A manufacturing process for a special-shaped light guide film with high brightness and high uniformity and the obtained light guide film

Abstract

The present invention discloses a process for producing a high-brightness and high-uniformity special-shaped light-guiding film and the light-guiding film produced therefrom. The process for producing a high-brightness and high-uniformity special-shaped light-guiding film comprises the following steps: producing a special-shaped light-guiding film substrate with a special-shaped step surface formed on the surface; producing a prefabricated mold and recasting it to obtain a dot mold; producing a primary mold and recasting it to obtain a microstructure mold; forming a dot structure on the bottom surface of the special-shaped light-guiding film substrate, and forming a serrated microstructure on the light-emitting surface of the special-shaped light-guiding film substrate: die-cutting the special-shaped light-guiding film substrate with the dot structure formed on the bottom surface and the serrated microstructure formed on the light-emitting surface to obtain a light-guiding film sheet; polishing the light-guiding film sheet; forming a serrated microstructure on the light-incident surface of the polished light-guiding film sheet to obtain a light-guiding film. The above process of the present application can produce a light-guiding film with a thickness of 0.1 mm and good brightness and brightness uniformity, can be used in the production of thin products, and is conducive to reducing the production cost of thin products.

Description

Technical Field

[0001] The present invention relates to the field of light guide film production, and in particular to a production process of a high-brightness and high-uniformity special-shaped light guide film and the light guide film produced therefrom. Background Art

[0002] Light guide films are commonly used in small-sized backlight products such as phones, tablets, NB-PCs, TVs, keyboards, and e-books. Currently, commercially available light guide films are primarily produced using injection molding. However, this process also has limitations. For example, the thickness of light guide films produced using injection molding is generally above 0.3mm, which cannot meet the requirements for thinner product upgrades.

[0003] OLEDs are often used in thin-film products due to their ultra-thin nature and excellent optical performance. However, OLED production is expensive. Therefore, developing an ultra-thin, low-cost light-guiding film with excellent optical performance that meets the requirements of thin-film products is a current research hotspot. Summary of the Invention

[0004] In order to provide an ultra-thin, low-cost, optically excellent light-guiding film that can meet the production requirements of thin products, the present application provides a high-brightness, high-uniformity, special-shaped light-guiding film production process and the light-guiding film produced therefrom.

[0005] The present application provides a high-brightness and high-uniformity special-shaped light guide film manufacturing process using the following technical solutions:

[0006] A process for producing a high-brightness and high-uniformity special-shaped light-guiding film comprises the following steps:

[0007] Producing a special-shaped light-guiding film substrate with a special-shaped step surface formed on the surface;

[0008] A prefabricated mold is formed by laser dotting on a steel mold to produce a plurality of dots with a central arc protrusion and a peripheral groove. The prefabricated mold is then recast using an electroforming process to obtain a dot mold for forming the dot structure on the bottom surface of the light guide film. The outer diameter r of the arc protrusion of the dot mold is 15-25 μm, and the outer diameter R of the groove of the dot mold is 8 μm-15 μm.

[0009] A plurality of V-shaped grooves are cut into the steel mold using an NC tool to obtain a primary mold; the primary mold is then recast using an electroforming process to obtain a microstructure mold for forming the light-emitting surface microstructure of the light-guiding film; the microstructure mold has triangular protrusions with a height of 1-3 μm and a width of 8.5-10.5 μm;

[0010] The dot structure is formed on the bottom surface of the special-shaped light-guiding film substrate by hot pressing equipment, and the sawtooth microstructure is formed on the light-emitting surface of the special-shaped light-guiding film substrate:

[0011] Die-cutting the special-shaped light guide film substrate having a dot structure formed on the bottom surface and a sawtooth microstructure formed on the light emitting surface to obtain a light guide film sheet;

[0012] Polishing the four sides of the light guide film sheet;

[0013] A sawtooth microstructure is produced on the light incident surface of the polished light guide film sheet to obtain a light guide film; the sawtooth microstructure on the light incident surface of the light guide film has a depth of 1-3 μm and a width of 14-16 μm.

