JP2010174125A - Composition for use in hard coat layer, and hard coat film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide such a composition for use in the formation of a hard coat layer which is capable of forming the hard coat layer which is imparted with a stain resistant function, consequently which has the high adhesion to a substrate as well as which is imparted with the excellent curling resistance, scratch resistance, surface hardness and from which the stain can easily be removed and which has always a high visibility without deteriorating the characteristics thereof; and a hard coat film. <P>SOLUTION: The composition for forming a hard coat layer includes a polyfunctional (meth)acrylic monomer (A), a hydroxyl group-containing (meth)acrylic monomer (B), a photoradical polymerization initiator (C), a polymerizable group-containing fluorocompound (D) and a solvent (E), with the solvent (E) having a boiling point of 50-120°C. The hard coat film has on a transparent substrate the hard coat layer, whose composition has been cured, whose surface has a surface free energy of 20 mN/m or below, and whose thickness is 5-25 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a hard coat used for the purpose of protecting the surface of a display such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display panel (PDP), or a field emission display (FED). The present invention relates to a layer forming composition and a hard coat film. More specifically, the present invention relates to a composition for forming a hard coat layer and a hard coat film that have high adhesion to a substrate, are excellent in curling resistance, and can impart excellent scratch resistance and surface hardness.

  A protective film for a circularly polarizing plate used for a polarizing plate protective film for a liquid crystal display, an organic EL display, or the like has a resin layer formed to have various functions. For example, an antistatic layer for providing an antistatic function, an antireflection layer for suppressing reflection, and a hard coat layer for improving surface hardness. In particular, the hard coat layer is indispensable for display applications, and not only is used as a single hard coat layer but also serves as a lower layer of the antireflection layer, which is an important technique.

  For example, Patent Document 1 discloses a thermoplastic norbornene-based material having a silicone-based hard coat layer having an adhesion in a cross-cut peel test of 50 or more in 100 on the surface of a substrate formed of a thermoplastic norbornene-based resin. A molded article made of a resin is disclosed, and Patent Document 2 is formed from a coating film component containing one or more organic components having a polymerizable functional group and an inorganic filler, and at least one of the organic components is A hard coat film for a plastic substrate film characterized by not having a hydrogen bond-forming group is disclosed. Patent Document 3 discloses a hard coat film which is a cured coating film layer on at least one surface of a transparent plastic film substrate. A hard coat film having a layer, wherein the hard coat layer forming material comprises urethane acrylate (A), isocyanuric acid acrylate (B) and Hard coat film characterized by containing inorganic ultrafine particles (C) is disclosed.

  In recent years, the demand for increasing the hardness of a hard coat film provided with a hard coat layer as a protective function of these polarizing plates has become very high. However, cellulose ester films are mainly used as the hard coat film substrate for the protective film of these polarizing plates, but since this film substrate is soft, it is very difficult to increase the hardness as a hard coat film. is there.

  In addition, as the application application of these polarizing plates spreads widely to liquid crystal televisions, notebook computers, etc., various characteristics are required, antireflection function with less reflection of fluorescent light, antistatic function that is hard to get dust, Characteristics such as an antifouling function capable of wiping off fingerprints have been required. In particular, notebook computers and the like often have fingerprints, sebum, sweat, cosmetics, and the like attached to them by human use. Generally, since the surface energy of a polarizing plate is large, such dirt is likely to adhere. Moreover, since the surface of the antireflection film has fine irregularities, it is not easy to remove the dirt. Furthermore, only the portion where such dirt is attached becomes highly reflective, and there is a problem because the dirt is conspicuous.

  Therefore, as a means for solving the problem of contamination, various techniques for forming an antifouling layer on the surface of the optical member that has a performance in which the contamination is difficult to adhere and can be easily wiped off have been proposed.

  For example, Patent Document 4 discloses an anti-fouling and friction-resistant anti-reflection article in which an anti-reflection film mainly composed of silicon dioxide is provided on the surface of a base material and the surface is further treated with a compound containing an organosilicon substituent. Has been proposed. Patent Document 5 similarly proposes an antifouling and friction-resistant CRT filter in which the substrate surface is coated with a terminal silanol organopolysiloxane. Further, Patent Document 6 proposes an antifouling and low-reflective plastic having an antireflection film on its surface containing mono- and disilane compounds containing polyfluoroalkyl groups and halogen, alkyl or alkoxy silane compounds. ing.

