TW202009474A - Method for evaluating fingerprint resistance, method for manufacturing optical member, and optical member capable of evaluating fingerprint resistance quantitatively with high reproductivity - Google Patents

Abstract

To provide a method for evaluating fingerprint resistance capable of evaluating fingerprint resistance quantitatively with high reproductivity, a method for manufacturing an optical member by using the evaluation method, and an optical member excellent in fingerprint resistance. A method for evaluating fingerprint resistance includes measuring the lightness L* prescribed according to the CIE1976L*a*b* color system of the surface of a to-be-measured object, then, applying an oleic acid diluent onto the surface of the to-be-measured object, drying, followed by measuring the lightness prescribed according to the CIE1976L*a*b*color system, and evaluating the fingerprint resistance of the surface of the to-be-measured object using the lightness L*before and after the oleic acid diluent being applied to the surface of the to-be-measured object as an index.

Description

Fingerprint resistance evaluation method, production method of optical component and optical component

The present invention relates to an evaluation method of fingerprint resistance, a production method of an optical member using the evaluation method, and an optical member, and particularly to an optical member excellent in fingerprint resistance.

In recent years, in various electronic devices, touch panels with both display devices and input methods have been used. In order to prevent scratches, the surface of the touch panel is usually provided with a hard coating film having a hard coating layer.

Since such a touch panel is operated by fingers, fingerprints are usually attached to the surface of the touch panel due to finger grease. When fingerprints are attached to the surface of such a touch panel, the appearance deteriorates and the display screen becomes difficult to see. Therefore, the hard coating film requires fingerprint resistance that is difficult to visually recognize the performance of the attached fingerprint.

In the past, there was no clear index for evaluating the fingerprint resistance, and it was only used to determine the contact angle of water and oleic acid as a reference, or a method for functional evaluation to see the actual attached fingerprint. However, the correlation between the measured contact angle and the evaluation of functionality is low, and the visual evaluation of functionality alone has a problem of low reproducibility.

Therefore, Patent Document 1 proposes a pollution evaluation method for illuminating a test body, detecting reflected or transmitted scattered light of the test body, and evaluating the degree of contamination on the surface of the test body. Specifically, using the ΔE✽ab in the L✽a✽b✽ color mode specified by the International Commission on Illumination (CIE), based on the ΔE✽ab after the surface has been artificially contaminated and the ΔE✽ab after the subsequent cleaning treatment Poor, to assess the degree of pollution. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2008/029946

[Problems to be solved by the invention]

However, in the case where ΔE✽ab is used as in Patent Document 1, the difference between ΔE✽ab after the surface is artificially contaminated and ΔE✽ab after the washing process is absolutely small, and it is difficult to understand the degree of fingerprint adhesion. Therefore, it is not a sufficient index in evaluating fingerprint resistance.

The present invention has been completed in view of such actual conditions, to provide a fingerprint resistance evaluation method capable of evaluating fingerprint resistance quantitatively and with high reproducibility, a production method of an optical member using the evaluation method, and fingerprint resistance Good optical components are for the purpose. [Technical means to solve the problem]

In order to achieve the above object, first, the present invention provides a fingerprint resistance evaluation method, which is characterized by measuring the lightness L✽ specified by the surface color system of CIE1976L✽a✽b✽ on the surface of the object to be evaluated, and then, After applying the oleic acid diluent to the surface of the object to be evaluated and drying it, the lightness L✽ specified by the CIE1976L✽a✽b✽ color system was measured, and the lightness L before and after the application of the oleic acid diluent was measured. ✽ As an index, the fingerprint resistance of the surface of the aforementioned object to be evaluated was evaluated (Invention 1).

In addition, the "fingerprint resistance" in the present invention refers to the performance of attached fingerprints that are difficult to visually recognize.

According to the above invention (Invention 1), fingerprint resistance can be evaluated quantitatively and with high reproducibility. In addition, the correlation with visual assessment is also high.

In the above invention (Invention 1), the oleic acid diluent is preferably a liquid in which oleic acid is diluted with a volatile solvent. The volatile solvent is preferably an alcohol solvent, and the alcohol solvent is preferably ethanol. The oleic acid concentration in the oleic acid dilution is preferably 0.12% by mass or more and 12% by mass or less. The oleic acid diluent is preferably coated on the surface of the object to be evaluated by a bar coater.

In the above invention (Invention 1), the lightness L✽ before the application of the oleic acid dilution is taken as the lightness L✽ before application, and the lightness L✽ after the application of the oleic acid dilution is taken as the lightness after application L✽, based on the change amount ΔL✽ of the brightness L✽ before coating subtracted from the brightness L✽ after coating, to evaluate the fingerprint resistance of the surface of the object to be evaluated, or before the coating of the oleic acid diluent The lightness L✽ of the above is the lightness L✽ before coating, the lightness L✽ of the oleic acid dilution after coating is the lightness L✽ after coating, and the change rate (%) calculated according to the following formula is The fingerprint resistance on the surface of the evaluation object is better (Inventions 2 and 3). Also, it can be evaluated based on both. Rate of change = ((lightness after coating L✽-lightness before coating L✽)/lightness before coating L✽}×100

In the above inventions (Inventions 1 to 3), it is preferable that a hard coat layer is present on the surface to which the oleic acid diluent is applied (invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the object to be evaluated is an optical member (Invention 5).

Second, the present invention provides a method for producing an optical member, characterized by comprising: a step of obtaining an optical member; and the above-mentioned optical member as an object to be evaluated, according to the above-mentioned fingerprint resistance evaluation method (Inventions 1 to 5) , To carry out the evaluation step of fingerprint resistance evaluation (Invention 6).

Thirdly, the present invention provides an optical member characterized in that the brightness L✽ specified according to the CIE1976L✽a✽b✽ color system before coating of the oleic acid diluent is used as the brightness L✽ before coating, in oil After the application of the acid diluent according to the lightness L✽ specified in the CIE1976L✽a✽b✽ color system, as the lightness L✽ after coating, the lightness L✽ before coating is subtracted from the lightness L✽ after coating The amount of change ΔL✽ is less than 0.3 (Invention 7).

Fourth, the present invention provides an optical member, characterized in that the brightness L✽ specified according to the CIE1976L✽a✽b✽ color system before coating of the oleic acid diluent is used as the brightness L✽ before coating in the oil After the application of the acid diluent, the lightness L✽ specified according to the CIE1976L✽a✽b✽ color system is the lightness L✽ after coating, and the change rate calculated according to the following formula is 6% or less (Invention 8). Rate of change = ((lightness after coating L✽-lightness before coating L✽)/lightness before coating L✽}×100

In the above inventions (Inventions 7 and 8), it is preferable that a hard coat layer is present on the surface of the optical member coated with the oleic acid dilution liquid (Invention 9). [Efficacy of invention]

According to the fingerprint resistance evaluation method of the present invention, the fingerprint resistance can be evaluated quantitatively and with high reproducibility. According to the production method of the optical member of the present invention, in addition to being able to evaluate fingerprint resistance quantitatively and with high reproducibility, it is also possible to produce an optical member. Furthermore, the optical member of the present invention is excellent in fingerprint resistance.

[Appearance to implement invention]

The embodiment of the present invention will be described below. [Evaluation method of fingerprint resistance] An evaluation method of fingerprint resistance according to an embodiment of the present invention is to measure the brightness L✽ of the surface of the object to be evaluated according to the CIE1976L✽a✽b✽ surface color system, and then coat the surface of the object to be evaluated After the oleic acid diluent is dried, the lightness L✽ specified in the CIE1976L✽a✽b✽ color system is measured, and the above lightness L✽ before and after the application of the oleic acid diluent is used as an indicator to evaluate the evaluation object. Fingerprint resistance on the surface.

