High-shielding diffusion plate master batch and preparation method of diffusion plate using master batch

Abstract

The invention relates to the technical field of diffusion plate preparation, in particular to a high-shielding diffusion plate master batch and a diffusion plate preparation method applying the master batch, and the master batch comprises the following components in parts by mass: 40-60 parts of polybutylene terephthalate, 20-30 parts of polyethylene glycol terephthalate-1, 2, 4-triazole-1, 2, 4-triazole-1, 2, 4-triazole-1, 2, 4-triazole-1, 2, 4-triazole-1, 2, 4-triazole-1 The material is prepared from the following raw materials in parts by weight: 10-20 parts of 1, 4-cyclohexanedimethanol ester, 10-20 parts of unsaturated polyester, 8-10 parts of rutile type TiO2, 3-5 parts of nano barium sulfate, 2-4 parts of modified porous silicon microspheres, 0.2-0.5 part of a light stabilizer, 0.3-0.8 part of a processing aid, 0.5-1 part of a dispersing agent and 1-3 parts of a compatilizer. According to the high-shielding diffusion plate master batch provided by the invention, the polyester resin is taken as a matrix, and a multi-scale shielding system is combined, so that the light transmittance of a diffusion plate prepared according to the master batch can be precisely regulated and controlled, and meanwhile, the diffusion plate has excellent mechanical properties; besides, the master batch is produced by adopting universal equipment, has the advantages of low production cost, high batch stability and the like, and is suitable for the fields of LED illumination, display screens, automobile optical components and the like.

Description

Technical Field

[0001] This invention relates to the field of diffusion plate preparation technology, specifically to a high-shield diffusion plate masterbatch and a method for preparing diffusion plates using the masterbatch. Background Art

[0002] The backlight module of a display device typically consists of core components such as a light source, a light guide plate, a light reflector, a diffuser plate, and a brightness enhancement film. Among these, the light diffuser plate primarily serves multiple functions, including light uniformity, shielding the light source's glare, and supporting the optical thin-film components. The light source layout of backlight modules mainly falls into two technical routes: direct-lit and edge-lit. Direct-lit backlights use cold cathode tubes or LEDs arranged in an array on the bottom surface of the light guide plate to achieve direct light emission; edge-lit backlights arrange the light sources along the edge of the light guide plate, achieving overall light emission through side-incident light. Although the direct-lit design has advantages in light source brightness, the market share of edge-lit structures is gradually increasing as LCD monitors and LED TVs evolve towards ultra-thin designs. This trend has driven the demand for light diffusers that combine high light transmittance and high shielding performance.

[0003] In terms of material selection, polystyrene (GPPS) has long been the mainstream substrate for diffuser plates due to its excellent dimensional stability, thermal stability, light transmittance, and low moisture absorption. However, its high light transmittance in its unmodified state can easily lead to glare exposure from LED light sources. In recent years, polyester materials have been regarded as potential alternatives to polystyrene due to their superior comprehensive properties. Taking polybutylene terephthalate (PBT) as an example, this material has a linear molecular chain structure formed by ester bonds, possessing characteristics such as high melting point, low water absorption, strong chemical corrosion resistance, and stress cracking resistance, and exhibits significant stability during long-term thermal aging. However, the existing technology system has not yet overcome the key bottlenecks in the industrial application of PBT resin in light diffuser plates, and its optical control capabilities and processing adaptability still need further optimization.

[0004] Therefore, developing a diffusion plate that can overcome the shortcomings of the aforementioned diffusion plates is not only of great environmental significance, but also of high economic value.

