CN109571836B

CN109571836B - Method for producing antifouling film

Info

Publication number: CN109571836B
Application number: CN201811142590.6A
Authority: CN
Inventors: 厚母贤; 芝井康博; 中松健一郎
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2017-09-29
Filing date: 2018-09-28
Publication date: 2020-10-30
Anticipated expiration: 2038-09-28
Also published as: JP6550434B2; CN109571836A; JP2019064056A

Abstract

The invention provides a method for producing an antifouling film, which can inhibit the reduction of the release performance of a polymer layer and a mold and improve the antifouling performance and the scraping resistance even if the transfer frequency of the mold is increased. The method for producing an antifouling film according to the present invention is a method for producing an antifouling film having a base material and a polymer layer that is disposed on a surface of the base material and has a concavo-convex structure in which a plurality of convex portions are provided at a pitch of a visible light wavelength or less on the surface, the method comprising: the method for producing a resin layer having a concavo-convex structure on the surface thereof comprises a step of applying a first resin to the surface of a mold, a step of applying a second resin to the surface of a substrate, a step of forming a resin layer having a concavo-convex structure on the surface by pressing the substrate against the mold with the first resin and the second resin interposed therebetween, and a step of curing the resin layer to form a polymer layer, wherein the first resin contains at least one fluorine-based release agent and 2- (2-vinyloxyethoxy) ethyl acrylate, and contains 40 to 95 wt% of 2- (2-vinyloxyethoxy) ethyl acrylate in terms of active ingredients.

Description

Method for producing antifouling film

Technical Field

The present invention relates to a method for producing an antifouling film. More specifically, the present invention relates to a method for producing an antifouling film having a nano-sized uneven structure.

Background

Various studies have been made on optical films having antireflection properties (see, for example, patent documents 1 and 2). In particular, an optical film having a nano-sized uneven structure (nanostructure) is known to have excellent antireflection properties. Since the refractive index is continuously changed from the air layer to the substrate by such a concave-convex structure, the reflected light can be drastically reduced.

Documents of the prior art

Patent document

[ patent document 1] Japanese patent laid-open No. 2013-3978-

[ patent document 2] Japanese patent laid-open publication No. 2013-252689

Disclosure of Invention

Technical problem to be solved by the invention

However, in such an optical film, although it has excellent antireflection properties, on the other hand, since the surface thereof has a concavo-convex structure, if dirt such as fingerprints (sebum) is adhered, the adhered dirt is easily spread, and it becomes difficult to wipe off dirt entering between the convex portions. Moreover, since the reflectance is greatly different from that of the optical film, the attached dirt is easily visually recognized. Therefore, a functional film (antifouling film) having a nano-sized uneven structure on the surface and excellent in wiping properties against stains (for example, fingerprint wiping properties), that is, antifouling properties, is required.

The present inventors have studied this and, as a result, have found that: when a fluorine-based release agent is blended as a constituent material in a polymer layer constituting an uneven structure of an optical film, the antifouling property is improved. In addition, it can be seen that: when the monofunctional amide monomer is blended, compatibility with the fluorine-based release agent is improved, and the active ingredient in the fluorine-based release agent becomes easily oriented on the surface of the polymer layer, and therefore, it is effective for improving the antifouling property.

However, the present inventors further studied and found that: in the case of using a mold for forming the uneven structure of the polymer layer, if a monofunctional amide monomer is blended as a constituent material of the polymer layer, the releasability of the polymer layer and the mold is liable to decrease with the increase in the number of times of mold transfer, and as a result, the antifouling property of the obtained antifouling film is liable to decrease. Furthermore, it can be seen that: when the amount of the monofunctional amide monomer to be blended is large, the crosslinking density of the polymer layer is hardly increased, and as a result, the scratch resistance is easily lowered.

As described above, the following problems have been found: in the production of a stain-proofing film, even if the number of times of transfer of a mold is increased, the decrease in releasability of a polymer layer and the mold is suppressed, and stain-proofing property and scratch resistance are improved. However, no technical means for solving the above problems has been found. For example, patent documents 1 and 2 describe no decrease in releasability of a polymer layer and a mold as the number of times of transfer of the mold increases, and do not solve the above-mentioned problems.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a method for producing a stain-proofing film, which can suppress a decrease in releasability of a polymer layer and a mold even when the number of times of transferring the mold is increased, and can improve stain-proofing property and scratch resistance.

Means for solving the problems

The present inventors have made various studies on a method for producing a stain-proofing film which can suppress the decrease in releasability of a polymer layer and a mold even when the number of times of transfer of the mold is increased and can improve the stain-proofing property and scratch resistance, and as a result, focused on a method in which a first resin is applied to the surface of the mold, a second resin is applied to the surface of a base material, and then both resins are integrated. Further, a method has been found in which a fluorine-based release agent and 2- (2-vinyloxyethoxy) ethyl acrylate are blended in place of the monofunctional amide monomer in the first resin, and the blending amount of the 2- (2-vinyloxyethoxy) ethyl acrylate is set to a predetermined range. The present invention has been achieved by devising a solution to the above problems satisfactorily.

That is, one aspect of the present invention is a method for producing an antifouling film having a base material and a polymer layer disposed on a surface of the base material and having a concavo-convex structure in which a plurality of convex portions are provided at a pitch of a visible light wavelength or less on the surface, the method comprising: a step (1) of applying a first resin to the surface of a mold; a step (2) of applying a second resin to the surface of the base material; a step (3) of pressing the base material against the mold with the first resin and the second resin interposed therebetween to form a resin layer having the uneven structure on the surface; and a step (4) of curing the resin layer to form the polymer layer; the first resin contains at least one fluorine-based release agent and 2- (2-ethyleneoxyethoxy) ethyl acrylate, and contains 40 to 95 wt% of the 2- (2-ethyleneoxyethoxy) ethyl acrylate in terms of active ingredients.

The at least one fluorine-based release agent may be a plurality of fluorine-based release agents.

The at least one fluorine-based release agent may include at least one of a fluorine-based release agent having a perfluoropolyether group and a fluorine-based release agent having a perfluoroalkyl group.

The second resin may contain at least one of the at least one fluorine-based release agents.

The second resin may contain a monofunctional amide monomer.

The mold surface may be subjected to a mold release treatment with a mold release treating agent.

The polymer layer may have a thickness of 5.0 to 20.0 μm.

The average pitch of the plurality of projections may be 100 to 400 nm.

The average height of the plurality of projections may be 50 to 600 nm.

The average aspect ratio of the plurality of projections may be 0.8 to 1.5.

Effects of the invention

According to the present invention, it is possible to provide a method for producing a stain-proofing film, which can suppress a decrease in releasability of a polymer layer and a mold even when the number of times of transferring the mold is increased, and can improve stain-proofing property and scratch resistance.

Drawings

Fig. 1 is a schematic cross-sectional view for explaining a method of manufacturing an antifouling film according to an embodiment.

Fig. 2 is a schematic perspective view showing the polymer layer in fig. 1 (e).

Detailed Description

The present invention will be described in more detail with reference to the accompanying drawings, but the present invention is not limited to the embodiments. The respective configurations of the embodiments may be appropriately combined or modified within a range not departing from the gist of the present invention.

In the present specification, "X to Y" mean "X or more and Y or less".

