A high temperature resistant foaming diffusion plate and preparation method thereof

Abstract

The invention discloses a high-temperature resistant foaming diffusion plate and a preparation method thereof, wherein the preparation method comprises the following steps: preparing modified glass microspheres; uniformly stirring the modified glass microspheres and GPPS resin, PC resin, SMA resin, antioxidant, liquid paraffin or silicone oil, light stabilizer, ultraviolet absorber and brightener to obtain a mixture A, and then feeding the mixture A into a single screw extruder; then heating the single screw extruder to melt the mixture A, and then extruding and molding the mixture A through the single screw extruder to obtain a finished product; the diffusion plate has the advantages of both the GPPS diffusion plate and the PC diffusion plate, and is not only flame retardant, high temperature resistant and strong impact resistant, but also has high light transmittance and good uniformity.

Description

Technical Field

[0001] The invention relates to the technical field of diffusion plates, in particular to a high temperature resistant foamed diffusion plate and a preparation method thereof. Background Art

[0002] The diffuser uses chemical or physical means to utilize the physical phenomena of refraction, reflection and scattering that occur when light encounters two media with different refractive indices on its way, thereby changing the path of light and achieving full dispersion of the incident light to produce an optical diffusion effect.

[0003] Traditional diffuser plates usually use GPPS resin as the base material, and directly add glass fiber or glass microspheres into the GPPS resin as a light diffuser to prepare the diffuser plate. However, this type of diffuser plate is not only easily deformed by heat and has poor impact resistance, but also has poor light diffusion effect. This may be due to the following reasons. First, the selected base material itself has poor heat resistance and impact resistance. When in use, the LED lamp will generate a lot of heat. Excessive heat will damage and deform the diffuser plate, and then cause refraction or random reflection, deflection and other phenomena, which ultimately lead to poor light diffusion effect; second, the refractive index of the base material does not match the diffuser, resulting in poor light diffusion effect; third, the compatibility between the light diffuser and the base material is not good, and the diffuser may aggregate or distribute unevenly, resulting in poor light diffusion effect. Summary of the invention

[0004] In order to solve the above problems, one of the purposes of the present invention is to provide a method for preparing a high temperature resistant foamed diffusion plate, comprising the following steps:

[0005] Preparation of modified glass microspheres;

[0006] 2 to 8 parts of the modified glass microspheres, 21 to 33 parts of GPPS resin, 28 to 32 parts of PC resin, 28 to 35 parts of SMA resin, 0.2 to 0.6 parts of antioxidant, 1 to 5 parts of liquid paraffin or silicone oil, 0.6 to 1.2 parts of light stabilizer, 0.4 to 0.8 parts of ultraviolet absorber, and 0.8 to 2.4 parts of brightener are uniformly stirred to obtain a mixture A, and the mixture A is then put into a single screw extruder; then the single screw extruder is heated to melt the mixture A, and then the mixture A is extruded by the single screw extruder to obtain a finished product;

[0007] Among them, the temperatures of each zone of the single-screw extruder are: zone one temperature is 180-190°C, zone two temperature is 190-200°C, zone three temperature is 210-220°C, zone four temperature is 210-220°C, zone five temperature is 225-235°C, zone six temperature is 215-225°C, zone seven temperature is 210-220°C, and the die head temperature is 205-215°C.

[0008] Furthermore, the preparation of modified glass microspheres includes the following steps: firstly placing the glass microspheres in a 0.3-0.7 mol / L sodium hydroxide solution, stirring at room temperature for activation for 1-3 hours, filtering out the filter residue, washing the filter residue with pure water, and drying to obtain a hydroxylated glass microsphere sample; adding a silane coupling agent to a 75-95% ethanol aqueous solution to prepare a silane coupling agent ethanol aqueous solution with a concentration of 0.5-3wt%, and adjusting the solution to a pH of 3-5, and stirring sufficiently to obtain a silane coupling agent treatment solution; adding the hydroxylated glass microsphere sample to the silane coupling agent treatment solution, stirring sufficiently, filtering out the filter residue, and drying to obtain a modified glass microsphere.

