TWI818011B - Fingerprint resistance evaluation method, optical component production method, and optical component - Google Patents

Abstract

[Problem] To provide a fingerprint resistance evaluation method that can quantitatively and highly reproducibly evaluate fingerprint resistance, a production method of an optical member using this evaluation method, and an optical member with excellent fingerprint resistance. [Solution] Measure the lightness L✽ specified in the CIE1976L✽a✽b✽ colorimetric system on the surface of the object to be evaluated. Then, apply an oleic acid diluent to the surface of the object to be evaluated, dry it, and measure according to the CIE1976L✽a✽b✽ expresses the lightness L✽ specified in the color system, and uses the lightness L✽ before and after coating of oleic acid diluent as an index to evaluate the fingerprint resistance of the surface of the object to be evaluated.

Description

Fingerprint resistance evaluation method, optical component production method, 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. In particular, the present invention relates to an optical member having excellent fingerprint resistance.

In recent years, touch panels that have both a display device and an input method are often used in various electronic devices. The surface of this touch panel is usually provided with a hard coating film having a hard coating layer to prevent scratches.

Since such a touch panel is often operated with fingers, fingerprints are usually attached to the surface of the touch panel due to finger grease. When fingerprints adhere to the surface of such a touch panel, the appearance of the touch panel deteriorates and the display screen becomes difficult to read. Therefore, the above-mentioned hard coat film is required to have fingerprint resistance that makes it difficult to visually recognize attached fingerprints.

In the past, there were no clear indicators used to evaluate fingerprint resistance. They only used the contact angle measurement of water and oleic acid as a reference, or the functional evaluation method when actual attached fingerprints could be seen. However, the correlation between the measured contact angle and functionality evaluation is low, and functionality evaluation based only on visual inspection has a problem of low reproducibility.

Therefore, Patent Document 1 proposes a contamination assessment method that irradiates a test object with light, detects scattered light reflected or transmitted through the test object, and evaluates the degree of contamination on the surface of the test object. Specifically, using ΔE✽ab in the L✽a✽b✽ color model stipulated by the International Commission on Illumination (CIE), based on the ΔE✽ab after artificial contamination of the surface and the ΔE✽ab after subsequent cleaning. If it is poor, assess the degree of contamination. [Prior technical literature] [Patent Document]

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

[Problem to be solved by the invention]

However, when ΔE✽ab is used as in Patent Document 1, the difference between ΔE✽ab after artificial contamination of the surface and ΔE✽ab after subsequent cleaning treatment is absolutely small, making it difficult to understand the degree of fingerprint adhesion. Therefore, it is not a sufficient indicator for evaluating fingerprint resistance.

The present invention was completed in view of such actual circumstances, and is intended to provide a fingerprint resistance evaluation method that can quantitatively and highly reproducibly evaluate fingerprint resistance, a production method of an optical member using the evaluation method, and fingerprint resistance. Excellent optical components for the purpose. [Technical means to solve problems]

In order to achieve the above object, first, the present invention provides a method for evaluating fingerprint resistance, which is characterized by measuring the lightness L✽ specified in the CIE1976L✽a✽b✽ color system of the surface of the object to be evaluated, and then, The surface of the object to be evaluated is coated with an oleic acid diluent and dried, and then the lightness L✽ specified in the CIE1976L✽a✽b✽ color system is measured as the above-mentioned brightness L before and after the application of the oleic acid diluent. ✽As an index, the fingerprint resistance of the surface of the object to be evaluated is evaluated (Invention 1).

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

According to the above invention (Invention 1), fingerprint resistance can be evaluated quantitatively and with high reproducibility. In addition, the correlation with visual evaluation 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. In addition, alcoholic solvents are preferred as volatile solvents, and ethanol is preferred as alcoholic solvents. The oleic acid concentration in the oleic acid diluent is preferably not less than 0.12% by mass and not more than 12% by mass. It is better to apply the oleic acid diluent on the surface of the object to be evaluated by using a rod coater.

In the above invention (Invention 1), the above-mentioned brightness L✽ before application of the above-mentioned oleic acid dilution liquid is used as the brightness L✽ before application, and the above-mentioned brightness L✽ after application of the above-mentioned oleic acid dilution liquid is used as the post-application brightness L✽, the fingerprint resistance of the surface of the object to be evaluated is evaluated by subtracting the change amount ΔL✽ of the brightness L✽ before coating from the brightness L✽ after coating, or the fingerprint resistance of the surface of the object to be evaluated before coating. The above-mentioned lightness L✽ is taken as the lightness L✽ before coating, and the above-mentioned lightness L✽ after coating of the aforementioned oleic acid diluent is taken as the post-coating brightness L✽. The change rate (%) calculated according to the following formula is used to evaluate the aforementioned object. It is preferable to evaluate the fingerprint resistance of the surface of the object (Inventions 2 and 3). Furthermore, it can also be evaluated based on both. Change rate = {(Lightness after coating L✽-Brightness before coating L✽)/Lightness before coating L✽}×100

In the above-mentioned inventions (Inventions 1 to 3), it is preferable that a hard coat layer exists on the surface of the object to be evaluated on which the oleic acid diluent is coated (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).

Secondly, the present invention provides a production method of an optical member, which is characterized by: the steps of obtaining an optical member; and using the above-mentioned optical member as an object to be evaluated, according to the above-mentioned fingerprint resistance evaluation method (Inventions 1 to 5) , perform an evaluation procedure for evaluating fingerprint resistance (Invention 6).

