JP6039460B2 - Coating composition and coating film - Google Patents

Description

  The present invention relates to a coating composition for forming a coating layer on a substrate film and the like, and a coating film formed by forming a coating layer.

  In order to prevent scratches, a hard coat film having a hard coat layer is often provided on the surface of a display in a mobile device such as a mobile phone. And the surface of the hard coat film may be subjected to printing for the purpose of enhancing the design. Moreover, the protective film with an adhesive layer may be affixed on the surface of the said hard coat film further by the user.

  On the other hand, a laminated structure in which a large number of layers are laminated in order to incorporate various optical elements is often formed between a substrate and a liquid crystal module in a liquid crystal display. In some cases, a hard coat film is used for this laminated structure. In this case, the surface of the hard coat film on the hard coat layer side is also bonded to another layer (optical film) via an adhesive. .

  Here, the material constituting the hard coat layer is blended with a silicone-based or fluorine-based leveling agent for the purpose of smoothing the surface of the hard coat layer or suppressing coating defects such as repellency during coating. There is a case. In a hard coat layer containing such a leveling agent, the leveling agent is likely to bleed out to the surface, thereby reducing the surface free energy and reducing the adhesion of printing materials and adhesives. ing.

  In order to solve the above problems, for example, Patent Document 1 discloses a photopolymerization initiator, (Metal) for the purpose of providing a hard coat film having a hard coat layer having scratch resistance and printability. ) Acrylate monomer and (meth) acrylic monomer having alkylamide group and / or phosphate (meth) acrylate, blending amount of (meth) acrylate monomer and (meth) acrylic monomer having alkylamide group And / or the hard coat film which has the hard-coat layer which hardened the coating composition whose mass ratio with the compounding quantity of a phosphate (meth) acrylate is 100: 5-100: 50 is disclosed.

  Patent Document 2 discloses a hard coat layer having a surface tension of 35 mN / m or more for the purpose of providing a hard coat film that can be directly printed on the hard coat layer by a thermal transfer printing method using a thermal transfer printer. A coated film is disclosed.

JP 2009-161609 A JP 2011-110902 A

  However, as disclosed in Patent Document 1, even when a (meth) acrylic monomer and / or phosphate (meth) acrylate having an alkylamide group is used as a material for forming a hard coat layer, a printing material or adhesive The effect of improving the adhesiveness of the agent is still insufficient. Patent Document 2 does not disclose a specific means for controlling the surface tension of the hard coat layer surface as described above.

  The present invention has been made in view of such a situation, and a coating composition that can form a coating layer excellent in adhesiveness with a printing material, an adhesive, etc. while containing a leveling agent, And it aims at providing the coating film which has such a coating layer.

  In order to achieve the above object, first, the present invention comprises an active energy ray-curable compound, silica nanoparticles having an average particle diameter of 2 to 300 nm, and a leveling agent, and the content of the silica nanoparticles is It is 10-280 mass parts with respect to 100 mass parts of active energy ray hardening-type compounds, and content of the said leveling agent is 0.00 with respect to 100 mass parts of total amounts of the said active energy ray-curable compound and the said silica nanoparticle. Provided is a coating composition characterized by being 007 to 0.5 parts by mass (Invention 1).

  The coating composition according to the invention (Invention 1) contains a predetermined amount of a leveling agent and contains a predetermined amount of silica nanoparticles having a predetermined average particle diameter, so that there is no defect and the appearance is excellent, and a printing material It is possible to form a coat layer having excellent adhesion with the adhesive or the like.

  In the said invention (invention 1), you may further contain organic fine particles (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said active energy ray hardening-type compound is a polyfunctional (meth) acrylate type monomer and / or (meth) acrylate type prepolymer (invention 3).

  2ndly, this invention was equipped with the base film and the coating layer formed by apply | coating and hardening the said coating composition (invention 1-3) on the at least one surface of the said base film, It is characterized by the above-mentioned. A coating film is provided (Invention 4).

  In the said invention (invention 4), it is preferable that the wetting tension in the surface on the opposite side to the said base film side of the said coating layer is 30 mN / m or more (invention 5).

