Resin film, electric circuit body, healthcare sensor, wearable sensor, and display

Abstract

To provide a resin film with high flexibility and recoverability, having sufficient stiffness near room temperature, and exhibiting minimal change in mechanical characteristics depending on temperature.SOLUTION: A resin film comprising a resin having segments of Chemical Formula 1 and Chemical Formula 2, the resin film being characterized in that a storage modulus E'(25) at 25°C is 10 MPa or more, and storage moduli E'(0) at 0°C and E'(50) at 50°C satisfy the following formulae: 1.0≥E'(25) / E'(0)≥0.20 and 1.0≥E'(50) / E'(25)≥0.20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin film, and to an electric circuit body, a healthcare sensor, a wearable sensor, and a display using the same. [Background technology]

[0002] As the IoT (Internet of Things) society advances, sensors that detect minute changes in pressure, temperature, distortion, etc. are being attached to various objects in our daily lives, and utilizing this data is helping to improve our quality of life.

[0003] Furthermore, if devices that allow such sensors to be attached to the human body for long periods of time without causing discomfort become commercially available, it will become possible to easily obtain long-term data on the human body that could previously only be obtained for short periods of time using special equipment. This could lead to major changes in our lives, such as the prevention of diseases that were previously difficult to detect, and the improvement of skills in sports and music.

[0004] Small devices incorporating sensors and other components have been available in the past, and their base material is made of a resin film that can be bent and stretched freely.

[0005] As an example of an existing resin film that can be freely bent and stretched, Patent Document 1 proposes "a polyurethane produced by reacting a polyether polyol (a) having a carbonate bond with an isocyanate compound (b), wherein the hydroxyl value of the polyether polyol (a) is 55 or less."

[0006] Furthermore, Patent Document 2 proposes "an active energy ray-curable resin composition containing at least (a-1) a polyisocyanate, (a-2) a low-molecular-weight polyol having an alicyclic structure and a number-average molecular weight of 500 or less, and (a-3) a urethane (meth)acrylate oligomer (A) which is a reaction product of a hydroxyalkyl (meth)acrylate, wherein the calculated network molecular weight between crosslinking points in the composition is 1,000 or more and 6,000 or less."

[0007] Furthermore, Non-Patent Document 1 proposes a cross-linkable industrial silicone film.

[0008] Furthermore, as a material that has excellent elasticity and is easy to handle as a resin film, Patent Document 3 proposes "a flexible resin-forming composition containing (A) an elastomer containing a monomer unit derived from styrene, (B) a polymerizable compound, and (C) a polymerization initiator, wherein the mass ratio of the monomer unit derived from styrene to the total amount of (A) the elastomer is 27 mass% or more."

[0009] Furthermore, Patent Document 4 proposes a "curable resin composition for forming a flexible resin, which contains (A) a styrene-based elastomer, (B) a polymerizable monomer, and (C) a polymerization initiator, and the polymerizable monomer contains a silicone compound having a (meth)acryloyloxy group." [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-189886 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-222568 [Patent Document 3] Japanese Patent Application Publication No. 2018-172460 [Patent Document 4] Japanese Patent Application Publication No. 2018-203827 [Non-patent literature]

[0011] [Non-Patent Document 1] Asahi Kasei Wacker homepage “ELASTOSIL” (registered trademark) FILM2030 http: / / www.aws-silicone.com / dcms_media / other / EL%20FILM.pdf Summary of the Invention [Problem to be solved by the invention]

[0012] While films with rigid chemical bonds, such as polyimide, can be bent freely, they are difficult to deform and quickly restore. Therefore, resin films that can be bent and stretched freely are in demand. These films also need to be as durable as existing film materials, preventing sensors and wiring from deteriorating under operating conditions.

[0013] In devices such as the above-mentioned sensors, so-called wearable sensors and healthcare sensors, resin films are required to have flexibility and recovery that allow them to bend and stretch freely when attached to the human body, etc., as well as sufficiently high rigidity near room temperature and little change in mechanical properties due to temperature. However, the materials proposed in Patent Documents 1 to 4 did not satisfy all of these requirements.

[0014] Therefore, an object of the present invention is to provide a resin film that is flexible and has high restoring properties, and also has sufficiently high rigidity at around room temperature, and exhibits little change in mechanical properties due to temperature. [Means for solving the problem]

[0015] In order to solve the above problems, the present inventors have conducted extensive research and have completed the following invention. That is, one preferred embodiment of the present invention is as follows. <1> A resin film made of a resin having a segment of Chemical Formula 1 and a segment of Chemical Formula 2, A resin film characterized in that the storage modulus E'(25) at 25°C is 10 MPa or more, and the storage modulus E'(0) at 0°C and the storage modulus E'(50) at 50°C satisfy the following formula:

[0016] 1.0 ≧ E'(25) / E'(0) ≧ 0.20 1.0 ≧ E'(50) / E'(25) ≧ 0.20 The storage modulus is measured under the following conditions. The storage modulus is measured based on the tensile vibration-non-resonance method of JIS K7244 (1998) with a chuck distance of 20 mm, a test piece width of 10 mm, a frequency of 1 Hz, a strain amplitude of 10 μm, an initial force amplitude of 40 mN, a temperature rise rate of 5°C / min, and a measurement temperature range of -100°C to 100°C.

[0017] [ka]

[0018] [ka]

[0019] R 1 refers to a hydrogen or methyl group.

[0020] R 2 refers to one of the following: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group, an ester group, or an amide group therein an arylene group having an ether group, an ester group, or an amide group therein Unsubstituted alkylene group having an ether group, ester group, or amide group inside An unsubstituted arylene group having an ether group, an ester group, or an amide group therein. <2> The following condition 1 is satisfied: <1> The resin film according to claim 1.

[0021] Condition 1: When a regression line is calculated using the least squares method for the relationship between E'(0), E'(25), and E'(50) and each temperature, the coefficient of determination of the regression line must be 0.85 or greater. <3> The following condition 2 is satisfied: <1> or <2> The resin film according to claim 1.

[0022] Condition 2: The 5% strain stress of the resin film is 1.0 MPa or more. <4> The following condition 3 is satisfied: <1> ~ <3> The resin film according to any one of the preceding items.

[0023] Condition 3: The glass transition temperature of the resin film determined by the dynamic viscoelasticity method is 0°C or lower. <5> The following condition 4 is satisfied: <1> ~ <4> The resin film according to any one of the preceding items.

[0024] Condition 4: The haze of the resin film is 10% or less. <6> The following condition 5 is satisfied: <1> ~ <5> The resin film according to any one of the preceding items.

[0025] Condition 5: A resin film obtained by curing a component A having a segment of chemical formula 1 and a segment of chemical formula 2, and a component B having a segment of chemical formula 1, wherein components A and B are different components, and the resin film has a phase-separated structure. <7> The following condition 6 is satisfied: <1> ~ <6> The resin film according to any one of the preceding items.

[0026] Condition 6: The resin film is made of a resin having at least one of a segment of Chemical Formula 3 and a segment of Chemical Formula 4.

