Matt PETG polyester material and preparation method thereof

Abstract

The invention discloses a matte PETG polyester material and a preparation method thereof, and relates to the technical field of high polymer materials. The matte PETG polyester material is prepared from the following raw materials in parts by weight: 60 to 80 parts of PETG resin, 5 to 12 parts of modified silicon dioxide, 4 to 10 parts of a modified ethylene-methyl acrylate copolymer, 1 to 3 parts of polyethylene glycol 4000, 0.2 to 0.5 part of an antioxidant 1010, 0.1 to 0.3 part of an antioxidant 168, 0.3 to 0.8 part of calcium stearate and 0.2 to 0.6 part of an ultraviolet light absorber UV-531. The matte PETG polyester material is scientific in formula, and the performance of the material is improved through the synergistic effect of the modified silicon dioxide and the modified ethylene-methyl acrylate copolymer. The preparation process is controllable, parameters of steps of drying, mixing, extruding and the like are clear, and the product stability is good. The antioxidant, the ultraviolet light absorber and the like are added, so that the anti-aging and anti-ultraviolet functions are achieved, and the application prospect is wide.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a matte PETG polyester material and its preparation method. Background Technology

[0002] PETG polyester material, as a non-crystalline copolyester, combines the excellent mechanical properties of PET with the good processability of PC. It is also environmentally friendly, non-toxic, chemically resistant, and highly transparent, making it widely used in packaging containers, sheets, films, and daily necessities. As market demand for material appearance, texture, and functional diversity continues to rise, matte PETG polyester material, due to its ability to effectively avoid glare, present a soft visual effect, and offer a comfortable touch, is gradually becoming the preferred choice for high-end packaging and decorative materials.

[0003] However, the preparation of existing matte PETG polyester materials still faces many technical challenges. Traditional matte modification is mostly achieved by adding unmodified inorganic powders (such as ordinary silica and talc). However, inorganic powders have poor compatibility with the PETG resin matrix, easily leading to agglomeration, which significantly reduces the mechanical properties of the material. Simultaneously, the matte effect is uneven, and the surface roughness is high, affecting the product's appearance and user experience. Furthermore, some formulations use a single matting agent or conventional copolymer modification, making it difficult to balance matteness, mechanical strength, and processing stability. This results in insufficient matte effect or excessive matteness leading to loss of light transmittance.

[0004] During processing, PETG materials are susceptible to thermal oxidation degradation due to high temperatures and oxygen, resulting in poor melt flowability and defects such as yellowing and embrittlement in the products. At the same time, in outdoor use scenarios, ultraviolet radiation will accelerate material aging and shorten service life, and most existing matte PETG materials lack an effective anti-oxidation and anti-ultraviolet synergistic protection system.

[0005] Furthermore, the interfacial bonding between existing modified copolymers and PETG resin is weak, failing to effectively transfer stress. This results in key mechanical properties such as impact strength and elongation at break failing to meet the demands of high-end applications. Therefore, developing a matte PETG polyester material that combines a uniform matte finish, excellent mechanical properties, good processing stability, and anti-aging functions, and optimizing its formulation and preparation process, has become a pressing technical challenge for the industry. This is of great significance for expanding the application scenarios of PETG materials and increasing product added value. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a matte PETG polyester material and its preparation method, solving the problems of uneven matte finish, poor compatibility, decreased mechanical properties, insufficient aging resistance, and poor processing stability of existing matte PETG polyester materials.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A matte PETG polyester material comprising the following raw materials in parts by weight: 60-80 parts PETG resin, 5-12 parts modified silica, 4-10 parts modified ethylene-methyl acrylate copolymer, 1-3 parts polyethylene glycol 4000, 0.2-0.5 parts antioxidant 1010, 0.1-0.3 parts antioxidant 168, 0.3-0.8 parts calcium stearate, and 0.2-0.6 parts ultraviolet absorber UV-531.

[0008] Furthermore, the intrinsic viscosity of the PETG resin is 0.75-0.90 dL / g, and the density is 1.26-1.28 g / cm³. 3 Furthermore, its melt flow rate at 230℃ and 2.16kg is 10-15g / 10min. PETG resin with these parameters possesses both suitable rigidity and fluidity, ensuring stable melt molding during processing and avoiding product defects caused by excessive flow. It also provides a stable matrix for modified silica, modified copolymers, and other components, ensuring that each functional component works synergistically and balancing the material's mechanical properties and processing efficiency.

