KR102104388B1 - Manufacturing method of a color film for protecting glass cover of liquid crystal display and the color film made therefrom - Google Patents

Abstract

The present invention is to increase the surface energy by irradiating oxygen plasma (O ₂ plasma) on the front of the film to increase the adhesion with the oxide, the film surface is coated with Nb ₂ Ox / SiO ₂ / Nb ₂ Ox oxide to be stable It relates to a manufacturing method of a color film for protecting a smartphone cover glass that forms a thin film of high uniformity and effectively blocks harmful light, and a color film produced therefrom.

Description

Manufacturing method of color film for smartphone cover glass protection and color film manufactured therefrom {MANUFACTURING METHOD OF A COLOR FILM FOR PROTECTING GLASS COVER OF LIQUID CRYSTAL DISPLAY AND THE COLOR FILM MADE THEREFROM}

The present invention combines the high refractive index (n = 2.2) of NbOx and the low refractive index of SiOx (n = 1.45) based on the refractive index (n = 1.66) of the film, thereby causing a transflective action due to the difference in refractive index of light. It is smart to achieve the desired color (blue, violet & deep blue, etc.) while filtering unwanted wavelengths to obtain decorative and harmless effects through the tuning of light passing through the front glass of the smartphone. It relates to a method for manufacturing a color film for protecting the phone cover glass and a color film prepared therefrom.

There are many products for protecting the liquid crystal of mobile phones. Generally, an acrylic hard coating having a hardness level of 1H to 3H on both sides of a PET film is attached to the upper glass of a mobile phone.

In this case, the life of the product is short, and after desorption, residues, etc., remain on the glass surface, which is inconvenient to undergo a separate washing process.

In addition, in some products, transparent PET film was used as a double-sided adhesive film for attaching tempered glass, but recently, a functional dry type for pursuing a luxurious color screen by blocking harmful light from the display and improving the illuminance of the standby screen A coating film is required.

In addition, the existing product basically coextrudes very thin thicknesses of about 1 micro before and after simultaneously alternating low and high refractive layers according to the refractive index. Form a film. In this case, by forming a filter-type film that filters out blue-blue wavelengths due to a difference in refractive index, it serves to block light in a specific wavelength range.

Also, by coextruding a very thin film, wrinkles are formed by thermal control, or a defect occurs in optical characteristics due to inflow of air bubbles or other foreign matter in a specific film. In addition, the mechanical properties are very irregular, and there is a high possibility of defective surface optical properties such as a rainbow phenomenon or stain.

In order to solve the problems of the prior art, the present invention uses an Nb ₂ Ox / SiO ₂ / Nb ₂ Ox ceramic material as a material for effectively blocking harmful light, and a refractive index of the material and a filter of a special wavelength band The effect was confirmed. In addition, by developing the Nb ₂ Ox / SiO ₂ / Nb ₂ Ox ceramic material in an appropriate thickness as a single film in a film sputter process, a product was developed to deposit a uniform film on a wide film.

Republic of Korea Patent Publication 10-2009-0004942 (published on 2009.01.12) Republic of Korea Patent Publication 10-2015-0090914 (published date 2015.08.06) Republic of Korea Registered Patent 10-1355020 (Registration Date 2014.01.17)

The present invention combines the high refractive index (n = 2.2) of NbOx and the low refractive index of SiOx (n = 1.45) based on the refractive index (n = 1.66) of the film, thereby causing a transflective action due to the difference in refractive index of light. It is smart to achieve the desired color (blue, violet & deep blue, etc.) while filtering unwanted wavelengths to obtain decorative and harmless effects through the tuning of light passing through the front glass of the smartphone. It is an object of the present invention to provide a method for manufacturing a color film for protecting a phone cover glass and a color film prepared therefrom.

In order to achieve the above object,

In the present invention, when the base film supplied from the unwinding roller travels in close contact with the drum,

A first step (S10) of irradiating plasma on the front surface of the base film to increase the surface energy of the base film to increase the adhesion strength and to remove fine foreign matter or oligomers, etc. existing on the surface of the base film. ,

A second process (S20) of forming a first NbOx coating layer on top of the base film subjected to the above step (S10) by sputtering NbOx using DC plasma (DC Plasma);

A third process (S30) of depositing SiOx on top of the first NbOx coating layer through reactive sputtering to form an SiOx coating layer;

Provided is a method of manufacturing a color film for protecting a smartphone cover glass, which is performed through a fourth process (S40) of depositing NbOx on the SiOx coating layer by reactive sputtering to form a second NbOx coating layer.