[0027] [ka]

[0028] R 3 refers to one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein

[0029] [ka]

[0030] R 4 refers to one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein <8> <1> ~ <7> A laminate comprising the resin film according to any one of the above items. <9> <1> ~ <7> and a conductor circuit formed on the resin film. <10> <1> ~ <7> 10. A healthcare sensor comprising the resin film according to any one of claims 1 to 9 and a conductor circuit formed on the resin film. <11> <1> ~ <7> 10. A wearable sensor comprising the resin film according to any one of claims 1 to 9, and a conductor circuit formed on the resin film. <12> <1> ~ <7> A display comprising the resin film according to any one of the above items. [Effects of the Invention]

[0031] According to the present invention, it is possible to provide a resin film that has high flexibility and recovery, and also has sufficiently high rigidity at around room temperature, and whose mechanical properties change little with temperature. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a cross-sectional view showing an example of a resin film in the present invention. [Figure 2] 1 is a cross-sectional view showing an example of a laminate using a resin film according to the present invention. [Figure 3] 1 is a cross-sectional view showing an example of a laminate using a resin film according to the present invention. [Figure 4] 1 is a plan view showing an example of an electric circuit body according to the present invention. [Figure 5] 1 is a plan view showing an example of an electric circuit body according to the present invention. [Figure 6] FIG. 2 is a diagram showing an example of the storage modulus of the resin film of the present invention. [Figure 7] FIG. 1 is a diagram showing an example of calculating a regression line of the relationship between each temperature and storage modulus in the present invention. [Figure 8] FIG. 2 is a diagram showing an example of loss tangent when the resins in the present invention are compatible with each other. [Figure 9] FIG. 2 is a diagram showing an example of a loss tangent when the resin in the present invention forms a certain phase separation structure. DETAILED DESCRIPTION OF THE INVENTION

[0033] [Comparison of the present invention and the prior art] While conventional materials exhibit flexibility and resilience, their use as resin films has not always been suitable. For example, when attempting to incorporate such resin films into products such as flexible displays and wearable sensors, the resin films often lack sufficient rigidity, leading to poor integration or deformation or breakage under heavy loads. Furthermore, elastomer materials are an example of materials that exhibit flexibility and resilience. However, even if such materials have good mechanical properties at room temperature, their mechanical properties are highly temperature-dependent, resulting in significant changes in their mechanical properties (e.g., becoming hard, brittle, or soft) in slightly different low-temperature or high-temperature environments. Therefore, they are not necessarily suitable for stable use. Therefore, the properties of conventional materials were insufficient for precision products such as the flexible displays and wearable sensors described above.

[0034] To address these issues, the inventors conducted detailed studies, focusing particularly on the mechanical properties required of resin films. As a result, they found that it is preferable for resin films to have a certain level of stress or more and for the changes in their mechanical properties to be within a certain range of temperatures. Furthermore, they found that if the changes in these mechanical properties with respect to temperature are linear, products incorporating the resin film can operate stably even when the temperature changes, and the resin film can be particularly suitable for flexible displays and wearable devices, which are precision products that are prone to deformation.

[0035] Specifically, it is preferable that the resin film has a storage modulus E'(25) at 25°C of 10 MPa or more, and the storage modulus E'(0) at 0°C and the storage modulus E'(50) at 50°C satisfy the following formula:

[0036] 1.0 ≧ E'(25) / E'(0) ≧ 0.20 1.0 ≧ E'(50) / E'(25) ≧ 0.20 Furthermore, when a regression line is calculated by the least squares method for the relationship between E'(0), E'(25), and E'(50) and each temperature, the coefficient of determination of the regression line is preferably 0.85 or more.

[0037] Furthermore, the present inventors conducted detailed studies on the resin structure of the resin film required to achieve these mechanical properties. It is generally known that resin properties are highly temperature-dependent, changing significantly in particular in the glass transition region. While it is possible to significantly shift the glass transition temperature itself and suppress changes in mechanical properties near the target temperature range, raising the glass transition temperature too much makes the resin excessively hard, while lowering the glass transition temperature too much makes the resin excessively soft. This makes it difficult to suppress changes while maintaining stable rigidity. Therefore, the present inventors focused on glass transition and resin structure and discovered that temperature-dependent changes in mechanical properties can be suppressed by controlling the phase-separated structure of the resin. When the resins constituting a resin film are completely compatible, one (or possibly multiple) large glass transitions are exhibited, which is thought to cause the above-mentioned problems. On the other hand, when the resins are completely incompatible, the resins do not mix, resulting in unstable physical properties, failure to form a resin film, and deterioration of optical properties (e.g., cloudiness, opacity). Therefore, when the material has a partially compatible phase-separated structure, which can be considered intermediate between the two, the temperature range in which the glass transition phenomenon occurs becomes wider, and the change in mechanical properties within that temperature range becomes relatively small. Furthermore, because it is in an intermediate state, it is believed that mechanical properties such as hardness can be appropriately controlled.

[0038] Specifically, it is a resin film obtained by curing a component A having a segment of chemical formula 1 and a segment of chemical formula 2, and a component B having a segment of chemical formula 1, where components A and B are different components and the resin film preferably has a phase-separated structure.

[0039] Furthermore, the inventors have discovered that in order to suppress temperature-dependent changes in mechanical properties near room temperature while maintaining the flexibility and resilience of the resin film, it is advantageous for the chemical structure of the resin that constitutes the resin film to have high mobility, and therefore it is preferable for the glass transition temperature to be sufficiently low.

[0040] Specifically, the glass transition temperature of the resin film is preferably 0° C. or lower.

[0041] [Embodiments of the present invention] Hereinafter, embodiments of the present invention will be specifically described.

[0042] A preferred embodiment of the resin film of the present invention is a resin film made of a resin having a segment of Chemical Formula 1 and a segment of Chemical Formula 2, The resin film is characterized in that the storage modulus E'(25) at 25°C is 10 MPa or more, and the storage modulus E'(0) at 0°C and the storage modulus E'(50) at 50°C satisfy the following formula:

[0043] 1.0 ≧ E'(25) / E'(0) ≧ 0.20 1.0 ≧ E'(50) / E'(25) ≧ 0.20 The storage modulus is measured under the following conditions. The storage modulus is measured based on the tensile vibration-non-resonance method of JIS K7244 (1998) with a chuck distance of 20 mm, a test piece width of 10 mm, a frequency of 1 Hz, a strain amplitude of 10 μm, an initial force amplitude of 40 mN, a temperature rise rate of 5°C / min, and a measurement temperature range of -100°C to 100°C.

[0044] Here, the segment in Chemical Formula 1 refers to a (meth)acrylic residue obtained by crosslinking a (meth)acrylic group. The resin film of the present invention preferably has a (meth)acrylic residue obtained by crosslinking a (meth)acrylic group, because it has improved restorability and stress. It is also preferable because it has improved heat resistance, which improves stability during processing at high temperatures and in high-temperature environments.

[0045] The individual segments contained in the resin constituting the resin film can be confirmed by TOF-SIMS, FT-IR, or the like.

[0046] The segment in Chemical Formula 2 represents a urethane bond. The resin film of the present invention preferably has a urethane bond, since this improves recovery and flexibility.

[0047] It is preferable that the resin film contains 10% by mass or more and 100% by mass or less of a resin having a segment of Chemical Formula 1 and a segment of Chemical Formula 2, based on 100% by mass of the resin film. This is preferable because it can improve the restorability of the resin film.

[0048] The storage modulus E'(25) at 25°C is preferably in the range of 10 MPa or more, more preferably 20 MPa or more, and particularly preferably 50 MPa or more.

