JP2023054858A - Laminate and structure - Google Patents

Abstract

To provide a laminate and a structure, which can be easily handled by the lamination of a reinforcing layer onto a film having satisfactory strength and elongation regardless of a resin material, while suppressing labor and cost at the time of manufacture.SOLUTION: The laminate includes a film and a reinforcing layer which is laminated on at least one surface of the film, in which the film and the reinforcing layer are formed of a resin material. The film has an uneven structure in which a front surface and a rear surface correspond to each other in a cross-sectional shape at least in a predetermined direction; and the uneven structure has a periodic structure in which at least one uneven structure is repeated along the predetermined direction. A peel strength at the time when the reinforcing layer is peeled from the film is 0.01 N or larger and 0.4 N or smaller.SELECTED DRAWING: Figure 7

Description

The present invention relates to laminates and structures.

In general, plastic films have properties such as being lightweight, chemically stable, easy to process, flexible and strong, and mass-producible, and are used for various purposes. Its applications include, for example, packaging materials for packaging foodstuffs and pharmaceuticals, drip packs, shopping bags, posters, tapes, optical films used for liquid crystal televisions, protective films, window films for bonding to windows, A wide variety of products such as vinyl houses and building materials. Specific materials include, for example, thermoplastic resins such as polyethylene, polypropylene, polystyrene, acrylic polymethyl methacrylate, polycarbonate, polyamide, polyethylene terephthalate, and polybutylene terephthalate, and thermosetting resins such as epoxy resins, polyurethanes, and polyimides. is mentioned.

Appropriate plastic materials are selected depending on the application, and a plurality of types of these materials are stacked to form a laminate. There is also a method of use in which a plurality of plastic materials are mixed in one layer to compensate for the shortcomings of a single material. In many cases, appropriate plastic film materials are selected based on heat resistance, mechanical strength, or transparency.

However, the mechanical properties of plastic films are generally determined by the material and layer structure. For this reason, strength-oriented materials tend to have low elongation, and there is a strong demand for film materials that can ensure sufficient elongation while having high strength. In addition, barrier packaging materials in which a vapor deposition layer is laminated on a base material have the problem that when stretched, the vapor deposition layer immediately cracks and the barrier property disappears. There is also a strong demand for film materials that ensure the Furthermore, for example, polylactic acid films are strong and biodegradable, and are attracting attention from the viewpoint of environmental protection, but their applications are limited due to their relatively low elongation and poor impact resistance. . In this way, in response to the demand for film materials that can achieve both strength and elongation, countermeasures such as mixing multiple materials and bonding multiple types of films are being considered. At present, it is difficult to obtain a sufficient effect.

Therefore, as shown in Patent Literature 1 and Patent Literature 2, attempts have been made to achieve both strength and elongation by providing a film with an uneven structure.

Japanese Patent Application Laid-Open No. 2019-90006 JP 2019-89319 A

However, the films disclosed in Patent Documents 1 and 2 are very thin as a single unit and weak in bending rigidity in the direction perpendicular to the direction in which the concave-convex structure is arranged. As a method for making the film easier to handle, thickening the film can be mentioned, but the thickening of the film impairs the elongation characteristic of the film.

In view of the problems of the prior art, the present invention provides easy handling by laminating a reinforcing layer on a film having good strength and elongation regardless of the resin material, while suppressing the labor and cost at the time of production. An object of the present invention is to provide a laminate and a structure that can be

In order to solve the above problems, one representative laminate of the present invention is a laminate having a film and a reinforcing layer laminated on at least one surface of the film,
The film and the reinforcing layer are made of a resin material,
The film has an uneven structure in which the front surface and the back surface correspond at least in a cross-sectional shape in a predetermined direction, and the uneven structure is a periodic structure in which at least one or more of the uneven structures are repeated along the predetermined direction,
This is achieved by setting the peel strength when peeling the reinforcing layer from the film to 0.01 N or more and 0.4 N or less.

