TW201307059A - Hard coat film - Google Patents

Abstract

To provide a hard coat film having a simple layer constitution, high pencil hardness (3H or higher), excellent in transmittance image clarity which is suitable as a member of electronic equipments such as various displays or touch screens. Provided is a hard coat film which has a hard coat layer having a thickness of 7 to 14 μ m formed on one face of a transparent base film by curing a hard coat layer forming material containing a monomer having 3 to 6 functionality and, as an inorganic component, 35 to 65 % by mass of organic-modified silica fine particles based on the solid content of the material. The hard coat film has following characteristics: (1) an arithmetic mean surface roughness Ra of the surface of the hard coat layer determined in accordance with JIS B 0601-1994 is 0.008 μ m or less, (2) an arithmetic mean surface roughness Ra of the surface of the transparent base film opposite the side of the hard coat layer determined in accordance with JIS B 0601-1994 is 0.01 to 0.05 μ m, and (3) a transmittance image clarity defined as a sum of image clarities in transmittance determined for 5 kinds of slits (width of slits: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm and 2 mm) in accordance with JIS K 7374: 2007 is 450 or larger.

Description

Hard coating

The present invention relates to a hard coat film, and more particularly relates to a hard pencil (3H or more), and has process suitability and excellent transmission image clarity, and is suitable as a member of electronic devices such as various display devices or touch panels. Coating film.

Hard coating films are mainly used for display surfaces, but in recent years, they have become more and more widely used in mobile devices such as touch panels. The display for a touch panel is required to have different performance requirements than a general display. In particular, since it is often carried and brought into contact with a hard coated surface, it is strongly desired to increase the surface hardness. The technical department to improve the surface hardness has been discussed in the past. For example, in the methods of Patent Documents 1 and 2, a buffer layer or a hard coat layer having a low hardness is provided on the underlayer of the hard coat layer to achieve high pencil hardness. However, since this method forms a multilayer structure, occurrence of appearance defects such as interference fringes or improvement in manufacturing cost is a concern. In addition, a high pencil hardness can be obtained only by thickening the hard coat layer, but in this case, there is a problem that the bendability is lowered, the tailoring workability, or the press workability is lowered.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. 11-300873

Patent Document 2 Japanese Patent Laid-Open Publication No. 2007-219013

The present invention is carried out under such circumstances, which is simple in providing a layer structure, high in pencil hardness (3H or more), processing suitability, and excellent in transmission image definition, and is suitable as various display devices or touch panels. A hard coat film of a member of an electronic device is used for the purpose.

The inventors of the present invention have repeatedly conducted intensive studies in order to achieve the above object, and have obtained the following findings. The pencil hardness of the hard coat film was measured by a pencil scratch hardness tester in accordance with JIS K 5600-5-4. In this case, the hard coat film is placed on the surface of the hard material such as glass, and the hard coat film is placed on the surface of the hard material such as glass, and the member is tilted to 45 degrees at a speed of 1 mm/sec while applying a predetermined load to the pencil scratch member. Perform the operation of scratching the surface of the hard coat layer.

At this time, it was found that if the surface of the hard material is in close contact with the surface of the substrate of the hard coat film and the film is not deflected, the load of the scratch member is applied to the surface of the hard coat layer, and the hardness of the pencil is lowered. When the coating film is not in close contact with the surface of the hard material and has deflection, the pencil hardness is improved.

As a result of further investigation based on the above findings, the present inventors have found that the hard coat layer forming material having a specific composition is cured on one surface of the transparent base film to form an arithmetic mean roughness Ra having a surface of 0.008 μm or less. a hard coat layer having a predetermined thickness, and by setting the arithmetic mean roughness Ra of the surface on the opposite side to the hard coat layer of the transparent base film to a specific range, a pencil having high transmission image clarity and a pencil can be obtained. A hard coat film having a hardness of 3H or more.

The present invention has been completed based on these findings.

