Resin film, laminate, laminate manufacturing method, electric circuit, health care sensor, wearable sensor, and manufacturing method of resin film processed product

Abstract

To provide: the resin film and laminate having both printing plate separability and adhesiveness with a printed layer while having high flexibility and restorability; laminate production method; electric circuit; healthcare sensor; wearable sensor; and production method for resin film processed goods.SOLUTION: The resin film satisfying all of the following conditions 1 to 3 is provided. Condition 1: the storage elastic modulus of the resin film at 25°C under the condition of frequency 1 Hz is 0.5 MPa or more and 50 MPa or less. Condition 2: the loss tangent of the film at 25°C is 0.5 or less. Condition 3: the flat part percentage in at least one surface of the film by a laser microscope is 70% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin film that has high flexibility and resilience while achieving both good plate releasability during the printing process and good adhesion to a printing layer, a laminate, a method for manufacturing a laminate, an electric circuit, a healthcare sensor, a wearable sensor, and a method for manufacturing a resin film processed product. [Background technology]

[0002] In recent years, with the advancement of the IoT society, there has been active development of wearable sensors. Wearable sensors are attached to parts of the body, such as the arms, legs, or head, and constantly monitor the dynamic movements of the entire body, as well as minute pressures and electrical signals inside the body. Development is underway in a variety of fields, including industrial and medical applications, and it is expected that these sensors will fundamentally change our lives by collecting massive amounts of data and using this data to provide alarms and advice.

[0003] Various resin films have been considered as the substrate for these devices. However, conventional materials, such as polyimide, have rigid chemical bonds and strong crystallinity, and while they can bend freely, they cannot be stretched or contracted. Therefore, there is a need for a substrate material that can be easily stretched and instantly restored to its original shape.

[0004] As a representative example of a resin film having such high flexibility and recovery, 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." Also proposed is Patent Document 2, which proposes "a conductive film that has good wearability and shape conformability, as well as small changes in electrical resistance when stretched," and Patent Document 3, which proposes "a stretchable film that has excellent stretchability and strength, and also has excellent water repellency on the film surface, and is not sticky on the surface." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-189886 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-199654 [Patent Document 3] Japanese Patent Application Publication No. 2020-105485 Summary of the Invention [Problem to be solved by the invention]

[0006] To be used as a sensor, it is necessary to mount stretchable wiring and electrodes on the substrate, and possible mounting methods include offset printing, gravure printing, and screen printing. As the realization of sensors using materials that can be easily stretched and instantly restored approaches, there has recently been a demand for increasing productivity by ensuring adhesion between the printed layer, including the wiring and electrodes, and the resin film, while avoiding printing defects such as sticking between the printing plate and the resin film during the printing process.

[0007] The resin film used in the aforementioned wearable sensors must have both flexibility, allowing it to be stretched significantly with a weak force, and resilience, allowing it to almost completely recover at temperatures below 0°C and at a rapid cycle of more than once per second. Highly flexible materials generally have high tackiness, but it has been found that high tackiness can lead to printing defects caused by the film sticking to the printing plate during printing. One way to achieve both flexibility and plate releasability is to reduce the polarity of the resin film surface, thereby reducing the interfacial interaction between the printing plate and the resin film. However, this also reduces the interfacial interaction between the resin film and printed layers, such as wiring and electrodes, making adhesion weaker. In other words, resin films must meet all four of their properties—flexibility, resilience, plate releasability, and print layer adhesion—at high levels.

[0008] In response to the above demands, the present inventors checked the above-mentioned points and found that the material proposed in Patent Document 1 had excellent "flexibility" and good "printing layer adhesion," but was insufficient in "resilience" and "printing plate releasability."

[0009] The material proposed in Patent Document 2 is excellent in "printing plate releasability" and "printing layer adhesion," but is insufficient in "flexibility" and "restorability."

[0010] Furthermore, the material proposed in Patent Document 3 is excellent in "flexibility," "resilience," and "printing plate releasability," but is insufficient in "printing layer adhesion." Furthermore, when the material described in Patent Document 1 is given an uneven shape as described in Patent Document 3, the "printing plate releasability" is improved compared to Patent Document 1, but is insufficient, and the "printing layer adhesion" is improved compared to Patent Document 3, but is insufficient.

[0011] In view of the above, an object of the present invention is to provide a resin film or laminate that has high flexibility and resilience while achieving both good releasability of the printing plate during the printing process and good adhesion to the printing layer, a method for manufacturing a laminate, an electric circuit, a healthcare sensor, a wearable sensor, and a method for manufacturing a resin film processed product. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above problems and have completed the following inventions. That is, preferred embodiments of the resin film, laminate, laminate manufacturing method, electric circuit, healthcare sensor, wearable sensor, and resin film processed product manufacturing method of the present invention are as follows. (1) A resin film that meets all of the following conditions 1 to 3.

[0013] Condition 1: The storage modulus of the resin film at a temperature of 25°C and a frequency of 1 Hz is 0.5 MPa or more and 50 MPa or less.

[0014] Condition 2: The loss tangent of the resin film at 25°C is 0.5 or less.

[0015] Condition 3: The flat area ratio on at least one surface of the resin film measured by a laser microscope is 50% or less . (2) The resin film according to (1), which satisfies the following condition 4:

[0016] Condition 4: The root mean square roughness Rq of at least one surface of the resin film is 400 nm or more. (3) The resin film according to (1) or (2), which satisfies the following condition 5:

[0017] Condition 5: On at least one surface of the resin film, the contact angle hysteresis of the resin film with water, as measured by the dynamic contact angle expansion / contraction method, is 5° or more.

[0018] Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle. (4) A resin film according to any one of (1) to (3), which satisfies the following condition 6:

[0019] Condition 6: The arithmetic mean roughness Ra on at least one surface of the resin film is 430 nm or more. (5) A resin film according to any one of (1) to (4), which satisfies the following condition 7:

[0020] Condition 7: The maximum height Rz on at least one surface of the resin film is 8 μm or more. (6) A resin film according to any one of (1) to (5), which satisfies the following condition 8:

[0021] Condition 8: The surface free energy of at least one surface of the resin film is 30 mN / m or more. (7) A resin film according to any one of (1) to (6), which satisfies the following condition 9:

[0022] Condition 9: On at least one surface of the resin film, the surface area per 1 mm square of the resin film is 1.3 mm 2 That's all. (8) A resin film according to any one of (1) to (7), which satisfies the following condition 10:

[0023] Condition 10: On at least one surface of the resin film, the contact angle hysteresis of the resin film with propylene glycol monomethyl ether acetate (PGMEA) obtained by the dynamic contact angle expansion and contraction method is 5° or more.

[0024] Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle. (9) A resin film according to any one of (1) to (8), which satisfies the following condition 11:

[0025] Condition 11: Haze of the resin film is 30% or more and 70% or less (10) A resin film according to any one of (1) to (9), which contains a structure of Chemical Formula 1 and a urethane bond.

[0026] [ka]

[0027] In addition, R in Chemical Formula 1 1 refers to a hydrogen or methyl group. (11) A resin film according to any one of (1) to (10), which contains a segment of Chemical Formula 2 and further contains either a segment of Chemical Formula 3 or a segment of Chemical Formula 4.

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] p is an integer of 1 or greater.

[0032] r is an integer of 1 or greater.

[0033] s is an integer of 1 or greater. (12) The resin film according to any one of (1) to (11), comprising at least one segment selected from the group consisting of a segment of Chemical Formula 5, a segment of Chemical Formula 6, a segment of Chemical Formula 7, a segment of Chemical Formula 8, and a segment of a hydrogenated product thereof.

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] (13) The resin film according to any one of (1) to (12), which is a single layer. (14) A laminate comprising a substrate on at least one of the resin films according to any one of (1) to (13). (15) The method for producing a laminate according to (14), wherein steps 1, 2, 3, and 4 are carried out in this order. Step 1: A step of applying a coating composition containing a resin precursor containing a segment of Chemical Formula 9 and a solvent onto a substrate A that satisfies Condition 12 to form a coating layer. Condition 12: The flat area ratio of at least one surface of the substrate A measured by a laser microscope is 50% or less .

[0039] [ka]

[0040] Step 2: Removing the solvent from the coating layer. Step 3: A step of crosslinking the resin precursor by irradiating it with active energy rays. Step 4: A step of attaching a substrate B to the surface of the coating layer opposite to the substrate A, and then peeling off the substrate A. (16) An electric circuit body comprising the resin film according to any one of (1) to (13) above and a conductor circuit formed on the resin film. (17) A healthcare sensor comprising the resin film according to any one of (1) to (13) and a conductor circuit formed on the resin film. (18) A wearable sensor comprising the resin film according to any one of (1) to (13) and a conductor circuit formed on the resin film. (19) A method for producing a resin film processed product, comprising a step of processing the resin film according to any one of (1) to (13) by screen printing. [Effects of the Invention]

[0041] It is possible to provide resin films and laminates that have high flexibility and resilience while also achieving both ease of separation from the printing plate during the printing process and adhesion to the printing layer, as well as methods for manufacturing laminates, electrical circuits, healthcare sensors, wearable sensors, and methods for manufacturing resin film processed products. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a cross-sectional view showing an example of a laminate according to the present invention. [Figure 2] 1 is a cross-sectional view showing an example of a laminate according to the present invention. [Figure 3]1 is a cross-sectional view showing an example of a laminate according to the present invention. [Figure 4] 1 is a cross-sectional view showing an example of a laminate according to the present invention. [Figure 5] FIG. 1 is a plan view showing an example of a screen plate according to the present invention. [Figure 6] FIG. 1 is a plan view showing an example of a screen plate according to the present invention. [Figure 7] 1 is a plan view showing an example of an electric circuit body according to the present invention. [Figure 8] 1 is a plan view showing an example of an electric circuit body according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] The present inventors believe that the reason why it is difficult to solve the problems of the present invention using conventional techniques is as follows.

[0044] First, let us consider the mechanism by which a resin film sticks to a printing plate. A highly flexible resin film, such as that required for this application, easily conforms to the uneven shape of the printing plate, resulting in interfacial interaction between the resin film and the printing plate, creating "tackiness." In particular, a flat resin film is thought to have a high degree of tackiness, as its entire surface conforms to the uneven shape of the printing plate. Therefore, a highly flexible and flat resin film is more likely to stick to the printing plate during the printing process.