According to the above evaluation method, fingerprint resistance can be evaluated quantitatively and with high reproducibility. In addition, the correlation with visual assessment is also high.

The type of the object to be evaluated is not particularly limited, and according to the above-mentioned fingerprint resistance evaluation method, fingerprint resistance can be evaluated for various objects to be evaluated. As such an object to be evaluated, preferably, for example, an article with easy fingerprint attachment, or an article with obvious fingerprint attachment, and particularly preferably, for example, an article with a smooth surface. In addition, the object to be evaluated may be a transparent article, an opaque article, a colorless article, or a colored article. Among them, a transparent article is preferable, and a colorless transparent article is particularly preferable. . Specific objects to be evaluated include, for example, optical members, optical discs, and chassis. Examples of the optical member include plastic films, plastic plates, and glass plates; various functional layers (transparent conductive film, metal layer, silicon layer, hard coat layer, anti-glare layer, etc.) are provided on one or both sides of these Those with such displays, touch panels, or such components. Among the above, plastic films, plastic plates, glass plates, displays, touch panels, etc. having hard coatings on the outermost surface (finger contact surface) are particularly preferred.

The detailed measurement method of the above-mentioned lightness L✽ will be described later, but when the object to be evaluated is a transparent member (especially a transparent film), it is preferable that the object to be evaluated is attached to a black plate for measurement. According to this, the fingerprint attached to the object to be evaluated as the brightness L✽ can be measured more surely.

The color of the black board used in this case is the lightness L✽ of 0.1~60, the chromaticity a✽ of -40~40, and the chromaticity b✽ of -40~ according to the CIE1976L✽a✽b✽ color system. 40 is better, especially the lightness L✽ is 1~30, the color a✽ is -20~20, the color b✽ is -20~20, and the lightness L✽ is 2~15, color Degree a✽ is -10~10, and chroma b✽ is -10~10.

The material of the black plate is not particularly limited. For example, a plastic plate, a metal plate, a ceramic plate, etc. may be used. Among them, a plastic plate that easily exhibits the black color is preferred. Examples of plastic plates include acrylic plates, polycarbonate plates, polyethylene terephthalate plates, and vinyl chloride resin plates. Among them, acrylic plates that easily exhibit the above black color are preferred.

The method of attaching the object to be evaluated to the black plate is not particularly limited, but it is preferable to use an adhesive sheet having an adhesive layer with a high transparency and a refractive index close to 1. The haze value (value measured according to JIS K7136:2000) of the adhesive layer is preferably 10% or less, particularly preferably 5% or less, and further preferably 1% or less. In addition, the refractive index of the adhesive layer (according to Method B of JIS K7142) is preferably 1.2 to 1.8, particularly preferably 1.3 to 1.6, and even more preferably 1.4 to 1.55.

The oleic acid diluent applied to the surface of the object to be evaluated is preferably a liquid diluted with oleic acid with a volatile solvent. The volatile solvent preferably has a boiling point of 35 to 110°C. Examples of such volatile solvents include alcohols such as methanol, ethanol, butanol, and isopropanol; ethers such as diethyl ether and tetrahydrofuran; ketones such as acetone; esters such as ethyl acetate; and hexane Aliphatic hydrocarbons, aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as dichloromethane and trichloroethane. These can be used alone or in combination of two or more.

Among these, from the viewpoint of increasing the lightness L✽ after application of the oleic acid diluent and easily evaluating fingerprint resistance, alcoholic solvents are preferred, and ethanol is particularly preferred.

The lower limit of the oleic acid concentration in the oleic acid dilution liquid is preferably 0.12% by mass or more, particularly preferably 0.15% by mass or more, and further preferably 0.18% by mass or more. According to this, it becomes close to the fact that fingerprint attachment is easy. In addition, the oleic acid concentration in the oleic acid dilution liquid is preferably 12% by mass or less, more preferably 6% by mass or less, particularly preferably 2% by mass or less, and further preferably 0.5% by mass or less. According to this, it becomes close to the fact that fingerprint wiping is easy.

The method of applying the oleic acid diluent on the surface of the object to be evaluated can be, for example, a bar coating method, a blade coating method, a roll coating method, a plate coating method, a die coating method, a gravure coating method, or the like. Among these, coating by a bar coating method, that is, by a bar coater is preferable. Via a bar coater, the oleic acid diluent can be evenly coated on the planar surface of the object to be evaluated. According to this, the oleic acid layer can be uniformly formed on the surface of the object to be evaluated, and the oleic acid diluent can be accurately measured after application The lightness L✽. The bar coater is preferably a Mayer bar.

After applying the oleic acid diluent to the surface of the object to be evaluated, the aforementioned oleic acid diluent is dried to form an oleic acid layer on the surface of the object to be evaluated. The drying conditions can be appropriately determined according to the dilution solvent used, but from the viewpoint of uniform formation of the oleic acid layer on the surface of the object to be evaluated, drying at 5°C to 80°C, especially at 20°C to 40°C is preferred. Especially when using ethanol as the diluent solvent, it is better to dry naturally at normal temperature and pressure (mainly 23°C, 50%RH).

After drying the oleic acid diluent as described above, the brightness L✽ of the surface of the object to be evaluated (the surface on which the oleic acid layer is formed) is measured according to the same method as described above.

Here, the lightness L✽ measured before the application of the oleic acid diluent is called "brightness L✽ before coating", and the lightness L✽ measured after the application of the oleic acid diluent is called "after coating" Brightness L✽". In this embodiment, the lightness L✽ before coating and the lightness L✽ after coating are used as indicators to evaluate the fingerprint resistance of the surface of the object to be evaluated.

Specifically, first, the fingerprint resistance of the surface of the object to be evaluated can be evaluated by subtracting the change amount ΔL✽ of the brightness L✽ before coating from the brightness L✽ after coating. In this case, it can be said that the small change amount ΔL✽ is excellent in fingerprint resistance. In order to have excellent fingerprint resistance, the amount of change ΔL✽ is preferably less than 0.3, preferably 0.2 or less, particularly preferably 0.12 or less, and further preferably 0.04 or less. The lower limit of the change amount ΔL✽ is preferably 0, but it is usually preferably 0.01 or more, and particularly preferably 0.02 or more.

Second, according to the change rate (%) of the lightness L✽ calculated by the following formula, the fingerprint resistance of the surface of the object to be evaluated can be evaluated. Rate of change = ((lightness after coating L✽-lightness before coating L✽)/lightness before coating L✽}×100 In this case, it can be said that the smaller the rate of change, the better the fingerprint resistance. In order to have so-called excellent fingerprint resistance, the change rate of lightness L✽ is preferably 6% or less, preferably 4% or less, especially 2% or less, further preferably 1.0% or less, and most preferably 0.9% or less . The lower limit of the change rate is preferably 0%, but usually 0.01% or more is preferable, and particularly 0.1% or more is preferable.

In addition, in the present invention, the evaluation method of fingerprint resistance using the brightness L✽ before coating and the brightness L✽ after coating as indicators is not limited to the above. For example, the value of (lightness after application L✽) ^2- (lightness before application L✽) ² or the square root of the aforementioned value may be used as an index.