[0014] In this application, an EPI hot pressing process is used to produce a light guide film with a thickness of 0.1mm. To address the problem that the brightness uniformity of the backlight source is easily deteriorated after the thickness of the light guide film is reduced, this application designs a 0.04-0.06mm thick special-shaped step surface on the light output surface of the light guide film. The special-shaped step surface can effectively absorb light energy to the bottom surface, and then the special-shaped mesh structure on the bottom surface increases the refractive efficiency, effectively improving the utilization rate of light efficiency. Then, a serrated microstructure is designed on the light input surface of the light guide film, a special-shaped mesh structure is designed on the bottom surface of the light guide film, and a microstructure is designed on the light output surface of the light guide film. Through the coordination of the special-shaped step surface, the serrated microstructure on the light input surface, the mesh structure on the bottom surface, and the microstructure on the light output surface, the brightness of the backlight source made of the 0.1mm thick light guide film produced by the hot pressing process is improved, while the brightness uniformity of the backlight source is improved, so that the brightness of the backlight source reaches 120%, and the brightness uniformity reaches more than 95%.

[0015] However, it should be noted that the sizes of the serrated microstructure on the light incident surface, the dot structure on the bottom surface, and the microstructure on the light emitting surface in this application are also key features for improving the light guiding efficiency and uniformity of the light guiding film of this application. When the size of the serrated microstructure on the light incident surface of the light guiding film is relatively small, the light guiding performance of the light guiding film is reduced, and the brightness of the backlight source is reduced; and when the size of the serrated microstructure on the light incident surface of the light guiding film is relatively large, there will be a lamp shadow phenomenon when the light enters the backlight source, resulting in uneven brightness of the backlight source. When the size of the dot structure on the bottom surface of the light guiding film is relatively small, the optical brightness of the backlight source is reduced; when the size of the dot structure is relatively large, the shielding property becomes worse, and dots are visible in the visual effect. When the size of the microstructure on the light emitting surface of the light guiding film is relatively small, the brightness of the backlight source is reduced, and when the size of the microstructure on the light emitting surface of the light guiding film is relatively large, the picture is uneven.

[0016] Because the light-guiding film produced using the aforementioned EPI hot-pressing process is ultra-thin and has excellent optical properties, it can meet the requirements of thin-profile products. Furthermore, because the light-guiding film produced using the aforementioned EPI hot-pressing process also has the advantages of high product qualification rates and low scrap rates, when producing a thin light source with similar optical intensity, the production cost of producing an OLED is more than four times that of producing a backlight source containing the light-guiding film of this application.

[0017] Optionally, the electroforming process in the process of manufacturing the dot mold or the microstructure mold includes the following steps:

[0018] Surface cleaning: Use a detergent to ultrasonically clean the precast mold or preliminary mold, and then use deionized water to ultrasonically clean the precast mold or preliminary mold. After cleaning, use an ion air gun to blow dry it to obtain the precast mold or preliminary mold with a cleaned surface; Electroforming recasting: Place the precast mold or preliminary mold after surface cleaning into an electroforming tank, which is prepared with electrolytic solution and nickel material with a purity of more than 99.9%. The electroforming temperature is controlled at 30-60℃ and the current density is controlled at 1-30A / dm 2 , recast through 8H electroforming process, and then separate the electroformed layer from the prefabricated mold or the primary mold to obtain a dot mold or a microstructure mold.

[0019] Before the electroforming recasting step, the preformed or primary mold is cleaned to remove any impurities. This helps improve the accuracy of the dot structure on the bottom surface of the light-guiding film and the microstructure dimensions on the light-emitting surface of the film, thereby improving the film's light-guiding efficiency and uniformity. Furthermore, the dot protrusions created through the electroforming recasting process are larger and deeper, increasing the refractive surface when thermally transferred to the film, which helps improve the film's light-guiding efficiency and boosts the backlight's brightness.

[0020] Optionally, the electrolytic solution includes the following raw materials in percentage by weight:

[0021] Nickel sulfamate: 30-45%

[0022] Nickel chloride: 0.5-2.5%

[0023] Boric acid: 3-4.5%

[0024] Deionized water: balance.

