JP2019098748A - Release film - Google Patents

Abstract

To provide a release film which can transfer an uneven structure on a surface of an adhesive film, where air is satisfactorily released when sticking the adhesive film having the uneven structure transferred and yet, the uneven structure can be made difficult to see after sticking the adhesive tape.SOLUTION: Provided is a release film which includes an uneven structure having a configuration where, when viewed in a plane view, protruding parts of the uneven structure form irregular shapes, an area ratio of the protruding parts to a surface of the uneven structure is 10 to 90%, a maximum difference of elevation of the uneven structure is 0.5 μm or more, and the protruding parts in the uneven structure is, when viewed in a plane view, continuous.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a release film having a concavo-convex structure on the surface, which is capable of transferring the concavo-convex structure to the surface of a film laminated on the release film.

  For example, decorative films, UV blocking films, blue light blocking films, scratch-resistant films, heat-resistant films, shatterproof films, fingerprints, etc. for building walls and windows, car decorations and windows, mobile phones and personal computer image display parts etc. It has been practiced to attach an adhesive film (referred to as a "functional adhesive film") having various functions, such as a sebum adhesion prevention film.

When such a functional adhesive film is bonded to an adherend surface, air may be taken in to cause air bubbles (air accumulation) between the adherend surface and the functional adhesive film. If air bubbles remain between the functional adhesive film and the adherend, not only the aesthetics are impaired, but also the function of the functional adhesive film may be lowered.
Then, when bonding together a functional adhesive film, in order to prevent such entrapment of air, an unevenness | corrugation is provided in the surface of a functional adhesive film, and the air entrapped between a functional adhesive film and a sticking surface is the exterior. It is devised to make it easy 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. The pressure-sensitive adhesive film having such a concavo-convex shape tends to cause air trapped between the adherend and the pressure-sensitive adhesive film because air taken up when sticking to the adherend easily escapes to the outside through the concavo-convex shape. It becomes difficult to do.

  In Patent Document 2, as a pressure-sensitive adhesive film in which a pressure-sensitive adhesive layer is provided on a sheet substrate and a method for producing the same, the pressure-sensitive adhesive layer is a point-like material formed by phase separation of a pressure-sensitive adhesive from a mixed solvent. At the time of manufacturing, a step of applying a coating solution containing a pressure sensitive adhesive and a mixed solvent consisting of a good solvent and a poor solvent for the pressure sensitive adhesive on a sheet substrate, and evaporating the mixed solvent, the pressure sensitive adhesive And phase separation to form a point-like material.

  Patent Document 3 discloses a pressure-sensitive adhesive film in which a resin layer having tackiness is provided on a base material, and it is disclosed that an irregular-shaped concave portion is self-formed by containing fine particles in the resin layer.

  Further, according to Patent Document 4, by applying and curing a curable material containing a specific alkylated melamine resin as a main component to a substrate, the surface roughening effect is high and random on the surface of the cured film. 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 the irregularities of the pattern. It is done. 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, and the resin layer is formed on the surface of the release agent layer. The mold release film in which the unevenness | corrugation was provided so that the ridgeline which becomes 0.5 micrometers or more of average peak height exists is disclosed.

JP, 2006-70273, A Unexamined-Japanese-Patent No. 2004-277534 WO 2015/152352 JP, 2016-188344, A

  As for the functional adhesive film having a concavo-convex structure on the surface, if the concavo-convex depth of the concavo-convex structure is large, there is an advantage that the air is easily released, but after sticking the adhesive film, the pattern of the concavities and convexities can be seen It had a problem that it could cause damage to the appearance.

  Then, this invention relates to the release film which can transcribe | transfer a concavo-convex structure on the surface of an adhesive film, and the omission of the air at the time of sticking the adhesive film which transcribe | transferred the concavo-convex structure is good. It is intended to propose a new release film that can make the uneven structure inconspicuous after adhesion.

  The present invention is a release film provided with a concavo-convex layer having a concavo-convex structure on the surface on at least one surface side of a substrate, and the concavo-convex structure has a convex portion of the concavo-convex structure when viewed in plan. It has a configuration in which a regular shape is formed, and the area ratio of the convex portion occupying on the surface of the concavo-convex structure is 10 to 90%, and the maximum height difference of the concavo-convex structure is 0.5 μm or more We propose a release film characterized by

  When the mold release film proposed by the present invention is planarly viewed, the area ratio of the convex portion on the surface of the concavo-convex structure is 10 to 90%, and the maximum height difference of the concavo-convex structure is 0.5 μm or more Since it exists, in the adhesive film which transcribe | transferred the said uneven structure, the omission of the air at the time of sticking the said adhesive film can be made favorable. Furthermore, since the projections of the concavo-convex structure in the release film form an irregular shape, the irregular shape is also formed in the concavo-convex structure transferred to the pressure-sensitive adhesive film, and the concavo-convex structure is difficult to see after adhesion. Can.

It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 1 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 2 by VertScan (trademark). It is an enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven layer surface of the release film (sample) produced in Example 3 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 4 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 5 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 6 by VertScan (trademark). It is an enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven layer surface of the release film (sample) produced in Example 7 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 8 by VertScan (trademark). It is the enlarged image (scale: 703.12 micrometers x 937.42 micrometers) which detected the uneven | corrugated layer surface of the release film (sample) produced in Example 9 by VertScan (trademark). It is a scale figure of the enlarged image in the said FIGS. 1-9, and a white part corresponds to a convex part and a black part corresponds to a concave part in the right vertical band.

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

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

  The present release film may be provided with a concavo-convex 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 concavo-convex layer. Also, another layer such as the same layer as the uneven layer may be provided on the side opposite to the uneven layer of the base material, or another layer such as a “peel layer” may be provided outside the uneven layer. You may have.

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

  Examples of the paper base include thin paper, medium paper, high quality paper, impregnated paper, coated paper, art paper, sulfuric acid paper, glassine paper and the like.

Examples of the resin film include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene, polypropylene, polymethylpentene and cyclic polyolefin; polycarbonate, polyvinyl acetate, polysulfone, polyetheretherketone, polyether Examples thereof include resin films containing various resins such as sulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, fluorine resin, polyvinyl chloride, polystyrene, polyurethane and acrylic resin as main components.
The resin film may be a non-oriented film (sheet) or a stretched film. Among them, a stretched film is preferable, and a biaxial stretched film is more preferable. Since the pressure-sensitive adhesive film to which the uneven shape of the present release film is transferred is generally a flexible material, if the substrate is a biaxially stretched film, the rigidity of the present release film becomes high, so the releasability from the pressure-sensitive adhesive film etc. Tend to be good.

As a base material which laminated the above-mentioned paper base material with resin, laminated paper etc. which laminated the above-mentioned paper base material with thermoplastic resins, such as polyethylene, can be mentioned, for example.
Moreover, an aluminum foil etc. can be mentioned as said metal foil.

Among these, the above-mentioned resin film is preferable because no paper dust is generated at the time of cutting (cutting) of the present release film, and no adhesion of paper dust occurs to an adhesive film or the like transferring the concavo-convex structure. From the viewpoints of ease of use, durability, heat resistance, cost and the like, a resin film containing polyester as a main component resin is more preferable, and in particular, a resin film containing polyethylene terephthalate as a main component resin is more preferable.
Here, the "main component resin" means a resin having the largest content among the resins constituting the base material, specifically, 50% by mass or more, 70% by mass or more, 80% by mass or more among them Among these, the resin which occupies 90 mass% or more (100 mass% is included) is said.

  The substrate may have a single-layer structure, or may have a multilayer structure of two or more layers mainly composed of the same or different resins.

  The thickness of the substrate is preferably selected as appropriate depending on the application. In general, the thickness is preferably 5 μm to 500 μm, more preferably 10 μm or more and 300 μm or less, and still more preferably 15 μm or more and 200 μm or less.

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

The shape of the particles is also not particularly limited. For example, it may be spherical, massive, rod-like, flat or the like.
Further, there is no particular limitation on the hardness, specific gravity, color and the like of the particles. These series of particles may be used in combination of two or more as needed.

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

  In addition to the above-mentioned particles, the above-mentioned substrate may, if necessary, be a conventionally known antioxidant, heat stabilizer, lubricant, UV absorber, antistatic agent, softener, crystal nucleating agent, dye, pigment and the like. You may contain.

