TWI817160B - Optical film with antifouling layer - Google Patents

Abstract

The optical film with an antifouling layer of the present invention includes a base material layer, an optical functional layer including an inorganic layer, and an antifouling layer in order toward one side in the thickness direction. The surface roughness Ra of the antifouling layer is 2 nm or more and 15 nm or less.

Description

Optical film with antifouling layer

The present invention relates to an optical film with an antifouling layer.

Previously, from the viewpoint of preventing the adhesion of dirt (hand stains and fingerprints), it has been known to form an antifouling layer on the surface of a film base material and on the surface of optical components.

Specifically, an antireflection film is proposed that includes a transparent film, an antireflection layer, and an antifouling layer in order toward one side in the thickness direction (for example, see Patent Document 1).

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2017-227898

When dirt adheres to the antifouling layer, the dirt may be removed by wiping the dirt. Therefore, the antifouling layer is required to have durability against wiping (sliding).

On the other hand, if the antifouling layer is irradiated with ultraviolet rays, there is a drawback that the durability of the antifouling layer against sliding is reduced.

The present invention provides an optical film with an antifouling layer that can suppress a decrease in the sliding durability of the antifouling layer even if the antifouling layer is irradiated with ultraviolet rays.

The present invention [1] is an optical film with an antifouling layer, which has a substrate layer, an optical functional layer including an inorganic layer, and an antifouling layer in order on one side in the thickness direction, and the surface roughness of the antifouling layer is Ra is 2 nm or more and 15 nm or less.

The present invention [2] includes the optical film with an antifouling layer as described in the above [1], wherein the optical functional layer is an anti-reflective layer.

The present invention [3] includes the optical film with an antifouling layer as described in the above [2], wherein the anti-reflection layer alternately has a high refractive index layer with a relatively large refractive index, and a low refractive index layer with a relatively small refractive index. rate layer.

The present invention [4] includes the optical film with an antifouling layer as described in any one of the above [1] to [3], wherein the base layer is provided with a base material and a hard coat layer in order on one side in the thickness direction.

The present invention [5] includes the optical film with an antifouling layer as described in the above [4], wherein the hard coat layer contains metal oxide fine particles.

The present invention [6] includes the optical film with an antifouling layer as described in the above [5], wherein the metal oxide microparticles are nanosilica particles.

The present invention [7] includes the optical film with an antifouling layer according to any one of the above [4] to [6], wherein the surface roughness Ra of one surface in the thickness direction of the hard coat layer is 0.5 nm or more and 20 nm or less. .

In the optical film with an antifouling layer of the present invention, the surface roughness Ra of the antifouling layer is 2 nm or more and 15 nm or less. Therefore, even if the antifouling layer is irradiated with ultraviolet rays, the antifouling layer can be prevented from being reduced in sliding durability.

1: Optical film with antifouling layer

2: Base material layer

3: Adhesive layer

4: Optical functional layer

5: Antifouling layer

10:Substrate

11:Hard coating

21: 1st high refractive index layer

22: 1st low refractive index layer

23: 2nd high refractive index layer

24: 2nd low refractive index layer

FIG. 1 shows one embodiment of the optical film with an antifouling layer of the present invention.

2A to 2D illustrate one embodiment of a method for manufacturing an optical film with an antifouling layer of the present invention. Figure 2A shows the step of preparing the substrate in the first step. FIG. 2B shows the first step of arranging the hard coating layer on the base material in the first step. Figure 2C shows the second step of sequentially arranging the adhesive layer and the optical functional layer on the base material layer. Figure 2D shows the third step of disposing the antifouling layer on the optical functional layer.

Referring to FIG. 1 , one embodiment of the optical film with an antifouling layer of the present invention will be described.

In FIG. 1 , the upper and lower directions on the paper are the upper and lower directions (thickness direction). In addition, the upper side on the paper is the upper side (one side in the thickness direction). In addition, the lower side of the paper surface is the lower side (the other side in the thickness direction). In addition, the left-right direction and the depth direction of the paper surface are the surface directions orthogonal to the up-down direction. Specifically, follow the directional arrows in each figure.

<Optical film with antifouling layer>

The optical film 1 with an antifouling layer has a film shape (including a sheet shape) with a specific thickness. The optical film 1 with the antifouling layer extends in the plane direction orthogonal to the thickness direction. The optical film 1 with an antifouling layer has a flat upper surface and a flat lower surface.

As shown in FIG. 1 , the optical film 1 with an antifouling layer includes a base material layer 2 , an adhesion layer 3 , an optical functional layer 4 and an antifouling layer 5 in order toward one side in the thickness direction. More specifically, the optical film 1 with an antifouling layer includes a base material layer 2, an adhesion layer 3 directly disposed on the upper surface (one surface in the thickness direction) of the base material layer 2, and an adhesion layer 3 directly disposed on the upper surface of the adhesion layer 3. The optical functional layer 4 (one surface in the thickness direction), and the antifouling layer 5 directly disposed on the upper surface of the optical functional layer 4 (one surface in the thickness direction).

The thickness of the optical film 1 with the antifouling layer is, for example, 300 μm or less, preferably 200 μm or less, and, for example, 1 μm or more, preferably 5 μm or more.

<Substrate layer>

The base material layer 2 is an object to be treated that is provided with antifouling properties by the antifouling layer 5 .

The total light transmittance (JIS K 7375-2008) of the base material layer 2 is, for example, 80% or more, preferably More than 85%.

The base material layer 2 includes a base material 10 and a hard coat layer 11 in order toward one side in the thickness direction.

<Substrate>

The base material 10 has a film shape. The base material 10 is flexible. The base material 10 is disposed on the entire lower surface of the hard coating layer 11 in contact with the lower surface of the hard coating layer 11 .