That is, the present invention provides the following invention: [1] A hard coat film having a hard coat layer having a thickness of 7 to 14 μm on one side of a transparent base film, which is made to contain a 3-6 functional monomer. And a hard coat forming material of the organically modified vermiculite particles, wherein the hard coat layer forming material is contained in a ratio of 35 to 65 mass%, and the organic modified vermiculite particles are used as an inorganic component in the solid matter. The hard coat film is characterized in that (1) the arithmetic mean roughness Ra of the surface of the hard coat layer measured according to JIS B 0601-1994 is 0.008 μm or less, and (2) the transparent base film measured according to JIS B 0601-1994. The arithmetic mean roughness Ra of the surface on the opposite side of the hard coat layer is 0.01 to 0.05 μm, and (3) for 5 kinds of slits (slit width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) in accordance with JIS K 7374:2007, the transmission image resolution expressed by the total value of the image clarity by the transmission method is 450 or more; [2] The hard coat film of the above [1], wherein the 3-6 functional monomer (3) The hard coat film of the above [1] or [2], wherein the haze value measured according to JIS K 7136 is 2 [4] The hard coat film according to any one of the above [1] to [3], which is used as a member for a touch panel; and [5] a hard coat film according to [4] above, Among them, the touch panel is a resistive film type.

According to the present invention, it is possible to provide a hard coat film which has a simple layer structure and a high pencil hardness (3H or more), and has process suitability and excellent transmission image definition, and is suitable as an electronic device of various display devices or touch panels. Components.

The hard coat film of the present invention is a hard coat layer having a thickness of 7 to 14 μm which is formed by hardening a hard coat material comprising a 3-6 functional monomer and an organically modified vermiculite particle on one side of a transparent base film. The hard coat layer forming material contains the organically modified vermiculite particles in an amount of 35 to 65 mass% as an inorganic component in the solid matter, and is characterized by an arithmetic mean of the surface of the hard coat layer measured in accordance with JIS B 0601-1994. The roughness Ra is not more than 0.008 μm, and the arithmetic mean roughness Ra of the surface opposite to the hard coat layer of the transparent base film measured in accordance with JIS B 0601-1994 is 0.01 to 0.05 μm, and is for 5 slits (slits). Width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) The transmission image resolution expressed by the total value of the image clarity by the transmission method was 450 or more in accordance with JIS K 7374:2007.

[Transparent substrate film]

The transparent base film used in the hard coat film of the present invention is not particularly limited, and can be appropriately selected from those conventionally known as a base material for an optical hard coat film. Examples of such a plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene film, and polypropylene. Film, cellophane, diacetyl cellulose film, triethylene fiber Film, cellulose acetate butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate film, polystyrene film, polycarbonate film, polymethyl pentylene Alkene film, polyfluorene film, polyetheretherketone film, polyether fluorene film, polyether quinone film, polyimide film, fluororesin film, polyamide film, acrylic resin film, norbornene resin A plastic film such as a film norbornene resin film or a cycloolefin resin film.

These plastic films can be colored or uncolored, and can be appropriately selected depending on the use. For example, when it is used for the protective use of a liquid crystal display, it is suitable as a colorless transparent film.

The thickness of these plastic films is not particularly limited and may be appropriately selected depending on the case, and is usually in the range of 15 to 300 μm, preferably 30 to 200 μm. Further, in order to improve the adhesion to the layer provided on the surface of the plastic film, surface treatment may be performed on one side or both sides by an oxidation method, an unevenness method, or the like as desired. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), hot air treatment, and ozone. For the embossing method, for example, a blasting method, a solvent treatment method, or the like is exemplified. These surface treatment methods can be appropriately selected depending on the type of the plastic film, and it is generally preferred to use a corona discharge treatment method from the viewpoints of effects and workability. Alternatively, a primer layer may be provided on the surface of the hard coat layer.

[hard coating forming material]

In the hard coat film of the present invention, a hard coat layer obtained by curing a hard coat layer forming material is provided on one surface of the transparent base film.

The hard coat layer forming material contains 3 to 6 functional monomers and organically modified vermiculite particles as essential components.

(3~6 functional monomer)

In the present invention, the 3-6 functional single system refers to a monomer compound having 3 to 6 ethylenically unsaturated groups in the molecule and crosslinked and hardened by irradiation with an active energy ray, preferably (meth) Acrylate monomer.

Further, the active energy ray means an energy quantum among electromagnetic waves or charged particle rays, that is, ultraviolet rays or electron beams.

Further, the (meth) acrylate monomer means both an acrylate monomer and a methacrylate monomer. Below, similar terms are also the same.