[Production method of optical member] An optical member production method according to an embodiment of the present invention includes a step of obtaining an optical member, and using the optical member as an object to be evaluated, and performing an evaluation step of fingerprint resistance evaluation according to the fingerprint resistance evaluation method described above . According to such a production method of an optical member, in the above-mentioned evaluation step, in addition to quantifiable and highly reproducible evaluation of fingerprint resistance, an optical member can also be produced. Therefore, an optical member excellent in fingerprint resistance can be produced at a high yield.

More specifically, by manufacturing an optical member as a sample (step of obtaining an optical member), using the aforementioned optical member as an object to be evaluated, a fingerprint resistance evaluation (evaluation step) is performed according to the above-mentioned fingerprint resistance evaluation method, according to the judgment as It is preferable that the optical member (the step of obtaining the optical member) be manufactured by the same manufacturing method as the manufacturing method of the sample excellent in fingerprint resistance.

The types of optical members can be mentioned as described above. Among these, a plastic film, a plastic plate, a glass plate, a display, a touch panel, etc. having a hard coating on the outermost surface (the surface where the finger touches) are particularly preferred.

The optical member itself can be manufactured according to a conventional method. However, an optical member excellent in fingerprint resistance is preferably manufactured by a method described below.

[Optical components] The optical member according to the first embodiment of the present invention is an optical member in which the amount of change ΔL✽ of the brightness L✽ before coating minus 0.3 before subtracting from the brightness L✽ after coating is less than 0.3. In addition, the optical member of the second embodiment of the present invention is an optical member based on the above-mentioned brightness L✽ after coating and brightness L✽ before coating, and the rate of change calculated according to the following formula is 6% or less. Rate of change = ((lightness after coating L✽-lightness before coating L✽)/lightness before coating L✽}×100

The optical member of the first embodiment and the optical member of the second embodiment of the present invention are excellent in fingerprint resistance, that is, the performance of a fingerprint that is difficult to visually recognize is excellent. This excellent fingerprint resistance can be evaluated quantitatively and with high reproducibility.

From the viewpoint of fingerprint resistance, the amount of change ΔL✽ of the optical member of the first embodiment is preferably 0.2 or less, particularly 0.12 or less, and further 0.04 or less. From the viewpoint of fingerprint resistance, the above-mentioned change rate of the optical member of the second embodiment is preferably 4% or less, especially 2% or less, and further preferably 1.0% or less, 0.9 % Is best. In addition, the lower limit of the change amount ΔL✽ is preferably 0, but usually 0.01 or more is preferable, and particularly 0.02 or more is preferable. In addition, the lower limit of the change rate is preferably 0%, but usually 0.01% or more is preferable, especially 0.1% or more.

The types of optical members in this embodiment can be exemplified as described above. Among these, particularly preferred are plastic films, plastic plates, glass plates, displays, touch panels, etc. with hard coating on the outermost surface (finger contact surface).

The optical member of this embodiment will be described with reference to FIG. 1. As shown in FIG. 1, the optical member 1 of this embodiment is composed of a base material 11 and a hard coat layer 12 formed on one side of the base material 11.

1. Components 1-1. Substrate The substrate 11 of the optical member 1 of the present embodiment is not particularly limited, and preferably includes plastic films, plastic plates, and glass plates. The surface opposite to the hard coat layer 12 in the base material 11 may be provided with various functional layers, such as a transparent conductive film, a metal layer, a silicon layer, a hard coat layer, and an anti-glare layer. In addition, various functional layers such as a transparent conductive film, a metal layer, a silicon layer, a hard coating layer, and an anti-glare layer may be provided between the base material 11 and the hard coating layer 12.

Examples of plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polyethylene films and polypropylene films. , Cellophane (cellophane), cellulose diacetate film, cellulose triacetate film, cellulose acetate butyl film, polyvinyl chloride film, polyvinyl chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer Film, Polystyrene film, Polycarbonate film, Polymethylpentane film, Polyester film, Polyetheretherketone film, Polyether film, Polyetherimide film, Fluorine resin film, Polyimide film , Acrylic resin film, polyurethane resin film, norbornene polymer film, cyclic olefin polymer film, cyclic conjugated diene polymer film, vinyl alicyclic hydrocarbon polymer film, etc. Plastic film, or such laminated film. Among these, from the viewpoint of mechanical strength, etc., polyethylene terephthalate film, polycarbonate film, norbornene-based polymer film, etc. are preferred.

In addition, in the above-mentioned plastic film, for the purpose of enhancing the adhesion of the layer (hard coat layer 12 or adhesive layer, etc.) provided on the surface thereof, primer treatment, oxidation method, and unevenness may be applied on one or both sides as necessary Methods such as surface treatment. The oxidation method can be exemplified by corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone, ultraviolet treatment and the like, and the bumping method can be exemplified by sand blasting method and solvent treatment method. These surface treatment methods can be appropriately selected according to the type of plastic film, but in general, the corona discharge treatment method is preferably used in terms of effects and operability.

The thickness of the plastic film is usually about 15 to 300 μm, preferably about 30 to 200 μm.

The plastic plate is not particularly limited, such as acrylic plate, polycarbonate plate, etc. The thickness of the plastic plate is not particularly limited, and is usually 0.3 to 5 mm, preferably 0.5 to 3 mm.

The glass plate is not particularly limited, for example, chemically strengthened glass, alkali-free glass, quartz glass, soda lime glass, barium-containing strontium glass, aluminum silicate glass, lead glass, borosilicate glass, barium borosilicate glass, and the like. The thickness of the glass plate is not particularly limited, but it is usually 0.1 to 5 mm, preferably 0.2 to 3 mm.

1-2. Hard coating The hard coat layer 12 of the optical member 1 of the present embodiment may be formed of any material as long as the change amount ΔL✽ or the change rate satisfying the above-mentioned brightness L✽ and brightness L✽ as indexes after coating However, it is preferably formed by curing the coating composition C described below. According to the coating composition C, the hard coat layer 12 satisfying the above value is easily formed.

The coating composition C of this embodiment contains an active energy ray-curable component, fine particles, and a set surface modifier.

(1) Ingredients (1-1) Active energy ray hardening component If the coating composition C contains an active energy ray-curable component, the hard coating layer 12 obtained by curing the coating composition C with an active energy ray has a desired hardness and scratch resistance.

Examples of active energy ray-curable components include polyfunctional (meth)acrylate-based monomers, (meth)acrylate-based prepolymers, and active energy ray-curable polymers. The active energy ray-curable component is preferably at least a multifunctional (meth)acrylate-based monomer, especially a combination of a multifunctional (meth)acrylate-based monomer and a (meth)acrylate-based prepolymer Better. In this specification, (meth)acrylate refers to both acrylate and methacrylate. Other similar terms are also the same.

Multifunctional (meth)acrylate monomers such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di( Methacrylate, polyethylene glycol di(meth)acrylate, hydroxytrimethylacetate neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, caprolactone Modified dicyclopentenyl di(meth)acrylate, ethylene oxide modified di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, triisocyanate (Meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dineopentyltriol tri(meth)acrylate, Neopentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane tri (meth) acrylate, ginseng (acryloxyethyl) tripolyisocyanate, propionic acid modified di neopentyl Tetraol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified di neopentaerythritol hexa (meth) acrylate, caprolactone modified di neopentyl Multifunctional (meth)acrylates such as tetraol hexa(meth)acrylate. Among the above, dimethentaerythritol (meth)acrylates are preferred, especially dipentaerythritol hexa(meth)acrylate, and dipentaerythritol hexaacrylate is preferred. Better. These can be used alone or in combination of two or more.

