WO2019087963A1 - Hard coat film with adhesive layer and image display device - Google Patents

Abstract

The present invention provides a hard coat film provided with an adhesive layer, having a pencil hardness of 3H or more, and capable of improving the visibility of a screen by suppressing the reflection of external light and of ensuring the visibility of the screen regardless of any angle when wearing polarized sunglasses. The hard coat film with the adhesive layer comprises: a base material made of a transmissive resin film with a retardation of 5,000 – 30,000 nm; a hard coat layer provided on one surface of the base material; an antireflection layer provided on the opposite side of the hard coat layer from the base material; and an adhesive layer provided on the opposite side of the base material from the hard coat layer. The hard coat layer has a thickness of 3 – 15 µm and is made of a curable resin. The antireflection layer has a thickness of 50 – 150 nm and a refractive index of 1.20 – 1.40. The adhesive layer has a thickness of 5 – 20 µm and a coefficient of dynamic friction of 0.05 – 0.30 on the outermost surface that is opposite the base material.

Description

Hard coat film with adhesive layer, image display device

The present invention relates to a hard coat film with a pressure sensitive adhesive layer, and more particularly to a hard coat film with a pressure sensitive adhesive layer in which the inconspicuousness of the screen due to the angle is eliminated and the scratch is less likely to occur.

Polarized sunglasses are those in which a polarizing film is mounted on the lens part of ordinary sunglasses. The polarizing film can cut off reflected light (omnitric light) coming from the upper and lower sides of the field of vision, so that the field of view can be improved and the desired image can be clearly seen. For example, in driving a car, the reflected light from the road surface or the windshield disappears and a clear view can be maintained. In fishing, the reflected light from the water surface disappears, making it easy to see the water.

However, if you wear polarized sunglasses and look at the LCD screen (car navigation system, smartphone, etc.), depending on the angle, you may not be able to see the screen (blackout problem). This is because the light emitted from the liquid crystal display is linearly polarized light and is cut by polarized sunglasses depending on the angle. Therefore, in Patent Document 1, a polymer film having a specific retardation is used so that the light transmitted through the film is no longer linearly polarized light, and “it is affixed to the surface of the display even after the image display device is purchased. Adhesive film that can prevent image loss (blackout), iridescent unevenness (rainbow unevenness), color shift (color shift), etc. when observed through polarized sunglasses simply by attaching it, and can give good visibility. (Patent Document 1, paragraph 0005) is disclosed.

In order to produce a thin film having a large retardation as large as 5000 to 30000 nm and having a large area as described in Patent Document 1, a method of producing the film by stretching is used. When the film is stretched, the polymer chains are oriented along the stretching direction, and the in-plane retardation increases. In addition, the tensile modulus in the polymer chain direction (stretching direction) increases with the orientation of the polymer chain (Non-Patent Document 1). However, it is known that the tensile modulus in the direction perpendicular to the polymer chain decreases (Non-patent Document 2). It has been pointed out that the mechanical strength in the direction perpendicular to the polymer chains is significantly reduced even when a film having a large in-plane retardation is actually produced by increasing the draw ratio (Patent Document 2, paragraph 0084, 0086). Thus, there is a trade-off between obtaining a film of large retardation by stretching and increasing its tensile modulus in the direction perpendicular to stretching, and it is technically difficult to simultaneously achieve both.

JP 2014-215509 A Patent No. 6146008 gazette

When the liquid crystal screen is a touch panel specification, the surface of the screen is required to have a certain degree of hardness so that the screen is not easily damaged. Generally, the hardness of human nails is said to be about 2H in pencil hardness, and in order for the touch panel to obtain sufficient scratch resistance, it is necessary to set the hardness of the surface of the screen to at least 3H. However, it is a thin base material in which the retardation is increased by stretching, and a pencil is formed by providing a hard coat layer having a thickness that does not increase the curl too much on one side with respect to the base material having a small tensile elastic modulus in at least one direction. It turned out that it is difficult to obtain a film having a hardness of 3H or more.
Therefore, the present invention suppresses the reflection of external light to improve the visibility of the screen, can ensure the visibility of the screen at any angle when wearing polarized sunglasses, and has a pencil hardness of 3H or more, a hard coat film provided with an adhesive layer Intended to provide.

The present inventors diligently studied to solve the above problems. As a result, a hard coat layer and an antireflection layer are provided on the base film, and the specific range of the dynamic friction coefficient on the outermost surface thereof is combined with the specific range of the thickness of the adhesive layer when the film is attached to the liquid crystal screen. It has been found that the surface hardness can be improved even by using a thin substrate having a large retardation by stretching and having a small tensile modulus in at least one direction. It was completed.

The hard coat film with a pressure-sensitive adhesive layer according to the first aspect of the present invention is, for example, as shown in FIG. 1, a substrate of a translucent resin film having a retardation of 5000 to 30000 nm; The hard coat layer has an antireflective layer on the side opposite to the base of the hard coat layer; and an adhesive layer on the side opposite to the hard coat of the base. The hard coat layer has a thickness of 3 to 15 μm and is formed of a curable resin. The antireflective layer has a thickness of 50 to 150 nm and a refractive index of 1.20 to 1.40. The pressure-sensitive adhesive layer has a thickness of 5 to 20 μm, and the dynamic friction coefficient at the outermost surface opposite to the pressure-sensitive adhesive layer is 0.05 to 0.30. The term “surface side” is not limited to the case where the layers are laminated in contact with the surface, but also includes the case where the layers are laminated via other layers.
With this configuration, the retardation within the above range improves the visibility of the liquid crystal screen when the polarized sunglasses are attached, and the thickness of the adhesive layer, the thickness of the hard coat layer, and the dynamic friction coefficient on the outermost surface fall within the above range. The pencil hardness can be improved by being present. Furthermore, the reflected light can be weakened and the glare can be reduced by the interference between the surface reflected light of the antireflective layer and the interface reflected light of the lower layer of the antireflective layer. Furthermore, a favorable antireflection film can be formed as an antireflection layer by the refractive index of a suitable antireflection layer. Furthermore, the adhesion of the film can be improved by the adhesive layer, and the convenience at the time of use can be enhanced.

The hard coat film with a pressure-sensitive adhesive layer according to the second aspect of the present invention is the hard coat film with a pressure-sensitive adhesive layer according to the first aspect of the present invention, wherein the tensile modulus of elasticity of at least one direction of the translucent resin film is , 1.0 to 2.6 GPa.
With such a configuration, it is possible to efficiently produce a thin film with a retardation of 5000 to 30000 nm by stretching.

The hard coat film with a pressure-sensitive adhesive layer according to the third aspect of the present invention is the hard coat film with a pressure-sensitive adhesive layer according to the first aspect or the second aspect of the present invention, wherein the hard coat layer contains particles.
According to this structure, the incident light can be diffused by the particles contained in the hard coat layer. Furthermore, the coefficient of dynamic friction of the surface can be reduced to impart slipperiness.

The hard coat film with a pressure-sensitive adhesive layer according to a fourth aspect of the present invention is the hard coat film with a pressure-sensitive adhesive layer according to the third aspect of the present invention, wherein the particles are silica particles.
According to this structure, the hard coat layer has antiglare property, and the silica particles contained in the hard coat layer can diffuse incident light to reduce reflection.

The hard coat film with a pressure-sensitive adhesive layer according to the fifth aspect of the present invention is the hard coat film with a pressure-sensitive adhesive layer according to any one of the first to fourth aspects of the present invention. An easily adhesive layer is provided in contact therewith.
According to this structure, the adhesion of the hard coat layer and the adhesive layer to the substrate can be improved, and peeling of the layer due to long-term use can be suppressed. Moreover, when the easily bonding layer which has a suitable refractive index and thickness is provided, the interference fringe resulting from the thickness nonuniformity of a hard-coat layer can be suppressed.

The hard coat film with a pressure-sensitive adhesive layer according to the sixth aspect of the present invention is a pencil when the hard coat film with a pressure-sensitive adhesive layer according to any one of the first to fifth aspects of the present invention is attached to glass. Hardness is 3H or more.
With this configuration, when the film of the present invention is attached to the screen of the touch panel specification, the screen can be less likely to be damaged.

The image display apparatus according to the seventh aspect of the present invention is provided with the hard coat film with an adhesive layer according to any one of the first to sixth aspects of the present invention on a screen.
With this configuration, the visibility of the screen is prevented from being deteriorated due to the reflection of external light, and the screen of the image display device can not be seen by the angle when the polarized sunglasses are attached. An image display device that is difficult to attach can be provided.

The hard coat film with adhesive layer of the present invention can prevent the deterioration of the visibility of the screen due to the reflection of external light by sticking to the screen, and can ensure the visibility of the screen at any angle when wearing polarized sunglasses And, the pencil hardness can provide the damage prevention property of 3H or more.

