WO2022014569A1

WO2022014569A1 - Optical film with anti-fouling layer

Info

Publication number: WO2022014569A1
Application number: PCT/JP2021/026247
Authority: WO
Inventors: 幸大宮本; 智剛梨木
Original assignee: 日東電工株式会社
Priority date: 2020-07-13
Filing date: 2021-07-13
Publication date: 2022-01-20
Also published as: JPWO2022014569A1; KR20230005424A; TW202215074A; JP7185101B2; TWI817160B; CN115812035A; CN115812035B; KR102518012B1

Abstract

An optical film with an anti-fouling layer according to the present invention comprises a substrate layer, an optical function layer comprising an inorganic layer, and an anti-fouling layer arranged in this order towards one side of the film in the thickness direction. The surface roughness Ra of the anti-fouling layer is 2-15 nm inclusive.

Description

Optical film with antifouling layer

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

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

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

Japanese Unexamined Patent Publication No. 2017-227898

If dirt adheres to the antifouling layer, the dirt may be wiped off. Therefore, the antifouling layer is required to have durability against wiping (sliding).

On the other hand, when the antifouling layer is irradiated with ultraviolet rays, there is a problem that the durability of the antifouling layer against sliding is lowered.

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

In the present invention [1], a base material layer, an optical functional layer composed of an inorganic layer, and an antifouling layer are provided in order toward one side in the thickness direction, and the surface roughness Ra of the antifouling layer is 2 nm or more and 15 nm. The following is an optical film with an antifouling layer.

The present invention [2] includes the optical film with an antifouling layer according to the above [1], wherein the optical functional layer is an antireflection layer.

The present invention [3] is described in the above [2], wherein the antireflection layer alternately has a high refractive index layer having a relatively large refractive index and a low refractive index layer having a relatively small refractive index. Includes an optical film with an antifouling layer.

In the present invention [4], the antifouling layer according to any one of the above [1] to [3], wherein the base material layer comprises a base material and a hard coat layer in order toward one side in the thickness direction. Includes optical film with.

The present invention [5] includes the optical film with an antifouling layer according to 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 according to the above [5], wherein the metal oxide fine particles are nanosilica particles.

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

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, it is possible to suppress a decrease in the durability of the antifouling layer against sliding.

FIG. 1 shows an embodiment of an optical film with an antifouling layer of the present invention. 2A to 2D show an embodiment of the method for manufacturing an optical film with an antifouling layer of the present invention. FIG. 2A shows a step of preparing a base material in the first step. FIG. 2B shows the first step of arranging the hard coat layer on the base material in the first step. FIG. 2C shows a second step of sequentially arranging the adhesion layer and the optical functional layer on the base material layer. FIG. 2D shows a third step of arranging the antifouling layer on the optical functional layer.

An embodiment of the optical film with an antifouling layer of the present invention will be described with reference to FIG.

In FIG. 1, the vertical direction of the paper surface is the vertical direction (thickness direction). Further, the upper side of the paper surface is the upper side (one side in the thickness direction). Further, the lower side of the paper surface is the lower side (the other side in the thickness direction). Further, the left-right direction and the depth direction of the paper surface are plane directions orthogonal to the vertical direction. Specifically, it conforms to the direction 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) having a predetermined thickness. The optical film 1 with an antifouling layer extends in a 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 arranged on the upper surface of the base material layer 2 (one surface in the thickness direction), and an upper surface (thickness) of the adhesion layer 3. It includes an optical functional layer 4 directly arranged on one side in the direction) and an antifouling layer 5 directly arranged on the upper surface (one side in the thickness direction) of the optical functional layer 4.

The thickness of the optical film 1 with an 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.

<Base layer>
The base material layer 2 is a treated body to which antifouling property is imparted 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 85% or more.

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.

<Base material>
The base material 10 has a film shape. The base material 10 has flexibility. The base material 10 is arranged on the entire lower surface of the hard coat layer 11 so as to come into contact with the lower surface of the hard coat layer 11.

Examples of the base material 10 include a polymer film.

Examples of the material of the polymer film include polyester resin, (meth) acrylic resin, olefin resin, polycarbonate resin, polyether sulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin. Can be mentioned. 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.

Examples of the material of the polymer film include cellulose resin, and more preferably triacetyl cellulose.

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, more preferably 100 μm or less.

