Stretchable substrate, stretchable device, and method for manufacturing the same

Abstract

A stretchable substrate having a first main surface and a second main surface opposite to each other, the stretchable substrate satisfying any one of: (1) the oxygen atom ratio of at least one of the first main surface and the second main surface as measured by X-ray photoelectron spectroscopy is 5 atom % or more with respect to all atoms; (2) in the first main surface or the second main surface, the arithmetic average surface roughness of the surface measured by a laser microscope is 6 μm or more; (3) at least one of the first main surface and the second main surface has a metal-containing portion; and (4) a metal-containing region is positioned along at least one of the first main surface and the second main surface.

Description

[Technical Field]

[0001] The present invention relates to a stretchable substrate, a stretchable device, and methods for producing the same. [Background Art]

[0002] Conventionally, fluororubber molded articles and elastomers described in Japanese Patent Laid-Open No. 2002-293950 (Patent Document 1) have been used as stretchable substrates. In the above document, the fluororubber molded article contains 0.01 to 10 parts by weight of silica powder per 100 parts by weight of fluororubber, has a crosslinked structure formed by a polyamine-based crosslinking agent, and has a wrinkle-shaped fine uneven structure on the surface. Such a stretchable substrate has appropriate stretchability. Furthermore, the stretchable substrate has a wrinkle-shaped fine uneven structure on its surface, which results in low frictional resistance on the surface. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2002-293950 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In order to produce a conventional stretchable substrate with reduced tackiness, it has been necessary to additionally add a composition containing an inorganic filler such as silica. In such a stretchable substrate, for example, the inclusion of silica can change the properties of the stretchable substrate. For example, there has been a concern that the stretch properties may change, causing plastic deformation of the stretchable substrate, specifically, an increase in permanent set.

[0005] An object of the present invention is to provide a stretchable substrate, a stretchable device, and methods for producing the same that can suppress self-adhesion on the surface while suppressing permanent set. [Means for Solving the Problem]

[0006] To solve the aforementioned problems, a stretchable substrate in one aspect of this disclosure is A stretchable substrate having a first main surface and a second main surface facing each other, The aforementioned stretchable substrate is (1) The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms. (2) The arithmetic mean surface roughness of the first or second main surface, as measured by a laser microscope, is 6 μm or more. (3) At least one of the first main surface and the second main surface has a metal-containing portion containing metal atoms, (4) A metal-containing region containing metal atoms is located along at least one of the first principal surface and the second principal surface, It has one of the following:

[0007] The above configuration results in a stretchable substrate with a modified surface. As a result, the tackiness and self-adhesion of the stretchable substrate can be suppressed.

[0008] A stretchable substrate in one aspect of this disclosure is It has a first principal surface and a second principal surface that are opposite to each other, The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms.

[0009] The above configuration results in a stretchable substrate with a modified surface. As a result, the tackiness and self-adhesion of the stretchable substrate can be suppressed.

[0010] A stretchable substrate in one aspect of this disclosure is It has a first principal surface and a second principal surface that are opposite to each other, On the first main surface or the second main surface, the arithmetic mean surface roughness of the surface measured by a laser microscope is 6 μm or more.

[0011] With the above configuration, a stretchable substrate having a modified surface is obtained. As a result, self-adhesion of the stretchable substrate can be suppressed.

[0012] In one aspect of the present disclosure, the stretchable substrate is: having a first main surface and a second main surface facing each other, at least one of the first main surface and the second main surface has a metal-containing portion containing metal atoms.

[0013] When at least one of the first main surface and the second main surface of the stretchable substrate has the metal-containing portion, molecular diffusion that causes self-adhesion is suppressed, and self-adhesion of the stretchable substrate can be suppressed. Here, the metal-containing portion means a portion containing a metal-containing compound.

[0014] having a first main surface and a second main surface facing each other, a metal-containing portion containing metal atoms is located along at least one of the first main surface and the second main surface, a stretchable substrate.

[0015] With the above configuration, molecular diffusion that causes self-adhesion is suppressed, and self-adhesion of the stretchable substrate can be suppressed. Furthermore, the metal-containing portion adheres to another substrate other than the stretchable substrate, improving the adhesion between the stretchable base material and the other base material.

[0016] In one aspect of the present disclosure, a stretchable device includes the stretchable substrate according to the present disclosure, and a wiring disposed on the first main surface of the stretchable substrate.

[0017] With the above configuration, a stretchable device with suppressed tackiness and self-adhesion can be provided.

[0018] In one aspect of the present disclosure, the stretchable device further includes a protective layer.

[0019] With the above configuration, the wiring can be protected.

[0020] A method for manufacturing a stretchable substrate according to one aspect of the present disclosure is a preparation step of preparing a base material; an ozone treatment step of performing ozone treatment on at least one of a first main surface of the base material and a second main surface located on an opposite side of the first main surface; comprising.

[0021] By performing the above steps, a stretchable substrate containing oxygen atoms can be formed. As a result, the surface of the base material is modified, and the tackiness and self-adhesion of the stretchable substrate can be suppressed.

[0022] A method for manufacturing a stretchable device according to one aspect of the present disclosure is a preparation step of preparing a base material having a first main surface and a second main surface facing each other; an arrangement step of arranging a wiring on the first main surface of the base material; after the arrangement step, an ozone treatment step of performing ozone treatment on at least one of the first main surface and the second main surface, and comprising.

[0023] By performing the above steps, a stretchable device with suppressed self-adhesion can be formed. Further, ozone treatment can be performed in a state where the wiring is provided, and the manufacturing method can be simplified.

[0024] A method for manufacturing a stretchable device according to one aspect of the present disclosure is a preparation step of preparing a base material having a first main surface and a second main surface facing each other; an arrangement step of arranging a wiring on the first main surface of the base material; after the arrangement step, an embossing step of performing embossing on at least one of the first main surface and the second main surface, and comprising.

[0025] By performing the above steps, self-adhesion on the surface of the stretchable device can be suppressed. Further, embossing can be performed in a state where the wiring is provided, and the manufacturing method can be simplified.

[0026] A method for manufacturing a stretchable device according to one aspect of the present disclosure is A preparation step of preparing a first substrate having a first main surface and a second main surface facing each other, A forming step of forming a metal-containing portion on the second main surface of the first substrate, It holds.

[0027] A method for manufacturing a stretchable device in one aspect of this disclosure is: Preparation process for preparing the base material, A forming step of forming a metal-containing portion on at least one of the first main surface and the second main surface located on the opposite side of the first main surface of the substrate, Includes.

[0028] By having at least one of the first and second main surfaces of the stretchable substrate have a metal-containing portion, molecular diffusion that causes self-adhesion is suppressed, thereby preventing self-adhesion of the stretchable device.

[0029] A method for manufacturing a stretchable device in one aspect of this disclosure is: A preparation step of preparing a first substrate having a first main surface and a second main surface facing each other, A placement step of arranging wiring on the first main surface of the first substrate, After the arrangement step, a forming step is performed to form a metal-containing portion on at least the second main surface of the first substrate, It holds.

[0030] By performing the above process, a stretchable device with suppressed self-adhesion can be formed. [Effects of the Invention]

[0031] According to this disclosure, it is possible to provide a stretchable substrate, a stretchable device, and a method for manufacturing the same, which can suppress permanent deformation while suppressing self-adhesion on the surface. [Brief explanation of the drawing]

[0032] [Figure 1] This is a partial top view of the expandable device according to the first embodiment. [Figure 2]This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3A] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the first embodiment. [Figure 3B] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the first embodiment. [Figure 3C] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the first embodiment. [Figure 4] This is a cross-sectional view of the stretchable device according to the second embodiment. [Figure 5A] This is a schematic diagram showing the first main surface of the stretchable substrate of the second embodiment. [Figure 5B] This is a schematic diagram showing an embossing sheet material for forming the first main surface of a stretchable substrate according to the second embodiment. [Figure 6A] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the second embodiment. [Figure 6B] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the second embodiment. [Figure 6C] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the second embodiment. [Figure 7A] This is a schematic diagram of a modified example 1 showing the first main surface of the stretchable substrate of the second embodiment. [Figure 7B] This is a schematic diagram showing an embossing sheet material of a modified example 1 for forming the first main surface of a stretchable substrate of the second embodiment. [Figure 8A] This is a schematic diagram showing a modified example of a sheet material for embossing. [Figure 8B] This is a schematic diagram showing a modified example of a sheet material for embossing. [Figure 8C] This is a schematic diagram showing a modified example of a sheet material for embossing. [Figure 8D] This is a schematic diagram showing a modified example of a sheet material for embossing. [Figure 9] This is a cross-sectional view of the stretchable device according to the third embodiment. [Figure 10A] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the third embodiment. [Figure 10B]This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the third embodiment. [Figure 10C] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the third embodiment. [Figure 11] This is a cross-sectional view of a modified example 1 of the third embodiment. [Figure 12] This is a cross-sectional view of a modified example 2 of the third embodiment. [Figure 13] This is a cross-sectional view of the stretchable device according to the fourth embodiment. [Figure 14A] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the fourth embodiment. [Figure 14B] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the fourth embodiment. [Figure 14C] This is an explanatory diagram illustrating the manufacturing method of the stretchable device according to the fourth embodiment. [Figure 15] This is an explanatory diagram showing the surface roughness of the stretchable substrate of Example 15. [Figure 16] This is an explanatory diagram illustrating the phase-rigid portion of the stretchable substrate of Example 19. [Figure 17] This is an explanatory diagram describing the measurement method for the peel test. [Figure 18] This is a measurement diagram showing the relationship between displacement distance and peeling force in the peeling test in Example 40 and Comparative Example 5. [Figure 19] This is a measurement diagram showing the relationship between press temperature and peel strength in a peel test. [Modes for carrying out the invention]

[0033] Hereinafter, an expandable device, which is one aspect of this disclosure, will be described in detail with reference to the illustrated embodiment. Note that some of the drawings are schematic and may not reflect actual dimensions or proportions.