[ embodiment ]

The method for producing the antifouling film according to the embodiment will be described below with reference to fig. 1. Fig. 1 is a schematic cross-sectional view for explaining a method of manufacturing an antifouling film according to an embodiment.

(a) Application of first resin (step (1))

As shown in fig. 1(a), a first resin 6 is applied to the surface of a mold 5.

Examples of the method for applying the first resin 6 include a method of applying the first resin by a spray method, a gravure method, a slot die method, a bar coating method, and the like. Among them, from the viewpoint of making the film thickness uniform and improving productivity, a method of coating by a gravure method or a slot die method is preferable.

When the first resin 6 contains a solvent (a component other than the active ingredient), a heating process (drying process) for removing the solvent may be performed after the first resin 6 is applied. The heat treatment is preferably performed at a temperature equal to or higher than the boiling point of the solvent.

(b) Application of second resin (step (2))

The second resin 7 is applied to the surface of the substrate 2 as shown in fig. 1 (b).

Examples of the method for applying the second resin 7 include the same methods as those for applying the first resin 6 described above.

When the second resin 7 contains a solvent (a component other than the active ingredient), a heating process (drying process) for removing the solvent may be performed after the application of the second resin 7. The heat treatment is preferably performed at a temperature equal to or higher than the boiling point of the solvent.

The application of the first resin 6 (the above (a)) and the application of the second resin 7 (the above (b)) may be performed at the same timing or at different timings.

(c) Formation of resin layer (step (3))

The base material 2 is pressed against the mold 5 with the first resin 6 and the second resin 7 interposed therebetween. As a result, the first resin 6 and the second resin 7 are integrated, and as shown in fig. 1 c, a resin layer 8 having an uneven structure on the surface (the surface on the opposite side of the substrate 2) is formed. The resin layer 8 is formed by integrating the first resin 6 and the second resin 7, and does not have an interface between the two resins.

(d) Formation of Polymer layer (step (4))

The resin layer 8 is hardened. As a result, the polymer layer 3 is formed as shown in fig. 1 (d).

Examples of the method for curing the resin layer 8 include irradiation with active energy rays, heating, and the like. In the present specification, the term "active energy ray" refers to ultraviolet rays, visible rays, infrared rays, plasma, and the like. The curing of the resin layer 8 is preferably performed by irradiation with an active energy ray, and more preferably, the curing of the resin layer 8 is performed by irradiation with ultraviolet rays. The irradiation with the active energy ray may be performed from the substrate 2 side of the resin layer 8, or may be performed from the mold 5 side of the resin layer 8. The number of irradiation of the resin layer 8 with the activation energy ray may be only one or multiple. The curing of the resin layer 8 (the above (d)) may be performed at the same timing as the formation of the uneven structure (the above (c)).

(e) Stripping of the mold

The mold 5 is peeled from the polymer layer 3 as shown in fig. 1 (e). As a result, the antifouling film 1 is completed.

In the present embodiment, for example, if the substrate 2 is in a roll form, the above-described (a) to (e) can be continuously and efficiently performed. In the present specification, the series of steps (a) to (e) may be referred to as "mold transfer".

The antifouling film 1 has a base material 2 and a polymer layer 3 disposed on the surface of the base material 2.

The polymer layer 3 has an uneven structure, i.e., a moth-eye structure (moth-eye structure), in which a plurality of convex portions (protrusions) 4 are provided on the surface at a pitch P (distance between the apexes of adjacent convex portions 4) of the wavelength (780nm) of visible light. Therefore, the antifouling film 1 can exhibit excellent antireflection property (low reflectance) of the moth-eye structure.

The thickness T of the polymer layer 3 is preferably small from the viewpoint of orienting the active ingredient in the fluorine-based release agent described later at a high concentration on the surface of the polymer layer 3 (the surface on the opposite side of the substrate 2). Specifically, the thickness T of the polymer layer 3 is preferably 5.0 to 20.0. mu.m, and more preferably 8.0 to 12.0. mu.m.

Examples of the shape of the plurality of convex portions 4 include a shape (a taper shape) tapered toward the tip, such as a shape (a bell shape) having a columnar lower portion and a hemispherical upper portion, and a cone shape (a taper shape, a cone shape). In fig. 1(e), the bottom side of the gap between adjacent convex portions 4 is inclined, but may be horizontal without being inclined.

The average pitch of the plurality of projections 4 is preferably 100 to 400nm, more preferably 100 to 200nm, from the viewpoint of sufficiently preventing the occurrence of optical phenomena such as moire fringes and rainbow unevenness. The average pitch of the plurality of projections 4 is specifically an average value of pitches (P in fig. 1 (e)) of all adjacent projections in a region of 1 μm square of a plane photograph taken by a scanning electron microscope.

The average height of the plurality of projections 4 is preferably 50 to 600nm, more preferably 100 to 300nm, from the viewpoint of satisfying a preferable average aspect ratio of the plurality of projections 4 described later. The average height of the plurality of projections 4 is specifically an average value of the heights (H in fig. 1 (e)) of 10 projections arranged in series in a cross-sectional photograph taken by a scanning electron microscope. When 10 convex portions are selected, the convex portions having a defective or deformed portion (a portion deformed when preparing a measurement sample, etc.) are excluded.

The average aspect ratio of the plurality of projections 4 is preferably 0.8 to 1.5, more preferably 1.0 to 1.3. When the average aspect ratio of the plurality of projections 4 is less than 0.8, the following phenomenon occurs: the occurrence of optical phenomena such as moire fringes and rainbow unevenness cannot be sufficiently prevented, and excellent antireflection properties cannot be obtained. In the case where the average aspect ratio of the plurality of projections 4 is larger than 1.5, there is a phenomenon that: the workability of the uneven structure is lowered, stickiness is generated, and the transfer state when the uneven structure is formed is deteriorated (clogging of the mold 5, winding, etc.). The average aspect ratio of the plurality of projections 4 is a ratio (height/pitch) of an average height to an average pitch of the plurality of projections 4.

The plurality of projections 4 may be arranged randomly or periodically (regularly). When the plurality of projections 4 are periodically arranged, unnecessary diffracted light is generated due to the periodicity, and therefore, it is preferable that the plurality of projections 4 are randomly arranged as shown in fig. 2. Fig. 2 is a schematic perspective view showing the polymer layer in fig. 1 (e).

From the viewpoint of stain resistance, it is preferable that the water contact angle is 110 ° or more and the hexadecane contact angle is 60 ° or more with respect to the surface of the polymer layer 3 (the surface on the opposite side of the base material 2).

The use of the antifouling film 1 is not particularly limited if the excellent antifouling property is effectively utilized, and for example, the use may be an optical film such as an antireflection film. Such an antireflection film can contribute to improvement of visibility by being mounted inside or outside the display device.

The antifouling property of the antifouling film 1 may mean that the dirt adhering to the surface of the polymer layer 3 (the surface on the opposite side of the base material 2) can be easily removed, or that the dirt is less likely to adhere to the surface of the polymer layer 3 (the surface on the opposite side of the base material 2). Further, according to the stain-resistant film 1, a higher stain resistance is obtained than a conventional stain-resistant film (for example, a fluorine-containing film) having a normal surface such as a flat surface due to the effect of the moth-eye structure.

Next, each member used in the production of the antifouling film 1 will be described below.