(Functional layer)
A layer (referred to as a “functional layer”) provided with various functions can be provided as necessary. For example, a functional layer can be provided on one side or both sides of the above-mentioned base material as needed. For example, a functional layer can be provided between the base and the uneven layer. Alternatively, a functional layer can be provided on the opposite surface of the uneven layer to the base material. Furthermore, a functional layer can also be provided on the surface of the uneven layer. When providing the functional layer on the surface of the concavo-convex layer, it is preferable to design the material, thickness and the like so that the concavo-convex structure (described later) formed by the concavo-convex layer is not damaged. For example, the thickness at the time of providing the functional layer on the surface of the uneven layer is usually 1 nm to 5 μm, preferably about 1 nm to 1 μm.
The functional layer may be, for example, an adhesive layer, an antistatic layer, a lubricating layer, a gas barrier layer such as water vapor, a deposition preventing layer of inclusions in a substrate, an ultraviolet absorbing layer, an anti-scratch layer, an antifouling layer, an antibacterial layer, The layer provided with various functions, such as a reflection prevention layer, a gloss layer, a mat | matte layer, an ink receiving layer, a colored layer, a printing layer, can be mentioned.

<Uneven layer>
The concavo-convex layer is preferably a layer provided on its surface with a concavo-convex structure having a convex portion and a portion other than the convex portion (referred to as a “concave portion”).

It is preferable that the uneven structure has a configuration in which the convex portion forms an irregular shape when the surface is viewed in plan. In addition, in FIGS. 1-9, a white part corresponds to a convex part.
Here, "irregular shape" means a shape that does not have a certain regularity and periodicity. In other words, like the shape formed only by straight lines, the shape formed by curves of the same pattern, the shape transferred by emboss roll, and the shape combining these, the same shape (pattern) is repeated at regular intervals It can be said that the shape other than the shape that is used is "irregular shape". Moreover, the irregularity in the present invention not only means irregularity in the pattern itself, but also irregularity in the size of elements constituting the shape (for example, irregularity in the size of the polka dots in the polka-dot pattern) And irregularities in the arrangement of elements that make up the shape (eg, irregularities in the arrangement of polka dots in a polka-dot pattern) and the like.
As the irregular shape, typically, a shape with a sea-island structure formed spontaneously when mixing an incompatible polymer or the like as shown in FIGS. It is possible to cite a shape in which projections having irregular shapes are present irregularly. However, it is not limited to such a shape.
By forming the irregular shape on the surface of the mold release film as described above, the irregular shape is formed even in the concavo-convex structure transferred to the adhesive film, and the concavo-convex structure is hardly visible after adhesion. can do.
A specific method for forming such a concavo-convex structure will be described later.

The uneven structure has a configuration in which an irregular shape is continuously formed in the circumferential direction, for example, up and down, left and right direction, with an irregular pattern, for example, a mesh pattern, when the surface is planarly viewed. It may be
When the irregular shape is continuous in the circumferential direction, it is preferable that the size or shape of the irregular shape is not constant, the shape not be repeated, and the arrangement of the irregular shape is also irregular. Is preferred.

Further, the convex portions in the concavo-convex structure may be appropriately scattered as a block having an area, may be present intermittently, or may be continuously connected when viewed in a plan view.
Under the present circumstances, let the diameter of the largest value among the diameters of the center of X coordinates of each convex part and the center of Y coordinates be "the longest diameter", and the diameter which shows the largest value in a measurement field among the said longest diameters "Maximum maximum diameter"
The maximum longest diameter of the convex portion makes it possible to make the air escape well when sticking the pressure-sensitive adhesive film to which the concavo-convex shape has been transferred, and from the viewpoint of making the concavo-convex structure inconspicuous after adhesion. The thickness is preferably 1 μm to 1500 μm, more preferably 10 μm or more and 1200 μm or less, among them 100 μm or more and 1000 μm or less, and still more preferably 300 μm or more and 800 μm or less.

Moreover, the convex part in the said uneven structure may be continuous, and it may be exhibiting the linear form which continued the length suitably suitably, when it planarly views.
From the viewpoint of making air leakage more favorable when sticking the pressure-sensitive adhesive film to which the concavo-convex structure has been transferred, in particular, it is preferable that the film peripheral edge portion be continuous. More specifically, in an image obtained by measuring the surface of the concavo-convex structure of the release film surface by light interference method, an image area of 703.13 μm × 937.42 μm of the release film surface (equivalent to a 5 × objective lens) In the above, it is preferable that the convex portion is connected from the edge of the image area to the corresponding edge, for example, from the upper side to the lower side or from the left side to the right side. More preferably, in a 5 mm × 5 mm square, particularly preferably a 30 mm × 30 mm square, and most preferably a 100 mm × 100 mm square, it is preferable that the projections be connected from the edge to the corresponding edge.
In the pressure-sensitive adhesive film or the like to which the convex / concave structure has been transferred by the main mold release film, the convex portions in the concave / convex structure form a concave portion. In the adhesive film etc., the escape route of air will also be continuous. However, in this case, there may be a discontinuous portion in part of the convex portion.
As an example, the case where the irregular shape is continuously forming a mesh pattern by the convex part continuing to the film peripheral edge part can be mentioned as an example.

In addition, since the convex part of the uneven structure disclosed by the prior patent document 4 (Unexamined-Japanese-Patent No. 2016-188344) mentioned above is not continuous as mentioned above, the convex part is continuous as mentioned above. Then, the air can be more preferably released.
Moreover, the prior patent document 2 (Unexamined-Japanese-Patent No. 2004-277534) similarly previously described has disclosed the aspect which the adhesive layer of an adhesive film has an unevenness | corrugation, and forms the convex part thru | or uneven structure which were temporarily continued in this aspect. However, when the pressure-sensitive adhesive film is stacked or formed into a roll, since the unevenness may be crushed or blocked, the pressure-sensitive adhesive that can be used is considerably limited, which is not realistic.

The number of convex portions present in the concavo-convex structure makes it possible to make the air escape well when sticking the adhesive film to which the concavo-convex shape has been transferred, and can make the concavo-convex structure difficult to see after adhesion. From the viewpoint of this, the number is preferably 1 to 1000 per area of 703.12 μm × 937.42 μm, particularly 500 or less, preferably 100 or less, and more preferably 10 or less.
In addition, the said number of convex parts which exist in the said uneven structure can be calculated | required by counting the number of convex parts which appear on the release film surface in unit area, for example using image analysis software.

It is preferable that the lower limit of the area ratio of the convex part occupied to the surface is 10% or more, when the said uneven | corrugated structure planarly views the surface. If the area ratio occupied by the convex portions is 10% or more, the air release tends to be good.
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, for the same reason as described above.
On the other hand, it is preferable that the upper limit of the area ratio of the convex part in this release film is 90% or less. If the area ratio which a convex part occupies is 90% or less, when forming an adhesive film, it is preferable in order to maintain adhesiveness.
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, most preferably 70% or less, for the same reason as described above.
Among them, if the area ratio of the convex portion is in the range of 10 to 50%, the uneven structure of the release film becomes difficult to be seen when the pressure-sensitive adhesive film is attached, and a good appearance can be obtained. Moreover, if the area ratio of a convex part is 50 to 90% of range, since the omission of the air at the time of sticking an adhesive film can be made favorable, it is further more preferable.

The area ratio of the convex portion to the concave and convex structure can be analyzed by binarizing the surface of the concave and convex structure into two regions of the concave portion and the convex portion by image analysis.
When the surface of the concavo-convex structure is binarized into two regions of concave and convex portions by image analysis in this manner, the entire surface of the concavo-convex structure may be binarized, or the surface of the concavo-convex structure may be binarized. It may be divided into a plurality of places, binarized at each place, and the average thereof may be obtained. In that case, it is preferable to find an average of at least three places, at least five places, and at least 10 places.

  In the said uneven structure, the method mentioned later is mentioned as a method of enlarging the area of a convex part. For example, it can adjust by increasing the compounding quantity of the component B which makes the main component of a convex part, or enlarging the molecular weight of this component B. However, it is not limited to such a method.

