Method for preparing super-strong aging-resistant strength-maintaining polyester yarn and modified polyester yarn

Abstract

The invention relates to the technical field of functional fiber preparation, and discloses a method for preparing super-strong aging-resistant strength-maintaining polyester yarn and modified polyester yarn. The method comprises the following steps: (1) soaking polyester yarns in a modification solution containing a monoamino silane coupling agent, and then taking out the polyester yarns for padding; and (2) soaking the polyester yarns treated in the step (1) in a diisocyanate compound solution. According to the method, the monoamino silane coupling agent and the diisocyanate compound are sequentially used for carrying out surface treatment on the polyester yarn, so that the light resistance and durability of the polyester yarn are improved, the tolerance of the polyester yarn to ultraviolet rays is enhanced, the problems of yellowing and breakage caused by long-term outdoor use are solved, the increasingly stringent industrial application requirements are met, and the application prospect is wide. Substantive technical innovation and economic benefits are brought to related industries. According to the method, the traditional method of coating a high-performance material on the surface of the yarn is abandoned, and the method has the advantages of washing resistance, friction resistance and no influence on subsequent coloring.

Description

Technical Field

[0001] The invention relates to the technical field of functional fiber preparation, and in particular to a method for preparing super aging-resistant and strong polyester yarn and a modified polyester yarn. Background Art

[0002] Polyester fiber (polyester) has the characteristics of high strength, good elasticity, heat resistance, thermal insulation, wear resistance, corrosion resistance, etc. The yarn made from it is high in strength, can always remain flat and beautiful, without shrinkage, excellent in wear resistance, and has good high temperature resistance, low temperature resistance, light resistance and water resistance. As the demand for polyester yarn in the industrial field continues to grow, the durability of these products is significantly affected when they are exposed to strong ultraviolet rays outdoors for a long time. After continuous sunlight, the mechanical properties of the yarn will seriously decline, which will greatly reduce its service life and cannot meet the high standards of industrial applications.

[0003] In view of this, it is urgent to develop a rope that can maintain excellent mechanical properties even under long-term sunlight conditions to meet the requirements of industrial applications for high-performance yarns. Therefore, polyester yarns need to be functionalized to a certain extent. Currently, the most widespread and simplest method is coating finishing. However, the coating of yarns is often accompanied by problems such as poor wear resistance, easy yellowing and brittleness, and uneven coating. Therefore, in long-term outdoor environments, it is necessary to find a method for preparing functional yarns that are super resistant to aging, UV resistance, wear resistance, and do not require coating. Summary of the invention

[0004] The purpose of the present invention is to overcome the difficulties commonly faced by polyester yarns in outdoor applications in the prior art, namely, insufficient light resistance, degradation of mechanical properties, easy yellowing and brittle fracture caused by long-term exposure to ultraviolet rays, which seriously affect the durability and reliability of the polyester yarn during actual use, thereby shortening its service life and limiting its potential in many industrial applications. A method for preparing super aging-resistant and strong polyester yarn and a modified polyester yarn are provided. The method sequentially surface-treats the polyester yarn with a monoaminosilane coupling agent and a diisocyanate compound to improve the light resistance and durability of the polyester yarn, so as to enhance its tolerance to ultraviolet rays, solve the problems of yellowing and fracture caused by long-term outdoor use, meet the increasingly stringent requirements of industrial applications, and bring substantial technological innovation and economic benefits to related industries.

[0005] In order to achieve the above object, the present invention provides a method for preparing a super strong aging-resistant and strong polyester yarn, which comprises the following steps:

[0006] (1) soaking the polyester yarn in a modification solution containing a monoaminosilane coupling agent, and 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 monoaminosilane coupling agent in the modified solution is 0.009 to 2% by weight.

[0009] Preferably, the pH value of the modified liquid is 4-5.

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

[0011] Preferably, in step (1), the preparation process of the modified liquid containing the monoaminosilane coupling agent comprises: dissolving the monoaminosilane 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 monoaminosilane coupling agent to the mixed solvent is 0.01 to 2:100.

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

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

[0015] Preferably, in step (1), the rolling rate is 40 to 80%.

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

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

[0018] Preferably, in step (2), the concentration of the diisocyanate compound solution is 0.05 to 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 invention provides a modified polyester yarn prepared by the method described above.

