KR100781327B1 - Panel coating device and method, and coating panel manufactired by which - Google Patents

Abstract

An apparatus for coating and curing a panel and a coated panel manufactured by the apparatus are provided to press and heat a panel coated with a coating solution to form a coating layer before the UV curing process to prevent the oxygen from being contacted with the coating layer to suppress the bad effect by oxygen during a UV curing process, thereby improving the surface strength of the panel. A film(16) is transferred along one surface or both surfaces of a panel. A storing tank(10) supplies a coating solution on the film. A coater(12) coats the film with the coating solution to the film. A pressing roll(18) presses the coated film. A heater(20) heats the panel, onto which the film is attached by the pressing roll, to disperse the coating solution of the film in a surface of the panel. A thickness controlling roll(21) controls the thickness of a coating layer, which is formed by pressing the panel passed by the heater. A UV irradiator(22) irradiates UV to the coating layer to cure the coating layer on the surface of the panel.

Description

PANEL COATING DEVICE AND METHOD, AND COATING PANEL MANUFACTIRED BY WHICH

1 is a block diagram showing a first embodiment of a panel curing apparatus according to the present invention.

2 is a configuration diagram showing a second embodiment of the panel curing apparatus according to the present invention.

3 is a flowchart illustrating a panel coating method according to an embodiment of the present invention.

Explanation of symbols on main parts of the drawings

10: reservoir 10a: first reservoir

10b: second storage tank 11: coating solution

11a: first coating solution 11b: second coating solution

12: coater 12a: first coater

12b: second coater 15: film storage roll

15a: first film storage roll 15b: second film storage roll

16: panel 17: coating roll

17a: first coating roll 17b: second coating roll

18: pressing roll 18a: first pressing roll

18b: second pressing roll 20: heater

20a: 1st heater part 20b: 2nd heater part

21: thickness control roll 22: UV irradiation

22a: 1st ultraviolet ray irradiator 22b: 2nd ultraviolet ray irradiator

23: deodorizing roll 23a: first deodorizing roll

23b: 2nd deodorization roll 24: winding roll

24a: 1st winding roll 24b: 2nd winding roll

25: coating panel 30: panel transfer means

The present invention relates to a panel coating curing apparatus and a coating curing method, and more particularly, to provide a curing apparatus and a curing method for coating a plastic panel used in a display window using ultraviolet rays.

The modern IT environment represented by multimedia is characterized by the transmission of visual information. As a means of expressing visual information, display modules such as LCDs and OLEDs that can be slimmed and miniaturized are widely used. In order to protect these modules from physical and chemical stimuli, the demand for plastic panels for display windows mounted on the front of the module is increasing.

These plastic panels, commonly called display windows, must have both optical and mechanical and chemical properties. Polymethylmethacrylate (PMMA) and Polycarbonate (PC) are mainly used as materials, and these materials have a weak wear resistance. If a display window made of such materials is used for a long time, scratches are generated on the surface. The scratches on the surface of the panel had a big problem of impairing the appearance and impeding the effective transmission of visual information.

In order to solve the problem of the material, a method of coating a hard resin, which can impart impact resistance and chemical resistance to the surface of the plastic panel, by UV curing method has been introduced.

Conventional UV curing coating curing method is to dilute a solution mixed with an acrylic monomer and oligomer capable of radical polymerization with a photoinitiator with UV initiation with an appropriate solvent and coated on a plastic panel, and the solvent is volatilized into the atmosphere to reduce gravity and surface tension. The coating solution was applied by waiting for the coating solution to flatten and irradiating ultraviolet rays.

However, this conventional coating curing method has a problem that the ultraviolet curing coating solution is cured in the state exposed to oxygen in the atmosphere. When the coating solution is exposed to oxygen, deterioration of surface properties such as lowering the surface hardness of the cured coating is inevitable due to the effect of oxygen interference. In order to compensate for this, there is a problem that many limitations are applied to the formulation of the coating solution since the use of an excessive amount of initiator and a low functional acrylic monomer cannot be used.