[0045] One method for suppressing adhesion to the printing plate is to reduce the surface free energy of the resin film, such as by using silicone-based or olefin-based materials. In this case, the interfacial interaction with the printing layer is reduced, which can result in a trade-off in "printing layer adhesion." Another method is to reduce tackiness by increasing the elastic modulus of the resin film, but this increases the crosslink density of the resin film, which can result in a trade-off in "flexibility." Therefore, it is thought that these measures will be difficult to satisfy all of the requirements for "flexibility," "resilience," "printing plate release," and "printing layer adhesion."

[0046] From the above perspective, we will consider in detail why the materials described in the patent documents were unable to satisfy the four requirements of "flexibility," "resilience," "printing plate releasability," and "printing layer adhesion."

[0047] The material described in Patent Document 1 uses polyurethane, with the polyether polyol portion functioning as a flexible soft segment and the urethane portion functioning as a hard segment with high cohesive strength, forming a microphase-separated structure. To impart flexibility, the cohesive strength of the urethane portion, which is the hard segment, is reduced, resulting in reduced recovery. This material is also highly flexible and has a flat shape all over. Therefore, it is believed that the entire surface of this material conforms to the uneven shape of the printing plate, resulting in insufficient plate releasability. On the other hand, both the soft and hard segments are formed from segments with relatively high polarity, which is believed to provide good adhesion to the printing layer.

[0048] The material described in Patent Document 2 is an epoxy material with a high elastic modulus, to which a substrate with a textured surface created by plasma treatment has been transferred. The high elastic modulus results in low tackiness and good plate releasability, but the high crosslink density is thought to result in insufficient flexibility.

[0049] The material described in Patent Document 3 is a silicone material with a concave-convex pattern. Because the surface free energy is low and the surface is shaped, when the resin film comes into contact with the printing plate, some areas are not in contact, reducing the contact area. Therefore, it is believed that the printing plate releasability is good. On the other hand, the low surface free energy of this material reduces the interfacial interaction with the printing layer. Furthermore, this material contains flat areas and has a sharp change in the height difference direction of the concave-convex shape. It is believed that the printing paste does not easily penetrate into the concave portions of the resin film during printing, creating a gradient in the printing layer at the concave and convex portions. Therefore, it is presumed that the adhesion of the printing layer was insufficient.

[0050] Furthermore, when the polyurethane described in Patent Document 1 is given an uneven shape as described in Patent Document 3, the contact area with the printing plate is reduced, which is thought to improve printing plate releasability compared to Patent Document 1. However, although there are raised portions, they are flat, and it is thought that these portions cause the printing plate to stick, resulting in insufficient printing plate releasability. Furthermore, although the increased polarity of the resin composition improves printing layer adhesion compared to Patent Document 3, this material includes flat portions and changes rapidly in the height direction of the uneven shape, making it difficult for the printing paste to penetrate into the recessed portions of the resin film during printing, resulting in a gradient of the printing layer at the recessed and raised portions, which is thought to result in insufficient adhesion to the printing layer.

[0051] In response to this, the inventors have succeeded in solving the above-mentioned problems by using a material with high flexibility and resilience and reducing the flat surface ratio on the surface to obtain a resin film that satisfies both the printing plate releasability during the printing process and adhesion to the printing layer, thereby arriving at the present invention. Furthermore, it has been discovered that an unexpected effect obtained by achieving both the printing plate releasability and adhesion to the printing layer is that changes in the resistance value of the printing layer can be suppressed even when stretching is repeated, enabling stable detection of electrical signals. The details of the present invention are described below.

[0052] A preferred embodiment of the laminate of the present invention is a resin film that satisfies all of the following conditions 1 to 3.

[0053] Condition 1: The storage modulus of the resin film at a temperature of 25°C and a frequency of 1 Hz is 0.5 MPa or more and 50 MPa or less.

[0054] Condition 2: The loss tangent of the resin film at 25°C is 0.5 or less.

[0055] Condition 3: The flat area ratio on at least one surface of the resin film is 70% or less as measured by a laser microscope.

[0056] By adopting the above-mentioned embodiment, it is possible to achieve both high flexibility and recovery, good releasability during the printing process, and good adhesion to the printing layer. Furthermore, it is possible to suppress changes in the resistance value of the printing layer when it expands or contracts.

[0057] (Condition 1, 2) The resin film of the present invention preferably has a storage modulus of 0.5 MPa or more and 50 MPa or less under conditions of a temperature of 25°C and a frequency of 1 Hz. A storage modulus of 0.5 MPa or more can prevent the resin film from becoming too tacky and making it difficult to handle, while a storage modulus of 50 MPa or less can make the resin film easily deformable. From the same viewpoint, a storage modulus of 1.0 MPa or more and 25 MPa or less is more preferable, and a storage modulus of 3.0 MPa or more and 10 MPa or less is even more preferable.

[0058] The resin film of the present invention preferably has a loss tangent at 25°C of 0.5 or less. By setting the loss tangent to 0.5 or less, sufficient restorability can be obtained when used as a resin film. From the same viewpoint, the loss tangent of the resin film at 25°C is more preferably 0.2 or less, and even more preferably 0.05 or less.

[0059] The storage modulus and loss tangent refer to values ​​measured by DMA (dynamic mechanical analysis), and the measurement method will be described later.

[0060] To achieve the storage modulus and loss tangent of a resin film within the above ranges, it is important that the polymer has flexible soft segments and hard segments with high cohesive strength, which form a microphase-separated structure. It is also important that these hard segments form small, strong chemical crosslinks, such as acrylic crosslinks, at a low density while minimizing the contribution of physical crosslinks, such as π-π interactions and hydrogen bonds. To allow physical crosslinks, such as π-π interactions and hydrogen bonds, to function as hard segments, the volume of the hard segments must be increased. This increases the elastic modulus and reduces flexibility. Therefore, it is necessary to form small, strong chemical crosslinks at a low density. A specific method is to mix one or more polymer polyols having an alkyl group or an alkenyl group having 3 or more carbon atoms, which are selected from polyester polyols, polyether polyols, polycarbonate polyols, and polyolefin diols, with TDI (tolylene diisocyanate), MDI (4,4'-diphenylmethane diisocyanate), NDI (1,5-naphthalene diisocyanate), TODI (tolidine diisocyanate), XDI (xylylene diisocyanate), PPDI (paraphenylene diisocyanate), TMXDI (tetramethyl methyl methacrylate), and the like. A preferred method involves reacting one or more bifunctional isocyanates selected from methylxylylene diisocyanate, HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), H6XDI (hydrogenated xylylene diisocyanate), and H12MDI (dicyclohexylmethane diisocyanate) with one or more acrylic raw materials selected from HEA (hydroxyethyl acrylate) and 4HBA (4-hydroxybutyl acrylate) in a molar ratio of 1:(1-2:(0.4-1.0)), followed by polymerization using heat or active energy rays. Here, when the molar ratio of the high molecular weight polyol is taken as 1, the amount of low molecular weight polyol with a molecular weight of 500 g / mol or less, such as 1,6-hexanediol, triethylene glycol, or 3-methyl-1,5-pentanediol, is preferably 0.1 or less.Regarding the molar ratio of the feed, when the feed amount of the difunctional isocyanate is 1, the feed amount of the tri- or higher functional isocyanate is preferably 0.1 or less. In addition, the ash content in 100% by mass of the resin film is preferably 1% by mass or less. Here, ash content refers to the components when heated at 500°C under nitrogen for 1 hour.

[0061] Furthermore, to obtain a resin film with a desired storage modulus and loss tangent, it is preferable that, relative to 1 mole of the monomer units derived from the polymer polyol, the content of the monomer units derived from the difunctional isocyanate is 1 to 2 moles, the content of the monomer units derived from the acrylic raw material is 0.4 to 1.0 moles, the content of the monomer units derived from the low-molecular-weight polyol is 0.1 moles or less, and the content of the monomer units derived from the trifunctional or higher isocyanate is 0.2 moles or less. Qualitative and quantitative analysis of each monomer unit can be performed by alkaline hydrolysis of the resin film followed by a combination of nuclear magnetic resonance spectroscopy, GC-MS, size exclusion chromatography, and time-of-flight mass spectrometry.

[0062] (Condition 3) The resin film of the present invention preferably satisfies condition 3.

[0063] Condition 3: The flat area ratio of at least one surface of the resin film is 70% or less when measured with a laser microscope.

[0064] The flat area ratio of the resin film surface is a parameter that indicates the frequency of thickness variations of 100 nm or less per 1 μm in the planar direction in line roughness data obtained by observing the resin film with a laser microscope. In other words, by reducing this value, the thickness variations of the resin film surface constantly change, resulting in a matte surface overall. This reduces the number of contact points with the printing plate during the printing process and improves plate releasability. Even if protrusions are present in some areas, if their pitch is wide and the flat area ratio exceeds 70%, the impact of the large number of localized flat areas can be significant, resulting in poor plate releasability. Therefore, a flat area ratio of 70% or less is important from the perspective of plate releasability. Furthermore, if the protrusions are small and the flat area ratio exceeds 70%, the printing plate and resin film may come into full contact due to factors such as the flexibility of the printing plate, resulting in poor plate releasability. Therefore, a flat area ratio of 70% or less is also important from the perspective of plate releasability. Furthermore, by setting the flat area ratio to 70% or less, the entire surface becomes matte, exerting an anchoring effect across the entire interface between the resin film and the printing layer, thereby improving adhesion to the printing layer. If only a portion of the resin film becomes matte, the anchoring effect may only be exerted in a portion, resulting in uneven adhesion between the resin film and the printing layer at the interface. In this case, smooth areas with weak adhesion between the resin film and the printing layer may trigger peeling, resulting in weak adhesion to the printing layer across the entire resin film. Therefore, reducing the flat area ratio of the surface is a method for improving both printing plate releasability and adhesion to the printing layer. In particular, for a material that satisfies conditions 1 and 2, in order to provide printing plate releasability and printing layer adhesion while maintaining both flexibility and resilience, it is important that the flat area ratio shown above is 70% or less. From the same perspective, the flat area ratio of the resin film surface is more preferably 50% or less, and even more preferably 40% or less.

