Optical mirror material PETG material and preparation method thereof

Abstract

The application relates to the technical field of PETG materials, in particular to a PETG material for optical mirror materials and a preparation method thereof, which comprises the following raw materials in parts by weight: transparent polyester resin 30-60 parts, antioxidant 1-3 parts, lubricant 0.5-2.5 parts, anti-yellowing agent 0.5-1.5 parts, plastic brightener 1-3 parts, polymer resin 5-10 parts, nucleating agent 1-3 parts and modified glass fiber 5-10 parts. The PETG material has excellent optical performance, a high-gloss surface and low turbidity, and the light transmittance can reach more than 90%; meanwhile, the PETG material has good toughness, excellent tensile resistance and good impact resistance; the prepared PETG material can be used for preparing GAG three-layer co-agent sheets, so that the GAG three-layer co-agent sheets have good transparency and good texture and are suitable for products with high transparency.

Description

Technical Field

[0001] This invention relates to the field of PETG material technology, specifically to a PETG material for optical mirrors and its preparation method. Background Technology

[0002] High-transparency polymer materials refer to polymer materials with a light transmittance of over 80% in everyday light. These materials are widely used in optical components, packaging, construction, medical supplies, optical fibers, and optical disc materials due to their unique optical properties. In recent years, the requirements for transparent polymer materials have become increasingly stringent, while the demand has increased dramatically. Common transparent polymer materials mainly include transparent PP, PETG / PCTG, PC, PMMA, and polycyclic cyclic olefins. Among them, PETG is a non-crystalline copolyester. The commonly used comonomer for PETG is 1,4-cyclohexanediethanol (CHDM), also known as polyethylene terephthalate-1,4-cyclohexanediethanol ester. Compared to PET, PETG contains the 1,4-cyclohexanediethanol comonomer, and compared to PCT, it contains the ethylene glycol comonomer. Therefore, the properties of PETG are quite different from those of PET and PCT. PETG sheets possess outstanding toughness and high impact strength, 3 to 10 times that of modified polyacrylates. They also offer a wide processing range, high mechanical strength, and excellent flexibility. Compared to PVC, they have higher transparency, better gloss, and are easier to print on, making them a new generation of environmentally friendly plastics. PETG is increasingly entering high-end fields such as packaging, medical applications, and optical lenses as an important optical resin. However, during the synthesis process, uneven or unstable refractive indices may occur, leading to irregular refraction of light as it passes through the material, affecting the consistency of optical performance. PETG material has relatively low hardness, making it prone to scratches and wear during synthesis and subsequent processing, reducing the lifespan and quality of optical lenses. Furthermore, PETG material may exhibit poor adhesion when bonding or coating with other materials, affecting the overall performance and reliability of optical lenses.

[0003] Therefore, developing a new type of PETG material for optical mirrors is of great significance to the sustainable development of this field. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a PETG material for optical mirrors. This PETG material has excellent optical properties, a high-gloss surface and low turbidity, and its light transmittance can reach more than 90%. At the same time, it also has good toughness, excellent tensile strength and good impact resistance.

[0005] The purpose of this invention is to provide a method for preparing PETG material for optical mirrors. This method is simple and efficient, easy to operate and control, produces high-quality products, and is conducive to industrial production.

[0006] The objective of this invention is achieved through the following technical solution: a PETG material for optical mirrors, comprising the following raw materials in parts by weight: 30-60 parts of transparent polyester resin, 1-3 parts of antioxidant, 0.5-2.5 parts of lubricant, 0.5-1.5 parts of anti-yellowing agent, 1-3 parts of plastic brightener, 5-10 parts of polymer resin, 1-3 parts of nucleating agent, and 5-10 parts of modified glass fiber.