< first resin >

The first resin 6 contains at least one fluorine-based release agent and 2- (2-ethyleneoxyethoxy) ethyl acrylate, and contains 40 to 95 wt% of 2- (2-ethyleneoxyethoxy) ethyl acrylate in terms of active ingredients. In the present specification, the "active ingredient" refers to a compound which becomes a constituent of the polymer layer 3 after curing, and components (for example, a solvent) which do not participate in the curing reaction (polymerization reaction) are removed.

The components in the first resin 6 will be described below.

(fluorine-based mold release agent)

The fluorine-based release agent contains a compound containing a fluorine atom in the molecule (fluorine-containing compound) as an active ingredient. The fluorine-based release agent causes the active ingredient in the fluorine-based release agent to be oriented on the surface of the polymer layer 3 (the surface on the opposite side of the base material 2), and the surface free energy of the polymer layer 3 is lowered, thereby improving the antifouling property. Further, the surface of the polymer layer 3 (the surface on the opposite side of the substrate 2) is improved in slidability, and as a result, scratch resistance is improved. In the present embodiment, the first resin 6 mainly constituting the surface of the resin layer 8 (the surface on the opposite side of the substrate 2) contains a fluorine-based release agent, and therefore the active ingredient in the fluorine-based release agent becomes easily oriented to the surface of the resin layer 8 (the surface on the opposite side of the substrate 2). Therefore, according to the present embodiment, the effective component in the fluorine-based release agent can be efficiently oriented on the surface of the polymer layer 3 (the surface on the opposite side of the substrate 2), that is, the stain-proofing property and scratch resistance can be efficiently improved.

The first resin 6 may contain one kind of fluorine-based release agent or may contain a plurality of kinds of fluorine-based release agents, but preferably contains a plurality of kinds of fluorine-based release agents from the viewpoint of antifouling property. As a result, the active ingredient in the various fluorine-based release agents is oriented at a high concentration on the surface of the polymer layer 3 (the surface on the opposite side of the base material 2), and the antifouling property is further improved.

Preferably, the fluorine-based release agent contains at least one of a fluorine-based release agent having a perfluoropolyether group and a fluorine-based release agent having a perfluoroalkyl group. The fluorine-based release agent having a perfluoropolyether group facilitates movement of the active ingredient (fluorine-containing compound), and the surface of the polymer layer 3 (the surface on the opposite side of the substrate 2) is likely to have improved slidability, so that as a result, scratch resistance is likely to be improved. On the other hand, the fluorine-based release agent having a perfluoroalkyl group is easy to orient (transfer) to the surface of the polymer layer 3 (the surface on the opposite side of the substrate 2) because of its small molecular weight, and even if the amount to be blended is small, the desired stain-proofing property and scratch resistance are easily obtained. Such a fluorine-based release agent further improves stain resistance and scratch resistance as compared with other types of release agents (for example, silicon-based release agents, phosphate-based release agents, and the like).

The first resin 6 may contain at least one fluorine-based release agent having a perfluoropolyether group, may contain at least one fluorine-based release agent having a perfluoroalkyl group, and may contain at least one of each of the fluorine-based release agents.

The content of the fluorine-based release agent in the first resin 6 is preferably 5 to 50% by weight, more preferably 20 to 40% by weight, in terms of the effective component. When the content of the fluorine-based release agent in the first resin 6 is less than 5% by weight in terms of the active ingredient, the following phenomenon occurs: the amount of the active ingredient oriented on the surface of the polymer layer 3 (the surface opposite to the base material 2) is reduced, and the antifouling property is lowered. When the content of the fluorine-based release agent in the first resin 6 is more than 50% by weight in terms of the effective component, the following phenomenon occurs: the polymer layer 3 becomes soft and scratch resistance is reduced. When the first resin 6 contains a plurality of fluorine-based release agents, the total content of the plurality of fluorine-based release agents is preferably (more preferably) within the above range in terms of the effective components.

Known examples of the fluorine-based release agent include: "FOMBLIN (registered trademark) MT 70", "fluoralink (registered trademark) AD 1700" manufactured by sovery, a "OPTOOL (registered trademark) DAC" and "OPTOOL DAC-HP" manufactured by dawn industries, "Megafac (registered trademark) RS-76-NS" manufactured by Dean (DIC), a "chemlinox (registered trademark) FAAC-4" and "chemlinox FAAC-6" manufactured by Unimatec, and the like.

(acrylic acid 2- (2-ethyleneoxyethoxy) ethyl ester)

2- (2-ethyleneoxyethoxy) ethyl acrylate is a hetero-polymerizable monomer in which a vinyl ether group and an acryloyl group coexist in a molecule. The 2- (2-vinyloxyethoxy) ethyl acrylate has a low viscosity and improves compatibility with a fluorine-based release agent, and as a result, the effective component in the fluorine-based release agent is easily oriented on the surface of the polymer layer 3, and the stain resistance and scratch resistance are improved. Further, the compatibility between the first resin 6 and the second resin 7 is improved by 2- (2-ethyleneoxyethoxy) ethyl acrylate, and thus the adhesion between the two resins is improved.

In the present embodiment, 2- (2-ethyleneoxyethoxy) ethyl acrylate is blended in the first resin 6 applied to the surface of the mold 5 instead of the monofunctional amide monomer, and therefore, even if the number of times of transfer of the mold 5 is increased, the decrease in releasability of the polymer layer 3 and the mold 5 can be suppressed. As a result, the antifouling property of the obtained antifouling film 1 can be maintained high. On the other hand, if 2- (2-ethyleneoxyethoxy) ethyl acrylate is not blended in the first resin 6, but another monomer (for example, a polyfunctional acrylate) is blended, the reactivity is low, and therefore the crosslinking density of the polymer layer 3 is not increased, and as a result, the scratch resistance is lowered.

The content of 2- (2-ethyleneoxyethoxy) ethyl acrylate in the first resin 6 is 40 to 95 wt%, preferably 40 to 80 wt%, and more preferably 60 to 80 wt% in terms of the effective components. When the content of 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin 6 is less than 40% by weight in terms of the active ingredient, the content of the fluorine-based release agent is relatively increased, and the polymer layer 3 is excessively softened, so that scratch resistance is lowered. When the content of 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin 6 is higher than 95% by weight in terms of the active ingredient, the content of the fluorine-based release agent is relatively decreased, and the amount of the active ingredient oriented on the surface of the polymer layer 3 (the surface on the opposite side of the base material 2) is excessively decreased, so that the antifouling property is decreased.

As known examples of 2- (2-ethyleneoxyethoxy) ethyl acrylate, there are mentioned "VEEA" manufactured by Japan catalyst Co.

Preferably, the first resin 6 does not contain monofunctional amide monomers. In the present specification, "monofunctional amide monomer" means a monomer having an amide group and one acryloyl group per molecule. If the monofunctional amide monomer is formulated in the first resin 6 applied on the surface of the mold 5, there is a phenomenon that the monofunctional amide monomer penetrates into the surface of the mold 5 when the mold 5 is transferred (the mold 5 is in contact with the first resin 6 (resin layer 8)). Here, for example, when the surface of the mold 5 is subjected to a mold release treatment in advance with a mold release treatment agent, the penetrating monofunctional amide monomer is compatible with the mold release treatment agent, and therefore the mold release treatment agent is easily peeled off from the mold 5. Therefore, as the number of times of transfer of the mold 5 increases, the releasability of the polymer layer 3 and the mold 5 is easily lowered, and as a result, the antifouling property of the antifouling film 1 obtained is easily lowered.

