JP2023038209A - Optical layered body and manufacturing method thereof - Google Patents

Abstract

Kind Code: A1 To provide an optical layered body capable of preventing abnormal discharge to a marker layer indicating a defective portion and marking the defective portion at low cost in a small number of steps, and a method for manufacturing the same.
Kind Code: A1 An optical layered body formed by laminating a base material and an optical function layer, wherein the optical function layer contains an inorganic oxide or an inorganic nitride, and the surface of the optical function layer has: A marker layer is locally formed, the marker layer is made of a semiconductor material, and has a reflectance of 40% or more with respect to light having a wavelength of 400 nm to 700 nm.
[Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to an optical layered body provided with a marker layer for indicating defect positions occurring in an optical function layer, and a method for producing the same.

For example, in flat panel displays (FPDs), touch panels, solar cells, etc., optical laminates (antireflection films) with various structures are used to prevent surface reflection of incident external light and improve visibility. It is

Conventionally, as an antireflection film, an antireflection film provided with a multilayer film (optical function layer) in which a high refractive index layer and a low refractive index layer are sequentially laminated on a transparent substrate has been proposed. In manufacturing such an antireflection film, an optical function layer composed of a high refractive index film and a low refractive index film is formed by laminating a metal oxide film or a metal nitride film on one surface of a transparent substrate by, for example, sputtering. After that, it is common to perform surface treatment such as formation of an antifouling layer as necessary.

Defects may occur in the optical functional layer during the production of such an antireflection film. Such defects are detected by optical inspection equipment or the like. Then, when a defect is detected in the optical function layer, a method is known in which the position of the defect is marked so that it can be easily identified in a post-process or the like (for example, Patent Documents 1 to 3).

For example, Patent Literature 1 discloses a marking forming method for forming markings on defect locations by pressing an embossing roll on the surface of a film in areas containing detected defects to perform embossing.

In addition, Patent Document 2 discloses a method for manufacturing a double-sided laminated film in which marking is formed at the defect location by forming recesses or through holes in the area containing the detected defect, applying ink, or the like. .

Further, Patent Document 3 discloses a defect marking method of writing a mark on a defective portion of an optical film using a marking pen.

However, the methods disclosed in Patent Documents 1 to 3 require a transfer device for forming embossing, an ink ejection device, etc., in addition to the sputtering device for forming the optical function layer, which complicates the process. Therefore, there is a concern that the manufacturing cost will increase. In addition, there is a concern that further defects may occur when physical pressing such as embossing is performed.

For this reason, for example, along with the formation of the optical function layer, it is conceivable to mark the defective portion by forming a sputtering film on the defective portion using a sputtering apparatus for displaying the defective portion. Such a method has the merit of enabling an in-line process, since the marking of the defective portion is also performed by the same method as the sputtering for forming the optical function layer.

JP 2017-137527 A JP 2019-173061 A JP 2014-016217 A

As described above, when the marking of the defective portion is formed by sputtering, it is conceivable to use a metal material with high reflectance for marking in order to improve visibility. However, since the defect marker layer formed using a metal material is a conductive metal sputtering film, when corona treatment or the like is performed in a post-process, an abnormal discharge is induced to this marker layer, and the optical function layer There was concern that it would cause further damage to

The present invention has been made in consideration of such circumstances, and an optical laminated body that prevents abnormal discharge to the marker layer that displays the defective portion and allows marking of the defective portion at low cost in a small number of steps. , and a method for producing the same.

That is, in order to solve the above problems, the present invention proposes the following means.
The optical laminate of the present invention is an optical laminate obtained by laminating a base material and an optical functional layer, wherein the optical functional layer contains an inorganic oxide or an inorganic nitride, and the optical functional layer contains: A marker layer is locally formed on the surface, and the marker layer is made of a semiconductor material and has a reflectance of 40% or more with respect to light in a wavelength range of 400 nm to 700 nm.

According to the present invention, the marker layer formed at the defective portion of the optical function layer is made of a semiconductor material having a reflectance of 40% or more with respect to light rays in the wavelength range of 400 nm to 700 nm. It is easy to detect a defect location by using, and when corona treatment or the like is performed on the optical layered body 10 in a post-process, it is possible to effectively suppress the occurrence of abnormal discharge toward the marker layer. .

Also, in the present invention, the marker layer may contain germanium or silicon.

According to the present invention, the marker layer may be formed so that at least a portion of the marker layer overlaps the defect site of the optical function layer.

According to the invention, the marker layer may be a sputtered film formed by sputtering.

According to the invention, the optical layered body may be an antireflection film, and the optical function layer may be composed of a layered body in which low refractive index layers and high refractive index layers are alternately laminated.

The method for producing an optical layered body of the present invention is a method for producing an optical layered body according to each of the above items, comprising: an optical function layer forming step of forming the optical function layer on the substrate; The method is characterized by comprising a defect inspection step of inspecting a defect, and a defect area display step of forming the marker layer in an area including the defect when the defect is detected in the defect inspection step.

ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body which can prevent an abnormal electric discharge to the marker layer which displays a defect location, and can mark a defect location at low cost by few processes, and its manufacturing method can be provided.

1 is a plan view of an optical layered body according to an embodiment of the present invention, viewed from above; FIG. FIG. 2 is a cross-sectional view of the optical laminate of FIG. 1; It is a schematic diagram which shows the optical laminated body manufacturing apparatus used for the manufacturing method of an optical laminated body. It is a graph which shows the result of an Example.

An optical layered body according to one embodiment of the present invention and a method for manufacturing the same will be described below with reference to the drawings. It should be noted that each embodiment shown below is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make it easier to understand the features of the present invention, there are cases where the main parts are enlarged for convenience, and the dimensional ratio of each component is the same as the actual one. not necessarily.

(Optical laminate)
An antireflection film will be described as an example of an optical laminate according to one embodiment of the present invention.
FIG. 1 is a plan view of an optical layered body according to one embodiment of the present invention, viewed from above. 2 is a cross-sectional view of the optical layered body of FIG.
An optical laminate (antireflection film) 10 of this embodiment has a transparent base material (base material) 11 and an optical function layer 12 formed on one surface of the transparent base material 11 . Further, a marker layer 13 is formed so as to overlap the defect portion D of the optical function layer 12 .

The transparent base material 11 may be formed from a transparent material that can transmit light in the visible light range, and for example, a plastic film is preferably used. Specific examples of plastic film constituent materials include polyester-based resins, acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic-based resins, and polychlorinated resins. Examples include vinyl resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins.

The transparent substrate 11 may contain a reinforcing material, for example, cellulose nanofiber, nanosilica, etc., as long as the optical properties are not significantly impaired. In particular, polyester-based resins, acetate-based resins, polycarbonate-based resins, and polyolefin-based resins are preferably used. Specifically, a triacetyl cellulose (TAC) substrate is preferably used.
Moreover, a glass film can also be used as an inorganic base material.

The transparent base material 11 may be a film provided with an optical function or a physical function. Examples of substrates having optical functions and physical functions include polarizing plates, retardation compensation films, heat ray shielding films, transparent conductive films, brightness improving films, and barrier property improving films.

Although the thickness of the transparent substrate 11 is not particularly limited, it is preferably 25 μm or more, for example. More preferably, the film thickness of the transparent substrate 11 is 40 μm or more.
When the thickness of the transparent base material 11 is 25 μm or more, the rigidity of the base material itself is ensured, and even when stress is applied to the optical layered body 10, wrinkles are less likely to occur. When the thickness of the transparent substrate 11 is 40 μm or more, wrinkles are less likely to occur, which is preferable.

When the optical layered body 10 is manufactured by roll-to-roll as in the method for manufacturing an optical layered body described later, the thickness of the transparent substrate 11 is preferably 1,000 μm or less, more preferably 600 μm or less. preferable. When the thickness of the transparent substrate 11 is 1000 μm or less, the optical layered body 10 in the middle of production and the optical layered body 10 after production can be easily wound into a roll, and the optical layered body 10 can be efficiently produced. Further, when the thickness of the transparent substrate 11 is 1000 μm or less, it is possible to reduce the thickness and weight of the optical layered body 10 . When the thickness of the transparent substrate 11 is 600 μm or less, the optical layered body 10 can be manufactured more efficiently, and further thinning and weight reduction are possible, which is preferable.

The optical function layer 12 is a layer that exhibits an optical function. The term "optical function" as used herein refers to a function of controlling reflection, transmission, and refraction, which are properties of light, and includes, for example, antireflection function, selective reflection function, antiglare function, and lens function.
The optical function layer 12 may be an antireflection layer, a selective reflection layer, an antiglare layer, or the like. In this embodiment, an antireflection layer is formed as the optical function layer 12 .

The optical function layer 12 is a laminate in which a high refractive index layer 12a and a low refractive index layer 12b are laminated in order from the transparent substrate 11 side. The number of layers of the high refractive index layer 12a and the low refractive index layer 12b can be any number of layers, such as two layers or more as in the present embodiment.

In the optical layered body 10 of the present embodiment, the optical function layer 12 is composed of a layered body in which the low refractive index layer 12b and the high refractive index layer 12a are layered. For example, external light is diffused by the optical function layer 12 . Therefore, it is possible to obtain an antireflection function that prevents external light incident from the low refractive index layer 12b side from being reflected in one direction. Therefore, if such an optical layered body 10 is provided, for example, on the display surface side of the display device, it is possible to suppress the reflection of external light and improve the visibility of the display device.

The optical function layer 12 is composed of a material containing inorganic oxides or inorganic nitrides.
Silicon oxide (SiO ₂ ) can be used for the low refractive index layer 12b in terms of availability and cost. The _SiO2 monolayer film is colorless and transparent. For example, the low refractive index layer 12b may contain 50% by mass or more of SiO ₂ .

