JP2023064290A - Film improved in light resistance - Google Patents

Abstract

To provide a film improved in light resistance capable of realizing excellent low reflectiveness and light resistance, and having excellent recoatability.SOLUTION: A film improved in light resistance includes: a substrate; and a light resistance-improved layer provided on one surface side of the substrate, where the diffuse reflectance of the light resistance-improved layer is 3% or lower as an average value of light of a wave length of 380 nm-780 nm, the water contact angle of a surface opposite side to the substrate of the light resistance-improved layer is lower than 80°, the light transmittance of the film improved in light resistance is 40% or lower as an average value of light of a wave length of 310 nm-380 nm, and the light resistance-improved layer contains a light stabilizer.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a light fastness improving film that can be used for displays and the like, and more particularly to a light fastness improving film that is suitable for use in a display with an antireflection layer laminated thereon.

In a display such as a liquid crystal display or an organic EL display, light incident on the display surface from the outside may be reflected, making it difficult for a viewer to visually recognize display contents. From the viewpoint of reducing such reflection of light from the outside, the display surface of the display may be subjected to an antireflection treatment. As one of them, Patent Document 1 discloses providing an antireflection film having at least one low refractive index layer on a transparent support on the display surface of a display.

In addition, when the display surface of the display body is damaged, it becomes difficult to visually recognize the display content. In particular, such scratches usually remain permanently on the display surface, so that the value of the display as a product is also impaired. From the viewpoint of preventing such damage, the display surface of the display unit is sometimes treated to prevent damage. As one of them, Patent Literature 2 discloses that an optical laminate including a transparent substrate, a hard coat layer, an intermediate layer, and an antireflection layer in this order is provided on a display surface of a display. ing. The optical layered body includes a hard coat layer for preventing scratches and an antireflection layer for preventing reflection, and a certain effect can be expected for not only scratch prevention but also the above-described antireflection. ing.

JP 2010-152311 A JP 2017-161893 A

However, in a conventional optical layered body having a hard coat layer, such as the optical layered body disclosed in Patent Document 2, when exposed to external light for a long time, the hard coat layer peels off from the substrate, There is a problem that the color changes. In particular, these problems tend to occur when the optical layered body is used in a vehicle-mounted display or an outdoor display that is exposed to sunlight.

In addition, when a coating liquid, which is a material for the antireflection layer, is applied onto the hard coat layer, repelling of the coating liquid may occur, making it difficult to form a good antireflection layer. . In particular, the formation of the antireflection layer may be performed independently of the production of the hard coat film comprising the substrate and the hard coat layer. That is, a hard coat film comprising a substrate and a hard coat layer is prepared in advance (or purchased from an external source), and a desired antireflection layer may be formed on the hard coat layer side of the hard coat film. . In this case, compared to the case where the hard coat layer and the antireflection layer are formed in a series of steps, it becomes difficult to strictly control the conditions at the time of production, etc., and it is difficult to form a good antireflection layer. rises.

Under these circumstances, it is possible to realize low reflectivity that can sufficiently reduce antireflection, and it has light resistance that does not easily cause layer peeling or color change even when exposed to external light for a long time. There is a need for a lightfastness-enhancing film with good recoatability during lamination of layer materials.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a film for improving light resistance, which can realize excellent low reflectivity and light resistance, and has excellent recoatability.

In order to achieve the above object, the first aspect of the present invention is a light resistance improving film comprising a substrate and a light resistance improving layer provided on one side of the substrate, wherein the light resistance The diffuse reflectance of the improving layer is 3% or less as an average value for light with a wavelength of 380 nm to 780 nm, and the water contact angle of the surface of the light resistance improving layer opposite to the substrate is less than 80°. and the light transmittance of the light resistance improving film is 40% or less as an average value for light with a wavelength of 310 nm to 380 nm, and the light resistance improving layer contains a light stabilizer. To provide a film for improving light resistance (Invention 1).

The light resistance-improved film according to the above invention (Invention 1) satisfies the light transmittance described above and the light resistance-improved layer contains a light stabilizer, thereby exhibiting excellent light resistance. Furthermore, by satisfying the water contact angle condition described above, the material of the antireflection layer can be applied satisfactorily on the surface of the light resistance improving layer (that is, excellent recoatability is exhibited), thereby The resulting antireflection layer-attached film for improving light resistance satisfies the above-described diffuse reflectance, thereby exhibiting excellent low reflectivity.

In the above invention (invention 1), the light stabilizer is preferably a hindered amine light stabilizer (invention 2).

In the above inventions (inventions 1 and 2), the CIE1976L ^* a ^* b ^* chromaticity a ^* defined by the color system in the light resistance improving film and the light resistance improving film conforming to JIS B7751: 2007 It is preferable that the absolute value of the difference from the chromaticity a ^* is 0 or more and 3 or less after 400 hours of light resistance test using an ultraviolet carbon arc lamp (Invention 3).

In the above inventions (inventions 1 to 3), the CIE1976L ^* a ^* b ^* chromaticity b ^* specified by the color system in the light resistance improving film and the light resistance improving film conforming to JIS B7751: 2007 It is preferable that the absolute value of the difference from the chromaticity b ^* after the UV carbon arc lamp type light resistance test is performed for 400 hours is 0 or more and 3 or less (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the surface of the light resistance improving layer opposite to the substrate is a surface on which an antireflection layer is laminated (Invention 5).

In the above inventions (inventions 1 to 5), it is preferably used as a member constituting a display (invention 6).

In the above invention (invention 6), it is preferable that the display is a vehicle-mounted display or an outdoor display (invention 7).

The light resistance improving film according to the present invention can realize excellent low reflectivity and light resistance, and has excellent recoatability.

Embodiments of the present invention will be described below.
The light resistance improving film according to this embodiment includes a base material and a light resistance improving layer provided on one side of the base material.

The diffuse reflectance of the light resistance improving layer is preferably 3% or less as an average value for light with a wavelength of 380 nm to 780 nm. Further, the water contact angle of the surface of the light resistance improving layer opposite to the substrate is preferably less than 80°. Further, the light transmittance of the light resistance improving film is preferably 40% or less as an average value for light with a wavelength of 310 nm to 380 nm. Further, the light resistance improving layer preferably contains a light stabilizer.

The light resistance improving film according to the present embodiment is a light resistance improving film with an antireflection layer obtained by forming an antireflection layer on the surface of the light resistance improving layer by satisfying the diffuse reflectance described above. It exhibits excellent low reflectivity. In addition, in a display body in which the light resistance improving film with the antireflection layer is laminated on the display surface, it is possible to display images with high visibility in which glare due to reflection is suppressed.

Further, the light resistance improving film according to the present embodiment satisfies the above-described water contact angle condition, so that the material for the antireflection layer (especially, the composition for forming the antireflection layer) is formed on the surface of the light resistance improving layer. When the material is applied, repelling of the material is suppressed, and excellent recoatability is exhibited. As a result, it is possible to suppress the occurrence of defects in the formed coating film and form a good antireflection layer.

Furthermore, the light resistance-improving film according to the present embodiment satisfies the light transmittance described above, and the light resistance-improving layer contains a light stabilizer, so that the adhesion between the light resistance-improving layer and the substrate and the , the adhesion between the light resistance improving layer and the antireflection layer laminated thereon is improved, and even when exposed to light for a long period of time, the layers constituting the light resistance improving film do not peel off. In addition, the change in color of the light resistance improving layer is less likely to occur. That is, the light resistance improving film according to this embodiment has excellent light resistance.