Moreover, it is preferable that the minimum of the maximum height difference of the unevenness | corrugation in the said uneven structure is 0.5 micrometer or more. If the maximum height difference of the asperities is 0.5 μm or more, there is a tendency for the air to be well released when the pressure-sensitive adhesive film to which the asperity structure has been transferred is attached.
For the same reason as above, the lower limit of the maximum height difference of the irregularities in the concavo-convex structure is preferably 1.0 μm or more, more preferably 1.5 μm or more, still more preferably 2.0 μm or more, 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 unevenness structure tends to be difficult to see after sticking to the adhesive film.
For the same reason as above, the upper limit of the maximum height difference of the irregularities in the concavo-convex 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, most preferably 15 μm or less .
Above all, when the maximum height difference of the concavities and convexities of the concavo-convex structure is 0.5 to 15 μm, not only sufficient air leakage can be obtained, but also when using a pressure-sensitive adhesive film in which the substrate is transparent, the concavo-convex structure after sticking Can be particularly obscured. In addition, when the maximum height difference of the concavities and convexities of the concavo-convex structure is 15 to 40 μm, the concavo-convex structure after sticking when using a pressure-sensitive adhesive film not only having excellent air escapeability but having a matte tone or opaque substrate Can be obscured.

In addition, the maximum height difference of unevenness | corrugation can be adjusted by adjusting the application | coating thickness at the time of forming an uneven | corrugated layer, for example. However, it is not limited to this.
In addition, the maximum height difference of the unevenness may be determined as the maximum value between 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. it can.
A specific method for forming the maximum height difference of such unevenness will be described later.

<Material to form an uneven layer>
The uneven | corrugated layer in this release film does not limit the material to form.
The uneven layer preferably contains two or more types of polymers, oligomers or monomers (these are collectively referred to as "polymer etc."), and is formed from a coating composition containing two or more types of polymers etc. preferable.
Under the present circumstances, the aspect which forms an uneven | corrugated layer using the phase-separating property between different polymers etc. as mentioned later is preferable. That is, in the uneven layer, it is preferable that two or more types of polymers and the like form a phase separation structure.
In the present invention, the term "polymer" is intended to encompass a cured product of a curable resin composition. Moreover, a monomer is taken as the concept including the monomer as a raw material of superposition | polymerization or a crosslinking reaction, or a raw material of curable resin composition.

  In the said uneven structure, the example which mutually differs in the composition which forms a recessed part, and the composition which forms a convex part can be mentioned. For example, when the component occupying a large proportion of the components forming the concave portion is the component A, and the component occupying a large proportion of the components forming the convex portion is the component B, the components A and B and Can give different examples.

(Component A)
The component A which occupies the most of the components forming the recess is incompatible with the component B, and the solubility parameter (SP (A)) is 8 from the viewpoint of mainly forming the recess and recess after the coating. It is preferably -21, more preferably 10 or more or 20 or less, and still more preferably 12 or more or 19 or less.
Further, from the viewpoint of making the coating property of the coating solution good, it is preferable that the mass average molecular weight (Mw) of the component A is a polymer etc. of 300 to 300,000, among which 2,000 More preferably, it is 200,000 or less, and more preferably 5,000 or 100,000 or less.

  Examples of the component A include acrylic polymers such as poly (meth) acrylate, polyesters, polyurethanes, polyolefins, polyethers, polystyrenes, polycarbonates, polyacrylonitriles, polyamides, polyimides and the like. Among them, poly (meth) acrylates are preferable from the viewpoint of easy adjustment of molecular weight and SP value and easy control of the concavo-convex shape. One of these components A may be used alone, or two or more thereof may be used in combination.

  For example, when the component A is an acrylic polymer or the like, in order to increase its SP value, for example, the side chain of the resin of the acrylic polymer may be designed to include many functional groups with high polarity. Specifically, for example, a homopolymer or copolymer containing a structural unit such as hydroxy (meth) acrylate having a hydroxyl group, (meth) acrylic acid having a carboxyl group, glycidyl (meth) acrylate having a glycidyl group, etc. It can be mentioned.

(Component B)
On the other hand, the component B which occupies the largest portion among the components forming the convex portion is incompatible with the component A, and the solubility parameter of the component B (from the viewpoint of mainly forming the convex portion with an uneven shape after coating) SP (B) is preferably 7 to 20, more preferably 8 or more and 18 or less, and still more preferably 9 or more or 17 or less.

The solubility parameter (SP (B)) of component B is preferably 0.01 to 10 lower than the solubility parameter (SP (A)) of component A, and more preferably 0.05 or less or 7 or less. The lower one is preferably in the range of 0.1 or more or 4 or less.
In addition, when this mold release film forms uneven structure using phase separation between different polymers etc., the solubility parameter (SP (B)) of component B is the solubility parameter (SP (component (A)) of component A. It may be 0.01 to 10 higher than A).
When the concavo-convex layer is formed of three or more types of polymers, and at least one of the component A and the component B is formed of two or more types of polymers, the above-mentioned relationship is possessed in any combination thereof. Just do it. The same applies to the mass average molecular weight described next.

In addition, from the viewpoint of setting the coating property of the coating solution to be good, the mass average molecular weight (Mw) of the component B is preferably 500 to 400,000, and in particular 2,000 or more It is more preferable that it is 300,000 or less, and more preferably 10,000 or more or 250,000 or less.
The mass average molecular weight (Mw) of the component B is more preferably 1000 or more larger than the mass average molecular weight (Mw) of the component A.

  Component B mainly forming the convex portion can sufficiently withstand the drying temperature when forming the concavo-convex structure, and from the viewpoint of maintaining the shape, the glass transition temperature of component B is preferably 40 ° C. or higher It is more preferable that the temperature is 50 ° C. or more, and more preferably 60 ° C. or more.

  Component B includes, for example, acrylic polymers such as poly (meth) acrylate, polyesters, polyurethanes, polyolefins, polyethers, polystyrenes, polycarbonates, polyacrylonitriles, polyamides, polyimides, etc. Among them, poly (meth) acrylates are preferable from the viewpoint of easy adjustment of molecular weight and SP value and easy control of the concavo-convex shape. One of these components B may be used alone, or two or more thereof may be used in combination.

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

In addition, the said solubility parameter (SP value) is Solubility Parameter, and becomes a scale of solubility. The solubility parameter indicates that the higher the value, the higher the polarity, and the smaller the value, the lower the polarity.
The SP value can be measured by methods such as the turbidity method and the Fedors estimation method.

In the above-mentioned concavo-convex layer, in order to maintain the shape, in particular, the convex portions among all the concave portions and the convex portions are preferably crosslinked from the viewpoint of enhancing the heat resistance and the solvent resistance, that is, have a crosslinked structure.
It is preferable to determine whether or not crosslinking has occurred by measuring the gel fraction at each site and confirming that the value is greater than 0%, particularly 5% or more, and more preferably 10% or more.

At this time, at least one of the two or more types of polymers, etc. is a thermoplastic resin having a crosslinkable structure, or a curable resin composition, or a curable resin having a crosslinkable structure. Preferably it is a composition. In these cases, by crosslinking or curing the uneven layer, the uneven layer contains a cured product, and the heat resistance and the solvent resistance can be enhanced.
Here, the said hardened | cured material means the thing in which the said thermoplastic resin or curable resin composition which has a crosslinkable structure hardened | cured.
In addition, a crosslinkable structure means the structure which has the property to bridge | crosslink, and a crosslinked structure means the structure formed by bridge | crosslinking.

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

  Examples of the curable resin composition may include, for example, a two-component curable resin composition, a room temperature curable resin composition, a photocurable resin composition, a thermosetting resin composition, etc., among which light energy or thermal energy is given. A photocurable resin composition or a thermosetting resin composition is preferred, in which the composition reacts and cures (crosslinks).

  The cured product of the curable resin composition may constitute the component A or the component B itself, or the curable resin composition may be used as a component other than the component A and the component B which form the uneven layer. . When component A or component B itself is a curable resin composition, a monomer constituting these components is used as a raw material of the concavo-convex layer, and a concavo-convex structure is formed by setting it as component A or component B by curing reaction. be able to.

