KR100905683B1 - Hard coat film, base on which hard coat film is formed, image display having them - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard coat film having excellent scratch resistance and surface hardness, further improving curl, brittleness, a substrate on which a hard coat film is laminated, and an image display apparatus formed thereon. The hard coat film of the present invention is a hard coat film formed by laminating a hard coat layer on at least one side of a base film, wherein the product of the surface elastic modulus of the hard coat layer and the cube of the thickness of the hard coat layer is 30 KPa · ㎣ or more and 700 KPa · ㎣ or less. It is a hard coat film characterized by the above-mentioned. The hard coat film of the present invention preferably has a surface elastic modulus of 4.0 GPa or more and 9.0 GPa or less, and the hard coating layer is a layer mainly composed of a curable composition cured by irradiation of active energy rays, and after curing of the curable composition It is preferable that the volume shrinkage is 0 to 15%.

Hard coating film, image display device

Description

Hard coating film, base material laminated with hard coating film, and image display apparatus formed thereon {HARD COAT FILM, BASE ON WHICH HARD COAT FILM IS FORMED, IMAGE DISPLAY HAVING THEM}

The present invention provides an antireflection layer, an ultraviolet ray / infrared ray absorbing layer, a selective wavelength absorbing layer, an antistatic layer, an electromagnetic shielding layer, an antiglare layer, and an antifouling layer on a hard coat film and a hard coat film having excellent scratch resistance and surface hardness. It is related with the hard coat film with a functional thin film which formed functional thin films, such as 防汚 性 層. Moreover, this invention relates to the base material which laminated | stacked the hard coat film. Moreover, this invention relates to the image display apparatus which formed the hard coat film or the base material which laminated this.

In recent years, plastic products have tended to replace glass products from the viewpoint of processability and weight reduction. Since the surfaces of these plastic products are easily damaged, they are often used by adhering a hard coat film for the purpose of imparting scratch resistance. Moreover, although the case where the plastic film is adhere | attached also for the conventional glassware for shatterproof is increasing, it is widely practiced to form a hard-coat layer on the surface because of the lack of hardness of the film surface.

Conventional hard coating films usually have an active energy ray-polymerizable resin such as a thermosetting resin or an ultraviolet curing resin directly on a plastic base film or about 3 to 15 μm with a primer layer of about 1 μm or less therebetween. It is manufactured by forming a thin coating film.

However, in the conventional hard coating film, due to insufficient hardness of the hard coating layer and thin coating film thickness, when the base plastic base film is deformed, the hard coating layer is deformed accordingly so that the entire hard coating film is deformed. Since hardness fell, it was not fully satisfactory. For example, in the hard-coating film which coated the ultraviolet curable paint to the said thickness on the polyethylene terephthalate film widely used as a plastic base film, 2 to 3H level is common with pencil hardness, and 9H which is the pencil hardness of glass. Does not fall at all.

In order to increase the hardness of the hard coating layer, the coating composition containing the resin-forming component of the layer as a polyfunctional acrylate ester monomer and containing a powdered inorganic filler such as alumina, silica, titanium oxide and a polymerization initiator is Japanese Patent. No. 1815116. Further, a photopolymerizable composition comprising an inorganic filler made of silica or alumina surface-treated with an alkoxysilane or the like is disclosed in Japanese Patent No. 1416240. Moreover, the filling of crosslinked organic microparticles | fine-particles is also examined recently. Although these have the effect of increasing the surface hardness of some hard coat films, they also have problems of haze increase and brittleness deterioration, and this alone has not been able to sufficiently meet the surface hardness performance of recently demanded hard coat films.                 

Further, Japanese Laid-Open Patent Publication No. 2000-52472 proposes a method of satisfying curl and damage resistance by setting a hard coat layer in a two-layer structure and adding fine silica silica to the first layer. In addition, Japanese Laid-Open Patent Publication No. 2000-71392 has a hard coating layer composed of two layers, and a cured resin layer composed of only a radical curable resin is used as the upper layer using a cured resin layer composed of a blend of a radical curable resin and a cation curable resin. The hard coat film used is described. However, these were not hardness enough to be satisfied enough.

On the other hand, it is known that making the thickness of the hard coating layer thicker than the usual 3 µm to 10 µm is effective for increasing the hardness. In particular, the thickness of the hard coating film can be further improved by thickening the hard coating layer containing inorganic and organic fillers. However, by increasing the thickness of the hard coating layer, the haze increases, making cracks and peeling of the hard coating layer more likely to occur, and at the same time, curing shrinkage. There is a problem that the curl of the hard coat film is increased. For this reason, in the prior art, it was difficult to obtain the hard coat film which has the favorable characteristic which can be used practically.

Moreover, although it is described in Unexamined-Japanese-Patent No. 2000-15734 by making a hardening resin film layer into a specific elasticity modulus, it was difficult to make pencil hardness more than 5H.

The first problem to be solved by the present invention is to provide a hard-coated film having a pencil hardness of 4H or more using a base film such as PET film and having a large surface hardness and improved curl and brittleness, and furthermore, reflection. It is to provide a hard coating film with a functional thin film having functions of prevention, antiglare, antifouling and the like. A second object of the present invention is to provide a substrate on which a hard coat film is laminated. A third problem to be solved by the present invention is to provide an image display apparatus in which a hard coat film or a base material laminated thereon is formed.

It has been found that the first problem can be achieved by the following solutions.

In the hard coat film formed by laminating | stacking a hard coat layer on at least one surface of a base film, the product of the surface elastic modulus of the said hard coat layer and the cube of the thickness of a hard coat layer is 30 KPa * Pa or more and 700 KPa * Pa or less, The hard coat film characterized by the above-mentioned. .

Moreover, it discovered that the said 2nd subject can be achieved by the following solutions.

A substrate on which the hard coating layer is laminated.