[0065] The flat portion ratio is preferably 5% or more, and more preferably 10% or more. By adopting the above-mentioned embodiment, it is possible to prevent the depressions on the surface from becoming a trigger for breakage when the resin film is stretched, and the inherent stretchability of the resin film can be maintained.

[0066] The flat area ratio of the resin film surface is calculated using the following method. Specifically, a laser microscope (Keyence VK9700) is used to observe the surface at a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm. Line roughness data for 100 μm is then acquired at any point on the observed surface using analysis software (VK viewer). The number of pixels per μm is calculated from the XY calibration values ​​(X and Y distances per pixel) of the acquired line roughness data. The difference in the actual cross-sectional profile (Z-direction height per pixel) is then acquired to determine the Z-direction height difference (a) per μm. This procedure is repeated three times, and a histogram is created from the three acquired line roughness data to calculate the frequency of occurrences of 100 nm or less. The orientation of the three acquired line roughness data is shifted by 120° from any one direction.

[0067] Specific methods for satisfying condition 3 include preferably using a substrate into which particles have been kneaded, a substrate that has been subjected to sandblasting, or a substrate on which a coating layer containing particles has been laminated when producing a resin film; these methods will be described in detail later.

[0068] The resin film required for this application is one that is flexible and resilient, while also achieving both ease of release from the printing plate during the printing process and adhesion to the printing layer. Conditions 1 and 2 relate to flexibility and resilience, respectively, and by satisfying these conditions, high levels of flexibility and resilience can be achieved. On the other hand, as mentioned above, highly flexible resin films tend to be tacky and therefore more likely to stick to the printing plate during the printing process. Three methods can be considered to reduce sticking to the printing plate: 1. reducing surface free energy, 2. increasing the elastic modulus to reduce tackiness, and 3. matting the surface. Method 1 reduces the interfacial interaction on the resin film surface, resulting in a trade-off in adhesion to the printing layer. Method 2 increases the crosslink density within the resin film, resulting in a trade-off in flexibility. Method 3, on the other hand, does not change the interfacial interaction on the resin film surface or the crosslink density within the resin film, and is therefore a preferred method for reducing sticking to the printing plate while maintaining high levels of flexibility, resilience, and adhesion to the printing layer. However, simply providing a matte surface is not sufficient, and the method of providing a pattern on the surface of a resin film to increase the surface roughness or surface height, as described in Patent Document 3, resulted in insufficient plate releasability. Investigation into the cause of this revealed that these resin films had high surface roughness, but the pitch of the unevenness was large, and flat areas were present in the concave or convex areas. It was speculated that these flat areas adhered strongly to the printing plate, resulting in insufficient plate releasability.

[0069] Therefore, in the present invention, we focus on the flat surface ratio and set this value to 70% or less, making it possible to achieve flexibility, resilience, printing plate release properties, and printing layer adhesion, all of which were previously unattainable. Furthermore, as a result of extensive research, the inventors have found that printing plate releasability and printing layer adhesion affect the change in resistance value of the printing layer during expansion and contraction. It is believed that high printing plate releasability reduces the occurrence of blurring or uneven thickness in the wiring of the printing layer, allowing the wiring to expand and contract uniformly when the resin film is expanded and contracted, thereby suppressing wiring breakage. It is also believed that high printing layer adhesion allows the resin film and the printing layer to expand and contract uniformly without peeling when the resin film is expanded and contracted, thereby suppressing wiring breakage. Therefore, it has been found that by setting the surface flatness ratio to 70% or less as in the present invention, it is possible to achieve all of flexibility, recovery, printing plate releasability, and printing layer adhesion, and furthermore, it is possible to suppress changes in the resistance value of the printing layer during expansion and contraction. (Condition 4) The resin film of the present invention preferably satisfies condition 4.

[0070] Condition 4: The root mean square roughness Rq of at least one surface of the resin film is 400 nm or more.

[0071] The root mean square roughness (Rq) is the standard deviation of the arithmetic mean roughness, and a large value indicates that the surface irregularities are non-uniform in size. Therefore, increasing this value reduces the number of contact points with the printing plate during the printing process, improving plate releasability. It also increases the interface between the resin film and the printing layer, enhancing adhesion to the printing layer through an anchoring effect. From a similar perspective, the Rq of the resin film is preferably 600 nm or greater, and even more preferably 800 nm or greater.

[0072] The Rq of a resin film is calculated using the following method. Specifically, in accordance with the measurement of the flat area ratio, observation is performed using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm, and surface roughness data of 100 μm x 100 μm is obtained at any point on the observed surface using analysis software (VK viewer). This operation is performed three times, and the average Rq value of each data is used as the Rq of the resin film.

[0073] Specific methods for satisfying condition 4 include preferably using a substrate into which particles have been kneaded, a substrate that has been subjected to sandblasting, or a substrate that has been laminated with a coating layer containing particles when producing a resin film; these methods will be described in detail later.

[0074] (Condition 5) The resin film of the present invention preferably satisfies condition 5.

[0075] Condition 5: On at least one surface of the resin film, the contact angle hysteresis of the resin film with water, as measured by the dynamic contact angle expansion / contraction method, is 5° or more.

[0076] Here, contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle (θa) and the receding contact angle (θr) obtained by the dynamic contact angle expansion / contraction method. In the so-called "Wenzel mode," where a solid surface has a matte shape and a droplet penetrates into a recess on the solid surface, the droplet senses the surface roughness of the matte shape, and the surface roughness acts as a resistance to the droplet's movement when the droplet expands and contracts. Therefore, the greater the surface roughness of the matte shape, the greater the contact angle hysteresis. On the other hand, when a solid surface has flat areas and deep recesses, the droplet does not penetrate into the recesses on the solid surface, resulting in an air layer in the recesses, known as the "Cassie mode." This "Cassie mode" is known to occur particularly easily when using water, which has a high surface tension. In this case, the droplet cannot sense the unevenness of the surface, and the contact angle hysteresis is smaller than in the "Wenzel mode." Therefore, by increasing this contact angle hysteresis, droplets land on the solid surface in the "Wenzel mode," reducing the number of contact points with the printing plate and improving plate releasability. From a similar perspective, it is more preferable that the contact angle hysteresis of the resin film with water is 8° or more.

[0077] Specific methods for satisfying condition 5 include preferably using a substrate that has been subjected to a sandblasting treatment or a substrate that has been laminated with a coating layer containing particles when producing a resin film, and these methods will be described in detail later.

[0078] (Method for measuring dynamic contact angle) Dynamic contact angle measurements were performed after pre-settling the sample at 25°C for 12 hours. Using a Kyowa Interface Science Co., Ltd. Drop Master DM-501, droplets were generated using conditions that allowed for the smallest droplets possible without creeping up the needle. Dynamic contact angles were measured by repeatedly injecting and aspirating the droplet onto the resin film surface at a rate of 8.5 μL / s while the syringe needle tip remained pointed. Images of the droplet's shape during contraction were captured every 100 milliseconds, and the contact angle was measured for each step. The contact angle during the droplet expansion and contraction process initially changed as the droplet expanded and contracted, then became constant. The contact angle during expansion was defined as the advancing contact angle, and the contact angle during contraction as the droplet contracted. The contact angle was defined as the first time the standard deviation of five consecutive contact angles, measured in the direction of the droplet's expansion and contraction, fell below 1°.

[0079] (Condition 6) The resin film of the present invention preferably satisfies condition 6.

[0080] Condition 6: The arithmetic mean roughness Ra on at least one surface of the resin film is 430 nm or more.

[0081] Increasing the arithmetic mean roughness Ra reduces the number of contact points with the printing plate during the printing process, improving plate releasability. It also increases the interface between the resin film and the printing layer, resulting in an anchor effect that improves adhesion to the printing layer. From a similar perspective, the Ra of the resin film is more preferably 550 nm or greater, and even more preferably 600 nm or greater.

[0082] The Ra of a resin film is calculated using the following method. Specifically, as with the Rq described above, observation is performed using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm, and surface roughness data of 100 μm x 100 μm is obtained at any point on the observed surface using analysis software (VK viewer). This procedure is performed three times, and the average Ra value of each data point is used as the Ra of the resin film.

[0083] Specific methods for satisfying condition 6 include preferably using a substrate that has been subjected to a sandblasting treatment or a substrate that has been laminated with a coating layer containing particles when producing a resin film, and these methods will be described in detail later.

[0084] (Condition 7) The resin film of the present invention preferably satisfies condition 7.

[0085] Condition 7: The maximum height Rz on at least one surface of the resin film is 8 μm or more.

[0086] A large maximum height Rz means a large absolute value of surface roughness, which reduces the number of contact points with the printing plate during the printing process and improves plate release. It also increases the interface between the resin film and the printing layer, enhancing adhesion to the printing layer through an anchoring effect. From a similar perspective, the Rz of the resin film is preferably 9 μm or greater, and more preferably 10 μm or greater.

[0087] The Rz of a resin film is calculated using the method described below. Specifically, as with the Rq and Ra described above, observations are made using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm, and surface roughness data of 100 μm x 100 μm is obtained at any point on the observed surface using analysis software (VK viewer). This procedure is performed three times, and the average Rz value of each data point is used as the Rz of the resin film.

[0088] Specific methods for satisfying condition 7 include using a substrate that has been sandblasted to have an Ra of 620 nm or more when producing a resin film, or a substrate that has a coating layer laminated thereon containing 20 parts by mass or more of particles of 5 μm or more; these methods will be described in detail later.

[0089] (Condition 8) The resin film of the present invention preferably satisfies condition 8.

[0090] Condition 8: The surface free energy of at least one surface of the resin film is 30 mN / m or more.

[0091] Here, the surface free energy of a resin film refers to a value found by measuring the static contact angles of water, ethylene glycol, and diiodomethane at 25°C on the surface of the resin film, and then incorporating the static contact angles with each liquid and the dispersion term, polarity term, and hydrogen bond term of the surface free energy of each liquid described in Non-Patent Document 1 below into the "Extended Hawks' Equation of Hata and Kitazaki" described in Non-Patent Document 2 below, and solving the simultaneous equations. Details of the measurement method will be described later. Non-patent document 1: J. Panzer: J. Colloid Interface Sci., 44, 142 (1973). Non-patent document 2: Kitazaki, Yasuaki, Hata, Toshio: Japan Adhesion Association Journal, 8, (3) 131 (1972).

