JP7188029B2 - release film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a release film having an uneven structure on its surface, and to a release film capable of transferring the uneven structure to the surface of a film laminated on the release film.

For walls and windows of buildings, decorations and windows of automobiles, image display parts of mobile phones and personal computers, etc. Adhesive films having various functions (referred to as “functional adhesive films”) such as sebum adhesion prevention films are applied.

When such a functional pressure-sensitive adhesive film is attached to an adherend surface, air may be entrapped to form air bubbles (air pockets) between the surface of the adherend and the functional pressure-sensitive adhesive film. If air bubbles remain between the functional pressure-sensitive adhesive film and the adherend, it not only impairs the appearance, but may also deteriorate the functions of the functional pressure-sensitive adhesive film.
Therefore, in order to prevent such entrainment of air when attaching functional adhesive films, unevenness is provided on the surface of the functional adhesive film, and air trapped between the functional adhesive film and the adherend surface is released to the outside. It is devised to make it easier to escape.

For example, Patent Document 1 discloses a release liner having an embossed pattern composed of a plurality of interconnected linear ridges and an adhesive sheet article using the release liner. With such a pressure-sensitive adhesive film having an uneven shape, the air caught in when it is attached to the adherend easily escapes to the outside through the uneven shape, so air pools occur between the adherend and the pressure-sensitive adhesive film. difficult to do.

Patent Document 2 describes an adhesive film in which an adhesive layer is provided on a sheet base material and a method for producing the adhesive film, wherein the adhesive layer is a point-like object formed by phase-separating an adhesive from a mixed solvent, When manufacturing, a step of applying a coating liquid containing an adhesive and a mixed solvent consisting of a good solvent and a poor solvent for the adhesive onto a sheet substrate, evaporating the mixed solvent, and adding the adhesive and phase-separating to form dots.

Patent Document 3 discloses an adhesive film in which a resin layer having adhesiveness is provided on a base material, and irregular recesses are self-formed by containing fine particles in the resin layer.

Further, in Patent Document 4, a curable material containing a specific alkylated melamine resin as a main component is applied to a substrate and cured, so that the surface of the cured film has a high roughening effect and a random Disclosed is a release film comprising a substrate, a resin layer provided on the substrate, and a release agent layer provided on the surface of the resin layer opposite to the substrate by a method of forming unevenness in a pattern. It is Specifically, the resin layer is formed by curing a curable material containing an alkylated melamine resin (A) having an alkyl group having 4 to 18 carbon atoms as a main component. discloses a release film provided with unevenness so as to have ridges with an average peak height of 0.5 μm or more.

JP-A-2006-70273 JP 2004-277534 A WO2015/152352 JP 2016-188344 A

Regarding a functional adhesive film having an uneven structure on its surface, if the unevenness depth of the uneven structure is large, there is an advantage that air can easily escape. There was a problem that the appearance could be spoiled by putting it away.

Therefore, the present invention relates to a release film capable of transferring a concavo-convex structure to the surface of an adhesive film. To propose a new release film that makes it difficult to see the uneven structure after sticking.

The present invention is a release film comprising an uneven layer having an uneven structure on at least one surface side of a substrate, wherein the uneven structure has uneven protrusions when viewed in plan. It has a structure formed by forming a regular shape, the area ratio of the protrusions to the surface of the uneven structure is 10 to 90%, and the maximum height difference of the uneven structure is 0.5 μm or more. We propose a release film characterized by:

In the release film proposed by the present invention, when viewed from above, the area ratio of the convex portions to the surface of the uneven structure is 10 to 90%, and the maximum height difference of the uneven structure is 0.5 μm or more. Therefore, in the pressure-sensitive adhesive film to which the uneven structure is transferred, air can be easily released when the pressure-sensitive adhesive film is attached. Furthermore, since the convex portions of the uneven structure on the release film form an irregular shape, the uneven structure transferred to the adhesive film also has an irregular shape, making it difficult to see the uneven structure after adhesion. can be done.

1 is an enlarged image (scale: 703.12 μm×937.42 μm) of the uneven layer surface of the release film (sample) produced in Example 1 detected by VertScan (registered trademark). 2 is an enlarged image (scale: 703.12 μm×937.42 μm) of the uneven layer surface of the release film (sample) produced in Example 2 detected by VertScan (registered trademark). 2 is an enlarged image (scale: 703.12 μm×937.42 μm) detected by VertScan (registered trademark) of the uneven layer surface of the release film (sample) produced in Example 3. FIG. 2 is an enlarged image (scale: 703.12 μm×937.42 μm) detected by VertScan (registered trademark) of the uneven layer surface of the release film (sample) produced in Example 4. FIG. 2 is an enlarged image (scale: 703.12 μm×937.42 μm) of the uneven layer surface of the release film (sample) produced in Example 5 detected by VertScan (registered trademark). 2 is an enlarged image (scale: 703.12 μm×937.42 μm) detected by VertScan (registered trademark) of the uneven layer surface of the release film (sample) produced in Example 6. FIG. 2 is an enlarged image (scale: 703.12 μm×937.42 μm) detected by VertScan (registered trademark) of the uneven layer surface of the release film (sample) produced in Example 7. FIG. 2 is an enlarged image (scale: 703.12 μm×937.42 μm) of the uneven layer surface of the release film (sample) produced in Example 8 detected by VertScan (registered trademark). FIG. 10 is an enlarged image (scale: 703.12 μm×937.42 μm) of the uneven layer surface of the release film (sample) produced in Example 9 detected by VertScan (registered trademark). FIG. 10 is a scale diagram of the enlarged images in FIGS. 1 to 9, and in the vertical band on the right, white portions correspond to convex portions and black portions correspond to concave portions.

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiments described below.

[Release film]
A release film according to an example of the embodiment of the present invention (referred to as "this release film") is a release film provided with an uneven layer having an uneven structure on at least one surface side of a substrate. .
Since the present release film can transfer the uneven structure to the surface of an adhesive film or the like laminated on the release film, it can also be called an uneven structure transfer film.

Since the present release film may be provided with an uneven layer on at least one surface side of the substrate, for example, another layer such as a "functional layer" may be provided between the substrate and the uneven layer. In addition, another layer such as a layer similar to the uneven layer may be provided on the opposite side of the substrate to the uneven layer, and another layer such as a "release layer" may be provided outside the uneven layer. may be provided.

<Base material>
As the substrate, for example, paper, various resin films, substrates obtained by laminating a paper substrate with a resin, glass, metal foil, substrates obtained by laminating a metal foil with a resin, and the like can be used. However, it is not limited to these.

Examples of the paper substrate include thin paper, medium quality paper, fine paper, impregnated paper, coated paper, art paper, sulfate paper, and glassine paper.

Examples of the resin film include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene, polypropylene, polymethylpentene, and cyclic polyolefins; polycarbonates, polyvinyl acetates, polysulfones, polyetheretherketones, and polyethers. Resin films containing various resins such as sulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, fluororesin, polyvinyl chloride, polystyrene, polyurethane, and acrylic resin as main component resins can be mentioned.
The resin film may be an unstretched film (sheet) or a stretched film. Among them, a stretched film is preferred, and a biaxially stretched film is more preferred. Since the adhesive film that transfers the uneven shape of the release film is generally made of a flexible material, if the base material is a biaxially stretched film, the rigidity of the release film will be high, so the peelability from the adhesive film etc. tend to be better.

Examples of the base material obtained by laminating the paper base material with a resin include laminated paper obtained by laminating the above paper base material with a thermoplastic resin such as polyethylene.
Moreover, an aluminum foil etc. can be mentioned as said metal foil.

Among these, the above resin film is preferable because paper dust is not generated when cutting (cutting) the release film, and paper dust does not adhere to the adhesive film or the like that transfers the uneven structure. From the viewpoints of ease of use, durability, heat resistance, cost, etc., a resin film containing polyester as a main resin is more preferable, and a resin film containing polyethylene terephthalate as a main resin is more preferable.
Here, the "main component resin" means a resin having the highest content among the resins constituting the base material, specifically 50% by mass or more, especially 70% by mass or more, and especially 80% by mass or more. , a resin that accounts for 90% by mass or more (including 100% by mass) of them.

The base material may have a single-layer structure, or may have a multi-layer structure of two or more layers containing resins of the same or different types as main components.

It is preferable to appropriately select the thickness of the substrate according to the application. Generally, it is preferably 5 μm to 500 μm, more preferably 10 μm or more or 300 μm or less, and more preferably 15 μm or more or 200 μm or less.

When a resin film is used as the base material, it is possible to incorporate particles mainly for the purpose of imparting lubricity.
The type of particles to be contained in the substrate is not particularly limited as long as the particles can impart lubricity. For example, inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, titanium oxide, acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, Organic particles such as benzoguanamine resin can be used.

The shape of the particles is also not particularly limited. For example, it may be spherical, blocky, rod-shaped, or flat.
Further, the hardness, specific gravity, color, etc. of the particles are not particularly limited. Two or more types of these series of particles may be used in combination, if necessary.

The average particle diameter of the particles is preferably 5 μm or less, more preferably 0.1 μm or more or 3 μm or less. When the average particle diameter of the particles is within the above range, the substrate can be provided with an appropriate surface roughness, and good lubricity and smoothness can be imparted.

