A high-strength, high-stability polyester cord and its preparation method

Abstract

This invention relates to the field of polyester cord technology, specifically to a high-strength, high-stability polyester cord and its preparation method. The invention involves the following steps: high-viscosity polyester chips are subjected to screw melt spinning, air cooling and shaping, initial application of spinning oil, hot stretching, heat setting, relaxation heat treatment, impregnation with an activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester fibers are then heat-treated and stored to obtain modified polyester fibers. These modified polyester fibers are then doubling, twisting, and heat-set to obtain polyester strands. The polyester strands are then twisted using a twisting machine to obtain twisted cords. The twisted cords are immersed in a first adhesive solution for a first impregnation treatment, and then immersed in a second adhesive solution for a second impregnation treatment. After drying and heat treatment, the polyester cord is obtained. The polyester cord prepared by this invention not only possesses excellent mechanical properties but also excellent interfacial adhesion, enabling effective bonding with a rubber matrix.

Description

Technical Field

[0001] This invention relates to the field of polyester cord technology, specifically to a high-strength, high-stability polyester cord and its preparation method. Background Technology

[0002] Tires are typical rubber products, belonging to the category of composite materials reinforced with rubber and cord. Currently, the tire industry has formed a situation where various reinforcing materials with different properties coexist, such as steel wire, rayon, nylon, polyester, and aramid. Among them, polyester cord has become the most widely used fiber reinforcing material in tires due to its high strength, good dimensional stability, and high cost-effectiveness.

[0003] Polyester fiber, as a reinforcing material, can significantly improve the strength and dimensional stability of rubber products. However, because polyester fiber contains only ester bonds and has one hydroxyl and one carboxyl group at each end, it has few surface-active groups and lacks hydrogen bonds to form bonds with rubber, resulting in poor interfacial adhesion between polyester fiber and the rubber matrix. Furthermore, amine accelerators in tire compounds may migrate to the surface of polyester fibers during use, leading to ammonolysis of ester bonds. Polyester cords generate significant heat during tire use, thereby reducing the adhesion between tire components.

[0004] Therefore, we propose a high-strength, high-stability polyester cord and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength, high-stability polyester cord and its preparation method, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing high-strength, high-stability polyester cord includes the following steps:

[0008] Step S1: High-viscosity polyester chips are subjected to screw melt spinning, blow cooling and shaping, initial application of spinning oil, hot stretching, heat setting, relaxation heat treatment, impregnation with activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester fibers are then heat-treated and stored to obtain modified polyester fibers.

[0009] The spinning oil is a mixed solution containing 3-aminopropyltriethoxysilane, with a concentration of 15-20 wt% and the proportion of 3-aminopropyltriethoxysilane in the spinning oil being 5-20 wt%.

[0010] The process conditions for hot drawing are: hot roller temperature 90-150℃, hot drawing roller speed 3000m / min-4000m / min; the process conditions for heat setting and relaxation heat treatment are: hot roller temperature 200-255℃, hot roller speed 4500m / min-6000m / min.

[0011] The activator is a mixed solution containing caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and water;

[0012] The heat treatment storage specifically involves: subjecting the pre-activated polyester fiber to heat treatment at a temperature of 50-100℃ for 96-110 hours.

[0013] Step S2: After the modified polyester fibers are doubling, twisting, and heat-setting, polyester strands are obtained; the polyester strands are twisted into shape by a twisting machine to obtain twisted cord.

[0014] Step S3: The twisted cord is immersed in the first adhesive solution for a first impregnation treatment, and after being irradiated with ultraviolet light, it is immersed in the second adhesive solution for a second impregnation treatment. After drying and heat treatment, polyester cord is obtained.

[0015] Furthermore, in step S1, the mixed solution of 3-aminopropyltriethoxysilane is composed of deionized water and 3-aminopropyltriethoxysilane in a mass ratio of (2-3):(0.2-0.4).

[0016] Furthermore, in step S1, the mass ratio of caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and water is 1:(0.1-0.2):(15-20).