It is sectional drawing of an example of the hard coat film 1 with the adhesion layer which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of a structure of the image display apparatus 2 which concerns on the 2nd Embodiment of this invention. (A) is a figure for demonstrating the function of a glare-proof layer. (B) is a figure for demonstrating the function of a reflection prevention layer.

This application is based on Japanese Patent Application No. 2017-211382 filed on Oct. 31, 2017 in Japan, the contents of which form a part of the contents of the present application. The invention will be more fully understood from the following detailed description. Further areas of applicability of the present invention will become apparent as the description proceeds. However, the detailed description and the specific examples are the preferred embodiments of the present invention and are described for the purpose of illustration only. Various changes and modifications will be apparent to those skilled in the art from the detailed description within the spirit and scope of the present invention. The applicant does not intend to give the public any of the described embodiments, and modifications, alternatives, which may not be literally included within the scope of the claims, are also included under the equivalent theory. Part of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same or similar reference numerals, and redundant description will be omitted. Further, the present invention is not limited to the following embodiments.
In the present invention, the coating liquid contains a curable resin, and may be a curable resin alone or a mixture of a curable resin and a solvent.

«Hard coat film 1 with adhesive layer»
With reference to FIG. 1, a hard coat film 1 with a pressure-sensitive adhesive layer (hereinafter, also referred to as a film 1) according to a first embodiment of the present invention will be described. In addition, FIG. 1 illustrates the layer configuration of the film 1 configured in multiple layers, and the thickness of each layer is exaggerated. The hard coat film with adhesive layer 1 includes a transparent film-like substrate 10, an antireflection layer 11, a hard coat layer 12, and an adhesive layer 13. As shown in FIG. 1, the hard coat layer 12 and the antireflective layer 11 are sequentially laminated on one surface of the transparent film-like substrate 10 (the upper side of the substrate 10 in FIG. 1). The adhesive layer 13 is laminated on the surface of the substrate (in FIG. 1, the lower side of the substrate 10).

When the hard coat layer functions as an antiglare layer, the hard coat film with an adhesive layer of the present invention has a hard coat property as well as suppressing reflection and reflection due to the combination of the antiglare layer and the antireflective layer. it can. The antiglare layer, as shown in FIG. 3A, has a function of diffusing incident light due to the contained particles and surface irregularities and reducing the glare of reflected light. As shown in FIG. 3B, the antireflective layer weakens the reflected light by glare due to the interference between the surface reflected light of the antireflective layer and the interface reflected light of the lower layer (the base material in FIG. 3B). Have the function of reducing However, FIG. 3 is for explaining the image of anti-glare and anti-reflection visually in an easy-to-understand manner, and does not represent the principle correctly.

The hard coat film with an adhesive layer of the present invention has an angle formed by the alignment main axis of the film and the polarization axis of the viewing side polarizer of the display with respect to the display device to be attached (the film and the polarizer It is preferable to stick so that it is close to 45 degrees (approx. 45 degrees), assuming that. For example, the angle is preferably 45 degrees ± 25 degrees or less, more preferably 45 degrees ± 20 degrees or less. In particular, from the viewpoint of reducing the deterioration in image quality when the display device is viewed obliquely through polarized sunglasses, the angle is further 45 degrees ± 15 degrees or less, 45 degrees ± 10 degrees or less, 45 degrees ± 5 degrees or less, 45 Degree ± 3 degrees or less, 45 degrees ± 2 degrees or less, 45 degrees ± 1 degrees or less, 45 degrees in order is more preferable. In the present specification, “45 degrees ± 15 degrees or less”, for example, means to allow fluctuation of a range of 15 degrees up and down around 45 degrees.

Generally, a liquid crystal display which is a fixed example of a display has a light source and a liquid crystal cell. In this document, the side on which an image of a liquid crystal display is displayed (the side on which a person views an image) is called the “viewing side”, and the side opposite to the viewing side (that is, in a liquid crystal display, usually called a backlight source The side on which the light source is set is referred to as the “light source side”. A polarizing plate is provided on each of the light source side and the viewing side of the liquid crystal cell, and each polarizing plate typically has a structure in which a polarizer protective film is laminated on both sides of a film called a polarizer. In general, the polarizer on the viewing side of the liquid crystal cell is installed such that the polarization axis is approximately parallel, substantially perpendicular, or approximately 45 degrees with respect to the longitudinal direction in the screen of the display device. Therefore, the alignment main axis of the hard coat film with a pressure-sensitive adhesive layer of the present invention is preferably any one of substantially parallel, substantially vertical, and substantially 45 degrees with the long side (one side if square) of the pressure-sensitive adhesive film.

[Base material 10]
As the substrate 10, a translucent resin film having a retardation of 5000 nm or more and 30000 nm or less is used. The lower limit of the retardation is preferably 7000 nm or more, more preferably 8000 nm or more. The upper limit of the retardation is preferably 20000 nm or less, more preferably 15000 or less. If it is 5000 nm or more, rainbow unevenness can be suppressed when the polarizing sunglasses are attached, and if it is 30000 nm or less, the mechanical strength of the substrate can be secured, and the handling is easy.

The retardation of the translucent resin film can be measured according to a known method. As in the example, it can also be determined using a commercially available ellipsometer (manufactured by JA Woollam Japan Co., Ltd.).

As a translucent resin used for a translucent resin film, for example, polyester resin, polycarbonate resin, polystyrene resin, syndiotactic polystyrene resin, polyether ether ketone resin, polyphenylene sulfide resin, cycloolefin resin, liquid crystalline polymer resin, The resin which added the liquid crystal compound to cellulose resin, or these mixtures can be mentioned.

Preferably, polycarbonate resins, polyester resins, syndiotactic polystyrene resins are used. Since these resins are excellent in transparency, and also excellent in thermal characteristics and mechanical characteristics, retardation can be easily controlled by stretching. Polyester resins represented by polyethylene terephthalate and polyethylene naphthalate are preferable because they have large intrinsic birefringence, and even if the film thickness is thin, large retardation can be obtained relatively easily. In particular, since polyethylene naphthalate has a large intrinsic birefringence among polyester resins, it is possible to make the retardation particularly high or make the film thinner while keeping the retardation high.
Furthermore, polyethylene terephthalate and polyethylene naphthalate are excellent in mechanical strength, dimensional stability, heat resistance, chemical resistance, optical properties, etc., and smoothness and handling of the film surface. Polycarbonate is excellent in transparency, impact resistance, heat resistance, dimensional stability, and flammability. Triacetyl cellulose has small optical anisotropy. Polyethylene terephthalate is particularly preferred in consideration of cost and availability.

The film thickness of the substrate 10 is preferably 50 to 500 μm, more preferably 50 to 400 μm, further 50 to 300 μm, further 55 to 200 μm, further 55 to 100 μm, further 60 to 90 μm And particularly preferably 75 to 85 μm. The mechanical strength of a base material is enough that the film thickness of the base material 10 is 50 micrometers or more, and it becomes easy to form each layer in a base material. In addition, when the film thickness is 500 μm or less, the thickness of the hard coat film 1 with the adhesive layer does not become too thick, and a product using this film (for example, a display device described later) is compact, and further sufficient flexibility Have.

The present invention is to improve the surface hardness of a thin substrate having a large retardation by stretching and using a substrate having a tensile modulus of at least one of 1.0 to 2.6 GPa. Can. Here, at least one direction means any one direction of 360 ° of the film used for the substrate. In the Example of this invention, MD (machine direction) and TD (width direction) were measured as a representative value of the tensile elasticity modulus of the film used for the base material. Specifically, the configuration of the hard coat film with adhesive layer of the present invention is effective when the tensile modulus of elasticity of the substrate 10 is 1.0 to 2.6 GPa, and depending on the case of 1.5 to 2.6 GPa. It is valid. If the tensile modulus of elasticity in at least one direction is 1.0 to 2.6 GPa, it is possible to efficiently prepare a film having a retardation of 5000 to 30000 nm by stretching.

[Hard coat layer 12]
The hard coat 12 is formed by applying a coating liquid of a resin composition containing a curable resin onto a transparent film-like substrate 10 as shown in FIG. 1 and curing the obtained coating film. Ru. In laminating the hard coat 12, it is preferable to use a wet coating method for uniformly coating a coating solution. As the wet coating method, a bar coating method, a gravure coating method, a die coating method or the like can be used.

Other wet coating methods include spin coating, reverse coating, roll coating, slit coating, dipping, spray coating, kiss coating, reverse kiss coating, air knife coating, curtain coating, rod coating Law etc. can be mentioned. The method of laminating can be appropriately selected according to the film thickness required from these methods.
By using the wet coating method, it is possible to laminate at a line speed of several tens of meters per minute (for example, about 20 m / min) and a large area, so that mass production can be achieved, and the production efficiency can be increased.