According to the present invention, a laminate and a structure that can be easily handled by laminating a reinforcing layer on a film that has good strength and elongation regardless of the resin material while suppressing labor and cost during production. can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 1 is a perspective view showing an example of the film of this embodiment. FIG. 2 is a perspective view showing an example of the film of this embodiment. FIG. 3 is a perspective view showing an example of the film of this embodiment. FIG. 4 is a perspective view showing an example of the film of this embodiment. FIG. 5 is a cross-sectional view showing an example of the film of this embodiment. FIG. 6 is a cross-sectional view showing an example in which the film of the present embodiment is stretched and deformed. FIG. 7 is a cross-sectional view showing an example of the laminate of this embodiment. FIG. 8 is a diagram showing an overview of the peel strength measurement of the laminate of this embodiment. FIG. 9 is a cross-sectional view showing an example of the film of this embodiment. FIG. 10 is a diagram showing an outline of the loop stiffness test of the film of this embodiment. FIG. 11 is a cross-sectional view showing an example of the structure of this embodiment. FIG. 12 is a plan view showing sections of the film of this embodiment. FIG. 13 is a diagram showing the dimensions of each part of the concave-convex structure of the rolls used in this example and comparative example.

An embodiment of the film of the present invention and a laminate and structure using the film will be described below with reference to the drawings.
Each figure is a schematic diagram, and the size, shape, etc. of each part are appropriately exaggerated for easy understanding. In order to simplify the explanation, the same reference numerals are given to the corresponding parts in each figure.

(the film)
1 to 4 are perspective views showing examples of the film 1 of this embodiment. 5(a) is a cross-sectional view of the film 1 of FIGS. 1 and 2 in the X direction, FIG. 5(b) is a cross-sectional view of the film 1 of FIG. 3 in the X direction, and FIG. 5(c) is the film of FIG. 5(d) is a cross-sectional view of the film 1 of FIG. 4 in the Y direction.

As shown in FIGS. 1 to 5, the film 1 has peaks 2a and troughs so that the front surface and the back surface correspond (preferably so that the film thickness is substantially uniform) in the cross-sectional shape in one or two directions. It has a concavo-convex structure that repeats the portion 2b, and the concavo-convex structure has at least one or more periodic structures. The film 1 in FIG. 2 has the same concave-convex structure in the X-direction cross section and the Y-direction cross section, but the X-direction cross section has a structure with one period shorter than the Y-direction cross section. The concave-convex structure may have a shape combining straight lines and curves, or may combine different shapes.

Specifically, the cross-sectional shape may be formed by connecting a plurality of trapezoids as shown in FIGS. 1, 2 and 5(a), or the cross-sectional shape by connecting a plurality of triangles as shown in FIGS. Alternatively, as shown in FIGS. 5(c) and 5(d), trapezoids and triangles may be alternately combined on the same cross section. A shape in which the peaks 2a and the valleys 2b are gentle may be used, and the shape is not limited to these shapes. Also, as shown in FIG. 4, different shapes may be combined for different cross sections in different directions, such as a trapezoid and a triangle in the cross section in the Y direction and a trapezoid and a trapezoid in the X direction.

FIG. 6 shows schematic diagrams before and after the film 1 is stretched. When the film 1 is pulled in the left-right direction in FIG. 6, elongation can be expressed not by elastic deformation but by the shape change of the concave-convex structure that the cross-sectional internal angle between the intersecting surfaces increases. , has the property of stretching regardless of the material of the film 1 . The film shape shown in FIG. 1 extends in the X direction, and the film shape shown in FIGS. 2 to 4 extends in both the X and Y directions, especially in the X direction more than in the Y direction.

However, when the film 1 is used alone, the flexural rigidity is low due to its irregular shape, so there is a problem that the handleability of the film 1 is low. Therefore, in the present embodiment, handling property is improved by forming a laminate in which a reinforcing layer is laminated on the film 1 as described below. When using the film 1, the reinforcing layer can be peeled off.