[0007] The PETG material in this invention possesses excellent optical properties, a high-gloss surface, and low turbidity, with a light transmittance approaching 92%. It also exhibits good toughness, excellent tensile strength, and good impact resistance. It can be used to prepare GAG ​​three-layer co-agent sheets, resulting in sheets with excellent transparency (over 90%) and a superior texture, suitable for products requiring high transparency. Its excellent impact resistance and rigidity make it hard and durable, suitable for applications requiring high impact strength. It also exhibits excellent processability, allowing for sawing, die-cutting, drilling, and laser cutting. Furthermore, it can be cold-bent, hot-bent, bonded, welded, polished, printed, and coated. Cold bending does not cause self-destruction, resulting in a bright appearance. It also boasts excellent thermoforming properties, requiring no preheating for molding, high precision, a shrinkage rate of approximately 0.5%, excellent deep-forming properties, and is crack-free with uniform thickness. The transparent polyester resin used as the base material has excellent mechanical properties and high transparency. The addition of modified glass fiber effectively improves the strength of PP material. At the same time, due to the good compatibility between modified glass fiber and transparent polyester resin and polymer resin, the synergistic effect of modified glass fiber and nucleating agent can not only improve the tensile strength of PETG material, but also effectively improve the compatibility between various additives and transparent polyester resin, effectively avoiding the problem of additives reducing the surface smoothness of PP material and improving product quality. The nucleating agent promotes the crystallization of PETG (that is, it decomposes in PETG melt to generate new substances, which act as crystallization nuclei to promote the crystallization of PETG), improves the crystallinity and heat resistance of the material, improves the optical properties of the material, reduces the haze of the material, and improves the transparency.

[0008] Preferably, the transparent polyester resin is one or a mixture of PETGCR-5511 and PETGCR-5531.

[0009] Preferably, the transparent polyester resin is a non-crystalline copolyester resin polymerized from ethylene glycol, terephthalic acid, 1,4-cyclohexanediol and a catalyst.

[0010] Preferably, the catalyst is at least one selected from antimony oxide, antimony glycolate, antimony acetate, stannous chloride, stannous octoate, germanium chloride, and germanium oxide.

[0011] Preferably, the molar ratio of ethylene glycol, terephthalic acid and 1,4-cyclohexanediol is 1.0:1.0-4.0:0.3-0.7.

[0012] Preferably, the polymerization includes pre-condensation and condensation, wherein the temperature during pre-condensation is 150-220℃ and the pre-condensation time is 30-120 min; the temperature during condensation is 200-260℃ and the condensation time is 1-4 h.

[0013] The transparent polyester resin in this invention is prepared by polycondensation reaction of ethylene glycol, terephthalic acid, and 1,4-cyclohexanediethanol. Unlike the previous structure in which diacids and diols react to form ester bonds and polycondensation to form polymer chains, in this invention, a portion of the ethylene glycol is replaced by cyclohexanediethanol (CHDM). The addition of CHDM can prevent crystallization and improve processing performance, toughness, transparency, and chemical resistance.

[0014] Preferably, the antioxidant is at least one of phenolic antioxidant 1010 and phosphite antioxidant 168.

[0015] The antioxidants used in this invention can prevent PETG materials from being oxidized during processing and use, extend the service life of the materials, inhibit yellowing and degradation caused by oxidation, and maintain the optical and mechanical properties of the materials.

[0016] Preferably, the lubricant is at least one of white mineral oil, silicone powder, stearic acid and its salts, paraffin wax, hydrocarbons, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer.

[0017] The lubricant used in this invention can improve the fluidity of PETG material during processing, reduce processing difficulty, reduce friction between PETG material and processing equipment, and prevent the material from overheating or degrading due to friction during processing. Adding a certain amount of lubricant as an auxiliary material is beneficial for extrusion molding into rolls or sheets.

[0018] Preferably, the polymeric resin is composed of polyethylene naphthalate, epoxy resin and PET in a mass ratio of 0.8-1.2:0.4-0.8:0.3-0.7.

