JP2013137485A - Film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film that has excellent optical characteristics and heat resistance, small reflection, high light extraction efficiency, and small warpage and residual strain.SOLUTION: The film includes a surface fine rugged structure and a heat resistant acrylic film. It is preferable that the glass-transition temperature of the heat resistant acrylic film is equal to or more than 110°C, and the heat resistant acrylic film includes a heat resistant acrylic polymer having a ring structure such as a lactone ring structure in a main chain.

Description

  The present invention relates to a film including a fine relief structure useful for various displays such as a liquid crystal display and an organic electroluminescence display.

Display devices using organic electroluminescence (organic EL) elements have attracted attention as display devices that replace liquid crystal display devices. Since the organic EL element is a self-luminous element, when used in a display device, there are advantages that the viewing angle is wide and the response speed is fast. Furthermore, since a backlight is not required, it is possible to reduce the thickness and weight.
However, when a surface light emitting element such as an EL element emits light, light emitted inside the light emitting layer having a high refractive index travels in various directions, and the element substrate and the air are emitted on the emission surface of the surface light emitting element. Since light incident on an interface having a large refractive index difference, such as an interface, at a larger angle than the critical angle is totally reflected, there is much light confined inside the surface light emitting element. Therefore, in general, only 20% to 30% of the light emitted from the surface light emitting element can be extracted outside the surface light emitting element, and there is a problem that sufficient brightness cannot be obtained. In particular, in the case of an organic EL element, there is also a problem that the lifetime of the element is shortened if the brightness is compensated by the magnitude of the current. Therefore, a proposal has been made to increase the light extraction efficiency by providing a prism member or the like on the light extraction surface of the element.

  Conventionally, in optical components and lenses used in various displays such as liquid crystal displays and organic electroluminescence (organic EL) displays, reflection of sunlight, illumination, etc. at the interface in contact with air reduces visibility. It can cause and is often a problem. In general, an AG (Anti-Glare) process or an AR (Anti-Refrection) process is well known as a device for suppressing reflection on the surface of the optical member. The AG process is a process in which irregularities are formed on the surface of the optical member by coating with fine particles or the like, and a reflection image is scattered by scattering of light to blur the outline. In the AR treatment, a film having a refractive index different from that of the base material is coated on the surface of the base material with a thickness of about the wavelength of light, thereby causing light interference and reducing the reflectance.

  By the way, the provision of a moth eye structure is known as a new anti-reflection and a method for improving the light extraction efficiency different from the above (Non-patent Document 1). This is to form a ridge-shaped protrusion smaller than the wavelength of visible light on the surface of the optical member, so that the refractive index of the region between the base material portion and the air layer is the refractive index of the material forming the protrusion. And the intermediate refractive index of air. The refractive index of this intermediate region continuously changes within a distance shorter than the wavelength of visible light because the occupation ratio of the protrusion and air changes depending on the height. As a result, the interface between the air and the substrate does not function as an interface having a different refractive index, and reflection of visible light at the interface can be suppressed.

  As a method for imparting such a moth-eye structure, there is a technique for transferring nanometer-sized irregularities engraved in a mold onto a substrate, so-called nanoimprint technique. Nanoimprint technology includes a method of softening a thermoplastic substrate by heating, pressing a mold onto it to mold it, then cooling and demolding, or applying a mold to a curable material coated on the substrate. A method is known in which the curable material is cured by pressing and heating with active energy rays or heating. Particularly in the latter nanoimprint technology, a method for curing a curable material using active energy rays is to form a thin film of an ultraviolet curable resin on a transparent substrate, press a mold on the thin film, and then apply ultraviolet light. By irradiating, a thin film having a moth-eye structure with a reversal shape of the mold is formed on the substrate, which is preferable in terms of shortening the molding time compared to molding using heat. Patent Document 1 discloses a method of creating an antireflection article by imparting a moth-eye structure to a transparent substrate by such a method.

  When an organic EL element is used in a display device, a circularly polarizing plate is generally provided to prevent reflection of external light inside the display device. This circularly polarizing plate is composed of a ¼λ plate and a polarizer. When a circularly polarizing plate is used, external light that has passed through a polarizer is converted into linearly polarized light, and then converted into circularly polarized light by a ¼λ plate. Even if this light is reflected inside the organic EL element, it is converted again into linearly polarized light that is 90 ° different from the direction of the polarizer when passing through the circularly polarizing plate, so that reflection is prevented. In order to prevent reflection by external light in this way, it is important that no member having birefringence exists between the light emitting layer and the 1 / 4λ plate, and between the light emitting layer and the 1 / 4λ plate. It is desirable that the member for improving the light extraction efficiency provided in the above has an intrinsic birefringence value of substantially zero (in-plane retardation value of less than 5 nm).

  As a polarizer protective film, a cellulose acetate (TAC) film has been conventionally used because of its high light transmittance and adhesiveness to the polarizer. In recent years, an acrylic having excellent optical properties such as a low photoelastic coefficient. Application of optical films containing a resin is being studied. In addition, a general acrylic resin has a glass transition temperature of about 100 ° C. and is insufficient in heat resistance for use in a polarizer protective film, but heat resistance is improved by introducing a ring structure into the main chain. Is known (Patent Document 2).

JP 2008-209540 A International Publication No. 2006/025445 Pamphlet

OPTICA ACTA, 1982, Vol. 29, No. 7, 993-1009

  However, when a curable resin is applied and cured on a film-like substrate, there is a problem that optical anisotropy is likely to occur due to warping of the film or residual strain due to heat generation during curing or shrinkage of the curable material. It was. Moreover, when it was going to improve the mold release property of curable resin, the phenomenon that the adhesiveness with a base material fell or a repellency was produced when apply | coated was seen. On the other hand, when trying to improve the adhesion, the curable resin may erode the surface of the base material, resulting in a problem that the smoothness and transparency are impaired.

  In addition, it is not preferable to newly stack an optical member having a moth-eye structure on the surface of various displays from the viewpoints of miniaturization, weight reduction, and cost reduction of display devices required for flat panel displays and the like.

  The present invention has been made paying attention to the above-mentioned circumstances, and its purpose is a film having excellent optical characteristics and heat resistance, low reflection, high light extraction efficiency, and small warpage and residual distortion. Is to provide.

The film of the present invention capable of achieving the above object has a gist in that it includes a fine uneven structure on the surface and a heat-resistant acrylic film.
In the film of this invention, it is preferable that the glass transition temperature of the said heat-resistant acrylic film is 110 degreeC or more.
In the film of the present invention, the heat-resistant acrylic film preferably contains a heat-resistant acrylic polymer having a ring structure in the main chain. Here, the ring structure preferably has at least one selected from the group consisting of an ester group, an imide group and an acid anhydride. The ring structure is preferably at least one selected from the group consisting of a lactone ring structure, a glutarimide ring structure, and a glutaric anhydride structure. Further, the ring structure is preferably a lactone ring structure. The lactone ring structure is preferably a lactone ring structure represented by the following general formula (1).

(In the formula (1), R ¹ , R ² and R ³ each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom. .)
In the film of the present invention, the in-plane retardation value is preferably 5 nm or less.
In the film of the present invention, the absolute value of the difference in refractive index between the material constituting the fine concavo-convex structure and the heat-resistant acrylic film is preferably 0.1 or less.
In the film of the present invention, the fine uneven structure is preferably formed by curing a curable composition. The fine uneven structure is preferably made of a thermoplastic resin.
The film of the present invention is preferably used for an organic electroluminescence light emitting device. Moreover, it is also preferable that the film of this invention is a polarizer protective film.
Further, the present invention includes an organic electroluminescence light emitting device comprising the light emitting layer and the film of the present invention on the light extraction surface side of the light emitting layer.

  According to the film of the present invention, since it includes a fine concavo-convex structure on the surface and a heat-resistant acrylic film, it has excellent optical characteristics and heat resistance, low reflection, high light extraction efficiency, and low warpage and residual strain. Can do.

  Furthermore, in the present invention, when the absolute value of the difference in refractive index between the material constituting the fine concavo-convex structure and the heat-resistant acrylic film is 0.1 or less, reflection at the interface between the concavo-convex structure and the heat-resistant acrylic film is further reduced. In addition, it is possible to provide an optical member with less reflection.

  Furthermore, in the present invention, when the heat-resistant acrylic polymer constituting the heat-resistant acrylic film has a ring structure (particularly a lactone ring structure) in the main chain, the (meth) acrylic acid ester monomer of the heat-resistant acrylic polymer Since the negative birefringence expressed by the structure derived from it is canceled by the positive birefringence expressed by the ring structure of the main chain, the intrinsic birefringence of the heat-resistant acrylic film is made substantially zero. Even if the film is stretched, it becomes a low birefringence film. And, if the birefringence is zero or low heat-resistant acrylic film, birefringence can be kept low even if a fine concavo-convex structure is provided on the surface. For example, when combined with a circularly polarizing plate, There is an effect that reflection can be efficiently prevented.

It is a figure which shows the structural example of the organic electroluminescent light emitting device using the film of this invention.

<Film>
The film of the present invention includes a fine relief structure on the surface and a heat-resistant acrylic film. That is, it includes a heat-resistant acrylic film and has a fine uneven structure on the surface. Here, the fine concavo-convex structure may be formed of a material different from the heat-resistant acrylic film (for example, a cured product of a curable composition described later), or the fine concavo-convex structure is formed on the surface of the heat-resistant acrylic film itself. It may be. The heat-resistant acrylic film and the fine uneven structure will be described later.

  The film of the present invention preferably has an intrinsic birefringence value of substantially zero. Specifically, the in-plane retardation value (Re) at a wavelength of 589 nm is preferably 5 nm or less, and is preferably 4 nm or less. More preferably, it is 1 nm or less. When the in-plane retardation value (Re) is within the above range, reflection by external light can be efficiently prevented when combined with a circularly polarizing plate. In the film of the present invention, for the same reason as described above, the absolute value (| Rth |) of the thickness direction retardation value is preferably 5 nm or less, more preferably 3 nm or less, and 1 nm or less. More preferably it is. The “phase difference value” is also referred to as a retardation value, or simply “phase difference” or “retardation”.

In the present invention, the in-plane retardation value (Re) is
Re = (nx−ny) × d
The thickness direction retardation value (Rth) is defined as
Rth = [(nx + ny) / 2−nz] × d
Defined by Here, nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the direction perpendicular to nx in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness (nm). Represent. The slow axis direction is a direction in which the refractive index in the film plane is maximum.

