JP5838668B2 - Article having fine uneven structure on surface, and article with protective film - Google Patents

Description

  The present invention relates to an article having a fine concavo-convex structure on its surface and an article with a protective film.

  In recent years, articles such as a functional film having a fine concavo-convex structure on the surface have been proposed for the purpose of imparting antireflection properties, antifogging properties, antifouling properties, water repellency and the like. In particular, it is known that a fine concavo-convex structure called a Moth-Eye structure exhibits excellent antireflection properties.

  As a method for forming a fine concavo-convex structure on the surface of an article, there are a method for directly processing the surface of a material, a transfer method for transferring the structure using a stamper (mold) having an inverted structure corresponding to the fine concavo-convex structure, and the like. The latter method is superior in terms of productivity and economy. As a method for forming an inverted structure in a stamper, an electron beam drawing method, a laser beam interference method, and the like are known, but in recent years, an alumina having a fine concavo-convex structure formed by anodization as a stamper that can be more easily manufactured. Is attracting attention.

Ordinarily, an article having a fine concavo-convex structure formed on the surface is used for the purpose of preventing dirt and the like from adhering to the surface and maintaining (protecting) the shape of the fine concavo-convex structure. In the meantime, a protective film is affixed on the surface where the fine uneven structure was formed.
However, an article having a fine concavo-convex structure on the surface has a smaller contact area with the protective film than an article having a flat surface, so the protective film does not adhere sufficiently, and the protective film may be peeled off during storage or transportation. there were. In particular, the fine concavo-convex structure of the Moth-Eye structure has a smaller contact area with the protective film because the interval (period) between the convex portions is narrower than that of a normal fine concavo-convex structure, and it is difficult to adhere the protective film. there were.

Therefore, when sticking a protective film on the article | item which has a fine uneven structure on the surface, it was necessary to use the protective film (strong adhesive protective film) provided with the adhesive layer with strong adhesive force.
However, when a strong adhesive protective film is used, the adhesive of the protective film penetrates into the fine uneven structure as time passes, and the adhesive remains inside the fine uneven structure even after the protective film is peeled off. However, as a result, there is a problem that the antireflection property of the fine concavo-convex structure is lowered due to an increase in reflectance.

  Therefore, as a method for solving the problem of sticking of the protective film and the problem of adhesive residue, a region having a fine uneven structure (uneven portion) on the surface of the article and a flat region having no fine uneven structure (flat portion) And a method of adhering a protective film to the flat part so as to cover the uneven part has been proposed (see, for example, Patent Documents 1 and 2). According to Patent Documents 1 and 2, since a sufficient adhesion strength can be secured in the flat part by sticking the protective film to the flat part, there is no need to use a protective film having a strong adhesive layer. The protective film can be attached to the article while suppressing the adhesive residue.

JP 2010-107858 A International Publication No. 2010/113868

By the way, for example, when continuously producing a film-like article having a fine concavo-convex structure on the surface, a protective film is continuously adhered to obtain an article with a protective film, and then wound into a roll and stored as a roll. May be transported.
However, in the methods described in Patent Documents 1 and 2, when a protective film is attached to an article having a fine concavo-convex structure on the surface and stored or transported as it is, the protective film is closely attached, The protective film was easily peeled off when the article with film was wound up in a roll or when the article with protective film was unwound from the roll. In particular, when the width of the concavo-convex portion was wide and the width of the flat portion was narrow, peeling of the protective film was remarkable.

  The present invention has been made in view of the above circumstances, and even if the protective film is attached and wound up or unrolled into a roll shape, the protective film is difficult to peel off, and when the protective film is peeled off, there is little adhesive residue. An object is to provide an article having a concavo-convex structure on the surface, and an article with a protective film in which a protective film is attached to the surface of the article.

  As a result of intensive studies, the present inventors have sufficiently adhered the protective film by prescribing the peel strength with the protective film of the flat portion, and as a result, the protective film is attached to an article having a fine uneven structure on the surface. In order to complete the present invention, it is found that the protective film is difficult to peel off even if the article with a protective film is rolled up or the article with the protective film is unwound from the roll. It came.

That is, the article having the fine concavo-convex structure on the surface thereof according to the present invention is an article having the fine concavo-convex structure on the surface, and the surface is protected by a protective film, wherein the surface is a region (I ) And a region (II) having a peel strength with respect to the protective film of more than 1 N / 25 mm.
The surface preferably has a region (III) adjacent to the region (II) and having a lower peel strength from the protective film than the region (II).
Further, the base material, the intermediate layer formed on the surface of the base material, and the curing formed on the surface of the intermediate layer so that at least a part of the surface of the intermediate layer is exposed has a fine uneven structure. It is preferable that the surface of the cured layer is the region (I) and the exposed surface of the intermediate layer is the region (II).
Moreover, it is preferable that the said intermediate | middle layer is formed in the surface of a base material so that at least one part of the surface of the said base material may be exposed, and the exposed surface of the said base material is the said area | region (III).
Furthermore, the region (II) is preferably located on both sides of the region (I).
Moreover, it is preferable that the said area | region (III) is located in the edge part of this surface of the article | item which has a fine concavo-convex structure on the surface.
Furthermore, it is preferable that the surface of the region (II) does not have the fine uneven structure.
Moreover, the article with a protective film of the present invention is characterized in that the surface of the article having the fine concavo-convex structure on the surface is protected by a protective film.

  According to the present invention, an article having a fine concavo-convex structure on its surface that is difficult to peel off even when the protective film is stuck and wound up or unrolled into a roll, and has little adhesive residue when the protective film is peeled off. And an article with a protective film in which a protective film is attached to the surface of the article.

