KR100813142B1 - Reflective sheet and the method of preparing it - Google Patents

Abstract

A reflective sheet and a manufacturing method for the same are provided to secure good durability and high reflectivity of the reflective sheet by continuously preventing corrosion generated at a boundary of a silver reflecting layer. A reflective sheet manufacturing method comprises the steps of: making aluminum thin films or aluminum foils(14) into an adhesive laminated sheet by applying an acryl resin adhesive on one surface of polyester; degreasing the surface of the aluminum thin film or aluminum foil by alkali solution and rinsing the aluminum thin film or aluminum foil, and then electrolytic-polishing and rinsing the aluminum thin film or aluminum foil; activating the pretreated aluminum surface by HF(Hydrofluoric acid) diluted solution; continuously inserting a sheet having the activated aluminum surface, into a plating bath and electrodepositing nickel on the aluminum surface by applying the aluminum thin film or foil as the cathode and nickel as the anode; continuously inserting the sheet plated with nickel, into an electric plating bath and forming a reflecting surface by electrodepositing silver on the aluminum thin film or foil by applying the aluminum thin film or foil as the cathode and silver as the anode; and forming a protecting film(11) by coating the silver reflecting layer with non-polar hydrophobic thermoplastic resin solution.

Description

Reflector and its manufacturing method {REFLECTIVE SHEET AND THE METHOD OF PREPARING IT}

1 is a cross-sectional view of the conventional fluorescent lamp reflector most commonly used

2 is a cross-sectional view of the high reflectivity reflector of the present invention.

3 is a plating electrodeposition apparatus of the present invention is a silver reflection layer

* Description of the symbols for the main parts of the drawings *

Supply roller (101) Al foil and PET laminated sheet (102)

Speed Rollers (103,103 ') Guide Rollers (104)

Nickel Plating Tank 105 Cathode Rollers 106, 107, 108, Wash Tank 110

Interlocking Information Rollers (111, 111 ') Information Rollers (112),

Silver Plating Tank 113 Cathode Roller 114 and Interlocking Roller 114 '

Guide Roller (115) Flush Tank (116)

Guide Roller 117 and Interlocking Roller 117 'Guide Roller 118

Dryer (119) Draw-out roller (120) and Interlocking roller (120 ')

Plated Sheet (121) Rewinder Roller (122)

The present invention is masked with non-conductive PET film or other synthetic resin film on one side of aluminum foil or aluminum foil, and the other side is subjected to a series of pretreatments such as degreasing, polishing, etc. Electrodeposited from acid or alkali solution to make silver reflector, and thermoplastic non-polar water-repellent paint was applied to reflector surface to prevent corrosion of silver reflecting surface and corrosive penetration that is generated at the interface between silver reflecting surface and coated synthetic resin The present invention relates to a reflector and a method for manufacturing the same, which can be increased to 99.9% by a combination of electrodeposition and coating.

In recent years, with the rapid development of industrial technology, solar panels, various TVs, TFT LCDs, video cell phones, electronic cameras, monitors, etc. There is a demand for high efficiency reflectors in the field.

Accordingly, the quality, performance, processability, and durability of reflectors, which are the core of various displays, are extremely important. Until now, reflectors capable of satisfying such moisture resistance, cold resistance, heat resistance, corrosion resistance, and arbitrary processability have been There was little.

As a conventional technology, there is a reflector that has obtained mirror surface by chemically treating silver on glass, but it is generally seen as a mirror rather than a reflector, and it has a relatively good function in terms of reflecting function. It is weak, and air, gas, and moisture penetrate between glass and silver film frequently to corrode, and it takes a lot of time for the reaction time to form a mirror surface, and continuous production is impossible. In the case of using the glass surface as a mirror surface, it is impossible to be processed after bending or perforation, and thus it is rarely used as an optical concept.

As another prior art, anodizing reflector (light) produced by anodizing aluminum to form a reflective aluminum oxide surface is produced, but this also has the disadvantage that the base material should be aluminum and reflectance is 85 ~ 93% range. As a result, the optical efficiency of the optical concept is much lower than that of the silver reflector, and the reflective alumina (Al ₂ O ₃ ) particles are ruptured during post-processing such as bending. There is a flaw.