And as manufactured according to the color film manufacturing method,

Base film,

A first NbOx coating layer formed by depositing on the base film;

An SiOx coating layer formed by depositing on the first NbOx coating layer;

A second NbOx coating layer formed by depositing on the SiOx coating layer is formed, and the desired color is achieved by controlling the thickness of the multilayer layer to control the thickness of the multilayer layer so that the transmission and reflection effect is caused by the difference between the refractive index of NbOx and the refractive index of SiOx. Alternatively, the unwanted wavelength provides a color film for protecting the cover glass of a smartphone configured to be filtered.

The manufacturing method of the color film for protecting a smartphone cover glass according to the present invention and the color film produced therefrom have the following effects.

first. An important result in the present invention is a combination of a high refractive index (n = 2.2) of NbOx and a low refractive index of SiOx (n = 1.45) based on the refractive index (n = 1.66) of the film, and the transmission reflection effect due to the difference in refractive index of light. Will cause By deriving the optimum thickness through optical design and applying it through vacuum deposition on the actual film, it realizes the desired color (blue, violet & deep blue, etc.) while filtering unwanted wavelengths from the front glass of the smartphone. Through the tuning of the light passing through, it is possible to obtain a decorative effect and a harmless effect to the human body.

second. It is cheaper than a multilayer film and can be manufactured through a simple process, resulting in high productivity.

third. Since it is deposited at room temperature, the thermal damage to the film is relatively small.

fourth. Since there is almost no foreign matter inflow, it is possible to produce in a clean environment.

fifth. Because the film of each layer is controlled and manufactured through optical design, the characteristic variation between products is relatively small.

Sixth. Wide manufacturing is possible. In general, the multilayer film has a maximum width of 1,200 mm, whereas in the case of a sputter deposition film, it can be produced up to 2,300 mm or 2,500 mm.

1 is a flow chart according to the manufacturing process of the color film according to the present invention.
Figure 2 is a schematic diagram of a manufacturing apparatus used for manufacturing a color film according to the present invention.
Figure 3 is a side cross-sectional view showing a laminated structure of a color film according to the present invention.
Figure 4 is a graph of the transmittance of the color film according to the present invention.
5 is a graph of reflectance of the color film according to the present invention.
6 is a view showing a laminated structure of the AB film to which the color film according to the present invention is applied.

Hereinafter, a detailed description of the color film for protecting a smartphone cover glass according to the present invention and a manufacturing method thereof will be described with reference to the drawings.

1 is a flow chart according to the manufacturing process of the color film according to the present invention.

As shown in Figure 1,

When the color film 1 according to the present invention is rotated in close contact with the drum (Drum) 200, the base film 10 supplied from the unwinding roller 100,

Plasma is irradiated on the front surface of the base film 10 to increase the surface energy of the base film 10 to increase the adhesion strength, and to remove fine foreign matter or oligomers present on the surface of the base film 10. The first step of removing (S10),

A second process (S20) of forming a first NbOx coating layer 20 on the base film which has been subjected to the above step (S10) by sputtering NbOx using DC plasma (DC Plasma);

A third process (S30) of depositing SiOx on top of the first NbOx coating layer 20 through reactive sputtering to form an SiOx coating layer 30;

It is manufactured through a fourth process (S40) of depositing NbOx on the SiOx coating layer 30 by reactive sputtering to form a second NbOx coating layer 40.

Figure 2 is a schematic diagram of a manufacturing apparatus used for manufacturing a color film according to the present invention.

The manufacturing process of the color film according to the present invention together with the manufacturing apparatus shown in FIG. 2 will be described.

First, the whole process is briefly described as follows.

The base film 10 is supplied from the unwinding roller 100 and moves in one direction while rotating in close contact with the drum 200 and sequentially at predetermined intervals along the outer circumferential surface of the drum 200 Plasma pre-treatment and deposition process is performed using the High Density Plasma source (400), NbOx target (500), SiOx target (600), and NbOx target (700) installed as NbOx on the base film By forming a multilayer film of / SiOx / NbOx, the color film according to the present invention is completed, and the completed color film is wound on a winding roller 300.

The base film is not particularly limited, but for example, a PET film may be used.

Cooling water of -10 ° C to 5 ° C continuously circulates in the drum 200 while continuously dropping the temperature of the rotating base film in close contact with the drum 200 while passing through the plasma. The thermal damage of the base film through a high temperature process is minimized, and the stretching of the base film is minimized through tension control.

At this time, the thermal damage and stretching of the base film act as important variables that affect the quality of the product.

Then, the drum 200 rotates at a speed of 1 to 5 m / min.