[0005] Purpose of the invention To overcome the shortcomings of the prior art, the present invention aims to provide a high-shield diffuser masterbatch and a method for preparing a diffuser using the masterbatch. The masterbatch comprises the following components by weight: 40-60 parts polybutylene terephthalate, 20-30 parts polyethylene terephthalate-1,4-cyclohexanediol ester, 10-20 parts unsaturated polyester, 8-10 parts rutile TiO2, 3-5 parts nano-barium sulfate, 2-4 parts modified porous silica microspheres, 0.2-0.5 parts light stabilizer, 0.3-0.8 parts processing aid, 0.5-1 part dispersant, and 1-3 parts compatibilizer. The high-shield diffuser masterbatch provided by this invention uses polyester resin as a matrix and combines a multi-scale shielding system, which can precisely control the light transmittance of the diffuser made from the masterbatch. At the same time, the diffuser also has excellent mechanical properties. In addition, the masterbatch is produced using general-purpose equipment, which has the advantages of low production cost and high batch stability, and is suitable for LED lighting, display screens and automotive optical components.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-shielding diffuser masterbatch comprises the following components by weight: 40-60 parts polybutylene terephthalate, 20-30 parts polyethylene terephthalate-1,4-cyclohexanediol ester, 10-20 parts unsaturated polyester, 8-10 parts rutile TiO2, 3-5 parts nano-barium sulfate, 2-4 parts modified porous silica microspheres, 0.2-0.5 parts light stabilizer, 0.3-0.8 parts processing aid, 0.5-1 part dispersant, and 1-3 parts compatibilizer.

[0007] Preferably, the modified porous silicon microspheres are prepared by the following steps: S11. Clean the silicon powder with acetone, ethanol and deionized water in sequence for 15-20 minutes to remove organic matter and metal impurities on the surface of the silicon powder. Immerse the silicon powder in a 5-10% hydrofluoric acid solution at room temperature for 2-3 minutes and rinse with deionized water until neutral. S12. Immerse the silicon powder treated in step S11 into the etching solution, react in a water bath at 35-40℃ for 30-60 min, centrifuge, wash with ethanol and deionized water in sequence, and vacuum dry at 60-80℃ for 12-15 h to obtain porous silicon powder. S13. Disperse the porous silicon powder in ethanol, add 1-3% polyvinylpyrrolidone as a dispersant, sonicate for 30-40 minutes and then spray dry to obtain porous silicon microspheres. S14. Immerse the porous silica microspheres in the reaction solution, stir magnetically at 60-70℃ for 4-5 hours, collect the product by centrifugation, wash with ethanol 3-4 times, and vacuum dry at 80-85℃ for 6-7 hours to obtain the modified porous silica microspheres.

[0008] Preferably, in step S12, the etching solution is a mixture of hydrofluoric acid with a concentration of 30-40%, nitric acid with a concentration of 50-65%, and deionized water in a mass ratio of 3-4:1-2:6-8. In step S13, the operating parameters of the spray drying are set as follows: inlet temperature 200-220℃, outlet temperature 80-100℃, feed rate 5-6 mL / min, and atomization pressure 0.3-0.5 MPa; In step S14, the reaction solution is a mixture of hydrogen-containing silicone oil and ethanol in a mass ratio of 1-2:9-10.

[0009] Preferably, the rutile TiO2 has a particle size range of 0.2-0.5 μm; and the nano-barium sulfate has a particle size range of 50-80 nm.

[0010] Preferably, the light stabilizer is further defined as a hindered amine light stabilizer; the processing aid is further defined as a polytetrafluoroethylene processing aid; the dispersant is further defined as an organosilicon dispersant; and the compatibilizer is further defined as an acrylic acid graft copolymer.

[0011] Preferably, the high-shield diffuser masterbatch is prepared by the following steps: S21. Raw material premixing: Add the raw materials in the mass fractions into a high-speed mixer and mix for 10-20 minutes to obtain the raw material premix; S22. Extrusion granulation: The raw material premix is ​​extruded and granulated through a twin-screw extruder to obtain a high-shielding diffuser masterbatch.

[0012] Preferably, in step S22, the temperatures of each zone of the twin-screw extruder are as follows: zone 1 is 160-170℃, zone 2 is 175-185℃, zone 3 is 190-200℃, zone 4 is 205-215℃, zone 5 is 200-210℃, zone 6 is 220-230℃, and zone 7 is 235-245℃.