[0025] The dot mold or microstructure mold made by using the above electrolytic solution has the advantages of low internal stress, high hardness and tensile strength and good toughness, which is conducive to extending the service life of the dot mold and microstructure mold.

[0026] Optionally, the electroforming process in the process of manufacturing the dot mold or microstructure mold further includes a demolding pretreatment step, which is performed after the surface cleaning step and before the electroforming recasting step; the cleaning agent used in the surface cleaning step includes the following raw materials in parts by weight:

[0027] Anhydrous sodium carbonate: 6-10 parts

[0028] Nano silicon oxide: 4-8 parts

[0029] Deionized water: 100 parts.

[0030] Using the above-mentioned cleaning agent to clean the prefabricated mold or the primary mold can effectively remove impurities such as oil and rust on the mold, which is beneficial to improving the accuracy of the dot structure on the bottom surface of the light-guiding film and the microstructure size of the light-emitting surface, thereby improving the light-guiding efficiency and light-guiding uniformity of the light-guiding film.

[0031] Optionally, the cleaning agent used in the surface cleaning step includes the following raw materials in parts by weight:

[0032] Anhydrous sodium carbonate: 6-10 parts

[0033] Modified nano-silicon oxide: 4-8 parts

[0034] Deionized water: 100 parts;

[0035] The preparation method of the modified nano-silicon oxide comprises the following steps:

[0036] 4-6 parts by weight of nano-silica and 1-3 parts by weight of a silane coupling agent are added to 100 parts by weight of an ethanol solution, stirred for 20-30 minutes, and then 0.5-1 parts by weight of OP-10 and 2-5 parts by weight of polyethylene glycol are added, and ultrasonic dispersion is performed to obtain a dispersion liquid; 10-15 parts by weight of vinyl acetate, 1-2 parts by weight of sodium acrylate, and 3-6 parts by weight of acrylate are added to the dispersion liquid, and stirred evenly, nitrogen is introduced to deoxygenate, and then 4-6 parts by weight of a saturated aqueous solution of potassium persulfate are added dropwise while stirring. After the addition is complete, the mixture is heated under reflux at 70-80°C for 4-5 hours. After the reaction is completed, the mixture is cooled to room temperature, demulsified, filtered, washed, and dried to obtain the modified nano-silica.

[0037] When the modified nano-silica described above in the present application is used to replace the nano-silica in the cleaning agent, it can not only effectively remove impurities such as oil and rust on the mold, but also prevent the nano-silica from scratching the prefabricated mold or the primary mold, which is conducive to obtaining a prefabricated mold and the primary mold with a smooth surface, so that the dot mold and the microstructure mold can be smoothly demolded without adding a release layer or an isolation layer to the prefabricated mold and the primary mold, reducing the problem of small size of the dot structure on the bottom surface of the light-guiding film and the microstructure on the light-emitting surface due to the setting of the release layer or the isolation layer, which is conducive to further improving the accuracy of the size of the dot structure on the bottom surface of the light-guiding film and the microstructure on the light-emitting surface, and further improving the light-guiding efficiency and light-guiding uniformity of the light-guiding film.

[0038] Optionally, the particle size of the modified nano-silicon oxide is 30-40 nm.

[0039] When the particle size of the modified nano-silicon oxide is 30-40 nm, the dispersion performance is further improved, so that the modified nano-silicon oxide is not easy to deposit and adhere to the prefabricated mold or the primary mold.

[0040] Optionally, the dropping speed of the saturated aqueous solution of potassium persulfate is 0.4-0.5 g / min.

[0041] Controlling the dropping speed of the saturated aqueous solution of potassium persulfate at 0.4-0.5 g / min can prevent the problem of excessive temperature rise and the inability of the organic polymer material to stably coat the surface of the nano-silicon oxide.

[0042] Optionally, the polyethylene glycol is selected from any one of polyethylene glycol 200 and polyethylene glycol 400, or a combination of the two.