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

Fourthly, the present invention provides an optical member, characterized in that the lightness L✽ specified in the CIE1976L✽a✽b✽ colorimetric system before coating of the oleic acid diluent is used as the pre-coating brightness L✽. When the lightness L✽ specified in the CIE1976L✽a✽b✽ color system after application of the acid diluent is used as the post-coating lightness L✽, the change rate calculated from the following formula is 6% or less (Invention 8). Change rate = {(Lightness after coating L✽-Brightness before coating L✽)/Lightness before coating L✽}×100

In the above-mentioned inventions (Inventions 7 and 8), it is preferable that a hard coat layer exists on the surface of the optical member to which the oleic acid diluent is applied (Invention 9). [The effect of invention]

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

[Mode for carrying out the invention]

The embodiments of the present invention will be described below. [Evaluation method of fingerprint resistance] The fingerprint resistance evaluation method according to one embodiment of the present invention is to measure the lightness L✽ specified in the CIE1976L✽a✽b✽ color system on the surface of the object to be evaluated, and then apply coating on the surface of the object to be evaluated. After drying the oleic acid diluted liquid, measure the lightness L✽ specified in the CIE1976L✽a✽b✽ colorimetric system. Use the above lightness L✽ before and after coating of the oleic acid diluted liquid as an index to evaluate the quality of the object to be evaluated. Surface fingerprint resistance.

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

The types of objects to be evaluated are not particularly limited. According to the fingerprint resistance evaluation method described above, fingerprint resistance can be evaluated for various objects to be evaluated. Preferable examples of such objects to be evaluated include items to which fingerprints are easily attached or items to which fingerprints are clearly attached. Particularly preferred examples include items with a smooth surface. In addition, the aforementioned object to be evaluated may be a transparent object or an opaque object, a colorless object or a colored object. Among them, a transparent object is preferred, especially a colorless and transparent object. . Specific objects to be evaluated include, for example, optical components, optical discs, cabinets, etc. Examples of optical components include plastic films, plastic plates, and glass plates; various functional layers (transparent conductive films, metal layers, silicone layers, hard coat layers, anti-glare layers, etc.) are provided on one or both sides of these. Those who have such a display, a touch panel, or a component thereof, etc. Among the above, plastic films, plastic plates, glass plates, displays, touch panels, etc. with a hard coating layer on the outermost surface (finger contact surface) are particularly preferred.

The detailed measurement method of the above-mentioned lightness L✽ will be described later. However, when the object to be evaluated is a transparent member (especially a transparent film), it is better to measure the object to be evaluated by attaching it to a black board. According to this, the fingerprint attached to the object to be evaluated can be measured more reliably as the brightness L✽.

The color of the black plate used in this case is, according to the CIE1976L✽a✽b✽ color table, the lightness L✽ is 0.1~60, the chroma a✽ is -40~40, and the chroma b✽ is -40~ 40 is preferred, especially those with lightness L✽ of 1~30, chroma a✽ of -20~20, and chroma b✽ of -20~20. Furthermore, those with lightness L✽ of 2~15 and color It is better if the degree a✽ is -10~10 and the color 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. can be used. Among them, a plastic plate that easily exhibits the black color is preferred. Examples of the plastic board include an acrylic board, a polycarbonate board, a polyethylene terephthalate board, a chlorinated vinyl resin board, and the like. Among them, an acrylic board that easily exhibits the black color is preferred.

The method of attaching the object to be evaluated to the black plate is not particularly limited, but it is better to use an adhesive sheet with high transparency and an adhesive layer with 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 5% or less, and further preferably 1% or less. In addition, the refractive index of the adhesive layer (based on method B of JIS K7142) is preferably 1.2 to 1.8, particularly preferably 1.3 to 1.6, and further preferably 1.4 to 1.55.

The oleic acid dilution liquid applied to the surface of the object to be evaluated is preferably a liquid in which oleic acid is diluted with a volatile solvent. Volatile solvents are preferably those with boiling points between 35 and 110°C. Examples of such volatile solvents include alcohols such as methanol, ethanol, butanol, and isopropyl alcohol; ethers such as diethyl ether and tetrahydrofuran; ketones such as acetone; esters such as ethyl acetate; and hexane. Aliphatic hydrocarbons such as benzene and toluene, aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as methylene chloride and trichloroethane, etc. These may be used individually by 1 type, and may be used in combination of 2 or more types.

Among these, alcohol solvents are preferred, and ethanol is particularly preferred, from the viewpoint of increasing the brightness L✽ after application of the oleic acid diluent and making it easy to evaluate the fingerprint resistance.

The lower limit of the oleic acid concentration in the oleic acid diluent is preferably 0.12 mass% or more, particularly 0.15 mass% or more, and further preferably 0.18 mass% or more. According to this, it becomes almost easy to actually attach fingerprints. Furthermore, the upper limit of the oleic acid concentration in the oleic acid diluent is preferably 12 mass% or less, more preferably 6 mass% or less, particularly preferably 2 mass% or less, and further preferably 0.5 mass% or less. Accordingly, it becomes nearly easy to wipe fingerprints in practice.

As a method of applying the oleic acid dilution to the surface of the object to be evaluated, for example, rod coating, blade coating, roll coating, plate coating, die coating, gravure coating, etc. can be used. Among these, the bar coating method, that is, coating with a bar coater, is preferred. The oleic acid diluent can be evenly coated on the flat surface of the object to be evaluated via a bar coater. This will form an oleic acid layer uniformly on the surface of the object to be evaluated, and the oleic acid diluent can be accurately measured after application. The lightness is L✽. The bar coater is preferably a Mayer bar.

After the oleic acid dilution is applied to the surface of the object to be evaluated, the oleic acid dilution 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 diluting solvent used, but from the perspective of uniformly forming an oleic acid layer on the surface of the object to be evaluated, drying at 5°C to 80°C, especially 20°C to 40°C, is preferred. Especially when ethanol is used as the dilution solvent, it is better to dry naturally at normal temperature and pressure (mainly 23°C, 50% RH).

After drying the oleic acid diluted solution 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 in the same manner as above.

