Light guide plate and manufacturing method thereof

Abstract

The invention relates to the technical field of light guide plates, in particular to a light guide plate and a manufacturing method thereof. The light guide plate provided by the invention comprises a light guide plate substrate, the upper edge of the light guide plate substrate is coated with a light-proof material, the light-proof material is a light-proof coating, and the thickness of the light-proof coating is gradually reduced from the outer side to the inner side; the light guide plate substrate comprises a polycarbonate composite material, and the polycarbonate composite material comprises PC and modified titanium dioxide. The polycarbonate composite material is used as the light guide plate substrate, and the lightproof material is arranged at the edge of the light guide plate, so that the light transmission efficiency can be effectively improved, the reflection and refraction loss of light at an interface can be reduced, the light leakage problem can be reduced, and the stability of the light guide plate can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of light guide plates, and specifically to a light guide plate and a manufacturing method thereof. Background Art

[0002] Light guide plates play an important role in many fields such as the liquid crystal display field, lighting, automotive lighting, medical device displays, and smart home displays. Common light guide plate materials include traditional polycarbonate (PC), acrylic (PMMA), etc., as well as new nanomaterials, graphene, etc., to improve the performance of light guide plates. With the popularization of electronic devices and the development of display technologies, the global light guide plate market size has been showing a continuous growth trend. Asia is the main production and consumption region, and countries such as China, South Korea, and Japan occupy an important position in the production and application of light guide plates. However, existing light guide plates still have some disadvantages: 1. In terms of optical performance: Despite continuous technological progress, when light propagates in the light guide plate, certain light losses will still occur due to reflection, refraction, scattering, etc., resulting in a decrease in the intensity of the finally emitted light and affecting the brightness of the display or lighting; 2. Limitation of uniformity: In some large-sized light guide plates or light guide plates with special shapes, it is difficult to achieve a completely uniform light distribution, and there may be phenomena such as bright edges and dark centers, or local brightness differences; 3. Easy aging of materials: Commonly used materials such as PC and PMMA are prone to becoming brittle and deformed under the influence of environmental factors such as light, temperature, and humidity during long-term use, thereby reducing the optical and mechanical properties of the light guide plate. Summary of the Invention

[0003] The purpose of the present invention is to provide a light guide plate and a manufacturing method thereof to solve the problems raised in the above background art. The present invention manufactures a light guide plate substrate by using a specific light guide plate material with high light transmittance, high uniformity, and high stability, and by setting a light leakage prevention adhesive film at the edge of the light guide plate. Finally, the manufactured light guide plate has good optical performance, mechanical properties, and stability.

[0004] In a first aspect, the present invention provides a light guide plate, including a light guide plate substrate, wherein an opaque material is coated on the upper edge of the light guide plate substrate, and the opaque material is an opaque coating; the thickness of the opaque material decreases from the outside to the inside; the light guide plate substrate includes a polycarbonate composite material, and the polycarbonate composite material includes PC and modified titanium dioxide.

[0005] Further, the opaque coating includes epoxy resin, silane coupling agent, modified carbon black, curing agent, and nano-level auxiliary filler.

[0006] Furthermore, the light-proof coating comprises 45-60 parts of epoxy resin, 1-2 parts of silane coupling agent, 5-12 parts of modified carbon black, 5-8 parts of curing agent, and 1-3 parts of nano-scale auxiliary filler.

[0007] Furthermore, the nanometer-scale auxiliary filler is selected from at least one of nanometer silicon dioxide and nanometer titanium dioxide; the nanometer-scale size of these nanoparticles can be beneficial to fill the tiny bumps and grooves on the coating surface caused by adding large particles such as modified carbon black, making the surface smoother, and the special optical properties of the nanometer-scale auxiliary filler can also reduce light reflection, which can better prevent the reflected light from interfering with the normal light output direction and affecting the light guiding effect; Furthermore, the size of the nano-scale auxiliary fillers is below 200 nm, which can better fill gaps and improve surface smoothness.

[0008] Furthermore, the thickness of the opaque coating can be adjusted according to actual needs; Preferably, the outermost thickness of the opaque coating is 0.1-0.3 mm.