  However, the antifouling layer formed by the conventional method has insufficient antifouling property, and in particular, dirt such as fingerprints, sebum, sweat, cosmetics, etc. is difficult to wipe off, and the antifouling performance decreases greatly with use. . For this reason, development of the antifouling layer excellent in antifouling property and durability is desired.

Japanese Unexamined Patent Publication No. 7-97468 JP 2000-159916 A JP 2006-106427 A Japanese Unexamined Patent Publication No. 1-086101 JP-A-4-338901 JP 61-247743 A

  None of the conventional hard coat films have antifouling properties such as fingerprint wiping properties, and even if antifouling properties are imparted, they have very weak antifouling performance. For this reason, there is a problem that fingerprints and the like are easily stained, and once attached, it is difficult to remove the stain. Even with insufficient anti-smudge treatment, simply wiping with general paper or cloth will spread the dirt over the entire surface, and the contaminated surface will reflect external light, blocking transmitted light and displaying. There was a problem that the characteristics were remarkably lowered and the initial visibility could not be maintained. In addition, when a fluorine-based additive is added to impart antifouling properties to the hard coat surface, the normal fluorine-based additive does not have a reactive group, so the adhesion with the hard coat layer is insufficient, When the surface is wiped, the antifouling component can be wiped off. Therefore, in general, many antifouling layers are provided separately from the hard coat layer to impart antifouling properties.

  Therefore, the object of the present invention is to solve such a problem, without providing a separate antifouling layer, imparting an antifouling function to the hard coat layer, and having high adhesion to the substrate, A composition for forming a hard coat layer that can impart excellent curl resistance, scratch resistance, surface hardness, can easily remove stains, and can always form a hard coat layer with high visibility without deteriorating its characteristics, and To provide hard coat film.

  The invention according to claim 1 includes a polyfunctional (meth) acrylic monomer (A), a (meth) acrylic monomer (B) having a hydroxyl group, a radical photopolymerization initiator (C), and a polymerizable group. A composition for forming a hard coat layer comprising a fluorine compound (D) and a solvent (E), wherein the solvent (E) has a boiling point of 50 ° C. or higher and 120 ° C. or lower. It is a composition.

  The invention according to claim 2 is characterized in that the polyfunctional (meth) acrylic monomer (A) is mainly composed of a urethane (meth) acrylate monomer and / or an oligomer. It is a composition for layer formation.

  The invention according to claim 3 is characterized in that the polyfunctional acrylate monomer (A) is 50 to 95 with respect to the total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having a hydroxyl group. 3. The composition for forming a hard coat layer according to claim 1, wherein the composition is contained by weight%.

  In the invention according to claim 4, the addition amount of the fluorine-containing compound (D) having the polymerizable group is such that the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer having a hydroxyl group (B The hard coat layer forming composition according to claim 1, wherein the composition is 0.01 to 10% by weight based on the total of

  In the invention according to claim 5, the addition amount of the radical photopolymerization initiator (C) is a total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having the hydroxyl group. The hard coat layer forming composition according to claim 1, wherein the content is 0.01 to 10% by weight.

  Invention of Claim 6 has the hard-coat layer which hardened the composition for hard-coat layer formation in any one of Claims 1-5 on a transparent base material, And the said hard-coat layer surface The hard coat film has a surface free energy of 20 mN / m or less and a film thickness of the hard coat layer of 5 to 25 μm.

  When the hard coat film is produced by applying the composition for forming a hard coat layer according to any one of claims 1 to 5 on a transparent substrate, drying, and curing steps. The temperature of the said drying process is 50 degreeC or more and 100 degrees C or less, It is a hard coat film characterized by the above-mentioned.

  The invention according to claim 8 is the hard coat film according to claim 6 or 7, wherein the transparent substrate is cellulose triacetate.

