JP6836373B2 - Production method of a coating film having a fine uneven structure on the surface - Google Patents

Description

The present invention relates to a coating film having a fine uneven structure on the surface.

In recent years, nanoimprint technology has been attracting attention, and coating films having a fine concavo-convex structure formed on the surface using an imprint mold can be used for optical diffraction elements, optical polarization separation elements, holograms, semiconductor patterns, magnetic recording media, and the like. It has been applied. By the way, in such a product, if air or the like is caught between the paint and the imprint mold, the shape of the imprint mold cannot be accurately transferred, resulting in a serious functional defect. Therefore, it is an important quality assurance requirement to reliably find and remove defects from the product, and there are many proposals (for example, Patent Documents 1 and 2). However, it is not fully satisfactory in terms of ease and certainty of defect detection.

JP-A-2015-0327992 JP-A-2015-028978

An object of the present invention is that when a coating film having a fine concavo-convex structure on the surface is produced, when any defect occurs in the fine concavo-convex structure, the defective portion can be easily identified, which imposes a burden on quality assurance. An object of the present invention is to provide a coating film that can be reduced.

As a result of diligent research, the present inventor has found that the defect portion becomes fluorescent in color by using a specific paint, and the above-mentioned problems can be achieved.

That is, the present invention comprises 95 to 10% by mass of (A) polyfunctional (meth) acrylate and 5 to 90% by mass of (B) N-substituted (meth) acrylamide compound, wherein the component (A) and the above are described. 100 parts by mass of the active energy ray-curable resin mixture in which the sum of the components (B) is 100% by mass; and (C) 0.1 to 10 parts by mass of the acylphosphine oxide-based photopolymerization initiator; (α) It is a coating material composed of paint and having a fine uneven structure on the surface.

The second invention is a coating film laminated film having the coating film according to the first invention on at least one side of the resin film.

The third invention is an article containing the coating film according to the first invention or the coating film laminated film according to the second invention.

The fourth invention is a method for producing a coating film having a fine concavo-convex structure on the surface, wherein (1) the above-mentioned coating film (α) is applied on the surface of a resin film; (2) the above-mentioned step (1). This method includes a step of placing an imprint mold on the surface of the coating film formed in () and pressing it; and (3) a step of curing the coating film using active energy rays.

A fifth invention is a method for producing a coating film having a fine uneven structure on the surface, wherein (1') the above-mentioned coating film (α) is applied onto an imprint mold; (2') the above-mentioned step (1'). This method includes a step of placing and pressing the resin film on the surface of the coating film formed in (') so as to cover it; and (3) a step of curing the coating film using active energy rays. ..

The coating film of the present invention has a fine uneven structure on the surface. Further, the coating film of the present invention develops a color when the defective portion illuminates the ultraviolet rays, and can be easily identified. Therefore, the burden on quality assurance can be reduced.

As used herein, the term "film" is used as a term that also includes sheets. The term "resin" is used as a term that also includes a resin mixture containing two or more resins and a resin composition containing a component other than the resin. Further, in the present specification, laminating a certain layer and another layer in order means directly laminating those layers and interposing one or more other layers such as an anchor coat between the layers. Includes both stacking. The term "greater than or equal to" related to a numerical range is used to mean a certain numerical value or a certain numerical value or more. For example, 20% or more means 20% or more than 20%. The term "less than or equal to" related to a numerical range is used to mean a certain numerical value or less than a certain numerical value. For example, 20% or less means 20% or less than 20%. Furthermore, the "~" symbol related to the numerical range is used to mean a certain numerical value, more than a certain numerical value and less than another certain numerical value, or another certain numerical value. Here, it is assumed that some other numerical value is larger than a certain numerical value. For example, 10-90% means 10%, greater than 10% and less than 90%, or 90%.

The coating film of the present invention has a fine concavo-convex structure on its surface. The coating film of the present invention comprises 95 to 10% by mass of (A) polyfunctional (meth) acrylate and 5 to 90% by mass of (B) N-substituted (meth) acrylamide compound, where the above component (A) is used. The sum of the above components (B) is 100% by mass, which is 100 parts by mass of the active energy ray-curable resin mixture; and (C) 0.1 to 10 parts by mass of the acylphosphine oxide-based photopolymerization initiator; ) Consists of paint.