On the other hand, examples of (meth)propyl ester prepolymers include polyester acrylates, epoxy acrylates, urethane acrylates, and polyol acrylates. Prepolymer. These prepolymers may be used alone or in combination of two or more.

As the polyester acrylate-based prepolymer, for example, the hydroxyl group of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polycarboxylic acid and a polyhydric alcohol can be esterified with (meth)acrylic acid or via a polycarboxylic acid The hydroxyl group at the terminal of the oligomer obtained by acid addition of alkylene oxide is esterified with (meth)acrylic acid.

The epoxy acrylate-based prepolymer can be obtained by reacting and esterifying (meth)acrylic acid with an ethylene oxide ring such as a relatively low molecular weight biphenyl type epoxy resin or phenol type epoxy resin.

Urethane acrylate-based prepolymers, such as polyurethane oligomers obtained by reacting polyisocyanates with polyether polyols, polyester polyols, etc., obtained by (meth)acrylic acid esterification By.

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

Among the above, the urethane acrylate prepolymer (multifunctional urethane (meth)acrylate) is preferred, and the multifunctional urethane acrylate is particularly preferred. It is also preferable to use polyfunctional urethane (meth)acrylate and polyfunctional (meth)acrylate monomers together, especially in combination with dipentaerythritol hexa(meth)acrylate.

When polyfunctional urethane (meth)acrylate and polyfunctional (meth)acrylate monomers (especially dipentaerythritol hexa(meth)acrylate) are used in combination, the 100 parts by mass of (meth)acrylate monomers, the amount of polyfunctional urethane (meth)acrylate blended is preferably 50 parts by mass or more, particularly preferably 80 parts by mass or more, and further 95 parts by mass More than copies are better. Furthermore, the aforementioned blending amount is preferably 150 parts by mass or less, particularly preferably 120 parts by mass or less, and further preferably 105 parts by mass or less.

(1-2) particles The fine particles may be either inorganic fine particles or organic fine particles, but inorganic fine particles in which the change amount and change rate of the lightness L✽ before and after coating are likely to have the aforementioned values are preferred. In addition, the shape of the fine particles, especially the inorganic fine particles, is preferably non-spherical, particularly preferably indefinite. This "indefinite shape" refers to a shape that is not a regular shape such as a spherical or elliptical shape, but has irregular polygons or faces. The microparticles can be used alone or in combination of two or more.

Examples of the inorganic fine particles include metal oxides such as silicon dioxide, aluminum oxide, zirconium dioxide, titanium dioxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide; fluorine Fine particles composed of metal fluorides such as magnesium fluoride and sodium fluoride. Among these, silicon dioxide and aluminum oxide are preferred, especially silicon dioxide, and amorphous silicon dioxide is preferred. In addition, the surface of the inorganic fine particles may be chemically modified with organic compounds or the like.

The average particle diameter of the fine particles is preferably 0.1 μm or more, particularly preferably 0.4 μm or more, and further preferably 0.6 μm or more. The average particle diameter of the fine particles is preferably 20 μm or less, preferably 10 μm or less, particularly preferably 4 μm or less, and further preferably 2 μm or less. In addition, the average particle diameter of the fine particles in this specification is a value measured by a laser diffraction scattering type particle size analyzer (manufactured by Takada Manufacturing Co., Ltd., product name "LA-920").

With regard to the particle size distribution of the fine particles, the particle size variation coefficient (CV value) represented by the following formula is preferably 10% or more, particularly preferably 50% or more, and further preferably 80% or more. The CV value is preferably 300% or less, preferably 200% or less, particularly preferably 150% or less, and further preferably 100% or less. Coefficient of particle size variation (CV value) (%) = (standard deviation particle size/average particle size) × 100 The coefficient of variation in particle size (CV value) is a value measured by a laser diffraction scattering particle size analyzer (manufactured by Takada Manufacturing Co., Ltd., product name "LA-920").

The mixing ratio of the fine particles is preferably 1 part by mass or more, particularly 6 parts by mass or more, and more preferably 12 parts by mass or more relative to 100 parts by mass of the active energy ray-curable component. In addition, the above mixing ratio is preferably 50 parts by mass or less, particularly preferably 30 parts by mass or less, and further preferably 20 parts by mass or less. Since the blending ratio of the fine particles is within the above range, the amount of change and the rate of change of the lightness L✽ before and after coating easily become the aforementioned values.

(1-3) Surface conditioner The surface modifier contained in the coating composition C is preferably a fluorine compound in order to obtain an optical member excellent in fingerprint resistance. Fluorine compounds include, for example, fluorinated alkyl carboxylates, fluorinated alkyl phosphates, fluorinated alkyl sulfates, fluorinated alkyl ammonium salts, fluorinated alkyl ethylene oxide derivatives, fluorinated alkenes Oligomer derivatives, fluorinated adamantane derivatives, etc. Among these, from the viewpoint of fingerprint resistance, a fluorine compound having an adamantane structure is particularly preferred.

In addition, the above-mentioned fluorine compound is preferably one having a polymerizable functional group, that is, a fluorine compound containing a polymerizable functional group from the viewpoint of fingerprint resistance. Among these, from the viewpoint of fingerprint resistance, a polymerizable functional group-containing fluorine compound having an adamantane structure, that is, a polymerizable functional group-containing fluorine-containing adamantane derivative is particularly preferred. The surface conditioner may be used alone or in combination of two or more.

The fluorine-containing adamantane derivative containing a polymerizable functional group is preferably represented by the following general formula (I). [Chemical 1]

In the above general formula (I), s is an integer of 1-15, preferably 1-12, t is an integer of 1-15, preferably 4-15, u is 0-14, preferably 0~ An integer of 4, and s+t+u=16. In the general formula (I) listed above, F represents a fluorine atom.

In the general formula (I) listed above, Y represents a hydrogen atom, a hydrocarbon group, an alkoxy group, a halogen-substituted hydrocarbon group, a cyclic hydrocarbon group, a halogen-substituted cyclic hydrocarbon group, a hydroxyl group, a carboxyl group, and a group bonded to the same carbon atom Two Y and carbon atoms together form the base of C=O.

Examples of the hydrocarbon group represented by Y include an alkyl group having 1 to 10 carbon atoms. The alkyl group may be linear, branched, or cyclic, and specific examples include methyl, ethyl, propyl, and butyl. Examples of the alkoxy group include methoxy and ethoxy. The halogen-substituted hydrocarbon group is a group in which the hydrogen atom of the above-mentioned hydrocarbon group is substituted with one or more halogen atoms, and examples thereof include trifluoromethyl. Halogen atoms such as fluorine, chlorine, bromine and iodine (the same applies hereinafter).

The cyclic hydrocarbon group represented by Y is, for example, a cycloalkyl group having 5 to 10 carbon atoms, and specific examples thereof include cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, and ethylcyclohexyl. The halogen-substituted cyclic hydrocarbon group is a group in which the hydrogen atom of the cyclic hydrocarbon group is substituted with one or more halogen atoms, and examples thereof include fluorinated cyclopentyl, fluorinated cyclohexyl, trifluoromethylcyclopentyl, and trifluoro. Methyl cyclohexyl and so on.

In the above general formula (I), Z ¹ represents a base represented by the following general formula (II) or (III). [Chem 2]

In the above general formula (II) or (III), R ¹ to R ⁴ each independently represent a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, which may also contain heteroatoms . n and m are integers of 0 or more.

Among the aliphatic hydrocarbon groups having 1 to 20 carbon atoms and preferably 1 to 15 carbon atoms represented by R ¹ to R ⁴ , those containing no hetero atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and iso Butyl, second butyl, third butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, A linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, such as hexadecyl, octadecyl, and icosyl.