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

<Hard coat layer>
The hard coat layer 11 is a protective layer for suppressing the occurrence of scratches on the base material 10. Further, the hard coat layer 11 is a layer capable of imparting antiglare property to the base material 10 according to the purpose and use.

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

The hardcourt composition contains resin and particles. That is, the hardcourt layer 11 contains resin and particles.

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

Examples of the curable resin include an active energy ray-curable resin that is cured by irradiation with active energy rays (for example, ultraviolet rays and electron beams) and a thermosetting resin that is cured by heating. The curable resin is preferably an active energy ray curable resin.

Examples of the active energy ray-curable resin include (meth) acrylic ultraviolet curable resin, urethane resin, melamine resin, alkyd resin, siloxane-based polymer, and organic silane condensate. The active energy ray-curable resin is preferably a (meth) acrylic ultraviolet curable resin.

Further, the resin can contain, for example, the reactive diluent described in JP-A-2008-88309. Specifically, the resin can include polyfunctional (meth) acrylates.

Examples of the particles include metal oxide fine particles and organic fine particles. Examples of the material of the metal oxide fine particles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. As the material of the metal oxide fine particles, silica is preferable. That is, examples of the metal oxide fine particles include silica particles, and more preferably nanosilica particles from the viewpoint of adjusting the surface roughness Ra of the antifouling layer 5 described later to a predetermined range described later. Examples of the material of the organic fine particles include polymethylmethacrylate, 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 alone or in combination of two or more.

Then, by adjusting the mixing ratio of the particles and / or the average particle diameter of the particles to a predetermined ratio, the surface roughness Ra of the antifouling layer 5 described later can be adjusted to a predetermined range described later.

Specifically, the mixing ratio of the particles is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and for example, 30 parts by mass or more, or, for example, 20 parts by mass with respect to 100 parts by mass of the resin. It is as follows.

If the mixing ratio of the particles is not more than the above upper limit, the surface roughness Ra of the antifouling layer 5 described later can be adjusted to a predetermined range described later.

The average particle size 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 the particles, the average particle size 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 size of the particles is determined as a D50 value (cumulative 50% median diameter) based on, for example, the particle size distribution obtained by the particle size distribution measurement method in the laser scattering method.

If the average particle size of the particles is within the above range, the surface roughness Ra of the antifouling layer 5 described later can be adjusted to a predetermined range described later.

Further, the hard coat composition may contain, if necessary, a thixotropy-imparting agent, a photopolymerization initiator, a filler (for example, organic clay), and a leveling agent in an appropriate ratio. Further, the hard coat composition can be diluted with a known solvent.

Further, in order to form the hard coat layer 11, a diluted solution of the hard coat composition is applied to one surface of the base material 10 in the thickness direction and dried, which will be described in detail later. After drying, the hardcourt composition is cured, for example, by irradiation with active energy rays.

This forms the hard coat layer 11.

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

If 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 later can be adjusted to a predetermined range described later.

The surface roughness Ra can be obtained from, for example, an observation image of 1 μm square by an AFM (atomic force microscope) (the same applies hereinafter).

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, for example, a transmission electron microscope.

<Adhesion layer>
The adhesion layer 3 is a layer for ensuring an adhesion between the base material layer 2 and the optical functional layer 4.

The adhesion layer 3 has a film shape. The adhesion layer 3 is arranged on the entire upper surface of the base material layer 2 (hard coat layer 11) so as to be in contact with the upper surface of the base material layer 2 (hard coat layer 11).

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

Examples of the material of the adhesion layer 3 include silicon oxide (SiOx) and indium tin oxide (ITO) from the viewpoint of adhesion and transparency. When silicon oxide is used as the material of the adhesion layer 3, SiOx having a smaller oxygen content than the stoichiometric composition is preferably used, and more preferably SiOx having x of 1.2 or more and 1.9 or less is used. ..

The thickness of the adhesion layer 3 is, for example, 1 nm or more, and for example, 10 nm from the viewpoint of ensuring the adhesion between the base material layer 2 and the optical functional layer 4 and achieving both the transparency of the adhesion layer 3. It is as follows.

<Optical functional layer>
In one embodiment, the optical functional layer 4 is an antireflection layer for suppressing the reflection intensity of external light. That is, the optical film 1 with an antifouling layer is an antireflection film with an antifouling layer.