In addition to SiO ₂ , the low refractive index layer 12b may contain, for example, Na for the purpose of improving durability, Zr, Al and N for the purpose of improving hardness, and Zr and Al for the purpose of improving alkali resistance. preferable.

The refractive index of the low refractive index layer 12b is preferably 1.20 to 1.60, more preferably 1.30 to 1.50.
Moreover, the film thickness of the low refractive index layer 12b may be in the range of 1 nm or more and 200 nm or less, and may be appropriately selected according to the wavelength region requiring the antireflection function.

Examples of the high refractive index layer 12a include niobium pentoxide (Nb ₂ O ₅ , refractive index 2.33), titanium oxide (TiO ₂ , refractive index 2.33 to 2.55), tungsten oxide (WO ₃ , refractive index 2.2), cerium oxide ( _CeO2 , refractive index 2.2 ₎ , tantalum pentoxide ( _Ta2O5 , refractive index 2.16), zinc oxide (ZnO, refractive index 2.1), indium tin oxide. (ITO, refractive index 2.06), zirconium oxide (ZrO ₂ , refractive index 2.2), or the like can be used. Further, when it is desired to impart conductive properties to the high refractive index layer 12a, for example, ITO or indium zinc oxide (IZO) can be used.
The film thickness of the high refractive index layer 12a may be, for example, 1 nm or more and 200 nm or less, and is appropriately selected according to the wavelength range requiring the antireflection function.

The optical function layer 12 of the present embodiment uses niobium pentoxide (Nb ₂ O ₅ , refractive index 2.33) as the high refractive index layer 12a, and silicon oxide (SiO ₂ ) as the low refractive index layer 12b. I use everything.

In addition, the optical layered body 10 can also form a hard coat layer or an adhesion layer between the transparent substrate 11 and the optical function layer 12 .
The hard coat layer may consist of only the binder resin, or may contain a filler together with the binder resin within a range that does not impair the transparency. As the filler, an organic substance may be used, an inorganic substance may be used, or an organic substance and an inorganic substance may be used.

As the binder resin used in the hard coat layer, a transparent one is preferable. For example, an ionizing radiation-curable resin, a thermoplastic resin, a thermosetting resin, etc., which are resins that are cured by ultraviolet rays or electron beams, can be used. . Moreover, the hard coat layer may be a single layer, or may be a laminate of a plurality of layers. Further, the hard coat layer may be further provided with known functions such as ultraviolet absorption performance, antistatic performance, refractive index adjustment function, and hardness adjustment function.

The adhesion layer is a layer formed to improve the adhesion between the transparent substrate 11 or hard coat layer, which is an organic material film, and the optical function layer 12, which is an inorganic material film. The adhesion layer is preferably made of, for example, an oxygen-deficient metal oxide or metal. The term "oxygen-deficient metal oxide" refers to a metal oxide in which the number of oxygen atoms is less than the stoichiometric composition. Examples of oxygen-deficient metal oxides include SiOx, ALOx, TiOx, ZrOx, CeOx, MgOx, ZnOx, TaOx, SbOx, SnOx, and MnOx.
Examples of metals include Si, Al, Ti, Zr, Ce, Mg, Zn, Ta, Sb, Sn, Mn, and In. The adhesion layer may be, for example, SiOx in which x is greater than 0 and less than 2.0.

From the viewpoint of maintaining transparency and obtaining good optical properties, the thickness of the adhesion layer is, for example, preferably more than 0 nm and 20 nm or less, and particularly preferably 1 nm or more and 10 nm or less.

The marker layer 13 is formed so as to overlap at least a portion of the defect portion D that has occurred in the manufacturing stage of the optical function layer 12 .
The marker layer 13 is made of a semiconductor material having a reflectance of 40% or more with respect to light rays in the wavelength range of 400 nm to 700 nm.

Examples of the semiconductor material forming the marker layer 13 include an intrinsic semiconductor composed of a single element, a p-type or n-type semiconductor obtained by adding a small amount of Group III or V element to an intrinsic semiconductor, or a compound composed of a plurality of elements. Examples include semiconductors.

The marker layer 13 of this embodiment uses a sputtered film formed by sputtering a material containing germanium or silicon. More specifically, compounds such as germanium, iron silicide containing 5 to 10% iron, and titanium silicide can be used.

Among these, it is particularly preferable to form the marker layer 13 by sputtering with germanium as a target because of the deposition rate and availability by sputtering compared to silicon, which is frequently used as a semiconductor. Germanium has a high film formation rate among semiconductor materials, and therefore can be formed by sputtering with lower power than other semiconductor materials. Thereby, thermal damage to the optical function layer 12 can be suppressed when the marker layer 13 is formed.