[0019] The polymer resin used in this invention is polyethylene naphthalate (PEN), which is similar to PET, but the naphthalene ring in the molecular chain replaces the benzene ring in PET. This gives PEN a higher glass transition temperature, better heat resistance, and higher physical and mechanical properties. In transparent PETG materials, the addition of PEN can improve the overall heat resistance of the material, enabling its use in higher temperature environments and expanding its application range. PEN also has good optical properties; its molecular structure results in high transmittance in the visible light range and effective blocking of ultraviolet light. In transparent PETG materials, the addition of PEN can further improve the transparency and optical purity of the material, while enhancing its UV resistance and reducing UV radiation. The influence of the coating on the contents of the packaging; epoxy resin has strong adhesive ability and can be tightly combined with PEN, PET and other additives to improve the integrity and stability of the material. In the synthesis of transparent PETG material, epoxy resin can act as a binder to enhance the interaction between the components, making the material structure more compact, thereby improving the mechanical strength and chemical resistance of the material; finally, PET is a common thermoplastic polyester. In transparent PETG material, PET is one of the main components, providing the material with basic physical and processing properties, enabling the material to meet the requirements of various molding processes, such as injection molding, extrusion, blow molding, etc.; by adjusting the ratio of PET to PEN and epoxy resin, the performance balance of transparent PETG material can be adjusted.

[0020] Preferably, the nucleating agent is at least one of carboxylates, sorbitols, and polymeric nucleating agents.

[0021] Preferably, the anti-yellowing agent is prepared by loading hindered amine light stabilizer (HALS) onto the surface of nano-silica or nano-zinc oxide through physical adsorption.

[0022] The above-mentioned anti-yellowing agent in this invention, when combined with PETG material, can improve the dispersibility and stability of the anti-yellowing agent. At the same time, the nanoparticles themselves may also have certain anti-yellowing properties, thereby synergistically improving the anti-yellowing effect of PETG material.

[0023] Preferably, the modified glass fiber is prepared by the following method:

[0024] A1. Take glass fibers and clean them with deionized water. Then, perform plasma etching on the cleaned glass fibers to obtain pre-etched glass fibers. The plasma etching conditions are as follows: the plasma gas is either nitrogen or argon; the power density is 200-300W; the pressure is 300-1000Pa; and the etching time is 15-30 minutes.

[0025] A2. Prepare an acrylic acid solution with a mass concentration of 10-20%, then immerse the pre-etched glass fiber in it, maintain the temperature at 70-120℃, apply vacuum pressure to 800-1200Pa and react for 20-40 minutes. After that, clean it with deionized water and dry it to obtain the pretreated material for later use.

[0026] A3. Take an appropriate amount of phosphoric acid solution, soak the pretreated material in it and stir for 10-20 minutes. Take out the pretreated material, wash and dry it. Then add it to an ethanol solution of coupling agent KH550 with a concentration of 0.5 g / ml, and disperse it by ultrasonication. Then put the dispersed mixture into a vacuum drying oven at 70-80℃ to dry it and obtain modified glass fiber.

[0027] In this invention, the glass fiber is first etched using plasma etching during modification. Adding an acrylic acid solution enhances the surface activity of the glass fiber. Acrylic acid, with its active groups such as carboxyl groups, can chemically react or physically adsorb with substances on the glass fiber surface during immersion. This interaction alters the surface chemical properties of the glass fiber, increasing its surface activity. Consequently, during subsequent etching, the etchant more easily contacts and reacts with the glass fiber surface, improving etching efficiency and uniformity. Furthermore, the acrylic acid solution improves the wettability of the glass fiber: the surface of glass fiber typically exhibits some hydrophobicity, which may hinder etching. The spreading and penetration of the etching agent on its surface is limited. Immersion in acrylic acid improves the wettability of the glass fiber, allowing the etching agent to spread and penetrate better, ensuring a uniform etching reaction across the entire glass fiber surface and avoiding uneven etching in certain areas. The coating or adsorption layer formed by acrylic acid on the glass fiber surface can provide some protection, reducing the direct erosion of the glass fiber by the etching agent, thus maintaining the structural integrity and mechanical strength of the glass fiber. Acrylic acid may also have a synergistic effect with the etching agent, promoting the etching reaction and accelerating its rate, thereby improving the etching effect. The pretreatment of etched glass fibers with phosphoric acid solution primarily serves to clean and activate the glass fiber surface: Etching products and impurities may remain on the surface of the glass fiber after etching. Immersing it in phosphoric acid solution allows the phosphoric acid to react chemically with these residues, dissolving and removing them, thus cleaning the glass fiber surface. Simultaneously, phosphoric acid treatment can break some chemical bonds on the glass fiber surface, generating new active sites such as hydroxyl groups, increasing the surface activity of the glass fiber and preparing it for subsequent grafting reactions with silane coupling agents. Furthermore, glass fibers themselves possess a certain degree of hydrophobicity, which affects their bonding effect with subsequent treatment agents. Phosphoric acid solution can improve the wettability of glass fibers, making the glass fiber surface easier to wet with the subsequent silane coupling agent solution, ensuring that the silane coupling agent can be evenly distributed on the glass fiber surface. After treatment with phosphoric acid solution, when the silane coupling agent comes into contact with the glass fiber, its hydrolyzable groups will undergo a hydrolysis reaction under certain conditions (such as the presence of moisture) to generate silanols (Si(OH)n). These silanols can undergo condensation reactions with the active groups such as hydroxyl groups generated on the glass fiber surface due to phosphoric acid treatment, thereby forming chemical bonds on the glass fiber surface to form a "molecular bridge." One end of the silane coupling agent is firmly bound to the glass fiber surface, while the organic functional groups at the other end extend outward. When subsequently compounded with polyester resin and polymer resin, these organic functional groups can undergo chemical reactions or physical interactions with the resin molecules, just like building a "molecular bridge" between the inorganic glass fiber and the organic resin, thereby greatly improving the interfacial bonding force between the glass fiber and the resin and improving the performance of the composite material.