[0043] Polyethylene glycol 200 and polyethylene glycol 400 have good dispersing properties and can promote the uniform dispersion of lipophilic nano-silica in the dispersion liquid.

[0044] Optionally, the special-shaped light-guiding film substrate is selected from any one of a PC substrate and a PMMA substrate.

[0045] In a second aspect, the present application provides a light-guiding film produced by any one of the above-mentioned manufacturing processes.

[0046] The above-mentioned process can produce a light-guiding film with a thickness of 0.1mm. This light-guiding film also exhibits excellent light-guiding efficiency and uniformity. This results in a 20% increase in brightness for backlights using this light-guiding film compared to those produced using an injection molding process. The brightness uniformity reaches over 95%, reaching a level comparable to or better than that of OLEDs. Furthermore, the production cost and maintenance cost of this light-guiding film backlight are lower than those of OLEDs.

[0047] In summary, the technical solution of this application has at least the following beneficial effects:

[0048] (1) The present application adopts a hot pressing EPI process to prepare a light-guiding film with a thickness of 0.1 mm. At the same time, the light-guiding film has good light-guiding efficiency and light-guiding uniformity, so that the brightness of the backlight source containing the light-guiding film of the present application is increased by 20% compared with the brightness of the light-guiding film backlight source produced by the injection molding process, and the brightness uniformity is more than 95%, reaching the same or better level as OLED.

[0049] (2) The production cost of the light-guiding film backlight source of the present application is lower than that of OLED, and the maintenance cost is also lower than that of OLED. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural schematic diagram of the special-shaped light-guiding film of this application.

[0051] Description of reference numerals:

[0052] 1. Special-shaped step surface; 2. Bottom surface; 21. Dot structure; 3. Light-emitting surface; 31. Light-emitting surface microstructure; 4. Light-entering surface; 41. Sawtooth microstructure of light-entering surface. DETAILED DESCRIPTION

[0053] The following is combined with Figure 1 This application is described in further detail.

[0054] Example

[0055] Example 1

[0056] A high-brightness, high-uniformity, shaped light-guiding film comprises a light-guiding film substrate having a bottom surface 2, a light-incident surface 4, and a light-exiting surface 3. The bottom surface 2 and light-exiting surface 3 are disposed opposite each other, and a shaped stepped surface 1 is provided on the side of the light-exiting surface 3 adjacent to the light-incident surface 4. To improve light efficiency, the bottom surface 2 of the light-guiding film is provided with a dot structure 21, the light-exiting surface 3 is provided with a serrated light-exiting surface microstructure 31, and the light-incident surface 4 is provided with a serrated light-incident surface microstructure 41.

[0057] A process for producing a high-brightness, high-uniformity, special-shaped light-guiding film comprises the following steps:

[0058] S1. Production of special-shaped light guide film substrate:

[0059] S1. Put the PC raw material into the charging hopper for dust removal, and then put the PC raw material after dust removal into the extruder, so that the PC raw material is melted at 230-240℃ and extruded through the die head, and then passed through the mirror roller with a temperature of 75℃ and the special-shaped roller with a temperature of 5℃ and a special-shaped step surface engraved on the surface, and finally pulled into shape to obtain a special-shaped light-guiding film substrate with a special-shaped step surface formed on the surface, the thickness of the special-shaped step surface is 0.05mm, and the thickness of the special-shaped light-guiding film substrate is 0.1mm (excluding the thickness of the special-shaped step surface).

[0060] S2. Make dot mold:

[0061] S21. Optimize the optical distribution of the light guide plate through dot design. Then, transfer the design to the laser processing equipment using software. The laser processing equipment is adjusted to a frequency of 30 kHz, a pulse rate of 13 pls, a laser energy of 3 W, and a lens angle of 75 cm. Several dots with central arc-shaped protrusions and peripheral grooves are formed on the surface of the steel plate mold to obtain a prefabricated mold. In the prefabricated mold, the outer diameter r of the arc-shaped protrusions is 19-21 μm, and the outer diameter R of the grooves is 10-12 μm.