In addition to the particles described above, the base material may contain conventionally known antioxidants, heat stabilizers, lubricants, ultraviolet absorbers, antistatic agents, softeners, crystal nucleating agents, dyes, pigments, etc., if necessary. may contain.

(functional layer)
A layer having various functions (referred to as a "functional layer") can be provided as necessary. For example, a functional layer can be provided on one side or both sides of the substrate, if desired. For example, a functional layer can be provided between the substrate and the uneven layer. Alternatively, a functional layer can be provided on the opposite side of the uneven layer to the substrate. Furthermore, a functional layer may be provided on the surface of the uneven layer. When providing the functional layer on the surface of the uneven layer, it is preferable to design the material, thickness, etc. so as not to impair the uneven structure (described later) formed by the uneven layer. For example, the thickness of the functional layer provided on the uneven layer is usually 1 nm to 5 μm, preferably about 1 nm to 1 μm.
The functional layer includes, for example, an easy adhesion layer, an antistatic layer, an easy slip layer, a gas barrier layer for water vapor and the like, a layer for preventing precipitation of substances contained in the substrate, an ultraviolet absorbing layer, an anti-scratch layer, an antifouling layer, an antibacterial layer, Layers having various functions such as an antireflection layer, a glossy layer, a matte layer, an ink-receiving layer, a colored layer, and a printing layer can be mentioned.

<Uneven layer>
The uneven layer is preferably a layer having, on its surface, an uneven structure having protrusions and portions other than the protrusions (referred to as “recesses”).

It is preferable that the concave-convex structure has a configuration in which the convex portions form an irregular shape when viewed from above. In addition, in FIGS. 1 to 9, white portions correspond to convex portions.
Here, "irregular shape" means a shape that does not have regularity and periodicity. In other words, the same shape (pattern) is repeated at regular intervals, such as a shape formed only by straight lines, a shape formed by curves of the same pattern, a shape transferred by an embossing roll, and a shape combining these. Any shape other than a shape that is irregular can be said to be an "irregular shape". In addition, the irregularity in the present invention means not only the irregularity of the pattern itself, but also the irregularity of the size of the elements constituting the shape (for example, the irregularity of the size of the polka dots in the polka dot pattern). and irregularities in the placement of elements that make up the shape (for example, irregularities in the placement of polka dots in a polka dot pattern).
The irregular shape typically includes a shape due to a sea-island structure that is naturally formed when immiscible polymers or the like are mixed, as shown in FIGS. A shape and a shape in which convex portions of non-uniform shape are present irregularly can be mentioned. However, it is not limited to such a shape.
By forming the irregular shape of the protrusions on the surface of the release film in this way, the uneven structure transferred to the adhesive film also has an irregular shape, making it difficult to see the uneven structure after adhesion. can do.
A specific method for forming such an uneven structure will be described later.

The uneven structure has a configuration in which, when the surface is viewed in plan, an irregular shape, such as a mesh pattern, is formed by the protrusions so that the irregular shape continues in the peripheral direction, for example, in the vertical and horizontal directions. may be
When the irregular shapes are continuous in the circumferential direction, it is preferable that the size and shape of the irregular shapes are not uniform and that the shapes do not repeat, and the arrangement of the irregular shapes is also irregular. is preferred.

In addition, the protrusions in the uneven structure may be scattered as lumps having an appropriate area when viewed from above, may be present intermittently, or may be continuously connected.
At this time, the maximum diameter among the diameters passing through the center of the X coordinate and the center of the Y coordinate of each convex portion is defined as the "maximum diameter", and among the maximum diameters, the diameter showing the maximum value in the measurement area. "Maximum longest diameter".
The maximum longest diameter of the projections is such that when an adhesive film onto which an uneven shape is transferred can be adhered, air can be easily removed, and the uneven structure can be made difficult to see after adhesion. It is preferably 1 μm to 1500 μm, more preferably 10 μm or more and 1200 μm or less, more preferably 100 μm or more and 1000 μm or less, and more preferably 300 μm or more and 800 μm or less.

In addition, the projections in the uneven structure may be continuous when viewed from above, and may have a linear shape with an appropriate continuous length.
From the viewpoint of better air release when the pressure-sensitive adhesive film having the uneven structure transferred thereon is adhered, it is particularly preferable that the film is continuous to the peripheral edges. More specifically, in the image obtained by measuring the uneven structure surface of the release film surface by the optical interferometry, the image area of 703.13 μm × 937.42 μm on the release film surface (equivalent to a 5-fold objective lens) In the above, it is preferable that the convex portion is connected from the edge portion of the image area to the corresponding edge portion, for example, from the upper side portion to the lower side portion or from the left side portion to the right side portion. More preferably 5 mm×5 mm square, particularly preferably 30 mm×30 mm square, and most preferably 100 mm×100 mm square, it is preferable that the projections are connected from the edge to the corresponding edge.
Since the convex portions of the uneven structure form concave portions in the adhesive film or the like to which the uneven structure is transferred by the release film, if the convex portions of the release film are continuous as described above, In the adhesive film or the like, the escape route for air is also continuous. However, in this case, a part of the convex portion may have a discontinuous portion.
As an example, a case where irregular shapes are continuously formed to form a mesh pattern by projections extending to the peripheral edges of the film can be cited.

In addition, since the convex portion of the concave-convex structure disclosed in the above-mentioned prior patent document 4 (Japanese Patent Application Laid-Open No. 2016-188344) is not continuous as described above, the convex portion is continuous as described above. If so, it is possible to make the escape of air more favorable.
In addition, the above-mentioned prior patent document 2 (Japanese Patent Laid-Open No. 2004-277534) discloses an aspect in which the adhesive layer of the adhesive film has unevenness. Even if this is the case, when the adhesive film is stacked or rolled, the unevenness may be crushed or blocked, so the usable adhesive is considerably limited, and it can be said that it is not realistic.

The number of protrusions present in the uneven structure allows air to escape when the adhesive film having the uneven shape transferred is adhered, and makes it difficult to see the uneven structure after adhesion. From this point of view, the number per region of 703.12 μm×937.42 μm is preferably 1 to 1000, preferably 500 or less, preferably 100 or less, and preferably 10 or less.
The number of protrusions present in the uneven structure can be obtained by counting the number of protrusions appearing on the surface of the release film per unit area using, for example, image analysis software.

When the surface of the uneven structure is viewed from above, the lower limit of the area ratio of the protrusions to the surface is preferably 10% or more. If the area ratio occupied by the projections is 10% or more, there is a tendency for good air release.
For the same reason as above, the lower limit of the area ratio of the projections is more preferably 15% or more, still more preferably 20% or more, particularly preferably 25% or more, and most preferably 30% or more.
On the other hand, the upper limit of the area ratio of the projections in the release film is preferably 90% or less. If the area ratio of the convex portions is 90% or less, it is preferable in order to maintain the adhesiveness when the adhesive film is formed.
For the same reason as above, the upper limit of the area ratio of the projections is more preferably 85% or less, still more preferably 80% or less, particularly preferably 75% or less, and most preferably 70% or less.
In particular, when the area ratio of the convex portions is in the range of 10 to 50%, the concave-convex structure of the release film becomes difficult to see when the pressure-sensitive adhesive film is adhered, and a good appearance can be obtained, which is more preferable. Moreover, if the area ratio of the projections is in the range of 50 to 90%, air can be easily released when the adhesive film is adhered, which is more preferable.

The area ratio of the protrusions in the uneven structure can be analyzed by binarizing the surface of the uneven structure into two areas, ie, recesses and protrusions, by image analysis.
In addition, when the surface of the uneven structure is binarized into two regions of concave and convex portions by image analysis in this way, the entire surface of the uneven structure may be binarized, or the surface of the uneven structure may be binarized. It may be divided into a plurality of locations, binarized at each location, and the average obtained. At that time, it is preferable to obtain an average of at least three arbitrary locations, five locations among them, and ten locations among them.

In the concave-convex structure, the method described later can be used as a method for increasing the area of the convex portion. For example, it can be adjusted by increasing the compounding amount of the component B which forms the main component of the projections or by increasing the molecular weight of the component B. However, it is not limited to such a method.

Further, the lower limit of the maximum height difference of the unevenness in the uneven structure is preferably 0.5 μm or more. If the maximum height difference of the irregularities is 0.5 μm or more, there is a tendency that air can be easily released when the pressure-sensitive adhesive film onto which the irregular structure is transferred is adhered.
For the same reason as above, the lower limit of the maximum height difference of the unevenness in the uneven structure is preferably 1.0 μm or more, more preferably 1.5 μm or more, still more preferably 2.0 μm or more, and particularly preferably 3.0 μm or more. , and most preferably 4.0 μm or more.
On the other hand, the upper limit of the maximum height difference of the unevenness of the uneven structure is not particularly limited. The maximum height difference of the unevenness is usually 40 μm or less. If the maximum height difference of the unevenness is 40 μm or less, it is preferable because the uneven structure tends to be difficult to see after being attached to the adhesive film.
For the same reason as above, the upper limit of the maximum height difference of the unevenness in the uneven structure is preferably 35 μm or less, more preferably 30 μm or less, still more preferably 25 μm or less, particularly preferably 20 μm or less, and most preferably 15 μm or less. .
Among them, if the maximum height difference of the unevenness of the uneven structure is 0.5 to 15 μm, not only can sufficient air release property be obtained, but also when using an adhesive film whose substrate is transparent, the uneven structure is formed after sticking. can be made particularly invisible. In addition, when the maximum height difference of the unevenness of the uneven structure is 15 to 40 μm, it not only has excellent air release properties, but also when using an adhesive film whose base material is matte or opaque, the uneven structure after sticking. can be made invisible.

