Release film, method for manufacturing the same, and method for manufacturing artificial leather using the same

Abstract

The present application relates to a release film, wherein the release film comprises: a substrate; and a resin layer provided on one side or both sides of the substrate; the resin layer comprises a convex part and a concave part, the convex part comprises a first pattern layer, the concave part comprises a second pattern layer, and the height difference between the convex part and the concave part is 1 microns or more and 1000 microns or less. The present application also relates to a manufacturing method of the release film and a manufacturing method of artificial leather using the same.

Description

TECHNICAL FIELD

[0001] The present specification relates to a release film, a manufacturing method thereof, and a manufacturing method of artificial leather using the same. BACKGROUND

[0002] General artificial leather is manufactured by forming a film of PVC or PU (polyurethane) or the like synthetic resin on a release paper formed with a leather pattern or other prescribed pattern, and then using an adhesive to complex the film with a fabric, knit, or nonwoven fabric. At this time, when forming a pattern or the like pattern on the surface of the artificial leather, a method of transferring the pattern to the surface of the synthetic resin by the release paper is generally used.

[0003] On the other hand, when a pattern is expressed on artificial leather, in order to form a more fine pattern, a film or paper is used as a base layer, and a photocurable composition is used as a synthetic resin layer formed on the base layer. However, even when the photocurable composition is used, in many cases, since the pattern formed on the surface of the artificial leather to be transferred cannot reflect sufficient light, there is a limitation in securing visual recognition, such as blurring of a pattern to be emphasized, and the like.

[0004] Therefore, in general, when a diverse and fine pattern, that is, a complex pattern or characters, and the like, is expressed on artificial leather, there is a problem in that an additional printing process needs to be introduced or a method of forming a gravure is used.

[0005] (PRIOR ART DOCUMENTS)

[0006] (PATENT DOCUMENT) Korean Patent Laid-Open Publication No. 20-0345187 (Date of Grant: March 5, 2004) SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The present specification provides a release film, a manufacturing method thereof, and a manufacturing method of artificial leather using the same.

[0009] SOLUTION TO PROBLEM

[0010] One embodiment of the present invention provides a release film, wherein

[0011] The release film includes:

[0012] a base material; and

[0013] a resin layer disposed on one side or both sides of the base material;

[0014] The resin layer includes a protrusion and a recess,

[0015] The protrusion includes a first pattern layer,

[0016] The recesses include a second pattern layer,

[0017] The height difference between the convex portions and the recesses is 1 μm or more and 1000 μm or less.

[0018] Further, one embodiment of the present application provides a method for manufacturing the release film described above, including the steps of:

[0019] preparing a substrate; and

[0020] forming a resin layer provided on one side or both sides of the substrate.

[0021] Further, one embodiment of the present application provides a method for manufacturing artificial leather, including the steps of:

[0022] preparing the release film described above;

[0023] forming a resin surface layer on the resin layer of the release film;

[0024] forming an adhesive layer on the resin surface layer;

[0025] stacking a fabric on the adhesive layer; and

[0026] peeling the resin surface layer from the resin layer.

[0027] Effects of the Invention

[0028] The release film according to one embodiment of the present application can be used to manufacture artificial leather including both a matt surface and a hologram surface, and can prevent foreign matter from adhering to the hologram. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic view of a method for manufacturing a release film of an embodiment.

[0030] Figures 2 to 6 shows a surface of a release film of an embodiment.

[0031] Figure 7 shows a method for manufacturing artificial leather using a release film according to one embodiment of the present application.

[0032] Figure 8 shows a measurement of a height difference between a recess and a convex portion of Example 1.

[0033] Figure 9 shows a measurement of a height difference between a recess and a convex portion of Example 5.

[0034] Figures 10 to 14 shows an appearance of artificial leather manufactured using release films of Examples 1 to 5.

[0035] BEST MODE FOR CARRYING OUT THE INVENTION

[0036] Hereinafter, the present specification will be described in more detail.

[0037] In the present specification, the term "comprise, comprises, comprising" means including the mentioned item, step or group of items and steps, but not used as a meaning of excluding any other item, step or group of items and steps.