[0017] Furthermore, in step S2, the heat setting process conditions are: heat setting for 30-80 minutes at a temperature of 60-80℃ and a pressure of 0.05-0.08 MPa.

[0018] Furthermore, in step S2, the number of polyester strands is 2.

[0019] Furthermore, in step S3, the preparation method of the first adhesive solution is as follows:

[0020] The thiol compound, 2-mercaptobenzothiazole, ammonia and deionized water are mixed evenly, and then the photoinitiator and styrene-butadiene pyridine latex are added and mixed evenly to obtain the first adhesive solution.

[0021] Furthermore, the first adhesive solution comprises the following components by weight: 5-10 parts of a thiol compound, 1-3 parts of a photoinitiator, 3-5 parts of 2-mercaptobenzothiazole, 2-4 parts of styrene-butadiene pyridine latex, 10-40 parts of ammonia, and 30-50 parts of deionized water.

[0022] Furthermore, the method for preparing the thiol compound is as follows:

[0023] Glutathione, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, N-hydroxysuccinimide, N,N-diisopropylethylamine and 4-pyrrolylpyridine were mixed evenly, deionized water and anhydrous ethanol were added, and the mixture was stirred at 20-30℃ for 30-50 min. Polylysine was added, and the mixture was stirred for another 20-24 h. After filtration, rotary evaporation and drying, the thiol compound was obtained.

[0024] In the above technical solution, glutathione is grafted onto the polylysine (LYS) backbone containing a large number of amino and carboxyl groups through an amidation reaction to obtain a thiol compound with excellent adhesive properties. It can further undergo a thiol-alkene click reaction with the double bonds in caffeic acid.

[0025] Furthermore, the mass ratio of glutathione, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, N-hydroxysuccinimide, N,N-diisopropylethylamine and 4-pyrrolidinylpyridine is 1:(1.8-2.0):(1.0-1.2):(3.5-3.8):(0.02-0.04).

[0026] Furthermore, the volume ratio of deionized water to anhydrous ethanol is 1:2, the ratio of glutathione to deionized water is 5g / 100mL, and the mass of polylysine is 1.5-2.0 times the mass of glutathione.

[0027] Furthermore, in step S3, the preparation method of the second adhesive solution is as follows: trimethylolpropane triglycidyl ether and deionized water are mixed evenly, triethylenetetramine is added, and the mixture is stirred at 60-80°C for 30-50 min. Then, styrene-butadiene-pyridine latex solution is added, and the mixture is stirred at 20-30°C for 1-2 h to obtain the second adhesive solution.

[0028] Furthermore, the second adhesive solution comprises the following components by weight: 5-10 parts of trimethylolpropane triglycidyl ether, 1-5 parts of triethylenetetramine, 100-110 parts of styrene-butadiene-pyridine latex solution, and 90-180 parts of deionized water.

[0029] In the above technical solution, the amine and epoxy groups in the second adhesive solution react with the amide, amino, and hydroxyl groups in the twisted cord treated with the first adhesive solution. In addition, the styrene-butadiene pyridine latex dispersed in the resin network can participate in the vulcanization of rubber to form crosslinks, thereby obtaining excellent interfacial adhesion between the fiber and the rubber.

[0030] Furthermore, the concentration of the styrene-butadiene-pyridine latex solution is 40 wt%.

[0031] Furthermore, in step S3, the time for the first immersion treatment is 10-30 minutes; the time for the second immersion treatment is 1-3 minutes.

[0032] Furthermore, in step S3, the ultraviolet irradiation process conditions are: irradiation with 360-400nm ultraviolet light for 5-20 minutes, with an irradiation intensity of 20-35mW / cm². 2 .