It is a longitudinal section showing typically an example of the article which has the fine concavo-convex structure of the present invention on the surface. It is a top view of the article | item which has the fine concavo-convex structure shown in FIG. 1 on the surface. It is a longitudinal cross-sectional view which shows typically the hardened layer with which the article | item which has the fine concavo-convex structure shown in FIG. It is a longitudinal cross-sectional view which shows typically the other example of the article | item which has the fine concavo-convex structure of this invention on the surface. It is a longitudinal cross-sectional view which shows typically the other example of the article | item which has the fine concavo-convex structure of this invention on the surface. It is a longitudinal cross-sectional view which shows typically the other example of the article | item which has the fine concavo-convex structure of this invention on the surface. It is a longitudinal cross-sectional view which shows typically the other example of the article | item which has the fine concavo-convex structure of this invention on the surface. It is a longitudinal cross-sectional view which shows typically the other example of the article | item which has the fine concavo-convex structure of this invention on the surface. It is a longitudinal cross-sectional view which shows typically an example of the molded object with a protective film of this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.
2 to 9, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof may be omitted. Moreover, in FIGS. 1-9, in order to make each member into the magnitude | size which can be recognized on drawing, the scale is varied for every member.
In the present specification, “(meth) acrylate” means acrylate and methacrylate. “(Co) polymer” means a polymer and a copolymer.

[Articles having fine concavo-convex structure on the surface]
The article having the fine concavo-convex structure on the surface thereof has the fine concavo-convex structure on the surface, and the surface is usually protected with a protective film until it is used. The surface of the article having a fine concavo-convex structure has a region (I) of the fine concavo-convex structure and a region (II) having a peel strength of more than 1 N / 25 mm from the protective film. It is preferable to have a region (III) adjacent to (II) and having a lower peel strength from the protective film than the region (II).
In addition, in this invention, this surface (namely, surface protected by a protective film) of the article | item which has a fine uneven structure on the surface is called "the surface of an article | item."

1 and 2 show an example of an article having the fine concavo-convex structure of the present invention on the surface. FIG. 1 is a longitudinal sectional view schematically showing an article 10 having a fine concavo-convex structure on the surface (hereinafter sometimes simply referred to as “article”), and FIG. 2 schematically shows the article 10 shown in FIG. It is a top view. In the article 10 of this example, the base 11, the intermediate layer 12 formed on the surface of the base 11 so that both ends of the surface of the base 11 are exposed, and both ends of the surface of the intermediate layer 12 are exposed. As described above, the intermediate layer 12 has a hardened layer 13 having a fine concavo-convex structure formed on the surface thereof.
In the case of the article 10 illustrated in FIG. 1, the surface of the article 10 includes a surface 13 a of the cured layer 13, an exposed surface 12 a of the intermediate layer 12, and an exposed surface 11 a of the substrate 11. The surface 13a is the region (I), the exposed surface 12a of the intermediate layer 12 is the region (II), and the exposed surface 11a of the substrate 11 is the region (III).
1 is a long film, and both ends of the surface of the base material 11 and the intermediate layer 12 are end portions of the surface in the width direction.

Region (I) is a region having a fine concavo-convex structure on the surface of the article 10 and is a region that exhibits functions such as antireflection properties. When a protective film is attached to the surface of the article 10, the protective film may be attached to the region (I), or the protective film may float on the region (I).
The peel strength (peel strength (I)) with the protective film in region (I) when the protective film is attached to the surface of region (I) and peeled is not particularly limited, but is 1.0 N / 25 mm or less. Preferably, 0.03 to 0.5 N / 25 mm is more preferable. If the peel strength (I) exceeds 1.0 N / 25 mm, the protective film may be firmly adhered in the region (I) and it may be difficult to peel off the protective film.

The peel strength (I) is a value measured as follows.
A product with a protective film attached to the surface of the article (article with protective film) is set on a peel strength measuring machine, and a 90 ° peel test is performed at the place where the region (I) and the protective film are attached. The peel strength is measured, and this is defined as peel strength (I).

Region (II) is the exposed surface 12a of the intermediate layer 12 among the surfaces of the article 10, and when the protective film is attached to the surface of the article 10, the flat surface to which the protective film is attached, that is, It is an area | region which does not have a fine uneven structure.
Further, the region (II) has a peel strength (peel strength (II)) with a protective film in the region (II) of 1N / when the protective film is attached to the surface of the region (II) and peeled off. It is an area that is greater than 25 mm. If the peel strength (II) exceeds 1 N / 25 mm, the protective film adheres sufficiently in the region (II) when the protective film is attached to the surface of the article 10, so that the protective film is on the region (I). Even if it is in a floating state, there is no risk that the protective film will be inadvertently peeled off. Furthermore, even if a protective film is attached to the surface of the article 10 to form an article with a protective film, and this is rolled up into a roll, or an article with a protective film is unwound from a roll, The protective film is difficult to peel off. In addition, since sufficient adhesion strength can be secured in the region (II), it is not necessary to use a protective film having a strong adhesive layer, and even in a state where the protective film floats on the region (I) Since it is good, the adhesive residue can be suppressed when the protective film is peeled off.

The upper limit of the peel strength (II) is preferably 10 N / 25 mm or less from the viewpoint that cohesive failure of the intermediate layer 12 can be suppressed when the protective film is peeled off, and particularly 2.5 N from the point that the protective film is easily peeled off. / 25 mm or less is more preferable.
Peel strength (II) is determined by performing a peel test at a location where region (II) and the protective film are adhered and measuring the peel strength in the same manner as peel strength (I).

Region (III) is the exposed surface 11a of the base material 11 among the surfaces of the article 10, and when the protective film is adhered to the surface of the article 10, the flat surface to which the protective film is adhered, that is, It is an area | region which does not have a fine uneven structure.
The area (III) has a peel strength (peel strength (III)) with the protective film in the area (III) when a protective film is attached to the surface of the area (III) and peeled. It is a region lower than (II). Because the peel strength (III) is lower than the peel strength (II), when the protective film is peeled off from the article to which the protective film is attached, the area (III) becomes the starting point of peeling, so the protective film can be easily peeled off. it can.