[0009] Furthermore, the curing agent is a conventional curing agent capable of curing epoxy resin, which is not limited here.

[0010] Furthermore, the mass ratio of PC to modified titanium dioxide in the polycarbonate composite material is 62-85:12-28.

[0011] Furthermore, the polycarbonate composite material further includes an auxiliary agent with a mass percentage of no more than 8%, wherein the auxiliary agent is at least one of a toughening agent, a flame retardant, and a lubricant; the auxiliary agent may be added or not added according to actual application scenarios and functional requirements.

[0012] Furthermore, the auxiliary agent does not include an antioxidant; the polycarbonate composite material of the present invention contains phenyl, has good antioxidant properties, and does not need to be additionally added with antioxidants. The additional addition of antioxidants may also cause uneven mixing and affect the uniformity of the light guide plate.

[0013] Furthermore, the toughening agent may be at least one of maleic anhydride and methyl methacrylate double-grafted ethylene elastomer, EVA, MBS or a silicone-based toughening agent.

[0014] Furthermore, the silane coupling agent includes vinyl triethoxysilane, aminopropyl trimethoxysilane, vinyl trichlorosilane; other silane coupling agents may also be selected. The function of the silane coupling agent is to increase cross-linking, improve the adhesion of the opaque material to the light guide plate, and improve the overall stability of the light guide plate.

[0015] In a second aspect, the present invention provides a method for manufacturing a light guide plate, comprising: (1) Weigh PC, toughening agent, modified titanium dioxide, flame retardant and lubricant and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into sheets at 220-260° C., and cooling and characterizing the sheets to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material is controlled to decrease from the outside to the inside, and the light guide plate is obtained after curing.

[0016] Furthermore, the modified titanium dioxide in step (1) is obtained by reacting titanium sol, aromatic alcohol substances and silk fibroin.

[0017] Furthermore, the aromatic alcohol substance is benzyl alcohol (C 6 H 5 CH 2 OH), m-methoxybenzyl alcohol (CH 3 C 6 H 4 CH 2 OH), p-methylbenzyl alcohol (CH 3 C 6 H 4 CH 2 OH).

[0018] Furthermore, the preparation method of the modified titanium dioxide in step (1) comprises: Step 1, add silk fibroin to titanium sol and mix evenly, then let stand for 10-20 minutes; Step 2, adding aromatic alcohols to the mixed solution obtained in step 1, heating to 60-80° C. for reaction, and then standing for 16-48 hours to obtain modified titanium oxide gel; Step 3: crushing the modified titanium oxide gel, and then drying it under normal pressure to obtain the modified titanium dioxide.

[0019] Using silk fibroin and aromatic alcohols to modify titanium oxide in situ at the same time, the active groups on silk fibroin, such as amino, carboxyl or hydroxyl groups, condense with the hydroxyl groups on titanium sol, and the hydroxyl groups on aromatic alcohols condense with the hydroxyl groups on titanium sol, thereby connecting silk fibroin and aromatic alcohols to titanium oxide, which has many advantages: (1) Modified titanium dioxide can effectively improve the light scattering and refraction properties of the light guide plate, making the light propagating and scattering more evenly in the light guide plate, improving the light uniformity and brightness of the light guide plate, and thus improving the overall optical quality of the light guide plate. In addition, silk fibroin itself has certain optical properties and can regulate the propagation and scattering of light to a certain extent. The synergistic effect with titanium dioxide and other materials can help further optimize the optical properties of the light guide plate and make the light propagation more even. (2) Silk fibroin has good flexibility and mechanical properties, which can enhance the toughness of the light guide plate material to a certain extent, reduce the possibility of material breakage during processing and use, and improve the impact resistance of the material; the use of titanium sol can form a polymer network, and the silk fibroin and aromatic alcohol substances can be modified to form an organic-inorganic hybrid structure in the polymer network. The modified titanium dioxide can also improve the mechanical properties of the material such as hardness and wear resistance, making the light guide plate more durable; (3) After titanium dioxide modified with silk fibroin and aromatic alcohols is combined with PC, the thermal stability and chemical stability of the light guide plate material can be improved; the addition of silk fibroin modification may bring about material stability problems due to the relatively poor antioxidant properties of silk fibroin, while the phenyl group in aromatic alcohols can better resist the influence of environmental factors such as ultraviolet rays and oxidation, and can enhance the material's antioxidant, weather resistance and chemical corrosion resistance, which can effectively solve the adverse effects of adding silk fibroin and keep the performance of the light guide plate stable under different environmental conditions; (4) Silk fibroin is a natural polymer material with good biocompatibility and degradability, which makes the prepared light guide plate material more in line with environmental protection requirements. After being discarded, it can be relatively easily degraded by the environment, reducing pollution to the environment.