[0009] Furthermore, the above-mentioned silane coupling agent is a silane coupling agent having an unsaturated double bond.

[0010] Furthermore, the silane coupling agent is a silane coupling agent having an acryloxy group.

[0011] Furthermore, the silane coupling agent is a silane coupling agent having an amino group.

[0012] Furthermore, the pH value of the solution is adjusted with glacial acetic acid or citric acid.

[0013] Furthermore, the drying temperature is 80-100° C., and the drying time is 15-30 minutes.

[0014] Furthermore, the antioxidant is any one of antioxidant 1024, antioxidant 1010 or antioxidant 1076.

[0015] Furthermore, the light stabilizer is selected from any one of light stabilizer 770, light stabilizer 944 or light stabilizer 622.

[0016] Another object of the present invention is to provide a high temperature resistant foamed diffuser plate obtained by the above preparation method.

[0017] The beneficial effects are:

[0018] The present application promotes the compatibility between GPPS and PC by introducing SMA resin as a compatibilizer. SMA resin is a copolymer of styrene-maleic anhydride, containing styrene and maleic anhydride segments. The styrene segment is compatible with GPPS resin, and the maleic anhydride segment can undergo a grafting reaction with PC resin, thereby building a bridge between GPPS resin and PC resin, improving the interfacial compatibility between the two, and forming a stable and uniform system. At the same time, a modified glass microsphere is obtained through a special process. The surface of the modified glass microsphere has a coupling agent with sufficient cross-linking degree and uniform distribution. After the modified glass microsphere is added to the system, it is cross-linked with SMA resin, GPPS resin and PC resin to form an interpenetrating network. The density of the interpenetrating network can be controlled to obtain a foamed diffuser. The foamed diffuser has the advantages of both GPPS diffuser and PC diffuser, and is not only flame retardant, high temperature resistant, and impact resistant, but also has high light transmittance and good uniformity. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0020] The following embodiments are only used to illustrate the present invention, but are not limited to the scope of the present invention. Based on the specific embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work belong to the protection scope of the present invention.

[0021] In the examples of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the examples of the present invention, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art.

[0022] Source of raw materials:

[0023] GPPS resin, model GPPS-300NT, was purchased from PetroChina Dushanzi Petrochemical Company;

[0024] PC resin, model PC-110, purchased from Chi Mei Industrial Co., Ltd. in Taiwan, China;

[0025] SMA resin, model SMA-700, was purchased from Jiaxing Huawen Chemical Co., Ltd.;

[0026] Antioxidants were purchased from Shandong Xuxiang Chemical Co., Ltd.

[0027] Silicone oil was purchased from Jinan Xuchuang Chemical Technology Co., Ltd.

[0028] Liquid paraffin was purchased from Hefeng New Energy Co., Ltd.;

[0029] Light stabilizer, purchased from Shanghai Tiandui New Materials Co., Ltd.;

[0030] Ultraviolet absorber, purchased from Jinan Xiangfeng Weiye Chemical Co., Ltd.;

[0031] Brightener, model CBS-127, purchased from Guangzhou Yuanda New Materials Co., Ltd.;

[0032] Ethanol was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0033] Sodium hydroxide was purchased from Jinan Jumeihui Chemical Co., Ltd.

[0034] Silane coupling agent, purchased from Shandong Yuanjin New Materials Co., Ltd.;

[0035] Glacial acetic acid was purchased from Shandong Huayu Chemical Technology Co., Ltd.;

[0036] Citric acid was purchased from Zhonghe New Materials (Dezhou) Co., Ltd.;

[0037] Glass microspheres were purchased from Dongguan Xingyuan Chemical Co., Ltd.;

[0038] The remaining reagents are commercially available.