As another conventional technique, recent developments in the deposition technique have used silver or aluminum as a reflector by vacuum depositing silver or aluminum on the glass surface, but also because the adhesion between the glass and the silver film is weak and the difference in the number of thermal expansion as a heterogeneous material is large, a gap is generated. It is easily corroded and lacks processability, so its use is limited because it cannot be used at all in the reflector for fluorescent lamps or CCFL cover of electronic products. In addition, the silver-deposited polyester film reflector, which is currently widely used as a reflector for fluorescent lamps, has a protective film (1), a multi-micron PET film (2), a silver deposition film (3), and an anti-corrosion coating layer, as shown in the cross-sectional structure. (4), the adhesive layer (5), 0.4-6mm aluminum support plate (6) laminated in the order (see Fig. 1) This is a manufacturing process by degreasing the polyester film, moisture-proof coating and then one side of the film Since the reflector can be obtained only after forming a silver deposited surface on the surface and then anti-corrosion coating and adhesive coating on the aluminum plate, it is relatively expensive for facility investment and high production cost. This has a growing problem. The reflector manufactured in this way cannot be used for compression molded products such as various container shapes due to the physical properties of polyester film, and it cannot be used for various electronic products (TFT LCD, PC note book, etc.). Due to the rapid development of the electromechanical and optical industries, the demand for reflectors continues to be created. However, the silver-deposited PET reflector (light), which is mainly used in Korea, has been severely limited in terms of its physical properties. I will say that.

In addition, silver reflectors (plates) may be manufactured by the method of sputtering and vacuum ion printing, which are one of vacuum deposition methods. Corrosion due to infiltration of ozone, air, moisture, and other gases in the atmosphere is inevitable, and the manufacturing cost is high, and thus the industrial value is still low.

The present invention is a reflector plate having a high reflectance that improves the problems of various reflectors, including a reflector by a chemical reduction method or a PET film reflector by vacuum deposition, instead of a reflective layer formed by a silver deposition method on a PET film as a conventional support. As the silver reflective layer is formed by electroplating on aluminum foil or aluminum foil bonded to PET film, strong bonding and adhesion force is generated from the aluminum surface, so the gap between the two sides is inherently blocked and other silver reflective layer is prevented. The reflective surface on the side is coated with a non-polar hydrophobic thermoplastic (primer) solution to form a protective film, and thus has a high reflectivity that is higher than that which can be raised to a silver reflector up to now, and is not permanently altered or corroded by air, gas, or moisture. Durability, easy processability and high durability The reflector is possible and a method of manufacturing the same rate used in various products to provide its predecessor.

In order to achieve the object of the present invention, a strong bonding force to the support of the silver reflective layer and the protective film of the mirror surface (reflection surface), as well as the reinforcement of airtightness and watertightness, especially in the side cross-section of the laminated reflector, as well as the coefficient of thermal expansion between heterogeneous materials Through countless experiments to prevent gaps, electrophoretic silver is deposited on aluminum plate to realize strong bonding force, and strong adhesive force, and cushioning function against shearing force generated between layers due to thermal changes. When the excellent non-polar hydrophobic thermoplastic resin is selected as the mirror protective film, the reflector having a high reflectance according to the present invention is brought to be described.

Applying an acrylic resin adhesive on one side of the polyester to form an adhesive laminate sheet of aluminum foil or aluminum foil and

Degreasing the aluminum thin plate or aluminum foil surface through the above step with alkaline (NaoH) solution, washing with electrolytic polishing and then washing with water and activating the pretreated aluminum surface with a hydrofluoric acid dilution solution;

Continuously introducing the sheet having activated the aluminum surface into the plating bath and depositing nickel on the aluminum surface by using the aluminum sheet or foil as the cathode and the anode of the nickel;

Continuously introducing the nickel plated sheet into an electroplating bath to form a reflective surface by electrodepositing silver on an aluminum thin plate or foil surface using an aluminum thin plate or foil as a cathode and silver as an anode;

It is a method of manufacturing a high efficiency reflector comprising the step of forming a protective film by coating with a non-polar hydrophobic thermoplastic resin solution on the silver reflecting layer formed in the above step.