Here, the lightness L✽ measured before the application of the oleic acid diluted liquid is called "the lightness L✽ before application", and the lightness L✽ measured after the application of the oleic acid diluted liquid is called "after application". Lightness L✽". In this embodiment, the brightness L✽ before coating and the brightness 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 lightness L✽ before application from the lightness L✽ after application. In this case, it can be said that the one with a smaller change amount ΔL✽ has excellent fingerprint resistance. In order to have excellent fingerprint resistance, the change amount ΔL✽ is preferably less than 0.3, more preferably 0.2 or less, particularly preferably 0.12 or less, and further preferably 0.04 or less. The lower limit value of the change amount ΔL✽ is preferably 0, but it is generally preferably 0.01 or more, and particularly preferably 0.02 or more.

Second, the fingerprint resistance of the surface of the object to be evaluated can be evaluated based on the change rate (%) of the lightness L✽ calculated by the following formula. Change rate = {(Lightness after coating L✽-Brightness before coating L✽)/Lightness before coating L✽}×100 In this case, it can be said that the one with a smaller change rate has excellent fingerprint resistance. In order to have so-called excellent fingerprint resistance, the change rate of lightness L✽ is preferably 6% or less, more 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 it is preferably 0.01% or more, especially 0.1% or more.

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 (brightness after coating L✽) ² - (brightness before coating L✽) ² or the square root of the above value may be used as an index.

[Production method of optical components] A method for producing an optical member according to an embodiment of the present invention includes the steps of obtaining an optical member, and using the optical member as an object to be evaluated, and performing an evaluation step of evaluating fingerprint resistance based on the above fingerprint resistance evaluation method. . According to such an optical member production method, in the above-mentioned evaluation step, in addition to the fingerprint resistance that can be evaluated quantitatively and with high reproducibility, an optical member can be produced. Therefore, optical members with excellent fingerprint resistance can be produced at a high yield.

More specifically, an optical member as a sample is produced (the step of obtaining the optical member), and the optical member is used as the object to be evaluated. The fingerprint resistance evaluation (evaluation step) is performed according to the above fingerprint resistance evaluation method, and it is determined according to The method for producing a sample with excellent fingerprint resistance is preferably the same method used to produce an optical member (step of obtaining an optical member).

Types of optical components are as mentioned above. Among these, plastic films, plastic plates, glass plates, displays, touch panels, etc. with a hard coating layer on the outermost surface (the surface where fingers touch) are particularly preferred.

The optical component itself can be manufactured according to conventional methods. However, optical members with excellent fingerprint resistance are preferably produced according to the method described below.

[Optical components] The optical member according to the first embodiment of the present invention is an optical member in which the change amount ΔL✽ of the brightness L✽ before coating minus the brightness L✽ before coating is less than 0.3. Furthermore, the optical member according to the second embodiment of the present invention has a change rate of 6% or less calculated from the following formula based on the brightness L✽ after coating and the brightness L✽ before coating. Change rate = {(Lightness after coating L✽-Brightness before coating L✽)/Lightness before coating L✽}×100

The optical member according to the first embodiment and the optical member according to the second embodiment of the present invention have excellent fingerprint resistance, that is, they have excellent performance in making it difficult to recognize attached fingerprints. This excellent fingerprint resistance can be evaluated quantitatively and with high reproducibility.

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

Types of optical components in this embodiment include those mentioned above. Among these, plastic films, plastic plates, glass plates, displays, touch panels, etc. with a hard coating layer on the outermost surface (finger contact surface) are particularly preferred.

The optical component of this embodiment will be described with reference to Figure 1 . As shown in FIG. 1 , the optical member 1 according to 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. Each component 1-1.Substrate The base material 11 of the optical component 1 in this embodiment is not particularly limited, and preferably includes a plastic film, a plastic plate, and a glass plate. The surface opposite to the hard coat layer 12 of the base material 11 may also be provided with various functional layers, such as a transparent conductive film, a metal layer, a silicon layer, a hard coat layer, an anti-glare layer, and the like. In addition, various functional layers may also be provided between the base material 11 and the hard coating layer 12, such as a transparent conductive film, a metal layer, a silicon layer, a hard coating layer, an anti-glare layer, etc.

Examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; and polyolefin films such as polyethylene films and polypropylene films. , Xelofen (cellophane), cellulose diacetate film, cellulose triacetate film, cellulose acetate butyl film, polyvinyl chloride film, polyvinylene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer Film, polystyrene film, polycarbonate film, polymethylpentane film, polyurethane film, polyetheretherketone film, polyetheretherketone film, polyetherimide film, fluororesin 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, polyethylene terephthalate films, polycarbonate films, norbornene-based polymer films, and the like are preferred from the viewpoint of mechanical strength and the like.

In addition, in order to improve the adhesion with the layer (hard coat layer 12 or adhesive layer, etc.) provided on the surface of the above-mentioned plastic film, one or both sides may be subjected to primer treatment, oxidation method, and roughening as necessary. surface treatment. Examples of the oxidation method include corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone, and ultraviolet treatment. Examples of the roughening method include sand blasting, solvent treatment, and the like. These surface treatment methods can be appropriately selected according to the type of plastic film, but generally speaking, the corona discharge treatment method is better used in terms of effects and operability.

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

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

The glass plate is not particularly limited, and may include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, barium-strontium-containing 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 is usually 0.1~5mm, preferably 0.2~3mm.

1-2.Hard coating The hard coat layer 12 of the optical member 1 according to this embodiment may be made of any material as long as the change amount ΔL✽ or the change rate as an indicator of the post-coating brightness L✽ and the pre-coating brightness L✽ satisfies the above values. , but 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 values is easily formed.

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

(1) Each ingredient (1-1) Active energy ray hardening ingredient If the coating composition C contains an active energy ray-curable component, the hard coat layer 12 obtained by hardening the coating composition C with the active energy ray will have desired hardness and scratch resistance.