[0009] Furthermore, the modified silica is prepared using the following specific steps: A1. Dissolve silane coupling agent KH550 in a mixture of anhydrous ethanol and deionized water, and stir until homogeneous. Then adjust the pH of the system to 4-5 with 0.1 mol / L acetic acid aqueous solution, add hydrophilic fumed silica, and stir at 60-70℃ for 3-4 hours. After the reaction is complete, filter, wash the filter cake three times with anhydrous ethanol, and dry it under vacuum at 80℃ to constant weight to obtain aminated silica. The silane coupling agent KH550 grafts amino groups to provide active sites for subsequent carboxylation. At the same time, the ethanol produced by silane hydrolysis and the washing step can remove physically adsorbed free silanes, preventing them from occupying surface active sites, thereby ensuring that the subsequent carboxylation reaction proceeds fully.

[0010] A2. Add adipic anhydride to N,N-dimethylformamide, mix well, then add aminated silica, and slowly add triethylamine as a catalyst. Heat to 80-90℃ and stir for 5-6 hours. After the reaction is complete, filter and wash the filter cake alternately with N,N-dimethylformamide and deionized water until the filtrate is neutral. Then dry the filter cake under vacuum at 100℃ to constant weight to obtain carboxylated silica. The carboxyl group is introduced by the reaction of adipic anhydride and amino groups, which provides a reaction bridge for the hydrophobic modification of stearic acid. The small molecules of byproducts generated by the amidation reaction can be removed by alternating washing with N,N-dimethylformamide / water to avoid residues affecting the activity of subsequent esterification reactions.

[0011] A3. Stearic acid was added to toluene, and the mixture was heated to 50-60℃ under nitrogen protection, stirring until the stearic acid was completely dissolved. Carboxylated silica and p-toluenesulfonic acid were added, and stirring was continued for 10 minutes. The mixture was then heated to 110-120℃ and refluxed for 6-7 hours. After the reaction, the mixture was filtered, and the filter cake was washed three times with toluene. Finally, the filter cake was vacuum dried at 120℃ to constant weight to obtain modified silica. Grafting hydrophobic segments through esterification significantly improves the compatibility of silica with PETG resin, avoids agglomeration, and lays the foundation for a uniform matte finish.

[0012] Furthermore, during the dissolution of stearic acid in toluene in A3, the nitrogen purging rate is 0.5-1 L / min, and the exhaust valve of the reaction apparatus needs to be opened once every 1 hour during the reflux reaction, with each depressurization lasting 10-15 seconds. Nitrogen protection can prevent the carboxyl groups on the surface of carboxylated silica from being prematurely acidified by moisture in the air, which would lead to a decrease in the activity of the esterification reaction, and also prevent the vapor of toluene from forming an explosive mixture with air during reflux. Timed depressurization can remove small molecule products and residual air generated in the reaction, avoid excessive system pressure affecting the reaction stability, and at the same time promote the forward esterification reaction and improve the hydrophobic modification efficiency.

[0013] Furthermore, the ratio of silane coupling agent KH550, anhydrous ethanol, deionized water, and hydrophilic fumed silica in A1 is 20-24g: 200-250ml: 32-35ml: 100g.

[0014] Furthermore, the ratio of adipic anhydride, N,N-dimethylformamide, aminated silica, and triethylamine in A2 is 15-17g: 150-180ml: 100g: 5-6ml.

[0015] Furthermore, the ratio of stearic acid, toluene, carboxylated silicon dioxide, and p-toluenesulfonic acid in A3 is 12-14g: 100-120ml: 100g: 0.5-1g.

[0016] Furthermore, the modified ethylene-methyl acrylate copolymer is prepared using the following specific steps: B1. Dissolve the ethylene-methyl acrylate copolymer in xylene, heat to 100-110℃, add maleic anhydride and dicumyl peroxide, stir at a constant temperature for 4-5 hours, and after the reaction is completed, allow it to cool naturally to room temperature, precipitate in ethanol, filter and collect the product, wash twice with acetone, and dry under vacuum at 60℃ to constant weight to obtain the maleic anhydride-grafted ethylene-methyl acrylate copolymer. Grafting maleic anhydride under the action of dicumyl peroxide initiator introduces polar anhydride groups, enhancing the interaction between the copolymer and the PETG matrix. After the reaction, filter and wash to remove unreacted monomers to avoid residues affecting the efficiency of subsequent hydroxylation reactions.