In the aliphatic hydrocarbon group having 1 to 20 carbon atoms and preferably 1 to 15 carbon atoms represented by R ¹ to R ⁴ , those containing a hetero atom have, for example, -O-(carbon atoms of 1 to 20, preferably carbon atoms of 1 to 15). Chain or branched alkyl group), -S- (C 1-20, preferably C 1-15 linear or branched alkyl group), -CO- (C 1-19, more Straight chain or branched alkyl group having a preferable carbon number of 1 to 14), -NH- (straight chain or branched alkyl group having a carbon number of 1 to 20, preferably carbon number of 1 to 15), -N( Those having a carbon number of 1 to 19, preferably a linear number of 1 to 7 or a branched alkyl group) ₂ or the like.

The heteroatom-containing aliphatic hydrocarbon group having 1 to 20 carbon atoms and preferably 1 to 15 specifically includes, for example, methoxy, ethoxy, butoxy, hydroxymethyl, hydroxyethyl, methylthio, and ethylthio Group, methylamino group, dimethylamino group, ethylamino group, diethylamino group, etc.

In the above general formula (II), n is an integer of 0 or more, such as an integer of 0-20, preferably an integer of 0-10, and preferably 0, 1, 2, 3, 4 or 5.

In the above general formula (III), m is an integer of 0 or more, such as an integer of 0-20, preferably an integer of 0-10, preferably 0, 1, 2, 3, 4 or 5, especially 0 or 1 is better.

In the above general formula (I), X ¹ represents a polymerizable group represented by the following general formula (IV), the following general formula (V), or the following general formula (VI). [Chemical 3]

In the general formula (IV) listed above, R ⁵ represents a hydrogen atom, a methyl group, or a trifluoromethyl group. In the general formula (VI) above, R ⁶ represents a hydrocarbon group having 1 to 5 carbon atoms. Examples of the hydrocarbon group having 1 to 5 carbon atoms include alkyl groups and alkoxy groups. The alkyl group may be linear, branched, or cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, and Tributyl, pentyl, etc. Examples of the alkoxy group include methoxy and ethoxy groups.

The above-mentioned fluorine-containing adamantane derivatives containing polymerizable groups are 1-perfluoroadamantane methacrylate, perfluoro-1,3-bis(acryloyloxyethoxy)adamantane and perfluoro-1, 3-adamantanediol dimethacrylate is particularly preferred.

The above-mentioned fluorine-containing adamantane derivative containing a polymerizable group has a polymerizable group of X ¹ in the molecule, such as a reactive (meth)acrylate group, irradiation with active energy rays, and active energy as a main agent The linear hardening components react to form an integrated hard coat layer 12. According to this hard coat layer 12, the amount of change and the rate of change of the lightness L✽ before and after coating easily become the aforementioned values, and the continuity of the physical properties is high.

Commercial products of fluorine-based surface conditioners, such as MEGAFACE F series, MEGAFACE R series, and MEGAFACE RS series manufactured by DIC Corporation; FUTADEND series manufactured by NEOS Corporation; FC-4430 and FC-4432 manufactured by 3M JAPAN Corporation; SURFLON series manufactured by AGC SEMICHEMICAL Stock Co., Ltd.

The mixing ratio of the surface modifier is preferably 0.01 parts by mass or more, particularly 0.08 parts by mass or more, and more preferably 0.12 parts by mass or more with respect to 100 parts by mass of the active energy ray-curable component. In addition, the above mixing ratio is preferably 1 part by mass or less, particularly preferably 0.6 parts by mass or less, and further preferably 0.2 parts by mass or less. Since the content of the surface modifier is in the above range, the amount of change and the rate of change of the lightness L✽ before and after coating easily become the aforementioned values.

(1-4) Photopolymerization initiator When ultraviolet light is used as the active energy ray for curing the active energy ray-curable component, the coating composition C preferably contains a photopolymerization initiator. By containing the photopolymerization initiator in this way, the active energy ray-curable components can be efficiently polymerized, and the polymerization hardening time and the amount of ultraviolet radiation can be reduced.

Such photopolymerization initiators, such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dibenzoin Methylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl- 1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1 -Ketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl) ketal, diphenyl ketone, p-phenyl diphenyl ketone, 4,4'-diethyl Amine diphenyl ketone, dichlorodiphenyl ketone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-tertiary butyl anthraquinone, 2-amino anthraquinone, 2-methyl thioxanthene Ketone (2-methyl-thioxanthone), 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl Ketal, acetophenone dimethyl ketal, p-dimethylamino benzoate, oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)benzene Group] acetone], 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, etc. These can be used alone or in combination of two or more.

The blending ratio of the photopolymerization initiator is preferably 0.01 parts by mass or more, particularly preferably 0.1 parts by mass or more, and more preferably 1 part by mass or more with respect to 100 parts by mass of the active energy ray-curable component. In addition, the above mixing ratio is preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, and further preferably 5 parts by mass or less.

(1-5) Other ingredients The coating composition C may contain various additives in addition to the above components. Various additives, such as ultraviolet absorbers, antioxidants, light stabilizers, antistatic agents, silane coupling agents, anti-aging agents, thermal polymerization inhibitors, colorants, surfactants, storage stabilizers, plasticizers, lubricants, Defoamer, wettability improver, coating improver, etc.

(2) Thickness of hard coating The thickness of the hard coat layer 12 is preferably 1 μm or more, particularly preferably 2 μm or more, and further preferably 3 μm or more. Since the lower limit value of the thickness of the hard coat layer 12 is the above value, the hard coat layer has a desired scratch resistance and pencil hardness. The thickness of the hard coat layer 12 is preferably 20 μm or less, particularly preferably 15 μm or less, and further preferably 10 μm or less. Since the upper limit value of the thickness of the hard coat layer 12 is the above value, the amount of change and the rate of change of the lightness L✽ before and after coating easily become the aforementioned values. Furthermore, from the viewpoint that the amount of change and the rate of change of the lightness L✽ before and after coating are preferred values, the thickness of the hard coat layer 12 is preferably 8 μm or less, particularly 5 μm or less, and further 4 μm or less. good.

2. Manufacturing method of optical components The optical member 1 of the present embodiment can be hardened by coating the substrate 11 with a coating composition for forming a hard coat layer 12, preferably a coating composition C, and an optional solvent The hard coat layer 12 is formed and manufactured.

The solvent can be used for improvement of coating properties, adjustment of viscosity, adjustment of solid content concentration, and the like, and it is not particularly limited as long as it dissolves curable components and the like and disperses fine particles, etc., and can be used.

Specific examples of solvents include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, Esters of butyl acetate, ethyl lactate, γ-butyrolactone, etc.; ethylene glycol monomethyl ether (methylcellulose), ethylene glycol monoethyl ether (ethylcellulose), diethyl Ethers such as glycol monobutyl ether (butylcellulose), propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene, xylene; dimethylformamide, dimethylacetamide , N-methylpyrrolidone and other amides. Among the above, from the viewpoint of the dispersibility or coating properties of the components in the coating liquid, ethers are preferred, and propylene glycol monomethyl ether is particularly preferred.

The concentration (solid content concentration) of the coating liquid is preferably 10% by mass or more, particularly preferably 20% by mass or more, and further preferably 25% by mass or more. The concentration is preferably 60% by mass or less, especially 48% by mass or less, and more preferably 42% by mass or less. When the concentration of the coating liquid is within the above range, the in-plane uniformity of the coating surface (coating layer surface) is improved, and the reproducibility of the lightness L✽ is further improved.