Examples of the photocurable or thermosetting resin composition include a photocrosslinkable compound, a photocurable composition containing a photocrosslinking initiator, a thermosetting resin composition, and the like.
As a photocrosslinkable compound, the compound which has a crosslinkable unsaturated bond, specifically, the monomer or oligomer which has an ethylenically unsaturated bond can be mentioned.
As a photocrosslinking initiator, when applying ultraviolet irradiation as an active energy ray, photocrosslinking initiators, such as benzoin type, acetophenone type, thioxanthone type, phosphine oxide type and peroxide type, can be used, for example.
As a thermosetting resin, a urethane resin, a urea resin, a melamine resin, an acrylic resin, a transparent polyimide precursor varnish etc. can be mentioned, for example.

In summary, the method of forming the uneven layer to which two or more types of polymers contribute is classified into, for example, the following formation examples. However, it is not limited to these combinations. Also, the following description does not exclude the inclusion of additional optional components other than Component A and Component B.
(A) An uneven layer is formed by two or more types of thermoplastic polymers.
(B) An uneven layer is formed by using two or more types of thermoplastic polymers and a crosslinking agent as raw materials and curing the crosslinking agent.
(C) Of the two or more thermoplastic polymers, at least one thermoplastic polymer has a crosslinkable structure, and the uneven layer is formed by crosslinking the crosslinkable structure.
(D) At least one thermoplastic polymer of two or more thermoplastic polymers has a crosslinkable structure, and a crosslinker-containing raw material further contains a crosslinkable structure and a crosslinker The uneven layer is formed by cross-linking and curing.
(E) An uneven layer is formed by polymerizing and curing a polymerizable monomer and a crosslinking agent, using as raw materials one or more types of thermoplastic polymers, a polymerizable monomer and a crosslinking agent.
(F) For a raw material having a crosslinkable structure in at least one or more polymers and further containing a polymerizable monomer and a crosslinking agent, polymerization between the crosslinkable structure, the polymerizable monomer and the crosslinking agent Form an uneven layer by crosslinking and curing.
(G) At least two or more of the above (a) to (f) are used in combination.

(Peeling component)
The said uneven layer may contain the peeling component which has peelability.

When the polymer etc. which form the said uneven structure have peelability, this polymer etc. become a peeling component. Moreover, when the component which has peelability as an additive is added, this additive turns into a peeling component.
As a component which has peelability, compounds other than a silicone type compound specifically, for example, a fluorine compound, an olefin compound, a long chain alkyl group containing compound, etc. are mentioned. These may be polymers, etc., or low molecular weight compounds, and a layer containing one or more of these is preferable.

  The content of the peeling component in the concavo-convex layer is preferably 0.5% by mass to 90% by mass, and more preferably 1.0% by mass or more or 85% by mass or less, among them 2.0% by mass or more or 80% by mass It is preferable that it is% or less.

(Other ingredients)
The concavo-convex layer may contain components other than the components A and B and the mold release component described above as needed. Specifically, antifoaming agents, coatability improvers, thickeners, organic lubricants, organic particles, inorganic particles, antioxidants, ultraviolet absorbers, infrared absorbers, light blocking agents, foaming agents, coloring agents And the like.

<Peeling layer>
The peelability can be enhanced by further laminating a peel layer on the surface of the uneven layer.
However, it is not always necessary to provide a release layer on the outer surface of the uneven layer. If the releasability is sufficient, for example, when the uneven layer contains the release component, it is not necessary to further provide the release layer. On the other hand, even if the uneven layer contains the peeling component, if the peelability is not sufficient, a peeling layer may be further laminated on the surface of the uneven layer.

The release layer is, for example, one or two of release agents such as silicone resin release agents, alkyd resin types, olefin resin types, acrylic types, long chain alkyl group-containing compound types, rubber type non-silicone resin types, etc. It is preferred to contain more than species.
Each of the release agents 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, the thickness 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 in the above range, the function as the release surface can be sufficiently exhibited, and the uneven shape can be maintained.

As the silicone resin-based release agent, there are solvent type and non-solvent type. The solvent type silicone resin can be widely used from high molecular weight (that is, high viscosity) polymers to low viscosity low molecular weight polymers (oligomers) because the solvent dilution is carried out to make a coating liquid. Therefore, as compared with the non-solvent type, the control of the releasability is easy, and it is easy to design according to the required performance (quality).
Further, as silicone resin release agents, there are addition reaction type, condensation reaction type, ultraviolet ray curing type, electron beam curing type and the like.
Among these, the addition reaction type silicone resin has high reactivity, is excellent in productivity, and has merits such as a small change in peel force after production and no curing shrinkage as compared with the condensation reaction type. It is preferable to use for the release agent to form.

There is no restriction | limiting in particular as said addition reaction type silicone resin, A various thing can be used. For example, those conventionally used as conventional thermosetting addition reaction type silicone resin release agents can be used. As this addition reaction type silicone resin, for example, those having an alkenyl group such as a vinyl group or the like and an electrophilic group such as a hydrosilyl group as a functional group in the molecule are mentioned as the addition reaction type silicone resin which can be easily cured. It is possible to use polydimethylsiloxane having such functional groups, and those obtained by substituting part or all of methyl groups of polydimethylsiloxane with aromatic functional groups such as phenyl group.
If necessary, silica, silicone resin, antistatic agent, dye, pigment and other additives may be added to the silicone resin release agent.

  A crystalline olefin resin can be used as the olefin resin release agent. As this crystalline olefin resin, polyethylene, a crystalline polypropylene resin, etc. 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 structure or syndiotactic structure, and propylene-α-olefin copolymers. One of these crystalline olefin resins may be used alone, or two or more thereof may be used in combination.

As the acrylic release agent, an acrylic resin having a crosslinked structure can generally 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.
As the long-chain alkyl group-containing compound release agent, for example, polyvinyl carbamate obtained by reacting a polyvinyl alcohol-based polymer with a long-chain alkyl isocyanate having 8 to 30 carbon atoms or polyethylene imine having 8 to 30 carbon atoms The alkyl urea derivative etc. which were obtained by making long-chain alkyl isocyanate of this react, etc. can be used.

  As the rubber release agent, for example, natural rubber resins and synthetic rubber resins such as butadiene rubber, isoprene rubber, styrene-butadiene rubber, methyl methacrylate-butadiene rubber, acrylonitrile-butadiene rubber and the like can be used.

<Laminated structure of this release film>
As a lamination structure of this release film, a base material / uneven layer, a base material / uneven layer / peeling layer, a functional layer / base material / uneven layer, a base material / functional layer / uneven layer, a functional layer / base material, for example / Functional layer / concave / convex layer, functional layer / substrate / corrugated layer / peeling layer, substrate / functional layer / concave / convex layer / peeling layer, functional layer / substrate / functional layer / concave / convex layer / peeling layer It can be mentioned. However, the present invention is not limited to these laminated structures, and other layers can be appropriately added and laminated.

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

The present release film can be produced by providing an uneven layer on a substrate. Under the present circumstances, the method of providing an uneven | corrugated layer is not limited. For example, methods such as physical cutting, cutting by laser irradiation, transfer by mold, etc., photo masking used for resist materials, 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 using phase separation between different polymers and the like is preferable.
By utilizing the phase separation between different polymers, etc., a concavo-convex structure based on a phase separation structure on the order of several μm to several mm is formed, so the adhesive film to which this concavo-convex structure has been transferred has good adhesiveness. It becomes possible to make it hard to visually recognize a concavo-convex structure after pasting. In addition, if phase separation between different polymers etc. is used, the irregularity and continuity of the convex shape of the concavo-convex structure and the area ratio of convex parts by the selection of the polymer etc used and the optimization of the blending ratio etc. Since it is possible to control the maximum height difference and the like of the concavo-convex structure, it is preferable as one of the specific means for achieving the present invention.

  When forming an uneven | corrugated layer using phase separation property between different polymers etc., as long as 2 or more types of polymers etc. are used, the specific method is not limited. Specifically, the following aspects (1) to (5) can be mentioned. Also, a plurality of these methods may be combined.

