22 of the base material 2.

[0033] The average value of the tensile strength of the base material 2 before being irradiated with the electron beam 8 is, for example, 180 MPa or more. The average value of the tensile strength of the base material 2 is the average value of the tensile strength along the flow direction MD and the tensile strength along the width direction TD. If the average value of the tensile strength of the base material 2 before being irradiated with the electron beam 8 is 180 MPa or more, the base material 2 is difficult to break during the manufacturing process. The average value of the tensile strength of the base material 2 before being irradiated with the electron beam 8 may be 190 MPa or more, or 195 MPa or more.

[0034] The tensile strength along the flow direction of the base material 2 and the tensile test along the width direction TD are obtained by taking a test piece from the base material 2, setting the test piece on a commercially available tensile testing machine, and performing a tensile test at a tensile speed of 300 mm / min. The size of the test piece is 15 mm in width and 220 mm in length.

[0035] ≪Irradiation conditions of the electron beam≫ In the first step, the irradiation conditions of the electron beam 8 vary depending on whether the thickness 2T of the base material 2 is 50 μm or more.

[0036] When the thickness 2T of the substrate 2 is less than 50 μm, the electron beam 8 is irradiated at a dose of 1200 kGy or more but less than 2400 kGy with an acceleration voltage of 200 kV or more. When the thickness 2T of the substrate 2 is less than 50 μm, the electron beam 8 can be transmitted through the thickness of the substrate 2 by setting the dose of the electron beam 8 to 1200 kGy or more and the acceleration voltage to 200 kV or more. By transmitting the electron beam 8 through the entire thickness of the substrate 2, the entire substrate 2 is likely to be weakened. The more weakened the substrate 2, the more likely it is that the label 1 including this substrate 2 will tear rather than peel cleanly when peeled from an object. When the thickness 2T of the substrate 2 is less than 50 μm, the substrate 2 can be sufficiently weakened even with a dose of the electron beam 8 less than 2400 kGy. A dose of less than 2400 kGy does not require an excessively large dose, resulting in excellent productivity.

[0037] When the thickness 2T of the substrate 2 is less than 50 μm, the dose of the electron beam 8 may be set to 1300 kGy or more, 1400 kGy or more, or 1500 kGy or more.

[0038] When the thickness 2T of the substrate 2 is less than 50 μm, for example, the electron beam 8 is irradiated so that the average tensile strength of the substrate 2 is 100 MPa or less. When the thickness 2T of the substrate 2 is less than 50 μm, the electron beam 8 may be irradiated so that the average tensile strength of the substrate 2 is 90 MPa or less, 80 MPa or less, 75 MPa or less, or 72 MPa or less. In other words, when the thickness 2T of the substrate 2 is less than 50 μm, the dose and acceleration voltage of the electron beam 8 may be adjusted so that the average tensile strength of the substrate 2 after irradiation with the electron beam 8 is 100 MPa or less, 90 MPa or less, 80 MPa or less, 75 MPa or less, or 72 MPa or less.

[0039] When the thickness 2T of the base material 2 is 50 μm or more, the electron beam 8 is irradiated with a dose of 2400 kGy or more at an acceleration voltage of 200 kV or more. The thicker the thickness 2T of the base material 2, the more difficult it is for the electron beam 8 to penetrate in the thickness direction of the base material 2. If the dose of the electron beam 8 is 2400 kGy or more, the energy imparted to the base material 2 can be increased. When the thickness 2T of the base material 2 is 50 μm or more, by setting the dose of the electron beam 8 to 2400 kGy or more and the acceleration voltage to 200 kV or more, the electron beam 8 can be made to penetrate in the thickness direction of the base material 2.

[0040] When the thickness 2T of the base material 2 is 50 μm or more, the dose of the electron beam 8 may be 2500 kGy or more, 2600 kGy or more, or 2700 kGy or more.

[0041] When the thickness 2T of the base material 2 is 50 μm or more, the dose of the electron beam 8 is, for example, 3200 kGy or less. Due to the thickness 2T of the base material 2, even if the dose of the electron beam 8 is 3200 kGy or less, the base material 2 can be sufficiently embrittled. If the dose is less than 3200 kGy, there is no need to make the dose excessively large, and the productivity is excellent.

[0042] When the thickness 2T of the base material 2 is 50 μm or more, for example, the base material 2 is irradiated with the electron beam 8 so that the average value of the tensile strength of the base material 2 becomes 50 MPa or less. When the thickness 2T of the base material 2 is 50 μm or more, the base material 2 may be irradiated with the electron beam 8 so that the average value of the tensile strength of the base material 2 becomes 49 MPa or less, or 48 MPa or less. In other words, when the thickness 2T of the base material 2 is 50 μm or more, the dose and acceleration voltage of the electron beam 8 may be adjusted so that the average value of the tensile strength of the base material 2 after irradiation with the electron beam 8 becomes 50 MPa or less, 49 MPa or less, or 48 MPa or less.