The peel strength (III) is not particularly limited as long as it is lower than the peel strength (II), but is preferably higher than the peel strength (I), specifically 0.01 to 1 N / 25 mm, preferably 0.04. -0.25N / 25mm is more preferable. When the peel strength (III) is less than 0.01 N / 25 mm, the protective film may be inadvertently peeled off in the region (III), and when an article with a protective film is taken up or unrolled from a roll May interfere. On the other hand, when the peel strength (III) exceeds 1 N / 25 mm, the protective film is more closely adhered than necessary in the region (III), and when the protective film is peeled off, the region (III) may become difficult to be a starting point of peeling.
The peel strength (III) is determined by performing a peel test at a location where the region (III) and the protective film are adhered in the same manner as the peel strength (I) and measuring the peel strength.

  The position of the region (II) and the region (III) is not particularly limited. However, the region (II) is preferably adjacent to the region (I), and particularly located on both sides of the region (I) as shown in FIG. It is preferable to do. If the region (II) is adjacent to the region (I), the protective film is sufficiently adhered in the region (II) when the protective film is attached to the surface of the article 10, so that the region (I) and the region ( It is possible to prevent dust and the like from entering from the interface with II). In particular, even when the protective film floats on the region (I), entry of dust and the like can be prevented. Therefore, the fine concavo-convex structure in the region (I) can be more effectively protected. Further, when the article 10 is continuously produced as a long film, as will be described in detail later, when the cured layer 13 is formed on the intermediate layer 12 formed on the substrate 11, the application width and application of the cured layer 13 By adjusting the position, the region (II) can be easily provided adjacent to the region (I).

On the other hand, the region (III) is not particularly limited as long as it is adjacent to the region (II), but the region (III) is preferably located at the end of the surface of the article 10 as shown in FIG. If area | region (III) is located in the edge part of the surface of the article | item 10, since the starting point of peeling when peeling a protective film will also be located in an edge part, it will become easier to peel off a protective film. Further, when the article 10 is continuously produced as a long film, as will be described in detail later, by adjusting the coating width and coating position of the intermediate layer 12 when forming the intermediate layer 12 on the substrate 11, Region (III) can be easily provided at the end of the surface of the article 10.
In addition, the edge part of the surface of the article | item 10 is an edge part of the surface in the width direction, when the article | item 10 is a elongate film.

  The size of the region (II) and the region (III) is not particularly limited. For example, as shown in FIG. 2, the width w2 of the region (II) is preferably 0.001 mm or more, and is 0.1 mm or more. It is more preferable. If the width w2 is 0.001 mm or more, the contact area with the protective film can be secured, so that the protective film can be easily adhered to the article 10, and the article with the protective film can be wound or unwound from the roll. However, the protective film is difficult to peel off. The upper limit of the width w2 is not particularly limited, but when the article 10 is used as an antireflection film, for example, the region (I) exhibits antireflection properties. Therefore, from the viewpoint of reducing the portion that does not exhibit antireflection properties when the article 10 is attached to a display device or the like and reducing the cost, the width w2 is preferably 100 mm or less, and is preferably 20 mm or less. More preferred.

Moreover, as shown in FIG. 2, the width w3 of the region (III) is preferably 0.001 mm or more, and more preferably 0.1 mm or more. If width w3 is 0.001 mm or more, since the starting point of peeling at the time of peeling off a protective film can be ensured, it becomes easy to peel off a protective film. The upper limit value of the width w3 is not particularly limited, but the width w3 is 100 mm or less from the viewpoint of reducing a portion that does not exhibit antireflection properties when the article 10 is attached to a display device or the like and reducing the cost. It is preferable that it is 20 mm or less.
Note that the width w1 of the region (I) is not particularly limited, and may be set as appropriate according to the use of the article 10.

Here, each layer which comprises the article | item 10 shown in FIG. 1 is demonstrated.
As described above, the exposed surface 11a of the substrate 11 is the region (III), the exposed surface 12a of the intermediate layer 12 is the region (II), and the surface 13a of the hardened layer 13 is the region (I). .
The material constituting the substrate 11 is not particularly limited as long as the peel strength (III) is lower than the peel strength (II). However, a material that transmits light is preferable. ) Synthetic polymers such as polymers, polycarbonates, styrene (co) polymers, (meth) acrylate-styrene copolymers, semi-synthetic polymers such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, polyethylene terephthalate, poly Polyester such as lactic acid, polyamide, polyimide, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polyurethane, and composites of these polymers (for example, polymethyl methacrylate and Composite polylactic acid, a composite of polymethyl methacrylate and polyvinyl chloride), glass and the like.

There is no restriction | limiting in particular in the shape of the base material 11, Although it can select suitably according to the articles | goods 10 to manufacture, For example, when the articles | goods 10 are antireflection films, a sheet form and a film form are preferable. In particular, from the viewpoint of continuously producing the article 10, it is preferable that the base material 11 has a bendable sheet shape or film shape. Moreover, when the base material 11 is a sheet form or a film form, it is preferable that the thickness is 500 micrometers or less.
Further, if the peel strength (III) can be maintained lower than the peel strength (II), the intermediate layer 12 of the substrate 11 is used for the purpose of improving the properties such as adhesion, antistatic properties, scratch resistance, and weather resistance. A surface treatment such as coating or corona treatment may be applied to the surface on which the surface is formed.

The intermediate layer 12 is not particularly limited as long as the peel strength (II) is greater than 1 N / 25 mm, but the peel strength when adhered to a flat plate made of acrylic resin is 0.01 to 10 N / It is preferable that it is 25 mm, More preferably, it is 0.1-1 N / 25mm. If the peel strength of the intermediate layer 12 with respect to the acrylic resin flat plate is within the above range, the peel strength with respect to the protective film in the region (II) (that is, the intermediate layer 12) can be selected by selecting an adhesive used for the protective film described later. And the adhesion of the protective film) can be easily adjusted to more than 1 N / 25 mm. Accordingly, the protective film is sufficiently adhered in the region (II), and cohesive failure of the intermediate layer 12 can be suppressed when the protective film is peeled off. In particular, if the peel strength of the intermediate layer 12 with respect to the acrylic resin flat plate is within a range of 0.1 to 1 N / 25 mm, the intermediate layer 12 and the protective film can be easily peeled when the protective film is peeled off.
For the peel strength of the intermediate layer 12 with respect to the acrylic resin flat plate, set the intermediate layer formed on the acrylic resin flat plate on a peel strength measuring machine, and perform a 90 ° peel test to measure the peel strength. Is required.

