Resin film and laminate

Abstract

To provide a resin film that satisfies both elasticity and tack resistance.SOLUTION: There is provided a resin film having a restoration rate of 80% or more, and having an uneven structure on at least one surface thereof.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a resin film and a laminate that are both stretchable and tack-resistant. [Background technology]

[0002] In recent years, display-equipped devices such as smartphones, tablets, personal computers, and LCD televisions, as well as various other devices, have become increasingly popular, and many of these devices use film and sheet materials made from synthetic resins, etc. In this context, research and development into flexible and wearable devices has been active in recent years, and progress is being made in the development of deformable devices and components.

[0003] Due to this situation, new technological fields are likely to emerge that are difficult to apply with the materials used in conventional displays and devices, and the need for new materials with high flexibility and stretchability is expected to increase.

[0004] On the other hand, as an example of an existing material that has flexibility and stretchability, Patent Document 1 proposes "a laminate having at least a layer made of a first polyethylene, a thermoplastic polyurethane layer laminated on the layer made of the first polyethylene, and a layer made of a second polyethylene laminated on the thermoplastic polyurethane layer, wherein the heat of crystallization of the first polyethylene is greater than the heat of crystallization of the second polyethylene."

[0005] Furthermore, Non-Patent Document 1 lists so-called "silicone materials," and proposes a sheet material using silicone rubber as an example of the silicone material.

[0006] Furthermore, Patent Document 2 proposes "an elastic film characterized by comprising an SBS resin composition prepared by mixing a styrene-butadiene-styrene copolymer (SBS-A) containing 65 to 95% by mass of a styrene component and a styrene-butadiene-styrene copolymer (SBS-B) containing 5 to 40% by mass of a styrene component in a composition ratio of (SBS-A) / (SBS-B) = 75 / 25 to 95 / 5, and a filler (C) blended in an amount of 20 to 45 parts by mass per 100 parts by mass of the SBS resin composition, and having a specific gravity of 1.10 to 1.32."

[0007] Furthermore, Patent Document 3 proposes "a foamed urethane sheet having a foam on a substrate, the foam being obtained by applying a mixture of urethane resin, organic solvent, water and fluorine-based surfactant to a substrate which is a polyethylene terephthalate film, a polypropylene film or a methylpentene polymer film and has an adhesive on one side, and then heating the applied mixture, wherein the organic solvent is a mixed solution of toluene and methyl ethyl ketone, and the foam is composed of fine cells with a continuous air permeability structure."

[0008] Furthermore, in terms of materials simply having high flexibility, the adhesive materials described in Non-Patent Document 2 can be mentioned, although they cannot be said to be stretchable materials.

[0009] Furthermore, as a flexible material having a specific shape on its surface, Patent Document 4 proposes an optical sheet having "a structured surface and including a cured resin layer made of a curable resin composition containing an organic compound and metal oxide nanoparticles, wherein pressure is applied from above the structured surface using a flat indenter at a rate of 0.2031 mN / sec until a maximum compressive force of 1 gf or 2 gf is reached, and when the maximum compressive force is reached, compression is stopped for 5 seconds and then the compressive force is released, and the optical sheet has an elastic recovery rate, expressed by the following mathematical formula 1, of 80% or more." [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-91223 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-88293 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-231170 [Patent Document 4] Special Publication No. 2015-514229 [Non-patent literature]

[0011] [Non-Patent Document 1] Silicone Handbook, Nikkan Kogyo Shimbun, Ltd., 1990 [Non-patent document 2] Learn about adhesives from the basics - Why does it stick? Why does it peel off? - Maruzen Publishing Co., Ltd. Summary of the Invention [Problem to be solved by the invention]

[0012] However, when the inventors checked the material proposed in Patent Document 1, they found that although it had a certain degree of stretchability, it lacked heat resistance at high temperatures and was therefore unsuitable for post-processing involving heating, which is necessary for application as a component for displays and devices.

[0013] The silicone rubber material proposed in Non-Patent Document 1 provided a certain degree of stretchability and tack resistance, but had poor adhesion to other materials and was unsuitable for post-processing. Furthermore, the stretchability was also insufficient.

[0014] Next, it was found that the material proposed in Patent Document 2 had a certain degree of flexibility, but was insufficient in terms of stretchability and transparency.

[0015] Furthermore, although the material proposed in Patent Document 3 was confirmed to have a certain degree of flexibility and stretchability, it had insufficient transparency.In addition, due to the presence of foamed portions, it was found to be unsuitable for post-processing steps involving coating.

[0016] Furthermore, although the material proposed in Non-Patent Document 2 was confirmed to have a certain degree of flexibility, it was not a material that exhibited stretchability. In addition, since it was an adhesive material, it was not suitable for post-processing and did not exhibit tack prevention properties.

[0017] Furthermore, a certain degree of flexibility was confirmed for the material proposed in Patent Document 4. However, the flexible resin film is used in combination with a supporting substrate, and the flexible resin film cannot be used alone, and similarly does not exhibit stretchability.

[0018] Therefore, an object of the present invention is to provide a resin film that has stretchability and is excellent in tack prevention, reworkability, and post-processability. [Means for solving the problem]

[0019] In order to solve the above problems, the present inventors have conducted extensive research and have completed the following invention. <1> A resin film having a recovery rate of 80% or more and having an uneven structure on at least one surface. <2> A laminate having a resin film on one side of a release film, the release film has an uneven structure on at least one surface, The resin film has a recovery rate of 80% or more and has an uneven structure on at least one surface, the surface of the release film having the concave-convex structure and the surface of the resin film having the concave-convex structure are in contact with each other so that the convex portions of the concave-convex structure of the release film fit into the concave-convex structure of the resin film, and the convex portions of the concave-convex structure of the resin film fit into the concave-convex structure of the release film, A laminate characterized in that the peel strength between the release film and the resin film is 1,000 mN / 50 mm or less. [Effects of the Invention]

[0020] According to the present invention, it is possible to obtain a resin film and a laminate that are flexible yet have good post-processability and tack prevention properties. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a laminate, a resin film, and a release film in the present invention. [Figure 2] FIG. 1 is a cross-sectional view showing an example of a laminate, a resin film, and a release film in the present invention. [Figure 3] FIG. 1 is a cross-sectional view showing an example of a laminate, a resin film, and a release film in the present invention. [Figure 4] 1 is a cross-sectional view showing an example of a resin film in the present invention. [Figure 5] 1 is a bird's-eye view showing an example of a resin film in the present invention, in which the surface uneven structure is striped. [Figure 6] This is an example of a method for forming a concave-convex structure on the release film of the present invention. [Figure 7] FIG. 1 is a perspective view showing an example of a mold for forming a concave-convex structure in the present invention. [Figure 8] FIG. 2 is a cross-sectional view showing an example of a mold for forming a concave-convex structure in the present invention. [Figure 9] 1 is a cross-sectional view showing an example of a method for forming a resin film in the present invention. [Figure 10] 1 is a cross-sectional view showing an example of a method for forming a resin film in the present invention. [Figure 11] 1 is a cross-sectional view showing an example of a method for forming a resin film in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Before describing the embodiments of the present invention, the problems of the prior art, that is, the compatibility of stretchability with tack prevention and reworkability, will be considered from the viewpoint of the present inventor.

[0023] [Comparison of the present invention and the prior art] While conventional stretchable materials exist, their stretchability often results in poor tack resistance and reworkability. Therefore, even if a material is suitable from the perspective of stretchability, it is difficult to process properly and is difficult to apply in actual applications, such as displays, devices, and sensors, where film materials are often used after various post-processing processes. Furthermore, in applications where such stretchable materials come into direct contact with human skin, such as wearable sensors and hygienic materials, the stretchability can cause tackiness, which can cause discomfort when touching human skin. Furthermore, reworkability can be poor, making it difficult to remove the material when correcting its placement.

[0024] Therefore, the inventors investigated ways to impart the aforementioned tack prevention and reworkability to such stretchable materials while taking advantage of their properties. As a result, they found that imparting a textured structure to the surface of stretchable materials is effective. By imparting a textured surface, the contact area can be reduced when attaching a resin film to human skin, etc. This prevents tack and reduces discomfort. Furthermore, it facilitates peeling after application, improving reworkability. When processing for applications such as displays, devices, and sensors, the positioning can be easily adjusted when applying the film to human skin, which is desirable not only for proper use but also from the perspective of reducing material waste.

[0025] Specifically, it is preferable that at least one surface of the resin film has an uneven structure.

[0026] Furthermore, the inventors of the present invention have studied the above-mentioned uneven structure and found that by forming the uneven structure in a specific shape, air escape properties can be imparted during application. When a resin film having an uneven structure is applied, the convex portions of the uneven structure are the portions that actually come into contact, while the concave portions are floating without contact. Therefore, by forming the uneven structure in a striped shape, the concave portions are connected and become floating portions, which serve as passageways for air pockets that tend to form during application. As a result, it is possible to improve the air escape properties during application of the resin film.

[0027] Furthermore, the present inventors focused on the height of the uneven structure and found that a certain range of maximum height is preferable. As described above, when a resin film has an uneven structure, it can impart tack prevention and reworkability. However, it was found that if the height of the uneven structure is too low, the above effects become insufficient, and a certain height or greater is required. On the other hand, if the height of the uneven structure is too high, the uneven structure may deform when a force is applied, such as when attaching the resin film. In such cases, even if an attempt is made to reduce the contact area during attachment by using an uneven structure, the uneven structure may deform, resulting in an unintended increase in contact area and insufficient tack prevention and reworkability. Furthermore, deformation of the uneven structure may result in insufficient rigidity of the resin film. Therefore, it was found that it is more effective to set the height of the uneven structure below a certain level.

[0028] Specifically, it is preferable that the uneven structure of the resin film is striped, and that the maximum height of the uneven structure is 5 μm or more and 100 μm or less.

[0029] The present inventors also investigated methods for imparting a textured structure to the surface of a resin film. One method for imparting a surface shape to a resin film is, for example, applying a heated mold to the resin film. However, with a resin film having a high recovery rate such as that of the present invention, the shape is restored even when the mold is applied, and it was not possible to successfully impart a textured structure. Furthermore, the material of such a resin film does not necessarily have thermoplasticity, and it is thought that imparting a shape using heat is difficult.

[0030] When other methods were investigated, it was found that a method of forming a surface structure by applying a roll of a specific shape to a resin before hardening, or a method of imparting a specific shape to a release film serving as a supporting substrate and then coating the release film with a resin film was effective. In particular, it was found that the latter method can protect the uneven structure formed on the surface of the resin film until the resin film is peeled off from the release film for use.

[0031] Specifically, the method for producing a laminate comprises the steps of applying a coating composition containing components that constitute a resin film to the surface of a release film having a concave-convex structure on at least one surface, the surface having the concave-convex structure, and curing the components.

[0032] [Embodiments of the present invention] Hereinafter, embodiments of the present invention will be specifically described.