  The coating composition according to the present invention contains a predetermined amount of a leveling agent and a predetermined amount of silica nanoparticles having a predetermined average particle diameter, thereby forming a coating layer having an excellent appearance without defects and the like. In addition, it is possible to form a coat layer having excellent adhesion to a printing material, an adhesive, and the like. Moreover, the coating film which concerns on this invention has a coating layer excellent in adhesiveness with a printing material, an adhesive, etc. like that.

It is sectional drawing of the coating film which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Coating composition]
The coating composition according to the present embodiment contains an active energy ray-curable compound, silica nanoparticles having an average particle size of 2 to 300 nm, and a leveling agent, and may further contain organic fine particles as desired. And content of a silica nanoparticle is 10-280 mass parts with respect to 100 mass parts of active energy ray hardening-type compounds, and content of a leveling agent is 100 mass of total amounts of an active energy ray hardening-type compound and silica nanoparticles. 0.007 to 0.5 parts by mass with respect to parts.

  Since the coating composition which concerns on this embodiment contains a leveling agent, the effect by a leveling agent is acquired. That is, at the time of coating, it is presumed that the leveling agent is present on the surface of the coating film, application defects such as repelling can be suppressed, and the surface of the formed coating layer can be smoothed.

  On the other hand, the content of the leveling agent is specified as described above, and the coating layer formed by containing a predetermined amount of silica nanoparticles having a predetermined average particle size can be used for printing materials such as inks and adhesives. It becomes excellent in adhesiveness with agents. The reason is that due to the hydrophilicity of the silanol group of the silica nanoparticles, the silica nanoparticles are likely to collect on the surface of the coating layer to be formed, whereby the silica nanoparticles appear on the surface of the coating layer and the surface area of the coating layer is reduced. It is estimated that the leveling agent on the surface of the coating layer is reduced and the leveling agent present on the coating film surface during coating is adsorbed on the silica nanoparticles during the formation of the coating layer, thereby reducing the leveling agent concentration on the surface of the coating layer. The

(1) Active energy ray-curable compound The active energy ray-curable compound contained in the coating composition according to this embodiment is not particularly limited, and the active energy ray-curable compound depends on the performance to be imparted to the coating layer to be formed. What is necessary is just to select suitably. For example, when a hard coat layer is formed, a layer that can form a hard coat layer may be selected.

  Here, active energy rays refer to those having energy quanta among electromagnetic waves or charged particle beams, and specific examples include ultraviolet rays and electron beams. Among active energy rays, ultraviolet rays that are easy to handle are particularly preferable.

  As the active energy ray-curable compound, it is preferable to use a polyfunctional (meth) acrylate monomer and / or a (meth) acrylate prepolymer. The polyfunctional (meth) acrylate monomer and the (meth) acrylate prepolymer may be used alone or in combination. In the present specification, (meth) acrylate means both acrylate and methacrylate. The same applies to other similar terms.

  Examples of the multifunctional (meth) acrylate monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol diene. (Meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate phosphoric acid, allylation Cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentae Thritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol Examples include polyfunctional (meth) acrylates such as hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These may be used individually by 1 type and may be used in combination of 2 or more type.

  On the other hand, examples of the (meth) acrylate prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate.

  Examples of the polyester acrylate-based prepolymer include esterification of a hydroxyl group of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to carboxylic acid with (meth) acrylic acid.

  The epoxy acrylate prepolymer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it.

  The urethane acrylate-based prepolymer can be obtained, for example, by esterifying, with (meth) acrylic acid, a polyurethane oligomer obtained by a reaction between polyether polyol or polyester polyol and polyisocyanate.

  The polyol acrylate prepolymer can be obtained, for example, by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  The above prepolymers may be used alone or in combination of two or more.