[0039] Example 1

[0040] This embodiment provides a method for preparing a high temperature resistant foam diffuser plate, comprising the following steps:

[0041] Preparation of modified glass microspheres: firstly, the glass microspheres are placed in a 0.5 mol / L sodium hydroxide solution, stirred at room temperature for activation for 2 h, filtered to obtain the residue, washed the residue with pure water for 5 times, and dried at 100°C for 15 min to obtain a hydroxylated glass microsphere sample; a silane coupling agent is added to an 85% ethanol aqueous solution to prepare a silane coupling agent ethanol aqueous solution with a concentration of 1.75 wt%, and the solution is adjusted to pH=4 with glacial acetic acid, and stirred sufficiently to obtain a silane coupling agent treatment solution; the hydroxylated glass microsphere sample is added to the silane coupling agent treatment solution, stirred sufficiently, filtered to obtain the residue, and dried at 100°C for 15 min to obtain modified glass microspheres, and modified glass microspheres with a diameter of 300 μm are screened out;

[0042] 5 parts of the modified glass microspheres with a diameter of 300 μm, 27 parts of GPPS resin, 30 parts of PC resin, 31.5 parts of SMA resin, 0.4 parts of antioxidant, 3 parts of silicone oil, 0.9 parts of light stabilizer, 0.6 parts of ultraviolet absorber and 1.6 parts of brightener are uniformly stirred to obtain a mixture A, and the mixture A is then put into a single screw extruder; then the single screw extruder is heated to melt the mixture A, and then the single screw extruder is used to extrude and mold the mixture A to obtain a finished product;

[0043] The silane coupling agent is a silane coupling agent with unsaturated double bonds, specifically vinyl trimethoxy silane, the antioxidant is specifically antioxidant 1024, the light stabilizer is specifically light stabilizer 770, and the ultraviolet absorber is specifically ultraviolet absorber UV-327;

[0044] The temperatures of each zone of the single-screw extruder are: zone 1 is 185°C, zone 2 is 195°C, zone 3 is 215°C, zone 4 is 215°C, zone 5 is 230°C, zone 6 is 220°C, zone 7 is 215°C, and the die head temperature is 210°C.

[0045] Example 2

[0046] This embodiment provides a method for preparing a high temperature resistant foam diffuser plate, comprising the following steps:

[0047] Preparation of modified glass microspheres: firstly, placing the glass microspheres in a 0.3 mol / L sodium hydroxide solution, stirring at room temperature for activation for 1 hour, filtering out the residue, washing the residue with pure water for 3 times, and drying at 80°C for 30 minutes to obtain a hydroxylated glass microsphere sample; adding a silane coupling agent to a 75% ethanol aqueous solution to prepare a silane coupling agent ethanol aqueous solution with a concentration of 0.5 wt%, adjusting the solution to pH=3 with citric acid, and stirring sufficiently to obtain a silane coupling agent treatment solution; adding the above hydroxylated glass microsphere sample to the above silane coupling agent treatment solution, stirring sufficiently, filtering out the residue, and drying at 80°C for 30 minutes to obtain modified glass microspheres, and screening out modified glass microspheres with a diameter of 50 μm;

[0048] 8 parts of the modified glass microspheres with a diameter of 50 μm, 33 parts of GPPS resin, 28 parts of PC resin, 28 parts of SMA resin, 0.2 parts of antioxidant, 1 part of liquid paraffin, 0.6 parts of light stabilizer, 0.4 parts of ultraviolet absorber, and 0.8 parts of brightener are uniformly stirred to obtain a mixture A, and the mixture A is then put into a single screw extruder; then the single screw extruder is heated to melt the mixture A, and then the mixture is extruded by the single screw extruder to obtain a finished product;

[0049] The silane coupling agent is a silane coupling agent having an acryloxy group, specifically y-methacryloxypropyltrimethoxysilane, the antioxidant is specifically antioxidant 1010, the light stabilizer is specifically light stabilizer 944, and the ultraviolet absorber is specifically ultraviolet absorber UV-329;

[0050] The temperatures of each zone of the single-screw extruder are: zone 1 is 180°C, zone 2 is 190°C, zone 3 is 210°C, zone 4 is 210°C, zone 5 is 225°C, zone 6 is 215°C, zone 7 is 210°C, and the die head temperature is 205°C.