[0033] [Resin film] In order to satisfy the above-mentioned objectives, i.e., stretchability, tack prevention, reworkability, and post-processability, the resin film of the present invention is preferably a resin film characterized by having a recovery rate of 80% or more and having an uneven structure on at least one surface.

[0034] The method for measuring the restoration rate will be described later.

[0035] From the viewpoint of stretchability, the recovery rate of the resin film is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more.

[0036] Regarding the restoration rate of the resin film, a restoration rate of 80% or more is preferable because even if the resin film is deformed by applying a load, it will return to its original shape when the load is removed. The higher the restoration rate, the greater the above effect, but the upper limit of the restoration rate is 100%.

[0037] From the viewpoint of tack prevention and reworkability, the resin film of the present invention preferably has a concave-convex structure on at least one surface of the resin film. Due to the above-mentioned effects, the concave-convex structure on the surface of the resin film can impart tack prevention and reworkability to stretchable materials without impairing their properties. The concave-convex structure formed on at least one surface of the resin film is not particularly limited from the viewpoints of tack prevention, reworkability, and post-processability, and may have a random or regular shape. From the viewpoint of air release, it is more preferable that the recesses of the concave-convex structure of the resin film are not independent, but are partly or entirely connected in the in-plane direction. Examples of a concave-convex structure in which part or all of the recesses of the concave-convex structure are connected include a stripe shape, a grid shape, and a lattice shape. As described below, it is particularly preferable that the concave-convex structure of the resin film be stripe-shaped.

[0038] Furthermore, from the viewpoint of flexibility, the resin film preferably satisfies the following condition 1.

[0039] Condition 1: The 5% strain stress of the resin film is 10 MPa or less.

[0040] The method for measuring the 5% strain stress will be described later.

[0041] From the viewpoint of flexibility, the 5% strain stress of the resin film of the present invention is preferably 10 MPa or less, more preferably 5 MPa or less.

[0042] Regarding the 5% strain stress of the resin film, if the 5% strain stress is 10 MPa or less, the resin film will exhibit good stretchability. There is no particular limit on the lower limit of the 5% strain stress; the lower the stress, the better the stretchability. However, if the stress is extremely low, the resin film may lack rigidity, so the lower limit is thought to be around 0.01 MPa. On the other hand, if the 5% strain stress exceeds 10 MPa, the resin film may lack stretchability.

[0043] The 5% strain stress of the resin film can be set to 10 MPa or less, for example, by using the materials described below.

[0044] Furthermore, from the viewpoint of transparency, the resin film preferably satisfies the following condition 2.

[0045] Condition 2: The total light transmittance of the resin film must be 80% or more.

[0046] The method for measuring the total light transmittance will be described later.

[0047] From the viewpoint of transparency, the resin film of the present invention preferably has a total light transmittance of 80% or more, more preferably 85% or more, and particularly preferably 90% or more.

[0048] Regarding the total light transmittance of a resin film, if the total light transmittance is 80% or more, the resin film exhibits good transparency. The higher the total light transmittance, the more improved the transparency, but the upper limit of the total light transmittance is 100%. On the other hand, if the total light transmittance is less than 80%, the resin film may be unsuitable for applications requiring transparency.

[0049] The total light transmittance of the resin film can be increased to 80% or more, for example, by using the materials described below.

[0050] Furthermore, from the viewpoint of air release properties, the resin film preferably satisfies the following condition 3.

[0051] Condition 3: The uneven structure of the resin film is striped.

[0052] When the uneven structure of the resin film is striped, the above-mentioned effects can improve tack prevention, air release, and reworkability.

[0053] Here, when the uneven structure of the resin film is said to be striped, it is sufficient if even a part of the uneven structure is striped, but the greater the proportion of striped shapes, the more preferable, and it is particularly preferable for the entire uneven structure to be striped.

[0054] Furthermore, from the viewpoint of tack prevention, it is preferable that the resin film satisfy the following condition 4.

[0055] Condition 4: The maximum height of the uneven structure of the resin film is 5 μm or more and 100 μm or less.

[0056] The method for measuring the maximum height will be described later.

[0057] From the viewpoint of tack prevention, the maximum height of the uneven structure in the resin film of the present invention is preferably 5 μm or more and 100 μm or less, more preferably 5 μm or more and 100 μm or less, and particularly preferably 5 μm or more and 100 μm or less.

[0058] Regarding the maximum height of the concave-convex structure of the resin film, if the maximum height is within a certain range, both stretchability and tack prevention can be achieved. On the other hand, if the maximum height exceeds 100 μm or less, the rigidity of the resin film may be insufficient. Furthermore, if the maximum height is less than 5 μm, tack prevention may be insufficient.

[0059] The maximum height of the uneven structure of the resin film refers to the difference between the lowest position of the recessed portion and the highest position of the protruding portion of the resin film. The uneven structure can be formed, for example, by the method described below. Multiple uneven structures with different heights can also be formed. In this case, the maximum height refers to the average difference between the lowest position of each recessed portion and the highest position of each protruding portion. Specific measurement methods are described in the Examples section.

[0060] [Laminate] Furthermore, the laminate of the present invention is a laminate having a resin film on one side of a release film, wherein the release film has an uneven structure on at least one surface, the resin film has a recovery rate of 80% or more and an uneven structure on at least one surface, the surface of the release film having an uneven structure and the surface of the resin film having an uneven structure are in contact with each other so that the convex portions of the uneven structure of the release film fit into the concave portions of the uneven structure of the resin film and the convex portions of the uneven structure of the resin film fit into the concave portions of the uneven structure of the release film, and the peel force between the release film and the resin film is preferably 1,000 mN / 50 mm or less.

[0061] The uneven structure and restoration rate of the resin film in the laminate are as explained above in the section [Resin Film]. That is, the resin film in the laminate also has a restoration rate of 80% or more and a uneven structure on at least one surface, and further, the resin film in the laminate also preferably satisfies the above-mentioned conditions 1, 2, 3, and 4.

[0062] The release film in the laminate of the present invention has an uneven structure on at least one surface. When the release film has a specific uneven structure, an uneven structure corresponding to the uneven structure of the release film can be formed on the surface of the resin film by, for example, the manufacturing method described below.

[0063] In the laminate of the present invention, the peel strength between the release film and the resin film is 1,000 mN / 50 mm or less, preferably 700 mN / 50 mm or less, and particularly preferably 500 mN / 50 mm or less.

[0064] Regarding the peel strength between the release film and the resin film, if the peel strength is in the range of 1,000 mN / 50 mm or less, the resin film can be easily peeled from the release film, which is preferable. On the other hand, if the peel strength exceeds 1,000 mN / 50 mm, the resin film may not be peeled from the release film, and the resin film may not be usable as a resin film.

[0065] The peel force between the resin film and the release film can be reduced to 1,000 mN / 50 mm or less, for example, by using the materials described below.

[0066] Furthermore, in the laminate of the present invention, it is important that the surface of the release film having the concave-convex structure and the surface of the resin film having the concave-convex structure are in contact with each other so that the convex portions of the concave-convex structure of the release film fit into the concave-convex structure of the resin film, and the convex portions of the concave-convex structure of the resin film fit into the concave-convex structure of the release film. By arranging the release film and the resin film in this manner in the laminate, the concave-convex structure of the resin film can be protected from external loads until the resin film is peeled off from the release film. Furthermore, the concave-convex structure of the resin film can be exposed at any time, making it possible to exhibit the effects of the above-mentioned concave-convex structure when necessary.

[0067] Furthermore, it is preferable that the laminate satisfy the following condition 1.

[0068] Condition 1: The 5% strain stress of the resin film is 10 MPa or less.

[0069] The 5% strain stress of the resin film is as described above.

[0070] Furthermore, it is preferable that the laminate satisfy the following condition 2.

[0071] Condition 2: The total light transmittance of the resin film must be 80% or more.

[0072] The method for measuring the total light transmittance will be described later.

[0073] The total light transmittance of the resin film is as described above.

[0074] Furthermore, it is preferable that the laminate satisfy the following conditions 3 and 5.

[0075] Condition 3: The uneven structure of the resin film is striped.

[0076] Condition 5: The uneven structure of the release film is striped.

[0077] The uneven structure of the resin film is as described above.

[0078] Regarding the uneven structure of the release film, if the release film has a specific uneven structure, it is possible to form an uneven structure corresponding to the uneven structure of the release film on the surface of the resin film by, for example, the manufacturing method described below. Therefore, by forming the uneven structure of the release film in a striped shape, it is possible to form the uneven structure formed on the resin film in a striped shape.

[0079] Furthermore, it is preferable that the laminate satisfy the following conditions 4 and 6.

[0080] Condition 4: The maximum height of the uneven structure of the resin film is 5 μm or more and 100 μm or less.

[0081] Condition 6: The maximum height of the uneven structure of the release film is 5 μm or more and 100 μm or less.

[0082] The maximum height of the concave-convex structure of the resin film is as described above. As for the maximum height of the concave-convex structure of the release film, as described above, a concave-convex structure corresponding to the concave-convex structure of the release film can be formed on the resin film.

[0083] [Method for producing resin film] The method for producing the resin film of the present invention is not particularly limited, but the method for producing the resin film of the present invention is preferably as follows.

[0084] A method for producing a resin film having a restoration rate of 80% or more and an uneven structure on at least one surface, the method comprising a step of peeling a release film from the laminate of the present invention.

[0085] By adopting a method for producing the resin film of the present invention that includes a step of peeling off the release film from the laminate of the present invention, the concave-convex structure of the resin film can be protected from external loads until the resin film is peeled off from the release film. Furthermore, the concave-convex structure of the resin film can be exposed at any timing, making it possible to exhibit the effects of the concave-convex structure when necessary.

[0086] [Method for manufacturing laminate] The method for producing the laminate of the present invention is not particularly limited, but preferably includes the steps of applying a coating composition containing components that constitute a resin film to the surface of a release film having a concave-convex structure on at least one surface, the surface having the concave-convex structure, and curing the components.

[0087] According to the method for producing a laminate of the present invention, as described above, it is possible to form a desired uneven structure even in a resin that does not exhibit thermoplasticity, such as the resin film of the present invention.

[0088] Details of the process of applying a coating composition containing components that constitute a resin film to the surface of the release film having the uneven structure, and details of the process of curing the components that follows this process will be described later.

[0089] [Release film] The release film used in the present invention may be a substrate film made of a resin that itself has releasability, or a substrate film to which releasability has been imparted by forming a release layer on the surface thereof. Commercially available general-purpose resins having releasability or general-purpose release coating materials can be used as materials for forming the release layer.

[0090] The resin constituting the substrate film used in the release film 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 supporting substrate is preferably one that has good moldability, and from this point of view, a thermoplastic resin is more preferred.