[0062] S22. Surface Cleaning: Ultrasonic cleaning of the precast mold is performed using a detergent, with the ultrasonic vibration frequency controlled at 20 kHz and the cleaning time controlled at 10 minutes. The precast mold is then ultrasonically cleaned three times with deionized water. After cleaning, the precast mold is blown dry with an ion air gun to obtain a surface-cleaned precast mold. The detergent is prepared by uniformly mixing 6-10 kg of anhydrous sodium carbonate, 4-8 kg of nano-silicon oxide, and 100 kg of deionized water. The detergent used for the precast mold in this embodiment is prepared by uniformly mixing 8 kg of anhydrous sodium carbonate, 6 kg of nano-silicon oxide, and 100 kg of deionized water.

[0063] S23, electroforming recasting: Place the prefabricated mold with an isolation layer into the electroforming tank, which is filled with electrolytic solution and nickel material with a purity of more than 99.9%. The electroforming temperature is controlled at 45°C and the current density is controlled at 10A / dm 2 , recast through the 8H electroforming process, and then separate the electroformed layer from the prefabricated mold to obtain a dot mold. The outer diameter r of the arc protrusion of the dot mold is 15-25μm, and the outer diameter R of the groove of the dot mold is 8μm-15μm. The electrolytic solution is made of 30-45wt% nickel sulfamate, 0.5-2.5wt% nickel chloride, 3-4.5wt% boric acid, and the balance is water. In this embodiment, the electrolytic solution is made of 40wt% nickel sulfamate, 1.5wt% nickel chloride, 4wt% boric acid, and the balance is water.

[0064] S3. Making microstructure mold:

[0065] S31. Cut a plurality of V-shaped grooves on the steel mold using an NC tool to obtain a primary mold; the depth of the V-shaped grooves is 1-3 μm, the width is 8.5-10.5 μm, and the interval between two adjacent V-shaped grooves is 24-26 μm.

[0066] S32. Surface Cleaning: Ultrasonic cleaning of the primary mold is performed using a detergent, with the ultrasonic vibration frequency controlled at 20 kHz and the cleaning time controlled at 10 minutes. The primary mold is then ultrasonically cleaned three times with deionized water. After cleaning, the mold is dried with an ionizing air gun to obtain a surface-cleaned mold. The detergent used for the primary mold in this embodiment is prepared by uniformly mixing 8 kg of anhydrous sodium carbonate, 6 kg of nano-silicon oxide, and 100 kg of deionized water.

[0067] S33, electroforming recasting: Place the primary mold into the electroforming tank, which is filled with electrolytic solution and nickel material with a purity of more than 99.9%. The electroforming temperature is controlled at 50°C and the current density is controlled at 5A / dm 2 , recasting is performed using an 8H electroforming process, and then the electroformed layer is separated from the primary mold to obtain a microstructure mold. The microstructure mold has triangular protrusions with a height of 1-3 μm and a width of 8.5-10.5 μm. The electrolytic solution in this embodiment is made of 40 wt% nickel sulfamate, 1.5 wt% nickel chloride, 4 wt% boric acid, and the balance water.

[0068] S4, hot pressing of dots:

[0069] S41, loading the special-shaped light guide film substrate into a hot pressing device and fixing it on the device conveyor belt through CCD positioning;

[0070] S42, fixing the microstructure mold on the hot-pressing upper roller of the hot rolling equipment, and fixing the dot mold on the hot-pressing lower roller of the hot rolling equipment;

[0071] S43. Setting the roller pressure on the hot pressing device to 4-5.5 kN, the temperature to 120-140° C., and the rotation speed to 3000-4000 r / s, then starting the hot pressing device for hot pressing, followed by cooling, laminating, and winding, to obtain a special-shaped light guide film substrate having a dot structure formed on the bottom surface and a serrated microstructure formed on the light-emitting surface. In this embodiment, the roller pressure is 5 kN, the temperature is 130° C., and the rotation speed is 3500 r / s.