The intermediate layer 12 is preferably formed from an intermediate layer material containing a highly adhesive resin. Examples of the resin having high adhesion include acrylic resins, polyester resins, polyurethane resins, acrylic graft polyester resins, polyethyleneimine resins, polycarbonate resins, polybutadiene resins, and polystyrene resins.
Among these highly adhesive resins, a resin containing a low molecular weight component having a number average molecular weight of 1,000,000 or less, preferably 100,000 or less, more preferably 40,000 or less, a crosslinking agent amount of 20 parts or less, A resin having a low crosslinking density of preferably 10 parts or less, more preferably 1 part or less, and a resin having an elastic modulus at room temperature of 10 ¹⁰ Pa or less, preferably 10 ⁹ Pa or less, more preferably 10 ⁸ Pa or less are preferred.

  Although the optimal thickness of the intermediate layer 12 varies depending on the application of the article 10 to be manufactured, it is generally preferably 0.1 to 80 μm, more preferably 0.5 to 40 μm, and particularly preferably 1 to 10 μm. If the intermediate layer 12 is thinner than the above range, light may not be recognized as a layer. The intermediate layer 12 also plays a role of enhancing the adhesion between the base material 11 and the cured layer 13. However, if the intermediate layer 12 is too thin, the adhesion between the base material 11 and the cured layer 13 is improved, hard coating, charging. Functions such as prevention are not sufficiently developed. On the other hand, if the intermediate layer 12 is thicker than the above range, cracks may occur on the surface. Moreover, it is not economical because of the increased cost.

The intermediate layer 12 is made of an ultraviolet absorber, an antioxidant, a release agent, a lubricant, a plasticizer, an antistatic agent, a light stabilizer, a flame retardant, a flame retardant aid, a polymerization inhibitor, a filler, and a silane as necessary. You may contain additives, such as a coupling agent, a coloring agent, a reinforcement | strengthening agent, an inorganic filler, an impact modifier, and a near-infrared absorber.
Further, the intermediate layer 12 may be a single layer or a multilayer.

The cured layer 13 is a layer formed on the base material 11 via the intermediate layer 12, and is formed, for example, by polymerizing and curing an active energy ray-curable resin composition.
The thickness of the hardened layer 13 is preferably 6 to 29 μm, and more preferably 8 to 21 μm. If the hardened layer 13 is thinner than the above range, it may break. On the other hand, if the cured layer 13 is thicker than the above range, curing may not proceed sufficiently with normal ultraviolet irradiation when the cured layer 13 is formed using the active energy ray-curable resin composition.

On the surface 13a of the hardened layer 13, as shown in FIG. 1, a fine concavo-convex structure that exhibits functions such as surface antireflection and water repellency is formed. Specifically, as shown in FIG. 3, a plurality of convex portions 13 b and concave portions 13 c are formed at equal intervals on the surface 13 a of the hardened layer 13.
Examples of the shape of the convex portion 13b include a conical shape, a pyramid shape, and a bell shape. However, the shape of the convex portion 13b is not limited thereto, and may be a structure in which the occupation ratio of the cross-sectional area when the hardened layer 13 is cut by the film surface continuously increases. Further, finer convex portions may be united to form a fine concavo-convex structure. That is, the shape may be any shape as long as the refractive index is continuously increased from the air to the surface of the material and the antireflection performance is achieved with both low reflectance and low wavelength dependency.

When the article 10 of the present invention is used as an antireflection film, for example, in order to develop good antireflection performance, the interval between adjacent convex portions 13b or concave portions 13c of the fine concavo-convex structure (in FIG. 3, adjacent convex portions 13b). The distance p) between the center points (tops) must be smaller than the wavelength of visible light. Here, “visible light” refers to light having a wavelength of 380 to 780 nm. If this space | interval is 380 nm or less, scattering of visible light can be suppressed and the article | item of this invention can be used conveniently for optical uses, such as an antireflection film.
Further, from the viewpoint of suppressing an increase in the minimum reflectance and the reflectance at a specific wavelength, the height of the convex portion 13b or the depth of the concave portion 13c (in FIG. 3, from the center point (bottom point) of the concave portion 13c to the convex portion 13b. The vertical distance d) to the center point (top) is preferably 60 nm or more, more preferably 90 nm or more.
In addition, about the shape of the fine concavo-convex structure which expresses favorable antireflection performance, it describes in Unexamined-Japanese-Patent No. 2009-31764 etc., The same shape can be used also in this invention.

Next, an active energy ray-curable resin composition suitable as a raw material for the cured layer 13 will be described. The active energy ray-curable resin composition is a resin composition that cures by irradiating active energy rays so that a polymerization reaction proceeds.
This active energy ray-curable resin composition (hereinafter sometimes simply referred to as “resin composition”) comprises a polymerization reactive monomer component, an active energy ray polymerization initiator, and other components as necessary. contains.

Known components can be applied to the polymerization reactive monomer component and the active energy ray polymerization initiator suitable for forming the fine uneven structure. For example, examples of the polymerization reactive monomer component include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule.
Examples of the monomer having a radical polymerizable bond include monofunctional monomers and polyfunctional monomers, and specific examples include various (meth) acrylates and derivatives thereof.
Examples of the monomer having a cationic polymerizable bond include monomers having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group, and the like.
As a polymerization reactive monomer component and an active energy ray polymerization initiator suitable for forming a fine concavo-convex structure, for example, various compounds described in JP 2009-31764 A can be used.

  Resin composition is UV absorber, antioxidant, mold release agent, lubricant, plasticizer, antistatic agent, light stabilizer, flame retardant, flame retardant auxiliary, polymerization inhibitor, filler, silane as necessary You may contain additives, such as a coupling agent, a coloring agent, a reinforcement | strengthening agent, an inorganic filler, and an impact modifier.