(2) Silica nanoparticles The silica nanoparticles contained in the coating composition according to the present embodiment are nano-order silica fine particles having an average particle diameter of 2 to 300 nm. When the coating composition according to the present embodiment contains a predetermined amount of silica nanoparticles having such an average particle diameter, the formed coating layer has excellent adhesion to a printing material, an adhesive, and the like. In addition, the average particle diameter of a silica nanoparticle shall be measured by the zeta potential measuring method.

  When the average particle diameter of the silica nanoparticles is less than 2 nm, the area of the silica nanoparticles that appears on the surface of the coating layer to be formed is small, and the effect of improving the adhesion with a printing material, a pressure-sensitive adhesive or the like cannot be obtained. On the other hand, when the average particle diameter of the silica nanoparticles exceeds 300 nm, the surface area of the coat layer is not sufficiently increased, and the effect of improving the adhesion with a printing material, an adhesive, or the like cannot be obtained. Further, the light transmittance is lowered, and the formed coating layer becomes cloudy. The average particle diameter of the silica nanoparticles is preferably 6 to 100 nm, and particularly preferably 8 to 50 nm.

  Silica nanoparticles usually have a silanol group on the surface, and it is presumed that the above-described effects can be obtained by the hydrophilicity of the silanol group. The silica nanoparticles may be modified with an organic material for the purpose of improving dispersibility, as long as the effects of the present invention are not impaired. Silica nanoparticles are preferably used in the form of an organosol (colloid). By using it in the form of an organosol, the dispersibility of the silica nanoparticles is improved, and the homogeneity and light transmittance of the resulting coating layer are improved.

Modification with an organic substance can be performed by a conventional method. For example, a silane coupling agent having a structure such as CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₃ Si (OCH ₃ ) ₃ is added to the organosol of silica nanoparticles, heated to about 50 ° C., and stirred for several hours. By doing so, the surface of the silica particles can be modified. The structure and amount of the silane coupling agent to be used are appropriately selected according to the required degree of dispersibility of the silica nanoparticles.

  As the organic solvent used in the organosol, methyl ethyl ketone, methyl isobutyl ketone and the like, which are excellent in compatibility with the active energy ray-curable compound and the leveling agent and excellent in volatility when forming the coating layer, are preferable.

  As said silica nanoparticle, what is marketed can be used, It is preferable to use the organosilica sol MEK-ST, MIBK-ST, etc. by Nissan Chemical Co., Ltd. especially.

  Content of the silica nanoparticle in the coating composition which concerns on this embodiment is 10-280 mass parts with respect to 100 mass parts of active energy ray hardening-type compounds, Preferably it is 15-260 mass parts, Most preferably 100 to 240 parts by mass. When the content of the silica nanoparticles is less than 10 parts by mass, the effect of improving the adhesion with a printing material, an adhesive, or the like cannot be obtained. On the other hand, when the content of the silica nanoparticles exceeds 280 parts by mass, the silica nanoparticles are aggregated, and the effect of improving the adhesion with a printing material or an adhesive cannot be obtained. Permeability decreases.

(3) Leveling agent As a leveling agent contained in the coating composition according to the present embodiment, a desired leveling effect, that is, an effect of suppressing application defects such as repellency during coating, and a surface smoothing effect of the coating layer to be formed If it is possible to obtain the above, there is no particular limitation. Examples of such leveling agents include silicone leveling agents, fluorine leveling agents, acrylic leveling agents, siloxane-modified acrylic leveling agents, vinyl leveling agents, and the like.

  As the silicone leveling agent, a copolymer of polyoxyalkylene and polydimethylsiloxane can be used. Examples of commercially available silicone leveling agents include FZ-2118, FZ-77, and FZ-2161 manufactured by Toray Dow Corning, and KP321, KP323, KP324, KP326, KP340, and KP341 manufactured by Shin-Etsu Chemical Co., Ltd. , TSF4440, TSF4441, TSF4445, TSF4450, TSF4452, TSF4452, TSF4460, BYK-300, BYK-306, BYK-306 manufactured by BYK Japan 307, BYK-320, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, BYK-345, BYK-346, BYK 348, such as BYK-377, BYK-378, BYK-UV3500, BYK-3510, BYK-UV3570 and polyester-modified silicone oil and the like.

