KR102743808B1 - Surface treatment method for preventing light reflection that can reduce process step and reduce cost - Google Patents

Abstract

The present invention relates to a surface treatment method, and more specifically, to a surface treatment method for preventing light reflection, which performs a wet haze coating on a surface such as glass or glasstic, thereby improving quality without causing any damage to the surface or side, is environmentally friendly, and significantly reduces existing process steps and reduces costs.

Description

Surface treatment method for preventing light reflection that can reduce process steps and reduce cost

The present invention relates to a surface treatment method, and more specifically, to a surface treatment method for preventing light reflection, which performs a wet haze coating on the surface of glass or the like, thereby improving quality without causing any damage to the surface and side surfaces, is environmentally friendly, and significantly reduces existing process steps and reduces costs.

Glass used in windows of electronic products (mobile phones, digital cameras, monitors, LCDs, PDP TVs, etc.) can be difficult to identify with the naked eye due to reflections from sunlight or light from lighting devices when the surface has not been treated.

Accordingly, a layer or film for anti-glare and anti-reflection is generally formed on the glass surface to counteract this phenomenon. This anti-glare and anti-reflection (Non-Glare) film has the function of reducing reflectivity by utilizing light scattering by surface protrusions and thin film interference. For example, in image display devices such as CRT, PDP, ELD, and LCD, this film is usually arranged on the outermost surface of the display to prevent a decrease in contrast due to reflection of external light or to prevent entering due to image reflection.

In other words, anti-glare treatment of electronic device screens is an important task that reduces eye fatigue and makes it easier to identify the screens of all electronic devices that use glass windows by creating an uneven surface on the glass surface to diffuse external light.

Generally, as an anti-reflection treatment, a method is used in which the glass surface is etched by spraying a hydrofluoric acid (HF)-containing etchant to make the surface rough.

However, hydrofluoric acid is a colorless toxic gas, a substance harmful to the human body, and has strong flammability, irritation, and explosiveness, so there are problems with the risk of handling and storage, and there is a problem with surface damage caused by chemical etching. In addition, there is also a problem with the strength of the glass being reduced due to poor chipping during side processing.

As a way to solve these problems, there was a conventional problem in that the process steps became complicated because an acid-resistant protective treatment had to be performed on the glass surface before surface treatment and an additional polishing process had to be performed after surface treatment.

Republic of Korea Patent No. 10-1214524

The present invention is intended to solve the above problems, and to provide a surface treatment method for preventing light reflection, which performs a wet haze coating on the surface of glass or the like, thereby improving quality without causing any damage to the surface and side surfaces, is environmentally friendly, and significantly reduces existing process steps and reduces costs.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object is characterized by including the steps of preparing a substrate layer; performing wet haze coating by ultrasonically spraying a coating solution including polysilazane, polysiloxane, and an anti-fingerprint coating composition with a nozzle, thereby forming a haze coating layer on the surface of the substrate layer; and drying the haze coating layer.

The above-mentioned substrate layer is characterized by being composed of glass.

The coating solution is characterized in that it is manufactured as a first coating solution containing polysilazane, a second coating solution containing polysiloxane, and a third coating solution containing an anti-fingerprint coating composition, and the nozzle is configured to include a first nozzle, a second nozzle, and a third nozzle.

The above wet haze coating is characterized in that the first coating liquid is sprayed ultrasonically by a first nozzle, the second coating liquid is sprayed ultrasonically by a second nozzle, and the third coating liquid is sprayed ultrasonically by a third nozzle, respectively, and the first spray, the second spray, and the third spray are simultaneously performed so that the first coating liquid, the second coating liquid, and the third coating liquid are mixed in the air.

The above mixing is characterized in that the first coating solution, the second coating solution, and the third coating solution are mixed in the form of a layered structure by overlapping each other in the air, and the mixing ratio of the first coating solution, the second coating solution, and the third coating solution is a weight ratio of 1:2.8 to 3.2:2.8 to 5.0.

One side of the above nozzle is further provided with an ultrasonic vibrator that provides ultrasonic waves and an ultrasonic generator that amplifies ultrasonic waves generated from the ultrasonic vibrator to provide a certain ultrasonic frequency.