The thickness of the marker layer 13 to be formed is not particularly limited as long as a desired reflectance is obtained, but is preferably 10 nm or more and 30 nm or less, for example. When the marker layer 13 is formed with a thickness of more than 30 nm, the time required for film formation increases, and excessive heat is applied during sputtering, which may increase thermal damage to the optical function layer 12 . In addition, if the thickness of the marker layer 13 is less than 10 nm, there is a concern that the desired reflectance may not be obtained, and visual detection may be particularly difficult.

The conductivity of the marker layer 13 may be within a range that can suppress corona discharge, for example, about 1×10 ³ (S/cm) to 1×10 ⁻⁸ (S/cm).

The formation range of the marker layer 13 may be formed so as to completely cover the planar shape of the defective portion D of the optical function layer 12, or may be formed so that only a part of the planar shape of the defective portion D overlaps. The film formation range may be appropriately selected in consideration of the ease of detection of the marker layer 13 in the post-process and the film formation speed of the marker layer 13 .

As described above, according to the optical layered body 10 of the present embodiment, the marker layer 13 formed at the defect portion D of the optical function layer 12 has a reflectance of 40 for light rays in the wavelength range of 400 nm to 700 nm, for example, visible light. % or more, it is easy to detect a defective portion with visible light in a post-process, and when performing a corona treatment or the like on the optical laminate 10 in a post-process, the marker layer 13 has Therefore, it is possible to effectively suppress the occurrence of abnormal discharge.

(Method for manufacturing optical laminate)
Next, one embodiment of the method for manufacturing the optical layered body of the embodiment described above will be described.
In the present embodiment, as an example of the method for manufacturing the optical layered body 10, the optical layered body 10 is manufactured using the transparent base material 11 wound in a roll shape, and the optical layered body 10 is wound into a roll. An example will be described.

First, the transparent base material (base material) 11 wound in a roll shape is unwound. Then, an optical function layer forming step is performed to form the optical function layer 12 on the one surface 11 a of the transparent base material 11 . Next, a defect inspection step for inspecting the presence or absence of defects in the formed optical function layer 12 is performed. Then, when a defect is detected in the optical function layer 12 in the defect inspection process, a defect area display process is performed to form a marker layer in the area including the defect. After that, a surface treatment process is performed to treat the surface of the optical function layer 12, and then the formed optical layered body 10 is wound up.

After unwinding the transparent base material (base material) 11, a hard coat layer forming step of forming a hard coat layer on the transparent base material 11 and an adhesion layer forming step of forming an adhesion layer may be further provided. . Moreover, after performing a surface treatment process, you may further provide the optical function layer formation process of forming an antifouling layer.

In the method for manufacturing the optical layered body 10 of the present embodiment, the optical function layer forming step, the defect inspection step, the defect area display step, and the surface treatment step are performed continuously while the optical layered body during manufacture is maintained under reduced pressure. It is preferable to When these optical function layer formation step, defect inspection step, defect area display step, and surface treatment step are continuously performed while maintaining the optical laminate in the middle of production under reduced pressure, for example, a known sputtering apparatus is used. A thin film forming apparatus can be used.

FIG. 3 is a schematic diagram showing an optical layered body manufacturing apparatus used in the method for manufacturing an optical layered body according to the present embodiment.
A specific example of a manufacturing apparatus that can be used in the method for manufacturing an optical layered body according to the present embodiment is an optical layered body manufacturing apparatus 20 shown in FIG.
The optical laminate manufacturing apparatus 20 includes a roll unwinding device 4 , a sputtering device 1 , a surface treatment device 2 and a roll winding device 5 . As shown in FIG. 3, the roll unwinding device 4, the sputtering device 1, the surface treatment device 2, and the roll winding device 5 are connected in this order. The optical laminated body manufacturing apparatus 20 is a roll-to-roll system in which a substrate is unwound from a roll, passed through each connected device continuously, and then wound up to continuously form a plurality of layers on the substrate. manufacturing equipment.

When the optical layered body 10 is manufactured using the roll-to-roll type optical layered body manufacturing apparatus 20, the transport speed (line speed) of the optical layered body 10 during manufacturing can be appropriately set. The conveying speed is, for example, preferably 0.5 to 20 m/min, more preferably 0.5 to 10 m/min.

<Roll unwinding device>
The roll unwinding device 4 includes a chamber 34 having a predetermined reduced-pressure atmosphere inside, and one or more vacuum pumps 21 (one in FIG. 3) for discharging the gas in the chamber 34 to create a reduced-pressure atmosphere. , has an unwind roll 23 and a guide roll 22 placed in the chamber 34 . As shown in FIG. 3, the chamber 34 is connected with the chamber 31 of the sputtering apparatus 1 .
A transparent substrate 11 is wound around the feed roll 23 . The unwinding roll 23 supplies the transparent substrate 11 to the sputtering device 1 at a predetermined transport speed.