  As the fluorine leveling agent, a copolymer of polyoxyalkylene and fluorocarbon can be used. As a commercial item of a fluorine-type leveling agent, MEGAFAC series by DIC, FC series by Sumitomo 3M, etc. are mentioned, for example.

  Examples of commercially available acrylic leveling agents include BYK-350, BYK-352, BYK-354, BYK-355, BYK-358N, BYK-361N, BYK-380N, BYK-381, manufactured by BYK Japan, Inc. BYK-392 etc. are mentioned.

  Examples of commercially available siloxane-modified acrylic leveling agents include BYK-3550 manufactured by Big Chemie Japan.

  Said leveling agent may be used independently and may be used in combination of 2 or more type. Among these, a silicone leveling agent is preferable from the viewpoint of affinity with silica nanoparticles, and a polyester-modified silicone leveling agent is particularly preferable.

  The content of the leveling agent in the coating composition according to the present embodiment is 0.007 to 0.5 parts by mass, preferably 0 with respect to 100 parts by mass of the total amount of the active energy ray-curable compound and the silica nanoparticles. 0.009 to 0.4 parts by mass, particularly preferably 0.01 to 0.3 parts by mass. The effect by a leveling agent is not exhibited as content of a leveling agent is less than 0.007 mass part. On the other hand, when the content of the leveling agent exceeds 0.5 parts by mass, the adhesion with the printing material, the pressure-sensitive adhesive and the like in the formed coating layer is lowered.

(4) Organic fine particles The coating composition according to this embodiment may further contain organic fine particles. By containing organic fine particles, a desired function can be imparted to the resulting coating layer. For example, the slipperiness of the coat layer surface can be improved, or the antiglare property can be imparted to the coat layer. When the slipperiness of the coat layer surface is improved, blocking in the coating film can be prevented / suppressed.

  Examples of the organic fine particles include silicone fine particles, melamine resin fine particles, acrylic resin fine particles (for example, polymethyl methacrylate resin fine particles), acrylic-styrene copolymer fine particles, polycarbonate fine particles, polyethylene fine particles, polystyrene. Fine particles, benzoguanamine resin fine particles, and the like. One kind of organic fine particles may be used alone, or two or more kinds thereof may be used in combination.

The organic fine particles are preferably spherical and have a narrow particle size distribution. The average particle size of the organic fine particles is preferably 1 to 10 μm, and particularly preferably 2 to 5 μm. Further, the coefficient of variation (CV value) of the particle size represented by the following formula is preferably 40% or less, and particularly preferably 20% or less.
Coefficient of variation of particle size (CV value) (%) = (standard deviation particle size / average particle size) × 100
In addition, the average particle diameter and the coefficient of variation (CV value) in this specification are measured using a laser diffraction scattering type particle size distribution measuring apparatus (in the examples, LA-920 manufactured by Horiba, Ltd.) is used. Using a few drops of a 5% strength by weight dispersion prepared with methyl ethyl ketone as a sample, the measured value is obtained.

  When organic fine particles are contained in the coating composition according to the present embodiment, the content of the organic fine particles in the coating composition is 0.1 to 10 parts by mass with respect to 100 parts by mass of the active energy ray-curable compound. It is preferable that it is preferably 0.2 to 5 parts by mass, more preferably 0.5 to 2 parts by mass.

  The coating composition in this embodiment may contain third components such as various additives and solvents in addition to the above components. As various additives, for example, photopolymerization initiator, ultraviolet absorber, antioxidant, light stabilizer, antistatic agent, silane coupling agent, anti-aging agent, thermal polymerization inhibitor, colorant, surfactant, Examples include storage stabilizers, plasticizers, lubricants, antifoaming agents, organic fillers, wettability improvers, and coating surface improvers.

  Examples of the photopolymerization initiator include 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′-diethylaminobenzof Non, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type. Content of the photoinitiator in a coating composition is normally chosen in the range of 0.2-10 mass parts with respect to 100 mass parts of active energy ray hardening-type compounds.