In contrast, in the present embodiment, 2- (2-ethyleneoxyethoxy) ethyl acrylate is blended in the first resin 6 applied to the surface of the mold 5 instead of the monofunctional amide monomer as described above, and therefore, even if the number of transfers of the mold 5 increases, the releasability of the polymer layer 3 and the mold 5 can be suppressed from decreasing. As a result, the antifouling property of the obtained antifouling film 1 can be maintained high.

The first resin 6 may further contain a solvent (a component other than the active ingredient). In this case, the solvent may be contained in each component (for example, a fluorine-based release agent) together with the active ingredient, or may be contained independently of each component.

Examples of the solvent include alcohols (having 1 to 10 carbon atoms such as methanol, ethanol, n-or isopropanol, n-or tert-butanol, benzyl alcohol, octanol and the like), ketones (having 3 to 8 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, dibutyl ketone, cyclohexanone and the like), esters or ether esters (having 4 to 10 carbon atoms such as ethyl acetate, butyl acetate, ethyl lactate and the like), γ -butyrolactone, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, ethers (having 4 to 10 carbon atoms such as EG monomethyl ether (methyl cellosolve), EG monoethyl ether (ethyl cellosolve), diethylene glycol monobutyl ether (butyl cellosolve), propylene glycol monomethyl ether and the like), aromatic hydrocarbons (having 6 to 10 carbon atoms such as benzene, toluene, xylene and the like), amides (having 3 to 10 carbon atoms such as dimethylformamide, dimethylacetamide, xylene, and the like), amides, N-methylpyrrolidone, etc.), halogenated hydrocarbons (carbon number 1 to 2: for example, dichloromethane, 1, 2-dichloroethane, etc.), petroleum solvents (for example, petroleum ether, naphtha, etc.), and the like.

The thickness T1 of the first resin 6 is preferably 0.5 to 3 μm, and more preferably 1 to 2 μm. When the thickness T1 of the first resin 6 is less than 0.5 μm, the amount of the active ingredient in the fluorine-based release agent present in the polymer layer 3 (resin layer 8) is reduced, and the stain-proofing property is lowered. When the thickness T1 of the first resin 6 is greater than 3 μm, the physical property balance of the polymer layer 3 (resin layer 8) is disturbed, and as a result, the scratch resistance is lowered.

The viscosity of the first resin 6 is preferably less than 30cP, more preferably less than 20cP at 25 ℃. When the viscosity of the first resin 6 is 30cP or more, the compatibility between the first resin 6 and the second resin 7 is lowered, and the adhesion between the two resins is lowered.

< second resin >

The second resin 7 preferably contains at least one of the at least one fluorine-based release agents in the first resin 6. Since the same fluorine-based release agent is thus blended in the first resin 6 and the second resin 7, the fluorine-based release agent in the second resin 7 is easily attracted to the fluorine-based release agent in the first resin 6 when the two resins are integrated. As a result, the active ingredient in the fluorine-based release agent is oriented at a high concentration on the surface of the polymer layer 3 (the surface on the opposite side of the base material 2), and the antifouling property is further improved.

The content of the fluorine-based release agent in the second resin 7 is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight, in terms of the effective component. If the content of the fluorine-based release agent in the second resin 7 is within the above range in terms of the effective component, the stain resistance can be further improved while maintaining the scratch resistance. When the second resin 7 contains a plurality of fluorine-based release agents, the total content of the plurality of fluorine-based release agents is preferably (more preferably) within the above range in terms of the effective components.

Preferably, the second resin 7 contains a monofunctional amide monomer. When a monofunctional amide monomer is added to the second resin 7 applied to the surface of the base material 2, curing shrinkage of the resin layer 8 is suppressed, and the cohesive force with the base material 2 is increased, so that the adhesion between the polymer layer 3 and the base material 2 is improved. Furthermore, the compatibility between the first resin 6 and the second resin 7 is improved by the monofunctional amide monomer, and thus the adhesiveness between both resins is improved. In the case where the monofunctional amide monomer is formulated in the second resin 7, the monofunctional amide monomer becomes difficult to penetrate to the surface of the mold 5 as compared with the case where it is formulated in the first resin 6, and therefore even if the number of transfers of the mold 5 increases, the releasability of the polymer layer 3 and the mold 5 is difficult to decrease.

The content of the monofunctional amide monomer in the second resin 7 is preferably 1 to 14% by weight, and more preferably 1.5 to 10% by weight, in terms of the active ingredient. When the content of the monofunctional amide monomer in the second resin 7 is less than 1% by weight in terms of the active ingredient, the adhesion between the polymer layer 3 and the base material 2 may not be sufficiently improved. When the content of the monofunctional amide monomer in the second resin 7 is higher than 14% by weight in terms of the active ingredient, the crosslinking density of the polymer layer 3 is not increased, and as a result, the scratch resistance is decreased. When the second resin 7 contains a plurality of types of monofunctional amide monomers, the total content of the plurality of types of monofunctional amide monomers is preferably (more preferably) within the above range in terms of the effective components.

Examples of monofunctional amide monomers include: n-acryloylmorpholine, N-dimethylacrylamide, N-diethylacrylamide, N- (2-hydroxyethyl) acrylamide, diacetone acrylamide, N-N-butoxymethacrylamide and the like.

Examples of known N-acryloylmorpholine include "ACMO (registered trademark)" manufactured by KJ Chemicals. Examples of known N, N-dimethylacrylamide include "DMAA (registered trademark)" manufactured by KJ Chemicals corporation. Examples of known N, N-diethylacrylamide include "DEAA (registered trademark)" manufactured by KJ Chemicals. Examples of known N- (2-hydroxyethyl) acrylamide include "HEAA (registered trademark)" manufactured by KJ Chemicals. Examples of the diacetone acrylamide known in the art include "DAAM (registered trademark)" manufactured by japan chemical industries, inc. Examples of N-N-butoxymethylacrylamide known per se include "NBMA" manufactured by MRC UNITEC.

The second resin 7 may also contain a multifunctional acrylate. The polyfunctional acrylate increases the crosslinking density of the polymer layer 3, and provides appropriate elasticity (hardness), thereby improving scratch resistance. In the present specification, the "multifunctional acrylate" refers to an acrylate having at least an acryloyl group and having a total of two or more acryloyl groups and polymerizable functional groups other than the acryloyl group per molecule. The polymerizable functional group other than the acryloyl group means at least one functional group selected from the group consisting of a methacryloyl group, a vinyl ether group, and an allyl group.

The number of functional groups of the multifunctional acrylate is two or more, preferably four or more, and more preferably six or more. If the number of functional groups of the multifunctional acrylate is too large, the molecular weight becomes large, and therefore the following phenomenon occurs: the compatibility with other components (for example, a fluorine-based release agent) is lowered, and the transparency of the antifouling film 1 (polymer layer 3) is lowered. In addition, there is a phenomenon in which the adhesion between the polymer layer 3 and the substrate 2 is reduced by curing shrinkage of the resin layer 8. From this viewpoint, the preferable upper limit of the number of functional groups of the multifunctional acrylate is 10. In the present specification, the "number of functional groups of the multifunctional acrylate" refers to the total number of acryloyl groups and polymerizable functional groups other than acryloyl groups (one or more acryloyl groups) per molecule.