The optical functional layer 4 (antireflection layer) is made of an inorganic layer, and has a high refractive index layer having a relatively large refractive index and a low refractive index layer having a relatively small refractive index alternately in the thickness direction. In the antireflection layer, the net reflected light intensity is attenuated by the interference action between the reflected light at the plurality of interfaces in the plurality of thin layers (high refractive index layer, low refractive index layer) contained therein. Further, in the antireflection layer, an interference effect for attenuating the reflected light intensity can be exhibited by adjusting the optical film thickness (product of the refractive index and the thickness) of each thin layer. Specifically, in the present embodiment, the optical functional layer 4 as such an antireflection layer includes a first high refractive index layer 21, a first low refractive index layer 22, and a second high refractive index layer 23. The second low refractive index layer 24 is provided in order toward one side in the thickness direction.

The first high-refractive index layer 21 and the second high-refractive index layer 23 are each made of 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 achieving both high refractive index and low absorption of visible light, examples of the high refractive index material include niobium oxide (Nb ₂ O ₅ ), titanium oxide, zirconium oxide, tin-doped indium oxide (ITO), and tin-doped indium oxide (ITO). Antimonated tin oxide (ATO) is mentioned, preferably niobium oxide. That is, preferably, 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 (product of refractive index and thickness) of the first high refractive index layer 21 is, for example, 20 nm or more, and 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, and for example, 330 nm or less.

The first low refractive index layer 22 and the second low refractive index layer 24 are each made of 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 achieving both low refractive index and low absorption of visible light, examples of the low refractive index material include silicon dioxide (SiO ₂ ) and magnesium fluoride, preferably silicon dioxide. That is, preferably, 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, if 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 is excellent.

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

Further, 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.

<Anti-fouling layer>
The antifouling layer 5 is a layer for preventing adhesion of dirt (for example, dirt and fingerprints) to one side of the base material layer 2 in the thickness direction.

The antifouling layer 5 has a film shape. The antifouling layer 5 is arranged on the entire upper surface of the optical functional layer 4 so as to be in contact with the upper surface of the optical functional layer 4.

Examples of the material forming the antifouling layer 5 include an alkoxysilane compound having a perfluoropolyether group. In other words, the antifouling layer 5 contains an alkoxysilane compound having a perfluoropolyether group. The antifouling layer 5 is preferably made of an alkoxysilane compound having a perfluoropolyether group.

When the antifouling layer 5 contains an alkoxysilane compound having a perfluoropolyether group, the antifouling property of the antifouling layer 5 is 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 an alkyl fluoride group in which one or more hydrogen atoms are substituted with a fluorine atom. R ² is a structure containing at least one repeating structure of a perfluoropolyether group. R ³ indicates an alkyl group having 1 or more and 4 or less carbon atoms. L indicates an integer of 1 or more.)
R ¹ represents a linear or branched alkyl fluoride group (1 or more and 20 or less carbon atoms) in which one or more hydrogens are substituted with a fluorine atom. R ¹ preferably represents a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms.

R ² is a repeating structure of the perfluoropolyether group exhibits at least one containing structure. R ² preferably shows a structure containing two repeating structures of 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. As the repeating structure of the linear perfluoropolyether group, for example,-(OC _n F _2n ) _m- (m indicates an integer of 1 or more and 50 or less, and n indicates an integer of 1 or more and 20 or less. The same shall apply hereinafter.) 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- .

The repeating structure of the perfluoropolyether group is preferably a repeating structure of a linear perfluoropolyether group, more preferably-(OCF ₂ ) _m- , and-(OC ₂ F ₄ ) _m-. Can be mentioned.

R ³ represents an alkyl group having 1 or more and 4 or less carbon atoms. R ³ preferably represents a methyl group.

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

L represents an integer of 1 or more, 20 or less, preferably 10 or less, and more preferably 5 or less. l more preferably indicates 3.

Among such alkoxysilane compounds having a perfluoropolyether group, a compound represented by the following general formula (2) is preferable.
CF _3- (OCF ₂ ) _P- (OC ₂ F ₄ ) _Q- O- (CH ₂ ) _3- Si (OCH ₃ ) ₃ (2)
(In the above equation (2), P indicates an integer of 1 or more and 50 or less. Q indicates an integer of 1 or more and 50 or less.)

As the alkoxysilane compound having a perfluoropolyether group, a commercially available product can also be used. Specific examples of commercially available products include KY-1901 (alkoxysilane compound containing a perfluoropolyether group, manufactured by Shin-Etsu Chemical Co., Ltd.) and Optool UD120 (alkoxysilane compound containing a perfluoropolyether group).