  The solvent is not particularly limited as long as it can be used for improving coating properties, adjusting viscosity, adjusting solid content concentration, etc., and can dissolve the active energy ray-curable compound and leveling agent. Can be used.

  Specific examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl lactate and γ-butyrolactone Ethers such as ethylene glycol monomethyl ether (methyl cellosorb), ethylene glycol monoethyl ether (ethyl cellosorb), diethylene glycol monobutyl ether (butyl cellosorb), propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene and xylene; dimethylformamide Amides such as dimethylacetamide and N-methylpyrrolidone.

  The coating composition described above can be applied to a desired substrate and cured to form a coat layer (for example, a hard coat layer) having a desired function on the surface of the substrate. The substrate to be coated is usually a transparent plastic film, a plastic plate, a glass plate or the like.

[Coating film]
As shown in FIG. 1, the coating film 1 according to this embodiment includes a base film 11 and a coat layer 12 formed on one surface of the base film 11.

  What is necessary is just to select suitably as the base film 11 according to the use of the coating film 1, Preferably a plastic film with favorable affinity with the coating layer 12 is selected.

  Examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyolefin films such as polyethylene film and polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, Polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether ketone film, polyether sulfone film, poly Etherimide film, fluororesin film Plastic films such as polyamide film, acrylic resin film, polyurethane resin film, norbornene polymer film, cyclic olefin polymer film, cyclic conjugated diene polymer film, vinyl alicyclic hydrocarbon polymer film, or laminates thereof A film is mentioned. Of these, a polyethylene terephthalate film, a polycarbonate film, a norbornene polymer film, and the like are preferable in terms of mechanical strength and the like.

  Moreover, in the said base film 11, in order to improve adhesiveness with the layers (coat layer 12, the adhesive layer mentioned later, etc.) provided in the surface, it is a primer process and an oxidation method on one side or both sides as desired. The surface treatment can be performed by an uneven method or the like. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment, and examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatment methods are appropriately selected according to the type of the base film 11, but in general, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  Although the thickness of the base film 11 is suitably determined according to the use of the coating film 1, it is about 15-300 micrometers normally, Preferably it is about 30-200 micrometers.

  The coat layer 12 is formed by applying the above-described coating composition to the base film 11 and curing it.

  The coating composition may be applied by a conventional method, for example, a bar coating method, a knife coating method, a Mayer bar method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method. When the coating composition is applied, the coating film is preferably dried at 80 to 150 ° C. for about 30 seconds to 5 minutes.

  Since the coating composition contains a leveling agent, application defects such as repellency are suppressed when the coating composition is applied, and the surface of the coating film, and thus the surface of the coating layer 12, becomes smooth. . Thereby, it is possible to form the coat layer 12 having no defects and excellent appearance.

Curing of the coating composition is performed by irradiating the coating film of the coating composition with active energy rays such as ultraviolet rays and electron beams. UV irradiation, high-pressure mercury lamp, a fusion H lamp, can be carried out by a xenon lamp or the like, the dose of ultraviolet ray is illuminance 50~1000mW / cm ^2, about the amount of light 50~1000mJ / cm ² is preferred. On the other hand, the electron beam irradiation can be performed by an electron beam accelerator or the like, and the irradiation amount of the electron beam is preferably about 10 to 1000 krad.

  The thickness of the coating layer 12 after curing is preferably 0.1 to 20 μm, particularly preferably 1 to 10 μm, and further preferably 2 to 7 μm. Further, when the coat layer 12 is a hard coat layer, the thickness of the coat layer 12 is preferably 1 to 15 μm, particularly preferably 2 to 10 μm, in order to effectively exhibit the scratch prevention performance and scratch resistance.

  The coating film 1 which concerns on this embodiment should just have the base film 11 and the coating layer 12, and may have another layer further. For example, a similar coat layer may be formed on the opposite surface of the base film 11 to the coat layer 12, an adhesive layer may be formed, and a release sheet is laminated on the adhesive layer. May be.