Moreover, it discovered that the said 3rd subject can be achieved by the following solutions.

An image display device comprising the hard coat film or a base material laminated thereon.

The surface elastic modulus in this invention is the value calculated | required using the micro surface hardness meter (Fisher Instruments Co., Ltd. product: Fisher Scope H100VP-HCU). Specifically, using a diamond square indenter (tip-to-face angle; 136 °), the indentation depth under a suitable test load is measured within a range where the indentation depth does not exceed 1 μm. The elastic modulus obtained.                 

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. As a base film used for the hard coat film of this invention, a plastic film is preferable, Cellulose resins, such as polyester, such as polyethylene terephthalate and a polyethylene naphthalate, polycarbonate, triacetyl cellulose, and diacetyl cellulose, polyolefin (polypropylene, Polystyrene such as polyethylene, polymethylpentene, syndiotactic polystyrene, norbornene-based resins of cyclic olefins (e.g., Nihon Xeon Co., Ltd. Zeonoa, Zeonex, JSR Co., Ltd.), polysulfone, polyether Films, such as sulfone, polyarylate, polyetherimide, polymethyl methacrylate and polyether ketone, are preferable. The thickness of the film is preferably 20 to 500 µm, and when too thin, the film strength is weak and thick, the rigidity is too large, and 80 to 200 µm is more preferable. Here, 20-500 micrometers means "20 micrometers or more and 500 micrometers or less". In this invention, it is the same below. It is preferable that a base film is transparent, and the light transmittance of a transparent base film is 80% or more, More preferably, it is 90% or more in the wavelength range of 400 nm-780 nm. Naturally, it is also possible to apply the hard coat layer in the present invention to sheet-like, panel-like bases, preferably transparent bases, other than films.

In order to reduce the deformation of the base film, it is effective to increase the modulus of elasticity of the base film. On the other hand, as a result of the study of reducing the deformation of the hard coating layer and reducing the stress on the base film, the rigidity of the hard coating layer is increased. Found that it was valid. The rigidity of the hard coating layer is proportional to the magnitude of the bending stiffness related to the elastic modulus and the film thickness. By making elastic modulus x (cubic of the film thickness) concerning the bending rigidity of a hard-coat layer into a specific range, and improving rigidity, the objective pencil hardness can be improved. If the bending strength of the hard coating layer is small, the hard coating layer itself is easily deformed, and the load of the pencil test is applied to the base film to deform the base film. By increasing the bending rigidity of the hard coating layer, the deformation caused by the load of the pencil test is reduced, and the deformation of the base film can be suppressed. Although it is preferable to enlarge bending rigidity, since it handles with a roll etc., it is necessary to be below fixed bending rigidity as a base film. The product of the surface elastic modulus of the hard coat layer and the cube of the hard coat layer thickness is preferably 30 KPa · Pa to 700 KPa · ㎣, particularly preferably 100 KPa · ㎣ to 400 KPa · ㎣.

In order to prevent damage by a pencil hardness test, it is preferable that the hardness of the hard coat layer itself is somewhat large, and the surface elastic modulus of the hard coat layer is 4.0 GPa or more, preferably 4.5 GPa or more. In the hard coating layer whose surface elastic modulus is less than 4.0 GPa, sufficient pencil hardness and damage resistance may not be acquired.

On the other hand, to increase the hardness, it is effective to increase the surface elastic modulus, but brittleness may deteriorate, and the surface elastic modulus is preferably 9.0 GPa or less, more preferably 7.0 GPa or less.

It is preferable that it is 4.0 GPa or more and 9.0 GPa or less, and, as for the surface elasticity modulus of a hard coat layer, it is more preferable that they are 4.5 GPa or more and 7.0 GPa or less.

The surface elastic modulus of a hard coat layer can be adjusted by changing a crosslinking density by selection of the polyfunctional monomer used for the curable composition hardened | cured by heat or an active energy ray, or addition of the polymer containing a polymerizable group. Moreover, it can also adjust by adding inorganic fine particles of metal oxides, such as a silica, alumina, titania, and organic fine particles, such as a crosslinked polymer, to a hard-coat layer.

10 micrometers or more are preferable and, as for the thickness of the hard coat layer of this invention, 20 micrometers or more are preferable. When the thickness is increased, the pencil hardness is improved, but it is more difficult to bend the film, and cracks are more likely to occur due to the bending, and more preferably 60 µm or less and 50 µm or less. More preferably, it is 10-60 micrometers, Especially preferably, it is 20-60 micrometers, Most preferably, it is 20-50 micrometers. The hard coat layer is composed of at least one layer, and may also be formed in two or more layers.

In this invention, it is preferable to bend the hard coating layer outward and to reduce the crackability of the hard coating represented by the winding diameter when a crack occurs in the hard coating layer. The cracking property of the hard coat layer of the present invention is preferably 150 mm or less and more preferably 80 mm or less.

A well-known curable composition can be used for the hard coat layer used for this invention. The curable composition includes a thermosetting composition, an active energy ray polymerizable composition, and the like. As the thermosetting composition, it is possible to use crosslinking reaction of prepolymers such as melamine resin, urethane resin and epoxy resin or sol-gel reaction of silicate, but active energy ray-polymerizable resin is preferably used in view of ease of reaction control. do.

It is preferable that the hard coat layer in this invention is a layer which mainly uses the curable composition hardened | cured by irradiation of an active energy ray.

In the present invention, the term "layer mainly composed of the curable composition cured by irradiation of active energy rays" means that the inorganic or organic fine particles, polymerization initiator, and other additives described below may be contained in addition to the curable composition by active energy rays. do.

Curable compositions containing a polyfunctional polymerizable group or a compound having a crosslinking group reacted by active energy ray irradiation generally used have a problem in that curling occurs when volume shrinkage occurs to increase the film thickness. In order to make curl small, it is preferable that shrinkage at the time of hardening is small. The volume shrinkage before and after curing at 25 ° C. is within € 15%, preferably 0 to 13%, more preferably 0 to 11%.