  The film of the present invention has a high light transmittance. The total light transmittance measured in accordance with JIS K7361-1 is preferably 95% or more, more preferably 96% or more.

  In the film of the present invention, the absolute value of the difference in refractive index between the material constituting the fine uneven structure and the heat-resistant acrylic film is preferably 0.1 or less, more preferably 0.07 or less, and still more preferably Is 0.05 or less. When the absolute value of the difference in refractive index between the material constituting the fine concavo-convex structure and the heat-resistant acrylic film is within the above range, reflection at the interface between the concavo-convex structure and the heat-resistant acrylic film can be more easily reduced. The most preferable is the case where the absolute value of the difference in refractive index between the material constituting the fine concavo-convex structure and the heat-resistant acrylic film is 0 (that is, when both refractive indexes are the same). The fine concavo-convex structure is preferably formed of a heat-resistant acrylic film.

<Heat resistant acrylic film>
The heat-resistant acrylic film in the present invention is made of a heat-resistant acrylic resin. The heat resistant acrylic resin includes a heat resistant acrylic polymer. The content of the heat-resistant acrylic polymer in the heat-resistant acrylic resin is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95%. It is at least mass%.

  In the present specification, “resin” is a broader concept than “polymer”. The resin may be composed of, for example, one or two or more polymers, and if necessary, materials other than the polymer, for example, additives such as ultraviolet absorbers, antioxidants, fillers, compatibilizing agents, A stabilizer and the like may be included.

  Further, “heat resistance” in the present invention means that the glass transition temperature (Tg) is 100 ° C. or higher. More preferably, it is 110 degreeC or more, More preferably, it is 115 degreeC or more, Most preferably, it is 120 degreeC or more. Moreover, although an upper limit is not specifically limited, From viewpoints of a moldability etc., Preferably it is 200 degrees C or less, More preferably, it is 170 degrees C or less.

  The heat-resistant acrylic polymer preferably contains a structural unit derived from (meth) acrylic acid ester, and the main chain has a ring structure to realize low birefringence (optical isotropy) in addition to heat resistance. It is preferable to make it. In the present specification, a resin containing a heat-resistant acrylic polymer having a ring structure in the main chain, a heat-resistant acrylic resin having a ring structure in the main chain, or an acrylic resin having a ring structure in the main chain, May be described.

  In introducing the ring structure of the main chain of the heat-resistant acrylic polymer, for example, N-substituted maleimide (cyclohexylmaleimide, methylmaleimide, phenylmaleimide, benzylmaleimide, etc.) or maleic anhydride is copolymerized for copolymerization. A ring structure derived from maleimide or a ring structure derived from anhydride may be introduced, or a lactone ring structure, glutaric anhydride structure, glutarimide structure, N-substituted in the main chain by a cyclization reaction after polymerization. A ring structure derived from maleimide may be introduced. From the viewpoint of heat resistance, the ring structure of the main chain preferably has one or more selected from the group consisting of an ester group, an imide group and an acid anhydride. For example, a lactone ring structure, a cyclic imide structure (N-alkyl) A ring structure derived from a substituted maleimide, a glutarimide ring and the like) and a cyclic acid anhydride structure (such as a ring structure derived from maleic anhydride and a glutaric anhydride) are preferred. Positive intrinsic birefringence can be imparted to the resin. As a result, the positive birefringence and the negative birefringence due to the structure derived from the (meth) acrylate monomer of the heat-resistant acrylic polymer The main chain ring structure is selected from the group consisting of a lactone ring structure, a glutarimide ring structure, and a glutaric anhydride structure in that a film having a low birefringence can be obtained even when stretched. One or more are preferable. Among these, those having a lactone ring structure in the main chain are particularly preferred from the viewpoint of optical properties such as low wavelength dependency.

  The main chain lactone ring structure may be any of 4- to 8-membered rings, but a 5- to 6-membered ring is more preferable, and a 6-membered ring is more preferable in view of the stability of the structure. When the lactone ring structure of the main chain is a 6-membered ring, a polymer having a high polymerization yield when synthesizing a polymer before introducing the lactone ring structure into the main chain, or a polymer having a high content of the lactone ring structure It is preferable that it is a structure represented by the following general formula (1) in that it is easy to obtain, and further has good copolymerizability with (meth) acrylic acid esters such as methyl methacrylate.

(In the formula (1), R ¹ , R ² and R ³ each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom. .)

In formula (1), examples of the organic residue represented by R ¹ , R ² , and R ³ include an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, and a propyl group; an ethenyl group; An unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms such as propenyl group; an aromatic hydrocarbon group having 6 to 20 carbon atoms such as phenyl group and naphthyl group; the alkyl group and the unsaturated group In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, a group in which one or more hydrogen atoms are substituted with at least one group selected from the group consisting of a hydroxyl group, a carboxyl group, an ether group and an ester group; It is preferable.

  The content of the ring structure in the heat-resistant acrylic polymer is not particularly limited, but is usually 5 to 90% by mass, preferably 10 to 70% by mass, more preferably 10 to 60% by mass, 50 mass% is more preferable. When the ring structure content is excessively small, the heat resistance of a film obtained by molding a resin may be lowered, or the solvent resistance and surface hardness may be insufficient. On the other hand, when the ring structure content is excessively large, the moldability and handling properties of the resin tend to decrease.

  Examples of acrylic resins having a lactone ring structure in the main chain include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, JP 2005-2005. Examples thereof include acrylic resins having a lactone ring structure described in Japanese Patent No. 146084.

  Examples of the acrylic resin having a glutarimide structure in the main chain include JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, JP-A-2006-328334, and JP-A-2006. Acrylic resins having a glutarimide structure described in Japanese Patent No. 337491, Japanese Patent Application Laid-Open No. 2006-337492, Japanese Patent Application Laid-Open No. 2006-337493, Japanese Patent Application Laid-Open No. 2006-337569, Japanese Patent Application Laid-Open No. 2007-009182, and the like. It is done.

  As the acrylic resin having a glutaric anhydride structure in the main chain, the glutaric anhydride structure described in JP-A-2006-283013, JP-A-2006-335902, JP-A-2006-274118 and the like is used. Acrylic resin that can be used.

  As a monomer which comprises the said heat-resistant acrylic polymer, well-known (meth) acrylic acid ester is mentioned. The total content of structural units derived from the (meth) acrylic acid ester of the heat-resistant acrylic polymer is preferably 10% by mass or more, more preferably 30% by mass or more, still more preferably 50% by mass or more, and particularly preferably. 70% by mass or more. Further, the total content of the structural units derived from the ring structure of the main chain and the (meth) acrylic acid ester is preferably 30% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more. Especially preferably, it is 90 mass% or more.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid t. (Meth) acrylic acid C _1-10 (cyclo) alkyl ester such as butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate; (meth) acrylic acid C ₇ such as benzyl (meth) acrylate _-20 aralkyl; chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3, (meth) acrylic acid 4,5,6-pentahydroxyhexyl, 2,3,4,5-tetrahydroxypentyl (meth) acrylate, etc. ) Halogen atom or a hydroxyl group include compounds obtained by replacing the alkyl moiety of the acrylate C _1-10 (cyclo) alkyl esters. The heat-resistant acrylic polymer particularly preferably has a methyl (meth) acrylate unit, and in this case, the optical properties and thermal stability of the film are improved. The heat-resistant acrylic polymer may have two or more types of structural units derived from the above monomers as (meth) acrylic acid ester units.

  The heat-resistant acrylic polymer may have a structural unit other than a (meth) acrylic acid ester unit. Examples of the monomer for introducing such a structural unit include styrene monomers such as styrene, vinyltoluene, α-methylstyrene, α-hydroxymethylstyrene, α-hydroxyethylstyrene; acrylonitrile, methacrylonitrile, and the like. Nitrile monomers; Olefin monomers such as ethylene, propylene and 4-methyl-1-pentene; O-containing vinyl compounds such as vinyl acetate, 2-hydroxymethyl-1-butene and methyl vinyl ketone; N-vinylpyrrolidone, N- Examples thereof include N-containing vinyl compounds such as vinyl carbazole. The heat-resistant acrylic polymer may have two or more structural units derived from these monomers.

When a cyclic structure is introduced into the main chain by a cyclization reaction, the heat-resistant acrylic polymer is preferably copolymerized with a monomer having a hydroxyl group or a carboxylic acid group at the time of polymerization. Specifically, as a monomer having a hydroxyl group, a compound having a hydroxyalkyl (preferably methyl) vinyl structure, such as methyl 2- (hydroxymethyl) acrylate, 2- (hydroxymethyl) ethyl acrylate, 2- 2 such as 2- (hydroxymethyl) acrylic acid C _1-10 (cyclo) alkyl ester such as isopropyl (hydroxymethyl) acrylate and 2- (hydroxymethyl) butyl acrylate, and 2- (hydroxyethyl) methyl acrylate -(Hydroxyethyl) acrylic acid C _1-10 (cyclo) alkyl ester; methallyl alcohol, allyl alcohol, and the like. Examples of the monomer having a carboxylic acid group include compounds having an acrylic acid skeleton, such as acrylic acid. , Methacrylic acid, crotonic acid, 2- (hydroxymethyl) acryl Acid, 2- (hydroxyethyl) acrylic acid. These monomers may have two or more types copolymerized. A monomer having a hydroxyl group or a carboxylic acid group changes to a ring structure by a cyclization reaction, but is derived from a monomer having an unreacted hydroxyl group or carboxylic acid group in an acrylic polymer having a ring structure in the main chain. A structural unit may be included.

  The weight average molecular weight of the heat-resistant acrylic polymer is not particularly limited, but is preferably 10,000 to 500,000, more preferably 50,000 to 300,000.

  The heat-resistant acrylic resin preferably has thermoplasticity. The Tg (glass transition temperature) of the heat-resistant acrylic resin is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, still more preferably 115 ° C. or higher, and particularly preferably 120 ° C. or higher. The upper limit value of Tg of the thermoplastic resin is not particularly limited, but is preferably 200 ° C. or less, more preferably 170 ° C. or less from the viewpoint of moldability and the like.