(A) Polyfunctional (meth) acrylate:
The component (A) is a (meth) acrylate having two or more (meth) acryloyl groups in one molecule. Since the component (A) has two or more (meth) acryloyl groups in one molecule, it functions to polymerize and cure with active energy rays such as ultraviolet rays and electron beams to form a coating film.

Examples of the polyfunctional (meth) acrylate include diethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 2, (Meta) acryloyl group-containing bifunctional reaction such as 2'-bis (4- (meth) acryloyloxypolyethyleneoxyphenyl) propane and 2,2'-bis (4- (meth) acryloyloxypolypropylene oxyphenyl) propane Sexual monomer; (meth) acryloyl group-containing trifunctional reactive monomer such as trimethylolpropane tri (meth) acrylate, trimethylol ethanetri (meth) acrylate, and pentaerythritol tri (meth) acrylate; pentaerythritol tetra (meth) acrylate. Etc. (meth) acryloyl group-containing tetrafunctional reactive monomer; (meth) acryloyl group-containing hexafunctional reactive monomer such as dipentaerythritol hexaacrylate; (meth) acryloyl group-containing octafunctional reactive monomer such as tripentaerythritol acrylate. And polymers (oligoforms and prepolymers) having one or more of these as constituent monomers can be mentioned. Examples of the polyfunctional (meth) acrylate include polyurethane (meth) acrylate, polyester (meth) acrylate, polyacrylic (meth) acrylate, polyalkylene glycol poly (meth) acrylate, epoxy (meth) acrylate, and polyether (meth). Prepolymers or oligomers such as acrylates having two or more (meth) acryloyl groups in one molecule can be mentioned. As the component (A), one kind or a mixture of two or more kinds of these can be used. In addition, in this specification, (meth) acrylate means acrylate or methacrylate.

(B) N-substituted (meth) acrylamide compound:
The component (B) is an N-substituted (meth) acrylamide compound. Since the paint (α) contains the component (B) and the component (C), when cured using active energy rays under the condition of oxygen, the paint (α) develops color by illuminating ultraviolet rays. On the other hand, when it is similarly cured in the absence of oxygen, it does not develop color even when irradiated with ultraviolet rays.

Although it is not intended to be bound by theory, it is considered that when a defect occurs in the coating film of the present invention, the portion becomes colored by irradiating with ultraviolet rays due to the mechanism described later. When air is caught between the paint and the imprint mold, oxygen is present at the portion. Therefore, the portion is cured by the active energy ray under the condition in which oxygen is present, and the defect generated at the portion develops color by illuminating the ultraviolet ray. Similarly, when a foreign substance is caught between the paint and the imprint mold, oxygen is present in the portion around the foreign substance that is not filled with the paint. Therefore, the portion is cured by the active energy ray under the condition in which oxygen is present, and the defect generated at the portion develops color by illuminating the ultraviolet ray.

The N-substituted (meth) acrylamide compound as the component (B) is not particularly limited, but may be typically a compound having a structure represented by the following general formula (1). In the formula, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ₃ represents an alkyl group having 1 to 6 carbon atoms which may have a hydroxyl group or an amino group, or R ₂ and R ₃ represent. Together, they form a 5- or 6-membered ring that may have an oxygen atom as a ring member, together with the nitrogen atom to which they are bonded. The "N-substituted (meth) acrylamide compound" means an N-substituted acrylamide compound or an N-substituted methacrylamide compound.

Examples of the component (B) include N-methyl (meth) acrylamide, N-methylol (meth) acrylamide butyl ether, N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, and N-isopropyl (meth). ) Acrylamide, N-cyclopropyl (meth) acrylamide, diacetone (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N -Diethyl (meth) acrylamide, N-methyl, N-ethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-methylol (meth) acrylamide methyl ether, N-methylol (meth) acrylamide ethyl ether , N-methylol (meth) acrylamide propyl ether, N-butoxymethyl (meth) acrylamide, N-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam, and (meth) acryloylmorpholine. Of these, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and (meth) acryloylmorpholine are preferred, and N, N-dimethylacrylamide, N, N-diethylacrylamide, and acryloyl. Morpholine is more preferred. As the component (B), one kind or a mixture of two or more kinds of these can be used.

