Light guide plate and preparation process thereof
A light guide plate with a cross-linked network structure was prepared by polymerizing p-hydroxystyrene, methyl methacrylate and polyene benzoxazine, which solved the problem of insufficient performance of PMMA light guide plates under impact and high temperature, and achieved better heat resistance and mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHONGQING EFAN THINREX PHOTOELECTRIC TECH CO LTD
- Filing Date
- 2026-02-11
- Publication Date
- 2026-05-12
AI Technical Summary
Existing PMMA light guide plates are not performing well under external impact and high temperature conditions, and are prone to cracking, breaking and having poor heat resistance.
A light guide plate was prepared by using p-hydroxystyrene, methyl methacrylate and polyene benzoxazine as raw materials through manniene reaction and polymerization reaction. The cross-linking network of the benzoxazine structure was used to improve the heat resistance and mechanical properties of the material.
The prepared light guide plate remains stable at high temperatures, exhibits excellent impact resistance, and extends its service life.
Smart Images
Figure SMS_4
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to a light guide plate and its preparation process. Background Technology
[0002] A light guide plate is an optical component widely used in backlighting and uniform illumination. Its core function is to convert point or line light sources into uniform, soft, and efficient surface light sources. It is widely used in LCD backlighting and other lighting applications. Polymethyl methacrylate (PMMA) is one of the most widely used materials for light guide plates; however, its application in light guide plates has the following drawbacks: high brittleness and poor impact resistance, making it prone to cracking and breakage with silver streaks when subjected to external impacts; and poor heat resistance, where localized temperatures in poorly heated equipment may exceed PMMA's tolerance limits, leading to material deformation and affecting the overall performance of the light guide plate. Summary of the Invention
[0003] The purpose of this invention is to provide a light guide plate and its preparation process. Using p-hydroxystyrene, methyl methacrylate, etc. as raw materials, a light guide plate is prepared through a manniene reaction and a polymerization reaction. By utilizing the alkenyl group and benzoxazine structure contained in polyene benzoxazine, the mechanical properties and heat resistance of the light guide plate are improved, thus overcoming the problem of poor heat resistance and mechanical properties of the current PMMA light guide plate.
[0004] It should be noted that the light guide plate in this invention is actually a blank for a light guide plate (referred to as a light guide plate). This blank needs to undergo fine processing (such as screen printing, laser engraving, grid engraving, UV screen printing) before a light guide plate product that can be directly applied to electronic products can be obtained.
[0005] The objective of this invention can be achieved through the following technical solutions: A light guide plate, which is mainly prepared by polymerization of methyl methacrylate, styrene, and polyene benzoxazine; The preparation process includes the following steps: Step 1: Using p-hydroxystyrene, alkylamine, and formaldehyde as raw materials, polyene benzoxazine is obtained through the Manniene reaction; Step 2: Using methyl methacrylate, styrene, and polyene benzoxazine as raw materials, the mixture undergoes a polymerization reaction, is heated to melt, injected into a mold, and cooled to form a light guide plate.
[0006] Furthermore, the specific preparation method of the polyene benzoxazine includes the following steps: Alkylamine and formaldehyde were added to a solvent and dispersed by stirring at room temperature. Then, p-hydroxystyrene was added and the mixture was refluxed for 5-8 hours. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure, and purified to obtain polyene benzoxazine.
[0007] Furthermore, the molar ratio of the alkylamine, formaldehyde, and p-hydroxystyrene is 1:4-6:2-3.
[0008] Furthermore, the solvent is one of chloroform, dioxane, and toluene.
[0009] Further, the alkylamine is one or more of ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octanediamine.
[0010] Furthermore, the alkylamine also includes tris(2-aminoethyl)amine.
[0011] Furthermore, the specific preparation method of the light guide plate includes the following steps: Methyl methacrylate, styrene, and polyene benzoxazine are added to deionized water, and the temperature is controlled at 70-80℃. The mixture is stirred and dispersed for 40-60 minutes. Then, potassium persulfate aqueous solution is added, and the reaction is carried out for 10-14 hours. After the reaction is completed, the mixture is filtered, dissolved in tetrahydrofuran, precipitated in deionized water, dried, heated and melted, injected into a mold, and cooled to form a light guide plate.
[0012] Furthermore, the mass fraction of the potassium persulfate aqueous solution is 1%.
[0013] Furthermore, the molar ratio of methyl methacrylate, styrene, and polyene benzoxazine is 1:0.1-0.3:0.05-0.1.