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

[0022] (1) The present invention soaks polyester yarn in a modification liquid containing a monoaminosilane coupling agent. The alkoxy groups in the monoaminosilane coupling agent are converted into hydrolysis products having reactive silanol groups through hydrolysis. The silanol groups may undergo dehydration condensation reactions to form oligomeric siloxanes. These oligomers still have reactive silanol groups. These silanol groups can form covalent bonds and hydrogen bonds with carboxyl groups or hydroxyl groups on the surface of the polyester fiber to produce chemical reactions. These silanol groups can also react with isocyanate groups.

[0023] (2) The hydrolysis product of the alkoxy group in the monoaminosilane coupling agent that has not undergone condensation reaction after hydrolysis has multiple silanol groups, which are highly active and can further react chemically with functional groups such as carboxyl or hydroxyl groups on the surface of polyester fibers. These reactions may include the formation of hydrogen bonds and covalent bonds, such as -SiO-M (M represents the surface of polyester fibers). It can also further react with the isocyanate group (-NCO) in the diisocyanate compound to form a carbamate structure (the amino group comes from the monoaminosilane coupling agent). In this process, the hydrogen atom of the silanol group combines with the carbon atom in the isocyanate group to form a carbamate group and release a hydroxyl group.

[0024] R-Si(OH)+OCN-R'→Si(ONC-R')+HO

[0025] (3) By introducing monoaminosilane coupling agent, Si-O-Si bonds can be formed between polyurethane chains, which increase the crosslinking density of the material and form a more stable three-dimensional network structure. This is a gradual polymerization and crosslinking process, which ultimately forms a silicone-modified waterborne polyurethane with a three-dimensional network structure.

[0026] (3) The present invention forms a high-performance material inside the polyester yarn without changing the original color by sequentially surface-treating the yarn in a solution containing a monoaminosilane coupling agent and a diisocyanate compound. The method abandons the traditional method of coating the high-performance material on the surface of the yarn. The yarn can withstand long-term outdoor exposure to wind and sun, and the hand feel is basically maintained at the original level without changing the original color. The yarn has the advantages of being resistant to washing and friction and not affecting subsequent coloring.

[0027] (4) After being irradiated with ultraviolet radiation for more than 2000 hours, the breaking strength of the modified polyester yarn prepared by the present invention is still maintained at more than 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1It is a schematic diagram of the structure of the modified polyester yarn prepared by the method of the present invention.

[0029] Figure 2 are infrared images of unmodified polyester yarn and modified polyester yarn prepared in Example 1;

[0030] Figure 3 1 are the tensile breaking curves of the unmodified polyester yarn and the modified polyester yarn prepared in Example 1. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0033] The method for preparing a super strong aging-resistant and strong polyester yarn provided by the present invention comprises the following steps:

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

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

[0036] In the method of the invention, the polyester yarn is first immersed in a modification liquid containing a monoaminosilane coupling agent, and the monoaminosilane coupling agent is hydrolyzed to generate a hydrolysis product having silanol groups. On the one hand, the silanol groups can chemically react with the hydroxyl or carboxyl functional groups on the surface of the polyester fiber to form a covalent bond. This chemical bonding can change the molecular arrangement on the fiber surface, thereby enhancing the structural stability of the fiber; on the other hand, the monoaminosilane coupling agent can form a silane film on the surface of the polyester yarn by self-assembly, and the silane film can absorb ultraviolet rays and reduce the direct exposure of ultraviolet rays to the fiber; on the third hand, the silane film formed by the monoaminosilane coupling agent on the surface of the polyester yarn can be used as a physical Barrier, reflecting or scattering part of the ultraviolet rays to prevent them from penetrating into the fiber, which can effectively reduce the damage of ultraviolet rays to the molecular structure inside the fiber and improve the ultraviolet resistance of the fiber; fourthly, the monoaminosilane coupling agent modified on the surface of the polyester yarn may also act as a light stabilizer to help the polyester fiber remain stable under ultraviolet irradiation; after the polyester yarn treated with the modified liquid is immersed in a diisocyanate compound solution, the silicon hydroxyl group in the hydrolyzate of the monoaminosilane coupling agent modified on the polyester yarn can react with the diisocyanate compound to form a stable carbamate structure, so as to effectively improve its ultraviolet resistance, reduce the damage of ultraviolet rays to the fiber and extend the service life of the fiber.