The maximum height difference of the unevenness can be adjusted, for example, by adjusting the coating thickness when forming the uneven layer. However, it is not limited to this.
In addition, the maximum height difference of the unevenness can be obtained as the maximum value among the difference between the minimum value of the recess and the maximum value around the recess, or the difference between the maximum value of the protrusion and the minimum value around the protrusion. can.
A specific method for forming such a maximum height difference of unevenness will be described later.

<Material for Forming Concavo-convex Layer>
The uneven layer in the present release film is not limited to a material to be formed.
The uneven layer preferably contains two or more types of polymers, oligomers, or monomers (collectively referred to as "polymers, etc."), and may be formed from a coating composition containing two or more types of polymers, etc. preferable.
At this time, as will be described later, it is preferable to form the uneven layer by utilizing the phase separation between different polymers or the like. That is, it is preferable that two or more kinds of polymers or the like form a phase separation structure in the uneven layer.
In addition, let the polymer in this invention be a concept including the hardened|cured material of a curable resin composition. In addition, the concept of monomer includes a monomer as a raw material for polymerization or crosslinking reaction or a raw material for a curable resin composition.

In the concave-convex structure, an example in which the composition forming the concave portions and the composition forming the convex portions are different from each other can be cited. For example, when the component A accounts for a large proportion of the components forming the concave portions, and the component B accounts for a large proportion of the components forming the convex portions, the component A and the component B are different.

(Component A)
Component A, which accounts for the largest proportion of the components that form recesses, is incompatible with component B, and from the viewpoint of mainly forming uneven recesses after coating, the solubility parameter (SP (A)) is 8. to 21, preferably 10 or more or 20 or less, more preferably 12 or more or 19 or less.
Further, from the viewpoint of obtaining a viscosity for improving the coatability of the coating liquid, it is preferable that the weight average molecular weight (Mw) of component A is a polymer or the like of 300 to 300,000, especially 2,000. It is more preferably 5,000 or more or 100,000 or less.

Examples of component A include acrylic polymers such as poly(meth)acrylate, polyesters, polyurethanes, polyolefins, polyethers, polystyrenes, polycarbonates, polyacrylonitriles, polyamides, and polyimides. Among them, poly(meth)acrylates are preferable from the viewpoint of easy adjustment of molecular weight and SP value and easy control of uneven shape. These component A may be used individually by 1 type, and may be used in combination of 2 or more type.

For example, when component A is an acrylic polymer or the like, in order to increase the SP value, for example, the side chain of the resin of the acrylic polymer may be designed to contain many highly polar functional groups. Specifically, for example, homopolymers or copolymers containing structural units such as hydroxy (meth) acrylate having a hydroxyl group, (meth) acrylic acid having a carboxyl group, and glycidyl (meth) acrylate having a glycidyl group. can be mentioned.

(Component B)
On the other hand, component B, which accounts for the largest proportion of the components that form the protrusions, is incompatible with component A, and from the viewpoint of mainly forming uneven protrusions after coating, the solubility parameter of component B ( SP (B)) is preferably 7 to 20, more preferably 8 or more or 18 or less, more preferably 9 or more or 17 or less.

The solubility parameter of component B (SP (B)) is preferably 0.01 to 10 lower than the solubility parameter of component A (SP (A)), especially in the range of 0.05 or more or 7 or less. Low, preferably 0.1 or more or 4 or less.
In the present release film, when the uneven structure is formed by utilizing the phase separation between different polymers, the solubility parameter of component B (SP (B)) is the solubility parameter of component A (SP ( It may be 0.01 to 10 higher than A)).
When the uneven layer is formed of three or more types of polymers, and at least one of component A and component B is formed of two or more types of polymers, any combination thereof has the above relationship. All you have to do is The same applies to the mass average molecular weight described below.

In addition, from the viewpoint of viscosity for improving the coatability of the coating liquid, the mass average molecular weight (Mw) of component B is preferably 500 to 400,000, especially 2,000 or more, or 300,000 or less, more preferably 10,000 or more or 250,000 or less.
More preferably, the weight average molecular weight (Mw) of component B is greater than the weight average molecular weight (Mw) of component A by 1000 or more.

Component B, which mainly forms the projections, can sufficiently withstand the drying temperature when forming the uneven structure, and from the viewpoint of maintaining the shape, the glass transition temperature of component B is preferably 40° C. or higher. , more preferably 50°C or higher, more preferably 60°C or higher.

Examples of component B include acrylic polymers such as poly(meth)acrylate, polyesters, polyurethanes, polyolefins, polyethers, polystyrenes, polycarbonates, polyacrylonitriles, polyamides, and polyimides. Among them, poly(meth)acrylates are preferable from the viewpoint of easy adjustment of the molecular weight and SP value and easy control of the uneven shape. These components B may be used individually by 1 type, and may be used in combination of 2 or more types.

For example, when component B is an acrylic polymer or the like, in order to lower the SP value, for example, in the acrylic polymer, the SP value as a monomer and / or oligomer containing one or more (meth)acryloyl groups should select the one with the lowest Specifically, structures such as alkyl (meth)acrylates having an aliphatic hydrocarbon group, cycloalkyl (meth)acrylates having an alicyclic hydrocarbon group, and phenylalkyl (meth)acrylates having an aromatic hydrocarbon group Homopolymers or copolymers containing units may be mentioned.

The solubility parameter (SP value) is a solubility parameter and serves as a measure of solubility. A larger value of the solubility parameter indicates a higher polarity, and a smaller value indicates a lower polarity.
The SP value can be measured by a method such as the turbidity method or Fedors' estimation method.

In the uneven layer, both the concave portions and the convex portions, especially the convex portions, preferably have a cross-linked structure from the viewpoint of improving heat resistance and solvent resistance in order to maintain the shape.
Whether or not there is cross-linking is preferably determined by measuring the gel fraction at each site and confirming that the value is greater than 0%, particularly 5% or more, and especially 10% or more.

At this time, at least one of the two or more types of polymers is a thermoplastic resin having a crosslinkable structure, a curable resin composition, or a curable resin containing a thermoplastic resin having a crosslinkable structure It is preferably a composition. In these cases, by cross-linking or curing the uneven layer, the uneven layer will contain a cured product, and the heat resistance and solvent resistance can be enhanced.
Here, the cured product means a product obtained by curing the thermoplastic resin or the curable resin composition having a crosslinkable structure.
The term "crosslinkable structure" refers to a structure having the property of being crosslinked, and the term "crosslinked structure" refers to a structure formed by crosslinking.

A method for introducing a crosslinkable structure into a thermoplastic resin is not limited. For example, a method of introducing a crosslinkable structure into component A, component B, or other thermoplastic resins can be mentioned.
At this time, the crosslinkable structure is not limited. For example, crosslinkable unsaturated bonds such as carbon-carbon double bonds, functional groups capable of chemical bonding such as hydroxyl groups, carboxyl groups, amino groups, isocyanate groups, glycidyl groups, oxazoline groups, acid anhydride groups, aldehydes groups, mercapto groups, epoxy groups, carbodiimide groups, and the like. The crosslinkable structures exemplified by these can be introduced into component A, component B, or other thermoplastic resins by copolymerization or polymer reaction.
The crosslinked structure referred to here is not limited to covalent bonds, and includes quasi-crosslinks such as ionic bonds, coordinate bonds, and hydrogen bonds.

Examples of the curable resin composition include a two-component curable resin composition, a room temperature curable resin composition, a photocurable resin composition, a thermosetting resin composition, and the like. A photocurable resin composition or a thermosetting resin composition in which the composition reacts and cures (crosslinks) is preferred.

The cured product of the curable resin composition may constitute component A or component B itself, or the curable resin composition may be used as a component other than component A and component B that form the uneven layer. . When component A or component B itself is a curable resin composition, the uneven structure is formed by using the monomers constituting these components as raw materials for the uneven layer and converting them into component A or component B through a curing reaction. be able to.

Examples of the photo- or thermosetting resin composition include a photo-curable composition containing a photo-crosslinkable compound and a photo-crosslinking initiator, and a thermosetting resin composition.
Examples of photocrosslinkable compounds include compounds having crosslinkable unsaturated bonds, specifically monomers or oligomers having ethylenically unsaturated bonds.
As the photocrosslinking initiator, for example, when ultraviolet irradiation is applied as the active energy ray, photocrosslinking initiators such as benzoin, acetophenone, thioxanthone, phosphine oxide and peroxide can be used.
Examples of thermosetting resins include urethane resin, urea resin, melamine resin, acrylic resin, and transparent polyimide precursor varnish.