Preferably, the multifunctional acrylate comprises at least one multifunctional acrylate having an oxirane group. This imparts appropriate elasticity (hardness) to the polymer layer 3, thereby further improving scratch resistance.

The content of the multifunctional acrylate in the second resin 7 is preferably 75 to 98% by weight, more preferably 80 to 97.5% by weight, in terms of the effective component. If the content of the multifunctional acrylate in the second resin 7 is less than 75% by weight in terms of the effective component, the polymer layer 3 may become hard, and as a result, scratch resistance may be reduced. When the content of the multifunctional acrylate in the second resin 7 is more than 98% by weight in terms of the effective component, the crosslinking density of the polymer layer 3 is not increased, and as a result, the scratch resistance is lowered. When the second resin 7 contains a plurality of types of polyfunctional acrylates, the total content of the plurality of types of polyfunctional acrylates is preferably (more preferably) within the above range in terms of effective component conversion.

Examples of the polyfunctional acrylate include urethane acrylate, 2- (2-ethyleneoxyethoxy) ethyl acrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, and dipropylene glycol diacrylate.

Examples of the known urethane acrylate include "U-10 HA" (number of functional groups: 10) manufactured by Nippon Miura chemical industries, Ltd. Examples of known 2- (2-vinyloxyethoxy) ethyl acrylate include "VEEA" (number of functional groups: 2, number of ethylene oxide groups: 2 per molecule) manufactured by Nippon catalyst Co., Ltd. Examples of known polyethylene glycol (200) diacrylate include "NK ESTER A-200" (number of functional groups: 2, number of ethylene oxide groups: 4 per molecule) manufactured by Mitsumura chemical industries, Ltd. Examples of known polyethylene glycol (400) diacrylate include "NK ESTER A-400" (number of functional groups: 2, number of ethylene oxide groups: 9 per molecule) manufactured by Mitsumura chemical industries, Ltd. Examples of known polyethylene glycol (600) diacrylate include "NK ESTER A-600" (number of functional groups: 2, number of ethylene oxide groups: 14 per molecule) manufactured by Mitsumura chemical industries, Ltd. Examples of the known dipropylene glycol diacrylate include NK ESTER APG-100 (the number of functional groups: 2, the number of propylene oxide groups: 2 per molecule) manufactured by Mitsumura chemical industries, Ltd.

The second resin 7 may also contain a polymerization initiator. The hardening of the resin layer 8 can be improved by the polymerization initiator.

Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator, and among them, a photopolymerization initiator is preferable. The photopolymerization initiator is active to active energy rays and is added to start a polymerization reaction for polymerizing monomers.

Examples of the photopolymerization initiator include a radical polymerization initiator, an anionic polymerization initiator, and a cationic polymerization initiator. Examples of such photopolymerization initiators include acetophenones such as p-tert-butyltrichloroacetophenone, 2' -diethoxyacetophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one; ketones such as benzophenone, 4' -bisdimethylaminobenzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone and 2-isopropylthioxanthone; benzoin ethers such as benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and the like; benzil ketals such as benzil dimethyl ketal and hydroxycyclohexyl phenyl ketone; acylphosphine oxides such as 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide and bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide; and alkylphenols such as 1-hydroxycyclohexyl phenyl ketone.

Examples of known 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide include "LUCIRIN (registered trademark) TPO" and "IRGACURE (registered trademark) TPO" manufactured by IGM Resins, Inc. Examples of the known bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide include "IRGACURE 819" manufactured by IGM Resins. Examples of the known 1-hydroxycyclohexyl phenyl ketone include "IRGACURE 184" manufactured by IGM Resins, Inc.

The second resin 7 may contain a solvent in the same manner as the first resin 6.

The thickness T2 of the second resin 7 is preferably 5 to 15 μm, and more preferably 7 to 12 μm. In the case where the thickness T2 of the second resin 7 is less than 5 μm, there is a phenomenon in which the scratch resistance is reduced. When the thickness T2 of the second resin 7 is greater than 15 μm, the adhesion between the polymer layer 3 and the base material 2 may be reduced.

The viscosity of the second resin 7 is preferably less than 200cP, more preferably less than 150cP at 25 ℃. When the viscosity of the second resin 7 is 200cP or more, the compatibility between the first resin 6 and the second resin 7 is lowered, and the adhesion between the two resins is lowered.

< substrate >

Examples of the material of the substrate 2 include resins such as triacetyl cellulose (TAC), polyethylene terephthalate (PET), and Methyl Methacrylate (MMA). The base material 2 may contain additives such as a plasticizer in addition to the above materials.

The surface of the substrate 2 (the surface on the polymer layer 3 side) may be subjected to an easy-adhesion treatment (e.g., undercoating treatment), and for example, a triacetyl cellulose film subjected to an easy-adhesion treatment may be used. Further, the surface of the base material 2 (the surface on the polymer layer 3 side) may be subjected to saponification treatment, and for example, a saponified triacetyl cellulose film may be used.

When the antifouling film 1 is mounted on a display device having a polarizing plate such as a liquid crystal display device, the base material 2 may constitute a part of the polarizing plate.

The thickness of the substrate 2 is preferably 50 to 100 μm from the viewpoint of ensuring transparency and workability.

< mold >

The mold 5 can be produced by the following method, for example. First, aluminum, which is a material of the mold 5, is formed on the surface of the support base material by a sputtering method. Next, anodization and etching are alternately repeated for the formed aluminum layer, whereby a negative mold (mold 5) having a moth-eye structure can be produced. In this case, the time for performing the anodic oxidation and the time for performing the etching can be adjusted to change the uneven structure of the mold 5.

Examples of the material of the support substrate include: glass; metals such as stainless steel and nickel; polyolefin resins such as polypropylene, polymethylpentene, and cyclic olefin polymers (typically, "ZEONOR (registered trademark)" manufactured by japanese ruisane corporation and "ARTON (registered trademark)" manufactured by JSR corporation, which are norbornene resins); a polycarbonate resin; resins such as polyethylene terephthalate, polyethylene naphthalate and triacetyl cellulose. Further, an aluminum substrate may be used instead of the one formed with an aluminum film on the surface of the supporting substrate.

Examples of the shape of the mold 5 include a flat plate shape and a roll shape.

The surface of the mold 5 is preferably subjected to a mold release treatment with a mold release treating agent. This improves the releasability (e.g., water repellency) of the mold 5, and thus the mold 5 can be easily peeled from the polymer layer 3. Further, since the surface free energy of the mold 5 is low, the effective component in the fluorine-based release agent can be uniformly oriented on the surface of the resin layer 8 (the surface on the opposite side of the substrate 2) when the substrate 2 is pressed against the mold 5 (the above (c)). In addition, the effective component in the fluorine-based release agent can be prevented from peeling off from the surface of the resin layer 8 (the surface on the opposite side of the substrate 2) before the resin layer 8 is cured. As a result, in the antifouling film 1, the active ingredient in the fluorine-based release agent can be uniformly oriented on the surface of the polymer layer 3 (the surface on the opposite side of the base material 2). Since the peeling of the release treatment agent due to the penetration of the monofunctional amide monomer is prevented by this embodiment, the releasability (e.g., water repellency) of the mold 5 can be maintained high even if the number of transfers of the mold 5 is increased.