[0037] In the present invention, the polyester yarn may be a conventional choice in the art. Exemplarily, the polyester yarn is a polyester filament sewing thread.

[0038] In the method of the present invention, the monoaminosilane coupling agent can be a common silane coupling agent in the art. In some embodiments, the monoaminosilane 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 monoaminosilane coupling agent in the modifying liquid in step (1) can be 0.009 to 2 weight %. Limiting the concentration of the monoaminosilane coupling agent in the modifying liquid to within this range can control the hydrolysis process, control the amount of silanol generated, and further control the reaction of silanol.

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

[0041] In one embodiment, the preparation process of the modified liquid containing a monoaminosilane coupling agent includes: dissolving the monoaminosilane coupling agent in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH value to 4-5 to generate silanol groups. In a more preferred embodiment, the pH value of the modified liquid needs to be adjusted to 4-5. In the present invention, the pH value of the modified liquid can be adjusted to 4-5 using an acid commonly used in the art. In order to prevent excessive acid from damaging the polyester yarn, 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 monoaminosilane coupling agent to the mixed solvent may be 0.01 to 2:100, for example, 0.01:100, 0.05:100, 0.1:100, 0.5:100, 1:100, 1.5:100 or 2:100.

[0042] In the method of the present invention, in order to improve the uniformity and stability of the reaction of the monoaminosilane coupling agent and avoid the reaction speed being too fast or too slow, it is necessary to optimize the temperature at which the polyester yarn is immersed in the modifying liquid containing the monoaminosilane coupling agent in step (1). In a preferred embodiment, the temperature at which the polyester yarn is immersed in the modifying liquid containing the monoaminosilane coupling agent is 50 to 80°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0043] In some preferred embodiments, the bath ratio of the polyester yarn soaked in the modified solution containing the monoaminosilane coupling agent is 1:5 to 10. Limiting the bath ratio to this range can effectively control the self-polymerization of silanol groups, because the self-polymerization and reaction activity of silanol groups is higher, and excessive amounts will lead to excessive self-polymerization and this part of the reaction, making it difficult to form a polyurethane network.

[0044] In some other preferred embodiments, the polyester yarn is immersed in the modification liquid containing the monoaminosilane coupling agent for 1 to 3 hours. When the time is controlled within this range, sufficient hydrolysis can be achieved.

[0045] In some embodiments, after the polyester yarn soaked in the modifying liquid is taken out and padded, the padded liquid rate can be controlled to be 40-80%, for example, 40%, 50%, 60%, 70% or 80%. In the present invention, the number of padded times can be multiple times, preferably 2 times. In the present invention, the method further includes: rinsing the padded polyester yarn with cold water for 2-5 times and then drying it.

[0046] In the method of the present invention, the diisocyanate compound in the diisocyanate compound solution of step (2) can be a conventional choice in the art. In some embodiments, the diisocyanate compound in the diisocyanate compound solution of step (2) is selected from at least one 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 in step (2) is 0.05-5% by weight. Controlling the concentration of the diisocyanate compound solution within this range enables the silanol group and the diisocyanate compound to react at an appropriate rate.

[0048] In the present invention, the diisocyanate compound solution can be prepared according to a conventional method. In one embodiment, the preparation process of the diisocyanate compound solution includes: mixing the diisocyanate compound with a solvent. In the present invention, the solvent can be an organic solvent commonly found in the art. In some embodiments, the solvent of the diisocyanate compound solution in step (2) is selected from at least one of acetone, toluene, xylene and cyclohexanone, preferably acetone.

[0049] In the method of the present invention, the temperature of soaking the polyester yarn treated in step (1) in the diisocyanate compound solution can be room temperature, such as 15-35°C, and the time can be 5-10 minutes. In some preferred embodiments, the bath ratio of soaking the polyester yarn treated in step (1) in the diisocyanate compound solution is 1:5-20. In step (2), the bath ratio is controlled within this range to fully react.

[0050] In the present invention, the method further comprises: soaking the polyester yarn treated in step (1) in a diisocyanate compound solution, taking out the polyester yarn, and drying it.