[0049] If the storage modulus E'(25) at 25°C is 10 MPa or more, the rigidity at around room temperature will be sufficient, which is preferable because it will be easier to handle when processing the resin film of the present invention or when incorporating it into a product. A higher storage modulus improves handling, but if it is too high, flexibility will be lost, so the upper limit of the preferred range of storage modulus E'(25) is thought to be 1,000 MPa. On the other hand, if the storage modulus E'(25) at 25°C is less than 10 MPa, the rigidity at around room temperature may be insufficient.

[0050] Furthermore, when the storage modulus E'(25) at 25°C, the storage modulus E'(0) at 0°C, and the storage modulus E'(50) at 50°C satisfy the above-mentioned relational expressions, when the resin film of the present invention is incorporated into a product, the product can maintain its functionality even if the temperature environment changes, which is preferable.

[0051] In order for the storage modulus at each temperature to satisfy the above-mentioned relationship, for example, it is preferable that the resin constituting the resin film has the segments described below, and it is also preferable that the resin constituting the resin film has a network-like crosslinked structure. Furthermore, in order for the resin constituting the resin film to have a network-like crosslinked structure, it is preferable that the resin constituting the resin film is a resin obtained by crosslinking (meth)acrylic groups, or has crosslinks due to urethane bonds. Furthermore, it is preferable that the resin has both crosslinked structures, because the restoring property is improved due to the effects of both crosslinked structures.

[0052] Furthermore, the resin film of the present invention preferably satisfies the following condition 1.

[0053] Condition 1: When a regression line is calculated using the least squares method for the relationship between E'(0), E'(25), and E'(50) and each temperature, the coefficient of determination of the regression line must be 0.85 or greater.

[0054] The method for calculating the regression line will be described later.

[0055] The coefficient of determination of the regression line is preferably in the range of 0.85 or more, more preferably 0.90 or more, and particularly preferably 0.92 or more.

[0056] When the coefficient of determination of the regression line is 0.85 or more, the change in mechanical properties of the resin film of the present invention due to temperature is small, and when the resin film is incorporated into products such as flexible displays and wearable sensors that undergo deformation at around room temperature, the product can maintain its functionality even when the temperature environment changes, which is preferable.Furthermore, since the linearity of the change in mechanical properties with temperature is high, it becomes easier to control the change in mechanical properties of sensors and devices incorporating the resin film due to temperature change using sensor structure and software, which is preferable because it makes such sensors and devices easier to control and improves their accuracy.

[0057] In order to make the coefficient of determination of the regression line 0.85 or more, for example, it is preferable that the resin constituting the resin film has the segments described below, and it is also preferable that the resin constituting the resin film has a network-like crosslinked structure. Furthermore, as described below, it is desirable that the resin film has a phase-separated structure, which can suppress a sudden change in mechanical properties due to temperature changes, and as a result, it is preferable because the coefficient of determination of the regression line can be improved.

[0058] Furthermore, the resin film of the present invention preferably satisfies the following condition 2.

[0059] Condition 2: The 5% strain stress of the resin film is 1.0 MPa or more.

[0060] The method for measuring the 5% strain stress will be described later.

[0061] The preferred range of the 5% strain stress is 1.0 MPa or more, and more preferably 1.5 MPa or more.

[0062] When the strain stress at 5% elongation, which corresponds to the initial stage of deformation, is 1.0 MPa or more, the rigidity of the resin film is improved and extreme deformation at the initial stage of deformation can be suppressed. Therefore, when a product using the resin film of the present invention (e.g., a wearable sensor or a flexible display) is deformed, it is possible to suppress excessive deformation beyond what is expected or localized deformation, which can cause a sudden increase in circuit resistance or partial damage.

[0063] Furthermore, the resin film of the present invention preferably satisfies the following condition 3.

[0064] Condition 3: The glass transition temperature of the resin film determined by the dynamic viscoelasticity method is 0°C or lower.

[0065] The method for measuring the glass transition temperature will be described later.

[0066] The glass transition temperature is preferably in the range of 0°C or lower, more preferably -30°C or lower.

[0067] A glass transition temperature of 0°C or lower is preferable because it can suppress changes in mechanical properties due to temperature changes around room temperature. On the other hand, if the glass transition temperature exceeds 0°C, changes in mechanical properties due to temperature changes around room temperature may become significant.

[0068] In this case, when there are multiple temperatures at which the loss tangent obtained by the measurement method described below shows a maximum value, the temperature at which the loss tangent shows a maximum value in the temperature range where the storage modulus is 10 MPa or more is given priority as the glass transition temperature, and when the temperature at which the loss tangent shows a maximum value is not determined to be a single point, the glass transition temperature refers to the temperature at which the loss tangent shows the maximum value.

[0069] The glass transition temperature can be reduced to 0°C or below by reducing the segment of chemical formula 1 (acrylic residue) in the resin precursor that makes up the resin film, by reducing the segment of chemical formula 2 (urethane bond), or by increasing the molecular weight of the polyol or isocyanate that makes up the segment of chemical formula 2.

[0070] Furthermore, the resin film of the present invention preferably satisfies the following condition 4.

[0071] Condition 4: The haze of the resin film is 10% or less.

[0072] The method for measuring the haze will be described later.

[0073] From the viewpoint of optical properties, the resin film of the present invention preferably has a haze of 10% or less, more preferably 7% or less, and particularly preferably 5% or less. By setting the haze of the resin film within a specific range, it is possible to improve the optical quality of products using the resin film of the present invention and to improve product inspectability during the manufacturing process.

[0074] The haze of the resin film can be set within the above range by, for example, selecting a specific resin as described later for the resin layer or by selecting a specific supporting substrate as described later.

[0075] Furthermore, the resin film of the present invention preferably satisfies the following condition 5.

[0076] Condition 5: A resin film obtained by curing a component A having a segment of chemical formula 1 and a segment of chemical formula 2, and a component B having a segment of chemical formula 1, wherein components A and B are different components, and the resin film has a phase-separated structure.

[0077] The resin film preferably has a phase-separated structure, since this can suppress changes in mechanical properties due to temperature changes. Whether or not a resin film has a phase-separated structure can be determined from the shape of the loss tangent curve in a dynamic viscoelasticity method.

[0078] In order for a resin film to have a phase-separated structure, the glass transition temperatures of components A and B must be significantly different from each other, and components A and B must be contained in a certain ratio or more.

[0079] The ratio of component A to component B is not particularly limited, but for example, if the mass ratio of component B to component A in the resin film is 0.25 or more and 4.0 or less, a phase separation structure is easily formed in the resin film, which is preferable.

[0080] Furthermore, the resin film of the present invention preferably satisfies the following condition 6.

[0081] Condition 6: The resin film is made of a resin having at least one of a segment of Chemical Formula 3 and a segment of Chemical Formula 4.

[0082] Here, the segment of Chemical Formula 3 represents a polyester polyol, and the segment of Chemical Formula 4 represents a polyether polyol. The resin film of the present invention preferably contains a polyester polyol or a polyether polyol, as this improves flexibility and recovery. The individual segments contained in the resin constituting the resin film can be confirmed by TOF-SIMS, FT-IR, or the like.

[0083] [ka]

[0084] R 3 refers to one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein

[0085] [ka]

[0086] R 4 refers to one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein [Resin film] The resin film of the present invention may have other functions such as fingerprint resistance, formability, designability, scratch resistance, antifouling, antireflection, antistatic properties, conductivity, heat ray reflection, near-infrared absorption, electromagnetic wave shielding, etc., in addition to the flexibility, recovery properties, and sufficiently high rigidity at around room temperature, and in this case, one or more layers may be further formed. For example, a functional layer having the above-mentioned functions, an adhesive layer, an electronic circuit layer, a printing layer, an optical adjustment layer, or other functional layers may be provided.