Further, by changing the material forming the antifouling layer 5, the surface roughness Ra of the antifouling layer 5 described later can be adjusted to a predetermined range described later.

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

The antifouling layer 5 is formed by the method described later.

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, more preferably 15 nm or less.

If the thickness of the antifouling layer 5 is at least the above lower limit, the antifouling property of the antifouling layer 5 can be improved.

If the thickness of the antifouling layer 5 is not more than the above upper limit, unevenness can be suppressed when the antifouling layer 5 is manufactured. As a result, the design of the antifouling layer 5 is improved.

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

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.

If the water contact angle of the antifouling layer 5 is equal to or greater than the above lower limit, the antifouling property of the antifouling layer 5 can be improved.

The method for measuring the water contact angle of the antifouling layer 5 will be described in detail in Examples described later.

Then, in such an antifouling layer 5, the surface roughness Ra is within a predetermined 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, more preferably 7 nm or less. be.

If the surface roughness Ra of the antifouling layer 5 is equal to or higher than the above lower limit, it is possible to suppress a decrease in the durability of the antifouling layer 5 against sliding even if it is irradiated with ultraviolet rays.

On the other hand, if the surface roughness Ra of the antifouling layer 5 is less than the above lower limit, the anchor effect becomes insufficient and the antifouling layer 5 is peeled off from the optical functional layer 4, so that the antifouling layer 5 is against sliding. The decrease in durability cannot be suppressed.

Further, if the surface roughness Ra of the antifouling layer 5 is not more than the above upper limit, it is possible to suppress a decrease in the durability of the antifouling layer 5 against sliding even if it is irradiated with ultraviolet rays.

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, so that the deterioration of the antifouling layer 5's durability against sliding cannot be suppressed.

To adjust the surface roughness Ra of the antifouling layer 5 to the above-mentioned predetermined range, for example, in the hard coat layer 11 (hard coat composition), the type of particles and / or the blending ratio of the particles and / or the particles. Adjust the average particle size of the hard coat layer 11 to a predetermined ratio and / or prepare the surface roughness Ra of the hard coat layer 11 and / or change the material forming the antifouling layer 5 to a predetermined material. And / or, the method of arranging the antifouling layer 5 on the optical functional layer 4 is changed to a predetermined method.

<Manufacturing method of optical film with antifouling layer>
A method for manufacturing the optical film 1 with an antifouling layer will be described with reference to FIGS. 2A to 2D.

The manufacturing method of the optical film 1 with an antifouling layer includes a first step of preparing the base material layer 2, a second step of arranging the base material layer 2, the adhesion layer 3 and the optical functional layer 4 in order, and optical. The functional layer 4 is provided with a third step of arranging the antifouling layer 5.

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

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 arranged on the base material 10. Specifically, the hard coat layer 11 is arranged on one surface of the base material 10 in the thickness direction.

Specifically, a diluted solution of the hard coat composition is applied to one surface of the base material 10 in the thickness direction and dried. After drying, the hardcourt composition is cured by irradiation with ultraviolet rays. As a result, the hard coat layer 11 is formed on one surface of the base material 10 in the thickness direction.

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

In order to arrange the adhesion layer 3 and the optical functional layer 4 on the substrate layer 2 in order, first, from the viewpoint of improving the adhesion between the substrate layer 2 and the adhesion layer 3, the surface of the substrate layer 2 is surfaced. Apply processing.

Examples of the surface treatment include corona treatment, plasma treatment, frame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment. The surface treatment preferably includes plasma treatment.

Then, as a method of arranging the adhesion layer 3 and the optical functional layer 4 in order on the base material layer 2, for example, a vacuum vapor deposition method, a sputtering method, a laminating method, a plating method, and an ion plating method can be mentioned. As a method of arranging each layer in order, a sputtering method is preferable.

In the sputtering method, the target (each layer (adhesion 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 24) is placed in the vacuum chamber. Material) and the base material layer 2 are arranged so as to face each other. Next, the gas ions are accelerated by supplying gas and applying a voltage from the power source to irradiate the target, and the target material is ejected from the target surface. Then, each layer is sequentially deposited on the surface of the base material layer 2 with the target material.

Examples of the gas include an inert gas. Examples of the inert gas include argon gas. Further, for example, a reactive gas (for example, oxygen gas) can be used in combination, if necessary. When the reactive gas is used in combination, the flow rate ratio (sccm) of the reactive gas is not particularly limited. Specifically, the flow rate ratio of the reactive gas is, for example, 0.1 flow rate% or more and 100 flow rate% or less with respect to the total flow rate ratio of the sputter gas and the reactive gas.