Plasma treatment of the first process (S10) is performed through a high density plasma source, and the high density plasma source is used to remove particles of the reaction gas introduced into the hermetic chamber. Ionization is made into a plasma state, and by directly exposing the generated plasma or irradiating an ion beam (or neutral beam) extracted from the plasma to the base film, the surface energy of the base film is increased by using ion energy and chemical action to adhere. It increases the strength and removes fine foreign substances, oligomers, and the like existing on the surface of the base film.

And through this, it is possible to optimize the thickness uniformity of the very thin film while minimizing the interface interdiffusion between the base film and NbOx.

In addition, the adhesive strength is increased by 50% or more when compared with the case where plasma pretreatment is not performed.

The pre-treatment by the plasma was performed by applying argon gas at a vacuum of 1 to 5 × 10 ^-3 torr, 250 to 500 sccm, and applying DC power at 12 to 15 kW while moving the base film at a traveling speed of 1 to 5 m / min. Process.

Basically, NbOx is a material having a high optical refractive index. And, in general, it is a very effective material to block areas such as IR or Near IR in the visible light area.

In the case of SiOx, it is a typical low-refractive material, and serves to convert the light reflection angle more horizontally.

An important result in the present invention is based on the refractive index (n = 1.66) of the base film, and the combination of high refractive index (n = 2.2) of NbOx and low refractive index of SiOx (n = 1.45) reflects the transmitted reflection due to the difference in refractive index of light. Is to cause action.

By deriving the optimal thickness through the optical design and applying it through vacuum deposition on the actual base film, the desired wavelength (blue, violet & deep blue, etc.) is realized while filtering unwanted wavelengths and filtering the front glass of the smartphone. The decorative effect and the harmless effect of the human body can be obtained through the tuning of light passing through.

The first NbOx coating layer is formed to a thickness of 15 nm to 40 nm through sputtering using DC plasma according to optical design.

The sputtering is a process condition. First, the initial vacuum is pumped to 3 × 10 ^-6 torr to reach the vacuum level.

After that, argon gas and oxygen gas are respectively added at a ratio of 80 vol%: 20 vol%. Next, when the working vacuum level reaches the level of 5 ~ 6 × 10 ^-3 torr, power is applied to initially clean the surface of the target by pre-sputtering with 2 ~ 3 Kw, and then gradually increasing the power to 10 While applying at ~ 12 Kw, sputter coating is performed while driving the base film at a speed of 1.3 to 2 m / min.

When the thickness of the first NbOx coating layer is less than 15 nm, the continuous thin film is not formed in the following cases, and it is difficult to exhibit a uniform optical characteristic by forming an island structure layer, and when it exceeds 40 nm, it is too thick. It is difficult to have a blue characteristic to be achieved in the present invention because a crack occurs or the color changes to yellow, so the thickness of the first NbOx coating layer is preferably limited to within a range of 15 nm to 40 nm.

The SiOx coating layer is formed by depositing silicon to a thickness of 50 nm to 100 nm using a reactive sputter.

The reactive sputter first uses a silicon target to sputter argon and oxygen at a ratio of 65 vol%: 35 vol% as a gas used, and further oxygen is blown around the target to create an oxidizing atmosphere to prepare an SiOx thin film. .

When the thickness of the SiOx coating layer is less than 50 nm, the color of the thin film is shifted to the region of purple or ultraviolet rays, not blue, and the color is disturbed. When it exceeds 100 nm, the film itself is too thick and easily Since cracks occur and the production rate is too slow, there is a problem that productivity is rapidly lowered, it is preferable to limit the thickness of the SiOx coating layer to be in the range of 50 nm to 100 nm.

The second NbOx coating layer is formed by depositing NbOx to a thickness of 15 nm to 40 nm using a reactive sputtering method.

At this time, the second NbOx coating layer is formed through the same process as the first NbOx coating layer.

When the thickness of the second NbOx coating film is less than 15 nm, it is difficult to form a continuous thin film and form an island structure layer in the following cases, and it is difficult to exhibit uniform optical properties, and when it exceeds 40 nm, it is too thick to crack Since (crack) occurs or the color is changed to yellow, it is difficult to have a blue characteristic to be achieved in the present invention, so it is preferable to limit the thickness of the second NbOx coating film to within a range of 15 nm to 40 nm.

The entire process from the plasma pretreatment process to the final deposition process is performed in an independent plasma environment by introducing a vacuum atmosphere and gas.

As described above, the specific manufacturing process according to the method for manufacturing a color film for protecting a smart phone cover glass of the present invention is as shown in Example 1.