[0038] The existing artificial leather aims to include both a matte surface and a hologram surface, so that the hologram surface is highlighted by the matte surface. However, there are problems of color expression reduction due to contamination of the hologram surface by body oil such as sebum of the user and external pollution sources, or abrasion or loss of the hologram surface due to washing, etc.

[0039] As a means to solve the above problems, the present inventors have developed a release film for manufacturing artificial leather.

[0040] Specifically, an embodiment of the present application provides a release film, wherein the release film comprises: a base material; and a resin layer provided on one side or both sides of the base material; the resin layer comprises a convex portion and a concave portion, the convex portion comprises a first pattern layer, the concave portion comprises a second pattern layer, and the height difference between the convex portion and the concave portion is 1 μm or more and 1000 μm or less.

[0041] In the present specification, the first pattern layer is a region capable of transferring a hologram surface to artificial leather. The hologram surface means a region in which the color varies variously according to the direction in which the user views.

[0042] In the present specification, the second pattern layer is a region capable of transferring a matte surface to artificial leather. The matte surface means a region in which the color does not vary variously according to the direction in which the user views, which can be distinguished from the hologram surface.

[0043] According to the release film of an embodiment of the present application, since the height difference between the convex portion and the concave portion is 1 μm or more and 1000 μm or less, there is a height difference between the hologram surface and the matte surface of the artificial leather manufactured using the same. The matte surface of the artificial leather formed by the concave portion of the release film is formed on the outermost surface of the artificial leather, and the hologram surface of the artificial leather formed by the convex portion of the release film is formed on the inside of the artificial leather. The matte surface of the artificial leather thus manufactured functions as a protective layer of the hologram surface.

[0044] In one embodiment of the present application, the height difference between the convex portions and the concave portions can be 1 μm or more and 700 μm or less, 5 μm or more and 500 μm or less, or 10 μm or more and 400 μm or less. When the above numerical ranges are satisfied, the height difference between the convex portions and the concave portions can be sufficiently ensured, so that the height difference between the hologram surface and the matte surface of the artificial leather manufactured can be sufficiently ensured, and the hologram surface can be prevented from being contaminated by external contamination sources.

[0045] In one embodiment of the present application, the resin layer can include two or more convex portions and two or more concave portions, and the average height difference between the convex portions and the concave portions can be 1 μm or more and 1,000 μm or less. The average height difference between the convex portions and the concave portions means the average of two or more unit height differences when the height difference between the convex portions and the concave portions adjacent to each other is referred to as a unit height difference.

[0046] In one embodiment of the present application, the average height difference between the convex portions and the concave portions can be 1 μm or more and 700 μm or less, 5 μm or more and 500 μm or less, or 10 μm or more and 400 μm or less. When the above numerical ranges are satisfied, the average height difference between the convex portions and the concave portions can be sufficiently ensured, so that the height difference between the hologram surface and the matte surface of the artificial leather manufactured can be sufficiently ensured, and the hologram surface can be prevented from being contaminated by external contamination sources.

[0047] In one embodiment of the present application, an inclined layer can be included, which is disposed between the convex portions and the concave portions, and the inclination angle is 1 degree or more and 90 degrees or less. The inclination angle can be 1 degree or more and 60 degrees or less, or 1 degree or more and 45 degrees or less. The inclination angle can be an angle formed by a straight line perpendicular to the horizontal direction of the release film and the inclined surface of the inclined layer.

[0048] In one embodiment of the present application, the first pattern layer can include a pattern having a height of 1 nm or more and 2,000 nm or less. The hologram surface of the artificial leather formed by the first pattern layer can exhibit a hologram effect according to an optical interference phenomenon caused by the pattern of the pattern layer. Specifically, when external light is incident on the hologram surface, light absorption is achieved in the incident path and the reflection path at the time of reflection, respectively, and the external light is reflected on the hologram surface, so that constructive and destructive interference phenomena occur between the respective reflected lights. A specific color can be expressed by the light absorption, the constructive interference, and the destructive interference phenomena in the incident path and the reflection path as described above. At this time, by adjusting the height of the first pattern layer to be 1 nm or more and 2,000 nm or less, the hologram effect can be greatly emphasized.