  The heat-resistant acrylic resin may contain an additive. Examples of additives include hindered phenol-based, phosphorus-based and sulfur-based antioxidants; light-resistant stabilizers, weather-resistant stabilizers, heat stabilizers and other stabilizers; reinforcing materials such as glass fibers and carbon fibers; ultraviolet rays Absorber; near infrared absorber; flame retardant such as tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide; antistatic agent such as anionic, cationic and nonionic surfactants; inorganic pigments, organic pigments, Colorants such as dyes; organic fillers and inorganic fillers; antiblocking agents; resin modifiers; organic fillers and inorganic fillers; plasticizers; lubricants; antistatic agents; flame retardants; Among these, an ultraviolet absorber is particularly preferably blended.

  Although the content rate of the additive in heat-resistant acrylic resin is not specifically limited, Preferably it is 0-5 mass%, More preferably, it is 0-2 mass%, More preferably, it is 0-0.5 mass%.

  Examples of the ultraviolet absorber include benzophenone compounds (such as 2-hydroxybenzophenone), salicinate compounds (such as phenyl salicate), benzoate compounds, and triazole compounds ((2,2′-hydroxy-5-methylphenyl)). Benzotriazole, etc.), triazine compounds (2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (3-alkyloxy-2-hydroxypropyloxy) -5-α-cumylphenyl) ] -S-Triazine skeleton (alkyloxy; long-chain alkyloxy group such as octyloxy, nonyloxy, decyloxy, etc.), 2,4,6-tris (hydroxyphenyl) -1,3,5-triazine skeleton Compound, etc.). Of these, triazine-based UV absorbers and triazole-based UV absorbers are preferred because they are highly compatible with amorphous thermoplastic resins, particularly acrylic resins, and have excellent absorption characteristics. An ultraviolet absorber can be used individually or in combination of 2 or more types.

  The blending amount of the ultraviolet absorber is not particularly limited, but is preferably 0 to 5.0% by mass, more preferably 0.7 to 3.0% by mass in a layer mainly composed of a thermoplastic resin. More preferably, it is 1.0-2.0 mass%. If the amount added is too small, the contribution to improving the weather resistance is low, and if it is too large, the mechanical strength may be lowered or yellowing may be caused.

  The heat-resistant acrylic resin may contain other thermoplastic polymers in addition to the heat-resistant acrylic polymer. Examples of other thermoplastic polymers include olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1-pentene); vinyl chloride, vinylidene chloride, chlorinated vinyl resins, and the like. Acrylic polymers such as polymethyl methacrylate; Styrenes such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer Polymer: Polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; Polyamide such as nylon 6, nylon 66, nylon 610; Polyacetal; Polycarbonate; Polyphenylene oxide; Polyphenylenes Polyetheretherketone; Polysulfone; Polyethersulfone; Polyoxybenzylene; Polyamideimide; Rubber polymer such as ABS resin, MBS resin and ASA resin blended with polybutadiene rubber and acrylic rubber; . In particular, when a styrenic polymer is contained, a film having a low retardation can be obtained by canceling the positive phase difference of the acrylic polymer having a ring structure in the main chain with the negative phase difference of the styrenic polymer. can get. Of the styrene polymers, styrene-acrylonitrile copolymers are particularly preferred from the viewpoint of compatibility with acrylic polymers. In addition, since both low retardation and flexibility can be imparted to the optical film, rubbery polymers such as ABS resin, MBS resin, and ASA resin containing rubbery with a styrene-based polymer are also preferable.

  The content ratio of the other thermoplastic polymer in the heat-resistant acrylic resin is preferably 0 to 50% by mass, more preferably 0 to 40% by mass, further preferably 0 to 30% by mass, and particularly preferably 0 to 20% by mass. It is.

  In order to produce a heat-resistant acrylic resin, for example, a polymer or additive may be pre-blended with any suitable mixer such as an omni mixer, and then the resulting mixture may be extrusion kneaded. In this case, the mixer used for extrusion kneading is not particularly limited, and for example, any suitable mixer such as an extruder such as a single screw extruder or a twin screw extruder or a pressure kneader may be used. Can do.

  The thickness of the heat-resistant acrylic film in the present invention is not particularly limited, but particularly when used as an optical film for a flat panel display, it is 10 μm or more in order to reduce the thickness and thickness of the panel itself while maintaining the film strength. It is preferable that it is 200 micrometers or less, More preferably, it is 15 micrometers or more and 150 micrometers or less, More preferably, they are 20 micrometers or more and 100 micrometers or less.

  The Tg (glass transition temperature) of the heat-resistant acrylic film in the present invention is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, more preferably 110 ° C. or higher, still more preferably 115 ° C. or higher, particularly preferably. 120 ° C. or higher. Moreover, although an upper limit is not specifically limited, Preferably it is 200 degrees C or less, More preferably, it is 180 degrees C or less, More preferably, it is 170 degrees C or less, Most preferably, it is 160 degrees C or less. If Tg is lower than 100 ° C, warping or distortion may occur after molding, and if it exceeds 200 ° C, moldability may be inferior.

  The heat-resistant acrylic film in the present invention preferably has an ultraviolet absorbing ability. For example, the transmittance of light having a wavelength of 380 nm is preferably less than 30%, more preferably less than 20%, and still more preferably less than 10%. What is necessary is just to measure this transmittance | permeability based on prescription | regulation of JISK7361: 1997.

  The heat-resistant acrylic film in the present invention preferably has a visible light transmittance. For example, the transmittance of light having a wavelength of 500 nm is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. The transmittance can be measured in the same manner as the transmittance of light having a wavelength of 380 nm.

  The heat-resistant acrylic film in the present invention preferably has a haze of 3% or less, more preferably 1% or less, and still more preferably 0.5% or less. A film having a haze exceeding 3% has a low transmittance and may not be suitable for optical applications. In addition, the haze of a film can be measured by the method as described in the Example mentioned later, for example.

  The heat-resistant acrylic film in the present invention is less colored, and the b value per 250 μm thickness is preferably 0.5 or less, more preferably 0.3 or less. In addition, b value of a film can be measured by the method as described in the Example mentioned later, for example.

The heat-resistant acrylic film in the present invention preferably has few appearance defects. Specifically, the number of defects in the heat-resistant acrylic film is preferably 1000 / m ² or less, more preferably 500 / m ² or less, having a diameter of 20 μm or more, More preferably, it is 200 pieces / m ² or less, ideally 0 pieces / m ² . Appearance defects are caused by raw materials such as resin, foreign matters mixed in the manufacturing process, bubbles during molding, die lines and scratches in the die and roll part during molding, etc. It can be reduced by cleaning and optimizing molding conditions. In addition, the fault of a film can be measured by the method as described in the Example mentioned later, for example.

  The production method of the heat-resistant acrylic film in the present invention is not particularly limited, and a known production method is possible, and the above-described heat-resistant acrylic resin (a composition containing a thermoplastic polymer, fine particles, and other additives) is formed into a film. It is obtained by doing. Examples of the film forming method include known film forming methods such as a melt extrusion method, a solution casting method (solution casting method), a calendar method, and a compression molding method. Among these, the melt extrusion method and the solution cast method (solution casting method) are preferable.

  Moreover, you may extend | stretch a heat-resistant acrylic film as needed. The method of uniaxially or biaxially stretching the obtained (unstretched) film is not particularly limited, and a known method may be followed. Uniaxial stretching may be longitudinal stretching (stretching in the film winding direction) or transverse stretching (stretching in the film width direction). In the case of longitudinal stretching, it is typically free end uniaxial stretching in which the change in the width direction of the film is free. Fixed-end uniaxial stretching is also possible in which the change in the width direction of the film is fixed. The biaxial stretching is typically sequential biaxial stretching in which transverse stretching is performed after longitudinal stretching, but simultaneous biaxial stretching in which longitudinal and transverse stretching is simultaneously performed can also be suitably used. Furthermore, it is also possible to stretch in the oblique direction with respect to stretching in the thickness direction or film roll. The stretching method, the stretching temperature, and the stretching ratio can be appropriately selected according to the target optical characteristics and mechanical characteristics.

<Surface micro-concave structure>
The fine concavo-convex structure on the surface of the film of the present invention is not particularly limited as long as reflection on the surface of the film is suppressed or light extraction efficiency is increased.

  The fine concavo-convex structure preferably has convex portions having an average height of 100 nm to 1000 nm or concave portions having an average depth of 100 nm to 1000 nm. The average height or average depth is more preferably 150 nm or more, further preferably 200 nm or more, still more preferably 250 nm or more, and particularly preferably 280 nm or more. Moreover, it is more preferable that it is 600 nm or less, and it is further more preferable that it is 500 nm or less. If the average height or the average depth is too small, good optical properties may not be exhibited. If the average height or average depth is too large, production may be difficult.

  In the case where the convex part and concave part are connected and have a wavy structure, the average length of the highest part (above the convex part) and the deepest part (below the concave part) (the highest in the direction perpendicular to the film surface) The average length from the part to the deepest part, that is, the height difference) is preferably 100 nm or more and 1000 nm or less for the same reason as the average height or the average depth. Here, the convex portion refers to a portion protruding from the reference surface, and the concave portion refers to a portion recessed from the reference surface.

  The fine concavo-convex structure is at least an average period of convex portions or concave portions in the horizontal direction with respect to the surface of the heat-resistant acrylic film (“period” when there is regularity in the arrangement positions of the convex portions or concave portions, (Referred to collectively as “average period”) is preferably less than or equal to the wavelength of visible light, specifically 100 nm or more and 400 nm or less. The average period is more preferably 120 nm or more, and further preferably 150 nm or more. The average period is more preferably 250 nm or less, and further preferably 200 nm or less. By setting the average period of the convex part or the concave part to 100 nm or more and 400 nm or less, a film having higher antireflection performance or light extraction efficiency can be provided. If the average period is too short or too long, the antireflection effect or light extraction effect may not be sufficiently obtained.

  As the shape of the convex portion or the concave portion in the fine concavo-convex structure, a conical shape, a triangular pyramid shape, a bell shape or the like is preferably exemplified. With such a shape, the average refractive index from the air interface to the heat-resistant acrylic film tends to change continuously. The arrangement of the convex portions or the concave portions is not particularly limited, but is preferably arranged with regularity such as a square arrangement or a three-way arrangement.