[0017] B2. Ethyl glycol monomethyl ether was dissolved in ethyl acetate, and maleic anhydride-grafted ethylene-methyl acrylate copolymer and tetrabutyl titanate were added. The system was heated to 70-80℃ and stirred for 3-4 hours. After the reaction, the mixture was filtered, cooled to room temperature and filtered again. The product was washed with ethyl acetate until the washing liquid was clear. Then, it was dried under vacuum at 70℃ to constant weight to obtain hydroxylated ethylene-methyl acrylate copolymer. The introduction of hydroxyl-terminated flexible segments through an anhydride ring-opening esterification reaction further enhanced the polarity of the copolymer and improved the interfacial bonding with the PETG matrix.

[0018] B3. Methyl methacrylate was dissolved in butyl acetate, and hydroxylated ethylene-methyl acrylate copolymer and azobisisobutyronitrile were added. After sealing the reaction apparatus, nitrogen gas was introduced for purging at a rate of 1-2 L / min for 30 min, ensuring the oxygen content of the system was ≤100 ppm. The system was then heated to 80-90℃ and reacted at this temperature for 5 h. After the reaction was completed and cooled to room temperature, the mixture was filtered, and the product was washed three times with butyl acetate. Finally, it was vacuum dried at 80℃ to constant weight to obtain the modified ethylene-methyl acrylate copolymer. Under nitrogen protection, the free radicals generated by the decomposition of azobisisobutyronitrile can stably initiate the graft polymerization of methyl methacrylate; nitrogen purging simultaneously removes byproducts such as tetramethylsuccinate generated in the reaction, preventing them from inhibiting polymerization.

[0019] Furthermore, the ratio of ethylene-methyl acrylate copolymer, xylene, maleic anhydride, and dicumyl peroxide in B1 is 100g: 180-200ml: 8-12g: 0.5-0.7g.

[0020] Furthermore, the ratio of ethylene glycol monomethyl ether, ethyl acetate, maleic anhydride-grafted ethylene-methyl acrylate copolymer, and tetrabutyl titanate in B2 is 10-15g: 120-150ml: 100g: 0.3-0.4g.

[0021] Furthermore, the ratio of methyl methacrylate, butyl acetate, hydroxylated ethylene-methyl acrylate copolymer, and azobisisobutyronitrile in B3 is 15-20g: 180-220ml: 100g: 0.4-0.5g.

[0022] A method for preparing a matte PETG polyester material, specifically comprising the following steps: S1. Vacuum dry PETG resin at 80-90℃ for 4-6 hours; Vacuum dry modified silica, modified ethylene-methyl acrylate copolymer, polyethylene glycol 4000, antioxidant 1010, antioxidant 168, calcium stearate, and ultraviolet absorber UV-531 at 60℃ for 2-3 hours respectively. S2. First, mix 60-80 parts of PETG resin, 5-12 parts of modified silica, 4-10 parts of modified ethylene-methyl acrylate copolymer, and 1-3 parts of polyethylene glycol 4000. Adjust the speed to 1000-1200 r / min and mix for 6-8 min. Then add 0.2-0.5 parts of antioxidant 1010, 0.1-0.3 parts of antioxidant 168, 0.3-0.8 parts of calcium stearate, and 0.2-0.6 parts of ultraviolet absorber UV-531. Continue mixing at the same speed for 4-7 min to ensure that all components are uniformly blended to obtain a premix. S3. Add the premixed material to the twin-screw extruder, set the temperature of Zone 1 to 205-210℃, Zone 2 to 210-215℃, Zone 3 to 215-220℃, the die head temperature to 225-230℃, and the screw speed to 200-220 r / min. After the material is extruded from the die head, it immediately enters a water cooling tank at 20-25℃ to cool. After ensuring that the material is completely cooled to room temperature, it is pelletized by a pelletizer. After pelletizing, the pellets are placed in a hot air drying oven at 60℃ and dried for 2 hours to remove surface moisture, thus obtaining matte PETG polyester material.