The ratio of the component (B) in the active energy ray-curable resin mixture is 100% by mass, which is the sum of the component (A) and the component (B), and the defective portion is colored by illuminating ultraviolet rays. From the viewpoint of making the above, usually 5% by mass or more (95% by mass or less of the above component (A)), preferably 10% by mass or more (90% by mass or less of the above component (A)), more preferably 20% by mass or more ( The above component (A) is 80% by mass or less). On the other hand, from the viewpoint of curability of the coating material (α), it is usually 90% by mass or less (10% by mass or more of the component (A)), preferably 85% by mass or less (15% by mass or more of the component (A)). It may be preferably 80% by mass or less (20% by mass or more of the above component (A)).

The blending amount of the component (B) is preferably equal to or greater than the blending amount of the component (C), and more preferably the blending amount of the component (C), from the viewpoint of allowing the defective portion to develop color by illuminating the ultraviolet rays. The blending amount may be twice or more, more preferably three times or more the blending amount of the above component (C). On the other hand, from the viewpoint of curability, the blending amount of the component (C) is usually 50 times or less, preferably 30 times or less the blending amount of the component (C).

(C) Acylphosphine oxide-based photopolymerization initiator :
The component (C) is an acylphosphine oxide-based photopolymerization initiator. Since the coating film contains the above-mentioned component (B) and the above-mentioned component (C), the coating film of the present invention develops color when a defect portion generated in the coating film is illuminated with ultraviolet rays.

Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. be able to. As the component (C), one kind or a mixture of two or more kinds of these can be used.

The blending amount of the component (C) is usually 10 parts by mass or less from the viewpoint of preventing the formed coating film from becoming yellow-colored with respect to 100 parts by mass of the active energy ray-curable resin mixture. It may be preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and further preferably 3 parts by mass or less. On the other hand, from the viewpoint of curability of the coating material (α), it may be usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more.

The coating material (α) can further contain a compound having two or more isocyanate groups (−N = C = O) in one molecule. Examples of the compound having two or more isocyanate groups in one molecule include methylenebis-4-cyclohexylisocyanate; trimethylolpropane adduct of tolylene diisocyanate, trimethylolpropane adduct of hexamethylene diisocyanate, and trimethylol of isophorone diisocyanate. Polyisocyanate such as propane adduct, isocyanurate of tolylene diisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate, biuret of hexamethylene diisocyanate; and urethane such as block type isocyanate of the above polyisocyanate. A cross-linking agent or the like can be given. As the compound having two or more isocyanate groups in one molecule, one kind or a mixture of two or more kinds thereof can be used. Further, at the time of cross-linking, a catalyst such as dibutyltin dilaurate or dibutyltin diethylhexoate may be added as needed.

The blending amount of the compound having two or more isocyanate groups in one molecule is usually 40 parts by mass or less, preferably 40 parts by mass or less, with respect to 100 parts by mass of the active energy ray-curable resin mixture from the viewpoint of curability by active energy rays. May be 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less. On the other hand, the lower limit of the blending amount is not particularly limited because it is an optional component, but from the viewpoint of surely obtaining the effect of using the compound having two or more isocyanate groups in one molecule, it is usually 0.1 part by mass or more, preferably 0.1 part by mass or more. It may be 0.3 parts by mass or more, more preferably 0.5 parts by mass or more.

The paint (α) may contain a leveling agent, an antistatic agent, a surfactant, a thixo property-imparting agent, a stain inhibitor, a printability improver, an antioxidant, a weather resistance stabilizer, and a light resistance stability, if desired. One or more kinds of additives such as an agent, a heat stabilizer, inorganic fine particles, organic fine particles, an inorganic colorant, and an organic colorant can be contained.