  In the fine concavo-convex structure, the aspect ratio which is a value obtained by dividing the average height or the average depth by the average period is not particularly limited, but the lower limit is preferably 1 or more in terms of optical properties, and 1.5 or more. More preferred is 2 or more. Further, the upper limit is preferably 5 or less, more preferably 3 or less, in view of the production process. When the fine concavo-convex structure is formed by curing a (meth) acrylic curable composition described later, the aspect ratio can be easily adjusted to the above range (preferably 1.5 or more, more preferably 2 or more).

  The method for forming the fine concavo-convex structure on the surface of the film of the present invention is not particularly limited, but a method for forming the fine concavo-convex structure on at least one surface of the heat-resistant acrylic film using a mold having the fine concavo-convex structure on the surface. Is preferred. Specifically, for example, a method of softening a thermoplastic resin such as the acrylic film by heating, pressing a molding die having a fine concavo-convex structure on the surface, and then cooling and releasing the mold Is possible. In this case, the fine uneven structure is made of a thermoplastic resin (preferably a heat-resistant acrylic resin). In addition, a method of pressing a mold having a fine concavo-convex structure on the surface of the curable material coated on the acrylic film and curing the curable material by active energy rays or heating is also one preferred form. In this method, when a curable composition is used as the curable material, the fine uneven structure is formed by curing the curable composition.

  The fine concavo-convex structure may be made of a thermoplastic resin or may be formed by curing a curable composition. The material constituting the fine concavo-convex structure described above and a heat-resistant acrylic film In consideration of making the difference in refractive index zero with respect to the display device and further reducing the size, weight, and cost of the display device, the fine concavo-convex structure is preferably formed of a heat-resistant acrylic film.

  The mold having a fine concavo-convex structure on the surface preferably has a convex portion having an average height of 100 nm to 1000 nm or a concave portion having an average depth of 100 nm to 1000 nm on at least one surface thereof. Here, the convex portion refers to a portion protruding from the reference surface, and the concave portion refers to a portion recessed from the reference surface. The mold of the present invention may have a convex portion or a concave portion on the surface thereof. Moreover, you may have both a convex part and a recessed part, Furthermore, they may connect and may have an uneven structure. In addition, what is necessary is just to use a concave-shaped shaping | molding die, when forming a convex shape on the surface of a molded product, and using a convex-shaped shaping | molding die, when shaping a concave shape on the surface of a molded product.

  It is preferable that the average height or the average depth from the reference surface of both the convex portion and the concave portion of the mold is 100 nm or more and 1000 nm or less. The height or depth may not be constant, and the average value may be within the range, but preferably has a substantially constant height or depth.

  Whether the mold is a convex portion or a concave portion, the average height or average depth is more preferably 150 nm or more, and further preferably 200 nm or more. Moreover, it is more preferable that it is 600 nm or less, and it is further more preferable that it is 500 nm or less. If the average height or the average depth is too small, good optical properties may not be exhibited. If the average height or average depth is too large, production may be difficult. When the convex part and concave part are connected and have a wavy structure, the average length of the highest part (above the convex part) and the deepest part (below the concave part) (perpendicular to the reference surface) The average of the length from the highest part to the deepest part, that is, the height difference) is preferably 100 nm or more and 1000 nm or less for the same reason as the average height or the average depth.

  The convex portion or concave portion of the mold is an average period of the convex portion or concave portion in the horizontal direction with respect to the surface (“period” when there is regularity in the location of the convex portion or concave portion, but is summarized in this specification. (Referred to as “average period”) is preferably not more than the wavelength of visible light, specifically, not less than 100 nm and not more than 400 nm. The average period is more preferably 120 nm or more, and further preferably 150 nm or more. The average period is more preferably 250 nm or less, and further preferably 200 nm or less. If the average period is too short or too long, the antireflection effect or light extraction effect may not be sufficiently obtained. The convex part or the concave part may be arranged at random or may be arranged with regularity. In any case, it is preferable in terms of antireflection properties and transmission improvement properties that the convex portions or the concave portions are disposed substantially uniformly over the entire surface of the mold. Further, it is only necessary that the average period be at least 100 nm to 400 nm in at least one direction, and the average period does not have to be 100 nm to 400 nm in all directions.

  When the convex portions or concave portions of the mold are arranged with regularity, the average period in the horizontal direction with respect to the surface of the mold may be arranged to be 100 nm or more and 400 nm or less. Are preferably arranged such that the period in the short direction is not less than 100 nm and not more than 400 nm. That is, it is preferable that the period is within the above range when the direction having the shortest period is taken as one of the horizontal directions with respect to the mold surface. Further, at that time, it is particularly preferable that the period is also set to be 100 nm or more and 400 nm or less in the direction perpendicular to the direction having the shortest period.

  The area occupation ratio of the fine concavo-convex structure in the mold is preferably 40% or more, more preferably 60% or more, and most preferably 80% or more per unit area of the mold surface (reference surface). If the area occupancy ratio of the fine concavo-convex structure is lower than 40%, the area of the flat portion increases and reflection may increase.

The number of fine irregularities in the mold is preferably 4 or more, more preferably 9 or more, and most preferably 16 or more per 1 μm ^{2 of the} mold surface (reference surface), and the upper limit is preferably 100. Or less, more preferably 90 or less, and most preferably 80 or less. If the number of fine irregularities is too large or too small, the antireflection effect or light extraction effect may not be sufficiently obtained.

  There is no restriction | limiting in particular as a shape of the fine concavo-convex structure of the said shaping | molding die, According to the objective, it can select suitably. For example, when used for an antireflection film, the surface fine uneven structure of the film (molded product) has a conical shape, a triangular pyramid shape, a bell shape, or the like, from the air interface to the heat-resistant acrylic film. A structure in which the average refractive index continuously changes is preferable. Therefore, as the shape of the fine concavo-convex structure on the surface of the molding die necessary for this purpose, a conical shape such as a cone shape, a triangular pyramid shape, or a bell shape is required. In particular, those having no directionality in the fine concavo-convex structure such as a conical shape, a triangular pyramid shape, and a bell shape are more preferable, and a continuous change in refractive index in the thickness direction is linear such as a conical shape and a triangular pyramid shape. Is more preferable.

  The aspect ratio which is a value obtained by dividing the average height or average depth of the fine concavo-convex structure of the mold by the average period is not particularly limited, but 1 or more is preferable in terms of optical properties, and 1.5 or more is particularly preferable. Two or more are more preferable. Moreover, it is preferable on the structure manufacturing process that an aspect ratio is 5 or less, and 3 or less is especially preferable.

  As the surface shape processing method of the mold, a semiconductor device or photomask manufacturing process can be used. The surface shape processing of the nanoimprint mold requires extremely high accuracy, and as a method to achieve this accuracy, dry etching is performed using a resist pattern formed on the surface of a silicon or quartz substrate by photolithography or electron beam lithography as a mask. There is a way to do it. By using this method, a pattern with a fine width of several tens of nm can be formed in an arbitrary shape.

  Further, it is possible to use an electroforming process in which a replica such as a concave and convex portion is produced by plating using a fine pattern of silicon, quartz or the like prepared by the above method as a master. As a result, a large number of molds such as nickel can be duplicated with one master mold, which is very advantageous economically.

  In the case of using a method of softening a thermoplastic base material by heating, forming the mold by pressing the mold there, and then cooling and demolding as a method for forming a fine relief structure on the surface of the film of the present invention The mold heated to the glass transition temperature or higher can be bonded to the heat-resistant acrylic film. Further, the heat-resistant acrylic film can be heated to the glass transition temperature or higher and then pressure-bonded to a mold. In this case, the fine uneven structure is made of a heat-resistant acrylic resin.

  The temperature in thermocompression bonding is preferably (glass transition temperature of the heat-resistant acrylic film) to (glass transition temperature of the heat-resistant acrylic film + 60 ° C.), more preferably (glass transition temperature of the heat-resistant acrylic film + 5). ° C) to (glass transition temperature of the heat-resistant acrylic film + 40 ° C). Within this range, the fine pattern of the mold can be efficiently formed on the heat-resistant acrylic film (transfer layer).

  When removing the mold, it is preferable to cool the heat-resistant acrylic film to a glass transition temperature or lower. More preferably, it is (glass transition temperature of the heat-resistant acrylic film −10 ° C.) to (glass transition temperature of the heat-resistant acrylic film −50 ° C.). In this range, the shape of the fine pattern formed on the heat-resistant acrylic film can be more retained.

  As a method for forming a fine concavo-convex structure on the surface of the film of the present invention, a mold having a fine concavo-convex structure on the surface is pressed against the curable material coated on the heat-resistant acrylic film, and curable by active energy rays or heating When using the method of hardening material, the curable composition which changes from a liquid to a solid by active energy ray irradiation or a heating can be used as a curable material.

  Although it will not specifically limit if the said curable composition can transfer the surface shape of a shaping | molding die, It is preferable that a reactive monomer, a reactive oligomer, a polymerization initiator, etc. are included. Reactive components such as reactive monomers and reactive oligomers can be used with any reaction mechanism such as radical polymerizability, ionic polymerizability, and addition reactivity, but radical polymerizability from the viewpoint of reaction rate. Among them, the (meth) acrylic curable composition is preferable from the viewpoints of safety, variety of physical properties, and economy. Moreover, it is preferable to set it as a (meth) acrylic-type curable composition also from the point of adhesiveness with a heat-resistant acrylic film. Thereby, even if it does not perform special pretreatments such as corona discharge treatment and primer coating on the base material, it is possible to give a fine surface irregularity layer with good adhesion without causing repelling during coating. The (meth) acrylic curable composition is a composition containing 50% by mass or more of a compound having a (meth) acryloyl group.

  Examples of the reactive component (reactive monomer) contained in the curable composition include (meth) acrylic acid, (meth) acrylic acid esters, (meth) acrylamides, N-vinyl compounds, and vinyl compounds. , Vinyl ethers, α, β-unsaturated compounds, epoxy compounds, oxetane compounds and the like can be used, but are not particularly limited thereto.

Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate, Monofunctional (meth) acrylic acid such as methoxypolyethylene glycol (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 3-hydroxypropyl (meth) acrylate Esters;
Monofunctional (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide;
Monofunctional N-vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinylacetamide;
Monofunctional vinyl compounds such as styrene, α-methylstyrene, vinyl acetate;
Monofunctional vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether;
Maleic anhydride, maleic acid, dimethyl maleate, diethyl maleate, fumaric acid, dimethyl fumarate, diethyl fumarate, monomethyl fumarate, monoethyl fumarate, itaconic anhydride, itaconic acid, dimethyl itaconate, methylenemalonic acid, methylene Monofunctional α, β-unsaturated compounds such as dimethyl malonate, cinnamic acid, methyl cinnamate, crotonic acid, methyl crotonic acid;
Monofunctional epoxy compounds such as methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, cyclohexyl glycidyl ether, methoxyethyl glycidyl ether;
Monofunctional oxetane compounds such as 3-methyl-3-phenoxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane;
Polyfunctional (meth) acrylic acid esters such as trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerol tri (meth) acrylate;
Polyfunctional vinyl ethers such as trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether;
Polyfunctional α, β-unsaturated compounds such as divinylbenzene;
Ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, butylene glycol diglycidyl ether, hexanediol diglycidyl ether, bisphenol A alkylene oxide diglycidyl ether, bisphenol F alkylene oxide diglycidyl ether, trimethylolpropane triglycidyl Polyfunctional epoxy compounds such as ether and glycerin triglycidyl ether;
Di [1-methyl (3-oxetanyl)] methyl ether, di [1-ethyl (3-oxetanyl)] methyl ether, 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, Polyfunctional oxetane compounds such as bis {4-[(3-ethyl-3-oxetanyl) methoxy] methyl} benzyl ether;
Etc. can be used.

  As the reactive component contained in the curable composition, a compound having a (meth) acryloyl group and a vinyl ether group in one molecule, a compound having a (meth) acryloyl group and an epoxy group in one molecule, A heteropolymerizable monomer such as a compound having a (meth) acryloyl group and an oxetane group in one molecule can also be used.

  Examples of the compound having (meth) acryloyl group and vinyl ether group in one molecule include 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, and 1-methyl-2-vinyloxyethyl (meth) acrylate. 2-vinyloxypropyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 1-methyl-3-vinyloxypropyl (meth) acrylate, 1-vinyloxymethylpropyl (meth) acrylate, (meth ) 2-methyl-3-vinyloxypropyl acrylate, 3-methyl-3-vinyloxypropyl (meth) acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth) acrylate, 3- (meth) acrylic acid 3- Vinyloxybutyl, 1-methyl-2-vinyloxypropyl (meth) acrylate, (meth) acrylic 2-vinyloxybutyl acid, 4-vinyloxycyclohexyl (meth) acrylate, 5-vinyloxypentyl (meth) acrylate, 6-vinyloxyhexyl (meth) acrylate, 4-vinyloxymethylcyclohexylmethyl (meth) acrylate , (Meth) acrylic acid p-vinyloxymethylphenylmethyl, (meth) acrylic acid 2- (vinyloxyethoxy) ethyl, (meth) acrylic acid 2- (vinyloxyisopropoxy) ethyl, (meth) acrylic acid 2- (Vinyloxyethoxy) propyl, 2- (vinyloxyethoxy) isopropyl (meth) acrylate, 2- (vinyloxyisopropoxy) propyl (meth) acrylate, 2- (vinyloxyisopropoxy) isopropyl (meth) acrylate , (Meth) acrylic acid 2- (vinyloxyethoxyethoxy) ) Ethyl, 2- (vinyloxyethoxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyisopropoxy) propyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) isopropyl (meth) acrylate, (Meth) acrylic acid 2- (vinyloxyethoxyisopropoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyethoxyethoxyethoxy) ethyl, (meth) acrylic acid polyethylene glycol monovinyl ether, (meth) acrylic acid polypropylene glycol mono Vinyl ether or the like can be used.

As a compound having a (meth) acryloyl group and an epoxy group in one molecule, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and the like can be used.
As a compound having a (meth) acryloyl group and an oxetane group in one molecule, 3-ethyl-3-methacryloxyoxetane and the like can be used.

  As the reactive component (reactive oligomer) contained in the curable composition, urethane (meth) acrylates, epoxy (meth) acrylates, polyester (meth) acrylates, silicone (meth) acrylates, and the like are used. However, the present invention is not limited to these.

  The urethane (meth) acrylates are not particularly limited as long as they are (meth) acrylate compounds having a urethane bond in the molecule. For example, the position and number of urethane bonds and the position and number of (meth) acryl groups are particularly It is not limited. As a preferable chemical structure of urethane (meth) acrylates, a hydroxyl group and (preferably a plurality of) (meth) acrylic groups are included in the molecule with respect to a compound having (preferably a plurality of) isocyanate groups in the molecule. A compound having a structure obtained by reacting a compound having a compound, a compound having a plurality of hydroxyl groups with a diisocyanate compound or a triisocyanate compound, and an unreacted isocyanate group of the obtained compound to hydroxyethyl (meth) acrylate And the like having a structure obtained by reacting a compound having a hydroxyl group and a (meth) acrylic group in the molecule.

  The epoxy (meth) acrylate is not particularly limited as long as it is a (meth) acrylate compound having a structure obtained by reaction of (meth) acrylic acid with an epoxy group. For example, the position of the (meth) acryl group or The number is not particularly limited. Preferred chemical structures of epoxy (meth) acrylates include polyglyceryl glycol diglycidyl ethers such as polyethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether; glycerin glycidyl such as glycerin diglycidyl ether Ethers; bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide modified products, diglycidyl ethers of bisphenol compounds such as bisphenol F diglycidyl ether; ) Those having a structure to which acrylic acid is added.

  The polyester (meth) acrylates are not particularly limited as long as they are (meth) acrylate compounds having a plurality of ester bonds in the molecule. Preferable chemical structures of polyester (meth) acrylates include esterification reaction products of polyester polyol and (meth) acrylic acid obtained by condensation of polyhydric alcohol and polycarboxylic acid.

  The silicone (meth) acrylates are not particularly limited as long as they are (meth) acrylate compounds having a plurality of siloxane bonds in the molecule. As a preferable chemical structure of silicone (meth) acrylates, for example, a siloxane compound having a (meth) acryloyl group is condensed with a tetraalkoxysilane compound, a trialkoxysilane compound, a dialkoxysilane compound, a monotetraalkoxysilane compound, or the like. Is obtained.

  As the polymerization initiator, a radical photopolymerization initiator, a thermal radical polymerization initiator, a cationic photopolymerization initiator, a thermal cationic polymerization initiator, and the like can be used, but are not particularly limited thereto.

  As the radical photopolymerization initiator, the following compounds are suitable. For example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1- Hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy-2- Acetophenones such as methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, o-ben Methyl ylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxylcarbonyl) benzophenone, 2,4,6-trimethyl Benzophenones such as benzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride; 2 -Isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4-dimethyl -9H-thioxan Thioxanthones such as ton-9-one mesochloride; Acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide And the like. Among these, acetophenones, benzophenones, and acylphosphine oxides are preferable, and in particular, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-thiol) Methylphenyl) propan-1-one is preferred.

  As the thermal radical polymerization initiator, the following compounds are suitable. For example, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl acetate peroxide, 1,1-bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl Cyclohexane, 1,1-bis (t-butylperoxy) butane, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, lauroyl Peroxide, succinic acid peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodeca Noate, t-hexylperoxypivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxyisopropylmonocarbonate, t- Butyl peroxyisobutyrate, t-butyl peroxymalate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxyacetate, t-butyl peroxybenzoate, bis (t- (Butylperoxy) isophthalate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, t-hexylperoxybenzoate, t-butyltrimethylsilyl peroxide, 3,3 ′, 4,4 ′ -Tetra (t-butylperoxycarbonyl) ben Organic peroxide initiators such as phenone and 2,3-dimethyl-2,3-diphenylbutane; 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazoline) -2-yl) propane] dihydrochloride, 2,2′-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2,2 '-Azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] pro Onamide}, 2,2′-azobis (2-methylpropionamide), 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl 2, Azo initiators such as 2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis [2- (hydroxymethyl) propionitrile] And the like. Among these, radicals can be efficiently generated by catalytic action of metal soaps such as methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, t-butyl peroxybenzoate, benzoyl peroxide, and / or amine compounds. Preferred compounds are 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile).

  As the photocationic polymerization initiator, the following compounds are suitable. For example, arylsulfonium salts such as triphenylsulfonium hexafluorophosphate and triphenylsulfonium hexafluoroantimonate; Aryl iodonium salts; aryl diazonium salts such as phenyldiazonium tetrafluoroborate; and the like. Among these, arylsulfonium salts, aryldiazonium salts, and aryliodonium salts are preferable, and (triylcumyl) iodonium tetrakis (pentafluorophenyl) borate is particularly preferable.

  As the thermal cationic polymerization initiator, the following compounds are suitable. For example, Lewis acids (eg, boron trifluoride, titanium chloride, ferrous chloride, ferric chloride, zinc chloride, stannous chloride, stannic chloride, dibutylstannic dichloride, tetrabutyltin, Triethylaluminum, diethylaluminum chloride, etc.) and electron donating compounds (for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoric triamide, dimethyl sulfoxide, trimethyl phosphate, phosphoric acid Complex with triethyl, etc .; protonic acid (for example, halogenocarboxylic acids, sulfonic acids, sulfuric monoesters, phosphoric monoesters, phosphoric diesters, polyphosphoric esters, boric monoesters, boric diesters) Etc.) with a base (eg, ammonia, monoethylamine, diethylamino) , Triethylamine, pyridine, piperidine, aniline, morpholine, cyclohexylamine, monoethanolamine, diethanolamine, triethanolamine, compounds were neutralized with butylamine, etc.), and the like. Among these, amine complexes of various protonic acids are preferable because a good pot life can be secured.

  The total amount of the polymerization initiator added to the entire curable composition is preferably 0.05% by mass or more, and more preferably 20% by mass or less. If it is less than 0.05% by mass, sufficient curing may not be obtained, and if it exceeds 20% by mass, no further improvement in the physical properties of the cured product is observed, and there is a possibility that it may adversely affect the economy. Sexuality may be impaired. The total addition amount of the polymerization initiator is more preferably 0.1% by mass or more, further preferably 0.2% by mass or more, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

  If necessary, the curable composition further includes a polymerization inhibitor, a curing accelerator, a photosensitizer, a release agent, an antistatic agent, an antifouling agent, a refractive index adjusting agent, a viscosity adjusting agent, A binder polymer, fine particles, an antioxidant, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a lubricant, a leveling agent, a solvent, and the like can also be blended. These can be appropriately selected from conventionally known ones.