Here, the curable resin refers to an active energy ray curable resin which is crosslinked by irradiation with an active energy ray such as α rays, β rays, γ rays, neutron rays, electron beams, and ultraviolet rays, and a thermosetting resin which is crosslinked by heating. is there. As a curable resin, a silicone resin, an acrylic resin, a methacryl resin, an epoxy resin, a melamine resin, a polyester resin, a urethane resin etc. are mentioned.

As the active energy ray curable resin, unsaturated bonds capable of radical polymerization such as urethane (meth) acrylate resin, polyester (meth) acrylate resin, (meth) acrylate monomer, unsaturated polyester resin, epoxy (meth) acrylate resin and the like The resin which has can be mentioned. These resins may be used alone, or a plurality of resins may be used in combination. Among them, urethane (meth) acrylate resin and polyester (meth) acrylate resin are preferable. The urethane (meth) acrylate resin is easy to obtain a tough coating due to the urethane structure, and at the same time has flexibility.

As a urethane (meth) acrylate resin, for example, after reacting a polyisocyanate with a polyhydroxy compound or a polyhydric alcohol, further reacting a hydroxyl group-containing (meth) acrylic compound and, if necessary, a hydroxyl group-containing allyl ether compound And radically polymerizable unsaturated group-containing oligomers which can be obtained by
Specific examples of the polyisocyanate include 2,4-tolylene diisocyanate and isomers thereof, diphenylmethane diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate Nert, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, Burnock D-750, Klisson NK (trade name: Dainippon Ink and Chemicals, Inc.), Desmodur L (trade name: Sumitomo Bayer Urethane Co., Ltd., Coronate L (trade name: Nippon Polyurethane Industry Co., Ltd.), Takenate D102 (trade name: Mitsui Takeda Chemical Co., Ltd.), Isonate 143 L (trade name: Mitsubishi Chemical Co., Ltd.) And the like.
Examples of the polyhydroxy compounds include polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, etc. Specifically, glycerin-ethylene oxide adduct, glycerin-propylene oxide adduct, glycerin-tetrahydrofuran adduct, glycerin- Ethylene oxide-propylene oxide adduct, trimethylolpropane-ethylene oxide adduct, trimethylolpropane-propylene oxide adduct, trimethylolpropane-tetrahydrofuran adduct, trimethylolpropane-ethylene oxide-propylene oxide adduct, dipentaerythritol-ethylene oxide adduct , Dipentaerythritol-propylene oxide adduct, dipentaerythritol - tetrahydrofuran adduct, dipentaerythritol - ethylene oxide - propylene oxide adduct and the like.
Specific examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, and 1,3-alcohols. Butanediol, adduct of bisphenol A with propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1,3-butanediol, 1,2-cyclohexane glycol, 1,3 -Cyclohexane glycol, 1,4-cyclohexane glycol, paraxylene glycol, bicyclohexyl-4,4-diol, 2,6-decalin glycol, 2,7-decalin glycol and the like .
The hydroxyl group-containing (meth) acrylic compound is not particularly limited, but a hydroxyl group-containing (meth) acrylic acid ester is preferable. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, tris (hydroxyethyl) isocyanuric acid di (meth) acrylate, pentaerythritol tri (meth) An acrylate etc. are mentioned.

As polyester (meth) acrylate resin, (1) polyester of terminal carboxyl group obtained from saturated polybasic acid and / or unsaturated polybasic acid and polyhydric alcohol contains α, β-unsaturated carboxylic acid ester group (Meth) acrylate obtained by reacting an epoxy compound, (2) a polyester having a terminal carboxyl group obtained from a saturated polybasic acid and / or an unsaturated polybasic acid and a polyhydric alcohol, and obtained by reacting a hydroxyl group-containing acrylate (Meth) acrylates obtained by reacting (meth) acrylic acid with polyester of terminal hydroxyl group obtained from (meth) acrylate, (3) saturated polybasic acid and / or unsaturated polybasic acid and polyhydric alcohol .
As a saturated polybasic acid used as a raw material of polyester (meth) acrylate, for example, polybasic having no polymerizable unsaturated bond such as phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid and the like Examples thereof include acids or their anhydrides, and polymerizable unsaturated polybasic acids or their anhydrides such as fumaric acid, maleic acid and itaconic acid. Furthermore, as the polyhydric alcohol component, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2- Methyl 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, cyclohexane-1,4-dimethanol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc. may be mentioned. .

Examples of the (meth) acrylate monomer include compounds obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol. For example, polyalkylene glycol di (meth) acrylate, ethylene glycol (meth) acrylate, propylene glycol (meth) acrylate, polyethylenepolytrimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytriol (Meth) acrylate, trimethylolpropane diethoxy tri (meth) acrylate, trimethylolpropane triethoxy tri (meth) acrylate, trimethylolpropane tetraethoxy tri (meth) acrylate, trimethylolpropane pentaethoxy tri (meth) acrylate, tetra Methylolmethane tetra (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, pentaerythrito Tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate.

As an unsaturated polyester resin, a product obtained by dissolving a condensation product (unsaturated polyester) by the esterification reaction of a polyhydric alcohol and an unsaturated polybasic acid (and optionally a saturated polybasic acid) in a polymerizable monomer Can be mentioned.
The unsaturated polyester can be produced by polycondensation of an unsaturated acid such as maleic anhydride and a diol such as ethylene glycol. Specifically, a polybasic acid having a polymerizable unsaturated bond such as fumaric acid, maleic acid, itaconic acid or the anhydride thereof is used as an acid component, and this together with ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2 -Butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, cyclohexane Polyhydric alcohols such as 1,4-dimethanol, ethylene oxide adduct of bisphenol A, and propylene oxide adduct of bisphenol A are reacted as an alcohol component, and if necessary, phthalic acid, isophthalic acid, terephthalic acid, Tetrahydrophthalic acid, adipic acid, sebacic acid Polymerizable not have an unsaturated bond or a polybasic acid anhydrides may include those prepared by adding as an acid component.

As an epoxy (meth) acrylate resin, a polymerizable unsaturated bond generated by a ring-opening reaction of a compound having a glycidyl group (epoxy group) and a carboxyl group of a carboxyl compound having a polymerizable unsaturated bond such as acrylic acid is What melt | dissolved the compound (vinyl ester) which it had in the polymerizable monomer is mentioned.
As said vinyl ester, it manufactures by a well-known method and the epoxy (meth) acrylate obtained by making an epoxy resin react an unsaturated monobasic acid, for example, acrylic acid or methacrylic acid, is mentioned.
In addition, various epoxy resins are reacted with bisphenol (for example, type A) or dibasic acid such as adipic acid, sebacic acid, dimer acid (Haridimer 270S (trade name): Harima Chemicals, Inc.) to impart flexibility. May be
As an epoxy resin as a raw material, bisphenol A diglycidyl ether, its high molecular weight homologue, novolak-type glycidyl ethers, etc. are mentioned.

Among these curable resins, preferably, from the viewpoint of productivity, an ultraviolet curable resin which is film-formed and cured in a short time by ultraviolet irradiation. UV curable resins are usually used with the addition of a photopolymerization initiator. Examples of the photopolymerization initiator include various benzoin derivatives, benzophenone derivatives, phenyl ketone derivatives and the like. The addition amount of the photopolymerization initiator is preferably 1 to 10% by weight with respect to 100% by weight of the ultraviolet curable resin. When it is 1% by weight or more, curing failure hardly occurs, and when it is 10% by weight or less, it is difficult to cause coloring and the like. In addition, curable resin is used in the state of a coating liquid, in order to apply | coat. Therefore, the curable resin is preferably liquid. When the curable resin is solid, it may be used by dissolving it in a solvent.

The concentration of the curable resin in the coating solution can be selected so that the viscosity of the coating solution is a viscosity according to the laminating method such as the wet coating method. The concentration is preferably 1 to 80% by weight, more preferably 2 to 60% by weight. The concentration of the curable resin in the coating solution can be adjusted using, for example, a solvent such as methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and the like. Further, if necessary, other known additives, for example, a leveling agent such as a surfactant may be added to the coating liquid. When the leveling agent is added, the surface tension of the coating solution can be controlled, and surface defects such as repelling and crater formation can be suppressed.

Examples of the curing treatment for curing the curable resin include curing treatments such as heating, ultraviolet irradiation, and electron beam irradiation. In the case where the coating contains a solvent, the coating is usually heated for several tens of seconds to several minutes within the range of 50 to 200 ° C. to remove the solvent remaining in the coating, and then cured. It is preferred to carry out the treatment. The curing by heating may be, for example, heating at a temperature of usually 180 to 250 ° C., preferably 200 to 250 ° C. At this time, heating may be performed for 30 to 90 minutes when an oven is used, and for 5 to 30 minutes when a hot plate is used. In addition, as curing by UV irradiation, UV light of a wavelength of 200 to 400 nm is applied from a UV lamp (for example, high pressure mercury lamp, ultra high pressure mercury lamp, metal halide lamp, high power metal halide lamp) to a coating film for a short time (several seconds to several tens of minutes). Within the range of seconds). Moreover, what is necessary is just to irradiate a low energy electron beam to a coating film from a low energy electron accelerator of 300 keV or less self-shielding type | mold as hardening by electron beam irradiation.