As described above, the reflector having a high reflectance may be formed from the upper layer as shown in FIG. 2 by the reflective layer protective film 11, the silver reflective layer 12, the nickel plated layer 13, the aluminum sheet or foil 14, and the acrylic adhesive layer 15. ) Is a reflector having a high reflectance laminated with the polyester layer 16.

In another embodiment of the method, a method of omitting the nickel plating process on an aluminum foil or an aluminum foil, even if silver is directly deposited on an aluminum foil or an aluminum foil, there is little difference in bonding strength with aluminum and no difference in reflectance. In the case of forming the undercoat layer, there is a slight difference in the sharpness of the reflecting surface, and in the case of directly depositing silver on the aluminum surface, it is necessary to extend the time for passing the silver plating bath to achieve the object of the present invention. There is no problem with the ship.

In the manufacturing method, the PET film is capable of masking one surface of the aluminum foil or foil in the plating bath as well as the support and the career function, and has a surface protection function of the aluminum foil or foil after the reflector is completed. In addition, the core technology of the present method is characterized by the fact that it has a strong bonding force by electrodepositing silver on an aluminum sheet or foil by a plating method and a protective film of a non-polar hydrophobic thermoplastic resin film on the silver reflecting surface.

In order to be an excellent reflector, the reflectance is inevitably determined by the metal forming the reflecting surface, but even if the same metal (silver) is used, the reflectance can be improved depending on the method selected, and the reflectance is continuously preserved without alteration or corrosion. will be. In conclusion, the electrical and electronic bonds of anions and cations are more dense in the structure of the silver reflecting layer than the bonds by vacuum deposition or silver reaction, and have stronger bonding strength with the support. The lighting that can absorb the shear force to mutually enable the present invention. As a result, even under severe conditions, no gap is generated between the support and the silver reflective layer, and a non-polar hydrophobic thermoplastic resin (primer) is coated with a protective film on the reflective surface of the silver reflective layer to have a strong adhesive force, and the protective film has a difference in coefficient of thermal expansion. Since the furnace has viscoelasticity capable of absorbing and buffering the shear force generated between the interfaces, it is possible to prevent the occurrence of gaps between layers. Therefore, the front and rear surfaces of the silver reflecting layer are guaranteed airtightness and watertightness to prevent deterioration or corrosion, so that the high reflectivity can be continuously maintained. Deposition is much denser and more robust than film, which can improve the average roughness (lux / cm ² ) value by at least 7-8%, and is therefore suitable for various optical machines (e.g. fluorescent reflector, CCFL cover, mobile phone) Reflective plates, BLUs of various computers, projection TVs, etc.) can be processed into reflecting plates or films. The non-polar hydrophobic thermoplastic resins are epoxy, alkyl ester vinyl chloride, vinyl acetate copolymer, polyvinyl butyral, polyurethane rubber and the like.

In order to clearly understand the function and operation of the reflector having a high reflectance, an example was given.

Example 1

Apply acrylic adhesive on one side of PET film, adhesively laminate aluminum foil of 1300m / m width and 40 micron thickness, degrease alkaline in 5% NaoH solution, wash and then 10% phosphoric acid and 10% H ₂ SO ₄ 2: 1 After mixing at a rate of a little, anhydrous chromium-free solution was heated to 70 ℃ or higher, and then electropolished for 1 minute with aluminum foil as an anode, followed by pretreatment, followed by 30 seconds in a 5% HF (fluoric acid) solution. Immerse it to an extent and activate the aluminum foil surface.

Introduced to the first Ni plating bath and blown with air while electrodelizing Nickel metal for about 3 minutes at 50 ~ 60 ℃ with nickel metal as anode and aluminum foil as cathode.

Introduced into the secondary silver plating bath while blowing air and applying aluminum foil to the cathode as a cathode, plating silver (Ag) at a temperature of about 30 ~ 40 ℃ for about 2 minutes, washing with water, and drying it with a comma coater. By applying the solution, a reflector 200 m having a high reflectance according to the present invention was prepared.

The composition of the plating liquid and the apparatus used in the above embodiment are as follows.