Since the paint (α) is diluted to a concentration that is easy to apply, it may contain a solvent if desired. The solvent is particularly limited as long as it does not react with the components (A) to (C) and other optional components, or catalyze (promote) the self-reaction (including deterioration reaction) of these components. Not done. Examples of the solvent include 1-methoxy-2-propanol, ethyl acetate, nbutyl acetate, toluene, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol, acetone and the like. As the solvent, one kind or a mixture of two or more kinds of these can be used.

The paint (α) can be obtained by mixing and stirring these components.

The method for forming the coating film using the coating material (α) is not particularly limited, and a known coating method can be used. Examples of the above method include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and die coating.

The thickness of the coating film of the present invention (thickness with respect to the top of the convex portion of fine irregularities) is not particularly limited, but may be usually 0.5 μm or more, preferably 5 μm or more from the viewpoint of scratch resistance. On the other hand, from the viewpoint of handleability, it may be usually 200 μm or less, preferably 120 μm or less.

Imprint mold:
The imprint mold is not limited as long as it can give fine irregularities to the surface of the coating film of the present invention, and any imprint mold can be used.

The fine concavo-convex structure formed on the surface of the coating film of the present invention using the imprint mold is not particularly limited and may have any shape. The fine concavo-convex structure includes, for example, a so-called moth-eye structure in which a plurality of protrusions such as a substantially conical shape and a substantially pyramidal shape are arranged; a so-called pillar structure in which a plurality of protrusions such as a substantially cylindrical shape and a substantially prismatic shape are arranged; A structure in which multiple peaks are connected in one direction and the cross section of the mountain is approximately semi-circular; multiple peaks / valleys are continuous in one direction and the cross section of the peak is approximately triangular. A structure in which peaks / valleys are connected in one direction and a plurality of peaks having a substantially quadrangular cross section are lined up; and a combination thereof can be mentioned.

The imprint mold may be one that transmits the active energy ray or may not transmit the active energy ray. When the imprint mold that does not transmit the active energy ray is used, the resin film that transmits the active energy ray is used.

The imprint mold may be made by using any material. The imprint mold may be made of, for example, resin, glass, metal, ceramic, or a combination of these materials.

Such imprint molds are commercially available, and examples such as "Filfille (trade name)" of Soken Kagaku Co., Ltd. can be mentioned. In addition, NTT Advanced Technology Co., Ltd., Dai Nippon Printing Co., Ltd., Canon Marketing Japan Inc., etc. also market imprint molds.

Resin film:
The resin film is a film base material for forming the coating film of the present invention on at least one surface thereof. Further, in the resin film, the surface of the coating film made of the paint (α) opposite to the imprint mold side is shielded from the atmosphere (oxygen), and the normal portion of the coating film of the present invention is not colored. To work.

Examples of the resin film include polyester resins such as aromatic polyesters and aliphatic polyesters; acrylic resins; polycarbonate resins; poly (meth) acrylicimide resins; polyolefin resins such as polyethylene, polypropylene, and polymethylpentene. Resins: Cellulosic resins such as cellophane, triacetyl cellulose, diacetyl cellulose, and acetyl cellulose butyrate; polystyrene, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), styrene-ethylene-butadiene-styrene copolymer, styrene- Polyethylene resins such as ethylene / propylene / styrene copolymers and styrene / ethylene / ethylene / propylene / styrene copolymers; polyvinyl chloride resins; polyvinylidene chloride resins; fluororesins such as vinylidene fluoride; In addition, resin films such as polyvinyl alcohol, ethylene vinyl alcohol, polyether ether ketone, nylon, polyamide, polyimide, polyurethane, polyetherimide, polysulphon, polyethersulphon; and the like can be mentioned. These films include non-stretched films, uniaxially stretched films, and biaxially stretched films. Further, it includes a laminated film in which two or more layers of one or more of these are laminated.

The resin film may be colored with an arbitrary colorant. The resin film may be entirely or partially printed with any printing ink.

The resin film may be one that transmits the active energy ray or may not transmit the active energy ray. When a resin film that does not transmit the active energy ray is used, a film that transmits the active energy ray is used as the imprint mold.