Examples of the base material 10 include a polymer film.

Examples of materials for the polymer film include polyester resin, (meth)acrylic resin, olefin resin, polycarbonate resin, polyether resin, polyarylate resin, melamine resin, polyamide resin, polyamide resin, Imide resin, cellulose resin, and polystyrene resin. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the (meth)acrylic resin include polymethylmethacrylate. Examples of the olefin resin include polyethylene, polypropylene, and cycloolefin polymers. Examples of the cellulose resin include triacetyl cellulose.

As the material of the polymer membrane, cellulose resin is preferably used, and triacetyl cellulose is more preferably used.

The thickness of the base material 10 is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and, for example, 200 μm or less, preferably 150 μm or less, and more preferably 100 μm or less.

The thickness of the base material 10 can be measured using a dial gauge (manufactured by PEACOCK, "DG-205").

<Hard coat>

The hard coat layer 11 is a protective layer for preventing damage to the base material 10 . In addition, the hard coat layer 11 is a layer that can provide anti-glare properties to the base material 10 depending on the purpose and use.

The hard coat layer 11 is formed of a hard coat composition, for example.

The hard coating composition contains resin and particles. That is, the hard coat layer 11 contains resin and particles.

Examples of the resin include thermoplastic resin and curable resin. Examples of the thermoplastic resin include polyolefin resin.

Examples of the curable resin include active energy ray-curable resins that are cured by irradiation with active energy rays (eg, ultraviolet rays and electron beams) and thermosetting resins that are cured by heating. Preferred examples of the curable resin include active energy ray-curable resins.

Examples of the active energy ray-curable resin include: (meth)acrylic ultraviolet curable resin, polyurethane resin, melamine resin, alkyd resin, siloxane-based polymer, and organosilane condensation things. Preferable examples of the active energy ray-curable resin include: (Meth)acrylic ultraviolet curable resin.

Moreover, the resin may contain the reactive diluent described in Japanese Patent Application Laid-Open No. 2008-88309, for example. Specifically, the resin may include polyfunctional (meth)acrylates.

Examples of the particles include metal oxide fine particles and organic fine particles. Examples of materials for the metal oxide fine particles include silicon dioxide, aluminum oxide, titanium oxide, zirconium oxide, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. As a material of the metal oxide fine particles, a preferred example is silicon dioxide. That is, as the metal oxide fine particles, silica particles are preferably exemplified, and from the viewpoint of adjusting the surface roughness Ra of the antifouling layer 5 below to the following specific range, nanoparticles are more preferably exemplified. Silica particles. Examples of materials for organic fine particles include polymethyl methacrylate, silicone, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate. . Preferred materials for the organic fine particles include silicone and polymethylmethacrylate.

Particles can be used individually or in combination of 2 or more types.

Furthermore, by adjusting the blending ratio of particles and/or the average particle diameter of the particles to a specific ratio, the surface roughness Ra of the antifouling layer 5 described below can be adjusted to a specific range described below.

Specifically, the compounding ratio of the particles is, for example, 1 part by mass or more, preferably 3 parts by mass or more, for example, 30 parts by mass or more, and, for example, 20 parts by mass or less based on 100 parts by mass of the resin.

As long as the blending ratio of particles is below the upper limit, the surface roughness Ra of the antifouling layer 5 described below can be adjusted to the specific range described below.

The average particle diameter of the particles is, for example, 10 μm or less, preferably 8 μm or less, and, for example, 1 nm or more. When nanoparticles are used as particles, the average particle diameter of the particles is, for example, 100 nm or less, preferably 70 nm or less, and, for example, 1 nm or more. The average particle diameter of the particles can be determined as a D50 value (cumulative 50% median particle diameter) based on the particle size distribution determined by a particle size distribution measurement method in laser scattering, for example.

As long as the average particle diameter of the particles is within the above range, the surface roughness Ra of the antifouling layer 5 described below can be adjusted to the following specific range.

Moreover, a thixotropy imparting agent, a photopolymerization initiator, a filler (for example, organoclay), and a leveling agent can be mix|blended in an appropriate ratio to a hard-coat composition as needed. In addition, the hard coating composition can be diluted with a known solvent.

In order to form the hard coat layer 11, as described below in detail, a diluted solution of the hard coat composition is applied to one surface in the thickness direction of the base material 10 and dried. After drying, the hard coat composition is hardened by, for example, active energy ray irradiation.

Thereby, the hard coat layer 11 is formed.

The surface roughness Ra of the hard coat layer 11 (specifically, the surface roughness Ra of one surface in the thickness direction of the hard coat layer 11) is, for example, 0.5 nm or more, and, for example, is 20 nm or less.

As long as the surface roughness Ra of the hard coat layer 11 is within the above range, the surface roughness Ra of the antifouling layer 5 described below can be adjusted to the following specific range.

In addition, the surface roughness Ra can be calculated|required from the observation image of 1 micrometer square obtained by AFM (atomic force microscope), for example (the same applies below).

From the viewpoint of scratch resistance, the thickness of the hard coat layer 11 is, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 3 μm or more, and, for example, 50 μm or less. The thickness of the hard coat layer 11 can be measured by cross-sectional observation using a transmission electron microscope, for example.

<Adhesive layer>

The adhesive layer 3 is a layer for ensuring the adhesive force between the base material layer 2 and the optical functional layer 4 .

The adhesive layer 3 has a film shape. The adhesive layer 3 is disposed on the entire upper surface of the base layer 2 (hard coat layer 11) in contact with the upper surface of the base layer 2 (hard coat layer 11).