1. Physical properties of light resistance improving film (1) Diffuse reflectance In the light resistance improving film according to the present embodiment, as described above, the diffuse reflectance in the light resistance improving layer is 3 as an average value for light with a wavelength of 380 nm to 780 nm. % or less. The light resistance improving film according to the present embodiment has excellent low reflectivity by satisfying the diffuse reflectance conditions. From this point of view, the diffuse reflectance is preferably 2.5% or less, more preferably 2% or less, particularly preferably 1.6% or less, further preferably 1.4% or less. is preferably The lower limit of the diffuse reflectance is usually 0% or more, may be 0.1% or more, particularly 0.5% or more, and further 0.8% or more. good. The details of the method for measuring the diffuse reflectance are as shown in the test examples described later.

(2) Water contact angle In the light resistance improving film according to the present embodiment, as described above, the water contact angle of the surface of the light resistance improving layer opposite to the substrate is preferably less than 80°. As a result, the surface of the light resistance improving film on the side of the light resistance improving layer exhibits excellent recoatability. From this point of view, the water contact angle is preferably 76° or less, particularly preferably 72° or less, and further preferably 70° or less. The lower limit of the water contact angle is usually 0° or more, may be 20° or more, particularly 40° or more, and further may be 60° or more. The details of the method for measuring the water contact angle are as shown in the test examples described later.

(3) Light transmittance In the light resistance improving film according to the present embodiment, as described above, the light transmittance is 40% or less as an average value for light with a wavelength of 310 nm to 380 nm (light in the near-ultraviolet region). is preferred. The light resistance improving film according to the present embodiment satisfies the light transmittance condition and has excellent light resistance because the light resistance improving layer contains a light stabilizer. From this point of view, the light transmittance is preferably 35% or less, particularly preferably 30% or less, and more preferably 25% or more. The lower limit of the light transmittance is usually 0% or more, may be 1% or more, particularly 5% or more, and further may be 10% or more.

In addition, in the light resistance improving film according to the present embodiment, the light transmittance obtained as an average value for light with a wavelength of 380 nm to 420 nm (light in the ultraviolet region) is preferably 98 to 30%, preferably 95 to 50%. %, particularly preferably 92 to 70%, even more preferably 90 to 80%. Since the light transmittance for light with a wavelength of 380 nm to 420 nm is within the above range, the light transmittance for a wavelength of 310 nm to 380 nm easily satisfies the above range.

The details of the method for measuring the light transmittance described above are as shown in the test examples described later.

(4) Change in chromaticity In the light resistance improving film according to the present embodiment, the chromaticity a ^* defined by the CIE1976L ^* a ^* b ^* color system (hereinafter referred to as the “initial value” of the chromaticity a ^* ) is preferably -10 to 10, more preferably -5 to 5, particularly preferably -2 to 2, further preferably -1 to 1, -0.5 to 0.5 is most preferred. When the initial value of the chromaticity a ^* is within the above range, the content displayed on the display using the light fastness improving film according to the present embodiment can be easily viewed by a viewer with an appropriate color tone.

Then, when an ultraviolet carbon arc lamp type light resistance test conforming to JIS B7751:2007 is performed for 400 hours on the light resistance improving film according to the present embodiment, the chromaticity of the light resistance improving film after the light resistance test The absolute value of the difference between a ^* and the initial value of the chromaticity a ^* described above is preferably 3 or less, more preferably 2 or less, particularly preferably 1 or less, or even 0. It is preferably 0.5 or less, most preferably 0.1 or less. Since the light resistance improving film according to the present embodiment exhibits excellent light resistance as described above, the absolute value of the difference in chromaticity a ^* before and after the light resistance test can easily fall within the above range. Further, when the absolute value of the difference is within the above range, even when the display body using the light resistance improving film according to the present embodiment is exposed to light for a long period of time, the change in color is prevented. It is possible to suppress it and display appropriate display contents for a long period of time. In addition, the lower limit of the absolute value of the difference is usually 0 or more, may be 0.001 or more, and may be 0.01 or more.

In addition, in the light resistance improving film according to the present embodiment, the chromaticity b ^* defined by the CIE1976L ^* a ^* b ^* color system (hereinafter sometimes referred to as the “initial value” of the chromaticity b ^* ) is , -10 to 10 is preferable, -5 to 5 is more preferable, -2 to 2 is particularly preferable, and -1 to 1 is further preferable. When the initial value of the chromaticity b ^* is within the above range, the content displayed on the display body using the light fastness improving film according to the present embodiment can be easily recognized by a viewer with an appropriate color tone.

Then, when an ultraviolet carbon arc lamp type light resistance test conforming to JIS B7751:2007 is performed for 400 hours on the light resistance improving film according to the present embodiment, the chromaticity of the light resistance improving film after the light resistance test The absolute value of the difference between b ^* and the initial value of the chromaticity b ^* is preferably 3 or less, preferably 2 or less, particularly preferably 1 or less, and further preferably 0. It is preferably 5 or less, most preferably 0.1 or less. Since the light resistance improving film according to the present embodiment exhibits excellent light resistance as described above, the absolute value of the difference in chromaticity b ^* before and after the light resistance test can easily fall within the above range. Further, when the absolute value of the difference is within the above range, even when the display body using the light resistance improving film according to the present embodiment is exposed to light for a long period of time, the change in color is prevented. It is possible to suppress it and display appropriate display contents for a long period of time. The lower limit of the absolute value of the difference is usually 0 or more, may be 0.001 or more, particularly 0.01 or more, and further may be 0.05 or more.

The details of the chromaticity measurement and the light resistance test described above are as described in the test examples described later.

(5) Haze value In the film for improving light resistance according to the present embodiment, the haze value is preferably 40% or less, particularly preferably 30% or less, from the viewpoint of easily ensuring sufficient transparency. 25% or less is preferable from the viewpoint that it is easy to effectively suppress the occurrence of a phenomenon in which image light is scattered and the part glares and shines (hereinafter sometimes referred to as "glare"). is preferably 20% or less. In addition, in the display body using the light resistance improving film according to the present embodiment, the haze value is preferably 1% or more from the viewpoint of suppressing glare, and 2% or more from the viewpoint of imparting antiglare properties. is preferably 4% or more, more preferably 5% or more, and most preferably 5.5% or more. The haze value was measured according to JIS K7136:2000, and the detailed measurement method is as described in the test examples described later.

(6) Total light transmittance In the light resistance improving film according to the present embodiment, the total light transmittance is preferably 80% or more, more preferably 85% or more, from the viewpoint of easily ensuring sufficient transparency. is more preferably 88% or more, and more preferably 91% or more. On the other hand, the upper limit of the total light transmittance is usually 100% or less, may be 99% or less, particularly 98% or less, and further may be 95% or less. The above total light transmittance was measured according to JIS K7361-1:1997, and the detailed measurement method is as described in the test examples described later.

(7) Transmission clarity In the light resistance improving film according to the present embodiment, the transmission clarity (image definition) is 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm comb width. It is preferably 250% or more and 500% or less when represented by the total value of the transmission clarity of the optical comb. As a result, in the display body using the light fastness improving film according to the present embodiment, the display content can be clearly and easily viewed. Among them, it is preferably 280% or more from the viewpoint of suppressing the occurrence of glare, and more preferably 300% or more, especially 350 % or more, more preferably 380% or more, more preferably 400% or more, most preferably 440% or more. In addition, the transmission clarity is preferably 495% or less, and from the viewpoint of imparting antiglare properties, is preferably 485% or less, particularly preferably 480% or less, and further preferably 475% or less. Preferably. The details of the method for measuring the transmission clarity are as described in the test examples described later.

(8) 60° gloss In the light resistance improving film according to the present embodiment, the 60° gloss measured on the surface on the light resistance improving layer side is preferably 30% or more from the viewpoint of suppressing the occurrence of glare, as described above. From the viewpoint that the diffuse reflectance obtained tends to be in the desired range, it is more preferably 40% or more, particularly preferably 50% or more, further preferably 60% or more, and most preferably 80% or more. preferable. In addition, the 60° gloss is preferably 160% or less, more preferably 158% or less, and from the viewpoint of easily exhibiting the desired antiglare properties, is preferably 150% or less, particularly 135% or less. is preferably 125% or less. The above 60° gloss was measured according to JIS Z8741:1997, and the detailed measurement method is as described in the test examples described later.