<Sputtering device>
The sputtering apparatus 1 shown in FIG. 3 includes a chamber 31 having a predetermined reduced-pressure atmosphere therein, and one or more vacuum pumps 21 (two pumps in FIG. ), a film forming roll 25, a plurality of (two in FIG. 3) guide rolls 22, a plurality of (three in the example shown in FIG. 4) film forming units 41 (41A, 41B, 41C), and defect detection a portion 42;

As shown in FIG. 3 , the film forming roll 25 , the guide roll 22 , the film forming section 41 and the defect detecting section 42 are installed inside the chamber 31 . Chamber 31 is connected to chamber 34 of roll unwinding device 4 .

The film forming roll 25 and the guide roll 22 transport the transparent substrate 11 sent from the roll unwinding device 4 at a predetermined transport speed, and the optical function layer 12 is formed on the one surface 11a of the transparent substrate 11. The transparent base material 11 thus obtained is supplied to the surface treatment apparatus 2 .
In the sputtering apparatus 1 shown in FIG. 3, the high refractive index layer 12a is formed by the film forming section 41A on the one surface 11a of the transparent substrate 11 running on the film forming roll 25, and the high refractive index layer 12a is formed thereon by the film forming section 41B. The optical function layer 12 is formed by forming the low refractive index layer 12b. Then, the defect detection unit 42 inspects the optical function layer 12 for defects, and when a defect is found in the optical function layer 12, the film formation unit 41C detects the marker layer 13 (see FIGS. 1 and 2) at the defect location D. is formed.

As shown in FIG. 3 , the film forming units 41 are arranged to face the outer peripheral surface of the film forming roll 25 at a predetermined interval, and are provided in plurality so as to surround the film forming roll 25 . The number of film-forming portions 41 may be the total number of laminated layers of the high refractive index layers 12 a and the low refractive index layers 12 b forming the optical function layer 12 plus the number of layers forming the marker layer 13 .

When it is difficult to secure the distance between the adjacent film forming portions 41 because the total number of laminated layers of the high refractive index layers 12a and the low refractive index layers 12b forming the optical function layer 12 is large, A plurality of film forming rolls 25 may be provided, and the film forming section 41 may be arranged around each film forming roll 25 .

When a plurality of film forming rolls 25 are provided, guide rolls 22 may be further provided as necessary. A plurality of chambers 31 in which the film forming rolls 25 and the film forming units 41 are provided may be connected. Further, the diameter of the film-forming roll 25 may be appropriately changed in order to easily secure the distance between the adjacent film-forming units 41 .

A predetermined target (not shown) is installed in each film forming unit 41 . A voltage is applied to the target by a known structure. In this embodiment, in the vicinity of the target, a gas supply unit (not shown) that supplies a predetermined reactive gas and a carrier gas to the target at a predetermined flow rate, and a known magnetic field generation source that forms a magnetic field on the surface of the target ( (not shown) are provided.

The material of the target and the type and flow rate of the reactive gas are determined by the high refractive index layer 12a and the low refractive index layer 12a formed on the transparent substrate 11 by passing between the film forming unit 41 and the film forming roll 25. 12b and the composition of the marker layer 13 formed at the defect portion D are appropriately determined.

For example, when forming the high refractive index layer 12a made of Nb ₂ O ₅ using the film forming unit 41A, Nb is used as the target and O ₂ is used as the reactive gas. Further, for example, when forming a layer made of SiO ₂ as the low refractive index layer 12b using the film forming unit 41B, Si is used as the target and O ₂ is used as the reactive gas. When forming a layer made of Ge as the marker layer 13 for the defect portion D using the film forming section 41C, Ge is used as the target and Ar is used as the carrier gas.

In the present embodiment, it is preferable to use magnetron sputtering as the sputtering method from the viewpoint of increasing the film formation speed.
The sputtering method is not limited to the magnetron sputtering method, and a two-electrode sputtering method using plasma generated by DC glow discharge or high frequency, a three-electrode sputtering method using a hot cathode, or the like may be used. .

The defect detection unit 42 may be an optical monitor that detects any defect in the optical function layer 12 after each layer to be the optical function layer 12 is formed. Thereby, the presence or absence of defects can be confirmed with respect to the formed optical function layer 12 . Defects that may occur in the optical function layer 12 include, for example, portions where the optical characteristics do not satisfy desired values, foreign matter, pinholes, and the like. These defects can be detected by an optical monitor.

As an optical monitor constituting the defect detection unit 42, for example, an optical head capable of scanning in the width direction perpendicular to the extension direction of the optical layered body 10 is used to detect the optical functional layer 12 formed on the one surface 11a of the optical layered body 10. The defect location D can be detected by measuring the optical characteristics in the width direction of the film, for example, the change in reflectance. When the defect detection unit 42 detects the defect location D, the defect detection unit 42 outputs the position information of the defect location D to the control unit (not shown).

A control unit (not shown) controls the direction of film formation by the film formation unit 41C based on the input position information of the defect location D. FIG. Then, the film forming section 41C forms the marker layer 13 made of a semiconductor, germanium in this embodiment, so as to overlap the defect portion D. As shown in FIG.