[0033] Furthermore, in step S3, the drying and heat treatment process conditions are as follows: drying at 120-180℃ for 20-40 minutes, and then heat treatment at 200-240℃ for 0.5-3.0 minutes.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. The present invention discloses a high-strength, high-stability polyester cord and its preparation method. This involves adding 3-aminopropyltriethoxysilane to a spinning oil to introduce an amino group, followed by an amidation reaction between the amino group and caffeic acid in an activator to introduce catechol groups with adhesive properties, thereby improving the adhesion of the polyester fiber. Simultaneously, double bonds are introduced to provide sites for subsequent reactions, resulting in pre-activated polyester fiber. The pre-activated polyester fiber is then heat-treated and stored to improve its stability, yielding modified polyester fiber. Based on this, the twisted cord made from the modified polyester fiber is impregnated with rubber, significantly improving the adhesion between the polyester fiber and rubber materials.

[0036] 2. The present invention discloses a high-strength, high-stability polyester cord and its preparation method. Glutathione is grafted onto the polylysine (LYS) backbone via an amidation reaction to obtain a biomass-based adhesive, namely a thiol compound, which exhibits excellent bonding properties. Using the thiol compound as an adhesive, 2-mercaptobenzothiazole as a constant adhesive, and styrene-butadiene rubber as an elastomer, under the action of a photoinitiator, it can further undergo a thiol-olefin click reaction with the double bonds on the modified fiber surface to form a strong cross-linked network structure. This significantly improves the bonding strength between the fiber and the rubber, reducing interfacial debonding.

[0037] A second adhesive solution is then used for impregnation. The amine and epoxy groups in the second adhesive solution react with the amide, amino, and hydroxyl groups on the twisted cord treated with the first adhesive solution, forming a more compact cross-linked network. Additionally, the styrene-butadiene-pyridine latex solution dispersed in the resin network participates in rubber vulcanization, further enhancing the interfacial adhesion between the fiber and rubber. Through these two impregnation treatments, the interfacial bonding between the fiber and rubber is significantly improved, reducing the risk of interfacial delamination and ensuring material stability. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In this embodiment, the high-viscosity polyester chips are Changzhou Huarun CR-882; the styrene-butadiene pyridine latex is YT-14, sourced from Jiangsu Yatai Chemical Co., Ltd.; and the oil is Fasavin 2744.

[0040] In the following examples and comparative examples, 1 part equals 10g.

[0041] Example 1: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0042] Step S1: High-viscosity polyester chips are subjected to screw melt spinning, blow cooling and shaping, initial application of spinning oil, hot stretching, heat setting, relaxation heat treatment, impregnation with activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester industrial yarn is then heat-treated and stored to obtain modified polyester fibers.

[0043] The spinning oil is a mixed solution containing 3-aminopropyltriethoxysilane, with a concentration of 15 wt% and 3-aminopropyltriethoxysilane accounting for 5 wt% of the spinning oil. The mixed solution of 3-aminopropyltriethoxysilane is composed of deionized water and 3-aminopropyltriethoxysilane in a mass ratio of 2:0.2.

[0044] The hot drawing process conditions are: hot roller temperature 90℃, hot drawing roller speed 3000m / min; the heat setting and relaxation heat treatment process conditions are: hot roller temperature 200℃, hot roller speed 4500m / min.

[0045] The activator is a mixed solution containing caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and water in a mass ratio of 1:0.1:15;

[0046] The heat treatment storage specifically involves: subjecting the pre-activated polyester fiber to heat treatment at a temperature of 50°C for 96 hours.

[0047] Step S2: After the modified polyester fiber is doubling, twisting, and heat-setting (heat-setting at 60℃ and 0.05Mpa for 30min), polyester strands are obtained; two strands of polyester are twisted together by a twisting machine to obtain twisted cord.

[0048] Step S3: Immerse the twisted cord in the first adhesive solution for 10 minutes, then irradiate it with 360nm ultraviolet light for 5 minutes at an irradiation intensity of 20mW / cm. 2 Then, immerse it in the second adhesive solution for 1 minute, dry it at 120°C for 20 minutes, and then heat treat it at 200°C for 0.5 minutes to obtain polyester cord.

[0049] In step S3, the preparation method of the first adhesive solution is as follows:

[0050] Mix 5 parts of mercapto compound, 3 parts of 2-mercaptobenzothiazole, 10 parts of ammonia and 30 parts of deionized water evenly, then add 1 part of photoinitiator and 2 parts of styrene-butadiene-pyridine latex and mix evenly to obtain the first adhesive solution.