In order to solve the problem caused by the oxygen disturbance, there is also a method of substituting nitrogen for the atmosphere to which the coating solution is exposed. However, in order to exhibit a substitution effect that exhibits an oxygen excluding effect, a huge nitrogen substitution cost is required or the entire coating system must be closed. In order to replace the atmosphere with nitrogen, a large amount of nitrogen has to be forced convection, so the problem of poor coating surface smoothness caused by nitrogen convection, and the lack of oxygen in the work space, cause worker's choking hazard. In addition, when the entire coating system is carried out in a closed state, there was a problem that the productivity is lowered.

In addition, organic solvents such as ethanol, ethyl acetate, and toluene are used to control the viscosity of the coating solution, the flattening of the coating solution, and the thickness of the coating film, and directly damage the worker by volatile organic solvents (VOC). It also had a problem that adversely affects the environment.

Accordingly, the present invention is to solve the above-mentioned problems, in the method and apparatus for coating an ultraviolet curable coating film on a plastic panel, blocking the contact of the coating solution and oxygen in the atmosphere, the formulation of the coating solution freely It is an object of the present invention to provide a UV curing coating curing method of a plastic panel having a thickness and excellent surface smoothness, without causing problems due to volatile organic solvents.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention is a film transported along one or both sides of the panel to be coated; A reservoir for supplying a coating solution to the film; A coater for applying the coating solution of the reservoir to the film; A pressing roll for pressing the film coated with the coating solution onto a panel; A heater unit which passes the pressing roll and heats the panel to which the film is attached to diffuse the coating solution applied to the film onto the panel surface; A thickness control roll for adjusting the thickness of the coating layer formed of the coating solution by pressing the panel with the film passing through the heater unit; And a UV irradiator for irradiating ultraviolet rays to the coating layer whose thickness is adjusted through the thickness control roll and curing the coating layer on the surface of the panel.

In addition, the present invention comprises the steps of applying a coating solution to the film; Attaching the coated film to the panel; Heating the panel to which the film is attached; Pressing the heated panel to adjust the thickness of the coating layer formed of the coating solution between the film and the panel; Irradiating the coating layer with ultraviolet rays to cure the coating layer to form a coating film; And separating the film from the panel.

Other specific details of the embodiments of the present invention are included in the following detailed description and the accompanying drawings.

Hereinafter, specific embodiments of the present invention will be described in detail to enable those skilled in the art to clearly appreciate. However, this is presented as an example of the present invention, whereby the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

1 is a block diagram showing a first embodiment of a panel curing apparatus according to the present invention.

As shown, the first embodiment shows an apparatus for coating only on the cross section of the panel 19 in which the film 16 is conveyed along one side of the panel 19.

The panel coating curing apparatus according to the first embodiment includes a film 16 transferred along one surface of a panel 19 to be coated, a reservoir 10 for supplying a coating solution 11 to the film 16, A coater 12 for applying the coating solution 11 of the reservoir 10 to the film 16 and a compression roll 18 for pressing the film 16 to which the coating solution 11 is applied to the panel 19. ) And a heater unit for heating the panel 19 to which the film 16 is attached and passing through the pressing roll 18 to diffuse the coating solution 11 applied to the film 16 to the surface of the panel 19. 20 and the thickness of the coating layer formed of the coating solution 11 by pressing the panel 19 to which the film 16, which is located downstream of the heater unit 20 and has passed through the heater unit 20, is pressed. It includes a thickness adjusting roll 21 for controlling the, and an ultraviolet irradiator 22 disposed downstream of the thickness adjusting roll 21 to form a coating film by irradiating UV light on the coating layer is adjusted thickness.

In addition, the panel conveying means 30 for conveying the panel 19 at the same speed as the film 16 may be further provided. As the panel transfer means 30, a panel such as a power conveyor, a powerless conveyor, a transfer carrier, and the like may be moved together with the film 16. In particular, when the panel 19 is small and light, the non-powered conveying means such as a non-powered conveyor may be sufficient because it is attached to the film 16 and can move together.