(1) Using two or more thermoplastic resins (polymers), 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 solidification from the molten state How to form a structure.
(2) A method in which a thermoplastic resin and a curable resin composition are mixed and phase separation is performed by eliminating the thermoplastic polymer in the curing process of the curable resin composition to form an uneven structure.
(3) A curable resin composition is compounded, and in the curing process of 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 a concavo-convex structure by forming a protrusion.
(4) A method of fixing at least one thermoplastic resin in (1) above to have a crosslinkable structure and performing a crosslinking reaction after forming an uneven structure by phase separation to fix the uneven structure.
(5) In the above (1), the curable resin composition is mixed with two or more thermoplastic resins, and after the uneven structure is formed by phase separation of the thermoplastic resin, the curable resin composition is cured. To fix the uneven structure by

  In addition, when using a method that causes phase separation in the process of distilling off the solvent from the state of being dissolved in the solvent, as described later, it is used by mixing two or more solvents and using the difference in solubility of polymers etc. The method of forming a concavo-convex structure is preferable. If this method is adopted, it is possible to form a target uneven structure simply by selecting a specific polymer and the like and a specific solvent. Therefore, the object of the present invention can be easily achieved without using a cutting apparatus, a mold or the like.

Hereinafter, among various aspects mentioned above, the case where a photocurable resin composition is used is concretely explained to the example of the mode of (5).
A mixed resin of the component A, the component B and, if necessary, the crosslinking initiator C is a solvent which is a good solvent for a predetermined mixed solvent Z, for example, the component A, the component B and the crosslinking initiator C X and a solvent Y which is a good solvent for the component A and the crosslinking initiator C (that is, a cosolvent for these), a poor solvent for the component B, and having a boiling point higher than the solvent X The mixed solvent Z is added and dissolved to prepare a curable coating composition, and the curable coating composition is applied to the surface of the substrate. In the process of drying the mixed solvent Z, the solvent X is relatively quickly volatilized and the proportion occupied by the solvent Y is increased, so that the component B which is difficult to dissolve in the solvent Y is precipitated to form a convex portion. By further drying, a concave part is formed by the component A to form a concavo-convex structure. Alternatively, the concavo-convex structure may be formed by exciting and curing the crosslinking initiator C by light irradiation, for example.
According to such a preparation method, it is possible to form a concavo-convex structure provided with projections having irregular shapes, and further, selection of materials of component A, component B, crosslinking initiator C, solvents X and Y The size of the unevenness can be controlled by adjusting the amount blended.
However, it is not limited to such a manufacturing method.
The crosslinking initiator C is not necessarily required to be blended. The mixed solvent Z is preferably miscible with the solvent X and the solvent Y. However, they do not necessarily have to be uniformly mixed, and may be suspensions.

  In the above preparation method, as the principle of forming the concavo-convex layer, in the process of drying the curable coating composition after application, the environment in the solvent is changed as the mixed solvent Z decreases, The components A and B that are incompatible with each other are phase separated, and the components dissolved in both solvents are dissolved in the solvent until further drying proceeds. It is presumed that the component A which forms a part and which is dissolved in both solvents mainly forms a recess, and a concavo-convex structure is formed spontaneously.

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

(Component A, B)
It is preferable that the component A which occupies most among the components which form a recessed part is a polymer etc. which have predetermined | prescribed mass mean molecular weight (Mw) and predetermined | prescribed SP value as mentioned above.
On the other hand, it is preferable that the component B which occupies most among the components which form a convex part is a polymer etc. which have predetermined | prescribed mass mean molecular weight (Mw) and predetermined | prescribed SP value as mentioned above.
For example, the area of the projections in the concavo-convex structure may be increased, or the shape of the projections may be changed, by increasing the content of the component B which is the main component of the projections or increasing the molecular weight of the component B. can do. Further, by controlling the crystallinity of the component B, it is possible to adjust the maximum value of the convex portion, that is, the maximum height difference of the unevenness. However, it is not limited to such a method.

The blending mass ratio of the component A and the component B is preferably 1:99 to 99: 1, and more preferably 5:95 to 95: 5, and 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, it is set as the mass ratio which totaled 2 or more types of components, respectively.
As one of the control factors for setting the area ratio of the convex portion in the concavo-convex structure to the above range, a method of optimizing the blending mass ratio of the component A and the component B can be mentioned. In addition, since a convex part and a recessed part are not necessarily comprised only with the component B and the component A, said compounding mass ratio and the area ratio of a convex part are not synonymous.

(Crosslinking initiator C)
As the crosslinking initiator C, a photocrosslinking initiator, a thermal crosslinking initiator, etc. can be mentioned. Among them, a curing system having fast curing is preferable from the viewpoint of holding the uneven shape formed in the drying step, and a photocrosslinking initiator is preferable from such a viewpoint.

  As a photocrosslinking initiator, for example, 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-diphenylethane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 Etc. can be mentioned. These crosslinking initiators may be used alone or in combination of two or more. Among them, UV-curable polyfunctional acrylates are preferred.

  The compounding amount of the crosslinking initiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the components A and B, and more preferably 0.1 parts by mass or more and 10 parts by mass or less, among them 1 It is more preferable to set it as the mass part or more.

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

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

  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; toluene, xylene, solvent naphtha, hexane, cyclohexane, ethylcyclohexane, Le cyclohexane, heptane, may be mentioned octane, organic solvents such as hydrocarbon solvents 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 crosslinking initiator C and a poor solvent for the component B. That is, Component A and the crosslinking initiator C can be dissolved, but a solvent having low solubility in Component B is preferable. In this case, the low solubility of the component B includes the case where the component B is classified as insoluble or swelling.

The boiling point of the solvent Y is preferably 51 ° C. to 201 ° C., and more preferably 61 ° C. or more or 141 ° C. or less, and particularly 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 earlier than the solvent Y, and it is preferably 1 to 80 ° C. in particular, and 2 ° C. among them. As described above, it is more preferable that the temperature be 5 ° C. or higher.
When the solvent Y has a boiling point higher than that of the solvent X, the solvent X is volatilized prior to the solvent Y, and the component B which is difficult to dissolve in the solvent Y precipitates to easily form a convex portion mainly.

In addition, the said solvent X and solvent Y which are used can be selected by the difference in a boiling point. However, it can also be selected by the difference of other characteristics. Specific properties include relative evaporation rates, vapor pressure at a given temperature and pressure, affinity of component A or component B.
For example, from the same viewpoint, that is, from the viewpoint that the solvent X can be volatilized before the solvent Y, the relative evaporation rate of the solvent X is preferably higher than the relative evaporation rate of the solvent Y. Among them, the relative evaporation rate of the solvent X is preferably 1 or more, or preferably not less than the relative evaporation rate of butyl acetate, and the relative evaporation rate of the solvent Y is less than 1 or butyl acetate Preferably it is 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. under atmospheric pressure is defined as 1. For example, as relative evaporation rates of various solvents, 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; methyl acetate, ethyl acetate, butyl acetate, methoxybutyl acetate, amyl acetate, propyl acetate, ethyl acetate, ethyl lactate, methyl lactate, butyl lactate and other ester solvents; toluene, Carbonized water such as xylene, solvent naphtha, hexane, cyclohexane, ethylcyclohexane, methylcyclohexane, heptane, octane and decane There can be mentioned organic solvents and water. These solvents may be used alone or in combination of two or more.

(Mixed solvent Z)
The mixed solvent Z preferably contains the solvent X and the solvent Y in a mass ratio of 0.1: 99.9 to 99.9: 0.1, and in particular 1:99 to 99: 1, and in particular 10:90. It is more preferable to contain by a mass ratio of -90: 10, in particular 15:85 to 85:15, and in that 80:20 to 20:80. In addition, when the solvent X or the solvent Y consists of 2 or more types of solvent, it is set as the mass ratio which each 2 or more types of solvent was totaled.

(Application of a curable coating composition)
As a method of apply | coating the said curable coating composition on the surface of a base material, well-known and usual methods, such as a kiss roll coater, a bead coater, a rod coater, a Mayer bar coater, a die coater, a gravure coater, are employable, for example.

(Dried)
The drying temperature after application is preferably set to 10 ° C. to 150 ° C. in view of the relationship with the boiling points of the solvents X and Y in order to volatize the solvent X prior to the solvent Y after application and volatilize. It is more preferable to set at 20 ° C. or more or 140 ° C. or less, and it is more preferable to set at 40 ° C. or more or 125 ° C. or less. In addition, you may make it dry at normal temperature.
By adjusting the heating (drying) temperature, the maximum height difference of the unevenness can be adjusted, and as the drying temperature is lower, the maximum height difference of the unevenness tends to be larger. In general, the solvent has volatility at a temperature lower than the boiling point, and the volatility property changes depending not only on the boiling point but also on the vapor pressure characteristics, the affinity with a polymer, and the like. Therefore, the drying temperature may be set according to the type and blending mass ratio of the polymer and the like used in the concavo-convex layer, the shape of the intended concavo-convex structure, and the like.