  According to the present invention, without providing another antifouling layer, the hard coat layer is imparted with an antifouling function, has high adhesion to the substrate, and has excellent curl resistance, scratch resistance, It is possible to provide a composition for forming a hard coat layer and a hard coat film which can impart surface hardness, can easily remove dirt, and can always form a hard coat layer with high visibility without deterioration of its characteristics.

It is explanatory sectional drawing of the hard coat film of this invention.

  As a result of examining the application of antifouling properties to the hard coat layer on the transparent substrate, the present inventor has found that the polyfunctional (meth) acrylic monomer (A) of the present invention and the (meth) acrylic monomer (B) having a hydroxyl group. A composition for forming a hard coat layer comprising: a radical photopolymerization initiator (C); a fluorine-containing compound (D) having a polymerizable group; and a solvent (E) having a boiling point of 50 ° C. or higher and 120 ° C. or lower. The inventors have found that the above conventional problems can be solved.

  Hereinafter, embodiments of the present invention will be described in detail.

  The polyfunctional (meth) acrylic monomer (A) constituting the composition for forming a hard coat layer of the present invention has two or more hydroxyl groups of a polyhydric alcohol having two or more alcoholic hydroxyl groups in one molecule. A compound which is an esterified product of (meth) acrylic acid is preferred. Others include polyester acrylates, urethane acrylates, epoxy acrylates and polyether acrylates, such as those in which reactive acrylic groups are bonded to an acrylic resin skeleton, and rigid skeletons such as melamine and isocyanuric acid. An acrylic group-bonded one or the like can also be used, but in the present invention, particularly when a urethane (meth) acrylate monomer and / or oligomer is used, the hardness and flexibility of the hard coat layer can be remarkably improved.

  In the present invention, “(meth) acrylic monomer” indicates both “acrylic monomer” and “methacrylic monomer”. For example, “polyfunctional (meth) acrylic monomer” indicates both “polyfunctional acrylic monomer” and “polyfunctional methacrylic monomer”. Moreover, the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having a hydroxyl group of the present invention may be oligomers.

  As the urethane acrylate as the polyfunctional (meth) acrylic monomer (A) preferred in the present invention, it is generally easy to react a polyester polyol with an isocyanate monomer or a product obtained by reacting a prepolymer with an acrylate monomer having a hydroxyl group. Can be mentioned.

  Specific examples include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate urethane prepolymer. Pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer, and the like can be used. Moreover, these monomers can be used 1 type or in mixture of 2 or more types. Further, these may be monomers in the coating liquid, or may be oligomers that are partially polymerized.

  Commercially available polyfunctional acrylic monomers include Mitsubishi Rayon Co., Ltd. (trade name “Diabeam” series, etc.), Nagase ChemteX Corporation (trade name “Denacol” series, etc.), Shin-Nakamura Chemical Co., Ltd .; (Product name “NK Ester” series, etc.), Dainippon Ink and Chemicals Co., Ltd .; (Product name “Unidic” series, etc.), Toa Gosei Co., Ltd. (product name “Aronix” series, etc.), Nippon Oil & Fats Corporation; (Product name "Blemmer" series, etc.), Nippon Kayaku Co., Ltd .; (Product name "KAYARAD" series, etc.), Kyoeisha Chemical Co., Ltd. (Product names "Light ester" series, "Light acrylate" series, etc.) Can be used.

  As commercially available urethane (meth) acrylate monomers and / or oligomers, Kyoeisha Chemical Co., Ltd .; UA-306H, UA-306T, UA-306I, etc., Nippon Synthetic Chemical Industry Co., Ltd .; UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV-7650B, etc., Shin-Nakamura Chemical Co., Ltd .; U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U- 324A, etc., Daicel UCB Corporation; Ebecryl-1290, Ebecryl-1290K, Ebecryl-5129, etc., Negami Industrial Co., Ltd .; UN-3220HA, UN-3220HB, UN-3220HC, UN-3220HS, etc. it can.

  As the (meth) acrylate compound (B) having a hydroxyl group constituting the composition for forming a hard coat layer of the present invention, a polyfunctional (meth) acrylate is preferable, and a polymerizable group is a polyfunctional (meth) acrylate compound. Compatibility with the fluorine-containing compound (D) is improved, and problems such as white turbidity and precipitation of the hard coat coating liquid do not occur. Preferred is hydroxyethyl acrylate, hydroxyethyl methacrylate, pentaerythritol triacrylate, or dipentaerythritol pentaacrylate.