The thickness of the hard coat layer 12 is 3 to 15 μm, preferably 3 to 8 μm, and particularly preferably 4 to 7 μm. When the film thickness is 3 μm or more, sufficient pencil hardness can be obtained. When the film thickness is 15 μm or less, curling of the film due to the tensile stress of the cured film can be suppressed, the handleability can be improved, and positional deviation at the time of bonding and peeling after bonding can be avoided. In addition, when the film thickness is 15 μm or less, the hard coat layer has appropriate flexibility and is not easily broken.

The dynamic hardness of the hard coat layer 12 of the curable resin containing no particles and no leveling agent is preferably 20 to 100, and more preferably 30 to 80. When the dynamic hardness is 20 or more, sufficient scratch resistance can be obtained. When the dynamic hardness is 100 or less, the hard coat layer has appropriate flexibility and is not easily broken. Furthermore, curing shrinkage is small, and curling of the film can be suppressed.

The hard coat layer 12 may contain silica (silicon oxide) particles so that the hard coat layer 12 after curing diffuses incident light and functions as an antiglare layer. In addition, in order to adjust the refractive index of the hard coat layer 12 and to impart conductivity, organic or inorganic particles may be contained. More specifically, organic particles or inorganic oxide particles can be used.

Specific examples of organic particles contained in the hard coat layer include acrylic resin particles, acrylic-styrene resin particles, polystyrene resin particles, polyurethane resin particles, epoxy resin particles, polyethylene resin particles, benzoguanamine resin particles, and melamine resin. There are fine particles. These may be used alone or in combination of two or more.

Specific examples of the inorganic oxide fine particles contained in the hard coat layer include silicon oxide, aluminum oxide (alumina), zirconium silicate, rutile titanium oxide, tin oxide, zirconium oxide, cerium oxide, magnesium fluoride Iron oxide, zinc oxide, copper oxide, antimony oxide, cryolite, fluorite, apatite, calcite, gypsum and talc. Preferably, silicon oxide, aluminum oxide, zirconium oxide, zirconium silicate, rutile titanium oxide, tin oxide, cerium oxide, magnesium fluoride and iron oxide are used, and more preferably, rutile titanium oxide having a large refractive index, oxide Zirconium, conductive doped tin oxide, inexpensive aluminum oxide, silicon oxide. These may be used alone or in combination of two or more.

The content of the silica particles is preferably 10 to 50% by weight, more preferably 15 to 25% by weight in the hard coat layer. The content is preferably 10% by weight or more in order to develop good antiglare property, and is preferably 50% by weight or less in order to maintain good adhesion to the substrate.
The volume average particle diameter of the silica particles is preferably 0.3 to 0.9 μm, and in view of the transparency of the coating film, 0.4 to 0.7 μm is preferable. When the volume average particle diameter is 0.3 μm or more, incident light can be sufficiently diffused, and when the volume average particle diameter is 0.9 μm or less, the antireflective layer can easily follow the surface irregularities of the hard coat layer functioning as an antiglare layer. .
The volume average particle size of the fine particles was measured using a laser diffraction / scattering particle size distribution measuring apparatus (LA-950V2, manufactured by Horiba, Ltd.). It is also possible to use volume average particle size information provided by the material manufacturer, and some differences in particle size values should be accepted as machine differences.
The shape of the silica particles is spherical, hollow, porous, rod-like (a shape with an aspect ratio of more than 1 and 10 or less), plate-like, fibrous, or indeterminate, and indeterminate-shaped silica particles preferable. The use of irregularly shaped particles can effectively impart unevenness to the coating film surface.
The content of particles other than silica, the volume average particle diameter, and the shape can also be the same as those of silica.

As described above, when particles are added to the hard coat layer 12, the hard coat layer 12 having desired antiglare property can be easily obtained by adjusting the type and amount of the particles.
The refractive index of the hard coat layer 12 may be set to 1.45 to 1.58. Preferably, it is 1.48 to 1.52. If the refractive index is 1.45 or more, the difference in refractive index with the below-described antireflection layer 11 will not be too small, and reflection and reflection can be sufficiently prevented. On the other hand, when the refractive index is 1.58 or less, a hard coat layer can be formed based on an acrylic resin or the like, and sufficient hardness can be secured.

[Antireflection layer 11]
The antireflective layer 11 is formed by applying a coating solution of a resin composition containing a curable resin onto the hard coat layer 12 as shown in FIG. 1 and curing the obtained coating film. The type of curable resin used for the antireflective layer 11, the method of laminating the curable resin, and the method of curing treatment may be the type of curable resin described for the hard coat layer 12, the method of laminating, and the curing method. In addition, the kind of curable resin used for the reflection preventing layer 11 and the hard-coat layer 12 may be the same, and may differ. When the same curable resin is used, the same material can be used, so that productivity can be improved. The use of different curable resins broadens the range of selectable refractive indices and facilitates adjustment of the refractive index. In particular, in the case of the antireflective layer, it is preferable to reduce the refractive index by means of dispersing hollow silica, using a fluorine-based resin, or the like.

The thickness of the antireflective layer 11 is 50 to 150 nm, preferably 70 to 110 nm, and more preferably 80 to 100 nm. When the film thickness of the antireflective layer is 50 to 150 nm, the wavelength at which the reflectance is minimum can be made near the center (550 nm) of the wavelength of visible light, and the luminous reflectance can be greatly reduced. In addition, when the film thickness of the antireflective layer is 50 nm or more, it can be avoided that the reflected light becomes yellow. While being able to avoid that reflected light becomes blue as it is 150 nm or less, the surface of a reflection prevention layer does not become too smooth, and it has anti-glare property, anti-glare property can be maintained.

The refractive index of the antireflective layer 11 is 1.20 to 1.40, preferably 1.25 to 1.38, and more preferably 1.30 to 1.38. When the refractive index is 1.20 or more, the amount of the inorganic substance (such as hollow silica) to be added becomes excessive and the ratio of the curable resin becomes relatively small, whereby the strength of the curable resin layer becomes insufficient. Can be avoided. Alternatively, when a mixture containing a fluorocarbon resin is used as the curable resin, it can be avoided that the amount of the fluorocarbon resin becomes excessive and the strength of the curable resin layer becomes insufficient. When the refractive index is 1.40 or less, the difference in refractive index with the above-described hard coat layer 12 is small, and it is possible to avoid that the reflection and reflection can not be sufficiently prevented. In addition, it is essential to adjust the refractive index of the antireflective layer 11 to be lower than the refractive index of the hard coat layer 12.

The dynamic friction coefficient of the surface of the antireflection layer 11 disposed on the outermost surface of the hard coat film with adhesive layer is preferably 0.05 to 0.30, and more preferably 0.10 to 0.25. When the dynamic friction coefficient of the surface is 0.05 to 0.30, the slipperiness of the surface of the hard coat film with an adhesive layer can be improved, which can contribute to the prevention of damage. In addition, when used on the touch panel surface, it has good finger slipperiness and is excellent in operation feeling.
In order to set the dynamic friction coefficient in the range of 0.05 to 0.30, it is effective to add particles to the hard coat layer and to make the surface uneven to reduce the contact area with the contact material. It is also effective to use a resin or an additive containing fluorine or siloxane in the antireflective layer.

As one embodiment of the antireflective layer 11, a photocurable low refractive index resin composition containing the following can be used.
(A) Metal oxide fine particles (B) Fluorinated polymer having a polymerizable group and monomer (C) (meth) acrylic monomer (D) photopolymerization initiator (E) solvent This photocurable low refractive index resin composition The product may be used as a commercially available product, or may be used as a mixture of the components (A) to (E). As commercially available products, TU-2361 and TU-2360 (both manufactured by JSR Corporation) can be used.

The metal oxide fine particles (A) may be particles in which the metal oxide fine particles (A1) and an organic compound (A2) containing a polymerizable group are bonded. The bonding may be covalent bonding or non-covalent bonding such as physical adsorption. As a slurry of metal oxide fine particles modified with a polymerizable organic compound, organosilica sols PGM-AC-2140Y and PGM-AC-4130Y (both are manufactured by Nissan Chemical Industries, Ltd.), Adoma Nano YA010C-SM1 and YA050C-SM1 (both Any of them can be used by Admatex Co., Ltd. and the like. The metal oxide fine particles (A) are preferably those obtained by combining (A1) and (A2) in consideration of the dispersibility of the particles and the strength of the coating film, but they are necessarily obtained by combining (A2). It does not have to be.
As the fluorine-containing polymer having a polymerizable group and the monomer (B), Defensa OP-3803 (manufactured by DIC Corporation), low refractive index fluorine monomer LINC-202UA, LINC-152EPA (all manufactured by Kyoeisha Chemical Co., Ltd.) Can be used.
As the (C) (meth) acrylic monomer, the (D) photopolymerization initiator, and the (E) solvent, the same ones as used in the preparation of the hard coat layer can be used.