(Reinforcement layer and laminate)
FIG. 7 is a cross-sectional view showing an example of the laminate 3 of this embodiment. As shown in FIG. 7, the laminate 3 is obtained by laminating the reinforcing layer 4 on the film 1 . The reinforcing layer 4 may be provided on at least one side of the film 1, and may be provided on one side of the film 1 as shown in FIG. You can prepare for both sides. Further, as shown in FIG. 7(c), two or more reinforcing layers 4 may be provided, and the shape is not limited to these. By providing the reinforcing layer 4 on the film 1, the bending rigidity is increased and the handling is facilitated.

However, if the reinforcing layer 4 is easily peeled off from the film 1, peeling may occur during transportation and the value of the product may be lost. This may be inconvenient for users who want to Therefore, it is desirable to give the laminate 3 a predetermined peel strength as an index for peeling the reinforcing layer 4 from the film 1 .

<Peel strength>
The peel strength is a resistance value when the film 1 and the reinforcing layer 4 are separated from each other in the laminate 3 , and varies depending on the shape and direction of the film 1 laminated on the laminate 3 . In general, it is considered that the direction in which the change in cross-sectional shape is smaller due to tension is easier to separate. For example, the shapes shown in FIGS. 1 to 4 are resistant to separation in the Y direction and weak in the X direction. Here, for example, when the reinforcing layer 4 is peeled off in the X direction in the shape shown in FIG. 1, the peeled portion is pulled in the direction in which the film 1 is stretched, so the film 1 is stretched simultaneously with the peeling. However, if the film 1 stretches beyond the restorable region during peeling, the elongation characteristic of the film 1 is lost. Therefore, it is preferable that the peeling is performed in a direction in which the film 1 is difficult to stretch, such as the Y direction in the example of FIG.

According to the study results of the present inventors, it was found that the peel strength when peeled is preferably 0.01 N or more and 0.4 N or less regardless of the peel direction. More preferably, the peel strength is 0.01 N or more, and is less than the test force at strain=5% when a tensile test is performed on the film 1. If it is less than the above range, the film 1 and the reinforcing layer 4 will naturally separate from each other, making it difficult to handle. The characteristic elongation will be lost.

Peel strength can be measured by using a general tensile tester. FIG. 8 shows a cross section of the laminate 3 when measuring the peel strength. After cutting out the laminate 3 to have a width of 15 mm and a length of 150 mm, the film 1 and the reinforcing layer 4 are separated by 50 mm. The exfoliated ends are held by chucks 21 of a tensile tester, and the film 1 and reinforcing layer 4 are pulled apart at a chuck distance of 50 mm and a tensile speed of 200 mm/min to conduct a tensile test. The peel strength indicates the maximum load obtained in this test.

The film 1 can be easily handled by peeling it from the laminate 3 immediately before use.

<Film thickness>
FIG. 9 is a cross-sectional view showing an example of the film 1 of this embodiment.
The film thickness t1 not including the uneven structure of the film 1 is preferably 3 μm or more and 50 μm or less. More preferably, it is 5 μm or more and 30 μm or less. If the thickness is less than the above range, the film 1 is deformed beyond the restorable region when the film 1 and the reinforcing layer 4 are peeled off, and the characteristic elongation of the film 1 is lost. On the other hand, if the above range is exceeded, the elongation due to the change in shape shown in FIG.

It should be noted that the concave-convex structure and each thickness need not be uniform depending on the location of the film 1 and may be non-uniform as long as the effects of the present invention are not impaired. However, when it is non-uniform, it is preferable that it falls within the above range at any location.

Furthermore, it is preferable that the height difference H (=T−t1) of the uneven structure exceeds the film thickness t1 and is 5 μm or more and 150 μm or less. More preferably, the height difference H is 10 μm or more and 100 μm or less. This is because the elongation characteristic of the film 1 can thereby be obtained. If it is less than the above range, the amount of elongation due to the change in shape shown in FIG. In addition, if the above range is exceeded, the peel strength between the film 1 and the reinforcing layer 4 becomes strong, and the film 1 stretches beyond the region where the film 1 can be restored at the time of peeling, and the elongation characteristic of the film 1 is impaired. become.

