Method of making super strong, age resistant, high tenacity polyester yarns and modified polyester yarns

Abstract

The application relates to the technical field of functional fiber preparation, and discloses a method for preparing super-strong anti-aging and high-strength polyester yarn and modified polyester yarn. The method comprises the following steps: (1) soaking the polyester yarn in a modification liquid containing a mono-amino silane coupling agent, and then taking out the polyester yarn for padding; and (2) soaking the polyester yarn treated in the step (1) in a diisocyanate compound solution. The method sequentially carries out surface treatment on the polyester yarn through the mono-amino silane coupling agent and the diisocyanate compound, improves the light resistance and durability of the polyester yarn, enhances the resistance of the polyester yarn to ultraviolet rays, solves the yellowing and breaking problems caused by long-term outdoor use, meets the increasingly stringent industrial application requirements, and brings substantial technical innovation and economic benefits to the related industry. The method discards the traditional method of coating high-performance materials on the surface of the yarn, and has the advantages of washing resistance, friction resistance and no influence on subsequent coloring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional fiber preparation, in particular to a method for preparing super strong anti-aging and strength maintaining polyester yarn and modified polyester yarn. BACKGROUND

[0002] Polyester fiber (polyester) has the characteristics of high strength, good elasticity, heat resistance, thermal insulation, wear resistance, corrosion resistance, etc. The yarn made of it has high strength and can always maintain flatness and beauty, has excellent wear resistance, good resistance to high temperature, low temperature, light and water. With the increasing demand for polyester yarn in the industrial field, the durability of these products is significantly affected when exposed to strong ultraviolet light for a long time outdoors. After continuous sunshine, the mechanical properties of the yarn will deteriorate seriously, thereby greatly reducing its service life and failing to meet the high standards of industrial application.

[0003] In view of this, it is urgent to develop a rope that can still maintain excellent mechanical properties even under long-term sunshine conditions to meet the requirements of high-performance yarn application occasions in industry. Therefore, the polyester yarn needs to be functionalized and finished. The most widely used and simplest method is coating finishing. However, the coating of the yarn is often accompanied by problems such as poor wear resistance, easy yellowing and brittle damage, uneven coating, etc. Therefore, it is necessary to find a method for preparing a functional yarn that is super strong, anti-aging, anti-ultraviolet and wear-resistant without coating. SUMMARY

[0004] The purpose of the present application is to overcome the problems existing in the prior art that polyester yarns generally face in outdoor applications, i.e. insufficient light resistance, mechanical property degradation, easy yellowing and brittle fracture when exposed to ultraviolet light for a long time, which seriously affects the durability and reliability of the polyester yarn in actual use, thereby shortening its service life and limiting its potential in many industrial applications. A method for preparing super strong anti-aging and strength maintaining polyester yarn and modified polyester yarn is provided, which sequentially treats the surface of the polyester yarn with a monoamino silane coupling agent and a diisocyanate compound to improve the light resistance and durability of the polyester yarn, enhance its resistance to ultraviolet light, solve the yellowing and fracture problems caused by long-term outdoor use, meet the increasingly stringent requirements of industrial application, and bring substantial technical innovation and economic benefits to the related industry.

[0005] In order to achieve the above-mentioned purpose, the present application provides a method for preparing super strong anti-aging and strength maintaining polyester yarn, which comprises the following steps:

[0006] (1) Soaking the polyester yarn in a modified liquid containing a monoamino silane coupling agent, then taking out the polyester yarn for padding;

[0007] (2) soaking the polyester yarn treated in step (1) in a diisocyanate compound solution.

[0008] Preferably, in step (1), the concentration of the monoamino silane coupling agent in the modifying solution is 0.009-2% by weight.

[0009] Preferably, the pH value of the modifying solution is 4-5.

[0010] Preferably, in step (1), the conditions for soaking the polyester yarn in the modifying solution containing the monoamino silane coupling agent include a bath ratio of 1:5-10, a temperature of 50-80°C, and a time of 1-3 hours.

[0011] Preferably, in step (1), the preparation of the modifying solution containing the monoamino silane coupling agent includes dissolving the monoamino silane coupling agent in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH value to 4-5.

[0012] Preferably, the weight ratio of the monoamino silane coupling agent to the amount of the mixed solvent is 0.01-2:100.