[0028] In summary, the above modification methods can effectively modify glass fibers, improve their compatibility and interfacial bonding with organic materials, and thus result in composite materials with better performance.

[0029] This invention also provides a method for preparing PETG material for optical mirrors, comprising the following steps:

[0030] S1. Place the transparent polyester resin in a dryer at 65-70℃ and dry for 3-6 hours, controlling the moisture content to be below 0.1%, and set aside for later use.

[0031] S2. Take the dried transparent polyester resin, and add the transparent polyester resin, antioxidant, lubricant and nucleating agent to the mixer according to the weight parts and mix for 10-20 minutes. Then add the anti-yellowing agent, plastic brightener and polymer resin and continue to mix and stir for 20-40 minutes. Set aside.

[0032] S3. The mixed material is fed through a twin-screw extruder via the main feeder and the modified glass fiber via the side feeder for blending and granulation. The temperature settings of the twin-screw extruder are as follows: Zone 1: 190±5℃; Zone 2: 200±10℃; Zone 3: 220±10℃; Zone 4: 220±10℃; Die temperature: 220±10℃; Screw speed: 300-380 r / min. The PETG material is obtained through extrusion and granulation.

[0033] The beneficial effects of the present invention are as follows: the PETG material of the present invention has excellent optical properties, high gloss surface and low turbidity, and its light transmittance can reach more than 90%; at the same time, it also has good toughness, excellent tensile strength and good impact resistance.

[0034] The present invention provides a simple and efficient method for preparing PETG material for optical mirrors, which is easy to operate and control, produces high-quality products, and is conducive to industrial production. Detailed Implementation

[0035] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0036] A PETG material for optical mirrors comprises the following raw materials in parts by weight: 30 parts transparent polyester resin, 1 part antioxidant, 0.5 parts lubricant, 0.5 parts anti-yellowing agent, 1 part plastic brightener, 5 parts polymer resin, 1 part nucleating agent, and 5 parts modified glass fiber.

[0037] The transparent polyester resin is PETGCR-5511.

[0038] The antioxidant is a phenolic antioxidant 1010.

[0039] The lubricant is white mineral oil.

[0040] The polymer resin is composed of polyethylene naphthalate, epoxy resin and PET in a mass ratio of 0.8:0.4:0.3.

[0041] The nucleating agent is a carboxylate, preferably the sodium carboxylate nucleating agent model 101 provided by Dongguan Baolimei Plastics Co., Ltd.

[0042] The anti-yellowing agent is prepared by loading hindered amine light stabilizer (HALS) onto the surface of nano-silica or nano-zinc oxide through physical adsorption.