Summarizing the above, the formation method for forming the concave-convex layer to which two or more types of polymers contribute is classified into the following formation examples, for example. However, it is not limited to these combinations. Further, the following description does not exclude the inclusion of additional optional components other than component A and component B.
(a) forming an uneven layer with two or more types of thermoplastic polymers;
(b) Two or more types of thermoplastic polymers and a cross-linking agent are used as raw materials, and the uneven layer is formed by curing the cross-linking agent.
(c) At least one of the two or more thermoplastic polymers has a crosslinkable structure, and the crosslinkable structure is crosslinked to form the uneven layer.
(d) At least one of the two or more thermoplastic polymers has a crosslinkable structure, and a raw material containing a crosslinker is added to the crosslinkable structure and the crosslinker. Cross-linking and curing between them to form a textured layer.
(e) Using one or more thermoplastic polymers, a polymerizable monomer, and a cross-linking agent as raw materials, and forming an uneven layer by polymerizing and curing the polymerizable monomer and the cross-linking agent.
(f) At least one polymer has a crosslinkable structure, and for a raw material containing a polymerizable monomer and a crosslinker, polymerization and polymerization between the crosslinkable structure, the polymerizable monomer, and the crosslinker Forms uneven layer by cross-linking and curing.
(g) At least two of the above (a) to (f) are used in combination.

(Peeling component)
The concavo-convex layer may contain a release component having releasability.

When the polymer or the like forming the concave-convex structure has releasability, the polymer or the like becomes the release component. Further, when a component having releasability is added as an additive, the additive becomes the releasable component.
Specific examples of the component having releasability include, in addition to silicone compounds, compounds such as fluorine compounds, olefin compounds, and long-chain alkyl group-containing compounds. These may be polymers or the like or low-molecular-weight compounds, and a layer containing one or more of these is preferred.

The content of the release component in the uneven layer is preferably 0.5% by mass to 90% by mass, especially 1.0% by mass or more or 85% by mass or less, and among them 2.0% by mass or more or 80% by mass % or less.

(other ingredients)
The uneven layer may contain components other than the components A and B and the release component described above, if necessary. Specifically, antifoaming agents, coatability improvers, thickeners, organic lubricants, organic particles, inorganic particles, antioxidants, ultraviolet absorbers, infrared absorbers, light shielding agents, foaming agents, colorants. etc. can be mentioned.

<Release layer>
A peeling layer can be further laminated on the surface of the uneven layer to enhance the peelability.
However, it is not always necessary to provide the release layer on the outer surface of the uneven layer. For example, when the uneven layer contains the release component, the release layer need not be provided if the release property is sufficient. On the other hand, even if the uneven layer contains the release component, if the release property is not sufficient, a release layer may be further laminated on the surface of the uneven layer.

The release layer may be made of one or two of non-silicone resin release agents such as alkyd resin release agents, olefin resin release agents, acrylic release agents, long-chain alkyl group-containing compounds, and rubber release agents, in addition to silicone resin release agents. It preferably contains more than one seed.
Further, each release agent may further contain other components such as a curing agent and a catalyst.

The thickness of the release layer is not particularly limited. For example, it is preferably 25 nm to 1000 nm, and more preferably 40 nm or more or 500 nm or less.
By setting the thickness of the release layer within the above range, the function as the release surface can be sufficiently exhibited, and the uneven shape can be maintained.

The silicone resin-based release agent includes solvent type and non-solvent type. Since the solvent-type silicone resin is diluted with a solvent to form a coating liquid, it can be widely used from high-molecular-weight (that is, high-viscosity) polymers to low-viscosity, low-molecular-weight polymers (oligomers). Therefore, it is easier to control the releasability than the non-solvent type, and it is easy to design according to the required performance (quality).
Examples of silicone resin-based release agents include those of addition reaction type, condensation reaction type, ultraviolet curing type, electron beam curing type, and the like.
Of these, the addition reaction type silicone resin has high reactivity and excellent productivity, and compared to the condensation reaction type, it has advantages such as less change in release force after manufacturing and no curing shrinkage. It is preferably used in forming release agents.

The addition reaction type silicone resin is not particularly limited, and various resins can be used. For example, one commonly used as a conventional thermosetting addition reaction type silicone resin release agent can be used. As the addition reaction type silicone resin, for example, those having an alkenyl group such as a vinyl group or an electrophilic group such as a hydrosilyl group as a functional group in the molecule are listed as addition reaction type silicone resins that are easily heat cured. Polydimethylsiloxane having such functional groups, polydimethylsiloxane in which some or all of the methyl groups are substituted with aromatic functional groups such as phenyl groups, and the like can be used.
Silica, silicone resin, antistatic agents, dyes, pigments and other additives may be added to the silicone resin-based release agent, if necessary.

A crystalline olefin resin can be used as the olefin resin release agent. As the crystalline olefin resin, polyethylene and crystalline polypropylene resin are suitable. Examples of polyethylene include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and the like. Examples of crystalline polypropylene-based resins include propylene homopolymers having an isotactic or syndiotactic structure, and propylene-α-olefin copolymers. These crystalline olefin resins may be used singly or in combination of two or more.

As the acrylic release agent, an acrylic resin generally having a crosslinked structure can be used. The acrylic resin may be a modified product such as a long-chain alkyl-modified acrylic resin or a silicone-modified acrylic resin.
Examples of the long-chain alkyl group-containing compound-based release agent include polyvinyl carbamate obtained by reacting a polyvinyl alcohol-based polymer with a long-chain alkyl isocyanate having 8 to 30 carbon atoms, and polyethyleneimine with 8 to 30 carbon atoms. Alkyl urea derivatives obtained by reacting with a long-chain alkyl isocyanate can be used.

Examples of the rubber-based release agent include natural rubber-based resins and synthetic rubber-based resins such as butadiene rubber, isoprene rubber, styrene-butadiene rubber, methyl methacrylate-butadiene rubber, and acrylonitrile-butadiene rubber.

<Lamination structure of the release film>
The laminate structure of the release film includes, for example, base material/uneven layer, base material/uneven layer/release layer, functional layer/base material/uneven layer, base material/functional layer/uneven layer, functional layer/base material. /functional layer/uneven layer, functional layer/base material/uneven layer/release layer, base material/functional layer/uneven layer/release layer, functional layer/base material/functional layer/uneven layer/release layer, etc. can be mentioned. However, it is not limited to these laminated structures, and other layers may be added and laminated as appropriate.

<Method for producing this release film>
The present release film can be produced, for example, as follows. However, the manufacturing method is not limited to the following.

The present release film can be produced by providing an uneven layer on a substrate. At this time, the method for providing the uneven layer is not limited. For example, physical cutting, cutting by laser irradiation, etc., methods such as transfer using a mold, photomasking used for resist materials, etc., printing, methods of forming an uneven layer using phase separation between different polymers, etc. The aspect of can be mentioned. Among them, a method of forming an uneven layer by utilizing phase separation between different polymers or the like is preferable.
By utilizing the phase separation between different polymers, etc., an uneven structure based on the phase separation structure on the order of several μm to several mm is formed. At the same time, it is possible to make the concave-convex structure less visible after attachment. In addition, if the phase separation between different polymers is used, the irregularity and continuity of the convex shape of the concave-convex structure, the area ratio of the convex part, the area ratio of the convex part, Since it is possible to control the maximum height difference of the uneven structure, it is preferable as one of specific means for achieving the present invention.

When the uneven layer is formed by utilizing phase separation between different polymers or the like, the specific method is not limited as long as two or more types of polymers or the like are used. Specifically, the following aspects (1) to (5) can be mentioned. Also, a plurality of these methods may be combined.

(1) Two or more thermoplastic resins (polymers) are used, and the unevenness is caused by phase separation in the process of distilling off the solvent from the state dissolved in the solvent, or phase separation in the process of cooling and solidifying from the molten state. How to form a structure.
(2) A method in which a thermoplastic resin and a curable resin composition are blended, and during the curing process of the curable resin composition, the thermoplastic polymer is removed to cause phase separation, thereby forming an uneven structure.
(3) A curable resin composition is blended, and in the process of curing the curable resin composition, the curable resin composition that has become a high molecular weight is expelled from the unreacted curable resin composition. A method of forming an uneven structure by forming projections.
(4) A method in (1) above, in which at least one thermoplastic resin has a crosslinkable structure, and after forming an uneven structure by phase separation, a crosslinking reaction is performed to fix the uneven structure.
(5) In the above (1), the curable resin composition is mixed with two or more thermoplastic resins, and after forming an uneven structure by phase separation of the thermoplastic resin, the curable resin composition is cured. A method of fixing an uneven structure by

In addition, when using a method that causes phase separation in the process of distilling off the solvent from the state dissolved in the solvent, as described later, two or more solvents are mixed and used, and the difference in solubility of polymers etc. is used. A method of forming a concave-convex structure is preferable. By adopting this method, it is possible to form the intended concave-convex structure simply by selecting a specific polymer or the like and a specific solvent. Therefore, the object of the present invention can be easily achieved without using a cutting device, a mold, or the like.

Hereinafter, the case where the photocurable resin composition is used will be specifically described by taking the aspect (5) as an example among the various aspects described above.
A mixed resin of the component A, the component B, and optionally a cross-linking initiator C is mixed with a predetermined mixed solvent Z, for example, a solvent that is a good solvent for the component A, the component B, and the cross-linking initiator C. X and a solvent Y that is a good solvent (that is, a co-solvent for them) for component A and cross-linking initiator C, is a poor solvent for component B, and has a boiling point higher than that of solvent X. It is added to the mixed solvent Z and dissolved to prepare a curable coating composition, and this curable coating composition is applied to the surface of the substrate. In the process of drying the mixed solvent Z, the solvent X evaporates relatively quickly and the ratio of the solvent Y increases, so the component B that is difficult to dissolve in the solvent Y is precipitated to form protrusions. By further drying, recesses are formed by the component A to form an uneven structure. Alternatively, the uneven structure may be formed by exciting the cross-linking initiator C by, for example, irradiating it with light and hardening it.
According to such a manufacturing method, it is possible to form a concave-convex structure having projections of irregular shapes, and furthermore, selection of materials for component A, component B, cross-linking initiator C, solvent X and Y. The size of the unevenness can be controlled by adjusting the blending amount.
However, it is not limited to such a manufacturing method.
The cross-linking initiator C does not necessarily have to be blended. Further, it is preferable that the solvent X and the solvent Y are mixed in the mixed solvent Z. However, it is not necessary to be uniformly mixed, and a suspension may be used.