The above ultrasonic frequency is characterized as being in the range of 20 to 200 KHz. The thickness of the haze coating layer is characterized as being formed to be 0.5% to 10% of the thickness of the substrate layer. The drying is characterized as being performed at a temperature range of 200 to 400°C by an IR or thermal drying method.

According to the present invention, by performing wet haze coating on the surface of glass, glasstic, etc., the effect of quality improvement can be achieved without causing any damage to the surface and side surfaces.

According to the present invention, by using a wet coating method in which polysilazane and polysiloxane are mixed together as an anti-reflection coating solution, it is environmentally friendly and the risk of handling and storage can be significantly improved. Furthermore, compared to the sole use of expensive polysilazane, it can exhibit a cost reduction effect of about 46% or more while maintaining reliability.

In addition, the antireflection coating solution of the present invention can omit the deposition step of an antifingerprint coating layer, which is a process performed later, by mixing and using it together with an anti-fingerprint coating composition, thereby reducing the process cost and simplifying the process, while maintaining the physical properties and reliability of the antifingerprint deposition layer the same as before.

In addition, since there is no need to perform additional processes such as acid-resistant protective printing and polishing that are involved in the existing etching method using hydrofluoric acid components, the number of process steps can be reduced and the cost can be reduced.

In other words, since it is not a method of etching the surface like the existing technology, surface damage does not occur, so an additional polishing process is unnecessary, and there is no concern about secondary side effects such as underpolishing or overpolishing caused by the existing polishing process, and there is no concern about strength reduction because chipping defects do not occur even during side processing. Accordingly, it is possible to simplify the entire surface treatment process, thereby reducing costs and improving quality.

In addition, according to the present invention, by using a spraying method using ultrasonic waves, a straight spraying type of mist (fog) is possible instead of a fan-shaped spraying by a conventional spray method, so that the coating liquid can be sprayed very uniformly. Accordingly, by reducing the deviation of the Haze value, Ra value, and contact angle of the surface of the coating layer, the quality of the haze coating layer can be significantly improved compared to conventional technologies.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Figure 1 is a drawing schematically showing a surface treatment method using a wet coating method according to one embodiment of the present invention.
Figure 2 is a schematic drawing showing an anti-fingerprint deposition layer formed by a conventional method.
Figure 3 is a photograph showing the shape of a nozzle according to one embodiment of the present invention.
Figure 4 is a photograph comparing the contact angle of a comparative example, which is a conventional anti-fingerprint deposition layer, and a coating layer according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples and drawings of the present invention. It will be apparent to those skilled in the art that these examples are merely presented as examples to more specifically explain the present invention, and that the scope of the present invention is not limited by these examples.

Additionally, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and in case of conflict, the description in this specification, including definitions, shall prevail.

In order to clearly explain the invention proposed in the drawings, parts that are not related to the description have been omitted, and similar parts have been given similar drawing reference numerals throughout the specification. In addition, when a part is said to "include" a certain component, this does not mean that other components are excluded, but rather that other components can be further included, unless otherwise specifically stated. In addition, a "part" described in the specification means a single unit or block that performs a specific function.

The identification codes (1st, 2nd, etc.) for each step are used for convenience of explanation and do not describe the order of each step. Each step may be performed in a different order than stated unless the context clearly indicates a specific order. That is, each step may be performed in the same order as stated, may be performed substantially simultaneously, or may be performed in the opposite order.

In the present invention and specification, the term 'wet coating' or 'wet haze coating' refers to an anti-reflection coating that reduces the amount of reflection by diffusely reflecting external light incident on the screen of a display of various electronic devices, thereby preventing glare.

One aspect of the present invention provides a method for surface treatment for a light-reflecting ring, characterized by including the steps of: preparing a substrate layer; performing wet haze coating by ultrasonically spraying a coating solution including polysilazane, polysiloxane, and an anti-fingerprint coating composition with a nozzle, thereby forming a haze coating layer on a surface of the substrate layer; and drying the haze coating layer.