Examples of the 3-6 functional (meth) acrylate monomer include stilbene (2-propenyl methoxyethyl) isomeric cyanurate and stilbene (3-acryloxypropyl) heterotrimer. Cyanate, ginseng (2-methacryloxyethyl) isomeric cyanurate, ginseng (3-methylpropenyloxypropyl) isocyanurate, etc. [(methyl) ) acryloxyalkyl]isocyanurate, and trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tris(methyl) Acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, propionic acid modified dipentaerythritol penta (methyl) A (meth) acrylate such as acrylate, dipentaerythritol hexa(meth) acrylate or caprolactone modified dipentaerythritol hexa(meth) acrylate. These may be used alone or in combination of two or more. Among these, a 3 to 4-functional (meth) acrylate monomer is preferable.

(organic modified vermiculite particles)

In the hard coat layer forming material, the organically modified vermiculite particles as an essential component mean the vermiculite particles modified with the surface of the organic compound having a polymerizable unsaturated group.

The vermiculite particles modified with the surface of the organic compound having a polymerizable unsaturated group, for example, can be usually obtained by the surface of the vermiculite particles having an average particle diameter of usually about 0.5 to 500 nm, preferably an average particle diameter of 1 to 100 nm. The stanol group is obtained by reacting with an organic compound containing a polymerizable unsaturated group, and the organic compound containing a polymerizable unsaturated group is a (meth) propylene oxime having a functional group reactive with the stanol group. base.

As the polymerizable unsaturated group-containing organic compound having a functional group reactive with a stanol group, for example, a compound represented by the formula (1) is preferably used.

(wherein R ¹ is a hydrogen atom or a methyl group, and R ² is a halogen atom or -OCH ₂ CH ₂ NCO, a group represented by -OCH ₂ CH ₂ OH, -OH, -O(CH ₂ ) ₃ -Si(OCH ₃ ) ₃ . ).

As such a compound, for example, acrylic acid, acrylonitrile chloride, 2-isocyanate ethyl acrylate, glycidyl acrylate, 2,3-iminopropyl acrylate, 2-hydroxyethyl acrylate, acryloxy group can be used. A methacrylic acid derivative such as propyltrimethoxydecane or the like and an acrylic acid derivative thereof. These acrylic acid derivatives or methacrylic acid derivatives may be used singly or in combination of two or more.

An active energy ray-sensitive composition containing a compound obtained by combining an organic compound having a polymerizable unsaturated group in the form of a vermiculite particle, for example, is commercially available under the trade names "Opstar Z7530" and "Opstar Z7524" manufactured by JSR Corporation. , "Opstar TU4086" and so on.

In the present invention, the vermiculite particles which have been surface-modified with the organic compound having a polymerizable unsaturated group, as the inorganic component, must be contained in the hard coat layer forming material in a ratio of 35 to 65 mass%. The solid matter is preferably contained in a ratio of 38 to 62% by mass. If the content of the aforementioned organically modified vermiculite particles is in the above range, the arithmetic mean roughness Ra of the surface of the hard coat layer can be maintained below 0.008 μm, and the pencil hardness of the hard coat layer is increased.

Further, the primary average particle diameter of the vermiculite particles modified with the surface of the organic compound having a polymerizable unsaturated group can be measured by a Coulter counter method. The organically modified vermiculite particles are crosslinked and hardened together with the aforementioned 3-6 functional monomers by irradiation with an active energy ray.

((meth)acrylate prepolymer)

In the hard coat layer forming material, a (meth) acrylate type prepolymer may be contained together with the above-mentioned 3-6 functional monomer and organically modified vermiculite fine particles in the range which does not impair the effect of this invention.

Examples of the (meth) acrylate-based prepolymer include polyester acrylates, epoxy acrylates, urethane acrylates, and polyol acrylates. Here, as the polyester acrylate type prepolymer, for example, a hydroxyl group of a polyester oligomer having a hydroxyl group at both terminals obtained by condensing a polyvalent carboxylic acid and a polyhydric alcohol can be used as (meth) propyl group. The olefin is esterified or obtained by (meth)acrylation by a hydroxyl group at the terminal of the oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid.