An example of the material of the adhesion layer 3 is metal. Examples of the metal include silicon, indium, nickel, chromium, aluminum, tin, gold, silver, platinum, zinc, titanium, tungsten, zirconium, and palladium. Furthermore, examples of the material of the adhesion layer 3 include alloys of two or more of the above-mentioned metals and oxides of the above-mentioned metals.

As a material of the adhesion layer 3, from the viewpoint of adhesion and transparency, silicon oxide ( _SiOx ) and indium tin oxide (ITO) are preferably exemplified. When silicon oxide is used as the material of the adhesion layer 3, it is preferable to use SiO _x whose oxygen content is less than the stoichiometric composition, and more preferably to use SiO _x whose x is 1.2 or more and 1.9 or less.

From the viewpoint of ensuring the adhesion between the base material layer 2 and the optical functional layer 4 and the transparency of the adhesion layer 3 , the thickness of the adhesion layer 3 is, for example, 1 nm or more, and, for example, 10 nm or less.

<Optical functional layer>

In one embodiment, the optical functional layer 4 is an anti-reflective layer used to suppress the reflection intensity of external light. That is, the optical film 1 with an antifouling layer is an antireflective film with an antifouling layer.

The optical functional layer 4 (anti-reflection layer) includes an inorganic layer and alternately has a high refractive index layer with a relatively large refractive index and a low refractive index layer with a relatively small refractive index in the thickness direction. In the anti-reflection layer, the intensity of the net reflected light is attenuated by the interference between the reflected light at the multiple interfaces in the multiple thin layers (high refractive index layer, low refractive index layer) it contains. In addition, in the anti-reflection layer, by adjusting the optical film thickness (the product of the refractive index and the thickness) of each thin layer, the interference effect of attenuating the intensity of reflected light can be exhibited. In this embodiment, the optical functional layer 4 as such an antireflection layer specifically includes a first high refractive index layer 21, a first low refractive index layer 22, and a second high refractive index layer in order toward one side in the thickness direction. layer 23, and the second low refractive index layer 24.

The first high refractive index layer 21 and the second high refractive index layer 23 each include a high refractive index material having a refractive index of preferably 1.9 or more at a wavelength of 550 nm. From the viewpoint of balancing high refractive index with low absorption of visible light, examples of high refractive index materials include: niobium oxide (Nb ₂ O ₅ ), titanium oxide, zirconium oxide, tin-doped indium oxide (ITO), And antimony-doped tin oxide (ATO), preferably niobium oxide. That is, it is preferable that the material of the first low refractive index layer 22 and the material of the second low refractive index layer 24 are both niobium oxide.

The optical film thickness (the product of the refractive index and the thickness) of the first high refractive index layer 21 is, for example, 20 nm or more, and may be, for example, 55 nm or less. The optical film thickness of the second high refractive index layer 23 is, for example, 60 nm or more, or, for example, 330 nm or less.

The first low refractive index layer 22 and the second low refractive index layer 24 each include a low refractive index material having a refractive index of preferably 1.6 or less at a wavelength of 550 nm. From the viewpoint of balancing low refractive index and low absorption of visible light, examples of the low refractive index material include silicon dioxide (SiO ₂ ) and magnesium fluoride, and silicon dioxide is preferred. That is, it is preferable that the material of the first low refractive index layer 22 and the material of the second low refractive index layer 24 are both silicon dioxide.

In particular, as long as the material of the second low refractive index layer 24 is silicon dioxide, the adhesion between the second low refractive index layer 24 and the antifouling layer 5 will be excellent.

The optical film thickness of the first low refractive index layer 22 is, for example, 15 nm or more, and may be, for example, 70 nm or less. The optical film thickness of the second low refractive index layer 24 is, for example, 100 nm or more, or, for example, 160 nm or less.

Furthermore, in the optical functional layer 4, the thickness of the first high refractive index layer 21 is, for example, 1 nm or more, preferably 5 nm or more, and, for example, 30 nm or less, preferably 20 nm or less. The thickness of the first low refractive index layer 22 is, for example, 10 nm or more, preferably 20 nm or more, and, for example, 50 nm or less, preferably 30 nm or less. The thickness of the second high refractive index layer 23 is, for example, 50 nm or more, preferably 80 nm or more, and, for example, 200 nm or less, preferably 150 nm or less. The thickness of the second low refractive index layer 24 is, for example, 60 nm or more, preferably 80 nm or more, and, for example, 150 nm or less, preferably 100 nm or less.

<Antifouling layer>

The antifouling layer 5 is a layer for preventing dirt (for example, dirt and fingerprints) from adhering to one side in the thickness direction of the base material layer 2 .

The antifouling layer 5 has a film shape. The antifouling layer 5 is disposed on the entire upper surface of the optical functional layer 4 in contact with the upper surface of the optical functional layer 4 .

As a material forming the antifouling layer 5, an alkoxysilane compound having a perfluoropolyether group can be exemplified. In other words, the antifouling layer 5 contains an alkoxysilane compound having a perfluoropolyether group. The antifouling layer 5 preferably contains an alkoxysilane compound having a perfluoropolyether group.

If the antifouling layer 5 contains an alkoxysilane compound having a perfluoropolyether group, the antifouling property of the antifouling layer 5 will be improved.

Examples of the alkoxysilane compound having a perfluoropolyether group include compounds represented by the following general formula (1).

R ¹ -R ² -X-(CH ₂ ) _l -Si(OR ³ ) ₃ (1)

(In the above formula (1), R ¹ represents a fluorinated alkyl group in which more than one hydrogen atom is replaced by a fluorine atom. R ² represents a repeating structure containing at least one perfluoropolyether group. ^{R 3} represents carbon Alkyl group with a number of 1 to 4. l represents an integer of 1 or more)

R ¹ represents a linear or branched fluorinated alkyl group (carbon number 1 to 20) in which one or more hydrogen atoms are replaced by fluorine atoms. R ¹ preferably represents a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are replaced by fluorine atoms.