When the resin film is one of the constituent layers of the coating film laminated film, the coating film forming surface of the resin film is corona from the viewpoint of improving the adhesion between the resin film and the coating film of the present invention. It may be one that has been subjected to an easy adhesion treatment such as a discharge treatment or an anchor coat formation.

When the resin film is one of the constituent layers of the coating film laminated film, the thickness of the resin film is not particularly limited, but from the viewpoint of handleability, it may be usually 20 μm or more, preferably 30 μm or more. When the coating film laminated film is used in an application that does not require high rigidity, it may be usually 250 μm or less, preferably 150 μm or less, from the viewpoint of economy. When the coating film laminated film is used in an application requiring high rigidity, it may be usually 300 μm or more, preferably 500 μm or more, and more preferably 600 μm or more from the viewpoint of maintaining the rigidity. Further, from the viewpoint of meeting the demand for thinning of the article using the coating film laminated film, it may be usually 1500 μm or less, preferably 1200 μm or less, and more preferably 1000 μm or less.

When the coating film of the present invention formed on the surface of the resin film is transferred to another resin film or the like and used, the coating film-forming surface of the resin film is easily peeled off. It's okay.

When the coating film of the present invention formed on the surface of the resin film is transferred to another resin film or the like and used, the thickness of the resin film is not particularly limited, but is usually 20 μm from the viewpoint of handleability. As mentioned above, it may be preferably 30 μm or more. On the other hand, from the viewpoint of economy, it may be usually 100 μm or less, preferably 75 μm or less.

Production method:
The coating film of the present invention uses the above-mentioned coating film (α), an arbitrary imprint mold, and an arbitrary resin film, for example, (1) the above-mentioned coating film (α) is applied on the surface of the above-mentioned resin film. Steps; (2) The step of placing the imprint mold on the surface of the coating film formed in the above step (1) and pressing it; and (3) curing the coating film using active energy rays. It can be obtained by a method including the step;

In the step (1), the method of applying the coating material (α) on the surface of the resin film is not particularly limited, and a known coating method can be used. Examples of the above method include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and die coating.

The thickness of the coating film formed in the above step (1) is not particularly limited. The thickness of the coating film formed in the above step (1) is, for example, such that the coating film thickness after curing (thickness with respect to the top of the convex portion of fine irregularities) is usually 0.5 to 200 μm, preferably 5 to 120 μm. , The determination may be made in consideration of the solid content of the paint (α).

Pre-drying may be performed after the step (1) and before the step (2).

By placing the imprint mold on the surface of the coating film formed in the step (1) in the step (2), both sides of the coating film are shielded from the atmosphere (oxygen). .. The coating film is cured by active energy rays in the above step (3) in this state. Since the normal portion of the coating film is cured under the absence of oxygen, it does not develop color even when exposed to ultraviolet rays.

Further, in the step (2), the imprint mold is placed on the surface of the coating film formed in the step (1) and pressed, so that the coating film has a fine concavo-convex structure of the imprint mold. Transferred. The pressing pressure is appropriately selected in consideration of the viscosity of the paint (α), the fine uneven structure of the imprint mold, and the like. The pressing pressure is usually about 0.05 to 2 MPa, preferably about 0.1 to 1 MPa.

Examples of the active energy ray used in the above step (3) include ultraviolet rays and ionizing radiation such as an electron beam. Examples of the active energy ray used in the above step (3) include a white active energy ray using a high-pressure mercury lamp, a metal halide lamp, or the like as a light source. Further, the white active energy ray may be monochromaticized by using a filter such as a 365 filter (short wave cut filter), a 254 filter (long wave cut filter), and a 300 filter.

The irradiation amount of the active energy ray in the step (3) is appropriately adjusted depending on the curing characteristics of the paint (α), the coating film thickness, the line speed, and the like. The irradiation amount may be usually 10 to 10000 mJ / cm ² , preferably 100 to 1000 mJ / cm ² .

The coating film of the present invention is a step of applying the coating film (α) on, for example, (1') the imprint mold using the coating film (α), an arbitrary imprint mold, and an arbitrary resin film. (2') A step of placing and pressing the resin film on the surface of the coating film formed in the above step (1') so as to cover it; and (3) the above coating film using active energy rays. Can be obtained by a method including the step of curing.