[0013] A method for preparing a diffusion plate using the aforementioned high-shield diffusion plate masterbatch includes the following steps: The high-shielding diffuser masterbatch is fed into a twin-screw extruder, melt-blended, extruded, and pressed to obtain the diffuser plate.

[0014] Preferably, the temperatures of each zone of the twin-screw extruder are as follows: Zone 1: 170-180℃, Zone 2: 185-195℃, Zone 3: 200-210℃, Zone 4: 215-225℃, Zone 5: 220-230℃, Zone 6: 235-245℃, and Zone 7: 240-250℃.

[0015] Preferably, the working parameters for the printing and molding process are: die head pressure of 5-6 MPa.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses a polyester resin system as the matrix and combines it with multi-scale scattering particles to construct a composite optical structure, which can effectively control the light propagation path and achieve a more uniform light distribution while reducing light transmittance. The surface treatment process of the modified porous silicon microspheres enhances their interfacial bonding with the resin matrix. Combined with the synergistic scattering effect of rutile titanium dioxide and nano-barium sulfate, a multi-layered light blocking network can be formed, thereby suppressing light source glare and eliminating bright lines. 2. The temperature gradient design of the twin-screw extrusion process balances the thermal stability of the polyester material with the uniform dispersion of the filler, ensuring the formation of a stable three-dimensional scattering system within the masterbatch. The introduction of hindered amine light stabilizers and PTFE processing aids further optimizes the material's weather resistance and processing flowability, enabling the diffuser plate to maintain stable shielding performance and surface smoothness during long-term use. The application of acrylic graft copolymers as compatibilizers promotes molecular-level bonding between the organic and inorganic phases, effectively avoiding mechanical property degradation caused by phase separation. Thus, this approach, while maintaining the inherent heat resistance and moisture resistance of polyester materials, provides a reliable technical path for the development of high-shield optical devices through systematic material design and process adaptation. Attached Figure Description

[0017] Figure 1 This is a flow chart of the preparation process of the high-shield diffusion plate masterbatch described in this invention; Figure 2 This is a process flow diagram for preparing the modified porous silicon microspheres described in this invention; Figure 3 This is a SEM image of the modified porous silicon microspheres described in this invention. Detailed Implementation

[0018] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-3 The present invention provides a technical solution: Example 1 A high-shielding diffuser masterbatch comprises the following components by weight (each weight part is specified as 100g): The polybutylene terephthalate is designated as Crastin® 6130NC010; The grade of the polyethylene terephthalate-1,4-cyclohexanediol ester is Dynacoll 7150; The unsaturated polyester is specifically an isophthalic unsaturated polyester, with the grade Wanqian Chemical TC9508. The rutile TiO2 has a particle size of 0.2-0.5 μm, and the specific model is ATR312, which was purchased from Songda Chemical (Fujian) Co., Ltd. The nano-barium sulfate has a particle size of 50-80nm, and the specific model is WT-88, which was purchased from Wufeng Weitai Mining Co., Ltd. The light stabilizer is specifically a hindered amine light stabilizer, with the specific model being HS-944; The processing aid is specifically a polytetrafluoroethylene processing aid, with the specific model being DAI-EL DA-310ST; The dispersant is specifically an organosilicon-based dispersant, specifically Dowsil™ Q2-3238; The compatibilizer is an acrylic graft copolymer, specifically model BYK-P104S; The modified porous silicon microspheres are prepared by the following steps: S11. Clean the silicon powder with acetone, ethanol and deionized water in sequence for 15 minutes to remove organic matter and metal impurities on the surface of the silicon powder. Immerse the silicon powder in a 5% hydrofluoric acid solution at room temperature for 2 minutes and rinse with deionized water until neutral. S12. The silicon powder treated in step S11 is immersed in an etching solution, reacted in a water bath at 35°C for 30 min, centrifuged at 6000 rpm for 10 min, washed successively with ethanol and deionized water, and vacuum dried at 60°C for 12 h to obtain porous silicon powder. S13. Disperse 8 parts of the porous silicon powder in 100 parts of ethanol by mass, add 1% of polyvinylpyrrolidone as a dispersant, sonicate for 30 min and then spray dry to obtain porous silicon microspheres. S14. Immerse the porous silica microspheres in the reaction solution, stir magnetically at 60°C for 4 hours, collect the product by centrifugation, wash three times with ethanol, and vacuum dry at 80°C for 6 hours to obtain the modified porous silica microspheres.