[0092] By having a surface free energy of 30 mN / m or more, the adhesion between the resin film and the printing layer can be made more sufficient, and when a circuit pattern is formed on the resin film and the film is repeatedly stretched and contracted, an increase in resistivity and a decrease in the S / N ratio of the signal obtained from the sensor can be reduced. Furthermore, the occurrence of poor conductivity due to breakage of the circuit pattern can be suppressed. From the same perspective, it is more preferable that the surface free energy of at least one surface of the resin film is 35 mN / m or more.

[0093] The surface free energy can be adjusted to fall within the above range by appropriately selecting the materials including the resin film and the surface treatment method, which will be described later.

[0094] (Method for measuring static contact angle) The static contact angle is measured after leaving the sample in a 25°C environment for 12 hours. A Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. is used to create droplets, and conditions are selected to create droplets as small as possible without causing them to creep up the needle. The static contact angle is calculated using an image taken 5 seconds after the droplet has landed on the resin film surface using the θ / 2 method.

[0095] (Condition 9) The resin film of the present invention preferably satisfies condition 9.

[0096] Condition 9: On at least one surface of the resin film, the surface area per 1 mm square of the resin film is 1.3 mm 2 That's all.

[0097] Here, the surface area per 1 mm square is a value calculated based on line roughness data obtained by observing the resin film with a laser microscope. In other words, by increasing this value, the interface between the resin film and the printing layer can be increased, and the anchor effect can increase adhesion with the printing layer. From the same perspective, the surface area per 1 mm square is 1.5 mm 2 More preferably, it is 2.0 mm 2 More preferably, it is equal to or greater than this.

[0098] The surface area per 1 mm square of resin film is calculated using the method described below. Specifically, similar to the flat area ratio of the surface described above, a laser microscope (Keyence VK9700) is used to observe with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm, and line roughness data for 100 μm is obtained at any point on the observed surface using analysis software (VK viewer). The number of pixels per μm is calculated from the XY calibration values ​​(XY direction distance per pixel) of the obtained line roughness data. The difference in the actual cross-sectional profile (Z direction height per pixel) is obtained so that it becomes the difference in height (a) in the Z direction per μm. Next, the surface length per 1 μm (L1 = (1 + a) 1 / 2 ) is calculated, and the sum is taken of the actual cross-sectional profile data, and then normalized to the surface length (L2) per 1 mm. By squaring this value, the surface area per 1 mm square (S = (L2) 2 )

[0099] Specific methods for satisfying condition 9 include preferably using a substrate that has been subjected to sandblasting or a substrate that has been laminated with a coating layer containing particles when producing a resin film; these methods will be described in detail later.

[0100] (Condition 10) The resin film of the present invention preferably satisfies condition 10.

[0101] Condition 10: On at least one surface of the resin film, the contact angle hysteresis of the resin film with propylene glycol monomethyl ether acetate (PGMEA) obtained by the dynamic contact angle expansion and contraction method is 5° or more.

[0102] Here, contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle (θa) and the receding contact angle (θr), as determined by the dynamic contact angle expansion / contraction method, as in condition 5. PGMEA is a commonly used solvent contained in printing pastes used during printing. In other words, increasing this value allows droplets to land on solid surfaces in the "Wenzel mode," reducing contact points with the printing plate and improving plate releasability. Furthermore, during printing, the printing paste penetrates into the irregularities on the resin film surface, improving the adhesion of the printed layer to the resin film after solvent removal. From a similar perspective, it is preferable for the contact angle hysteresis of the resin film with PGMEA to be 8° or greater.

[0103] Specific methods for satisfying condition 10 include using a substrate that has been sandblasted to have an Ra of 620 nm or more when producing a resin film, or a substrate that has a coating layer laminated thereon containing 20 parts by mass or more of particles of 5 μm or more; these methods will be described in detail later.

[0104] (Condition 11) The resin film of the present invention preferably satisfies condition 11.

[0105] Condition 11: The haze of the resin film is 30% or more and 70% or less.

[0106] Here, the haze of a resin film refers to the degree of cloudiness of the resin film, a parameter that indicates the degree of light diffusion. Increasing the size of the surface irregularities increases the haze. On the other hand, if this value is too large, the film becomes opaque, blurring the shape, color, markings, etc. of objects placed underneath the film, making it difficult to adjust their position when modularizing. From a similar perspective, the haze of a resin film is preferably between 40% and 60%.

[0107] The haze of the resin film is measured three times using an NDH-5000 (Nippon Denshoku Co., Ltd.) with the rougher surface of the resin film facing upward, and the average value is taken as the haze.

[0108] In particular, when a layer containing particles is laminated on a resin film, the difference in composition between the particles and the resin film tends to change the refractive index and increase the haze. Therefore, a preferred method for satisfying condition 11 is not to laminate a layer containing particles, but to transfer a substrate when producing a resin film.

[0109] (Material / Structure / Bond) The resin film of the present invention preferably contains one or more resins selected from acrylic resins, methacrylic resins, silicone resins, urethane resins, acrylic urethane resins, epoxy resins, and styrene resins, from the viewpoint of obtaining appropriate stretchability.

[0110] In particular, the resin film of the present invention preferably contains the structure of Chemical Formula 1 and a urethane bond.

[0111] [ka]

[0112] In addition, R in Chemical Formula 1 1 refers to a hydrogen or methyl group.

[0113] Whether a resin film contains the above-mentioned structures or bonds can be determined by various analytical methods, but if it is found to contain the above-mentioned structures or bonds by at least an analytical method using FT-ATR-IR (Fourier transform attenuated total reflection infrared spectroscopy) or pyrolysis GC-MS (gas chromatography mass spectrometry), or if it can be determined from the raw materials that form the resin film that it contains the above-mentioned structures or bonds, the resin film is considered to contain the above-mentioned structures or bonds.

[0114] The resin film having the above structure forms a strong chemical cross-linked structure and can impart strong resilience. In addition, the resin film containing urethane bonds forms weak physical cross-links due to hydrogen bonds, thereby imparting resilience while maintaining flexibility.

[0115] More preferably, the structure of Chemical Formula 1 includes the structure of Chemical Formula 10.

[0116] [ka]

[0117] In addition, R in Chemical Formula 10 1 refers to a hydrogen or methyl group.

[0118] R in Chemical Formula 10 2 refers to one of the following: a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having an internal ether group, ester group, or amide group; an arylene group having an ether group, an ester group, or an amide group therein; an unsubstituted alkylene group having an internal ether group, ester group, or amide group; An unsubstituted arylene group having an internal ether group, ester group, or amide group.

[0119] The urethane bond segment preferably includes a structure shown in Chemical Formula 11.

[0120] [ka]

[0121] In addition, R in Chemical Formula 11 3 refers to one of the following: a substituted or unsubstituted alkylene group, Substituted or unsubstituted arylene groups.

[0122] Additionally, it is preferable that the resin film of the present invention contains 30% by mass or more of an acrylic urethane resin relative to 100% by mass, from the viewpoint of obtaining high levels of flexibility and recovery.

[0123] The resin film of the present invention contains a segment of Chemical Formula 2, and preferably further contains either a segment of Chemical Formula 3 or a segment of Chemical Formula 4.

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] p is an integer of 1 or greater.

[0128] r is an integer of 1 or greater.

[0129] s is an integer of 1 or greater.

[0130] Here, the segment of Chemical Formula 2 is preferable as the urethane bond described above. The segment of Chemical Formula 3 and the segment of Chemical Formula 4 are preferable as polyol residues. By combining the segment of Chemical Formula 2 with the segment of Chemical Formula 3, or the segment of Chemical Formula 2 with the segment of Chemical Formula 4, the interaction between the segments can be set within a preferable range, and strong chemical crosslinks of acrylic crosslinks can be formed at a low density while suppressing the formation of physical crosslinks such as hydrogen bonds.

[0131] The resin film of the present invention preferably contains at least one segment selected from the group consisting of a segment of Chemical Formula 5, a segment of Chemical Formula 6, a segment of Chemical Formula 7, a segment of Chemical Formula 8, and hydrogenated segments thereof. In Chemical Formulas 5 to 8, any substituent may be used for the omitted substituent, but a hydrogen atom is preferred.

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135] [ka]

[0136] Here, segments of Chemical Formula 5, segments of Chemical Formula 6, segments of Chemical Formula 7, segments of Chemical Formula 8, and segments of their hydrogenated derivatives are preferred as polyol residues. In particular, segments of hydrogenated derivatives of Chemical Formula 5 or segments of hydrogenated derivatives of Chemical Formula 6 are particularly preferred. By using segments of Chemical Formula 5, segments of Chemical Formula 6, segments of Chemical Formula 7, segments of Chemical Formula 8, and segments of their hydrogenated derivatives, it is possible to form strong chemical crosslinks of acrylic crosslinks at a low density while further suppressing the formation of physical crosslinks such as hydrogen bonds. In addition, it is possible to improve solvent resistance when applying a printing paste to a resin film.

[0137] (Layer composition) The resin film of the present invention is preferably composed of a single layer. "Composed of a single layer" here means that no discontinuous boundary surface is observed when the cross section is observed by scanning electron microscopy (SEM). A specific observation method involves cutting a resin film embedded with a UV-curable resin together with the embedded resin using a microtome to obtain a cross section in the thickness direction. Platinum is then vapor-deposited on the cross section using an autofine coater at 30 mA x 20 seconds x 2 times, and the resulting test piece is observed using a scanning electron microscope (SEM) at a magnification of 5000x and an accelerating voltage of 3 kV. Further details of the observation method are described in detail in the measurement method of the examples.

[0138] (Laminated structure) The laminate of the present invention is preferably a laminate including a substrate on at least one side of the resin film. An example is shown in FIG. 1. Here, the substrate is an article on whose surface the resin film-forming coating composition can be spread. The reason why a substrate is preferably provided in the laminate of the present invention is to ensure transportability and processability during the production and processing of the resin film.