As will be described in detail later, the hardened layer 13 is formed using, for example, a stamper in which an inverted structure of a fine concavo-convex structure is formed. In the step of forming the cured layer 13, when the resin composition is poured into a stamper and cured, the viscosity of the resin composition measured with a rotary B-type viscometer at 25 ° C. is 10,000 mPa · s. The following is preferable, 5000 mPa · s or less is more preferable, and 2000 mPa · s or less is particularly preferable. However, even if the viscosity of the resin composition exceeds 10,000 mPa · s, it can be used without impairing workability if the resin composition can be preheated and lowered in viscosity when poured into the stamper.
Further, the viscosity of the resin composition measured with a rotary B-type viscometer at 70 ° C. is preferably 5000 mPa · s or less, and more preferably 2000 mPa · s or less.

  In addition, in the process of forming the cured layer 13, when continuous production is performed using a belt-shaped or roll-shaped stamper, the viscosity of the resin composition measured with a rotary B-type viscometer at 25 ° C. is taken into consideration. Is preferably 100 mPa · s or more, more preferably 150 mPa · s or more, and particularly preferably 200 mPa · s or more. If the viscosity of the resin composition is 100 mPa · s or more, the resin composition is difficult to leak to the side beyond the width of the stamper in the step of pressing the stamper against the resin composition. In addition, it is easy to arbitrarily adjust the thickness of the hardened layer 13.

  The viscosity of the resin composition can be adjusted by adjusting the type and content of the monomer contained. Specifically, when a large amount of a monomer containing a functional group having an intermolecular interaction such as a hydrogen bond or a chemical structure is used, the viscosity of the resin composition increases. Further, when a large amount of a low molecular weight monomer having no intermolecular interaction is used, the viscosity of the resin composition becomes low.

In addition, if the cured resin composition is soft, the nano-sized convex portions 13b may come close to each other when or after the cured product is peeled off from the stamper that forms the fine concavo-convex structure. In the nano region, even surface tension that does not cause a problem in the macro region works remarkably. That is, in order to reduce the surface free energy, a force is applied to make the surface area smaller by closely approaching the convex portions 13b of the fine concavo-convex structure. When this force exceeds the hardness of the cured product, the convex portions 13b are closely attached to each other. In such a fine concavo-convex structure, desired antireflection performance and water repellent functionality may not be sufficiently exhibited.
From the above points, the tensile elastic modulus of the cured product of the resin composition is preferably 1 GPa or more. If such a resin composition is used, it will be easy to avoid that the convex parts 13b adjoin each other.

<Method for producing article having fine concavo-convex structure on surface>
The article 10 shown in FIG. 1 is obtained, for example, by forming an intermediate layer 12 on a base material 11 and then forming a cured layer 13 on the intermediate layer 12 using a stamper having a reverse structure of a fine concavo-convex structure on the surface. It is done.
As a method for forming the intermediate layer 12, the above-described resin or additive is dissolved or dispersed in a solvent and the intermediate layer material is applied onto the substrate 11, and then the solvent is dried. Examples thereof include a method in which a material for an intermediate layer containing a reactive resin is applied on the substrate 11 and then cured by light or heat, a method in which these are combined in multiple stages, and the like.

As a method of forming the hardened layer 13, a method of batch-forming the hardened layer 13 by injection molding or press molding using a stamper having an inverted structure of a fine concavo-convex structure on the surface, a roll-shaped stamper, The resin composition is disposed between the intermediate layer on the substrate 11, the resin composition is cured by irradiation with active energy rays, the uneven shape of the stamper is transferred, and then the stamper is peeled to remove the cured layer 13. Method of forming continuously, transferring the stamper uneven shape to the resin composition, peeling off the stamper, and then irradiating the active energy ray to cure the resin composition to continuously form the cured layer 13 The method etc. are mentioned.
A method for forming a fine concavo-convex structure that exhibits good antireflection performance is described in Japanese Patent Application Laid-Open No. 2009-31764, and the same formation method can be used in the present invention.

In addition, when manufacturing the article | item 10 continuously, the material for intermediate | middle layers and a resin composition may be apply | coated simultaneously, you may apply | coat continuously, and may apply | coat each independently.
Moreover, the method for forming the inverted structure of the fine concavo-convex structure on the stamper used for forming the hardened layer 13 is not particularly limited, and examples thereof include an electron beam lithography method and a laser beam interference method. For example, a mold having a fine concavo-convex structure can be obtained by coating a suitable photoresist film on a suitable support substrate, exposing the film with light such as an ultraviolet laser, an electron beam, or X-ray, and developing. Further, anodized porous alumina can be used as a stamper. For example, a pore structure having an interval of 20 to 200 nm formed by anodizing aluminum with oxalic acid, sulfuric acid, phosphoric acid or the like as an electrolyte at a predetermined voltage may be used as a stamper.

<Effect>
Since the surface of the article of the present invention described above has the above-described regions (I) and (II), the protective film adheres sufficiently in the region (II) when the protective film is attached. Therefore, even if a protective film is attached to the surface of the article to form an article with a protective film, and this is rolled up into a roll, or an article with a protective film is unwound from the roll, The film is difficult to peel off. Furthermore, since sufficient adhesion strength can be secured in the region (II), it is not necessary to use a protective film having a strong adhesive layer, and the protective film may be in a floating state on the region (I). Therefore, the adhesive residue can be suppressed when the protective film is peeled off.

  Further, according to the present invention, by providing a region (region (II)) having a peel strength of more than 1 N / 25 mm on the surface of the article, the protective film is sufficiently adhered to the region (II). Therefore, even if the width of the region (I) is widened and the width of the region (II) is narrowed, the protective film is hardly peeled off. That is, since the width of the region (II) can be narrowed in the case of the article of the present invention, the effective area can be increased by reducing the portion where functions such as antireflection are difficult to develop, and the cost can be reduced.