[0020] In step S12, the etching solution is a mixture of 30% hydrofluoric acid, 50% nitric acid, and deionized water in a mass ratio of 3.5:1.2:6.3. In step S13, the operating parameters of the spray drying are set as follows: inlet temperature is 210℃, outlet temperature is 80℃, feed rate is 5mL / min, and atomization pressure is 0.3 MPa. In step S14, the reaction solution is a mixture of hydrogen-containing silicone oil and ethanol in a mass ratio of 1.5:9.3; The high-shielding diffuser masterbatch is prepared through the following steps: S21. Raw material premixing: Add the raw materials to the high-speed mixer in the order of mass parts, mix and stir at 500 rpm for 10 minutes to obtain the raw material premix; S22. Extrusion granulation: The raw material premix is ​​extruded and granulated through a twin-screw extruder to obtain a high-shielding diffuser masterbatch.

[0021] In step S22, the temperatures of each zone of the twin-screw extruder are as follows: zone 1 is 165°C, zone 2 is 175°C, zone 3 is 195°C, zone 4 is 205°C, zone 5 is 210°C, zone 6 is 220°C, and zone 7 is 235°C.

[0022] A method for preparing a diffusion plate using the aforementioned high-shield diffusion plate masterbatch includes the following steps: The high-shielding diffuser masterbatch is fed into a twin-screw extruder, melt-blended, extruded, and pressed to obtain the diffuser plate.

[0023] During the preparation of the above-mentioned diffuser plate, the temperatures of each zone of the twin-screw extruder are as follows: Zone 1 is 170℃, Zone 2 is 185℃, Zone 3 is 205℃, Zone 4 is 215℃, Zone 5 is 220℃, Zone 6 is 240℃, and Zone 7 is 250℃. The working parameters for the printing and pressing process are: die head pressure is 5MPa.

[0024] Example 2: Example 2 differs from Example 1 in that, in Example 2, the high-shield diffuser masterbatch comprises the following components by weight: The remaining steps are exactly the same as in Example 2 and Example 1.

[0025] Example 3: Example 3 differs from Example 1 in that, in Example 3, the high-shield diffuser masterbatch comprises the following components by weight: The remaining steps are exactly the same as in Example 3 and Example 1.

[0026] Example 4: Example 4 differs from Example 1 in that, in Example 4, the high-shielding diffuser masterbatch comprises the following components by weight: The remaining steps are exactly the same as in Example 4 and Example 1.

[0027] Comparative Example Comparative Example 1: The only difference between Comparative Example 1 and Example 1 is that the modified porous silicon microspheres were omitted in Comparative Example 1. The remaining steps are exactly the same in Comparative Example 1 and Example 1.

[0028] Comparative Example 2: The only difference between Comparative Example 2 and Example 1 is that the use of rutile TiO2 and nano barium sulfate was omitted in Comparative Example 2. The remaining steps are exactly the same in Comparative Example 2 and Example 1.

[0029] Comparative Example 3: The only difference between Comparative Example 3 and Example 1 is that the use of rutile TiO2 and modified porous silicon microspheres was omitted in Comparative Example 3. The remaining steps are exactly the same in Comparative Example 3 and Example 1.

[0030] Comparative Example 4: The only difference between Comparative Example 4 and Example 1 is that the use of nano-barium sulfate and modified porous silica microspheres was omitted in Comparative Example 4. The remaining steps are exactly the same in Comparative Example 4 and Example 1.