  The curable composition preferably has a viscosity of 1 mPa · s or more, more preferably 3 mPa · s or more, and most preferably 5 mPa · s or more. Further, it is preferably 10,000 mPa · s or less, more preferably 5000 mPa · s or less, and most preferably 1000 mPa · s or less. If the viscosity is less than 1 mPa · s, the volatility of the curable composition may increase and bubbles may be generated during molding. On the other hand, when the viscosity is greater than 10,000 mPa · s, the curable material may not enter the unevenness of the nanometer size, and the mold shape transferability may decrease.

  It is preferable that hardening of the said curable composition is performed by active energy ray irradiation and / or a heating. As a method of filling the curable composition between the heat-resistant acrylic film and the mold, first, the curable composition is uniformly applied to the surface of the heat-resistant acrylic film, and then the mold may be pressed or molded. After the curable composition is uniformly applied to the surface of the mold, a heat-resistant acrylic film may be pressed. This operation is preferably performed in a reduced pressure environment in order to avoid mixing of bubbles. In addition, when an acrylic curable composition is used, it is preferably cured in a reduced pressure environment or in an inert gas atmosphere because of inhibition of curing by oxygen.

  Next, when an active energy ray is used as a curing method, the irradiation method may be irradiation from the heat-resistant acrylic film direction or irradiation from the mold direction. In the case of irradiation from the heat-resistant acrylic film direction, it is necessary to use a heat-resistant acrylic film that transmits active energy rays. In the case of irradiation from the mold direction, the mold is activated energy rays such as quartz. It is necessary to use a material that transmits light. The light source used for irradiation is not particularly limited, such as a low pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, a gallium lamp, and a xenon lamp, but a high pressure mercury lamp, an ultra high pressure mercury lamp, and a metal halide lamp are preferable.

  In the case of curing by heat, for example, heating by infrared rays, far infrared rays, hot air, high frequency heating or the like can be used. Active energy ray irradiation and heating can be used in combination.

Irradiation energy of the active energy ray are not particularly limited as long as the amount necessary to the curing reaction proceeds sufficiently, for example, preferably 300 mJ / cm ² or more 1500 mJ / cm ² or less, 400 mJ / cm ² or more 1000 mJ / cm ² The following is more preferable, and more preferably 500 mJ / cm ² or more and 800 mJ / cm ² or less.
In the case of curing by heating, the heating temperature is preferably 30 ° C. or higher and 200 ° C. or lower, more preferably 40 ° C. or higher and 150 ° C. or lower, and further preferably 50 ° C. or higher and 100 ° C. or lower. The heating time is preferably from 30 seconds to 1 hour, more preferably from 1 minute to 30 minutes, and even more preferably from 2 minutes to 15 minutes.

<Polarizer protective film>
The film of the present invention is preferably used as a polarizer protective film because it has low light reflectance and high light transmittance. The “light” in this case is light including at least light having a wavelength in the visible light region.

  When the film of the present invention is used as a polarizer protective film, the film of the present invention is preferably bonded to the polarizer via an adhesive layer. The polarizer may be any polarizer as long as it has a function of transmitting only light having a specific vibration direction. For example, a polyvinyl alcohol film stretched and dyed with iodine or a dichroic dye. Alcohol polarizers; Polyene polarizers such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride; reflective polarizers using multilayer laminates or cholesteric liquid crystals; thin film crystal film polarizers, etc. Can be used. Among these, a polarizer obtained by uniaxially stretching a polyvinyl alcohol-based fat film dyed with a dichroic material is preferably used. The thickness of these polarizers is not particularly limited, and is generally about 5 to 100 micrometers.

  Preferred adhesives used for bonding to the polarizer include, for example, adhesives including polyvinyl alcohol resins, polyacrylic resins, polyurethane resins, polyester resins, etc .; cured with active energy rays such as ultraviolet rays and electron beams And adhesives such as acrylic, silicone, and rubber adhesives. In addition, it cannot be overemphasized that it may heat-compression-bond on the conditions which the polarizing function of a polarizer does not fall, In that case, it can adhere | attach on gentle thermocompression-bonding conditions.

  The adhesive may contain an additive as necessary. Examples of the additive include a crosslinking agent such as a compound having at least two functional groups reactive with the resin contained in the adhesive; an adhesion promoter represented by a silane coupling agent or ethylene oxide; a transparent protective film; Additives that improve the wettability of materials; sensitizers that increase the curing speed and sensitivity by electron beams typified by carbonyl compounds, machinery represented by acryloxy group compounds and hydrocarbon compounds (natural and synthetic resins), etc. Additives that improve mechanical strength and processability; UV absorbers, anti-aging agents, dyes, processing aids, ion trapping agents, antioxidants, tackifiers, fillers (preferably other than metal compound fillers), plastics Agents, leveling agents, foaming inhibitors, antistatic agents and the like.

  The method of adhering using the adhesive is not particularly limited. For example, kiss coat, spin coat, roll coat, dip coat, curtain coat, bar coat, doctor blade coat, knife coat, air knife coat, die coat, gravure coat Various methods such as micro gravure coating, offset gravure coating, lip coating, spray coating, and comma coating may be used, and an adhesive may be applied to the adhesive surface of the polarizer and the two may be superimposed. For example, after applying an adhesive, the polarizer and a film bonded thereto are sandwiched by nip rolls and bonded together. When bonding, it is preferable to arrange | position the optical axis of the film of this invention, and the absorption axis of a polarizer orthogonally or in parallel.

  When the film of the present invention is used as a polarizer protective film, an easy adhesion treatment can be performed on the surface in contact with the polarizer to improve adhesion. Examples of the easy adhesion treatment include plasma treatment, corona treatment, ultraviolet irradiation treatment, solvent treatment, flame (flame) treatment, saponification treatment, and a method of forming an anchor layer, and these can be used in combination as appropriate. Among these, a corona treatment, a method of forming an anchor layer, and a method of using these in combination are preferable.

  The resin for forming the anchor layer is not particularly limited, and a known resin conventionally used for forming the anchor layer is used. For example, acrylic-based, cellulose-based, urethane-based, silicone-based, polyester-based, and polyethyleneimine-based polymers, polymers containing amino groups in the molecule, and the like are used. These anchor layer forming resins may be used alone or in combination of two or more. Moreover, you may laminate | stack the anchor layer formed with a different resin.

  The thickness of the anchor layer is a thickness after drying / curing or drying, for example, preferably 0.01 μm or more and 10 μm or less, more preferably 0.05 μm or more and 3 μm or less, and further preferably 0.1 μm or more and 1 μm or less. . If the thickness of the anchor layer is less than 0.01 μm, the adhesive strength between the polarizer and the protective film may be insufficient. On the other hand, when the thickness of the anchor layer exceeds 10 μm, color loss or discoloration of the polarizing plate may easily occur.

  The coating composition for forming the anchor layer may contain a known material in addition to the resin used for the anchor layer. Examples of the material include a crosslinking agent, an antiblocking agent, a dispersion stabilizer, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersant, a surfactant, a catalyst, and an antistatic agent. is there.

  As a method for applying the coating composition for forming an anchor layer on the surface of the film of the present invention facing the polarizer, a normal coating technique using a bar coater, a roll coater, a gravure coater or the like may be employed. It is not limited. Moreover, the method and conditions for drying the applied coating composition are not particularly limited. For example, using a hot air dryer or an infrared dryer, preferably 50 to 130 ° C., more preferably 75 to 110. What is necessary is just to dry at the temperature of ° C. Moreover, there is no problem even if a curing process is provided for crosslinking and curing of the coating composition. When a curing process is required, the curing temperature is, for example, preferably 20 to 100 ° C., more preferably 20 to 50 ° C. However, the crosslinking and curing of the composition proceeds to some extent by the heat used for drying. Further, since the process further proceeds in the bonding process between the polarizer and the film using an adhesive, sufficient physical properties can be obtained even at room temperature curing.

  In addition, in order to adjust the surface wetting tension, the surface of the anchor layer is, for example, corona discharge treatment, plasma treatment, ozone spraying, solvent treatment, ultraviolet irradiation, flame treatment, chemical treatment, and other conventionally known surfaces. Processing can be performed.

  Although the polarizer protective film which consists of a film of this invention is not specifically limited, Liquid crystal display devices (LCD), such as VA type | mold and IPS type | mold, organic electroluminescent light-emitting device (organic EL), a plasma display, electronic paper, 3D display, In an image display device such as a field emission display (FED), it can be suitably used as an optical film for protecting a polarizer due to its high optical characteristics and heat resistance.

<Organic electroluminescence light emitting device>
The film of the present invention is preferably used for an organic electroluminescence (organic EL) light-emitting device because of its low light reflectance and high light extraction efficiency.

  The organic EL light emitting device using the film of the present invention includes the light emitting layer and the film of the present invention on the light extraction surface side of the light emitting layer. In the organic EL light emitting device of the present invention, for example, as shown in FIG. 1, an anode electrode 12 such as ITO is connected to one side of the light emitting layer 14 via a hole transport layer / hole injection layer 13. A cathode electrode 16 is connected to the other side of the cathode electrode 16 via an electron transport layer / electron injection layer 15, a transparent protective layer 17 is laminated on the cathode electrode 16, and a glass substrate 11 is laminated on the anode electrode 12. . The glass substrate 11 is further provided with the film 10 of the present invention so that the surface on which the fine concavo-convex structure is formed becomes the light extraction surface side. In such a configuration, light generated in the light emitting layer 14 is extracted from the surface of the film 10 laminated on the glass substrate 11. That is, the upper side in FIG. 1 is the light extraction surface side.

  In the organic EL light-emitting device of the present invention, the film of the present invention is placed on the light extraction surface side of the light-emitting layer of the self-light-emitting device such as organic EL so that the surface on which the fine concavo-convex structure is formed is on the light extraction surface side. By using it, the light extraction efficiency is improved. As a result, a simpler method such as bonding the film of the present invention to the glass substrate without performing complicated processing on the glass substrate on the light extraction surface side of the light emitting layer, the self-luminous device such as organic EL Brightness can be improved.