The polyfunctional (meth) acrylic monomer (A) is used in an amount of 1 to 99 weights based on the total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having the hydroxyl group. % Is preferable, and 50 to 95% by weight is more preferable. When the usage ratio of the polyfunctional (meth) acrylic monomer (A) is less than 50% by weight, it may be insufficient in terms of obtaining a hard coat layer having sufficient hardness, and the hard coat layer to be formed In some cases, the pencil hardness is reduced.
Moreover, when the usage-amount of the said polyfunctional (meth) acryl monomer (A) exceeds 95 weight%, a film curls large by the cured film side by cure shrinkage of a polyfunctional (meth) acryl monomer (A). May cause inconvenience such as. In addition, since the use ratio of the (meth) acrylic monomer (B) having a hydroxyl group is small, the compatibility of the fluorine-containing compound (D) having a polymerizable group is not sufficient, and the coating liquid becomes cloudy and precipitates are generated. In some cases, this is insufficient in terms of obtaining a hard coat composition having good storage stability.

  As the radical photopolymerization initiator (C) constituting the composition for forming a hard coat layer of the present invention, a compound that generates radicals by irradiating ionizing radiation and initiates a polymerization reaction of an acrylic monomer is preferable.

  Specific examples of the photoradical polymerization initiator (C) include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4 ′. -Dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2,2 -Carbonyl compounds such as dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfide, tetramethylthiuramdisulfur And sulfur compounds such as thioxanthone, 2-chlorothioxanthone and 2-methylthioxanthone can be used. These photopolymerization initiators may be used alone or in combination of two or more.

  The use amount of the photo radical polymerization initiator (C) of the present invention is that of the polyfunctional (meth) acrylic monomer (A) of the hard coat layer forming composition and the (meth) acrylic monomer (B) having the hydroxyl group. 0.01 to 10% by weight is appropriate based on the total. When the amount is less than 0.01% by weight, a sufficient curing reaction does not proceed when the ionizing radiation is irradiated. When the amount exceeds 10% by weight, the ionizing radiation does not reach the lower part of the hard coat layer.

  As the fluorine-containing compound (D) having a polymerizable group constituting the hard coat layer forming composition of the present invention, it is possible to impart antifouling properties to the hard coat layer surface by adding a fluorine-based additive. However, in the case of a fluorine-based additive having no polymerizable group, the additive floats on the surface of the hard coat layer, so that it is removed from the surface of the hard coat by wiping with a cloth or the like. For this reason, once the surface is wiped with a cloth or the like, the antifouling property is lost. In the present invention, by adding a polymerizable group to the fluorine compound having antifouling properties, the fluorine additive is also polymerized at the time of forming the hard coat layer, and the antifouling properties can be obtained even if the surface is wiped with a cloth or the like. Has the advantage of being maintained.

  The fluorine-containing compound (D) having a polymerizable group of the present invention is more preferably a compound in which this polymerizable group has a (meth) acrylate group. This is because it can be copolymerized with a polyfunctional (meth) acrylate compound, and high hardness can be achieved by radical polymerization by ionizing radiation.

  As such a fluorine-containing compound (D) having a polymerizable group of the present invention, OPTOOL DAC (manufactured by Daikin Industries, Ltd.), SUA1900L10, SUA1900L6 (manufactured by Shin-Nakamura Chemical Co., Ltd.), UT3971 (Nihon Gosei Co., Ltd.) )), Defencer TF3001, Defencer TF3000, Defencer TF3028 (Dainippon Ink Co., Ltd.), Light Procoat AFC3000 (Kyoeisha Chemical Co., Ltd.), KNS5300 (Shin-Etsu Silicone Co., Ltd.), UVHC1105, UVHC8550 (GE) Toshiba Silicone Co., Ltd.).