The atmospheric 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 of a DC power supply, an AC power supply, an MF power supply, and an RF power supply. Further, these combinations may be used.

As a result, the adhesion layer 3 and the optical functional layer 4 are sequentially arranged on one surface of the base material layer 2 in the thickness direction.

(Third step)
In the third step, as shown in FIG. 2D, the antifouling layer 5 is arranged on the optical functional layer 4. Specifically, the antifouling layer 5 is arranged on one side of the optical functional layer 4 in the thickness direction.

As a method of arranging the antifouling layer 5 on the optical functional layer 4, for example, a dry coating method can be mentioned. Examples of the dry coating method include a vacuum vapor deposition method, a sputtering method, and a CVD method, preferably a vacuum vapor deposition method from the viewpoint of adjusting the surface roughness Ra of the antifouling layer 5 to the above-mentioned predetermined range.

As a result, the antifouling layer 5 is arranged on the optical functional layer 4. Then, an optical film 1 with an antifouling layer is manufactured, which comprises the base material layer 2, the adhesion layer 3, the optical functional layer 4, and the antifouling layer 5 in order toward one side in the thickness direction.

Then, in the optical film 1 with the antifouling layer, the surface roughness Ra of the antifouling layer 5 is within a predetermined range. Therefore, even if it is irradiated with ultraviolet rays, it is possible to suppress a decrease in the durability of the antifouling layer 5 against sliding.

<Modification example>
In the modified example, the same members and processes as in one embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, the modified example can exhibit the same effect as that of the first embodiment, except for special mention. Further, one embodiment and a modification thereof can be appropriately combined.

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 does not include the hard coat layer 11 and may be made of the base material 10.

In one embodiment, the optical film 1 with an antifouling layer includes an adhesion layer 3. However, the optical film 1 with an antifouling layer does not have to include the adhesion layer 3. In such a 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 includes two high refractive index layers having a relatively high refractive index and two low refractive index layers having 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 antireflection 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 having an electromagnetic wave reflecting ability).

Examples and comparative examples are shown below, and the present invention will be described in more detail. The present invention is not limited to Examples and Comparative Examples. In addition, specific numerical values such as the compounding ratio (content ratio), physical property values, parameters, etc. used in the following description are described in the above-mentioned "form for carrying out the invention", and the compounding ratios corresponding to them ( Can be replaced with the upper limit value (value defined as "less than or equal to" or "less than") or the lower limit value (value defined as "greater than or equal to" or "excess") such as content ratio), physical property value, parameter, etc. ..

1. 1. Production of Optical Film with Antifouling Layer Example 1
(First step)
A hardcourt layer was formed on one side of a triacetyl cellulose (TAC) film (thickness 80 μm) as a transparent resin film. In this step, first, an organosilica sol (trade name "MEK-ST-L") containing 100 parts by mass of an ultraviolet curable acrylic monomer (trade name "GRANDIC PC-1070", manufactured by DIC) and nanosilica particles as particles is contained. , The average primary particle size of the nanosilica particles is 50 nm, the solid content concentration is 30% by mass, manufactured by Nissan Chemical Co., Ltd.) A synthetic smectite, manufactured by Corp Chemical, Inc., 1.5 parts by mass, a photopolymerization initiator (trade name "OMNIRAD907", manufactured by BASF), and a leveling agent (trade name "LE303", manufactured by Kyoeisha Chemical Co., Ltd.). A composition (crocodile) having a solid content concentration of 55% by mass was prepared by mixing with 0.15 parts by mass. An ultrasonic disperser was used for mixing. Next, the composition was applied to one side of the TAC film to form a coating film. Next, this coating film was cured by irradiation with ultraviolet rays and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as a light source, ultraviolet rays having a wavelength of 365 nm were used, and the integrated irradiation light amount was set to 200 mJ / cm ² . The heating time was 80 ° C., and the heating temperature was 3 minutes. As a result, a hard coat layer (second HC layer) having a thickness of 6 μm was formed on the TAC film. As a result, a base material layer (TAC film with an HC layer) was obtained.

(Second step)
Next, the surface of the HC layer of the TAC film with the HC layer was plasma-treated in a vacuum atmosphere of 1.0 Pa by a roll-to-roll type plasma processing apparatus. In this plasma treatment, argon gas was used as the inert gas, and the discharge power was set to 150 W.