[0034] The stretchable device of this disclosure comprises a stretchable substrate and wiring provided on a first main surface of the stretchable substrate.

[0035] The above stretchable substrate is, A stretchable substrate having a first main surface and a second main surface facing each other, The aforementioned stretchable substrate is (1) The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms. (2) The arithmetic mean surface roughness of the first or second main surface, as measured by a laser microscope, is 6 μm or more. (3) At least one of the first main surface and the second main surface has a metal-containing portion containing metal atoms, (4) A metal-containing region containing metal atoms is located along at least one of the first principal surface and the second principal surface, It has one of the following. Each of (1) to (4) will be described below as a specific embodiment.

[0036] <First Embodiment> [composition] The structure of the stretchable device 100 according to the first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a partial top view of the stretchable device 100. Figure 2 is a cross-sectional view of the stretchable device 100 taken along line II-II in Figure 1.

[0037] As shown in Figures 1 and 2, the stretchable device 100 includes a stretchable substrate 1 and wiring 2 provided on the first main surface 1a of the stretchable substrate 1.

[0038] The shape of the stretchable device 100 is not particularly limited. In this specification, a structure in which one stretchable substrate is connected to the stretchable device 100 is described as an example, but two or more stretchable substrates may be connected to the stretchable device 100. Also, the wiring 2 is not limited to the arrangement shown in Figure 1, nor is its stretching direction limited. Specifically, the longitudinal direction of the stretchable substrate 1 and the stretching direction of the wiring 2 do not have to coincide, and they do not have to stretch in one direction. Furthermore, the number of wirings 2 is not particularly limited; there may be one or more.

[0039] Furthermore, the term "above" in this specification does not necessarily correspond to the up and down directions when the stretchable device 100 is in use. More specifically, "on the main surface of the stretchable substrate 1" does not refer to an absolute, unidirectional direction such as vertically upward as defined by the direction of gravity, but rather to a direction toward the outside, with respect to the main surface of the stretchable substrate 1 as the boundary between the outside and inside of the main surface. Also, "above" an element includes not only a position above the element at a distance, i.e., a position above the element via another object or at a distance above the element, but also a position directly above (on) the element in contact with it.

[0040] The stretchable substrate 1 has a first main surface 1a and a second main surface 1b located on opposite sides of each other. The stretchable substrate 1 has a stretchable substrate end 11 connecting the first main surface 1a and the second main surface 1b. The stretchable substrate 1 is stretchable. Because the stretchable substrate 1 is stretchable, it does not suppress the expansion and contraction of the wiring 2, and the risk of breakage during expansion and contraction when using the stretchable device 100 can be reduced.

[0041] In the stretchable substrate 1, the oxygen atom ratio of the first main surface 1a, as measured by X-ray photoelectron spectroscopy (XPS), is 5 atomic percent or more. Preferably, the oxygen atom ratio is 25 atomic percent or less. By having the above configuration, the surface of the stretchable substrate is modified. As a result, the tackiness and self-adhesion of the stretchable substrate 1 can be suppressed. Normally, it is thought that the tackiness and self-adhesion of the stretchable substrate 1 are improved by including oxygen atoms. However, in this embodiment, it has been found that the tackiness and self-adhesion can be suppressed by including oxygen atoms. For example, the stretchable substrate 1 can be used on living organisms. As a result, the stretchable substrate 1 becomes easier to handle, and living organisms (e.g., the user) can use the stretchable substrate 1 comfortably. In this embodiment, oxygen atoms are introduced on the first main surface 1a, but they may also be introduced on the second main surface 1b, or on both the first main surface 1a and the second main surface 1b. Furthermore, the above oxygen atom ratio is the ratio to the total number of atoms.

[0042] X-ray photoelectron spectroscopy can be used to determine the ratio of constituent elements on the first main surface 1a because of its high detection sensitivity on the first main surface 1a. The ratio of oxygen atoms can be determined by measuring with X-ray photoelectron spectroscopy in areas on the first main surface 1a where wiring 2 is absent. These areas may be located at the edges of the stretchable substrate 1 or between the stretchable substrate 1 and the wiring. From the viewpoint of suppressing self-adhesion, it is preferable to location these areas at the edges of the stretchable substrate 1. The second main surface 1b may have the same oxygen atom ratio as the first main surface 1a. The ratio of oxygen concentrations on the second main surface 1b can be measured in the same way as the ratio of oxygen atoms on the first main surface 1a.

[0043] Preferably, the oxygen atom ratio in the central portion of the first main surface 1a and the second main surface 1b in a direction perpendicular to the first main surface 1a and the second main surface 1b is 5 atomic percent or less, more preferably 1 atomic percent or less. For example, by performing ozone treatment, the portion on the first main surface 1a side or the second main surface 1b side is oxidized more than the central portion, and there are more oxygen atoms on the first main surface 1a side or the second main surface 1b side than the central portion. Having such a configuration makes it possible to suppress the tackiness and self-adhesion of the stretchable substrate 1. The central portion of the first main surface 1a and the second main surface 1b refers to the intersection of the center of the height direction of the first main surface 1a and the second main surface 1b and the center of the width direction of the stretchable substrate, when viewed from a direction perpendicular to the first main surface 1a and the second main surface 1b. The central portion may be approximately in the center, and for example, it may be measured in a range ±20% away from the center of the first main surface 1a and the second main surface 1b.

[0044] The oxygen atom ratio of the first main surface 1a is 5 atomic percent or more relative to the total atoms, and may be 4 atomic percent or more higher than the oxygen atom ratio in the central portions of the first main surface 1a and the second main surface 1b in directions perpendicular to the first main surface 1a and the second main surface 1b. For example, the oxygen atom ratio in the central portions of the first main surface 1a and the second main surface 1b in directions perpendicular to the first main surface 1a and the second main surface 1b is 1 atomic percent relative to the total atoms, and the oxygen atom ratio of at least one of the first main surface 1a and the second main surface 1b is 5 atomic percent or more.

[0045] Oxygen atoms can be introduced to the first main surface 1a of the stretchable substrate 1, for example, by ozone treatment. Ozone treatment can be performed, for example, using a low-pressure mercury lamp. Ozone treatment can be performed, for example, by exposing the substrate to ultraviolet (UV) irradiation for about 1 to 3 minutes with the ozone concentration set to approximately 10 to 120 ppm. The introduction of oxygen atoms can be performed similarly when introducing them to the second main surface 1b.

[0046] Preferably, the stretchable substrate 1 does not require the addition of inorganic materials. This configuration suppresses permanent deformation and prevents self-adhesion on the surface. The stretchable substrate 1 can be used as a sensor device.

[0047] Examples of the stretchable substrate 1 include sheet-like, film-like, or block-like substrates made of a stretchable resin material. The resin material is preferably rubber or elastomer. By using the above substrate, the surface of the stretchable substrate 1 is modified, and as a result, the tackiness and self-adhesion of the stretchable substrate 1 can be suppressed.

[0048] The resin material is not particularly limited as long as it is rubber or elastomer, but examples include acrylic resins, styrene resins, urethane resins, etc. Preferably, it includes at least one resin selected from the group consisting of acrylic resins, styrene resins, and urethane resins. Examples of acrylic resins include acrylic thermoplastic elastomers. Examples of styrene-based resins include styrene-based elastomers. Examples of urethane-based resins include thermoplastic polyurethane.