[0051] The preparation method of thiol compounds is as follows:

[0052] Five parts of glutathione, nine parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, five parts of N-hydroxysuccinimide, 17.5 parts of N,N-diisopropylethylamine, and 0.1 parts of 4-pyrrolidinylpyridine were mixed evenly. 100 mL of deionized water and 200 mL of anhydrous ethanol were added, and the mixture was stirred at 20 °C for 30 min. Then, 7.5 parts of polylysine were added, and the mixture was stirred for another 20 h. After filtration, rotary evaporation, and drying, the thiol compound was obtained.

[0053] In step S3, the preparation method of the second adhesive solution is as follows: 5 parts of trimethylolpropane triglycidyl ether and 90 parts of deionized water are mixed evenly, 1 part of triethylenetetramine is added, and the mixture is stirred at 60°C for 30 min. Then, 100 parts of styrene-butadiene-pyridine latex solution are added, and the mixture is stirred at 20°C for 1 h to obtain the second adhesive solution.

[0054] Example 2: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0055] Step S1: High-viscosity polyester chips are subjected to screw melt spinning, air cooling and shaping, spinning oiling, hot stretching, heat setting, relaxation heat treatment, impregnation with activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester industrial yarn is then heat-treated and stored to obtain modified polyester fibers.

[0056] The spinning oil is a mixed solution containing 3-aminopropyltriethoxysilane, with a concentration of 18 wt% and 3-aminopropyltriethoxysilane accounting for 15 wt% of the spinning oil. The mixed solution of 3-aminopropyltriethoxysilane is composed of deionized water and 3-aminopropyltriethoxysilane in a mass ratio of 2.5:0.3.

[0057] The hot drawing process conditions are: hot roller temperature 100℃, hot drawing roller speed 3500m / min; the heat setting and relaxation heat treatment process conditions are: hot roller temperature 220℃, hot roller speed 5000m / min.

[0058] The activator is a mixed solution containing caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and water in a mass ratio of 1:0.15:18;

[0059] The heat treatment storage specifically involves: subjecting the pre-activated polyester fiber to heat treatment at a temperature of 50-100℃ for 96-110 hours.

[0060] Step S2: After the modified polyester fiber is doubling, twisting, and heat-setting (heat-setting at 70℃ and 0.06Mpa for 50min), polyester strands are obtained; two strands of polyester are twisted together by a twisting machine to obtain twisted cord.

[0061] Step S3: Immerse the twisted cord in the first adhesive solution for 20 minutes, then irradiate it with 380nm ultraviolet light for 10 minutes at an irradiation intensity of 25mW / cm². 2 Then, immerse it in the second adhesive solution for 2 minutes, dry it at 140°C for 30 minutes, and then heat treat it at 220°C for 1 minute to obtain polyester cord.

[0062] In step S3, the preparation method of the first adhesive solution is as follows:

[0063] Mix 7 parts of mercapto compound, 4 parts of 2-mercaptobenzothiazole, 30 parts of ammonia and 40 parts of deionized water evenly, then add 2 parts of photoinitiator and 3 parts of styrene-butadiene-pyridine latex and mix evenly to obtain the first adhesive solution.

[0064] The preparation method of thiol compounds is as follows:

[0065] Seven parts of glutathione, 13 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, eight parts of N-hydroxysuccinimide, 25 parts of N,N-diisopropylethylamine, and 0.21 parts of 4-pyrrolidinylpyridine were mixed evenly, 140 mL of deionized water and 280 mL of anhydrous ethanol were added, and the mixture was stirred at 25 °C for 40 min. Then, 12 parts of polylysine were added, and the mixture was stirred for another 22 h. After filtration, rotary evaporation, and drying, the thiol compound was obtained.

[0066] In step S3, the preparation method of the second adhesive solution is as follows: 8 parts of trimethylolpropane triglycidyl ether and 130 parts of deionized water are mixed evenly, 3 parts of triethylenetetramine are added, and the mixture is stirred at 70°C for 40 min. Then, 105 parts of styrene-butadiene-pyridine latex solution are added, and the mixture is stirred at 25°C for 1.5 h to obtain the second adhesive solution.