R ² represents a structure containing a repeating structure of at least one perfluoropolyether group. R ² preferably represents a repeating structure containing two perfluoropolyether groups.

Examples of the repeating structure of the perfluoropolyether group include a repeating structure of a linear perfluoropolyether group and a repeating structure of a branched perfluoropolyether group. Examples of the repeating structure of the linear perfluoropolyether group include: -(OC _n F _2n ) _m -(m represents an integer from 1 to 50. n represents an integer from 1 to 20. The same applies below) . Examples of the repeating structure of the branched perfluoropolyether group include -(OC(CF ₃ ) ₂ ) _m - and -(OCF ₂ CF(CF ₃ )CF ₂ ) _m -.

As the repeating structure of the perfluoropolyether group, the repeating structure of the linear perfluoropolyether group is preferably exemplified, and the repeating structure of the perfluoropolyether group is more preferably: -(OCF ₂ ) _m -, and -(OC ₂ F ₄ ) _m- .

R ³ represents an alkyl group having 1 to 4 carbon atoms. R ³ preferably represents methyl.

X represents an ether group, a carbonyl group, an amine group, or an amide group, and preferably represents an ether group.

l represents an integer of not less than 1 and not more than 20, preferably an integer of not more than 10, more preferably not more than 5. l further preferably represents 3.

Among such alkoxysilane compounds having a perfluoropolyether group, preferred examples include compounds represented by the following general formula (2).

CF ₃ -(OCF ₂ ) _P -(OC ₂ F ₄ ) _Q -O-(CH ₂ ) ₃ -Si(OCH ₃ ) ₃ (2)

(In the above formula (2), P represents an integer from 1 to 50. Q represents an integer from 1 to 50)

Commercially available alkoxysilane compounds having a perfluoropolyether group can also be used. Specific examples of commercially available products include: KY-1901 (perfluoropolyether group-containing alkoxysilane compound, manufactured by Shin-Etsu Chemical Industry Co., Ltd.), OPTOOL UD120 (perfluoropolyether group-containing alkoxysilane compound) silane compounds).

In addition, by changing the material forming the antifouling layer 5, the surface roughness Ra of the antifouling layer 5 described below can be adjusted to the specific range described below.

The alkoxysilane compound having a perfluoropolyether group can be used alone or in combination of two or more types.

The antifouling layer 5 can be formed by the following method.

The thickness of the antifouling layer 5 is, for example, 1 nm or more, preferably 5 nm or more, and, for example, 30 nm or less, preferably 20 nm or less, and more preferably 15 nm or less.

As long as the thickness of the antifouling layer 5 is more than the above lower limit, the antifouling property of the antifouling layer 5 can be improved.

As long as the thickness of the antifouling layer 5 is equal to or less than the above upper limit, unevenness can be suppressed when the antifouling layer 5 is produced. As a result, the designability of the antifouling layer 5 is improved.

Furthermore, the thickness of the antifouling layer 5 can be measured by fluorescent X-ray (ZXS PrimusII manufactured by Rigaku).

Moreover, the water contact angle of the antifouling layer 5 is, for example, 100° or more, preferably 110° or more, more preferably 114° or more, and, for example, 130° or less.

As long as the water contact angle of the antifouling layer 5 is above the above-mentioned lower limit, the antifouling property of the antifouling layer 5 can be improved.

Furthermore, the method for measuring the water contact angle of the antifouling layer 5 can be described in detail through the following examples.

Furthermore, in this antifouling layer 5, the surface roughness Ra is within a specific range.

Specifically, the surface roughness Ra of the antifouling layer 5 is 2 nm or more, preferably 3 nm or more, more preferably 5 nm or more, and 15 nm or less, preferably 10 nm or less, and more preferably 7 nm or less.

As long as the surface roughness Ra of the antifouling layer 5 is equal to or higher than the above-mentioned lower limit, even if the antifouling layer 5 is irradiated with ultraviolet rays, the deterioration of the sliding durability of the antifouling layer 5 can be suppressed.

On the other hand, as long as the surface roughness Ra of the antifouling layer 5 does not reach the above-mentioned lower limit, the anchoring effect becomes insufficient and the antifouling layer 5 is peeled off from the optical functional layer 4. As a result, the antifouling layer 5 cannot be suppressed from sliding. Reduction in durability.

In addition, as long as the surface roughness Ra of the antifouling layer 5 is below the above upper limit, even if ultraviolet rays are irradiated, the deterioration of the sliding durability of the antifouling layer 5 can be suppressed.

On the other hand, if the surface roughness Ra of the antifouling layer 5 exceeds the above upper limit, the amount of ultraviolet rays irradiated to the antifouling layer 5 increases, and therefore the decrease in the sliding durability of the antifouling layer 5 cannot be suppressed.

The surface roughness Ra of the antifouling layer 5 is adjusted to the above-mentioned specific range, for example: the type of particles and/or the blending ratio of the particles and/or the average particle size of the particles in the hard coating layer 11 (hard coating composition) Adjust to a specific ratio; and/or prepare the surface roughness Ra of the hard coating layer 11; and/or change the material forming the antifouling layer 5 to a specific material; and/or configure the antifouling layer 5 on the optical functional layer 4 The method is changed to a specific method.

<Manufacturing method of optical film with antifouling layer>

Referring to FIGS. 2A to 2D , a method for manufacturing the optical film 1 with an antifouling layer will be described.