Examples of the active energy ray curable component include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, active energy ray curable polymers, and the like. It is preferable to use at least a polyfunctional (meth)acrylate monomer as the active energy ray-curable component, especially a combination of a polyfunctional (meth)acrylate monomer and a (meth)acrylate prepolymer. Better. In addition, in this specification, (meth)acrylate means both acrylate and methacrylate. The same applies to other similar terms.

Multifunctional (meth)acrylate monomers, such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxytrimethylacetate neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, caprolactone Modified dicyclopentenyl di(meth)acrylate, ethylene oxide modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, tripolysocyanate di(meth)acrylate (meth)acrylate, trimethylolpropane tri(meth)acrylate, dineopenterythritol tri(meth)acrylate, propionic acid modified dineopenterythritol tri(meth)acrylate, Neopenterythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, ginseng(acryloyloxyethyl)tripolyisocyanate, propionic acid modified dineopentyl Tetraol penta(meth)acrylate, dipenterythritol hexa(meth)acrylate, ethylene oxide modified dipenterythritol hexa(meth)acrylate, caprolactone modified dipentyl Polyfunctional (meth)acrylates such as tetrol hexa(meth)acrylate. Among the above, dipenterythritol (meth)acrylate is preferred, particularly dipenterythritol hexa(meth)acrylate is preferred, and dipenterythritol hexaacrylate is further preferred. Better. These may be used individually by 1 type, or in combination of 2 or more types.

On the other hand, examples of the (meth)acrylate prepolymer include polyester acrylates, epoxy acrylates, urethane acrylates, polyol acrylates, and the like. Prepolymer. These prepolymers may be used individually by 1 type, or in combination of 2 or more types.

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

The epoxy acrylate prepolymer can be obtained by reacting and esterifying an ethylene oxide ring of a relatively low molecular weight biphenyl epoxy resin, phenolic epoxy resin, etc. with (meth)acrylic acid.

Urethane acrylate prepolymers, for example, can be obtained by esterifying polyurethane oligomers obtained by reacting polyether polyols, polyester polyols, etc. with polyisocyanates with (meth)acrylic acid. By.

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

Among the above, urethane acrylate prepolymer (polyfunctional urethane (meth)acrylate) is preferred, and polyfunctional urethane acrylate is particularly preferred. It is also better to use polyfunctional ethyl urethane (meth)acrylate and multifunctional (meth)acrylate monomers together, especially to use it together with dipenterythritol hexa(meth)acrylate.

When polyfunctional urethane (meth)acrylate and polyfunctional (meth)acrylate monomers (especially dipenterythritol hexa(meth)acrylate) are used together, compared to polyfunctional 100 parts by mass of the polyfunctional (meth)acrylate monomer, the blending amount of the polyfunctional urethane (meth)acrylate is preferably 50 parts by mass or more, especially 80 parts by mass or more, and further 95 parts by mass More than one serving is better. The aforementioned blending amount is preferably 150 parts by mass or less, particularly 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 are preferably those in which the change amount and change rate of the brightness L✽ before and after coating can easily reach the aforementioned values. In addition, the shape of the fine particles, especially the inorganic fine particles, is preferably aspherical, and particularly preferably amorphous. The term “indeterminate shape” refers to a shape that is not a regular shape such as a sphere or an ellipse, but has irregular polygons or faces. In addition, the fine particles can be used individually by 1 type or in combination of 2 or more types.

Examples of 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 Particles composed of metal fluorides such as magnesium chloride and sodium fluoride. Among these, silica and alumina are preferred, silica is particularly preferred, and amorphous silica is further 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 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, more preferably 10 μm or less, particularly preferably 4 μm or less, and further preferably 2 μm or less. In addition, the average particle size of fine particles in this specification is a value measured by a laser diffraction and scattering particle size analyzer (manufactured by Kikiba Seisakusho Co., Ltd., product name "LA-920").

Regarding 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 50% or more, and further preferably 80% or more. The CV value is preferably 300% or less, more preferably 200% or less, especially 150% or less, and further preferably 100% or less. Particle size variation coefficient (CV value) (%) = (standard deviation particle size/average particle size) × 100 In addition, the particle size variation coefficient (CV value) is a value measured by a laser diffraction and scattering particle size analyzer (manufactured by Kikiba Seisakusho Co., Ltd., product name "LA-920").

The blending ratio of the fine particles is preferably 1 part by mass or more, particularly 6 parts by mass or more, and further preferably 12 parts by mass or more based on 100 parts by mass of the active energy ray curable component. In addition, the above-mentioned blending ratio is preferably 50 parts by mass or less, particularly 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 change amount and rate of change in the brightness L✽ before and after coating can easily reach the above-mentioned values.

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

Furthermore, from the viewpoint of fingerprint resistance, the above-mentioned fluorine compound is preferably a fluorine compound having a polymerizable functional group, that is, a fluorine compound containing a polymerizable functional group. Among these, 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 from the viewpoint of fingerprint resistance. The surface conditioner may be used alone or in combination of two or more types.

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

In the above general formula (I), 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. The two Y and carbon atoms together form a C=O base.

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 thereof include methyl, ethyl, propyl, butyl, and the like. Examples of the alkoxy group include methoxy group, ethoxy group, and the like. The halogen-substituted hydrocarbon group is a group in which a hydrogen atom of the hydrocarbon group is substituted by one or more halogen atoms, and examples thereof include trifluoromethyl and the like. Also, halogen atoms include fluorine, chlorine, bromine and iodine (the same applies below).