[0013] Preferably, in the mixed solvent, the weight ratio of the amount of ethanol to water is 0.65-1.5:1.

[0014] Preferably, in step (1), the monoamino silane coupling agent is selected from at least one of KH550, KH551 and A-1100.

[0015] Preferably, in step (1), the padding has a padding rate of 40-80%.

[0016] Preferably, in step (2), the diisocyanate compound in the diisocyanate compound solution is selected from at least one of isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

[0017] Preferably, in step (2), the conditions for soaking the polyester yarn treated in step (1) in the diisocyanate compound solution include a bath ratio of 1:5-20, a temperature of 15-35°C, and a time of 5-10 minutes.

[0018] Preferably, in step (2), the concentration of the diisocyanate compound solution is 0.05-5% by weight.

[0019] Preferably, in step (2), the solvent of the diisocyanate compound solution is selected from at least one of acetone, toluene, xylene and cyclohexanone.

[0020] The second aspect of the present application provides a modified polyester yarn prepared by the method described above.

[0021] Compared with the prior art, the present application has at least the following beneficial effects:

[0022] (1) The present application soaks polyester yarn in a modified solution containing a mono-amino silane coupling agent. The alkoxyl group in the mono-amino silane coupling agent is converted into a hydrolysis product with a reactive silicon hydroxyl group through hydrolysis. Dehydration condensation reactions can occur between silicon hydroxyl groups, forming oligosiloxane. These oligomers still have reactive silicon hydroxyl groups, which can form covalent bonds and hydrogen bonds with carboxyl or hydroxyl groups on the surface of polyester fibers, and undergo chemical reactions. These silicon hydroxyl groups can also react with isocyanate groups.

[0023] (2) The hydrolysis product of the alkoxyl group in the mono-amino silane coupling agent after hydrolysis does not undergo condensation reactions, but has multiple silicon hydroxyl groups with high activity, which can further react with functional groups such as carboxyl or hydroxyl groups on the surface of polyester fibers. These reactions can include the formation of hydrogen bonds and covalent bonds, such as -SiO-M (M represents the surface of polyester fibers), and can further react with isocyanate groups (-NCO) in diisocyanate compounds to form urethane structures (amino groups come from mono-amino silane coupling agents). In this process, the hydrogen atom of the silicon hydroxyl group combines with the carbon atom in the isocyanate group to form an urethane group, and a hydroxyl group is released.

[0024] R-Si(OH)+OCN-R'→Si(ONC-R')+HO

[0025] (3) By introducing mono-amino silane coupling agents, Si-O-Si bonds can be formed between polyurethane chains, which increases the crosslinking density of the material and forms a more stable three-dimensional network structure. This is a gradual polymerization and crosslinking process that ultimately forms a three-dimensional network structure of organosilicon modified waterborne polyurethane.

[0026] (3) The present application can form high-performance materials inside the polyester yarn by sequentially treating the yarn in solutions containing mono-amino silane coupling agents and diisocyanate compounds, without changing the original color. This method eliminates the need for traditional surface coating of high-performance materials on yarn, which can withstand long-term outdoor wind and sun exposure, maintains the original hand feel to a certain extent, and does not change the original color. It also has the advantages of wash resistance, friction resistance, and no impact on subsequent coloring.

[0027] (4) The modified polyester yarn prepared by the present application still maintains a breaking strength of more than 70% after undergoing 2000+ hours of strong ultraviolet radiation. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1is a structural schematic diagram of the modified polyester yarn prepared by the method of the present application.

[0029] Figure 2 is an infrared spectrum of the unmodified polyester yarn and the modified polyester yarn prepared in Example 1;

[0030] Figure 3 is a tensile fracture curve of the unmodified polyester yarn and the modified polyester yarn prepared in Example 1. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application are described in detail below. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the application, are given by way of illustration only, and are not by way of limitation.

[0032] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The approximate values allow for variation based on the intended application of the compositions and methods disclosed herein. The approximate values allow for some flexibility in the upper and lower limits of the range and the individual values. The upper and lower limits of the ranges and individual values can be combined to form new ranges, and the new ranges are understood to be within the scope of the present application.

[0033] The present application provides a method for preparing super strong and aging resistant polyester yarns with high strength, comprising the following steps:

[0034] (1) soaking the polyester yarn in a modification liquid containing a monoamino silane coupling agent, and then taking out the polyester yarn for padding;

[0035] (2) soaking the polyester yarn treated in step (1) in a solution of a diisocyanate compound.