Example 1 shows an example of a process for manufacturing a color film for protecting a smart phone cover glass according to the present invention, and the process is in the following order.

1. When the PET film, which is the base film 10 wound on the unwinding roller 100, is supplied to the drum 200, the PET film is in close contact with the drum 200 and rotates. At this time, by applying 300 sccm of argon gas at 3 × 10 ^-3 torr and applying DC power to 14 kW, the PET film is irradiated with plasma on the front of the PET film moving at an average running speed of 3 m / min. To increase the adhesive strength by increasing the surface energy of the, and removes fine foreign matter or oligomers present on the surface of the base film.

By circulating the cooling water at 2 ° C inside the drum 200, thermal damage of the PET film due to high temperature is minimized, and stretching of the film is minimized through tension control.

2. After completing the plasma irradiation process, in order to proceed with a sputtering process, the initial vacuum degree is pumped to 3 × 10 ⁻⁶ torr to match the vacuum degree.

Next, argon gas and oxygen gas were respectively added at a rate of 80 vol%: 20 vol%, and when the working vacuum level reached a level of 6 × 10 ^-3 torr, power was applied to initially pre-sputter at 2 Kw (pre-sputtering). ) To clean the surface of the target, then gradually increase the power and apply it at 12 Kw while sputter coating while driving the base film at a speed of 2 m / min. At this time, the average thickness of the first NbOx coating layer through sputtering is 20 nm.

3. After depositing the first NbOx coating layer 20 over the PET film, SiOx is deposited over the first NbOx coating layer 20 through reactive sputtering of SiOx.

Reactive sputtering is performed by first mixing silicon with argon and oxygen in a ratio of 65 vol%: 35 vol% as a gas to use, and then sputtering additional oxygen around the target to create an oxidizing atmosphere to deposit the SiOx coating layer. .

At this time, the average thickness of the SiOx coating layer 30 through sputtering is 70 nm.

4. Next, a second NbOx coating layer 40 is deposited on the SiOx coating layer 30 to form it. At this time, the deposition process of the second NbOx coating layer 40 is performed to the same thickness as the first NbOx coating layer.

The color film manufactured through such a manufacturing process is as shown in Figure 3,

Base film (10),

A first NbOx coating layer 20 formed on the base film 10,

An SiOx coating layer 30 formed on the first NbOx coating layer 20,

The multilayer film structure of the second NbOx coating film layer 40 formed on the SiOx coating film layer 30 is formed, and the thickness of the multilayer film is controlled to control the thickness of the multilayer film so that a reflection effect is caused by a difference between the refractive index of NbOx and the refractive index of SiOx. Colors that are embodied or undesired are configured to be filtered.

The base film 10 is made of a base film such as a PET film.

The first NbOx coating layer 20 is formed by depositing NbOx on top of the base film 10 that has undergone a plasma pre-treatment process. At this time, NbOx may be variously applied, but as a specific example, Nb ₂ Ox (3.5 <x < 5) is used.

The SiOx coating layer 30 is formed by depositing SiOx on top of the first NbOx coating layer 20. At this time, SiOx may be variously applied, but SiO ₂ is used as a specific example.

The second NbOx coating layer 40 is formed by depositing NbOx on top of the SiOx coating layer 30. At this time, NbOx may be variously applied, but as a specific example, Nb ₂ 0 ₅ is used.

As described above, the present invention combines the high refractive index (n = 2.2) of NbOx and the low refractive index of SiOx based on the refractive index (n = 1.66) of the base film, thereby causing a transflective action due to the difference in refractive index of light. , While implementing the desired color (blue, violet & deep blue, etc.), filtering unwanted wavelengths can achieve the decorative effect and harmless effect of the human body through tuning of the light passing through the windshield of the smartphone. .

Therefore, the thickness of the first NbOx coating film, the SiOx coating film, and the second NbOx coating film forming the multi-layer film of the color film is an important technical configuration, and it is desirable to maintain thicknesses of 15 to 40 nm, 50 to 100 nm, and 15 to 40 nm, respectively. Do.

In relation to the effect of the color film according to the present invention, the transmittance and reflectance of the color film prepared through Example 1 are as shown in FIGS. 4 and 5.

4 is a graph of transmittance of a color film according to the present invention.

As shown in FIG. 4, the transmittance (light beam: L) of the NbOx / SiO ₂ / NbOx multilayer film is about 90% based on 400 nm, a * is -5.06, and b * is about 9.17, which is the surface of the human eye. It shows a typical blue color when observed. And to maximize the visual effect, after attaching the black black sheet, make the reflection close to 100%, and see the blue color more clearly.