<Form of this mold release film>
As the form of the present release film, any form known at present can be adopted. Among them, a form having a large area in consideration of the characteristics of the present release film, for example, the good release of air when sticking the pressure-sensitive adhesive film, and the fact that the uneven structure can not be seen easily after adhesion. Is preferred. From this point of view, the film or roll body is, for example, 0.1 m or more in length, 1 m or more in length, 10 m or more in roll body, or 0.1 m or more in width, 0.2 m or more in particular, 0.3 m or more in it A preferred example of the film is a roll body or a film having an area of 0.01 m ² or more, in particular 0.1 m ² or more, and more preferably 1 m ² or more.

<Use of this release film>
The present release film can transfer the uneven structure to the pressure-sensitive adhesive film, for example, by laminating an adhesive film in a peelable manner on the uneven layer having the uneven structure.
And when sticking on a to-be-adhered body, the adhesive film which transferred the uneven | corrugated structure in this way can make the omission of air favorable, and can make the said uneven | corrugated structure inconspicuous after adhesion.

  The present release film can also be provided as a laminate having a configuration obtained by laminating with an adhesive film. The laminate may have a configuration in which the uneven structure of the present release film is transferred to the surface of the pressure-sensitive adhesive film. By setting it as such a laminated body, the present release film can have a role which protects an adhesive film between the folds which use the adhesive film which has uneven structure.

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

If the said adhesive film is equipped with the adhesive layer, the structure is arbitrary.
For example, as the pressure-sensitive adhesive film, a sheet substrate provided with a pressure-sensitive adhesive layer can be mentioned. Under the present circumstances, as an adhesive which comprises an adhesive layer, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a polyester adhesive, a urethane adhesive, a polyolefin adhesive etc. can be mentioned, for example. . However, it is not limited to these.

  The thickness of the pressure-sensitive adhesive film is not limited, and can be appropriately selected according to the application. It is preferable that the lower limit of the thickness of the adhesive film exceeds the maximum height difference of the concavo-convex structure of the present release film. The lower limit of the thickness of the pressure-sensitive 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 also not limited. 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 substrate constituting the pressure-sensitive adhesive film may be transparent, matt or opaque. When the sheet substrate is transparent, the appearance of the pressure-sensitive adhesive film will be more noticeable. For this reason, in order to make the concavo-convex structure difficult to see, it is preferable to optimize the maximum height difference of the concavities and convexities. When the sheet base material is matt or opaque, appearance defects due to the concavo-convex structure are less likely to occur as compared with the transparent sheet base material.

<Explanation of the phrase>
In the present specification, when expressing as “X to Y” (X and Y are arbitrary numbers), “preferably greater than X” or “preferably Y” with the meaning of “X or more and Y or less” unless otherwise stated. Also includes the meaning of "smaller".
Also, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), “greater than X is preferable” or “preferably less than Y” It also includes the intention.

  In general, “sheet” is thin as defined in JIS, and its thickness is small and flat for length and width, and “film” is generally thicker than its length and width. A thin flat product of extremely small size and optionally limited maximum thickness, usually supplied in roll form (Japanese Industrial Standard JIS K 6900). However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish between the two in the present invention, in the present invention, even when it is referred to as "film", "sheet" is included and referred to as "sheet". Even in the case of "film" shall be included.

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

[Measurement, evaluation method]
<Mass average molecular weight (Mw)>
The mass average molecular weight (Mw) of each component is a value measured under the following conditions by GPC method.
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: Monodispersed polystyrene Calibration method: polystyrene conversion

<SP value>
The solubility parameter (SP value) of the component A, the component B and the photocrosslinking initiator C was calculated by the method proposed by Fedors et al. Specifically, based on "Basic, application and calculation method of SP value" (Hideki Yamamoto, Information Technology Co., Ltd.), each polymer is referred to the estimation method of Fedors among the estimation methods of solubility parameter of the polymer. From the cohesive energy density of each substituent contained in the component: E (J / mol) and the molar molecular volume: V (cm ³ / mol), calculation is made based on the following equation, and the SP value (σ (cal / cm ³ ) I asked for ^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 asperities, area ratio of projections, number of projections, and maximum longest diameter of asperities>
Using a surface shape measurement system ("VertScan" (registered trademark) R5500 of Hitachi High-Tech Science, Inc.), the surface unevenness of the surface in the area of 703.12 μm × 937.42 μm on the surface of the release film (sample) is interfered by light The data was measured by the method, and the correction and baseline correction were performed under the following conditions. The magnification of the objective lens at the time of measurement was set to 5 times.

(Correction condition)
· Complementary correction: Complete · Baseline correction: surface correction (polynomial approximation fourth order)

From the measurement data, the maximum height difference of the unevenness is the difference between the minimum value of the recess and the maximum value of the protrusion around the recess, or the difference between the maximum value of the protrusion and the minimum value of the recess around the protrusion. It calculated | required as the height difference of unevenness. And the height difference of this unevenness was measured at arbitrary 10 points in the above-mentioned field, and the maximum value in it was made the maximum height difference of unevenness. The difference between the maximum value and the minimum value in the measurement data is not taken as the maximum height difference of the unevenness.
The area ratio of the convex portion was binarized by setting the peak height threshold and the valley height threshold to 0.0 μm using the bearing function, and the area ratio of the convex portion was determined.
The number of convex portions and the maximum longest diameter of the concavo-convex shape were calculated by the particle analysis function under the following measurement conditions. Of the longest diameters detected, the one with the largest value was taken as the maximum longest diameter.

(Particle analysis)
・ Surface correction: Not ・ Analysis: Collision analysis ・ Binarization threshold: 100 nm
・ Particle molding: Not performed ・ Target judgment 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 convexity continuity>
The surface of the mold release film (sample) is observed by the above-mentioned surface shape measurement system to evaluate whether the shape of the convex portion has a certain regularity or periodicity, and has regularity and periodicity. If not, the convex regularity was evaluated as "irregular".
In addition, the surface of the release film (sample) is observed in the same manner as described above, and the convex portion (white portion) extends from one edge to the opposite edge of the enlarged image (from the upper side to the lower side or from the right side to the left side) ) It was evaluated whether they were connected continuously.
When the convex portions are continuously connected, the convex portion continuity is “presenced”, the convex portions are scattered or intermittently present, and when the convex portions are not continuously connected, the convex portion continuous The sex was evaluated as "none".

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

The replica film is cut into a size of 70 mm square, and the replica film and a polyester film having a hole with a diameter of 5 mm are laminated on the center of the replica film so that the uneven structure surface of the replica film contacts the polyester film. Was measured.
The air flow index was measured using a Digibec smoothness tester (DB-2, manufactured by Toyo Seiki Co., Ltd.) under an atmosphere of temperature 23 ° C. and humidity 50% RH. At this time, the pressure of the pressurizing device is 100 kPa, and the vacuum vessel uses a small vacuum vessel having a volume of 38 ml, and the time during which 1 mL of air flows, ie, 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 leak index.
The smaller the value of the air loss index, the more quickly the air is released from the gap, which indicates that the air is more likely to be removed.

<Appearance>
The acrylic adhesive composition was applied to the opposite surface of the substrate of the release film (sample), and then heat treated at 100 ° C. for 5 minutes to obtain an adhesive layer having a thickness (after drying) of 50 μm.
Under the present circumstances, 98.6 mass parts of BPS5762K (made by Toyo Chem Co., Ltd., solid content 45.5 mass%), and 1.4 mass parts of BXX 5627 (50 mass% manufactured by Toyo Chem Co., Ltd.) were mixed as said acrylic adhesive composition. The composition was used.
Thereafter, a base film was further stacked on the pressure-sensitive adhesive layer and attached by a roller to obtain a pressure-sensitive adhesive film. In the case of a transparent substrate, a transparent polyester film (thickness 50 μm, manufactured by Mitsubishi Chemical Corporation) is used as a substrate film used at this time, and in the case of an opaque substrate, a white polyester film (thickness 50 μm, manufactured by Mitsubishi Chemical Corporation) is used. It was.
Then, the release film was peeled off from the obtained adhesive film and attached to an acrylic plate with one reciprocation with a 2 kg rubber roller, and the substrate surface of the adhesive film was observed with the naked eye.
And when observed, when the unevenness of the adhesive layer can not be recognized on the substrate surface, it is evaluated as "good (good)", and the unevenness of the adhesive layer can be recognized on the substrate surface, but the unevenness is a pattern Because it can not be recognized and does not stand out, it is evaluated as "usual" when there is no problem in practical use, and the unevenness of the pressure-sensitive adhesive layer can be recognized on the substrate surface, and the unevenness can be recognized as a pattern and becomes noticeable. When there was a problem in practical use, it was evaluated as "x (poor)".

