High flame-retardant montmorillonite modified PTT fiber and preparation method thereof
By combining ultrasonic dispersion and stirring techniques with nonionic surfactant treatment, the problems of poor flame retardancy of PTT fibers and dispersion of montmorillonite were solved, achieving high efficiency in flame retardancy and mechanical properties, avoiding melt dripping, and expanding the application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NINGBO JUHUA CHEM TECH CO LTD
- Filing Date
- 2026-02-02
- Publication Date
- 2026-06-05
AI Technical Summary
Existing PTT fibers have poor flame retardant properties, and montmorillonite has poor dispersibility in the matrix, making it difficult to balance dispersion effect with polymer basic properties. Existing modification methods affect the fiber appearance and feel, and have a narrow range of applications.
Montmorillonite and PTT fibers were mixed using a combination of ultrasonic dispersion and stirring techniques. The nonionic surfactant glyceryl cocoate was added, and the mixture was processed using a dyeing machine with controlled temperature and pressure. This process, combined with washing with nonionic surfactant and rinsing with deionized water, achieved uniform dispersion and adsorption of montmorillonite in the PTT fibers.
This method achieves uniform dispersion of montmorillonite in PTT fibers, improves flame retardant and mechanical properties, avoids melt dripping, reduces costs, and expands application areas.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to a highly flame-retardant montmorillonite-modified PTT fiber and its preparation method. Background Technology
[0002] Polypropylene terephthalate (PTT) fiber is a high-performance synthetic fiber with excellent elastic recovery, dyeability, and UV aging resistance. It has wide applications in clothing fabrics, home décor, industrial filtration materials, automotive interiors, and architectural textiles. Standard PTT fiber molecules have a linear structure, and its chemical structure is prone to breakage and thermal decomposition at high temperatures. The amorphous and crystalline regions are loosely distributed, lacking microscopic barrier structures. During combustion, PTT produces a large amount of flammable small molecules, accompanied by severe melting and dripping, which can easily cause fire to spread. It also releases toxic and harmful gases and dense smoke, posing significant safety hazards and failing to meet the stringent fire safety requirements of public building interiors and automotive interiors.
[0003] Montmorillonite, as a natural layered silicate nanomaterial, is widely available, environmentally friendly, and low-cost. Its unique layered structure, when combined with polymers, can enhance the flame-retardant effect of materials through physical barrier and synergistic flame-retardant action, making it an ideal filler for flame-retardant modification of PTT fibers. Chinese patent application CN104861497A discloses a PTT polyester composition modified by blending a phosphate ester flame retardant with nano-montmorillonite. Its components include PTT, a phosphate ester flame retardant, nano-montmorillonite, a flame-retardant synergist, an anti-drip agent, an antioxidant, and a lubricant. This modified PTT polyester composition exhibits good melt-resistant flame-retardant effects and is low-cost. However, nano-montmorillonite has poor dispersibility in the matrix, is prone to agglomeration, and has poor processing fluidity and spinnability, making it difficult to balance dispersion effect with the basic properties of the polymer.
[0004] In addition, existing technologies can also use surface coating methods or aqueous dispersion treatment methods for other fibers, which will damage the original appearance, feel and function of PTT fibers. Furthermore, the requirements for the amount and type of nano-montmorillonite are strict, the scope of application is narrow, and it cannot be effectively applied to the flame retardant modification of polyester fibers.
[0005] Therefore, improving the dispersibility of montmorillonite and efficiently and uniformly introducing it into PTT fibers to prepare a PTT fiber with excellent flame retardant and mechanical properties has important practical significance and application value. Summary of the Invention
[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a highly flame-retardant montmorillonite-modified PTT fiber and its preparation method, which solves the problem of poor flame-retardant performance of PTT fiber and prepares a modified PTT fiber with excellent flame-retardant and mechanical properties.
[0007] (II) Technical Solution To achieve the above objectives, this invention discloses a method for preparing highly flame-retardant montmorillonite-modified PTT fibers, comprising the following steps: S1. Mix montmorillonite and deionized water, and disperse them by ultrasonication. During the dispersion process, stir and mix to obtain a nano-montmorillonite dispersion. S2. Add a nonionic surfactant to the nano-montmorillonite dispersion prepared in S1, stir and mix evenly to form a modified liquid; S3. Place the PTT fiber in the dyeing vat of the dyeing machine, add the modified liquid of S2, immerse it, heat it, stir and mix it, and cool it to obtain the modified PTT fiber. S4. The modified PTT fibers in S3 are washed, rinsed and dehydrated in sequence, and dried to obtain highly flame-retardant montmorillonite modified PTT fibers.