The volume shrinkage rate by hardening can be calculated | required from the density change before and after hardening of a curable composition, and it is the value calculated | required by Formula A using the density measured by MULTIVOLUME PYCNOMETER by the micrometric company (25 degreeC) specifically ,.

Equation A: Volumetric shrinkage = {1- (density before curing / density after curing)} × 100 (%)

By making the volume shrinkage ratio at the time of hardening of a hard coat layer small, it becomes possible to make the curl of the hard coat film which laminated | stacked the hard coat layer on the base film small. In practice, the curl value of the hard coat film at 25 ° C. 60% RH is preferably in the range of minus 15 to plus 15.                 

Further, it is preferable that the value of the curl value for the film thickness of the hard coating, that is, the value (absolute value) obtained by dividing the curl value by the film thickness (μm) of the hard coating, is 0.45 (1 / (m · μm)). The following is preferable and it is preferable that it is 0.35 (1 / (m * micrometer)) or less.

Here, a curl value is the value calculated | required by following formula B.

Formula B: curl value = 1 / R (R is the radius of curvature of the curl (m))

In addition, the hard coat layer may expand and contract in volume by moisture absorption amount. It is preferable that the absolute value of the difference of the curl value in 25 degreeC 10% RH and 25 degreeC 80% RH is 24 or less. In order to suppress a change in the curl value, the smaller the hydrophilicity of the curable composition after curing by active energy ray irradiation is preferable, and the I / O value of the curable composition after curing related to hydrophilicity is preferably 0.1 to 0.85. More preferably 0.25 to 0.8, most preferably 0.35 to 0.75. When the I / O value exceeds 0.85, the hydrophilicity of the polymer produced by curing increases, the volume expansion or hardness of the hard coating layer is greatly influenced by humidity, and the hard coating film having high surface hardness and good curl characteristics is obtained. It tends to be difficult to obtain. If the I / O value is too small, the hygroscopic expansion may be small and curl at normal humidity may be large.

The above I / O values are obtained by the methods described in Takata Fujita, `` Physical Organic Qualitative Analysis Pure Water '' (Kazama Shobo, 1970), Koda Yoshio, `` Organic Concept Diagram '' (Sankyo Publishing, 1984). (I) / organicity (O) ". I / O values are used as a means to predict various physicochemical properties of organic compounds. Organics are obtained in comparison of the case of carbon number, inorganics are obtained in comparison of the boiling point of hydrocarbons of the same carbon number. For example, one (-CH _2- ) (actually C) is determined to have an organic value of 20, and the inorganic property is defined as an inorganic value of 100 in the influence of the hydroxyl group (-OH) on the boiling point. The thing which calculated | required the value of another substituent (inorganic group) on the basis of the inorganic value 100 of (-OH) is shown as an "inorganic group table." The ratio of the said inorganic value and organic value in the composition after irradiating and hardening an active energy ray to the curable composition which forms a hard-coat layer was used as I / O value. That is, the I / O value of the curable composition cured by active energy ray irradiation is a value obtained by multiplying the mass fraction of each repeating unit by the I / O value for each repeat unit of the polymer produced by irradiation of active energy ray. In order to make the I / O value of the curable composition hardened | cured by active energy ray irradiation to 0.1-0.85, it is possible by setting the composition of the curable composition before hardening suitably. For example, the I / O value can be controlled to 0.1 to 0.85 by reducing the groups such as -OH, -COOR, -NH ₂ , and -CO- in the curing composition.

Moreover, moisture absorption can be reduced by suppressing the I / O value of a curable composition to the said range. The moisture absorption amount at 25 ° C. 60% RH of the hard coat layer of the present invention is preferably 3% by mass or less, more preferably 2.5% by mass or less, and most preferably 2% by mass or less with respect to the hard coat layer when dried. .

The active energy ray-polymerizable resin layer which is preferably used as the hard coating layer of the present invention comprises a coating liquid containing an oligomer, a polymer and a polymerization initiator having a polyfunctional monomer and / or a polymerizable functional group or a crosslinkable reactor in a side chain thereof. It can form by apply | coating on a superposition | polymerization and polymerizing a polyfunctional monomer, an oligomer, and a polymer. As a polymerizable functional group of these active energy ray polymeric resin layers, a radically polymerizable unsaturated double bond group and a ring-opening polymerizable cyclic ether group are preferable.

Acryloyl group, methacryloyl group, a vinyl group, an allyl group, etc. are mentioned as a polymerizable unsaturated double bond group, Acryloyl group and a methacryloyl group are used preferably from a reactive viewpoint. Specific examples of the polyfunctional polymerizable unsaturated double bond group-containing monomer include glycol-based (meth) acrylates such as ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acrylate, and n-hexanediol di (meth). Acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylol propane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-cyclohexanedioldi (meth) acrylate, 1,3,5-cyclohexanetriol tri (meth) ) Acrylates, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terphthalic acid and glycols (ethylene glycol, polyethylene glycol, propylene glycol, etc.) and triols (glycerol Polyol polyacrylates such as oligomers of polyester-based polyols and reactions of (meth) acrylates by reaction of lean, trimethylolpropane, etc.), bisphenol A, glycidyl (meth) acrylate, hexanediol and glycy When obtained by the reaction of hydroxyl group containing acrylates, such as polyisocyanate polyurethane type oligomer which consists of condensation products of polyisocyanate and polyol, epoxy acrylates, such as a reactant of di (meth) acrylate, and polyol And ethane acrylates.

Examples of the ring-opening polymerizable cyclic ether compound include cyclic imino ethers such as epoxy derivatives, oxetane derivatives, tetrahydrofuran derivatives, and oxazoline derivatives. In particular, epoxy derivatives, oxetane derivatives, and oxazoline derivatives include desirable.