  The amount of the fluorine-containing compound (D) having a polymerizable group of the present invention is such that the polyfunctional (meth) acrylic monomer (A) of the composition for forming a hard coat layer and the (meth) acrylic monomer having a hydroxyl group ( 0.01 to 10% by weight is suitable with respect to the sum of B). When the amount is less than 0.01% by weight, sufficient antifouling properties are not exhibited, and the surface energy is larger than 20 mN / m. When the amount exceeds 10% by weight, the compatibility with the polymerizable monomer and the solvent is high. Since it is not good, the coating liquid may become cloudy and precipitate may occur, which may cause inconveniences such as generation of defects in the coating liquid and hard coat layer.

  As the solvent (E) of the present invention, there are no particular limitations on the type of solvent such as ester, ketone, ether, alcohol, and aromatic hydrocarbon, but the boiling point is 50 ° C. or higher and 120 ° C. The following are desirable: Specifically, methyl acetate, ethyl acetate, isobutyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropyl alcohol, isobutanol, 1-butanol, tetrahydrofuran, 1,3-dioxolane, n-hexane, cyclohexane, Toluene or the like can be used. Note that the solvent is not limited to one type, and may be a mixed solvent as long as a plurality of solvents are mixed and fall within the above boiling point range.

If the boiling point of these solvents (E) is less than 50 ° C., they will volatilize at room temperature and it will be difficult to form a uniform hard coat layer due to an increase in viscosity. Further, since the evaporation rate is high, the substrate cannot be sufficiently dissolved, and the adhesion between the hard coat layer and the substrate is lowered.
On the other hand, if the boiling point of the solvent (E) exceeds 120 ° C., it will be difficult to evaporate the solvent sufficiently in the drying step, and it will remain as a residual solvent in the hard coat layer. The result will be reduced.

  In the present invention, as a modifier for the hard coat layer, a coating property improver, an antifoaming agent, a thickener, an antistatic agent, inorganic particles, organic particles, an organic lubricant, an organic polymer compound, an ultraviolet ray, Absorbers, light stabilizers, dyes, pigments, stabilizers, and the like can be used, and these are used as a composition component of the coating layer constituting the hard coat layer within a range that does not impair the reaction by actinic radiation. Accordingly, the characteristics of the hard coat layer can be improved.

  In the present invention, the method for curing the hard coat layer forming composition is preferably a method of irradiating actinic rays, particularly ultraviolet rays. When these methods are used, the hard coat layer forming composition is used. The product can be cured by ultraviolet irradiation by adding a radical photopolymerization initiator. In the ultraviolet irradiation, light having a wavelength of 400 nm or less may be used. For example, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a halogen lamp, or the like can be used. Moreover, you may add a heating process as needed.

  In the composition for forming a hard coat layer used in the present invention, thermal polymerization such as hydroquinone, hydroquinone monomethyl ether or 2,5-tert-butyl hydroquinone is used to prevent thermal polymerization during production and dark reaction during storage. It is desirable to add an inhibitor. The addition amount of the thermal polymerization inhibitor is preferably 0.005 to 0.05% by weight with respect to the solid content of the composition for forming a hard coat layer.

  The composition for forming a hard coat layer of the present invention can be made into a hard coat film by coating on a substrate to form a hard coat layer.

  As a method for applying the hard coat layer forming composition, the hard coat layer forming composition may be applied using a known coating means such as a bar coater, applicator, doctor blade, roll coater, die coater, and comma coater. Can do.

  As a base material, the film-form thing which has translucency is preferable, and should just have moderate transparency and mechanical strength as a base material. For example, polyethylene terephthalate (PET), cellulose triacetate (TAC), diacetyl cellulose, acetyl cellulose butyrate, polyethylene naphthalate (PEN), cycloolefin polymer, polyimide, polyethersulfone (PES), polymethyl methacrylate (PMMA), A film such as polycarbonate (PC) can be used. Among them, when a hard coat film is provided on the front surface of the liquid crystal display, cellulose triacetate (TAC) is preferably used because it has no optical anisotropy.

  In the present invention, a hard coat film having antifouling properties is provided. FIG. 1 shows an explanatory cross-sectional view of the hard coat film of the present invention. In the hard coat film of the present invention, the outermost layer is provided with a hard coat layer. At this time, the hard coat film of the present invention preferably has a surface energy on the surface of the hard coat layer of 20 mN / m or less.