Furthermore, if the surface of the article has the above-described region (III), the region (III) serves as a starting point for peeling when the protective film is peeled off, so that the protective film can be easily peeled off.
Further, as shown in FIG. 1, if the cured layer 13 is formed on the base material 11 via the intermediate layer 12, the intermediate layer 12 also serves as an adhesive. The adhesion is improved.

  The article of the present invention is optimal as a functional article having a fine relief structure on the surface. Examples of such a functional article include an antireflection article and a water-repellent article provided with the article of the present invention. In particular, a display or an automobile member provided with the article of the present invention is suitable as a functional article.

<Other embodiments>
The article of the present invention is not limited to the article 10 shown in FIG. In the article 10 shown in FIG. 1, the region (III) is located at both ends of the surface of the article, and the region (II) is located on both sides of the region (I). For example, FIG. A region (III) may be provided only at one end of the surface of the article as in the article 20a shown in FIG. In addition, although the area | region (I) is located in the other edge part of the surface of an article | item 20a shown in FIG.4 (a), like the article | item 20b shown in FIG.4 (b), the surface of an article | item is shown. Region (II) may be located at the other end.
However, if the region (III) is located at both ends of the surface of the article as shown in FIG. 1, it can be easily peeled from both sides of the article 10 when the protective film is peeled off. As shown in FIGS. 1 and 4 (b), if the region (II) is located on both sides of the region (I), the adhesion with the article 10 is further improved when the protective film is attached. Therefore, it can suppress more effectively that a protective film peels in the case of winding up and unwinding. Furthermore, although mentioned later in detail, since the protective film 70 covers the surface of the article 10 in a state where it is bridged to the region (I) as shown in FIG. 9, the article 10 can be more effectively prevented from being stained or damaged. .

Further, the article 10 shown in FIG. 1 has a fine uneven structure formed on the entire surface 13a of the hardened layer 13, but, for example, as shown in the article 30a shown in FIG. A flat portion having no uneven structure may be formed. This flat area is referred to as area (IV). The peel strength (IV) with the protective film in the region (IV) when the protective film is attached to the surface of the region (IV) and peeled is not particularly limited, but the peel strength (IV) exceeds 1 N / 25 mm. If so, the region (IV) can also serve as the region (II). For example, the cured layer 13 can be directly formed on the substrate 11 as in the article 30b shown in FIG.
However, if the hardened layer 13 is formed on the base material 11 via the intermediate layer 12 as shown in FIGS. 1 and 5 (a), the adhesion between the base material 11 and the hardened layer 13 is further improved.

Moreover, although the cured layer 13 is formed on the intermediate layer 12 in the article 10 shown in FIG. 1, at least the surface 11 a of the substrate 11 is formed on the substrate 11, for example, as the article 40 shown in FIG. 6. The intermediate layer 12 and the hardened layer 13 may be formed adjacent to each other so that a part is exposed.
However, if the cured layer 13 is formed on the base material 11 via the intermediate layer 12 as shown in FIG. 1, the adhesion between the base material 11 and the cured layer 13 is further improved.

In addition, the article | items 10, 20a, 20b, 30a, 30b, 40 mentioned above are the intermediate | middle layer 12 which has area | region (II), and the hardened layer 13 which has area | region (I) on the base material 11 which has area | region (III). However, as in the article 50 shown in FIG. 7, for example, the cured layer 13 having the region (I), the member 14 having the region (II), and the member 15 having the region (III) are arranged side by side. It may be arranged adjacent to. The order of these arrangements is not particularly limited as long as the member 15 is adjacent to the member 14, but the member 15 is made of the article 50 in that the protective film is more easily adhered and the protective film is more easily peeled off. It is preferable that the member 14 is located on both sides of the hardened layer 13 and located at the end in the width direction.
The material of the members 14 and 15 is not particularly limited as long as the peel strengths (I) to (III) satisfy the above-described relationship.

Moreover, although the article | items 10, 20a, 20b, 30a, 30b, 40, 50 mentioned above have area | region (III) on the surface of an article | item, even if the surface of an article | item does not have area | region (III). Good. As such an article, for example, as shown in FIG. 8A, the base material 11, the intermediate layer 12 formed on the entire surface of the base material 11, and both ends of the surface of the intermediate layer 12 are exposed. Thus, an article 60 a having the cured layer 13 formed on the surface of the intermediate layer 12 can be cited. In addition, the flat part may be formed in the surface 13a of the hardened layer 13 similarly to the article | item 30a shown to Fig.5 (a). In particular, if the peel strength (IV) with the protective film in the region (IV) including the flat portion is more than 1 N / 25 mm, the region (IV) can also serve as the region (II). For example, FIG. It is also possible to form the hardened layer 13 directly on the entire surface of the substrate 11 like the article 60b shown. Furthermore, like the article 60c shown in FIG. 8C, the intermediate layer 12 and the cured layer 13 may be formed adjacent to the entire surface of the base material 11, and the base material 11 is not provided in the article 60c. Also good.
However, if the surface of the article has the region (III), the region (III) serves as a starting point for peeling when the protective film is peeled off, so that the protective film can be easily peeled off.

[Article with protective film]
The article with a protective film of the present invention is such that the protective film is adhered to the surface of the article of the present invention described above, and the surface of the article is protected with the protective film.
FIG. 9 shows an example of an article with a protective film of the present invention. In the article with a protective film 1 of this example, a protective film 70 is stuck on the surface of the article 10 shown in FIG.

<Protective film>
The protective film 70 shown in FIG. 9 has a pressure-sensitive adhesive layer 72 laminated on a base film 71.
Examples of the material constituting the base film 71 include polyester resins, nylon resins, polyvinyl alcohol resins, polypropylene resins, polyethylene resins, cellophane, polyvinylidene chloride, polystyrene, polyvinyl chloride, polycarbonate, and polymethyl. Examples include methacrylate, polyurethane, fluororesin, polyacrylonitrile, polybutene resin, polyimide resin, polyarylate resin, and acetyl cellulose. Of these, polyethylene resins are preferred from the viewpoints of flexibility and transparency.