[0023] This invention provides a matte PETG polyester material and its preparation method, which has the following beneficial effects: 1. This invention significantly improves the compatibility of silica with the PETG resin matrix by amylating, carboxylating, and modifying it with stearic acid, effectively avoiding powder agglomeration. Simultaneously, the synergistic effect of the modified ethylene-methyl acrylate copolymer creates a uniformly dispersed matte system within the material. The product exhibits a soft and delicate matte texture, free from glare interference, with moderate surface roughness, ensuring a consistent visual effect and a comfortable tactile experience. This meets the stringent requirements for appearance and texture in high-end packaging and decorative materials, solving the problems of uneven matte finish and rough surface in traditional matte materials.

[0024] 2. A stable interfacial bond is formed between modified silica, PETG resin, and the modified copolymer. The modified copolymer introduces hydroxyl and methyl methacrylate segments through a multi-step grafting reaction, enhancing stress transfer with the matrix and effectively compensating for the mechanical property degradation caused by the addition of inorganic powders in traditional matte materials. The finished material possesses excellent impact strength, tensile strength, and elongation at break, with a balance between toughness and rigidity. It can withstand stress during processing and external impacts during use, and can be widely used in the production of various forms of products such as packaging containers, sheets, and films, adapting to diverse application needs.

[0025] 3. The formula incorporates antioxidants 1010 and 168, forming a synergistic anti-thermal oxidation system that effectively inhibits oxidative degradation of materials during high-temperature processing and use, preventing yellowing and embrittlement. The addition of UV absorber UV-531 imparts excellent UV aging resistance to the material, slowing down the aging rate during outdoor use and extending the product's service life. Simultaneously, the precise proportioning and pretreatment of each component ensures stable melt flow during twin-screw extrusion, a reasonable processing temperature range, and reduces the likelihood of melt fracture and product defects, guaranteeing the continuity and stability of industrial production. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: Preparation of matte PETG polyester material. The specific preparation steps are as follows: S1. Vacuum dry PETG resin at 80℃ for 4h; Modified silica, modified ethylene-methyl acrylate copolymer, polyethylene glycol 4000, antioxidant 1010, antioxidant 168, calcium stearate, and ultraviolet absorber UV-531 are vacuum dried at 60℃ for 2h respectively. S2. First, mix 60 parts PETG resin, 5 parts modified silica, 4 parts modified ethylene-methyl acrylate copolymer, and 1 part polyethylene glycol 4000 at a speed of 1000 r / min for 6 min. Then add 0.2 parts antioxidant 1010, 0.1 parts antioxidant 168, 0.3 parts calcium stearate, and 0.2 parts ultraviolet absorber UV-531. Continue mixing at the same speed for 4 min to ensure that all components are uniformly blended to obtain a premix. S3. Add the premixed material to the twin-screw extruder, set the temperature of zone 1 to 205℃, zone 2 to 210℃, zone 3 to 215℃, the die head temperature to 225℃, and the screw speed to 200r / min. After the material is extruded from the die head, it immediately enters a 20℃ water cooling tank to cool. After ensuring that the material is completely cooled to room temperature, it is pelletized by a pelletizer. After pelleting, the pellets are placed in a 60℃ hot air drying oven to dry for 2 hours to remove surface moisture and obtain matte PETG polyester material.

[0028] Example 2: Preparation of matte PETG polyester material. The specific preparation steps are as follows: S1. Vacuum dry PETG resin at 90℃ for 6h; Modified silica, modified ethylene-methyl acrylate copolymer, polyethylene glycol 4000, antioxidant 1010, antioxidant 168, calcium stearate, and ultraviolet absorber UV-531 are vacuum dried at 60℃ for 3h respectively. S2. First, mix 80 parts PETG resin, 12 parts modified silica, 10 parts modified ethylene-methyl acrylate copolymer, and 3 parts polyethylene glycol 4000 at a speed of 1200 r / min for 8 min. Then add 0.5 parts antioxidant 1010, 0.3 parts antioxidant 168, 0.8 parts calcium stearate, and 0.6 parts ultraviolet absorber UV-531. Continue mixing at the same speed for 7 min to ensure that all components are uniformly blended to obtain a premix. S3. Add the premixed material to the twin-screw extruder, set the temperature of zone 1 to 210℃, zone 2 to 215℃, zone 3 to 220℃, the die head temperature to 230℃, and the screw speed to 220r / min. After the material is extruded from the die head, it immediately enters a 25℃ water cooling tank to cool. After ensuring that the material is completely cooled to room temperature, it is pelletized by a pelletizer. After pelletizing, the pellets are placed in a 60℃ hot air drying oven to dry for 2 hours to remove surface moisture and obtain matte PETG polyester material.