The epoxy acrylate prepolymer can be obtained, for example, by reacting and esterifying (meth)acrylic acid in an oxirane ring of a lower molecular weight bisphenol type epoxy resin or a novolak type epoxy resin. . The urethane acrylate prepolymer can be obtained, for example, by esterifying an urethane urethane oligomer with (meth) acrylate, the polyurethane urethane oligomer by The reaction of a polyether polyol or a polyester polyol with a polyisocyanate is obtained. Further, the polyol acrylate prepolymer can be obtained by esterifying a hydroxyl group of a polyether polyol with (meth) acrylate. These prepolymers may be used alone or in combination of two or more.

(photopolymerization initiator)

Preferably, in the hard coat layer forming material, a photopolymerization initiator may be contained as desired. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, and benzoin isobutyl ether. Acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxyl -2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-iforolin- Propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4'-diethyl Amino benzophenone, dichlorobenzophenone, 2-methyl hydrazine, 2-ethyl hydrazine, 2-tributyl fluorene, 2-amino hydrazine, 2-methyl thioxanthone , 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ketal, acetophenone Dimethyl ketal, p-dimethylamino benzoate, and the like.

These may be used alone or in combination of two or more kinds, and the content thereof is usually selected from the range of 0.2 to 10 parts by mass based on 100 parts by mass of the solid matter of the total active energy ray-curable compound.

(Preparation of hard coat forming material)

The hard coat layer forming material may be prepared by using the aforementioned 3-6 functional monomer, organically modified vermiculite particles, and a (meth)acrylate prepolymer or photopolymerization initiator used as desired. And various added components, such as antioxidants, ultraviolet absorbers, infrared absorbers, antistatic agents, photosensitizers, leveling agents, antifoaming agents, etc., respectively, added, dissolved or dispersed in a suitable solvent in a predetermined ratio preparation.

Examples of the solvent to be used in this case include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane and dichloroethane, and methanol, ethanol, and C. Alcohol, butanol and other alcohols, acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone and other ketones, ethyl acetate, butyl acetate and other esters, ethyl cellosolve and other cellosolve solvents, An ether solvent such as propylene glycol monomethyl ether or the like.

The concentration and viscosity of the hard coat layer forming material prepared in this manner are not particularly limited as long as they are coatable, and may be appropriately selected depending on the case.

[Formation of hard coating]

The hard coat layer is formed by applying a conventionally known method such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like on one surface of the transparent base film described above. A coating film is formed by the material, and after drying, the active energy ray is irradiated to harden the coating film to form a hard coat layer.

Examples of the active energy ray include ultraviolet rays, electron beams, and the like. The ultraviolet light is obtained by a high-pressure mercury lamp, an electrodeless lamp, a metal halide lamp, a xenon lamp, or the like, and the irradiation amount is usually 100 to 500 mJ/cm ² . On the other hand, the electron beam is obtained by an electron beam accelerator or the like, and the irradiation amount is usually 150~350kV. Among the active energy rays, ultraviolet rays are preferred. Further, in the case of using an electron beam, it is possible to obtain a cured film without adding a photopolymerization initiator.

[Characteristics of hard coating]

The hard coat layer thus formed must have a thickness in the range of 7 to 14 μm. When the thickness is less than 7 μm, sufficient pencil hardness cannot be obtained. On the other hand, when it exceeds 14 μm, there is a problem that the bendability is lowered, the tailoring workability, and the press workability are lowered. The thickness is more preferably 8 to 13 μm.

Further, the surface of the hard coat layer must have an arithmetic mean roughness Ra measured in accordance with JIS B 0601-1994, and must be 0.008 μm or less. When the Ra exceeds 0.008 μm, the transmission image resolution described later cannot be made 450 or more, and the sharpness is impaired.

[Characteristics of hard coating film]

The hard coat film of the present invention having the hard coat layer formed as described above on one side of the transparent base film has the following properties. The surface on the opposite side to the hard coat layer side of the base film must be in the range of 0.01 to 0.05 μm in accordance with the arithmetic mean roughness Ra measured in accordance with JIS B 0601-1994. When the Ra is less than 0.01 μm, the force applied to the surface of the hard coat layer cannot be alleviated in the pencil scratch test, and the pencil hardness is lowered. On the other hand, if it exceeds 0.05 μm, the transmission image sharpness described later is less than 450, which is not obtained. A sense of clarity. Moreover, the adjustment of the Ra can also be directly performed on the transparent substrate film. The unevenness may be provided or may be carried out by forming a Ra of the surface as a coating layer (hard coat layer) in the above range, similarly to the formation of the hard coat layer described above.