These ring-opening polymerizable cyclic ether compounds are preferably compounds having two or more, preferably three or more, cyclic structures as described above in the same molecule. For example, as trifunctional glycidyl ether, tetrafunctional or more than trifunctional glycidyl, such as trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, glycerol triglycidyl ether, and triglycidyl trihydroxy hydroxyethyl isocyanurate As ether, it is an epoxide as trifunctional or more than trifunctional epoxy, such as sorbitol tetraglycidyl ether, pentaerythritol tetraglycidyl ether, polyglycidyl ether of cresol novolak resin, and polyglycidyl ether of phenol novolak resin. Examples of trifunctional or higher functional oxetanes such as GT-301, epoxide GT-401, EHPE (above, manufactured by Daicel Chemical Industries, Ltd.), and polycyclohexyl epoxymethyl ether of phenol novolak resins include OX-SQ and PNOX. -1009 (above, manufactured by Dong-A Synthetic Co., Ltd.), etc. are mentioned.

It is also possible to add a monofunctional monomer to a polyfunctional monomer as needed in order to adjust surface elastic modulus, reduce hardening shrinkage, and improve adhesiveness. As a monofunctional monomer, alkyl ester of acrylic acid, such as methyl (meth) acrylate and butyl (meth) acrylate, hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, glycidyl (meth) Existing monomers, such as acrylic acid ester containing polar groups, such as acrylate, acrylamide, such as (meth) acrylamide and N-methylol (meth) acrylamide, N-vinylpyrrolidone, styrene, vinyl acetate, maleic anhydride Can be mentioned.

On the other hand, the compound which has one or two ring-opening polymerizable groups in the same molecule can also be used together as needed, Preferably, as a compound, monofunctional or bifunctional glycidyl ether, monofunctional or bifunctional alicyclic Epoxy, monofunctional, or bifunctional oxetane can be mentioned, and various commercially available or well-known compounds can be used.

Similarly, it is also possible to add oligomers or polymers containing at least two or more radically polymerizable groups to the polyfunctional monomer. As an oligomer or polymer containing a radically polymerizable group, there exists an oligomer / polymer which has polymerizable groups, such as a (meth) acryloyl group and an allyl group, as a pendant group, For example, it is synthesize | combined with the oligomer polymer which has a hydroxyl group, and (meth) acrylic acid. Such as ester derivatives and glycidyl (meth) acrylates, which are synthesized with ester derivatives, oligomer polymers having carboxylic acids, hydroxyl group-containing (meth) acrylic acid esters (hydroxyethyl (meth) acrylates, etc.), allyl alcohols, and the like. The epoxy ring-opening polymer oligomer polymer, the polymer which introduce | transduced the acryloyl group synthesize | combined by the dehydrochlorination reaction of the oligomer polymer which has a chlorethyl group, etc. are mentioned.

Moreover, as a compound which has three or more ring-opening polymerizable groups in the same molecule, it is especially preferable to contain the crosslinkable polymer containing the repeating unit represented by General formula (1). In the formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group. L ¹ is a single bond or a divalent linking group, preferably a single bond, -O-, an alkylene group, an arylene group, and * -COO-, * -CONH-, * -OCO-, *- NHCO-. P ¹ is a monovalent group containing an epoxy ring, an oxetane ring, a tetrahydrofuran ring, a lactone ring, a carbonate ring, imino ether ring, and the like, such as oxazoline ring A preferred P ¹ as a monovalent including a ring-opening polymerizable group A group is mentioned, Especially preferably, it is a monovalent group containing an epoxy ring, an oxetane ring, and an oxazoline ring.

The crosslinkable polymer containing the repeating unit represented by General formula (1) of this invention is preferable because it is easy to synthesize | combine and synthesize | combine the corresponding monomer. As the polymerization reaction in this case, radical polymerization is the simplest and preferred. Specific examples include polyglycidyl methacrylate, polymethylglycidyl methacrylate, polyepoxycyclohexylmethyl methacrylate, poly-3-ethyl-3-oxetanylmethyl methacrylate, and the like.

In the above formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, P ¹ is a monovalent group including a ring-opening polymerizable group, and L ¹ is a single bond or a divalent linking group.

Although the preferable specific example of the repeating unit represented by General formula (1) is shown below, the crosslinkable polymer which can be used for this invention is not limited to these specific examples.

The said polyfunctional polymerizable unsaturated double bond group containing monomer or oligomer, a polymer, and a polyfunctional cyclic structure containing compound can also be mixed and used.

When a monofunctional monomer, an oligomer or polymer containing at least two or more polymerizable unsaturated double bond groups, or a ring-opening polymerizable cyclic ether compound is added, the amount added to the polyfunctional polymerizable unsaturated double bond-containing monomer is 50% by mass or less. Is preferable and 35 mass% or less is more preferable. If the ratio of monofunctional monomers, oligomers or polymers containing at least two or more polymerizable unsaturated double bond groups, or ring-opening polymerizable cyclic ether compounds is too large, the desired hardness cannot be obtained.

Curing of a hard coat film can be reduced by adding inorganic or organic microparticles | fine-particles to these active energy ray polymerizable resin layers, adjusting the surface elastic modulus of a hard coat layer, or making hardening shrinkage rate small.

Examples of the fine particles include inorganic oxides and polymer resin particles of internal crosslinking. As the inorganic oxide particles, those having high hardness are preferable, and inorganic oxide particles having a Mohs hardness of 6 or more are preferable. Examples include silicon dioxide particles, titanium dioxide particles, zirconium oxide particles, aluminum oxide particles, and the like.