[0049] The thickness of the stretchable substrate 1 is not particularly limited, but from the viewpoint of not hindering the stretching and contracting of the biological surface when attached to a living body, it is preferably 1 mm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. Furthermore, the thickness of the stretchable substrate 1 is more preferably 1 μm or more.

[0050] The wiring 2 is provided on the first main surface 1a of the stretchable substrate 1. The wiring 2 is preferably stretchable. Examples of materials for the wiring 2 include a mixture of metal powder such as Ag, Cu, or Ni as conductive particles and an elastomer resin such as a silicone resin. The average particle size of the conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. The shape of the conductive particles is preferably spherical, but is not limited to spherical; they may also be flattened or have protrusions to improve stretchability. The elastomer resin includes at least one resin (elastomer resin) selected from the group consisting of epoxy resins, urethane resins, acrylic resins, and silicone resins, which is preferable for ensuring stretchability. Note that only one wiring 2 may be provided on the first main surface 1a of the stretchable substrate 1, or two to three or five or more may be provided.

[0051] The thickness of wiring 2 is preferably 100 μm or less, and more preferably 50 μm or less. Wiring 2 The thickness of the wire is more preferably 1 μm or more, and may be 5 μm or more. Furthermore, the thickness, width, and length of the wiring 2 are not particularly limited. Note that the wiring 2 does not need to be elastic.

[0052] (Manufacturing method) The manufacturing method of the stretchable device 100 will be described with reference to Figures 3A, 3B, and 3C.

[0053] First, as shown in Figure 3A, a substrate 80 having a first surface 80a and a second surface 80b facing each other is prepared (preparation step). As shown in Figure 3B, the material for the wiring 2 is applied to the first surface 80a of the substrate 80. If the material for the wiring 2 is a conductive paste containing, for example, a mixture of Ag and resin, the conductive paste is applied to the substrate. The application method may be screen printing, gravure printing, or inkjet printing. Then, the wiring 2 is formed on the substrate 80 by heat curing the conductive paste to obtain a predetermined resistance value (placement step). As shown in Figure 3C, a sheet material 3 is prepared. The sheet material 3 is used to cover the parts that should not be treated with ozone. The sheet material 3 has a first main surface 3a and a second main surface 3b located on the opposite side of the first main surface 3a. As shown in Figure 3C, the second main surface 3b of the sheet material 3 is provided on the upper surface of the wiring 2 opposite to the substrate 80. Ozone L is irradiated onto the first main surface 3a of the sheet material 3 and the first surface 80a of the base material 80 (ozone treatment step). That is, the wiring 2 is not irradiated with ozone L. This forms the stretchable device 100. In Figure 3C, the sheet material 3 is separated from the wiring 2, but it may be provided in contact with the wiring 2. In the first embodiment, the wiring 2 is provided on the base material 80, but the target of the first embodiment may be the base material 80 alone without the wiring 2. In the first embodiment, one base material 80 is used as the base material 80, but multiple base materials 80 may be laminated together. By performing the above steps, a stretchable device 100 with suppressed self-adhesion can be formed. In addition, ozone treatment can be performed with the wiring 2 present, and the manufacturing method can be simplified. After the ozone treatment step, an embossing step may be performed in which an embossing sheet material is pressed against the first surface 80a of the base material 80.

[0054] (First variation) In the stretchable substrate 1, in addition to the ratio of oxygen atoms on the first main surface 1a being 5 atomic percent or more, the arithmetic mean surface roughness Ra of the first main surface 1a, as measured by an atomic force microscope (AFM), is 8 nm or more, and may be, for example, 10 nm or more. By having the above configuration, the surface can be roughened, and the tackiness and self-adhesion of the stretchable substrate 1 can be further suppressed. For example, self-adhesion can be reduced not only at room temperature but also under more severe conditions (e.g., 70°C). Specifically, the evaluation of self-adhesion is performed in accordance with JIS K 6404-3:1999, by stacking the stretchable substrates 1 in a 70°C environment and placing a weight on the stacked stretchable substrates for measurement. Similarly to the measurement in a 70°C environment, the stretchable substrates 1 are also stacked and a weight is placed on the stacked stretchable substrates for measurement in a room temperature environment. In this embodiment, the arithmetic mean surface roughness Ra of the first main surface 1a is measured, but the second main surface 1b may also have a similar arithmetic mean surface roughness Ra. The arithmetic mean surface roughness Ra may be, for example, 100 nm or less. The measurement using an atomic force microscope may be performed at the end of the stretchable substrate 1, or on the stretchable substrate 1 located between the wirings 2. From the viewpoint of suppressing self-adhesion, it is preferable to perform the above measurement at the end of the stretchable substrate 1. The second main surface 1b of the stretchable substrate 1 may have the same arithmetic mean surface roughness Ra as the first main surface 1a.

[0055] A first modification can be obtained, for example, by heat-treating the stretchable substrate 1 obtained in the first embodiment. The heat treatment is not particularly limited, but can be performed at, for example, 150°C or higher, specifically 160°C or higher. The heat treatment can be performed at, for example, 180°C or lower. The heat treatment time is not particularly limited, but can be performed at, for example, 10 minutes or more and 180 minutes or less, specifically 20 minutes or more, and more specifically 30 minutes or more.

[0056] (Second variation) In the stretchable substrate 1, in addition to having a surface oxygen atom ratio of 5 atomic percent or more, it further has a first part and a second part with different phases as measured by an atomic force microscope, where the phase of the first part is 10° or more ahead of the phase of the second part, and the surface occupancy rate of the first part may be 80% or more. That is, the first part of the stretchable substrate 1 is harder than the second part, and the surface occupancy rate of the harder first part may be 80% or more of the stretchable substrate 1. The surface occupancy rate may be, for example, 100% or less of the stretchable substrate 1. By having the above configuration, the surface of the stretchable substrate 1 becomes harder, and the tackiness and self-adhesion of the stretchable substrate 1 can be further suppressed. For example, the self-adhesion of the stretchable substrate 1 can be reduced not only at room temperature but also under more severe conditions (e.g., 70°C). Note that "surface occupancy rate" means the ratio of the area occupied by the first part to the measured area. In this embodiment, the measured surface occupancy rate of the first main surface 1a is used, but the above value may be the surface occupancy rate of the second main surface 1b, or the surface occupancy rate of both the first main surface 1a and the second main surface 1b.

[0057] The surface occupancy is measured using an atomic force microscope. Specifically, in the region on the first main surface 1a where no wiring 2 exists, a phase image that allows for the measurement of viscoelasticity is obtained using an atomic force microscope, and the surface occupancy of the hard portion where the phase is advanced by 10° or more is determined from this phase image.

[0058] The above-mentioned region may be provided at the end of the stretchable substrate 1, or on the stretchable substrate 1 between the wiring 2. From the viewpoint of suppressing self-adhesion, it is preferable to provide the above-mentioned region at the end of the stretchable substrate 1.

[0059] The second modified stretchable substrate 1 can be obtained by heat-treating a substrate 80 having an oxygen atom ratio of 5 atomic percent or more. The heat treatment is not particularly limited, but can be carried out at, for example, 70°C or higher, specifically 80°C or higher. The heat treatment can be carried out at, for example, 110°C or lower, specifically 100°C or lower. The heat treatment time is not particularly limited, but can be carried out at, for example, 20 minutes or more and 120 minutes or less, specifically 30 minutes or more and 90 minutes or less.

[0060] Furthermore, in the stretchable substrate 1, the ratio of oxygen atoms on the surface measured by X-ray photoelectron spectroscopy is 5 atomic percent or more, the arithmetic mean surface roughness Ra of the surface measured by atomic force microscopy is 8 nm or more, and the surface occupancy rate of hard portions with a phase advance of 10° or more measured by atomic force microscopy may be 80% or more.

[0061] <Second Embodiment> The configuration of the stretchable device 100A according to the second embodiment will be described with reference to Figure 4. Unlike the first embodiment, the stretchable substrate 1A of this embodiment has an arithmetic mean surface roughness of a specific surface. That is, in the second embodiment, the ratio of oxygen atoms on the surface of the stretchable substrate 1A does not need to be 5 atomic percent or more. The other configurations are the same as those of the first embodiment and will not be described. Unless otherwise stated below, the configurations and materials of the stretchable substrate 1A, the first main surface 1a, the second main surface 1b, and the base material 80 may be the same as those of the stretchable substrate 1, the first main surface 1a, the second main surface 1b, and the base material 80 of the first embodiment. Note that the ratio of oxygen atoms on the surface of the stretchable substrate 1A may be 5 atomic percent or more.