[0031] Performance testing: According to the requirements of GB / T 2410-2008 standard, the light transmittance and haze of the prepared diffuser plate were tested; according to the requirements of GB / T1040.2-2006 standard, the tensile strength of the prepared diffuser plate was tested; according to the requirements of GB / T 1634.2-2004 standard, the heat deformation temperature of the prepared diffuser plate was tested; according to the requirements of GB / T 2410-2008 standard, the shading uniformity of the prepared diffuser plate was tested. The test results are shown below: Referring to the performance test data of Examples 1-4 and Comparative Example 4, it can be seen that in the performance test of the light diffusion plate, in Examples 1 to 4, as the amount of rutile TiO2 (8 parts to 10 parts), nano-barium sulfate (3.5 parts to 5 parts), and modified porous silica microspheres (2 parts to 4 parts) gradually increased, the scattering particles significantly enhanced the light blocking and diffusion capabilities through the synergistic effect of micron-level reflection, nano-level filling, and secondary scattering by the porous structure. The transmittance gradually decreased from 12.5% ​​to 6.2%, while the haze increased from 98.2% to 99.3%, indicating that the shielding performance was continuously optimized with the increase of the filler ratio. In contrast, Comparative Example 1, lacking the secondary scattering structure due to the absence of porous silica microspheres, saw its transmittance increase to 18.7% and its haze decrease to 92.5%; Comparative Example 2, completely lacking the two core scatterers, TiO2 and barium sulfate, saw its transmittance surge to 45.3% and its haze to only 78.0%, fully verifying the necessity of multi-component synergistic scattering. The significant deterioration of shielding performance in Comparative Examples 3-4 due to the absence of some fillers further demonstrates the importance of the integrity of the scattering system.

[0032] The test results for mechanical properties and thermal stability show that increasing the filler ratio has a differentiated impact on material properties. In Examples 1 to 4, although the increase in filler ratio gradually reduced the tensile strength from 68.5 MPa to 64.0 MPa, the thermal stability of the filler (such as the high-temperature resistance of TiO2 and silicon microspheres) significantly improved the material's heat distortion temperature, increasing it from 130℃ to 138℃. This trend indicates that the introduction of filler, while sacrificing some mechanical strength, significantly enhances the material's high-temperature applicability. Comparative Example 2, due to the absence of TiO2 and barium sulfate, had an increased resin matrix ratio, achieving the highest tensile strength of 72.1 MPa, but its heat distortion temperature was only 125℃, highlighting the crucial role of filler in thermal stability. This balance between mechanical and thermal properties provides a basis for selecting practical application scenarios.

[0033] The test data on uniformity of shading (CV value) further revealed the importance of the interface optimization process. In Examples 1 to 4, as the amounts of dispersant and compatibilizer increased from 0.5 parts and 1.1 parts to 1 part and 3 parts respectively, the uniformity of filler dispersion improved significantly, and the CV value decreased from 3.2% to 1.8%. This optimization stems from the synergistic effect of the acrylic graft copolymer and the silicone dispersant: the former enhances the interfacial bonding between the filler and the resin matrix through chemical bonding, while the latter inhibits filler agglomeration through physical anchoring, thereby ensuring the consistency of the light scattering path. In contrast, Comparative Examples 1-4, due to incomplete dispersion systems, had CV values ​​increasing to 8.7%-15.4%, resulting in uneven light spot distribution.

[0034] The above performance test data strongly demonstrates that the high-shield diffuser masterbatch provided by the present invention uses polyester resin as the matrix and combines a multi-scale shielding system, which can precisely control the light transmittance of the diffuser plate made based on the masterbatch. At the same time, the diffuser plate also has excellent mechanical properties. In addition, the masterbatch is produced using general-purpose equipment, which has the advantages of low production cost and high batch stability, and is suitable for LED lighting, display screens and automotive optical components.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-shielding diffuser masterbatch, characterized in that, The product comprises the following components by weight: 40-60 parts polybutylene terephthalate, 20-30 parts polyethylene terephthalate-1,4-cyclohexanediol ester, 10-20 parts unsaturated polyester, 8-10 parts rutile TiO2, 3-5 parts nano barium sulfate, 2-4 parts modified porous silica microspheres, 0.2-0.5 parts light stabilizer, 0.3-0.8 parts processing aid, 0.5-1 part dispersant, and 1-3 parts compatibilizer.