<Surface treatment equipment>
The surface treatment apparatus 2 shown in FIG. 3 includes a chamber 32 having a predetermined reduced pressure atmosphere, a can roll 26 , a plurality of guide rolls 22 (two in FIG. 3), and a plasma discharge device 43 . As shown in FIG. 3, the can roll 26, the guide roll 22, and the plasma discharge device 43 are installed inside the chamber 32. As shown in FIG. As shown in FIG. 3, chamber 32 is connected to chamber 35 of roll winder 5 .

The can roll 26 and the guide roll 22 transport the transparent substrate 11 on which the optical function layer 12 sent from the sputtering apparatus 1 and the marker layer 13 in the case where the defect portion D is present are formed at a predetermined transport speed. Then, the optical layered body 10 having the surface of the optical functional layer 12 treated is delivered to the roll winding device 5 .

The plasma discharge device 43 is a type of corona discharge device, and as shown in FIG. The plasma discharge device 43 ionizes the gas by glow discharge. As the gas, it is preferable to use a gas that is inexpensive, inert, and does not affect optical properties. For example, argon gas, oxygen gas, nitrogen gas, helium gas, and the like can be used. Argon gas is preferably used as the gas because it has a large mass, is chemically stable, and is easily available.
In this embodiment, as the plasma discharge device 43, it is preferable to use a glow discharge device that ionizes argon gas with high-frequency plasma.

When the optical function layer 12 is surface-treated by the plasma discharge (corona discharge) of the plasma discharge device 43, the marker layer 13 formed when there is a defective portion D is made of a semiconductor material such as a germanium film. Therefore, the plasma discharge does not abnormally discharge toward the marker layer 13 . Since the marker layer 13 is made of a semiconductor material, it has low electrical conductivity and can prevent abnormal plasma discharge from occurring toward the marker layer 13 .

<Roll take-up device>
The roll winding device 5 shown in FIG. 3 includes a chamber 35 having a predetermined reduced pressure atmosphere therein, and one or more vacuum pumps 21 (in FIG. 3, 1), and take-up roll 24 and guide roll 22 located within chamber 35 .

The optical laminate 10 is wound around the take-up roll 24 . The take-up roll 24 and the guide roll 22 take up the optical laminate 10 at a predetermined take-up speed.

Examples of the vacuum pumps 21 provided in the optical laminated body manufacturing apparatus 20 shown in FIG. can be used. The vacuum pump 21 can be appropriately selected or used in combination to create a desired reduced pressure state in each of the chambers 31 , 32 , 34 and 35 .

Next, using the optical layered body manufacturing apparatus 20 shown in FIG. A method of continuously performing while maintaining the state below will be described.
First, the unwinding roll 23 around which the transparent substrate 11 is wound is placed in the chamber 34 of the roll unwinding device 4 . Then, the unwinding roll 23 and the guide roll 22 are rotated to feed the transparent substrate 11 to the sputtering apparatus 1 at a predetermined transport speed.

Next, in the chamber 31 of the sputtering apparatus 1, an optical function layer formation process, a defect inspection process, and, if necessary, a defect area display process are performed. Specifically, while the film forming roll 25 and the guide roll 22 are rotated and the transparent substrate 11 is conveyed at a predetermined conveying speed, the surface 11a of the transparent substrate 11 running on the film forming roll 25 is covered with , forming the optical function layer 12 .

In this embodiment, the high refractive index layers 12a and the low refractive index layers 12b are alternately laminated by the film forming section 41A and the film forming section 41B, respectively. Thereby, an optical function layer 12, which is an antireflection layer, for example, is formed.

The pressure during sputtering when forming the optical function layer 12 varies depending on the metal to be sputtered, but may be 2 Pa or less, preferably 1 Pa or less, more preferably 0.6 Pa or less, and 0.5 Pa or less. .2 Pa or less is particularly preferred. When the pressure during sputtering is a reduced pressure of 1 Pa or less, the mean free path of the film-forming molecules is lengthened, and the films are laminated while the energy of the film-forming molecules is high, resulting in a dense and better film quality.

Next, the formed optical function layer 12 is scanned by a defect detector 42, for example, an optical monitor to detect the presence or absence of defects in the optical function layer 12 (defect inspection step). Then, when the defect location D is found in the optical function layer 12, the defect detector 42 outputs the position information of the defect location D to the control unit (not shown).

Next, in the film forming unit 41C, the marker layer 13 made of semiconductor, germanium in this embodiment, is formed so as to overlap the defect location D based on the positional information of the defect location D input to the control unit (not shown). film (defect area display step).

Next, a surface treatment process is performed on the optical function layer 12 within the chamber 32 of the surface treatment apparatus 2 .
In the present embodiment, the transparent substrate 11 having the optical functional layer 12 obtained by the optical functional layer forming step is continuously subjected to the surface treatment step while being kept under reduced pressure without being exposed to the atmosphere. conduct.