[0043] <Second step> In the second step, as shown on the left side of FIG. 3 , an adhesive layer 3 and a separator 4 are provided on the first surface 21 of the substrate 2 that has undergone the first step. In this example, the second step includes preparing a laminate 5 in which the adhesive layer 3 is laminated on the first surface 41 of the separator 4, and bonding the laminate 5 to the substrate 2 so that the adhesive layer 3 faces the first surface 21 of the substrate 2 that has undergone the first step. The substrate 2 shown in FIG. 3 is a resin film irradiated with an electron beam 8. For ease of understanding, the lamination direction of the laminate 5 is indicated by an arrow in FIG. 3 . The laminate 5 is produced, for example, by applying a constituent material of the adhesive layer 3 to the first surface 41 of the separator 4 and then curing this constituent material. By preparing a laminate 5 in which the adhesive layer 3 and the separator 4 are integrated and then bonding this laminate 5 to the substrate 2, external forces that could tear the substrate 2 are less likely to be applied to the substrate 2 during the manufacturing process. In the second step, the adhesive layer 3 and the separator 4 may be formed in this order on the first surface 21 of the substrate 2 that has been subjected to the first step.

[0044] The substrate of separator 4 may be any material commonly used for separators, such as paper, synthetic paper, or polyolefin resin film. The substrate of separator 4 may be a laminate of a polyethylene layer and a paper layer. Separator 4 contains a release agent. The release agent is provided so as to face at least adhesive layer 3. Separator 4 is removed when substrate 2 is attached to the desired location.

[0045] The adhesive layer 3 is unlikely to affect the tearability of the label 1 having the substrate 2 when peeled off from an object after being attached thereto. Therefore, as shown in the test examples described later, the adhesive layer 3 can be ignored when evaluating the tearability.

[0046] [Variations] As shown in FIG. 4, the label manufacturing method may involve irradiating electron beam 8 onto a laminate 5 including a substrate 2, an adhesive layer 3, and a separator 4. The substrate 2 in the laminate 5 is a resin film prior to irradiation with electron beam 8. In the modified sheet manufacturing method, in the second step, a laminate 5 is prepared in which the adhesive layer 3 and the separator 4 are provided on a first surface 21 of the substrate 2 prior to irradiation with electron beam 8, and in the first step, the prepared laminate 5 is irradiated with electron beam 8. The electron beam 8 is irradiated in a direction from the second surface 22 toward the first surface 21 of the substrate 2, as indicated by the white arrow in FIG. 4.

[0047] In the modified example, the electron beam 8 is irradiated on the substrate 2 with the adhesive layer 3 and separator 4 provided thereon, so unintended breakage of the substrate 2 is less likely to occur during the manufacturing process than when the adhesive layer 3 and separator 4 are provided on the substrate 2 that has been irradiated with the electron beam 8. The substrate 2 is often formed into the desired shape and dimensions after the adhesive layer 3 and separator 4 are provided on the substrate 2. In the modified example, the electron beam 8 is irradiated on the laminate 5 having the desired shape and dimensions, so the device for irradiating the electron beam 8 can be easily made smaller.

[0048] [Test example] In the test example, a label was produced having a substrate irradiated with an electron beam, and a sensory test was conducted to determine whether the label would tear when peeled off from an object.

[0049] <Preparation of substrate> A substrate made of biaxially oriented polypropylene was prepared. The planar shape of the substrate was rectangular. The substrate size was 25 mm in both vertical and horizontal directions. The thickness of the substrate was as shown in Table 1. The thickness of the substrate for samples No. 1 to No. 6 was 40 μm. The thickness of the substrate for samples No. 7 and No. 8 was 50 μm. For all samples, the direction along the horizontal sides of the substrate was the machine direction, and the direction along the vertical sides of the substrate was the width direction.

[0050] For Samples No. 2 to No. 8, the prepared substrate was irradiated with an electron beam. The electron beam irradiation conditions are as shown in Table 1. For Sample No. 1, the prepared substrate was not irradiated with an electron beam.

[0051] <Tensile strength of base material> The tensile strength of the substrate was measured by cutting test specimens from the same substrate as each sample, placing them in a commercially available tensile testing machine, and conducting a tensile test at a rate of 300 mm / min. The test specimens were 15 mm wide and 220 mm long. For each sample, the tensile strength along the machine direction and the width direction were measured, and the average value was calculated. The results are shown in Table 1. Table 1 shows both values in mN / 15 mm (millinewtons / 15 mm) and values in MPa. The value in MPa is a unit conversion value obtained by using the value in mN / 15 mm and the width and thickness of the substrate. Specifically, the value in MPa was calculated by calculating the area using a substrate with a width of 15 mm and a thickness of 40 μm or 50 μm, and then dividing the value in mN / 15 mm by the area. The tensile strength of the substrate was not measured for Samples No. 2 and No. 3. In Table 1, the average tensile strength values for Sample No. 2 and Sample No. 3 are marked with "-".

