JP2003291236A - Optical hard-coat film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical hard-coat film which can be used suitably in various image displays, controls the occurrence of interference fringes, warpage, and cracks, and has good visibility. <P>SOLUTION: In the hard-coat film, a primer layer and a hard-coat layer are laminated in turn on at least one side of a base material film. The difference in refractive index between the primer layer and the hard-coat layer is 0.05 or below, the thickness of the hard-coat layer is preferably 10 μm or below, and the total thickness of the two layers is preferably 7-50 μm. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical hard coat film, and more specifically, an LCD (liquid crystal display), a touch panel, a CRT (cathode ray tube), a PDP.
The present invention relates to an optical hard coat film that is suitable for use in various image display devices such as (plasma display panel) and EL (electroluminescence) and that has suppressed visibility and improved visibility.

[0002]

2. Description of the Related Art Conventionally, transparent hard coat films have been used for various image display devices such as LCDs, touch panels and CRs.
In T, PDP, EL and the like, it is used for the purpose of surface protection, antiglare property and antireflection. This transparent hard coat film has a hard coat layer formed by heat curing, ionizing radiation curing, or the like on the base film, but it is preferable that interference fringes occur on the film surface and the visibility is impaired. It often brought about situations that were not. The causes of the interference fringes are mainly the light reflected on the surface of the hard coat layer and the light transmitted through the coat layer.
Further, it is due to the interference with the light reflected at the laminated interface. It is disclosed that the occurrence of such interference fringes is suppressed by, for example, setting the thickness of the hard coat layer to 11 μm or more (Japanese Patent Laid-Open No. 2001-26451). However, such a thick hard coat layer causes problems such as warping of the obtained hard coat film and easy occurrence of cracks in the hard coat layer. Therefore, it has been desired to develop an optical hard coat film that suppresses the generation of interference fringes, has good visibility, has less warpage and cracks, and is excellent in quality.

[0003]

Under the circumstances described above, the present invention is directed to an LCD, a touch panel, a CRT, a PD.
The purpose of the present invention is to provide an optical hard coat film suitable for various image display devices such as P and EL, which has suppressed occurrence of interference fringes, has good visibility, and has less warpage and cracks. It is a thing.

[0004]

Means for Solving the Problems As a result of intensive studies to develop an optical hard coat film having the above-mentioned preferable properties, the present inventors have found that a primer layer is provided between a base film and a hard coat layer. It has been found that the object can be achieved by interposing, and suppressing the difference in refractive index between the primer layer and the hard coat layer to a certain value or less, and completed based on this finding. That is,
The present invention provides (1) a hard coat film in which a primer layer and a hard coat layer are sequentially laminated on at least one surface of a substrate film, and the difference in refractive index between the primer layer and the hard coat layer is 0.05. An optical hard coat film, characterized in that (2) the thickness of the hard coat layer is 10 μm or less, and the total thickness of the primer layer and the hard coat layer is 7 to 50 μm.
(3) The optical hard coat film according to item (3), and (3) the optical hard coat film according to item 1 or 2, which is used for an image display device.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The optical hard coat film of the present invention has a structure in which a primer layer and a hard coat layer are sequentially laminated on at least one surface of a base film. Is not particularly limited, and can be appropriately selected and used from the plastic films known as the base material of the conventional optical hard coat film. Examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyethylene films, polypropylene films, cellophane, diacetyl cellulose films, triacetyl cellulose films, acetyl cellulose butyrate films, polychlorinated films. Vinyl film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film,
Examples thereof include polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic resin film and the like. These base films may be transparent or translucent, and may be colored or non-colored, and may be appropriately selected depending on the application. For example, when used for protection of a liquid crystal display, a colorless transparent film is suitable. The thickness of these base material films is not particularly limited and may be appropriately selected depending on the situation.
It is in the range of 5 to 250 μm, preferably 30 to 200 μm. In addition, one surface or both surfaces of the base film can be subjected to a surface treatment, if desired, by an oxidation method or a roughening method for the purpose of improving the adhesiveness with a layer provided on the surface thereof. Examples of the oxidization method include corona discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like, and as the roughening method, for example, sandblast method, solvent treatment method, etc. Is mentioned. These surface treatment methods are appropriately selected according to the type of the base film, but in general, the corona discharge treatment method is preferably used in terms of effects and operability.