[0043] The modified glass fiber is prepared by the following method:

[0044] A1. Take glass fibers, clean them with deionized water, and then perform plasma etching on the cleaned glass fibers to obtain pre-etched glass fibers. The plasma etching conditions are as follows: the plasma gas is nitrogen, the power density is 200-300W, the pressure is 300Pa, and the etching time is 15min.

[0045] A2. Prepare an acrylic acid solution with a mass concentration of 10%, then immerse the pre-etched glass fiber in it, maintain the temperature at 70°C, apply vacuum pressure to 800Pa and react for 20 minutes, then clean it with deionized water and dry it to obtain the pretreated material for later use.

[0046] A3. Take an appropriate amount of phosphoric acid solution, soak the pretreated material in it and stir for 10 minutes. Take out the pretreated material, wash and dry it. Then add it to an ethanol solution of coupling agent KH550 with a concentration of 0.5 g / ml, disperse it by ultrasonication, and then put the dispersed mixture into a vacuum drying oven at 70°C to dry it to obtain modified glass fiber.

[0047] A method for preparing PETG material for optical mirrors includes the following steps:

[0048] S1. Place the transparent polyester resin in a dryer at 65℃ and dry for 3 hours, controlling the moisture content to be below 0.1%, and set aside for later use;

[0049] S2. Take the dried transparent polyester resin, add the transparent polyester resin, antioxidant, lubricant and nucleating agent to the mixer according to the weight parts and mix for 10 minutes. Then add the anti-yellowing agent, plastic brightener and polymer resin and continue to mix and stir for 20 minutes. Set aside.

[0050] S3. The mixed material is fed through a twin-screw extruder via the main feeder and the modified glass fiber via the side feeder for blending and granulation. The temperature settings of the twin-screw extruder are as follows: Zone 1: 190±5℃; Zone 2: 200±10℃; Zone 3: 220±10℃; Zone 4: 220±10℃; Die temperature: 220±10℃; Screw speed: 300-380 r / min. The PETG material is obtained through extrusion and granulation.

[0051] A PETG material for optical mirrors comprises the following raw materials in parts by weight: 45 parts transparent polyester resin, 2 parts antioxidant, 2.0 parts lubricant, 1.0 part anti-yellowing agent, 2 parts plastic brightener, 8 parts polymer resin, 2 parts nucleating agent, and 8 parts modified glass fiber.

[0052] The transparent polyester resin is a non-crystalline copolyester resin polymerized from ethylene glycol, terephthalic acid, 1,4-cyclohexanediol and a catalyst.

[0053] The catalyst is antimony glycol.

[0054] The molar ratio of ethylene glycol, terephthalic acid, and 1,4-cyclohexanediol is 1.0:2.0:0.5.

[0055] The polymerization includes pre-condensation and condensation. The temperature during pre-condensation is 200°C and the pre-condensation time is 60 min. The temperature during condensation is 240°C and the condensation time is 2 h.

[0056] The antioxidant is a phenolic antioxidant 1010.

[0057] The lubricant is composed of paraffin wax, ethylene-vinyl acetate copolymer and ethylene-acrylic acid copolymer in a mass ratio of 0.5:0.7:0.3.

[0058] The polymeric resin is composed of polyethylene naphthalate, epoxy resin and PET in a mass ratio of 1.0:0.6:0.5.

[0059] The nucleating agent is sorbitol, preferably the WBQ-88 transparent sorbitol PP nucleating agent provided by Guangdong Weilinna New Material Technology Co., Ltd.

[0060] The anti-yellowing agent is prepared by loading hindered amine light stabilizer (HALS) onto the surface of nano-silica or nano-zinc oxide through physical adsorption.

[0061] The modified glass fiber is prepared by the following method:

[0062] A1. Take glass fibers, clean them with deionized water, and then perform plasma etching treatment on the cleaned glass fibers to obtain pre-etched glass fibers. The plasma etching conditions are as follows: the plasma gas is nitrogen, the power density is 250W, the pressure is 600Pa, and the etching time is 25min.