[0036] In the method of the present application, the polyester yarn is first immersed in a modification liquid containing a monoamino silane coupling agent which is hydrolyzed to form a hydrolysis product with silicon hydroxyl groups. On the one hand, the silicon hydroxyl groups can chemically react with the hydroxyl or carboxyl functional groups on the surface of the polyester fiber to form covalent bonds. This chemical bonding can change the molecular arrangement on the surface of the fiber, thereby enhancing the structural stability of the fiber. On the other hand, the monoamino silane coupling agent can form a silane film on the surface of the polyester yarn through self-assembly. The silane film can absorb ultraviolet light, reducing the direct irradiation of ultraviolet light on the fiber. Thirdly, the silane film formed by the monoamino silane coupling agent on the surface of the polyester yarn can act as a physical barrier to reflect or scatter part of the ultraviolet light, preventing it from penetrating into the interior of the fiber. This can effectively reduce the damage of ultraviolet light to the molecular structure inside the fiber, thereby improving the ultraviolet resistance of the fiber. Fourthly, the monoamino silane coupling agent modified on the surface of the polyester yarn can also act as a light stabilizer to help the polyester fiber remain stable under ultraviolet irradiation. After the polyester yarn treated by the modification liquid is immersed in a solution of a diisocyanate compound, the silicon hydroxyl groups in the hydrolysis product of the modified monoamino silane coupling agent on the surface of the polyester yarn can react with the diisocyanate compound to form a stable urethane structure, thereby effectively improving the ultraviolet resistance of the polyester yarn, reducing the damage of ultraviolet light to the fiber, and prolonging the service life of the fiber.

[0037] In the present application, the polyester yarn can be a conventional choice in the art. For example, the polyester yarn is a polyester sewing thread.

[0038] In the method of the present application, the monoamino silane coupling agent can be a common silane coupling agent in the art. In some embodiments, the monoamino silane coupling agent in step (1) is selected from at least one of KH550, KH551 and A-1100, preferably KH550.

[0039] In some preferred embodiments, the concentration of the monoamino silane coupling agent in the modification liquid in step (1) can be 0.009-2% by weight. Limiting the concentration of the monoamino silane coupling agent in the modification liquid to this range can control the hydrolysis process, the amount of silicon hydroxyl groups generated, and the reaction of the silicon hydroxyl groups.

[0040] In the present application, the solvent of the modification liquid containing the monoamino silane coupling agent is preferably a mixture of ethanol and water. Using ethanol and water as the mixed solvent can improve the swelling effect of the polyester yarn, making it easier for the monoamino silane coupling agent and the diisocyanate compound to enter the polyester yarn, thereby further improving the modification effect and further improving the light resistance and durability of the polyester yarn. In some embodiments, the weight ratio of the amount of anhydrous ethanol to water in the mixed solvent of anhydrous ethanol and water can be 0.65-1.5:1, for example 2:3, 1:1 or 3:2.

[0041] In one embodiment, the preparation of the modified liquid containing monoamino silane coupling agent includes dissolving monoamino silane coupling agent in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH value to 4-5 to generate silicon hydroxyl. In a more preferred embodiment, the pH value of the modified liquid needs to be adjusted to 4-5. In the present application, the pH value of the modified liquid can be adjusted to 4-5 by using an acid commonly used in the art. In order to prevent the damage to the polyester yarn caused by the excess acid, in a preferred embodiment, a weak acid is used to adjust the pH value of the modified liquid to 4-5. In some embodiments, the weak acid used to adjust the pH value of the modified liquid to 4-5 can be citric acid and / or acetic acid (acetic acid). In other embodiments, the weight ratio of the amount of the monoamino silane coupling agent to the amount of the mixed solvent can be 0.01-2:100, such as 0.01:100, 0.05:100, 0.1:100, 0.5:100, 1:100, 1.5:100 or 2:100.