[0052] <Creating labels> For Samples No. 2 to No. 8, a laminate in which an adhesive layer and a separator were integrated was attached to the first surface of the substrate that had been irradiated with electron beams to form a label.

[0053] <Sensory test> For Samples No. 2 to No. 8, labels with the separator removed were pasted onto a stainless steel plate, and 10 subjects peeled the labels from the stainless steel plate. The 10 subjects peeled the labels from the stainless steel plate in their own arbitrary ways. An arbitrary way means a way in which the subject arbitrarily decides where and how to peel the label. For example, it may be peeled from the corner of the label or from the side of the label. Also, the label may be peeled with a hand including nails, or with tools such as a ruler or something with a pointed tip. For each sample, it was determined whether the label tore in the middle when peeled, and the tearability was calculated. If the label was torn or had cracks but was not torn, it was evaluated as torn in the middle, and the tearability was set to 100%. If the state before peeling was almost maintained without tearing or cracking of the label, it was evaluated as not torn in the middle, and the tearability was set to 0%. The 10 subjects tested each sample 5 times. For example, if a certain subject peeled a certain label and it tore 3 times out of 5 times and did not tear 2 times, the tearability is 60%. The tearability of each sample is the average value of the tearability by 10 subjects. The higher the value of the tearability, the more likely it is that the label will not be peeled cleanly and will be easily torn when peeled. The results are shown in Table 1.

[0054]

Table 1

[0055] As shown in Table 1, when the thickness of the base material was 40 μm and irradiated with an electron beam at a dose of 1200 kGy or more and an acceleration voltage of 200 kV or more, the tearability was 90%. When the thickness of the base material is 40 μm, by irradiating the electron beam at a dose of 1200 kGy or more and an acceleration voltage of 200 kV or more, the entire base material is weakened, and it is considered that it becomes easy to break no matter where the label is peeled off. When the thickness of the base material was 50 μm and irradiated with an electron beam at a dose of 2400 kGy or more and an acceleration voltage of 200 kV or more, the tearability was 92%. When the thickness of the base material is 50 μm, by irradiating the electron beam at a dose of 2400 kGy or more and an acceleration voltage of 200 kV or more, the entire base material is weakened, and it is considered that it becomes easy to break no matter where the label is peeled off. That is, it can be said that by adjusting the dose and acceleration voltage of the electron beam according to the thickness of the base material and irradiating the adjusted electron beam to the base material, a label that is easy to break no matter where it is peeled off can be obtained.

Explanation of symbols

[0056] 1 Label 2 Base material, 21 First surface, 22 Second surface, 2T Thickness 3 Adhesive layer 4 Separator, 41 First surface 5 Laminate 8 Electron beam MD Flow direction, TD Width direction

Claims

1. A first step of irradiating a base material made of polypropylene with an electron beam; A second step of forming a label by providing an adhesive layer and a separator on a first surface of the base material; and, In the first step, When the thickness of the base material is less than 50 μm, irradiate the electron beam at a dose of 1200 kGy or more and less than 2400 kGy with an acceleration voltage of 200 kV or more, When the thickness of the base material is 50 μm or more, irradiate the electron beam at a dose of 2400 kGy or more with an acceleration voltage of 200 kV or more, A method for manufacturing a label.

2. The second step includes: A step of preparing a laminate in which the adhesive layer is laminated on a first surface of the separator; A step of bonding the laminate to the base material so that the adhesive layer faces the first surface of the base material that has undergone the first step; The method for manufacturing a label according to claim 1.

3. In the second step, prepare a laminate provided with the adhesive layer and the separator on the first surface of the base material before irradiating the electron beam, In the first step, irradiate the laminate with the electron beam; The method for manufacturing a label according to claim 1.

4. The method for manufacturing a label according to claim 2 or claim 3, wherein the thickness of the base material is 30 μm or more and 60 μm or less.

5. The average value of the tensile strength of the base material before being irradiated with the electron beam is 180 MPa or more, The average value of the tensile strength of the base material is the average value of the tensile strength along the flow direction of the raw material during the manufacture of the base material and the tensile strength along the width direction perpendicular to the flow direction; The method for manufacturing a label according to claim 2 or claim 3.

6. In the first step, when the thickness of the base material is less than 50 μm, irradiate the electron beam so that the average value of the tensile strength of the base material becomes 100 MPa or less, The average value of the tensile strength of the base material is the average value of the tensile strength along the flow direction of the raw material during the manufacture of the base material and the tensile strength along the width direction perpendicular to the flow direction; The method for manufacturing a label according to claim 2 or claim 3.

7. In the first step, when the thickness of the base material is 50 μm or more, irradiate the electron beam so that the average value of the tensile strength of the base material becomes 50 MPa or less, The average value of the tensile strength of the base material is the average value of the tensile strength along the flow direction of the raw material during the manufacture of the base material and the tensile strength along the width direction perpendicular to the flow direction; The method for manufacturing a label according to claim 2 or claim 3.

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