[0063] A2. Prepare an acrylic acid solution with a mass concentration of 15%, then immerse the pre-etched glass fiber in it, maintain the temperature at 100℃, apply vacuum pressure to 1000Pa and react for 30 minutes, then clean it with deionized water and dry it to obtain the pretreated material for later use.

[0064] A3. Take an appropriate amount of phosphoric acid solution, soak the pretreated material in it and stir for 15 minutes. Take out the pretreated material, wash and dry it. Then add it to an ethanol solution of coupling agent KH550 with a concentration of 0.5 g / ml, disperse it by ultrasonication, and then put the dispersed mixture into a vacuum drying oven at 75°C to dry it to obtain modified glass fiber.

[0065] A method for preparing PETG material for optical mirrors includes the following steps:

[0066] S1. Place the transparent polyester resin in a dryer at 68℃ and dry for 5 hours, controlling the moisture content to be below 0.1%, and set aside for later use;

[0067] S2. Take the dried transparent polyester resin, add the transparent polyester resin, antioxidant, lubricant and nucleating agent to the mixer according to the weight parts and mix for 15 minutes. Then add the anti-yellowing agent, plastic brightener and polymer resin and continue to mix and stir for 30 minutes. Set aside.

[0068] S3. The mixed material is fed through a twin-screw extruder via the main feeder and the modified glass fiber via the side feeder for blending and granulation. The temperature settings of the twin-screw extruder are as follows: Zone 1: 190±5℃; Zone 2: 200±10℃; Zone 3: 220±10℃; Zone 4: 220±10℃; Die temperature: 220±10℃; Screw speed: 300-380 r / min. The PETG material is obtained through extrusion and granulation.

[0069] A PETG material for optical mirrors comprises the following raw materials in parts by weight: 60 parts transparent polyester resin, 3 parts antioxidant, 2.5 parts lubricant, 1.5 parts anti-yellowing agent, 3 parts plastic brightener, 10 parts polymer resin, 3 parts nucleating agent, and 10 parts modified glass fiber.

[0070] The transparent polyester resin is a non-crystalline copolyester resin polymerized from ethylene glycol, terephthalic acid, 1,4-cyclohexanediol and a catalyst.

[0071] The catalyst is stannous octoate.

[0072] The molar ratio of ethylene glycol, terephthalic acid, and 1,4-cyclohexanediol is 1.0:4.0:0.7.

[0073] The polymerization includes pre-condensation and condensation. The temperature during pre-condensation is 220°C and the pre-condensation time is 30 min. The temperature during condensation is 260°C and the condensation time is 4 h.

[0074] The antioxidant is a phenolic antioxidant 1010.

[0075] The lubricant is silicone powder.

[0076] The polymeric resin is composed of polyethylene naphthalate, epoxy resin and PET in a mass ratio of 1.2:0.8:0.7.

[0077] The nucleating agent is a carboxylate, preferably the sodium carboxylate nucleating agent model 101 provided by Dongguan Baolimei Plastics Co., Ltd.

[0078] The anti-yellowing agent is prepared by loading hindered amine light stabilizer (HALS) onto the surface of nano-silica or nano-zinc oxide through physical adsorption.

[0079] The modified glass fiber is prepared by the following method:

[0080] A1. Take glass fibers, clean them with deionized water, and then perform plasma etching on the cleaned glass fibers to obtain pre-etched glass fibers. The plasma etching conditions are as follows: the plasma gas is either nitrogen or argon, the power density is 300W, the pressure is 1000Pa, and the etching time is 30min.

[0081] A2. Prepare an acrylic acid solution with a mass concentration of 20%, then immerse the pre-etched glass fiber in it, maintain the temperature at 120°C, and react under vacuum and pressure of 1200Pa for 40 minutes. Afterwards, clean it with deionized water and dry it to obtain the pretreated material for later use.

[0082] A3. Take an appropriate amount of phosphoric acid solution, soak the pretreated material in it and stir for 20 minutes. Take out the pretreated material, wash and dry it. Then add it to an ethanol solution of coupling agent KH550 with a concentration of 0.5 g / ml, disperse it by ultrasonication, and then put the dispersed mixture into a vacuum drying oven at 80°C to dry it to obtain modified glass fiber.