When the coating solution 11 contained in the reservoir 10 is applied to the film 16 and the panel 19 is formed, the coating solution 11 between the panel 19 and the film 16 forms a layer. In the above, the layer of the coating solution 11 before curing is referred to as a coating layer, and the state in which the curing is completed is expressed as a coating film.

The film 16 is wound and stored on the film storage roll 15, and then moved along the panel 19, and then wound again on the winding roll 24. In other words, the film 16 moves from the film storage roll 15 to the take-up roll 24 and passes through a predetermined path. The moving speed of the film 16 is determined by the winding speed of the take-up roll 24. .

Looking at the movement path of the film 16, it is separated from the film storage roll 15 to pass through the coating roll (17). The coating roll 17 is disposed adjacent to the coater 12. The coating solution 11 is applied to the film by the coater 12 when the film 16 passes through the coating roll 17. The film 16 which has passed through the coating roll 17 is pressed onto the surface of the panel 19 by the pressing roll 18. Then, the film 16 passes through the heater unit 20, the thickness control roll 21, the ultraviolet irradiator 22 in sequence, and is separated from the panel 19 in the deodorizing roll 23 and the odor roll 24. Is wound into.

The role of the film 16 serves as a medium for transferring the coating solution 11 to the surface of the panel 19, and also serves as a barrier for preventing oxygen from reacting with the coating solution 11. In addition, the film 16 has to pass the ultraviolet light in the ultraviolet irradiator (22).

Therefore, as the material of the film 16, it is preferable to use polyethylene terephthalate or polypropylene, which is a material having high UV absorption. Especially. The polyethylene terephthalate film 16 may be released in advance on the surface on which the coating solution 11 is applied, so that the film 16 may be easily separated from the coating film after the coating solution is cured.

As the coater 12 for applying the coating solution 11 to the film 16, a knife coater, a roll coater, a comma coater and the like as shown in the figure can be used. The coater 12 coats the coating solution with a primary thickness on the film 16 continuously supplied. The primary thickness is set 5-10% thicker than the desired coating thickness. This is because the final thickness of the coating film is determined by the pressure of the thickness control roll 21, the viscosity of the coating solution 11, and the curing shrinkage rate.

The pressing roll 18 serves to attach the film 16 to which the coating solution 11 is applied to the panel 19. When the film 16 to which the coating solution 11 is applied and the panel 19 are supplied at the same speed, the pressing roll 18 presses the film 16 to the panel 19 at a predetermined pressure. When passing through the pressing roll 18, the thickness of the coating solution layer between the film 16 and the panel 19 is reduced than the thickness applied by the coater 12. The cause of poor quality in the process of passing through the pressing roll 18 is the adhesion of foreign matter or bubbles are generated in the coating solution layer, so that proper supply speed and pressure control are essential to block this.

The heater unit 20 is for applying heat to the panel 19 to which the film 16 is attached while passing through the pressing roll 18. As the heater unit 20, an infrared heater may be typically used, and other heating devices capable of supplying predetermined heat may be used.

After attaching the film 16 coated with the coating solution 11 to the panel 19 and immediately irradiating ultraviolet rays, since the adhesion of the coating film to the panel 19 is unstable, the coating film is removed when the film 16 is removed. The film 16 has a problem of being separated to the side.

In order to prevent this, the heater unit 20 is provided. When passing through the heater unit 20, the component of the coating solution 11 is diffused to the panel 19 can solve the problem of unstable adhesion. However, the temperature applied by the heater unit 20 should not exceed the heat deformation temperature of the panel 19.

The thickness control roll 21 serves to finally determine the thickness and smoothness of the coating film before curing the coating solution (11). Curing of the coating solution 11 is made by ultraviolet irradiation, and curing is not yet performed until it passes through the thickness control roll 21. Therefore, the thickness of the coating layer for the final purpose is determined through the surface management and pressure control of the thickness control roll (21). While passing through the thickness control roll 21, the coating layer of the coating solution between the film 16 and the panel 19 is adjusted to the second thickness, and when the coating layer is cured through the ultraviolet irradiator 22, the coating film is formed It has a third thickness. The second thickness and the third thickness have a difference as much as the curing shrinkage ratio, and the third thickness becomes the thickness of the final coating film.