The manufacturing method of the optical film 1 with an antifouling layer includes: the first step, which prepares the base material layer 2; the second step, which sequentially arranges the base material layer 2, the adhesion layer 3 and the optical functional layer 4; and the third step, An antifouling layer 5 is disposed on the optical functional layer 4 .

(Step 1)

In the first step, base material layer 2 is prepared.

In order to prepare the base material layer 2, first, as shown in FIG. 2A, the base material 10 is prepared.

Next, as shown in FIG. 2B , the hard coat layer 11 is placed on the base material 10 . Specifically, the hard coat layer 11 is disposed on one surface of the base material 10 in the thickness direction.

Specifically, a diluted solution of the hard coating composition is applied to one surface in the thickness direction of the base material 10 and dried. After drying, the hard coat composition is hardened by ultraviolet irradiation. Thereby, the hard coat layer 11 is formed on one surface of the base material 10 in the thickness direction.

(Step 2)

In the second step, as shown in FIG. 2C , the adhesive layer 3 and the optical functional layer 4 are sequentially arranged on the base material layer 2 (hard coat layer 11 ). Specifically, the adhesion layer 3 is disposed on one surface in the thickness direction of the base layer 2 (hard coat layer 11 ), and then the optical functional layer 4 is disposed on one surface of the adhesion layer 3 in the thickness direction. Even Specifically, the adhesive layer 3 is arranged on one side of the base material layer 2 (hard coat layer 11) in the thickness direction, the first high refractive index layer 21 is arranged on one side of the adhesive layer 3 in the thickness direction, and the first high refractive index layer 21 is arranged on one side of the adhesive layer 3 in the thickness direction. The first low refractive index layer 22 is arranged on one side of the index layer 21 in the thickness direction, and the second high refractive index layer 23 is arranged on one side of the first low refractive index layer 22 in the thickness direction. The second low refractive index layer 24 is arranged on one surface in the thickness direction.

In order to sequentially arrange the adhesion layer 3 and the optical functional layer 4 on the base material layer 2, from the viewpoint of improving the adhesion between the base material layer 2 and the adhesion layer 3, first, the surface of the base material layer 2 is subjected to surface treatment.

Examples of surface treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment. Preferable examples of surface treatment include plasma treatment.

Furthermore, as a method of sequentially arranging the adhesion layer 3 and the optical functional layer 4 on the base material layer 2, examples include vacuum evaporation method, sputtering method, lamination method, plating method, and ion plating method. As a method of sequentially arranging each layer, a sputtering method is preferably used.

In the sputtering method, targets (each layer (adhesive layer 3, first high refractive index layer 21, first low refractive index layer 22, second high refractive index layer 23, and second low refractive index layer 23) are arranged facing each other in a vacuum chamber). The material of the rate layer 24) and the base material layer 2. Next, by supplying gas and applying voltage from a power source, gas ions are accelerated and irradiated to the target, causing the target material to be sputtered from the target surface. Then, each layer formed of the target material is sequentially deposited on the surface of the base material layer 2 .

Examples of the gas include inert gases. Examples of the inert gas include argon gas. Furthermore, for example, a reactive gas (for example, oxygen) may be used in combination if necessary. When a reactive gas is used together, the flow rate ratio (sccm) of the reactive gas is not particularly limited. Specifically, the flow rate ratio of the reactive gas to the total flow rate ratio of the sputtering gas and the reactive gas is, for example, 0.1 flow % or more and 100 flow % or less.

The gas pressure during sputtering is, for example, 0.1 Pa or more, and, for example, 1.0 Pa or less, preferably 0.7 Pa or less.

The power supply may be, for example, any one of DC (Direct Current) power supply, AC (Alternating Current, AC) power supply, MF (Medium Frequency, intermediate frequency) power supply, and RF (Radio Frequency, radio frequency) power supply. Also, it can be a combination of these.

Thereby, the adhesive layer 3 and the optical functional layer 4 are sequentially arranged on one surface of the base material layer 2 in the thickness direction.

(Step 3)

In the third step, as shown in FIG. 2D , the antifouling layer 5 is disposed on the optical functional layer 4 . Specifically, the antifouling layer 5 is disposed on one surface of the optical functional layer 4 in the thickness direction.

An example of a method for disposing the antifouling layer 5 on the optical functional layer 4 is a dry coating method. Examples of dry coating methods include vacuum evaporation, sputtering, and CVD (Chemical Vapor Deposition), from the viewpoint of adjusting the surface roughness Ra of the antifouling layer 5 to the above-mentioned specific range, a preferred example is vacuum evaporation.

Thereby, the antifouling layer 5 is disposed on the optical functional layer 4 . Then, an optical film 1 with an antifouling layer can be produced. The optical film 1 with an antifouling layer has a base material layer 2, an adhesion layer 3, an optical functional layer 4, and an antifouling layer 5 in order toward one side in the thickness direction.

Furthermore, in the optical film 1 with an antifouling layer, the surface roughness Ra of the antifouling layer 5 is within a specific range. Therefore, even if ultraviolet rays are irradiated, the antifouling layer 5 can be prevented from being reduced in sliding durability.

<Example of changes>

In the modified example, the same components and steps as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In addition, the modified examples can exhibit the same functions and effects as those of the first embodiment, unless otherwise specified. Furthermore, an embodiment and its modification can be combined appropriately.

In one embodiment, the base material layer 2 includes the base material 10 and the hard coat layer 11 in order toward one side in the thickness direction. However, the base material layer 2 may include the base material 10 without the hard coat layer 11 .