  This is surface free energy as an index of a method for evaluating the antifouling property of the hard coat layer surface, and the presence / absence / absence of the antifouling property of the hard coat surface can be estimated from this surface energy. The surface free energy can be obtained from the surface contact angle by the extended Fowkes equation, and the smaller this value, the better the antifouling property. In the hard coat film of the present invention, since the surface energy is 20 mN / m or less, a hard coat film having high antifouling properties can be obtained.

  In the hard coat film of the present invention, the surface free energy of the hard coat layer surface is preferably 15 mN / m or more. The smaller the surface free energy, the higher the antifouling property of the hard coat film. However, when the surface free energy of the hard coat layer surface is less than 15 mN / m, it is necessary to add a considerable amount of the fluorine-containing compound (D) having a polymerizable group. At this time, the composition is whitened and formed. The hard coat film may become whitish and become a hard coat film that is not suitable for being provided on the display surface.

  In preparing the hard coat film of the present invention, the hard coat layer-forming composition is applied on a transparent substrate, dried and cured to produce a hard coat film. In the present invention, The drying temperature in the stage of the drying process is 50 ° C. or higher and 100 ° C. or lower.

  When the drying temperature is increased, the fluorine-containing compound (D) having a polymerizable group contained in the hard coat layer forming composition is likely to move to the hard coat layer surface, and the fluorine compound is aligned and oriented on the surface. Therefore, the surface contact angle and antifouling property of the hard coat layer surface are improved. However, when the drying temperature is increased, the evaporation rate is increased, so that the solvent cannot sufficiently dissolve the substrate surface, and as a result, the adhesion between the hard coat layer and the substrate is lowered. On the other hand, if the drying temperature is increased too much, the softening temperature of the base material will be exceeded, which may cause the base material to be deformed or wrinkled.

  On the other hand, when the drying temperature is lowered, the base material dissolution rate of the solvent is improved, so that the adhesion between the hard coat layer and the base material is improved. However, if the base material dissolution is advanced too much, the thickness of the hard coat layer portion decreases. As a result, the pencil hardness is lowered, and the movement of the fluorine-based additive to the hard coat surface in the drying process does not proceed sufficiently. As a result, the surface contact angle and antifouling property of the hard coat layer surface are lowered.

  From the above results, the drying temperature in the drying process when the hard coat film-forming composition of the present invention is applied on a transparent substrate, dried and cured to produce a hard coat film is 50 ° C. or higher and 100 ° C. or lower. Is preferred.

  Although the film thickness of the hard coat layer obtained by coating is determined by the required hardness, the preferable film thickness is 3 to 30 μm, and more preferably 5 to 25 μm. If the film thickness is less than 3 μm, sufficient hardness cannot be obtained. On the other hand, if the film thickness exceeds 30 μm, the base material is very curled due to curing shrinkage of the hard coat layer, and problems such as breakage occur in the next process.

  The hard coat film of the present invention is provided with a functional layer as necessary. The functional layer is provided between the transparent substrate and the hard coat layer or on the transparent substrate surface on the side where the hard coat layer is not provided. Examples of these functional layers include an antireflection layer, an antistatic layer, an antiglare layer, an electromagnetic wave shielding layer, an infrared absorption layer, an ultraviolet absorption layer, and a color correction layer. These functional layers may be a single layer or a plurality of layers. A hard coat film in which a hard coat layer is formed on a transparent substrate and a hard coat film provided with these functional layers are bonded to various display surfaces such as a liquid crystal display, a plasma display, and a CRT display. Therefore, it is possible to provide a display having excellent scratch resistance and antifouling properties.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The performance of the hard coat film was evaluated according to the following method.
Haze: Measurement was performed according to JIS-K7105 using NDH-2000 manufactured by Nippon Denshoku.
Total light transmittance: Measured according to JIS-K7105 using NDH-2000 manufactured by Nippon Denshoku.
Pencil hardness: evaluated according to JIS-K5400.
Scratch resistance: Using a # 0000 steel wool, it was reciprocated 10 times while applying a load of 250 g / cm ² to confirm the presence or absence of scratches.