In the ultraviolet irradiator 22, a curing process occurs. At this time, since the surface of the coating solution 11 is completely covered with the film 16, oxygen in the atmosphere cannot affect the coating solution 11. Therefore, since oxygen interference does not occur due to the reaction with oxygen, the core and the surface of the coating solution 11 may exhibit the same degree of curing. Therefore, it is possible to form a coating film having high hardness, high mechanical properties, and excellent chemical resistance without being affected by oxygen interference.

Under oxygen-blocking conditions where oxygen reacts with the coating solution, the initiator radical component generated by ultraviolet light on the surface of the coating solution loses its activity by oxygen, and thus an excess amount of the initiator is administered or a polyfunctional monomer is used to compensate for this. Or the formulation restrictions that must be used oligomers are followed, but according to the present invention these formulation restrictions will also disappear.

When the coating solution 11 forms a coating film through the ultraviolet irradiator 22, the film 16 is separated from the deodorizing roll 23 and wound again on the winding roll 24. The feed speed of the film 16 is determined by the rotational speed of the take-up roll 24.

The coating panel 25 having the completed functional coating film is finished by the inspection process to coat the protective film, and the surface of the coating film is transferred to the surface of the film as it is, showing the excellent gloss and high smoothness of the film as it is. Alternatively, the film can be selected to have a special optical function.

2 is a configuration diagram showing a second embodiment of the panel curing apparatus according to the present invention.

While the first embodiment is a panel curing apparatus for forming a coating film on one side of the panel. The second embodiment is a panel curing apparatus for forming a coating film on both sides of a panel.

Thus, as shown, the panel curing apparatus according to the second embodiment has a difference in that a pair of films are transferred along both sides of the panel.

The same components having the same function as the first embodiment are arranged above and below, and in the second embodiment, the first reservoir 10a, by adding a and b to the same reference numerals as in FIG. It distinguished like the 2nd reservoir 10b.

In particular, since the thickness adjusting roll 21 is the same as pressing both sides of the panel 19 in the first embodiment, there is a difference that only one is provided unlike other components.

The panel curing apparatus according to the second embodiment includes the first and second films 16a and 16b and the first and second films 16a and 16b respectively transferred along both surfaces of the panel 19 to be coated. The first and second reservoirs 10a and 10b supplying the coating solutions 11a and 11b, respectively, and the coating solutions 11a and 11b of the first and second reservoirs 10a and 10b, respectively. 2nd and 2nd which coater 12a and 12b apply | coated to the film 16a and 16b, and the 1st and 2nd films 16a and 16b which apply | coated the said coating solution 11a and 11b to the panel. The panel 19 to which the films 16a and 16b are attached and passed through the pressing rolls 18a and 18b and the first and second pressing rolls 18a and 18b is heated to the films 16a and 16b. The first and second heaters 20a and 20b for diffusing the coated coating solutions 11a and 11b to the surface of the panel 19 and the film passing through the first and second heaters 20a and 20b Pressing the attached panel 19 and the thickness control roll 21 for adjusting the thickness of the coating layer formed of the coating solution, and Through the thickness control roll 21 and a first, a second ultraviolet irradiator (22a, 22b) is irradiated with ultraviolet rays to the coating layer thickness is adjusted to make the coating layer in the coating film was cured to the surface of the panel.

The first coater 12a shows the shape of the knife coater, and the second coater 12b shows the shape of the roll coater 12b. However, the first coater 12a is not limited to this form, and the coating solution is applied to the film 16. You can also use coaters in other forms.

The first coating solution 11a stored in the first reservoir 10a and the second coating solution 11b stored in the second reservoir 10b may be a solution having the same component, and different components may be used as necessary. The eggplant may be a solution. This is because when used as a panel for window display, different characteristics may be required on both sides.