In the present invention, as the primer constituting the primer layer provided on the surface of the substrate film, the difference between the refractive index of the primer layer and the refractive index of the hard coat layer provided thereon is 0.05 or less. To be
Depending on the type of the hard coat layer, it is appropriately selected from those having good adhesion to the hard coat layer and good adhesion to the base film. When the difference in the refractive index between the primer layer and the hard coat layer exceeds 0.05, the interference fringes cannot be sufficiently suppressed when the thickness of the hard coat layer is 10 μm or less, and the interference fringes are practically generated. The thickness of the hard coat layer should be 10
It is necessary to make the thickness larger than μm, and the object of the present invention cannot be achieved. As the primer, conventionally known ones, for example, acrylic, polyester, polyurethane, silicone, rubber and the like can be used, but acrylic primer is preferable from the viewpoint of durability and adhesion. Is. If desired, an antioxidant, a UV absorber, a light stabilizer, a leveling agent, etc. can be added to the primer. In the present invention, the thickness of this primer layer is selected so that the total thickness with the hard coat layer provided thereon is preferably in the range of 7 to 50 μm from the viewpoint of suppressing the generation of interference fringes. It If this total thickness is less than 7 μm, the effect of suppressing the generation of interference fringes is insufficient, and even if it is 50 μm or less, the generation of interference fringes can be sufficiently suppressed in practical use, and if it exceeds 50 μm, the hard coat film obtained is rather A warp may occur, which is not preferable. For these reasons, the total thickness of the primer layer and the hard coat layer is more preferably in the range of 7 to 25 μm. The thickness of the primer layer itself is preferably in the range of 3 to 40 μm, particularly 3 to 20 from the viewpoints of uniform coating property, adhesiveness, prevention of interference fringes and the like.
The range of μm is preferred. The formation of this primer layer is a conventionally known method, for example, a bar coating method, a knife coating method,
It can be carried out by coating on a base material film using a roll coating method, a blade coating method, a die coating method, a gravure coating method, a curtain coating method or the like, followed by a drying treatment.

Thus, by interposing the primer layer between the base film and the hard coat layer, the hard coat film obtained has a durability as an effect other than the effect of suppressing the generation of interference fringes and the effect of improving the adhesion. Good in light resistance and light resistance. In the hard coat film of the present invention, both the thermosetting resin composition and the ionizing radiation curable resin composition can be used for the hard coat layer provided on the primer layer. The thermosetting resin composition is not particularly limited, and can be appropriately selected and used from conventionally known ones. This thermosetting resin composition generally contains a thermosetting resin as a basic component and, if desired, further contains other resins and a curing agent. As the thermosetting resin, one having a molecular weight of about 200 to 2,000,000 is generally used.
Examples of the thermosetting resin include an acrylate polymer having a carbon-carbon double bond or a glycidyl group, an unsaturated polyester, an isoprene polymer, a butadiene polymer,
Examples thereof include epoxy resin, phenol resin, urea resin, melamine resin and the like. These may be used alone,
You may use it in combination of 2 or more type. Examples of other resins include acrylic resin, acetic acid, vinyl resin, urethane resin, polyester resin, polystyrene resin, polyamide resin, polycarbonate resin, polyimide resin, nitrile resin, and silicone resin. These resins are used for adjusting the viscosity of the coating liquid and for imparting desired physical properties to the hard coat layer, and may be used alone or in combination of two or more kinds.

