Weatherable polyester and method of making same

Abstract

The application discloses weather-resistant polyester and a preparation method thereof, and relates to the technical field of polyester fibers. The weather-resistant polyester is prepared from the following components in parts by mass: 90-110 parts of polyethylene terephthalate resin, 1-2 parts of a weather-resistant agent, 2-5 parts of a dispersing agent, 1.5-3 parts of a lubricant, and 5-15 parts of a nano functional filler. The weather-resistant agent is added to efficiently absorb ultraviolet light, block photoaging chain reactions, reduce performance degradation of the polyester in adverse environments such as ultraviolet light and heat and moisture, and effectively delay the aging process.

Description

Technical Field

[0001] This invention relates to the field of polyester fiber technology, specifically to a weather-resistant polyester and its preparation method. Background Technology

[0002] Polyester is a synthetic fiber widely used in textiles, clothing, and other industrial fields. It is favored for its high strength, good abrasion resistance, and resistance to chemical corrosion. However, polyester is prone to aging when exposed to harsh environments such as ultraviolet light, humidity, heat, and oxygen for extended periods. This leads to a decline in the fiber's mechanical properties, yellowing, and surface cracking, severely impacting its service life and value.

[0003] Currently, to improve the weather resistance of polyester, the industry typically uses additives such as antioxidants and UV stabilizers. However, the weather resistance and efficiency of these traditional additives are often limited, failing to fundamentally solve the problem of polyester's easy aging. Furthermore, some additives suffer from poor migration and insufficient stability, resulting in less than ideal performance. Further analysis reveals a lack of a weather-resistant agent that effectively integrates multiple functions, as well as a systematic solution addressing the specific challenges faced by polyester fibers in terms of weather resistance. Therefore, there is an urgent need to develop an innovative method that can significantly improve the weather resistance of polyester, ensuring both improved lightfastness and oxidation resistance while also possessing good compatibility and processing performance.

[0004] Therefore, we designed a highly efficient weather-resistant agent and combined it with a unique formulation and process to comprehensively optimize the weather resistance of polyester and meet the long-term demand of modern industry and daily applications for high-performance polyester fibers. Summary of the Invention

[0005] The purpose of this invention is to address the problems of limited weather resistance and stability in existing technologies by providing a weather-resistant polyester and its preparation method. This method involves adding a weather-resistant agent with excellent comprehensive performance and combining it with a unique formula and process to develop a polyester with outstanding weather resistance and mechanical stability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A weathering agent, wherein the weathering agent is a compound represented by Formula 1:

[0008] Formula 1: ;

[0009] R1 is an alkyl group with 1-5 carbon atoms, an alkoxy group with 1-5 carbon atoms, a nitro group, a halogen, or a phenyl group.

[0010] Furthermore, the alkyl group having 1-5 carbon atoms is selected from: methyl, ethyl, tert-butyl;

[0011] The alkoxy group with 1-5 carbon atoms is selected from: methoxy and ethoxy.

[0012] Furthermore, the weather-resistant agent is any one of the compounds shown in the following structures:

[0013] ;

[0014] ;

[0015] ;

[0016] .

[0017] A weather-resistant polyester, wherein the polyester contains the aforementioned weather-resistant agent.

[0018] Furthermore, the polyester is prepared from the following components in parts by weight: polyethylene terephthalate resin: 90-110 parts, weather resistant agent: 1-2 parts, dispersant: 2-5 parts, lubricant: 1.5-3 parts, and nano-functional filler: 5-15 parts.

[0019] Furthermore, the dispersant is at least one of calcium stearate and zinc stearate.

[0020] Furthermore, the lubricant is at least one of ethylene bis-stearamide and pentaerythritol stearate.

[0021] Furthermore, the nano-functional filler is nano-silica with a particle size of 30-100 nm.