[0067] Example 3: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0068] Step S1: High-viscosity polyester chips are subjected to screw melt spinning, blow cooling and shaping, initial application of spinning oil, hot stretching, heat setting, relaxation heat treatment, impregnation with activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester industrial yarn is then heat-treated and stored to obtain modified polyester fibers.

[0069] The spinning oil is a mixed solution containing 3-aminopropyltriethoxysilane, with a concentration of 20 wt% and the proportion of 3-aminopropyltriethoxysilane in the spinning oil being 20 wt%. The mixed solution of 3-aminopropyltriethoxysilane is composed of deionized water and 3-aminopropyltriethoxysilane in a mass ratio of 3:0.4.

[0070] The hot drawing process conditions are: hot roller temperature 150℃, hot drawing roller speed 4000m / min; the heat setting and relaxation heat treatment process conditions are: hot roller temperature 255℃, hot roller speed 6000m / min.

[0071] The activator is a mixed solution containing caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and water in a mass ratio of 1:0.2:20;

[0072] The heat treatment storage specifically involves: subjecting the pre-activated polyester fiber to heat treatment at a temperature of 100°C for 110 hours.

[0073] Step S2: After the modified polyester fiber is doubling, twisting, and heat-setting (heat-setting at 80℃ and 0.08Mpa for 80min), polyester strands are obtained; two strands of polyester are twisted together by a twisting machine to obtain twisted cord.

[0074] Step S3: Immerse the twisted cord in the first adhesive solution for 30 minutes, then irradiate it with 400nm ultraviolet light for 20 minutes at an irradiation intensity of 35mW / cm². 2 Then, immerse it in the second adhesive solution for 3 minutes, dry it at 180°C for 40 minutes, and then heat treat it at 240°C for 3.0 minutes to obtain polyester cord.

[0075] In step S3, the preparation method of the first adhesive solution is as follows:

[0076] Mix 10 parts of mercapto compound, 5 parts of 2-mercaptobenzothiazole, 40 parts of ammonia and 50 parts of deionized water evenly, then add 3 parts of photoinitiator and 4 parts of styrene-butadiene-pyridine latex and mix evenly to obtain the first adhesive solution.

[0077] The preparation method of thiol compounds is as follows:

[0078] 10 parts of glutathione, 20 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, 12 parts of N-hydroxysuccinimide, 38 parts of N,N-diisopropylethylamine and 4 parts of 4-pyrrolidinylpyridine were mixed evenly, 200 mL of deionized water and 400 mL of anhydrous ethanol were added, and the mixture was stirred at 30 °C for 50 min. Then, 20 parts of polylysine were added, and the mixture was stirred for another 24 h. After filtration, rotary evaporation and drying, the thiol compound was obtained.

[0079] In step S3, the preparation method of the second adhesive solution is as follows: 10 parts of trimethylolpropane triglycidyl ether and 180 parts of deionized water are mixed evenly, 5 parts of triethylenetetramine are added, and the mixture is stirred at 80°C for 50 min. Then, 110 parts of styrene-butadiene-pyridine latex solution are added, and the mixture is stirred at 30°C for 2 h to obtain the second adhesive solution.

[0080] Comparative Example 1: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0081] Compared with Example 2, Comparative Example 1 does not include step S1, but replaces the modified polyester fiber with commercially available polyester fiber (1100dtex, HMLS industrial yarn, sourced from Jiangsu Taiji Industrial New Materials Co., Ltd.), and the other steps are the same as in Example 2.

[0082] Comparative Example 2: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0083] Compared with Example 2, Comparative Example 2 does not include step S3. The twisted cord obtained in step S2 is polyester cord, and the other steps are the same as in Example 2.

[0084] Comparative Example 3: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0085] Step S3: Immerse the twisted cord in the first adhesive solution for 20 minutes, then irradiate it with 380nm ultraviolet light for 10 minutes at an irradiation intensity of 25mW / cm². 2 Polyester cord was obtained; compared with Example 2, Comparative Example 3 did not use the second adhesive solution for impregnation treatment, and the other steps were the same as those in Example 2.