[0051] Example 3

[0052] This embodiment provides a method for preparing a high temperature resistant foam diffuser plate, comprising the following steps:

[0053] Preparation of modified glass microspheres: firstly, the glass microspheres are placed in a 0.7 mol / L sodium hydroxide solution, and activated by stirring at room temperature for 3 h, and the residue is filtered out, and the residue is washed with pure water for 4 times, and dried at 90°C for 23 min to obtain a hydroxylated glass microsphere sample; a silane coupling agent is added to a 95% ethanol aqueous solution to prepare a silane coupling agent ethanol aqueous solution with a concentration of 3 wt%, and the solution is adjusted to pH=5 with glacial acetic acid, and a silane coupling agent treatment solution is obtained after sufficient stirring; the hydroxylated glass microsphere sample is added to the silane coupling agent treatment solution, and the mixture is sufficiently stirred, and the residue is filtered out, and the modified glass microsphere is obtained after drying at 90°C for 23 min, and the modified glass microsphere with a diameter of 600 μm is screened out;

[0054] 2 parts of the modified glass microspheres with a diameter of 600 μm, 21 parts of GPPS resin, 32 parts of PC resin, 35 parts of SMA resin, 0.6 parts of antioxidant, 5 parts of liquid paraffin, 1.2 parts of light stabilizer, 0.8 parts of ultraviolet absorber, and 2.4 parts of brightener are uniformly stirred to obtain a mixture A, and the mixture A is then put into a single screw extruder; then the single screw extruder is heated to melt the mixture A, and then the mixture is extruded by the single screw extruder to obtain a finished product;

[0055] The silane coupling agent is an amino group-containing silane coupling agent, specifically y-aminopropyltrimethoxysilane, the antioxidant is specifically antioxidant 1076, the light stabilizer is specifically light stabilizer 622, and the ultraviolet absorber is specifically ultraviolet absorber UV-531;

[0056] The temperatures of each zone of the single-screw extruder are: zone 1 is 190°C, zone 2 is 200°C, zone 3 is 220°C, zone 4 is 220°C, zone 5 is 235°C, zone 6 is 225°C, zone 7 is 220°C, and the die head temperature is 215°C.

[0057] Comparative Example 1

[0058] The difference between this comparative example and Example 1 is that 5 parts of glass microspheres with a diameter of 300 μm are used to replace 5 parts of modified glass microspheres in Example 1, and the other components and experimental steps are the same as those in Example 1.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 is that the GPPS resin is increased from 27 parts to 58.5 parts, and SMA resin is not added. The other components and experimental steps are the same as those in Example 1.

[0061] Comparative Example 3

[0062] The difference between this comparative example and Example 1 is that the GPPS resin is increased from 27 parts to 57 parts, and no PC resin is added. The other components and experimental steps are the same as those in Example 1.

[0063] Comparative Example 4

[0064] The difference between this comparative example and Example 1 is that the amount of PC resin is increased from 30 parts to 57 parts, and GPPS resin is not added. The other components and experimental steps are the same as those in Example 1.

[0065] Comparative Example 5

[0066] The difference between this comparative example and Example 1 is that 5 parts of modified glass microspheres with a diameter less than 50 μm are used to replace the 5 parts of modified glass microspheres in Example 1, and the other components and experimental steps are the same as those in Example 1.

[0067] Comparative Example 6

[0068] The difference between this comparative example and Example 1 is that 5 parts of modified glass microspheres with a diameter greater than 600 μm are used to replace the 5 parts of modified glass microspheres in Example 1, and the other components and experimental steps are the same as those in Example 1.