Next, an adhesion layer and an antireflection layer were sequentially formed on the HC layer of the TAC film with the HC layer after the plasma treatment. Specifically, a roll-to-roll sputter film forming apparatus is used to form an indium tin oxide (ITO) layer having a thickness of 1.5 nm as an adhesion layer on the HC layer of the TAC film with an HC layer after plasma treatment. _{, Nb 2} O ₅ layer with a thickness of 12 nm as the first high refractive index layer _{, SiO 2} layer with a thickness of 28 nm as the first low refractive index layer, and Nb with a thickness of 100 nm as the second high refractive index layer. and ₂ O ₅ layer, a SiO2 layer having a thickness of 85nm as a second low-refractive index layer, are sequentially formed. In the formation of the adhesion layer, an ITO target is used, an argon gas as an inert gas and 10 parts by volume of oxygen gas as a reactive gas with respect to 100 parts by volume of the argon gas are used, and the discharge voltage is set to 400 V. The pressure in the film chamber (deposition pressure) was 0.2 Pa, and the ITO layer was formed by MFAC sputtering. The conditions for forming 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 first high refractive index layer and the first in Comparative Example 1. The conditions for forming the low refractive index layer, the second high refractive index layer, and the second low refractive index layer are the same as described above.

(Third step)
Next, an antifouling layer was formed on the formed antireflection layer. Specifically, it is the same as the third step in Comparative Example 1 (as a vapor deposition source, a solid obtained by drying "Optur UD120" (alkoxysilane compound containing a perfluoropolyether group) manufactured by Daikin Industries, Ltd.). Minutes were used). As a result, an optical film with an antifouling layer was manufactured.

Example 2
An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, the third process has been changed as follows.

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

Example 3
An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, the first process was changed as follows.

(First step)
Acrylic monomer composition containing nanosilica particles (trade name "NC035", average primary particle diameter of nanosilica particles is 40 nm, solid content concentration is 50%, ratio of nanosilica particles in solid content is 60% by mass, manufactured by Arakawa Chemical Industry Co., Ltd.) 67 parts by mass, UV curable polyfunctional acrylate (trade name "Binder A", solid content concentration 100%, manufactured by Arakawa Chemical Industry Co., Ltd.) 33 parts by mass, and polymethylmethacrylate particles as particles (trade name "Techpolymer") , Average particle diameter 3 μm, refractive index 1.525, manufactured by Sekisui Kasei Kogyo Co., Ltd.) and silicone particles as particles (trade name “Tospearl 130”, average particle diameter 3 μm, refractive index 1.42, momentum -Performance Materials Japan Co., Ltd.) 1.5 parts by mass, thixotropy-imparting agent (trade name "Lucentite SAN", organic clay synthetic smectite, manufactured by Corp Chemical Co., Ltd.) 1.5 parts by mass, photopolymerization A mixture of 3 parts by mass of an initiator (trade name "OMNIRAD907", manufactured by BASF), 0.15 parts by mass of a leveling agent (trade name "LE303", manufactured by Kyoeisha Chemical Co., Ltd.) and toluene, and a solid content concentration of 45 mass. % Composition (Wanis) was prepared. An ultrasonic disperser was used for mixing. Next, the composition was applied to one side of the TAC film to form a coating film. Next, this coating film was cured by irradiation with ultraviolet rays and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as a light source, ultraviolet rays having a wavelength of 365 nm were used, and the integrated irradiation light amount was set to 200 mJ / cm ² . The heating time was 60 ° C., and the heating temperature was 60 seconds. As a result, an antiglare hard coat layer (third HC layer) having a thickness of 7 μm was formed on the TAC film. As a result, a base material layer (TAC film with an HC layer) was obtained.