In the case of the second embodiment, since the panel 19 is sandwiched between the first film 16a and the second film 16b, the panel 19 is transported. Therefore, when the size of the panel 19 is small, no film is required without any additional panel transport means. The conveyance can be sufficiently carried out by the fields 16a and 16b. However, when the size of the panel 19 is large or heavy, a separate transport carrier or panel transport means for transporting the panel while fixing the edge of the separate panel should be provided.

In addition, although the first embodiment and the second embodiment of FIG. 1 are both shown in the form in which the panel 19 is cut to a certain size, the application is also applicable to the case of the continuous state in which the panel is continuously extruded from the extruder. Possibility is obvious.

3 is a flowchart illustrating a panel coating method according to an embodiment of the present invention.

As shown, the panel coating method according to the present invention comprises the step of applying a coating solution to the film (S-1), the step of attaching a film to which the coating solution is applied to the panel (S-2), and the film Heating the attached panel (S-3), adjusting the thickness of the coating layer formed of the coating solution between the film and the panel by pressing the heated panel (S-4), and irradiating UV with the coating layer Curing the coating layer to form a coating film (S-5), and separating the film from the panel (S-6).

The film coated with the coating solution is attached to one or both sides of the panel and then separated from the panel after the heating step (S-3), the thickness control step (S-4) and the curing step (S-5).

In particular, the film in step S-5 blocks the coating layer from reacting with oxygen in the atmosphere, so that oxygen does not occur because there is no oxygen between the film and the coating layer, the inner surface of the film by ultraviolet irradiation When a predetermined shape is formed in the film, the shape can be transferred to the coating film as it is.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

<Example 1>

40 wt% (wt%) of Hexanediol Diacrylate (HDDA), which is a bifunctional monomer, and 60 wt% of Trimethylolpropane Triacrylate (TMPTA), which is a trifunctional monomer, are mixed with 1 wt% of Irgacure 184, which is a photoinitiator, in the mixed solution. Mix additional amounts to. The prepared coating solution was coated on both sides of the PMMA extruded sheet (Rohm) having a thickness of 1.0 mm by the apparatus and method of the present invention. The amount of irradiated ultraviolet light was adjusted to 2000 mJ / cm 2.

Pencil hardness, abrasion resistance, fracture strength, and yellowing after harsh conditions were measured for the coated panel after curing.

-Pencil hardness: Rub five times with a Mitsubishi pencil to check for scratches.

-Abrasion resistance: 575 loads are applied to RCA abrasion tester with wide paper and checked for scratches.

-Breaking strength: Prepare 10 specimens cut to 30 x 40 mm size and drop the STEEL BALL (about 20.7mm in diameter, about 36g in weight) at the center of the specimen and record the ratio of not breaking.

-Severe yellowness: Measure the Yellow Index of the specimen before and after standing for 72 hours at 50 ° C and 95% RH with a UV-Vis Spectrometer and record the increase in value (ΔYI).

Comparative Example 1

In order to lower the viscosity of the same coating solution as in Example 1, 50 wt% of organic solvents Isopropyl alcohol and 50 wt% of n-propyl alcohol were mixed to lower the viscosity and general flow on both sides of a 1.0 mm thick PMMA extruded sheet (Rohm). After coating by coating method, the organic solvent was evaporated through infrared heating and irradiated with UV light at 2000 mJ / cm2, but the coating solution was not cured at all and remained on the hands.

<Example 2>

20 wt% of monofunctional monomer Methylmethacrylate (MMA), 40 wt% of trifunctional monomer TMPTA, 40 parts of trifunctional monomer Tris (2-Hydroxyethyl) Isocyanurate Triacrylate (THEIC), and Darocure 1173 as a photoinitiator The coating solution prepared by adding 5 wt% of the prepared solution was coated on both sides of a 0.8 mm thick PMMA extruded sheet (Rohm) by the method of the present invention, and the amount of irradiated UV light was adjusted to 2000 mJ / cm 2.

The physical properties of the coating sheet after curing was measured in the same manner as in Example 1.