In the above production method, the principle of forming the uneven layer is that the environment in the solvent changes as the mixed solvent Z decreases in the process of drying the curable coating composition after coating, Component A and component B, which have poor compatibility, are phase-separated, and the component that is soluble in both solvents dissolves in the solvent until drying proceeds further, so component B, which is difficult to dissolve in one solvent Y, precipitates and is mainly convex. It is presumed that component A, which forms the part and is soluble in both solvents, mainly forms the recesses, and the uneven structure is formed spontaneously.

Components A and B are preferably immiscible.
From this point of view, the SP value of the component B, which is the main component of the convex portion, is preferably lower than the SP value of the component A by 0.01 to 10, especially in the range of 0.05 or more or 7 or less. Among them, it is preferable that it is lower than 0.1 or lower than 4.

(Components A and B)
Component A, which accounts for the largest proportion of the components forming the recesses, is preferably a polymer or the like having a predetermined mass-average molecular weight (Mw) and a predetermined SP value, as described above.
On the other hand, the component B, which accounts for the largest proportion of the components forming the protrusions, is preferably a polymer or the like having a predetermined mass-average molecular weight (Mw) and a predetermined SP value, as described above.
For example, by increasing the compounding amount of the component B that forms the main component of the protrusions or by increasing the molecular weight of the component B, the area of the protrusions in the uneven structure can be increased or the shape of the protrusions can be changed. can do. Further, by controlling the crystallinity of the component B, it is possible to adjust the maximum value of the protrusions, that is, the maximum height difference of the unevenness. However, it is not limited to such a method.

The mixing weight ratio of component A and component B is preferably 1:99 to 99:1, more preferably 5:95 to 95:5, more preferably 90:10 to 10:90.
In addition, when the component A or the component B consists of 2 or more types of components, let it be the mass ratio which totaled 2 or more types of components, respectively.
One of the control factors for setting the area ratio of the projections in the uneven structure within the above range is a method of optimizing the mixing mass ratio of the component A and the component B. Since the convex portions and the concave portions are not necessarily composed of only the component B and the component A, respectively, the blended mass ratio and the area ratio of the convex portions are not synonymous.

(Crosslinking initiator C)
Examples of the cross-linking initiator C include a photo-crosslinking initiator and a thermal cross-linking initiator. Among them, from the viewpoint of maintaining the uneven shape formed in the drying process, a curing system having a fast curing property is preferable, and from this viewpoint, a photocrosslinking initiator is preferable.

Examples of photocrosslinking initiators include 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1-[4-(methylthio)phenyl] -2-morpholinopropan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 etc. can be mentioned. One of these crosslinking initiators may be used alone, or two or more thereof may be mixed and used. Among them, a polyfunctional acrylate that cures with ultraviolet rays is preferable.

The amount of the cross-linking initiator compounded is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of components A and B, especially 0.1 parts by mass or more or 10 parts by mass or less. It is more preferable to set it to 1 part by mass or more.

(Solvent X)
The solvent X is preferably a good solvent for component A, component B and cross-linking initiator C. That is, it is preferably a solvent capable of dissolving all of component A, component B and cross-linking initiator C.

The boiling point of the solvent X is preferably 50° C. to 200° C., more preferably 60° C. or higher or 140° C. or lower, and more preferably 70° C. or higher or 120° C. or lower.

Examples of the solvent X include ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone and diacetone alcohol; alcohol solvents such as pentanol, hexanol, heptanol and octanol; ethylene glycol monoethyl; Ether solvents such as ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate; methyl acetate, ethyl acetate, butyl acetate, methoxybutyl acetate, amyl acetate, propyl acetate, ethyl lactate, methyl lactate, ester solvents such as butyl lactate; and organic solvents such as hydrocarbon solvents such as toluene, xylene, solvent naphtha, hexane, cyclohexane, ethylcyclohexane, methylcyclohexane, heptane, octane, and decane. These organic solvents may be used alone or in combination of two or more.

(Solvent Y)
The other solvent Y is preferably a good solvent for the component A and the cross-linking initiator C and a poor solvent for the component B. That is, a solvent in which component A and cross-linking initiator C can be dissolved, but in which component B has low solubility is preferred. At this time, the low solubility of the component B includes cases in which the component B is classified as being insoluble (insoluble) or swelling (swelling).

The boiling point of the solvent Y is preferably 51° C. to 201° C., more preferably 61° C. or more or 141° C. or less, and more preferably 71° C. or more or 121° C. or less.
However, the boiling point of the solvent Y is preferably higher than the boiling point of the solvent X from the viewpoint that the solvent X can be volatilized before the solvent Y, preferably 1 to 80 ° C. higher, and among them 2 ° C. Above all, it is more preferable that the temperature is higher than 5°C.
By using a solvent Y having a higher boiling point than the solvent X, the solvent X is volatilized earlier than the solvent Y, and the component B, which is difficult to dissolve in the solvent Y, precipitates, making it easier to mainly form protrusions.

The solvent X and solvent Y to be used can be selected depending on the difference in boiling points. However, they can also be selected according to differences in other characteristics. Specific properties include relative evaporation rate, vapor pressure at a given temperature and pressure, affinity for component A or component B.
For example, the relative evaporation rate of solvent X is preferably higher than the relative evaporation rate of solvent Y from the same point of view, that is, from the point of view that solvent X can be volatilized earlier than solvent Y. Among them, the relative evaporation rate of solvent X is preferably 1 or more, or the relative evaporation rate of butyl acetate or more, and the relative evaporation rate of solvent Y is less than 1, or Preferably less than the relative evaporation rate.
In this case, the "relative evaporation rate" is defined as the specific evaporation rate when the evaporation rate of butyl acetate at 25°C and atmospheric pressure is defined as 1. For example, the relative evaporation rates of various solvents are butyl acetate: 1, MEK: 4.52, cyclohexane: 2.9, toluene: 2.66, methoxypropanol: 0.71, n-butanol: 0.39.

Examples of the solvent Y include alcohol solvents such as methanol, ethanol, butanol, isobutanol, and propyl alcohol; ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone diacetone alcohol; Ether solvents such as alcohol diethylene glycol monomethyl ether and propylene glycol monomethyl ether; Ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methoxybutyl acetate, amyl acetate, propyl acetate, ethyl lactate, methyl lactate and butyl lactate; toluene, Examples include hydrocarbon solvents such as xylene, solvent naphtha, hexane, cyclohexane, ethylcyclohexane, methylcyclohexane, heptane, octane, and decane, and water. These solvents may be used alone or in combination of two or more.

(Mixed solvent Z)
The mixed solvent Z is preferably a mixture of solvent X and solvent Y in a mass ratio of 0.1:99.9 to 99.9:0.1, especially 1:99 to 99:1, especially 10:90. It is more preferably contained in a mass ratio of up to 90:10, especially 15:85 to 85:15, especially 80:20 to 20:80. In addition, when the solvent X or the solvent Y consists of 2 or more types of solvents, let it be the mass ratio which totaled 2 or more types of solvents, respectively.

(Application of curable coating composition)
As a method for applying the above-mentioned curable coating composition to the surface of the substrate, known and commonly used methods such as a kiss roll coater, a bead coater, a rod coater, a Mayer bar coater, a die coater, and a gravure coater can be employed.

(dry)
The drying temperature after application is preferably set to 10° C. to 150° C. in view of the boiling points of solvents X and Y in order to volatilize solvent X over solvent Y after application. Among them, it is more preferable to set the temperature to 20° C. or higher or 140° C. or lower, and among them, it is more preferable to set the temperature to 40° C. or higher or 125° C. or lower. In addition, you may dry at normal temperature.
By adjusting the heating (drying) temperature, the maximum height difference of the unevenness can be adjusted, and the lower the drying temperature, the larger the maximum height difference of the unevenness tends to be. Solvents are generally volatile at temperatures below their boiling point, and their volatility varies depending not only on their boiling point but also on their vapor pressure characteristics, affinity with polymers and the like. Therefore, the drying temperature may be set according to the type and mass ratio of the polymer or the like used in the uneven layer, the shape of the intended uneven structure, and the like.

<Form of this release film>
Any currently known form can be employed as the form of the present release film. Among them, the features of the present release film, for example, good air release when attaching the adhesive film, and the fact that the uneven structure is difficult to see after adhesion are considered. is preferred. From this point of view, the film or roll body has a length of 0.1 m or more, especially 1 m or more, especially 10 m or more, or a width of 0.1 m or more, especially 0.2 m or more, especially 0.3 m or more. or a film having an area of 0.01 m ² or more, especially 0.1 m ² or more, especially 1 m ² or more.