[0029] Example 3: Preparation of matte PETG polyester material. The specific preparation steps are as follows: S1. Vacuum dry PETG resin at 85℃ for 5h; modify silica, modify ethylene-methyl acrylate copolymer, polyethylene glycol 4000, antioxidant 1010, antioxidant 168, calcium stearate, and ultraviolet absorber UV-531 are vacuum dried at 60℃ for 2.5h respectively. S2. First, mix 70 parts PETG resin, 8 parts modified silica, 7 parts modified ethylene-methyl acrylate copolymer, and 2 parts polyethylene glycol 4000 at a speed of 1100 r / min for 7 min. Then add 0.3 parts antioxidant 1010, 0.2 parts antioxidant 168, 0.5 parts calcium stearate, and 0.4 parts ultraviolet absorber UV-531. Continue mixing at the same speed for 5 min to ensure that all components are uniformly blended to obtain a premix. S3. Add the premixed material to the twin-screw extruder, set the temperature of zone 1 to 207℃, zone 2 to 212℃, zone 3 to 217℃, the die head temperature to 227℃, and the screw speed to 210r / min. After the material is extruded from the die head, it immediately enters a 22℃ water cooling tank to cool. After ensuring that the material is completely cooled to room temperature, it is pelletized by a pelletizer. After pelletizing, the pellets are placed in a 60℃ hot air drying oven to dry for 2 hours to remove surface moisture and obtain matte PETG polyester material.

[0030] Example 4: Preparation of modified silica. The specific preparation steps are as follows: A1. Dissolve 20g of silane coupling agent KH550 in a mixture of 200ml anhydrous ethanol and 32ml deionized water, and stir until homogeneous. Then adjust the pH of the system to 4 with 0.1mol / L acetic acid aqueous solution, add 100g of hydrophilic fumed silica, and stir at 60℃ for 3h. After the reaction is complete, filter, wash the filter cake three times with anhydrous ethanol, and dry it under vacuum at 80℃ to constant weight to obtain aminated silica. A2. Add 15g of adipic anhydride to 150ml of N,N-dimethylformamide, mix well, then add 100g of aminated silica, slowly add 5ml of triethylamine as a catalyst, heat to 80℃ and stir for 5h. After the reaction is complete, filter, wash the filter cake alternately with N,N-dimethylformamide and deionized water until the filtrate is neutral, and then dry the filter cake under vacuum at 100℃ to constant weight to obtain carboxylated silica. A3. Add 12g of stearic acid to 100ml of toluene, heat to 50℃ under nitrogen protection, and stir until the stearic acid is completely dissolved; add 100g of carboxylated silica and 0.5g of p-toluenesulfonic acid, continue stirring for 10min, then heat to 110℃ and reflux for 6h. After the reaction, filter, wash the filter cake three times with toluene, and finally dry the filter cake under vacuum at 120℃ to constant weight to obtain modified silica.

[0031] Example 5: Preparation of modified silica. The specific preparation steps are as follows: A1. Dissolve 24g of silane coupling agent KH550 in a mixture of 250ml anhydrous ethanol and 35ml deionized water, and stir until homogeneous. Then adjust the pH of the system to 5 with 0.1mol / L acetic acid aqueous solution, add 100g of hydrophilic fumed silica, and stir at 70℃ for 4h. After the reaction is complete, filter, wash the filter cake three times with anhydrous ethanol, and dry it under vacuum at 80℃ to constant weight to obtain aminated silica. A2. Add 17g of adipic anhydride to 180ml of N,N-dimethylformamide, mix well, then add 100g of aminated silica, slowly add 6ml of triethylamine as a catalyst, heat to 90℃ and stir for 6h. After the reaction is complete, filter, wash the filter cake alternately with N,N-dimethylformamide and deionized water until the filtrate is neutral, and then dry the filter cake under vacuum at 100℃ to constant weight to obtain carboxylated silica. A3. Add 14g of stearic acid to 120ml of toluene, heat to 60℃ under nitrogen protection, and stir until the stearic acid is completely dissolved; add 100g of carboxylated silica and 1g of p-toluenesulfonic acid, continue stirring for 10min, then heat to 120℃ and reflux for 7h. After the reaction, filter, wash the filter cake three times with toluene, and finally dry the filter cake under vacuum at 120℃ to constant weight to obtain modified silica.