The cyclic hydrocarbon group represented by Y is, for example, a cycloalkyl group having 5 to 10 carbon atoms. Specific examples thereof include cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, and the like. The halogen-substituted cyclic hydrocarbon group is a group in which the hydrogen atom of the above-mentioned cyclic hydrocarbon group is substituted by one or more halogen atoms. Examples thereof include fluorinated cyclopentyl, fluorinated cyclohexyl, trifluoromethylcyclopentyl, and trifluoromethyl. Methylcyclohexyl etc.

In the above general formula (I), Z ¹ represents a group represented by the following general formula (II) or (III). [Chemicalization 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 with a carbon number of 1 to 20, preferably 1 to 15, which may also contain heteroatoms. . n and m are integers above 0.

Among the aliphatic hydrocarbon groups represented by R ¹ to R ⁴ having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, those that do not contain heteroatoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isopropyl, etc. Butyl, 2nd butyl, 3rd 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 a hexadecyl group, an octadecyl group, or an eicosyl group.

Among the aliphatic hydrocarbon groups having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, represented by R ¹ to R ⁴ , those containing heteroatoms include, for example, -O- (a straight aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms). straight chain or branched alkyl group), -S- (straight chain or branched alkyl group with carbon number of 1 to 20, preferably 1 to 15 carbon atoms), -CO- (straight chain or branched alkyl group with carbon number of 1 to 19, preferably Preferably, a straight chain or branched alkyl group with 1 to 14 carbon atoms), -NH- (a straight chain or branched alkyl group with 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms), -N( A structure having a carbon number of 1 to 19, preferably a linear or branched alkyl group of 1 to 7 carbon atoms) ₂ , etc.

The heteroatom-containing aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, specific examples include methoxy, ethoxy, butoxy, hydroxymethyl, hydroxyethyl, methylthio, and ethylthio. base, methylamino group, dimethylamino group, ethylamino group, diethylamine group, etc.

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

In the above general formula (III), m is an integer above 0, such as an integer from 0 to 20, preferably an integer from 0 to 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 above general formula (IV), R ⁵ represents a hydrogen atom, a methyl group or a trifluoromethyl group. In the above general formula (VI), R ⁶ represents a hydrocarbon group having 1 to 5 carbon atoms. Examples of the hydrocarbon group having 1 to 5 carbon atoms include an alkyl group, an alkoxy group, and the like. The alkyl group may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, third Tributyl, pentyl, etc. Examples of the alkoxy group include methoxy group, ethoxy group, and the like.

The above-mentioned fluorine-containing adamantane derivatives containing polymerizable groups include 1-perfluoroadamantane methacrylate, perfluoro-1,3-bis(acryloxyethoxy)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. The linear hardenable components react to form an integrated hard coating layer 12 . According to this hard coat layer 12, the change amount and change rate of the brightness L✽ before and after coating can easily reach the aforementioned values, and the physical properties can be maintained with high sustainability.

Commercially available products of fluorine-based surface conditioners, such as MEGAFACE F series, MEGAFACE R series, and MEGAFACE RS series made by DIC Co., Ltd.; FUTADEND series made by NEOS Co., Ltd.; FC-4430 and FC-4432 made by 3M JAPAN Co., Ltd.; SURFLON series manufactured by AGC SEMICHEMICAL CO., LTD., etc.

The blending ratio of the surface modifier is preferably 0.01 parts by mass or more, particularly 0.08 parts by mass or more, and further preferably 0.12 parts by mass or more based on 100 parts by mass of the active energy ray curable component. In addition, the above-mentioned blending ratio is preferably 1 part by mass or less, particularly preferably 0.6 part by mass or less, and further preferably 0.2 part by mass or less. Since the content of the surface conditioner is within the above range, the change amount and change rate of the brightness L✽ before and after coating are likely to become the above values.

(1-4) Photopolymerization initiator When ultraviolet rays are used as active energy rays 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 component can be polymerized efficiently, and the polymerization curing time and the amount of ultraviolet irradiation can be reduced.

Such photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, benzoin ether, etc. Methylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl- 1-Phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1 -Ketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketal, diphenylketone, p-phenyldiphenylketone, 4,4'-diethyl Aminodiphenylketone, dichlorodiphenylketone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthene Ketone (2-methyl-thioxanthone), 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl methyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)benzene base] acetone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, etc. These can be used individually or in combination of 2 or more types.

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

(1-5) Other ingredients Coating composition C may contain various additives in addition to the above-mentioned 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, Defoaming agent, 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 2 μm or more, and further preferably 3 μm or more. Since the lower limit of the thickness of the hard coat layer 12 is the above value, the hard coat layer has desired scratch resistance and pencil hardness. The thickness of the hard coat layer 12 is preferably 20 μm or less, particularly 15 μm or less, and further preferably 10 μm or less. Since the upper limit of the thickness of the hard coat layer 12 is the above-mentioned value, the change amount and change rate of the brightness L✽ before and after coating are likely to become the above-mentioned values. Furthermore, from the viewpoint of achieving optimal values for the change amount and change rate of brightness L✽ before and after coating, the thickness of the hard coat layer 12 is preferably 8 μm or less, particularly 5 μm or less, and further preferably 4 μm or less. good.

2. Manufacturing method of optical components The optical member 1 according to this embodiment can be made by applying a coating liquid containing a coating composition for forming the hard coat layer 12, preferably the coating composition C, and an optional solvent to the base material 11, and then hardening it. The hard coat layer 12 is formed and manufactured.

The solvent can be used for improving coatability, adjusting viscosity, adjusting solid content concentration, etc. It is not particularly limited and can be used as long as it dissolves curable components and the like and disperses fine particles.

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

The concentration (solid content concentration) of the coating liquid is preferably 10 mass% or more, particularly 20 mass% or more, and further preferably 25 mass% or more. The aforementioned concentration is preferably 60 mass% or less, particularly 48 mass% or less, and further preferably 42 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 brightness L✽ is further improved.