[0022] A method for preparing weather-resistant polyester includes the following steps:

[0023] S1. Raw material pretreatment: Dry the polyethylene terephthalate resin at 120-140℃ for 4-6 hours to remove moisture;

[0024] S2. Mixing: Add the pretreated polyethylene terephthalate resin, weathering agent, dispersant, lubricant and nano-functional filler to a high-speed mixer. Mix at a temperature of 260-275℃, a stirring speed of 800-1200 rpm and a stirring time of 10-20 minutes until the mixture is homogeneous to obtain the mixture.

[0025] S3. Melt extrusion: The mixture is added to an extruder and melt-extruded at a temperature of 260-280°C, while controlling the screw speed of the extruder to be 180-220 rpm;

[0026] S4. Spinning: The extruded melt is passed through the spinneret of the spinning assembly and spun into fibers at a spinning speed of 200-220 m / min and a winding speed of 700-900 m / min. The fibers are then heat-set at 165-185℃ to obtain a weather-resistant polyester fiber.

[0027] Furthermore, in step S3, the extruder is a twin-screw extruder, and the temperature distribution of each section of the twin-screw extruder is as follows: feeding section 250-260℃, melting section 265-275℃, homogenization section 270-280℃, and die head 265-275℃.

[0028] The weathering agent described in this invention blocks the photoaging chain reaction by efficiently absorbing / quenching ultraviolet light. The weathering agent's molecular structure contains a conjugated aromatic ring system, amino groups, nitro groups, and other ultraviolet-absorbing groups. Through active absorption of ultraviolet light, the conjugated system can absorb ultraviolet light energy via π-π electron transitions, converting harmful ultraviolet light into harmless "molecular vibrational energy" or "thermal energy" for slow release, thus preventing direct ultraviolet light from acting on the PET molecular chain. It also quenches excited-state molecules; the amino groups and other electron-donating groups in the molecule can undergo energy transfer or electron transfer with the "excited-state molecules" of PET, reducing them to stable ground-state molecules and blocking the "excited state → free radical" conversion process, thus cutting off the photoaging chain reaction at its source. Furthermore, it captures active free radicals and inhibits oxidative degradation. The amino and phenolic hydroxyl groups in the weathering agent molecule have strong "free radical capturing ability," which can react with active species such as hydroxyl and alkoxy free radicals generated by PET degradation to generate stable "weathering agent-free radical adducts," terminating the "chain proliferation" of free radicals. This weathering agent optimizes molecular compatibility, reduces the migration and loss of additives, and ensures long-term weather resistance. Through specific substituent design, it enhances compatibility with PET. The short-chain alkyl and alkoxy groups in the molecule have similar "polarity and spatial structure" to the methylene and ester groups in the PET molecular chain. They can be tightly bound to the PET molecular chain through van der Waals forces, reducing intermolecular phase separation and ensuring the weather resistance stability of polyester under long-term exposure.

[0029] The components of this invention achieve a synergistic effect through physical-chemical coupling and processing integration. Weather-resistant agents and nanofillers provide complementary protection; the weather-resistant agent addresses UV absorption and chemical free radical quenching, while nano-silica acts as a physical barrier, reflecting residual UV light (especially long-wave UVA) and reducing the load on the weather-resistant agent. Simultaneously, the silane-modified layer of the nanofiller and the alkyl substituents of the weather-resistant agent interact hydrophobically to form a stable network, inhibiting migration. Dispersants and lubricants ensure uniformity and stability; the dispersant promotes uniform dispersion of the weather-resistant agent and nanofiller during high-speed mixing, while the lubricant reduces shear heat during melt extrusion, preventing thermal decomposition of the weather-resistant agent and ensuring all components maintain their integrity and activity during fiber forming. The PET resin and additives are integrally integrated; the compatibility design of the weather-resistant agent and the interface modification of the nanofiller allow the additives to embed into the gaps between PET molecular chains, forming a dense structure after heat setting. This effectively blocks oxygen and moisture penetration, solving the migration problem of traditional additives and meeting the high requirements of industrial and everyday applications.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. Significantly improves the weather resistance of polyester: This invention adds a new type of weather-resistant agent, which efficiently absorbs ultraviolet light, blocks the photoaging chain reaction, reduces the performance degradation of polyester in harsh environments such as ultraviolet light and humid heat, and effectively slows down the aging process.