5 is a graph of reflectance of a color film according to the present invention.

It is well known by measuring the reflection spectrum to more clearly judge the blue color or the violet color. The results are as shown in FIG. 5. Reflectance (all light: L) is about 10%, a * is 16.12 and b * is -23.27, which can be observed to be skewed toward the very blue color. This reduces the shine when mounted on the actual smartphone's windshield, allowing the screen to be viewed smoothly even in a lot of sunlight. Especially at night, when harmful light comes out of the screen, it effectively filters (blue light cut effect).

The following Table 1 shows the results obtained by comparing the product according to the present invention (Example 1) and a Japanese company M product (Comparative Example).

Measurement item Comparative example Example Transmission reflect Transmission reflect L 96.32 34.55 94.65 41.77 a * -5.06 11.32 -5.05 16.12 b * 14.72 -16.45 9.17 -23.27 Y (400 nm) 71.47 23.74 86.79 12.34 Haze 2.07 1.04

6 is a view showing a laminated structure of the AB film to which the color film according to the present invention is applied.

As shown in Figure 6, the AB film is made by forming an adhesive layer on both sides of the color film according to the present invention, and forming a protective layer on each of the adhesive layer.

The AB film prepared as described above can be provided as a high-quality blue film having high functionality by expressing the effect of the color film according to the present invention as it is.

The color film for protecting a smartphone cover glass according to the present invention is cheaper than a multilayer film and can be manufactured through a simple process, so productivity is high and thermal damage to the film is relatively small because it is deposited at room temperature. Because the film of each layer is controlled and produced through, the variation in characteristics between products is relatively small. In general, the maximum width of a multilayer film is 1,200 mm, whereas in the case of a sputter deposition film, it is possible to produce up to 2,300 mm or 2,500 mm, which makes wider manufacturing possible. Therefore, it has great industrial applicability.

1: Color film 10: Film
20: first NbOx coating layer 30: SiOx coating layer
40: second NbOx coating film layer 100: unwinding roller
200: Drum 300: Winding roller
400: High Density Plasma source
500: NbOx target
600: SiOx target
700: NbOx target

Claims (7)

While the base film 10 supplied from the unwinding roller 100 rotates in close contact with the drum 200,
The surface film 10 is irradiated with oxygen plasma (O ₂ plasma) on the front surface of the base film 10 to increase the surface energy of the base film 10 to increase adhesion strength and to remove fine foreign matter or oligomers present on the surface of the base film 10 The first process (S10),
A second process (S20) of forming a first NbOx coating layer 20 on the base film 10 subjected to the above step (S10) by sputtering NbOx using DC plasma (DC Plasma);
A third process (S30) of depositing SiOx on top of the first NbOx coating layer 20 through reactive sputtering to form an SiOx coating layer 30;
In the NbOx is formed through a fourth step (S40) to deposit a second NbOx coating layer 40 by depositing on the SiOx coating layer 30 through reactive sputtering (sputtering),

A first NbOx coating layer 20 having a thickness of 15 nm to 40 nm having a refractive index of 2.2 is deposited on the base film 10 having a refractive index of 1.66,
An SiOx coating layer 30 having a thickness of 50 nm to 100 nm having a refractive index of 1.45 is deposited on the first NbOx coating layer 20,
A method of manufacturing a color film for protecting a smartphone cover glass, characterized in that a second NbOx coating layer 40 of a thickness of 15 nm to 40 nm having a refractive index of 2.2 is deposited on the SiOx coating layer 30.
delete delete As manufactured by the manufacturing method of claim 1,
Base film (10),
A first NbOx coating layer 20 formed by depositing on the base film 10,
An SiOx coating layer 30 formed by depositing on the first NbOx coating layer 20,
The multilayer film structure of the second NbOx coating film layer 40 formed by depositing on the SiOx coating film layer 30 is formed, and the thickness of the multilayer film is controlled so that a transmission and reflection effect is caused by a difference between the refractive index of NbOx and the refractive index of SiOx. In order to realize the desired color or to filter the unwanted wavelengths,

A first NbOx coating layer 20 having a thickness of 15 nm to 40 nm having a refractive index of 2.2 is deposited on the base film 10 having a refractive index of 1.66,
An SiOx coating layer 30 having a thickness of 50 nm to 100 nm having a refractive index of 1.45 is deposited on the first NbOx coating layer 20,
A color film for protecting a smartphone cover glass, characterized in that a second NbOx coating layer 40 of a thickness of 15 nm to 40 nm having a refractive index of 2.2 is deposited on the SiOx coating layer 30.




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