[0008] Preferably, in S1, the mass ratio of montmorillonite to deionized water is 100:(4500-5800), the ultrasonic dispersion power is 1500-2500W, the ultrasonic dispersion time is 10-20min, and the stirring speed is 50-70r / min.
[0009] Preferably, the montmorillonite in S1 is Cloisite 15A.
[0010] Furthermore, Cloisite15A in S1 can also be replaced by any one of alkyl quaternary ammonium modified montmorillonite or amino modified montmorillonite DK2.
[0011] Preferably, the nonionic surfactant in S2 is glycerol cocoate, with a concentration of 0.5-1.0 g / L.
[0012] Preferably, the stirring speed in step S2 is 40-60 r / min, and the stirring time is 10-20 min.
[0013] Preferably, the specific process for preparing modified PTT fibers in S3 is as follows: PTT fibers are placed in the dyeing vat of a dyeing machine, and the PTT fibers are completely immersed in the modified liquid in S2. The bath ratio is 1:45-50. The temperature is raised to 125-135℃ at a heating rate of 2-3℃ / min, and kept at this temperature for 1-2 hours. During the heating process, the pressure is maintained at 0.05-0.15MPa, and the stirring and mixing rate is 30-40r / min. After the heat preservation is completed, the temperature is cooled to 80℃, and the material is discharged to obtain modified PTT fibers.
[0014] Preferably, the PTT fiber in S3 includes any one of PTT staple fiber, PTT filament, and PTT yarn.
[0015] Preferably, the specific process for preparing high flame-retardant montmorillonite-modified PTT fibers in step S4 is as follows: the modified PTT fibers in step S3 are washed with a nonionic surfactant detergent. After washing, they are rinsed 2-3 times with deionized water. After rinsing, excess moisture on the surface of the material is removed by a dehydration device, and the moisture content after dehydration is controlled to be ≤30%. During the drying process, a hot air oven is used at 85-95℃ with an air velocity of 0.5m / s inside the oven. The moisture content at the material outlet is ≤5%, thus obtaining high flame-retardant montmorillonite-modified PTT fibers.
[0016] Preferably, in the washing process of S4, the detergent is the nonionic surfactant TX-10, the detergent concentration is 5 g / L, the washing temperature is 55-65℃, and the washing time is 30-40 min. Using the nonionic surfactant TX-10 as a detergent is low in cost, high in safety, and can effectively remove free montmorillonite particles.
[0017] Preferably, in the high flame-retardant montmorillonite modified PTT fiber in S4, the montmorillonite loading is 3.0%-6.0% of the PTT fiber mass.
[0018] A highly flame-retardant montmorillonite-modified PTT fiber prepared by any one of the methods described above.
[0019] (iii) Beneficial technical effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, modified montmorillonite is used as a flame retardant modifier. Through ultrasonic dispersion and stirring, the nano-montmorillonite is uniformly dispersed, effectively avoiding agglomeration problems. No additional modification treatment is required, reducing the complexity and cost of the process. Furthermore, by introducing the surfactant glycerol cocoate, the interfacial tension between montmorillonite and PTT is reduced. Through the "hydrophilic-hydrophobic" effect, the compatibility between montmorillonite and PTT fibers is improved, effectively avoiding the decline in mechanical properties and preserving the original elastic recovery of PTT fibers.
[0020] (2) This invention uses a dyeing machine as a processing carrier. By precisely controlling conditions such as temperature and pressure, montmorillonite can effectively penetrate and adsorb onto the surface and internal microporous structure of PTT fibers, while avoiding the melting and deformation of the fibers due to high temperatures. This achieves stable quality control in industrial continuous production. The post-treatment process of washing with nonionic surfactant detergent and rinsing with deionized water precisely removes free flame retardants and excess surfactants from the material surface, preventing residual substances from affecting the material's performance.