Examples of the metal oxide fine particles (A1) include titanium oxide, silica, alumina, zirconia, zinc oxide, germanium oxide, indium oxide, tin oxide, antimony-containing tin oxide (ATO), tin-containing indium oxide (ITO), and oxide Particles of antimony, cerium oxide and the like can be mentioned. In particular, amorphous silica is preferable because it is easy to adjust the high hardness and the refractive index to a lower value.
The volume average particle diameter of the metal oxide fine particles (A1) is preferably 5 to 70 nm, and is preferably 30 to 60 nm in consideration of the thickness after curing.
The shape of the metal oxide fine particles (A1) is spherical, hollow, porous, rod-like (a shape having an aspect ratio of more than 1 and 10 or less), plate-like, fiber-like or indeterminate shape, preferably It has a spherical shape, an irregular shape, a rod shape, and a hollow shape capable of reducing the refractive index, which can impart coating film strength. As the hollow silica, available are Silinax series (manufactured by Nittetsu Mining Co., Ltd.) and Thruria series (manufactured by JGC Catalysts Chemical Co., Ltd.).

The content of (A) in the antireflective layer is preferably 10 to 80% by weight, more preferably 20 to 60% by weight. In order to express the function of (A), 10% by weight or more is preferable, and in order to maintain good coating film strength and good adhesion to the lower layer, 80% by weight or less is preferable. The content of the photopolymerization initiator (D) is preferably 0.1 to 10% by weight in the antireflective layer. If the content is 0.1% by weight or more, curing failure hardly occurs, and if the content is 10% by weight or less, it is difficult to cause coloring and the like. The content of the solvent (E) is preferably 80% by weight to 99% by weight based on the total weight of the coating solution. If it is 80% by weight or more, the viscosity of the coating solution is not too high, and it is possible to form a uniform thin film of several tens to several hundreds of nm. If it is 99% by weight or less, the viscosity of the coating solution is not too small It is possible to form a uniform thin film of several tens to several hundreds of nm.

[Adhesive layer 13]
The hard coat film with adhesive layer further comprises an adhesive layer 13 on the other side of the hard coat layer / substrate without an antireflective layer. The adhesive layer is not particularly limited as long as it improves the adhesiveness of the hard coat film with adhesive layer.

The adhesive layer can be formed using various materials generally used as an adhesive. As an example, an acrylic adhesive, a urethane adhesive, an olefin adhesive, a rubber adhesive, a silicone adhesive, and a polyester adhesive can be mentioned. As products, SK dyne series (made by Soken Chemical Co., Ltd.), Finetack series (DIC, made), LKG series (made by Fujikura Kasei Co., Ltd.), coponyl series (made by Japan Synthetic Chemical Industry Co., Ltd.), etc. Is available.

Among these, removable pressure-sensitive adhesives are preferable in terms of ease of handling. Examples of the releasable pressure-sensitive adhesive include those obtained by adjusting the tackiness by performing silicone modification or fluorine modification on the above-mentioned pressure-sensitive adhesive, or those using a flexible polymer having self-adhesiveness.
In the case where it is attached within the manufacturing process of the display device and there is no need to re-peel, an acrylic pressure-sensitive adhesive which is high in transparency and can increase adhesion can be preferable.

As self-adhesive flexible polymers, mention may be made of those consisting of rubbers, elastomers or plastomers. Examples of the rubber include natural rubber, silicone rubber, ethylene propylene rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, chloroprene rubber, acrylic rubber, fluorine rubber and urethane rubber. As elastomers, polyester-based, polyamide-based and polyolefin-based thermoplastic elastomers can be mentioned. As plastomers, mention may be made of polyolefin plastomers. These flexible polymers may be used alone or in combination of two or more. Among these, polyolefin-based thermoplastic elastomers are preferable in terms of cost and processability.

Each of the above-mentioned pressure-sensitive adhesives or flexible polymers can contain various functionalizing agents, stabilizers, and the like as long as the transparency is not impaired. In addition, a tackifier can be blended to enhance the adhesion. Moreover, according to each resin, it can be set as a crosslinked structure using crosslinking agents, such as an isocyanate, an epoxy, and a double bond containing compound.

The adhesive layer 13 can also be formed using an adhesive (OCA, Optical Clear Adhesive) of a type in which both surfaces are laminated with a release film. As a product, transparent adhesive sheet LUCIACS series for optics (made by Nitto Denko Corp.), highly transparent double-sided tape 5400A series (made by Sekisui Chemical Co., Ltd.), optical adhesive sheet Opperia series (made by Lintec Co., Ltd.), SANCUARY series (Manufactured by San-A Co., Ltd.), optically transparent adhesive OAD series (manufactured by Toyo Packing Materials Co., Ltd.), coreless double-sided tape RA series for optical use (manufactured by Sumiron), Panaclean series (manufactured by PANAK Co., Ltd.) Etc. are available.

The thickness of the adhesive layer is preferably 5 to 20 μm, more preferably 6 to 19 μm, still more preferably 8 to 18 μm, and particularly preferably 10 to 15 μm. If the thickness of the adhesive layer is 5 μm or more, the adhesiveness can be sufficiently maintained, and if it is 20 μm or less, it can contribute to the improvement of the surface hardness of the hard coat film with an adhesive layer.

It does not specifically limit as a manufacturing method of an adhesion layer, The well-known method used for manufacture of an adhesive tape etc. is employable. Specifically, a method of coating the substrate 10 with a paint of a pressure-sensitive adhesive composition in which the components forming the above-mentioned pressure-sensitive adhesive layer are dissolved or dispersed in a suitable organic solvent or water, and drying and curing The components forming the pressure-sensitive adhesive layer, double bond-containing monomers, oligomers, crosslinking agents and the like are applied to the substrate 10 without solvent, and then cross-linked by radiation etc., formed by any method such as extrusion lamination method can do.
In the case of using OCA, a pressure-sensitive adhesive layer with a release film can be formed by peeling off the release film on the light release side of the OCA and bonding the adhesive surface to the base of the hard coat film.

[Peeling film]
A release film (not shown) is preferably laminated on the adhesive layer 13. By laminating the release film, it is possible to prevent the adhesion layer from adhering to something other than the adherend when the hard coat film with the adhesion layer is not in use. The thickness of the release film is not particularly limited, and can be appropriately determined.

As the release film, a film obtained by coating a substrate with a release agent such as silicone-containing resin, fluorine-containing resin, amino resin, wax, polyolefin, etc., or only the substrate can be appropriately adopted according to the adhesive layer. Moreover, a commercially available peeling film can also be used. As the substrate, paper, PET, polyethylene, polypropylene, polystyrene or the like is used. The release film may be provided with a guide line for cutting out in accordance with the size, shape, etc. of the display of the display device.

[Easy adhesion layer]
An easily adhesive layer may be provided between the substrate 10 and the hard coat layer 12 and between the substrate 10 and the adhesive layer 13.

The easy adhesion layer preferably has an interference reducing function from the viewpoint of suppressing the interference due to the reflected light. In order to exert an interference reduction function, the easy adhesion layer is thinly coated, the refractive index of the easy adhesion layer is made closer to the refractive index of the substrate 10 or the refractive index of the hard coat layer, the highest refractive index of the substrate 10 There is a method of providing a refractive index which is intermediate between the refractive index in the direction and the refractive index of the hard coat layer. Alternatively, the refractive index of the easily bonding layer may be intermediate between the refractive index in the direction of the highest refractive index of the substrate 10 and the refractive index in the direction of the lowest refractive index. The refractive index of the easily bonding layer can be adjusted by a known method, and can be easily adjusted, for example, by adding titanium, zirconium, or other metal species to the binder resin.

[Hard coat film with adhesive layer]
The hard coat film with adhesive layer preferably has a luminous reflectance of 2.0% or less, more preferably 1.2% or less, in a wavelength range of 380 to 780 nm. Within this range, glare and glare of external light can be further suppressed.
Furthermore, the haze of the hard coat film with adhesive layer is 0.1 to 20%, preferably 2 to 20%, and more preferably 3 to 10%. Reflection can be further suppressed as it is 0.1% or more. If it is 20% or less, it is possible to prevent the displayed image from being blurred.
In the hard coat film with adhesive layer, when the adhesive layer is exposed, the light is diffused by the unevenness of the adhesive layer, and the haze becomes larger than in the pasted state. Therefore, the haze value described herein is a value measured in a state in which the adhesive surface is attached to a haze glass of 0.5% or less of haze so as to simulate actual use conditions.