In one embodiment, the optical film 1 with an antifouling layer is provided with an adhesive layer 3 . However, the optical film 1 with the antifouling layer does not need to have the adhesive layer 3 . In this case, the optical film 1 with an antifouling layer includes a base material layer 2, an optical functional layer 4, and an antifouling layer 5 in order toward one side in the thickness direction.

In one embodiment, the optical functional layer 4 has two high refractive index layers with a relatively high refractive index, and two low refractive index layers with a relatively low refractive index. However, the number of high refractive index layers and low refractive index layers is not particularly limited.

In one embodiment, the optical functional layer 4 is an anti-reflective layer, but is not limited thereto. Examples of the optical functional layer 4 include a transparent electrode film (ITO film) and an electromagnetic wave shielding layer (a metal thin film with electromagnetic wave reflection capability).

[Example]

Examples and comparative examples are shown below to explain the present invention more specifically. In addition, the present invention is not limited to any Examples and Comparative Examples. In addition, specific numerical values such as blending ratios (content ratios), physical property values, and parameters used in the following description may be replaced with corresponding blending ratios (content ratios), physical property values, and parameters described in the above "Embodiments." etc. correspondingly recorded upper limit value (defined as a value "below" or "under") or lower limit value (defined as a value "above" or "exceeded").

1. Manufacturing of optical film with antifouling layer

Example 1

(Step 1)

A hard coat layer was formed on one side of a triacetyl cellulose (TAC) film (thickness: 80 μm) as a transparent resin film. In this step, first, 100 parts by mass of an ultraviolet curable acrylic monomer (trade name "GRANDIC PC-1070", manufactured by DIC Corporation) and an organosilica sol (trade name) containing nanosilica particles as particles "MEK-ST-L", the average primary particle diameter of nanosilica particles is 50nm, the solid content concentration is 30% by mass, manufactured by Nissan Chemical Co., Ltd.) 25 parts by mass (converted amount of nanosilica particles), 1.5 parts by mass of a variable imparting agent (trade name "Lucentite SAN", synthetic bentonite which is an organoclay, manufactured by Co-op Chemical Company), 3 parts by mass of photopolymerization initiator (trade name "OMNIRAD 907", manufactured by BASF Company) , and 0.15 parts by mass of a leveling agent (trade name "LE303", manufactured by Kyoeisha Chemical Co., Ltd.) were mixed to prepare a composition (varnish) with a solid content concentration of 55% by mass. Mix using an ultrasonic disperser. Next, the composition is coated on one side of the TAC film to form a coating film. Next, the coating film is hardened by ultraviolet irradiation and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as the light source, ultraviolet light with a wavelength of 365 nm was used, and the cumulative irradiation light amount was set to 200 mJ/cm ² . Moreover, the heating time was set to 80°C, and the heating temperature was set to 3 minutes. Thereby, a hard coat layer (second HC layer) with a thickness of 6 μm was formed on the TAC film. Thereby, a base material layer (TAC film with HC layer) was obtained.

(Step 2)

Secondly, the surface of the HC layer of the TAC film with the HC layer was plasma treated using a roll-to-roll plasma treatment device in a vacuum atmosphere of 1.0 Pa. In this plasma treatment, argon was used as an inert gas and the discharge power was set to 150W.

Secondly, a close contact layer and an anti-reflective layer are sequentially formed on the HC layer of the TAC film with HC layer after plasma treatment. Specifically, using a roll-to-roll sputtering film forming device, on the HC layer of the TAC film with HC layer after plasma treatment, a 1.5nm thick indium tin oxide (ITO) is formed as an adhesive layer. ) layer, a 12 nm thick Nb ₂ O ₅ layer as the first high refractive index layer, a 28 nm thick SiO ₂ layer as the first low refractive index layer, and a 100 nm thick Nb ₂ O ₅ layer as the second high refractive index layer. layer, and a SiO ₂ layer with a thickness of 85 nm as the second low refractive index layer. In the formation of the adhesion layer, an ITO target was used, argon as an inert gas, and oxygen as a reactive gas in an amount of 10 parts by volume relative to 100 parts by volume of argon, and the discharge voltage was set to 400V. The air pressure (film forming pressure) is set to 0.2Pa, and the ITO layer is formed by sputtering using MFAC (Model Free Adaptive Control). The formation conditions of the first high refractive index layer, the first low refractive index layer, the second high refractive index layer, and the second low refractive index layer in Example 2 are the same as those of the first high refractive index layer, the first high refractive index layer, and the second low refractive index layer in Comparative Example 1. The above formation conditions of the first low refractive index layer, the second high refractive index layer, and the second low refractive index layer are the same.

(Step 3)

Secondly, an antifouling layer is formed on the formed anti-reflective layer. Specifically, it was the same as the 3rd step in Comparative Example 1 (as a vapor deposition source, "OPTOOL UD120" (a perfluoropolyether group-containing alkoxysilane compound) manufactured by Daikin Industrial Co., Ltd. was used and obtained by drying it. solid content). Thereby, an optical film with an antifouling layer is produced.

Example 2

An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, change step 3 as follows.

As a vapor deposition source, a solid component obtained by drying "KY-1901" (perfluoropolyether group-containing alkoxysilane compound) manufactured by Shin-Etsu Chemical Industry Co., Ltd. was used.

Example 3

An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, change step 1 as follows.