[0042] In the method described in the present application, in order to improve the uniformity and stability of the reaction of the monoamino silane coupling agent and avoid too fast or too slow reaction speed, the temperature at which the polyester yarn is soaked in the modified liquid containing the monoamino silane coupling agent in step (1) needs to be optimized. In a more preferred embodiment, the temperature at which the polyester yarn is soaked in the modified liquid containing the monoamino silane coupling agent is 50-80°C, such as 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0043] In some preferred embodiments, the bath ratio at which the polyester yarn is soaked in the modified liquid containing the monoamino silane coupling agent is 1:5-10. Limiting the bath ratio to this range can effectively control the self-polymerization of silicon hydroxyl, because the self-polymerization and reactivity of silicon hydroxyl are higher, and an excess amount will cause excessive self-polymerization and reaction, making it difficult to form a polyurethane network.

[0044] In other preferred embodiments, the time at which the polyester yarn is soaked in the modified liquid containing the monoamino silane coupling agent is 1-3 hours. Controlling the time to this range can sufficiently hydrolyze.

[0045] In some embodiments, after the polyester yarn soaked in the modified liquid is taken out and padded, the padding pick-up rate of the padding can be controlled to 40-80%, such as 40%, 50%, 60%, 70% or 80%. In the present application, the number of times of padding can be multiple, preferably 2 times. In the present application, the method further includes: after the polyester yarn after padding is rinsed with cold water for 2-5 times and dried.

[0046] In the method of the present application, the diisocyanate compound in the diisocyanate compound solution of step (2) can be selected from the group consisting of isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI), preferably isophorone diisocyanate.

[0047] In some preferred embodiments, the concentration of the diisocyanate compound solution of step (2) is 0.05 to 5% by weight. Controlling the concentration of the diisocyanate compound solution within this range enables the reaction of the silicon hydroxyl group and the diisocyanate compound to be completed at an appropriate rate.

[0048] In the present application, the diisocyanate compound solution can be prepared by a conventional method. In one embodiment, the preparation of the diisocyanate compound solution comprises mixing the diisocyanate compound with a solvent. In the present application, the solvent can be an organic solvent commonly used in the art. In some embodiments, the solvent of the diisocyanate compound solution of step (2) is selected from the group consisting of acetone, toluene, xylene, and cyclohexanone, preferably acetone.

[0049] In the method of the present application, the temperature at which the polyester yarn treated in step (1) is immersed in the diisocyanate compound solution can be room temperature, for example, 15 to 35°C, and the time can be 5 to 10 minutes. In some preferred embodiments, the bath ratio at which the polyester yarn treated in step (1) is immersed in the diisocyanate compound solution is 1:5 to 20. Controlling the bath ratio within this range in step (2) enables the reaction to be sufficiently carried out.

[0050] In the present application, the method further comprises removing the polyester yarn from the diisocyanate compound solution after the polyester yarn treated in step (1) is immersed in the diisocyanate compound solution and drying the polyester yarn.

[0051] In one preferred embodiment, a method of preparing a polyester yarn having super-aging resistance and maintaining strength comprises the following steps:

[0052] 1) Dissolving KH550 in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH to 4 to 5 to obtain a modification solution;

[0053] 2) Immersing the polyester yarn in the modification solution at a bath ratio of 1:5 to 10 at a temperature of 50 to 80°C for 1 to 3 hours, removing the polyester yarn, padding the polyester yarn, and then rinsing the polyester yarn with cold water several times and air-drying the polyester yarn;

[0054] 3) The polyester yarn treated in step 2) is soaked in isophorone diisocyanate solution for 5-10 minutes, and then taken out and dried at room temperature.

[0055] The method of the present application not only can prepare modified polyester yarn with super strong resistance to ultraviolet rays, but also focuses on the selection of raw materials and the optimization of manufacturing process of the yarn to achieve a balance of cost effectiveness, while ensuring that the product has sufficient market competitiveness.

[0056] The present application provides a modified polyester yarn prepared by the method described above. The structure of the modified polyester yarn is as shown in Figure 1 The modified polyester yarn provided by the present application still maintains a breaking strength of more than 70% after experiencing super strong ultraviolet radiation for more than 2000 hours.

[0057] The modified polyester yarn provided by the present application is a kind of anti-aging composite yarn, which can be used as outdoor clothing such as jackets, sun-protecting clothes, etc., sports equipment such as sports shoes, sports bags, etc., sun-shading products such as sunshades, sunhats, etc., tents and sunshading canopies, car interiors, building field such as sun-shading nets, protective nets, etc., safety protection products, etc. The use scenarios of these products all need to maintain good performance in various harsh environments, such as ultraviolet resistance, oxidation resistance, high temperature resistance, etc. Therefore, the present design not only has a wide range of applications, but also has a simple preparation method, which is economical and efficient.