[0051] In a preferred embodiment, a method for preparing a super strong aging-resistant and strong polyester yarn comprises the following steps:

[0052] 1) Dissolve KH550 in a mixed solvent of anhydrous ethanol and water, and then adjust the pH value to 4-5 to obtain a modified solution;

[0053] 2) soaking the polyester yarn in the modified solution at a bath ratio of 1:5-10, at a temperature of 50-80° C., for 1-3 hours, then taking out the polyester yarn for padding, then rinsing it with cold water for several times and then drying it;

[0054] 3) Soaking the polyester yarn treated in step 2) in an isophorone diisocyanate solution for 5 to 10 minutes, taking it out and drying it at room temperature.

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

[0056] The second aspect of the present invention provides a modified polyester yarn prepared by the method described above. The structure of the modified polyester yarn is as follows: Figure 1 After being irradiated with ultraviolet radiation for more than 2000 hours, the breaking strength of the modified polyester yarn provided by the present invention is still maintained at more than 70%.

[0057] The modified polyester yarn provided by the present invention is an aging-resistant composite yarn, which can be used as outdoor clothing: such as assault jackets, sun-proof clothing, etc.; sports equipment: such as sports shoes, sports bags, etc.; sunshade products: parasols, sun hats, etc.; tents and awnings; car interiors; construction fields: such as sunshade 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 UV resistance, oxidation resistance, high temperature resistance, etc. Therefore, the design not only has a wide range of applications, but also has a simple preparation method and is economical and efficient.

[0058] The following examples further illustrate the method for preparing the super aging-resistant and strong polyester yarn and the modified polyester yarn of the present invention. The examples are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

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

[0060] In the following examples and comparative examples, the polyester yarn (polyester yarn before modification) was purchased from Shaoxing Weipu Wire Industry Co., Ltd., with a specification of 630D×3.

[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 were uniformly mixed, and the pH value was adjusted to 4.5 with citric acid to obtain a KH550 modified liquid;

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

[0064] S3. Immerse 10 parts by weight of polyester yarn in KH550 modifying liquid at 60° C. for 120 minutes with a bath ratio of 1:8. Then take out the polyester yarn and perform double dipping and double rolling with a small rolling mill with a rolling rate of 60%.

[0065] S4. Rinse the polyester yarn with cold water for 3 times and then dry it, soak it in IPDI solution at room temperature (25°C) for 8 minutes with a bath ratio of 1:8, take out the polyester yarn and dry it at 45°C to obtain an aging-resistant composite yarn.

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

[0067] Example 2

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

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

[0070] S3. Immerse 10 parts by weight of polyester yarn in KH550 modified solution at 80° C. for 120 minutes with a bath ratio of 1:10. Then take out the polyester yarn and perform double dipping and double rolling with a small rolling mill with a rolling rate of 40%.

[0071] S4. Rinse the polyester yarn with cold water for 3 times and then dry it. Soak it in IPDI solution at room temperature (25°C) for 8 minutes with a bath ratio of 1:15. Take out the polyester yarn and dry it at 35°C to obtain an aging-resistant composite yarn.

[0072] Example 3

[0073] S1, 1 part by weight of KH550, 60 parts by weight of anhydrous ethanol and 40 parts by weight of water were mixed evenly, and the pH value was adjusted to 4.5 with citric acid to prepare a KH550 modified liquid;

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

[0075] S3. Immerse 10 parts by weight of polyester yarn in KH550 modifying liquid at 80° C. for 100 minutes with a bath ratio of 1:20. Then take out the polyester yarn and perform double dipping and double rolling with a small rolling mill with a rolling rate of 50%.

[0076] S4. Rinse the polyester yarn with cold water for 3 times and then dry it. Soak it in IPDI solution at room temperature (25°C) for 8 minutes with a bath ratio of 1:12. Take out the polyester yarn and dry it at 60°C to obtain an aging-resistant 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 were mixed evenly, and the pH value was adjusted to 4.5 with citric acid to prepare a KH550 modified liquid;

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

[0080] S3. Immerse 10 parts by weight of polyester yarn in KH550 modifying liquid at 80° C. for 100 minutes with a bath ratio of 1:10. Then take out the polyester yarn and perform double dipping and double rolling with a small rolling mill with a rolling rate of 50%.

[0081] S4. Rinse the polyester yarn with cold water for 3 times and then dry it. Soak it in IPDI solution at room temperature (25°C) for 10 minutes with a bath ratio of 1:10. Take out the polyester yarn and dry it at 50°C to obtain an aging-resistant composite yarn.