[0062] As shown in Figure 4, in the stretchable substrate 1A, the arithmetic mean surface roughness Ra' of the surface measured by a laser microscope, i.e., the first main surface 1a, is 6 μm or more. By having the above configuration, the surface of the stretchable substrate 1A is modified. As a result, tackiness and self-adhesion of the stretchable substrate 1A can be suppressed. The arithmetic mean surface roughness Ra' of the first main surface 1a of the stretchable substrate 1A may be, for example, 10 μm or less. The arithmetic mean surface roughness Ra' can be measured in a region on the first main surface 1a where wiring 2 does not exist. The above region may be provided at the edge of the stretchable substrate 1A, or it may be provided on the stretchable substrate 1A between wiring 2. From the viewpoint of suppressing self-adhesion, it is preferable to provide the above region at the edge of the stretchable substrate 1A. The arithmetic mean surface roughness Ra' can be measured, for example, using a non-contact film thickness measuring device. Note that the arithmetic mean surface roughness Ra' can also be measured with a contact film thickness measuring device. In this embodiment, the arithmetic mean surface roughness Ra' of the first main surface 1a of the stretchable substrate 1A is stated to be 6 μm or more, but it may be, for example, 3 μm or more. Also, in this embodiment, the arithmetic mean surface roughness Ra' of the first main surface 1a is stated, but the arithmetic mean surface roughness Ra' of the second main surface 1b may also be within the above range.

[0063] As shown in Figure 5A, the first main surface 1a of the stretchable substrate 1A preferably has a grid shape. The grid shape consists of multiple rectangular first shapes 4A and rectangular second shapes 4B arranged alternately in the vertical and horizontal directions. The rectangles are, for example, 10 to 100 μm square.

[0064] The first shape 4A has a plurality of protrusions 4a1 and recessed grooves 4a2. The recessed grooves 4a2 extend in the lateral direction. The recessed grooves 4a2 are arranged in parallel in the lateral direction. The protrusions 4a1 are located between adjacent recessed grooves 4a2. By performing the above process, irregularities can be formed on the surface of the stretchable substrate 1A. That is, by performing the above process, the surface roughness can be increased. In addition, the surface of the stretchable substrate 1A can be hardened. As a result, the self-adhesion of the stretchable substrate 1A can be further suppressed.

[0065] The second shape 4B has a plurality of protrusions 4b1 and recessed grooves 4b2. The recessed grooves 4b2 extend in the lateral direction. The recessed grooves 4b2 are arranged in parallel in the lateral direction. The protrusions 4b1 are located between adjacent recessed grooves 4b2. With the above configuration, it is difficult for members to come into contact with the first main surface 1a, and the tackiness and self-adhesion of the stretchable substrate 1A can be suppressed. Note that the above grid shape may be provided only on a part of the first main surface 1a. Furthermore, the above grid shape may be provided not only on the first main surface 1a but also on the second main surface 1b.

[0066] As shown in Figure 5B, the grid pattern is formed on the first main surface 1a by embossing using an embossing sheet material 5. In the embossing sheet material 5, warp threads 5a1 and weft threads 5b1 are woven alternately. The embossing process includes a heat treatment and pressurization process.

[0067] The manufacturing method of the stretchable device 100A will be described with reference to Figures 6A, 6B, and 6C.

[0068] First, as shown in Figure 6A, a base material 80 is prepared (preparation step). As shown in Figure 6B, the material for the wiring 2 is applied to the first surface 80a of the base material 80 (placement step). As shown in Figure 6C, an embossing sheet material 5 having a surface pattern is placed on the upper surface of the wiring 2 opposite to the base material 80. The embossing sheet material 5 does not come into contact with the wiring 2. The embossing sheet material 5 is pressed against the first surface 80a of the base material 80. This transfers the shape of the embossing sheet material 5 to the first surface 80a, forming the first main surface 1a (embossing step). Note that the embossing sheet material 5 may only cover a portion of the area on the first surface 80a other than the wiring 2. By performing the above steps, self-adhesion on the surface of the stretchable device 100A can be suppressed. Furthermore, embossing can be performed with the wiring 2 present, simplifying the manufacturing method.

[0069] In this embodiment, the embossing sheet material 5 is provided so as not to overlap with the wiring 2. However, in another embodiment, a protective layer may be provided to protect the wiring 2, and the embossing sheet material 5 may be pressed against the base material 80 and the protective layer. Alternatively, embossing may be performed on the surface of the base material 80 opposite to the wiring 2.

[0070] (First variation) The first main surface 1a of the stretchable substrate 1A has the shape shown in Figure 7A, instead of the grid shape shown in Figure 5A.

[0071] As shown in Figure 7A, the first main surface 1a has a plurality of first recesses 4c1 and a plurality of second recesses 4c2 perpendicular to the first recesses 4c1. The angle θ between the extending direction of the first recesses 4c1 and the orthogonal line D perpendicular to the longitudinal direction of the stretchable substrate 1A is approximately 45°. The angle between the extending direction of the second recesses 4c2 and the orthogonal line D perpendicular to the longitudinal direction of the stretchable substrate 1A is approximately -45°. One first recess 4c1 and the other first recess 4c1 adjacent to it, one second recess 4c2 and the other second recess 4c2 adjacent to it form a rectangle 4c3. The above shape may be provided only on a part of the first main surface 1a. The shape of the first modified example may be provided not only on the first main surface 1a but also on the second main surface 1b. The angle at which the first recess 4c1 and the second recess 4c2 intersect does not have to be 90°, but may be approximately 90°. Furthermore, the angle θ is not limited to the above value, and may be, for example, 0°, 15°, or 30°. In other words, the angle θ may take any value between 0° and 90°.

[0072] The distance between adjacent first recesses 4c1 is, for example, 1 to 10 μm. The distance between adjacent second recesses 4c2 is, for example, 1 to 10 μm.

[0073] As shown in Figure 7B, the shape of the first modified example is formed on the first main surface 1a by embossing using an embossing sheet material 5C. The embossing sheet material 5C has a first convex portion 5c1, a second convex portion 5c2, and a recess surrounded by the first convex portion 5c1 and the second convex portion 5c2.

[0074] The embossing process can be performed using a sheet material that forms recesses and protrusions on the first main surface 1a of the stretchable substrate 1A. The recesses and protrusions may be arranged in a pattern or randomly. The protrusions may be of different sizes and shapes, and the recesses may be of different sizes and shapes. For example, the embossing sheet material 5 may be a sheet material that has a rhombus-shaped protrusion 4d1 and other partial recesses 4d2 on the first main surface 1a, as shown in Figure 8A. Alternatively, the embossing sheet material 5 may be a sheet material that has a wave-shaped protrusion 4e1 and other partial recesses 4e2 on the first main surface 1a, as shown in Figure 8B. Alternatively, the sheet material may have a circular shape 4f1 and other parts 4f2 on the first main surface 1a, as shown in Figure 8C. Alternatively, the sheet material may have a mesh-like protrusion 4g1 and other partial recesses 4g2 on the first main surface 1a, as shown in Figure 8D.

[0075] <Third Embodiment> The structure of the stretchable device 100B according to the third embodiment will be described with reference to Figure 9. Figure 9 is a cross-sectional view of the stretchable device 100B and corresponds to Figure 2. The third embodiment differs from the first embodiment in the processing method applied to the stretchable substrate. This difference in configuration will be described below. Other configurations are the same as those of the first embodiment and will not be described. Unless otherwise specified below, the configuration and materials of the stretchable substrate 1B, first main surface 1a, second main surface 1b, and base material 80 may be the same as those of the stretchable substrate 1, first main surface 1a, second main surface 1b, and base material 80 of the first embodiment.

[0076] As shown in Figure 9, the stretchable device 100B has a stretchable substrate 1B having a first main surface 1a and a second main surface 1b facing each other, and wiring 2 provided on the first main surface 1a. In the third embodiment, the first surface 80a of the base material 80 is the same as the first main surface 1a of the stretchable substrate 1B. The surface of the metal-containing portion 81 opposite to the second surface 80b is the second main surface 1b of the stretchable substrate 1B. By having the metal-containing portion 81, molecular diffusion that causes self-adhesion in the base material 80 is suppressed, and self-adhesion of the stretchable substrates 1B to each other can be suppressed. Here, the metal-containing portion 81 means a portion containing a metal-containing compound. Examples of metal-containing compounds include metals and metal oxides.

[0077] The metal-containing portion 81 may contain multiple metal atoms or one type of metal atom. In the third embodiment, the metal-containing portion 81 is located on the second main surface 1b side, but the metal-containing portion 81 may be located on the first main surface 1a side, or the metal-containing portion 81 may be located on both the first main surface 1a side and the second main surface 1b side. The stretchable substrate 1B may have a base material 80 having the metal-containing portion 81, wiring 2 located on the opposite side of the base material 80 from the metal-containing portion 81, and another base material 80 located on the wiring 2. The stretchable substrate 1B may also have the metal-containing portion 81 on the side of the other base material 80 opposite to the wiring 2. The base material 80 may consist of only one layer or multiple layers may be laminated. The stretchable substrate 1B may consist of only one layer or multiple layers may be laminated.