Comparative Example 2

In order to reduce the viscosity of the same coating solution as in Example 2, 50 wt% of organic solvents, 50 wt% of n-propyl alcohol, and 50 wt% of n-propyl alcohol were mixed to lower the viscosity and a general flow on both sides of a 1.0 mm thick PMMA extruded sheet (Rohm). After coating by coating method, the organic solvent was blown off through infrared heating, and then irradiated with UV 2000 mJ / cm 2.

The physical properties of the coating sheet after curing was measured in the same manner as in Example 1.

As shown in Table 1, <Comparative Example 1> which was subjected to UV curing coating by the conventional method was not cured due to oxygen interference, but the UV curing coating was performed by the method of the present invention with the coating solution having the same composition. In the case of 1>, it turns out that the high hardness film of pencil hardness 5H hardened on the panel surface.

In addition, the coating solution having the same composition as in the <Comparative Example 2>, which was cured by increasing the initiator to 5 wt% in the conventional coating curing method, was compared with the case of <Example 2> in which the UV curing coating was applied by the method of the present invention. It can be seen that the chemical stability is improved by showing the yellowing value as well as mechanical properties such as pencil hardness, abrasion resistance, and fracture strength, which are relatively improved in the coating properties of <Example 2> which blocked oxygen.

The panel coating curing apparatus and method according to the present invention prevents oxygen in the atmosphere from contacting the coating layer during the ultraviolet curing process, thereby protecting the oxygen barrier effect from occurring during the curing process. As a result, since the conversion rate of the monomer is not increased and the surface crosslinking density is not lowered, the surface hardness and the mechanical strength can be improved as compared with the general atmospheric curing method.

In addition, chemical resistance increases as the unreacted monomer decreases, and the film smoothes the surface of the solution, thereby making it possible to manufacture a UV-curable coating panel having excellent surface gloss and surface smoothness without using a separate organic solvent. To effect.

Claims (12)

A film transferred along one or both sides of the panel to be coated; A reservoir for supplying a coating solution to the film; A coater for applying the coating solution of the reservoir to the film; A pressing roll for pressing the film coated with the coating solution onto a panel; A heater unit which passes the pressing roll and heats the panel to which the film is attached to diffuse the coating solution applied to the film onto the panel surface; A thickness control roll for adjusting the thickness of the coating layer formed of the coating solution by pressing the panel with the film passing through the heater unit; And Panel coating curing apparatus comprising an ultraviolet irradiator for curing the coating layer on the surface of the panel by irradiating ultraviolet rays to the coating layer is passed through the thickness control roll thickness control. The method of claim 1, The film is moved through the coating roll disposed adjacent to the coater in the film storage roll, and moved between the pressing roll and the deodorization roll disposed adjacent to the surface of the panel with the panel is wound on the winding roll Curing device. The method of claim 1, The heater unit is a panel coating curing apparatus, characterized in that to irradiate the infrared radiation component of the coating solution to the panel. The method of claim 1, And a panel conveying means for conveying the panel. The method of claim 1, And said film is polyethylene terephthalate or polypropylene material. The method of claim 1, And said coater is a knife coater or a roll coater. Applying a coating solution to the film; Attaching the coated film to the panel; Heating the panel to which the film is attached; Pressing the heated panel to adjust the thickness of the coating layer formed of the coating solution between the film and the panel; Irradiating the coating layer with ultraviolet rays to cure the coating layer to form a coating film; And Panel coating curing method comprising the step of separating the film from the panel. The method of claim 7, wherein The film is a panel coating curing method, characterized in that the release treatment on the surface to which the coating solution is applied. The method of claim 7, wherein And said film is polyethylene terephthalate or polypropylene material. The method of claim 7, wherein In the step of curing the coating layer by irradiating the coating layer with ultraviolet rays to form a coating film, the panel coating curing method, characterized in that no oxygen is present between the film and the coating layer. Coating panel manufactured using the device of any one of claims 1 to 6. Coating panel manufactured using the method of any one of claims 7 to 10.

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