(9) Pencil hardness In the light resistance improving film according to the present embodiment, the surface on the light resistance improving layer side has a scratch hardness (pencil hardness) measured according to JIS K5600-5-4: 1999 by a pencil method. , H or more, particularly preferably 2H or more, and more preferably 3H or more. On the other hand, the pencil hardness is preferably 9H or less, more preferably 8H or less, particularly preferably 7H or less, further preferably 6H or less, especially 5H or less. Preferably, it is 4H or less, most preferably. By having such a pencil hardness, the light resistance improving film according to the present embodiment easily exhibits desired hardness and scratch resistance, and when used on the surface of a display, excellent surface protection In particular, since the surface is less likely to be damaged, the aesthetic appearance of the display can be easily maintained. In addition, the detailed measuring method of the pencil hardness is as described in the test examples described later.

(10) Scratch resistance In the light resistance improving film according to the present embodiment, #0000 steel wool is used for the surface of the light resistance improving layer side according to JIS K5600-5-10, and 250 g / cm ² It is preferable that the surface is not scratched after 10 reciprocating rubbings of 10 cm with a load. As a result, when used on the surface of a display, excellent surface protection properties are exhibited, and the surface is particularly resistant to damage, so that the aesthetic appearance of the display is favorably maintained. In addition, the detailed test method for the scratch resistance is as described in the test examples described later.

(11) Adhesion After performing an ultraviolet carbon arc lamp type light resistance test in accordance with JIS B7751: 2007 for 400 hours on the light resistance improving film according to this embodiment, according to JIS K5600-5-6, On the light resistance improving layer, 100 grids of 1 mm square were formed with a cutter knife, and then, under an environment of 23°C and 50% RH, adhesive tape was applied to the grid using a squeegee to form 30 grids. Seconds later, when the pressure-sensitive adhesive tape is peeled off in the direction of 90°, the number of grids in the light resistance improving layer remaining on the substrate without being separated from the substrate is preferably 90 or more, particularly 95. More preferably, it is 99 or more, and most preferably 100. By satisfying the above number, the obtained light resistance improving film exhibits excellent interlayer adhesion and is particularly excellent in light resistance. In addition, the detailed test method for the adhesion is as described in the test examples described later.

(12) Total Reflectance In the light resistance improving film according to the present embodiment, if the total reflectance (%) of the surface on the side of the light resistance improving layer before the antireflection layer is formed is less than 2%, the above diffuse reflectance can be easily satisfied, and excellent low reflectivity can be easily exhibited even after the formation of the antireflection layer. In this case, the total reflectance (%) of the surface on the side of the light resistance improving layer after the formation of the antireflection layer is preferably 1.5% or less, particularly preferably 1.2% or less, and further preferably 1.0% or less. preferable. The lower limit of the total reflectance (%) is usually 0% or more. As a result, particularly excellent low reflectivity is exhibited.

On the other hand, from the viewpoint of easily exhibiting excellent low reflectivity even after forming the antireflection layer, when the total reflectance (%) of the surface on the side of the light resistance improving layer before forming the antireflection layer is 2% or more, The total reflectance obtained by subtracting the total reflectance (%) of the surface of the light resistance improving layer side after the formation of the antireflection layer from the total reflectance (%) of the surface of the light resistance improving layer side before the formation of the antireflection layer. The difference is preferably 1.5 points or more, particularly preferably 2.0 points or more, further preferably 2.5 points or more. This makes it easy to satisfy the diffuse reflectance described above, and when an antireflection layer is formed on the light resistance improving film according to the present embodiment, good antireflection properties can be exhibited. The upper limit of the difference in total reflectance is not particularly limited, and may be, for example, 10 points or less, particularly 6 points or less, or even 4 points or less. A detailed test method for the total reflectance is as described in the test examples described later.

2. Each member constituting the light resistance improving film (1) Base material The base material constituting the light resistance improving film according to the present embodiment is not particularly limited, but it is preferable to use a resin film having a predetermined transparency. . Examples of such resin films include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyolefin films such as polyethylene film and polypropylene film, cellophane, diacetylcellulose film, triacetylcellulose film and acetylcellulose butyrate. Film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film , polyetherimide film, fluorine resin film, polyamide film, acrylic resin film, polyurethane resin film, norbornene polymer film, cyclic olefin polymer film, cyclic conjugated diene polymer film, vinyl alicyclic hydrocarbon polymer A resin film such as a film or a laminated film thereof may be mentioned. Among them, polyethylene terephthalate film, polycarbonate film, triacetyl cellulose film, norbornene-based polymer film and the like are preferable from the viewpoint of mechanical strength and the like, and triacetyl cellulose film is particularly preferable from the viewpoint of adhesion to the light resistance improving layer.

In addition, in the above base material, for the purpose of improving adhesion with a layer provided on the surface (particularly, a light resistance improving layer), if desired, one side or both sides may be subjected to a primer treatment, an oxidation method, a roughening method, or the like. Surface treatment can be applied. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone/ultraviolet treatment, and the like. Examples of the roughening method include sandblasting and solvent treatment. These surface treatment methods are appropriately selected according to the type of substrate, but in general, the corona discharge treatment method is preferably used from the viewpoint of the effect of improving adhesion and operability.

The thickness of the substrate is preferably 10 μm or more, more preferably 20 μm or more, from the viewpoint of handleability. From the viewpoint of alleviating the influence of , the thickness is preferably 40 μm or more, particularly preferably 60 μm or more, and further preferably 75 μm or more. The thickness of the substrate is preferably 250 μm or less, more preferably 225 μm or less, and preferably 200 μm or less from the viewpoint of thinning and the viewpoint of easily satisfying the optical properties described above. Among them, 150 μm or less is preferable, 110 μm or less is more preferable, and 90 μm or less is most preferable.

(2) Light resistance improving layer The light resistance improving layer constituting the light resistance improving film according to the present embodiment contains a light stabilizer, and the above-described diffuse reflectance, water contact angle, and light rays with a wavelength of 310 nm to 380 nm. It may be made of any material as long as it allows the transmission to be achieved.

An example of suitable materials for the light resistance improving layer includes a curable component (A), an ultraviolet absorber (B), a light stabilizer (C), a leveling agent (D), and a filler (E). Coating compositions containing. The light resistance improving layer is preferably formed by curing the coating composition.

(2-1) Curable component (A)
The curable component (A) is a component that is cured by triggers such as active energy rays and heat, and examples thereof include active energy ray-curable components and thermosetting components. In the light resistance improving layer of the present embodiment, it is preferable to use an active energy ray-curable component from the viewpoint of the hardness of the light resistance improving layer to be formed, the heat resistance of the base material, and the like.

As the active energy ray-curable component, a component that can be cured by irradiation with an active energy ray to exhibit a predetermined hardness and achieve the physical properties described above is preferable.

Specific active energy ray-curable components include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, active energy ray-curable polymers, etc. Among them, polyfunctional (meth)acrylates It is preferably a polyfunctional monomer and/or a (meth)acrylate prepolymer, more preferably a polyfunctional (meth)acrylate monomer. A polyfunctional (meth)acrylate-based monomer and a (meth)acrylate-based prepolymer may be used alone, or both may be used in combination. In this specification, (meth)acrylate means both acrylate and methacrylate. The same applies to other similar terms.

Examples of polyfunctional (meth)acrylate monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, (Meth)acrylates, neopentylglycol hydroxypivalate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated Cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate ) acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate ) acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and other polyfunctional (meth)acrylates. These may be used individually by 1 type, and may be used in combination of 2 or more type.

On the other hand, examples of (meth)acrylate prepolymers include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate prepolymers.