[0086] Comparative Example 4: A method for preparing high-strength, high-stability polyester cord, comprising the following processes:

[0087] Step S3: Immerse the twisted cord in the second adhesive solution for 2 minutes, dry it at 140°C for 30 minutes, and then heat treat it at 220°C for 1 minute to obtain the polyester cord; Compared with Example 2, Comparative Example 4 does not use the first adhesive solution for immersion treatment, and the other steps are the same as in Example 2.

[0088] Experiment: Polyester cords obtained in Examples 1-3 and Comparative Examples 1-4 were used to prepare samples. Their properties were tested and the test results were recorded.

[0089] The H-adhesion strength was determined according to the standard GB / T 2942-2009 "Determination of Static Adhesion Strength of Vulcanized Rubber and Fiber Cord - H-Extraction Method". The experimental procedure was as follows: The rubber compound was prepared according to the formula specified in GB / T 32105-2015. The rubber compound was cut into strips of 200mm×10mm×10mm. The cut strips were embedded into the grooves of the upper and lower molds. Then, the polyester cord was fixed in the mold grooves. After the mold was closed, vulcanization was performed. The temperature of the flat vulcanizer was set to 160℃, the pressure to 15MPa, and the time to 90min. After vulcanization, the strips were cut and left to stand for 16 hours before testing. The tensile speed was 100m / min. At least 8 samples were tested, and the maximum extraction force was recorded and the average value was taken.

[0090] The fatigue resistance performance was tested according to GB / T 30315-2013 standard. A bending fatigue test was conducted on the polyester cord under the following conditions: oscillation frequency 2.5Hz, load 9.8N, fatigue cycles 1×10⁻⁶. 5 The fracture strength retention rate after fatigue test was determined. The fracture strength was determined with reference to the test standard GB / T 32108-2015. An electronic tensile testing machine was used, and a special clamp for cord breakage was selected. The upper and lower clamps were set to 250 mm, and the tensile testing machine speed was set to 300 mm / min.

[0091] The test results are as follows:

[0092] H H adhesion force / N Fracture strength retention rate / % Example 1 150.7 84.6 Example 2 154.8 85.7 Example 3 153.6 85.2 Comparative Example 1 132.4 74.3 Comparative Example 2 121.2 70.4 Comparative Example 3 142.8 80.6 Comparative Example 4 146.5 82.5

[0093] Based on the data in the table above, the following conclusions can be clearly drawn:

[0094] 1. Compared with Examples 1-3, the H-adhesive strength and tensile strength retention rate of the product obtained in Comparative Example 1 both decreased, indicating that the modified polyester fiber prepared by the present invention has better interfacial bonding strength than commercially available polyester fiber, thereby effectively improving the adhesive performance and overall mechanical strength of the material.

[0095] 2. Compared with Examples 1-3, the H-adhesion and tensile strength retention rates of the products obtained in Comparative Examples 2 and 3 have decreased. This indicates that the present invention can enhance the interfacial bonding force between the fiber and the rubber through two impregnation treatments. At the same time, not using the second adhesive solution for impregnation treatment will lead to a weakening of the bonding force between the adhesive and the fiber, thereby affecting the durability of the material.

[0096] 3. Compared with Examples 1-3, the H-adhesion and tensile strength retention rate of the product obtained in Comparative Example 4 have both decreased. It can be seen that when the first adhesive solution is not used for impregnation treatment, the bonding force between the fiber and the rubber will be weakened, thereby reducing the adhesive performance and overall strength of the material.