[0082] Comparative Example 1

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

[0084] S2, soaking 10 parts by weight of polyester yarn in the modified solution at 80° C. for 1.5 hours, with a bath ratio of 1:5, and then taking out the polyester yarn and performing two dipping and two rolling with a small rolling mill, with a rolling rate of 50%;

[0085] S3. Rinse the polyester yarn with cold water for three times and then dry it. Soak it in acetone at room temperature (25°C) for 10 minutes with a bath ratio of 1:12. Take out the polyester yarn and dry it at 60°C.

[0086] Comparative Example 2

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

[0088] S2, soaking 10 parts by weight of polyester yarn in the modified solution at 60° C. for 1 hour, with a bath ratio of 1:15, and then taking out the polyester yarn and performing two dipping and two rolling with a small rolling mill, with a rolling rate of 80%;

[0089] S3. Rinse the polyester yarn with cold water for 3 times and then dry it. Soak it in acetone at room temperature (25°C) for 8 minutes with a bath ratio of 1:6. Take out the polyester yarn and dry it at 40°C.

[0090] Comparative Example 3

[0091] The method of Example 2 was followed, except that KH550 was not added to the modified solution, and only IPDI was used for modification.

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

[0093] S1, 50 parts by weight of anhydrous ethanol and 50 parts by weight of water were mixed evenly, and the pH value was adjusted to 4.5 with citric acid to prepare a modified liquid;

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

[0095] S3, immersing 10 parts by weight of polyester yarn in the modifying liquid at 80°C for 120 minutes with a bath ratio of 1:10, and then taking out the polyester yarn and performing two immersion and two rolling with a small rolling mill, with a rolling rate of 40%.

[0096] S4. Rinse the polyester yarn with cold water for 3 times and then dry it. Soak it in IPDI solution at room temperature (25°C) for 8 minutes with a bath ratio of 1:15. Take out the polyester yarn and dry it at 35°C to obtain an aging-resistant composite yarn.

[0097] Comparative Example 4

[0098] The method of Example 2 was followed, except that only KH550 was used for modification without adding IPDI for modification.

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

[0100] S1, 0.01 parts by weight of KH550, 50 parts by weight of anhydrous ethanol and 50 parts by weight of water were uniformly mixed, and the pH value was adjusted to 4.5 with citric acid to prepare a KH550 modified liquid;

[0101] S3. Immerse 10 parts by weight of polyester yarn in KH550 modified solution at 80° C. for 120 minutes with a bath ratio of 1:10. Then take out the polyester yarn and perform double dipping and double rolling with a small rolling mill with a rolling rate of 40%.

[0102] S4. Rinse the polyester yarn with cold water for 3 times and then air dry it. Soak it in acetone at room temperature (25°C) for 8 minutes with a bath ratio of 1:15. Take out the polyester yarn and dry it at 35°C to obtain an aging-resistant composite yarn.

[0103] Test Case

[0104] (1) The polyester yarn before modification and the modified polyester yarn prepared in the examples and comparative examples were irradiated with an ultraviolet light box for 2000 hours; then the tensile breaking strength was tested according to GB / T 3916-2013 "Determination of Breaking Tenacity and Elongation at Break of Single Yarn of Textile Package Yarn", and the strength retention was calculated; then the yarn color change rating was performed according to GB / T 250-2008 "Gray Scale Standard for Color Fastness Tests for Textiles to Evaluate Color Change". The test results are shown in Table 1. Figure 3 1 are the tensile breaking curves of the unmodified polyester yarn and the modified polyester yarn prepared in Example 1.

[0105] Among them, the conditions of UV light box irradiation include: UV wavelength is 340NM, light energy is 0.77, the testing instrument is Q-LAB aging test box, and the specification of polyester yarn before modification is 630D×3.

[0106]

[0107] Table 1

[0108]

[0109] It can be seen from the results in Table 1 that the breaking strength and strength retention rate of the modified polyester fiber prepared by the embodiment of the present invention after aging are significantly improved compared with the control example.