[0087] The thickness of the resin film of the present invention is not particularly limited and is appropriately selected depending on the application. The lower limit of the thickness of the resin film is not generally determined because it is affected by the elastic modulus, breaking elongation, peeling force and peeling angle from the laminate, etc. However, when the same physical properties as a general flexible material are to be achieved using the laminate manufacturing method described below, the lower limit is about 1 μm.

[0088] [Resin precursor] The resin precursor is not particularly limited as long as it is a compound having a crosslinkable moiety, but it preferably contains a segment of Chemical Formula 2, or a segment of Chemical Formula 3 or Chemical Formula 4. It is more preferable that it contains a segment of Chemical Formula 5 or Chemical Formula 6.

[0089] [ka]

[0090] [ka]

[0091] R 3 refers to a hydrogen or methyl group. R 4 , R 5 refers to one of the following: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group, an ester group, or an amide group therein an arylene group having an ether group, an ester group, or an amide group therein Unsubstituted alkylene group having an ether group, ester group, or amide group inside An unsubstituted arylene group having an ether group, an ester group, or an amide group therein. R 6 refers to one of the following: Substituted or unsubstituted alkylene groups a substituted or unsubstituted alkenylene group;

[0092] As described above, the segment of Chemical Formula 5 has a (meth)acrylic group (X) at its terminal, and this terminal (meth)acrylic group (X) corresponds to a site that can be crosslinked. Furthermore, the (meth)acrylic group (X) is adjacent to a polyisocyanate residue (Y) in the diagram. This also means that the other end of the urethane bond of the polyisocyanate residue (Y) is adjacent to a polyol residue (Z) (Z).

[0093] The polyisocyanate residue (Y) of Chemical Formula 5 is preferably a residue of a polyisocyanate such as TDI (tolylene diisocyanate), MDI (4,4'-diphenylmethane diisocyanate), NDI (1,5-naphthalene diisocyanate), TODI (tolidine diisocyanate), XDI (xylylene diisocyanate), PPDI (paraphenylene diisocyanate), TMXDI (tetramethylxylylene diisocyanate), HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), H6XDI (hydrogenated xylylene diisocyanate), or H12MDI (dicyclohexylmethane diisocyanate).

[0094] The polyol residue of Chemical Formula 5 is preferably a polyester polyol, a polyether polyol, or a polycarbonate polyol from the viewpoint of flexibility.

[0095] Examples of polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene sebacate diol, polybutylene sebacate diol, poly-ε-caprolactone diol, poly(3-methyl-1,5-pentylene adipate) diol, polycondensates of 1,6-hexanediol and dimer acid, and various derivatives thereof. Examples of polyether polyols include polyalkylene glycols having two or more oxyalkylene units, and specific examples include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, as well as various derivatives thereof.

[0096] Examples of polycarbonate polyols include reaction products of carbonates and glycols. Specific examples of carbonates include diaryl carbonates such as diphenyl carbonate, dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, ethylene carbonate, diphenyl phenyl carbonate, and phosgene. Examples of diols include ethylene glycol, propylene glycol, butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, nonanediol, cyclohexanedimethanol, neopentyl glycol, 3-methyl-1,5-pentanediol, hydroxypivalic acid neopentyl glycol ester, and various derivatives thereof.

[0097] [Laminate] The resin film of the present invention may form a laminate having a supporting substrate on one side thereof. The laminate is preferably a laminate in which the peel strength between the supporting substrate and the resin film is 1 N / 50 mm or less. Hereinafter, a supporting substrate having a peel strength of 1 N / 50 mm or less from the resin film will be referred to as a releasable supporting substrate.

[0098] As described above, in the laminate of the present invention, the peel strength between the support substrate and the resin film is preferably 1 N / 50 mm or less, and more preferably 800 mN / 50 mm or less. There is no particular lower limit to the peel strength between the support substrate and the resin film, but if it is less than 10 mN / 50 mm, the support substrate and the resin film may peel off or float during the manufacturing process, so the peel strength between the support substrate and the resin film is preferably 10 mN / 50 mm or more.

[0099] [Supporting base material] The supporting substrate used in the laminate may be either a thermoplastic resin or a thermosetting resin, and may be a homoresin, a copolymer, or a blend of two or more types. The resin constituting the supporting substrate is preferably one that has good moldability, and from this point of view, a thermoplastic resin is more preferred.

[0100] Examples of thermoplastic resins that can be used include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resin, polyimide resin, polyester resin, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, fluororesins such as tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, and vinylidene fluoride resin, acrylic resin, methacrylic resin, polyacetal resin, polyglycolic acid resin, and polylactic acid resin.

[0101] Examples of the thermosetting resin that can be used include phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane resin, polyimide resin, and silicone resin.

[0102] The thermoplastic resin is preferably a resin having sufficient stretchability and conformability. From the viewpoints of strength, heat resistance, and transparency, the thermoplastic resin is more preferably a polyester resin, a polycarbonate resin, an acrylic resin, or a methacrylic resin.

[0103] In the present invention, polyester resin is a general term for polymers in which ester bonds are the main bonding chains in the main chain, and is obtained by polycondensation of an acid component, its ester, and a diol component. Specific examples include polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, and polybutylene terephthalate. These may also be copolymerized with other dicarboxylic acids and their esters or diol components as the acid component or diol component. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferred in terms of transparency, dimensional stability, heat resistance, and the like.

[0104] The support substrate may also contain various additives, such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, and dopants for adjusting the refractive index.

[0105] Furthermore, the supporting substrate may have either a single layer structure or a laminated structure.

[0106] Furthermore, it is also possible to provide a functional layer such as an easy-adhesion layer, an antistatic layer, an undercoat layer, an ultraviolet absorbing layer, or a release layer on the surface of the support substrate in advance, in addition to the resin film of the present invention. In the present invention, the support substrate preferably has a release layer to reduce the peel force between the support substrate and the resin film. Details of the release layer will be described later.

[0107] Examples of the support substrate include "Lumirror" (registered trademark) and "Torayfan" from Toray Industries, Inc., "Cosmoshine" (registered trademark) and "Toyobo Ester" (registered trademark) films and "Teonex" (registered trademark) from Toyobo Co., Ltd., "Diafoil" (registered trademark) from Mitsubishi Chemical Corporation, and "Emblett" (registered trademark) and "Emblem" (registered trademark) from Unitika Ltd., and these products can also be used.

[0108] Examples of support substrates provided with a release layer made of a silicone-based material or a non-silicone-based material (fluorine-based, alkyl-based, etc.) include "Therapeel" (registered trademark) manufactured by Toray Advanced Film Co., Ltd., "Unipeel" (registered trademark) manufactured by Unitika Ltd., "Panapeel" (registered trademark) manufactured by Panac Corporation, and "Cosmopeel" (registered trademark) and "Purex" (registered trademark) manufactured by Toyobo Co., Ltd., and these products can also be used.

[0109] The surface of the support substrate can be subjected to various surface treatments before forming the resin film. Examples of surface treatments include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high-frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, sandblasting treatment, mixed acid treatment, and ozone oxidation treatment. Among these, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment, and flame treatment are preferred, and glow discharge treatment and ultraviolet treatment are more preferred.

[0110] [Release layer] The support substrate used in the laminate preferably has a release layer. A support substrate having a release layer is also called a release film. The release layer may be composed of multiple layers from the viewpoint of imparting adhesion, antistatic properties, solvent resistance, etc., and may be present on both sides of the support substrate.