[0021] (3) In this invention, by controlling the amount of montmorillonite added, the amount of montmorillonite added is low, and the flame retardant forms a stable functional layer on the surface of PTT fiber, which has excellent flame retardant properties. During vertical combustion, there is no melting and dripping phenomenon, and the cost is low, which expands the application field of PTT fiber. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0023] Example 1 A highly flame-retardant montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A and deionized water at a mass ratio of 100:4500, and disperse by ultrasonication at a power of 1500W for 20 minutes. During the dispersion process, stir and mix at a speed of 50 r / min to obtain a nano-montmorillonite dispersion. S2. Add nonionic surfactant glycerol cocoate at a concentration of 0.5 g / L to the nano-montmorillonite dispersion, stir and mix evenly at a speed of 40 r / min for 20 min to form a modified solution. S3. Place PTT short fibers in the dyeing vat of the dyeing machine. The PTT fibers are completely immersed in the modification solution with a bath ratio of 1:45. The temperature is increased to 125℃ at a heating rate of 2℃ / min and held for 2 hours. During the heating process, the pressure is maintained at 0.05MPa and the stirring and mixing rate is 30r / min. After the holding period, the temperature is cooled to 80℃ and the material is discharged to obtain modified PTT fibers. S4. The modified PTT fiber was washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 55℃, and a washing time of 40 min. After washing, it was rinsed twice with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 85℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in high flame retardant montmorillonite modified PTT fiber, in which the montmorillonite loading was 3.0% of the PTT fiber mass.
[0024] Example 2 A highly flame-retardant montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A and deionized water at a mass ratio of 100:5200, and disperse by ultrasonication at a power of 2000W for 18 minutes. During the dispersion process, stir and mix at a speed of 60 r / min to obtain a nano-montmorillonite dispersion. S2. Add nonionic surfactant glycerol cocoate at a concentration of 0.8 g / L to the nano-montmorillonite dispersion, stir and mix evenly at a speed of 50 r / min for 16 min to form a modified solution. S3. Place the PTT short fibers in the dyeing vat of the dyeing machine. The PTT fibers are completely immersed in the modification solution with a bath ratio of 1:48. The temperature is raised to 130℃ at a heating rate of 2.5℃ / min and held for 1.5h. During the heating process, the pressure is maintained at 0.1MPa and the stirring and mixing rate is 35r / min. After the holding period, the temperature is cooled to 80℃ and the material is discharged to obtain modified PTT fibers. S4. The modified PTT fiber was washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 60℃, and a washing time of 35 min. After washing, it was rinsed three times with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 90℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in high flame retardant montmorillonite modified PTT fiber, in which the montmorillonite loading was 4.0% of the PTT fiber mass.
[0025] Example 3 A highly flame-retardant montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A and deionized water at a mass ratio of 100:5500, and disperse by ultrasonication at a power of 2200W for 18 minutes. During the dispersion process, stir and mix at a speed of 65 r / min to obtain a nano-montmorillonite dispersion. S2. Add nonionic surfactant glycerol cocoate at a concentration of 0.9 g / L to the nano-montmorillonite dispersion, stir and mix evenly at a speed of 50 r / min for 18 min to form a modified solution. S3. Place PTT short fibers in the dyeing vat of the dyeing machine. The PTT fibers are completely immersed in the modification solution with a bath ratio of 1:48. The temperature is raised to 132℃ at a heating rate of 2.5℃ / min and held for 1.5h. During the heating process, the pressure is maintained at 0.12MPa and the stirring rate is 38r / min. After the holding period, the temperature is cooled to 80℃ and the material is discharged to obtain modified PTT fibers. S4. The modified PTT fiber was washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 60℃, and a washing time of 35 min. After washing, it was rinsed three times with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 90℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in high flame retardant montmorillonite modified PTT fiber, in which the montmorillonite loading was 4.5% of the PTT fiber mass.
[0026] Example 4 A highly flame-retardant montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A and deionized water at a mass ratio of 100:5800, and disperse by ultrasonication at a power of 2500W for 10 minutes. During the dispersion process, stir and mix at a speed of 70 r / min to obtain a nano-montmorillonite dispersion. S2. Add nonionic surfactant glycerol cocoate at a concentration of 1.0 g / L to the nano-montmorillonite dispersion, stir and mix evenly at a speed of 60 r / min for 10 min to form a modified solution. S3. Place the PTT short fiber in the dyeing vat of the dyeing machine. The PTT fiber is completely immersed in the modification solution with a bath ratio of 1:50. The temperature is raised to 135℃ at a heating rate of 3℃ / min and held for 1 hour. During the heating process, the pressure is maintained at 0.15MPa and the stirring and mixing rate is 40r / min. After the holding period, the temperature is cooled to 80℃ and the material is discharged to obtain the modified PTT fiber. S4. The modified PTT fiber was washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 65℃, and a washing time of 30 min. After washing, it was rinsed three times with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 95℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in high flame retardant montmorillonite modified PTT fiber, in which the montmorillonite loading was 6.0% of the PTT fiber mass.
