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KR-20260063013-A - METHOD AND APPARATUS FOR MANUFACTURING HIGH HARDNESS FILM

KR20260063013AKR 20260063013 AKR20260063013 AKR 20260063013AKR-20260063013-A

Abstract

The present invention relates to a method and apparatus for manufacturing a high-hardness film used as a surface protective film for mobile devices or display devices. By using a carrier film and simultaneously casting a UV curing solution onto both sides of a substrate film, a film with high pencil hardness can be manufactured while ensuring film flatness, and a high-hardness film can be manufactured in which high adhesion between the hard coating layer formed by the UV curing solution and the substrate film is ensured.

Inventors

  • 임현진

Assignees

  • 주식회사 스타테크

Dates

Publication Date
20260507
Application Date
20241030

Claims (10)

  1. A step of placing one base film in the center, arranging two carrier films on both sides of the base film, and transporting them in a parallel arrangement; A step of supplying a UV curing solution between the above-mentioned substrate film and carrier film; A step of controlling the thickness of the UV curing liquid supplied between the base film and the carrier film by pressing each of the two carrier films from the outer direction toward the inner direction; A step of adjusting the thickness of the above UV curing solution and then performing a pre-curing step; A step of performing a first ultraviolet (UV) irradiation on the product after the above-mentioned pre-curing to cure the pre-cured state of the UV curing liquid closely bonded to both sides of the substrate film, thereby forming a hard coating layer; A step of removing two carrier films placed on both sides of the substrate film from the result of the above first ultraviolet irradiation; A step of performing secondary ultraviolet (UV) irradiation on the result obtained by removing the two carrier films above to finally secure the pencil hardness of the hard coating layer closely bonded to both sides of the substrate film; and A method for manufacturing a high-hardness film, comprising the step of laminating a protective film to the outer surface of both hard coating layers after the above-mentioned second ultraviolet irradiation.
  2. In claim 1, Each of the above-mentioned base film and carrier film is Using polyethylene terephthalate (PET) film, The above protective film is A method for manufacturing a high-hardness film using a polyethylene (PE) film.
  3. In claim 1, The above UV curing solution is A method for manufacturing a high-hardness film, comprising a polyfunctional urethane acrylate as a main ingredient to reinforce the pencil hardness of the above-mentioned film, wherein the polyfunctional urethane acrylate comprises a polyfunctional group having at least 2 to 10 oligomer bonds.
  4. In claim 1, The above UV curing solution is Based on 100 parts by weight of a polyfunctional polyurethane acrylate having at least 2 to 10 oligomer bonds, 1 to 20 parts by weight of viscosity-regulating monomer, and A method for manufacturing a high-hardness film comprising 1 to 5 parts by weight of a photoinitiator.
  5. In claim 1, The above-mentioned substrate film has a thickness of 125 μm to 250 μm, and The above carrier film has a thickness of 75 μm to 125 μm, and A method for manufacturing a high-hardness film, wherein a hard coating layer closely bonded to one surface of the above-mentioned film has a thickness of 10 μm to 100 μm.
  6. In claim 1, The above first ultraviolet irradiation is Ultraviolet (UV) radiation in the short wavelength range of 300 nm to 350 nm is irradiated through a metal UV lamp at an irradiation dose of 1,000 mJ/ cm² to 3,000 mJ/ cm² , and The above secondary ultraviolet irradiation is A method for manufacturing a high-hardness film by irradiating ultraviolet (UV) rays in the long wavelength range of 365 nm to 385 nm through a UV LED lamp.
  7. In claim 1, The above-mentioned single substrate film and the two carrier films disposed on both sides of the substrate film are transported at a speed of 1 m/min to 3 m/min, and A method for manufacturing a high-hardness film, wherein the above UV curing solution has a viscosity of 3000 cPs to 6000 cPs.
  8. A substrate film supply roll that supplies one substrate film; A first carrier film supply roll and a second carrier film supply roll, each supplying two individual carrier films, arranged on both sides of the base film and supplied in a manner parallel to each other; A UV curing liquid supply device that supplies a UV curing liquid between the above-mentioned base film and carrier film; A thickness-adjusting gap roller that controls the thickness of the UV curing liquid supplied between the base film and the carrier film by pressing each of the two carrier films from the outer direction to the inner direction; A pre-curing treatment device that adopts a UV gel lamp used for pre-curing after adjusting the thickness of the above UV curing solution; A first ultraviolet irradiator equipped with a metal UV lamp that performs a first ultraviolet (UV) irradiation on the product after the above-mentioned curing to form a hard coating layer of the UV-cured liquid closely bonded to both sides of the substrate film; A carrier film remover for removing two carrier films placed on both sides of a substrate film from the result of the above-mentioned first ultraviolet irradiation; A second ultraviolet irradiator equipped with a UV LED lamp that performs secondary ultraviolet (UV) irradiation on the result obtained by removing the two carrier films above to finally secure the pencil hardness of the hard coating layer closely bonded to both sides of the substrate film; A protective film laminating machine that completes a high-hardness film by laminating a protective film onto the outer surface of both hard coating layers after the above-mentioned second ultraviolet irradiation; and A high-hardness film manufacturing apparatus comprising a winding roll for winding a high-hardness film laminated with the above protective film.
  9. In claim 8, The UV curing liquid supplied through the above UV curing liquid supply device is Based on 100 parts by weight of a polyfunctional polyurethane acrylate having at least 2 to 10 oligomer bonds, 1 to 20 parts by weight of viscosity-regulating monomer, and It consists of a mixed composition comprising 1 to 5 parts by weight of a photoinitiator, and The above UV curing liquid is a high-hardness film manufacturing apparatus having a viscosity of 3,000 cPs to 6,000 cPs.
  10. In claim 8, The above-mentioned single substrate film and the two carrier films disposed on both sides of the substrate film are transported at a speed of 1 m/min to 3 m/min, and The above metal UV lamp is Ultraviolet (UV) radiation in the short wavelength range of 300 nm to 350 nm is irradiated at an irradiation dose of 1,000 mJ/ cm² to 3,000 mJ/ cm² , and The above UV LED lamp is A high-hardness film manufacturing apparatus that irradiates ultraviolet (UV) light in the long wavelength range of 365 nm to 385 nm.