[0069] The diffuser plates prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were tested.

[0070] Test method:

[0071] Heat deformation temperature is tested according to ASTM D648 standard;

[0072] Impact strength is tested according to ASTM D256 standard;

[0073] Flame retardancy is tested according to UL94 standard;

[0074] Light transmittance and haze are tested according to ASTM D1003 standard;

[0075] Density is tested according to ASTM D792;

[0076] The center brightness and average brightness were tested according to GY / T 326-2019 standard, and the test results are shown in Table 1.

[0077] Table 1 Diffuser plate performance test results

[0078]

[0079]

[0080] From the data in the table, it can be analyzed that the diffuser plates prepared in Examples 1 to 3 have the advantages of both GPPS diffuser plates and PC diffuser plates, with flame retardancy reaching V0 level, high temperature resistance, strong impact resistance, and light transmittance between 30% and 50%, haze above 80%, center brightness above 2100, and average brightness above 1500. It can be seen from the size of the pores that an interpenetrating network is formed. By comparing and analyzing the data of Example 1 with Comparative Examples 1 to 4, it can be seen that the heat deformation temperature, impact strength, and flame retardancy of Comparative Example 1 are not much different from those of Example 1, but the light transmittance, haze, center brightness, and average brightness of Comparative Example 1 are worse than those of Example 1, and there are no pores. This may be because Comparative Example 1 uses unmodified glass microspheres, resulting in no interpenetrating network formed in Comparative Example 1. In addition, The refractive index of the unmodified glass microspheres is 1.48, while the refractive index of the substrate obtained by mixing GPPS resin, PC resin and SMA resin in Comparative Example 1 is 1.56. It may also be that the refractive index of the unmodified glass microspheres is too different from that of the substrate, which ultimately causes the poor light diffusion effect of Comparative Example 1. Continuing to analyze the data in the table, it can be seen that the heat deformation temperature and impact strength in Comparative Example 2 are worse than those in Example 1, which may be related to the increase of GPPS resin in Comparative Example 2. GPPS resin itself has low impact strength and poor heat resistance. Too much GPPS resin has a greater impact on the heat resistance and impact strength of the diffusion plate. In addition, the light transmittance, haze, center brightness and average brightness of Comparative Example 2 are also worse than those of Example 1, and there are no bubbles, which may be because Comparative Example 2 lacks SMA resin and does not form an interpenetrating network. The heat deformation temperature, impact strength and flame retardancy of Comparative Example 3 are the worst in the whole table. This may be because not only the GPPS resin is increased in Comparative Example 3, but also the PC resin is not added. In addition, the other performance indicators of Comparative Example 3 are also very poor and no bubbles are found, indicating that Comparative Example 3 does not form an interpenetrating network. The heat deformation temperature and impact strength of Comparative Example 4 are better than those of Comparative Examples 2 to 3. This may be because the PC resin is increased in Comparative Example 4 and the GPPS resin is not added. The PC resin itself has high impact strength and is heat-resistant and flame-retardant. Therefore, when there is too much PC resin in the diffuser plate, the heat resistance and impact strength of the diffuser plate will also be greatly affected. Continuing to analyze the data in the table, it can be seen that other data in Comparative Example 4, including transmittance, haze, center brightness, and average brightness, are also worse than those in Example 1. This may be because the refractive index of the substrate changes after the lack of GPPS resin in Comparative Example 4. At this time, the refractive index of the substrate is 1.65, which is too different from the refractive index of the modified glass microspheres of 1.52, resulting in a very poor light diffusion effect of the entire diffuser plate.Next, looking at the various performance data of Comparative Examples 5 and 6 in the table, it is found that the light transmittance, haze, center brightness and average brightness of the diffuser plate prepared by replacing the modified glass microspheres in Example 1 with modified glass microspheres with a diameter less than 50 μm or greater than 600 μm are all worse than those in Example 1. This may be because the refractive index of the modified glass microspheres with a diameter that is too large or too small is too different from the refractive index of the substrate, resulting in poor light diffusion effect of the entire diffuser plate.