[0020] Furthermore, the mass ratio of the titanium sol, silk fibroin and aromatic alcohol substances added in step 1 is 8-12:3:1; Furthermore, the PC in step (1) is polycarbonate.

[0021] Furthermore, the pressure of the hot pressing in step (2) is not limited. The pressure and temperature affect the thickness of the polycarbonate composite material. The thickness and size requirements of the light guide plate may be different in different application scenarios, but the temperature will also affect other properties of the light guide plate material. Therefore, the pressure of the hot pressing can be adjusted according to the actual thickness requirements when the temperature is constant.

[0022] Furthermore, the preparation method of the opaque material in step (3) is: The epoxy resin, silane coupling agent, modified carbon black, curing agent and nanometer-level auxiliary filler are mixed evenly to obtain the product.

[0023] Furthermore, the modified carbon black is silk fibroin modified carbon black, and the preparation method includes: The carbon black is added into N,N-dimethylformamide (DMF) or water solvent and dispersed evenly to obtain a carbon black suspension; the silk fibroin is then dissolved in the same solvent to prepare a 5-14wt% silk fibroin solution; the silk fibroin solution is then slowly added into the carbon black suspension and ultrasonic treatment is continued; finally, the modified carbon black is obtained through solid-liquid separation, washing and drying.

[0024] Silk fibroin modified carbon black can make carbon black have better dispersion in opaque materials, improve the uneven mixing and increase the uniformity of opaque materials; in addition, silk fibroin has good film-forming properties and can have good film-forming properties without adding film-forming aids; finally, silk fibroin modification can improve the fit between opaque materials and carbonate composite materials, and under the condition that the opaque materials have good adhesion, the bonding strength between the opaque materials and the light guide plate substrate is higher.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a specific polycarbonate composite material as a light guide plate substrate material. Since the polycarbonate composite material has good transparency, it can effectively improve the light transmission efficiency and reduce the reflection and refraction loss of light at the interface; since the polycarbonate composite material contains a polymer network, an organic-inorganic hybrid structure is formed in the polymer network, which effectively enhances the toughness of the light guide plate, making it difficult to break and damage, and improving the mechanical properties of the light guide plate; since the polycarbonate composite material has good water resistance, it can make the light guide plate difficult to absorb water and swell or undergo hydrolysis in a humid environment, so that the stability of its optical and mechanical properties can be better maintained, and it also has good resistance to acid and alkali; since the various components in the polycarbonate composite material have good compatibility, its uniformity and consistency are high, and it can better achieve completely uniform light distribution, solving the problem of bright edges and dark in the middle, or local light and dark differences that often occur; 2. The present invention uses a specific polycarbonate composite material as the light guide plate, and sets an opaque material on the edge of the light guide plate. Since the opaque material has excellent opacity and excellent adhesion to the light guide plate substrate, it can not only reduce the serious energy loss of light during the propagation process, block the propagation of light, and effectively solve the problem of light leakage at the bright edge, but also increase the stability of the material and improve the service life of the material. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The PC used in the examples and comparative examples has a melt index of 10-40 g / 10 min at 300° C. and 1.2 kg, and the size of the added nano-scale auxiliary filler is less than 200 nm.

[0028] Example 1 1. Preparation of modified titanium dioxide: Step 1: Take titanium sol, silk fibroin and CH 3 OC 6 H 4 CH 2 OH, first add the above silk fibroin into the titanium sol and mix evenly, then let it stand for 15 minutes; Step 2: Add CH 3 OC 6 H 4 CH 2 OH, heated to 70 °C for 6 h, and then allowed to stand for 24 h to obtain modified titanium oxide gel; Step 3: crush the modified titanium oxide gel to less than 2 μm, and then dry it at 60° C. and normal pressure for 24 hours to obtain the modified titanium dioxide.