Examples of the organic fine particles include resin particles such as acrylic resin, polystyrene, polysiloxane, melamine resin, benzoguanamine resin, polytetrafluoroethylene, cellulose acetate, polycarbonate, nylon, and the like, and polymethyl methacrylate (di Vinylbenzene copolymer), polysiloxane, polystyrene, melamine resin and benzoguanamine resin, and particles composed of these composites are preferable. Moreover, the polymer resin fine particle of internal crosslinking by copolymerization with the monomer which has a bifunctional or more than one functional group is preferable.

The volume average particle diameter of these microparticles | fine-particles is 1 nm or more and 400 nm or less, More preferably, they are 5 nm or more and 200 nm or less, More preferably, they are 10 nm or more and 100 nm or less. Dispersion is difficult at 1 nm or less, resulting in aggregated particles, and at 400 nm or more, haze increases, and both are inferior in transparency.

It is more preferable that it is 5-80 mass% of the whole quantity of an active-energy-ray-polymerizable resin layer, and, as for the addition amount of these microparticles | fine-particles, it is still more preferable that it is 10-50 mass%.                 

In general, the inorganic fine particles have a poor affinity with the active energy ray-polymerizable resin, and thus simply by mixing them, the interface is easily broken, and it is easy to crack as a film, and it is difficult to improve the damage resistance. In order to improve the affinity between the inorganic fine particles and the active energy ray-polymerizable resin, the surface of the inorganic fine particles may be treated with a surface modifier containing an organic segment. The surface modifier preferably forms a bond with the inorganic fine particles on the one hand and has a high affinity with the active energy ray polymerizable resin on the other hand. As the compound capable of forming a bond with the surface of the inorganic fine particles, an anionic compound having a metal alkoxide compound such as silicon, aluminum, titanium, zirconium, phosphate ester, phosphonic acid group, sulfate ester, sulfonic acid group, carboxylic acid group, etc. This is preferred. Moreover, it is preferable to chemically bond with active energy ray polymeric resin, and what introduce | transduced a vinylic polymerizer etc. at the terminal is preferable. For example, when synthesizing an active energy ray polymerizable resin from a monomer having an ethylenically unsaturated group as a polymerizable group and a crosslinkable group, a polymerizable unsaturated double bond group or a gated polymerizable cyclic ether group is used at the terminal of the metal alkoxide compound or the anionic compound. It is desirable to have.

When using a plastic film as a base film in this invention, since the heat resistance of the plastic film itself is low, when hardening curable resin by heating, it is preferable to harden at low temperature as possible. The heating temperature in that case is 140 degrees C or less, More preferably, it is 100 degrees C or less. On the other hand, hardening by the action of light often crosslinks at low temperatures and is preferably used.                 

In the case of using an active energy ray polymerizable resin for the hard coating layer, radiation, gamma rays, alpha rays, electron beams, ultraviolet rays, and the like can be cited as active energy rays, but ultraviolet rays are preferable, and among them, polymerization that generates radicals or cations by ultraviolet rays. Particularly preferred is a method of adding an initiator and curing with ultraviolet rays. Moreover, hardening can further advance by heating after irradiating an ultraviolet-ray, and it can use preferably. Preferable heating temperature in this case is 140 degrees C or less.

Examples of the radical photopolymerization initiator include acetophenones, benzophenones, Michler's ketones, benzoylbenzoate, benzoin, α-acyl oxime ester, tetramethylthiuram monosulfide, thioxanthone and the like. In addition to a photoinitiator, a photosensitizer can also be used. Examples of photosensitizers include n-butylamine, triethylamine, triethanolamine, tri-n-butylphosphine, thioxanthone, and the like.

Examples of photoacid generators for generating cations include compounds such as triarylsulfonium salts, diaryliodonium salts, and nitrobenzyl esters of sulfonic acid. Organic Organic Materials Research Society, Published by Organic Materials for Imaging (1997) Various well-known photo-acid generators, such as a compound described in these, can be used. Among them, particularly preferably diphenyl-4-thiophenoxy and a sulfonium salt or diphenyl iodonium salt, such as antimonate phenyl sulfonium hexafluoro when melted, as counter-ion _{^{PF 6 -, SbF 6 -,}} AsF 6 - , B (C ₆ F ₅ ) ₄ ^- and the like are preferred.

A monomer or oligomer containing a polyfunctional polymerizable unsaturated double bond group, a polymer, a polyfunctional ring-opening polymerizable cyclic ether compound, an optical radical initiator for generating a radical and a photoacid generator for generating a cation may be used in combination. In the case of a compound which generates all, it can be used alone. It is preferable to use a polymerization initiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, and it is more preferable to use in the range which is 1-10 mass parts.

The coating liquid of the active energy ray-polymerizable resin is polymerized with the above-mentioned polyfunctional monomer in an organic solvent such as ketones such as methyl ethyl ketone and methyl isobutyl ketone, alcohols such as ethyl alcohol and isopropyl alcohol, and esters such as ethyl acetate. It is prepared by dissolving the initiator mainly. In order to omit a drying process, it can also be made into a solvent-free.

The hard coat film of the present invention is known as a dipping method, spinner method, spray method, roll coating method, gravure method, wire bar method, extrusion molding, braiding method, die coating method, etc. It can form, dry and irradiate an active energy ray by the thin film formation method of the production.

Moreover, in order to improve the adhesiveness of a hard coat layer with a base film, surface treatment can be given to one or both surfaces by the oxidation method, an uneven | corrugated method, etc. as desired. Examples of the oxidation method include corona discharge treatment, glow discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone and ultraviolet irradiation treatment, and the like. Moreover, one or more undercoat layers can be formed. Examples of the material for the undercoat layer include copolymers such as vinyl chloride, vinylidene chloride, butadiene, (meth) acrylic acid ester and vinyl ester, or water-soluble polymers such as latex, low molecular weight polyester and gelatin. Metal oxides, such as tin oxide, ITO, and zinc oxide, and an ionic organic compound can also be added to an undercoat as a conductive substance.