Further, according to JIS K 7374:2007, a transmission image expressed by a total value of image sharpness by a transmission method for five kinds of slits (slit width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) The clarity must be above 450. If the transmission brightness is less than 450, a sufficient sense of clarity cannot be obtained, and the visibility is insufficient when used in various electronic devices such as display devices and touch panels.

Further, from the viewpoint of the visibility, the haze value measured in accordance with JIS K 7136 is preferably 2% or less.

In the hard coat film of the present invention, the pencil hardness of the hard coat layer measured at a scratch speed of 1 mm/sec in accordance with JIS K 5600-5-4 by a pencil scratch hardness tester may be 3H or more.

[Use of hard coating film]

The hard coat film of the present invention having the above-described properties is used as a member for electronic devices such as various display devices and touch panels, but is particularly suitable as a member for a touch panel.

As the touch panel, there are a resistive film type, a capacitive type, an electromagnetic induction type, an infrared type, etc., and the hard coat film of the present invention can be applied to any of them, but among these, it is particularly preferable to apply the hard coat film of the present invention. In the resistive film type.

Example

Next, the present invention will be further described in detail by way of examples, but the invention should not be construed as limited.

Moreover, the characteristics in each example were obtained by the following methods.

(1) Arithmetic mean roughness Ra of the surface

It was measured in accordance with JIS B 0601-1994 using a contact surface roughness meter [manufactured by Mitutoyo Co., Ltd., "SV3000S4").

(2) Film thickness

According to JIS K 7130, it was measured by a thickness meter [MH-15" manufactured by Nikon Corporation.

(3) Total light transmittance

The measurement was carried out in accordance with JIS K 7361-1 (1997) using a haze meter [manufactured by Nippon Denshoku Co., Ltd., "NDH-2000").

(4) Haze value

It was measured using a haze meter [manufactured by Nippon Denshoku Co., Ltd., "NDH-2000") in accordance with JIS K 7136 (2000).

(5) Pencil hardness

It was measured in accordance with JIS K 5600-5-4 using a pencil scratch hardness tester [manufactured by Yasuda Seiki Co., Ltd., "No. 553-M"). The scratch speed was 1 mm/sec.

(6) scratch resistance

Using steel wool # 0000, the friction was repeated 50 times with a load of 200 g/cm ² (1.96 N/cm ² ) for 5 times, and then visually confirmed whether or not there was damage. ○: No damage, ×: There is damage.

(7) Transmission image clarity

The image clarity is determined by the transmission image in accordance with the total of the five slits (slit width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) measured in accordance with JIS K 7374:2007. Degree tester [manufactured by Suga Test Instruments Co., Ltd., "ICM-1T"], And as the transmission image clarity. When the total value is 450 or more, the feeling of clarity is sufficient and it is qualified.

(8) Cutting processing adaptability

The hard coating film was cut linearly using a continuous automatic cutting machine [product name "PN1-600" manufactured by Takino Seiki Co., Ltd.) to confirm whether or not the hard coating layer was broken. ○: no crack, ×: cracked.

Preparation Example 1 Preparation of Hard Coating Liquid 1

Mixture of organically modified vermiculite particles and polyfunctional acrylate with propylene glycol monomethyl ether [Opstar Z7530, manufactured by JSR Corporation, concentration 73% by mass, inorganic component 60%, photopolymerization initiator] 100 parts by mass A flat agent [BYK-300, manufactured by BYK-Chemie Japan Co., Ltd., concentration: 52% by mass] was diluted with a mixture of 0.1 parts by mass to prepare a hard coating liquid 1 having a concentration of 40% by mass (the inorganic component in the solid matter was 60.0% by mass). ).