Examples of the mold release agent used for the mold release treatment of the mold 5 include fluorine-based materials, silicon-based materials, and phosphate-based materials. Examples of the fluorine-based material include "OPTOOL DSX" and "OPTOOL AES 4" manufactured by Dajin industries, Inc.

[ examples and comparative examples ]

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

In examples and comparative examples, materials for producing antifouling films are shown below.

< first resin >

The first resins A1-A7 and a 1-a 7 having the compositions shown in tables 1-4 were used. The outline of each component is as follows.

(fluorine-based mold release agent)

·“MT70”

FOMBLIN MT70 manufactured by Suwei corporation "

Perfluoropolyether group: is provided with

Perfluoroalkyl group: is free of

The effective components are as follows: 80 wt% (perfluoropolyether derivative)

Solvent: 20% by weight (methyl ethyl ketone)

·“AD1700”

FLUOROLINK AD1700 manufactured by Suwei corporation "

Perfluoropolyether group: is provided with

Perfluoroalkyl group: is free of

The effective components are as follows: 70 wt% (perfluoropolyether derivative)

Solvent: 30% by weight (ethyl acetate (15% by weight) and butyl acetate (15% by weight))

·“FAAC-6”

CHEMINOX FAAC-6 manufactured by Unimatec "

Perfluoropolyether group: is free of

Perfluoroalkyl group: is provided with

The effective components are as follows: 100% by weight

·“RS-76-NS”

"Megafac RS-76-NS" manufactured by Dielsen "

Perfluoropolyether group: is free of

Perfluoroalkyl group: is provided with

The effective components are as follows: 100 wt% (fluorine group-containing oligomer (20 wt%) and dipropylene glycol diacrylate (80 wt%))

(acrylic acid 2- (2-ethyleneoxyethoxy) ethyl ester)

·“VE”

"VEEA" manufactured by Japan catalyst Co "

The effective components are as follows: 100% by weight

(monofunctional amide monomer)

·“AC”

"ACMO" manufactured by KJ Chemicals "

The effective components are as follows: 100% by weight

·“DE”

"DEAA" manufactured by KJ Chemicals "

The effective components are as follows: 100% by weight

(polyfunctional acrylate)

·“APG-100”

"NK ESTER APG-100" manufactured by New Zhongcun chemical industries "

The effective components are as follows: 100% by weight

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

The results of converting the content of each component in the first resin into an effective component are shown in tables 5 to 8.

[ Table 5]

[ Table 6]

[ Table 7]

[ Table 8]

< second resin >

The second resins B1-B6 and B1-B4 having the compositions shown in tables 9-11 were used. The outline of each component is as follows.

(fluorine-based mold release agent)

·“MT70”

FOMBLIN MT70 manufactured by Suwei corporation "

Perfluoropolyether group: is provided with

Perfluoroalkyl group: is free of

The effective components are as follows: 80 wt% (perfluoropolyether derivative)

Solvent: 20% by weight (methyl ethyl ketone)

·“FAAC-6”

CHEMINOX FAAC-6 manufactured by Unimatec "

Perfluoropolyether group: is free of

Perfluoroalkyl group: is provided with

The effective components are as follows: 100% by weight

(monofunctional amide monomer)

·“AC”

"ACMO" manufactured by KJ Chemicals "

The effective components are as follows: 100% by weight

(polyfunctional acrylate)

·“A-200”

"NK ESTER A-200" manufactured by NEW CENTRIC CHEMICAL INDUSTRIAL CORPORATION "

The effective components are as follows: 100% by weight

·“A-400”

"NK ESTER A-400" manufactured by NEW CENTRIC CHEMICAL INDUSTRIAL CORPORATION "

The effective components are as follows: 100% by weight

·“A-600”

"NK ESTER A-600" manufactured by NEW CENTRIC CHEMICAL INDUSTRIAL CORPORATION "

The effective components are as follows: 100% by weight

·“U-10”

"U-10 HA" manufactured by New Zhongcun chemical industries "

The effective components are as follows: 100% by weight

(polymerization initiator)

·“819”

IRGACURE 819 manufactured by IGM Resins "

The effective components are as follows: 100% by weight

[ Table 9]

[ Table 10]

[ Table 11]

The results of converting the content of each component in the second resin into an effective component are shown in tables 12 to 14.

[ Table 12]

[ Table 13]

[ Table 14]

< substrate >

"TAC-TD 80U" manufactured by Fuji film corporation was used, and its thickness was 80 μm.

< mold >

A mold fabricated by the following method was used. First, aluminum, which is a mold material, was deposited on a 10cm square glass substrate by sputtering. The thickness of the aluminum layer formed was 1.0. mu.m. Next, by alternately repeating anodization and etching of the formed aluminum layer, an anodized layer provided with many fine holes (the distance between the bottom points of adjacent holes (recesses) is equal to or less than the wavelength of visible light) is formed. Specifically, by sequentially performing anodization, etching, and anodization (anodization: 5 times and etching: 4 times), many minute holes (recesses) having a shape (wedge shape) tapered toward the inside of the aluminum layer are formed, and as a result, a mold having an uneven structure is obtained. The anodic oxidation was carried out using oxalic acid (concentration: 0.03 wt%) under conditions of a liquid temperature of 5 ℃ and an applied voltage of 80V. The time for carrying out the primary anodization was 25 seconds. The etching was carried out at a liquid temperature of 30 ℃ using phosphoric acid (concentration: 1 mol/l). The time for performing one etching was 25 minutes. The mold was observed with a scanning electron microscope, and the depth of the concave portion was 290 nm. Thereafter, the surface of the mold was subjected to a mold release treatment in advance with "OPTOOL AES 4" manufactured by Daiki industries, Ltd. Next, the surface of the mold subjected to the release treatment was subjected to oxygen plasma cleaning (output: 100W) for 20 seconds, and the water contact angle (contact angle after dropping) was adjusted to 125 to 130 degrees. The purpose of such adjustment is to intentionally deteriorate the mold and to make the initial releasability of the mold uniform among the examples.

(example 1)

The antifouling film of example 1 was produced by the production method of the above embodiment.

(a) Application of first resin (step (1))

The first resin a1 was applied in a band shape to the mold surface (surface subjected to mold release treatment). Thereafter, the mold coated with the first resin a1 was put into an oven and subjected to a heat treatment at a temperature of 80 ℃ for 1 minute. The thickness of the first resin a1 was 1 μm.

(b) Application of second resin (step (2))

The second resin B1 was coated in a band shape on the surface of the base material. Thereafter, the substrate coated with the second resin B1 was placed in an oven and subjected to a heat treatment at a temperature of 80 ℃ for 1 minute. The thickness of the second resin B1 was 9 μm.

(c) Formation of resin layer (step (3))

The base material was pressed against the mold with a hand pressure roller with the first resin a1 and the second resin B1 sandwiched therebetween. As a result, a resin layer having an uneven structure on the surface (the surface on the opposite side of the substrate) is formed.

(d) Formation of Polymer layer (step (4))

The resin layer was irradiated with ultraviolet rays from the substrate side (irradiation dose: 1J/cm)²) And hardening it. As a result, a polymer layer is formed.

(e) Stripping of the mold

The mold is peeled away from the polymer layer. As a result, the antifouling film is completed. The thickness of the polymer layer was 10 μm.