[0072] S5. Cutting: Die-cutting the special-shaped light guide film substrate having a dot structure formed on the bottom surface and a sawtooth microstructure formed on the light-emitting surface to obtain a light guide film sheet;

[0073] S6, polishing: polishing the four sides of the light guide film sheet;

[0074] S7. Fabrication of a serrated microstructure on the light incident surface of a light-guiding film: A serrated microstructure is machined on the light incident surface of the polished light-guiding film sheet using a CNC machine tool. The serrated microstructure on the light incident surface of the light-guiding film has a depth of 1-3 μm and a width of 14-16 μm, thereby obtaining a light-guiding film.

[0075] Example 2

[0076] A high-brightness and high-uniformity special-shaped light-guiding film, which differs from Example 1 in that:

[0077] Before electroforming the precast mold and the primary mold after surface cleaning, a release agent is first used to perform demoulding pretreatment on the precast mold and the primary mold after surface cleaning.

[0078] Example 3

[0079] A high-brightness and high-uniformity special-shaped light-guiding film, which differs from Example 1 in that:

[0080] In this embodiment, the cleaning agent used in the surface cleaning process of the prefabricated mold and the primary mold is prepared by uniformly mixing 8 kg of anhydrous sodium carbonate, 6 kg of modified nano-silicon oxide, and 100 kg of deionized water.

[0081] The preparation method of modified nano-silicon oxide comprises the following steps:

[0082] 4-6 parts by weight of nano-silica and 1-3 parts by weight of a silane coupling agent are added to 100 parts by weight of an ethanol solution, stirred for 20-30 minutes, and then 0.5-1 parts by weight of OP-10 and 2-5 parts by weight of polyethylene glycol are added, and ultrasonic dispersion is performed to obtain a dispersion liquid; 10-15 parts by weight of vinyl acetate is added to the dispersion liquid, and after stirring, nitrogen is introduced to deoxygenate, and then 4-6 parts by weight of a saturated aqueous solution of potassium persulfate is added dropwise while stirring. After the addition is complete, the mixture is heated under reflux at 70-80°C for 4-5 hours. After the reaction is completed, the mixture is cooled to room temperature, demulsified, filtered, washed, and dried to obtain the modified nano-silica.

[0083] In this embodiment, the dosage of each component in the modified nano-silicon oxide is as follows:

[0084] Nano silicon oxide: 5kg

[0085] Silane coupling agent: 2kg

[0086] 35% ethanol aqueous solution by volume: 100 kg;

[0087] Op-10: 0.75kg;

[0088] Polyethylene glycol 200: 3kg

[0089] Vinyl acetate: 15kg

[0090] Saturated aqueous solution of potassium persulfate: 5kg.

[0091] In this embodiment, when preparing modified nano-silicon oxide, the dropping rate of the saturated aqueous solution of potassium persulfate is 0.4 g / min, the temperature of the heating reflux process is controlled at 75° C., and the reflux time is controlled at 4.5 h.

[0092] Example 4

[0093] A high-brightness and high-uniformity special-shaped light-guiding film, which differs from Example 3 in that:

[0094] In this embodiment, the dosage of each component in the modified nano-silicon oxide is as follows:

[0095] Nano silicon oxide: 5kg

[0096] Silane coupling agent: 2kg

[0097] 35% ethanol aqueous solution by volume: 100 kg;

[0098] Op-10: 0.75kg;

[0099] Polyethylene glycol 200: 3kg

[0100] Sodium acrylate: 9kg

[0101] Acrylate: 6kg

[0102] Saturated aqueous solution of potassium persulfate: 5kg.

[0103] Example 5

[0104] A high-brightness and high-uniformity special-shaped light-guiding film, which differs from Example 3 in that:

[0105] In this embodiment, the dosage of each component in the modified nano-silicon oxide is as follows:

[0106] Nano silicon oxide: 5kg

[0107] Silane coupling agent: 2kg

[0108] 35% ethanol aqueous solution by volume: 100 kg;

[0109] Op-10: 0.75kg;

[0110] Polyethylene glycol 200: 3kg

[0111] Vinyl acetate: 10kg

[0112] Sodium acrylate: 2kg

[0113] Acrylate: 3kg

[0114] Saturated aqueous solution of potassium persulfate: 5kg.