[0091] Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene; alicyclic polyolefin resins; polyamide resins such as nylon 6 and nylon 66; aramid resins; polyimide resins; polyester resins; polycarbonate resins; polyarylate resins; polyacetal resins; polyphenylene sulfide resins; fluororesins such as tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, and vinylidene fluoride resin; acrylic resins; methacrylic resins; polyacetal resins; polyglycolic acid resins; and polylactic acid resins. Examples of thermosetting resins include phenolic resins, epoxy resins, urea resins, melamine resins, unsaturated polyester resins, polyurethane resins, polyimide resins, and silicone resins. Thermoplastic resins with sufficient stretchability and conformability are preferred. From the viewpoint of moldability for forming a concave-convex structure on the surface, the thermoplastic resin is preferably a polyester resin, a polyolefin resin, a polycarbonate resin, an acrylic resin, or a methacrylic resin. In particular, a polyolefin resin is particularly preferable as a resin that itself has mold releasability.

[0092] In the present invention, polyester resin is a general term for polymers in which ester bonds are the main bonding chains in the main chain, and is obtained by polycondensation of an acid component, its ester, and a diol component. Specific examples include polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, and polybutylene terephthalate. These may also be copolymerized with other dicarboxylic acids and their esters or diol components as the acid component or diol component. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferred in terms of transparency, dimensional stability, heat resistance, and the like.

[0093] The polyolefin resin in the present invention refers to a polymer having repeating units derived from an olefin-based monomer. The polyolefin resin may be a polymer composed only of repeating units derived from an olefin-based monomer, or may be a copolymer having repeating units derived from an olefin-based monomer and repeating units derived from a monomer other than an olefin-based monomer.

[0094] The olefin monomer may have only one double bond in the molecule, or may have multiple double bonds in the molecule, such as a diene, triene, or tetraene. Specific examples of the olefin monomer include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, butadiene, pentadiene, and isoprene. These olefin monomers may be used alone or in combination of two or more.

[0095] The olefinic monomer may also be a cyclic olefin monomer. Specific examples of cyclic olefin monomers include monocyclic olefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, cyclopentadiene, and 1,3-cyclohexadiene, bicyclo[2,2,1]hept-2-ene, 5-methyl-bicyclo[2,2,1]hept-2-ene, 5,5-dimethyl-bicyclo[2,2,1]hept-2-ene, 5-ethyl-bicyclo[2,2,1]hept-2-ene, 5-butyl-bicyclo[2,2,1]hept-2-ene, 5-ethylidene-bicyclo[2,2,1]hept-2-ene, 5-hexyl-bicyclo[2,2,1]hept-2-ene, 5-octyl-bicyclo[2,2,1]hept-2-ene, 5-octadecyl-bicyclo[2,2,1]hept-2-ene, and 5-methylidene- Bicyclic olefins such as bicyclo[2,2,1]hept-2-ene, 5-vinyl-bicyclo[2,2,1]hept-2-ene, 5-propenyl-bicyclo[2,2,1]hept-2-ene, tricyclo[4,3,0,12.5]deca-3,7-diene, tricyclo[4,3,0,12.5]undeca-3,7-diene, tricyclo[4,3,0,12.5]undeca-3,8-diene, tricyclo[4,3,0,12.5]undeca-3-ene, 5-cyclopentyl-bicyclo[2,2,1]hept-2-ene, 5-cyclohexyl-bicyclo[2,2,1]hept-2-ene, 5-cyclohexenyl-bicyclo[2,2, 1]hept-2-ene, 5-phenyl-bicyclo[2,2,1]hept-2-ene, tricyclic olefins such as tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-methyltetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-ethyltetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-methylidenetetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-ethylidenetetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-vinyltetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-propenyl-tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, and tetracyclic olefins such as 8-cyclopentyl-tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-cyclohexyl-tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-cyclohexenyl-tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, 8-phenyl-cyclopentyl-tetracyclo[4,4,0,12.5,17.10]dodec-3-ene, tetracyclo[7,4,13.6,01.9,02.7]tetradec-4,9,11,13-tetraene, and tetracyclo[8,4,14.7,01.10,03. 8]pentadeca-5,10,12,14-tetraene, pentacyclo[6,6,13.6,02.7,09.14]-4-hexadecene, pentacyclo[6,5,1,13.6,02.7,09.13]-4-pentadecene, pentacyclo[7,4,0,02.7,13.6,110.13]-4-pentadecene, heptacyclo[8,7,0,12.9,14.7,111.17,03.8,012.16]-5-eicosene, heptacyclo[8,7,0,12.9,03.8,14.7,012.17,113.16]-14-eicosene, and polycyclic olefins such as tetramers such as cyclopentadiene. These cyclic olefin monomers can be used alone or in combination of two or more.

[0096] Examples of the monomer other than the olefin-based monomer include vinyl acetate, (meth)acrylic acid ester, and styrene.

[0097] Specific examples of polyolefin resins include very low-density polyethylene (VLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), ethylene-propylene copolymer, olefin-based elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer. The substrate film may also contain various additives, such as antioxidants, antistatic agents, nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, and dopants for adjusting the refractive index. The supporting substrate may have either a single-layer or a multilayer structure.

[0098] The surface of the substrate film 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.

[0099] 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 film in advance, separate from the resin film of the present invention. In the laminate of the present invention, it is particularly preferable to provide a release layer in order to reduce the peel force between the substrate film and the resin film.

[0100] Examples of films made of polyester resin provided with the aforementioned release layer include "Therapeel" (registered trademark) manufactured by Toray Advanced Film Co., Ltd., "Unipeel" (registered trademark) manufactured by Unitika Ltd., "Panapeel" (registered trademark) manufactured by Panac Corporation, "Toyobo Ester" (registered trademark) manufactured by Toyobo Co., Ltd., and "Purex" (registered trademark) manufactured by Teijin Limited, and these products can be used.

[0101] [Providing a surface texture to release films (creating a textured structure)] The method for producing a release film having a textured surface is not particularly limited, but the following methods are preferred: 1. a method of providing a release layer on a substrate film having a textured surface; 2. a method of providing a release layer having a textured surface on a flat substrate film; and 3. a method of imparting a textured structure to a substrate film having releasability. Furthermore, method 3 is more preferred in terms of air escape properties. Figures 1 to 3 show cross-sectional views of a laminate using release films produced by methods 1 to 3 above, and a method for producing a resin film from the laminate. Below, method 3, which is a method of imparting a textured structure to a release film having releasability, will be described in detail. Fig. 6 is a flow chart showing one example of an embodiment of a method for forming a concave-convex structure on the surface of a release film of the present invention using a mold, and Fig. 7 is a perspective view showing one example of an applied mold. First, a release film is prepared as shown in Figure 6(a). The glass transition temperature of the release film is designated as Tgr.

[0102] The release film prepared here may be a substrate film that itself has releasability, or a substrate film with a release layer provided on its surface. Alternatively, a substrate film without release properties may be provided with a release layer after a surface unevenness structure is formed by the method described below. Here, these are collectively referred to as release films.

[0103] The release film on whose surface the uneven structure is to be formed may be a continuous film transported in a roll-to-roll manner, or may be a sheet.

[0104] The glass transition temperature is the temperature at which tan δ becomes maximum when the temperature dependence (temperature dispersion) is measured according to the method described in JIS K 7244 (2007), with a sample dynamic amplitude speed (driving frequency) of 1 Hz, tension mode, chuck distance of 5 mm, and a heating rate of 2°C / min.

[0105] In the present invention, it is preferable to heat the mold 26 having the protrusion structure 27 on its surface. Heating is preferably carried out so that the mold is in a temperature range equal to or higher than the glass transition temperature of the release film. Heating may be carried out while the mold and the release film are in contact with each other. By keeping them in contact, the flatness of the release film can be maintained in a good condition.

[0106] Although there is no upper limit to the heating temperature of the mold, it is preferably equal to or lower than the thermal decomposition point of the release film.

[0107] Next, as shown in Fig. 6(b), it is preferable to pressurize the mold 26 so that the heated protrusion structure surface 27 contacts the release film. When the protrusion structure 27 has an appropriate height, the mold 26 and the release film are in contact with each other without any gaps.

[0108] The pressure and pressing time required depend on the film material, transfer shape, and particularly the aspect ratio of the unevenness, but generally the preferred range for the pressing pressure is 1 MPa or more, and the preferred range for the molding time is 0.01 seconds or more.

[0109] Alternatively, the mold 26 may be pressed against the release film by position control. That is, the mold 26 may be moved to a preset position and pressed against the release film. The preset position is a position where the protrusion structure 27 of the mold can be brought into close contact with the surface of the release film or base film on which the textured structure is to be formed.

[0110] After the pressure is increased, the pressure may be released while the mold is held in position, so that the mold 26 and the release film are kept in contact with each other.

[0111] Next, as shown in Fig. 6(b), it is preferable to cool the mold while maintaining the pressurized or contacted state. This is preferably done to a temperature below the glass transition temperature of the release film. Cooling to a temperature below the glass transition temperature is preferable because it is possible to suppress resin deformation after the mold 26 is peeled from the release film, and it is possible to form a groove shape with high precision.

[0112] Next, as shown in Figure 6(c), the release film is peeled off from the mold 26. It is preferable to peel the mold and the release film by moving them apart in a direction perpendicular to the surface of the release film. If the release film is a continuous film, it is preferable to apply tension continuously in a direction perpendicular to the surface of the release film so that the linear peel position moves continuously during peeling. This forms recesses 29 in the release film.

[0113] In the above manufacturing method, when the protrusion structure 27 is pressed, viscoelastic deformation occurs in the release film, and the protrusion structure 27 can smoothly enter the inside of the release film, so that recesses 29 having a shape corresponding to the protrusion structure of the mold are formed in the release film, and suitable molding is achieved.

[0114] In order to induce such viscoelastic deformation of the release film, the temperature T to which the mold 26 having the protrusion structure 27 on its surface is heated is preferably set to be equal to or higher than the glass transition temperature of the release film. The heating temperature T of the mold 26 is preferably 5°C to 60°C higher than the glass transition temperature of the release film. If the difference between the glass transition temperature of the release film and the heating temperature T of the mold 26 is less than 5°C, a large force is required to deform the release film, which may result in insufficient formation of the relief structure of the release film. Conversely, if the difference between the glass transition temperature of the release film and the heating temperature T of the mold 26 is greater than 60°C, the rear surface of the release film may begin to deform while the surface of the mold 26 is still deforming, making it difficult to flatten the rear surface of the release film.

[0115] Furthermore, by setting the storage modulus of the resin contained in the release film at the temperature T of the mold 26 during molding to a range of 0.005 GPa or more and 0.5 GPa or less, more preferably 0.01 GPa or more and 0.1 GPa or less, the shape accuracy of the recesses 29 in the release film can be further improved. If the storage modulus is less than 0.005 GPa, the shape of the recesses 29 in the release film may be easily deformed. On the other hand, if the storage modulus is greater than 0.5 GPa, the release film may be difficult to deform, and the protrusion structures 27 of the mold 26 may not be inserted all the way into the release film, making it difficult to form groove shapes with the desired shape accuracy.