[0027] Comparative Example 1 A montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A and deionized water at a mass ratio of 100:5500, and disperse by ultrasonication at a power of 2200W for 18 minutes. During the dispersion process, stir and mix at a speed of 65 r / min to obtain a nano-montmorillonite dispersion. S2. Place PTT short fibers in the dyeing vat of a dyeing machine. The PTT fibers are completely immersed in the nano-montmorillonite dispersion with a bath ratio of 1:48. The temperature is increased to 132℃ at a heating rate of 2.5℃ / min and held for 1.5h. During the heating process, the pressure is maintained at 0.12MPa and the stirring rate is 38r / min. After the holding period, the temperature is cooled to 80℃ and the material is discharged to obtain modified PTT fibers. S3. The modified PTT fibers were washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 60℃, and a washing time of 35 min. After washing, the fibers were rinsed three times with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 90℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in montmorillonite-modified PTT fibers, wherein the montmorillonite loading was 4.5% of the PTT fiber mass.
[0028] Comparative Example 2 A montmorillonite-modified PTT fiber, the preparation method of which includes the following steps: S1. Mix Cloisite15A, deionized water, and nonionic surfactant glycerol cocoate, wherein the mass ratio of Cloisite15A to deionized water is 100:5500, the concentration of glycerol cocoate is 0.9 g / L, stir and mix evenly at a speed of 50 r / min for 18 min to form a modified solution. S2. Place PTT short fibers in the dyeing vat of the dyeing machine. The PTT fibers are completely immersed in the modification solution with a bath ratio of 1:48. The temperature is raised to 132℃ at a heating rate of 2.5℃ / min and held for 1.5h. During the heating process, the pressure is maintained at 0.12MPa and the stirring and mixing rate is 38r / min. After the holding period, the temperature is cooled to 80℃ and discharged to obtain modified PTT fibers. S3. The modified PTT fibers were washed with nonionic surfactant TX-10 detergent at a concentration of 5 g / L, a washing temperature of 60℃, and a washing time of 35 min. After washing, the fibers were rinsed three times with deionized water. After rinsing, excess moisture on the surface of the material was removed by a dehydration device, and the moisture content after dehydration was controlled to be ≤30%. During the drying process, a hot air oven was used at 90℃ with an air velocity of 0.5 m / s. The moisture content at the material outlet was ≤5%, resulting in montmorillonite-modified PTT fibers, wherein the montmorillonite loading was 4.5% of the PTT fiber mass.
[0029] The montmorillonite-modified PTT fibers prepared in Examples 1-4 and Comparative Examples 1-2 were used as samples for corresponding tests. The test methods and results are shown below: (1) Flame retardant performance test: The test standard GB / T 5454-1997 "Test of Burning Performance of Textiles by Oxygen Index Method" was adopted. The sample was clamped on the sample holder and placed vertically inside the combustion tube. In the upward flow of oxygen and nitrogen gas, the upper end of the sample was ignited, and its combustion characteristics were observed. The afterflame time or damage length was compared with the specified limit value. Through a series of tests in different oxygen concentrations, the lowest oxygen concentration value expressed by the oxygen volume fraction when maintaining combustion was measured. The limiting oxygen index test was carried out on the JF-5 oxygen index analyzer. The LOI value of each sample was tested three times and the average value was taken. The sample was tested according to GB / T 5455-2014 "Determination of Vertical Damage Length, Smoldering and Afterflame Time of Burning Performance of Textiles". The vertical combustion melt dripping was observed. (2) The mechanical properties of the composite fiber were tested using a YG021A-Ⅲ electronic single yarn tensile tester. The tensile speed was 10 mm / min, and the tensile strength was recorded. Each sample was tested three times and the average value was taken. (3) Wash resistance test: Refer to GB / T 8629-2017 "Home washing and drying procedures for textile testing", test conditions: 40℃ water temperature, standard detergent, wash 20 times, and then test the LOI value and tensile strength according to the above method; The test results are shown in Table 1: Table 1 As can be seen from the test process in Table 1, the montmorillonite-modified PTT fibers corresponding to Examples 1-4 exhibit excellent flame retardant properties and tensile strength, reaching a flame retardant level without vertical burning melt dripping. The tensile strength of the montmorillonite-modified PTT fiber corresponding to Example 4 reaches 70.1 MPa. After 20 washes, Examples 1-4 still demonstrate excellent flame retardant properties and tensile strength. In Comparative Example 1, the nonionic surfactant glycerol cocoate was not introduced, resulting in poor compatibility between montmorillonite Cloisite 15A and PTT fibers, leading to a decrease in overall performance. In Comparative Example 2, the absence of a separate ultrasonic pre-dispersion step for montmorillonite Cloisite 15A resulted in direct mixing of montmorillonite Cloisite 15A with the surfactant, leading to poor dispersibility, easy agglomeration, and a decrease in both flame retardant properties and tensile strength. After 20 washes, the overall performance of the modified PTT fibers in Comparative Examples 1-2 was significantly reduced.