[0115] Performance test data

[0116] The following backlight brightness and brightness uniformity data are obtained by using a fixed module and then replacing different light guide films.

[0117] 1. The performance comparison of the ultra-thin light guide film backlight produced by the EPI hot pressing process of this application and the light guide film backlight produced by OLED, injection molding process and traditional hot pressing process is shown in Table 1 below.

[0118] Table 1 Performance comparison of different light sources

[0119]

[0120]

[0121] Note: The dot molds and microstructure molds used in traditional hot pressing processes are directly made by laser dotting without the electroforming recasting step.

[0122] (2) The usage of the master plates (i.e., prefabricated molds and primary molds) prepared in Examples 1-5 is shown in Table 2 below.

[0123] Table 2 Use times of prefabricated molds and primary molds in different embodiments

[0124]

[0125] Note: When the brightness of the ultra-thin light guide film backlight source made from the copied dot mold or microstructure mold is lower than 100% or the brightness uniformity is lower than 95%, replace the prefabricated mold and the primary mold.

[0126] Combining Example 1 and Example 2 and the data in Table 2, it can be seen that when a cleaning agent made from anhydrous sodium carbonate, nano-silicon dioxide and deionized water is used to clean a prefabricated mold or a preliminary mold, a release agent needs to be used to treat the prefabricated mold or the preliminary mold, otherwise the number of uses of the prefabricated mold and the preliminary mold will be greatly reduced.

[0127] Combining Example 1 with Examples 3-5 and the data in Table 2, it can be seen that when the cleaning agent prepared by using nano-silica modified with vinyl acetate, sodium acrylate, acrylate, etc., anhydrous sodium carbonate, and deionized water to clean the prefabricated mold or the preliminary mold, there is no need to use an additional release agent to treat the prefabricated mold or the preliminary mold, that is, the dot mold and the microstructure mold can be smoothly demolded, effectively extending the service life of the prefabricated mold or the preliminary mold.

[0128] (3) The optical data of the backlight source containing the light guide film in Examples 1-5 are shown in Table 3 below.

[0129] Table 3 Optical performance data of backlight sources containing light guide films in different embodiments

[0130]

[0131] Combining Example 1 and Example 2 and the data in Table 3, it can be seen that when a cleaning agent made from anhydrous sodium carbonate, nano-silicon dioxide and deionized water is used to clean the prefabricated mold or the primary mold, a release agent needs to be used to treat the prefabricated mold or the primary mold. Otherwise, the dot mold is difficult to separate from the prefabricated mold and the microstructure mold is difficult to separate from the primary mold, which can easily cause the dot mold and the microstructure mold copied from the prefabricated mold or the primary mold to have a decreased dimensional accuracy, thereby resulting in a decrease in the light-guiding performance and light-guiding uniformity of the light-guiding film, and a decrease in the brightness and brightness uniformity of the backlight source.

[0132] Combining Example 1 with Examples 3-5 and the data in Table 3, it can be seen that when a cleaning agent made from nano-silicon oxide modified with vinyl acetate, sodium acrylate, acrylate, etc., anhydrous sodium carbonate, and deionized water is used to clean the prefabricated mold or the primary mold, there is no need to use an additional release agent to treat the prefabricated mold or the primary mold, that is, an ultra-thin light-guiding film with good light-guiding effect and light-guiding uniformity can be obtained, which not only meets the use requirements of thin products, but also the backlight source containing the ultra-thin light-guiding film has a brightness of more than 120% and a brightness uniformity of more than 95%, and its optical performance is comparable to that of OLED products.