Further, examples of the curing agent include organic peroxides such as dibenzoyl peroxide, dilauroyl peroxide, t-butyl peroxybenzoate, and di-2-ethylhexyl peroxydicarbonate, 2,2 '.
-Azobisisobutyronitrile, 2,2'-azobis-2
-Azo compounds such as methylbutyronitrile, 2,2'-azobisdimethylvaleronitrile, polyisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate, phenylenediamine,
Hexamethylenetetramine, isophoronediamine, diaminodiphenylmethane and other polyamines, dodecenyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride and other acid anhydrides, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole and other imidazoles And dicyandiamide, Lewis acids such as p-toluenesulfonic acid and trifluoromethanesulfonic acid, and formaldehyde. These hardeners are
It is appropriately selected according to the type of thermosetting resin used.
Further, this thermosetting resin composition, if desired, for example, silica for the purpose of adjusting the refractive index of the hard coat layer, improving the flexural modulus, stabilizing the volumetric shrinkage, improving heat resistance, and the like, Various fillers such as alumina and hydrated alumina may be added. Further, various additives such as antioxidants, ultraviolet absorbers, light stabilizers, leveling agents, defoaming agents and the like can be added. On the other hand, as the ionizing radiation curable resin composition, for example, a photopolymerizable prepolymer and / or
Alternatively, there may be mentioned those containing a photopolymerizable monomer and optionally a photopolymerization initiator. The photopolymerizable prepolymer includes a radical polymerization type and a cationic polymerization type, and examples of the radical polymerization type photopolymerizable prepolymer include polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, and polyol acrylate-based. To be Here, as the polyester acrylate prepolymer, for example, by esterifying the hydroxyl group of the polyester oligomer having a hydroxyl group at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or It can be obtained by esterifying the terminal hydroxyl group of the oligomer obtained by adding alkylene oxide to polyvalent carboxylic acid with (meth) acrylic acid. The epoxy acrylate prepolymer can be obtained, for example, by reacting (meth) acrylic acid with the oxirane ring of a bisphenol type epoxy resin or novolac type epoxy resin having a relatively low molecular weight to esterify. The urethane acrylate prepolymer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate with (meth) acrylic acid. Furthermore, the polyol acrylate prepolymer can be obtained by esterifying the hydroxyl groups of the polyether polyol with (meth) acrylic acid.
These photopolymerizable prepolymers may be used alone,
You may use it in combination of 2 or more type.

On the other hand, an epoxy resin is usually used as the cationically polymerizable photopolymerizable prepolymer. Examples of the epoxy resin include compounds obtained by epoxidizing polyhydric phenols such as bisphenol and novolac resins with epichlorohydrin, compounds obtained by oxidizing linear olefin compounds and cyclic olefin compounds with peroxides, etc. Is mentioned. Further, as the photopolymerizable monomer, for example, 1,4-butanediol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) ) Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth)
Acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate Polyfunctional acrylates such as acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate . These photopolymerizable monomers may be used alone or in combination of two or more, and may be used in combination with the photopolymerizable prepolymer.

On the other hand, as a photopolymerization initiator optionally used, for a radical polymerization type photopolymerizable prepolymer or a photopolymerizable monomer, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, Benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2
-Methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1
-[4- (Methylthio) phenyl] -2-morpholino-
Propan-1-one, 4- (2-hydroxyethoxy)
Phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-
Diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butyl-anthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-
Ethylthioxanthone, 2-chlorothioxanthone,
2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethyl amine benzoate, etc. are mentioned. Further, as the photopolymerization initiator for the cationic polymerization type photopolymerizable prepolymer, for example, an onium such as an aromatic sulfonium ion, an aromatic oxosulfonium ion, or an aromatic iodonium ion,
Examples thereof include compounds consisting of anions such as tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate and hexafluoroarsenate. These may be used alone or in combination of two or more, and the compounding amount thereof is usually 0 with respect to 100 parts by weight of the photopolymerizable prepolymer and / or the photopolymerizable monomer. It is selected in the range of 0.2 to 10 parts by weight.