  Examples of the material constituting the adhesive layer 72 include a rubber adhesive, an acrylic adhesive, an ethylene-vinyl acetate copolymer (EVA) adhesive, a silicone adhesive, a urethane adhesive, and a vinyl alkyl ether. Examples thereof include an adhesive, a polyvinyl alcohol-based adhesive, a polyvinyl pyrrolidone-based adhesive, a polyacrylamide-based adhesive, and a cellulose-based adhesive. Of these, EVA adhesives are preferred from the viewpoint of water resistance, weather resistance, and flexibility.

Moreover, as the protective film 70, it is preferable that the peeling strength with respect to this flat plate when it sticks to the flat plate made from an acrylic resin is 0.01-10N / 25mm, More preferably, it is 0.1-2.5N / 25mm. And particularly preferably 1 to 2.5 N / 25 mm. If the peel strength of the protective film 70 is within the above range, the peel strength between the protective film 70 in the region (II) (that is, the close contact between the intermediate layer 12 and the protective film 70) is selected by selecting the resin or the like constituting the intermediate layer 12. Property) can be easily adjusted to more than 1 N / 25 mm. Therefore, sufficient adhesion between the article 10 and the protective film 70 is exhibited, and cohesive failure of the protective film 70 when the protective film 70 is peeled off can be suppressed. In particular, if the peel strength of the protective film 70 is in the range of 0.1 to 2.5 N / 25 mm, the intermediate layer 12 and the protective film 70 can be easily peeled when the protective film 70 is peeled off, and the protective film 70 is protected. Adhesive residue on the cured layer 13 having a fine uneven structure when the film 70 is peeled can be suppressed. Furthermore, if the peel strength of the protective film 70 is in the range of 1 to 2.5 N / 25 mm, the article 1 with a protective film is wound into a roll to obtain a roll, or the article 1 with a protective film from the roll. When unwinding, it can suppress more effectively that a protective film peels off. Moreover, adhesive residue can also be suppressed more.
The peel strength of the protective film 70 with respect to the acrylic resin flat plate is to set the peel strength measuring machine by attaching a protective film to an acrylic resin flat plate and measure the peel strength by performing a 90 ° peel test. Is required.

  As the protective film 70, a commercially available product may be used. For example, a polyolefin film “PAC-4-50” manufactured by Sanei Kaken Co., Ltd. is suitable.

<Method for producing article with protective film>
The article 1 with a protective film of the present invention can be manufactured by, for example, manufacturing the article 10 by the above-described method and then attaching the protective film 70 to the surface of the article 10. At this time, the protective film 70 may be adhered to the surface of the cured layer 13 (that is, the region (I)), or the protective film 70 may float on the cured layer 13.

<Effect>
In the article with a protective film of the present invention described above, since the protective film is adhered to the surface of the article of the present invention, the protective film is sufficiently adhered in the region (II) on the surface of the article. Therefore, even if it winds up in roll shape or unwinds from a roll-shaped thing, a protective film does not peel easily. Furthermore, since sufficient adhesion strength can be secured in the region (II), it is not necessary to use a protective film having a strong adhesive layer, and the protective film may be in a floating state on the region (I). Therefore, the adhesive residue can be suppressed when the protective film is peeled off.
Further, if the surface of the article has the region (III), the region (III) serves as a starting point for peeling when the protective film is peeled off, so that the protective film can be easily peeled off.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[Example 1]
<Manufacture of articles>
(Formation of intermediate layer)
A 145 mm × 145 mm triacetyl cellulose film (thickness 40 μm) was prepared as a substrate. On this base material, a material for an intermediate layer containing an acrylic resin using a bar coater (“Alontac S” manufactured by Toagosei Co., Ltd.) is used so that the surface of the base material is 10 mm wide from the end and exposed on four sides. −1511X ”, a viscosity of 3000 to 6000 mPa · s / 25 ° C., a peel strength of 26.5 N / 25 mm with respect to a flat plate made of an acrylic resin), and left to stand in a dryer at 70 ° C. for 5 minutes. A 135 mm intermediate layer (thickness 10 μm) was formed.

(Preparation of active energy ray-curable resin composition)
25 parts by mass of dipentaerythritol hexaacrylate (Shin-Nakamura Chemical Co., Ltd., “A-DPH”), 25 parts by mass of pentaerythritol triacrylate (Daiichi Kogyo Seiyaku Co., Ltd., “PET-3”), modified with ethylene oxide 25 parts by mass of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., “KAYARAD DPEA-12”), 25 parts by mass of polyethylene glycol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “A-600”), 1-hydroxy 1 part by mass of cyclohexyl phenyl ketone (Nippon Ciba-Geigy Co., Ltd., “IRG.184”), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (Nippon Ciba-Geigy Co., Ltd., “IRG.819”) 0 .5 parts by mass, polyoxyethylene Kill (12-15) ether phosphate (Nippon Chemicals Co., Ltd., "NIKKOL TDP-2") were mixed with 0.1 part by weight of the active energy ray curable resin composition.

(Formation of cured layer)
The active energy ray-curable resin composition prepared above is poured into the fine concavo-convex structure surface of the disc-shaped stamper having a fine concavo-convex structure on the surface, and the center of the base material on which the intermediate layer is formed from above. Cover the active energy ray-curable resin composition with the base material on which the intermediate layer is formed so that the center of the stamper is aligned and the active energy ray-curable resin composition is in contact with the intermediate layer. did. Subsequently, the active energy ray-curable resin composition was cured by irradiating ultraviolet rays with an energy of 1000 mJ / cm ² using a high-pressure mercury lamp from the substrate side. Thereafter, the stamper was peeled off to obtain an article having a fine relief structure on the surface.

The surface of the obtained article is transferred with a fine concavo-convex structure of a stamper. As shown in FIG. 3, the interval p between adjacent convex portions 13b is 100 nm, and the height d of the convex portions 13b is 180 nm. A fine concavo-convex structure was formed.
Further, in this article 10, an intermediate layer of 135 mm × 135 mm is formed on a substrate of 145 mm × 145 mm, and a cured layer having a fine concavo-convex structure is formed on the intermediate layer with a radius of 60 mm from the center of the substrate. Is formed.