[0081] In summary, the present application promotes the compatibility between GPPS and PC by introducing SMA resin as a compatibilizer. SMA resin is a copolymer of styrene-maleic anhydride, containing styrene and maleic anhydride segments. The styrene segment is compatible with GPPS resin, and the maleic anhydride segment can undergo a grafting reaction with PC resin, thereby building a bridge between GPPS resin and PC resin, improving the interfacial compatibility between the two, and forming a stable and uniform system. At the same time, a modified glass microsphere is obtained through a special process. The surface of the modified glass microsphere has a coupling agent with sufficient cross-linking degree and uniform distribution. After the modified glass microsphere is added to the system, it is cross-linked with SMA resin, GPPS resin and PC resin to form an interpenetrating network. The density of the interpenetrating network can be controlled to obtain a foamed diffuser. This foamed diffuser has the advantages of both GPPS diffuser and PC diffuser, and is not only flame retardant, high temperature resistant, and impact resistant, but also has high light transmittance and good uniformity.

[0082] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a high temperature resistant foaming diffusion plate, characterized in that: The following steps are involved: The preparation of modified glass microspheres includes the following steps: firstly placing the glass microspheres in a 0.3-0.7 mol / L sodium hydroxide solution, stirring at room temperature for activation for 1-3 hours, filtering to obtain filter residues, washing the filter residues with pure water, and drying to obtain hydroxylated glass microsphere samples; adding a silane coupling agent to a 75-95% ethanol aqueous solution to prepare a silane coupling agent ethanol aqueous solution with a concentration of 0.5-3wt%, adjusting the solution to a pH of 3-5, and fully stirring to obtain a silane coupling agent treatment solution; adding the hydroxylated glass microsphere sample to the silane coupling agent treatment solution, fully stirring, filtering to obtain filter residues, and drying to obtain modified glass microspheres, and screening out modified glass microspheres with a diameter of 50-600 μm; 2 to 8 parts of the modified glass microspheres, 21 to 33 parts of GPPS resin, 28 to 32 parts of PC resin, 28 to 35 parts of SMA resin, 0.2 to 0.6 parts of antioxidant, 1 to 5 parts of liquid paraffin or silicone oil, 0.6 to 1.2 parts of light stabilizer, 0.4 to 0.8 parts of ultraviolet absorber, and 0.8 to 2.4 parts of brightener are uniformly stirred to obtain a mixture A, and the mixture A is put into a single screw extruder; then the single screw extruder is heated to melt the mixture A, and the mixture A is extruded by the single screw extruder to obtain a finished product; Among them, the temperatures of each zone of the single-screw extruder are: zone one temperature is 180-190°C, zone two temperature is 190-200°C, zone three temperature is 210-220°C, zone four temperature is 210-220°C, zone five temperature is 225-235°C, zone six temperature is 215-225°C, zone seven temperature is 210-220°C, and the die head temperature is 205-215°C.

2. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The silane coupling agent is a silane coupling agent having an unsaturated double bond.

3. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The silane coupling agent is a silane coupling agent having an acryloxy group.

4. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The silane coupling agent is a silane coupling agent having an amino group.

5. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The pH value of the solution was adjusted with glacial acetic acid or citric acid.

6. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The drying temperature is 80-100° C., and the drying time is 15-30 minutes.

7. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The antioxidant is any one of antioxidant 1024, antioxidant 1010 or antioxidant 1076.

8. The method for preparing a high temperature resistant foamed diffuser plate according to claim 1, characterized in that: The light stabilizer is selected from any one of light stabilizer 770, light stabilizer 944 or light stabilizer 622.

9. A high temperature resistant foam diffuser plate, characterized in that: It is made according to the method for preparing a high temperature resistant foamed diffusion plate according to any one of claims 1 to 8.

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