Comparative Example 1
(First step)
An antiglare 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 an ultraviolet curable urethane acrylate (trade name "UV1700TL", manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and an ultraviolet curable polyfunctional acrylate (trade name "Viscoat # 300", the main components are Pentaeristol triacrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. 50 parts by mass and polymethylmethacrylate particles as particles (trade name "Techpolymer", average particle diameter 3 μm, refractive index 1.525, manufactured by Sekisui Kasei Kogyo Co., Ltd. ) 3 parts by mass, silicone particles as particles (trade name "Tospearl 130", average particle diameter 3 μm, refractive index 1.42, manufactured by Momentive Performance Materials Japan) 1.5 parts by mass, and thixotropy Leveling with 1.5 parts by mass of the agent (trade name "Lucentite SAN", synthetic smectite which is an organic clay, manufactured by Corp Chemical Co., Ltd.) and 3 parts by mass of the photopolymerization initiator (trade name "OMNIRAD907", manufactured by BASF). 0.15 parts by mass of the agent (trade name "LE303", manufactured by Kyoeisha Chemical Co., Ltd.) and a mixed solvent of toluene / ethyl acetate / cyclopentanone (mass ratio 35:41:24) are mixed to have a solid content concentration of 55% by mass. The composition (crocodile) of was prepared. An ultrasonic disperser was used for mixing.
Next, the composition was applied to one side of the TAC film to form a coating film. Next, this coating film was cured by irradiation with ultraviolet rays and then dried by heating. In the ultraviolet irradiation, a high-pressure mercury lamp was used as a light source, ultraviolet rays having a wavelength of 365 nm were used, and the integrated irradiation light amount was set to 300 mJ / cm ² . The heating temperature was 80 ° C., and the heating time was 60 seconds. As a result, an antiglare hard coat layer (first HC layer) having a thickness of 8 μm was formed on the TAC film. As a result, a base material layer (TAC film with an HC layer) was obtained.

(Second step)
Next, the surface of the HC layer of the TAC film with the HC layer was plasma-treated in a vacuum atmosphere of 1.0 Pa by a roll-to-roll type plasma processing apparatus. In this plasma treatment, argon gas was used as the inert gas, and the discharge power was set to 2400 W.

Next, an adhesion layer and an antireflection layer were sequentially formed on the HC layer of the TAC film with the HC layer after the plasma treatment. Specifically, a roll-to-roll sputter film forming apparatus is used to add a 3.5 nm-thick SiOx layer (x <2) as an adhesion layer on the HC layer of the TAC film with an HC layer after plasma treatment. _{Nb 2} O ₅ layer with a thickness of 12 nm as the first high refractive index layer _{, SiO 2} layer with a thickness of 28 nm as the first low refractive index layer, _{and Nb 2 with} a thickness of 100 nm as the second high refractive index layer. and O ₅ layer, a SiO2 layer having a thickness of 85nm as a second low-refractive index layer, are sequentially formed. In the formation of the adhesion layer, a Si target is used, an argon gas as an inert gas and 3 parts by volume of oxygen gas as a reactive gas with respect to 100 parts by volume of the argon gas are used, and the discharge voltage is set to 520 V. The pressure in the film chamber (deposition pressure) was 0.27 Pa, and the SiOx layer (x <2) was formed by MFAC sputtering. In the formation of the first high refractive index layer, an Nb target is used, 100 parts by volume of argon gas and 5 parts by volume of oxygen gas are used, the discharge voltage is 415 V, the film formation pressure is 0.42 Pa, and Nb is formed by MFAC sputtering. the ₂ O ₅ layer was formed. In the formation of the first low refractive index layer, a Si target is used, 100 parts by volume of argon gas and 30 parts by volume of oxygen gas are used, the discharge voltage is 350 V, the film formation pressure is 0.3 Pa, and SiO is used by MFAC sputtering. _Two layers were formed. In the formation of the second high refractive index layer, an Nb target is used, 100 parts by volume of argon gas and 13 parts by volume of oxygen gas are used, the discharge voltage is 460 V, the film formation pressure is 0.5 Pa, and Nb is Nb by MFAC sputtering. the ₂ O ₅ layer was formed. In the formation of the second low refractive index layer, a Si target is used, 100 parts by volume of argon gas and 30 parts by volume of oxygen gas are used, the discharge voltage is 340 V, the film formation pressure is 0.25 Pa, and SiO is used by MFAC sputtering. _Two layers were formed. As described above, the antireflection layer (first high refractive index layer, first low refractive index layer, second high refractive index layer, second low) is placed on the HC layer of the TAC film with the HC layer via the adhesion layer. The refractive index layer) was laminated and formed.

(Third step)
Next, an antifouling layer was formed on the formed antireflection layer. Specifically, an antifouling layer having a thickness of 7 nm was formed on the antireflection layer by a vacuum vapor deposition method using an alkoxysilane compound containing a perfluoropolyether group as a vapor deposition source. The vapor deposition source is a solid content obtained by drying "Optur UD509" manufactured by Daikin Industries, Ltd. (perfluoropolyether group-containing alkoxysilane compound represented by the above general formula (2), solid content concentration 20% by mass). be. The heating temperature of the vapor deposition source in the vacuum vapor deposition method was 260 ° C.