[0116] The depth and width of the recesses 29 formed in the release film can be selected arbitrarily depending on the application, but preferably both the width and depth are 1 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. If the groove width and depth are less than 1 μm, precision may be difficult, and if they are greater than 100 μm, a large pressure may be required to form the grooves, which may result in an increase in the size of the equipment. Note that if they are greater than 100 μm, mechanical processing such as directly cutting the release film is often appropriate, and processing suitability may be difficult.

[0117] Next, the shape of the mold will be described with reference to Figures 7 and 8. Figures 7(a) and 7(b) are perspective views showing an example of a mold applied to the present invention, and Figures 8(a) and 8(b) are cross-sectional views showing an example of a mold applied to the present invention.

[0118] As shown in Fig. 7, it is preferable that protrusion structures 27 are arranged at predetermined positions on the outer surface of a mold 26. The protrusion structures refer to convex structures provided on the mold, and the protrusion structures may be of the same shape only, or may have a plurality of different shapes. The width and height of the convex portions may also change along the way.

[0119] The arrangement and density of the protrusion structures 27 are preferably the same as the arrangement and density of the groove shapes required as product specifications. Generally, the pitch is 100 nm or more and 1 mm or less. The pitch refers to the repetition interval of the protrusion structures 21.

[0120] The protrusion structure 227 may be a wall-like structure as shown in Figure 7(a) or a grid-like structure as shown in Figure 7(b), and in this case, if the structure is repeated, it is preferable that it be repeated periodically in one direction.

[0121] The height and cross-sectional shape of the protrusion structure 21 are determined by the required groove shape and film thickness. The protrusion structure may be a rectangular shape with a flat tip, as shown in Figure 8(a), or may be a pointed tip, as shown in Figure 8(b).

[0122] The material of the mold is preferably a metal having high strength and thermal conductivity, such as nickel, steel, stainless steel, copper, etc. The mold may also be plated on its outer surface to improve workability.

[0123] Methods for producing molds having protrusion structures on their surfaces include direct cutting, laser processing, or electron beam processing of the metal surface, direct cutting, laser processing, or electron beam processing of a plating film formed on the metal surface, and electroforming of these. Other methods include applying resist to a substrate, forming a resist with a predetermined pattern using photolithography, etching the substrate to form recesses, and then removing the resist to obtain a reverse pattern using electroforming. Anisotropic etching can be used to obtain recessed patterns. In addition to metal plates, glass and silicon substrates can also be used as substrates.

[0124] [Resin film, laminate] The resin film and laminate of the present invention may be in a planar state or in a three-dimensional shape after molding, as long as it has a resin film exhibiting the above-mentioned physical properties. The number of layers of the resin film is not particularly limited, and the resin film may be formed from one layer or two or more layers.

[0125] The thickness of the resin film is not particularly limited, but the lower limit is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The upper limit is preferably 500 μm or less, more preferably 300 μm or less, and particularly preferably 200 μm or less. The thickness of the resin film can be selected depending on the other functions described above.

[0126] The resin film may have other functions such as gloss, fingerprint resistance, formability, designability, scratch resistance, stain resistance, solvent resistance, antireflection, antistatic properties, electrical conductivity, heat ray reflection, near-infrared absorption, electromagnetic wave shielding, and easy adhesion, in addition to the stretchability and tackiness that are the object of the present invention.

[0127] Furthermore, one or more layers may be formed on the resin film, such as a functional layer having the above-mentioned functions, an adhesive layer, an electronic circuit layer, a printing layer, an optical adjustment layer, or other functional layers.

[0128] [Paint composition] Although the method for producing the laminate of the present invention is not particularly limited, the laminate of the present invention can be obtained by applying a coating composition containing components that constitute a resin film to the surface of the release film having the uneven structure described above, drying the coating composition as needed, and curing the components. Here, the "coating composition" refers to a liquid composed of a solvent and a solute, and is a material that can form a resin film by applying the coating composition to the release film described above, volatilizing and removing the solvent in a drying process, and curing the coating composition.

[0129] Here, the term "type" of coating composition refers to liquids that contain different types of solutes, even if only partially. These solutes consist of resins or materials capable of forming resins during the coating process (hereinafter referred to as precursors), particles, and various additives such as polymerization initiators, curing agents, catalysts, leveling agents, UV absorbers, and antioxidants.

[0130] In the resin film and laminate of the present invention, it is preferable to form the resin film by applying the following coating composition onto a release film.

[0131] The coating composition is a liquid containing components suitable for forming the resin film of the present invention, and preferably contains a resin or precursor containing the following segments (1) and (2) as a solute. It may also contain a resin or precursor containing the segment (3). (1) A segment containing at least one selected from the group consisting of a polycaprolactone segment, a polycarbonate segment, and a polyalkylene glycol segment. (2) Urethane bond (3) A segment containing at least one selected from the group consisting of a fluorine compound segment, a polysiloxane segment, and a polydimethylsiloxane segment.

[0132] The individual segments contained in the components that make up this resin film can be confirmed by TOF-SIMS, FT-IR, or the like.

[0133] The parts by mass of (1), (2), and (3) contained in the coating composition are preferably (1) / (2) / (3) = 95 / 5 / 1 to 50 / 50 / 15, and more preferably (1) / (2) / (3) = 90 / 10 / 1 to 60 / 40 / 10. Details of (1), (2), and (3) are explained below.

[0134] The details of the (1) polycaprolactone segment, polycarbonate segment, and polyalkylene glycol segment will be described later, but the components constituting the resin film having these segments can improve the stretchability and flexibility of the resin film. Furthermore, from the viewpoint of the durability of the resin film, it is particularly preferable that the components constituting the resin film have a polyalkylene glycol segment.

[0135] The urethane bond will be described in detail below, but when the resin constituting the layer A on the surface of the resin film has this bond, the toughness and stretchability of the entire resin film can be improved.

[0136] Although the details of the fluorine compound segment, polysiloxane segment, and polydimethylsiloxane segment will be described later, when the components constituting the resin film contain these, molecules exhibiting low surface energy can be present at a high density on the outermost surface, thereby improving the solvent resistance of the resin film.

[0137] Another example of a resin suitable as a solute for a coating composition is urethane acrylate, which is available in a variety of general-purpose products and can also be synthesized to have various properties depending on the purpose.

[0138] In the present invention, a more preferred embodiment is a method of lowering the glass transition temperature of the resin film, and one of the means for this is to select the type of urethane acrylate.Similarly, a more preferred embodiment is to use a component obtained by curing a urethane acrylate having a certain number average molecular weight in the resin film, and one of the means for this is to select the type of urethane acrylate.

[0139] Commercially available examples of urethane acrylates include urethane acrylates manufactured by Asia Kogyo Co., Ltd., urethane acrylates manufactured by Kyoeisha Chemical Co., Ltd., urethane acrylates manufactured by Shin-Nakamura Chemical Co., Ltd., urethane acrylates manufactured by Taisei Fine Chemical Co., Ltd., "New Frontier" (registered trademark) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "EBECRYL" (registered trademark) manufactured by Daicel-Allnex Co., Ltd., "Shiko" (registered trademark) manufactured by Nippon Gohsei Co., Ltd., and urethane acrylates manufactured by DIC Corporation, and these products can be used.

[0140] The coating composition for resin films preferably contains a resin or precursor containing the polyether segment (4). These may all be present in one type of polymer or oligomer, including resins or precursors containing segments (1) to (3), or may be a mixture of different polymers or oligomers containing each of them.

[0141] For the resin film of the present invention, mechanical properties such as flexibility and stretchability of the resin film are important. Therefore, a method capable of controlling the structure of the polymer forming the resin film is preferred. Furthermore, since the laminate of the present invention requires a high level of appearance quality and thickness smoothness for the resin film, there is a preferred range for the viscosity of the coating composition for forming the resin film in the laminate manufacturing method described below. Furthermore, since the laminate of the present invention is processed in a subsequent process, it is preferable that it is as resistant to solvents as possible.

[0142] Therefore, it is preferable that the resin film coating composition be prepared by polymerizing a precursor containing a polyether segment of chemical formula 3, a (meth)acrylic segment of chemical formula 1, and a urethane segment of chemical formula 2 under conditions in which the molecular weight can be controlled to produce an oligomer, and then adding various additives to this to prepare a resin film-forming coating composition, which is then applied to a supporting substrate and crosslinked in the laminate manufacturing method described below to form a resin film.

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] Specifically, it is preferable to prepare a urethane acrylate oligomer by pre-polymerizing a polyether polyol, a compound containing an isocyanate group, and a hydroxyalkyl (meth)acrylate, or an acrylic-modified polyether polyol and a compound containing an isocyanate group, and then add appropriate additives to the oligomer to prepare a coating composition for forming a resin film.

[0147] Examples of polyether polyols include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and various derivatives thereof.

[0148] Examples of hydroxyalkyl (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate.

[0149] [Polycaprolactone segment, polycarbonate segment, polyalkylene glycol segment] First, a polycaprolactone segment refers to a segment shown in chemical formula 4. Polycaprolactone includes those in which the caprolactone repeating unit is 1 (monomer), 2 (dimer), or 3 (trimer), as well as oligomers with up to 35 caprolactone repeating units.

[0150] [ka]

[0151] Here, n is an integer from 1 to 35.

[0152] The resin containing the polycaprolactone segment preferably has at least one hydroxyl group, and the hydroxyl group is preferably located at the terminal of the resin containing the polycaprolactone segment.

[0153] As the resin containing a polycaprolactone segment, polycaprolactone having di- or tri-functional hydroxyl groups is particularly preferred. Specifically, polycaprolactone diol represented by Chemical Formula 5,

[0154] [ka]

[0155] Here, m+n is an integer between 4 and 35, m and n are each an integer between 1 and 34, and R is C2H4, C2H4OC2H4, or C(CH3)3(CH2)2 or a polycaprolactone triol represented by chemical formula 6:

[0156] [ka]

[0157] where l+m+n is an integer between 3 and 30, l, m, and n are each an integer between 1 and 28, and R is CH2CHCH2, CH3C(CH2)3, or CH3CH2C(CH2)3 Polycaprolactone polyols such as those listed above and polycaprolactone-modified hydroxyethyl (meth)acrylates represented by chemical formula 7

[0158] [ka]

[0159] Here, n is an integer of 1 to 25, and R can be H or CH. Examples of other active energy ray-polymerizable caprolactones include polycaprolactone-modified hydroxypropyl (meth)acrylate and polycaprolactone-modified hydroxybutyl (meth)acrylate.

[0160] Furthermore, in the present invention, the resin containing a polycaprolactone segment may contain (or copolymerize) other segments or monomers in addition to the polycaprolactone segment, such as a polydimethylsiloxane segment, a polysiloxane segment, or a compound containing an isocyanate compound, as described below.