[0139] In the method for producing a resin film of the present invention, steps 1, 2, 3, and 4 are preferably carried out in this order. Step 1: A step of applying a coating composition containing a resin precursor containing a segment of Chemical Formula 9 and a solvent onto a substrate A that satisfies Condition 12 to form a coating layer. Condition 12: The flat area ratio on at least one surface of the substrate A measured by a laser microscope is 70% or less.

[0140] [ka]

[0141] R 4 refers to a hydrogen or methyl group. R 5 is preferably one of the following: · Substituted or unsubstituted alkylene groups. Substituted or unsubstituted arylene groups. Alkylene groups containing an ether, ester, or amide group. Arylene groups containing an internal ether, ester, or amide group. An unsubstituted alkylene group having an internal ether group, ester group, or amide group. An unsubstituted arylene group having an internal ether group, ester group, or amide group. R 6 is preferably one of the following: · Substituted or unsubstituted alkylene groups. Substituted or unsubstituted arylene groups. Step 2: Removing the solvent from the coating layer. Step 3: A step of crosslinking the resin precursor by irradiating it with active energy rays. Step 4: A step of attaching a substrate B to the surface of the coating layer opposite to the substrate A, and then peeling off the substrate A.

[0142] Examples of the structure of the laminate are shown in Figures 2, 3, and 4. Here, substrate A is a substrate for improving transportability and may be a multilayer laminate including a release layer. The inclusion of a release layer makes it easier to peel substrate A from the resin film, facilitating transfer of the shape of substrate A to the resin film. Furthermore, when peeling substrate A from the resin film, peeling between substrate B (described below) and the resin film, known as "separation," can be suppressed.

[0143] Furthermore, substrate B is a substrate for improving transportability and preventing scratches after substrate A is peeled off, and may be a multilayer laminate including a release layer and an adhesive layer. The inclusion of a release layer makes it easy to peel substrate B from the resin film, allowing the resin film to be post-processed alone. The inclusion of an adhesive layer also strengthens the adhesion between substrate B and the resin film, preventing peeling between substrate B and the resin film when substrate A is peeled off from the resin film, a phenomenon known as "disconnection."

[0144] [Embodiments of the present invention] Hereinafter, embodiments of the present invention will be specifically described.

[0145] [Resin film] In addition to the desired flexibility, recovery, printing plate releasability, and printing layer adhesion, the resin film of the present invention may have other functions such as concealment, gloss, fingerprint resistance, moldability, designability, scratch resistance, stain resistance, solvent resistance, antireflection, antistatic properties, conductivity, heat ray reflection, near-infrared absorption, electromagnetic wave shielding, anchoring properties, and easy adhesion, and may further comprise one or more layers to form a laminate. For example, an adhesive layer, an electronic circuit layer, a printing layer, an optical adjustment layer, or other functional layers may be provided.

[0146] The thickness of the resin film 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 and breaking elongation of the resin film itself, the peeling force and peeling angle between the substrate and the resin film, etc. However, when the laminate manufacturing method described later is used to realize physical properties equivalent to those of a general flexible material, the lower limit is about several μm.

[0147] [Laminate] Preferred embodiments of the laminate of the present invention are as described above, but it is preferable that the laminate has a substrate on at least one side of a resin film exhibiting the above-mentioned physical properties, and the laminate may be in a planar state or in a three-dimensional shape after being molded.

[0148] [Base material] The substrate used in the laminate of the present invention 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 substrate is preferably one that has good moldability, and from this point of view, a thermoplastic resin is more preferred.

[0149] Examples of thermoplastic resins that can be suitably used for the substrate 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.

[0150] Examples of thermosetting resins suitable for use in the substrate include phenolic resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane resin, polyimide resin, and silicone resin. The thermoplastic resin is preferably a resin with sufficient stretchability and conformability. From the viewpoints of strength, heat resistance, and transparency, the thermoplastic resin is more preferably a polyester resin, polycarbonate resin, acrylic resin, or methacrylic resin.

[0151] Polyester resins suitable for use in substrates are a general term for polymers in which ester bonds are the main bonding chains in the main chain, and are 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.

[0152] The substrate preferably has a matte surface over the entire surface with a flat portion ratio of 40% or less. Methods for imparting a matte surface include adding particles when preparing the substrate, sandblasting after preparing the substrate, and coating with a particle layer, with sandblasting and particle layer coating being particularly preferred.

[0153] The 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.

[0154] Furthermore, the substrate may have either a single layer structure or a laminate structure.

[0155] 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 substrate in advance, in addition to the resin film of the present invention, and the laminate of the present invention preferably has a release layer to reduce the peel force between the substrate and the resin film. Details of the release layer will be described later.

[0156] The surface of the substrate may be subjected to various surface treatments before the resin film is formed. 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, 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.

[0157] [Release layer] In the laminate of the present invention, when the resin film alone is post-processed, it is preferable that the substrate has a release layer as described above. A 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 substrate.

[0158] The thickness of the release layer is preferably 10 to 500 nm, more preferably 20 to 300 nm, from the viewpoint of in-plane uniformity of the release layer, appearance quality, and peel strength.

[0159] [Manufacturing method of resin film] The method for producing the resin film of the present invention preferably involves applying a coating composition containing a resin precursor containing a segment of chemical formula 2 onto substrate A 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 finally attaching substrate B to the opposite surface of substrate A, and then peeling off substrate A (step 4).

[0160] The method for applying the coating composition onto substrate A in step 1 is not particularly limited as long as it is possible to apply the coating composition onto substrate A and form a uniform coating layer within the surface. The method for applying the coating onto the film 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 in the coating step.

[0161] 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 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.

[0162] 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.

[0163] 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 / cm 2 ), 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.

[0164] The substrate B in step 4 is not particularly limited as long as it has a higher peel strength than the substrate A. It may be a multilayer laminate including a release layer and an adhesive layer. The inclusion of a release layer makes it easier to peel the substrate B from the resin film, allowing the resin film to be post-processed alone. Furthermore, the inclusion of an adhesive layer allows the substrate B to adhere strongly to the resin film, preventing peeling between the substrate B and the resin film when the substrate A is peeled from the resin film, which is known as "cracked separation."

[0165] [Resin precursor] The resin precursor is not particularly limited as long as it is a compound having a crosslinkable moiety, but A resin precursor comprising the structure of Chemical Formula 9 is preferred, and a resin precursor comprising the structure of Chemical Formula 12 is more preferred.

[0166] [ka]

[0167] [ka]

[0168] R 4 and R 7 refers to a hydrogen or methyl group. R 5 , R 8 , and R 10 is preferably any one of the following, and n is preferably an integer of 3 or more. · Substituted or unsubstituted alkylene groups. Substituted or unsubstituted arylene groups. Alkylene groups containing an ether, ester, or amide group. Arylene groups containing an internal ether, ester, or amide group. An unsubstituted alkylene group having an internal ether group, ester group, or amide group. An unsubstituted arylene group having an internal ether group, ester group, or amide group. R 6 , R 9 is preferably one of the following: · Substituted or unsubstituted alkylene groups. Substituted or unsubstituted arylene groups.

[0169] As described above, the structures of Chemical Formulas 9 and 12 have a (meth)acrylic group, represented by X in the diagram, at their terminals, 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, represented by Y in the diagram. Furthermore, the segment of Chemical Formula 12 means that the other end of the polyisocyanate residue, represented by Y, is adjacent to a polyol residue, represented by Z in Chemical Formula 12, represented by Z.

[0170] The polyisocyanate residue (Y) of Chemical Formulas 9 and 12 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).

[0171] The polyol residue of Chemical Formula 12 is preferably a polyester polyol, a polyether polyol, a polycarbonate polyol, or a polyol containing one or more segments selected from the segments of Chemical Formulas 5 to 8 above.

[0172] [Paint composition] The "coating composition" used in the method for producing a laminate of the present invention is not particularly limited as long as it can be applied uniformly in-plane onto a substrate and can form a resin film exhibiting the properties of the present invention, but it is preferably a coating composition suitable for the method for producing the laminate described above. Specifically, it is preferable to prepare a coating composition by adding the resin precursor described above to a solvent and other components described below.

[0173] [solvent] The coating composition used in the method for producing a laminate of the present invention may contain a solvent, and it is preferable to contain 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. Here, the term "solvent" refers to a substance that is liquid at room temperature and normal pressure and can be evaporated almost entirely in the drying step described above.

[0174] Here, the type of solvent is determined by the molecular structure that makes up 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 perfectly overlap in three-dimensional space no matter what conformation they take (stereoisomers) are treated as different types of solvents. For example, 2-propanol and n-propanol are treated as different solvents.

[0175] [Other components in the coating composition] The coating composition used in the method for producing a laminate of the present invention 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.

[0176] 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 in inhibiting deterioration under high-temperature conditions, but 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 more preferred.

[0177] 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.

[0178] As the photopolymerization initiator, it is preferable to use an alkylphenone compound or an acylphosphine oxide compound from the viewpoint of curability. Furthermore, it is more preferable to use an alkylphenone compound into which a hydroxyethoxy group has been introduced from the viewpoint of moist heat resistance. Specific examples of alkylphenone compounds 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 of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and polymerized versions of these compounds. These compounds may be used alone or in combination.

[0179] 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.

[0180] 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.

[0181] [Application example] The resin film of the present invention has advantages such as excellent optical properties, flexibility, stretchability, transportability, and appearance quality, and can be suitably used in applications where particularly high flexibility and stretchability are required.

[0182] Examples include plastic molded products such as eyeglasses and sunglasses, cosmetic cases, and food containers; aquariums, display cases, smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, wearable devices, sensors, circuit materials, electrical and electronic applications; home appliances such as keyboards and 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; and various printed materials, medical films, sanitary film films, agricultural films, and building films. The quality of these materials can be improved by using the resin film of the present invention. Furthermore, because the resin film of the present invention exhibits excellent plate release properties and adhesion to the printing layer, it is particularly suitable for use in electronic device circuit board applications. [Example]

[0183] Next, the present invention will be described based on examples, but the present invention is not necessarily limited to these. In the following, Examples 1, 4, 11, 14, 20 to 22, 25, and 28 to 32 shall be read as Reference Examples 1, 4, 11, 14, 20 to 22, 25, and 28 to 32.