[0014] The beneficial effects of this invention are: This application uses p-hydroxystyrene, alkylamine, and formaldehyde as raw materials. Through the Manniene reaction, polyene-based benzoxazine is obtained, which is then polymerized with methyl methacrylate and styrene, heated to melt, and injection molded to obtain a light guide plate. The light guide plate prepared by this invention contains a heat-resistant rigid structure—a benzene ring structure—and a benzoxazine structure. When heated, the benzoxazine structure can undergo ring-opening crosslinking to form a dense three-dimensional network structure. This high crosslinking density not only restricts the movement of molecular chain segments during heating, further improving the heat resistance of the substrate, but also enhances the mechanical properties of the substrate. Specifically, when the heated substrate is subjected to external force, the external impact force can be dispersed along the larger three-dimensional network structure, thereby improving the mechanical properties of the substrate.
[0015] Furthermore, the polyene benzoxazine prepared by this invention contains dienyl and trienyl structures, which can copolymerize with methyl methacrylate under the action of an initiator, generating more crosslinking sites. When subjected to impact, the impact force can be dispersed along the crosslinking sites into other molecular chains, thereby achieving the effect of dispersing the impact force and improving the mechanical properties of the substrate. Detailed Implementation
[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments in the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. The raw materials used in this application are all commercially available products. Example 1
[0017] (1) 0.5 mol of 1,6-hexanediamine and 2 mol of formaldehyde were added to chloroform and stirred at room temperature to disperse them. Then, 1 mol of p-hydroxystyrene was added, and the mixture was refluxed for 5 h. After the reaction was completed, the mixture was cooled to room temperature, extracted and dried, concentrated under reduced pressure, and purified to obtain polyene benzoxazine A. The reaction formula is as follows: ; (2) Add 2 mol of methyl methacrylate, 0.2 mol of styrene and 0.1 mol of polyene benzoxazine A to deionized water, control the temperature at 75°C, stir and disperse for 60 min, then add 1% potassium persulfate aqueous solution, react for 12 h, filter, dissolve tetrahydrofuran, precipitate in deionized water, dry, heat to melt, inject into mold, cool and form to obtain light guide plate. Example 2
[0018] (1) 0.5 mol of tris(2-aminoethyl)amine and 3 mol of formaldehyde were added to chloroform and stirred at room temperature to disperse them. Then, 1.5 mol of p-hydroxystyrene was added and the mixture was refluxed for 7 h. After the reaction was completed, the mixture was cooled to room temperature, extracted and dried, concentrated under reduced pressure, and purified to obtain polyene benzoxazine B. The reaction formula is as follows: ; (2) Add 2 mol of methyl methacrylate, 0.2 mol of styrene and 0.1 mol of polyene benzoxazine B to deionized water, control the temperature at 80℃, stir and disperse for 40 min, then add 1% potassium persulfate aqueous solution, react for 12 h, filter, dissolve tetrahydrofuran, precipitate in deionized water, dry, heat to melt, inject into mold, cool and form to obtain light guide plate. Example 3
[0019] The difference between this embodiment and Embodiment 2 is as follows: 2 mol of methyl methacrylate, 0.5 mol of styrene, and 0.15 mol of polyene benzoxazine B (the preparation method of polyene benzoxazine B is the same as in Example 2) were added to deionized water. The temperature was controlled at 70°C, and the mixture was stirred and dispersed for 60 min. Then, a 1% potassium persulfate aqueous solution was added, and the reaction was carried out for 14 h. After the reaction was completed, the mixture was filtered, dissolved in tetrahydrofuran, precipitated in deionized water, dried, heated and melted, injected into a mold, and cooled to form a light guide plate. Example 4
[0020] The difference between this embodiment and Embodiment 2 is as follows: 2 mol of methyl methacrylate, 0.6 mol of styrene, and 0.2 mol of polyene benzoxazine B (the preparation method of polyene benzoxazine B is the same as in Example 2) were added to deionized water. The temperature was controlled at 75°C, and the mixture was stirred and dispersed for 50 min. Then, a 1% potassium persulfate aqueous solution was added, and the reaction was carried out for 10 h. After the reaction was completed, the mixture was filtered, dissolved in tetrahydrofuran, precipitated in deionized water, dried, heated and melted, injected into a mold, and cooled to form a light guide plate.
[0021] Comparative Example 1 The difference between this comparative example and Example 2 is that step (2) does not contain styrene, while the remaining steps are roughly the same as in Example 2.
[0022] Comparative Example 2 The difference between this comparative example and Example 2 is that step (2) does not contain polyene benzoxazine, while the remaining steps are roughly the same as in Example 2.