The above surface treatment method is a surface treatment method for preventing reflection of sunlight or light from lighting devices on glass used in displays of electronic and communication devices, and can be applied to the display manufacturing process of various electronic devices such as PC monitors, mobile devices, and tablet PCs, for example.

Hereinafter, implementation examples and embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention may not be limited to these implementation examples and embodiments and drawings.

Figure 1 is a drawing schematically showing a surface treatment method using a wet coating method according to one embodiment of the present invention.

Referring to Fig. 1, a substrate layer (100) can be prepared. The substrate layer (100) is a thin, flat layer applied to displays of various electronic devices, and can be made of a commonly used glass or glassic material.

In some cases, the substrate layer (100) may be composed of various materials that can be wet-coated, such as PC, PMMA, PVC, ABS, PP, PS, PET, Al, etc.

Next, a coating solution can be prepared. The coating solution can be an anti-reflection coating solution. The anti-reflection coating solution is a resin-type coating solution, and can include, for example, polysilazane and polysiloxane. More specifically, the anti-reflection coating solution can be prepared as a first coating solution (200) containing polysilazane and a second coating solution (210) containing polysiloxane, respectively.

Polysilazane is an inorganic substance that is not harmful to the human body and is therefore environmentally friendly.

Referring to the chemical formula 1 below, polysilazane is a polymer whose basic structure is formed by alternating silicon atoms and nitrogen atoms, with each silicon atom bonded to two individual nitrogen atoms and each nitrogen atom bonded to two silicon atoms.

These polysilazanes exhibit excellent adhesive properties, low odor and gas production, and high storage stability.

Polysiloxane has a structure in which an organic group is connected to a silicon atom, as shown in the chemical formula 2 below, and exhibits chemically stable characteristics.

In one embodiment of the present invention, the polysilazane and polysiloxane may be mixed and used as an antireflection coating solution.

Polysilazane exhibits excellent reliability when used alone, but has the problem of increased process costs due to its high unit price. On the other hand, when polysiloxane is used alone, the unit price is low, but there is the problem of reduced reliability.

Therefore, in one embodiment of the present invention, by using polysilazane and polysiloxane together, a cost reduction effect of about 46% or more can be achieved while maintaining reliability compared to using polysilazane alone.

The above polysilazane and polysiloxane have stable chemical structures. Therefore, since it is difficult to mix them into a single resin, the coating solutions, i.e., the first coating solution (200) and the second coating solution (210), can be prepared separately, and these can be individually sprayed using ultrasonic waves to mix them together in the air.

The method for manufacturing the above-mentioned anti-reflection coating solution, i.e., the first coating solution (200) and the second coating solution (210), and the additional components may be prepared according to known techniques.

Meanwhile, the coating solution may include an anti-fingerprint coating composition. Specifically, the coating solution may further include a third coating solution (220) including an anti-fingerprint coating composition, in addition to the first coating solution (200) and the second coating solution (210) described above.

In one embodiment of the present invention, by mixing and using the third coating solution (220) together with the anti-reflection coating solution (200, 210), anti-fingerprint deposition can be performed simultaneously with wet coating. As a result, the deposition step of the anti-fingerprint coating layer, which is a process that is performed separately in the past, can be omitted, thereby reducing the process cost and simplifying the process.

The components of the above anti-fingerprint coating composition are not particularly limited, and a composition according to a known technique commonly used in the relevant field can be used without limitation.

For example, the anti-fingerprint coating composition may include UV series, fluorine, etc.

The mixing of the first coating solution (200), the second coating solution (210), and the third coating solution (220) will be described in more detail later through the explanation of the “wet coating method.”

Next, a haze coating layer (400) can be formed on the substrate layer (100) by the “wet coating method” of the present invention. The “wet coating method” may be a method of forming a coating layer by ultrasonically spraying a coating solution containing polysilazane, polysiloxane, and an anti-fingerprint coating composition. That is, the coating solution is fixed to the surface of the substrate layer (100), thereby forming a haze coating layer (400) having a certain thickness and exhibiting an uneven embossed shape.

When surface treatment is performed using a conventional etching method, the surface becomes uneven as it is etched after the etching process, which inevitably causes damage to the surface and reduces the uniformity of the haze coating.