In the step (1'), the method of applying the paint (α) on the imprint mold is not particularly limited, and a known coating method can be used. Examples of the above method include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and die coating.

In the step (1'), a coating film made of the coating material (α) is formed on the imprint mold, so that the fine uneven structure of the imprint mold is transferred to the coating film.

The thickness of the coating film formed in the above step (1') is not particularly limited. The thickness of the coating film formed in the above step (1') is such that, for example, the coating film thickness after curing (thickness with respect to the top of the convex portion of fine irregularities) is usually 0.5 to 200 μm, preferably 5 to 120 μm. In addition, the determination may be made in consideration of the solid content of the coating film (α).

Pre-drying may be performed after the step (1') and before the step (2').

By placing the resin film on the surface of the coating film formed in the step (1') in the step (2') so as to cover it, both sides of the coating film are shielded from the atmosphere (oxygen). It will be in a state of being. The coating film is cured by active energy rays in the above step (3) in this state. Since the normal portion of the coating film is cured under the absence of oxygen, it does not develop color even when exposed to ultraviolet rays.

Further, in the step (2'), the pressure when the resin film is placed on the surface of the coating film formed in the step (1') so as to cover the resin film and pressed is the viscosity of the paint (α). Select as appropriate in consideration of such factors. The pressing pressure is usually about 0.01 to 1 MPa, preferably about 0.05 to 0.5 MPa.

The active energy rays used in the above step (3) and the irradiation amount thereof have been described above.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited thereto.

Measurement method (a) Reliability as an inspection method:
A square test piece with a side of 10 cm was collected from the coating film laminated film so as to include a part that developed color when illuminated with ultraviolet rays (because there was no part that developed color when illuminated with ultraviolet rays in Examples 3 and 5). A loupe was used to determine whether there is a defect in the place where the color does not develop even when illuminated with ultraviolet rays, and whether there is a defect in the place where the color develops when illuminated with ultraviolet rays. Visually observed. Evaluation was made based on the following criteria.
◯: There is no defect where the color does not develop even when illuminated with ultraviolet rays. On the other hand, there is always a defect in the place where the color is developed when illuminated with ultraviolet rays.
Δ: There is no defect where the color does not develop even when illuminated with ultraviolet rays. There are places where there are no defects even where the color develops when illuminated by ultraviolet rays.
X: There is a defect where the color does not develop even when illuminated with ultraviolet rays.

(B) Yellowness index;
The normal part of the coating film laminated film was measured using a chromaticity meter "SolidSpec-3700 (trade name)" manufactured by Shimadzu Corporation in accordance with JIS K 7105: 1981.

Raw material used (α) paint:
(Α-1) A coating material obtained by mixing and stirring 70 parts by mass of (A-1) below, 30 parts by mass of (B-1) below, and 3 parts by mass of (C-1) below.

(A) Polyfunctional (meth) acrylate:
(A-1) Polyester urethane acrylate "Art Resin UN-9000PEP (trade name)" of Negami Kogyo Co., Ltd. 2 sensuality.

(B) N-substituted (meth) acrylamide compound:
(B-1) N, N-diethylacrylamide.
(B-2) Acryloyl morpholine.

(B') Reference ingredient:
(B'-1) Tetrahydrofurfuryl acrylate.

(C) Acylphosphine oxide-based photopolymerization initiator:
(C-1) BASF's acylphosphine oxide-based photopolymerization initiator (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) "IRGACURE TPO (trade name)".
(C-2) BASF's acylphosphine oxide-based photopolymerization initiator (bis (2,4,6-trimethylbenzoyl) -phenyl-phosphine oxide) "IRGACURE 819 (trade name)".

(C') Photopolymerization initiator other than the above component (C):
(C'-1) BASF's acetophenone-based photopolymerization initiator (1-hydroxy-cyclohexyl-phenylketone) "IRGACURE184 (trade name)".
(C'-2) BASF's acetophenone-based photopolymerization initiator (2-hydroxy-2-methyl-1-phenylpropane-1-one) "IRGACURE 1173 (trade name)".
(C'-3) BASF's benzyl dimethyl ketal-based photopolymerization initiator (2,2-dimethoxy-1,2-diphenylethane-1-one) "IRGACURE651 (trade name)".