[0023] Comparative Example 3 (1) 0.5 mol of hexylamine and 1 mol of formaldehyde were added to chloroform and stirred at room temperature to disperse them. Then, 0.5 mol of p-hydroxystyrene was added, and the mixture was refluxed for 5 h. After the reaction was completed, the mixture was cooled to room temperature, extracted and dried, concentrated under reduced pressure, and purified to obtain alkenylbenzoxazine C. The reaction formula is as follows: ; (2) Add 2 mol of methyl methacrylate, 0.2 mol of styrene and 0.1 mol of alkenylbenzoxazine C to deionized water, control the temperature at 75°C, stir and disperse for 60 min, then add 1% potassium persulfate aqueous solution, react for 12 h, filter, dissolve tetrahydrofuran, precipitate in deionized water, dry, heat to melt, inject into mold, cool and form to obtain light guide plate.
[0024] Glass transition temperature was tested using a CDR-4P differential thermal analyzer.
[0025] The notched impact strength of the specimen is tested using an impact testing machine. The specimen is placed in an oven at 100°C for 10 minutes, and then the impact strength of the specimen is tested.
[0026] Table 1:
[0027] Therefore, the light guide plate prepared by this invention has good heat resistance and mechanical properties. Comparative Example 1 does not contain styrene, and styrene, as a rigid heat-resistant structure, can improve the heat resistance of the material. Since Comparative Example 1 does not contain this structure, its heat resistance is inferior to that of Example 2. Comparative Example 2 does not contain polyene benzoxazine. Benzoxazine can absorb heat and undergo ring-opening cross-linking to form a dense cross-linked network structure, improving the heat resistance and subsequent mechanical properties of the light guide plate. Since Comparative Example 2 does not contain this structure, its heat resistance and mechanical properties are poor. The structural formula used in Comparative Example 3 is: The substance replaces polyene benzoxazine, which forms a linear structure when copolymerized with methyl methacrylate, and cannot form a large cross-linked network structure. On the one hand, the cross-linked network structure can increase the rotational resistance within the molecular chain of the substrate when heated, thereby improving the heat resistance. On the other hand, when subjected to impact, the impact force can be dispersed in the cross-linked network structure, thereby improving the mechanical properties of the substrate. However, Comparative Example 3 does not contain the cross-linked network structure of the examples, therefore, its heat resistance and mechanical properties are not as good as those of the examples of the present invention.
[0028] The light guide plate of this application has strong performance and heat resistance, and still retains good mechanical properties after being heated. The light guide plate of this application has a long service life.
Claims
1. A light guide plate, characterized in that, The light guide plate is mainly prepared by polymerization of methyl methacrylate, styrene, and polyene benzoxazine. The preparation process includes the following steps: Step 1: Using p-hydroxystyrene, alkylamine, and formaldehyde as raw materials, polyene benzoxazine is obtained through the Manniene reaction; Step 2: Using methyl methacrylate, styrene, and polyene benzoxazine as raw materials, the mixture undergoes a polymerization reaction, is heated to melt, injected into a mold, and cooled to form a light guide plate.
2. The light guide plate according to claim 1, characterized in that, The specific preparation method of the polyene benzoxazine includes the following steps: adding alkylamine and formaldehyde to a solvent, stirring and dispersing at room temperature, adding p-hydroxystyrene, refluxing for 5-8 hours, cooling to room temperature after the reaction, concentrating under reduced pressure, separating and purifying to obtain polyene benzoxazine.
3. The light guide plate according to claim 2, characterized in that, The molar ratio of the alkylamine, formaldehyde, and p-hydroxystyrene is 1:4-6:2-3.
4. The light guide plate according to claim 2, characterized in that, The solvent is one of chloroform, dioxane, and toluene.
5. The light guide plate according to claim 2, characterized in that, The alkylamine is one or more of ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octanediamine.
6. The light guide plate according to claim 2, characterized in that, The alkylamine also includes tris(2-aminoethyl)amine.
7. The light guide plate according to claim 1, characterized in that, The specific preparation method of the light guide plate includes the following steps: Methyl methacrylate, styrene, and polyene benzoxazine are added to deionized water, and the temperature is controlled at 70-80℃. The mixture is stirred and dispersed for 40-60 minutes. Then, potassium persulfate aqueous solution is added, and the reaction is carried out for 10-14 hours. After the reaction is completed, the mixture is filtered, dissolved in tetrahydrofuran, precipitated in deionized water, dried, heated and melted, injected into a mold, and cooled to form a light guide plate.
8. The light guide plate according to claim 7, characterized in that, The mass fraction of the potassium persulfate aqueous solution is 1%.
9. The light guide plate according to claim 7, characterized in that, The molar ratio of methyl methacrylate, styrene, and polyene benzoxazine is 1:0.1-0.3:0.05-0.1.