[0110] The specific analysis is as follows:

[0111] (1) The original breaking strength of the aging-resistant yarn prepared in Example 1 was 129.54N. After continuous irradiation for 2000 hours by an ultraviolet lamp with a wavelength of 349nm and an illumination energy of 0.77, the breaking strength was tested to be 99.32N, the strength retention rate was 76.67%, and the color change was 4-5 levels; the polyester yarns prepared in Examples 2-4 were also continuously irradiated with ultraviolet lamps for 2000 hours, and their breaking strength retention rates were all higher than 70%. However, the polyester yarns of Comparative Examples 1 and 2 that were not treated with KH550 were continuously irradiated with ultraviolet lamps for 2000 hours, and their breaking strength retention rates were all lower than 60%. This is because by introducing KH550, Si-O-Si bonds can be formed between polyurethane chains, and these bonds increase the crosslinking density of the material, forming a more stable three-dimensional network structure. This is a step-by-step polymerization and crosslinking process, and finally a silicone-modified waterborne polyurethane (WPU-Si) with a three-dimensional network structure is formed. The hydrolysis product of KH550, silanol, can react with IPDI (isophorone diisocyanate) to form a stable carbamate structure, which can effectively improve its UV resistance, reduce UV damage to the fiber, and extend the service life of the fiber.

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

[0113] Coupling agent function: KH550 is a silane coupling agent, and its molecules contain functional groups that can react with the fiber surface. When KH550 reacts chemically with the surface of polyester fiber, its molecules will 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 UV rays and reduce the direct exposure of UV rays to the fiber. This is because the chemical bonds in the silane film can absorb the energy of UV rays and convert it into other forms of energy, such as heat energy, thereby protecting the fiber from damage by UV rays.

[0115] Physical barrier: The silane film formed by KH550 on the fiber surface can also serve as a physical barrier, reflecting or scattering part of the ultraviolet rays to prevent them from penetrating into the fiber. This can effectively reduce the damage of ultraviolet rays to the molecular structure inside the fiber and improve the fiber's ultraviolet resistance.

[0116] Light stabilizer: KH550 may also act as a light stabilizer to help polyester fibers remain stable under ultraviolet light. 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 not only improves the physical and chemical properties of polyester fibers through chemical reactions on the surface, but also improves the fiber's ability to protect against ultraviolet rays at the molecular level. These improvements help extend the life of polyester fibers in outdoor applications and maintain the stability of their performance and appearance.

[0118] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing super aging-resistant and strong polyester yarn, characterized in that: The method comprises the following steps: (1) soaking the polyester yarn in a modification solution containing a monoaminosilane 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.

2. The method according to claim 1, characterized in that In step (1), the concentration of the monoaminosilane coupling agent in the modified solution is 0.009 to 2% by weight; Preferably, the pH value of the modified liquid is 4-5.

3. The method according to claim 1 or 2, characterized in that: In step (1), the conditions for soaking the polyester yarn in the modified liquid containing the monoaminosilane coupling agent include: bath ratio of 1:5-10, temperature of 50-80°C, and time of 1-3 hours.

4. The method according to any one of claims 1 to 3, characterized in that: In step (1), the preparation process of the modified liquid containing the monoaminosilane coupling agent includes: dissolving the monoaminosilane coupling agent in a mixed solvent of anhydrous ethanol and water, and then adjusting the pH value to 4-5; Preferably, the weight ratio of the monoaminosilane coupling agent to the mixed solvent is 0.01 to 2:100; Preferably, in the mixed solvent, the weight ratio of anhydrous ethanol to water is 0.65 to 1.5:

1.

5. The method according to any one of claims 1 to 4, characterized in that: In step (1), the monoaminosilane coupling agent is selected from at least one of KH550, KH551 and A-1100.

6. The method according to any one of claims 1 to 5, characterized in that: In step (1), the rolling rate is 40 to 80%.

7. The method according to any one of claims 1 to 6, characterized in that: In step (2), the diisocyanate compound in the diisocyanate compound solution is at least one selected from isophorone diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

8. The method according to any one of claims 1 to 7, characterized in that: In step (2), the polyester yarn treated in step (1) is immersed in a diisocyanate compound solution under the following conditions: bath ratio of 1:5 to 20, temperature of 15 to 35°C, and time of 5 to 10 minutes.

9. The method according to any one of claims 1 to 8, characterized in that: In step (2), the concentration of the diisocyanate compound solution is 0.05 to 5% by weight; Preferably, in step (2), the solvent of the diisocyanate compound solution is selected from at least one of acetone, toluene, xylene and cyclohexanone.

10. The modified polyester yarn prepared by the method according to any one of claims 1 to 9.

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