[0058] The following examples will further illustrate the method for preparing super strong anti-aging and strength-maintaining polyester yarn and the modified polyester yarn according to the present application. The examples are implemented on the premise of the technical solutions of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0059] In the following examples, the experimental methods are conventional methods in the art unless otherwise specified. The experimental materials used in the following examples are commercially available unless otherwise specified.

[0060] In the following examples and comparative examples, the polyester yarn (before modification) is purchased from Shaoxing Weipu Thread Co., Ltd., and the specification is 630Dx3.

[0061] Example 1

[0062] S1, 0.05 parts by weight of KH550, 40 parts by weight of anhydrous ethanol and 60 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to prepare a KH550 modification solution;

[0063] S2, 0.02 parts by weight of IPDI and 1 part by weight of acetone are uniformly mixed to prepare an IPDI solution;

[0064] S3, 10 parts by weight of polyester yarn was soaked in the KH550 modification solution at 60°C for 120 minutes, bath ratio was 1:8, then the polyester yarn was taken out and dipped and rolled twice by small rolling machine, pick-up was 60%.

[0065] S4, the polyester yarn was rinsed with cold water for 3 times and dried, then soaked in the IPDI solution at room temperature (25°C) for 8 minutes, bath ratio was 1:8, the polyester yarn was taken out and dried at 45°C, the anti-aging composite yarn was prepared.

[0066] Figure 2 is the infrared spectrum of unmodified polyester yarn and modified polyester yarn prepared in Example 1.

[0067] Example 2

[0068] S1, 0.01 parts by weight of KH550, 50 parts by weight of absolute ethanol and 50 parts by weight of water were mixed uniformly, and the pH value was adjusted to 4.5 with citric acid to prepare a KH550 modification solution;

[0069] S2, 0.1 parts by weight of IPDI and 50 parts by weight of acetone were mixed uniformly to prepare an IPDI solution;

[0070] S3, 10 parts by weight of polyester yarn was soaked in the KH550 modification solution at 80°C for 120 minutes, bath ratio was 1:10, then the polyester yarn was taken out and dipped and rolled twice by small rolling machine, pick-up was 40%.

[0071] S4, the polyester yarn was rinsed with cold water for 3 times and dried, then soaked in the IPDI solution at room temperature (25°C) for 8 minutes, bath ratio was 1:15, the polyester yarn was taken out and dried at 35°C, the anti-aging composite yarn was prepared.

[0072] Example 3

[0073] S1, 1 parts by weight of KH550, 60 parts by weight of absolute ethanol and 40 parts by weight of water were mixed uniformly, and the pH value was adjusted to 4.5 with citric acid to prepare a KH550 modification solution;

[0074] S2, 0.15 parts by weight of IPDI and 50 parts by weight of acetone were mixed uniformly to prepare an IPDI solution;

[0075] S3, 10 parts by weight of polyester yarn was soaked in the KH550 modification solution at 80°C for 100 minutes, bath ratio was 1:20, then the polyester yarn was taken out and dipped and rolled twice by small rolling machine, pick-up was 50%.

[0076] S4, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in the IPDI solution at room temperature (25℃) for 8 minutes, bath ratio is 1:12, the polyester yarn is taken out and dried at 60℃, to obtain the anti-aging composite yarn.

[0077] Example 4

[0078] S1, 2 parts by weight of KH550, 60 parts by weight of anhydrous ethanol and 40 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to obtain a KH550 modification solution;

[0079] S2, 1 part by weight of IPDI and 50 parts by weight of acetone are uniformly mixed to obtain an IPDI solution;

[0080] S3, 10 parts by weight of polyester yarn is soaked in the KH550 modification solution at 80℃ for 100 minutes, bath ratio is 1:10, then the polyester yarn is taken out and dipped and rolled twice by a small rolling machine, with a pick-up rate of 50%.

[0081] S4, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in the IPDI solution at room temperature (25℃) for 8 minutes, bath ratio is 1:12, the polyester yarn is taken out and dried at 60℃, to obtain the anti-aging composite yarn.