Preparation Example 2 Preparation of Hard Coating Liquid 2

Mixture of organically modified vermiculite particles and polyfunctional acrylate with propylene glycol monomethyl ether [Opstar Z7530, manufactured by JSR Corporation, concentration 73% by mass, inorganic component 60%, photopolymerization initiator] 100 parts by mass, and more Functional acrylate (pentaerythritol triacrylate, concentration: 100%), 34 parts by mass, photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1.8 parts by mass, leveling agent [BYK-Chemie Japan, "BYK-300" "Concentration 52% by mass] A mixture of 0.1 parts by mass was diluted to prepare a hard coat liquid 2 (inorganic component: 40.9% by mass) in a concentration of 40% by mass.

Preparation Example 3 Preparation of Hard Coating Liquid 3

Mixture of organically modified vermiculite particles and polyfunctional acrylates with propylene glycol monomethyl ether [manufactured by JSR, "Opstar Z7530", concentration 73 % by mass, 60% by mass of inorganic component, 100 parts by mass of photopolymerization initiator, 111 parts by mass of polyfunctional acrylate (pentaerythritol triacrylate, concentration: 100%), photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) 5.8 parts by mass, a leveling agent [BYK-Chemie Japan, "BYK-300", concentration 52% by mass] 0.2 parts by mass of the mixture was diluted to prepare a hard coating liquid 3 having a concentration of 40% by mass (in solid form) The inorganic component was 23.8% by mass).

Preparation Example 4 Preparation of Hard Coating Liquid 4

Mixture of polyfunctional acrylate and urethane acrylate with propylene glycol monomethyl ether [Beamset 575CB, manufactured by Arakawa Chemical Industries Co., Ltd., concentration 100%, inorganic component 0%, photopolymerization initiator] 100 parts by mass, uniform The mixture [BYK-300, manufactured by BYK-Chemie Japan Co., Ltd., concentration: 52% by mass] was diluted with a mixture of 0.1 parts by mass to prepare a hard coat liquid 4 (0% of the inorganic component in the solid matter) having a concentration of 40% by mass.

Preparation Example 5 Preparation of Hard Coating Liquid 5

Mixture of organically modified vermiculite particles and polyfunctional acrylate with propylene glycol monomethyl ether [Opstar Z7530, manufactured by JSR Corporation, concentration 73% by mass, inorganic component 60%, photopolymerization initiator] 100 parts by mass, vermiculite Beads [made by Momentive Performance Materials, product name "Tospearl 145", average particle diameter 4.5 μm, concentration 100%] 0.15 parts by mass, leveling agent [BYK-Chemie Japan, "BYK-300", concentration 52% by mass 0.1 parts by mass of the mixture was diluted to prepare a hard coat liquid 5 (inorganic component 60.2% by mass in the solid matter) having a concentration of 40% by mass.

Preparation Example 6 Preparation of Hard Coating Liquid 6

Mixture of urethane acrylate and polyfunctional acrylate with propylene glycol monomethyl ether [Beamset 575CB, manufactured by Arakawa Chemical Co., Ltd., 100% concentration, photopolymerization initiator] 100 parts by mass, ultraviolet rays dispersed with vermiculite particles Hardening resin [made by Daisei Seiki Co., Ltd., product name "Seikabeam EXF-01L (BS)", vermiculite particle content 10% by mass, average particle diameter 4.7 μm, concentration 100%, photopolymerization initiator] 2 parts by mass A leveling agent [BYK-Chemie Japan Co., Ltd., "BYK-300", concentration: 52% by mass] 0.1 parts by mass of the mixture was diluted to prepare a hard coating liquid 6 having a concentration of 40% by mass (inorganic component in the solid form 0.2) quality%).

Example 1

A PET film having a double-sided easy-adhesion layer ("PET188O321" manufactured by Mitsubishi Plastics Co., Ltd., film thickness: 1188 μm] was used, and the film thickness after drying was set to 8 μm by a mayer bar #16, and hard coating was applied. After drying at 80 ° C for 1 minute, the liquid 1 was irradiated with ultraviolet rays (light amount: 200 mJ/cm ² ) to be hardened to form a hard coat layer, and the hard coat film of Example 1 was obtained.

Example 2

A hard coat film of Example 2 was obtained in the same manner as in Example 1 except that the hard coat liquid 2 was used in Example 1.

Example 3

A hard coat film of Example 3 was obtained in the same manner as in Example 1 except that the film thickness after drying was set to 13 μm by Meyer Bar #24.