<Thickness of reinforcing layer>
The thickness t2 of the reinforcing layer 4, as shown in FIG. 7, does not include the portion that enters into the concave-convex structure portion of the film 1 (that is, the distance from the lower surface of the film 1 to the lower surface of the reinforcing layer 4), and is 10 μm or more. It is preferably 20 μm or more, more preferably 20 μm or more. By setting the thickness of the reinforcing layer within the above range, the laminated body 3 obtained by laminating the film 1 and the reinforcing layer 4 can have appropriate bending rigidity and can be easily handled.

<Loop Stiffness>
It is preferable that each loop stiffness value obtained when the laminated body 3 is looped is within a specific range as an index value of bending rigidity. The loop stiffness value is measured, for example, under the conditions that the film 1 having a width of 15 mm is looped, the length (peripheral length) of the loop is 85 mm, and the indentation distance is 20 mm. It changes depending on the shape and direction of 1. For example, in the geometries shown in FIGS. 1-4, the loop stiffness values in the X direction are low compared to the loop stiffness values in the Y direction.

Specifically, the loop stiffness value measured in the weakest direction is preferably 1 mN/15 mm or more. If the loop stiffness value is less than the above range, sufficient flexural rigidity cannot be obtained, and handling of the laminate 3 becomes difficult.

The loop stiffness value can be measured by using a loop stiffness tester manufactured by Toyo Seiki Seisakusho. FIG. 10 shows the state of the laminate 3 during the loop stiffness test. In the loop stiffness test, as shown in FIG. 10, the laminated body 3 is fixed with a chuck 22 of a loop stiffness tester to form a loop, the loop-shaped laminated body 3 is pushed by an indenter 23, and the load of the indenter 23 at that time is measured. It is a test that measures The pushing distance of the indenter 23 is defined by the pushing distance, and the pushing distance represents the distance when the indenter 23 and the chuck 22 of the loop toughness tester are closest to each other. The loop stiffness value indicates the maximum load obtained in this test.

(functional layer and structure)
FIG. 11 is a cross-sectional view showing an example of the structure 5 of this embodiment.
As shown in FIG. 11, the structure 5 is obtained by laminating the functional layer 6 on the laminate 3 (the film 1 and the reinforcing layer 4). The functional layer 6 may be provided on the reinforcing layer 4 side as shown in FIG. 11(a), or may be provided on the film 1 side as shown in FIG. 6(b). Moreover, as shown in FIG. 6(c), it may be provided on both sides of the film 1 and the reinforcing layer 4, and as shown in FIG. isn't it.

<Array structure>
Moreover, as shown in FIG. 12(a), the film 1 may have a plurality of regions 7 including an uneven structure, and the regions may be aligned to form a film assembly. Since the film 1 has a shape with anisotropic physical properties as shown in FIG. In this way, the film assembly as a whole may be devised so that it can be handled as an isotropic film.

Also, as shown in FIG. 12(b), the left and right edge portions, the center portion in the width direction of the film, and between adjacent regions 7 are margins where no uneven structure (mountain portion 2a, valley portion 2b) is formed. There may be 8.

(material)
The material of the film 1 and the reinforcing layer 4 is preferably a thermoplastic resin. Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, polymethyl methacrylate, ethylene vinyl acetate, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, polyacrylonitrile, polylactic acid, cyclic polyolefin, polycarbonate, and polyamide. , polyethylene terephthalate, polybutylene terephthalate, and derivatives thereof, but are not particularly limited. These materials may be used alone, or a plurality of these materials may be used in combination. However, since the reinforcing layer 4 is peeled off and discarded immediately before use, it is preferably made of an inexpensive material that does not strongly adhere to various resins, and polyethylene and polypropylene are particularly preferred.

As for the material of the functional layer 6, similarly to the film 1 and the reinforcing layer 4, in addition to thermoplastic resins, curable resins (thermosetting resins, UV curable resins, etc.) and metals can be used. Examples of curable resins include epoxy resins, polyurethanes, polyimides, and derivatives thereof, but are not particularly limited. Examples of metals include Al, Si, Zn, Sn, Fe, Mn, and inorganic compounds containing one or more of these metals. Examples of inorganic compounds include oxides, nitrides, carbides, and fluorides. can be used, but is not particularly limited.