The surface specifications of the antifouling film are as follows.

Shape of the convex portion: clock shape

Average pitch of convex portions: 200nm

Average height of convex portion: 200nm

Average aspect ratio of convex portion: 1.0

The surface specification of the antifouling film was evaluated using a scanning electron microscope "S-4700" manufactured by hitachi high and new technologies. In addition, osmium oxide VIII (thickness: 5nm) manufactured by Wavefosis was applied to the surface of the polymer layer (the surface on the opposite side of the substrate) using an osmium coater "Neoc-ST" manufactured by Meiwafosis.

Thereafter, the above (a) to (e) (transfer of the mold) were repeated 20 times. Hereinafter, the case where the number of times of mold transfer is the first time is referred to as "specification 1", and the case where the number of times of mold transfer is the 20 th time is referred to as "specification 2". That is, the antifouling film obtained by the first mold transfer is referred to as "standard 1 antifouling film", and the antifouling film obtained by the 20 th mold transfer is referred to as "standard 2 antifouling film". The mold after the first transfer is referred to as a "mold of specification 1", and the mold after the 20 th transfer is referred to as a "mold of specification 2".

(examples 2 to 9 and comparative examples 1 to 8)

Antifouling films of the respective examples were produced in the same manner as in example 1, except that the conditions shown in tables 15 to 19 were changed.

[ evaluation ]

The antifouling films and molds of the respective examples were evaluated as follows. The results are shown in tables 15 to 19.

< antifouling Property >

The antifouling properties were evaluated for water repellency, oil repellency, and fingerprint wipeability of the antifouling film.

(Water repellency)

For each of the antifouling films of specifications 1 and 2, water was dropped on the surface of the polymer layer (the surface on the opposite side of the base material), and the contact angle after the dropping was measured.

(oil repellency)

With respect to each of the antifouling films of specifications 1 and 2, hexadecane was dropped on the surface of the polymer layer (the surface on the opposite side of the base material), and the contact angle after dropping was measured.

The contact angle is an average value of contact angles at three positions measured by a θ/2 method (θ/2 ═ arctan (h/r), θ: contact angle, r: radius of liquid droplet, and h: height of liquid droplet) using a portable contact angle meter "PCA-1" manufactured by synechia interface science. Here, the central portion of the antifouling film is selected as the measurement point of the first site, and two points which are separated by 20mm or more from the measurement point of the first site and are located at positions point-symmetrical to each other with respect to the measurement point of the first site are selected as the measurement points of the second site and the third site.

(fingerprint wipeability)

First, for the antifouling film of specification 2, a black acrylic plate was attached to the surface of the base opposite to the polymer layer via an optical adhesive layer. Next, after a fingerprint was attached to the surface of the polymer layer (the surface opposite to the base material) of the antifouling film of standard 2, the film was wiped 10 times with "BEMCOT (registered trademark) S-2" manufactured by asahi chemical textile company, and whether or not the fingerprint was wiped off was visually checked under an environment of an illuminance of 100lx (fluorescent lamp). The criteria for determination are as follows.

O: the fingerprint could be completely wiped off and no wiping residue was found.

And (delta): the fingerprint was not evident, but a slight visible wiping residue was visible when the fluorescent light was imaged.

X: fingerprints cannot be wiped off completely.

Here, the case where the determination is "o" or "Δ" is determined to be excellent in fingerprint wipeability.

< scratch resistance >

As for the scratch resistance, the steel wool resistance of the antifouling film was evaluated.

(Steel wool resistance)

First, the polymer layer surface (the surface on the opposite side of the base material) of the antifouling film of specification 2 was rubbed with a load of 400g applied to steel wool "# 0000" manufactured by nippon steel wool corporation. Next, the number of scratches "N" (unit: root) adhered to the polymer layer surface (the surface opposite to the base material) of the antifouling film of standard 2 was counted while visually checking the film under an illumination of 100lx (fluorescent lamp). In addition, in the case of rubbing with steel wool, a surface texture measuring machine "HEIDON (registered trademark) -14 FW" manufactured by new eastern science corporation was used as the testing machine, and the stroke width was 30mm, the speed was 100mm/s, and the number of rubbing times was 10 round trips. The criteria for determination are as follows.

◎：N＝0

○：N＝1～3

△：N＝4～10

×：N＝11～20

××：N≧21

Here, the steel wool resistance was judged to be excellent when judged as ∈ o, or Δ.

< mold releasability >

As the mold release property, water repellency of the mold was evaluated.

(Water repellency)

First, water was dropped on the surface (surface subjected to mold release treatment) of each of the molds of specifications 1 and 2, and the contact angle after the dropping was measured. Next, the rate of change (unit:%) of the water contact angle was calculated from the water contact angle (unit:%) of the mold of specifications 1 and 2 based on the following formula (X).

"rate of change in water contact angle" × (100 × ("water contact angle of mold of specification 1" - "water contact angle of mold of specification 2")/"water contact angle of mold of specification 1" (X)

The criteria for determination are as follows.

O: the rate of change of the water contact angle was less than 5%.

And (delta): the rate of change of the water contact angle is 5% or more and less than 10%.

X: the rate of change of the water contact angle is 10% or more.

Here, the case where the determination is "o" or "Δ" is determined to maintain the mold release property (water repellency) high even if the number of times of transfer of the mold is increased.

[ Table 15]

[ Table 16]

[ Table 17]

[ Table 18]

[ Table 19]

As shown in tables 15 to 17, in examples 1 to 9, even if the number of times of transfer of the mold was increased, the decrease in releasability of the polymer layer and the mold was suppressed, and a stain-proofing film having excellent stain-proofing property was realized. In examples 1 to 9, even if the number of times of transfer of the mold was increased, the antifouling film having excellent scratch resistance was realized.

On the other hand, as shown in tables 18 and 19, in comparative examples 1 to 8, if the number of times of transfer of the mold is increased, the decrease in releasability of the polymer layer and the mold is not suppressed, and a stain-proofing film having excellent stain-proofing property cannot be realized.

Comparative example 1 is an example in which 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin was changed to a monofunctional amide monomer (N-acryloylmorpholine) as compared to example 2. Therefore, in comparative example 1, if the number of times of transfer of the mold is increased, the releasability of the polymer layer and the mold is decreased, and as a result, the antifouling property of the antifouling film is decreased. In comparative example 1, the scratch resistance of the antifouling film was also low.

Comparative example 2 is an example in which 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin was changed to a monofunctional amide monomer (N, N-diethylacrylamide) as compared to example 4. Therefore, in comparative example 2, if the number of times of transfer of the mold is increased, the releasability of the polymer layer and the mold is decreased, and as a result, the antifouling property of the antifouling film is decreased.

Comparative example 3 is an example in which 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin was changed to a monofunctional amide monomer (N-acryloylmorpholine) as compared to example 5. Therefore, in comparative example 3, if the number of times of transfer of the mold is increased, the releasability of the polymer layer and the mold is decreased, and as a result, the antifouling property of the antifouling film is decreased. In comparative example 3, the scratch resistance of the antifouling film was also low.

Comparative example 4 is an example in which 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin was changed to a monofunctional amide monomer (N-acryloylmorpholine) as compared to example 6. Therefore, in comparative example 4, if the number of times of transfer of the mold is increased, the releasability of the polymer layer and the mold is decreased, and as a result, the antifouling property of the antifouling film is decreased. In comparative example 4, the scratch resistance of the antifouling film was also low.