[0111] The composition and thickness of the release layer are not particularly limited as long as the peel strength from the resin film can be within the preferred range described above. However, from the viewpoints of the in-plane uniformity, quality, and peel strength of the release layer, it is preferably 10 nm or more and 500 nm or less, and more preferably 20 nm or more and 300 nm or less.

[0112] [Protective material] The laminate described above may have a protective material on the surface of the resin film opposite to the supporting substrate, as shown in FIG. 3. The protective material and the supporting substrate are distinguished by the fact that in the manufacturing method of the laminate, the material to which the coating composition is applied is the supporting substrate, and the protective material is the material to which the resin film is attached after formation. The protective material may be the same as or different from the supporting substrate described above, but it is preferable that the protective material has a different peel strength from the supporting substrate described above when used in a subsequent process. The magnitude relationship between the peel strength of the protective material and the supporting substrate from the resin film is appropriately selected depending on the method of use in the subsequent process. Therefore, the protective material may have a release layer, an adhesive layer, or may be a single layer.

[0113] [Manufacturing method of resin film] The method for producing the resin film of the present invention is not particularly limited, but preferably includes the steps of applying a coating composition containing a resin precursor containing a segment of Chemical Formula 2, Chemical Formula 3, or Chemical Formula 4 onto a supporting substrate to form a coating layer (Step 1), then removing the solvent from the coating layer and drying it (Step 2), irradiating it with active energy rays to crosslink the resin precursor (Step 3), and peeling the supporting substrate from the laminate (Step 4).

[0114] Furthermore, it is preferable that after the aforementioned "Step 3", a step of applying a coating composition for a particle layer containing particles and a resin component to form a coating layer and a step of removing the solvent from the coating layer are carried out in this order, or after "Step 3", a step of applying a coating composition for a particle layer containing particles and a resin precursor to form a coating layer, a step of removing the solvent from the coating layer, and a step of irradiating with active energy rays to crosslink the resin precursor and form a laminate having a resin film on a support substrate are carried out in this order.

[0115] Furthermore, when a support substrate having a surface shape such as an uneven shape is used as the support substrate, it is possible to form a surface shape on the surface of the resin film by transferring the surface shape such as an uneven shape of the support substrate to the surface of the resin film obtained in the above-mentioned "Step 4" that was in contact with the support substrate. At this time, the surface shape of the support substrate and the surface shape of the resin film are reversed.

[0116] The method for applying the coating composition onto the support substrate in step 1 is not particularly limited as long as it is possible to apply the coating composition onto the support substrate and form a uniform coating layer within the surface. The coating method onto the support substrate can be appropriately selected from dip coating, roller coating, wire bar coating, gravure coating, die coating (U.S. Pat. No. 2,681,294), etc. Here, the coating layer refers to a "liquid layer" formed by the coating step.

[0117] The method for removing the solvent in step 2, i.e., the drying method, is not particularly limited as long as it can remove the solvent from the coating layer formed on the support substrate. Drying methods include heat transfer drying (contact with a high-temperature object), convection heat transfer (hot air), radiation heat transfer (infrared rays), and others (microwaves, induction heating), but among these, in the production method of the present invention, a method using convection heat transfer or radiation heat transfer is preferred because it is necessary to precisely uniform the drying speed even in the width direction.

[0118] In the crosslinking method of step 3, the coating layer from which the solvent has been removed after drying is irradiated with active energy rays to cause a reaction and crosslink the coating film.

[0119] Crosslinking by active energy rays is preferably performed using electron beams (EB) and / or ultraviolet rays (UV) from the viewpoint of versatility. The types of ultraviolet lamps used for irradiating ultraviolet rays include, for example, discharge lamps, flash lamps, laser lamps, and electrodeless lamps. When ultraviolet curing is performed using a high-pressure mercury lamp, which is a discharge lamp, the illuminance of the ultraviolet rays should be 100 to 3,000 (mW / cm). 2 ), and more preferably 200 to 2,000 (mW / cm2 ), more preferably 300 to 1,500 (mW / cm 2 ), and the cumulative amount of ultraviolet light is 100 to 3,000 (mJ / cm 2 ), and more preferably 200 to 2,000 (mJ / cm 2 ), more preferably 300 to 1,500 (mJ / cm 2 ) is the radiation intensity per unit area, which varies depending on the lamp output, light-emitting spectral efficiency, diameter of the light-emitting bulb, design of the reflector, and the distance between the irradiated object and the light source. However, irradiance does not vary depending on the transport speed. Furthermore, the cumulative amount of UV light is the radiation energy per unit area, which is the total amount of photons that reach the surface. The cumulative amount of light is inversely proportional to the radiation speed passing under the light source, and proportional to the number of irradiations and the number of lamps.

[0120] [Paint composition] The "coating composition" used in the aforementioned method for producing a resin film is not particularly limited as long as it can be applied uniformly in-plane onto a supporting substrate and can form a resin film exhibiting the properties of the present invention, but it is preferably a coating composition suitable for the aforementioned method for producing a laminate. Specifically, it is preferable to prepare a coating composition by adding the aforementioned resin precursor to a solvent and other components described below.

[0121] [solvent] The coating composition used in the resin film manufacturing method may contain a solvent, and preferably contains a solvent in order to form a coating layer uniformly within the surface. The number of solvents is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 6, and particularly preferably 1 to 4.

[0122] Here, the term "solvent" refers to a substance that is liquid at room temperature and pressure and can be evaporated almost entirely in the drying step described above.

[0123] Here, the type of solvent is determined by the molecular structure that constitutes the solvent. In other words, solvents that have the same elemental composition and the same type and number of functional groups but different bonding relationships (structural isomers), and solvents that are not structural isomers but do not exactly overlap in any conformation in three-dimensional space (stereoisomers) are treated as different types of solvents. For example, 2-propanol and n-propanol are treated as different solvents. Furthermore, when a solvent is included, it is preferable that the solvent exhibits the following characteristics:

[0124] Property 1: When solvent B is the solvent with the lowest relative evaporation rate (ASTM D3539-87(2004)) based on n-butyl acetate, the relative evaporation rate of solvent B is 0.4 or less.

[0125] Here, the relative evaporation rate based on the solvent n-butyl acetate is the evaporation rate measured in accordance with ASTM D3539-87 (2004). Specifically, it is a value defined as the relative value of the evaporation rate based on the time required for 90% by mass of n-butyl acetate to evaporate in dry air.

[0126] The lower limit of the relative evaporation rate of the solvent is not a problem as long as the solvent can be evaporated and removed from the coating film in the drying step, and in a general coating step, it is sufficient if it is 0.005 or more.

[0127] Solvents include isobutyl ketone (relative evaporation rate: 0.2), isophorone (relative evaporation rate: 0.026), diethylene glycol monobutyl ether (relative evaporation rate: 0.004), diacetone alcohol (relative evaporation rate: 0.15), oleyl alcohol (relative evaporation rate: 0.003), ethylene glycol monoethyl ether acetate (relative evaporation rate: 0.2), nonylphenoxyethanol (relative evaporation rate: 0.25), propylene glycol monoethyl ether (relative evaporation rate: 0.1), and cyclohexanone (relative evaporation rate: 0.32).