[0032] Example 6: Preparation of modified ethylene-methyl acrylate copolymer. The specific preparation steps are as follows: B1. Dissolve 100g of ethylene-methyl acrylate copolymer in 180ml of xylene, heat to 100℃, add 8g of maleic anhydride and 0.5g of dicumyl peroxide, stir at constant temperature for 4h, and after the reaction is completed, let it cool naturally to room temperature, precipitate in ethanol, filter to collect the product, wash twice with acetone, and dry under vacuum at 60℃ to constant weight to obtain maleic anhydride-grafted ethylene-methyl acrylate copolymer. B2. Dissolve 10g of ethylene glycol monomethyl ether in 120ml of ethyl acetate, add 100g of maleic anhydride-grafted ethylene-methyl acrylate copolymer and 0.3g of tetrabutyl titanate, heat the system to 70℃ and stir for 3h, filter after reaction, cool to room temperature and filter under vacuum, wash the product with ethyl acetate until the washing liquid is clear, and then dry under vacuum at 70℃ to constant weight to obtain hydroxylated ethylene-methyl acrylate copolymer; B3. Dissolve 15g of methyl methacrylate in 180ml of butyl acetate, add 100g of hydroxylated ethylene-methyl acrylate copolymer and 0.4g of azobisisobutyronitrile, seal the reaction apparatus, and purge with nitrogen at a rate of 1L / min for 30min to ensure that the oxygen content of the system is ≤100ppm. Then heat the system to 80℃ and react at a constant temperature for 5h. After the reaction is completed, cool to room temperature and filter. Wash the product three times with butyl acetate, and finally dry it under vacuum at 80℃ to constant weight to obtain the modified ethylene-methyl acrylate copolymer.

[0033] Example 7: Preparation of modified ethylene-methyl acrylate copolymer. The specific preparation steps are as follows: B1. Dissolve 100g of ethylene-methyl acrylate copolymer in 200ml of xylene, heat to 110℃, add 12g of maleic anhydride and 0.7g of dicumyl peroxide, stir at constant temperature for 5h, and after the reaction is completed, let it cool naturally to room temperature, precipitate in ethanol, filter to collect the product, wash twice with acetone, and dry under vacuum at 60℃ to constant weight to obtain maleic anhydride-grafted ethylene-methyl acrylate copolymer. B2. Dissolve 15g of ethylene glycol monomethyl ether in 150ml of ethyl acetate, add 100g of maleic anhydride-grafted ethylene-methyl acrylate copolymer and 0.4g of tetrabutyl titanate, heat the system to 80℃ and stir for 4h, filter after reaction, cool to room temperature and filter under vacuum, wash the product with ethyl acetate until the washing liquid is clear, and then dry under vacuum at 70℃ to constant weight to obtain hydroxylated ethylene-methyl acrylate copolymer; B3. Dissolve 20g of methyl methacrylate in 220ml of butyl acetate, add 100g of hydroxylated ethylene-methyl acrylate copolymer and 0.5g of azobisisobutyronitrile, seal the reaction apparatus, and purge with nitrogen at a rate of 2L / min for 30min to ensure that the oxygen content of the system is ≤100ppm. Then heat the system to 90℃ and react at a constant temperature for 5h. After the reaction is completed, cool to room temperature and filter. Wash the product three times with butyl acetate, and finally dry it under vacuum at 80℃ to constant weight to obtain the modified ethylene-methyl acrylate copolymer.

[0034] Comparative Example 1: Matte PETG polyester material was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified silica prepared in Example 4 used in Example 3 is replaced with unmodified silica to prepare matte PETG polyester material.

[0035] Comparative Example 2: Matte PETG polyester material was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified ethylene-methyl acrylate copolymer prepared in Example 7 and used in Example 3 are replaced with unmodified ethylene-methyl acrylate copolymer to prepare matte PETG polyester material.