As a result, an optical film with an antifouling layer was manufactured.

Comparative Example 2
An optical film with an antifouling layer was produced in the same manner as in Example 1.

However, the third step was changed as follows.
(Third step)
"Optur UD509" (manufactured by Daikin Industries, Ltd.) as a coating agent was diluted with a diluting solvent (trade name "Fluorinert", manufactured by 3M) to prepare a coating liquid having a solid content concentration of 0.1% by mass. Next, a coating liquid was applied by gravure coating on the antireflection layer formed in the second step to form a coating film. The coating was then dried by heating at 60 ° C. for 2 minutes. As a result, an antifouling layer having a thickness of 7 nm was formed on the antireflection layer.

2. 2. Evaluation (surface roughness Ra)
The surface roughness Ra of the antifouling layer was examined for the antifouling layer and the hard coat layer of the optical film with the antifouling layer of each Example and each comparative example. Specifically, the surface of the antifouling layer of each optical film with an antifouling layer is observed with an atomic force microscope (trade name "SPI3800", manufactured by Seiko Instruments, Inc.), and the surface roughness Ra is observed in a 1 μm square observation image. (Arithmetic mean roughness) was calculated. The results are shown in Table 1.

(Water contact angle)
In the optical film with the antifouling layer of each example and each comparative example, the antifouling layer was used with DMo-501 manufactured by Kyowa Interface Science Co., Ltd., and the water contact angle of the antifouling layer with respect to pure water was determined based on the following conditions. Initial water contact angle) was measured. The results are shown in Table 1.

<Measurement conditions>
Droplet volume: 2 μl
Temperature: 25 ° C
Humidity: 40%
(Durability test)
[Ultraviolet irradiation]
The optical film with an antifouling layer of each example and each comparative example was put into an eye supermarket (SUV-W161) manufactured by Iwasaki Electric Co., Ltd. Then, under the following conditions, ultraviolet irradiation was carried out from the antifouling layer side.

<Irradiation conditions>
BPT temperature: 80 ° C
Humidity: 45 ° C
UV intensity: 150mW / cm ²
Time: 32.5 hours

[Measurement of water contact angle after irradiation with ultraviolet rays]
After irradiation with ultraviolet rays, the water contact angle (water contact angle after irradiation with ultraviolet rays) of the antifouling layer with respect to pure water was measured by the same method as described above. The results are shown in Table 1.

[Observation of durability]
To prevent the surface of the sample from drying after UV irradiation, 2 mL of isopropyl alcohol was continuously dropped, and a polyester wiper ("Anticon Gold" manufactured by Sampler Tech) fixed to a 20 mm x 20 mm SUS jig was placed on a grid. Sliding (load: 1.5 kg, 1000 reciprocations). After that, the presence or absence of peeling was visually confirmed. The results are shown in Table 1.

Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be construed in a limited manner. Modifications of the present invention that will be apparent to those skilled in the art are included in the claims below.

The optical film with an antifouling layer of the present invention is suitably used, for example, in an antireflection 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 4 Optical functional layer 5 Antifouling layer 10 Base material 11 Hard coat layer

Claims

A base material layer, an optical functional layer composed of an inorganic layer, and an antifouling layer are provided in order toward one side in the thickness direction.
An optical film with an antifouling layer having a surface roughness Ra of the antifouling layer of 2 nm or more and 15 nm or less.
The optical film with an antifouling layer according to claim 1, wherein the optical functional layer is an antireflection layer.
The optical film with an antifouling layer according to claim 2, wherein the antireflection layer alternately has a high refractive index layer having a relatively large refractive index and a low refractive index layer having a relatively small refractive index.
The optical film with an antifouling layer according to any one of claims 1 to 3, wherein the base material layer comprises a base material and a hard coat layer in order toward one side in the thickness direction.
The optical film with an antifouling layer according to claim 4, wherein the hard coat layer contains metal oxide fine particles.
The optical film with an antifouling layer according to claim 5, wherein the metal oxide fine particles are nanosilica particles.
The optical film with an antifouling layer according to any one of claims 4 to 6, wherein the surface roughness Ra of one surface of the hard coat layer in the thickness direction is 0.5 nm or more and 20 nm or less.