The coating liquid of the coating composition can be applied according to a conventional method, 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. conduct. When applying the coating liquid of the coating composition, the coating film is preferably dried 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 or electron beams. conduct. Ultraviolet irradiation can be carried out through high-pressure mercury lamps, electrodeless H lamps, xenon lamps ^, etc. The optimal amount of ultraviolet irradiation is an illumination intensity of 50~1000mW/cm2 and a light intensity of about 50~1000mJ/ ^cm2 . Especially from the viewpoint of improving the in-plane uniformity of the coating surface, and because the reproducibility of the lightness L✽ is improved with the improvement of the in-plane uniformity, the change amount and change rate of the lightness L✽ before and after coating are likely to become From the viewpoint of desired values, an illumination intensity of 200 to 500 mW/cm ² and a light amount of 200 to 500 mJ/cm ² are preferred. On the other hand, electron beam irradiation can be performed by an electron beam accelerator or the like, and the electron beam irradiation dose is preferably about 10 to 1000 krad.

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

(2) Total light transmittance The total light transmittance of the optical member 1 of this embodiment is preferably 70% or more, particularly 80% or more, and further preferably 90% or more. When the total light transmittance is above 70%, it becomes suitable for use as a display. The upper limit of the total light transmittance is not particularly limited, but is generally preferably 100%, preferably 96% or less, and particularly preferably 92% or less. The total light transmittance is a value measured in accordance with JIS K7361-1:1997.

(3) Arithmetic average surface roughness (Ra) The arithmetic mean surface roughness (Ra) of the surface of the hard coat layer 12 of the optical member 1 according to this 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 becomes suitable for use in displays. On the other hand, when providing anti-glare properties to the hard coat layer 12, the arithmetic mean surface roughness (Ra) is preferably 0.01 μm or more, particularly 0.03 μm or more, and further preferably 0.08 μm or more. In addition, the arithmetic mean surface roughness (Ra) in this specification is calculated based on JIS B0601-1994 and the roughness curve measured using a contact roughness meter.

(4) Image clarity The total value of the image sharpness (%) of the optical combs of 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm measured for the optical component 1 of this embodiment is preferably 200 or more, especially 250 or more. It is better, and more than 300 is better. Accordingly, the display has excellent image visibility. On the other hand, when providing anti-glare properties to the optical member 1 or the hard coat layer 12, the total value of image sharpness is preferably 450 or less, particularly 405 or less, and further preferably 360 or less.

Here, the image sharpness is measured by passing the light amount of parallel rays transmitted through the test object through a light comb having a light-transmitting part and a light-shielding part. The smaller the width of the light-transmitting part and the light-shielding part (comb width) in the optical comb, the higher the precision of the image definition. 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 on the surface of the hard coat layer 12 of the optical member 1 according to this embodiment preferably has a lower limit value of 45° or more, particularly 55° or more, and further preferably 65° or more. This makes it difficult for fingerprints to adhere to the hard coat layer 12 and makes it easy to wipe off the adhered fingerprints. On the other hand, the upper limit of the water contact angle is not particularly limited, but it is preferably 90° or less, more preferably 85° or less, especially 80° or less, and further preferably 75° or less.

In addition, the water contact angle refers to the angle formed by the tangent line of the droplet at the contact portion of the water droplet on the surface of the hard coat layer and the surface of the hard coat layer in a state where the water droplet is left standing on the surface of the hard coat layer. , including the angle of the droplet side. Details of the method for measuring the water contact angle are described in the following test examples.

(5-2) Contact angle to oleic acid (oleic acid contact angle) The oleic acid contact angle on the surface of the hard coat layer 12 of the optical member 1 according to this embodiment preferably has a lower limit value of 10° or more, particularly 15° or more, and further preferably 20° or more. This makes it difficult for fingerprints to adhere to the hard coat layer 12 and makes it easy to wipe off the adhered fingerprints. 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 further preferably 30° or less.

In addition, the oleic acid contact angle refers to the angle formed by the tangent line of the droplet at the contact portion of the droplet on the surface of the hard coat layer and the surface of the hard coat layer in a state where the droplet of oleic acid is allowed to stand on the surface of the hard coat layer. , including the angle of the droplet side. The details of the method for measuring the oleic acid contact angle are described in the following test examples.

(6) Scratch resistance: The hard coating 12 of the optical component 1 in this embodiment can be wiped back and forth with 10cm and 10 times using #0000 steel wool under a load of 250g/ ^cm2 . There will be no scratches. The one with scars is better. By having scratch resistance based on such evaluation of the steel wool hardness, when the optical member 1 is used on the surface of a touch panel, scratches on the hard coat layer 12 can be suppressed.

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

The embodiments described above are descriptions for easy understanding of the present invention and are not descriptions for limiting the present invention. Therefore, the various requirements disclosed in the above embodiments also include all design changes or equivalents that fall within the technical scope of the present invention.

For example, the surface of the optical member 1 to which the oleic acid diluent is applied does not need to be flat. However, it is better to apply the oleic acid diluent evenly. [Example]

The present invention will be described in more detail below through examples, but the scope of the present invention is not limited to these examples.

The hard coat film as the object to be evaluated was produced according to the following Production Examples 1 to 6. [Manufacturing Example 1] Mix 50 parts by mass of dipenterythritol hexaacrylate (indicates the solid content conversion value. The same applies to other ingredients below) and 50 parts by mass of polyfunctional ethyl urethane acrylate (manufactured by Arakawa Chemical Industry Co., Ltd., product name "BEAMSET575CB") parts, 17 parts by mass of silica fine particles (average particle diameter 0.8 μm, CV value 93%, refractive index 1.46, amorphous), 3 parts by mass of α-hydroxyphenyl ketone as a photopolymerization initiator, and as surface adjustment 0.15 parts by mass of a polymerizable group-containing fluorine-containing adamantane derivative (manufactured by NEOS, product name "FUTADEND 602A") as an agent was added to obtain a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid with a solid content concentration of 30% by mass.