[0161] In the present invention, the weight-average molecular weight of the polycaprolactone segment in the resin containing the polycaprolactone segment is preferably 500 to 2,500, and more preferably 1,000 to 1,500. When the weight-average molecular weight of the polycaprolactone segment is 500 to 2,500, stretchability and flexibility are further improved, which is preferable.

[0162] Next, a polyalkylene glycol segment refers to a segment shown in chemical formula 8. Polyalkylene glycols include those with two (dimer) or three (trimer) alkylene glycol repeating units, as well as oligomers with up to 11 alkylene glycol repeating units.

[0163] [ka]

[0164] n is an integer of 2 to 4, and m is an integer of 2 to 11.

[0165] The resin containing the polyalkylene glycol segment preferably has at least one hydroxyl group, and the hydroxyl group is preferably located at the terminal of the resin containing the polyalkylene glycol segment.

[0166] The resin containing the polyalkylene glycol segment is preferably a polyalkylene glycol (meth)acrylate having an acrylate group at its terminal to impart elasticity. The number of acrylate functional groups (or methacrylate functional groups) in the polyalkylene glycol (meth)acrylate is not limited, but monofunctional groups are most preferred in terms of the elasticity and flexibility of the cured product.

[0167] Examples of polyalkylene glycol (meth)acrylates contained in the coating composition used to form the resin film include polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, and polybutylene glycol (meth)acrylate, which have structures represented by the following chemical formulas 9, 10, and 11, respectively.

[0168] Polyethylene glycol (meth)acrylate:

[0169] [ka]

[0170] Polypropylene glycol (meth)acrylate:

[0171] [ka]

[0172] Polybutylene glycol (meth)acrylate:

[0173] [ka]

[0174] In Chemical Formula 11, Chemical Formula 12, and Chemical Formula 13, R is hydrogen (H) or a methyl group (-CH3), and m is an integer between 2 and 11.

[0175] In the present invention, it is preferable to use a urethane (meth)acrylate obtained by reacting a compound containing an isocyanate group, which will be described later, with a hydroxyl group of a (poly)alkylene glycol (meth)acrylate in a resin film. This allows the components constituting the resin film to have (2) a urethane bond and (3) a (poly)alkylene glycol segment, which results in improved toughness of the resin film as well as improved stretchability and flexibility, which is preferable.

[0176] Examples of the hydroxyalkyl(meth)acrylate that is simultaneously blended during the urethane reaction of the compound containing an isocyanate group with the polyalkylene glycol(meth)acrylate include hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, and hydroxybutyl(meth)acrylate.

[0177] Next, a polycarbonate segment refers to a segment represented by chemical formula 12. Polycarbonates include those with two (dimer) or three (trimer) carbonate repeating units, as well as oligomers with up to 16 carbonate repeating units.

[0178] [ka]

[0179] n is an integer from 2 to 16. R4 represents an alkylene group or cycloalkylene group having 1 to 8 carbon atoms.

[0180] The resin containing the polycarbonate segment preferably has at least one hydroxyl group, and the hydroxyl group is preferably located at the terminal of the resin containing the polycarbonate segment.

[0181] As a resin containing a polycarbonate segment, a polycarbonate diol having a bifunctional hydroxyl group is particularly preferred. Specifically, it is represented by Chemical Formula 13. Polycarbonate diol:

[0182] [ka]

[0183] n is an integer of 2 to 16. R represents an alkylene group or cycloalkylene group having 1 to 8 carbon atoms.

[0184] The polycarbonate diol may have any number of repeating carbonate units, but if the number of repeating carbonate units is too large, the strength of the cured product of the urethane (meth)acrylate will decrease, so the number of repeating carbonate units is preferably 10 or less. The polycarbonate diol may also be a mixture of two or more polycarbonate diols having different numbers of repeating carbonate units.

[0185] The polycarbonate diol preferably has a number average molecular weight of 500 to 10,000, more preferably 1,000 to 5,000. If the number average molecular weight is less than 500, it may be difficult to obtain suitable stretchability, and if the number average molecular weight exceeds 10,000, heat resistance and solvent resistance may decrease, so those in the above range are suitable.

[0186] Suitable examples of polycarbonate diols used in the present invention include UH-CARB, UD-CARB, UC-CARB (Ube Industries, Ltd.), PLACCEL CD-PL, PLACCEL CD-H (Daicel Chemical Industries, Ltd.), Kuraray Polyol C Series (Kuraray Co., Ltd.), and Duranol Series (Asahi Kasei Chemicals Corporation). These polycarbonate diols can be used alone or in combination of two or more.

[0187] Furthermore, in the present invention, the resin containing a polycaprolactone segment may contain (or copolymerize) other segments or monomers in addition to the polycaprolactone segment, such as a polydimethylsiloxane segment, a polysiloxane segment, or a compound containing an isocyanate compound, as described below.

[0188] In the present invention, preferably, a compound containing an isocyanate group, which will be described later, is reacted with a hydroxyl group of a polycarbonate diol to form a urethane (meth)acrylate, which is then used in a resin film. This allows the components constituting the resin film to have the above-mentioned (2) urethane bond and (1) polycarbonate diol segment, and as a result, the toughness of the resin film can be improved, as well as the stretchability and flexibility.

[0189] [Compounds containing urethane bonds and isocyanate groups] In the present invention, the term "urethane bond" refers to the bond represented by Chemical Formula 2 above.

[0190] When the components constituting the resin film have this bond, the toughness and stretchability of the entire resin film can be improved.

[0191] The inclusion of a commercially available urethane-modified resin in the coating composition allows the components constituting the resin film to have urethane bonds. In addition, when forming a resin film, a coating composition containing a compound containing an isocyanate group and a compound containing a hydroxyl group as precursors is applied, dried, and cured to generate urethane bonds, which can then be incorporated into the resin film.

[0192] In the present invention, it is preferable to introduce a urethane bond into the components constituting the resin film by reacting an isocyanate group with a hydroxyl group to form a urethane bond, which can improve the toughness and stretchability of the resin film.

[0193] Furthermore, in the case of a resin containing the above-mentioned polycaprolactone segment, polycarbonate segment, or polyalkylene glycol segment, or in the case of a resin having a hydroxyl group, it is also possible to form a urethane bond between this resin and a compound containing an isocyanate group as a precursor by heat or the like.

[0194] Forming a resin film using a compound containing an isocyanate group and a resin containing a polysiloxane segment having a hydroxyl group, as described below, or a component containing a polydimethylsiloxane segment having a hydroxyl group, can improve the toughness and stretchability of the resin film, as well as the slipperiness of the surface, and is also more preferable from the viewpoint of solvent resistance.

[0195] In the present invention, the compound containing an isocyanate group refers to a resin containing an isocyanate group, or a monomer or oligomer containing an isocyanate group. Examples of the compound containing an isocyanate group include (poly)isocyanates such as methylenebis-4-cyclohexyl isocyanate, a trimethylolpropane adduct of tolylene diisocyanate, a trimethylolpropane adduct of hexamethylene diisocyanate, a trimethylolpropane adduct of isophorone diisocyanate, an isocyanurate of tolylene diisocyanate, an isocyanurate of hexamethylene diisocyanate, and a biuret of hexamethylene isocyanate, as well as blocked compounds of the above isocyanates.

[0196] Among these compounds containing an isocyanate group, aliphatic isocyanates are preferred because they have higher elasticity and flexibility than alicyclic or aromatic isocyanates. Hexamethylene diisocyanate is a more preferred compound containing an isocyanate group. Furthermore, isocyanates having an isocyanurate ring are particularly preferred in terms of heat resistance, with hexamethylene diisocyanate being the most preferred. Isocyanates having an isocyanurate ring form resin films that combine elasticity and heat resistance.

[0197] [Polysiloxane segment, polydimethylsiloxane segment] In the laminate of the present invention, the component constituting the resin film may have a segment containing at least one selected from the group consisting of a polysiloxane segment and a polydimethylsiloxane segment.

[0198] Furthermore, by using a resin containing a segment containing at least one selected from the group consisting of a polysiloxane segment and a polydimethylsiloxane segment, or a coating composition containing a precursor, as one of the coating compositions that form the resin film, the components that make up the resin film can contain these.

[0199] The polysiloxane segment and polydimethylsiloxane segment will be explained below.

[0200] The polysiloxane segment will now be described. In the present invention, the polysiloxane segment refers to a segment represented by Chemical Formula 14, which will be described later.

[0201] Here, polysiloxane includes both low molecular weight compounds having about 100 repeating siloxane units (so-called oligomers) and high molecular weight compounds having more than 100 repeating siloxane units (so-called polymers).

[0202] [ka]

[0203] R1 and R2 are either a hydroxyl group or an alkyl group having 1 to 8 carbon atoms, and the formula has at least one of each; n is an integer of 100 to 300.

[0204] The polysiloxane segment and polydimethylsiloxane segment will be described in detail later, but the components constituting the resin film having these segments can improve the heat resistance and weather resistance, and can also improve the slipperiness due to the lubricity of the resin film. More preferably, from the viewpoint of lubricity, the resin film contains a polydimethylsiloxane segment represented by Chemical Formula 20, which will be described later.

[0205] In the present invention, a partial hydrolyzate of a silane compound containing a hydrolyzable silyl group, an organosilica sol, or a coating composition in which a hydrolyzable silane compound having a radical polymer is added to the organosilica sol can be used as the resin containing a polysiloxane segment.

[0206] Examples of resins containing polysiloxane segments include complete or partial hydrolysates of silane compounds having hydrolyzable silyl groups, such as tetraalkoxysilane, methyltrialkoxysilane, dimethyldialkoxysilane, γ-glycidoxypropyltrialkoxysilane, γ-glycidoxypropylalkyldialkoxysilane, γ-methacryloxypropyltrialkoxysilane, and γ-methacryloxypropylalkyldialkoxysilane; organosilica sols dispersed in organic solvents; and organosilica sols to which hydrolyzed silane compounds having hydrolyzable silyl groups have been added on their surfaces.

[0207] In the present invention, the resin containing a polysiloxane segment may contain (copolymerize) other segments in addition to the polysiloxane segment, such as a monomer component having a polycaprolactone segment or a polydimethylsiloxane segment.

[0208] When the resin containing polysiloxane segments is a copolymer having hydroxyl groups, a resin film can be efficiently formed using a coating composition containing a resin (copolymer) containing polysiloxane segments having hydroxyl groups and a compound containing an isocyanate group, thereby making it possible to obtain a resin film having polysiloxane segments and urethane bonds.

[0209] Next, the polydimethylsiloxane segment will be described. In the present invention, the polydimethylsiloxane segment refers to a segment represented by chemical formula 15. Polydimethylsiloxane includes both low molecular weight ones (so-called oligomers) with 10 to 100 dimethylsiloxane repeating units and high molecular weight ones (so-called polymers) with more than 100 dimethylsiloxane repeating units.