[0032] 2. Optimize polyester stability and compatibility: The weather-resistant agent has enhanced compatibility with PET, reducing the migration and loss of additives and ensuring the long-term stability of polyester. At the same time, the synergistic effect of nanofillers further improves the overall stability of the material.

[0033] 3. Improve the overall mechanical properties of polyester: The synergistic effect of each component enhances the tensile strength and elongation at break of polyester, and the performance retention rate after aging is higher, so that polyester can still maintain good mechanical properties in harsh environments. Attached Figure Description

[0034] Figure 1 This is the NMR spectrum of the weathering agent 1 described in this invention. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely 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.

[0036] Synthesis example 1

[0037] Synthesis of weathering agent 1:

[0038] first step:

[0039] ;

[0040] Under a nitrogen atmosphere, 29.46 g of triethylamine was added to 300 mL of 1,4-dioxane, followed by 24.98 g of compound 2. 15.00 g of compound 1 was dissolved in 50 mL of 1,4-dioxane and slowly added dropwise to the solution while maintaining the temperature below 10 °C. After the addition was complete, the mixture was stirred at 60 °C for 12 h. After the reaction was complete, the mixture was concentrated under reduced pressure to obtain a concentrate, which was purified by column chromatography using a mixture of n-heptane and ethyl acetate as the eluent. The concentrate was evaporated to dryness to give 20.03 g of compound 3. Mass spectrometry (M / Z MS+1): 316.

[0041] Step Two:

[0042] ;

[0043] Under a nitrogen atmosphere, 20.03 g of compound 3, 14.91 g of compound 4, 33.74 g of potassium phosphate trihydrate, 0.60 g of CuI, 0.08 g of pyridine-2-carboxylic acid, and 300 mL of DMSO were added to the reaction system. The reaction mixture was heated at 85 °C for 16 h. After cooling, the reaction mixture was extracted with ammonia solution and methyl tert-butyl ether. The organic phase was washed five times with water and then twice with saturated NaCl solution. Finally, the combined organic phases were dried over anhydrous magnesium sulfate, concentrated, and fractionated to obtain 22.75 g of weathering agent 1. Mass spectrometry M / Z MS+1:471.

[0044] Structural assessment:

[0045] NMR of weathering agent 1: 1 H NMR (Chloroform-d, Figure 1 ): δ8.06(dd,1H),7.89-7.81(m,2H),7.44(d,1H),7.37-7.30(m,2H),7.25(dd,1H ),7.18(t,2H),4.01(tt,2H),2.47-2.33(m,5H),1.45-1.40(m,9H),1.37(d,9H).

[0046] Synthesis example 2

[0047] In Synthesis Example 2, weather-resistant agent 4 was synthesized by referring to the synthesis method of Synthesis Example 1, except that compound 1 was replaced with... The rest remains the same as in Synthesis Example 1.

[0048] Structure of weathering agent 4: Mass spectrometry (MS / Z) of weathering agent 4: 487.

[0049] Synthesis example 3

[0050] In Synthesis Example 3, weather-resistant agent 5 was synthesized by referring to the synthesis method of Synthesis Example 1, except that compound 1 was replaced with... The rest remains the same as in Synthesis Example 1.

[0051] Structure of weathering agent 5: Mass spectrometry (MS / Z) of weathering agent 5: 502.

[0052] Synthesis example 4

[0053] In Synthesis Example 4, weather-resistant agent 7 was synthesized by referring to the synthesis method of Synthesis Example 1, except that compound 1 was replaced with... The rest remains the same as in Synthesis Example 1.