○: No scratch ×: Scratch

  Adhesion: A 10 × 10 cross-cut peel test was performed to confirm the presence or absence of peeling of the hard coat layer.

○: No peeling ×: With peeling

Antifouling properties: Fingerprints are attached to the hard coat surface, and the fingerprints are wiped off using a cellulose nonwoven fabric (Pencot M-3: manufactured by Asahi Kasei Corporation) while applying a load of 250 g / cm ^2. Judgment was made. The judgment criteria were as follows.

○: Fingerprints can be completely wiped △: Fingerprint wipe marks remain ×: Fingerprints cannot be wiped off

  Surface energy: Using a contact angle meter (CA-X type: manufactured by Kyowa Interface Science Co., Ltd.), a droplet having a diameter of 1.8 mm is formed on the needle tip in a dry state (20 ° C.-65% RH). Droplets were made in contact with the surface of the sample (solid). The contact angle is an angle formed by a tangent to the liquid surface at a point where the solid and the liquid are in contact with the solid surface, and is defined as an angle on the side including the liquid. As the liquid, distilled water and n-hexadecane were used, respectively. It calculated | required with the extended Fowkes formula based on the contact angle of these two types of solutions.

<Example 1>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Pentaerythritol triacrylate, Kyoeisha Chemical)
10 parts by weight initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: Optool DAC (Daikin Industries) 0.5 parts by weight Solvent: ethyl acetate (boiling point 77 ° C.) The mixed coating solution was applied by a bar coating method so as to have a cured film thickness of 12 μm, dried at 70 ° C., and irradiated with 400 mJ / cm ² of ultraviolet rays by a metal halide lamp to form a hard coat layer. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Example 2>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UV-1700B (Nippon Synthetic Chemical) 90 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: OPTOOL DAC (Daikin Industries) 0.5 parts by weight solvent: ethyl acetate (boiling point 77 ° C.) A coating solution obtained by stirring and mixing 100 parts by weight was applied to a cured film thickness of 12 μm by the bar coating method and dried at 70 ° C. Then, a hard coat layer was formed by irradiating ultraviolet rays of 400 mJ / cm ² with a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Example 3>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical Co., Ltd.) 80 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical Co., Ltd.) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: Defensa TF3001 ( DIC Co., Ltd.) 1.0 parts by weight Solvent: ethyl acetate (boiling point 77 ° C.) 100 parts by weight of stirring and mixing was applied by a bar coating method to a cured film thickness of 12 μm, and the temperature reached 70 ° And dried, and a hard coat layer was formed by irradiating with 400 mJ / cm ² ultraviolet rays with a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Example 4>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: OPTOOL DAC ( Daikin Industries Co., Ltd. 0.5 parts by weight Solvent: methyl isobutyl ketone (boiling point 117 ° C.) 100 parts by weight of stirring and mixing was applied to a cured film thickness of 12 μm by the bar coating method and dried at 90 ° C. Then, a hard coat layer was formed by irradiating ultraviolet rays of 400 mJ / cm ² with a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Comparative Example 1>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Non-polymerizable fluorine-based additive: Megafac F470 (DIC) 1.0 part by weight Solvent: ethyl acetate (boiling point 77 ° C.) 100 parts by weight of stirring and mixing was applied to a cured film thickness of 12 μm by the bar coating method, and the temperature reached 70 ° C. And dried, and a hard coat layer was formed by irradiating with 400 mJ / cm ² ultraviolet rays with a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Comparative example 2>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: OPTOOL DAC ( Daikin Industries, Ltd. 0.5 parts by weight Solvent: dichloromethane (boiling point 40 ° C.) 100 parts by weight of stirring and mixing was applied to a cured film thickness of 12 μm by the bar coating method and dried at 70 ° C. A hard coat layer was formed by irradiating ultraviolet rays of 400 mJ / cm ^{2 with} a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Comparative Example 3>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Kyoeisha Chemical) 10 parts by weight Initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: OPTOOL DAC ( Daikin Industries Co., Ltd. 0.5 parts by weight Solvent: 100 parts by weight of propylene glycol methyl ether acetate (boiling point 121 ° C.) was stirred and mixed to apply a coating solution to a cured film thickness of 12 μm by the bar coating method. And dried, and a hard coat layer was formed by irradiating with 400 mJ / cm ² ultraviolet rays with a metal halide lamp. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Comparative example 4>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Pentaerythritol triacrylate, Kyoeisha Chemical)
10 parts by weight initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: Optool DAC (Daikin Industries) 0.5 parts by weight Solvent: ethyl acetate (boiling point 77 ° C.) The mixed coating solution was applied by a bar coating method so as to have a cured film thickness of 12 μm, dried at 40 ° C., and irradiated with 400 mJ / cm ² of ultraviolet rays by a metal halide lamp to form a hard coat layer. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