Further, this ionizing radiation curable resin composition, if desired, can be used in the same manner as the thermosetting resin composition described above.
For the purpose of adjusting the refractive index of the hard coat layer, improving the bending elastic modulus, stabilizing the volume shrinkage ratio, and improving the heat resistance, various fillers such as silica, alumina, and hydrated alumina may be added. . Further, various additives such as antioxidants, ultraviolet absorbers, light stabilizers, leveling agents, defoaming agents and the like can be added. In the present invention, a coating liquid containing the thermosetting resin composition or the ionizing radiation curable resin composition is prepared as the coating liquid for forming the hard coat layer. A suitable organic solvent can be used for the preparation of this coating solution, if necessary. As the solvent used at this time,
For example, hexane, heptane, aliphatic hydrocarbons such as cyclohexane, toluene, aromatic hydrocarbons such as xylene, methylene chloride, halogenated hydrocarbons such as ethylene chloride, methanol, ethanol, propanol, alcohols such as butanol, acetone, methyl ethyl ketone, Examples thereof include ketones such as 2-pentanone and isophorone, esters such as ethyl acetate and butyl acetate, and cellosolve-based solvents such as ethyl cellosolve. The concentration and viscosity of the coating liquid prepared in this way are not particularly limited as long as they can be coated, and can be appropriately selected depending on the situation. Next, the coating liquid is coated on the primer layer by a conventionally known method, for example, 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. To form a coating film, and after drying, when a thermosetting resin composition is used, it is heated to cure the coating film, and when an ionizing radiation curable resin composition is used, ionizing radiation is used. Is irradiated to cure the coating film, thereby forming a hard coat layer.

Examples of the ionizing radiation include ultraviolet rays and electron beams. The ultraviolet rays are obtained with a high pressure mercury lamp, a fusion H lamp, a xenon lamp, etc., and the irradiation amount is usually 100 to 500 mJ / cm ² , while the electron beam is obtained with an electron beam accelerator or the like, and the irradiation amount is It is usually 150 to 350 kV. Among these ionizing radiations, ultraviolet rays are particularly suitable. When an electron beam is used, a cured film can be obtained without adding a polymerization initiator. In the present invention, the hard coat layer thus formed needs to have a difference between the refractive index of the hard coat layer and that of the primer layer of 0.05 or less, as described above. The material for forming the coat layer is appropriately selected from the thermosetting resin composition or the ionizing radiation curable resin composition in consideration of the type of primer used. For example, when an acrylic primer is used for the primer layer, an acrylate polymer is used as the thermosetting resin in the thermosetting resin composition, and a photopolymerizable prepolymer is used in the ionizing radiation curing resin composition. An acrylate compound is preferably used as the photopolymerizable monomer. The thickness of this hard coat layer is 10 μm or less, and as described above, the total thickness with the primer layer is preferably in the range of 7 to 50 μm. The thickness of the hard coat layer is 10 μm
If it exceeds, it may cause cracks in the hard coat layer or warp in the obtained hard coat film. If the thickness of the hard coat layer is too small, the scratch resistance may not be sufficiently exhibited. The more preferred thickness of the hard coat layer is in the range of 0.5 to 10 μm, particularly 2 to 10 μm.

In the optical hard coat film of the present invention, the haze value is preferably 10% or less, more preferably 5% or less in view of display image quality (visibility), light transmittance, transparency and the like. The total light transmittance is preferably 70% or more, more preferably 75% or more, and further preferably 80 to 95%. The hardness of the hard coat layer is preferably H or higher in terms of pencil hardness. When the hardness is H or higher in terms of pencil hardness, the hard coat film can have the scratch resistance required, but more scratch resistance. A pencil hardness of 2 should be sufficient.
Those of H or more are particularly preferable. In the present invention,
If necessary, an antireflection layer such as a siloxane-based coating or a fluorine-based coating can be provided on the surface of the hard coat layer for the purpose of imparting antireflection properties. In this case, the thickness of the antireflection layer is preferably about 0.05 to 1 μm. By providing this antireflection layer, the reflection of the screen caused by the reflection of sunlight, fluorescent light, etc. is eliminated, and by suppressing the reflectance of the surface, the total light transmittance is increased and the transparency is improved. . Note that the antistatic property can be improved depending on the type of the antireflection layer. In the optical hard coat film of the present invention, a primer layer and a hard coat layer are provided on one surface of the substrate film, and the other surface is a pressure-sensitive adhesive layer for sticking to an adherend such as a liquid crystal display. Can be formed. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, those for optical use, such as acrylic pressure-sensitive adhesive, urethane pressure-sensitive adhesive, and silicone pressure-sensitive adhesive are preferably used. The pressure-sensitive adhesive layer has a thickness of usually 5 to 100 μm, preferably 10
Is in the range of up to 60 μm. Furthermore, a release film can be provided on the pressure-sensitive adhesive layer. Examples of the release film include papers such as glassine paper, coated paper, laminated paper and various plastic films coated with a release agent such as a silicone resin. The thickness of the release film is not particularly limited, but is usually about 20 to 150 μm.