[0054] Structure of weathering agent 7: Mass spectrometry (MS / Z) of weathering agent 7: 493.

[0055] Synthesis example 5

[0056] In Synthesis Example 5, weathering agent 8 was synthesized by referring to the synthesis method of Synthesis Example 1, except that compound 1 was replaced with... The rest remains the same as in Synthesis Example 1.

[0057] Structure of weathering agent 8: Mass spectrometry (MS / Z) of weathering agent 8: 533.

[0058] Example 1

[0059] Preparation of a weather-resistant polyester:

[0060] 1. Raw material ratio:

[0061] Polyethylene terephthalate resin: 100 parts, purchased from: Hubei Jusheng Technology Co., Ltd.;

[0062] Weathering agent: 1.5 parts, selected from weathering agent 1 synthesized in Synthesis Example 1;

[0063] Dispersant: 3 parts, selected from calcium stearate, purchased from Shanghai Yuanye Biotechnology Co., Ltd.;

[0064] Lubricant: 2 parts, selected from: pentaerythritol stearate, purchased from: Wuhan Xinyang Ruihe Chemical Technology Co., Ltd.;

[0065] Nanofunctional filler: 10 parts, selected from nano silica with a particle size of 50 nm.

[0066] 2. Preparation method:

[0067] S1. Raw material pretreatment: Place polyethylene terephthalate resin in an oven and dry it at 130℃ for 5 hours until the moisture content is <50 ppm;

[0068] S2. Mixing: Add the pretreated polyethylene terephthalate resin, weathering agent, dispersant, lubricant, and nano-functional filler to a high-speed mixer. Set the temperature to 265℃, the stirring speed to 1000 rpm, and the stirring time to 15 minutes to ensure that all components are uniformly mixed to obtain a mixture.

[0069] S3. Melt extrusion: The mixture is fed into a twin-screw extruder, and the temperature distribution of each section is controlled as follows: feeding section: 255℃, melting section: 270℃, homogenization section: 275℃, die head: 270℃. During the extrusion process, the screw speed is controlled at 200 rpm and the melt temperature is maintained at 270℃.

[0070] S4. Spinning: The extruded melt is passed through the spinneret of the spinning assembly. The spinning speed is set to 210 m / min and the winding speed is set to 800 m / min. After spinning, the melt is heat-set at 175°C for 10 minutes to obtain a weather-resistant polyester fiber.

[0071] Examples 2-5

[0072] The preparation of a weather-resistant polyester is carried out by referring to the preparation method of Example 1, except that the weather-resistant agent is replaced in sequence with the weather-resistant agent synthesized in Synthesis Examples 2-5, and the rest is the same as in Example 1.

[0073] Comparative Example 1

[0074] The preparation of a weather-resistant polyester is carried out by referring to the preparation method of Example 1, except that the weather-resistant agent is replaced with antioxidant 1010, and the rest is the same as in Example 1.

[0075] Comparative Example 2

[0076] The preparation of a weather-resistant polyester is carried out by referring to the preparation method of Example 1, except that the weather-resistant agent is replaced with antioxidant 1024, and the rest is the same as in Example 1.

[0077] Comparative Example 3

[0078] The preparation of a weather-resistant polyester is carried out according to the preparation method of Example 1, except that the weather-resistant agent is not added, and the rest is the same as in Example 1.

[0079] Comparative Example 4

[0080] The preparation of a weather-resistant polyester is carried out according to the preparation method of Example 1, except that the dispersant is not added, and the rest is the same as in Example 1.

[0081] Comparative Example 5

[0082] The preparation of a weather-resistant polyester is the same as in Example 1, except that the nano-functional filler is not added.

[0083] Performance testing

[0084] 1. The breaking strength and elongation at break of a weather-resistant polyester prepared in the examples and comparative examples were tested according to the standard GB / T 14337-2008 "Test Method for Tensile Properties of Chemical Fibers Short Fibers". The results are shown in Table 1.