As the polyester acrylate prepolymer, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyhydric carboxylic acid and a polyhydric alcohol with (meth)acrylic acid, or by esterifying a polyhydric It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a carboxylic acid with (meth)acrylic acid.

An epoxy acrylate prepolymer can be obtained, for example, by reacting (meth)acrylic acid with an oxirane ring of a relatively low-molecular-weight bisphenol-type epoxy resin or novolak-type epoxy resin to esterify it.

A urethane acrylate prepolymer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate with (meth)acrylic acid.

A polyol acrylate prepolymer can be obtained, for example, by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

One of the above prepolymers may be used alone, or two or more may be used in combination.

It is also preferable to use an organic-inorganic hybrid resin as the active energy ray-curable component. As the organic-inorganic hybrid resin, a substance obtained by bonding an organic compound having a polymerizable unsaturated group to inorganic fine particles such as silica via a silane coupling agent or the like is preferably exemplified. The inorganic fine particles contained in the organic-inorganic hybrid resin do not correspond to the fine particles and nanoparticles described later, but have a function as a binder and can improve the hardness of the formed light resistance improving layer. .

(2-2) UV absorber (B)
The ultraviolet absorber (B) is preferably contained in the coating composition from the viewpoint of easily achieving the physical properties related to the light transmittance at a wavelength of 310 nm to 380 nm.

Examples of the ultraviolet absorber (B) are not particularly limited, and examples thereof include triazine-based compounds, benzophenone-based compounds, benzotriazole-based compounds, benzoate-based compounds, benzoxazinone-based compounds, phenylsalicylate-based compounds, and cyanoacrylate-based compounds. , nickel complex salt compounds, and the like. These may be used individually by 1 type, or may use 2 or more types together. Among the above, triazine-based compounds, benzophenone-based compounds and benzotriazole-based compounds are preferred, and triazine-based compounds are particularly preferred.

Examples of the triazine compounds include 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2-[4, 6-di(2,4-xylyl)-1,3,5-triazin-2-yl]-5-octyloxyphenol and the like.

Examples of the benzophenone compounds include 2,2-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid water hydrates, 2-hydroxy-4-n-octyloxybenzophenone, and the like.

Examples of the benzotriazole compounds include 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, octyl-3-[3-t-butyl-4-hydroxy-5-(5- Chloro-2H-benzotriazol-2-yl)phenyl]propionate, 2-ethylhexyl-3-[3-t-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl] and propionate.

The content of the ultraviolet absorber (B) in the coating composition is such that the physical properties related to light transmittance at wavelengths of 310 nm to 380 nm described above, the physical properties related to chromaticity change and adhesion, etc. are easily achieved. It is preferably 0.1 parts by mass or more, preferably 1 part by mass or more, particularly preferably 2 parts by mass or more, and further preferably 3 parts by mass with respect to 100 parts by mass of the curable component (A). It is preferably at least 1 part. Further, the content of the ultraviolet absorber (B) is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, particularly 6 parts by mass, with respect to 100 parts by mass of the curable component (A). parts by mass or less, more preferably 4 parts by mass or less. As a result, the coatability of the coating composition is improved, it becomes easier to form a light resistance improving layer with a uniform thickness, and the water contact angle tends to easily satisfy the desired range. .

(2-3) Light stabilizer (C)
As described above, the light resistance improving layer in this embodiment contains a light stabilizer (C). Therefore, the coating composition for forming the light resistance improving layer preferably contains a light stabilizer (C). As a result, the light fastness-improving film according to the present embodiment can easily achieve physical properties related to chromaticity change and adhesion, and can easily have excellent light fastness.

Examples of the light stabilizer (C) are not particularly limited, and include, for example, hindered amine light stabilizers, benzophenone light stabilizers, benzotriazole light stabilizers, and the like. These light stabilizers (C) may be used alone or in combination of two or more.

（式中、Ｒ１は水素原子またはアルキル基を表す。）
からなる骨格を少なくとも１つ含む化合物であることが好ましい。 Among the examples of the light stabilizer (C) described above, it is preferable to use a hindered amine light stabilizer from the viewpoint of easily achieving excellent light resistance. Here, the hindered amine refers to an amine having substituents on both sides of an amino group. The hindered amine light stabilizer in the present embodiment has the following general formula (I)

(In the formula, R1 represents a hydrogen atom or an alkyl group.)
It is preferable that the compound contains at least one skeleton consisting of

In the hindered amine light stabilizer in the present embodiment, R ¹ in the general formula (I) is preferably an alkyl group, particularly preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group. Preferably. That is, the hindered amine compound in the present embodiment preferably has an N-alkyl group skeleton, particularly preferably has an N—C ₁ to C ₄ alkyl group skeleton, and further N—CH It preferably has ₃ skeletons.

The hindered amine light stabilizer in the present embodiment preferably has one or two or more skeletons represented by the general formula (I), more preferably 1 to 10 skeletons, and particularly preferably 1 to 7 skeletons. It is preferable to have 1 to 4, and most preferably 1 to 2. The skeleton of general formula (I) may exist at the terminal of the hindered amine light stabilizer, may exist in a side chain, or may exist in both the terminal and the side chain. When the hindered amine light stabilizer has one or two skeletons represented by the general formula (I), it preferably has them in side chains.

When the hindered amine light stabilizer has two or more skeletons represented by the general formula (I), each ^R1 may be the same or different.

The hindered amine light stabilizer in the present embodiment is preferably a compound in which the carbon atom at the 4-position in the skeleton represented by the general formula (I) is bonded to the oxygen atom of the --COO- skeleton.

（式中、ｎは１以上の整数である。）
で示される化合物、または下記構造式（Ｂ）

（式中、ｍは１以上の整数である。）
で示される化合物であることが特に好ましい。 As the hindered amine light stabilizer in the present embodiment, the following structural formula (A)

(In the formula, n is an integer of 1 or more.)
or a compound represented by the following structural formula (B)

(In the formula, m is an integer of 1 or more.)
Especially preferred is a compound represented by

n in the compound represented by the above structural formula (A) is preferably 1-20, particularly preferably 3-15, further preferably 5-10.

In the compound represented by the above structural formula (B), m is preferably 1-20, particularly preferably 3-15, further preferably 5-10. In the above formula, R ² is preferably an alkyl group, particularly preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

The compound represented by the structural formula (A) and the compound represented by the structural formula (B) can be used alone, but are preferably used in combination.

The content of the light stabilizer (C) in the coating composition is preferably 0.1 parts by mass or more, preferably 1 part by mass or more, relative to 100 parts by mass of the curable component (A). In particular, it is preferably at least 2 parts by mass, more preferably at least 2.5 parts by mass. As a result, the light fastness-improving film according to the present embodiment can easily achieve physical properties related to chromaticity change and adhesion, and can easily have excellent light fastness. The content of the light stabilizer (C) is preferably 10 parts by mass or less, preferably 7 parts by mass or less, particularly 5 parts by mass, with respect to 100 parts by mass of the curable component (A). or less, more preferably 3 parts by mass or less. As a result, the coatability of the coating composition is improved, it becomes easier to form a light resistance improving layer with a uniform thickness, and the water contact angle tends to easily satisfy the desired range. .

(2-4) Leveling agent (D)
The coating composition preferably contains a leveling agent (D) from the viewpoint that it is easy to form a light resistance improving layer having a uniform film thickness without streak-like defects and unevenness.

Examples of the leveling agent (D) are not particularly limited, and include, for example, fluorine-based leveling agents, silicone-based leveling agents, acrylic leveling agents, vinyl-based leveling agents, and the like. Among these, fluorine-based leveling agents are preferable from the viewpoint of easily satisfying the physical properties of the water contact angle described above. In addition, a leveling agent (D) may be used individually by 1 type, and may be used in combination of 2 or more type.