Description

Method and apparatus for manufacturing high hardness film The present invention relates to a method and apparatus for manufacturing a high-hardness film, and more specifically, to a method and apparatus for manufacturing a high-hardness film that can secure film flatness and produce a film with high pencil hardness, and can be easily manufactured regardless of film thickness. With the rapid development of the display industry within the IT sector recently, the importance of surface protection films used to safeguard display surfaces is increasing, and there is a growing demand for films with high pencil hardness, which are types capable of enhancing surface hardness compared to existing ones. Accordingly, in manufacturing surface protection films used to protect display screens of portable mobile devices or display devices, we are focusing on the production of high-hardness films to meet the increasing demand for films with high pencil hardness. Meanwhile, looking at conventional manufacturing technology for display surface protection films, a method of applying a UV-curing hard coating liquid to one side of a substrate film and then curing it is mainly used. However, this conventional manufacturing method has a problem in that the substrate film warps in the direction of curing as the UV-curing hard coating liquid shrinks during curing, causing the substrate film to curl in a wavy manner. This not only lowers the marketability and reliability of the manufactured film product but also causes problems that reduce productivity. Furthermore, conventional surface protection films have a problem of expanding or contracting after being attached to the display surface, failing to properly respond to rapid environmental changes such as atmospheric pressure, humidity, and temperature. As a result, the film attached to the display surface lifts upward. Since this lifting issue persists, improvements are required. FIG. 1 is a drawing illustrating a method for manufacturing a high-hardness film according to one embodiment of the present invention. FIG. 2 is a drawing showing a high-hardness film manufacturing apparatus according to one embodiment of the present invention. FIG. 3 is a drawing showing a gap roller for transporting a substrate film and a carrier film and adjusting their thickness in a high-hardness film manufacturing apparatus according to one embodiment of the present invention. Preferred embodiments of the present invention are described as follows, and through such detailed description and various examples, the purpose, structure, and features of the present invention will be better understood. FIG. 1 is a drawing illustrating a method for manufacturing a high-hardness film according to one embodiment of the present invention, FIG. 2 is a drawing showing a high-hardness film manufacturing apparatus according to one embodiment of the present invention, and FIG. 3 is a drawing showing a gap roller for transporting a base film and a carrier film and adjusting thickness in a high-hardness film manufacturing apparatus according to one embodiment of the present invention. Referring to FIGS. 1 to 3, a method for manufacturing a high-hardness film according to one embodiment of the present invention may include a step of transferring a base film and a carrier film (S10), a step of supplying an ultraviolet curing liquid (S20), a step of adjusting the thickness of the ultraviolet curing liquid (S30), a pre-curing step (S40), a first ultraviolet irradiation step (S50), a step of removing the carrier film (S60), a second ultraviolet irradiation step (S70), a step of laminating a protective film (S80), and a winding step (S90). The above-mentioned substrate film and carrier film transfer step (S10) is a step of placing one substrate film (1) in the center and transferring two carrier films (2) individually arranged on both sides of the substrate film (1) in a parallel arrangement relative to each other. Each of the above-mentioned base film (1) and carrier film (2) can be a polyethylene terephthalate (PET) film. The above substrate film (1) can be applied with a thickness of 125 μm to 250 μm, and the above carrier film (2) can be applied with a thickness of 75 μm to 125 μm. One base film (1) positioned in the center and two carrier films (2) positioned individually on both sides of the base film (1) can each be controlled to be transported at a speed of 1 m/min to 3 m/min. One substrate film (1) placed in the center above can be supplied through a substrate film supply roll (100). Two carrier films (2) arranged individually on both sides of the above-mentioned base film (1) can be supplied through a first carrier film supply roll (210) and a second carrier film supply roll (220). One base film (1) positioned in the center and two carrier films (2) positioned individually on both sides of the base film (1) may have a direction of travel in which they are transported horizontally at a certain point after being transp