[0049] In one embodiment of the present invention, the first pattern layer may include a pattern, the pattern including an inclined surface with an inclination angle greater than 0 degrees and less than 90 degrees. Specifically, the first pattern layer may include: a first inclined surface with an inclination angle greater than 0 degrees and less than 90 degrees; and a second inclined surface with an inclination angle greater than 0 degrees and less than 90 degrees.

[0050] In one embodiment of the present invention, the cross section of the pattern along the thickness direction may be triangular.

[0051] In one embodiment of the present invention, the first pattern layer may include an asymmetric cross-section or a symmetric cross-section.

[0052] In one embodiment of the invention, the term "section" refers to the surface of the first pattern layer when it is cut along a certain direction. For example, a section may refer to the surface of the first pattern layer when it is cut along a direction parallel to or perpendicular to the ground when the release layer is placed on the ground.

[0053] In one embodiment of the present invention, "asymmetric structural cross-section" means that the shape formed by the edges of the cross-section does not have a linear or point-symmetric structure. Linear symmetry means that when a shape is symmetrical about a straight line, it has the property of overlapping. Point symmetry means that when a shape is rotated 180 degrees about a point, it has the property of completely overlapping with the original shape. The edges of the asymmetric structural cross-section can be straight lines, curves, or combinations thereof.

[0054] In one embodiment of the present invention, the first pattern layer may include a convex shape or a concave shape. The "convex shape" may include one or more "convex unit shapes," and the "concave shape" may include one or more "concave unit shapes." The convex or concave unit shape refers to a shape comprising two inclined edges (a first inclined edge and a second inclined edge), rather than a shape comprising three or more inclined edges. The first inclined edge may be defined as the left inclined edge of either the convex or concave shape, and the second inclined edge may refer to the right inclined edge of either the convex or concave shape.

[0055] In one embodiment of the present invention, the angle a1 formed by the first inclined side S1 and the second inclined side S2 can be in the range of 80 degrees to 100 degrees. Specifically, the angle a1 can be above 80 degrees, above 83 degrees, above 86 degrees, or above 89 degrees, and below 100 degrees, below 97 degrees, below 94 degrees, or below 91 degrees. The angle can refer to the angle of the vertex formed by the first inclined side and the second inclined side. When the first inclined side and the second inclined side do not form a vertex with each other, the angle can refer to the angle of the vertex in the state where the first inclined side and the second inclined side are virtually extended to form a vertex.

[0056] In one embodiment of the present invention, the difference between the inclination angle α2 of the first inclined surface and the inclination angle α3 of the second inclined surface of the protrusion P1 can be in the range of 30 degrees to 70 degrees. For example, the difference between the inclination angle α2 of the first inclined surface and the inclination angle α3 of the second inclined surface can be 30 degrees or more, 35 degrees or more, 40 degrees or more, or 45 degrees or more, and can be 70 degrees or less, 65 degrees or less, 60 degrees or less, or 55 degrees or less. When the difference between the inclination angles of the first inclined surface and the second inclined surface is within the above range, it is advantageous in terms of the perceived texture according to direction.

[0057] In one embodiment of the present invention, the cross-section of the convex shape can be a triangular or quadrilateral polygonal shape.

[0058] In one embodiment of the present invention, the first pattern layer may include two or more convex shapes, and some or all of the convex shapes may also include flat portions.

[0059] In one embodiment of the invention, the surface with the convex or concave shape includes two or more of the convex or concave shapes. Thus, by having a surface with two or more convex or concave shapes, texture can be expressed more effectively. In this case, the two or more convex or concave shapes can be repeating the same shape, or they can include different shapes.

[0060] In one embodiment of the invention, the convex or concave shape having the asymmetrical cross-section includes at least two or more sides with different inclination angles, different curvatures, or different shapes. For example, the convex or concave portion has an asymmetrical structure when two sides among the multiple sides constituting at least one cross-section have different inclination angles, different curvatures, or different shapes.

[0061] In one embodiment of the invention, the convex or concave shape includes at least one first inclined edge and a second inclined edge with different inclination angles on at least one cross-section. The "edge" can be a straight line, but is not limited thereto; it can be wholly or partially curved. For example, the edge can include a portion of an arc of a circle or ellipse, a wavy structure, a zigzag structure, etc.