  It does not specifically limit as an adhesive which comprises an adhesive layer, Well-known adhesives, such as an acryl type, a rubber type, and a silicone type, can be used.

  A transparent conductive thin film layer, an antireflection layer, or the like may be formed on the coat layer 12.

  The coating film 1 according to the present embodiment can be used, for example, as a surface layer or an internal intermediate layer of various displays such as a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display (PDP), and a touch panel.

  The coating layer 12 of the coating film 1 according to the present embodiment has excellent adhesion to a printing material, a pressure-sensitive adhesive, and the like by using the above-described coating composition. Specifically, the wet tension of the surface of the coat layer 12 is preferably 30 mN / m or more, particularly preferably 35 mN / m or more, and more preferably 45 mN / m or more. When the wetting tension on the surface of the coat layer 12 is 30 mN / m or more, the adhesiveness with a printing material, an adhesive, or the like is excellent. The wetting tension is a value measured according to JIS K6768 (in the test example, a wetting tension test solution manufactured by Wako Pure Chemical Industries, Ltd. is used).

  The haze value of the coating film 1 according to this embodiment is preferably 3.0% or less, more preferably 1.0% or less, particularly preferably 0.8% or less. More preferably, it is 7% or less. When the haze value is 3.0% or less, the transparency is high and the optical application is suitable. The haze value is a value measured according to JIS K7136-2000 (in the test example, a haze meter “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd. is used).

The coating layer 12 of the coating film 1 according to the present embodiment has a high hardness by using the above-described coating composition. Specifically, using # 0000 steel wool, it is preferable that the coat layer 12 is rubbed 10 cm 10 times with a load of 250 g / cm ² so that no scratches are generated. By having such steel wool hardness, it is possible to suppress the coating layer 12 from being damaged when the coating film 1 is used for a display or the like.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, another layer may be interposed between the base film 11 and the coating layer 12 in the coating film 1.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
100 parts by mass of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Ester A-DPH) as an active energy ray-curable compound (solid content conversion value; the same shall apply hereinafter) and silica nanoparticles (manufactured by Nissan Chemical Industries, Ltd., 20 parts by mass of MIBK-ST, average particle size: 10 nm) and 0.01 parts by mass of acryloyl group-containing polyester-modified polydimethylsiloxane (BYK-UV3570, manufactured by BYK Chemie) as a silicone leveling agent (polyester-modified silicone oil) Leveling agent blending amount when the total amount of the active energy ray-curable compound and the silica nanoparticles is converted to 100 parts by mass: 0.01 part by mass, and 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF) as a photopolymerization initiator , Irgacure 184) 3 parts by mass It was mixed to obtain a coating composition. The coating composition was diluted with propylene glycol monomethyl ether to prepare a coating solution having a solid concentration of 30%.

The coating liquid obtained above was applied to one side of a polyester film (Toray Co., Ltd., Lumirror U46, thickness: 125 μm) as a base film with a Mayer bar # 14 and dried at 70 ° C. for 1 minute. Subsequently, ultraviolet rays were irradiated under the following conditions by an ultraviolet irradiation device (manufactured by Eye Graphics Co., Ltd., Igrantage ECS-401GX type) to form a coating layer having a thickness of 5.0 μm to obtain a coating film.
[UV irradiation conditions]
・ Light source: High pressure mercury lamp ・ Lamp power: 2 kW
・ Conveyor speed: 4.23 m / min
Illuminance: 240 mW / cm ²
-Light intensity: 307 mJ / cm ²

[Examples 2-5, Comparative Examples 1-5]
A coating film was produced in the same manner as in Example 1 except that the blending amounts of the components constituting the coating composition were changed as shown in Table 1. In Example 5, the coating was further blended with 2 parts by mass of crosslinked acrylic fine particles (manufactured by Soken Chemical Co., Ltd., Mx-300, average particle size: 3 μm, coefficient of variation of particle size (CV value): 15%) as organic fine particles. The composition was used.