The fluorine-based leveling agent is preferably a compound having a perfluoroalkyl group or a fluorinated alkenyl group in its main chain or side chain. Examples of commercially available fluorine-based leveling agents include the product names "Ftergent 602A" and "Ftergent 650A" manufactured by Neos, the product name "BYK-340" manufactured by BYK Chemie Japan, and the product name manufactured by DIC. "Megafac RS-75", product name "V-8FM" manufactured by Osaka Organic Chemical Industry Co., Ltd., and the like.

The content of the leveling agent (D) in the coating composition is preferably 0.001 to 1 part by mass or more, particularly 0.01 to 0.2 parts by mass, relative to 100 parts by mass of the curable component (A). It is more preferably at least 0.02 to 0.1 parts by mass, and more preferably at least 0.04 to 0.07 parts by mass. When the content of the leveling agent (D) is within the above range, it becomes easy to form a light resistance improving layer having a uniform film thickness and satisfying the physical properties of the water contact angle described above.

(2-5) Filler (E)
The coating composition preferably contains a filler (E) from the viewpoint of forming desired unevenness on the surface of the light resistance improving layer opposite to the base material and thereby easily imparting good antiglare properties. .

The filler (E) may be an organic filler, an inorganic filler, or a resin filler having both inorganic and organic properties. From the viewpoint of facilitating the expression of good dispersibility, coating stability, desired optical properties, good appearance, etc., the filler (E) is an organic filler or a resin filler having both inorganic and organic properties. Preferably, a resin filler having both inorganic and organic properties is preferred from the viewpoint of facilitating adjustment of the diffuse reflectance and optical properties described above within desired ranges.

Examples of organic fillers include acrylic resin fillers (e.g., polymethyl methacrylate fillers), silicone fillers, melamine resin fillers, acrylic-styrene copolymer fillers, polycarbonate fillers, polyethylene fillers, and polystyrene. and benzoguanamine-based resin fillers. These resins may be crosslinked. Among the above, acrylic resin fillers and silicone fillers are preferred. In particular, as the acrylic resin filler, a polymethyl methacrylate filler is preferable, and a crosslinked polymethyl methacrylate filler is more preferable.

Examples of inorganic fillers include fillers made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like.

As the resin filler having both inorganic and organic properties, a silicone filler (for example, Tospearl series manufactured by Momentive Performance Materials Japan) is particularly preferable.

In addition, the above filler (E) may be used individually by 1 type, and may be used in combination of 2 or more type.

The filler (E) may be subjected to desired surface modification. The shape of the filler may be a fixed shape such as a sphere, or may be an irregular shape whose shape is not specified.

The average particle size of the filler (E) is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, particularly preferably 2 to 7 μm, further preferably 3 to 5 μm. It is preferably 4 to 4.5 μm, and more preferably 4 to 4.5 μm. When the average particle size of the filler (E) is within the above range, it becomes easy to form the desired unevenness on the surface of the light resistance improving layer opposite to the base material, and the above-mentioned haze value, total light transmittance and It becomes easy to satisfy optical physical properties such as 60° gloss. The average particle size of the filler (E) is obtained by measuring the primary particle size by a laser diffraction measurement method.

The refractive index of the filler (E) is preferably 1.2 to 1.6, more preferably 1.3 to 1.55, particularly preferably 1.4 to 1.5, Further, it is preferably 1.42 to 1.45. As a result, the obtained light fastness improving film can easily satisfy the optical properties described above.

The content of the filler (E) in the coating composition is preferably 0.1 parts by mass or more, particularly 0.5 parts by mass or more, relative to 100 parts by mass of the curable component (A). Preferably, it is more preferably 1 part or more. This makes it easier to form desired irregularities on the surface of the light resistance improving layer opposite to the base material, and makes it easier to satisfy the aforementioned optical properties such as haze value, total light transmittance and 60° gloss. As a result, the desired anti-glare properties and the effect of suppressing the occurrence of glare tend to be exhibited more easily. In addition, the content of the filler (E) is preferably 20 parts by mass or less, particularly preferably 15 parts by mass or less, with respect to 100 parts by mass of the curable component (A), from the viewpoint of suppressing the occurrence of glare. And from the viewpoint that the diffuse reflectance tends to be in the desired range as described above, it is preferably 12 parts by mass or less, more preferably 8 parts by mass or less, particularly preferably 4 parts by mass or less, and further preferably 2 parts by mass or less. preferable. As a result, it becomes easy to form desired irregularities on the surface of the light resistance improving layer opposite to the substrate, and it is easy to exhibit desired anti-glare properties while suppressing the occurrence of glare and exhibiting low reflectivity. Become.

(2-6) Other Components The coating composition of the present embodiment may contain various additives in addition to the above components. Examples of various additives include dispersants, surface conditioners, photopolymerization initiators, antioxidants, antistatic agents, silane coupling agents, antioxidants, thermal polymerization inhibitors, colorants, surfactants, preservatives, Stabilizers, plasticizers, lubricants, antifoaming agents, organic fillers, wettability improvers, paint surface improvers and the like.

Above all, the coating composition preferably contains a dispersant from the viewpoint of improving the dispersibility of the components described above. Dispersants include, for example, carboxyl groups, hydroxyl groups, sulfo groups, primary amino groups, secondary amino groups, tertiary amino groups, amide groups, quaternary ammonium bases, pyridinium bases, sulfonium bases and phosphonium bases in the molecule. A compound having one or more polar groups selected from the group consisting of is preferable, and a compound having one or more polar groups of a carboxy group and a hydroxyl group is particularly preferable. One or more of the above polar groups may be introduced into the molecule. When a compound as a dispersant has a plurality of polar groups, the basic skeleton of the compound is preferably composed of an ester chain, a vinyl chain, an acrylic chain, an ether chain, a urethane chain, or the like. Specifically, acrylic resins, urethane resins, polyester resins and alkyd resins are preferred, acrylic resins, urethane resins and polyester resins are particularly preferred, and acrylic resins are more preferred. The polar groups may be randomly arranged in the molecule, but are preferably arranged on side chains. Therefore, the compound as the dispersant is preferably an acrylic resin having a carboxyl group and/or a hydroxyl group in its side chain. In addition, a dispersing agent may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the dispersant in the coating composition is preferably 0.01 to 2 parts by mass or more, and 0.05 to 1 part by mass or more, relative to 100 parts by mass of the curable component (A). is more preferable, particularly preferably 0.1 to 0.5 parts by mass or more, and more preferably 0.2 to 0.3 parts by mass or more. When the content of the dispersant is within the above range, the components contained in the coating composition can be easily dispersed well, and the obtained light resistance improving layer has the above-described diffuse reflectance, water contact angle and optical properties. It will be easy to fill well.

(2-7) Thickness of light resistance improving layer The thickness of the light resistance improving layer is preferably 1 μm or more, more preferably 1.5 μm or more, from the viewpoint of easily exhibiting desired hardness and scratch resistance. It is more preferably 2 μm or more, particularly preferably 3 μm or more, and most preferably 4 μm or more. In addition, the thickness of the light resistance improving layer is preferably 30 μm or less, more preferably 20 μm or less, from the viewpoint of handleability such that cracking of the light resistance improving layer is difficult to occur. From the viewpoint of suppressing peeling of the layer constituting the light resistance improving film even when exposed to light resistance improving film and making it difficult for the color of the light resistance improving layer to change, the thickness is preferably 10 μm or less, particularly It is preferably 7 μm or less, more preferably 5 μm or less.

(3) Other Configurations The light resistance improving film according to the present embodiment may include a layer other than the substrate and the light resistance improving layer. For example, the light resistance improving layer may be provided with an antireflection layer on the side opposite to the substrate. Since the light resistance improving film according to the present embodiment exhibits excellent recoatability as described above, it is preferable to laminate an antireflection layer on the side opposite to the substrate in the light resistance improving layer. is. In other words, in the light resistance improving film according to this embodiment, it is preferable that the surface opposite to the base material in the light resistance improving layer is the surface on which the antireflection layer is laminated. Since the light fastness improving film according to the present embodiment has an antireflection layer, a display using the light fastness improving film has excellent low reflectivity.