[0128] [Other components in the coating composition] The coating composition used in the aforementioned method for producing a resin film preferably contains an antioxidant, a polymerization initiator, a curing agent, and a catalyst. The polymerization initiator and catalyst are used to promote crosslinking of the resin film. The polymerization initiator is preferably one that can initiate or promote polymerization, condensation, or crosslinking reactions of components contained in the coating composition through anionic, cationic, or radical polymerization reactions, etc.

[0129] Antioxidants are broadly classified into radical chain initiation inhibitors, radical scavengers, and peroxide decomposers based on their mechanism of action. Any of these can achieve the effects of the present invention, namely, inhibiting deterioration under high-temperature conditions. However, radical scavengers or peroxide decomposers are more preferred, and hindered phenol-based or semi-hindered phenol-based radical scavengers, or phosphite-based or thioether-based peroxide decomposers are particularly preferred.

[0130] Various polymerization initiators, curing agents, and catalysts can be used. The polymerization initiators, curing agents, and catalysts may be used alone, or multiple polymerization initiators, curing agents, and catalysts may be used simultaneously. Furthermore, an acidic catalyst or a thermal polymerization initiator may be used in combination. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, and acetic acid. Examples of thermal polymerization initiators include peroxides and azo compounds. Examples of photopolymerization initiators include alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, and amine compounds. Examples of crosslinking catalysts that promote the urethane bond-forming reaction include dibutyltin dilaurate and dibutyltin diethylhexoate.

[0131] As the photopolymerization initiator, an alkylphenone compound is preferable from the viewpoint of curability. Specific examples of the alkylphenone compound include 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-phenyl)-1-butane, 2-benzyl-2-dimethylamino-1-(4- Examples include 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexyl-phenyl ketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, and polymerized versions of these materials.

[0132] Furthermore, a leveling agent, a lubricant, an antistatic agent, etc. may be added to the coating composition used to form the resin film, as long as the effects of the present invention are not impaired. As a result, the resin film can contain the leveling agent, the lubricant, the antistatic agent, etc.

[0133] Examples of the leveling agent include acrylic copolymers, silicone-based, and fluorine-based leveling agents. Examples of the antistatic agent include metal salts such as lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, magnesium salts, and calcium salts.

[0134] [Application example] The resin film of the present invention is flexible and has high restoring properties, and also has sufficiently high rigidity at around room temperature and exhibits little change in mechanical properties due to temperature, and can be suitably used in a variety of applications.

[0135] For example, the material can be suitably used for in-vehicle devices, wearable devices, components for healthcare devices, automobile parts, stretchable sensors, and stretchable actuators.

[0136] In addition, from the viewpoint of flexibility and high stress relaxation rate, it can be suitably used for various surface materials, internal materials, constituent materials and manufacturing process materials, such as adhesive tape substrates that require recovery, shock absorbing materials for displays, medical film substrates, automotive surface protection film substrates, pressure sensor core materials, plastic molded products such as eyeglasses and sunglasses, cosmetic boxes and food containers, aquariums, showcases for exhibitions and the like, smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, sensors, circuit materials, electrical and electronic applications, home appliances such as keyboards, television and air conditioner remote controls, mirrors, window glass, buildings, dashboards, car navigation systems and touch panels, vehicle parts such as rearview mirrors and windows, as well as various printed materials, medical films, sanitary material films, medical films, agricultural films and building material films.

[0137] Furthermore, it can be suitably used for applications involving roll-to-roll processes, adhesive tapes, various functional film substrates, sensor materials, shock absorbing materials, vibration absorbing materials, buffer materials, and sealing materials. [Example]

[0138] The present invention will now be described with reference to examples, but the present invention is not necessarily limited to these. The components and abbreviations used in the examples and comparative examples are as follows:

[0139] [Urethane acrylate] [Urethane acrylate 1] A four-neck flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet was charged with 0.43 mol% isophorone diisocyanate and 0.29 mol% polytetramethylene glycol (PTMG2000, manufactured by Mitsubishi Chemical Corporation), diluted with toluene to a solids concentration of 60% by mass, and the mixture was allowed to react at 90°C. When the remaining isocyanate groups reached 1.4% by mass of the initial amount added, the temperature was lowered to 70°C, and 0.29 mol% 4-hydroxybutyl acrylate was added and the reaction was continued. When the remaining isocyanate groups reached 0.3% by mass of the initial amount added, the reaction was terminated, and toluene was added to adjust the solids concentration to 60% by mass, thereby obtaining a toluene solution of urethane acrylate 1.

[0140] [Urethane acrylate 2] A four-neck flask equipped with a thermometer, stirrer, water-cooled condenser, and nitrogen gas inlet was charged with 0.43 mol% isophorone diisocyanate and 0.29 mol% polybutylene adipate ("Nippolan" (registered trademark) 3027, manufactured by Tosoh Corporation), diluted with toluene to a solids concentration of 60% by mass, and reacted at 90°C. When the remaining isocyanate groups reached 1.4% by mass of the initial amount added, the temperature was lowered to 70°C, and 0.29 mol% hydroxyethyl acrylate was added and reacted. When the remaining isocyanate groups reached 0.3% by mass of the initial amount added, the reaction was terminated, and toluene was added to adjust the solids concentration to 60% by mass, yielding a toluene solution of urethane acrylate 1.

[0141] [Urethane acrylate 3] 50 parts by mass of toluene, 50 parts by mass of isocyanurate-modified hexamethylene diisocyanate ("Takenate" (registered trademark) D-170N manufactured by Mitsui Chemicals, Inc.), 76 parts by mass of polycaprolactone-modified hydroxyethyl acrylate ("Placcel" (registered trademark) FA5 manufactured by Daicel Chemical Industries, Ltd.), 0.02 parts by mass of dibutyltin laurate, and 0.02 parts by mass of hydroquinone monomethyl ether were mixed and maintained at 70°C for 5 hours. Then, 79 parts by mass of toluene was added to obtain a toluene solution of urethane acrylate 3 with a solids concentration of 50% by mass.

[0142] [Acrylate] [Acrylate 1] As acrylate 1, IRR-214K (tricyclodecane dimethanol diacrylate manufactured by Daicel Allnex) was used.

[0143] [Acrylate 2] As acrylate 2, "Viscoat" V#310HP (tripropylene glycol diacrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used.

[0144] [Acrylate 3] As acrylate 3, tetraethylene glycol diacrylate was used.

[0145] [Photoradical polymerization initiator] [Photoradical polymerization initiator 1] As the photoradical polymerization initiator 1, "Omnirad" (registered trademark) 184 (manufactured by IGM Group BV) was used.

[0146] [Paint composition formulation] [Paint composition 1] The following materials were mixed in the following ratios and diluted with methyl ethyl ketone to obtain a coating composition 1 with a solids concentration of 30 mass %. Urethane acrylate 1: 35 parts by weight Acrylate 1: 15 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0147] [Paint composition 2] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition 2 having a solids concentration of 30% by mass. Urethane acrylate 1: 42.5 parts by weight Acrylate 1: 7.5 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0148] [Paint composition 3] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition 3 having a solids concentration of 30% by mass. Urethane acrylate 1: 37.5 parts by weight Acrylate 2: 12.5 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0149] [Paint composition 4] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition 4 having a solids concentration of 30 mass %. Urethane acrylate 1: 35 parts by weight Acrylate 3: 15 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0150] [Paint composition 5] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition 5 having a solids concentration of 30 mass %. Urethane acrylate 2: 35 parts by weight Acrylate 3: 15 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0151] [Paint composition 6] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition 6 having a solids concentration of 30 mass %. Urethane acrylate 1: 50 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0152] [Paint composition 7] The following materials were mixed and diluted with methyl ethyl ketone to obtain coating composition 7 with a solids concentration of 30 mass %. Urethane acrylate 3: 45 parts by weight Acrylate 1:5 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0153] [Supporting base material] [Support base material 1] As the supporting substrate 1, a PET film with a release layer, "Cerapeel" (registered trademark) SY (thickness: 50 μm, manufactured by Toray Advanced Film Co., Ltd.) was used.