[0210] [ka]

[0211] m is an integer from 10 to 300.

[0212] When the components constituting the resin film have polydimethylsiloxane segments, the polydimethylsiloxane segments are coordinated on the surface of the resin film. By coordinating the polydimethylsiloxane segments on the surface of the resin film, the lubricity of the resin film surface is improved and frictional resistance can be reduced. This is also preferable from the viewpoint of solvent resistance.

[0213] In the present invention, it is preferable to use a copolymer in which a vinyl monomer is copolymerized with a polydimethylsiloxane segment as the resin containing the polydimethylsiloxane segment.

[0214] For the purpose of improving the toughness of the resin film, it is preferable that the resin containing the polydimethylsiloxane segment is copolymerized with a monomer having a hydroxyl group that reacts with an isocyanate group.

[0215] When the resin containing polydimethylsiloxane segments is a copolymer having hydroxyl groups, a resin film can be efficiently produced that has polydimethylsiloxane segments and urethane bonds by forming the resin film using a coating composition that contains a resin (copolymer) that contains polydimethylsiloxane segments that have hydroxyl groups and a compound that contains an isocyanate group.

[0216] When the resin containing polydimethylsiloxane segments is a copolymer with a vinyl monomer, it may be a block copolymer, a graft copolymer, or a random copolymer. When the resin containing polydimethylsiloxane segments is a copolymer with a vinyl monomer, it is called a polydimethylsiloxane copolymer. Polydimethylsiloxane copolymers can be produced by living polymerization, polymer initiator methods, polymer chain transfer methods, etc., but in consideration of productivity, the polymer initiator method and polymer chain transfer method are preferably used.

[0217] When using the polymeric initiator method, copolymerization with other vinyl monomers can be performed using a polymeric azo-based radical polymerization initiator represented by Chemical Formula 16. Alternatively, a two-step polymerization can be performed in which a peroxy monomer and a polydimethylsiloxane having an unsaturated group are copolymerized at low temperature to synthesize a prepolymer with a peroxide group introduced into the side chain, and this prepolymer is then copolymerized with a vinyl monomer.

[0218] [ka]

[0219] m is an integer of 10 to 300, and n is an integer of 1 to 50.

[0220] When using the polymer chain transfer method, for example, HS-CH2COOH, HS-CH2CH2COOH, or the like is added to the silicone oil shown in Chemical Formula 17 to form a compound having an SH group, and then the silicone compound is copolymerized with a vinyl monomer using chain transfer of the SH group to synthesize a block copolymer.

[0221] [ka]

[0222] m is an integer from 10 to 300.

[0223] To synthesize a polydimethylsiloxane-based graft copolymer, for example, a compound shown in Chemical Formula 18, i.e., a methacrylic ester of polydimethylsiloxane, can be copolymerized with a vinyl monomer to easily obtain the graft copolymer.

[0224] [ka]

[0225] m is an integer from 10 to 300.

[0226] Examples of vinyl monomers used in copolymers with polydimethylsiloxane include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, and vinyl chloride. Examples of the vinyl acrylate copolymer include vinylidene fluoride, vinylidene fluoride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, acrylamide, methacrylamide, N-methylolacrylamide, N,N-dimethylacrylamide, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, diacetone acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and allyl alcohol.

[0227] Furthermore, the polydimethylsiloxane copolymer is preferably produced by solution polymerization in a solvent selected from the group consisting of aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, and alcohol solvents such as ethanol and isopropyl alcohol, either alone or in a mixture thereof.

[0228] If necessary, a polymerization initiator such as benzoyl peroxide, azobisisobutylnitrile, etc. is used in combination. The polymerization reaction is preferably carried out at 50 to 150°C for 3 to 12 hours.

[0229] In view of the lubricity and solvent resistance of the resin film, the amount of polydimethylsiloxane segments in the polydimethylsiloxane copolymer of the present invention is preferably 1 to 30 mass % relative to 100 mass % of all components of the polydimethylsiloxane copolymer, and the weight average molecular weight of the polydimethylsiloxane segments is preferably 1,000 to 30,000.

[0230] In the present invention, when a resin containing a polydimethylsiloxane segment is used as the coating composition used to form a resin film, other segments may be contained (copolymerized) in addition to the polydimethylsiloxane segment, such as a polycaprolactone segment or a polysiloxane segment.

[0231] The coating composition used to form the resin film can be a copolymer of a polycaprolactone segment and a polydimethylsiloxane segment, a copolymer of a polycaprolactone segment and a polysiloxane segment, a copolymer of a polycaprolactone segment, a polydimethylsiloxane segment and a polysiloxane segment, etc. The resin film obtained using such a coating composition can have a polycaprolactone segment and a polydimethylsiloxane segment and / or a polysiloxane segment.

[0232] The reaction of the polydimethylsiloxane-based copolymer, polycaprolactone, and polysiloxane in the coating composition used to form a resin film having polycaprolactone segments, polysiloxane segments, and polydimethylsiloxane segments can be copolymerized by adding the polycaprolactone segments and polysiloxane segments as appropriate during the synthesis of the polydimethylsiloxane-based copolymer.

[0233] [solvent] The coating composition may contain a solvent, and the number of types of solvents is preferably from 1 to 20, more preferably from 1 to 10, even more preferably from 1 to 6, and particularly preferably from 1 to 4.

[0234] Here, the term "solvent" refers to a substance that is liquid at room temperature and pressure and can be evaporated almost entirely in the drying process after application.

[0235] 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.

[0236] Furthermore, when a solvent is contained, it is preferable that the solvent exhibits the following properties.

[0237] Condition 1: When solvent B is the solvent with the lowest relative evaporation rate (ASTM D3539-87(2004)) based on n-butyl acetate, the relative evaporation rate of solvent B must be 0.4 or less.

[0238] Here, the relative evaporation rate based on the solvent n-butyl acetate is the evaporation rate measured in accordance with ASTM D3539-87 (2004). Specifically, it is a value defined as the relative value of the evaporation rate based on the time required for 90% by mass of n-butyl acetate to evaporate in dry air.

[0239] If the relative evaporation rate of the solvent is greater than 0.4, the time required for the aforementioned polysiloxane segments and / or polydimethylsiloxane segments and fluorine compound segments to be oriented to the outermost surface of the resin film will be shortened, which may result in a decrease in the solvent resistance of the resin film in the resulting laminate. Furthermore, the lower limit of the relative evaporation rate of the solvent is acceptable as long as it is a solvent that can be evaporated and removed from the coating film in the drying process, and in a typical coating process, a value of 0.005 or higher will suffice.

[0240] Solvents include isobutyl ketone (relative evaporation rate: 0.2), isophorone (relative evaporation rate: 0.026), diethylene glycol monobutyl ether (relative evaporation rate: 0.004), diacetone alcohol (relative evaporation rate: 0.15), oleyl alcohol (relative evaporation rate: 0.003), ethylene glycol monoethyl ether acetate (relative evaporation rate: 0.2), nonylphenoxyethanol (relative evaporation rate: 0.25), propylene glycol monoethyl ether (relative evaporation rate: 0.1), and cyclohexanone (relative evaporation rate: 0.32).

[0241] [Other components in the coating composition] The coating composition preferably contains a polymerization initiator, a curing agent, and a catalyst. The polymerization initiator and catalyst are used to promote curing of the resin film. The polymerization initiator is preferably one that can initiate or promote polymerization, condensation, or crosslinking reactions of the components contained in the coating composition through anionic, cationic, or radical polymerization reactions, etc.

[0242] 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.

[0243] The coating composition may also contain other crosslinkers, such as melamine crosslinkers, such as alkoxymethylol melamine, acid anhydride crosslinkers, such as 3-methyl-hexahydrophthalic anhydride, and amine crosslinkers, such as diethylaminopropylamine.

[0244] As the photopolymerization initiator, an alkylphenone compound is preferable from the viewpoint of curability. Specific examples of the alkylphenone compound include 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-phenyl)-1-butane, 2-benzyl-2-dimethylamino-1-(4- Examples include 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexyl-phenyl ketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, and polymerized versions of these materials.

[0245] Furthermore, leveling agents, UV absorbers, lubricants, antistatic agents, etc. may be added to the coating composition as long as the effects of the present invention are not impaired. This allows the resin film to contain leveling agents, UV absorbers, lubricants, antistatic agents, etc. Examples of leveling agents include acrylic copolymers, silicone-based, and fluorine-based leveling agents. Specific examples of UV absorbers include benzophenone-based, benzotriazole-based, oxalic acid anilide-based, triazine-based, and hindered amine-based UV absorbers. Examples of antistatic agents include metal salts such as lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, magnesium salts, and calcium salts.

[0246] [Method of manufacturing resin films and laminates] The method for producing the laminate of the present invention is not particularly limited, but it is preferably produced by a production method including the steps of applying a coating composition containing components constituting a resin film to the surface of a release film having a concave-convex structure on at least one surface, the surface having the concave-convex structure, and curing the components. Furthermore, the method for producing the resin film of the present invention is not particularly limited, but a preferred method for producing a resin film having a recovery rate of 80% or more and having a concave-convex structure on at least one surface is produced by a production method including the step of peeling the release film from the laminate of the present invention. Hereinafter, the step of applying each coating composition will be referred to as the coating step, the drying step as the drying step, and the curing step as the curing step. Two or more coating compositions may be applied sequentially or simultaneously to form a resin film consisting of two or more layers.

[0247] Here, "sequential application" means that one type of coating composition is applied to a release film, dried, and cured, and then another coating composition is applied thereon, dried, and cured to form a resin film consisting of two or more layers. By appropriately selecting the type of coating composition used, it is possible to control the magnitude and gradient of the flexibility and stretchability of the resin film between the resin film side and the release film side, as well as the magnitude and stretchability of the resin film itself. Furthermore, by appropriately selecting the type, composition, drying conditions, and curing conditions of the coating composition, it is possible to control the distribution of flexibility and stretchability within the resin film in a stepwise or continuous manner.

[0248] Furthermore, "coating simultaneously" means that two or more types of coating compositions are simultaneously coated onto a release film in the coating step, and then dried and cured.

[0249] In the coating step, the method for applying the coating composition is not particularly limited, but it is preferable to apply the coating composition to the supporting substrate by a dip coating method, roller coating method, wire bar coating method, gravure coating method, die coating method (U.S. Pat. No. 2,681,294), etc. Furthermore, among these coating methods, gravure coating method or die coating method is more preferable as the coating method.

[0250] When two or more types of coating compositions are applied simultaneously, methods such as multi-layer slide die coating, multi-layer slot die coating, and wet-on-wet coating can be used, although there are no particular limitations.

[0251] An example of multilayer slide die coating is shown in Figure 9. In multilayer slide die coating, liquid films consisting of two or more types of coating compositions are laminated in order using a multilayer slide die 31, and then coated onto a supporting substrate or a release film.