[0062] In one embodiment of the present invention, the shape of the protrusion or concave portion may be a cone-shaped protrusion protruding outward from the surface of the pattern layer or a cone-shaped concave portion recessed inward from the surface of the pattern layer.

[0063] In one embodiment of the invention, the first pattern layer may include a pattern with inclined surfaces having different inclination angles from one another.

[0064] In one embodiment of the present invention, the cross section of the pattern along the thickness direction may be a non-isosceles triangle.

[0065] In one embodiment of the present invention, the first pattern layer may include a prism shape.

[0066] In one embodiment of the present invention, the first pattern layer may include a pattern having a cone-shaped protrusion or groove, a pattern having a line-shaped protrusion at its highest point or a line-shaped groove at its lowest point, or a pattern having a cone-shaped protrusion or groove with a cut structure on its surface.

[0067] In one embodiment of the invention, the cone shape includes the shape of a cone, an elliptical cone, or a polygonal pyramid. Here, the base shape of the polygonal pyramid includes a triangle, a quadrilateral, and a star shape with five or more protruding points. According to one example, when the release film is placed on the ground, if the surface of the pattern layer has a cone-shaped protrusion, at least one of the protrusion shapes in a vertical section relative to the ground can be a triangular shape. According to another example, when the release film is placed on the ground, if the surface of the pattern layer has a cone-shaped concave shape, at least one of the concave shapes in a vertical section relative to the ground can be an inverted triangular shape.

[0068] In one embodiment of the present invention, the first pattern layer includes a pattern with a symmetrical structure. Such symmetrical structures include prism structures, lenticular lens structures, and the like.

[0069] The pattern includes a protrusion with a line shape at its highest point or a recess with a line shape at its lowest point. The line shape can be a straight line, a curved line, or both.

[0070] In one embodiment of the invention, when the edge comprises a portion of an arc of a circle or ellipse, the circle or ellipse may have a radius of curvature. When the shortest interval of a curve is converted into an arc, the radius of curvature may be defined as the radius of the arc.

[0071] In one embodiment of the invention, the first pattern layer includes a light-reflecting structure and a light-scattering structure. The light-reflecting structure, as a structure that can effectively reflect incident light as intended, includes a regularly arranged concave-convex structure of prism shapes and similar shapes, lenticular lens shapes and similar shapes, pyramidal shapes, conical shapes, or pyramidal shapes. When forming the pattern of the artificial leather, one or more combinations of light-reflecting structures selected from one or more of the aforementioned concave-convex structures can be used. The prism shape refers to a triangular prism with a cross-sectional shape of an equilateral or isosceles triangle and a flat surface. Prism-like shapes include shapes with a cross-sectional shape based on a triangle but with vertices cut off, or shapes with circular vertices (1d). Furthermore, shapes with regularly spaced triangular cross-sections are also included in prism-like shapes.

[0072] In one embodiment of the present invention, the second pattern layer may include a pattern having a height of more than 1 μm and less than 1 mm.

[0073] In one embodiment of the present invention, the second pattern layer may include one or more shapes selected from the group consisting of a matte shape, a prism shape, a lenticular lens shape, a microlens shape, a pyramid shape, a triangular pyramid shape, and a mirror surface. Here, the mirror surface may refer to a surface with a roughness value Ra of less than 1 nm.

[0074] In one embodiment of the present invention, a release layer disposed on the resin layer may be included.

[0075] In one embodiment of the invention, the release layer may include a release resin. The release resin may further include one or more components selected from the group consisting of silicone, acrylic acid, and polyurethane. For example, it may include a silicone-acrylate release agent.

[0076] In one embodiment of the present invention, the resin layer may include an ultraviolet-curable resin, a thermosetting resin, or an electron beam (EB)-curable resin. The ultraviolet-curable resin refers to a material that is cross-linked and cured by ultraviolet light (UV), the thermosetting resin refers to a material that is cross-linked and cured by high temperature, and the electron beam-curable resin refers to a material that is cross-linked and cured by an electron beam (EB).