[0082] Comparative Example 1

[0083] S1, 60 parts by weight of anhydrous ethanol and 40 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to obtain a modification solution;

[0084] S2, 10 parts by weight of polyester yarn is soaked in the modification solution at 80℃ for 1.5 hours, bath ratio is 1:5, then the polyester yarn is taken out and dipped and rolled twice by a small rolling machine, with a pick-up rate of 50%.

[0085] S3, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in acetone at room temperature (25℃) for 10 minutes, bath ratio is 1:12, the polyester yarn is taken out and dried at 60℃.

[0086] Comparative Example 2

[0087] S1, 40 parts by weight of anhydrous ethanol and 60 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to obtain a modification solution;

[0088] S2, 10 parts by weight of polyester yarn is soaked in the modification solution at 60℃ for 1 hour, bath ratio is 1:15, then the polyester yarn is taken out and dipped and rolled twice by a small rolling machine, with a pick-up rate of 80%.

[0089] S3, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in acetone at room temperature (25°C) for 8 minutes, bath ratio is 1:6, the polyester yarn is taken out and dried at 40°C.

[0090] Comparative Example 3

[0091] The method is implemented according to the method of Example 2, except that KH550 is not added in the modification liquid, only IPDI is used for modification.

[0092] The specific operation process of the method includes:

[0093] S1, 50 parts by weight of anhydrous ethanol and 50 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to prepare a modification liquid;

[0094] S2, 0.1 parts by weight of IPDI and 50 parts by weight of acetone are uniformly mixed to prepare an IPDI solution;

[0095] S3, 10 parts by weight of polyester yarn is soaked in the modification liquid at 80°C for 120 minutes, bath ratio is 1:10, then the polyester yarn is taken out and dipped and rolled twice by a small rolling machine, the pick-up rate is 40%.

[0096] S4, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in acetone at room temperature (25°C) for 8 minutes, bath ratio is 1:6, the polyester yarn is taken out and dried at 40°C.

[0097] Comparative Example 4

[0098] The method is implemented according to the method of Example 2, except that KH550 is not added in the modification liquid, only IPDI is used for modification.

[0099] The specific operation process of the method includes:

[0100] S1, 50 parts by weight of anhydrous ethanol and 50 parts by weight of water are uniformly mixed, and the pH value is adjusted to 4.5 with citric acid to prepare a modification liquid;

[0101] S3, 10 parts by weight of polyester yarn is soaked in the modification liquid at 80°C for 120 minutes, bath ratio is 1:10, then the polyester yarn is taken out and dipped and rolled twice by a small rolling machine, the pick-up rate is 40%.

[0102] S4, the polyester yarn is rinsed with cold water for 3 times, then air dried, soaked in acetone at room temperature (25°C) for 8 minutes, bath ratio is 1:6, the polyester yarn is taken out and dried at 40°C.

[0103] Test Example

[0104] (1) The polyester yarn before modification and the modified polyester yarn prepared in the examples and comparative examples were irradiated by a UV light box for 2000h; then the tensile breaking strength was tested according to GB / T 3916-2013 "Determination of breaking force and elongation at break of individual yarn in textile packages", and the strength retention rate was calculated; then the yarn discoloration rating was performed according to GB / T 250-2008 "Textiles-Color fastness test-Standard grey scale for assessing discoloration". The test results are shown in Table 1. Figure 3 is the tensile breaking curve of the polyester yarn before modification and the modified polyester yarn prepared in Example 1.

[0105] The conditions of the UV light box irradiation include: the UV wavelength is 340NM, the light energy is 0.77, the testing instrument is Q-LAB aging test test box, and the specification of the polyester yarn before modification is 630Dx3.

[0106]

[0107] Table 1

[0108]

[0109] As can be seen from the results in Table 1, the breaking strength and strength retention rate of the modified polyester fiber prepared by the examples of the present application after aging are significantly improved compared with the comparative examples.