The application of the coating liquid of the coating composition can be performed according to a common method, and can be based on, for example, a bar coating method, a blade coating method, a roll coating method, a plate coating method, a die coating method, a gravure coating method, etc. get on. When applying the coating liquid of the coating composition, it is preferable to dry the coating film at 40 to 120° C. for about 30 seconds to 5 minutes.

When the coating composition like the coating composition C is active energy ray curable, the coating composition can be cured by irradiating the coating film of the coating composition with active energy rays such as ultraviolet rays, electron beams, etc. get on. Ultraviolet irradiation can be carried out via high-pressure mercury lamps, electrodeless H lamps, xenon lamps, etc. The amount of ultraviolet irradiation is preferably illuminance 50-1000mW/cm ² and light quantity about 50-1000mJ/cm ² . In particular, from the viewpoint of improving the in-plane uniformity of the coated surface, and the reproducibility of the lightness L✽ is improved with the improvement of the in-plane uniformity, the amount of change and the rate of change of the lightness L✽ before and after coating can easily become From the viewpoint of the desired value, the illuminance is preferably 200 to 500 mW/cm ² and the light amount is 200 to 500 mJ/cm ² . On the other hand, the irradiation of the electron beam 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.

3. Physical properties of optical components (1) Haze value The haze value of the optical member 1 of this embodiment is preferably 30% or less, preferably 20% or less, and particularly preferably 15% or less. When the haze value is 30% or less, it is suitable for display users. On the other hand, when the optical member 1 or the hard coat layer 12 is given antiglare properties, the haze value is preferably 3% or more, preferably 4.5% or more, and particularly preferably 5.4% or more. The haze value is a value measured according to JIS K7136-2000.

(2) Total light transmittance The total light transmittance of the optical member 1 of the present embodiment is preferably 70% or more, especially 80% or more, and more preferably 90% or more. When the total light transmittance is 70% or more, it is suitable for display users. The upper limit of the total light transmittance is not particularly limited, but it is usually preferably 100%, preferably 96% or less, and particularly preferably 92% or less. The total light transmittance is a value measured according to JIS K7361-1:1997.

(3) Arithmetic average surface roughness (Ra) The arithmetic average surface roughness (Ra) of the surface of the hard coat layer 12 of the optical member 1 of the present embodiment is preferably 0.6 μm or less, particularly preferably 0.3 μm or less, and further preferably 0.15 μm or less. When the arithmetic average surface roughness (Ra) is 0.6 μm or less, it is suitable as a display user. On the other hand, when the antiglare property of the hard coat layer 12 is imparted, the arithmetic average surface roughness (Ra) is preferably 0.01 μm or more, particularly preferably 0.03 μm or more, and further preferably 0.08 μm or more. In addition, the arithmetic average surface roughness (Ra) of this specification was obtained based on the roughness curve measured using JIS B0601-1994 using a contact type roughness meter.

(4) Image clarity The total value of the image clarity (%) of 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm optical combs measured by the optical member 1 of this embodiment is preferably 200 or more, especially 250 or more Preferably, more than 300 is better. According to this, it becomes a person with good visibility of the image as a display. On the other hand, in the case of imparting antiglare properties to the optical member 1 or the hard coat layer 12, the total value of image sharpness is preferably 450 or less, particularly preferably 405 or less, and further preferably 360 or less.

Here, the image clarity is measured by passing the amount of parallel light rays passing through the test body through an optical comb having a light-transmitting portion and a light-shielding portion. The smaller the width of the light-transmitting portion and the light-shielding portion (comb width) in the optical comb, the higher the precision of image clarity. Image clarity is measured according to the transmission method of JIS K7374:2007.

(5) Contact angle (5-1) Contact angle to water (water contact angle) The water contact angle of the surface of the hard coat layer 12 of the optical member 1 of the present embodiment is preferably 45° or more, particularly 55° or more, and more preferably 65° or more. According to this, it becomes a person who hardly attaches fingerprints to the hard coat layer 12 and the attached fingerprints are easy to wipe. On the other hand, the upper limit of the water contact angle is not particularly limited, but it is preferably 90° or less, preferably 85° or less, especially 80° or less, and more preferably 75° or less.

Furthermore, the water contact angle refers to the angle between the droplet tangent of the contact portion of the surface of the hard coating layer and the surface of the hard coating layer in a state where the droplets of water are resting on the surface of the hard coating layer , Including the angle of the droplet side. The details of the measurement method of the water contact angle are described in the test examples below.

(5-2) Contact angle to oleic acid (oleic acid contact angle) The oleic acid contact angle of the surface of the hard coat layer 12 of the optical member 1 of the present embodiment is preferably 10° or more, particularly 15° or more, and more preferably 20° or more. According to this, it becomes a person who hardly attaches fingerprints to the hard coat layer 12 and the attached fingerprints are easy to wipe. On the other hand, the upper limit of the oleic acid contact angle is not particularly limited, but it is preferably 50° or less, particularly 40° or less, and more preferably 30° or less.

In addition, the oleic acid contact angle refers to the angle formed by the tangent of the droplet at the contact portion of the surface of the hard coating layer and the surface of the hard coating layer when the droplets of oleic acid are allowed to stand on the surface of the hard coating layer Including the angle of the droplet side. Details of the measurement method of oleic acid contact angle are described in the test examples below.

(6) Scratch resistance The hard coat layer 12 of the optical member 1 of the present embodiment is wiped back and forth with the hard coat layer 12 at 10 cm and 10 times with #0000 steel wool under a load of 250 g/cm ² . Scars are better. By having scratch resistance obtained from the evaluation of the hardness of such steel wool, when the optical member 1 is used on the surface of a touch panel, the hard coating layer 12 can be suppressed from being scratched.

(7) Pencil hardness The hard coat layer 12 of the optical member 1 of the present embodiment preferably has a pencil hardness of 2H or more. Since the hard coat layer 12 has such a pencil hardness that the surface of the optical member 1 has sufficient hardness, for example, when the optical member 1 is used for the surface of a touch panel, it can exhibit excellent surface protection.

The embodiments described above are intended to facilitate the understanding of the description of the present invention and are not intended to limit the description of the present invention. Therefore, the purpose of the various requirements disclosed in the foregoing embodiment also includes all design changes or equivalents that fall within the technical scope of the present invention.

For example, the surface to which the oleic acid dilution liquid is applied in the optical member 1 may not be flat. However, the oleic acid dilution is preferably applied uniformly. [Example]

Hereinafter, the present invention will be described more specifically through examples, but the scope of the present invention is not limited to these examples.

The hard coating film to be evaluated was manufactured according to the following manufacturing examples 1 to 6. [Production Example 1] Mixed 50 parts by mass of dipentaerythritol hexaacrylate (representing the converted value of solid content. The following, other components are also the same), multifunctional urethane acrylate (manufactured by Arakawa Chemical Industry Co., Ltd., product name "BEAMSET575CB") 50 parts Parts, 17 parts by mass of silica particles (average particle size 0.8 μm, CV value 93%, refractive index 1.46, indefinite shape), 3 parts by mass of α-hydroxyphenyl ketone as a photopolymerization initiator, and surface adjustment 0.15 parts by mass of a polymerizable group-containing fluorine-containing adamantane derivative (manufactured by NEOS, product name "FUTADEND602A") of the agent to obtain a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 30% by mass.