In contrast, the wet coating of the present invention uses a spraying method using ultrasonic waves, so that instead of a fan-shaped spray using a conventional simple spray method, a straight spraying type of mist (fog) is possible, allowing the coating liquid to be sprayed very uniformly. As a result, the haze coating layer (400) can be formed more uniformly. In addition, since the coating layer is formed using a method other than etching, there is no concern about damage to the substrate.

Meanwhile, the haze coating layer (400) can simultaneously perform the functions of an anti-reflection coating layer and an anti-fingerprint deposition layer by including an anti-fingerprint coating composition.

Referring to FIG. 2, in the past, an anti-fingerprint deposition layer (AF deposition) was formed separately on an anti-reflection coating layer, but the haze coating layer (400) of one embodiment of the present invention includes both an anti-reflection coating solution and an anti-fingerprint coating composition, so that both functions can be performed with only a single haze coating layer. That is, since the subsequent process for forming the anti-fingerprint deposition layer can be completely omitted, the process steps can be significantly reduced, thereby achieving a significant reduction in process unit cost and simplification of the process.

The above wet coating can be performed using a spraying device having a nozzle. At this time, the type of the spraying device is not particularly limited, and a commonly used known spraying device can be used. The spraying device can further have a conventional structure or configuration, such as a coating liquid storage unit, a coating liquid supply unit, a substrate, or a base material moving unit.

In one embodiment, the nozzle (300) may be capable of spraying the coating liquid to the outside. For example, the shape of the nozzle (300) itself may have a structure in which the nozzle part and the generator are formed as an integral part.

For example, the distance between the nozzle (300) and the substrate layer (100) is preferably 45 to 55 mm, specifically, 50 mm.

In one embodiment, the nozzles may be a plurality of nozzles, for example, 2 to 6 nozzles, spaced apart from each other in one lane. For example, a first nozzle (300), a second nozzle (310), and a third nozzle (320) may be spaced apart from each other.

For example, the first coating liquid (200) may be sprayed ultrasonically by the first nozzle (300), the second coating liquid (210) may be sprayed ultrasonically by the second nozzle (310), and the third coating liquid (220) may be sprayed ultrasonically by the third nozzle (320).

At this time, the order of the first nozzle (300), the second nozzle (310), and the third nozzle (320) is not limited. In other words, the third coating liquid (320) does not need to be sprayed only between the first coating liquid (310) and the second coating liquid (320), and for example, the first coating liquid (310) or the second coating liquid (320) may also be sprayed between the remaining coating liquids.

The first nozzle (300), the second nozzle (310), and the third nozzle (320) can be sprayed while moving together, and the first spray, the second spray, and the third spray can be performed simultaneously with the same spray amount and spray speed. Accordingly, the first coating liquid (200), the second coating liquid (210), and the third coating liquid (220) can be mixed in the air. To this end, conditions such as the gap between the nozzle and the substrate layer, the shape of the nozzle, and the amount of the coating liquid to be injected can all be set to be the same.

The above mixing ratio may be such that the first coating solution (200), the second coating solution (210), and the third coating solution (220), that is, the polysilazane, the polysiloxane, and the anti-fingerprint coating composition are mixed in a layered structure by being stacked one on top of the other in the air, rather than being closely mixed by a method such as chemically reacting the structures of the polysilazane, the polysiloxane, and the anti-fingerprint coating composition. At this time, the mixing ratio of the first coating solution (200), the second coating solution (210), and the third coating solution (220) may have a weight ratio of 1:2.8 to 3.2:2.8 to 5.0.

With the above-described mixing ratio, the performance of each of the formed haze coating layer and the anti-fingerprint deposition included therein can be maintained at the same level as before, while a reasonable process cost can be secured, so that improved productivity can be expected.

In one embodiment, each side of the nozzle (300, 310, 320) may be provided with an ultrasonic vibrator that provides ultrasonic waves and an ultrasonic generator (generator) that amplifies ultrasonic waves generated from the ultrasonic vibrator to provide a certain ultrasonic frequency, i.e., an ultrasonic oscillator. For example, referring to FIG. 3, each shape of the nozzle (300, 310, 320) may have a structure in which the nozzle part and the generator are formed as an integral part.