[0184] "Synthesis of resin precursors" The raw materials used in the synthesis of the resin precursor are as follows:

[0185] "Diisocyanate" IPDI: Isophorone diisocyanate HMDI: Hexamethylene diisocyanate MDI: 4,4'-diphenylmethane diisocyanate "Polyol" PBAA: Polybutylene adipate, Tosoh Corporation, "Nippolan" (registered trademark) 3027 (weight average molecular weight 2500) PTMG: Polytetramethylene glycol, Mitsubishi Chemical Corporation, PTMG2000 (weight average molecular weight 2000) PEAA: Polyethylene glycol adipate, manufactured by Tosoh Corporation, "Nippolan" (registered trademark) 4040 (weight average molecular weight 2000) MPDAA: Poly(3-methylpentanediol adipate) manufactured by Kuraray Co., Ltd., "Kuraray Polyol" (registered trademark) P-2010 (weight average molecular weight 2000) PB: Polybutadiene with hydroxyl groups at both ends, G-3000 (weight average molecular weight 3000) manufactured by Nippon Soda Co., Ltd. HPB: Hydrogenated polybutadiene with hydroxyl groups at both ends, GI-3000 (weight average molecular weight 3100) manufactured by Nippon Soda Co., Ltd. "Hydroxyacrylate" ·HEA: Hydroxyethyl acrylate [Resin precursor 1] A four-neck flask equipped with a thermometer, stirrer, water-cooled condenser, and nitrogen gas inlet was charged with IPDI as diisocyanate, PBAA as polyol, and toluene. The molar ratio of diisocyanate to polyol was 0.43:0.29, and the solids concentration was 60% by mass. The reaction was carried out at 90°C. When the residual isocyanate groups reached 1.4% by mass after the reaction, the temperature was lowered to 70°C, and HEA was added as the hydroxyacrylate. The molar ratio of diisocyanate to polyol to hydroxyacrylate before the reaction was 0.43:0.29:0.29. When the amount of residual isocyanate groups before reaction was taken as 100% by mass, the reaction was terminated by stopping heating when the amount of residual isocyanate groups reached 0.3% by mass. Toluene was then added to adjust the solid content to 60% by mass, thereby obtaining a toluene solution of resin precursor 1.

[0186] [Resin precursors 2-12] Toluene solutions of resin precursors 2 to 12 were obtained in the same manner as for resin precursor 1, except that the combinations and molar ratios of diisocyanate and polyol were changed to those shown in Table 1.

[0187] [Table 1]

[0188] [Photopolymerization initiator] The following materials were used as photopolymerization initiators: Photopolymerization initiator 1 "IRGACURE" (registered trademark) 184 (manufactured by BASF Japan Ltd.) [Leveling agent] The following materials were used as leveling agents 1 to 3. Leveling Agent 1 FT-650AC (NEOS Corporation): Fluorine-based Leveling agent 2 "BYK" (registered trademark)-394 (manufactured by BYK Japan Co., Ltd.): acrylic Leveling agent 3 "BYK" (registered trademark)-UV-3500 (manufactured by BYK Japan Co., Ltd.): Silicone-based [Preparation of coating compositions 1 to 13] The resin precursor, photopolymerization initiator, and leveling agent were mixed so that the solid contents were in the ratios shown in Table 2, and diluted with methyl ethyl ketone to obtain resin film-forming coating compositions 1 to 13 with a solid content concentration of 40 mass%.

[0189] [Table 2]

[0190] [Formulation of Paint Composition 14] A bifunctional methacrylic-modified polyisoprene with methacrylic groups on the side chains (Kuraray Co., Ltd.'s "Kurapren" (registered trademark) UC-102AM, weight average molecular weight 17,000) was diluted with toluene to obtain a toluene solution of resin precursor 14 with a solids concentration of 60% by mass.

[0191] [Preparation of Paint Composition 15] 74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 0.1 g of potassium siliconate were placed in a 300 mL separable flask equipped with a condenser and a stirring blade and purged with argon gas. The mixture was heated to 120°C and stirred for 30 minutes. The mixture was then heated to 155°C and stirred for 3 hours. After 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was stirred for an additional 4 hours at 155°C.

[0192] After four hours, the mixture was diluted with 250 mL of toluene and washed three times with water. The washed organic layer was reprecipitated and purified by washing several times with 1.5 L of methanol, separating the oligomer and polymer. The resulting polymer was dried overnight under reduced pressure at 60°C to obtain vinyl-containing linear organopolysiloxane A1.

[0193] Vinyl-containing linear organopolysiloxane A2 was synthesized in the same manner as in the synthesis of vinyl-containing linear organopolysiloxane A1, except that in the synthesis of vinyl-containing linear organopolysiloxane A1, 0.86 g (2.5 mmol) of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane was used in addition to 74.7 g (252 mmol) of octamethylcyclotetrasiloxane.

[0194] The following materials were mixed together in advance to obtain silicone rubber compound 1. Vinyl group-containing linear organopolysiloxane A1: 72 parts by mass. Vinyl group-containing linear organopolysiloxane A2: 18 parts by mass. Hexamethyldisilazane SIH6110.1 (manufactured by Gelest): 10 parts by mass. Divinyltetramethyldisilazane SID4612.0 (manufactured by Gelest): 0.5 parts by mass. Deionized water: 5.25 parts by weight.

[0195] Subsequently, 25 parts by mass of silica particles "AEROSIL" (registered trademark) 300 (manufactured by Nippon Aerosil Co., Ltd.) were added to 100 parts by mass of Silicone Rubber Compound 1, and the mixture was kneaded for 1 hour at 60 to 90°C under a nitrogen atmosphere in the first step for a coupling reaction, and then kneaded for 2 hours at 160 to 180°C under a reduced pressure atmosphere to remove the by-product (ammonia) in the second step. The mixture was then cooled, and 8 parts by mass of vinyl group-containing linear organopolysiloxane A1 and 2 parts by mass of vinyl group-containing linear organopolysiloxane A2 were added, and the mixture was kneaded for 20 minutes to obtain Silicone Rubber Compound 2.

[0196] Subsequently, the mixture was diluted with the following materials and toluene to obtain a resin film-forming coating composition 15 having a solid content concentration of 30% by mass. Silicone rubber compound 2: 100 parts by mass. Organohydrogenpolysiloxane 88466 (manufactured by Momentive): 0.35 parts by mass. Platinum catalyst SIP6831.2 (manufactured by Gelest): 0.05 parts by mass. Reaction inhibitor (1-ethynyl-1-cyclohexanol): 0.1 parts by mass.

[0197] [Coating composition for particle layer] This was prepared by dissolving or dispersing 47 parts by mass, in solid content, of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation), 23 parts by mass, in solid content, of an isocyanate-based crosslinking agent ("Coronate" (registered trademark) HL" manufactured by Nippon Polyurethane Industry Co., Ltd.), and 30 parts by mass, in solid content, of beads ("Silisia" (registered trademark) 740 silica particles, average particle size 5 μm, manufactured by Fuji Silysia Chemical Ltd.) in ethyl acetate.

[0198] [Original film] The following materials were used as raw films 1 to 8. Raw film 1: Biaxially stretched PET film, thickness 50 μm, Ra 80 nm. Raw film 2: Biaxially stretched PET film, thickness 50 μm, Ra 220 nm. Raw film 3: Biaxially stretched PET film, thickness 50 μm, Ra 420 nm. Raw film 4: "Lumirror" (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was sandblasted to have an Ra of 410 nm. Raw film 5 "Lumirror" (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was sandblasted to have an Ra of 550 nm. Raw film 6: "Lumirror" (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was sandblasted to have an Ra of 750 nm. Raw film 7 "Lumirror" (registered trademark) T60 50μm (manufactured by Toray Industries, Inc.) was coated with paint 1 described below so that the thickness after drying would be 5μm, and then dried at 100°C for 30 seconds. Raw film 8 "Lumirror" (registered trademark) T60 50μm (manufactured by Toray Industries, Inc.) was coated with paint 2 described below so that the thickness after drying would be 5μm, and then dried at 100°C for 30 seconds.

[0199] <Paint 1> This was prepared by dissolving or dispersing 53 parts by mass, in solid content, of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation), 27 parts by mass, in solid content, of an isocyanate-based crosslinking agent ("Coronate" (registered trademark) HL" manufactured by Nippon Polyurethane Industry Co., Ltd.), and 20 parts by mass, in solid content, of beads ("Silisia" (registered trademark) 740 silica particles manufactured by Fuji Silysia Chemical Ltd., average particle size 5 μm) in ethyl acetate.

[0200] <Paint 2> This was prepared by dissolving or dispersing 40 parts by mass, in solid content, of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation), 20 parts by mass, in solid content, of an isocyanate-based crosslinking agent ("Coronate" (registered trademark) HL" manufactured by Nippon Polyurethane Industry Co., Ltd.), and 40 parts by mass, in solid content, of beads ("Silisia" (registered trademark) 740 silica particles manufactured by Fuji Silysia Chemical Ltd., average particle size 5 μm) in ethyl acetate.

[0201] [Release layer coating composition] The following materials were mixed and diluted with a mixed solvent of methyl ethyl ketone and isopropyl alcohol (mixing ratio by mass: 50 / 50) to obtain a coating composition for a release layer having a solids concentration of 5% by mass. Side-chain carbinol-modified reactive silicone oil (X-22-4015 Shin-Etsu Chemical Co., Ltd. Solid content: 100% by mass): 5 parts by mass ·Both-end polyether modified reactive silicone oil (X-22-4952 Shin-Etsu Chemical Co., Ltd. Solid content: 100% by mass): 5 parts by mass Acrylic modified alkyd resin solution (Hariftar KV-905, Harima Chemicals Co., Ltd., solid content 53% by mass): 100 parts by mass Isobutyl alcohol modified melamine resin solution “Melan” (registered trademark) 2650L Hitachi Chemical Co., Ltd. Solid content concentration 60% by mass: 20 parts by mass Paratoluenesulfonic acid: 5 parts by weight. [Method of manufacturing laminate and resin film] [Formation of substrate with release layer] Using a coating device with a small-diameter gravure coater, the coating composition for the release layer was applied to the raw film by adjusting the gravure roll line number, the gravure roll peripheral speed, and the solids concentration of the coating composition for the release layer so that the release layer thickness after drying would be about 200 nm, and then drying and crosslinking were carried out by holding at a hot air temperature of 140 ° C. for 30 seconds, thereby obtaining substrates 1 to 8 with release layers. The raw film types used are as shown in Table 3.