(Β) Resin film:
(Β-1) A biaxially stretched polyethylene terephthalate film in which an anchor coat is laminated on one side. Thickness 100 μm.

(Γ) Imprint mold:
(Γ-1) Imprint mold "Filfille HOP1700 (trade name)" of Soken Kagaku Co., Ltd., a hole structure with a period of 3000 nm, a depth of 1700 nm, and a concave diameter of 1700 nm. When this is pressed against the coating film, a so-called pillar structure is formed on the surface of the coating film.

Example 1
The paint (α-1) was applied onto the anchor-coated laminated surface of the transparent resin film (β-1) using a baker-type applicator, and the thickness after curing (thickness with respect to the top of the convex portion of fine irregularities) was 100 μm. Immediately after applying the above-mentioned imprint mold (γ-1) on the surface of the coating film and pressing it under the conditions of a pressure of 0.25 MPa and a time of 20 seconds, a high-pressure mercury lamp was used. The paint (α-1) was cured by irradiating ultraviolet rays from the imprint mold side under the condition of an integrated light amount of 700 mJ / cm ^2. The imprinted film (γ-1) was peeled off and removed to obtain a nanoimprinted coating film laminated film. The above tests (a) and (b) were performed. The results are shown in Table 1.

Examples 2-9
The same procedure as in Example 1 was carried out except that the composition of the paint (α) was changed as shown in Table 1. The results are shown in Table 1.

The coating film of the present invention can be easily identified as a defective portion by observing it by illuminating it with ultraviolet rays. In addition, the place where no defect occurred did not develop color even when illuminated with ultraviolet rays.

Claims (5)

A method for producing a coating film having a fine uneven structure on the surface.
(1) Step of applying paint (α) on the surface of the resin film;
(2) A step of placing an imprint mold on the surface of the coating film formed in the above step (1) and pressing the imprint mold;
(3) using an active energy ray, a step of curing the coating film; and,
(4) A step of identifying defective parts of the fine uneven structure of the coating film by illuminating ultraviolet rays and removing those containing the defects;
Only including, wherein said coating material (α) is,
(A) Polyfunctional (meth) acrylate 95 to 10% by mass
(B) N-substituted (meth) acrylamide compound 5 to 90% by mass
Here, the sum of the above component (A) and the above component (B) is 100% by mass.
100 parts by mass of active energy ray-curable resin mixture;
(C) Acylphosphine oxide-based photopolymerization initiator 0.1 to 10 parts by mass;
The above method, including.
A method for producing a coating film having a fine uneven structure on the surface.
(1') Step of applying paint (α) on the imprint mold;
(2') A step of placing and pressing the resin film on the surface of the coating film formed in the above step (1') so as to cover it;
(3) using an active energy ray, a step of curing the coating film; and,
(4) A step of identifying defective parts of the fine uneven structure of the coating film by illuminating ultraviolet rays and removing those containing the defects;
Only including, wherein said coating material (α) is,
(A) Polyfunctional (meth) acrylate 95 to 10% by mass
(B) N-substituted (meth) acrylamide compound 5 to 90% by mass
Here, the sum of the above component (A) and the above component (B) is 100% by mass.
100 parts by mass of active energy ray-curable resin mixture;
(C) Acylphosphine oxide-based photopolymerization initiator 0.1 to 10 parts by mass;
The above method, including.
The amount of the component (B) N-substituted (meth) acrylamide compound in the paint (α) is more than twice and 30 times the amount of the component (C) acylphosphine oxide-based photopolymerization initiator. The method according to claim 1 or 2 below.
One selected from the group consisting of N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and (meth) acryloyl morpholine as the component (B) N-substituted (meth) acrylamide compound. The method according to any one of claims 1 to 3, which includes the above.
A method for producing an article containing a coating film having a fine uneven structure on the surface.
The above method including the step of forming a coating film having a fine concavo-convex structure on the surface using the method according to any one of claims 1 to 4.