As the antireflection layer, a desired antireflection layer can be used among conventionally known ones. In particular, even when a coating liquid is used as a material for forming the antireflection layer, in the light resistance improving film according to the present embodiment, when it is applied to the surface opposite to the substrate in the light resistance improving layer It is possible to suppress the occurrence of cissing in and to form a desired antireflection layer.

In addition, the light resistance improving film according to the present embodiment may have a pressure-sensitive adhesive layer on the side of the substrate opposite to the light resistance improving layer. In particular, when the light resistance improving film according to the present embodiment is laminated on the display surface of a completed display body, the light resistance improving film is provided with an adhesive layer so that the light resistance improving film is attached to the display surface. Good and easy to adhere.

The adhesive constituting the adhesive layer is not particularly limited, and known adhesives such as acrylic adhesives, rubber adhesives, and silicone adhesives can be used. Moreover, as the adhesive, it is preferable to use an adhesive having a predetermined transparency.

In the case where the light resistance improving film according to the present embodiment is provided with the pressure-sensitive adhesive layer described above, it is also preferable that a release sheet is further laminated on the surface of the pressure-sensitive adhesive layer opposite to the substrate. This allows the adhesive surface of the adhesive layer (the surface of the adhesive layer opposite to the substrate) to be protected by the release sheet until the adhesive surface is attached to the adherend. The release sheet is not particularly limited as long as it has the desired release property on its release surface (the surface in contact with the pressure-sensitive adhesive layer), and is a known release film such as a resin film having one surface treated with a release agent. can be used.

3. Method for producing light resistance-improved film The method for producing the light resistance-improved film according to the present embodiment is not particularly limited. It can be produced by coating and curing to form a light resistance improving layer.

The above solvent can be used for improving coatability, adjusting viscosity, adjusting solid content concentration, etc., and can be used without particular limitation as long as it dissolves the curable component and the like.

Specific examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate and γ-butyrolactone. Esters; ethers such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosol), diethylene glycol monobutyl ether (butyl cellosol), propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene, and xylene; dimethyl and amides such as formamide, dimethylacetamide, and N-methylpyrrolidone.

Application of the coating liquid of the coating composition may be carried out by a conventional method such as bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating. After applying the coating liquid of the coating composition, the coating film is preferably dried at 40 to 120° C. for about 30 seconds to 5 minutes.

When the coating composition is active energy ray-curable, the coating composition is cured by irradiating the coating film of the coating composition with an active energy ray such as an ultraviolet ray or an electron beam in a nitrogen atmosphere. Ultraviolet irradiation can be performed by a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, or the like, and the irradiation dose of ultraviolet rays is preferably about 50 to 1000 mW/cm ² and a light intensity of about 50 to 1000 mJ/cm ² . On the other hand, the electron beam irradiation can be performed by an electron beam accelerator or the like, and the irradiation dose of the electron beam is preferably about 10 to 1000 krad.

4. Method of using the light resistance improving film The light resistance improving film according to the present embodiment can be used as a member constituting a display. In particular, the light resistance improving film according to this embodiment is preferably used as a member constituting the outermost surface of the display surface of the display. In this case, the light resistance improving film according to the present embodiment may be incorporated into the display by being laminated on other members as the outermost surface member of the display when the display is manufactured. Alternatively, the light resistance improving film according to this embodiment may be laminated on the display surface of a completed display. When the light resistance improving film according to the present embodiment is laminated on a display body, the substrate side surface of the light resistance improving film and other members may be brought into close contact with each other using an adhesive layer or the like.

As described above, the light resistance improving film according to the present embodiment exhibits excellent light resistance even when exposed to light for a long period of time. The display used is preferably a vehicle-mounted display or an outdoor display. These displays are likely to be exposed to strong light such as direct sunlight for a long period of time, but according to the light resistance improving film according to the present embodiment, it exhibits good light resistance against such light. can do.

Moreover, when the light resistance improving film according to the present embodiment is used for a display, an antireflection layer may be laminated on the surface of the light resistance improving layer opposite to the base material. As described above, the light resistance improving film according to the present embodiment exhibits excellent recoating properties, and therefore can form a good antireflection layer. In addition, the light resistance improving film according to the present embodiment, on which the antireflection layer is formed, exhibits excellent low reflectivity.

Examples of the display are not particularly limited as long as they can display desired images and videos. Examples include liquid crystal (LCD) displays, organic electroluminescence (organic EL) displays, and light emitting diode (LED) displays. , electronic paper, and the like. Further, the display body may be a touch panel in which these displays and electronic paper are incorporated.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, another layer may be laminated between the substrate and the light resistance improving layer or on the side of the substrate opposite to the light resistance improving layer.

In this specification, when "X to Y" (where X and Y are arbitrary numbers), unless otherwise specified, it means "X or more and Y or less" and "preferably larger than X" or "preferably is smaller than Y'. In addition, when described as "X or more" (X is any number), unless otherwise specified, it includes the meaning of "preferably greater than X", and when described as "Y or less" (Y is any number) , also includes the meaning of "preferably smaller than Y" unless otherwise specified.

EXAMPLES The present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]
(1) Preparation of coating composition Organic-inorganic hybrid resin as curable component (A) (manufactured by Arakawa Chemical Industries, Ltd., product name “OPSTAR Z7530”, silica fine particles having an average particle size of 50 nm (CV value: 28%), acryloyl 100 parts by mass (solid content conversion value; the same shall apply hereinafter) of a mixture of a substance formed by bonding a group and a polyfunctional (meth)acrylate monomer), and a triazine-based ultraviolet absorber as the ultraviolet absorber (B) ( BASF Japan Co., Ltd., product name "tinuvin 400") 3.5 parts by mass, and a hindered amine light stabilizer as a light stabilizer (C) (BASF Japan Co., Ltd., product name "tinuvin 292") 2.7 parts by mass and 0.05 parts by mass of a fluorine-based leveling agent (manufactured by Neos, product name “Ftergent 602A”, denoted as “D1” in Table 1) as a leveling agent (D), and a silicone filler as a filler (E). (manufactured by Momentive Performance Materials Japan, product name “Tospearl 145L”, average particle diameter: 4.5 μm, refractive index: 1.43, indicated as “E1” in Table 1) 1.1 parts by mass, A coating composition with a solid content of 35% by mass was obtained by mixing 0.27 parts by mass of a carboxyl group-containing polymer modified product (manufactured by Kyoeisha Chemical Co., Ltd., product name “Floren G700”) as a dispersant in propylene glycol monomethyl ether. A coating solution for a product was prepared.

(2) Formation of light resistance improving layer On one side of a triacetyl cellulose film (manufactured by Konica Minolta, product name “Konicatac KC8UAW”, thickness 80 μm) as a substrate, the coating composition obtained in the above step (1) was applied. The coating liquid of the product was applied and dried at 70°C for 1 minute.

Next, in a nitrogen atmosphere, ultraviolet rays were irradiated under the following conditions using an ultraviolet irradiation device (manufactured by Eyegraphics, product name: "Eye Grantage ECS-401GX") to form a light resistance improving layer. As a result, a light fastness improving film composed of a substrate and a light fastness improving layer having a thickness of 5 μm was obtained.
[Ultraviolet irradiation conditions]
・Light source: High pressure mercury lamp ・Lamp power: 2 kW
・Conveyor speed: 4.23m/min
・Illuminance: 240mW/ ^cm2
・Light intensity: 307 mJ/cm ²

[Examples 2 to 7, Comparative Examples 1 to 5]
A film with improved light resistance was produced in the same manner as in Example 1, except that the composition of the coating composition was changed as shown in Table 1.