A polyethylene terephthalate film (manufactured by TORAY Co., Ltd., product name "LUMIRROR U48", thickness 125 μm) that was treated to facilitate adhesion was applied to both sides of the base film, and the coating obtained above was applied using Meyer rod #12. Distribute the liquid and dry at 70°C for 1 minute. Thereafter, an ultraviolet irradiation device (manufactured by EYEGRAPHICS, product name "EYEGRANTEGE ECS-401GX") was used to irradiate ultraviolet rays under the following conditions under a nitrogen atmosphere to form a hard coat layer with a thickness of 4 μm, and obtain a hard coat film. >UV irradiation conditions> ∙Light source: high-pressure mercury lamp ∙Lamp power: 2kW ∙Conveying speed: 4.23m/min ∙Illuminance: 240mW/cm ² ∙Light quantity: 307mJ/cm ²

[Manufacturing Example 2] Mix 100 parts by mass of dipenterythritol hexaacrylate, 14 parts by mass of silica fine particles (average particle diameter 1.5 μm, CV value 83%, refractive index 1.46, amorphous), and α-hydroxyl group 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 "FUTADEND 602A") as a surface conditioner were added to obtain a coating composition. This coating composition was diluted with propylene glycol monomethyl ether to prepare a coating liquid with a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coat film was produced in the same manner as in Production Example 1.

[Manufacturing 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 with a solid content concentration of 40% by mass. Using the obtained coating liquid, a hard coat film was produced in the same manner as in Production Example 1 except that the thickness of the hard coat layer was set to 6 μm.

[Manufacturing 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 with a solid content concentration of 35% by mass. Using the obtained coating liquid, a hard coat film was produced in the same manner as in Production Example 1 except that the thickness of the hard coat layer was set to 5 μm.

[Manufacturing Example 5] Mix 40 parts by mass of dipenterythritol hexaacrylate, 60 parts by mass of reactive silica particles (silica particles with an acryl group on the surface, the average particle size of the silica particles before surface modification is 40 nm), 4 parts by mass of cross-linked polymethylmethacrylate fine particles (average particle diameter 1.5 μm, CV value 23%, refractive index 1.49, spherical shape) and a modified carboxyl group-containing polymer as a dispersant (manufactured by Kyeisha 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 conditioner 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 with a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coat film was produced in the same manner as in Production Example 1.

[Manufacturing Example 6] Mix 50 parts by mass of dipenterythritol hexaacrylate, 50 parts by mass of polyfunctional ethyl urethane acrylate (manufactured by Arakawa Chemical Industry Co., Ltd., product name "BEAMSET575CB"), and silica fine 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 -Chemie Co., Ltd. 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 with a solid content concentration of 30% by mass. Using the obtained coating liquid, a hard coat 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 applies to the following) itself was used as sample 1 (oleic acid concentration: 100 mass%). A diluted solution of oleic acid in which 4 g of ethanol was added to 1 g of oleic acid and completely dissolved was used as sample 2 (oleic acid concentration: 20 mass%). A dilute solution of oleic acid in which 99 g of ethanol was added to 1 g of oleic acid and completely dissolved was used as sample 3 (oleic acid concentration: 1 mass%). A diluted solution of oleic acid in which 99.8 g of ethanol was added to 0.2 g of oleic acid and completely dissolved was used as sample 4 (oleic acid concentration: 0.2 mass%). Sample 5 (oleic acid concentration: 0.1 mass %) was obtained by adding 99.9 g of ethanol to 0.1 g of oleic acid and completely dissolving the oleic acid dilute solution.

Using finger cots, 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, actual fingerprints adhered to the hard coat surface of the hard coat film obtained in Production Example 1.

Visually compare the hard coating film attached to each sample 1 to 5 and the hard coating film attached to the actual fingerprint. In addition, each sample 1 to 5 and the actual fingerprint were wiped from the hard coat film attached to each sample 1 to 5 and the hard coat film attached to the actual fingerprint using a non-woven wiping cloth (manufactured by Asahi Kasei Co., Ltd., product name "BEMCOT S-2"). Compare the ease of wiping of each sample 1 to 5 and actual fingerprints. The results are shown in Table 1 respectively.

[Table 1]

From the results in Table 1, it can be seen that in terms of the degree of adhesion to the hard coat film (adhesion) and the ease of wiping off the hard coat film (wiping property), an oleic acid diluted solution with an oleic acid concentration of 0.2 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 film produced in each production example were determined according to JIS using a haze meter (manufactured by Nippon Denshoku Industry Co., Ltd., product name "NDH-5000"). K7136:2000 and JIS K7361-1997 measurement. The results are shown in Table 2.

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

[Test Example 3] (Measurement of image sharpness) For the hard coating film produced in each production example, five types of optical combs (comb width: 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm), the total value is calculated as the image sharpness. The results are shown in Table 2.

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

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

[Test Example 5] (Evaluation of Scratch Resistance) On the hard coating surface of the hard coating film produced in the Example and Comparative Example, #0000 steel wool was used, and the load was 250g/ ^cm2 , 10cm, 10 times. wipe. The surface of the hard coat layer was visually confirmed under a 3-wavelength fluorescent lamp, and the scratch resistance was evaluated based on the following standards. The results are shown in Table 2. A: No scars found B: Confirmed that there are scars

[Test Example 6] (Measurement of Pencil Hardness) The pencil hardness of the hard coat surface of the hard coat film produced in Examples and Comparative Examples was measured in accordance with JIS K5600 using an electric pencil scratch hardness tester (manufactured by Yasuda Seiki Co., Ltd., product name "No. 553-M1"). 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 coat film produced in each production example was The surface was bonded to a black acrylic plate (L✽3.42, a✽-0.17, b✽0.40) and used as an evaluation sample.