<Comparative Example 5>
Using a cellulose triacetate film substrate with a thickness of 80 μm,
Urethane acrylate: UA-306I (Kyoeisha Chemical) 90 parts by weight Acrylic monomer: PE-3A (Pentaerythritol triacrylate, Kyoeisha Chemical)
10 parts by weight initiator: Irgacure 184 (Ciba Specialty Chemicals) 1.5 parts by weight Fluorine-based additive: Optool DAC (Daikin Industries) 0.5 parts by weight Solvent: ethyl acetate (boiling point 77 ° C.) The mixed coating solution was applied by a bar coating method so as to have a cured film thickness of 12 μm, dried at 130 ° C., and irradiated with 400 mJ / cm ² of ultraviolet rays by a metal halide lamp to form a hard coat layer. Table 1 summarizes the measurement results of the total light transmittance, haze, scratch resistance test, pencil hardness, adhesion, and antifouling properties of this hard coat film.

  The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 5 are summarized in Table 1 below.

  Comparing Examples 1 to 4 with Comparative Example 1, it can be seen that a hard coat film having sufficient antifouling properties and surface energy can be produced by using a fluorine-containing compound having a polymerizable group.

  Furthermore, when Examples 1 to 4 and Comparative Examples 2 to 5 are compared, by using a fluorine-containing compound having a polymerizable group, not only has sufficient antifouling properties and surface energy, but depending on the solvent and the drying temperature, Further, it can be seen that a hard coat film having both pencil hardness and adhesion can be produced.

Claims (8)

  A polyfunctional (meth) acrylic monomer (A), a (meth) acrylic monomer (B) having a hydroxyl group, a photoradical polymerization initiator (C), a fluorine-containing compound (D) having a polymerizable group, a solvent ( A composition for forming a hard coat layer comprising E), wherein the solvent (E) has a boiling point of 50 ° C. or higher and 120 ° C. or lower.   The composition for forming a hard coat layer according to claim 1, wherein the polyfunctional (meth) acrylic monomer (A) contains a urethane (meth) acrylate monomer and / or an oligomer as a main component.   The polyfunctional acrylate monomer (A) is contained in an amount of 50 to 95% by weight based on the total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having a hydroxyl group. The composition for forming a hard coat layer according to claim 1 or 2.   The addition amount of the fluorine-containing compound (D) having a polymerizable group is 0.01 with respect to the total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having a hydroxyl group. It is 10 to 10 weight%, The composition for hard-coat layer formation in any one of Claims 1-3 characterized by the above-mentioned.   The addition amount of the radical photopolymerization initiator (C) is 0.01 to 10 weights with respect to the total of the polyfunctional (meth) acrylic monomer (A) and the (meth) acrylic monomer (B) having a hydroxyl group. The composition for forming a hard coat layer according to any one of claims 1 to 4, wherein the composition for forming a hard coat layer is%.   It has a hard-coat layer which hardened the composition for hard-coat layer formation in any one of Claims 1-5 on a transparent base material, and the surface free energy of the said hard-coat layer surface is 20 mN / m or less And the film thickness of the said hard-coat layer is 5-25 micrometers, The hard-coat film characterized by the above-mentioned.   When the hard coat layer-forming composition according to any one of claims 1 to 5 is applied on a transparent substrate, dried, and cured to produce a hard coat film, the temperature of the drying step is 50 ° C. The hard coat film is 100 ° C. or lower.   The hard coat film according to claim 6 or 7, wherein the transparent substrate is cellulose triacetate.

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