[0154] [Support base material 2] As the supporting substrate 2, a PET film "Lumirror" (registered trademark) S10 (thickness: 50 μm, manufactured by Toray Industries, Inc.) was used.

[0155] [Thermoplastic urethane film] [Thermoplastic urethane film 1] As the thermoplastic urethane film 1, "ESMER" (registered trademark) URS PX98 (thickness 150 μm, manufactured by Nihon Matai Co., Ltd.) was used.

[0156] Furthermore, when the composition of "ESMER" (registered trademark) URS PX98 was confirmed, it was found to be composed of a 50 μm thick polyester film layer, a 150 μm thick thermoplastic urethane film layer, and a 75 μm thick polyester film layer laminated in that order. Therefore, the 50 μm thick polyester film and the 75 μm thick polyester film were peeled off, and the thermoplastic urethane film was treated as a resin film.

[0157] [Formation of resin film] A laminate was formed on a supporting substrate by using the combinations shown in Table 1 of the coating composition for resin layer described above and the method for forming a resin layer described below.

[0158] [Method 1 for forming a resin layer] [Process 1] In step 1, the above-mentioned resin layer coating composition was applied to the supporting substrate (or the surface on the release layer side if a release layer was attached) using a continuous coating device such as a slot die coater, adjusting the discharge flow rate so that the thickness of the resin film after crosslinking would be the film thickness shown in the table, thereby forming a coating layer.

[0159] [Process 2] In step 2, the coating layer formed in step 1 was dried under the following conditions to remove the solvent. ·Blow temperature: Temperature: 80℃. ·Wind speed: Application side: 5m / sec, non-application side: 5m / sec. Wind direction: coated side: parallel to the surface of the substrate, non-coated side: perpendicular to the surface of the substrate. Dwell time: 2 minutes.

[0160] [Step 3] In step 3, the coating layer (uncrosslinked resin layer) obtained by removing the solvent was irradiated with active energy rays under the following conditions to be crosslinked, thereby obtaining a resin film and a laminate. · Light source: High pressure mercury lamp. Irradiation output: 400W / cm 2 . Accumulated light output: 120mJ / cm 2 . Oxygen concentration: 0.1% by volume.

[0161] The supporting substrate was peeled off from the laminate produced by the above method to produce resin films of Examples 1 to 6 and Comparative Examples 1 and 3. In Comparative Example 2, a thermoplastic urethane film 1 was used.

[0162] Table 1 also shows whether each segment of each chemical formula of the resin film is contained or not.

[0163] For Comparative Example 1, whether each segment was contained was confirmed by TOF-SIMS and FT-IR.

[0164] In Table 1, "contains" in the column for each chemical formula means that the resin film in each example contains a segment of the corresponding chemical formula, and "does not contain" means that the resin film in each example does not contain a segment of the corresponding chemical formula.

[0165] [Table 1]

[0166] [Evaluation of resin film] The resin films were evaluated for the following performance. Unless otherwise specified, measurements were taken three times for each sample in each example at different locations, and the average value was used.

[0167] [Thickness of resin film] The thickness of the resin film was measured by observing the cross section using a scanning electron microscope (SEM) according to the following method. The layer thickness was read from an image of a cross-sectional slice of the resin film taken with an SEM at 3,000x magnification using software (image processing software ImageJ). The layer thickness was measured at a total of 30 points, and the average value was used as the measured value.

[0168] [Recovery rate] The laminate was cut into a 10 mm wide x 150 mm long rectangle, and the resin film was peeled off from the support substrate to prepare a test specimen. The 150 mm long direction was aligned with the longitudinal direction of the laminate. Using a tensile tester (A&D Co., Ltd., Universal Material Tester RTG-1210), the initial chuck distance was set to 20 mm, the tensile speed was set to 300 mm / min, and the test specimen was stretched to a strain of 10 mm (50%). After the tensile load on the test specimen was released, the distance marked as the initial test length before measurement was measured and defined as L mm. The recovery rate was calculated using the following formula. Measurements were performed at a temperature of 23°C and a humidity of 65% RH.

[0169] Recovery rate [%] = (1-(L-20) / 10) x 100 [Storage modulus, glass transition temperature, calculation of regression line, determination of phase separation structure] Based on the tensile vibration-non-resonance method of JIS K7244 (1998) (this is called the dynamic viscoelasticity method), the storage modulus and loss modulus of the resin film were determined using a dynamic viscoelasticity measuring device DMS6100 manufactured by Seiko Instruments Inc. The loss tangent was calculated from the obtained values, and a curve of temperature vs. loss tangent was plotted. The temperature at which the loss tangent reached its maximum value was determined as the glass transition temperature.

[0170] In addition, when there are multiple temperatures at which the loss tangent shows a maximum value, the temperature at which the loss tangent shows a maximum value in the temperature range where the storage modulus is 10 MPa or more is prioritized as the glass transition temperature, and when the temperature at which the loss tangent shows a maximum value cannot be determined at a single point, the temperature at which the loss tangent shows the largest value is prioritized as the glass transition temperature. Measurement mode: Tensile Chuck distance: 20mm Test piece width: 10 mm Frequency: 1Hz Distortion amplitude: 10μm Initial force amplitude: 40 mN Measurement temperature: -100℃ to 100℃ Heating rate: 5°C / min Loss tangent: (loss modulus) / (storage modulus).

[0171] To calculate the regression line for the relationship between E'(0), E'(25), and E'(50) and each temperature using the least squares method, the average values ​​of E'(0), E'(25), and E'(50) were first calculated from each data point, and the regression line and its coefficient of determination were calculated from each average value using the least squares method.

[0172] Regarding whether a resin film has a phase-separated structure, if there are two or more glass transition temperatures in the graph of loss tangent versus temperature, it is judged to have a phase-separated structure. However, if the half-width at the maximum value is 5°C or less, it is judged to be noise and not an indication of a glass transition temperature.

[0173] [5% strain stress] The laminate was cut into a 10 mm wide x 150 mm long rectangle, and the resin film was peeled off from the support substrate to prepare a test specimen. The 150 mm long direction was aligned with the longitudinal direction of the laminate. Tensile tests were performed using a tensile testing machine (A&D Co., Ltd., Universal Material Testing Machine RTG-1210) with an initial tensile chuck distance of 50 mm and a tensile speed of 300 mm / min at a temperature of 23°C and a humidity of 65% RH.

[0174] Read the load b (N) applied to the sample when the chuck distance is a (mm), and use the following formula to calculate the strain [%] and stress y [MPa = N / mm 2 ] was calculated, where the sample thickness before the test is k [mm]. (Strain amount) = ((a-50) / 50) x 100 (Stress y) = b / (k × 10).

[0175] Of the data obtained above, the stress at a strain of 5% was defined as the 5% strain stress.

[0176] [Hayes] The laminate was cut into a 100 mm wide x 100 mm long piece, and the resin film was peeled off from the support substrate to prepare a test piece. Haze was measured using a haze meter (NDH-5000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7136 (2000).