<Manufacturing method>
As for the method for manufacturing the film 1, the laminate 3, and the structure 5, for example, a method using hot press or a method using extrusion molding can be used.

[Heat press]
In the hot press method, a plurality of releasable flat films are stacked, or a flat film holding a plurality of releasable layers is placed between heating rolls provided with uneven shapes, or between heated flat films. By passing it through a press, it is possible to impart an uneven structure. At this time, a desired uneven shape is imparted by adjusting the press depth and press pressure. At this time, a film 1 can be obtained if the flat film to be processed has a single layer, and a laminate 3 or a structure 5 can be obtained if it has a plurality of layers.

[Extrusion]
In addition, in the extrusion molding method, a plurality of extruders are used, and a plurality of different resins are co-extruded by a feed block method or a multi-manifold method to obtain the film 1, the laminate 3, and the structure 5. be able to. In the cooling step for film formation, the surface to be provided with the uneven structure is cooled using a cooling roll having unevenness on the surface, and the uneven structure can be formed by cooling while applying nip pressure.

At this time, when the height difference H between peaks and valleys of the rugged structure is large with respect to the film thickness t1 of the film 1 in contact with the cooling roll, the reinforcing layer 4 is similarly provided with the rugged structure.

In addition, any method for adding the concave-convex structure, such as injection molding, can be selected, and the method is not particularly limited.

The film 1 and laminate 3 are structures in which functional layers 6 such as a printed layer, a vapor deposition layer, a hard coat layer, an antireflection layer, and an anchor coat layer for improving adhesion to an adhesive are laminated on the surface in a post-process. 5 can also be used.

Although the embodiments of the present invention have been exemplified above, it goes without saying that the present invention is not limited to the above embodiments. Moreover, it is arbitrary to combine and use the above embodiments.

Examples prepared by the inventors will be described in detail below, but the present invention is not limited only to the following examples.

(Example 1)
As a material for Film 1, a polyester resin (A-PET) Bellpet EFG70 manufactured by Bell Polyester Products Co., Ltd. was used. As a material for the reinforcing layer 4, low-density polyethylene (LDPE) Novatec LDLC600A manufactured by Japan Polyethylene Co., Ltd. was used. The film 1 and the reinforcing layer 4 were co-extruded so that the film 1 side was nipped with uneven rolls to give an uneven structure, and the cross-sectional shape of the laminate 3 was produced as shown in FIG. 7(a).

The shape of the film 1 is shown in FIG. 1, and the trapezoidal shape is arranged periodically as shown in FIG. 5(a) in cross section. FIG. 13(a) is an enlarged view of the uneven shape of the roll used, and the height H of the protrusions of the uneven structure was set to 60 μm. The thickness t1 of the film 1 was set to 10 μm, and the thickness t2 of the reinforcing layer 4 was set to 20 μm.

(Example 2)
As a material for the reinforcing layer 4, a high-density polyethylene (HDPE) Novatec HD HS471 manufactured by Japan Polyethylene Co., Ltd. was used. A sample of Example 2 was produced in the same manner as in Example 1 except for the above.

(Example 3)
As a material for Film 1, ethylene-vinyl alcohol copolymer (EVOH) Soarnol D2908 manufactured by Mitsubishi Chemical Corporation was used. A sample of Example 3 was produced in the same manner as in Example 1 except for the above.

(Example 4)
The film 1 and the reinforcing layer 4 are co-extruded by nipping the film 1 side with an uneven roll to give an uneven structure, and at the same time, a biaxially stretched polyester film (stretched PET ) E5102 was adhered to the reinforcing layer 4 side, and the cross-sectional shape of the structure 5 was produced as shown in FIG. 11(a). A sample of Example 4 was produced in the same manner as in Example 1 except for the above.

(Example 5)
The uneven shape of the roll used was as shown in FIG. 13(b), the height H of the uneven structure was 5 μm, and the thickness t1 of the film 1 was 3 μm. A sample of Example 5 was produced in the same manner as in Example 1 except for the above.