[0014]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The performance of the hard coat film was evaluated according to the following method. (1) Total light transmittance and haze value Haze meter [NDH200 manufactured by Nippon Denshoku Industries Co., Ltd.
0 ”] was used in accordance with JIS K 7105. (2) Pencil hardness A pencil scratch coating film hardness tester [manufactured by Toyo Seiki Seisakusho Ltd., model "NP"] was used for measurement according to JIS K 5400. (3) Place a curl 100 mm x 100 mm sample on a horizontal table with the coated surface facing up, and observe the lifted state of the film corners, and calculate the total height from the four corners. It was measured. (4) Adhesion According to JIS K 5400, the cross-cut tape method was used for evaluation. (5) Interference fringes The sample is placed on the black plane with the coated side up and 3
The interference fringes were evaluated according to the following criteria by visually confirming the reflected light using a fluorescent lamp of wavelength. ◯: Generation of interference fringes is equal to or less than that in Comparative Example 2. X: The occurrence of interference fringes is larger than that in Comparative Example 2. (6) Acceleration test UV long life fade meter [Suga test machine
"U48" manufactured by Co., Ltd.] was used to perform an accelerated test for 100 hours at a temperature of 63 ± 3 ° C. and a relative humidity of 50% or less, and then the total light transmittance, haze value and adhesion were determined. .

Example 1 As a primer, an acrylic resin primer [Solgard Primer 85B manufactured by Nippon Dacro Shamrock Co., Ltd.
-2 ", solid content concentration 12.5% by weight] 100 parts by weight and 25 parts by weight of methyl ethyl ketone are mixed, and a solid content concentration of 10% by weight is used as a hard coating agent for an acrylic UV curable resin [ "SEICA BEAM EXF-01L (NS)" manufactured by Dainichiseika Co., Ltd., solid content concentration 100%] 1
A solid content concentration of 50% by weight was prepared by mixing 00 parts by weight and 100 parts by weight of isobutanol. Thickness 12
After coating the primer on one surface of a 5 μm polyethylene terephthalate film [“0300E” manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.] with a Meyer bar so that the coating film thickness after drying would be 5 μm, 100 ° C. Primer layer (refractive index 1.5
0) was formed. Then, the hard coat agent was applied onto the primer layer with a Meyer bar so that the coating film thickness after curing was 5 μm, and dried at 80 ° C. for 1 minute, and then 250 mJ / A hard coat layer (refractive index 1.51) was formed by irradiating with ultraviolet rays of cm ² and curing. The performance of the hard coat film thus obtained is shown in Table 1. Example 2 In Example 1, instead of the polyethylene terephthalate film having a thickness of 125 μm, a polycarbonate film having a thickness of 100 μm (“Pure Ace C1 manufactured by Teijin Ltd.”) was used.
10-100 "] was used to prepare a hard coat film in the same manner as in Example 1. The performance of this hard coat film is shown in Table 1. Example 3 Example 3 was repeated except that a 125 μm-thick polyethylene terephthalate film was replaced by a 80 μm-thick triacetyl cellulose film [“T80-UNZ” manufactured by Fuji Photo Film Co., Ltd.]. A hard coat film was produced in the same manner as in 1. The performance of this hard coat film is shown in Table 1. Example 4 As a primer, 100 parts by weight of an acrylic resin-based primer [“NWS16” manufactured by Shin-Nakamura Chemical Co., Ltd., solid content concentration 33% by weight], 100 parts by weight of methyl ethyl ketone and 100 parts by weight of isobutanol were mixed. A hard coating agent having a solid content of 11% by weight was used as a hard coating agent.
A solid content concentration of 50% by weight was prepared by mixing with 0 part by weight. The primer was applied to one side of a 125 μm thick polyethylene terephthalate film [“0300E” manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.] with a Meyer bar so that the coating film thickness after drying was 5 μm, and then 100 A primer layer (refractive index 1.54) was formed by drying for 1 minute in a dryer at ℃. Then, the hard coat agent was coated on the primer layer with a Meyer bar so that the coating thickness after curing was 8 μm.
After drying for 1 minute at 0 ° C dryer, 250mJ /
A hard coat layer (refractive index 1.52) was formed by irradiating and curing with ultraviolet rays of cm ² . The performance of the hard coat film thus obtained is shown in Table 1.