[0077] In one embodiment of the present invention, the UV-curable resin may be a polyurethane, polyacrylate, polyepoxy, polyurethane acrylate, polyester acrylate, polyepoxy acrylate, or silicone UV-curable resin. Preferably, it includes urethane acrylate, epoxy acrylate, polyester acrylate, and silicone acrylate resins with (meth)acrylate at the molecular ends, and may also include epoxy and vinyl curable resins that can react with cationic molecules at the molecular ends. For the UV-curable resin, those skilled in the art can appropriately select and use photocurable resins that readily form fine patterns in order to implement the present invention. For example, the photocurable resin composition disclosed in Korean Patent Publication No. 10-2014-0111603 (September 19, 2014) can be used in the patterned layer.

[0078] In one embodiment of the present invention, the thermosetting resin may be an organosilicon resin, silicone resin, furan resin, polyurethane resin, epoxy resin, amino resin, phenolic resin, urea resin, polyester resin or melamine resin, etc., but is not limited thereto.

[0079] In one embodiment of the present invention, the UV-curable resin may be an acrylic polymer, such as a polyester acrylate polymer, a polystyrene acrylate polymer, an epoxy acrylate polymer, a polyurethane acrylate polymer, or a polybutadiene acrylate polymer, an organosilicon acrylate polymer, or an alkyl acrylate polymer, but is not limited thereto.

[0080] In one embodiment of the invention, the thickness of the resin layer can be from 1 μm to 2 mm. Preferably, it can be from 1 μm to 500 μm, or from 5 μm to 100 μm. When the above ranges are met, the problem of release agent contained in the resin layer easily escaping can be prevented, and it has the effect of easily forming embossed patterns on the resin layer. The thickness of the resin layer refers to the shortest distance between the resin layer and other layers in the cross-section of the release film. On the other hand, when the thickness of the resin layer varies at various points, it can refer to the average thickness in any region of the resin layer.

[0081] In one embodiment of the present invention, the substrate may be TAC (triacetyl cellulose), norbornene derivatives, COP (cyclo olefin copolymer), PMMA (polymethyl methacrylate), PC (polycarbonate), PE (polyethylene), PP (polypropylene), PVA (polyvinyl alcohol), DAC (diacetyl cellulose), Pac (polyacrylate), PES (polyethersulfone), PEEK (polyetheretherketone), PPS (polyphenylsulfone), PEI (polyetherimide), PEN (polyethylenenaphthalate), PET (polyethylene... The following are examples of fluoropolymers, but not limited to: terephthalate (polyethylene terephthalate), PI (polyimide), PSF (polysulfone), PAR (polyarylate), or amorphous fluoropolymers.

[0082] An embodiment of the present invention provides a method for manufacturing the above-mentioned release film, which includes the following steps: preparing a substrate; and forming a resin layer disposed on one or both sides of the substrate.

[0083] In one embodiment of the present invention, the step of forming a resin layer disposed on one or both sides of the substrate may include the step of forming the resin layer from a resin layer forming composition.

[0084] In one embodiment of the present invention, the composition for forming the resin layer may include a curable resin.

[0085] In one embodiment of the present invention, the resin layer forming composition may include one or more components selected from the group consisting of organic solvents, release agents and initiators.

[0086] In one embodiment of the present invention, the release agent included in the resin layer forming composition may include a silicone-acrylate release agent. The weight-average molecular weight of the silicone-acrylate release agent may be 5,000 or more and 100,000 or less.

[0087] In one embodiment of the present invention, the initiator may include one or more photopolymerization initiators and thermal polymerization initiators. Any photopolymerization initiator can be used as long as it can induce the polymerization reaction of a free radical polymerizable compound during the curing process caused by light irradiation or the like. For example, benzoin-based, hydroxyketone-based, aminoketone-based, or phosphine oxide-based photoinitiators can be used. Thermal polymerization initiators are not particularly limited as long as they possess the aforementioned physical properties; for example, conventional initiators such as azo compounds, peroxide compounds, or redox compounds can be used.

[0088] In one embodiment of the present invention, the method for manufacturing the release film may include the following steps: forming a recess including a second pattern layer on the resin layer; and forming a protrusion including a first pattern layer on the resin layer.

[0089] In one embodiment of the invention, the step of forming the second pattern layer can be performed by pressing a pattern transfer mold having the shape of each pattern layer onto the resin layer. In this case, the material of the pattern transfer mold is not particularly limited, but high-hardness diamond or hard carbon materials can be used for precise pattern control.