[0029] 2. Manufacturing of light guide plate: (1) Weigh 70 parts of PC and 20 parts of modified titanium dioxide and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into a sheet at 240° C., and cooling and characterizing the sheet at room temperature to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material is controlled to decrease from the outer side to the inner side, and the outermost thickness is 0.2 mm and the innermost thickness is 0.1 mm. After curing, the light guide plate is obtained; Wherein, the preparation method of the light-proof material is: The carbon black is added into N,N-dimethylformamide (DMF) and dispersed uniformly to obtain a 35wt% carbon black suspension; the silk fibroin is then dispersed in a DMF solvent to prepare a 12wt% silk fibroin solution, and then the silk fibroin solution is slowly added into the carbon black suspension at a volume ratio of 1:1, and the ultrasonic treatment is continued for 20 minutes; finally, the modified carbon black is obtained by solid-liquid separation, deionized water washing, and complete drying at 60°C; Then, 50 parts of epoxy resin, 1 part of KH560, 9 parts of modified carbon black, 6 parts of triethylenetetramine, 2 parts of nano-silicon dioxide and 20 parts of water are mixed evenly to obtain the light-proof material.

[0030] Example 2 1. Preparation of modified titanium dioxide: Step 1: titanium sol, silk fibroin and benzyl alcohol are added in a mass ratio of 9:3:1, and silk fibroin is added to the titanium sol to mix evenly, and then allowed to stand for 12 minutes; Step 2, adding benzyl alcohol to the mixed solution obtained in step 1, heating to 60° C. for reaction for 8 hours, and then standing for 48 hours to obtain a modified titanium oxide gel; Step 3: crush the modified titanium dioxide gel to less than 2 μm, and then dry it at 60° C. and normal pressure for 24 hours to obtain the modified titanium dioxide.

[0031] 2. Manufacturing of light guide plate: (1) Weigh 80 parts of PC, 2 parts of maleic anhydride, and 20 parts of modified titanium dioxide and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into a sheet at 220° C., and cooling and characterizing the sheet at room temperature to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material decreases from the outer side to the inner side, the outermost thickness is 0.3 mm, and the innermost thickness is 0.2 mm, and the light guide plate is obtained after curing; Wherein, the preparation method of the light-proof material is: The carbon black is added to N,N-dimethylformamide (DMF) or water solvent and dispersed uniformly to obtain a 30wt% carbon black suspension; the silk fibroin is then dissolved in the same solvent to prepare a 14wt% silk fibroin solution, and then the silk fibroin solution is slowly added to the carbon black suspension at a volume ratio of 1:1, and ultrasonic treatment is continued; finally, the modified carbon black is obtained by solid-liquid separation, deionized water washing, and complete drying at 60°C; Then, 45 parts of epoxy resin, 1 part of KH570, 12 parts of modified carbon black, 5 parts of triethylenetetramine, 1 part of nano silicon oxide and 20 parts of water are mixed evenly to obtain the light-proof material.

[0032] Example 3 1. Preparation of modified titanium dioxide: Step 1: Take titanium sol, silk fibroin and CH 3 OC 6 H 4 CH 2 OH, add silk fibroin to titanium sol and mix well, then let it stand for 20 min; Step 2: Add CH 3 OC 6 H 4 CH 2 OH, heated to 80 °C for 4 h, and then allowed to stand for 16 h to obtain modified titanium oxide gel; Step 3: crush the modified titanium oxide gel to less than 2 μm, and then dry it at 60° C. and normal pressure for 24 hours to obtain the modified titanium dioxide.