The hard coat film with adhesive layer may have a functional layer on the other surface side (between the equipment 10 and the adhesive layer 13) of the substrate 10 without the hard coat layer 12 / antireflection layer 11. For example, a printable layer can be mentioned. The printable layer is a curable resin and is formed of an acrylic compound having at least one of a hydroxyl group, a carboxyl group, a polyethylene glycol chain, and a polypropylene glycol chain. The printable layer preferably has a surface free energy of 30 to 50 mN / m, preferably 35 to 45 mN / m, depending on the functional group (or polymer chain) contained in the curable resin. The ink to be printed is not particularly limited. The refractive index of the printable layer is 1.30 to 1.70, preferably 1.40 to 1.60. The film thickness of the printable layer is 0.5 to 5.0 μm, preferably 2.0 to 4.0 μm. By providing a printable layer, it becomes a hard coat film with an adhesive layer which prevents reflection and reflection and has printability.

«Image display device 2»
An image display apparatus 2 according to a second embodiment of the present invention will be described with reference to FIG. The image display device 2 includes the hard coat film 1 with an adhesive layer according to the present invention, and an image panel 15 for displaying an image projected by mechanical processing. Examples of the image panel 15 include a liquid crystal display, an organic EL display, a plasma display, and the like. Specifically, they are mobile phones, tablet terminals, personal computers, televisions, PDAs, electronic dictionaries, car navigation systems, music players, game machines, digital cameras, digital video cameras, and the like.
As shown in FIG. 2, the hard coat film 1 with an adhesive layer is placed on the image panel 15 so that the antireflection layer 11 (see FIG. 1) is on the outside. In FIG. 2, since the window frame 14 of the display is exaggerated, there is a space between the central portion of the image display device 2, that is, the hard coat film 1 with the adhesive layer and the image panel 15. The hard coat film 1 with a layer is closely placed on the image panel 14. Specifically, the hard coat film with an adhesive layer can be attached uniformly by the adhesive force of the adhesive layer by placing the adhesive layer on the front of the screen of the image panel as an adherend and pressing it by hand. It is also possible to attach by a dedicated device within the image panel manufacturing process.
By sticking the hard coat film with the adhesive layer of the present invention on the screen of the image panel, the visibility of the screen at the time of wearing the polarized sunglasses can be improved, and the scratch resistance of the screen at the time of touch panel operation can be improved.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the contents described in the following examples.

First, measuring methods of various physical properties and the like will be shown.

<Retardation>
The in-plane retardation of the base film was measured using an ellipsometer (manufactured by JA Woollam Japan Co., Ltd.). Since the retardation depends on the wavelength of light, the value at 589 nm was used. The retardation is defined as the product of the film thickness and the absolute value of the refractive index difference between the fast axis and the slow axis.

<Tensile modulus>
The tensile modulus of elasticity was measured using a tensile tester (AUTOGRAPH AGS-X, manufactured by Shimadzu Corporation) according to the standards of JIS K 7161 and JIS K 7127. The measurement was performed for the film flow direction (MD) and the width direction (TD), respectively. However, for a film-shaped sample, the range of strain for which the tensile modulus of elasticity is determined is not specified, so the slope was determined in the 0.2 to 1.0% strain region where the stress-strain curve is a straight line. The width of the sample was 10 mm, and the tensile speed was 5 mm / min.

<Thickness of Hard Coat Layer and Antireflection Layer>
The specular reflectance spectrum of the surface (hard coat layer or antireflective layer) was measured using a reflection spectral film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.). The film thickness was determined by the least squares method using the film thickness as a fitting parameter, using the measured value of the specular reflectance and the theoretical formula.

<Visual reflectance>
The absolute specular reflectance spectrum in the wavelength range of 380 to 780 nm is measured using a reflection spectral film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.), and the luminous reflectance (stimulus value) is obtained based on the following equation. Y) was calculated.

Where λ represents the wavelength (nm) of visible light, S (λ) is the light of D65 light source defined by CIE, y (λ) is the color matching function of 2 ° field of view defined by CIE, R (λ) ) Is an absolute specular reflectance measured by a reflection spectral film thickness meter.

<Gross>
As an index of the glossiness of the film, the gloss at an incident angle of 60 ° was measured using a gloss meter (VG-7000, manufactured by Nippon Denshoku Kogyo Co., Ltd.) according to the standard of JIS Z 8741. In addition, in order to prevent reflection of measurement light from the side (film back side) opposite to the side where the hard coat layer of the film and the antireflection layer are formed, black PET film (NE-B50S +, manufactured by Niei Kako Co., Ltd.) on the film back side ) Was attached and the measurement was performed.

<Image sharpness>
As an index of the degree of reflection to the display, according to the standard of JIS K 7374, using an image clarity measuring instrument (ICM-1T, Suga Test Instruments Co., Ltd.), the image sharpness in 60.degree. Reflection, comb width 2 mm ( Image clarity was measured. In addition, in order to prevent reflection of measurement light from the side (film back side) opposite to the side where the hard coat layer of the film and the antireflection layer are formed, black PET film (NE-B50S +, manufactured by Niei Kako Co., Ltd.) on the film back side ) Was attached and the measurement was performed.

<Dynamic friction coefficient>
The dynamic friction coefficient was measured using a surface property tester (Heidon 14FW, manufactured by Shinto Scientific Co., Ltd.) in accordance with JIS K 7125. The outermost surfaces (the surface of the antireflective layer or the surface of the hard coat layer) opposite to the adhesive surface were brought into contact with each other (the contact area is 40 cm ² ), a load of 200 gf was applied to the sliding piece, and measurement was performed at a speed of 10 mm / min.

<Liquid crystal display visibility when wearing polarized sunglasses>
Polarizers were placed in a cross nicol arrangement on the surface of a liquid crystal display (LIFEBOOK (trade name) U937 / P, manufactured by Fujitsu Ltd.) using a white LED as a backlight. At this time, light emitted from the liquid crystal display was blocked by the polarizing plate, and the liquid crystal display was not visible at all. Subsequently, the target film was inserted between the surface of the liquid crystal display and the polarizing plate. It was confirmed that there was an angle at which the liquid crystal display could be viewed by rotating the inserted film. The judgment was made as follows.
A: When the target film is inserted at a certain angle, the liquid crystal display can be viewed without problems.
B: When the target film is inserted at a certain angle, the liquid crystal display is visible, but rainbow unevenness occurs.
C: The liquid crystal display can not be viewed no matter which angle the target film is inserted at.

<Thickness of adhesive layer>
Using a contact-type film thickness meter (DIGIMICRO MFC-101A, manufactured by Nikon Corporation) with the film attached to blue sheet glass with a thickness of 1.8 mm via the adhesive layer, the adhesive layer based on the glass surface The thickness of the whole film including the substrate, the easy adhesion layer, the hard coat layer and the antireflective layer was measured. Subsequently, the thickness of the film (substrate, easy adhesion layer, hard coat layer, antireflective layer) in the non-adhesive processed state is measured by the same device, and this value is subtracted from the thickness of the entire film to form an adhesive layer. The thickness of was calculated.

<Pencil hardness>
With the film attached to the glass via the adhesive layer, using a scratching hardness (pencil method) tester (KT-VF2380, manufactured by Cortec Co., Ltd.) in accordance with the standard of JIS K 5600-5-4. , Pencil hardness test was done. The hardness of the pencil was 3 H, the load was 750 gf, and the film was scratched 5 times each in the machine direction (MD) and the transverse direction (TD). The evaluation results were divided into MD and TD and judged as follows.
A: 0 or 1 scratched B: 2 or 3 scratched C: 4 or 5 scratched

<Total ray transmittance>
As an index of the film transparency, the total light transmittance was measured using a haze meter (NDH-5000SP, manufactured by Nippon Denshoku Kogyo Co., Ltd.) according to the standard of JIS K 7361-1. The measurement was performed in a state where the target film was attached to a 1.8 mm thick blue sheet glass via the adhesive layer.

<Haze>
The haze was measured using a haze meter (NDH-5000SP, manufactured by Nippon Denshoku Kogyo Co., Ltd.) as an index of the degree of cloudiness of the film, in accordance with the standard of JIS K 7136. The measurement was performed in a state where the target film was attached to a 1.8 mm thick blue sheet glass via the adhesive layer.