Example 1
<Material of base material>
Polyester A: chip of polyethylene terephthalate homopolymer (intrinsic viscosity: 0.66 dl / g)
Polyester B: chip of polyethylene terephthalate homopolymer containing 1000 ppm of amorphous silica having an average particle diameter of 2 μm (Intrinsic viscosity: 0.62 dl / g)

Raw materials for coating solution for functional layer
60 parts by mass of a water-dispersed polycarbonate polyurethane resin (Tg: 35 ° C.) having a carboxyl group, 30 parts by mass of a polymer type crosslinking agent in which an oxazoline group is branched to an acrylic resin, silica sol aqueous dispersion (average particle size: 0 6 parts by mass of .07 μm) were mixed to prepare a coating solution for functional layer.

<Raw Material of Curable Coating Composition>
Acrylic polymer A1: Acrylic acid modified product 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: manufactured by IGM Resin, Omnirad 127
Solvent X: methyl ethyl ketone (a solvent capable of dissolving acrylic polymers A1 and B1, having a boiling point of 80 ° C.)
Solvent Y: methoxypropanol (a solvent which dissolves acrylic polymer A1 and B1 does not dissolve, and its boiling point is 120 ° C.)

(Preparation of base material)
The polyester A is used as a raw material for the intermediate layer, the polyester B is used as a raw material for the surface layer, and each raw material is melt-extruded by separate melt extruders to form a two-layer / three-layer amorphous of surface layer / interlayer / surface layer. The sheet was cooled and solidified on a cooled casting drum to obtain a non-oriented sheet.
Then, it was stretched 3.5 times at 90 ° C. in the machine direction (longitudinal direction). Thereafter, the coating solution for a functional layer is coated to a dry thickness of 0.05 μm and then guided to a tenter, and further subjected to a preheating step in a tenter and stretched in a transverse direction at 4.3 ° C. at 120 ° C. Heat treatment was performed 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 configuration of the 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 formation of a concavo-convex 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 hexamer as a photopolymerizable compound An acrylic polymer mixture containing 27.5 parts by mass of acrylate and 5 parts by mass of a photocrosslinking initiator C1 is mixed in a mass ratio of 72:28 of methyl ethyl ketone as the solvent X and methoxypropanol as the solvent Y The mixture was dissolved in the mixed solvent Z obtained, to prepare a curable coating composition having an acrylic polymer mixture concentration of 30% by mass.

  The curable coating composition is applied by Meyer bar to the surface of the functional layer of the polyester film as the substrate, the solvent X and the solvent Y are volatilized at 70 ° C., and then the ultraviolet light is irradiated by the ultraviolet irradiation device It was made to harden | cure and the film with an uneven | corrugated layer formed by forming the uneven | corrugated layer which has an uneven | corrugated structure on the surface on the one surface side of a base material was produced.

(Formation of 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) as a coating solution used for the release layer The ratio was diluted by 1: 1) to prepare a release layer coating solution having a silicone resin concentration of 4% by mass.
The coating solution for the release layer is applied by Meyer bar on the surface of the uneven layer of the film with the uneven layer, and the release layer is provided by heating, drying and curing at 120 ° C. A release film 1 (sample) was produced.

Example 2
A release film 2 (sample) was produced in the same manner as in Example 1 except that the thickness of the uneven layer was changed by changing the number of lines of the Meyer bar to set the maximum height difference of the projections to 8 μm.

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

Example 4
When producing a curable coating composition, the above acrylic polymer A1, the above acrylic polymer B1, and dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4) as a photopolymerizable compound Mixture obtained by mixing methyl ethyl ketone as the solvent X and methoxypropanol as the solvent Y in a mass ratio of 63: 37 with an acrylic polymer mixture in which the mixing ratio of parts by weight is 60: 20: 20 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 a concavo-convex layer was formed using a curable coating composition prepared as follows.
That is, as a coating liquid used for formation of a concavo-convex layer, graft copolymer B2 (mass average molecular weight (Mw): 16,000, SP as component B which uses polydimethylsiloxane as a branch polymer and an acrylic monomer as a base polymer) 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, photocrosslinking initiator C (IGM Obtained by mixing an acrylic monomer mixture containing 5 parts by mass of Opinrad 127, manufactured by resin, with methyl isobutyl ketone as solvent X, methyl ethyl ketone and methoxypropanol as solvent Y in a mass ratio of 28:26:46. The resulting mixture was dissolved in the mixed solvent Z to prepare a curable coat composition having a concentration of the acrylic polymer mixture of 16% by mass.

The graft copolymer B2 having the above acrylic monomer as a main polymer comprises 10: 10: 20: 60 of methyl methacrylate, stearyl methacrylate, a silicon macromer having a terminal methacryloyl group having a molecular weight of 5,000, and glycidyl methacrylate. It was an acrylic acid modified product copolymerized at a molar ratio.
The methyl isobutyl ketone and methyl ethyl ketone as the solvent X are solvents capable of dissolving the graft copolymer B2 and the acrylic polymer A1, and the boiling points thereof were 116 ° C. for methyl isobutyl ketone and 80 ° C. for methyl ethyl ketone.
On the other hand, methoxypropanol as the solvent Y is a solvent capable of dissolving only the graft copolymer B2 and the acrylic polymer A1 and has a boiling point of 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 to make the maximum height difference 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 heat drying was performed at 50 ° C. to form an uneven layer.
That is, 50 parts by mass of dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4) as component A as a coating solution used for forming the uneven layer, polypropylene as component B (Idemitsu Kosan Manufactured by “S400”, mass average molecular weight (Mw): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C. 50 parts by mass and photocrosslinking initiator (2-hydroxy-2-methyl-) A mixture obtained by blending a mixture containing 3 parts by mass of 1-phenyl-propan-1-one) with cyclohexane as solvent X, toluene and n-butanol as solvent Y in a mass ratio of 49: 49: 2 It was dissolved in a solvent (mixed solvent Z) to prepare a curable coat composition having a mixture concentration of 15% by mass.
Cyclohexane and toluene as the solvent X are solvents capable of dissolving the components A and B, and the boiling points thereof were 81 ° C. and 111 ° C., respectively.
On the other hand, methoxypropanol as the solvent Y is a solvent capable of dissolving only the component A among the components A and B, and its boiling point is 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 heat drying was performed at 50 ° C. to form a concavo-convex layer.
That is, as a coating liquid used for formation of an uneven | corrugated layer, the urethane acrylate as a component A (The brand name "U-15HA" by Shin-Nakamura Chemical Co., Ltd. make, mass mean molecular weight (Mw): 2205, SP value: 11.2) 50 parts by mass, 50 parts by mass of 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 3 parts by mass of a crosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one), cyclohexane as a solvent X, toluene, and methoxypropanol as a solvent Y 49: 49: It was made to melt | dissolve in the mixed solvent (mixed solvent Z) obtained by mix | blending by the mass ratio of 2, and the curable coating composition whose said mixture density | concentration is 15 mass% was prepared.

[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 heat drying was performed at 50 ° C. to form an uneven layer.
That is, as a coating liquid used to form the uneven layer, 50 parts by mass of an acrylic polymer A1 (mass average molecular weight (Mw): 20,000, SP value: 12.6, Tg: 32 ° C.) as component A, component B Hydrogenated end acrylate polybutadiene (Nippon Soda Co., Ltd. “TEAI-1000”, mass average molecular weight (Mw): 2,000 (catalog value), SP value: 9.9, Tg: −14 ° C. (catalog value)) 25 parts by mass, 25 parts by mass of dipentaerythritol hexaacrylate (mass average molecular weight (Mw): 578, SP value: 10.4), and a photocrosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propane-1) A mixture containing 5 parts by mass of cyclohexane, toluene, methyl ethyl ketone as solvent X, methoxypropanol as solvent Y, n- The ethanol 6: 25: 32: 31: 6 were blended at a mass ratio dissolved in a mixed solvent obtained in the previous mixture the concentration to prepare a curable coating composition is 15 mass%.