The hard coat layer may be a single layer but may be composed of two or more layers. The multilayer structure can also be made by stacking layers having different surface modulus. In the case of a multi-layer structure, the elastic modulus, cure shrinkage rate, I / O value, and moisture absorption rate of the layer can be determined as values obtained by correcting the thickness of each layer property.

In the present invention, a functional thin film such as an antireflection layer, an antiglare layer, an antifouling layer and the like can be formed on the hard coating layer. In addition, it is also possible to laminate and combine an ultraviolet or infrared absorbing layer, a selective wavelength absorbing layer, an antistatic layer, and an electromagnetic shielding layer, and is provided as a hard coating film with a high hardness functional thin film.

These functional thin films can be produced by a wet method of coating a solution of a known functional material or by a dry method of forming a vacuum film such as sputtering or vapor deposition.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the laminated constitution about the hard coat film as one Embodiment of this invention, and FIG. 2 is the schematic diagram which shows the laminated constitution about the hard coat film with a functional thin film as one Embodiment of this invention. 1 or 2, 1 is a base film, 2 is a hard coating layer, 3a is a high refractive index layer, 3b is a low refractive index layer, and 4 is an antistatic undercoat.

The base material which laminated | stacked these hard coat films is used suitably as a base material which has the outstanding scratch resistance and surface hardness. Specific examples of such substrates include a plastic sheet adhered to a hard coat film for preventing damage to the surface, and a show window or window glass adhered to a hard coat film for scattering prevention.

The hard coat film may be attached to a substrate by laminating an adhesive. The hard coat film may be attached only to one side of the substrate or to both sides of the substrate.

As a base material which laminated | stacks a hard coat film, glass or a plastic can be used. Specific examples of the plastic include cellulose esters, polyamides, polycarbonates, polyesters, polystyrenes, polyolefins, polysulfones, polyethersulfones, polyarylates, polyetherimides, polymethylmethacrylates and polyetherketones. have.

The substrate is preferably transparent, and the light transmittance of the substrate is preferably 80% or more, more preferably 90% or more in the wavelength range of 400 nm to 780 nm.

Moreover, it is preferable that the thickness of a base material is 1-30 mm, and a base material may be any shape, such as a sheet form, a panel form, and a plate form.

The image display apparatus in which the hard coat film of this invention or the base material which laminated this was formed is used suitably as an image display apparatus which has the outstanding scratch resistance and surface hardness. As an image display apparatus in which a hard coat film or a base material which laminated | stacked this was formed, FPD (flat), such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescent display (FED), an electroluminescent display (ELD), etc. Panel display), cathode ray tube display (CRT), touch panel, and the like.

FIG. 3 is a schematic diagram showing a cross section of an image display apparatus having a hard coat film as one embodiment of the present invention. FIG. 4 is an image display apparatus having a base material laminated with a hard coat film as one embodiment of the present invention. It is a schematic diagram which shows the cross section with respect to. In FIG. 3 or FIG. 4, A shows an image display apparatus, B shows a base material, C shows a hard coat film, or a hard coat film with a functional thin film.

According to the present invention in which the product of the surface elastic modulus of the hard coating layer and the cube of the thickness is a value of 30 KPa · Pa or more and 700 KPa · Pa or less, a hard coat film having a high pencil hardness and hard to be damaged on the surface can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the layer structure about one Embodiment of the hard coat film of this invention.

It is a schematic diagram which shows the layer structure about one Embodiment of the hard coat film with a functional thin film of this invention.

3 is a schematic diagram showing a cross section of an image display device on which a hard coat film or a hard coat film with a functional thin film of the present invention is formed.

Fig. 4 is a schematic diagram showing a cross section of an image display device in which a base material on which a hard coat film or a hard coat film with a functional thin film of the present invention is laminated is formed.

Although an Example is given to the following and this invention is further demonstrated, this invention is not limited to this.

(Making of hard coating film)                 

The curable resin of Table 1 was dissolved in methyl ethyl ketone (MEK), the polymerization initiator was added, and it filtered with the polypropylene filter of 1 micrometer of pore diameters, and prepared the curable composition.

A latex (LX407C5; manufactured by Nippon Xeon Co., Ltd.) and tin oxide / ammonium oxide composite oxide (FS-10D; manufactured by Ishihara Sangyo Co., Ltd.) made of a styrene-butadiene copolymer having a glass transition temperature of 37 ° C. in advance, by mass 5: 175 micrometers thick PET film (biaxially stretched polyester terephthalate film) and 80 micrometers triacetyl which formed the antistatic undercoat layer by mixing at the ratio of 5: 5, and apply | coating so that the film thickness after drying may be set to 0.2 micrometer. Cellulose film was prepared separately.

The curable composition was apply | coated so that it might become a predetermined thickness by the extrusion molding method on the 2 types of films which performed antistatic prevention (thickness is adjusted to the solubility concentration and application amount of a curable composition). After drying a curable composition at 100 degreeC, the ultraviolet-ray of 750 mJ / cm <2> was irradiated, and the hard coat film (what apply | coated t to the sample number to triacetyl cellulose) which formed the hard-coat layer was created. In the case of a radically polymerizable curable composition, Irgacure 184 (manufactured by Chiba-Geigi Co., Ltd.), a rod seal 2074 (manufactured by Rhodia Co., Ltd.) in the case of a cationically polymerizable composition, and each initiator in the case of the mixing of both Was used. The addition amount was 4 mass% with respect to curable resin.

Polyglycidyl methacrylate ^* in the table was obtained by dropping a reaction solution obtained by dissolving glycidyl methacrylate in MEK and reacting at 80 ° C. for 2 hours while dropping an initiator into hexane and drying the precipitate under reduced pressure. On the other hand, the molecular weight was 15000.