A polyethylene terephthalate film (manufactured by TORAY Co., Ltd., product name "LUMIRROR U48", thickness 125 μm) was applied on both sides as a base film, and the coating obtained above was applied with Meyer stick #12 The cloth liquid was dried at 70°C for 1 minute. After that, under a nitrogen atmosphere, an ultraviolet irradiation device (manufactured by EYEGRAPHICS, product name "EYEGRANTEGE ECS-401GX") was irradiated with ultraviolet light under the following conditions to form a hard coating layer with a thickness of 4 μm to obtain a hard coating film. >Ultraviolet irradiation conditions> ∙Light source: high-pressure mercury lamp ∙Lamp power: 2kW ∙Handling speed: 4.23m/min ∙Illumination: 240mW/cm ² ∙Light quantity:307mJ/cm ²

[Production Example 2] 100 parts by mass of dipentaerythritol hexaacrylate, 14 parts by mass of silica particles (average particle size 1.5 μm, CV value 83%, refractive index 1.46, indefinite shape), α-hydroxyl as a photopolymerization initiator 3 parts by mass of phenyl ketone and 0.15 parts by mass of a polymerizable group-containing fluorine-containing adamantane derivative (manufactured by NEOS, product name "FUTADEND602A") as a surface modifier were obtained as a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coating film was produced in the same manner as in Production Example 1.

[Production Example 3] The coating composition obtained in the same manner as in Production Example 1 was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 40% by mass. Using the obtained coating liquid, a hard coating film was produced in the same manner as in Production Example 1 except that the thickness of the hard coating layer was 6 μm.

[Production Example 4] The coating composition obtained in the same manner as in Production Example 1 was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 35% by mass. Using the obtained coating liquid, the hard coating film was produced in the same manner as in Production Example 1 except that the thickness of the hard coating layer was 5 μm.

[Production Example 5] Mixed 40 parts by mass of dipentaerythritol hexaacrylate, reactive silica particles (silica particles with acryl groups on the surface, the average particle size of the silica particles before surface modification is 40 nm), 60 parts by mass, Cross-linked polymethyl methacrylate fine particles (average particle size 1.5 μm, CV value 23%, refractive index 1.49, spherical) 4 parts by mass, modified polymer containing carboxyl group as dispersant (produced by Kyoeisha Chemical Co., Ltd., Product name "FLOWREN G-700") 0.2 parts by mass, 3 parts by mass of α-hydroxyphenyl ketone as a photopolymerization initiator, and acrylic modified polydimethylsiloxane (BYK-Chemie) as a surface modifier Co., Ltd., product name "BYK-3550") 0.2 parts by mass to obtain a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coating film was produced in the same manner as in Production Example 1.

[Production Example 6] Mixed 50 parts by mass of dipentaerythritol hexaacrylate, polyfunctional urethane acrylate (manufactured by Arakawa Chemical Industry Co., Ltd., product name "BEAMSET575CB") 50 parts by mass, silica particles (average particle size 0.8 μm, CV Value 93%, refractive index 1.46, amorphous) 15 parts by mass, 3 parts by mass of α-hydroxyphenyl ketone as a photopolymerization initiator, and acrylic modified polydimethylsiloxane (BYK) as a surface modifier -Product made by Chemie, product name "BYK-3550") 5 parts by mass to obtain a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid having a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coating film was produced in the same manner as in Production Example 1.

[Reference example] (Selection of oleic acid concentration) Oleic acid (manufactured by Tokyo Chemical Industry Co., Ltd.; the same below) is taken as sample 1 (oleic acid concentration: 100% by mass). An oleic acid dilution solution in which 4 g of ethanol was added to 1 g of oleic acid to completely dissolve was used as sample 2 (oleic acid concentration: 20% by mass). An oleic acid dilution solution in which 99 g of ethanol was added to 1 g of oleic acid to completely dissolve was used as Sample 3 (oleic acid concentration: 1% by mass). An oleic acid dilution solution in which 99.8 g of ethanol was added to 0.2 g of oleic acid to completely dissolve was used as sample 4 (oleic acid concentration: 0.2% by mass). An oleic acid dilution solution in which 99.9 g of ethanol was added to 0.1 g of oleic acid to completely dissolve was used as sample 5 (oleic acid concentration: 0.1% by mass).

Using a finger cot, each sample 1 to 5 was attached to the hard coat surface of the hard coat film obtained in Production Example 1. On the other hand, on the surface of the hard coat layer of the hard coat film obtained in Production Example 1, an actual fingerprint was attached.

Visually compare the hard coatings attached to samples 1 to 5 with the hard coatings attached to actual fingerprints. Furthermore, using a non-woven cloth (manufactured by Asahi Kasei Corporation, product name "BEMCOT S-2"), wipe the samples 1 to 5 and the actual fingerprint from the hard coating film to which each sample 1 to 5 is attached and the hard coating to which the actual fingerprint is attached. Compare the ease of wiping each sample 1~5 and the actual fingerprint. The results are shown in Table 1, respectively.

[Table 1]

From the results in Table 1, it can be seen that in the degree of adhesion (adhesion) to the hard coating film and the ease of wiping from the hard coating film (wiping property), an oleic acid dilution having an oleic acid concentration of 0.2% by mass is equivalent to an actual fingerprint.

[Test Example 1] (Measurement of haze value and total light transmittance) The haze value (%) and total light transmittance (%) of the hard coating films manufactured in each manufacturing example were used with a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH-5000"), according to JIS K7136:2000 and JIS K7361-1997. The results are shown in Table 2.

[Test Example 2] (Measurement of surface roughness) The arithmetic average surface roughness (Ra; unit μm) of the hard coating surface of the hard coating film manufactured in each manufacturing example is based on JIS B0601-1994, from the use of a contact type roughness meter (manufactured by MITUTOYO, product name "SV3000S4") ) The measured roughness curve is obtained. The results are shown in Table 2.

[Test Example 3] (Measurement of image clarity) For the hard coating film manufactured in each manufacturing example, a sharpness measuring instrument (manufactured by SUGA Testing Machine Co., Ltd., product name "ICM-10P") was used to measure five types of optical combs (comb width: comb width: 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm) image sharpness (%), the total value is calculated as the image sharpness. The results are shown in Table 2.

[Test Example 4] (Measurement of contact angle) (1) Measurement of water contact angle Using a fully automatic contact angle measuring instrument (manufactured by Kyowa Interface Science Co., Ltd., product name "DM-701"), the water contact angle of the surface of the hard coat layer of the hard coating film manufactured in each manufacturing example was measured under the following conditions. In addition, pure water is used for water. The results are shown in Table 2. ･Ambient temperature: 23℃ ･Water droplet volume: 2μl ･Measurement time: 3 seconds after dropping ･Image analysis method: θ/2 method

(2) Determination of oleic acid contact angle Using an automatic contact angle meter (produced by Kyowa Interface Science Co., Ltd., product name "DM-701"), the oleic acid contact angle of the surface of the hard coat layer of the hard coating film manufactured in each manufacturing example was measured under the following conditions. As the oleic acid, oleic acid manufactured by Tokyo Chemical Industry Co., Ltd. was used. The results are shown in Table 2. ･Ambient temperature: 23℃ ･Drop of oleic acid: 2μl ･Measurement time: 3 seconds after dropping ･Image analysis method: θ/2 method

[Test Example 5] (Evaluation of scratch resistance) For the hard coating surface of the hard coating film produced in the example and the comparative example, #0000 steel wool was used, under 250g/cm ² load, 10cm, 10 times back and forth wipe. Under a 3-wavelength fluorescent lamp, the surface of the hard coat layer was visually confirmed, and the scratch resistance was evaluated according to the following criteria. The results are shown in Table 2. A: No scars found B: No scars confirmed

[Test Example 6] (Measurement of pencil hardness) Using an electric pencil scratch hardness tester (manufactured by Yasuda Seiki Co., Ltd., product name "No. 553-M1"), the pencil hardness of the hard coat surface of the hard coating films produced in Examples and Comparative Examples was measured in accordance with JIS K5600. The results are shown in Table 2.