[Example 10]
While using the curable coating composition prepared as follows, changing the number of Meyer bar lines to change the thickness of the uneven layer, and changing the maximum height difference of the convex portion to 10.6 μm, Example 1 and The release film 10 (sample) was produced by the same method.
As a coating liquid used for formation of an 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 dipentaerythritol hexaacrylate 15 as a photopolymerizable compound Mixture obtained by mixing methyl ethyl ketone as solvent X and methoxypropanol as solvent Y in a mass ratio of 57: 43 with an acrylic polymer mixture containing 5 parts by mass of a photocrosslinking initiator C1 and a mass part By dissolving in solvent Z, a curable coating composition having an acrylic polymer mixture concentration of 30% by mass was prepared.

[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 heat drying was performed at 50 ° C. to form an uneven layer.
That is, as a coating liquid used for formation of an uneven | corrugated layer, the urethane acrylate as a component A (The brand name "U-15HA" by Shin-Nakamura Chemical Co., Ltd. make, mass mean molecular weight (Mw): 2205, SP value: 11.2) 50 parts by mass, 50 parts by mass of 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 3 parts by mass of a crosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one), heptane as solvent X, toluene, and butyl acetate as solvent Y 56: 24: It was made to melt | dissolve in the mixed solvent (mixed solvent Z) obtained by mix | blending by the mass ratio of 20, and the said curable mixture composition prepared the curable coating composition which is 32 mass%.

[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 heat drying was performed at 50 ° C. to form an uneven layer.
That is, as a coating solution used to form the uneven layer, dendrimer acrylate as component A (“Brand name: V # 1000, manufactured by Osaka Organic Chemical Industry Ltd., mass average molecular weight (Mw): 1900, SP value: 14.3 ( Turbidity method) 50 parts by mass, polypropylene as component B (made by Idemitsu Kosan "S400", number average molecular weight (Mn): 45,000 (catalog value), SP value: 8.2, Tg: 50 ° C) A mixture containing 50 parts by mass and 3 parts by mass of a photocrosslinking initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one) with heptane as solvent X, toluene and butyl acetate as solvent Y In a mass ratio of 56:24:20 (mixed solvent Z) to prepare a curable coating composition having a concentration of the mixture of 32% by mass.

Comparative Example 1
A release film 13 is prepared in the same manner as in Example 1 except that a release layer is provided in the same manner as in Example 1 without forming an uneven layer on the surface of the polyester film as the substrate used in Example 1. (Sample) was produced.

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

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

Comparative Example 4
In the formation method of the concavo-convex layer, 5 parts by mass of silicone modified acrylic polymer (manufactured by Kyoeisha Chemical Co., Ltd., GL04R) is further added to the curable coat composition to prepare a curable coat 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 thickness of the concavo-convex layer was changed by changing the number of Meyer bars and changing the thickness of the concavo-convex layer to 0.4 μm. Made.

Comparative Example 5
Butylated melamine resin containing 55 parts by mass of p-toluenesulfonic acid (acid catalyst), 15 parts by mass of triethylenediamine and 30 parts by mass of isopropyl alcohol so that the compounding amount of the acid catalyst is 0.9 parts by mass The curable coating composition was mixed with 100 parts by mass (based on nonvolatile components) and further diluted with a mixed solvent of toluene / methyl ethyl ketone = 6/4 (mass ratio) to prepare a curable coating composition having a nonvolatile component concentration of 30% by mass. The prepared curable coating composition is coated on one side of the polyester film as a substrate prepared in Reference Example 1 with a Mayer bar so that the film thickness after drying is 7 μm, and 5 at 150 ° C. It dried for a minute and formed the resin layer. The surface of the obtained resin layer was not roughened, and no unevenness was formed.
And the peeling layer was provided similarly to Example 1, and the release film 17 (sample) which consists of peeling layer / resin layer / base material was produced.

(Discussion)
From the results of the above Examples and Comparative Examples and the test results that the present inventor has conducted so far, a mold release film provided with a concavo-convex layer having a concavo-convex structure on the surface on at least one surface side of the substrate The pressure-sensitive adhesive film to which the concavo-convex structure has been transferred if the area ratio of the convex portion occupying on the surface of the concavo-convex structure is 10 to 90% and the maximum height difference of the concavo-convex structure is 0.5 μm or more In the above, it was found that the release of air at the time of applying the pressure-sensitive adhesive film can be improved.
In addition, it was also found that when the convex portion of the concavo-convex structure is formed in an irregular shape when viewed in plan, the concavo-convex structure is difficult to see after adhering the adhesive film to which the concavo-convex structure is transferred.
Examples 11 and 12 are good examples when high air bleeding is required, but were inferior to the other examples for applications requiring a good appearance. In addition, although the said external appearance evaluation is corresponded to the external appearance evaluation at the time of using the adhesive film which used the transparent polyester film as a base material, in the external appearance evaluation at the time of using the sticking sheet which used the opaque film as a base material, Examples 11 and 12 were also at good levels.

Claims (14)

It is a release film provided with the uneven | corrugated layer which has uneven structure on the surface in the at least one surface side of a base material,
The concavo-convex structure has a configuration in which convex portions of the concavo-convex structure form an irregular shape in plan view, and an area ratio of the convex portion on the surface of the concavo-convex structure is 10 to 90. %, And the maximum height difference of the uneven structure is 0.5 μm or more,
The convex part in the said uneven structure is continuous in planar view, The release film characterized by the above-mentioned.   The release film according to claim 1, wherein the uneven layer contains two or more types of polymers.   The release film according to claim 2, wherein the two or more types of polymers form a phase separation structure.   The release film according to claim 2 or 3, wherein at least one of the two or more types of polymers is a thermoplastic resin and / or a curable resin composition having a crosslinkable structure.   The mold-releasing film according to any one of claims 1 to 4, wherein the concavo-convex structure has a different composition for forming the concave part and a composition for forming the convex part.   In the concavo-convex layer, the SP value (A) of the component A that occupies the most of the components that form the recesses is 8 to 21 and the SP value of the component B that occupies the most of the components that form the protrusions. (B) is 7 to 20, and the SP value (A)-the SP value (B) = 0.01 to 10. The separation according to any one of claims 1 to 5, Mold film.   In the above-mentioned concavo-convex layer, the mass average molecular weight (Mw) of the component A which occupies the most of the components forming the concave is 300 to 300,000, and the component B which occupies the most of the components forming the convex The release film according to any one of claims 1 to 6, wherein the mass average molecular weight (Mw) of the film is 500 to 400,000.   The uneven layer is formed of a coating composition containing two or more types of polymers, oligomers or monomers, and the coating composition has an SP value (A) of component A that accounts for the most of the components forming the recess. Is 8 to 21, and the SP value (B) of the component B that occupies the most of the components forming the convex portion is 7 to 20, and the SP value (A)-the SP value (B) The release film according to any one of claims 1 to 6, which is in the range of 0.01 to 10.   The uneven layer is formed of a coating composition containing two or more types of polymers, oligomers or monomers, and the coating composition has a mass average molecular weight (Mw) of component A that accounts for the most of the components forming the recess. The mass average molecular weight (Mw) of the component B which occupies 300% to 300,000 and the component B forming the largest part among the components forming the convex portion is 500 to 400,000, The release film as described in any of the above.   The release film according to any one of claims 1 to 9, wherein the uneven layer contains a peeling component having peelability.   The release film according to any one of claims 1 to 10, further comprising a release layer on the surface side of the uneven layer.   The release film according to any one of claims 1 to 11, further comprising a functional layer between the substrate and the uneven layer.   The laminated body provided with the structure formed by laminating | stacking the release film in any one of Claims 1-12, and an adhesive film.   The laminate according to claim 13, wherein the concavo-convex structure formed on the surface of the release film is transferred to the surface of the adhesive film.