Comparative Example 1 A hard coat film was prepared in the same manner as in Example 1 except that the primer layer was not formed. The thickness of the hard coat layer was 5 μm. The performance of this hard coat film is shown in Table 1. Comparative Example 2 A hard coat film was produced in the same manner as in Example 1 except that the primer layer was not formed and the thickness of the hard coat layer was 11 μm. The performance of this hard coat film is shown in Table 1. Comparative Example 3 A hard coat film was produced in the same manner as in Example 2 except that the primer layer was not formed. The thickness of the hard coat layer was 5 μm. The performance of this hard coat film is shown in Table 1. Comparative Example 4 A hard coat film was produced in the same manner as in Example 3 except that the primer layer was not formed. The performance of this hard coat film is shown in Table 1. Comparative Example 5 As a primer, 100 parts by weight of a polyester resin-based primer [“Byron 20SS” manufactured by Toyobo Co., Ltd., solid content concentration 30% by weight], 50 parts by weight of methyl ethyl ketone, and 50 parts by weight of toluene were mixed to form a solid content. Acrylic UV-curable resin with a concentration of 15% by weight was used as a hard coat agent [“SEICA BEAM EXF-manufactured by Dainichiseika Co., Ltd.”
01L (NS) ", solid content concentration 100%] and 100 parts by weight of isobutanol were mixed to prepare a solid content concentration of 50% by weight. The primer was applied to one side of a 125 μm thick polyethylene terephthalate film [“0300E” manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.] with a Meyer bar so that the coating film thickness after drying was 5 μm, and then 100 A primer layer (refractive index: 1.59) was formed by performing a drying treatment for 1 minute in a drier at ℃. Then, the hard coat agent was applied onto the primer layer with a Meyer bar so that the coating film thickness after curing was 5 μm, and dried at 80 ° C. for 1 minute, and then 250 mJ / Irradiate with ultraviolet rays of cm ² to cure,
A hard coat layer (refractive index 1.51) was formed. The performance of the hard coat film thus obtained is shown in Table 1.

[0017]

[Table 1]

[0018]

[Table 2]

(Note) PET: Polyethylene terephthalate film PC: Polycarbonate film TAC: Triacetyl cellulose film

[0020]

According to the present invention, generation of interference fringes, which is suitable for various image display devices such as LCDs, touch panels, CRTs, PDPs, ELs, etc., is suppressed, and good visibility is obtained.
Moreover, it is possible to provide an optical hard coat film which is excellent in quality with less warpage and cracks.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshitaka Takesako             5-2-6 Tsuji, Saitama City, Saitama Prefecture             Leaf 103 F term (reference) 2K009 AA15 BB24 CC24 DD02 DD05                       DD06                 4F100 AK01A AK25 AK42 BA03                       BA05 BA10A BA10D BA10E                       CC00D CC00E EJ65B EJ65C                       GB41 JB14 JK12D JK12E                       JK14 JL04 JN18 JN30 YY00                       YY00D YY00E

Claims (3)

[Claims] 1. A hard coat film in which a primer layer and a hard coat layer are sequentially laminated on at least one surface of a base film, and the difference in refractive index between the primer layer and the hard coat layer is 0.05 or less. An optical hard coat film, which is characterized by being present. 2. The thickness of the hard coat layer is 10 μm or less,
The total thickness of the primer layer and the hard coat layer is 7 to 50
The optical hard coat film according to claim 1, which has a thickness of μm. 3. A display device used for an image display device.
Or the optical hard coat film according to 2 above.