(Example 6)
The uneven shape of the roll used was as shown in FIG. 13(c), and the height H of the uneven structure was 150 μm. A sample of Example 6 was produced in the same manner as in Example 1 except for the above.

(Example 7)
The thickness t1 of the film 1 was set to 3 μm. A sample of Example 7 was produced in the same manner as in Example 1 except for the above.

(Example 8)
The thickness t1 of the film 1 was set to 50 μm. A sample of Example 8 was produced in the same manner as in Example 1 except for the above.

(Example 9)
The thickness t2 of the reinforcing layer 4 was set to 10 μm. A sample of Example 9 was produced in the same manner as in Example 1 except for the above.

(Comparative example 1)
As an additive for the reinforcing layer 4, silicone resin powder KMP-590 manufactured by Shin-Etsu Silicone Co., Ltd. was added to 10 wt %. A sample of Comparative Example 1 was produced in the same manner as in Example 1 except for the above.

(Comparative example 2)
At the time of extrusion molding, a mirror-finished roll having no unevenness on the film 1 side was used to prepare a flat sample having no unevenness on the front and back sides. A sample of Comparative Example 2 was produced in the same manner as in Example 1 except for the above.

(Comparative Example 3)
As a material for film 1, ethylene-vinyl alcohol copolymer (EVOH) Soarnol D2908 manufactured by Mitsubishi Chemical Corporation was used. As a material for the reinforcing layer 4, a high-density polyethylene (HDPE) Novatec HD HS471 manufactured by Japan Polyethylene Co., Ltd. was used. A sample of Comparative Example 3 was produced in the same manner as in Example 1 except for the above.

(Comparative Example 4)
The uneven shape of the roll used was as shown in FIG. 12(d), and the height H of the uneven structure was 160 μm. A sample of Comparative Example 4 was prepared in the same manner as in Example 1 except for the above.

(Peel strength, loop stiffness value, ease of handling, and sensory evaluation of stretchability)
In each example and comparative example, the delamination strength between the film 1 and the reinforcing layer 4 and the loop stiffness values of the laminate 3 and structure 5 were measured.

The peel strength was evaluated using a Tensilon Universal Material Tester (RTC-1250A) manufactured by A&D Co., Ltd. In accordance with the test conditions of JIS Z0237: 2009 Adhesive tape/adhesive sheet test method, the sample width is 15 mm, the sample length is 150 mm, and the Y direction in FIG. was cut out in the longitudinal direction of the sample, one side of the sample was preliminarily peeled between the film 1 and the reinforcing layer 4 by 50 mm, and chucked at a distance between chucks of 50 mm. From this state, the sample was pulled at a tensile speed of 200 mm/min until it was completely peeled off, and a peeling test was carried out to measure the load when a force was applied. At this time, the maximum value of the load during the measurement was taken as the peel strength.

In addition, the length of the sample after the measurement of the peel strength was measured. In Comparative Example 1, the film 1 and the reinforcing layer 4 were separated from each other, and the laminate 3 was not formed, so the measurement was not carried out. In addition, since Comparative Example 2 does not have an uneven structure, the sample was cut out in any direction.

The loop stiffness value was evaluated using a loop stiffness tester (DA-S) manufactured by Toyo Seiki Seisakusho Co., Ltd. The sample width was 15 mm, the sample length was 200 mm, and the sample was cut so that the X direction in FIG. 1 was the longitudinal direction of the sample. In Comparative Example 1, the film 1 and the reinforcing layer 4 were separated from each other, and the laminate 3 was not formed, so the measurement was not carried out. In addition, since Comparative Example 2 does not have an uneven structure, the sample was cut out in any direction.

(Sensory evaluation method)
In order to evaluate the "handleability" of the laminate 3 and the "stretchability" of the film 1 in each example and comparative example, a sensory evaluation was carried out for each example and comparative example.

In the evaluation of "ease of handling", the tester held the laminate 3 in his/her hand and rated x when it was difficult to handle, ◯ when it was easy to handle, and ⊚ when it was particularly easy to handle.

The evaluation of "stretchability" was performed by the tester pulling the film 1 peeled from the laminate 3 in the X direction of FIG. The thing which felt was made into *.