[0090] In one embodiment of the present invention, the step of forming the first pattern layer can be performed using photolithography.

[0091] One embodiment of the present invention provides a method for manufacturing artificial leather, comprising the following steps: preparing the release film; forming a resin surface layer on the resin layer of the release film; forming an adhesive layer on the resin surface layer; layering a fabric on the adhesive layer; and peeling the resin surface layer off the resin layer.

[0092] In one embodiment of the invention, the step of forming an embossed pattern on the resin layer may be included. The embossed pattern may be formed by pressing a stamp, which includes a reverse image of the embossed pattern on a main surface, onto the resin layer.

[0093] In one embodiment of the invention, the process may include drying or curing the resin layer forming composition. Drying is a step of evaporating the organic solvent contained in the resin layer forming composition, and curing is a step of crosslinking and curing the curable resin contained in the resin layer forming composition.

[0094] In one embodiment of the invention, the curing process can be selected based on the type of curable resin and initiator. Specifically, the curing can be performed using either photocuring or thermocuring.

[0095] In one embodiment of the present invention, from a processability point of view, a photocuring method is preferred, which can be a method of irradiating the surface of the release film on which the resin layer is formed with light. Specifically, the light can be ultraviolet light.

[0096] One embodiment of the present invention provides a method for manufacturing artificial leather, comprising the following steps: preparing the release film; forming a resin surface layer on the resin layer of the release film; forming an adhesive layer on the resin surface layer; laminating a fabric on the adhesive layer; and peeling the resin surface layer off the resin layer.

[0097] In one embodiment of the present invention, the step of forming a resin surface layer on the resin layer of the release film can be performed by coating the release film with a resin surface layer forming solution once or more and then drying it.

[0098] In one embodiment of the invention, the step of laminating the fabric onto the adhesive layer is a step of transferring the surface properties of the resin layer of the release film to the fabric. Specifically, the embossed pattern of the resin layer of the release film is transferred to the fabric. Alternatively, the fabric can be a woven fabric, knitted fabric, nonwoven fabric, or hot melt film.

[0099] In one embodiment of the present invention, the step of peeling the resin surface layer from the resin layer is a step of removing the release film to obtain a fabric with a resin layer pattern transferred with the release film. Detailed Implementation

[0100] The present invention will now be described in more detail through examples. However, the scope of the present invention is not limited to the examples described below.

[0101] <Preparing the release film>

[0102] Example 1

[0103] Manufacturing such as Figure 1 The release film shown is formed by creating a resin layer on one side of a substrate, and then forming recesses on the resin layer using a mold that has corresponding unevenness in the resin layer. The protrusions are then selectively formed using photolithography.

[0104] The protrusions include a first patterned layer, and the recesses include a second patterned layer. The height difference between the protrusions and recesses is 9–18 μm. An Rf micrograph of the release film surface is shown below. Figure 2 .

[0105] At this point, the height difference between the convex and concave portions was confirmed using a laser microscope.

[0106] Example 2

[0107] Except for changing the height difference between the protrusions and concave portions to 20–29 μm, the release film was manufactured using the same method as in Example 1. Rf micrographs of the release film surface are shown below. Figure 3 .

[0108] Example 3

[0109] Except for setting a prism pattern in the concave portion and changing the height difference between the convex and concave portions to 23–29 μm, the release film was manufactured using the same method as in Example 1. An Rf micrograph of the release film surface is shown below. Figure 4 .

[0110] Example 4

[0111] Except for changing the height difference between the protrusions and concave portions to 18–27 μm, the release film was manufactured using the same method as in Example 1. An Rf micrograph of the release film surface is shown below. Figure 5 .

[0112] Example 5

[0113] Except for changing the height difference between the protrusions and concave portions to 33 μm, the release film was manufactured using the same method as in Example 1. An Rf micrograph of the release film surface is shown below. Figure 6 .

[0114] <Preparing artificial leather>

[0115] according to Figure 7 The process diagram illustrates the manufacture of artificial leather using the release films of Examples 1 to 5. A polyurethane resin surface layer is coated onto the resin layer of the release film. After applying an adhesive to the resin surface layer, a hot melt film is laminated and cured.