[0033] 2. Manufacturing of light guide plate: (1) Weigh 65 parts of PC, 2 parts of EVA, 28 parts of modified titanium dioxide, and 1 part of phosphate ester and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into a sheet at 250° C., and cooling and characterizing the sheet at room temperature to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material decreases from the outside to the inside, and the thickness of the outermost side is controlled to be 0.3 mm and the thickness of the innermost side is controlled to be 0.1 mm, and the light guide plate is obtained after curing; Wherein, the preparation method of the light-proof material is: The carbon black is added to the water solvent and dispersed evenly to obtain a 40wt% carbon black suspension; the silk fibroin is then dissolved in the water solvent at a volume ratio of 1:1 to prepare a 10wt% silk fibroin solution, and the silk fibroin solution is slowly added to the carbon black suspension, and ultrasonic treatment is continued; finally, the modified carbon black is obtained by solid-liquid separation, deionized water washing, and complete drying at 60°C; Then, 60 parts of epoxy resin, 2 parts of KH560, 7 parts of modified carbon black, 8 parts of triethylenetetramine, 3 parts of nano silicon oxide and 20 parts of water are mixed evenly to obtain the light-proof material.

[0034] Comparative Example 1 Light guide plate manufacturing: (1) Weigh 70 parts of PC and 20 parts of titanium dioxide and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into a sheet at 240° C., and cooling and characterizing the sheet at room temperature to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material decreases from the outside to the inside, and the thickness of the outermost side is controlled to be 0.2 mm and the thickness of the innermost side is controlled to be 0.1 mm, and the light guide plate is obtained after curing; Wherein, the preparation method of the light-proof material is: The carbon black is added into N,N-dimethylformamide (DMF) and dispersed uniformly to obtain a 35wt% carbon black suspension; the silk fibroin is then dispersed in a DMF solvent to prepare a 12wt% silk fibroin solution, and then the silk fibroin solution is slowly added into the carbon black suspension at a volume ratio of 1:1, and the ultrasonic treatment is continued for 20 minutes; finally, the modified carbon black is obtained by solid-liquid separation, deionized water washing, and complete drying at 60°C; Then, 50 parts of epoxy resin, 1 part of KH560, 9 parts of modified carbon black, 6 parts of triethylenetetramine, 2 parts of nano silicon oxide and 20 parts of water are mixed evenly to obtain the light-proof material.

[0035] Comparative Example 2 1. Preparation of modified titanium dioxide: The preparation process is the same as that in Example 1.

[0036] 2. Manufacturing of light guide plate: (1) Weigh 70 parts of PC and 20 parts of modified titanium dioxide and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into a sheet at 240° C., and cooling and characterizing the sheet at room temperature to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof material decreases from the outside to the inside, and the thickness of the outermost side is controlled to be 0.2 mm and the thickness of the innermost side is controlled to be 0.1 mm, and the light guide plate is obtained after curing; Wherein, the preparation method of the light-proof material is: Take 50 parts of epoxy resin, 1 part of KH560, 9 parts of carbon black, 6 parts of triethylenetetramine, 2 parts of nano silicon oxide and 20 parts of water and mix them evenly to obtain the opaque material.

[0037] Comparative Example 3 1. Preparation of modified titanium dioxide: Step 1, respectively taking titanium sol and silk fibroin in a mass ratio of 10:3, mixing them evenly, and then letting them stand for 15 minutes; Step 2, heating the mixed solution obtained in step 1 to 70° C. for 6 hours, and then standing for 24 hours to obtain a modified titanium oxide gel; Step 3: crush the modified titanium dioxide gel to less than 2 μm, and then dry it at 60° C. and normal pressure for 24 hours to obtain the modified titanium dioxide.

[0038] 2. Manufacturing of light guide plate: The preparation process is the same as that in Example 1.

[0039] Comparative Example 4 1. Preparation of modified titanium dioxide: Step 1: Take titanium sol and CH 3 OC 6 H 4 CH 2 OH mixed evenly and then allowed to stand for 15 min; Step 2, heating the mixed solution obtained in step 1 to 70° C. for 6 hours, and then standing for 24 hours to obtain a modified titanium oxide gel; Step 3: crush the modified titanium dioxide gel to less than 2 μm, and then dry it at 60° C. and normal pressure for 24 hours to obtain the modified titanium dioxide.

[0040] 2. Manufacturing of light guide plate: The preparation process is the same as that in Example 1.