[0097] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing high-strength, high-stability polyester cord, characterized in that: Includes the following steps: Step S1: High-viscosity polyester chips are subjected to screw melt spinning, blow cooling and shaping, initial application of spinning oil, hot stretching, heat setting, relaxation heat treatment, impregnation with activator, and winding to obtain pre-activated polyester fibers. The pre-activated polyester fibers are then heat-treated and stored to obtain modified polyester fibers. The spinning oil is a mixed solution containing 3-aminopropyltriethoxysilane, with a concentration of 15-20 wt% and the proportion of 3-aminopropyltriethoxysilane in the spinning oil being 5-20 wt%. The process conditions for hot drawing are: hot roller temperature 90-150℃, hot drawing roller speed 3000m / min-4000m / min; the process conditions for heat setting and relaxation heat treatment are: hot roller temperature 200-255℃, hot roller speed 4500m / min-6000m / min. The activator is a mixed solution containing caffeic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and water; The heat treatment storage specifically involves: subjecting the pre-activated polyester fiber to heat treatment at a temperature of 50-100℃ for 96-110 hours. Step S2: After the modified polyester fibers are doubling, twisting, and heat-setting, polyester strands are obtained; the polyester strands are twisted into shape by a twisting machine to obtain twisted cord. Step S3: The twisted cord is immersed in the first adhesive solution for a first impregnation treatment, and after being irradiated with ultraviolet light, it is immersed in the second adhesive solution for a second impregnation treatment. After drying and heat treatment, polyester cord is obtained.

2. The method for preparing a high-strength, high-stability polyester cord according to claim 1, characterized in that: In step S1, the mixed solution of 3-aminopropyltriethoxysilane is composed of deionized water and 3-aminopropyltriethoxysilane in a mass ratio of (2-3):(0.2-0.4).

3. The method for preparing a high-strength, high-stability polyester cord according to claim 1, characterized in that: In step S1, the mass ratio of caffeic acid to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 1:(0.1-0.2).

4. The method for preparing a high-strength, high-stability polyester cord according to claim 1, characterized in that: In step S3, the first adhesive solution is prepared as follows: The thiol compound, 2-mercaptobenzothiazole, ammonia and deionized water are mixed evenly, and then the photoinitiator and styrene-butadiene pyridine latex are added and mixed evenly to obtain the first adhesive solution.

5. The method for preparing a high-strength, high-stability polyester cord according to claim 4, characterized in that: The first adhesive solution comprises the following components by weight: 5-10 parts of a thiol compound, 1-3 parts of a photoinitiator, 3-5 parts of 2-mercaptobenzothiazole, 2-4 parts of styrene-butadiene pyridine latex, 10-40 parts of ammonia, and 30-50 parts of deionized water.

6. The method for preparing a high-strength, high-stability polyester cord according to claim 5, characterized in that: The method for preparing the thiol compound is as follows: Glutathione, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, N-hydroxysuccinimide, N,N-diisopropylethylamine and 4-pyrrolylpyridine were mixed evenly, deionized water and anhydrous ethanol were added, and the mixture was stirred at 20-30℃ for 30-50 min. Polylysine was added, and the mixture was stirred for another 20-24 h. After filtration, rotary evaporation and drying, the thiol compound was obtained.

7. The method for preparing a high-strength, high-stability polyester cord according to claim 6, characterized in that: The volume ratio of deionized water to anhydrous ethanol is 1:2, the ratio of glutathione to deionized water is 5g / 100mL, and the mass of polylysine is 1.5-2.0 times the mass of glutathione.

8. The method for preparing a high-strength, high-stability polyester cord according to claim 1, characterized in that: In step S3, the preparation method of the second adhesive solution is as follows: Trimethylolpropane triglycidyl ether and deionized water are mixed evenly, triethylenetetramine is added, and the mixture is stirred at 60-80℃ for 30-50 min. Then, styrene-butadiene-pyridine latex solution is added, and the mixture is stirred at 20-30℃ for 1-2 h to obtain the second adhesive solution.

9. The method for preparing a high-strength, high-stability polyester cord according to claim 8, characterized in that: The second adhesive solution comprises the following components by weight: 5-10 parts of trimethylolpropane triglycidyl ether, 1-5 parts of triethylenetetramine, 100-110 parts of styrene-butadiene-pyridine latex solution, and 90-180 parts of deionized water.

10. A high-strength, high-stability polyester cord prepared by the preparation method according to any one of claims 1-9.