[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.
Claims
1. A method for preparing highly flame-retardant montmorillonite-modified PTT fibers, characterized in that: Includes the following steps: S1. Mix montmorillonite and deionized water, and disperse them by ultrasonication. During the dispersion process, stir and mix to obtain a nano-montmorillonite dispersion. S2. Add a nonionic surfactant to the nano-montmorillonite dispersion prepared in S1, stir and mix evenly to form a modified liquid; S3. Place the PTT fiber in the dyeing vat of the dyeing machine, add the modified liquid of S2, immerse it, heat it, stir and mix it, and cool it to obtain the modified PTT fiber. S4. The modified PTT fibers in S3 are washed, rinsed and dehydrated in sequence, and dried to obtain highly flame-retardant montmorillonite modified PTT fibers.
2. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The mass ratio of montmorillonite to deionized water in S1 is 100:(4500-5800), the ultrasonic dispersion power is 1500-2500W, the ultrasonic dispersion time is 10-20min, and the stirring speed is 50-70r / min.
3. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The montmorillonite in S1 is Cloisite 15A.
4. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The nonionic surfactant in S2 is glycerol cocoate, with a concentration of 0.5-1.0 g / L.
5. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The specific process for preparing modified PTT fibers in S3 is as follows: PTT fibers are placed in the dyeing vat of a dyeing machine, and the PTT fibers are completely immersed in the modified liquid in S2. The bath ratio is 1:45-50. The temperature is raised to 125-135℃ at a heating rate of 2-3℃ / min, and kept at this temperature for 1-2 hours. During the heating process, the pressure is maintained at 0.05-0.15MPa, and the stirring and mixing rate is 30-40r / min. After the holding period, the temperature is cooled to 80℃, and the material is discharged to obtain modified PTT fibers.
6. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The PTT fiber in S3 includes any one of PTT staple fiber, PTT filament, and PTT yarn.
7. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: The specific process for preparing highly flame-retardant montmorillonite-modified PTT fibers in S4 is as follows: The modified PTT fibers in S3 are washed with a nonionic surfactant detergent. After washing, they are rinsed 2-3 times with deionized water. After rinsing, excess moisture on the surface of the material is removed by a dehydration device, and the moisture content after dehydration is controlled to be ≤30%. During the drying process, a hot air oven is used at 85-95℃ with an air velocity of 0.5m / s inside the oven. The moisture content at the material outlet is ≤5%, thus obtaining highly flame-retardant montmorillonite-modified PTT fibers.
8. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 7, characterized in that: During the washing process, the detergent is a nonionic surfactant TX-10, the detergent concentration is 5g / L, the washing temperature is 55-65℃, and the washing time is 30-40min.
9. The method for preparing highly flame-retardant montmorillonite-modified PTT fiber according to claim 1, characterized in that: In the S4 high flame retardant montmorillonite modified PTT fiber, the montmorillonite loading is 3.0%-6.0% of the PTT fiber mass.
10. A highly flame-retardant montmorillonite-modified PTT fiber prepared by the preparation method of the highly flame-retardant montmorillonite-modified PTT fiber according to any one of claims 1-9.