[0252] An example of multilayer slot die coating is shown in Figure 10. In multilayer slot die coating, a liquid film consisting of two or more types of coating compositions is applied and simultaneously laminated onto a supporting substrate or a release film using a multilayer slot die 32.

[0253] An example of wet-on-wet coating is shown in Figure 11. In wet-on-wet coating, one layer of liquid film made of a coating composition discharged from a single-layer slot die 33 is formed on a supporting substrate, and then, while the liquid film is still wet, a liquid film made of another coating composition discharged from another single-layer slot die 8 is laminated on top of the first liquid film.

[0254] Following the coating step, the liquid film coated on the release film is dried in a drying step. From the viewpoint of completely removing the solvent from the resulting laminate, the drying step preferably involves heating the liquid film.

[0255] Heating methods used in the drying process include heat transfer drying (contact with a hot object), convection heat transfer (hot air), radiation heat transfer (infrared rays), and others (microwaves, induction heating). Of these, methods using convection heat transfer or radiation heat transfer are preferred because of the need to precisely uniform the drying speed in the width direction.

[0256] There are no particular limitations as long as a desirable drying rate is obtained, but to achieve the above drying rate, the temperature is preferably 15°C to 129°C, more preferably 50°C to 129°C, and particularly preferably 50°C to 99°C.

[0257] The drying step is preferably followed by a further curing operation (curing step) by irradiation with heat or active energy rays.

[0258] As the active energy ray, electron beams (EB rays) and / or ultraviolet rays (UV rays) are preferred from the viewpoint of versatility. When curing with ultraviolet rays, it is preferable to keep the oxygen concentration as low as possible to prevent oxygen inhibition, and it is more preferable to cure in a nitrogen atmosphere (nitrogen purging). If the oxygen concentration is high, curing of the outermost surface may be inhibited, resulting in weak surface curing and reduced toughness. In addition, the type of ultraviolet lamp used for irradiating ultraviolet rays may include, for example, a discharge lamp type, a flash type, a laser type, an electrodeless lamp type, etc. When using a high-pressure mercury lamp that is a discharge lamp type, the illuminance of the ultraviolet rays is preferably 100 to 3,000 mW / cm. 2 , more preferably 200 to 2,000 mW / cm 2 , and more preferably 300 to 1,500 mW / cm 2 The ultraviolet irradiation is preferably carried out under the conditions of: The integrated light amount of ultraviolet light is preferably 100 to 3,000 mJ / cm 2 , more preferably 200 to 2,000 mJ / cm 2 , and more preferably 300 to 1,500 mJ / cm 2 It is best to irradiate ultraviolet light under the following conditions. Here, ultraviolet irradiance refers to the intensity of irradiation per unit area, and 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 ultraviolet light is the irradiation energy per unit area, and is the total amount of photons that reach the surface. The cumulative amount of light is inversely proportional to the irradiation speed passing under the light source, and proportional to the number of irradiations and the number of lamps.

[0259] [Application example] The resin film of the present invention has advantages such as excellent optical properties, flexibility, stretchability, anti-tack properties, transportability, air release properties, reworkability (repeated bonding and peeling), conformability, and anti-slip properties, and can be suitably used in applications where these properties are required.

[0260] 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. [Example]

[0261] Next, the present invention will be described based on examples, but the present invention is not necessarily limited to these.

[0262] [Urethane (meth)acrylate] [Synthesis of urethane (meth)acrylate 1] 100 parts by weight of toluene, 50 parts by weight of methyl-2,6-diisocyanate hexanoate (LDI, manufactured by Kyowa Hakko Kirin Co., Ltd.), and 119 parts by weight of polycarbonate diol (Placcel® CD-210HL, manufactured by Daicel Chemical Industries, Ltd.) were mixed, heated to 40°C, and maintained for 8 hours. Then, 28 parts by weight of 2-hydroxyethyl acrylate (Light Ester HOA, manufactured by Kyoeisha Chemical Co., Ltd.), 5 parts by weight of dipentaerythritol hexaacrylate (M-400, manufactured by Toagosei Co., Ltd.), and 0.02 parts by weight of hydroquinone monomethyl ether were added and maintained at 70°C for 30 minutes. Then, 0.02 parts by weight of dibutyltin laurate was added and maintained at 80°C for 6 hours. Finally, 97 parts by weight of toluene was added to obtain a toluene solution of urethane (meth)acrylate 1 with a solids concentration of 50% by weight. The number average molecular weight of urethane (meth)acrylate 1 was 5,800.

[0263] [Urethane (meth)acrylate 2] As the urethane (meth)acrylate 2, SUA-017 (manufactured by Asia Industries Co., Ltd., solid content concentration 100% by mass) having a number average molecular weight of 4,600 was used.

[0264] [Photoradical polymerization initiator] [Photoradical polymerization initiator 1] As the photoradical polymerization initiator 1, "Irgacure" (registered trademark) 184 (manufactured by BASF Japan Ltd., solid content concentration 100% by mass) was used.

[0265] [Base film] [Base film 1] As the base film 1, "TORAYFAN" (registered trademark) NO 3429K (thickness 100 μm, manufactured by Toray Advanced Film Co., Ltd.) was used.

[0266] [Base film 2] As the base film 2, "Lumirror" (registered trademark) X42 (thickness: 50 μm, manufactured by Toray Industries, Inc.) with a matte surface was used.

[0267] [Base film 3] As the base film 3, "Lumirror" (registered trademark) S10 (thickness: 50 μm, manufactured by Toray Industries, Inc.) having a smooth surface was used.

[0268] [How to make release film [Release film 1] The mold 1 was heated to 160°C in advance, and the base film 1 and the textured surface of the mold 1 were brought into contact and pressed at 5 MPa, and held in this state for 60 seconds. After that, the mold was cooled to 50°C, the press was released, and the release film 1 was removed from the mold. The method for forming the mold 1 is as follows.

[0269] A striped mold with wall structures 40 μm wide and 60 μm high periodically arranged at a 60 μm pitch was used as mold 1. The area where the protrusion structures were machined was 50 mm x 50 mm. The mold was formed by cutting a 10 mm thick Starbucks material that had been plated with 200 μm of nickel phosphorus.

[0270] [Release film 2] The mold 2 was heated to 160°C in advance, and the release substrate film 1 and the textured surface of the mold 2 were brought into contact and pressed at 5 MPa, and held in that state for 60 seconds. After that, the mold was cooled to 50°C, the press was released, and the release film 2 was removed from the mold. The method for forming the mold 2 is as follows.

[0271] A striped mold with wall structures 12 μm wide and 8 μm high periodically arranged at a pitch of 17 μm was used as mold 1. The area where the protrusion structures were machined was 50 mm x 50 mm. The mold was formed by cutting a 10 mm thick Starbucks material that had been plated with 200 μm of nickel phosphorus.

[0272] [Release film 3] 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 prepare a coating composition A for a release layer having a solids concentration of 5 mass %. Acrylic-modified alkyd resin (Hariftal KV-905, manufactured by Harima Chemicals Co., Ltd., solid content concentration 53% by mass): 100 parts by mass Isobutyl alcohol-modified melamine resin (Melan 2650L, manufactured by Hitachi Chemical Co., Ltd., solid content concentration 60% by mass): 20 parts by mass Paratoluenesulfonic acid: 5 parts by mass Side-chain modified reactive silicone oil (KF-6123, Shin-Etsu Chemical Co., Ltd., active ingredient 100% by mass): 5 parts by mass The release layer coating composition A was applied to the base film 2 having a matte surface using an application device with a small-diameter gravure coater, adjusting the gravure roll line count, the gravure roll peripheral speed, and the solids concentration of the release layer coating composition so that the release layer thickness would be approximately 200 nm.The coating composition was then dried and crosslinked by holding it at a hot air temperature of 140°C for 30 seconds, thereby forming a release layer.

[0273] [Release film 4] The following materials were mixed and diluted with a methyl ethyl ketone / isopropyl alcohol mixed solvent (mixing ratio by mass: 50 / 50) to prepare a coating composition B for a matte release layer having a solids concentration of 5 mass %. Acrylic-modified alkyd resin (Hariftal KV-905, manufactured by Harima Chemicals Co., Ltd., solid content concentration 53% by mass): 100 parts by mass Isobutyl alcohol-modified melamine resin (Melan 2650L, manufactured by Hitachi Chemical Co., Ltd., solid content concentration 60% by mass): 20 parts by mass Paratoluenesulfonic acid: 5 parts by mass Side-chain modified reactive silicone oil (KF-6123, Shin-Etsu Chemical Co., Ltd., active ingredient 100% by mass): 5 parts by mass Melamine resin-silica composite particles (Optobeads 3500M, Nissan Chemical Co., Ltd.): 14 parts by mass Release layer coating composition B was applied to base film 3 using an application device with a small-diameter gravure coater, adjusting the gravure roll line count, gravure roll peripheral speed, and solids concentration of the release layer coating composition so that the release layer thickness would be approximately 200 nm.The coating was then dried and crosslinked by holding it at a hot air temperature of 140°C for 30 seconds, thereby forming a release layer.

[0274] [Release film 5] The base film 1 was used as a release film without forming a textured structure thereon.

[0275] [Paint composition formulation] [Coating composition A1] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A1 with a solids concentration of 30 mass %.

[0276] Urethane (meth)acrylate 1 solution: 100 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0277] [Coating composition A2] The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A2 with a solids concentration of 30 mass %.

[0278] Urethane (meth)acrylate 2 solution: 50 parts by weight Photoradical polymerization initiator 1: 1.5 parts by mass.

[0279] [How to make resin film] [Preparation of resin film] The coating composition was applied onto the release film using a continuous coating device with a slot die coater, adjusting the discharge flow rate from the slot so that the resin film would have a specified thickness after drying. The combination of coating compositions used is as shown in Table 1.

[0280] The conditions of the drying air that hits the liquid film from application to drying and hardening are as follows:

[0281] Thereafter, the resin film was peeled off from the release film.

[0282] [Drying process] Air temperature and humidity: Temperature: 80°C, Relative humidity: 1% or less Wind speed: Coating side: 5m / sec, non-coating 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 [Curing process] Irradiation output: 400W / cm 2 Accumulated light intensity: 120mJ / cm 2 Oxygen concentration: 0.1% by volume.

[0283] [Table 1]

[0284] [Evaluation of resin films, release films, and laminates] The laminate, resin film, and release film were subjected to the following performance evaluations, and the results are shown in Tables 2 and 3. Unless otherwise specified, measurements were taken three times for one sample in each example and comparative example at different locations, and the average value was used.

[0285] [Thickness of Laminate and Resin Film] The thickness of the laminate and resin film was measured by observing the cross section using an electron microscope (SEM). The thickness of each layer was measured according to the following method. The cross-sectional slices of the laminate and resin film were photographed with an SEM at 3,000x magnification, and the thickness of each layer was read using software (image processing software ImageJ). The layer thickness was measured at a total of 30 points, and the average value was used as the measured value.