[0177] [Flexibility evaluation] The resin film was pulled by hand in a room temperature environment, and the result was evaluated according to the following criteria. 7 points: Can be stretched by hand. 1 point: Other (cannot be stretched by hand, breaks without stretching, etc.).

[0178] [Rigidity evaluation] The resin film was pulled by hand in a room temperature environment, and the result was evaluated according to the following criteria. 10 points: Does not deform even when strong force is applied. 7 points: Can be deformed with a moderate amount of force. 4 points: Can be deformed with light force. 1 point: Other (deforms with very little force, etc.).

[0179] [Evaluation of temperature dependency] The resin film was manually stretched in environments of 0°C, 25°C, and 50°C, and the linearity of the deformation behavior with respect to temperature was evaluated by comparing the difference between the deformation behavior at 0°C and that at 25°C (difference 1) and the difference between the deformation behavior at 25°C and that at 50°C (difference 2), and a judgment was made according to the following criteria. 10 points: Difference 1 and Difference 2 are exactly or almost the same. 7 points: Difference 1 and Difference 2 are slightly different. 4 points: Difference 1 and Difference 2 are significantly different. 1 point: Other (breaks depending on temperature, cannot deform depending on temperature, does not recover depending on temperature, etc.).

[0180] [Evaluation of heat resistance] The resin film was heated in a 200°C environment for 5 minutes, and then its appearance was observed and judged according to the following criteria. 10 points: The film retains its shape. 1 point: Other (melts and cannot maintain film shape, etc.).

[0181] [Evaluation of resilience] In a room temperature environment, the resin film was subjected to tensile deformation by applying a light force by hand, and the deformation was evaluated according to the following criteria. 10 points: After deformation, the material returns to its original shape when the load is removed. 7 points: After deformation, when the load is removed, the material returns to almost its original shape. 4 points: After deformation, when the load is removed, the material returns to its original shape slightly. 1 point: Other (no recovery, breakage, etc.).

[0182] Tables 2 and 3 summarize the evaluation results of each of the Examples and Comparative Examples.

[0183] [Table 2]

[0184] [Table 3] [Explanation of symbols]

[0185] 1 Resin film 2 Resin film 3 Supporting base material 4 Protective material 5 Resin film 6 Supporting base material 11 Electrical circuit body 12 Resin film 13 Electrical Circuits 21 Resin film 22 Wiring circuit 23 Electrode section 24 Electrical circuit body 31 Temperature [℃] 32 Storage modulus [MPa] 33 Storage modulus data 41 Temperature [℃] 42 Storage modulus [MPa] 43 Storage modulus data 44 Regression line of the relationship between temperature (0℃, 25℃, 50℃) and storage modulus 51 Temperature [℃] 52 Loss tangent 53 Loss tangent data 54 Temperature at which the loss tangent shows its maximum value [℃] [Industrial Applicability]

[0186] The resin film of the present invention is flexible and has high restoring properties, and also has sufficiently high rigidity at around room temperature and exhibits little change in mechanical properties due to temperature, and can be suitably used in a variety of applications.

[0187] For example, the material can be suitably used for in-vehicle devices, wearable devices, components for healthcare devices, automobile parts, stretchable sensors, and stretchable actuators.

[0188] In addition, from the viewpoint of flexibility and high stress relaxation rate, it can be suitably used for various surface materials, internal materials, constituent materials and manufacturing process materials, such as adhesive tape substrates that require recovery, shock absorbing materials for displays, medical film substrates, automotive surface protection film substrates, pressure sensor core materials, plastic molded products such as eyeglasses and sunglasses, cosmetic boxes and food containers, aquariums, showcases for exhibitions and the like, smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, sensors, circuit materials, electrical and electronic applications, home appliances such as keyboards, television and air conditioner remote controls, mirrors, window glass, buildings, dashboards, car navigation systems and touch panels, vehicle parts such as rearview mirrors and windows, as well as various printed materials, medical films, sanitary material films, medical films, agricultural films and building material films.

[0189] Furthermore, it can be suitably used for applications involving roll-to-roll processes, adhesive tapes, various functional film substrates, sensor materials, shock absorbing materials, vibration absorbing materials, buffer materials, and sealing materials.

Claims

1. A resin film made of a resin having a segment of Chemical Formula 1 and a segment of Chemical Formula 2, A resin film characterized in that the storage modulus E'(25) at 25°C is 10 MPa or more, and the storage modulus E'(0) at 0°C and the storage modulus E'(50) at 50°C satisfy the following formula: 1.0 ≧ E'(25) / E'(0) ≧ 0.20 1.0 ≧ E'(50) / E'(25) ≧ 0.20 The storage modulus is measured under the following conditions. The storage modulus is measured based on the tensile vibration-non-resonance method of JIS K7244 (1998) under the following conditions: distance between chucks 20 mm, test piece width 10 mm, frequency 1 Hz, strain amplitude 10 μm, initial force amplitude 40 mN, temperature rise rate 5°C / min, and measurement temperature range from -100°C to 100°C. 【Chemical 1】 【Chemistry 2】 R １ refers to a hydrogen or methyl group. R ２ refers to one of the following: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group, an ester group, or an amide group therein an arylene group having an ether group, an ester group, or an amide group therein Unsubstituted alkylene group having an ether group, ester group, or amide group inside An unsubstituted arylene group having an ether group, an ester group, or an amide group therein.

2. The resin film according to claim 1, which satisfies the following condition 1: Condition 1: When a regression line is calculated by the least squares method for the relationship between E'(0), E'(25), and E'(50) and each temperature, the coefficient of determination of the regression line is 0.85 or more.

3. The resin film according to claim 1 or 2, which satisfies the following condition 2: Condition 2: The 5% strain stress of the resin film is 1.0 MPa or more.

4. The resin film according to claim 3, which satisfies the following condition 3: Condition 3: The glass transition temperature of the resin film determined by the dynamic viscoelasticity method is 0°C or lower.

5. The resin film according to claim 4, which satisfies the following condition 4: Condition 4: The haze of the resin film is 10% or less.

6. 3. The resin film according to claim 1, wherein the resin film satisfies the following condition 5: Condition 5: A resin film obtained by curing a component A having a segment of Chemical Formula 1 and a segment of Chemical Formula 2, and a component B having a segment of Chemical Formula 1, wherein components A and B are different components, and the resin film has a phase-separated structure.

7. The resin film according to claim 6, which satisfies the following condition 6: Condition 6: The resin film is made of a resin having at least one of a segment of Chemical Formula 3 and a segment of Chemical Formula 4. 【Chemistry 3】 R ３ indicates one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein 【Chemistry 4】 R ４ indicates one of the following, where n is an integer of 5 or greater: Substituted or unsubstituted alkylene groups Substituted or unsubstituted arylene groups An alkylene group having an ether group or an ester group inside An arylene group having an ether group or an ester group therein Unsubstituted alkylene group having an internal ether group or ester group An unsubstituted arylene group having an ether group or an ester group therein

8. A laminate comprising the resin film according to claim 1 or 2.

9. An electric circuit body comprising the resin film according to claim 1 or 2 and a conductor circuit formed on the resin film.

10. A healthcare sensor comprising the resin film according to claim 1 or 2 and a conductor circuit formed on the resin film.

11. A wearable sensor comprising the resin film according to claim 1 or 2 and a conductor circuit formed on the resin film.

12. A display comprising the resin film according to claim 1 or 2.

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