[0036] Comparative Example 3: Matte PETG polyester material was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified silica prepared in Example 4 used in Example 3 is replaced with unmodified silica, and the modified ethylene-methyl acrylate copolymer prepared in Example 7 is replaced with unmodified ethylene-methyl acrylate copolymer, to prepare matte PETG polyester material.

[0037] Performance testing

[0038] Performance test results show that the matte PETG polyester materials of Examples 1-3 are significantly superior to those of Comparative Examples 1-3 in all key performance aspects: haze is above 86%, with Example 3 reaching a maximum of 90.2%; gloss at 60° is as low as 8.7-12.5 GU, and the matte effect is uniform and soft; tensile strength is 42.3-47.8 MPa, elongation at break is 280%-345%, and heat distortion temperature is 78.5-82.6℃, demonstrating excellent mechanical properties and thermal stability; while Comparative Examples 1-3, due to the use of unmodified silica, unmodified ethylene-methyl acrylate copolymer, or neither, have haze of only 65.8%-80.1% and gloss of 18.9-35.2 GU, resulting in poor matte effect, and their tensile strength, elongation at break, and heat distortion temperature are all significantly reduced, fully demonstrating that the synergistic effect of modified silica and modified ethylene-methyl acrylate copolymer can effectively improve the matte performance, mechanical properties, and thermal stability of the material.

[0039] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A matte PETG polyester material, characterized in that: It contains the following raw materials in parts by weight: 60-80 parts PETG resin, 5-12 parts modified silica, 4-10 parts modified ethylene-methyl acrylate copolymer, 1-3 parts polyethylene glycol 4000, 0.2-0.5 parts antioxidant 1010, 0.1-0.3 parts antioxidant 168, 0.3-0.8 parts calcium stearate, and 0.2-0.6 parts ultraviolet absorber UV-531.

2. The matte PETG polyester material according to claim 1, characterized in that: The intrinsic viscosity of the PETG resin is 0.75-0.90 dL / g, and the density is 1.26-1.28 g / cm³. 3 Furthermore, at 230℃, the melt flow rate of 2.16kg is 10-15g / 10min.

3. The matte PETG polyester material according to claim 1, characterized in that: The modified silica is prepared using the following specific steps: A1. Dissolve silane coupling agent KH550 in a mixture of anhydrous ethanol and deionized water, and stir to mix evenly; then adjust the pH of the system to 4-5 with 0.1 mol / L acetic acid aqueous solution, add hydrophilic fumed silica, and stir at 60-70℃ for 3-4 h. After the reaction is completed, filter, wash the filter cake 3 times with anhydrous ethanol, and dry it under vacuum at 80℃ to constant weight to obtain aminated silica. A2. Add adipic anhydride to N,N-dimethylformamide, mix well, then add aminated silica, slowly add triethylamine as a catalyst, heat to 80-90℃ and stir for 5-6 hours. After the reaction is complete, filter, wash the filter cake alternately with N,N-dimethylformamide and deionized water until the filtrate is neutral, and then dry the filter cake under vacuum at 100℃ to constant weight to obtain carboxylated silica. A3. Stearic acid is added to toluene, and the temperature is raised to 50-60℃ under nitrogen protection. The mixture is stirred until the stearic acid is completely dissolved. Carboxylated silica and p-toluenesulfonic acid are added, and the mixture is stirred for another 10 minutes. The temperature is then raised to 110-120℃ and refluxed for 6-7 hours. After the reaction, the mixture is filtered, and the filter cake is washed three times with toluene. Finally, the filter cake is vacuum dried at 120℃ to constant weight to obtain modified silica.

4. The matte PETG polyester material according to claim 3, characterized in that: In the dissolution process of stearic acid in toluene in A3, the nitrogen purging rate is 0.5-1 L / min, and the exhaust valve of the reaction device needs to be opened once every 1 hour during the reflux reaction, with each depressurization lasting 10-15 seconds.

5. The matte PETG polyester material according to claim 3, characterized in that: The ratio of silane coupling agent KH550, anhydrous ethanol, deionized water, and hydrophilic fumed silica in A1 is 20-24g: 200-250ml: 32-35ml: 100g. The ratio of adipic anhydride, N,N-dimethylformamide, aminated silica, and triethylamine in A2 is 15-17g: 150-180ml: 100g: 5-6ml; The ratio of stearic acid, toluene, carboxylated silicon dioxide, and p-toluenesulfonic acid in A3 is 12-14g: 100-120ml: 100g: 0.5-1g.