[0085] 2. The weather-resistant polyester prepared in the examples and comparative examples was placed in an aging test chamber and exposed for 4800 hours. Its breaking strength retention rate (breaking strength after aging / initial breaking strength × 100%) was tested according to GB / T 14337-2008. The results are shown in Table 1.

[0086] Aging conditions: UVA-340 fluorescent ultraviolet lamps (simulating outdoor near-ultraviolet light) were used, with an irradiance of 0.71 W / (m²). 2 nm), temperature (60±3)℃, relative humidity (50±5)%.

[0087] Table 1.

[0088]

[0089] The performance test data in Table 1 show that the polyester in the examples is generally superior to the comparative example in terms of breaking strength, elongation at break, and breaking strength retention. The polyester in the examples with different weather-resistant agents exhibited similar performance, all demonstrating high breaking strength and elongation at break, and maintaining high breaking strength after aging tests. In contrast, the polyester in the comparative example without weather-resistant agents or using traditional antioxidants showed a significant decrease in performance, especially in terms of breaking strength retention. This indicates that the weather-resistant agent and overall formulation described in this invention can effectively improve the comprehensive performance of polyester.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A weather-resistant agent, characterized in that, The weather-resistant agent is a compound represented by Formula 1: Formula 1: ; R1 is an alkyl group with 1-5 carbon atoms, an alkoxy group with 1-5 carbon atoms, a nitro group, a halogen, or a phenyl group.

2. The weathering agent according to claim 1, characterized in that, The alkyl group having 1-5 carbon atoms is selected from: methyl, ethyl, tert-butyl; The alkoxy group with 1-5 carbon atoms is selected from: methoxy and ethoxy.

3. A weather-resistant agent, characterized in that, The weather-resistant agent is any one of the compounds shown in the following structures: ； ； ； 。 4. A weather-resistant polyester, characterized in that, The polyester contains the weather-resistant agent as described in claim 3.

5. A weather-resistant polyester according to claim 4, characterized in that, The polyester is prepared from the following components in parts by weight: polyethylene terephthalate resin: 90-110 parts, weather resistant agent: 1-2 parts, dispersant: 2-5 parts, lubricant: 1.5-3 parts, and nano-functional filler: 5-15 parts.

6. The weather-resistant polyester according to claim 5, characterized in that, The dispersant is at least one of calcium stearate and zinc stearate.

7. A weather-resistant polyester according to claim 5, characterized in that, The lubricant is at least one of ethylene bis-stearamide and pentaerythritol stearate.

8. A weather-resistant polyester according to claim 5, characterized in that, The nanofunctional filler is nano-silica with a particle size of 30-100nm.

9. A method for preparing a weather-resistant polyester fiber according to any one of claims 4-8, characterized in that, Includes the following steps: S1. Raw material pretreatment: Dry the polyethylene terephthalate resin at 120-140℃ for 4-6 hours to remove moisture; S2. Mixing: Add the pretreated polyethylene terephthalate resin, weathering agent, dispersant, lubricant and nano-functional filler to a high-speed mixer. Mix at a temperature of 260-275℃, a stirring speed of 800-1200 rpm and a stirring time of 10-20 minutes until the mixture is homogeneous to obtain the mixture. S3. Melt extrusion: The mixture is added to an extruder and melt-extruded at a temperature of 260-280°C, while controlling the screw speed of the extruder to be 180-220 rpm; S4. Spinning: The extruded melt is passed through the spinneret of the spinning assembly and spun into fibers at a spinning speed of 200-220 m / min and a winding speed of 700-900 m / min. The fibers are then heat-set at 165-185℃ to obtain a weather-resistant polyester fiber.

10. The method for preparing weather-resistant polyester according to claim 9, characterized in that, In step S3, the extruder is a twin-screw extruder, and the temperature distribution of each section of the twin-screw extruder is as follows: feeding section 250-260℃, melting section 265-275℃, homogenization section 270-280℃, and die head 265-275℃.

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