On the other hand, alumina dispersion ^** is 234 parts of methyl isobutyl ketone, aronix M-5300 (carboxylic acid group-containing methacrylate; manufactured by Dong-A Synthetic Co., Ltd.), particulate alumina (AKP-G015; Sumitomo Chemical Co., Ltd. Note) Manufacture) Alumina fine particle dispersion in which 180 parts of the mixture is dispersed in a sand mill coated with ceramic coating using 1 mm zirconia beads in a media, and the surface is a mass of solid content.

(Characteristics of Hard Coating Film)

The product of the surface elastic modulus of the hard coating layer and the thickness of each of the manufactured hard coating films, the surface elastic modulus, the thickness, the curing shrinkage ratio of the curing composition, the pencil hardness and the curl value of the hard coating film when the PET or triacetyl cellulose is used as the base film. And cracking properties are shown in Table 1.                 

From Table 1, it turns out that the hard coat film of the pencil hardness of 4H or more can be obtained by making the product of the surface elastic modulus of a hard coat layer and the cube of the thickness of a hard coat layer into 30 KPa * Pa or more and 700 KPa * Pa or less.

More preferably, by using a hard coat material having a volume shrinkage ratio of 15% or less after curing, a small curl of the hard coat film can be obtained.

When the surface elastic modulus of the hard coating layer is 9 GPa or more, even if the curing shrinkage ratio is small, brittleness is significantly deteriorated, and the hard coating layer may easily crack.

In addition, the product of the surface elastic modulus and the cube of the thickness of the manufactured hard coating layer, the surface elastic modulus, the thickness, the curing shrinkage ratio, the I / O value of the cured composition, the pencil hardness, curl value and cracks of the hard coating film when the PET as a base film The surname and the like are shown in Table 2.                 

In the results shown in Table 2, the product of the surface elastic modulus and the cube of the film thickness is large, and the pencil shrinkage, curling, cracking and hygroscopicity are achieved by setting the volumetric shrinkage after curing of the curable composition to 15% by volume or less and I / O value to 0.85 or less. The target of the amount reduction can be achieved, and the expansion and contraction of the hard coat layer due to moisture absorption can be reduced.

(Formation of antifouling reflective layer)

(1) Preparation of high refractive index layer coating liquid (a-1)

30.0 parts by mass of titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.), 4.5 parts by mass of anionic monomer (M-5300, manufactured by Dong-A Synthetic Co., Ltd.) and 65.2 parts by mass of cyclohexanone are dispersed by sand grinder mill. And the titanium dioxide dispersion liquid of the mass mean diameter 55nm was prepared. The titanium dioxide dispersion and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), photopolymerization initiator (Irgacure 907, manufactured by Chiba Chemical Co., Ltd.), photosensitizer (Kayacure DETX, Nihon Kayakaku ( Note) Manufacture), the total amount of monomers (the total amount of dipentaerythritol hexaacrylate and anionic monomer) and the volume ratio of titanium dioxide is 60/40, the mass ratio of the photopolymerization initiator and the photosensitizer is 3/1, and the photopolymerization initiator and the light The high refractive index layer coating liquid was adjusted by adding and mixing to methyl ethyl ketone so that the mass ratio of the total amount of a sensitizer and the total amount of a monomer might be 6/100. The refractive index was 1.80.

(2) Preparation of low refractive index layer coating liquid (a-2)

Pentaerythritol tetraacrylate (PETA, Nippon Kayaku Co., Ltd.) 6 g, photopolymerization initiator (Irgacure 184, manufactured by Chiba Co., Ltd.) 0.5 g, 0.2 g, mega park 531A (C ₈ F ₁₇ SO ₂ N ( C ₃ H ₇ ) CH ₂ CH ₂ OCOCH = CH ₂ , 0.9 g of Dainippon Ink and Chemicals Co., Ltd., and 200 g of methyl ethyl ketone were mixed and stirred to prepare a coating solution of a low refractive index layer having a refractive index of 1.52. .

(3) Formation of hard coat film with antifouling antireflection layer

The high refractive index layer coating liquid of (a-1) was applied to the hard coat film of Example 43 using a wire bar, dried, and irradiated with ultraviolet rays, and then irradiated on the high refractive index layer (a-2). The low-refractive-index layer coating liquid of ()) was apply | coated so that a dry film thickness might be 85 nm, and it dried and irradiated with ultraviolet-ray, and obtained the hard coat film with an antifouling antireflective layer which formed the antireflective layer. An acrylic pressure sensitive adhesive was attached to this film and laminated on the plasma display front plate provided with an electromagnetic shielding layer, a near infrared absorbing layer, and a selective absorption filter. Table 3 shows the results of examining the surface properties.

What coated (a-1) and (a-2) directly on the PET film was created and laminated similarly. Table 3 shows the results of examining the surface properties.

In Table 3, by laminating the antifouling antireflection layer on the hard coat film of the present invention, a hard coating film with a functional thin film having both antifouling properties and antireflection functions can be obtained.

(4) Image display apparatus with hard coating film with antifouling antireflection layer                 

An acrylic adhesive is applied to the surface of the film of Example 44 or 46, which does not form a hard coat layer or an antifouling antireflective layer, and the front panel of PDP: 42 type plasma display (CMP4121HDJ) manufactured by Hitachi Seisakusho Co., Ltd. It adhere | attached on the glass surface of the absorption filter layer, the panel provided with a near-infrared absorption layer, and the plastic surface of the image display part of the Nintendo Co., Ltd. game boy, and investigated the image's ease, the wiping of a dirt, damage resistance, etc. The results are shown in Table 4.

In Table 4, it can be seen that the image display apparatus in which the hard coat film of the present invention is formed is hardly damaged by the surface hardness, and the image visibility is excellent.

Each evaluation method was implemented by the following method.