[0110] The specific analysis is as follows:

[0111] (1) The original breaking strength of the anti-aging yarn prepared in Example 1 is 129.54N, after being continuously irradiated by a UV lamp with a wavelength of 349nm and a light energy of 0.77 for 2000 hours, the breaking strength is tested to be 99.32N, the strength retention rate is 76.67%, and the discoloration is 4-5 levels; the polyester yarn prepared in Examples 2-4 also has a breaking strength retention rate higher than 70% after being continuously irradiated by a UV lamp for 2000 hours. The breaking strength retention rates of the polyester yarns without KH550 treatment in Comparative Example 1 and Comparative Example 2 are both lower than 60% after being continuously irradiated by a UV lamp for 2000 hours. This is because the introduction of KH550 can form Si-O-Si bonds between the polyurethane chains, which increases the crosslinking density of the material and forms a more stable three-dimensional network structure. This is a gradual polymerization and crosslinking process, finally forming a three-dimensional network structure of silicone-modified waterborne polyurethane (WPU-Si). The hydrolysis product of KH550, silicon hydroxyl, can react with IPDI (isophorone diisocyanate) to form a stable urethane structure, which can effectively improve the UV resistance and reduce the damage of UV to the fiber, prolonging the service life of the fiber.

[0112] (2) The mechanism of KH550 improving the UV resistance of polyester fiber:

[0113] Coupling agent function: KH550, as a silane coupling agent, contains functional groups that react with the fiber surface. When KH550 chemically reacts with the polyester fiber surface, its molecules form covalent bonds with the molecular structure of the fiber surface. This chemical bonding can change the molecular arrangement of the fiber surface, thereby enhancing the structural stability of the fiber.

[0114] UV absorption: The silane film formed by KH550 on the fiber surface can absorb ultraviolet rays and reduce the direct exposure of ultraviolet rays to the fiber. This is because the chemical bonds in the silane film can absorb the energy of ultraviolet rays and convert it into other forms of energy, such as heat, thereby protecting the fiber from damage by ultraviolet rays.

[0115] Physical barrier: The silane film formed by KH550 on the fiber surface also acts as a physical barrier, reflecting or scattering some UV rays, preventing them from penetrating into the fiber. This effectively reduces UV damage to the fiber's internal molecular structure and improves the fiber's UV resistance.

[0116] Light stabilizer: KH550 may also act as a light stabilizer to help polyester fibers remain stable under ultraviolet radiation. It can reduce the activation of photosensitive molecules in the fiber, thereby reducing the incidence of photodegradation reactions and extending the service life of the fiber.

[0117] In summary, KH550 improves the physical and chemical properties of polyester fibers through a chemical reaction with their surface, while also enhancing their UV protection at the molecular level. These improvements help extend the life of polyester fibers in outdoor applications, maintaining the stability of their performance and appearance.

[0118] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A process for making super strong age resistant retained strength polyester yarns, characterized by, The method comprises the following steps: (1) soaking the polyester yarn in a modification liquid containing a monoamino silane coupling agent, and then taking out the polyester yarn for padding; (2) soaking the polyester yarn treated in step (1) in a diisocyanate compound solution; In step (1), the preparation process of the modification liquid containing the monoamino silane coupling agent comprises: dissolving the monoamino silane coupling agent in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH value to 4-5; In step (1), the conditions for soaking the polyester yarn in the modification liquid containing the monoamino silane coupling agent include: bath ratio of 1:5-10, temperature of 50-80℃, and time of 1-3 hours; In step (2), the conditions for soaking the polyester yarn treated in step (1) in the diisocyanate compound solution include: bath ratio of 1:5-20, temperature of 15-35℃, and time of 5-10 minutes.

2. The method of claim 1, wherein, In step (1), the concentration of the monoamino silane coupling agent in the modification liquid is 0.009-2% by weight.

3. The method according to claim 1 or 2, characterized in that, The weight ratio of the amount of the monoamino silane coupling agent to the amount of the mixed solvent is 0.01-2:

100.

4. The method of claim 1, wherein, In the mixed solvent, the weight ratio of the amount of anhydrous ethanol to the amount of water is 0.65-1.5:

1.

5. The method according to claim 1 or 2, characterized in that, In step (1), the monoamino silane coupling agent is selected from at least one of KH550, KH551 and A-1100.

6. The method of claim 1, wherein, In step (1), the padding has a pick-up rate of 40-80%.

7. The method of claim 1, wherein, In step (2), the diisocyanate compound in the diisocyanate compound solution is selected from at least one of isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

8. The method of claim 1, wherein, In step (2), the concentration of the diisocyanate compound solution is 0.05-5% by weight.

9. The method according to claim 1 or 8, characterized in that, In step (2), the solvent of the diisocyanate compound solution is selected from at least one of acetone, toluene, xylene and cyclohexanone.

10. A modified polyester yarn prepared by the method of any one of claims 1-9.

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