<Particle size>
The particle diameter of the fine particles was measured using a laser diffraction / scattering particle size distribution measuring device (LA-950V2, manufactured by Horiba, Ltd.). The prepared coating solution was diluted with propylene glycol monomethyl ether and measured to obtain a volume average particle size and a particle size distribution. In the laser diffraction / scattering type particle size distribution measuring device, when the shape of the particles is not spherical, the particle size is determined as the particle size of spherical particles having the same light scattering characteristics as the particles to be measured.

<Dynamic hardness>
A mixture of a hard coat resin, a polymerization initiator, and a solvent, which does not contain fine particles and a leveling agent, was applied onto a 0.7 mm thick glass substrate such that the thickness after drying was 5 μm. After drying at 80 ° C. for 2 minutes, ultraviolet curing was performed at 300 mJ / cm ² of integrated light quantity (UVA) using a high pressure mercury lamp under a nitrogen atmosphere. The dynamic hardness (DHT115-1) of the cured film was measured using a dynamic ultra-microhardness tester (DUH-W201S, manufactured by Shimadzu Corporation). For the measurement, using a Triangular 115 indenter, a load-unload test with a test force of 5 mN, a load speed of 0.2844 mN / s, and a holding time of 10 s was performed. DHT115-1 is calculated by the following equation. In addition, since a dynamic ultra-micro hardness tester measures the hardness of a micro area | region, it is not suitable for the measurement of a cured film with an unevenness | corrugation on the surface.
(DHT115-1) = 3.8584P / D ²
However, P is a test force (mN), and D is a pressing depth (μm).

<Refractive index>
A thin film was formed on a glass substrate by spin coating, dried in an oven, and then irradiated with ultraviolet light to obtain a cured film for measuring the refractive index. The thickness of the cured film was measured using a surface roughness measuring device (Alpha step IQ, manufactured by KLA Tencor Co., Ltd.). Furthermore, the absolute reflectance spectrum of the cured film was measured using a reflection spectral film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.). The refractive index was determined by the least squares method using the measured value of the absolute reflectance and the theoretical formula and using the refractive index as a fitting parameter, contrary to the time of film thickness measurement. Although the refractive index is dependent on the wavelength of light, a value of 589 nm was used. However, since a thin film containing fine particles having a particle size of more than 100 nm is not smooth on the surface, it is difficult to accurately measure the refractive index of a cured film containing particles of more than 100 nm by this method.

Next, the preparation method of the photocurable resin composition (coating liquid) for hard-coat layer formation is shown.

Preparation of Photocurable Resin Composition A (Coating Liquid) Mixture of photopolymerizable acrylic ester oligomer and monomer: 30.6% by weight, photopolymerization initiator: 2.2% by weight, fine silica particles: 7. 2% by weight, 49.8% by weight of propylene glycol monomethyl ether, 7.7% by weight of butyl acetate, and 2.5% by weight of propylene glycol monomethyl ether acetate are mixed, and after stirring by a disper, the dispersion of silica fine particles is carried out with a bead mill. Done and filtered through a filter. Further, to 100 parts by weight of this mixed solution, 0.05 parts by weight of a leveling agent BYK-3550 was added before coating and sufficiently stirred to obtain a photocurable resin composition A. The volume average particle size of the silica fine particles in the obtained photocurable resin composition was measured using a laser diffraction / scattering type particle size distribution measuring apparatus. The volume average particle size of the silica fine particles was 0.6 μm.
The refractive index of only the resin (hard binder) of the hard coat layer is 1.52, and the refractive index of the silica fine particles is 1.46, so the apparent refraction of the hard coat layer formed from the photocurable resin composition A The rate is considered to be between 1.46 and 1.52. In addition, a photocurable resin composition containing no silica fine particles and a leveling agent was applied, dried and cured, and the dynamic hardness (DHT115-1) was measured to be 35.

Preparation of photocurable resin composition B (coating liquid) Mixture of photopolymerizable acrylic ester oligomer and monomer: 31.8% by weight, photopolymerization initiator: 1.4% by weight, acrylic resin fine particles (ENEOS Unipowder Submicron grade, volume average particle diameter 0.5 μm, manufactured by JX Energy Co., Ltd .: 5.6% by weight, propylene glycol monomethyl ether: 58.8% by weight, 2.4% by weight propylene glycol monomethyl ether acetate Mix and stir with a disper. A photocurable resin composition B was obtained by further adding 0.05 parts by weight of a leveling agent BYK-3550 to 100 parts by weight of this mixed solution before coating and sufficiently stirring.
The refractive index of the binder resin in the hard coat layer is 1.52, and the refractive index of the acrylic resin fine particles is 1.49, so the apparent refractive index of the hard coat layer formed from the photocurable resin composition B is It is considered to be between 1.49 and 1.52. In addition, a photocurable resin composition not containing acrylic resin fine particles and a leveling agent was applied, dried and cured, and the dynamic hardness (DHT115-1) was measured to be 35.

Furthermore, the preparation method of the photocurable low refractive index resin composition (coating liquid) for anti-reflective layer formation is shown.

Preparation of photocurable low refractive index resin composition C (coating liquid) fluorinated polymer containing ethylenic unsaturated group, metal oxide fine particles combined with organic compound having polymerizable unsaturated group (hollow silica), 25 wt% of a photocurable low refractive index resin composition (TU-2361, manufactured by JSR Corporation), which is a mixture of a (meth) acrylic monomer, a photopolymerization initiator and a solvent, is diluted with 75 wt% of a solvent, This was designated as photocurable low refractive index resin composition (coating liquid) C. It was 47 nm when the volume average particle diameter of metal oxide fine particles (silica) was measured using a laser diffraction / scattering type particle diameter distribution measuring apparatus. Moreover, the refractive index of the reflection preventing layer formed from the photocurable low-refractive-index resin composition C was 1.35.

Preparation of photocurable low refractive index resin composition D (coating liquid) Photocurable low refractive index resin composition which is a mixture of metal oxide fine particles (hollow silica), acrylic resin, photopolymerization initiator, solvent and the like A 20% by weight solution (RL-5, manufactured by KSM Co., Ltd.) was diluted with 80% by weight of a solvent and stirred to obtain a photocurable low refractive index resin composition D. The refractive index of the antireflective layer formed from the photocurable low refractive index resin composition D was 1.28.

The compositions of the photocurable resin compositions A to B and the photocurable low refractive index resin compositions C to D prepared above, and the dynamic hardness and refractive index of the resin after curing are summarized in Table 1.

 

Furthermore, a method of producing hard coat films a to g is shown.

Preparation of Hard Coat Film a As a translucent substrate, an 80 μm thick super-birefringent film (SRF, TA048, manufactured by Toyobo Co., Ltd.) which is easily adhered on both sides was used. The photocurable resin composition A (coating solution) was coated on this substrate using a bar coater so that the average film thickness after drying was 4 μm, and then dried in an oven at a temperature of 80 ° C. for 2 minutes. Thereafter, ultraviolet curing was performed with an integrated light amount (UVA) of 300 mJ / cm ² using a high pressure mercury lamp under a nitrogen atmosphere to form a hard coat layer.
Subsequently, a photocurable low refractive index resin composition C (coating liquid) is coated on the surface of the base material on which the hard coat layer is formed using a bar coater so that the average film thickness after drying becomes 90 to 100 nm. After drying, it was dried in an oven at a temperature of 80.degree. C. for 1 minute. Thereafter, photocuring was performed at a cumulative light amount (UVA) of 300 mJ / cm ² using a high pressure mercury lamp in a nitrogen atmosphere to form an antireflective layer.

Preparation of Hard Coat Film b A hard coat film b was prepared in the same manner as the hard coat film a except that the photocurable resin composition B (coating solution) was used as the hard coat layer forming coating solution.

Preparation of Hard Coat Film c A hard coat film c was prepared in the same manner as hard coat film a except that a photocurable low refractive index resin composition (coating solution) D was used as a coating solution for forming an antireflective layer. .

Preparation of Hard Coat Film d A hard coat film d was prepared in the same manner as hard coat film a, except that the antireflective layer was not formed. However, in order to make integrated light quantity the same as what formed the reflection prevention layer, ultraviolet irradiation was performed twice and the integrated light quantity (UVA) was 600 mJ / cm < ² >.

Preparation of Hard Coat Film e A hard coat film e was prepared in the same manner as hard coat film a, except that the photocurable resin composition (coating solution) A was applied so as to have an average film thickness of 7 μm after drying. did.

-Preparation of hard coat film f The same as hard coat film a except that a 100 μm thick polyethylene terephthalate film (U48, manufactured by Toray Industries, Inc.) with easy adhesion processing on both sides was used as a translucent substrate. Hard coat film f was produced.

-Preparation of hard coat film g Hard coat film g in the same manner as hard coat film a except that a triacetyl cellulose film (TD 80 ULM, manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm is used as a translucent substrate. Was produced.