Details of abbreviations and the like in Table 1 are as follows.
[Leveling agent]
D1: fluorine-based leveling agent (manufactured by Neos, product name "Ftergent 602A")
D2: Silicone leveling agent (manufactured by Dow Corning Toray, product name "SH28")
[Filler]
E1: Silicone filler (manufactured by Momentive Performance Materials Japan, product name “Tospearl 145L”, average particle size: 4.5 μm, refractive index: 1.43)
E2: Silicone filler (manufactured by Momentive Performance Materials Japan, product name “Tospearl 130”, average particle size: 3 μm, refractive index: 1.43)
E3: Silicone filler (manufactured by Momentive Performance Materials Japan, product name “Tospearl 120”, average particle size: 2 μm, refractive index: 1.43)
E4: Acrylic filler (manufactured by Sekisui Chemical Co., Ltd., product name “SSX-101”, average particle size: 1.5 μm, refractive index: 1.49)
E5: Acrylic filler (manufactured by Sekisui Chemical Co., Ltd., product name “SSX-103”, average particle size: 3 μm, refractive index: 1.49)
E6: acrylic filler (manufactured by Sekisui Chemical Co., Ltd., product name “SSX-105”, average particle size: 5 μm, refractive index: 1.49)

[Test Example 1] (Measurement of haze value and total light transmittance)
For the light resistance improving films produced in Examples and Comparative Examples, background measurement was performed with glass, and then a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") was used to improve light resistance. A light beam was irradiated from the surface side of the layer, and the haze value (%) and the total light transmittance (%) at 23°C were measured. Here, the haze value (%) was measured according to JIS K7136:2000, and the total light transmittance (%) was measured according to JIS K7361-1:1997. Table 2 shows the results.

[Test Example 2] (Measurement of light transmittance in near-ultraviolet region and ultraviolet region)
For the light resistance improving films produced in Examples and Comparative Examples, background measurement was performed with glass, and a UV-VIS-NIR measurement device (manufactured by Shimadzu Corporation, product name "UV-3600") was used to Light transmittance (%) was measured with a measurement wavelength of 310 to 830 nm. Based on the measurement results, the average light transmittance (%) at a wavelength of 310 to 380 nm (near ultraviolet region) and the average light transmittance (%) at a wavelength of 380 to 420 nm (ultraviolet region) were calculated. . These results are shown in Table 2.

[Test Example 3] (Measurement of transmission clarity)
For the light resistance improving films produced in Examples and Comparative Examples, light resistance was measured using an image clarity measuring instrument (manufactured by Suga Test Instruments Co., Ltd., product name "ICM-1T") according to the transmission method of JIS K7374:2007. The transmission definition (image definition) was measured by irradiating light from the surface on the enhancement layer side. The comb widths of the optical combs in the image clarity meter used were 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm. Table 2 shows the total value (%) of transmission clarity measured for each optical comb.

[Test Example 4] (Measurement of 60° gloss)
For the surface of the light resistance improving layer side of the light resistance improving film produced in Examples and Comparative Examples, a gloss meter (manufactured by Nippon Denshoku Industries, product name "VG7000") was used to measure according to JIS Z8741: 1997. Then, the 60° gloss (%) was measured. Table 2 shows the results.

[Test Example 5] (Measurement of diffuse reflectance)
The substrate-side surface of the light fastness-enhancing film produced in Examples and Comparative Examples was attached to a blackboard using an adhesive to obtain a sample for measurement. For the surface of the light resistance improving layer side of the measurement sample, background measurement was performed with a blackboard to which the light resistance improving film was not attached, and a UV-VIS-NIR measuring instrument (manufactured by Shimadzu Corporation, product name "UV-3600") was used to measure the diffuse reflectance (%). The measurement was performed by subtracting the specular reflectance from the total reflectance by the SCE method (method for removing specular reflection). Table 2 shows the results.

[Test Example 6] (Measurement of water contact angle)
The substrate-side surface of the light resistance improving film produced in Examples and Comparative Examples was attached to one surface of a glass plate. After that, the glass plate was placed on a test stand of an automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., product name "DM-701") so that the surface to which the light resistance improving film was attached faces up. Subsequently, 2 μL of pure water was dropped on the light resistance improving layer side of the light resistance improving film, and the contact angle (°) immediately after dropping was measured with the contact angle meter. and Table 2 shows the results.

[Test Example 7] (Measurement of pencil hardness)
The surface of the light resistance improving layer side of the light resistance improving films produced in Examples and Comparative Examples was measured for pencil hardness according to JIS K5600-5-4. For the measurement, a pencil scratch hardness tester (manufactured by Yasuda Seiki Seisakusho, product name "No. 553-M") is used, and a pencil manufactured by Mitsubishi Pencil Co., Ltd. under the product name "UNI" is used, and an angle of 45 °. A pencil was brought into contact with the surface to be measured, a load of 750 g was applied, and the pencil traveled 7 mm or more. While changing the hardness of the pencil, the test was repeated 5 times for one type of pencil, and the pencil with the highest hardness among them was identified, and the number of times that no scratches occurred on the surface of the light resistance improving layer side was 3 times or more. was taken as the pencil hardness. Table 2 shows the results.

[Test Example 8] (Evaluation of scratch resistance)
For the surface of the light resistance improving layer side of the light resistance improving film produced in Examples and Comparative Examples, #0000 steel wool was used according to JIS K5600-5-10, 10 cm with a load of 250 g / cm ² , After 10 reciprocating rubbings, the number of scratches on the surface was counted, and the scratch resistance was evaluated according to the following criteria. Table 2 shows the results.
◯: The number of scratches was 0.
x: The number of scratches was 1 or more.

[Test Example 9] (Evaluation of antiglare properties)
The substrate-side surface of the light fastness-enhancing film produced in Examples and Comparative Examples was attached to a blackboard using an adhesive to obtain a sample for measurement. For the measurement sample, a three-wavelength fluorescent lamp was turned on above the surface on the side of the light resistance improving layer, and the light was reflected on the surface. The reflected light was visually observed and the antiglare properties were evaluated according to the following criteria. Table 2 shows the results.
⊚: The visible outline of the fluorescent lamp was blurred due to the reflection on the film for improving light resistance.
◯: The visible outline of the fluorescent lamp was slightly blurred due to the reflection on the light fastness improving film.
Δ: The visible outline of the fluorescent lamp was slightly blurred due to the reflection on the film for improving light resistance.
x: The outline of the fluorescent lamp visually recognized by the reflection on the light fastness improving film was not blurred at all.

[Test Example 10] (Evaluation of glare)
For the display surface of a tablet terminal (manufactured by Apple Inc., product name “NEW iPad (registered trademark)”, resolution: 264 ppi), the light resistance improving film produced in Examples and Comparative Examples was applied to the display surface on the substrate side. was laminated so as to be in contact with the After that, the presence or absence of glare was visually confirmed in a state where the entire tablet terminal was displayed in green (RGB values (R, G, B)=0, 255, 0). Based on the results, glare was evaluated according to the following criteria. Table 2 shows the results.
⊚: No glare caused by the film for improving light resistance was observed.
◯: Slight glare due to the film for improving light resistance was observed.
Δ: Some glare caused by the film for improving light resistance was observed.
x: Glare caused by the film for improving light resistance was observed on the entire surface.

[Test Example 11] (Evaluation of recoatability)
10 parts by mass of acrylic resin containing polyfunctional (meth)acrylate (manufactured by Arakawa Chemical, product name “Beamset 575CB”, solid content 100%) and hollow silica fine particles (manufactured by JGC Shokubai Co., Ltd., product name “Sururia 4320”) , solid content 20.5%) 24.4 parts by mass, a photopolymerization initiator (manufactured by BASF, product name “OMNIRAD 907”, solid content 100%) 0.3 parts by mass, and a fluorine-based antifouling agent (DIC company, product name "Megafac RS-90", solid content 10%) and 0.2 parts by mass in a mixed solvent of methyl isobutyl ketone and cyclohexanone (mixing ratio 1: 1), solid content 1 0 to 2.0% by mass of a coating liquid of the composition for forming an antireflection layer was obtained.