<Manufacture of articles with protective film>
The entire surface on which the cured layer of the article is formed on the adhesive surface of a polyolefin-based film (manufactured by Sanei Kaken Co., Ltd., “PAC-4-50”, peel strength with acrylic resin flat plate 0.1 N / 25 mm) as a protective film The product with a protective film was obtained.

The obtained article with a protective film is set on an electric measurement stand (“MX500N”, manufactured by Imada Co., Ltd.), and the exposed surface of the intermediate layer (that is, region (II), width of about 7 to 36 mm) and a protective film The peel strength was measured by peeling the protective film to the article at a 90 ° angle and at a speed of 300 mm / min. As a result, the peel strength (II) between the protective film in region (II) was 8.8 N / 25 mm.
Similarly, a peel test was performed at a location where the exposed surface of the substrate (that is, the region (III)) and the protective film were adhered, and the peel strength was measured. As a result, the peel strength (III) from the protective film in the region (III) was 0.15 N / 25 mm.

Moreover, when the surface of the article | item after peeling off a protective film was observed visually, the adhesive residue did not arise in the fine concavo-convex structure.
Furthermore, the protective film was not peeled when the article with the protective film was wound into a roll having a diameter of 1 cm and extended from the roll.
Moreover, since the article with a protective film obtained in Example 1 is provided with regions (II) and (III) having different peel strengths on the surface thereof, the region (III) having a low peel strength is the starting point of peeling, It was easy to peel off the protective film.

[Example 2]
As an intermediate layer material, an intermediate layer material containing an acrylic resin (manufactured by Toagosei Co., Ltd., “Arontack S-3403”, viscosity 3500-4500 mPa · s / 25 ° C., peel strength 31 with acrylic resin flat plate 31 Except for using 4N / 25 mm), an article was produced in the same manner as in Example 1, and a protective film was attached to measure the peel strength.
As a result, the peel strength (II) with the protective film in region (II) was 9.7 N / 25 mm, and the peel strength (III) with the protective film in region (III) was 0.15 N / 25 mm.
Moreover, when the surface of the article | item after peeling off a protective film was observed visually, the adhesive residue did not arise in the fine concavo-convex structure.
Furthermore, the protective film was not peeled when the article with the protective film was wound into a roll having a diameter of 1 cm and extended from the roll.
Moreover, since the article with a protective film obtained in Example 2 is provided with regions (II) and (III) having different peel strengths on the surface thereof, the region (III) having a low peel strength is the starting point of peeling, It was easy to peel off the protective film.

[Example 3]
As an intermediate layer material, an intermediate layer material containing an acrylic resin (manufactured by Toagosei Co., Ltd., “Arontack M-300”, viscosity 3000 to 6000 mPa · s / 25 ° C., peel strength 17 with acrylic resin flat plate 17 Except for using 4N / 25 mm), an article was produced in the same manner as in Example 1, and a protective film was attached to measure the peel strength.
As a result, the peel strength (II) with the protective film in the region (II) was 4.1 N / 25 mm, and the peel strength (III) with the protective film in the region (III) was 0.15 N / 25 mm.
Moreover, when the surface of the article | item after peeling off a protective film was observed visually, the adhesive residue did not arise in the fine concavo-convex structure.
Furthermore, the protective film was not peeled when the article with the protective film was wound into a roll having a diameter of 1 cm and extended from the roll.
Moreover, since the article with a protective film obtained in Example 3 is provided with regions (II) and (III) having different peel strengths on the surface thereof, the region (III) having a low peel strength is the starting point of peeling, It was easy to peel off the protective film.

[Comparative Example 1]
An article was produced in the same manner as in Example 1 except that the intermediate layer was not formed (that is, the cured layer was directly formed on the substrate and the region (II) was not formed), and the protective film was produced. Was attached to produce an article with a protective film.
When the obtained article with a protective film was wound into a roll having a diameter of 1 cm and extended from the roll, the protective film was peeled off, and the protective film was not sufficiently adhered.

1 Article with protective film 10, 20a, 20b, 30a, 30b, 40, 50, 60a, 60b, 60c Article 11 Substrate 11a Exposed surface of substrate 12 Intermediate layer 12a Exposed surface of intermediate layer 13 Cured layer 13a Cured Surface 13b Convex part 13c Concave part 70 Protective film 71 Base film 72 Adhesive layer

Claims (7)

An article having a fine concavo-convex structure on the surface, the surface being protected with a protective film,
A base material, an intermediate layer formed on the surface of the base material, and a cured layer having a fine concavo-convex structure formed on the surface of the intermediate layer so that at least a part of the surface of the intermediate layer is exposed Have
Surface of the article, possess a region (I) of the fine concavo-convex structure, the peel strength between the protective film and the region (II) is a 1N / 25 mm greater,
The surface of the cured layer is the region (I), the exposed surface of the intermediate layer Ru said region (II) der article having a fine uneven structure on the surface. The surface of the article has a fine uneven structure according to claim 1, which has a region (III) adjacent to the region (II) and having a lower peel strength from the protective film than the region (II). Goods. The fine layer according to claim 2 , wherein the intermediate layer is formed on the surface of the base material so that at least a part of the surface of the base material is exposed, and the exposed surface of the base material is the region (III). Articles having an uneven structure on the surface. The article having a fine uneven structure according to claim 2 or 3 , wherein the region (III) is located at an end of the surface of the article having a fine uneven structure on the surface.   The article | item which has the fine concavo-convex structure as described in any one of Claims 1-4 in which the said area | region (II) is located in the both sides of the said area | region (I). The surface of the said area | region (II) does not have the said fine uneven structure, The article which has the fine uneven structure as described in any one of Claims 1-5 on the surface. An article with a protective film, wherein the surface of the article having the fine concavo-convex structure according to any one of claims 1 to 6 is protected by a protective film.

Images