  Here, the average particle diameter and the coefficient of variation (CV value) of the organic fine particles were measured and calculated as follows. Organic fine particles were dispersed in methyl ethyl ketone as a dispersion medium to prepare a dispersion having a concentration of 5% by mass. Using a few drops of the dispersion as a sample, a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) was used to measure the average particle size and standard deviation particle size, and from these measured values. The coefficient of variation (CV value) of the particle size was calculated.

[Test Example 1] (Measurement of haze value)
The haze value (%) of the coating film obtained in Examples and Comparative Examples was changed to JIS K7136-2000 using a haze meter (NDH-2000, manufactured by Nippon Denshoku Industries Co., Ltd.) with a D65 light source and measurement method 3. Measured in conformity. The results are shown in Table 1.

[Test Example 2] (Measurement of wetting tension)
The wetting tension (mN / m) on the surface of the coating layer of the coating film obtained in Examples and Comparative Examples was measured according to JIS K6768 using a wetting tension test solution manufactured by Wako Pure Chemical Industries. The results are shown in Table 1.

[Test Example 3] (Evaluation of anti-blocking property)
The surfaces of the coating layers in the two coating films obtained in the examples or comparative examples were pressed against each other with a load of 200 g / cm ² to evaluate whether blocking occurred. Those in which blocking did not occur were evaluated as good (◯), and those in which blocking occurred were evaluated as poor (×). The results are shown in Table 1.

[Test Example 4] (Evaluation of appearance)
The coating layer surfaces of the coating films obtained in the examples and comparative examples were observed under a three-wavelength fluorescent lamp, and the appearance was evaluated. A 10 cm square on the surface of the coating layer was evaluated as A having 4 defects or less, B having 5-9 defects, and C having 10 defects or more. A is judged as good appearance, and B and C are judged as poor appearance. The results are shown in Table 1.

[Test Example 5] (Steel Wool Hardness Test)
About the coating film obtained by the Example and the comparative example, the coating layer was rubbed 10 cm 10 times with a load of 250 g / cm < ² > using the steel wool of # 0000, and the presence or absence of the damage | wound was confirmed. The case where there was substantially no flaw was indicated by ○, and the case where flaws were observed was indicated by ×. The results are shown in Table 1.

※１：活性エネルギー線硬化型化合物およびシリカナノ粒子の合計１００質量部換算とした場合の配合量

* 1: Compounding amount when converted into 100 parts by mass of active energy ray-curable compound and silica nanoparticles.

  As is clear from Table 1, the coating films obtained in Examples 1 to 5 had high wet tension, no defects, excellent appearance, high hardness, and excellent scratch resistance. . In particular, the coating film obtained in Example 5 also had good antiblocking properties. On the other hand, the coating films obtained in Comparative Examples 1, 2, and 4 had many defects and poor appearance. Moreover, the coating film obtained in Comparative Examples 3 and 5 had low wetting tension.

  The coating composition and the coating film of the present invention are suitably used for a surface layer or an intermediate layer of various displays such as a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display (PDP), and a touch panel.

DESCRIPTION OF SYMBOLS 1 ... Coating film 11 ... Base film 12 ... Coat layer

Claims (5)

An active energy ray-curable compound;
Silica nanoparticles having an average particle size of 2 to 300 nm;
Containing a leveling agent,
The content of the silica particles is a 200 to 280 parts by weight with respect to the active energy ray-curable compound 100 parts by weight,
Content of the said leveling agent is 0.007-0.5 mass part with respect to 100 mass parts of total amounts of the said active energy ray hardening-type compound and the said silica nanoparticle, The coating composition characterized by the above-mentioned.   The coating composition according to claim 1, further comprising organic fine particles.   The coating composition according to claim 1, wherein the active energy ray-curable compound is a polyfunctional (meth) acrylate monomer and / or a (meth) acrylate prepolymer. A base film;
A coating film comprising: a coating layer formed by applying and curing the coating composition according to any one of claims 1 to 3 on at least one surface of the base film.   The coating film according to claim 4, wherein the wetting tension on the surface of the coating layer opposite to the base film side is 30 mN / m or more.

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