In the surface treatment step, the can roll 26 and the guide roll 22 are rotated to transport the transparent substrate 11 on which the optical function layer 12 is formed at a predetermined transport speed, while the optical function layer runs on the can roll 26. The surface of 12 is subjected to discharge treatment. Such a surface treatment step includes, for example, laminating a protective film on the surface of the optical function layer 12 after manufacturing the optical layered body 10, or forming another layer over the optical function layer 12. This is performed as a cleaning process for the surface of the optical function layer 12 in order to enhance the adhesion when performing the cleaning. Examples of the layer further formed over the optical function layer 12 include an antifouling layer formed by a vapor deposition method using a fluorine compound or a silicone compound.

As a surface treatment method for the optical function layer 12, for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, or the like can be used. Among these, it is preferable to use glow discharge treatment because it is possible to treat a large area.

When the surface of the optical function layer 12 is subjected to the discharge treatment, the surface of the optical function layer 12 is etched and the roughness of the surface of the optical function layer 12 is changed. The roughness Ra of the surface of the optical function layer 12 can be controlled by setting the integrated output during the discharge process within an appropriate range.

In such a surface treatment process, when the optical function layer 12 is surface-treated by electric discharge, the marker layer 13 formed when the defect portion D exists is made of a semiconductor material such as a germanium film. There is no abnormal discharge toward 13. Since the marker layer 13 is made of a semiconductor material, it has a low electrical conductivity, which can prevent an abnormal electrical discharge from occurring toward the marker layer 13 and causing further defects in the optical function layer 12 .

By the above method, the optical laminate 10 having the optical function layer 12 formed by sputtering is obtained. After that, the optical layered body 10 is delivered to the roll winder 5 by rotating the guide roll 22 .
Then, the optical laminate 10 is wound around the take-up roll 24 by rotating the take-up roll 24 and the guide roll 22 in the chamber 35 of the roll take-up device 5 .

In the optical layered body 10 thus obtained, the marker layer 13 is formed so as to overlap the defect portion D when the optical function layer 12 has a defect. Such a marker layer is a semiconductor, eg a germanium film, and thus can be easily detected by visible light. Therefore, when the optical layered body 10 is used by avoiding such a defective portion D in a post-process, the defective portion D can be easily identified visually or by a simple detector using visible light.

Note that the surface treatment process does not have to be a continuous process with the formation of the optical function layer, as shown in FIG. For example, the process up to the formation of the optical function layer 12 is consistently performed, wound once, the surface treatment process is performed at another place, and then a protective film is attached, or another function is added on the optical function layer 12. Formation of layers may also be carried out.

In addition, in the optical laminate 10 of the present embodiment, various layers may be provided on the other surface of the transparent substrate 11 opposite to the one surface 11a on which the optical function layer 12 and the like are formed, if necessary. For example, a pressure-sensitive adhesive layer used for bonding with other members may be provided. Further, another optical film may be provided via this pressure-sensitive adhesive layer. Other optical films include, for example, films functioning as polarizing films, retardation compensation films, half-wave plates, and quarter-wave plates.

In addition, on the other side of the transparent substrate, there is a layer having functions such as antireflection, selective reflection, antiglare, polarization, phase difference compensation, viewing angle compensation or enlargement, light guide, diffusion, luminance improvement, hue adjustment, and conductivity. It may be formed directly.
The shape of the optical layered body 10 may be a smooth shape or a shape having a nano-order concave-convex structure that exhibits moth-eye and anti-glare functions. Also, it may be a geometric shape of micro to millimeter order such as a lens or a prism. The shape can be formed by, for example, a combination of photolithography and etching, shape transfer, heat pressing, and the like. In this embodiment, since the film is formed by vapor deposition or the like, even if the substrate has an uneven shape, the uneven shape can be maintained.

The optical laminate 10 of this embodiment can be used as an antireflection film on the display surface of an image display section such as a liquid crystal display panel or an organic EL display panel. In addition to this, for example, window glass, goggles, solar cell light receiving surface, smartphone screen and personal computer display, information input terminal, tablet terminal, AR (augmented reality) device, VR (virtual reality) device, lightning The optical layered body 10 can also be applied to display boards, glass table surfaces, game machines, operation support devices for airplanes and trains, navigation systems, dashboards, surfaces of optical sensors, and the like.

Although embodiments of the invention have been described above, such embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and spirit of the invention, as well as in the scope of the invention described in the claims and equivalents thereof.

First, a film made of triacetyl cellulose (TAC) having a thickness of 80 μm was prepared as a transparent substrate. Then, a hard coat layer having a thickness of 5 μm made of an ultraviolet curable resin composition was formed on the transparent substrate. An optical functional layer (antireflection layer) was formed by reactive sputtering using a mixed gas of _{the two} gases. That is, on the hard coat layer, a low refractive index layer (first layer) made of SiO ₂ , a high refractive index layer (second layer) made of Nb ₂ O ₅ , and a low refractive index layer (third layer) made of SiO ₂ layer), a high refractive index layer (fourth layer) made of Nb ₂ O ₅ and a low refractive index layer (fifth layer) made of SiO ₂ were repeated in this order to form an optical function layer.