[0116] <Evaluating physical properties>

[0117] (1) Confirm the height difference between the concave and convex parts.

[0118] The height difference between the concave and convex portions of the release film was measured using an RF laser microscope. The measurement of the height difference between the concave and convex portions in Example 1 is shown below. Figure 8 The measurement of the height difference between the concave and convex portions in Example 5 is shown in... Figure 9 .on the other hand, Figures 2 to 5 (1) corresponds to the convex part, and 5(2) corresponds to the concave part.

[0119] (2) Evaluation of appearance

[0120] The surface of the manufactured artificial leather was visually inspected. The color changed in various ways depending on the direction of light, and no fingerprints appeared even when the artificial leather was rubbed by hand. Photographs of the artificial leather manufactured using the release film of the examples are shown below. Figure 10 (Example 1)Figure 11 (Example 2) Figure 12 (Example 3) Figure 13 (Example 4) Figure 14 (Example 5)

Claims

1. A release film, wherein, The release film includes: Substrate; and A resin layer, wherein the resin layer is disposed on one or both sides of the substrate; The resin layer includes protrusions and recesses. The protrusion includes a first pattern layer, which serves as an area capable of transferring a holographic image. This first pattern layer includes a pattern with a height of 1 nm or more and less than 2,000 nm, wherein the holographic image is an area whose color varies depending on the user's viewing direction. The recess includes a second pattern layer, which serves as an area capable of transferring a matte finish. This second pattern layer includes a pattern with a height of 1 μm or more and 1 mm or less, wherein the matte finish is an area whose color does not change depending on the user's viewing direction. The resin layer comprises an organosilicon-acrylate release agent with a weight average molecular weight of 5,000 or more and 100,000 or less. The height difference between the convex and concave portions is greater than 1 μm and less than 1000 μm.

2. The release film according to claim 1, wherein, The resin layer includes two or more protrusions and two or more recesses, and the average height difference between the protrusions and recesses is more than 1 μm and less than 1000 μm.

3. The release film according to claim 1, wherein, It includes an inclined layer disposed between the protrusion and the recess, and the inclined angle is more than 1 degree and less than 90 degrees.

4. The release film according to claim 1, wherein, The first pattern layer includes a pattern, the pattern including a tilted surface greater than 0 degrees and less than 90 degrees.

5. The release film according to claim 1, wherein, The first pattern layer comprises a pattern of inclined surfaces having different tilt angles from each other.

6. The release film according to claim 1, wherein, The first pattern layer includes a pattern with a cone-shaped protrusion or groove, a pattern with a line-shaped protrusion at the highest point or a line-shaped groove at the lowest point, or a pattern with a cone-shaped protrusion or groove having a cut structure on the top.

7. The release film according to claim 1, wherein, The second pattern layer includes one or more shapes selected from the group consisting of matte shapes, prism shapes, lenticular lens shapes, microlens shapes, pyramidal shapes, triangular pyramidal shapes, and mirror surfaces.

8. The release film according to claim 1, wherein, This includes a release layer disposed on the resin layer.

9. The release film according to claim 1, wherein, The resin layer includes ultraviolet-curable resin, thermosetting resin, or electron beam-curable resin.

10. The release film according to claim 1, wherein, The thickness of the resin layer is 1 μm to 2 mm.

11. A method for manufacturing a release film according to any one of claims 1 to 10, comprising the following steps: Prepare the substrate; A resin layer is formed by coating one or both sides of the substrate with a resin layer forming composition comprising an organosilicon-acrylate release agent having a weight average molecular weight of 5,000 or more and 100,000 or less. The resin layer is pressed using a pattern transfer mold having the shape of each pattern layer, and a recess is formed on the resin layer, wherein a second pattern layer having a pattern with a height of more than 1 μm and less than 1 mm is formed on the recess. The protrusion is formed using photolithography, wherein a first pattern layer having a pattern with a height of more than 1 μm and less than 1 mm is formed on the protrusion.

12. A method for manufacturing artificial leather, comprising the following steps: Prepare a release film according to any one of claims 1 to 10; A resin surface layer is formed on the resin layer of the release film; An adhesive layer is formed on the surface of the resin; A fabric is laminated on the adhesive layer; and The resin surface layer is peeled off from the resin layer.

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