[0041] Performance Testing The light guide plates in the embodiments and comparative examples were tested, and the results are shown in Table 1. Impact strength is tested according to ASTM D-256 standard; The heat deformation temperature is tested according to ASTM D648 standard, and the testing equipment is a computerized heat deformation temperature testing machine; The light reflectivity was tested using the Solar cell scan100 equipment, a solar cell QE / IPCE measurement system; Aging test, using high and low temperature alternating humidity test chamber and colorimeter to test the color difference of the sample after 48 hours of testing.

[0042] Table 1 It can be seen from the above results that the light guide plate prepared by the method of the present invention has high refractive index, uniformity and stability, and has good application prospects; Comparative Example 1 uses titanium dioxide instead of modified titanium dioxide, but due to the difficulty in mixing and poor light transmittance, the refractive index and uniformity of the light guide plate are affected, and the unevenness further affects the stability; Comparative Example 2 carbon black has not been modified, and there is a problem of difficulty in mixing with organic systems such as epoxy resin, resulting in poor light transmittance, and then causing a large color difference in the light guide plate; Comparative Example 3 does not add aromatic alcohol substances, and cannot improve the temperature resistance of the light guide plate material. The added silk fibroin has relatively poor stability, and the improvement of the light transmittance of the light guide plate is limited, resulting in a significant decrease in stability and refractive index; Comparative Example 4 does not add silk fibroin for modification, and cannot improve the light transmittance of the light guide plate, resulting in a relatively poor refractive index.

Claims

1. A light guide plate, comprising a light guide plate substrate, wherein the upper edge of the light guide plate substrate is coated with an opaque material, and the thickness of the opaque material decreases from the outer side to the inner side, characterized in that: The light-proof material is a light-proof coating; the light guide plate substrate comprises a polycarbonate composite material, and the polycarbonate composite material comprises PC and modified titanium dioxide.

2. The light guide plate according to claim 1, characterized in that: The light-proof coating comprises epoxy resin, silane coupling agent, modified carbon black, curing agent and nanometer-level auxiliary filler.

3. The light guide plate according to claim 2, characterized in that: The nano-scale auxiliary filler is selected from at least one of nano-silicon dioxide and nano-titanium dioxide, the particle size of the nano-scale auxiliary filler is below 200nm, and the nano-scale auxiliary filler is selected from at least one of nano-silicon dioxide and nano-titanium dioxide.

4. The light guide plate according to claim 1, characterized in that: The thickness of the outermost side of the opaque coating is 0.1-0.3 mm.

5. The light guide plate according to claim 1, characterized in that: The polycarbonate composite material further comprises an auxiliary agent, and the auxiliary agent does not include an antioxidant.

6. The light guide plate according to claim 5, characterized in that: The auxiliary agent is at least one of a toughening agent, a flame retardant and a lubricant.

7. The light guide plate according to claim 2, characterized in that: The silane coupling agent includes but is not limited to at least one of vinyl triethoxy silane, aminopropyl trimethoxy silane and vinyl trichloro silane.

8. A method for manufacturing a light guide plate according to any one of claims 1 to 7, characterized in that: include: (1) Weigh PC, toughening agent, modified titanium dioxide, flame retardant and lubricant and mix them evenly to obtain a mixture; (2) hot pressing the obtained mixture into sheets at 220-260° C., and cooling and characterizing the sheets to obtain a polycarbonate composite material; (3) Then, a light-proof material is coated on the upper edge of the polycarbonate composite material, and the thickness of the light-proof coating decreases from the outside to the inside, and the light guide plate is obtained after curing.

9. The method for manufacturing a light guide plate according to claim 8, characterized in that: The method for preparing the modified titanium dioxide described in step (1) comprises: Step 1, add silk fibroin to titanium sol and mix evenly, then let stand for 10-20 minutes; Step 2, adding aromatic alcohols to the mixed solution obtained in step 1, heating to 60-80° C. for reaction, and then standing for 16-48 hours to obtain modified titanium oxide gel; Step 3: crushing the modified titanium oxide gel, and then drying it under normal pressure to obtain the modified titanium dioxide.

10. The method for manufacturing a light guide plate according to claim 9, characterized in that: The aromatic alcohol substance is at least one of benzyl alcohol, m-methoxybenzyl alcohol and p-methylbenzyl alcohol.

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