[0078] Preferably, in the second main surface 1b, the metal content ratio in the metal-containing portion 81, as measured by X-ray photoelectron spectroscopy, is 0.5 atomic percent or more. The upper limit of the metal content ratio in the metal-containing portion 81 is not particularly limited, but may be, for example, 3 atomic percent or less. By having the above configuration, the metal atoms can be uniformly dispersed. This suppresses hardening of the stretchable substrate 1B. In addition, the uniform dispersion of metal atoms allows for the dispersion of coloration originating from the metal atoms. If the proportion of metal elements becomes too high, the safety of the stretchable substrate 1B decreases. If the proportion of metal elements becomes too low, molecular diffusion in the substrate 80 cannot be suppressed, and, for example, self-adhesion occurs between the stretchable substrates 1B.

[0079] Preferably, the metal-containing portion 81 includes at least one selected from the group consisting of Al, Fe, Ni, Au, Pt, Ag, and Ti. With the above configuration, molecular diffusion that causes self-adhesion in the substrate 80 is suppressed, and self-adhesion between stretchable substrates 1B can be further suppressed.

[0080] Preferably, the metal-containing portion 81 contains Al. This configuration is preferable from the viewpoint of biocompatibility. In particular, Al is considered to exist in a stabilized oxide form, which is preferable from the viewpoint of improving the safety of the stretchable substrate 1B. Furthermore, this configuration is also preferable from the viewpoint of cost. Note that Al may exist as a metal rather than an oxide.

[0081] Preferably, the metal-containing portion 81 contains at least one of a metal and a metal oxide. Having the above configuration, the metal-containing portion 81 can stably exist on the substrate 80. The metal-containing portion 81 may contain multiple metal atoms or only a single metal atom.

[0082] Preferably, the stretchable substrate 1B further has a protective layer to protect the wiring 2. The protective layer is provided in the same layer as the wiring 2 or covering the wiring 2. With the above configuration, the wiring 2 can be protected. The protective layer may be a single layer or a plurality of layers laminated together. The protective layer may be the base material 80.

[0083] Preferably, the protective layer covers the wiring 2, and the side of the protective layer opposite to the wiring 2 has a metal-containing portion 81.

[0084] (Manufacturing method) The manufacturing method of the stretchable device 100B will be described with reference to Figures 10A, 10B, and 10C.

[0085] First, as shown in Figure 10A, a substrate 80 is prepared (preparation step). As shown in Figure 10B, the material for the wiring 2 is formed on the first surface 80a of the substrate 80 (placement step). As shown in Figure 10C, a metal-containing portion 81 is formed on the second surface 80b by a sputtering method (formation step). The sputtering method can be performed using, for example, ULVAC's SV-200. In addition to the sputtering method, thin-film formation methods such as vapor deposition and chemical vapor deposition (CVD) may also be used to form the metal-containing portion 81. This forms the stretchable device 100B. Alternatively, in the preparation step, two substrates 80 may be prepared, and in the placement step, the material for the wiring 2 may be formed on the first surface 80a of one substrate 80, and the other substrate 80 may be formed on the wiring 2.

[0086] (First variation) As shown in Figure 11, in the stretchable device 100C, the base material 80 is formed from a base material 82 and a base material 83. Specifically, the stretchable device 100C has a base stretchable base material 82 that covers the metal-containing portion 81, a base material 83 on the side of the base material 82 opposite to the metal-containing portion 81, and wiring 2 on the side of the base material 83 opposite to the base material 82. The surface of the base material 83 on which the wiring 2 is located is the first main surface 1a of the stretchable substrate 1B. Note that the base material 80 may be formed from three or more layers. Note that reference numerals that are not specifically mentioned have the same configuration as in the third embodiment, and their explanation is omitted.

[0087] (Second variation) As shown in Figure 12, in the stretchable device 100D, the base material 80 is formed from base material 82 and base material 83, and the wiring 2 is sandwiched between base material 82 and base material 83. Specifically, the stretchable device 100C has a base material 82, has wiring 2 on base material 82, and has base material 83 so as to cover the wiring 2. The surface of base material 83 opposite to the wiring 2 is the first main surface 1a of the stretchable substrate 1B. The base material 82 has a metal-containing portion 81 on the side opposite to the wiring 2. Note that base material 82 may be formed from two or more layers. Base material 83 may be formed from two or more layers. In the second modified example, the metal-containing portion 81 is located on the surface of base material 82 opposite to the wiring 2, but may also be located on the surface of base material 83 opposite to the wiring 2, or on the surface of base material 82 opposite to the wiring 2 and the surface of base material 83 opposite to the wiring 2. Note that reference numerals that are not specifically mentioned have the same configuration as in the third embodiment, and their explanation is omitted.

[0088] <Fourth Embodiment> The configuration of the stretchable device 100E according to the fourth embodiment will be described with reference to Figure 13. Figure 13 is a cross-sectional view of the stretchable device 100E and corresponds to Figure 9. The fourth embodiment does not have the metal-containing portion 81 of the third embodiment, but has a metal-containing region 81d within the base material 80C. This difference in configuration will be described below. The other configurations are the same as those of the third embodiment, and their description will be omitted. Unless otherwise described below, the configuration and materials of the stretchable substrate 1C, the first main surface 1a, and the second main surface 1b may be the same as those of the stretchable substrate 1, the first main surface 1a, and the second main surface 1b of the first embodiment. The configuration and materials of the base material 80C may be the same as those of the base material 80 of the first embodiment, except for the metal-containing region 81d.

[0089] As shown in Figure 13, the stretchable device 100E has a stretchable substrate 1C having a first main surface 1a and a second main surface 1b facing each other, and wiring 2 provided on the first main surface 1a. In the fourth embodiment, the first surface 80a of the base material 80C is the same as the first main surface 1a of the stretchable substrate 1C. The second surface 80b of the base material 80C is the second main surface 1b of the stretchable substrate 1C. On the second surface 80b of the base material 80C, a metal-containing region 81d is located along the second surface 80b (second main surface 1b). The metal-containing region 81d is located within the stretchable substrate 1C. With the above configuration, molecular diffusion that causes self-adhesion in the base material 80C is suppressed, and self-adhesion of the stretchable substrate 1C can be suppressed. Furthermore, when bonded to a substrate other than the stretchable substrate 1C, the adhesion between the metal-containing region 81d and the other substrate is improved, and the adhesion force between the stretchable substrate 1C and the other substrate is improved. Furthermore, the stretchable substrate 1C, having a metal-containing region 81d, can adhere to other substrates even at low pressing temperatures. Therefore, even at low temperatures, it becomes possible to perform adhesion processing to other substrates, for example, and the load on the substrate 80C and wiring 2 due to heat treatment is reduced. Note that the metal-containing region 81d may be located at a position separated from the second main surface 1b of the stretchable substrate 1C.

[0090] Preferably, the ratio of metal atoms contained in the metal-containing region 81d on the second main surface 1b of the stretchable substrate 1C is 0.2 atomic% or more and 2.5 atomic% or less. Here, the ratio on the second main surface 1b refers to the relative abundance of metal atoms on the second main surface 1b to the total number of atoms. The ratio of metal atoms can be measured using X-ray photoelectron spectroscopy.

[0091] Preferably, the metal-containing regions 81d are scattered on the second surface 80b of the base material 80C. Specifically, between the metal-containing regions 81d, there are materials constituting the base material 80C, such as an elastic resin material. That is, the metal-containing regions 81d do not have a layered structure.

[0092] Preferably, the metal-containing region 81d is a metal or a metal oxide. With the above configuration, the metal-containing region 81d is safe to exist. The metal-containing region 81d may contain multiple metal atoms or only a single metal atom.

[0093] Preferably, the metal-containing region 81d contains a metal oxide.

[0094] Preferably, the metal-containing region 81d includes at least one selected from the group consisting of Al, Fe, Ni, Au, Pt, Ag, and Ti. With the above configuration, molecular diffusion that causes self-adhesion in the substrate 80C is suppressed, and self-adhesion between stretchable substrates 1C can be further suppressed.

[0095] Preferably, the metal-containing region 81d contains Al. This configuration is preferable from the viewpoint of biocompatibility. In particular, Al is thought to exist in a stabilized oxide state, which is preferable from the viewpoint of improving the safety of the stretchable substrate 1C. Furthermore, this configuration is also preferable from the viewpoint of cost. Note that Al may exist as a metal.