Subsequently, the coating liquid obtained as described above was applied to the surface of the light resistance improving layer side of the light resistance improving film prepared in Examples and Comparative Examples so that the thickness after drying was 100 nm. The behavior of the coating liquid at that time was confirmed, and recoating properties were evaluated according to the following criteria. Table 2 shows the results.
Good: Repelling of the coating liquid did not occur.
x: Repelling of the coating liquid occurred.

[Test Example 12] (Evaluation of low reflectivity)
The substrate-side surface of the light fastness-enhancing films prepared in Examples and Comparative Examples was bonded to a blackboard using an adhesive to obtain a measurement sample (before formation of the antireflection layer). For the surface of the light resistance improving layer side of the measurement sample, background measurement was performed with a blackboard to which the light resistance improving film was not attached, and a UV-VIS-NIR measuring instrument (manufactured by Shimadzu Corporation, product name "UV-3600") was used to measure the total reflectance (%) as the average value in the wavelength range of 400 to 600 nm. The measurement was performed by the SCI method (a method including regular reflection light). The total reflectance (%) obtained here was defined as "the total reflectance (%) before formation of the antireflection layer". Table 2 shows the results.

On the other hand, a coating solution of a composition for forming an antireflection layer prepared in the same manner as in Test Example 11 was applied to the surface of the light resistance improving layer side of the light resistance improving film prepared in Examples and Comparative Examples so that the thickness after drying was It was coated so as to be 100 nm. Then, the obtained coating film is irradiated with ultraviolet rays under the following conditions using an ultraviolet irradiation device (manufactured by Eye Graphics Co., Ltd., product name "Eye Grantage ECS-401GX type") under a nitrogen atmosphere. An antireflection layer was formed on the light resistance improving layer. As a result, a film with improved light resistance laminated with an antireflection layer was obtained.
[Ultraviolet irradiation conditions]
・Light source: High pressure mercury lamp ・Lamp power: 2 kW
・Conveyor speed: 4.23m/min
・Illuminance: 240mW/ ^cm2
・Light intensity: 307 mJ/cm ²

Regarding the light resistance improving film laminated with the antireflection layer obtained as described above, the surface on the substrate side and the blackboard are bonded together using an adhesive, and a sample for measurement (after forming the antireflection layer ). Then, the total reflectance (%) was measured in the same manner as above for the antireflection layer side surface of the measurement sample. The obtained total reflectance (%) was defined as "total reflectance (%) after formation of the antireflection layer". Table 2 shows the results.

The total reflectance (%) after formation of the antireflection layer was subtracted from the total reflectance (%) before formation of the antireflection layer measured as described above to calculate the difference in total reflectance (point). Table 2 shows the results.

Furthermore, when the total reflectance (%) before formation of the antireflection layer was less than 2%, low reflectivity was evaluated based on the following criteria (A). In addition, when the total reflectance (%) before formation of the antireflection layer was 2% or more, low reflectivity was evaluated based on the following criteria (B). These evaluation results are shown in Table 2.
[Criteria (A)]
A: The total reflectance (%) after the formation of the antireflection layer was 1.0% or less.
Good: The total reflectance (%) after the formation of the antireflection layer was more than 1.0% and 1.2% or less.
Δ: The total reflectance (%) after the formation of the antireflection layer was more than 1.2% and 1.5% or less.
x: The total reflectance (%) after the formation of the antireflection layer was over 1.5%.
[Criteria (B)]
A: The difference in total reflectance was 2.5 points or more.
Good: The difference in total reflectance was 2.0 points or more and less than 2.5 points.
Δ: The difference in total reflectance was 1.5 points or more and less than 2.0 points.
x: The difference in total reflectance was less than 1.5 points.

For Comparative Example 1, for which the recoating property was evaluated as "x" in Test Example 11, the final test was not performed.

[Test Example 13] (Evaluation of light resistance: adhesion)
On the surface of the light resistance improving layer side of the light resistance improving film prepared in Examples and Comparative Examples, using the product name "UV Fade Meter U48" manufactured by Suga Test Instruments Co., Ltd., according to JIS B7751-2007, ultraviolet light. was irradiated for 400 hours.

After that, according to JIS K5600-5-6, 100 grids of 1 mm square were formed on the light resistance improving layer with a cutter knife. Next, under the environment of 23° C. and 50% RH, an adhesive tape (cellophane tape manufactured by Nichiban Co., Ltd.) was pasted on the grid using a squeegee. Thirty seconds after the application, the adhesive tape was peeled off in the direction of 90°. Then, the number of grids of the light resistance improving layer remaining on the base material without being separated from the base material was counted. Table 2 shows the results.

[Test Example 14] (Evaluation of light resistance: color change)
Background measurement was performed on the surface of the light resistance improving layer side of the light resistance improving film produced in Examples and Comparative Examples, and then a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH7000") was used. , the surface on the side of the light resistance improving layer was irradiated with light, and the chromaticity a ^* and chromaticity b ^* defined by the CIE1976L ^* a ^* b ^* color system were measured. These measurement results are shown in Table 2 as initial chromaticity a ^* and chromaticity b ^* .

Furthermore, in the same manner as in Test Example 13, a film with improved light resistance was prepared by irradiating ultraviolet rays for 400 hours. The chromaticity a* and the chromaticity ^{b* defined} by the CIE1976L ^* a ^* b ^* color system were also measured for the surface of the lightfastness improving film on the side of the lightfastness improving layer in the same manner as described above. Then, the absolute value of the difference from the initial value was calculated. The results are also shown in Table 2.

In Test Example 13, the final test was not conducted for Comparative Examples 2 to 4 in which the light resistance improving layer was separated from the base material for all the number of grids.

As is clear from Table 2, the light fastness-enhancing films produced in Examples were excellent in recoatability, low reflectivity, and light fastness. Furthermore, the light fastness-enhancing films produced in the examples had good results in terms of scratch resistance, anti-glare properties, and glare resistance.

The light fastness improving film of the present invention can be suitably used as a member constituting a vehicle-mounted display or an outdoor display.

Claims (7)

A light resistance improving film comprising a substrate and a light resistance improving layer provided on one side of the substrate,
The diffuse reflectance of the light resistance improving layer is 3% or less as an average value for light with a wavelength of 380 nm to 780 nm,
The surface of the light resistance improving layer opposite to the base has a water contact angle of less than 80°,
The light transmittance of the light resistance improving film is 40% or less as an average value for light with a wavelength of 310 nm to 380 nm,
The light resistance improving film, wherein the light resistance improving layer contains a light stabilizer. 2. The light resistance improving film according to claim 1, wherein the light stabilizer is a hindered amine light stabilizer. CIE1976L ^* a ^* b ^* chromaticity a ^* defined by the color system in the light resistance improving film, and an ultraviolet carbon arc lamp type light resistance test in accordance with JIS B7751: 2007 for the light resistance improving film. 3. The light fastness improving film according to claim 1, wherein the absolute value of the difference from the chromaticity a ^* after 400 hours is 0 or more and 3 or less. CIE1976L ^* a ^* b ^* chromaticity b ^* specified by the color system in the light resistance improving film, and an ultraviolet carbon arc lamp type light resistance test in accordance with JIS B7751: 2007 for the light resistance improving film. 4. The light fastness improving film according to any one of claims 1 to 3, wherein the absolute value of the difference from the chromaticity b ^* after 400 hours is 0 or more and 3 or less. The light resistance improving film according to any one of claims 1 to 4, wherein the surface of the light resistance improving layer opposite to the substrate is a surface on which an antireflection layer is laminated. 6. The light resistance improving film according to any one of claims 1 to 5, which is used as a member constituting a display. 7. The light fastness improving film according to claim 6, wherein the display is an in-vehicle display or an outdoor display.