<Uses of this release film>
The present release film can transfer the uneven structure to the adhesive film by, for example, detachably laminating an adhesive film on the uneven layer having the uneven structure.
In addition, the pressure-sensitive adhesive film to which the uneven structure is transferred in this way can improve the release of air when it is attached to an adherend, and can make the uneven structure difficult to see after adhesion.

The present release film can also be provided as a laminate having a structure in which it is laminated with an adhesive film. This laminate may have a configuration in which the uneven structure of the present release film is transferred to the surface of the adhesive film. By forming such a laminate, the release film can play a role of protecting the adhesive film until the adhesive film having the concave-convex structure is used.

The release film may be transparent or opaque (including colored). When used as a laminate in which the adhesive film is transparent, it is also preferred that the release film is opaque. It is preferable that the adhesive film is transparent and the release film is opaque because the difference between the two films can be visually recognized.

The pressure-sensitive adhesive film may have any configuration as long as it has a pressure-sensitive adhesive layer.
For example, the adhesive film may include a sheet substrate having an adhesive layer. At this time, examples of adhesives constituting the adhesive layer include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, polyolefin adhesives, and the like. . However, it is not limited to these.

The thickness of the pressure-sensitive adhesive film is not limited, and can be appropriately selected depending on the application. It is preferable that the lower limit of the thickness of the adhesive film exceeds the maximum height difference of the uneven structure of the release film. The lower limit of the thickness of the adhesive film is more preferably 1 µm or more, still more preferably 5 µm or more, and particularly preferably 10 µm or more. On the other hand, the upper limit of the thickness of the adhesive film is not limited either. It is preferably 3 mm or less, more preferably 2 mm or less, still more preferably 1 mm or less, and particularly preferably 500 μm or less.

The sheet base material constituting the pressure-sensitive adhesive film may be transparent, matte, or opaque. When the sheet base material is transparent, the appearance of the pressure-sensitive adhesive film is more conspicuous. Therefore, it is preferable to optimize the maximum height difference of the unevenness in order to make the uneven structure difficult to see. When the sheet base material is matte or opaque, poor appearance due to the uneven structure is less likely to occur than when the sheet base material is transparent.

<Explanation of terms>
In this specification, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably Y It also includes the meaning of "less than".
In addition, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), "preferably larger than X" or "preferably less than Y" It also includes intent.

In general, "sheet" is defined in JIS as a thin, flat product whose thickness is small relative to its length and width. A thin flat product with an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (Japanese Industrial Standard JIS K6900). However, the boundary between a sheet and a film is not clear, and there is no need to distinguish between the two in the present invention. “Film” shall be included even in cases where

Hereinafter, the present invention will be described in further detail based on the following examples and comparative examples.

[Measurement and evaluation method]
<Mass average molecular weight (Mw)>
The mass average molecular weight (Mw) of each component is a value measured by the GPC method under the following conditions.
Equipment: "HLC-8120GPC" manufactured by Tosoh Corporation
Column: "TSKgel Super H3000 + H4000 + H6000" manufactured by Tosoh Corporation
Detector: Differential refractive index detector (RI detector/built-in)
Solvent: Tetrahydrofuran Temperature: 40°C
Flow rate: 0.5 ml/min Injection volume: 10 μL
Concentration: 0.2% by mass
Calibration sample: Monodisperse polystyrene Calibration method: Polystyrene conversion

<SP value>
The solubility parameters (SP values) of component A, component B and photocrosslinking initiator C were calculated by the method proposed by Fedors et al. Specifically, based on "Basics, Applications and Calculation Methods of SP Values" (Hideki Yamamoto, Information Organization Co., Ltd.), among the methods for estimating the solubility parameters of polymers, each polymer The cohesive energy density of each substituent contained in the component: E (J/mol) and the molar molecular volume: V (cm ³ /mol) are calculated based on the following formula, and the SP value (σ (cal/cm ³ ) ^1/2 ).
σ((J/cm ³ ) ^1/2 )=(ΣEcoh/ΣV) ^1/2
σ(cal/cm ³ ) ^1/2 =σ(J/cm ³ ) ^1/2 /2.0455

<Maximum height difference of unevenness, area ratio of convex portions, number of convex portions, and maximum longest diameter of uneven shape>
Using a surface shape measurement system (“VertScan” (registered trademark) R5500 from Hitachi High-Tech Science Co., Ltd.), the surface unevenness in an area of 703.12 μm × 937.42 μm on the surface of the release film (sample) was measured by optical interference. The data were read after performing correction and baseline correction under the following conditions. Note that the magnification of the objective lens during the measurement was set to 5 times.

(Correction conditions)
Complementary correction: Complete Baseline correction: Surface correction (Polynomial approximation 4th order)

The maximum height difference of the unevenness is the difference between the minimum value of the concave portion and the maximum value of the convex portion around the concave portion, or the difference between the maximum value of the convex portion and the minimum value of the concave portion around the convex portion, from the above measurement data. It was obtained as the height difference of unevenness. Then, the height difference of the unevenness was measured at arbitrary 10 points in the region, and the maximum value among them was taken as the maximum height difference of the unevenness. Note that the difference between the maximum value and the minimum value in the above measurement data is not the maximum height difference of the unevenness.
The area ratio of the convex portions was obtained by binarization using the bearing function and setting both the peak-side height threshold value and the valley-side height threshold value to 0.0 μm to obtain the area ratio of the convex portions.
The number of projections and the maximum longest diameter of the uneven shape were calculated under the following measurement conditions using a particle analysis function. Among the detected longest diameters, the one with the largest value was taken as the maximum longest diameter.

(particle analysis)
・Curved surface correction: No ・Analysis: Projection analysis ・Binary threshold: 100 nm
・Particle molding: No ・Object determination Height base: Curved surface Height: Upper limit 100000 nm, lower limit 0 nm
Maximum diameter: Upper limit 10000 μm, lower limit 0 μm
Volume: Lower limit 0.0 μm ³
Aspect ratio: lower limit 0.0

<Convex Regularity and Continuity of Convex>
Observe the surface of the release film (sample) with the above surface shape measurement system, evaluate whether the shape of the convex portion has a certain regularity or periodicity, and evaluate whether it has regularity or periodicity. If not, the convexity regularity was evaluated as "irregular".
In addition, the surface of the release film (sample) was observed in the same manner as above, and the convex part (white part) was from one edge of the enlarged image to the opposite edge (from the top side to the bottom side, or from the right side to the left side). ) was evaluated as to whether or not they were continuously connected.
If the projections are continuously connected, the projection continuity is set to "Yes". If the projections are scattered or intermittent, and the projections are not connected continuously gender was evaluated as “None”.

<Air release index>
60 parts by weight of dipentaerythritol hexaacrylate, 40 parts by weight of 1,9-nonanediol acrylate, and 2-hydroxy- A photocurable resin composition obtained by mixing 3 parts by mass of 2-methyl-1-phenyl-propan-1-one is applied, and a polyester film is layered thereon, and the photocurable resin is coated with a roller. The composition was uniformly stretched and irradiated with ultraviolet rays from an ultraviolet irradiation device to cure the resin composition and form an adhesive layer. Next, the release film (sample) was peeled off from the polyester film to obtain a replica film in which the uneven structure was transferred to the adhesive layer.

Cut the replica film into a size of 70 mm square, laminate the replica film and a polyester film with a hole of 5 mm in diameter in the center so that the uneven structure surface of the replica film is in contact with the polyester film, and air release index was measured.
The air release index was measured using a digibec smoothness tester (DB-2, manufactured by Toyo Seiki Co., Ltd.) under an atmosphere of 23° C. temperature and 50% RH humidity. At this time, the pressure of the pressure device is 100 kPa, the vacuum vessel is a small vacuum vessel with a volume of 38 ml, and the time for 1 mL of air to flow, that is, the time until the pressure in the vessel changes from 50.7 kPa to 48.0 kPa. (seconds) was measured, and 10 times the obtained number of seconds was taken as the air leakage index.
The smaller the value of this air escape index, the more quickly the air escapes from the gaps, indicating that the shape allows better air escape.

<Appearance>
After coating the acrylic pressure-sensitive adhesive composition on the opposite side of the release film (sample) to the substrate, it was heat-treated at 100° C. for 5 minutes to obtain a pressure-sensitive adhesive layer having a thickness (after drying) of 50 μm.
At this time, as the acrylic adhesive composition, 98.6 parts by mass of BPS5762K (manufactured by Toyochem Co., Ltd., solid content 45.5 mass%) and 1.4 parts by mass of BXX5627 (manufactured by Toyochem Co., Ltd., 50 mass%) were mixed. composition was used.
Thereafter, a base film was further overlaid on the adhesive layer and adhered with a roller to obtain an adhesive film. As the base film used at this time, in the case of a transparent base material, a transparent polyester film (50 μm thick, manufactured by Mitsubishi Chemical Co., Ltd.) is used, and in the case of an opaque base material, a white polyester film (50 μm thick, manufactured by Mitsubishi Chemical Co., Ltd.) is used. board.
Next, the release film was peeled off from the obtained adhesive film, and the adhesive film was adhered to an acrylic plate with a 2-kg rubber roller in one reciprocation motion, and the substrate surface of the adhesive film was observed with the naked eye.
Then, when observed, the case where the unevenness of the adhesive layer could not be recognized on the substrate surface was evaluated as "good", and the unevenness of the adhesive layer could be recognized on the substrate surface, but the unevenness was used as a pattern. Since it is not recognizable and is inconspicuous, it is evaluated as "△ (usual)" when there is no problem in practical use. When there was a problem in practical use, it was evaluated as "x (poor)".