[0096] In the fourth embodiment, the metal-containing region 81d is located on the second main surface 1b, but the metal-containing region 81d may also be located on the first main surface 1a, or on both the first main surface 1a and the second main surface 1b. In this case, the ratio on the first main surface 1a refers to the abundance ratio, similar to the ratio on the second main surface 1b. The ratio of metal atoms is the ratio to the total number of atoms.

[0097] (Manufacturing method) The manufacturing method of the stretchable device 100E will be described with reference to Figures 14A, 14B, and 14C.

[0098] As shown in Figure 14A, a substrate 80C is prepared having a first main surface 1a and a second main surface 1b facing each other. As shown in Figure 14B, wiring 2 is provided on the first main surface 1a of the substrate 80C. As shown in Figure 14C, a metal-containing region 81d is provided on the substrate 80C. This forms the expandable device 100E. [Examples]

[0099] This disclosure will be explained in more detail through the following examples, but is not limited to these examples.

[0100] <First Example> (Example 1) Two styrene elastomer films were prepared. These styrene elastomer films were subjected to ozone treatment using the following method. [Ozone treatment] Ozone treatment was performed using a Sun Energy SKB2003N, which generates ozone using a low-pressure mercury lamp.

[0101] The ratio of oxygen atoms on the surface of the substrate after ozone treatment was measured as follows. [Measurement of the ratio of oxygen atoms on the surface of the substrate] The ratio of oxygen atoms on the outermost surface of the substrate was measured using the following apparatus. Equipment: X-ray photoelectron spectroscopy (XPS, Quantes, ULVAC-PHI) Acceleration voltage: 15kV Measurement area: 1000μm x 200μm

[0102] After ozone treatment, the ozone-treated surfaces were placed on top of each other, and the following self-adhesion test was performed. [Self-attachment test] (1) Measured at 70°C The test was conducted in accordance with JIS K 6404-3:1999 (Test Methods for Rubber-Coated Fabrics and Plastic-Coated Fabrics). Specifically, in the blocking test, two glass plates measuring approximately 150 mm in length, 150 mm in width, and 3 mm in thickness were prepared, and two layers of the prepared film were placed between the glass plates. A weight of 5.0 kg was placed on the glass plates, and the test was left undisturbed for 3 hours at 70°C. After that, it was checked whether the two test pieces separated. The test specimens used were the films obtained in the examples or comparative examples. • Adhesion: The test piece cannot be peeled off. • Slightly adhesive: The film can be peeled off by applying force. • Non-adhesive: The film is not adhered. (2) Measured at room temperature Except for measuring at room temperature, the measurement and evaluation were performed in the same manner as the measurement at 70°C described above.

[0103] (Examples 2-6) Similar to Example 1, two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment. The ratio of oxygen atoms on the surface of the substrate after ozone treatment was the same as in Example 1. After ozone treatment, the ozone-treated surfaces were placed on top of each other, and a self-adhesion test was performed in the same manner as in Example 1.

[0104] (Comparative Example 1) Similar to Example 1, two styrene-based elastomer films were prepared. The ratio of oxygen atoms on the surface of the substrate was the same as in Example 1. Two styrene-based elastomer films were layered together, and a self-adhesion test was performed in the same manner as in Example 1.

[0105] (Comparative Example 2) Similar to Example 1, two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment. The ratio of oxygen atoms on the surface of the substrate after ozone treatment was the same as in Example 1. After ozone treatment, the ozone-treated surfaces were placed on top of each other, and a self-adhesion test was performed in the same manner as in Example 1.

[0106] The results are shown in Table 1.

[0107] [Table 1]

[0108] As shown in Table 1, Comparative Example 1 did not undergo ozone treatment, and the oxygen atom ratio was 1.4 atomic%. In other words, before ozone treatment, the styrene-based elastomer film contained almost no oxygen atoms. Comparative Example 1 was tacky at room temperature. Comparative Example 2 had an oxygen atom ratio of 2.3 atomic%, but was slightly tacky at room temperature and tacky under more severe conditions (70°C). Examples 1 to 6 contained even more oxygen atoms, were non-tacky at room temperature, and were slightly tacky even under more severe conditions (70°C). In the above example, it was not possible to add more oxygen atoms than the values ​​listed in Table 1.

[0109] <Second Example> (Example 7) Two urethane-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment using the same method as in Example 1. The ratio of oxygen atoms on the surface of the substrate after ozone treatment was measured in the same manner as in Example 1. After ozone treatment, the ozone-treated surfaces were placed on top of each other, and a self-adhesion test was performed in the same manner as in Example 1.

[0110] (Examples 8-12) Similar to Example 7, two urethane-based elastomer films were prepared. These urethane-based elastomer films were subjected to ozone treatment. The ratio of oxygen atoms on the surface of the substrate after ozone treatment was the same as in Example 1. After ozone treatment, the ozone-treated surfaces were placed on top of each other, and a self-adhesion test was performed in the same manner as in Example 1.

[0111] (Comparative Example 3) Similar to Example 7, two urethane-based elastomer films were prepared. The ratio of oxygen atoms on the surface of the substrate was the same as in Example 1. Two styrene-based elastomer films were layered together, and a self-adhesion test was performed in the same manner as in Example 1.

[0112] (Comparative Example 4) Similar to Example 7, two urethane-based elastomer films were prepared. These urethane-based elastomer films were subjected to ozone treatment. The ratio of oxygen atoms on the surface of the substrate after ozone treatment was the same as in Example 1. After ozone treatment, the ozone-treated surfaces were placed on top of each other, and a self-adhesion test was performed in the same manner as in Example 1.

[0113] The results are shown in Table 2.

[0114] [Table 2]

[0115] As shown in Table 2, when the ratio of oxygen atoms was low (Comparative Examples 3 and 4), adhesion occurred at room temperature and 70°C. It was found that by increasing the ratio of oxygen atoms (Examples 7 to 12), a non-adhesive surface could be formed at room temperature and 70°C.

[0116] <Third Example> (Example 13) Two styrene-based elastomer films, identical to those in Example 4, were prepared. These styrene-based elastomer films were subjected to ozone treatment. The arithmetic mean surface roughness Ra was measured on the main surface that underwent ozone treatment. <Measurement of Arithmetic Mean Surface Roughness Ra> Atomic force microscope: Atomic force microscope (AFM, manufactured by Bruker) Measurement area: 2μm x 2μm Measurement interval: 256 μm × 256 μm

[0117] The ozone-treated surfaces were placed on top of each other and heat-treated at 160°C for 10 minutes.

[0118] (Examples 14-17) Similar to Example 4, two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment. The arithmetic mean surface roughness Ra of the ozone-treated main surface was measured in the same manner as in Example 13. The ozone-treated surfaces were placed on top of each other and heat-treated as shown in Table 3.

[0119] The results are shown in Table 3. For comparison, Table 3 also includes Example 4, in which no heat treatment was performed.

[0120] [Table 3]

[0121] As shown in Table 3, in Example 4 (no heat treatment), the surface was non-sticky at room temperature but slightly sticky under more severe conditions (70°C). In Examples 14-17, the surface was non-sticky not only at room temperature but also at 70°C. In Examples 14-17, the arithmetic mean surface roughness Ra was large, and it is thought that having such a surface allows for the formation of a non-sticky surface at both room temperature and 70°C.

[0122] This will be explained in detail using Figure 15. Figure 15 is an explanatory diagram illustrating the surface roughness of a stretchable substrate. Figure 15 is based on a photograph of the surface roughness of the substrate of Example 15, obtained by atomic force microscopy. In Figure 15, the surface hardness increases in the order of white areas 61, coarse dot areas 62, and fine dot areas 63. It was found that by heat treatment at 160°C, the dot areas 62 and 63 increase, and the surface of the substrate can be roughened. In addition, in Examples 13 to 17 above, the proportion of oxygen atoms is considered to be 5 atomic percent or more.

[0123] <Fourth Example> (Example 18) Similar to Example 4, two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment. After ozone treatment, the films were divided into two parts, a first part and a second part, which had different phases as measured by electron force microscopy. The surface occupancy of the first part, the hard part without phase lag, was measured. <Measurement of surface occupancy> Equipment: Atomic force microscope (AFM, manufactured by Bruker) Measurement area: 2,000μm×2,000μm

[0124] Subsequently, the ozone-treated surfaces were placed together and heat-treated. After the heat treatment, a self-adhesion test was performed in the same manner as in Example 1.

[0125] (Examples 19-22) Similar to Example 18, two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to ozone treatment. After ozone treatment, the films were divided into a first and second portion with different phases as measured by an electron force microscope, and the surface occupancy of the first portion, which is a hard portion without phase lag, was measured in the same manner as in Example 18.

[0126] The results are shown in Table 4. For comparison, Table 4 also includes Example 4, in which no heat treatment was performed.