[Test Example 7] (Evaluation of Fingerprint Resistance) (1) Preparation of evaluation samples Using an acrylic transparent double-sided adhesive sheet (manufactured by Lintech, product name "OPTERIA MO-3006C", refractive index: 1.49, haze: >1.0%), the base film side of the hard coating film manufactured in each manufacturing example A black acrylic plate (L✽3.42, a✽-0.17, b✽0.40) was attached to the surface and used as an evaluation sample.

(2) Functional evaluation Fingerprints were attached to the hard coat surface of the evaluation sample obtained above. After that, under a 3-wavelength fluorescent lamp (1000 lux.), the attached fingerprint was visually observed, and the visibility of the fingerprint was evaluated according to the following criteria. Evaluation 3 or more is judged as good. The results are shown in Table 2. 5: The attached fingerprint is very difficult to detect 4: The attached fingerprint is difficult to detect 3: The attached fingerprint is a little obvious 2: The attached fingerprint is obvious 1: The attached fingerprint is very obvious

(3) Evaluation using the brightness L✽ before and after application of the oleic acid dilution as an indicator Initially, for the surface of the hard coat layer in the evaluation sample obtained above, a simultaneous photometric spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE6000") was used, and the measurement was performed according to CIE1976L✽a✽ under the following conditions b✽ The lightness L✽ (lightness L✽ before coating) specified by the surface color system. The results are shown in Table 2. >Measurement conditions> Light source: C light source Measurement method: reflection measurement Measuring area: ψ30mm (30mm diameter circle)

On the other hand, 99.8 g of ethanol was added to 0.2 g of oleic acid to completely dissolve it, which was used as a oleic acid diluent. The obtained oleic acid dilution solution was applied to the surface of the hard coat layer in the evaluation sample obtained above with Meyer stick #2, and naturally dried at 23° C. and 50% RH to form an oleic acid layer.

The lightness L✽ (lightness L✽ before and after coating) of the surface formed by the oleic acid layer of the above evaluation sample was measured in the same manner as described above. The results are shown in Table 2.

After that, the amount of change ΔL✽ by subtracting the brightness L✽ before coating from the brightness L✽ after coating is calculated. According to the following formula, the change rate (%) of the lightness L✽ is calculated. The results are shown in Table 2 respectively. Rate of change = ((lightness after coating L✽-lightness before coating L✽)/lightness before coating L✽}×100

[Table 2]

As can be seen from Table 2, according to those who use the brightness L✽ before coating and the brightness L✽ after coating as indicators, the correlation with the functional evaluation is high, and the fingerprint resistance can be quantitatively evaluated. In addition, the hard coating films of Production Examples 1 to 4 are excellent in fingerprint resistance.

[Test Example 8] (Reproducibility test of fingerprint resistance evaluation) As in Manufacturing Example 1, two other hard coating films were manufactured respectively. Another three hard coating films were manufactured on different days. For each of the obtained hard coating films, a fingerprint resistance test of Test Example 7 was performed to confirm the reproducibility. The hard coating film of Production Example 1 has N=1, the second hard coating film has N=2, and the third hard coating film has N=3. The results are shown in Table 3.

[table 3]

It can be seen from Table 3 that the change rate of the lightness L✽ of any hard coating film ΔL✽ and the change rate of the lightness L✽ are within a certain range, and the functional evaluation is related to the change rate of the lightness L✽ ΔL✽ and the change rate of the lightness L✽ Sex. That is, according to the above-mentioned fingerprint resistance evaluation method, the fingerprint resistance can be evaluated quantitatively and with high reproducibility. [Industry availability]

The evaluation method of fingerprint resistance of the present invention is suitable for evaluating the fingerprint resistance of, for example, a touch panel, particularly a hard coating film located on the outermost layer of the touch panel. Furthermore, the optical member of the present invention is suitable as a hard coating film located on the outermost layer of a touch panel, for example.

1‧‧‧Optical components 11‧‧‧ Base material 12‧‧‧hard coating

FIG. 1 is a cross-sectional view of an optical member according to an embodiment of the present invention.

1‧‧‧Optical components

11‧‧‧ Base material

12‧‧‧hard coating

Claims (9)

An evaluation method of fingerprint resistance, characterized in that Determine the lightness L✽ specified by CIE1976L✽a✽b✽ surface color system, Then, after applying an oleic acid diluent to the surface of the object to be evaluated and drying it, the lightness L✽ specified by the CIE1976L✽a✽b✽ color system is measured, Using the above-mentioned brightness L✽ before and after application of the oleic acid dilution as an index, the fingerprint resistance of the surface of the object to be evaluated was evaluated. The fingerprint resistance evaluation method as described in item 1 of the patent application scope, in which The lightness L✽ before coating of the oleic acid diluent is used as the lightness L✽ before coating, The above-mentioned brightness L✽ after application of this oleic acid diluent is regarded as the brightness L✽ after application, The fingerprint resistance of the surface of the object to be evaluated was evaluated by subtracting the change amount ΔL✽ of the brightness L✽ before coating from the brightness L✽ after coating. The fingerprint resistance evaluation method as described in item 1 of the patent application scope, in which The lightness L✽ before coating of the oleic acid diluent is used as the lightness L✽ before coating, The above-mentioned brightness L✽ after application of this oleic acid diluent is regarded as the brightness L✽ after application, According to the change rate (%) calculated by the following formula, the fingerprint resistance of the surface of the object to be evaluated is evaluated, Rate of change = {(lightness L✽ after coating-lightness L✽ before coating)/lightness L✽}100 before coating. The method for evaluating fingerprint resistance as described in item 1 of the patent application scope, wherein a hard coat layer is present on the surface coated with the oleic acid diluent in the evaluated object. The fingerprint resistance evaluation method as described in item 1 of the patent application scope, wherein the object to be evaluated is an optical member. An optical component production method, characterized by having: The steps of obtaining optical components; and Taking the above-mentioned optical member as the object to be evaluated, the evaluation step of the fingerprint resistance evaluation is performed according to the fingerprint resistance evaluation method described in any one of items 1 to 5 of the patent application. An optical component, characterized in that Before coating the oleic acid diluent, the brightness L✽ specified in the CIE1976L✽a✽b✽ color system is used as the brightness L✽ before coating, After coating the oleic acid diluent, the lightness L✽ specified in the CIE1976L✽a✽b✽ color system is used as the lightness L✽ after coating, The amount of change ΔL✽ after subtracting the brightness L✽ before coating from the brightness L✽ after coating was less than 0.3. An optical component, characterized in that The lightness L✽ specified in CIE1976L✽a✽b✽ color system is used as the lightness L✽ before coating, After coating the oleic acid diluent, the lightness L✽ specified in the CIE1976L✽a✽b✽ color system is used as the lightness L✽ after coating, The change rate (%) calculated according to the following formula is 6% or less, Rate of change = {(lightness L✽ after coating-lightness L✽ before coating)/lightness L✽}100 before coating. The optical member as described in item 7 or 8 of the patent application scope, wherein a hard coat layer is present on the surface coated with the oleic acid diluent in the optical member.

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