Claims

1. A process for producing a high-brightness, high-uniformity, special-shaped light-guiding film, characterized by: The following steps are involved: Producing a special-shaped light-guiding film substrate with a special-shaped step surface formed on the surface; A prefabricated mold is formed by laser dotting on a steel mold to produce a plurality of dots having a central arc protrusion and a peripheral groove. The prefabricated mold is then recast using an electroforming process to obtain a dot mold for forming the dot structure on the bottom surface of the light guide film. The outer diameter r of the arc protrusion of the dot mold is 15-25µm, and the outer diameter R of the groove of the dot mold is 8µm-15µm. A plurality of V-shaped grooves are cut into the steel mold using an NC tool to obtain a primary mold. The primary mold is then recast using an electroforming process to obtain a microstructure mold for forming the light-emitting surface microstructure of the light-guiding film. The microstructure mold has triangular protrusions with a height of 1-3µm and a width of 8.5-10.5µm. The dot structure is formed on the bottom surface of the special-shaped light-guiding film substrate by hot pressing equipment, and the sawtooth microstructure is formed on the light-emitting surface of the special-shaped light-guiding film substrate: Die-cutting a special-shaped light-guiding film substrate having a dot structure formed on the bottom surface and a sawtooth microstructure formed on the light-emitting surface to obtain a light-guiding film sheet; Polishing the four sides of the light guide film sheet; A sawtooth microstructure is formed on the light incident surface of the polished light guide film sheet to obtain a light guide film; the sawtooth microstructure on the light incident surface of the light guide film has a depth of 1-3 μm and a width of 14-16 μm; The electroforming process in the process of manufacturing the dot mold or microstructure mold is carried out in the following steps: Surface cleaning: ultrasonically clean the prefabricated mold or the preliminary mold with a detergent, and then ultrasonically clean the prefabricated mold or the preliminary mold with deionized water. After cleaning, blow dry with an ion air gun to obtain a prefabricated mold or the preliminary mold with a cleaned surface; Electroforming recasting: Place the prefabricated mold or primary mold after surface cleaning into the electroforming tank, which is filled with electrolytic solution and nickel material with a purity of more than 99.9%. The electroforming temperature is controlled at 30-60℃ and the current density is controlled at 1-30A / dm 2 , recasting through 8H electroforming process, and then separating the electroformed layer from the prefabricated mold or the primary mold to obtain a dot mold or a microstructure mold; The cleaning agent used in the surface cleaning step includes the following raw materials in parts by weight: Anhydrous sodium carbonate: 6-10 parts Modified nano-silicon oxide: 4-8 parts Deionized water: 100 parts; The preparation method of the modified nano-silicon oxide comprises the following steps: Add 4-6 parts by weight of nano-silicon oxide and 1-3 parts by weight of silane coupling agent to 100 parts by weight of ethanol solution, stir for 20-30 minutes, then add 0.5-1 parts by weight of OP-10 and 2-5 parts by weight of polyethylene glycol, and disperse uniformly by ultrasonication to obtain a dispersion; 10-15 parts by weight of vinyl acetate, 1-2 parts by weight of sodium acrylate, and 3-6 parts by weight of acrylate are added to the dispersion, stirred evenly, and nitrogen is introduced to deoxygenate. Then, 4-6 parts by weight of a saturated aqueous solution of potassium persulfate are added dropwise while stirring. After the addition is complete, the mixture is heated under reflux at 70-80° C. for 4-5 hours. After the reaction is completed, the mixture is cooled to room temperature, demulsified, filtered, washed, and dried to obtain modified nano-silica.

2. The process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to claim 1, characterized in that: The electrolytic solution comprises the following raw materials in percentage by weight: Nickel sulfamate: 30-45% Nickel chloride: 0.5-2.5% Boric acid: 3-4.5% Deionized water: balance.

3. The process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to claim 1, characterized in that: The particle size of the modified nano-silicon oxide is 30-40 nm.

4. The process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to claim 1, characterized in that: The dropping speed of the saturated aqueous solution of potassium persulfate is 0.4-0.5 g / min.

5. The process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to claim 1, characterized in that: The polyethylene glycol is selected from any one of polyethylene glycol 200 and polyethylene glycol 400 or a combination of the two.

6. The process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to claim 1, characterized in that: The special-shaped light-guiding film substrate is selected from any one of a PC substrate and a PMMA substrate.

7. A light-guiding film produced by the process for producing a high-brightness, high-uniformity, special-shaped light-guiding film according to any one of claims 1 to 6.

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