[0127] [Table 4]

[0128] As shown in Table 4, in Example 4, where only ozone treatment was performed, the material was non-sticky at room temperature but slightly sticky at 70°C. In contrast, in Examples 18-22, where heat treatment was performed after ozone treatment, the material was non-sticky at both room temperature and 70°C. In Examples 18-22, it is thought that the heat treatment increased the surface coverage, resulting in non-stickiness not only at room temperature but also at 70°C. Let's explain this in detail using Figure 16. In Figure 16, there is a first particulate portion 71 and a second part 72. As shown in Figure 16, it was found that the proportion of the first part 71 increased after heat treatment.

[0129] <Example 5> (Reference example 23) Similar to Comparative Example 3, two urethane-based elastomer films were prepared. These urethane-based elastomer films were stacked on top of each other, and an embossing film was pressed against them to perform embossing. <Embossing film> The embossing film had a grid pattern and consisted of a first rectangular shape 4A with vertical grooves and a second rectangular shape 4B with horizontal grooves. Each rectangle was 25 μm square. The first shape 5A and the second shape 4B each had 3 to 10 grooves.

[0130] After embossing, the arithmetic mean surface roughness Ra' of the surface was measured using a laser microscope. <Measurement of Arithmetic Mean Surface Roughness Ra'> Laser microscope: VK-9500 (manufactured by Keyence Corporation) Measurement method: Laser non-contact Measurement area: 1,012μm×1,350μm

[0131] (Examples 24 and 25) Similar to Reference Example 23, two urethane elastomer films were prepared. These urethane elastomer films were stacked and pressed under pressure using the same embossing film as in Reference Example 23, under the following conditions. However, the depth of the pressure press was greater than in Reference Example 23. <Pressure Press> It was heated to 70°C and then heat-pressed for 1 minute. The arithmetic mean surface roughness Ra' of the surface after embossing was measured in the same manner as in Reference Example 23.

[0132] The results are shown in Table 5.

[0133] [Table 5]

[0134] As shown in Table 5, in Comparative Example 3, no embossing was performed, and the material was adhesive at room temperature. In Reference Example 23, the material was non-adhesive at room temperature. In Examples 24 and 25, the material was non-adhesive at both room temperature and 70°C. This is thought to be because the arithmetic mean surface roughness Ra' increased after embossing (Reference Example 23, Examples 24 and 25) compared to before embossing (Comparative Example 3), resulting in a smaller area at the top of the convex parts and a reduced contact area.

[0135] <Sixth Example> (Examples 26-29) Two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to sputtering using Al metal with an ULVAC SV-200. X-ray photoelectron spectroscopy (XPS) revealed that aluminum oxide had formed.

[0136] The measurement of the Al element composition ratio of the substrate after sputtering and the measurement of the self-adhesion test were performed in the same manner as in Example 1.

[0137] The results are shown in Table 6. For comparison, Table 6 also includes Comparative Example 1, which did not undergo sputtering.

[0138] [Table 6]

[0139] As shown in Table 6, in Comparative Example 1, no sputtering treatment was performed, and self-adhesion occurred at both room temperature and 70°C. In Examples 26-29, non-adhesion was achieved by performing sputtering treatment. In particular, in Examples 28 and 29, where the Al ratio was 0.5 atomic% or higher, non-adhesion was maintained even under more severe conditions (70°C).

[0140] Furthermore, a cytotoxicity test, as specified in ISO 10993-5, was performed on the Al-containing stretchable substrate obtained in Example 26, but no toxicity was observed. This is likely because the amount of Al formed on the surface by this method is extremely small, and because the small amount present is stabilized by the oxide. Based on these results, we believe that the stretchable substrate obtained by this method is safe.

[0141] <Example 7> (Examples 30-33) Two urethane-based elastomer films were prepared. These urethane-based elastomer films were subjected to sputtering treatment using Al metal in the same manner as in Example 26. After sputtering, the sputtered surfaces were placed together, and a self-adhesion test was performed in the same manner as in Example 26.

[0142] The results are shown in Table 7. For comparison, Table 6 also shows Comparative Example 3, which did not undergo sputtering.

[0143] [Table 7]

[0144] As shown in Table 7, in Comparative Example 3, no sputtering treatment was performed, and self-adhesion occurred at both room temperature and 70°C. In Examples 30 to 33, non-adhesion was achieved by performing sputtering treatment. In particular, in Examples 32 and 33, where the Al ratio was 0.5 atomic% or higher, non-adhesion was maintained even under more severe conditions (70°C).

[0145] <Eighth Example> (Examples 34-39) Two urethane-based elastomer films were prepared. These urethane-based elastomer films were subjected to sputtering treatment using the metals shown in Table 8, in the same manner as in Example 26. After sputtering, the sputtered surfaces were placed together, and a self-adhesion test was performed in the same manner as in Example 26.

[0146] The results are shown in Table 8.

[0147] [Table 8]

[0148] As shown in Table 8, it was found that self-adhesion suppression effects could be obtained when using Fe, Ni, Au, Pt, Ag, and Ti. It was confirmed that self-adhesion could be suppressed by forming a film of metal or metal oxide on the substrate. It is thought that similar effects can be obtained not only when using Al and the metals shown in Table 8, but also when using other metals, as the presence of a small amount of metal on the substrate can create a film that suppresses molecular diffusion.

[0149] <Example 9> (Example 40) Two styrene-based elastomer films were prepared. These styrene-based elastomer films were subjected to plasma treatment. [Plasma treatment] Plasma treatment was performed using the PC-1000 (Samco Corporation).

[0150] X-ray photoelectron spectroscopy (XPS) measurements revealed that aluminum oxide was formed on the film after plasma treatment. The proportion of aluminum atoms on the plasma-treated surface was 0.8 atomic percent of the total elements.

[0151] After plasma treatment, the plasma-treated surfaces were placed together and an adhesion test was conducted. The adhesion test confirmed that there was no adhesion between the elastomers.

[0152] Furthermore, after plasma treatment, the material was press-bonded to a nylon substrate via a polyester-urethane adhesive at 100-120°C for 1 minute. The pressure was set to 0.6 MPa. Subsequently, a 180° peel test was performed as shown in Figure 17. The results are shown in Figures 18 and 19. Figure 18 shows the peel force of 2.19 N·10 mm using the substrate of Example 40. -1 The results showed that the peel force using the substrate of Comparative Example 5 was 0.28 N·10 mm -1 The results are shown below. [180° Peel Test (Peel Strength)] A 180° peel test was conducted based on JIS Z 0237, 180° peel test for adhesive tapes, and JIS Z 0238, test methods for heat-sealable flexible packaging bags and semi-rigid containers. Specifically, a plasma-treated substrate 80C and a nylon-based substrate 92 were bonded together via an adhesive layer 91 made of adhesive. A tensile force F was applied to the substrate 80C and the nylon-based substrate 92 in a direction away from each other, i.e., 180° apart, to peel them apart. A force gauge was used to measure the peel strength. Note that aluminum oxide, which is a metal-containing region 81d, was present on the side of the substrate 80C facing the adhesive layer 91.

[0153] (Examples 41, 42) After plasma treatment, the process was carried out in the same manner as in Example 40, except that the press temperature was changed, and a peel test was performed.

[0154] (Comparative Example 5) Similar to Example 40, two styrene-based elastomer films were prepared. The styrene-based elastomer films were overlapped and an adhesion test was performed. In addition, a 180° peel test was performed as shown in Figure 17. Note that, unlike Figure 17, no plasma treatment was performed in Comparative Example 5, and no aluminum oxide was formed. Of the two peel force measurement results shown in Figure 18, the peel force in Comparative Example 5 was the lower value of 0.28 N·10 mm -1 That was the case.

[0155] (Comparative Examples 6, 7) After plasma treatment, the process was carried out in the same manner as in Comparative Example 5, except that the press temperature was changed, and a peel test was performed.

[0156] The results are shown in Table 9.

[0157] [Table 9]

[0158] As shown in Table 9 and Figure 18, Example 40, which underwent plasma treatment, showed a greater peeling force in the 180° peel test than Comparative Example 5, which did not undergo plasma treatment. In other words, plasma treatment increased the adhesion strength.

[0159] Figure 19 shows the results of Examples 40-42 as black squares and the results of Comparative Examples 5-7 as black circles. As shown in Table 9 and Figure 19, in Examples 40-42, the peel strength did not fluctuate much even when the press temperature changed, and good peel strength was maintained regardless of the difference in press temperature. In contrast, in Comparative Examples 5-7, the peel force was lower than in Examples 40-42, and furthermore, the peel strength was affected by the fluctuation in press temperature. Specifically, in Comparative Examples 5-7, peeling became easier as the press temperature decreased. As described above, it was found that high peel strength can be obtained even at low press temperatures in Examples 40-41. By being able to adhere at low temperatures, the load caused by heat treatment on the stretchable substrate and wiring is reduced.