[0083] A method for preparing PETG material for optical mirrors includes the following steps:

[0084] S1. Place the transparent polyester resin in a dryer at 70℃ and dry for 6 hours, controlling the moisture content to be below 0.1%, and set aside for later use;

[0085] S2. Take the dried transparent polyester resin, add the transparent polyester resin, antioxidant, lubricant and nucleating agent to the mixer according to the weight parts and mix for 20 minutes. Then add the anti-yellowing agent, plastic brightener and polymer resin and continue to mix and stir for 40 minutes. Set aside.

[0086] S3. The mixed material is fed through a twin-screw extruder via the main feeder and the modified glass fiber via the side feeder for blending and granulation. The temperature settings of the twin-screw extruder are as follows: Zone 1: 190±5℃; Zone 2: 200±10℃; Zone 3: 220±10℃; Zone 4: 220±10℃; Die temperature: 220±10℃; Screw speed: 300-380 r / min. The PETG material is obtained through extrusion and granulation.

[0087] Battery separator.

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 2 above is that the PETG material in this comparative example uses commercially available PN300 PETG instead of transparent polyester resin. The rest of the contents of this comparative example are the same as in Example 2, and will not be repeated here.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 2 above is that no polymer resin was added to the raw materials of the PETG material in this comparative example. The rest of the contents of this comparative example are the same as in Example 2, and will not be repeated here.

[0092] Comparative Example 3

[0093] The difference between this comparative example and Example 2 above is that conventional glass fiber is used instead of modified glass fiber in the raw materials of the PETG material in this comparative example, and the remaining raw materials are mixed in the proportions of Example 2. The rest of the contents of this comparative example are the same as those of Example 2, and will not be repeated here.

[0094] The PETG materials prepared in Example 2 and Comparative Example 1 were placed in a mold, hot-pressed, cooled, and demolded to obtain samples for performance testing. The results are shown in Table 1 below:

[0095] Flowability: Refer to GB / T 3682 2000 "Determination of melt mass flow rate and melt volume flow rate of thermoplastics";

[0096] Bending strength: Tested according to GB9341 test standard, the test condition is 2mm / min;

[0097] Mechanical properties: Tensile strength and elongation at break were tested in accordance with GB / T1040.3.

[0098] The light transmittance was determined according to GB / T2410 2008, and the sample size was 100×100×2mm.

[0099] Table 1

[0100] project Moisture flow rate (MFR) [g·(10min⁻¹)] Flexural strength MPa Tensile strength (MPa) Elongation at break (%) transmittance % Example 2 15.36 175 63.8 63 91 Comparative Example 1 14.28 153 58.4 47 78

[0101] The PETG materials prepared in Example 2 and Comparative Example 1 were placed in a mold, hot-pressed, cooled, and demolded to obtain samples for performance testing. The results are shown in Table 2 below:

[0102] Mechanical properties: Tensile strength and elongation at break were tested in accordance with GB / T1040.3.

[0103] The light transmittance was determined according to GB / T2410 2008, and the sample size was 100×100×2mm.

[0104] Table 2

[0105] project Tensile strength (MPA) Elongation at break (%) transmittance % Example 2 63.8 63 91 Comparative Example 2 55.7 45 90

[0106] The PETG materials prepared in Example 2 and Comparative Example 1 were placed in a mold, hot-pressed, cooled, and demolded to obtain samples for performance testing. The results are shown in Table 3 below:

[0107] Mechanical properties: Tensile strength and elongation at break were tested in accordance with GB / T1040.3.

[0108] Surface gloss: Tested according to GB 8807 standard, with a test temperature of 60°.

[0109] Table 3

[0110] project Surface gloss GU Tensile strength (MPa) Elongation at break (%) transmittance % Example 2 86 63.8 63 91 Comparative Example 3 72 53.4 53 78

[0111] As can be seen from the data in Tables 1-3, the PETG material prepared in Example 2 of this invention has excellent light transmittance, which can reach more than 90%. It also has good toughness, excellent tensile strength, and good toughness and impact resistance. By adding special transparent polyester resin, polymer resin and modified glass fiber to the raw materials for preparing PETG material, the problems existing in the current PETG material are fundamentally solved.