[Example 1]
<Raw material for base material>
Polyester A: chips of polyethylene terephthalate homopolymer (intrinsic viscosity: 0.66 dl/g)
Polyester B: chips of polyethylene terephthalate homopolymer containing 1000 ppm of amorphous silica having an average particle size of 2 µm (intrinsic viscosity: 0.62 dl/g)

<Raw materials for functional layer coating solution>
60 parts by mass of a water-dispersible polycarbonate polyurethane resin (Tg: 35° C.) having a carboxyl group, 30 parts by mass of a polymer-type cross-linking agent in which an oxazoline group is branched to an acrylic resin, and an aqueous silica sol dispersion (average particle size: 0 .07 μm) was mixed to prepare a functional layer coating liquid.

<Raw material for curable coating composition>
Acrylic polymer A1: Modified acrylic acid obtained by copolymerizing glycidyl methacrylate, methyl methacrylate and ethyl acrylate at a molar ratio of 98:1:1 (mass average molecular weight (Mw): 20,000, SP value: 12.6 , Tg: 32°C)
Acrylic polymer B1: copolymer obtained by copolymerizing methyl methacrylate and methyl acrylate at a molar ratio of 99:1 (mass average molecular weight (Mw): 95,000, SP value: 9.9, Tg: 105°C)
Photopolymerizable compound: dipentaerythritol hexaacrylate (mass average molecular weight: 578, SP value: 10.4)
Photocrosslinking initiator C1: Omnirad127 manufactured by IGM Resin
Solvent X: Methyl ethyl ketone (solvent capable of dissolving acrylic polymers A1 and B1, boiling point 80°C)
Solvent Y: Methoxypropanol (a solvent that dissolves the acrylic polymer A1 and does not dissolve B1, and has a boiling point of 120° C.)

(Preparation of base material)
The polyester A is used as a raw material for the intermediate layer, and the polyester B is used as a raw material for the surface layer. The sheet was cooled and solidified on a cooled casting drum to obtain a non-oriented sheet.
It was then stretched 3.5 times at 90° C. in the machine direction (longitudinal direction). After that, the functional layer coating solution is applied so that the thickness after drying is 0.05 μm, and then introduced into a tenter. Further, the film is subjected to a preheating step in the tenter, and then stretched 4.3 times in the horizontal direction at 120° C. , and heat treatment at 230° C. for 2 seconds to obtain a polyester film as a substrate. The thickness of the obtained polyester film was 50 μm, and the thickness structure of functional layer/surface layer/intermediate layer/surface layer was 0.05 μm/5 μm/40 μm/5 μm.

(Formation of uneven layer)
As a coating liquid used for forming the uneven layer, 45 parts by mass of acrylic polymer A1 as component A, 27.5 parts by mass of acrylic polymer B1 as component B, and dipentaerythritol hexa as a photopolymerizable compound. An acrylic polymer mixture containing 27.5 parts by mass of acrylate and 5 parts by mass of photocrosslinking initiator C1 was mixed with methyl ethyl ketone as solvent X and methoxypropanol as solvent Y at a mass ratio of 72:28. was dissolved in the mixed solvent Z obtained above to prepare a curable coating composition having an acrylic polymer mixture concentration of 30% by mass.

On the functional layer surface of the polyester film as the base material, the curable coating composition is applied with a Meyer bar, the solvent X and the solvent Y are volatilized at 70 ° C., and then irradiated with ultraviolet rays with an ultraviolet irradiation device. By curing, a film with an uneven layer was produced by forming an uneven layer having an uneven structure on the surface on one surface side of the substrate.

(Formation of release layer)
As a coating liquid used for the release layer, 100 parts by mass of a curable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., KS-847H) and 1 part by mass of a curing agent (manufactured by Shin-Etsu Chemical Co., Ltd., PL-50T) are added to a methyl ethyl ketone / toluene mixed solvent (mixed A release layer coating solution having a silicone resin concentration of 4% by mass was prepared by diluting at a ratio of 1:1).
The release layer coating liquid is applied to the surface of the uneven layer of the uneven layer-attached film with a Meyer bar, dried and cured by heating to 120° C. to provide a release layer, and the release layer/uneven layer/substrate is formed. A release film 1 (sample) consisting of was produced.

[Example 2]
A release film 2 (sample) was produced in the same manner as in Example 1, except that the number of lines of the Meyer bar was changed to change the thickness of the uneven layer so that the maximum height difference of the convex portions was 8 μm.

[Example 3]
Release film 3 (sample) was prepared in the same manner as in Example 1, except that 3% by mass of a silicone-modified acrylic polymer (GL04R, manufactured by Kyoeisha Chemical Co., Ltd.) was further added to the curable coating composition instead of providing a release layer. was made.

[Example 4]
When preparing the curable coating composition, the acrylic polymer A1, the acrylic polymer B1, and dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4) as a photopolymerizable compound. Methyl ethyl ketone as solvent X and methoxypropanol as solvent Y are mixed at a mass ratio of 63:37 with an acrylic polymer mixture obtained by mixing a mixture ratio of 60:20:20 by mass. A release film 4 (sample) was produced in the same manner as in Example 1, except that it was dissolved in the solvent Z.

[Example 5]
A release film 5 (sample) was produced in the same manner as in Example 1, except that the uneven layer was formed using a curable coating composition prepared as follows.
That is, as the coating liquid used for forming the uneven layer, a graft copolymer B2 (mass average molecular weight (Mw): 16,000, SP value: 10.9) 65 parts by mass, acrylic polymer B1 as component A (mass average molecular weight (Mw): 95,000, SP value: 9.9) 35 parts by mass, and photocrosslinking initiator C (IGM Resin Co., Ominirad 127) 5 parts by mass, methyl isobutyl ketone and methyl ethyl ketone as solvent X, and methoxypropanol as solvent Y in a mass ratio of 28: 26: 46. was dissolved in mixed solvent Z to prepare a curable coating composition having a concentration of the acrylic polymer mixture of 16% by mass.

The graft copolymer B2 having the above acrylic monomer as a backbone polymer comprises methyl methacrylate, stearyl methacrylate, a silicon macromer having a terminal methacryloyl group with a molecular weight of 5,000, and glycidyl methacrylate in a ratio of 10:10:20:60. It was an acrylic acid-modified product obtained by copolymerization at a molar ratio.
Methyl isobutyl ketone and methyl ethyl ketone as solvent X are solvents capable of dissolving graft copolymer B2 and acrylic polymer A1, and the boiling points of methyl isobutyl ketone and methyl ethyl ketone were 116°C and 80°C, respectively.
On the other hand, methoxypropanol as the solvent Y was a solvent capable of dissolving only A1 out of the graft copolymer B2 and the acrylic polymer A1, and its boiling point was 120°C.

[Example 6]
A release film 6 (sample) was produced in the same manner as in Example 5, except that the thickness of the uneven layer was changed by adjusting the Meyer bar so that the maximum height difference was 1 μm.

[Example 7]
A release film 7 (sample) was produced in the same manner as in Example 2, except that a curable coating composition prepared as follows was used and the uneven layer was formed by heating and drying at 50°C.
That is, as the coating liquid used for forming the uneven layer, 50 parts by mass of dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4) as component A, and polypropylene (Idemitsu Kosan Co., Ltd.) as component B manufactured by "S400", mass average molecular weight (Mw): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C.) 50 parts by mass and a photocrosslinking initiator (2-hydroxy-2-methyl- 1-Phenyl-propan-1-one) 3 parts by mass, cyclohexane as solvent X, toluene, and n-butanol as solvent Y in a mass ratio of 49:49:2. A curable coating composition having a mixture concentration of 15% by mass was prepared by dissolving in a solvent (mixed solvent Z).
Cyclohexane and toluene as solvent X were solvents capable of dissolving components A and B, and their boiling points were 81° C. and 111° C., respectively.
On the other hand, methoxypropanol as solvent Y was a solvent capable of dissolving only component A out of components A and B, and its boiling point was 118°C.

[Example 8]
A release film 8 (sample) was produced in the same manner as in Example 7, except that a curable coating composition prepared as follows was used and the uneven layer was formed by heating and drying at 50°C.
That is, as the coating liquid used for forming the uneven layer, urethane acrylate as component A (manufactured by Shin-Nakamura Chemical Co., Ltd., "trade name: U-15HA", mass average molecular weight (Mw): 2205, SP value: 11.2) 50 parts by mass, polypropylene as component B ("S400" manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight (Mn): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C.) 50 parts by mass and light A mixture containing 3 parts by mass of a cross-linking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one) was mixed with cyclohexane as solvent X, toluene and methoxypropanol as solvent Y at 49:49: 2 in a mixed solvent (mixed solvent Z) to prepare a curable coating composition having a mixture concentration of 15% by mass.