* Ni plating composition

Heritage nickel _{(NiSO 4 · 6H26): 350g} / ℓ

Nickel Chloride (NiCl ₂ ): 50g / ℓ

   Boric acid: 45 g / ℓ

   PH: 3

   Temperature: keep at 50 ℃

Cathode Current Density: 7A / dm ²

   Polishing agent: 1.5g / ℓ

* Ag plating composition

K Ag (CN) ₂ : 100 g / l

   KCN: 42g / ℓ

K ₂ CO ₃ : 48g / ℓ

   Temperature: keep at 30 ~ 40 ℃

Current Density: 1.5A / dm ²

   Polishing agent: 1g / ℓ

* Equipment used: shown in Figure 3 (PET film and aluminum bonding process, aluminum foil pretreatment process and protective film forming process is omitted)

The reflectance of the reflector having the high reflectance manufactured in Example 1 is 99.7% on average, and the reflectance of 6 to 7% is improved on average over the silver reflector manufactured by conventional silver deposition. In order to confirm the performance of the silver reflector, the change state of the reflector was immersed in 10% saline solution, and the change state of the reflector is shown in Table 1, and the change state of the reflector is maintained by maintaining the hydrogen hydride gas concentration at 150 PPM in a sealed chamber. Represented by.

Table 1 State of change by salt immersion of reflector

Type ＼ Salt immersion time State of change Simple silver deposition reflector 24 hours Side corrosion Anti-Coating Silver Deposition Reflector 72 hours Lateral Corrosion Marks Invention reflector 120 hours No alteration

Table 2 State of change by emulsified water introduction of reflector

Type ＼ Leaving time in oil painting gas atmosphere (150PPM) State of change Simple silver deposition reflector 36 hours Side corrosion (gray black) Anticorrosive Coating Deposition Reflector 108 hours Lateral Corrosion Marks Invention reflector 180 hours No alteration

As can be seen from the examples, the silver reflector has the highest reflectance (199.7%) compared to the fluorescent lamp reflector produced in Korea. The reflecting layer is a layer formed by electrodeposition of plating method. Compared with the formed reflective layer, the structure is dense and strong gap between the front and back surfaces of the silver reflective layer does not cause gaps, so it is excellent in airtightness and water tightness, and thus it is possible to continuously prevent deterioration or corrosion of the reflective layer, which is why it is a durable or excellent reflector. It is a reflector that can be used for optical devices such as fluorescent lamp reflector, CCFL cover, mobile phone reflector, BLU of various computers, projection TU etc. that require high reflectance.

Claims (7)

Applying an acrylic resin adhesive on one side of the polyester to form an adhesive laminate sheet of aluminum foil or aluminum foil and Degreasing the aluminum thin plate or aluminum foil surface through the above steps with alkaline (NaoH) solution, washing with water, electropolishing and pre-treating by washing with water Activating the pretreated aluminum surface with a hydrofluoric acid dilution solution; Continuously introducing the sheet having activated the aluminum surface into the plating bath to electrodeposit the nickel onto the aluminum surface using an aluminum sheet or foil as a cathode and nickel as an anode; Continuously introducing the nickel-plated sheet into an electroplating bath to electrodeposit aluminum onto aluminium thin plates or foils using silver as an anode and silver as an anode to form a reflective surface; A method of manufacturing a reflector, comprising forming a protective film by coating a non-polar hydrophobic thermoplastic resin solution on the silver reflective layer formed in the step. The method of manufacturing a reflector according to claim 1, wherein the electrodeposition of the nickel is omitted. A reflector laminated from the upper layer in the order of a reflective layer protective film, a silver reflection layer, a nickel plating layer, an aluminum thin plate or foil, an acrylic adhesive layer, and a polyester film layer. Reflector laminated from the upper layer in the order of reflective layer protective film, silver reflecting layer, aluminum thin plate or foil, acrylic adhesive layer, polyester film layer The reflector according to claim 3, wherein the silver reflecting layer is a silver reflecting layer plated on a nickel electrodeposited layer plated on an aluminum thin plate or an aluminum foil. The reflector according to claim 3, wherein the reflective layer protective film is a reflective layer protective film coated with a nonpolar hydrophobic thermoplastic resin solution. The reflector according to claim 4, wherein the silver reflection layer is a silver reflector electrodeposited on an aluminum foil or an aluminum foil.

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