6. The matte PETG polyester material according to claim 1, characterized in that: The modified ethylene-methyl acrylate copolymer is prepared using the following specific steps: B1. Dissolve the ethylene-methyl acrylate copolymer in xylene, heat to 100-110℃, add maleic anhydride and dicumyl peroxide, stir at constant temperature for 4-5 hours, after the reaction is completed, let it cool naturally to room temperature, precipitate in ethanol, filter to collect the product, wash twice with acetone, dry under vacuum at 60℃ to constant weight, to obtain maleic anhydride-grafted ethylene-methyl acrylate copolymer. B2. Ethyl glycol monomethyl ether was dissolved in ethyl acetate, and maleic anhydride-grafted ethylene-methyl acrylate copolymer and tetrabutyl titanate were added. The system was heated to 70-80℃ and stirred for 3-4 hours. After the reaction, the mixture was filtered, cooled to room temperature and filtered under vacuum. The product was washed with ethyl acetate until the washing liquid was clear. Then it was dried under vacuum at 70℃ to constant weight to obtain hydroxylated ethylene-methyl acrylate copolymer. B3. Dissolve methyl methacrylate in butyl acetate, add hydroxylated ethylene-methyl acrylate copolymer and azobisisobutyronitrile, seal the reaction apparatus, purge with nitrogen at a rate of 1-2 L / min for 30 min to ensure the oxygen content of the system is ≤100 ppm, then heat the system to 80-90℃ and react at a constant temperature for 5 h; after the reaction is completed, cool to room temperature and filter, wash the product three times with butyl acetate, and finally dry under vacuum at 80℃ to constant weight to obtain the modified ethylene-methyl acrylate copolymer.

7. A matte PETG polyester material according to claim 6, characterized in that: The ratio of ethylene-methyl acrylate copolymer, xylene, maleic anhydride, and dicumyl peroxide in B1 is 100g: 180-200ml: 8-12g: 0.5-0.7g; The ratio of ethylene glycol monomethyl ether, ethyl acetate, maleic anhydride-grafted ethylene-methyl acrylate copolymer, and tetrabutyl titanate in B2 is 10-15g: 120-150ml: 100g: 0.3-0.4g. The ratio of methyl methacrylate, butyl acetate, hydroxylated ethylene-methyl acrylate copolymer, and azobisisobutyronitrile in B3 is 15-20g: 180-220ml: 100g: 0.4-0.5g.

8. A method for preparing a matte PETG polyester material, characterized in that: Specifically, it includes the following steps: S1. Vacuum dry PETG resin at 80-90℃ for 4-6 hours; Vacuum dry modified silica, modified ethylene-methyl acrylate copolymer, polyethylene glycol 4000, antioxidant 1010, antioxidant 168, calcium stearate, and ultraviolet absorber UV-531 at 60℃ for 2-3 hours respectively. S2. First, mix 60-80 parts of PETG resin, 5-12 parts of modified silica, 4-10 parts of modified ethylene-methyl acrylate copolymer, and 1-3 parts of polyethylene glycol 4000. Adjust the speed to 1000-1200 r / min and mix for 6-8 min. Then add 0.2-0.5 parts of antioxidant 1010, 0.1-0.3 parts of antioxidant 168, 0.3-0.8 parts of calcium stearate, and 0.2-0.6 parts of ultraviolet absorber UV-531. Continue mixing at the same speed for 4-7 min to ensure that all components are uniformly blended to obtain a premix. S3. Add the premixed material to the twin-screw extruder, set the temperature of Zone 1 to 205-210℃, Zone 2 to 210-215℃, Zone 3 to 215-220℃, the die head temperature to 225-230℃, and the screw speed to 200-220 r / min. After the material is extruded from the die head, it immediately enters a water cooling tank at 20-25℃ to cool. After ensuring that the material is completely cooled to room temperature, it is pelletized by a pelletizer. After pelletizing, the pellets are placed in a hot air drying oven at 60℃ and dried for 2 hours to remove surface moisture, thus obtaining matte PETG polyester material.

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