  Although it does not restrict | limit especially as a bonding method in the case of bonding the film of this invention to a glass substrate, For example, the method of bonding through an adhesive layer or an adhesive bond layer is employ | adopted. Examples of the adhesive or adhesive used for bonding to the glass substrate include an adhesive made of an acrylic resin, a silicon resin, a rubber resin, etc .; an acrylic resin, a urethane resin, a polyester resin, etc. Adhesives; Adhesives cured with active energy rays such as ultraviolet rays and electron beams; and the like. The refractive index difference between the refractive index of the pressure-sensitive adhesive layer or adhesive layer and the refractive index of the heat-resistant acrylic film, and the refractive index difference between the refractive index of the pressure-sensitive adhesive layer or adhesive layer and the refractive index of the glass substrate are both reduced. A pressure-sensitive adhesive or adhesive made of acrylic resin or urethane resin is preferable in that the effect of improving the light extraction efficiency is increased.

  The said adhesive or adhesive agent may contain the additive as needed. Examples of the additive include a crosslinking agent such as a compound having at least two functional groups reactive to the resin contained in the pressure-sensitive adhesive or adhesive; an adhesion promoter represented by silane coupling agent and ethylene oxide ; Additives that improve wettability with transparent protective film; Sensitizers that increase the curing speed and sensitivity by electron beams such as carbonyl compounds; Acryloxy group compounds and hydrocarbon compounds (natural and synthetic resins) Representative additives that improve mechanical strength, processability, etc .; UV absorbers, anti-aging agents, dyes, processing aids, ion trapping agents, antioxidants, tackifiers, fillers (preferably metal compounds Other than fillers), plasticizers, leveling agents, foaming inhibitors, antistatic agents and the like.

  As another bonding method in the case of bonding the film of the present invention to a glass substrate, for example, there is a method of thermocompression bonding under conditions that do not affect the fine uneven structure. In that case, it is desirable to bond them under mild thermocompression bonding conditions.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the examples shown below.

[Glass-transition temperature]
The glass transition temperature (Tg) of the resin was determined in accordance with the provisions of JIS K7121. Specifically, using a differential scanning calorimeter (“DSC-8230” manufactured by Rigaku Corporation), a sample of about 10 mg was heated from room temperature to 200 ° C. (temperature increase rate: 20 ° C./min) in a nitrogen gas atmosphere. From the obtained DSC curve, it evaluated by the starting point method. Α-alumina was used as a reference. In addition, evaluation of Tg with respect to the film produced by each manufacture example was performed similarly.

[Light transmittance]
The light transmittance of the film was evaluated by measuring the transmittance of the film with respect to light having a wavelength of 380 nm or 500 nm using a spectrophotometer (“UV-3100” manufactured by Shimadzu Corporation). The total light transmittance was measured according to JIS K7361-1.

[Haze]
The haze of the film was measured using a turbidimeter (“NDH 5000” manufactured by Nippon Denshoku Industries Co., Ltd.).

[Weight average molecular weight]
The weight average molecular weight was determined by gel permeation chromatography (GPC) under the following conditions.
System: Developing solvent manufactured by Tosoh Corporation: Chloroform (made by Wako Pure Chemical Industries, special grade), flow rate 0.6 mL / min Standard sample: TSK standard polystyrene ("PS-oligomer kit 12 type" manufactured by Tosoh Corporation)
Column configuration (measurement side): guard column (“TSK Guardcolumn SuperH-H” manufactured by Tosoh Corporation), separation column (“TSK gel Super HM-M” manufactured by Tosoh Corporation), two series connection column configuration (reference side): reference Column ("TSK gel SuperH-RC" manufactured by Tosoh Corporation)

[viscosity]
The viscosity of the curable composition was measured using a B-type viscometer in accordance with JIS K-7117-1.
[Film thickness]
The thickness of the film was measured using a Digimatic Micrometer (manufactured by Mitutoyo Corporation).

[Color difference]
The color difference (b value) was calculated as a value obtained by proportionally converting the film thickness to 250 μm based on the measured value of the film measured using a colorimetric color difference meter (“ZE 6000” manufactured by Nippon Denshoku Industries Co., Ltd.). . In addition, b value shows the value of b ^* by the display of the hue based on JISZ8729, and calculated | required as an average value of 10 places measured by putting a film on a standard white board.
[Number of defects]
According to the appearance observation method described in JIS K6718, the number of defects in the film is visually inspected under scattered light, and then defects having a diameter of 20 μm or more are magnified by 20 to 100 times. Measured by counting under a microscope.

[Refractive index anisotropy (in-plane retardation value Re, thickness direction retardation value Rth)]
For the refractive index anisotropy of the film, the in-plane retardation value (Re) and thickness direction retardation value (Rth) were measured using a retardation film / optical material inspection device ("RETS-100" manufactured by Otsuka Electronics Co., Ltd.). And measured at a measurement wavelength of 589 nm. The thickness direction retardation value Rth was measured by tilting 40 ° with the slow axis as the tilt axis.

[Refractive index]
The refractive index of the film was measured using a multi-wavelength Abbe refractometer ("DR-M4" manufactured by Atago Co., Ltd.) and the refractive index at D line (587.6 nm) and 20 ° C. On the other hand, the refractive index of the curable composition was such that a plate-shaped molded article (cured product) having a thickness of 1 mm was prepared, and the resulting molded article was refracted at D line (587.6 nm) and 20 ° C. in the same manner as the film. The rate was measured. A 1 mm thick plate-shaped product is sandwiched between two glass plates with a 1 mm thick spacer and a curable composition, and is irradiated with energy of ² J / cm ² with a high-pressure mercury lamp with the air shut off. It was produced by curing.
[Luminance]
As for the luminance, the front luminance at a measurement angle of 1 ° was measured using a spot type single-lens reflex digital luminance meter (“LS-100” manufactured by Konica Minolta).

(Production Example 1)
Into a reaction vessel having an internal volume of 1000 L equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introduction pipe, 40 parts by mass of methyl methacrylate (MMA), 10 parts by mass of methyl 2- (hydroxymethyl) acrylate (MHMA) In addition, 50 parts by mass of toluene as a polymerization solvent and 0.025 parts by mass of an antioxidant (“ADK STAB (registered trademark) 2112” manufactured by Asahi Denka Kogyo Co., Ltd.) were charged, and the temperature was raised to 105 ° C. while passing nitrogen through this. It was. When the reflux accompanying the temperature increase started, 0.05 parts by mass of t-amylperoxyisononanoate (“Lupelox (registered trademark) 570” manufactured by Arkema Yoshitomi) was added as a polymerization initiator, and 0.10 While part by mass of t-amylperoxyisononanoate was added dropwise over 3 hours, solution polymerization was allowed to proceed under reflux at about 105 to 110 ° C., followed by further aging for 4 hours.

  Next, 0.05 parts by mass of 2-ethylhexyl phosphate (“Phoslex A-8” manufactured by Sakai Chemical Industry) as a catalyst for the cyclization condensation reaction (cyclization catalyst) was added to the obtained polymerization solution, and about 90 The cyclization condensation reaction was allowed to proceed for 2 hours under reflux at ˜110 ° C., and then the polymerization solution was heated for 30 minutes by an autoclave at 240 ° C. to further proceed the cyclization condensation reaction to the lactone ring.

Next, the obtained polymerization solution was subjected to a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1 and a forevent number of 4 (first and 2, a third and a fourth vent), a side feeder is provided between the third vent and the fourth vent, and a leaf disk type polymer filter (filtration accuracy 5 μm, filtration area 1.5 m at the tip) ² ) was introduced into a vent type screw twin screw extruder (Φ = 50.0 mm, L / D = 30) at a processing rate of 45 kg / hour in terms of resin amount, and devolatilization was performed. At that time, a separately prepared UVA solution was prepared from the rear of the first vent at a charging rate of 0.68 kg / hour with a separately prepared mixed solution of antioxidant / cyclization catalyst deactivator. Ion exchange water was charged from behind the third vent at a charging rate of 25 kg / hour from the back of the third vent at a charging rate of 0.22 kg / hour. From the side feeder, styrene-acrylonitrile (AS) resin pellets ("Stylac (registered trademark) AS783" manufactured by Asahi Kasei Chemicals Corporation) were charged at a charging speed of 5 kg / hour.

  The mixed solution of the antioxidant / cyclization catalyst deactivator was composed of 50 parts by mass of an antioxidant (“Sumilyzer (registered trademark) GS” manufactured by Sumitomo Chemical Co., Ltd.) and 35 parts by mass of octylic acid as a deactivator. A solution in which zinc (“Nikka Octix Zinc 3.6%” manufactured by Nippon Chemical Industry Co., Ltd.) was dissolved in 200 parts by mass of toluene was used. The UVA solution contains an ultraviolet absorber containing a compound having a 2,4,6-tris (hydroxyphenyl) -1,3,5-triazine skeleton (“TINUVIN® 477” manufactured by BASF, 80% active ingredient) ) A solution prepared by dissolving 37.5 parts by mass in 12.5 parts by mass of toluene was used.

  Next, after the devolatilization is completed, the resin in the hot melt state remaining in the extruder is discharged while filtering through a polymer filter from the tip of the extruder, pelletized by a pelletizer, and an acrylic polymer having a ring structure in the main chain. A pellet of acrylic resin (A-1) containing coalescence was obtained. The weight average molecular weight of the resin (A-1) was 145000, and the glass transition temperature (Tg) was 126 ° C.

The obtained resin (A-1) was introduced into a vented single screw extruder having a barrier flight type screw at a processing speed of 30 kg / hour and melted while sucking from the vent port at a pressure of 13.3 hPa (10 mmHg). Kneaded. Then, it is filtered through a leaf disk polymer filter with a filtration accuracy of 5 μm and a filtration area of 0.75 m ² by a gear pump, and the filtered composition is discharged from a T die (width 700 mm) onto a cooling roll at a temperature of 90 ° C. An extruded film (B-1) having a thickness of 160 μm was obtained. At this time, the temperature of the cylinder, gear pump, polymer filter, and T-die was 265 ° C.

After the obtained extruded film was cut out to 97 mm × 97 mm, using a sequential biaxial stretching machine (“X-6S” manufactured by Toyo Seiki Seisakusho) at a temperature 15 ° C. higher than the glass transition temperature at a rate of 800 mm / min. Biaxial stretching was successively performed so as to be doubled in the order of the vertical and horizontal directions (MD and TD directions) to obtain a heat-resistant acrylic film (C-1).
The thickness of the film (C-1) is 40 μm, the haze (turbidity) is 0.2%, the b value is 0.2, the glass transition temperature (Tg) is 126 ° C., and the in-plane retardation value Re is 0.7 nm. The thickness direction retardation value Rth was 0.8 nm, the transmittance for light of 380 nm was 6.0%, the transmittance for light of 500 nm was 92.1%, and the number of defects was 1 / m ² . Further, this film had a refractive index of 1.51 at D line and 20 ° C.