[0202] [Table 3]

[0203] [Method for forming laminate] <Examples 1 to 9, 11 to 32, Comparative Examples 1 to 8> A laminate and a resin film were prepared by the following method.

[0204] (Process 1) The substrate with the release layer described above was used as substrate A, and using a continuous coating device with a slot die coater, the coating composition for forming a resin film described above was applied onto the release layer of the substrate with the release layer by adjusting the discharge flow rate so that the thickness of the resin film after crosslinking would be 50 μm, thereby forming a coating layer.

[0205] (Process 2) The coating layer formed in step 1 was dried under the following conditions to remove the solvent.

[0206] Air blowing temperature: 50℃ Wind speed; coated side: 5m / sec, anti-coated 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.

[0207] (Step 3) In step 2, the coating layer (uncrosslinked resin film) obtained by removing the solvent was irradiated with active energy rays under the following conditions to crosslink it, thereby obtaining a laminate consisting of substrate A, a release layer, and a resin film.

[0208] Irradiation light source: High-pressure mercury lamp Irradiation output: 400W / cm 2 Accumulated light output: 120mJ / cm 2 Oxygen concentration: 0.1% by volume.

[0209] (Step 4) The raw film 1 was laminated as the substrate B by roll-to-roll bonding to the surface of the coating layer obtained in step 3 opposite to the substrate A. Then, the substrate A was peeled off to obtain a laminate consisting of the substrate B and the resin film.

[0210] Example 10 A laminate and a resin film were prepared by the following method.

[0211] (Process 1) The substrate A was the aforementioned substrate 1 with a release layer, and a continuous coating device using a slot die coater was used to coat the coating composition 2 onto the release layer of the substrate with a release layer, adjusting the discharge flow rate so that the thickness of the resin film after crosslinking would be 50 μm, thereby forming a coating layer.

[0212] (Process 2) The coating layer formed in step 1 was dried under the following conditions to remove the solvent.

[0213] Air blowing temperature: 50℃ Wind speed; coated side: 5m / sec, anti-coated 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.

[0214] (Step 3) In step 2, the coating layer (uncrosslinked resin film) obtained by removing the solvent was irradiated with active energy rays under the following conditions to crosslink it, thereby obtaining a laminate consisting of substrate A, a release layer, and a resin film.

[0215] Irradiation light source: High-pressure mercury lamp Irradiation output: 400W / cm 2 Accumulated light output: 120mJ / cm 2 Oxygen concentration: 0.1% by volume.

[0216] (Step 4) The above-mentioned coating composition for the particle layer was applied to the resin layer side of the laminate using a continuous coating device such as a slot die coater, adjusting the discharge flow rate so that the film thickness after drying would be 2 μm, thereby forming a particle layer.

[0217] (Step 5) The coating layer formed in step 1 was dried under the following conditions to remove the solvent, and a laminate consisting of the substrate A, the resin film, and the particle layer was obtained.

[0218] Air blowing temperature: 100℃ Wind speed; coated side: 5m / sec, anti-coated 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: 30 seconds.

[0219] By the above method, laminates and resin films were prepared in Examples 1 to 32 and Comparative Examples 1 to 8. The coating composition for forming a resin film, the substrate with a release layer, and the particle layer corresponding to each Example and Comparative Example are shown in Table 4.

[0220] [Table 4]

[0221] [Evaluation of resin film] The resin film was subjected to the following performance evaluations, and the results are shown in the table.

[0222] The substrate was peeled off from the laminate to obtain a resin film measurement sample. Unless otherwise specified, measurements were taken three times for each sample in each Example and Comparative Example, at different locations, and the average value was used.

[0223] [Measurement of storage modulus and loss tangent of resin film] The measurement sample was cut into a rectangular shape with a width of 10 mm to be used as a test piece.

[0224] Based on the tensile vibration-non-resonance method of JIS K7244-4 (1999) (this is referred to as the dynamic viscoelasticity method), the storage modulus and loss tangent of the resin film were determined at a temperature of 25°C and a frequency of 1 Hz using a dynamic viscoelasticity measuring device DMS6100 manufactured by Seiko Instruments Inc. Measurement mode: Tensile Chuck distance: 20mm Test piece width: 10 mm Frequency: 1Hz Distortion amplitude: 10μm Minimum tension: 20mN Initial force amplitude: 40 mN Measurement temperature: -100℃ to 200℃ Heating rate: 5°C / min.

[0225] [Static contact angle measurement] The static contact angle was measured after the sample had been left to stand for 12 hours in a 25°C environment. A Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. was used, and conditions were selected to create droplets as small as possible without causing them to creep up the needle. The static contact angle was calculated using an image taken 5 seconds after the droplet landed on the resin film surface using the θ / 2 method.

[0226] [Calculation of the flat area ratio of the resin film surface and substrate] The flat area ratio of the resin film surface and substrate was measured using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm. Line roughness data for 100 μm was obtained at any point on the observed surface using analysis software (VK Viewer). The number of pixels per μm was calculated from the XY calibration values ​​of the obtained line roughness data (the distance in the X and Y directions per pixel). The difference in the actual cross-sectional profile (the height in the Z direction per pixel) was obtained to determine the difference in height in the Z direction (a) per μm. This procedure was performed three times, and a histogram was created from the obtained data, and the frequency of defects below 100 nm was calculated.

[0227] [Calculating the surface area per 1mm square of resin film] Specifically, the surface area per 1 mm square of the resin film was measured in the same way as the surface flatness ratio described above. Observations were performed using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02 μm, and line roughness data for 100 μm was obtained at any point on the observed surface using analysis software (VK viewer). The number of pixels per μm was calculated from the XY calibration values ​​of the obtained line roughness data (the distance in the X and Y directions per pixel). The difference in the actual cross-sectional profile (the height in the Z direction per pixel) was obtained to obtain the difference in height in the Z direction (a) per μm. Next, the surface length per 1 μm (L1 = (1 + a) 1 / 2 ) was calculated, and the sum was taken of the actual cross-sectional profile data, and normalized to the surface length (L2) per 1 mm. By squaring this value, the surface area per 1 mm square (S = (L2) 2 ) was decided.

[0228] [Calculation of Ra, Rq, and Rz of resin film] Specifically, the Ra, Rq, and Rz of the resin film were observed using a laser microscope (Keyence VK9700) with a 50x objective lens, 100% light intensity, and a Z measurement pitch of 0.02μm, and surface roughness data of 100μm x 100μm was obtained at any point on the observed surface using analysis software (VK viewer). This procedure was performed three times, and the average Ra, Rq, and Rz values ​​of each data were used to determine the Ra, Rq, and Rz of the resin film.

[0229] [Method for measuring dynamic contact angle] Dynamic contact angle measurements were performed after pre-settling the samples at 25°C for 12 hours. The measurement solvents were distilled water (Fujifilm Wako Pure Chemical Corporation) and Wako Grade 1 PGMEA (Fujifilm Wako Pure Chemical Corporation). For each solvent, a Drop Master DM-501 (Kyowa Interface Science Co., Ltd.) was used. Droplet creation conditions were selected to produce droplets as small as possible without creeping up the needle. Dynamic contact angles were measured by repeatedly injecting and aspirating the liquid at a rate of 8.5 μL / s while the syringe needle tip was still pointed at the resin film surface. Images of the droplet's contraction were captured every 100 milliseconds, and the contact angle during each process was measured. The contact angle during the droplet expansion and contraction process initially changed with expansion and contraction, then stabilized. The contact angle during expansion was defined as the advancing contact angle, and the contact angle during contraction was defined as the receding contact angle. Here, the contact angle was defined as the first time that the standard deviation of five consecutive contact angles, selected in the direction of the droplet's expansion and contraction, was 1° or less. The absolute value of the difference between the advancing and receding contact angles was defined as the contact angle hysteresis.

[0230] [Observation of resin film thickness and number of layers] The thickness and number of layers of the resin film were observed by cross-sectional SEM observation of the film using an SEM JSM-6700F manufactured by JEOL Ltd. The procedure for preparing test specimens for cross-sectional SEM observation was as follows. 1. The resin film was embedded in UV-curable resin. 2. The resin film was cut along with the embedded resin using a rotary microtome RMS manufactured by Nippon Microtome Co., Ltd. to obtain a cross section of the resin film in the thickness direction. 3. Using an Auto Fine Coater JFC-1600 manufactured by JEOL Ltd., platinum was vapor-deposited to a thickness of approximately 10 μm (conditions: 30 mA x 20 seconds x 2 times) on the cross section of the cut sample to prepare a test piece.

[0231] The cross-sectional SEM observation was carried out under the following conditions. Measurement mode: LEI mode ·Magnification: 5000x Acceleration voltage: 3 kV WD (sample distance): 8.0 mm.

[0232] The thickness of the resin film was calculated from the vertical distance between the resin layers in the cross-sectional SEM images, and the arithmetic mean value was used. The number of resin film layers was calculated from the number of discontinuous interfaces between the resin layers in the vertical direction in the cross-sectional SEM images.

[0233] [Method for measuring haze of resin film] The haze of the resin film was measured three times using an NDH-5000 (Nippon Denshoku Co., Ltd.) with the rougher surface of the resin film facing upward, and the average value was taken as the haze.

[0234] [Evaluation of resin film flexibility] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare a test piece. The 150 mm length was aligned with the longitudinal direction of the resin film. Using a tensile tester (Orientec "Tensilon" (registered trademark) UCT-100), the initial tensile chuck distance was set to 50 mm, the tensile speed was set to 300 mm / min, and the measurement temperature was 23°C.

[0235] 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 x (%) and stress y (N / mm 2) was calculated, where the sample thickness before the test is k (mm). Strain amount: x = ((a-50) / 50) x 100 Stress: y=b / (k×10).

[0236] When the longitudinal direction was unknown, the sample was taken in an arbitrary direction, and then rotated 60 degrees and 120 degrees to take another sample. The evaluation was based on the average value of the measurement results for a total of three samples.