Example 4

A hard coat film of Example 4 was obtained in the same manner as in Example 1 except that a PET film having a double-sided easy-adhesion layer ("PET125O321" manufactured by Mitsubishi Plastics Co., Ltd., film thickness: 1125 μm] was used.

Example 5

In the first embodiment, on the surface opposite to the hard coat layer side of the hard coat film 1, the film thickness after drying was set to 3.5 μm by Meyer bar #8, and the hard coat liquid 5 was applied at 80 ° C. After drying for 1 minute, ultraviolet rays (light quantity: 200 mJ/cm ² ) were irradiated and hardened to form a hard coat layer, and the hard coat film of Example 5 was obtained.

Comparative example 1

A hard coat film of Comparative Example 1 was obtained in the same manner as in Example 1 except that the hard coat liquid 3 was used.

Comparative example 2

A hard coat film of Comparative Example 2 was obtained in the same manner as in Example 1 except that a PET film having a double-sided adhesive layer ("PET188A4300", manufactured by Toyobo Co., Ltd., film thickness: 188 μm] was used.

Comparative example 3

In the first embodiment, on the surface on the opposite side to the hard coat layer side of the hard coat film 1, the film thickness after drying was set to 5.0 μm by Meyer bar #10, and the hard coat liquid 6 was applied at 80 ° C. After drying for 1 minute, ultraviolet rays (light amount: 200 mJ/cm ² ) were irradiated to form a hard coat layer, and a hard coat film of Comparative Example 3 was obtained.

Comparative example 4

A hard coat film of Comparative Example 4 was obtained in the same manner as in Example 1 except that the hard coat liquid 4 was used.

Comparative Example 5

A hard coat film of Comparative Example 5 was obtained in the same manner as in Example 1 except that the hard coat liquid 4 was used and the film thickness after drying was set to 13 μm.

The characteristics of each of the hard coat films obtained in the above Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated. The results are shown in Table 1 together with the hard coat film production conditions.

As can be seen from Table 1, the hard coat film of the present invention (Examples 1 to 5) has a total light transmittance of more than 90%, a haze value of less than 2%, and a pencil hardness of 3H or more. The scratch resistance is acceptable, and the transmission image clarity is also over 450, which is acceptable. Further tailoring and processing adaptability is also good.

On the other hand, in the hard coat films of Comparative Examples 1 to 5, the pencil hardness and/or the transmission image sharpness were inferior compared to the examples. Moreover, Comparative Example 5 has no tailoring process adaptability.

Industrial availability

The hard coat film of the present invention has high pencil hardness (3H or more), has process suitability, and is excellent in transmission image definition, and is suitable for use as various A member of an electronic device such as a display device or a touch panel is particularly suitable for use as a member of a resistive film type touch panel.

Claims (7)

A hard coat film having a hard coat layer having a thickness of 7 to 14 μm on one side of a transparent base film, which is formed of a hard coat layer containing a 3-6 functional monomer and an organically modified vermiculite particle. It is hardened, and the hard coat layer forming material is contained in a ratio of 35 to 65 mass%, and the organic modified vermiculite particles are inorganic components in the solid matter, and the hard coat film is characterized by (1) according to JIS B The arithmetic mean roughness Ra of the surface of the hard coat layer measured by 0601-1994 is 0.008 μm or less, and (2) the arithmetic mean roughness of the surface opposite to the hard coat layer of the transparent base film measured in accordance with JIS B 0601-1994. Degree Ra is 0.01 to 0.05 μm, and (3) is measured for 5 kinds of slits (slit width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) in accordance with JIS K 7374:2007, by transmission method. The total value of the sharpness indicates a transmission image resolution of 450 or more. The hard coat film of claim 1, wherein the 3-6 functional monomer is a (meth) acrylate monomer. A hard coat film according to claim 1 or 2, wherein the haze value measured in accordance with JIS K 7136 is 2% or less. The hard coat film of claim 1 or 2 is used as a member for a touch panel. A hard coat film according to item 3 of the patent application is used as a member for a touch panel. The hard coating film of claim 4, wherein the touch panel is a resistive film type. The hard coating film of claim 5, wherein the touch panel is a resistive film type.