(2)Sensory evaluation Fingerprints were attached to the hard coat surface of the evaluation sample obtained above. Thereafter, the attached fingerprints were visually observed under a 3-wavelength fluorescent lamp (1000 lux.), and the visibility of the fingerprints was evaluated based on the following criteria. An evaluation of 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 fingerprints are difficult to detect 3: The attached fingerprints are a bit obvious 2: The attached fingerprints are obvious 1: The attached fingerprints are very obvious

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

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

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

Thereafter, the amount of change ΔL✽ obtained by subtracting the lightness L✽ before application from the lightness L✽ after application was calculated. According to the following formula, the change rate (%) of the lightness L✽ is calculated. The results are shown in Table 2 respectively. Change rate = {(Lightness after coating L✽-Brightness before coating L✽)/Lightness before coating L✽}×100

[Table 2]

As can be seen from Table 2, using the brightness L✽ before coating and the brightness L✽ after coating as indicators has a high correlation with the sensory evaluation, and the fingerprint resistance can be quantitatively evaluated. Furthermore, the hard coat films of Production Examples 1 to 4 were excellent in fingerprint resistance.

[Test Example 8] (Reproducibility test for fingerprint resistance evaluation) In the same manner as in Production Example 1, the other two hard coat films were produced respectively. The three hard coat films were produced on different days. Each obtained hard coat film was subjected to the fingerprint resistance test of Test Example 7 to confirm its reproducibility. The hard coat film of Production Example 1 is N=1, the second hard coat film is N=2, and the third hard coat film is N=3. The results are shown in Table 3.

[table 3]

It can be seen from Table 3 that the change amount ΔL✽ and the change rate of lightness L✽ of any hard coating film are within a certain range. The sensory evaluation is related to the change amount ΔL✽ of lightness L✽ and the change rate of lightness L✽. sex. That is, according to the above-described fingerprint resistance evaluation method, fingerprint resistance can be evaluated quantitatively and with high reproducibility. [Industrial Availability]

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

1‧‧‧Optical components 11‧‧‧Substrate 12‧‧‧Hard coating

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

1‧‧‧Optical components

11‧‧‧Substrate

12‧‧‧Hard coating

Claims (9)

A method for evaluating fingerprint resistance, which is characterized by measuring the lightness L* specified in the CIE1976L*a*b* color system on the surface of the object to be evaluated, and then coating the surface of the object to be evaluated with volatile The solvent is diluted into an oleic acid dilution with an oleic acid concentration of 0.12 mass% or more and 12 mass% or less, and after drying, the brightness L* specified in the CIE1976L*a*b* color system is measured, and the oleic acid is diluted with the oleic acid. The above-mentioned brightness L* before and after application of the liquid was used as an index to evaluate the fingerprint resistance of the surface of the object to be evaluated. The method for evaluating fingerprint resistance as described in Item 1 of the patent application, wherein the above-mentioned brightness L* before coating of the oleic acid diluent is taken as the brightness L* before coating, and the brightness L* of the oleic acid diluent after coating The above-mentioned brightness L* is regarded as the brightness L* after coating, and the fingerprint resistance of the surface of the object to be evaluated is evaluated by subtracting the change amount ΔL* of the brightness L* before coating from the brightness L* after coating. The method for evaluating fingerprint resistance as described in Item 1 of the patent application, wherein the above-mentioned brightness L* before coating of the oleic acid diluent is taken as the brightness L* before coating, and the brightness L* of the oleic acid diluent after coating The above-mentioned brightness L* is used as the brightness L* after coating. The change rate (%) calculated according to the following formula is used to evaluate the fingerprint resistance of the surface of the object to be evaluated. The change rate = {(brightness L* after coating) - coating Lightness before cloth L*)/Lightness before coating L*}×100. The method for evaluating fingerprint resistance as described in Item 1 of the patent application, wherein a hard coating layer exists on the surface of the object to be evaluated coated with the oleic acid diluent. The method for evaluating fingerprint resistance as described in item 1 of the patent application, wherein the object to be evaluated is an optical component. A method for producing optical components, characterized by: the steps of obtaining optical components; and Using the above-mentioned optical member as an object to be evaluated, an evaluation step for 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 member having a hard coating layer on the outermost surface and a base material, characterized in that the optical member has a brightness L* specified in the CIE1976L*a*b* color system before coating with an oleic acid diluent. As the brightness L* before coating, the brightness L* specified in the CIE1976L*a*b* color system after coating of the oleic acid diluent is used as the brightness L* after coating, and from this brightness L* after coating After subtracting the change amount ΔL* of the brightness L* before coating, it is less than 0.3. The oleic acid diluent is diluted with a volatile solvent to an oleic acid concentration of 0.2 mass%. The optical member is coated with the oleic acid diluent. The hard coat layer is present on the surface of the cloth, and the hard coat layer is a cured product of a coating composition containing an active energy ray curable component. An optical member having a hard coating layer on the outermost surface and a base material, characterized in that the optical member has a brightness L* specified in the CIE1976L*a*b* color system before coating with an oleic acid diluent. As the brightness L* before coating, the brightness L* specified in the CIE1976L*a*b* color system after coating of the oleic acid diluent. As the brightness L* after coating, the change rate is calculated according to the following formula (%) is less than 6%, the oleic acid diluent is diluted with a volatile solvent to an oleic acid concentration of 0.2 mass%, the hard coating layer exists on the surface of the optical member coated with the oleic acid diluent, and the The hard coat layer is a cured product of a coating composition containing an active energy ray curable component, where the change rate = {(brightness after coating L* - brightness before coating L*)/brightness before coating L*}× 100. The optical component as described in item 7 or 8 of the patent application, wherein the thickness of the hard coating layer The thickness is 1 μm or more and 20 μm or less.