Subsequently, Ge (Example 1), FeSi (Fe 10%) (Example 2), Cu (Comparative Example 1), Ag (Comparative Example 2), Cr (Comparative Example 3) were superimposed on the optical function layer as sputtering targets. ) were used to form a thin film of each example (marker layer) and comparative example (metal film) with an output of 5 W/cm ² by DC sputtering and a film thickness of 20 nm under Ar gas.
Using the optical laminates (samples) of Examples 1 and 2 and Comparative Examples 1 to 3 thus obtained, the following tests were carried out.

(1) Abnormal discharge test during corona treatment Corona treatment device: CORONA STATION (manufactured by Kasuga Denki Co., Ltd.), high-frequency power supply: AGF-012 (manufactured by Kasuga Denki Co., Ltd.)
Output setting: 10
Table speed: 20
Under the above conditions, the presence or absence of abnormal discharge was visually confirmed.
(2) Measurement of surface resistance value of marker layer (example) and metal film (comparative example) Surface resistance measuring instrument: Loresta GX (manufactured by Nitto Seiko Analytic Tech Co., Ltd.)
(3) Detection test of marker layer (example) and metal film (comparative example) (3-1: Detection test 1) A measurement unit that irradiates a film with light and measures the light transmitted or reflected by the film, a moving mechanism for moving the measuring section in a first direction intersecting the transport direction of the film; Using a measuring device having a sphere and a light receiving portion for receiving light condensed by the integrating sphere, the detectability of the marker layer made of semiconductor was measured. The measurement was performed 10 times, and those that could be detected all the times were evaluated as acceptable, and those that failed to detect were evaluated as unacceptable.
(3-2: Detection Test 2) Visibility of the marker layer was confirmed visually under visible light. When the difference between the marker layer and its surrounding portion was easy to distinguish, it was evaluated as acceptable, and when it was difficult, it was evaluated as unacceptable.
(4) Measurement of Reflectance of Marker Layer (Example) and Metal Film (Comparative Example) Spectrophotometer: U3900 (manufactured by Hitachi High-Tech Science Co., Ltd.) Test results of (1) to (3) are shown in Table 1. Moreover, the test result of (4) is shown in FIG.

According to the results shown in Table 1, in the abnormal discharge test, abnormal discharge did not occur in any of the optical laminates (Examples 1 and 2) having a marker layer formed using a semiconductor even when corona treatment was performed. I didn't. On the other hand, in each of the optical laminates (Comparative Examples 1 to 3) formed with a metal film, abnormal discharge occurred, resulting in damage to the optical function layer.
Moreover, in the detection test, the metal film of Comparative Example 1 was difficult to detect. Therefore, it was confirmed that Examples 1 and 2 using the semiconductor film as the marker layer satisfied both the prevention of abnormal discharge and the ease of detection.

On the other hand, according to the results shown in FIG. 4, it was confirmed that Examples 1 and 2, in which the semiconductor film was used as the marker layer, exhibited relatively little change in reflectance over the entire wavelength range of 370 nm to 790 nm.

DESCRIPTION OF SYMBOLS 1... Sputtering apparatus 4... Roll unwinding apparatus 5... Roll winding apparatus 10... Optical laminated body 11... Transparent base material 12... Optical functional layer 12a... High refractive index layer 12b... Low refractive index layer 13... Marker layer 20... Optics Laminated body manufacturing apparatus 21... Vacuum pump 22... Guide roll 23... Unwinding roll 24... Winding roll 25... Film formation roll 26... Can roll 31, 32, 34, 35... Chamber 41, 41A, 41B, 41C... Film formation Part 42... Defect detection part 43... Plasma discharge device

Claims (6)

An optical laminate obtained by laminating a base material and an optical function layer,
The optical function layer contains an inorganic oxide or an inorganic nitride,
a marker layer is locally formed on the surface of the optical function layer,
The optical layered body, wherein the marker layer is made of a semiconductor material and has a reflectance of 40% or more with respect to light having a wavelength of 400 nm to 700 nm. 2. The optical stack of claim 1, wherein the marker layer comprises germanium or silicon. 3. The optical layered body according to claim 1, wherein the marker layer is formed so as to overlap at least a part of the defective portion of the optical function layer. The optical laminate according to any one of claims 1 to 3, wherein the marker layer is a sputtered film formed by sputtering. The optical laminate is an antireflection film,
5. The optical laminate according to any one of claims 1 to 4, wherein the optical function layer comprises a laminate in which low refractive index layers and high refractive index layers are alternately laminated. 6. The method for manufacturing the optical laminate according to any one of claims 1 to 5, comprising: an optical functional layer forming step of forming the optical functional layer on the substrate;
a defect inspection step of inspecting defects in the optical function layer;
and a defective area display step of forming the marker layer in an area including the defect when a defect is detected in the defect inspection step.

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