Surface elastic modulus: A range where the indentation depth does not exceed 1 μm using a diamond square indenter (tip to face angle; 136 °) using a microsurface hardness meter (Fisher Instruments Co., Ltd .: Fischer Scope H 100VP-HCU) The elastic modulus obtained from the change of load and displacement at the time of unloading by measuring the indentation depth under the appropriate test load at.                 

Curing shrinkage rate of the curing composition: in accordance with the method already described.

Pencil hardness test: The hardness of the pencil scratch test is a pencil prescribed by JIS K5400 using a test pencil prescribed by JIS S6006 after controlling the humidity of the produced hard coat film at a temperature of 25 ° C. and a relative humidity of 60% for 5 hours. According to the hardness evaluation method, it is the value of the hardness of the pencil by which the damage and dent are not found by the load of 9.8 N.

Mechanical pencil scratches: After adjusting the film at a temperature of 25 ° C. and a relative humidity of 60% for 5 hours, the mechanical pencil tip tilted at 45 ° in a HEIDON surface tester N-14 (manufactured by Shin-Do Science Co., Ltd.) The load at the time of damage was rubbed while varying the load on the tip of the metal part of PD355, Pentel Co., Ltd.).

Curl value: It is the value measured using the template for curl measurement of the method A of "the measuring method of the curl of a photographic film" of JISK7619-1988. The test conditions for 60% curl are 25 ° C and 60% relative humidity. The term "curl" as used in the present invention refers to curls on the inside of which the hard coating layer application forming side of the film is curved, and minus refers to curls on which the coating side is curved. The larger the value, the more noticeable the curl.

Curl humidity difference: The value of curl which is 80% and 10% of relative humidity was read at 25 degreeC, and it represented as the absolute value of the difference of both curl values.

Cracking property: After leaving a 35 mm width hard coat film in the atmosphere of 25 degreeC 60% RH for 5 hours, the hard coat layer was bent outside and the winding diameter at the time of a crack generate | occur | produced in a hard coat layer was calculated | required.

I / O value of the curing composition: by the method already described.                 

Moisture absorption amount: It left to stand in a dry atmosphere of dew point -40 degreeC for 2 hours, it was left to stand at 25 degreeC 60% RH for 3 hours after drying, and the moisture absorption amount was calculated | required from the weight change before and behind standing.

Surface reflectance: The surface reflectance of the specular reflection at 5 degrees of incident light in the wavelength range of 450-650 nm was calculated | required using the spectrophotometer (made by Nippon spectroscopy).

Eraser rub: Eraser No. Lion Co., Ltd. The surface damage was visually evaluated by reciprocating the surface 50 at a load of 1 kg using 50. It was set as ○ that no occurrence of damage or change was found.

Antifouling property: Evaluation of the state which wiped off the quick-dry oil-based ink (Merbrain made from Zebra, Maki (registered trademark)) on the film surface several times using Toray Corporation (trademark). In this completely wiped state, △ is a part that is left without being wiped, x is a state that most remain).

Easiness of view of screen: Visual evaluation evaluated that fluorescent light was easy to be seen (○ is hard to see, × is clearly visible, and △ is middle).

Fingerprint wipeability: The ease of removal when the fingerprint on the surface was wiped off using Toray Co., Ltd. "Toreshi" (registered trademark) was evaluated. Removed by rubbing, △ is the middle one).

Damage resistance: The number of occurrences of barely visible damage was observed by rubbing the surface of the hard coat film with a load of 1.96 N / cm 2 using a steel wall of # 0000.

Claims (14)

In a hard coat film obtained by laminating a hard coat layer on at least one side of a base film, the product of the surface elastic modulus of the hard coat layer and the cube of the thickness of the hard coat layer is 30 KPa · ㎣ or more and 700 KPa · ㎣ or less, and the hard coat layer is active. It is a layer containing the curable composition hardened | cured by the irradiation of an energy ray, The hard-coating film characterized by the volume shrinkage rate after hardening of the said curable composition being 0 to 15%. The hard coat film of Claim 1 whose surface elastic modulus of the said hard coat layer is 4.0 GPa or more and 9.0 GPa or less. delete The hard coating film according to claim 1, wherein the hard coating layer is a layer containing a curable composition cured by irradiation of active energy rays, and the I / O value after curing of the curable composition is 0.1 to 0.85. 2. The hard coat film of claim 1, wherein the curl value (curl value = 1 / R (R is radius of curvature (m))) of the hard coat film at 25 ° C 60% RH is in the range of minus 15 to plus 15. The hard coat film of Claim 1 whose absolute value of the difference of the curl value in 25 degreeC 80% RH and 25 degreeC 10% RH is 0 or more and 24 or less. The said hard coat layer is a layer containing the curable composition hardened | cured by irradiation of an active energy ray, The said curable composition is a polyfunctional polymerizable unsaturated double bond containing monomer and at least 2 cyclic structure in the same molecule | numerator. A hard coat film containing a ring-opening polymerizable cyclic ether compound having. The method of claim 1, wherein the hard coating layer is a layer containing a curable composition cured by irradiation of an active energy ray, the curable composition is a polyfunctional polymerizable unsaturated double bond-containing monomer and a repeating unit represented by the following formula (1) Hard coating films containing crosslinkable polymers, including: [Formula 1]

(Wherein, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, P ¹ is a monovalent group including a ring-opening polymerizable group, and L ¹ is a single bond or a divalent linking group). The hard coating film of claim 8, wherein P ¹ comprises an epoxy ring, an oxetane ring, or an oxazoline ring. The hard coating film of claim 1, wherein the hard coating layer has a film thickness of 20 to 60 μm. The hard coat film according to claim 1, wherein a functional thin film having an antireflection or antifouling function is laminated on the hard coat layer. The base material which laminated | stacked the hard coat film as described in any one of Claims 1, 2, and 4-11. The image display apparatus in which the hard coat film as described in any one of Claims 1, 2, 4-11 was formed. An image display apparatus comprising the substrate according to claim 12.

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