In comparative example 5, since 2- (2-ethyleneoxyethoxy) ethyl acrylate was not added to the first resin but a polyfunctional acrylate (dipropylene glycol diacrylate) was added, if the number of times of transferring the mold was increased, the releasability of the polymer layer and the mold was decreased, and as a result, the antifouling property of the antifouling film was decreased. In comparative example 5, the scratch resistance of the antifouling film was also low.

Comparative example 6 is an example in which 2- (2-vinyloxyethoxy) ethyl acrylate in the first resin was changed to a monofunctional amide monomer (N, N-diethylacrylamide) with respect to example 9. Therefore, in comparative example 6, if the number of times of transfer of the mold is increased, the releasability of the polymer layer and the mold is decreased, and as a result, the antifouling property of the antifouling film is decreased. In comparative example 6, the scratch resistance of the antifouling film was also low.

In comparative example 7, the content of 2- (2-ethyleneoxyethoxy) ethyl acrylate in the first resin was less than 40% by weight in terms of the effective component, and therefore the scratch resistance was low.

In comparative example 8, the content of 2- (2-ethyleneoxyethoxy) ethyl acrylate in the first resin was higher than 95% by weight in terms of the effective component, and therefore the antifouling property (particularly fingerprint wiping property) was low.

[ accompanying notes ]

One aspect of the present invention is a method for producing an antifouling film having a base material and a polymer layer disposed on a surface of the base material and having a concavo-convex structure in which a plurality of convex portions are provided at a pitch of a visible light wavelength or less on the surface, the method comprising: a step (1) of applying a first resin to the surface of a mold; a step (2) of applying a second resin to the surface of the base material; a step (3) of pressing the base material against the mold with the first resin and the second resin interposed therebetween to form a resin layer having the uneven structure on the surface; and a step (4) in which the resin layer is cured to form the polymer layer, wherein the first resin contains at least one fluorine-based release agent and 2- (2-vinyloxyethoxy) ethyl acrylate, and contains 40 to 95 wt% of the 2- (2-vinyloxyethoxy) ethyl acrylate in terms of the active ingredient. According to this aspect, even if the number of times of transfer of the mold is increased, a decrease in releasability of the polymer layer and the mold can be suppressed, and a stain-proofing film having excellent stain-proofing property and scratch resistance can be produced.

The at least one fluorine-based release agent may be a plurality of fluorine-based release agents. This further improves the antifouling property.

The at least one fluorine-based release agent may include at least one of a fluorine-based release agent having a perfluoropolyether group and a fluorine-based release agent having a perfluoroalkyl group. This further improves the stain resistance and scratch resistance as compared with other types of release agents (e.g., silicon-based release agents, phosphate-based release agents, etc.).

The second resin may contain at least one of the at least one fluorine-based release agents. In this way, since the same fluorine-based release agent is mixed in the first resin and the second resin, the fluorine-based release agent in the second resin is easily attracted to the fluorine-based release agent in the first resin when the two resins are integrated. As a result, the active ingredient in the fluorine-based release agent is oriented at a high concentration on the surface of the polymer layer (the surface opposite to the base material), and the antifouling property is further improved.

The second resin may also contain a monofunctional amide monomer. This suppresses curing shrinkage of the resin layer and improves cohesion between the resin layer and the base material, thereby improving adhesion between the polymer layer and the base material. Further, since the compatibility between the first resin and the second resin is improved, the adhesion between the two resins is improved.

The surface of the mold may be subjected to a mold release treatment with a mold release treating agent. This improves the releasability (e.g., water repellency) of the mold, and therefore the mold can be easily peeled from the polymer layer. Further, since the surface free energy of the mold is low, the active ingredient in the fluorine-based release agent can be uniformly oriented on the surface of the resin layer (the surface on the opposite side of the substrate) when the substrate is pressed against the mold (step (3)). Further, the effective component in the fluorine-based release agent can be prevented from being separated from the surface of the resin layer (the surface on the opposite side of the base material) before the resin layer is cured. As a result, in the antifouling film, the active ingredient in the fluorine-based release agent can be uniformly oriented on the surface of the polymer layer (the surface on the opposite side of the base material).

The thickness of the polymer layer may be 5.0 to 20.0 μm. Thereby, the active ingredient in the fluorine-based release agent is oriented at a higher concentration on the surface of the polymer layer (the surface on the opposite side of the substrate).

The average pitch of the plurality of projections may be 100 to 400 nm. This can sufficiently prevent the occurrence of optical phenomena such as moire fringes and rainbow unevenness.

The average height of the plurality of projections may be 50 to 600 nm. This can achieve a preferable average aspect ratio of the plurality of projections.

The average aspect ratio of the plurality of projections may be 0.8 to 1.5. This can sufficiently prevent the occurrence of optical phenomena such as moire fringes and rainbow unevenness, and realize excellent antireflection properties. In addition, the occurrence of tackiness due to the deterioration of the processability of the uneven structure and the deterioration of the transfer state when the uneven structure is formed can be sufficiently prevented.

Description of the reference numerals

1 antifouling film

2 base material

3 Polymer layer

4 convex part

5 mould

6 first resin

7 second resin

8 resin layer

Pitch of P convex part

Height of H convex part

Thickness of the T Polymer layer

Thickness of T1 first resin

Thickness of T2 second resin

Claims

1. A method for producing an antifouling film having a base material and a polymer layer disposed on a surface of the base material and having a concavo-convex structure in which a plurality of convex portions are provided at a pitch of a visible light wavelength or less on the surface, comprising:

a step (1) of applying a first resin to the surface of a mold;

a step (2) of applying a second resin to the surface of the base material;

a step (3) of pressing the base material against the mold with the first resin and the second resin interposed therebetween to form a resin layer having the uneven structure on the surface; and

a step (4) of hardening the resin layer to form the polymer layer,

the first resin contains at least one fluorine-based release agent and 2- (2-ethyleneoxyethoxy) ethyl acrylate, and contains 40 to 95 wt% of the 2- (2-ethyleneoxyethoxy) ethyl acrylate in terms of active ingredients.

2. The method for producing a stain-resistant film according to claim 1, wherein the at least one fluorine-based release agent comprises at least one of a fluorine-based release agent having a perfluoropolyether group and a fluorine-based release agent having a perfluoroalkyl group.

3. The method for producing a stain-proofing film according to claim 1 or 2, wherein the second resin contains at least one of the at least one fluorine-based release agents.

4. The method for producing a stain resistant film according to claim 1 or 2, wherein the second resin contains a monofunctional amide monomer.

5. The method for producing an antifouling film according to claim 1 or 2, wherein the mold surface is subjected to a mold release treatment with a mold release treatment agent.

6. The method for producing an antifouling film according to claim 1 or 2, wherein the polymer layer has a thickness of 5.0 to 20.0 μm.

7. The method for producing an antifouling film according to claim 1 or 2, wherein the average pitch of the plurality of projections is 100 to 400 nm.

8. The method for producing an antifouling film according to claim 1 or 2, wherein the average height of the plurality of projections is 50 to 600 nm.

9. The method for producing an antifouling film according to claim 1 or 2, wherein the average aspect ratio of the plurality of projections is 0.8 to 1.5.