[0237] [Evaluation of resin film restoration] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare a test piece. The 150 mm length was aligned with the longitudinal direction of the resin film. Using a tensile tester (Orientec "Tensilon" (registered trademark) UCT-100) at a measurement temperature of 23°C, evaluation was performed under two conditions with different deformation speeds to determine the superiority or inferiority of recovery properties.

[0238] Condition A: Initial chuck distance 50 mm, tensile speed 50 mm / min. After stretching the sample to a strain of 100%, the tensile load on the sample was released, and the distance marked as the initial test length before measurement was measured and recorded as L mm. The elastic recovery rate z1 (%) was calculated using the following formula.

[0239] Elastic recovery rate z1 = (1-(L-50) / 100) x 100 (%).

[0240] Condition B: Initial chuck distance 50 mm, tensile speed 300 mm / min. After stretching the sample to a strain of 100%, the tensile load on the sample was released, and the distance marked as the initial test length before measurement was measured and recorded as L mm. The elastic recovery rate z2% was calculated using the following formula.

[0241] Elastic recovery rate z2 = (1-(L-50) / 100) x 100 (%).

[0242] [Screen printing on resin film] A screen plate (100 x 100 SUS325-28-C NU-55 emulsion thickness 5 μm, manufactured by Nakanuma Art Screen Co., Ltd.) with the pattern shown in Figure 5 or Figure 6 was attached to a small screen printing machine (LS-150, manufactured by Newlong Precision Industry Co., Ltd.), and a printing paste (LS-453-6B, manufactured by Asahi Chemical Research Institute Co., Ltd.) was placed on the screen plate. Next, a resin film was fixed on the printing machine stage, and printing operation was started. After that, the resin film was dried at 80 °C for 30 minutes, and a printed layer with the pattern shown in Figure 7 or Figure 8 was formed on the resin film.

[0243] [Evaluation of printing plate release properties of resin film] When printing was performed using the screen printing plate shown in Figure 5, the presence or absence of sticking to the screen printing plate was visually checked and evaluated using the following three levels. ○: There was no adhesion between the printing plate and the resin film, and the resin film was on the printing press stage after printing. △: There is weak adhesion between the printing plate and the resin film, but the printing plate and the resin film peel off during the printing operation, and the resin film is on the printing press stage after printing. ×: The printing plate / resin film was strongly stuck together, and the resin film was not placed on the printing machine stage after printing.

[0244] [Evaluation of adhesiveness of printed layer on resin film] A printed layer with a solid pattern as shown in Figure 7 was formed on a resin film by screen printing. The adhesion between the printed layer and the resin film was evaluated according to the adhesion (cross-cut method) described in JIS K5600-5-6 (1999). [Measurement of resistance change rate] The rate of change in resistance value was measured by a method in which the resin film on which the wiring pattern print layer was formed was stretched by a tensile tester while measuring the resistance value with a digital multimeter. A printed wiring pattern with a 1 mm wide, 50 mm long straight section between the electrodes was formed on a resin film by screen printing, as shown in Figure 8. A 20 mm wide x 150 mm long specimen was cut out centered on this wiring pattern. The 150 mm long section was aligned with the longitudinal direction of the resin film. A 30 mm square copper plate was attached to the electrode section of the specimen and secured in place with tape. The specimen and copper plate were then connected to a tensile testing machine (Orientec "Tensilon" (registered trademark) UCT-100). The distance between the chucks was set to 50 mm, and the distance between the chucks was adjusted so that the straight section coincided with the distance between the chucks. The copper plate was connected to a digital multimeter (Keysight Technologies "Digital Multimeter" 34465A) via a clip. While recording the resistance value with the digital multimeter, the sample was stretched to a strain of 20% at a tensile speed of 100 mm / min, held for 10 seconds, restored to 0%, and held for 10 seconds. This cycle was repeated 20 times. The rate of change in resistance Q / P was calculated from the maximum resistance P (Ω) in the first cycle and the maximum resistance Q (Ω) in the 20th cycle.

[0245] When the longitudinal direction was unknown, a sample was prepared in an arbitrary direction, and then samples were prepared at 60° and 120° rotations, and the measurement results of a total of three samples were averaged for evaluation.

[0246] Table 5 summarizes the evaluation results for conditions 1 to 11 described above, Table 6 summarizes the structures of the resin films' chemical formulas 1 to 8 and whether or not they contain urethane bonds, as well as the layer structure of the resin films, and Table 7 summarizes the results for the resin films' flexibility, resilience, printing plate releasability, printing layer adhesion, and resistance change rate.

[0247] [Table 5]

[0248] [Table 6]

[0249] [Table 7]

[0250] In Table 6, "includes" in the column for the structure of Chemical Formula 1 means that each Example contains the structure of Chemical Formula 1, and "does not contain" means that each Example does not contain the structure of Chemical Formula 1. The same applies to Chemical Formulas 2 to 8 and the urethane bond. [Explanation of symbols]

[0251] 1, 4, 7, 11, 21, 24: Laminate 2, 5, 8, 12, 22, 25: Resin film 6, 9: Base material A 3, 10, 13: Base material B 14, 17: Screen version 15, 18: Emulsion 16: Mesh (solid pattern) 19: Mesh (wiring pattern electrode part) 20: Mesh (straight line part of wiring pattern) 23: Printing layer (solid pattern) 26: Printing layer (wiring pattern electrode part) 27: Printing layer (straight line part of wiring pattern) [Industrial Applicability]

[0252] The resin film of the present invention has advantages such as excellent optical properties, flexibility, stretchability, transportability, and appearance quality, and can be suitably used in applications where particularly high flexibility and stretchability are required.

[0253] To give just a few examples, it can be suitably used for surface materials, internal materials, constituent materials, and manufacturing process materials in plastic molded products such as eyeglasses and sunglasses, cosmetic cases, and food containers, aquariums, showcases for exhibitions, smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, wearable devices, sensors, circuit materials, electrical and electronic applications, home appliances such as keyboards and TV and air conditioner remote controls, mirrors, window glass, buildings, dashboards, car navigation systems and touch panels, vehicle parts such as rearview mirrors and windows, and various printed materials, medical films, sanitary material films, medical films, agricultural films, and building material films.

Claims

1. A resin film that satisfies all of the following conditions 1 to 3. Condition 1: The storage modulus of the resin film is 0.5 MPa at a temperature of 25°C and a frequency of 1 Hz. a or more and 50 MPa or less. Condition 2: The loss tangent of the resin film at 25° C. is 0.5 or less. Condition 3: Flat portion on at least one surface of the resin film measured by a laser microscope The ratio is less than 50%.

2. The resin film according to claim 1 , which satisfies the following condition 4: Condition 4: The root mean square roughness Rq of at least one surface of the resin film is 40 0 nm or more.

3. The resin film according to claim 1 or 2, which satisfies the following condition 5: Condition 5: On at least one surface of the resin film, the contact angle measured by the dynamic contact angle expansion / contraction method is The contact angle hysteresis of the resin film with water is 5° or more. Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle.

4. The resin film according to claim 1 , which satisfies the following condition 6: Condition 6: The arithmetic mean roughness Ra on at least one surface of the resin film is 430 nm That's all.

5. The resin film according to claim 1 , which satisfies the following condition 7: Condition 7: The maximum height Rz on at least one surface of the resin film is 8 μm or more.

6. The resin film according to claim 1 , which satisfies the following condition 8: Condition 8: The surface free energy of at least one surface of the resin film is 30 m N / m or more.

7. The resin film according to claim 1 , which satisfies the following condition 9: Condition 9: On at least one surface of the resin film, per 1 mm square of the resin film The surface area of ​​1.3 mm ２ That's all.

8. The resin film according to claim 1 , which satisfies the following condition 10: Condition 10: On at least one surface of the resin film, a contact angle obtained by the dynamic contact angle expansion / contraction method The resin film propylene glycol monomethyl ether acetate (PGME A) The contact angle hysteresis is 5° or more. Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle.

9. The resin film according to claim 1 , which satisfies the following condition 11: Condition 11: haze of the resin film is 30% or more and 70% or less

10. The resin film according to any one of claims 1 to 9, comprising a structure of Chemical Formula 1 and a urethane bond. Film. 【Chemical 1】 In addition, R in Chemical Formula 1 １ refers to a hydrogen or methyl group.

11. A segment of Chemical Formula 2, a segment of Chemical Formula 3 or a segment of Chemical Formula 4 The resin film according to claim 1 , comprising either one of the following: 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 p is an integer of 1 or more. r is an integer of 1 or more. s is an integer of 1 or more.

12. A segment of chemical formula 5, a segment of chemical formula 6, a segment of chemical formula 7, a segment of chemical formula 8 At least one selected from the group consisting of a segment of a hydroxyl group, a hydroxyl group, and a segment of a hydrogenated product thereof The resin film according to claim 1 , comprising a segment. 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】

13. The resin film according to claim 1 , which is a single layer.

14. A laminate comprising a substrate and at least one of the resin films according to any one of claims 1 to 13. body.

15. The method for producing a laminate according to claim 14, wherein steps 1, 2, 3, and 4 are carried out in this order. Step 1: A resin precursor containing a segment of Chemical Formula 9 and a solvent are applied to a substrate A that satisfies Condition 12. A step of applying a coating composition containing the above to form a coating layer. Condition 12: Flat area ratio on at least one surface of the substrate A measured by a laser microscope The rate is less than 50%. 【Chemistry 9】 Step 2: Removing the solvent from the coating layer. Step 3: A step of crosslinking the resin precursor by irradiating it with active energy rays. Step 4: A step of attaching a substrate B to the surface of the coating layer opposite to the substrate A, and then peeling off the substrate A.

16. The resin film according to any one of claims 1 to 13 and a film formed on the resin film. An electrical circuit body including a conductor circuit.

17. The resin film according to any one of claims 1 to 13 and a film formed on the resin film. A healthcare sensor comprising a conductive circuit.

18. The resin film according to any one of claims 1 to 13 and a film formed on the resin film. A wearable sensor including a conductive circuit.

19. A step of processing the resin film according to any one of claims 1 to 13 by screen printing A method for manufacturing a resin film processed product.

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