(Production Example 2)
An acrylic resin having a glutarimide ring structure in the main chain (“Pleximide 8813” manufactured by Daicel Evonik; glass transition temperature 132 ° C., weight average molecular weight 95000) is charged into a hopper, and a twin-screw extruder (Φ30 mm having two vents) , L / D = 42), and melted under the conditions of a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13 hPa, and a processing speed of 7.8 kg / hour. Next, a solution obtained by mixing 19 parts by mass of an ultraviolet absorber (“CGL777MPAD” manufactured by Ciba Specialty Chemicals Co., Ltd .; active ingredient 80% by mass) and 11 parts by mass of toluene with this molten resin is injected from the inlet before the vent. Styrene-acrylonitrile (AS) resin pellets ("Stylac (registered trademark) AS783" manufactured by Asahi Kasei Chemicals Co., Ltd.) were injected from the side feeder at a rate of 0.30 kg / hr under the condition of 2.2 kg / hr. This was charged to obtain an acrylic resin (A-2) pellet. In this acrylic resin (A-2), the ratio of acrylic polymer / AS resin / ultraviolet absorber having a glutarimide ring structure in the main chain is 78 parts by mass / 22 parts by mass / 1.5 parts by mass. The acrylic resin (A-2) had a glass transition temperature (Tg) of 127 ° C. and a weight average molecular weight of 129000.

Except having used acrylic resin (A-2), it carried out similarly to manufacture example 1, and obtained the extruded film (B-2) and the heat-resistant acrylic film (C-2) by which biaxial stretching was carried out sequentially.
The film (C-2) has a thickness of 40 μm, a haze (turbidity) of 0.5%, a b value of 0.4, a glass transition temperature (Tg) of 127 ° C., and an in-plane retardation value Re of 3.1 nm. The thickness direction retardation value Rth was 5.2 nm, the transmittance for light of 380 nm was 6.4%, the transmittance for light of 500 nm was 91.5%, and the number of defects was 4 / m ² . Moreover, the refractive index in 20 degreeC of the D line | wire of this film was 1.52.

(Examples 1-4, Comparative Examples 1-3)
Urethane acrylate (“UV-7600B” manufactured by Nippon Synthetic Chemical Co., Ltd.), ethoxylated bisphenol A diacrylate (“SR-601” manufactured by Sartomer Japan), polyethylene glycol diacrylate (“4EG-A” manufactured by Kyoeisha Chemical Co., Ltd.) ), Phenoxyethyl acrylate (“PO-A” manufactured by Kyoeisha Chemical Co., Ltd.), 2-vinyloxyethoxyethyl acrylate (“VEEA” manufactured by Nippon Shokubai Co., Ltd.), 2-hydroxy-2-methyl-1-phenyl-propane -1-one ("Darocur 1173" manufactured by BASF Japan Ltd.) was mixed according to the formulation shown in Table 1, stirred for 1 hour under light shielding, and then filtered through a filter with a pore size of 20 nm to obtain curable composition D-1. ~ D-3 was obtained. Table 1 shows the viscosity and refractive index of these curable compositions D-1 to D-3 (the refractive index is the refractive index of the cured products E-1 to E-3 cured under the above conditions).

Next, a film shown in Table 2 (a heat-resistant acrylic film produced in a production example or a comparative film) is pasted on a disk-shaped glass substrate having a diameter of 1 inch, and a liquid curing shown in Table 2 is applied thereon. The composition (cured products E-1 to E-3) was dropped using a dispenser. On top of that, a quartz mold having a conical recess having a diameter of 200 nm and a depth of 400 nm arranged at a period of 220 nm was pressed on the surface, and a pressure of 5 kN was applied while being controlled uniformly over the entire substrate surface. . Next, after irradiating UV with energy of 500 mJ / cm ² from the mold side with a high-pressure mercury lamp (350 W, main wavelength 365 nm), the glass substrate and the film are detached from the mold and further peeled off from the glass substrate. The film (polarizer protective film) of this invention was obtained.

  When the surface of the obtained film was observed with an atomic force microscope (AFM), a fine concavo-convex structure in which conical protrusions having an average height of 400 nm were arranged at an average period of 220 nm was formed on the surface of each film. I was able to confirm that.

  A black tape is pasted on the back surface (the surface on which the fine concavo-convex structure is not formed) of the obtained polarizer protective film, and the incident angle is 5 ° and the wavelength is 400 with a spectrophotometer (“UV-3100” manufactured by Shimadzu Corporation). The spectral reflectance of the film was measured in the range of ˜780 nm, and the specular reflectance (%) at 450 to 650 nm was calculated. The results are shown in Table 2.

  Furthermore, the obtained polarizer protective film is placed on a flat glass plate, and the degree of warpage is visually observed. If the height difference between the center and the edge of the film is very small, the warp is “small”. When the height difference between the central part and the edge part is large, the sled was evaluated as “large”. The results are shown in Table 2.

(Examples 5 and 6)
A mold for nanoimprint in which conical recesses having a diameter of 200 nm and a depth of 400 nm are arranged with a period of 220 nm with respect to the heat-resistant acrylic films (C-1) and (C-2) obtained in Production Examples 1 and 2 ( Made of Si, treated with a release agent), and held at 150 ° C. and 10 MPa for 2 minutes using a press device. Then, after cooling, the mold was removed to obtain the film of the present invention (polarizer protective film).

When the surface of the obtained film was observed with an atomic force microscope (AFM), a fine concavo-convex structure in which conical protrusions having an average height of 400 nm were arranged at an average period of 220 nm was formed on the surface of each film. I was able to confirm that.
For the obtained polarizer protective film, the reflectance and warpage were evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Example 7)
A quartz mold having three-sided arrangement of conical recesses with a diameter of 270 nm and a depth of 350 nm (period 280 nm) was pressed against the surface of the heat-resistant acrylic film (C-1) obtained in Production Example 1, and imprinted. Using a device (“TOS-02” manufactured by TOSHIBA MACHINERY CO., LTD.) While heating to 140 ° C. while applying a pressure of 5 kN so as to be uniform, the film is detached from the mold, and the present invention is applied. A film (F-1) was obtained.

When the surface of the obtained film (F-1) was observed with an atomic force microscope (AFM), a fine concavo-convex structure in which conical protrusions with an average height of 350 nm were arranged in three directions with an average period of 280 nm was formed on the surface. I was able to confirm.
Table 3 shows the in-plane retardation value Re and the total light transmittance of the obtained film (F-1).

The obtained film (F-1) is coated with an acrylic adhesive layer on a light emitting layer glass substrate of a commercially available organic EL light emitting device (“VELVE” manufactured by Mitsubishi Chemical Media Co., Ltd .: brightness adjusted to white at 242 cd / m ² ). After bonding, the brightness was measured. The results are shown in Table 3.
As shown in Table 3, it was confirmed that the luminance was improved by installing the obtained film in an organic EL light emitting device.

(Example 8)
Fine irregularities with conical projections arranged on the surface in the same manner as in Example 7, except that the heat-resistant acrylic film (C-1) was changed to the heat-resistant acrylic film (C-2) obtained in Production Example 2. A film (F-2) of the present invention having a structure was obtained.
When the surface of the obtained film (F-2) was observed with an atomic force microscope (AFM), a fine concavo-convex structure in which conical projections with an average height of 350 nm were arranged in three directions with an average period of 280 nm was formed on the surface. I was able to confirm.
Table 3 shows the in-plane retardation value Re and the total light transmittance of the obtained film (F-2).
Further, the luminance of the obtained film (F-2) was measured in the same manner as in Example 7. The results are shown in Table 3.
As shown in Table 3, it was confirmed that the luminance was improved by installing the obtained film in an organic EL light emitting device.

(Comparative Example 4)
The light-emitting layer glass substrate of the heat-resistant acrylic film (C-1) obtained in Production Example 1 is a commercially available organic EL light-emitting device (“VELVE” manufactured by Mitsubishi Chemical Media Corporation: brightness adjusted to white at 242 cd / m ² ). Then, after bonding using an acrylic adhesive layer, the luminance was measured. The results are shown in Table 3 together with the in-plane retardation value Re and the total light transmittance of the film (C-1).

10 Film of the present invention (fine relief structure heat-resistant acrylic film)
11 Glass substrate 12 Anode electrode (ITO)
13 hole transport layer / hole injection layer 14 light emitting layer 15 electron transport layer / electron injection layer 16 cathode electrode 17 transparent protective layer

Claims (14)

  A film containing a fine relief structure on the surface and a heat-resistant acrylic film.   The film according to claim 1, wherein the glass transition temperature of the heat-resistant acrylic film is 110 ° C. or higher.   The film according to claim 1, wherein the heat-resistant acrylic film contains a heat-resistant acrylic polymer having a ring structure in the main chain.   The film according to claim 3, wherein the ring structure has one or more selected from the group consisting of an ester group, an imide group and an acid anhydride.   The film according to claim 3, wherein the ring structure is one or more selected from the group consisting of a lactone ring structure, a glutarimide ring structure, and a glutaric anhydride structure.   The film according to claim 3, wherein the ring structure is a lactone ring structure. The film according to claim 5 or 6, wherein the lactone ring structure is a lactone ring structure represented by the following general formula (1).
(In the formula (1), R ¹ , R ² and R ³ each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom. .)   The in-plane retardation value is 5 nm or less, The film in any one of Claims 1-7.   The film according to any one of claims 1 to 8, wherein an absolute value of a difference in refractive index between the material constituting the fine uneven structure and the heat-resistant acrylic film is 0.1 or less.   The film according to claim 1, wherein the fine concavo-convex structure is formed by curing a curable composition.   The film according to claim 1, wherein the fine uneven structure is made of a thermoplastic resin.   The film in any one of Claims 1-11 used for an organic electroluminescent light-emitting device.   It is a polarizer protective film, The film in any one of Claims 1-11.   An organic electroluminescence light emitting device comprising: a light emitting layer; and the film according to claim 1 on the light extraction surface side of the light emitting layer.