[0160] In Examples 1-22, 24-42, and Reference Example 23, physical properties were measured using only the substrate; however, the same procedure can be followed even when wiring is attached.

[0161] This disclosure is not limited to the embodiments described above, and design modifications are possible without departing from the gist of this disclosure. For example, the features of each of the first to fourth embodiments may be combined in various ways.

[0162] This application claims priority under Japanese Patent Application No. 2023-116845, filed in Japan on 18 July 2023, the entirety of which is incorporated herein by reference.

[0163] This disclosure includes the following aspects: <1> A stretchable substrate having a first main surface and a second main surface facing each other, The aforementioned stretchable substrate is (1) The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms. (2) The arithmetic mean surface roughness of the first or second main surface, as measured by a laser microscope, is 6 μm or more. (3) At least one of the first main surface and the second main surface has a metal-containing portion containing metal atoms, (4) A metal-containing region containing metal atoms is located along at least one of the first principal surface and the second principal surface, A stretchable substrate having one of the following characteristics. <2> The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by the aforementioned X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms. <1> The stretchable substrate described above. <3> The oxygen atom ratio in the central portion of the first and second principal surfaces in directions perpendicular to the first and second principal surfaces is 5 atomic percent or less. <2> The stretchable substrate described above. <4> The arithmetic mean surface roughness of the first principal surface or the second principal surface, as measured by the atomic force microscope, is 10 nm or more. <2> or <3> The stretchable substrate described above. <5> The first main surface or the second main surface has a first portion and a second portion having different phases as measured by an atomic force microscope, The phase of the first part is advanced by 10° or more compared to the phase of the second part. The surface occupancy rate of the first portion is 80% or more. <2> from <4> A stretchable substrate as described in any one of the following. <6> In the first main surface or the second main surface, the arithmetic mean surface roughness of the surface measured by the laser microscope is 6 μm or more. <1> The stretchable substrate described above. <7> At least one of the first main surface and the second main surface has the metal-containing portion containing the metal atoms, <1> The stretchable substrate described above. <8> In the first or second main surface, the metal content ratio of the metal in the metal-containing portion, as measured by X-ray photoelectron spectroscopy, is 0.5 atomic percent or more. <7> The stretchable substrate described above. <9> The oxygen atom ratio in the central portion of the first and second principal surfaces in directions perpendicular to the first and second principal surfaces is 5 atomic percent or less. <7> or <8> The stretchable substrate described above. <10> The metal-containing region containing the metal atoms is located along at least one of the first main surface and the second main surface, <1> The stretchable substrate described above. <11> The ratio of metal atoms in the first main surface or the second main surface is 0.2 atomic% or more and 2.5 atomic% or less. <10> The stretchable substrate described above. <12> The aforementioned metal atom includes at least one selected from the group consisting of Al, Fe, Ni, Au, Pt, Ag, and Ti. <7> from <11> A stretchable substrate as described in any one of the following. <13> The metal-containing portion comprises at least one of a metal and a metal oxide. <7> from <9> or <12> A stretchable substrate as described in any one of the following. <14> The metal-containing region includes at least one of a metal and a metal oxide. <10> from <12> A stretchable substrate as described in any one of the following. <15> It is rubber or elastomer. <1> from <14> A stretchable substrate as described in any one of the following. <16> <1> from <15> A stretchable device comprising a stretchable substrate as described in any one of the above, and wiring arranged on the first main surface of the stretchable substrate. <17> <2> from <5> , <10> from <12> , <14> or <15> A stretchable device comprising a stretchable substrate as described in any one of the above, and wiring arranged on the first main surface of the stretchable substrate. <18> <6> from <9> , <12> , <13> or <15> A stretchable device comprising a stretchable substrate as described in any one of the above, and wiring arranged on the first main surface of the stretchable substrate. <19> Furthermore, it has a protective layer, <18> The stretchable device described. <20> The protective layer covers the wiring, The surface located opposite to the aforementioned wiring has the metal-containing portion. <19> The stretchable device described. <21> Preparation process for preparing the base material, An ozone treatment step of applying ozone to at least one of the first main surface of the substrate and the second main surface located on the opposite side of the first main surface, A method for manufacturing a stretchable substrate, including [the specified part of the method]. <22> The stretchable substrate contains 5 atomic percent or more of oxygen atoms in at least one of the first main surface and the second main surface. <21> A method for manufacturing a stretchable substrate as described above. <23> The stretchable substrate has a ratio of oxygen atoms in at least one of the first main surface and the second main surface that is increased by 5 atomic percent or more relative to the base material. <21> or <22> A method for manufacturing a stretchable substrate as described above. <24> Furthermore, after the ozone treatment process, an embossing process is performed on at least one of the first main surface and the second main surface. <21> from <23> A method for manufacturing a stretchable substrate as described in any one of the following. <25> A step of preparing a substrate having a first main surface and a second main surface facing each other, A placement step of arranging wiring on the first main surface of the substrate, After the arrangement step, an ozone treatment step is performed, in which at least one of the first main surface and the second main surface is subjected to ozone treatment. A method for manufacturing a stretchable device having [a certain characteristic]. <26> A step of preparing a substrate having a first main surface and a second main surface facing each other, A placement step of arranging wiring on the first main surface of the substrate, After the arrangement step, an embossing step is performed on at least one of the first main surface and the second main surface. A method for manufacturing a stretchable device having [a certain characteristic]. <27> Preparation process for preparing the base material, A forming step of forming a metal-containing portion on at least one of the first main surface and the second main surface located on the opposite side of the first main surface of the substrate, A method for manufacturing a stretchable device, including [the specified part of the method]. <28> A preparation step of preparing a first substrate having a first main surface and a second main surface facing each other, A forming step of forming a metal-containing portion on the second main surface of the first substrate, A method for manufacturing a stretchable device having [a certain characteristic]. <29> After the preparation step and before the forming step, a placement step is performed in which the wiring is placed on the first main surface of the substrate. Having <28> A method for manufacturing the stretchable device described above. <30> A second substrate having a first main surface and a second main surface facing each other is further prepared. In the arrangement step, the first main surface of the second substrate is placed on the wiring. <29> A method for manufacturing the stretchable device described above. [Explanation of Symbols]

[0164] 100, 100A, 100B, 100C, 100D, 100E stretchable devices 1,1A,1B,1C Stretchable board 2 Wiring 3 Sheet material 4A 1st shape 4B 2nd shape 4a1, 4b1 convex part 4a2,4b2 Concave groove part 5.5C embossing sheet material 5a1 Warp thread section 5b1 Weft 61 White part 62. Coarse dot area 63 Fine dot area 71 Part 1 72 Part 2 80,82,83 Base material 81 Metal-containing parts

Claims

1. A stretchable substrate having a first main surface and a second main surface facing each other, The aforementioned stretchable substrate is The oxygen atom ratio of at least one of the first principal surface and the second principal surface, as measured by X-ray photoelectron spectroscopy, is 5 atomic percent or more relative to the total atoms. The oxygen atom ratio in the central portion of the first and second principal surfaces in directions perpendicular to the first and second principal surfaces is 5 atomic percent or less. Stretchable substrate.

2. In the first main surface or the second main surface, the arithmetic mean surface roughness of the surface measured by a laser microscope is 6 μm or more. The stretchable substrate according to claim 1.

3. At least one of the first main surface and the second main surface has a metal-containing portion containing metal atoms. The stretchable substrate according to claim 1.

4. The stretchable substrate according to claim 3, wherein, in the first main surface or the second main surface, the composition ratio of the metal in the metal-containing portion to the total elements, as measured by X-ray photoelectron spectroscopy, is 0.5 atomic percent or more.

5. A metal-containing region containing metal atoms is located along at least one of the first main surface and the second main surface. The stretchable substrate according to claim 1.

6. The stretchable substrate according to claim 5, wherein the ratio of the metal atoms in the first main surface or the second main surface is 0.2 atomic% or more and 2.5 atomic% or less.

7. The stretchable substrate according to claim 3, wherein the metal atom comprises at least one selected from the group consisting of Al, Fe, Ni, Au, Pt, Ag, and Ti.

8. The stretchable substrate according to claim 1, wherein the material of the base material constituting the stretchable substrate is rubber or elastomer.

9. A stretchable device comprising a stretchable substrate according to any one of claims 1 to 8, and wiring arranged on the first main surface of the stretchable substrate.

10. The invention comprises a stretchable substrate according to claim 2 or 3, wiring arranged on the first main surface of the stretchable substrate, and a protective layer. The protective layer covers the wiring, The expandable device according to claim 9, wherein the surface located opposite to the wiring has the metal-containing portion.

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