(Step 1)

An acrylic monomer composition containing nanosilica particles (trade name "NC035"), the average primary particle size of the nanosilica particles is 40nm, the solid content concentration is 50%, and the nanoparticles in the solid content are The ratio of silica particles is 60 mass%, manufactured by Arakawa Chemical Industry Co., Ltd.) 67 parts by mass, ultraviolet curable polyfunctional acrylate (trade name "Binder A", solid content concentration 100%, manufactured by Arakawa Chemical Industry Co., Ltd. ) 33 parts by mass of polymethyl methacrylate particles as particles (trade name "Techpolymer", average particle diameter 3 μm, refractive index 1.525, manufactured by Sekisui Chemical Industry Co., Ltd.) 3 parts by mass of silicone particles as particles (product Name "Tospearl 130", average particle diameter 3 μm, refractive index 1.42, manufactured by Momentive Advanced Materials Japan Co., Ltd.) 1.5 parts by mass, thixotropy imparting agent (trade name "Lucentite SAN", synthetic bentonite as organoclay, Co- Op Chemical Co., Ltd.) 1.5 parts by mass, photopolymerization initiator (trade name "OMNIRAD 907", manufactured by BASF Co., Ltd.) 3 parts by mass, leveling agent (trade name "LE303", manufactured by Kyoeisha Chemical Co., Ltd.) 0.15 parts by mass , and toluene were mixed to prepare a composition (varnish) with a solid content concentration of 45% by mass. Mix using an ultrasonic disperser. Next, the composition is coated on one side of the TAC film to form a coating film. Next, the coating film is hardened by ultraviolet irradiation and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as the light source, ultraviolet light with a wavelength of 365 nm was used, and the cumulative irradiation light amount was set to 200 mJ/cm ² . Moreover, the heating time was set to 60°C, and the heating temperature was set to 60 seconds. Thereby, an anti-glare hard coat layer (3rd HC layer) with a thickness of 7 μm was formed on the TAC film. Thereby, a base material layer (TAC film with HC layer) was obtained.

Comparative example 1

(Step 1)

An anti-glare hard coat layer was formed on one side of a triacetyl cellulose (TAC) film (thickness: 80 μm) as a transparent resin film. In this step, first, 50 parts by mass of ultraviolet curable acrylic urethane (trade name "UV1700TL", manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and ultraviolet curable multifunctional acrylate (trade name "Viscoat #300" ”, the main component is pentaerythritol triacrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 50 parts by mass, as particles, polymethyl methacrylate particles (trade name “Techpolymer”, average particle diameter 3 μm, refractive index 1.525, hydrated product Industrial Co., Ltd.) 3 parts by mass of silicone particles as particles (trade name "Tospearl 130", average particle diameter 3 μm, refractive index 1.42, manufactured by Momentive Advanced Materials Japan Co., Ltd.), 1.5 parts by mass of a thixotropy imparting agent (product Named "Lucentite SAN", a synthetic bentonite which is an organoclay, manufactured by Co-op Chemical Company) 1.5 parts by mass, photopolymerization initiator (trade name "OMNIRAD 907", manufactured by BASF Company) 3 parts by mass, leveling agent ( Trade name "LE303" (manufactured by Kyeisha Chemical Co., Ltd.) 0.15 parts by mass and a toluene-ethyl acetate-cyclopentanone mixed solvent (mass ratio 35:41:24) were mixed to prepare a combination with a solid content concentration of 55% by mass. Object (varnish). Mix using an ultrasonic disperser.

Next, the composition is coated on one side of the TAC film to form a coating film. Next, the coating film is hardened by ultraviolet irradiation and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as the light source, ultraviolet light with a wavelength of 365 nm was used, and the cumulative irradiation light amount was set to 300 mJ/cm ² . Moreover, the heating temperature was set to 80°C, and the heating time was set to 60 seconds. Thereby, an anti-glare hard coat layer (first HC layer) with a thickness of 8 μm was formed on the TAC film. Thereby, a base material layer (TAC film with HC layer) was obtained.

(Step 2)

Secondly, the surface of the HC layer of the TAC film with the HC layer was plasma treated using a roll-to-roll plasma treatment device in a vacuum atmosphere of 1.0 Pa. In this plasma treatment, argon was used as an inert gas and the discharge power was set to 2400W.

Secondly, a close contact layer and an anti-reflective layer are sequentially formed on the HC layer of the TAC film with HC layer after plasma treatment. Specifically, using a roll-to-roll sputtering film forming device, a 3.5nm thick SiO _x layer (x< 2). A Nb ₂ O ₅ layer with a thickness of 12 nm as the first high refractive index layer, a SiO ₂ layer with a thickness of 28 nm as the first low refractive index layer, and an Nb ₂ O ₅ layer with a thickness of 100 nm as the second high refractive index layer. layer, and a SiO ₂ layer with a thickness of 85 nm as the second low refractive index layer. In the formation of the adhesion layer, a Si target was used, argon gas was used as an inert gas, and oxygen gas was used as a reactive gas in an amount of 3 parts by volume relative to 100 parts by volume of the argon gas, and the discharge voltage was set to 520V. The air pressure (film forming pressure) was set to 0.27Pa, and a SiO _x layer (x<2) was formed by MFAC sputtering. In the formation of the first high refractive index layer, an Nb target was used, 100 parts by volume of argon gas and 5 parts by volume of oxygen gas were used, the discharge voltage was set to 415V, and the film forming gas pressure was set to 0.42Pa, by MFAC sputtering A Nb ₂ O ₅ layer is formed. In the formation of the first low refractive index layer, a Si target was used, 100 parts by volume of argon gas and 30 parts by volume of oxygen gas were used, the discharge voltage was set to 350V, and the film forming gas pressure was set to 0.3Pa, by MFAC sputtering A SiO ₂ layer is formed. In the formation of the second high refractive index layer, an Nb target was used, 100 parts by volume of argon gas and 13 parts by volume of oxygen gas were used, the discharge voltage was set to 460V, and the film forming gas pressure was set to 0.5Pa, by MFAC sputtering A Nb ₂ O ₅ layer is formed. In the formation of the second low refractive index layer, a Si target was used, 100 parts by volume of argon gas and 30 parts by volume of oxygen gas were used, the discharge voltage was set to 340V, and the film forming gas pressure was set to 0.25Pa, by MFAC sputtering A SiO ₂ layer is formed. As shown above, the anti-reflection layer (the first high refractive index layer, the first low refractive index layer, the second high refractive index layer, the second low refractive index layer) is laminated on the HC layer of the TAC film with the HC layer through the adhesion layer. refractive index layer).