2. The high-shielding diffuser masterbatch according to claim 1, characterized in that, The modified porous silicon microspheres are prepared by the following steps: S11. Clean the silicon powder with acetone, ethanol and deionized water in sequence for 15-20 minutes to remove organic matter and metal impurities on the surface of the silicon powder. Immerse the silicon powder in a 5-10% hydrofluoric acid solution at room temperature for 2-3 minutes and rinse with deionized water until neutral. S12. Immerse the silicon powder treated in step S11 into the etching solution, react in a water bath at 35-40℃ for 30-60 min, centrifuge, wash with ethanol and deionized water in sequence, and vacuum dry at 60-80℃ for 12-15 h to obtain porous silicon powder. S13. Disperse the porous silicon powder in ethanol, add 1-3% polyvinylpyrrolidone as a dispersant, sonicate for 30-40 minutes and then spray dry to obtain porous silicon microspheres. S14. Immerse the porous silica microspheres in the reaction solution, stir magnetically at 60-70℃ for 4-5 hours, collect the product by centrifugation, wash with ethanol 3-4 times, and vacuum dry at 80-85℃ for 6-7 hours to obtain the modified porous silica microspheres.

3. The high-shielding diffuser masterbatch according to claim 2, characterized in that, In step S12, the etching solution is a mixture of hydrofluoric acid with a concentration of 30-40%, nitric acid with a concentration of 50-65%, and deionized water in a mass ratio of 3-4:1-2:6-8. In step S13, the operating parameters of the spray drying are set as follows: inlet temperature 200-220℃, outlet temperature 80-100℃, feed rate 5-6 mL / min, and atomization pressure 0.3-0.5 MPa; In step S14, the reaction solution is a mixture of hydrogen-containing silicone oil and ethanol in a mass ratio of 1-2:9-10.

4. The high-shielding diffuser masterbatch according to claim 1, characterized in that, The rutile TiO2 has a particle size range of 0.2-0.5 μm; the nano-barium sulfate has a particle size range of 50-80 nm.

5. The high-shielding diffuser masterbatch according to claim 1, characterized in that, The light stabilizer is further defined as a hindered amine light stabilizer; the processing aid is further defined as a polytetrafluoroethylene processing aid; the dispersant is further defined as an organosilicon dispersant; and the compatibilizer is further defined as an acrylic acid graft copolymer.

6. The high-shielding diffuser masterbatch according to claim 1, characterized in that, The high-shielding diffuser masterbatch is prepared through the following steps: S21. Raw material premixing: Add the raw materials in the mass fractions into a high-speed mixer and mix for 10-20 minutes to obtain the raw material premix; S22. Extrusion granulation: The raw material premix is ​​extruded and granulated through a twin-screw extruder to obtain a high-shielding diffuser masterbatch.

7. The high-shielding diffuser masterbatch according to claim 6, characterized in that, In step S22, the temperatures of each zone of the twin-screw extruder are as follows: Zone 1: 160-170℃, Zone 2: 175-185℃, Zone 3: 190-200℃, Zone 4: 205-215℃, Zone 5: 200-210℃, Zone 6: 220-230℃, and Zone 7: 235-245℃.

8. A method for preparing a diffusion plate using the high-shield diffusion plate masterbatch according to any one of claims 1-7, characterized in that, The following steps are involved: The high-shielding diffuser masterbatch is fed into a twin-screw extruder, melt-blended, extruded, and pressed to obtain the diffuser plate.

9. A method for preparing a diffusion plate using the high-shield diffusion plate masterbatch according to claim 8, characterized in that, The temperatures of each zone of the twin-screw extruder are as follows: Zone 1: 170-180℃, Zone 2: 185-195℃, Zone 3: 200-210℃, Zone 4: 215-225℃, Zone 5: 220-230℃, Zone 6: 235-245℃, and Zone 7: 240-250℃.

10. A method for preparing a diffusion plate using the high-shield diffusion plate masterbatch according to claim 8, characterized in that, The working parameters for the printing and molding process are: die head pressure of 5-6 MPa.

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