[0286] [Recovery rate] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare test specimens. The 150 mm length of each specimen was aligned with the longitudinal direction of the laminate. Using a tensile testing machine (A&D RTG-1210), the tensile test was performed at a temperature of 23°C, with an initial tensile chuck distance of 50 mm and a tensile speed of 50 mm / min. The sample was stretched to a strain of 10 mm (20%), after which the tensile load on the sample was released.

[0287] The distance marked as the initial test length before the measurement was measured and defined as L mm, and the elastic recovery rate z % was calculated using the following formula. Recovery rate: z=(1-(L-50) / 10 )×100 (%).

[0288] [5% strain stress] For evaluation of resin films, the laminate was cut into a 10 mm wide x 150 mm long rectangle, and the resin film was peeled off from the release film to prepare a test specimen. The 150 mm length of each specimen was aligned with the longitudinal direction of the laminate. Using a tensile tester (RTG-1210 manufactured by A&D), the tensile test was performed at a temperature of 23°C, with an initial tensile chuck distance of 50 mm and a tensile speed of 300 mm / min. When evaluating resin films without a release film, measurements were performed as described above, except that the resin film was cut to the above size.

[0289] The load b (N) applied to the sample when the chuck distance was a (mm) was read, and the strain x (%) and stress y (N / mm2) were calculated using the following formula, where k (mm) is the sample thickness before the test. Strain amount: x = ((a-50) / 50) x 100 Stress: y=b / (k×10).

[0290] Of the data obtained above, the stress at a strain of 5% was defined as the 5% strain stress.

[0291] [Total light transmittance] The resin film was cut into a 100 mm wide x 100 mm long specimen. Haze measurement was performed using a haze meter (NDH-5000 manufactured by Nippon Denshoku Industries Co., Ltd.) based on JIS K 7361-1 (1997). When evaluating the resin film in the laminate, the measurement was performed as described above except that the resin film was peeled off from the laminate.

[0292] [Maximum height] The maximum height of the uneven surface structure of the resin film was measured using a laser microscope (Keyence, VK-9700). Observation was performed using a 50x objective lens, with both the concave and convex portions of the uneven surface structure included in the field of view. The difference between the smallest height of the concave portion of the uneven surface structure and the largest height of the coating particles in the uneven surface structure was taken as the maximum height. The maximum height of the uneven surface structure of the release film was also measured in the same way.

[0293] [Peeling force] The resin film and release film of the laminate were previously peeled slightly from the edge to form a grip for measurement with a tensile tester. The resistance value (N) was then measured at 180° peeling at a speed of 300 mm / min using a tensile tester under an environment of 23°C and 65% RH. The resistance value (N) was divided by the width (mm) of the release film and resin film, then multiplied by 50 to convert it into a peel force (mN / 50 mm) equivalent to a width of 50 mm.

[0294] [Elasticity evaluation 1] In the laminate, the resin film was peeled from the release film, and then the resin film was pulled by hand and judged according to the following criteria: The resin film was also evaluated in the same way as the resin film and judged according to the following criteria, with a score of 4 or more being considered pass. 10 points: Can be transformed with very little force. 7 points: Can be deformed with light force. 4 points: Can be deformed with a moderate amount of force. 1 point: Other (requires a strong force to transform, etc.).

[0295] [Evaluation of elasticity 2] After peeling the resin film from the release film in the laminate, the resin film was subjected to tensile deformation by applying a light force by hand and evaluated according to the following criteria: The resin film was also evaluated in the same way as the resin film, and evaluated according to the following criteria, with a score of 4 or higher being considered a pass. 10 points: After deformation, the material returns to its original shape when the load is removed. 7 points: After deformation, when the load is removed, the material returns to almost its original shape. 4 points: After deformation, when the load is removed, the material returns to its original shape slightly. 1 point: Other (no restoration at all, etc.).

[0296] [Evaluation of Anti-tack Property and Reworkability] The resin film was placed on a glass plate and pressed against it with a load applied in the direction perpendicular to the resin film. The resin film was then pulled in its planar direction and its behavior was evaluated according to the following criteria, with a score of 4 or higher being considered pass. For resin films with an uneven surface, the surface pressed against the glass plate was the surface with the uneven structure. 10 points: Can be peeled off with almost no resistance and the position can be corrected. 7 points: Can be peeled off with little force and repositioned. 4 points: Can be peeled off with a little force and the position can be adjusted. 1 point: Other (can be peeled but requires too much force, cannot be peeled, etc.)

[0297] [Evaluation of Air Release] The resin film was lightly pressed against a glass plate, and the behavior of any air pockets that formed between the glass plate and the resin film was observed and judged according to the following criteria, with a score of 4 or higher being considered pass. For resin films with an uneven surface, the surface pressed against the glass plate was considered to be the surface with the uneven structure. 10 points: The air escapes quickly. 7 points: It takes a little time, but the air will escape. 4 points: A little air remains. 1 point: Other (lots of air remaining, no air can escape, etc.).

[0298] [Evaluation of peelability] In the laminate, the support substrate and resin layer were previously peeled slightly from the edge, and the peeled portion was grasped and the support substrate and resin layer were peeled by hand in a 180-degree direction, and evaluation was made according to the following criteria. 10 points: Can be peeled off without any feeling of resistance. 7 points: There is a slight feeling of resistance when peeling off. 4 points: There is a strong feeling of resistance when peeling off. 1 point: Other (cannot be peeled off, etc.).

[0299] Tables 2 and 3 summarize the evaluation results of the finally obtained laminate.

[0300] [Table 2]

[0301] [Table 3] [Explanation of symbols]

[0302] 1, 9, 18, 23 laminate 2, 5, 10, 14, 19, 21 Resin film 3, 6, 11, 15 Release layer 4, 7, 12, 16 Base film 5, 8, 13, 17, 20, 22 Release film 6 Release film 7 Resin film 8 Release film 24 Convex part of resin film 25 Recessed portion of resin film 26 Mold 27 Protrusion structure 28 Release film 29 Recess 31 Multi-layer slide die 32 Multi-layer slide die 33 Single layer slot die [Industrial Applicability]

[0303] The resin film and laminate of the present invention have advantages such as excellent optical properties, flexibility, stretchability, anti-tack properties, transportability, air release properties, reworkability (repeated lamination and peeling), conformability, and anti-slip properties, and can be suitably used in applications where these properties are required.

[0304] 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 characterized by having a recovery rate of 80% or more when measured under the following conditions, having an uneven structure on at least one surface, and having a maximum height of the uneven structure of 5 μm or more and 100 μm or less. [Conditions for measuring recovery rate] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare a test specimen. The direction of the 150 mm length was aligned with the longitudinal direction of the laminate. A tensile test was performed using a tensile tester (RTG-1210 manufactured by A&D Co., Ltd.) with an initial tensile chuck distance of 50 mm, a tensile speed of 50 mm / min, and a measurement temperature of 23°C. After the sample was stretched to a strain of 10 mm (= 20%), the tensile load on the sample was released. The distance marked as the initial test length before the measurement was measured and defined as L mm, and the elastic recovery rate z % was calculated using the following formula. Recovery rate: z = (1 - (L - 50) / 10) x 100 (%).

2. The resin film according to claim 1, which satisfies the following condition 1: Condition 1: The 5% strain stress of the resin film is 10 MPa or less.

3. The resin film according to claim 1 or 2, which satisfies the following condition 2: Condition 2: The total light transmittance of the resin film is 80% or more.

4. The resin film according to any one of claims 1 to 3, wherein the resin film satisfies the following condition 3: Condition 3: The uneven structure of the resin film is striped.

5. A laminate having a resin film on one side of a release film, the release film has an uneven structure on at least one surface, The resin film has a recovery rate of 80% or more as measured under the following conditions, has an uneven structure on at least one surface, and has a maximum height of the uneven structure of 5 μm or more and 100 μm or less, the surface of the release film having the concave-convex structure and the surface of the resin film having the concave-convex structure are in contact with each other so that the convex portions of the concave-convex structure of the release film fit into the concave-convex structure of the resin film, and the convex portions of the concave-convex structure of the resin film fit into the concave-convex structure of the release film, A laminate characterized in that the peel strength between the release film and the resin film is 1,000 mN / 50 mm or less. [Conditions for measuring recovery rate] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare a test specimen. The direction of the 150 mm length was aligned with the longitudinal direction of the laminate. A tensile test was performed using a tensile tester (RTG-1210 manufactured by A&D Co., Ltd.) with an initial tensile chuck distance of 50 mm, a tensile speed of 50 mm / min, and a measurement temperature of 23°C. After the sample was stretched to a strain of 10 mm (= 20%), the tensile load on the sample was released. The distance marked as the initial test length before the measurement was measured and defined as L mm, and the elastic recovery rate z % was calculated using the following formula. Recovery rate: z = (1 - (L - 50) / 10) x 100 (%).

6. The laminate according to claim 5, which satisfies the following condition 1: Condition 1: The 5% strain stress of the resin film is 10 MPa or less.

7. 7. The laminate according to claim 5 or claim 6, which satisfies the following condition 2: Condition 2: The total light transmittance of the resin film is 80% or more.

8. 8. The laminate according to claim 5, wherein the laminate satisfies the following conditions 3 and 5: Condition 3: The uneven structure of the resin film is striped. Condition 5: The uneven structure of the release film is striped.

9. 9. The laminate according to claim 5, wherein the laminate satisfies the following condition 6: Condition 6: The maximum height of the uneven structure of the release film is 5 μm or more and 100 μm or less.

10. A method for producing a resin film, the method having a recovery rate of 80% or more when measured under the following conditions, having an uneven structure on at least one surface, and the maximum height of the uneven structure being 5 μm or more and 100 μm or less, A method for producing a resin film, comprising a step of peeling off a release film from the laminate according to any one of claims 5 to 9. [Conditions for measuring recovery rate] The resin film was cut into a rectangular shape measuring 10 mm wide x 150 mm long to prepare a test specimen. The direction of the 150 mm length was aligned with the longitudinal direction of the laminate. A tensile test was performed using a tensile tester (RTG-1210 manufactured by A&D Co., Ltd.) with an initial tensile chuck distance of 50 mm, a tensile speed of 50 mm / min, and a measurement temperature of 23°C. After the sample was stretched to a strain of 10 mm (= 20%), the tensile load on the sample was released. The distance marked as the initial test length before the measurement was measured and defined as L mm, and the elastic recovery rate z % was calculated using the following formula. Recovery rate: z = (1 - (L - 50) / 10) x 100 (%).

11. A method for producing the laminate according to any one of claims 5 to 9, A method for producing a laminate, comprising the steps of: applying a coating composition containing components that constitute a resin film to the surface of a release film having a concave-convex structure on at least one surface thereof; and curing the components.

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