Example 1
As an adhesive layer, an optical adhesive film (PD-S1-10, manufactured by PANAC Co., Ltd.) in which an optical adhesive was sandwiched between two release films was used. The release film on the light release side of the optical adhesive film was peeled off, and the adhesive surface was bonded to the base of the hard coat film a to prepare a hard coat film with an adhesive layer.
Example 2
A hard coat film with a pressure-sensitive adhesive layer was produced in the same manner as in Example 1 except that an optical pressure-sensitive adhesive film (PD-S1-15, manufactured by Panac Corporation) having a different thickness of the pressure-sensitive adhesive layer was used.
Comparative Example 1
A hard coat film with a pressure-sensitive adhesive layer was produced in the same manner as in Example 1 except that optical pressure-sensitive adhesive films (PD-S1, manufactured by PANAK CORPORATION) having different thicknesses of the pressure-sensitive adhesive layer were used.

[Example 3]
In the same manner as in Example 1 except that the hard coat film b was used, a hard coat film with an adhesive layer was produced.
Example 4
In the same manner as in Example 2 except that the hard coat film b was used, a hard coat film with an adhesive layer was produced.
Comparative Example 2
A hard coat film with an adhesive layer was produced in the same manner as in Comparative Example 1 except that the hard coat film b was used.

Comparative Example 3
In the same manner as in Example 1 except that the hard coat film c was used, a hard coat film with an adhesive layer was produced.
Comparative Example 4
A hard coat film with an adhesive layer was produced in the same manner as in Example 2 except that the hard coat film c was used.
Comparative Example 5
A hard coat film with an adhesive layer was produced in the same manner as in Comparative Example 1 except that the hard coat film c was used.

Comparative Example 6
In the same manner as in Example 1 except that the hard coat film d was used, a hard coat film with an adhesive layer was produced.
Comparative Example 7
In the same manner as in Example 2 except that the hard coat film d was used, a hard coat film with an adhesive layer was produced.
Comparative Example 8
A hard coat film with an adhesive layer was produced in the same manner as in Comparative Example 1 except that the hard coat film d was used.

[Example 5]
A hard coat film with an adhesive layer was produced in the same manner as in Example 1 except that the hard coat film e was used.
[Example 6]
In the same manner as in Example 2 except that the hard coat film e was used, a hard coat film with an adhesive layer was produced.
Comparative Example 9
In the same manner as Comparative Example 1 except that the hard coat film e was used, a hard coat film with an adhesive layer was produced.

Comparative Example 10
A hard coat film with an adhesive layer was produced in the same manner as in Example 1 except that the hard coat film f was used.
Comparative Example 11
An adhesive layer-provided hard coat film was produced in the same manner as in Example 2 except that the hard coat film f was used.
Comparative Example 12
In the same manner as Comparative Example 1 except that the hard coat film f was used, a hard coat film with an adhesive layer was produced.

Comparative Example 13
A hard coat film with an adhesive layer was produced in the same manner as in Example 1 except that the hard coat film g was used.
Comparative Example 14
In the same manner as in Example 2 except that the hard coat film g was used, a hard coat film with an adhesive layer was produced.
Comparative Example 15
A hard coat film with an adhesive layer was produced in the same manner as in Comparative Example 1 except that the hard coat film g was used.

The constitutions and measured physical properties of Examples 1 to 6 and Comparative Examples 1 to 15 are shown in Table 2. The retardation and the tensile modulus in Table 2 are values measured only on the substrate having no hard coat layer and no antireflection layer. The physical properties of “after glass attachment” were measured by attaching the adhesive surface of the hard coat film with adhesive layer to blue sheet glass having a thickness of 1.8 mm.

Comparing “Examples 1 to 6 and Comparative Examples 1 to 9” with “Comparative Examples 10 to 15”, when the retardation of the substrate is 5000 to 30000 nm, the liquid crystal display can be viewed with no rainbow unevenness even when wearing polarized sunglasses It is understood that

In Examples 1 and 2 and Comparative Example 1 provided with a hard coat layer containing silica particles, a film having a thin adhesive layer (less than 25 μm) was judged as “A” in the pencil hardness test.
In Examples 3 to 4 and Comparative Example 2 provided with a hard coat layer containing acrylic resin particles, a film having a thin adhesive layer (less than 25 μm) was judged as “A” in the pencil hardness test. In Examples 3 to 4, the image definition is small, and it is difficult for the image to be reflected.
In Comparative Examples 3 to 5 in which the dynamic friction coefficient of the surface exceeds 0.30, "B" or "C" was determined in the pencil hardness test in the MD direction regardless of the thickness of the adhesive layer.
Comparative Examples 6 to 8 which do not have an antireflective layer, that is, Comparative Examples 6 to 8 different from the configuration of the present invention were determined as "B" or "C" in the pencil hardness test in the MD direction regardless of the thickness of the adhesive layer. .
Also in Examples 5 to 6 and Comparative Example 9 in which the thickness of the hard coat layer is different from Examples 1 and 2 and Comparative Example 1, the film having a thin adhesive layer thickness (less than 25 μm) is judged as “A” in the pencil hardness test. It became.

In addition, when the tensile modulus of elasticity of the base material is large (2.6 GPa or more), the dynamic friction coefficient of the surface is 0 when the tensile modulus of elasticity of the base material is compared with the result of the pencil hardness test regardless of Examples and Comparative Examples. .30 or less (TD of Examples 1 to 6, Comparative Examples 1 to 2, 9: Comparative Examples 10 to 12: MD of Comparative Examples 13 to 15), regardless of the thickness of the adhesive layer It turns out that there is sufficient scratch prevention performance. However, when the tensile modulus of elasticity of the substrate is small (2.6 GPa or less) (MDs of Examples 1 to 6 and Comparative Examples 1 to 2 and 9: TD of Comparative Examples 13 to 15), the thickness of the adhesive layer is It is understood that sufficient scratch resistance can be imparted by making the thickness thin (less than 25 μm) and making the coefficient of dynamic friction of the surface 0.30 or less.

All documents, including publications, patent applications and patents cited in the present specification, are specifically indicated by each document individually and are incorporated herein by reference, and all the contents thereof are the same as described herein. To the extent, incorporated herein by reference.

The use of nouns and similar designations used in connection with the description of the invention (in particular in connection with the following claims) is not specifically pointed out herein, or unless it is clearly inconsistent with the context , Both singular and plural. The terms "comprising", "having", "including" and "including" are to be construed as open end terms (ie meaning "including but not limited to") unless otherwise indicated. The recitation of numerical ranges herein is merely intended to serve as a shorthand method of referring individually to each value falling within the range, unless otherwise indicated herein. And each value is incorporated into the specification as if individually listed herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or otherwise obviously inconsistent with the context. Unless otherwise stated, all examples or exemplary phrases (e.g. "such as") used herein are merely intended to better illustrate the invention and provide a limitation on the scope of the invention. is not. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. Modifications of these preferred embodiments will be apparent to one of ordinary skill in the art upon reading the above description. The inventors expect skilled artisans to apply such variations as appropriate, and intend to practice the present invention in ways other than those specifically described herein. . Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Furthermore, any combination of the above-described elements in all variations is also encompassed within the invention, unless otherwise specifically indicated herein or otherwise obviously inconsistent with the context.

DESCRIPTION OF SYMBOLS 1 Hard coat film 2 with adhesive layer 2 Image display apparatus 10 Base material 11 Anti-reflective layer 12 Hard-coat layer 13 Adhesive layer 14 Window frame 15 Image panel

Claims (7)

1. A substrate of a translucent resin film having a retardation of 5000 to 30000 nm;
   A hard coat layer on one side of the substrate;
   An antireflective layer on the side of the hard coat layer opposite to the substrate;
   An adhesive layer on the side opposite to the hard coat layer of the substrate;
   The hard coat layer has a thickness of 3 to 15 μm, and is formed of a curable resin,
   The antireflective layer has a thickness of 50 to 150 nm and a refractive index of 1.20 to 1.40,
   The adhesive layer has a thickness of 5 to 20 μm,
   The dynamic friction coefficient at the outermost surface opposite to the adhesive layer is 0.05 to 0.30.
   Hard coat film with adhesive layer.
2. The tensile modulus of elasticity of at least one direction of the translucent resin film is 1.0 to 2.6 GPa,
   The hard coat film with an adhesive layer according to claim 1.
3. The hard coat layer contains particles,
   The hard coat film with the adhesion layer of Claim 1 or Claim 2.
4. The particles are silica particles,
   The hard coat film with an adhesion layer according to claim 3.
5. An easily adhesive layer in contact with one side or both sides of the substrate;
   The hard coat film with an adhesive layer according to any one of claims 1 to 4.
6. The pencil hardness when pasted on glass is 3H or more,
   The hard coat film with an adhesive layer according to any one of claims 1 to 5.
7. A hard coat film with an adhesive layer according to any one of claims 1 to 6 provided on a screen
   Image display device.

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