[0112] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A PETG material for optical mirrors, characterized in that: The raw materials include the following parts by weight: 30-60 parts transparent polyester resin, 1-3 parts antioxidant, 0.5-2.5 parts lubricant, 0.5-1.5 parts anti-yellowing agent, 1-3 parts plastic brightener, 5-10 parts polymer resin, 1-3 parts nucleating agent, and 5-10 parts modified glass fiber. The transparent polyester resin is a non-crystalline copolyester resin polymerized from ethylene glycol, terephthalic acid, 1,4-cyclohexanediol and a catalyst. The catalyst is at least one of antimony oxide, antimony glycol, antimony acetate, stannous chloride, stannous octoate, germanium chloride, and germanium oxide. The molar ratio of ethylene glycol, terephthalic acid, and 1,4-cyclohexanediol is 1.0:1.0-4.0:0.3-0.7; the polymerization includes pre-condensation and polycondensation, wherein the temperature during pre-condensation is 150-220℃ and the pre-condensation time is 30-120 min; the temperature during polycondensation is 200-260℃ and the polycondensation time is 1-4 h; The polymeric resin is composed of polyethylene naphthalate, epoxy resin, and PET in a mass ratio of 0.8-1.2:0.4-0.8:0.3-0.

7. The modified glass fiber is prepared by the following method: A1. Take glass fibers and clean them with deionized water. Then, perform plasma etching on the cleaned glass fibers to obtain pre-etched glass fibers. The plasma etching conditions are as follows: the plasma gas is either nitrogen or argon; the power density is 200-300W; the pressure is 300-1000Pa; and the etching time is 15-30 minutes. A2. Prepare an acrylic acid solution with a mass concentration of 10-20%, then immerse the pre-etched glass fiber in it, maintain the temperature at 70-120℃, apply vacuum pressure to 800-1200Pa and react for 20-40 minutes. After that, clean it with deionized water and dry it to obtain the pretreated material for later use. A3. Take an appropriate amount of phosphoric acid solution, soak the pretreated material in it and stir for 10-20 minutes. Take out the pretreated material, wash and dry it. Then add it to an ethanol solution of coupling agent KH550 with a concentration of 0.5 g / ml, and disperse it by ultrasonication. Then put the dispersed mixture into a vacuum drying oven at 70-80℃ to dry it and obtain modified glass fiber.

2. The PETG material for optical mirrors according to claim 1, characterized in that: The transparent polyester resin is one or a mixture of PETGCR-5511 and PETGCR-5531.

3. The PETG material for optical mirrors according to claim 1, characterized in that: The antioxidant is at least one of phenolic antioxidant 1010 and phosphite antioxidant 168; the nucleating agent is at least one of carboxylates, sorbitol, and polymeric nucleating agents.

4. The PETG material for optical mirrors according to claim 1, characterized in that: The lubricant is at least one of white mineral oil, silicone powder, stearic acid and its salts, paraffin wax, hydrocarbons, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer.

5. A method for preparing PETG material for optical mirrors as described in any one of claims 1-4, characterized in that: Includes the following steps: S1. Place the transparent polyester resin in a dryer at 65-70℃ and dry for 3-6 hours, controlling the moisture content to be below 0.1%, and set aside for later use. S2. Take the dried transparent polyester resin, and add the transparent polyester resin, antioxidant, lubricant and nucleating agent to the mixer according to the weight parts and mix for 10-20 minutes. Then add the anti-yellowing agent, plastic brightener and polymer resin and continue to mix and stir for 20-40 minutes. Set aside. S3. The mixed material is fed through a twin-screw extruder via the main feeder and the modified glass fiber via the side feeder for blending and granulation. The temperature settings of the twin-screw extruder are as follows: Zone 1: 190±5℃; Zone 2: 200±10℃; Zone 3: 220±10℃; Zone 4: 220±10℃; Die temperature: 220±10℃; Screw speed: 300-380 r / min. The PETG material is obtained through extrusion and granulation.