[Example 9]
A release film 9 (sample) was produced in the same manner as in Example 7, except that a curable coating composition prepared as follows was used and the uneven layer was formed by heating and drying at 50°C.
That is, as the coating liquid used for forming the uneven layer, 50 parts by mass of acrylic polymer A1 (mass average molecular weight (Mw): 20,000, SP value: 12.6, Tg: 32 ° C.) as component A, component B Hydrogenated terminal acrylate polybutadiene ("TEAI-1000" manufactured by Nippon Soda Co., Ltd., mass average molecular weight (Mw): 2,000 (catalog value), SP value: 9.9, Tg: -14 ° C. (catalog value)) 25 parts by mass, dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4) 25 parts by mass and a photocrosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propane-1 -on) was obtained by blending cyclohexane, toluene and methyl ethyl ketone as solvent X and methoxypropanol and n-butanol as solvent Y in a mass ratio of 6:25:32:31:6. It was dissolved in a mixed solvent to prepare a curable coating composition having a pre-mixture concentration of 15% by weight.

[Example 10]
The curable coating composition prepared as follows was used, and the number of lines of the Meyer bar was changed to change the thickness of the uneven layer to change the maximum height difference of the convex portions to 10.6 μm. A release film 10 (sample) was produced in the same manner.
As a coating liquid used for forming the uneven layer, 70 parts by mass of acrylic polymer A1 as component A, 15 parts by mass of acrylic polymer B1 as component B, and 15 parts by mass of dipentaerythritol hexaacrylate as a photopolymerizable compound. A mixture obtained by mixing an acrylic polymer mixture containing parts by mass and 5 parts by mass of a photocrosslinking initiator C1 with methyl ethyl ketone as a solvent X and methoxypropanol as a solvent Y at a mass ratio of 57:43. It was dissolved in solvent Z to prepare a curable coating composition having an acrylic polymer mixture concentration of 30% by mass.

[Example 11]
A release film 11 (sample) was produced in the same manner as in Example 7 except that a curable coating composition prepared as follows was used and the uneven layer was formed by heating and drying at 50°C.
That is, as the coating liquid used for forming the uneven layer, urethane acrylate as component A (manufactured by Shin-Nakamura Chemical Co., Ltd., "trade name: U-15HA", mass average molecular weight (Mw): 2205, SP value: 11.2) 50 parts by mass, polypropylene as component B ("S400" manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight (Mn): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C.) 50 parts by mass and light A mixture containing 3 parts by mass of a cross-linking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one) was mixed with heptane and toluene as solvent X and butyl acetate as solvent Y at 56:24: A curable coating composition having a mixture concentration of 32% by mass was prepared by dissolving in a mixed solvent (mixed solvent Z) obtained by blending at a mass ratio of 20%.

[Example 12]
A release film 12 (sample) was produced in the same manner as in Example 7 except that a curable coating composition prepared as follows was used and the uneven layer was formed by heating and drying at 50°C.
That is, as the coating liquid used for forming the uneven layer, dendrimer acrylate as component A ("trade name: V#1000" manufactured by Osaka Organic Chemical Industry Co., Ltd., mass average molecular weight (Mw): 1900, SP value: 14.3 ( Turbidity method)) 50 parts by mass, polypropylene as component B ("S400" manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight (Mn): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C.) A mixture containing 50 parts by weight and 3 parts by weight of a photocrosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one) was mixed with heptane and toluene as solvent X and butyl acetate as solvent Y. were dissolved in a mixed solvent (mixed solvent Z) obtained by blending at a mass ratio of 56:24:20 to prepare a curable coating composition having a mixture concentration of 32% by mass.

[Comparative Example 1]
Release film 13 in the same manner as in Example 1 except that a release layer was provided in the same manner as in Example 1 without forming an uneven layer on the surface of the polyester film as the base material used in Example 1. (sample) was produced.

[Comparative Example 2]
A release paper having a paper surface laminated with polyethylene and a silicone release layer provided on the surface of the polyethylene layer, wherein the silicone release layer side surface has a maximum height difference of 8.2 μm, a convex width of 40 μm, and a pitch A release paper having lattice-shaped projections composed of straight lines with a period of 310 μm was used as a release film 14 (sample).

[Comparative Example 3]
A release paper in which polyethylene is laminated on the paper surface and a silicone release layer is provided on the surface of the polyethylene layer, and the silicone release layer side surface has a maximum height difference of 30.2 μm, a convex width of 60 μm, and a pitch A release paper having lattice-shaped projections composed of straight lines with a period of 335 μm was used as a release film 15 (sample).

[Comparative Example 4]
In the method for forming the uneven layer, 5 parts by mass of a silicone-modified acrylic polymer (GL04R, manufactured by Kyoeisha Chemical Co., Ltd.) is further added to the curable coating composition to prepare a curable coating composition having an acrylic polymer mixture concentration of 15% by mass. Then, the release film 16 (sample) was prepared in the same manner as in Example 1, except that the number of lines of the Meyer bar was changed to change the thickness of the uneven layer so that the maximum height difference of the convex portions was 0.4 μm. made.

[Comparative Example 5]
A mixture of 55 parts by mass of p-toluenesulfonic acid (acid catalyst), 15 parts by mass of triethylenediamine and 30 parts by mass of isopropyl alcohol was mixed with a butylated melamine resin so that the amount of the acid catalyst was 0.9 parts by mass. 100 parts by mass (based on non-volatile components) and diluted with a mixed solvent of toluene/methyl ethyl ketone = 6/4 (mass ratio) to prepare a curable coating composition with a non-volatile component concentration of 30% by mass. The prepared curable coating composition was coated on one side of the polyester film as a substrate prepared in Reference Example 1 with a Meyer bar so that the film thickness after drying was 7 μm, and the coating was performed at 150° C. for 5 hours. It was dried for a minute to form a resin layer. The surface of the obtained resin layer was not roughened and unevenness was not formed.
Then, a release layer was provided in the same manner as in Example 1, and a release film 17 (sample) composed of release layer/resin layer/substrate was produced.

(Discussion)
From the results of the above Examples and Comparative Examples and the results of the tests conducted by the present inventors, it was found that a release film having an uneven layer having an uneven structure on the surface on at least one surface side of a substrate had a flat surface. When viewed, if the area ratio of the protrusions to the surface of the uneven structure is 10 to 90% and the maximum height difference of the uneven structure is 0.5 μm or more, the adhesive film to which the uneven structure is transferred. , it was found that air can be released well when the pressure-sensitive adhesive film is attached.
In addition, it has been found that if the convex portions of the uneven structure are formed in an irregular shape when viewed from above, the uneven structure is difficult to see after the adhesive film onto which the uneven structure is transferred is adhered.
Examples 11 and 12 are good examples when high air-releasability is required, but are inferior to other examples for applications requiring good appearance. The appearance evaluation corresponds to the appearance evaluation when using an adhesive film with a transparent polyester film as a base material, but in the appearance evaluation when using an adhesive sheet with an opaque film as a base material, Examples 11 and 12 were also at good levels.

Claims (12)

A release film provided with an uneven layer having an uneven structure on at least one surface side of a substrate, wherein the uneven layer contains two or more types of polymers, and the two or more types of polymers phase A separation structure is formed, and the uneven structure has a configuration in which the convex portions of the uneven structure form an irregular shape when viewed in plan, and the convex portions occupying the surface of the uneven structure are formed. The area ratio of the part is 10 to 90%, the maximum height difference of the uneven structure is 0.5 μm or more, and the convex part in the uneven structure is continuous when viewed in plan. release film. 2. The release film according to claim 1 , wherein at least one of the two or more polymers is a thermoplastic resin and/or a curable resin composition having a crosslinkable structure. 3. The release film according to claim 1, wherein the uneven structure has a different composition for forming the recesses and the composition for forming the projections. In the concavo-convex layer, the SP value (A) of component A, which occupies the largest proportion among the components forming the recesses, is 8 to 21, and the SP value (A) of the component B, which occupies the largest proportion among the components forming the protrusions. (B) is 7 to 20, and the SP value (A) - the SP value (B) = 0.01 to 10 . mold film. In the uneven layer, the mass average molecular weight (Mw) of component A, which accounts for the largest proportion of the components forming the concave portions, is 300 to 300,000, and component B, which accounts for the largest proportion of the components forming the convex portions. The release film according to any one of claims 1 to 4 , wherein the mass average molecular weight (Mw) of is 500 to 400,000. The uneven layer is formed from a coating composition containing two or more types of polymers, oligomers, or monomers, and the coating composition has the SP value (A) of component A, which accounts for the largest proportion of the components that form the recesses. is 8 to 21, the SP value (B) of component B, which occupies the largest proportion of the components forming the convex portion, is 7 to 20, and the SP value (A) - the SP value (B) = 0.01 to 10, the release film according to any one of claims 1 to 4 . The uneven layer is formed from a coating composition containing two or more types of polymers, oligomers or monomers, and the coating composition contains the mass average molecular weight (Mw ) is 300 to 300,000, and the mass-average molecular weight (Mw) of component B, which accounts for the largest proportion of the components forming the protrusions, is 500 to 400,000 . The release film according to any one of . 8. The release film according to any one of claims 1 to 7 , wherein the uneven layer contains a release component having releasability. 9. The release film according to any one of claims 1 to 8 , further comprising a release layer on the surface side of the uneven layer. 10. The release film according to any one of claims 1 to 9 , further comprising a functional layer between the substrate and the uneven layer. A laminate having a configuration in which the release film according to any one of claims 1 to 10 and an adhesive film are laminated. 12. The laminate according to claim 11 , wherein the uneven structure formed on the surface of the release film is transferred to the surface of the adhesive film.

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