(comprehensive evaluation)
In the examples and comparative examples, "×" was given when either one of them was "x", and "○" was given when both were "○ or ◎". In addition, those that were both marked with "◎" were marked with "◎".

Table 1 shows a list of conditions and evaluation results in each example. Table 2 shows a list of conditions and evaluation results in each comparative example.

(Overview of evaluation results)
Comparing the overall evaluation of the examples and comparative examples in Tables 1 and 2, some of the same materials are "○" and others are "×". ” and “×” are mixed.

(Evaluation result details)
In Comparative Example 1, the interlayer between the film 1 and the reinforcing layer 4 was spontaneously separated, and the laminate 3 was not formed, so the overall evaluation was "x".
Comparative Example 2 did not have an uneven structure, so the stretchability was poorly evaluated, so the overall evaluation was "x".
Comparative Examples 3 and 4 had high peel strength, and elongation had occurred in the peeled film 1 . Therefore, the feeling of stretchability was also poorly evaluated, and the overall evaluation was "x".

In Example 1, since the loop stiffness value was decreased, it became soft and difficult to handle.
In Example 5, since the height H of the concave-convex structure was reduced, the feeling of elongation was weakened.
In Example 6, by increasing the height H of the concave-convex structure, the elongation feeling was evaluated as “◎”, but the ease of handling was evaluated as “◯”, and the overall evaluation was “◯”. rice field.
In Example 7, by reducing the thickness t1 of the film 1, the stretch feeling was evaluated as "◎", but the ease of handling was evaluated as "◯", and the overall evaluation was "◯". .
In Example 8, since the thickness t2 of the reinforcing layer 4 was reduced, the evaluation of the ease of handling remained at "◯", and the overall evaluation was "◯".
In Example 9, by reducing the thickness t2 of the reinforcing layer 4, the stretch feeling was evaluated as “◎”, but the ease of handling was evaluated as “◯”, and the overall evaluation was “◯”. rice field.

On the other hand, Examples 2, 3, and 4 had high flexural rigidity and moderate peel strength, so that the film 1 did not stretch when peeled, and both ease of handling and stretchability were excellent, and the overall evaluation was good. It was "◎".

1 Film 2a Mountain portion 2b Valley portion 3 Laminate 4 Reinforcing layer 5 Structure 6 Functional layer 7 Region 8 Blank 21 Chuck 22 of tensile tester Chuck 23 of loop toughness tester Indenter

Claims (9)

A laminate having a film and a reinforcing layer laminated on at least one surface of the film,
The film and the reinforcing layer are made of a resin material,
The film has an uneven structure in which the front surface and the back surface correspond at least in a cross-sectional shape in a predetermined direction, and the uneven structure is a periodic structure in which at least one or more of the uneven structures are repeated along the predetermined direction,
The peel strength when peeling the reinforcing layer from the film is 0.01 N or more and 0.4 N or less.
A laminate characterized by: The peel strength is the peel strength of the laminate measured in the direction where the peel strength is the weakest.
The laminate according to claim 1, characterized in that: The thickness of the film not including the uneven structure is 3 μm to 50 μm.
The laminate according to claim 1 or 2, characterized in that: The height difference in the uneven structure is thicker than the thickness of the film and is 5 μm to 150 μm.
The laminate according to any one of claims 1 to 3, characterized in that: The reinforcing layer has a thickness of 10 μm or more,
The laminate according to any one of claims 1 to 4, characterized in that: When the laminate is formed into a loop with a width of 15 mm, the loop stiffness value is 1 mN/15 mm, which is measured under the measurement conditions that the length of the looped laminate is 85 mm and the indentation distance is 20 mm. is more than
The laminate according to any one of claims 1 to 5, characterized in that: A functional layer is laminated on at least one surface of the laminate according to any one of claims 1 to 6,
A structure characterized by the functional layer is laminated to the film;
8. The structure of claim 7, characterized by: The functional layer is laminated to the reinforcing layer,
9. The structure according to claim 7 or 8, characterized in that:

Images