The above ultrasonic generator is capable of providing a frequency in the range of, for example, 20 to 200 KHz, specifically, 100 to 140 KHz.

The range of the ultrasonic frequency described above enables the coating liquids to be sprayed in a straight line and very uniformly sprayed in the form of a mist, i.e., a fog, overall. Accordingly, by reducing the deviation of the Haze value, Ra value, and contact angle of the glass surface, the quality and reliability of the haze coating layer (400) can be significantly improved compared to the existing etching technology.

The thickness of the above haze coating layer (400) can be formed to be 0.5% to 10% of the thickness of the substrate layer (100).

Next, the haze coating layer (400) can be dried and cleaned. The method of drying and cleaning is not particularly limited and can be performed according to a known technique commonly used in the relevant field.

For example, the drying is preferably performed at a temperature range of 200 to 400°C, specifically, 300°C, depending on the thermal drying method such as IR or hot air.

Figure 4 is a photograph comparing the contact angle of a comparative example, which is an anti-fingerprint deposition layer formed according to a conventional method (see Figure 2), and a coating layer according to an embodiment of the present invention. For an accurate comparison, an anti-reflection coating layer on which an anti-fingerprint deposition layer was not formed was measured together as a negative control.

Referring to FIG. 4, when comparing the contact angle of the haze coating layer formed by mixing together the anti-fingerprint coating composition of the embodiment of the present invention with that of the comparative example, it was confirmed that almost the same performance was exhibited.

The best embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they have been used only for the purpose of describing the present invention and have not been used to limit the meaning or the scope of the present invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the appended claims.

100: Base layer
200: 1st coating solution
210: Second coating solution
220: 3rd coating solution
300: Nozzle 1
310 : 2nd nozzle
320 : 3rd nozzle
400: Haze coating layer

Claims (9)

Step for preparing the substrate layer;
A step of performing wet haze coating by ultrasonically spraying a coating solution containing polysilazane, polysiloxane, and an anti-fingerprint coating composition through a nozzle, thereby forming a haze coating layer on the surface of the substrate layer; and
A step of drying the above haze coating layer; including;
The above coating solution is prepared by a first coating solution containing polysilazane, a second coating solution containing polysiloxane, and a third coating solution containing an anti-fingerprint coating composition, respectively.
The above nozzle comprises a first nozzle, a second nozzle and a third nozzle,
The above wet haze coating is performed such that the first coating liquid is sprayed ultrasonically by the first nozzle, the second coating liquid is sprayed ultrasonically by the second nozzle, and the third coating liquid is sprayed ultrasonically by the third nozzle, respectively.
The above first injection, second injection and third injection are performed simultaneously, but are sprayed at the same injection amount and injection speed, so that the first coating liquid, second coating liquid and third coating liquid are mixed in the air.
The above mixing is such that the first coating solution, the second coating solution, and the third coating solution are mixed in the air in the form of a layered structure by being layered on top of each other.
The mixing ratio of the first coating solution, the second coating solution, and the third coating solution is a weight ratio of 1:2.8 to 3.2:2.5 to 5.0,
The gap between the nozzle and the substrate layer is formed to be 45 to 55 mm,
On one side of the above nozzle, an ultrasonic vibrator for providing ultrasonic waves and an ultrasonic generator for amplifying ultrasonic waves generated from the ultrasonic vibrator to provide a certain ultrasonic frequency are further provided.
A surface treatment method for a light reflecting ring, characterized in that the ultrasonic frequency is in the range of 20 to 200 KHz. In the first paragraph,
A surface treatment method for a light-reflecting ring, characterized in that the above-mentioned substrate layer is composed of a glass and glasstic material. delete delete delete delete delete In the first paragraph,
A surface treatment method for a light-reflecting ring, characterized in that the thickness of the haze coating layer is formed to be 0.5 to 10% of the thickness of the base layer. In the first paragraph,
A surface treatment method for a light-reflecting ring, characterized in that the drying is performed at a temperature range of 200 to 400°C by an IR or thermal drying method.