(Step 3)

Secondly, an antifouling layer is formed on the formed anti-reflective layer. Specifically, an antifouling layer with a thickness of 7 nm was formed on the antireflection layer by a vacuum evaporation method using a perfluoropolyether group-containing alkoxysilane compound as the evaporation source. The evaporation source is obtained by drying "OPTOOL UD509" (a perfluoropolyether group-containing alkoxysilane compound represented by the above general formula (2), solid content concentration 20% by mass) manufactured by Daikin Industrial Co., Ltd. The solid content. In addition, the heating temperature of the vapor deposition source in the vacuum vapor deposition method was set to 260°C.

Thereby, an optical film with an antifouling layer is produced.

Comparative example 2

An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, change step 3 as follows.

(Step 3)

"OPTOOL UD509" (manufactured by Daikin Industrial Co., Ltd.) as a coating agent was diluted with a dilution solvent (trade name "Fluorinert", manufactured by 3M Company) to prepare a mass with a solid content concentration of 0.1 Quantity % of coating fluid. Next, the coating liquid is coated on the anti-reflective layer formed in the second step by gravure coating to form a coating film. Next, the coating film was dried by heating at 60° C. for 2 minutes. Thereby, an antifouling layer with a thickness of 7 nm is formed on the anti-reflection layer.

2.Evaluation

(Surface roughness Ra)

The surface roughness Ra of the antifouling layer of the antifouling layer and the hard coat layer of the optical film with an antifouling layer in each of the Examples and Comparative Examples was studied. Specifically, the surface of the antifouling layer of each optical film with an antifouling layer was observed with an atomic force microscope (trade name "SPI3800", manufactured by Seiko Instruments), and the surface roughness Ra was calculated from the observation image of 1 μm square. (arithmetic mean roughness). The results are shown in Table 1.

(water contact angle)

In the optical films with antifouling layers in each of the examples and comparative examples, DMo-501 manufactured by Kyowa Interface Science Co., Ltd. was used for the antifouling layer. Based on the following conditions, the water contact angle of the antifouling layer to pure water was measured ( initial water contact angle). The results are shown in Table 1.

<Measurement conditions>

Drop volume: 2μl

Temperature: 25℃

Humidity: 40%

(Durability test)

[Ultraviolet irradiation]

The optical films with antifouling layers of each Example and each Comparative Example were put into Eye Super (SUV-W161) manufactured by Iwasaki Electric. Then, ultraviolet irradiation was performed from the antifouling layer side under the following conditions.

<Irradiation conditions>

BPT (Black Panel Thermometer, black panel thermometer) temperature: 80℃

Humidity: 45℃

UV intensity: 150mW/cm ²

Time: 32.5 hours

[Measurement of water contact angle after ultraviolet irradiation]

After ultraviolet irradiation, the water contact angle of the antifouling layer to pure water (water contact angle after ultraviolet irradiation) was measured in the same method as above. The results are shown in Table 1.

[Observation on durability]

Continuously add 2 mL of isopropyl alcohol dropwise so that the surface of the sample after ultraviolet irradiation will not dry out, and place a polyester wipe ("Anticon Gold" manufactured by Sanplatec) fixed on a 20 mm × 20 mm SUS jig on the grid. Sliding (load: 1.5kg, 1000 times back and forth). Thereafter, the presence or absence of peeling was visually confirmed. The results are shown in Table 1.

In addition, the above-mentioned invention is provided as an exemplary embodiment of the present invention, and they are only illustrative and should not be construed restrictively. Modifications of the present invention known to those skilled in the art are included in the scope of the following patent applications.

[Industrial availability]

The optical film with an antifouling layer of the present invention is suitable for, for example, an antireflective film with an antifouling layer, a transparent conductive film with an antifouling layer, and an electromagnetic wave shielding film with an antifouling layer.

1: Optical film with antifouling layer

2: Base material layer

3: Adhesive layer

4: Optical functional layer

5: Antifouling layer

10:Substrate

11:Hard coating

21: 1st high refractive index layer

22: 1st low refractive index layer

23: 2nd high refractive index layer

24: 2nd low refractive index layer

Claims (4)

An optical film with an antifouling layer, which has a base material layer, an optical functional layer including an inorganic layer, and an antifouling layer in sequence toward one side in the thickness direction, and the base material layer has a base material and an antifouling layer in sequence toward one side in the thickness direction. Hard coating, the above-mentioned hard coating contains nano-silica particles (excluding hollow silica sol), the average particle size of the above-mentioned nano-silica particles is 1 nm or more and 100 nm or less, and the surface of the above-mentioned antifouling layer is rough The degree Ra is 3 nm or more and 15 nm or less, and the thickness of the antifouling layer is 1 nm or more and 30 nm or less. The optical film with an antifouling layer as claimed in claim 1, wherein the optical functional layer is an anti-reflective layer. An optical film with an antifouling layer as claimed in claim 2, wherein the anti-reflection layer alternately has a high refractive index layer with a relatively large refractive index and a low refractive index layer with a relatively small refractive index. The optical film with an antifouling layer according to any one of claims 1 to 3, wherein the surface roughness Ra of one surface in the thickness direction of the hard coat layer is 0.5 nm or more and 20 nm or less.