A flame-retardant and ultraviolet-resistant fiber

Abstract

The present invention relates to a flame-retardant and ultraviolet-resistant fiber. The preparation process of the flame-retardant and ultraviolet-resistant fiber includes: pretreating Lyocell fiber; preparing oxidized Lyocell fiber; preparing flame-retardant Lyocell fiber: mixing the oxidized Lyocell fiber with an appropriate amount of ethanol aqueous solution, slowly dropping aluminum trichloride solution and heating in a water bath, washing and drying to obtain flame-retardant Lyocell fiber (FR-Lyocell); ultraviolet-resistant modification: cutting the Lyocell fiber, performing ultrasonic treatment, drying for later use, soaking the washed fiber in a newly prepared dopamine buffer solution, reacting under constant temperature water bath oscillation, taking out, rinsing, drying and marking as flame-retardant Lyocell-PDA, preparing a mixed solution of (NH4)2TiF6 and H3BO3, adjusting the pH, immersing the flame-retardant Lyocell-PDA fiber in this mixed solution, reacting at room temperature, rinsing and drying after completion to obtain flame-retardant Lyocell-PDA-TiO2 fiber. The present invention has outstanding characteristics such as being green and non-toxic, being naturally degradable, having a soft handfeel, high strength, good hygroscopicity, and ultraviolet resistance.

Description

Technical Field

[0001] The invention relates to a fiber, in particular to a flame retardant and anti-ultraviolet fiber. Background Art

[0002] Cellulose is a treasure given to mankind by nature. It is the most abundant and widely distributed polymer in nature. It is mainly produced through photosynthesis, with an annual biosynthesis of more than 1.5×10 12 Tons, widely found in tree trunks, cotton, hemp, straw and other higher plants. In addition, cellulose is not only widely available, but also a green renewable resource that is inexhaustible.

[0003] Cellulose fibers can be mainly divided into natural cellulose fibers and regenerated cellulose fibers. Natural cellulose fibers refer to fibers that exist naturally in nature, while regenerated cellulose fibers refer to fiber materials made from cellulose through processes such as dissolution and spinning.

[0004] Lyocell fiber is made by dissolving cellulose in an aqueous solution of N-methylmorpholine nitride (NMMO) as a solvent to form a spinning solution, spinning it using a dry-jet wet spinning method, and then coagulating it in a low-concentration NMMO aqueous solution as a coagulation bath. Finally, it is made through processes such as drawing and solvent recovery.

[0005] At present, cellulose fiber made from cellulose is widely used because of its advantages of being green, environmentally friendly, naturally degradable, and easy to wear. However, cellulose fiber is flammable and has low safety, which can easily pose a huge threat and harm to human life and property. Therefore, flame retardant modification of cellulose fiber and improving its safety have become major issues to be solved in the field of fiber textiles. Summary of the invention

[0006] The purpose of the present invention is to provide a flame retardant and anti-ultraviolet fiber to solve the problems of flammability, low safety and poor anti-ultraviolet of Lyocell fiber.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] A flame retardant and anti-ultraviolet fiber, the preparation process of which comprises the following steps:

[0009] (1) Pretreatment of Lyocell fibers;

[0010] (2) Preparation of oxidized lyocell fibers;

[0011] (3)Preparation of flame-retardant lyocell fiber: Mix oxidized lyocell fiber with an appropriate amount of ethanol aqueous solution, slowly add aluminum chloride solution dropwise, heat in a water bath, wash and dry to obtain flame-retardant lyocell fiber;

[0012] (4)Anti-ultraviolet modification: Cut lyocell fiber, perform ultrasonic treatment, dry for later use. Immerse the washed fiber in freshly prepared dopamine buffer solution, react with constant temperature water bath oscillation, take out, rinse, dry and label as flame-retardant lyocell—PDA. Prepare a mixed solution of (NH4)2TiF6 and H3BO3, adjust the pH, immerse the flame-retardant lyocell—PDA fiber in this mixed solution, react at room temperature, rinse and dry after completion to obtain flame-retardant lyocell—PDA—TiO2 fiber.

[0013] Preferably, the pretreatment of Lyocell fiber: Take 10 - 20 g of lyocell fiber and place it in a beaker containing deionized water, add 15 - 20 ml of absolute ethanol thereto, take it out after washing at room temperature for 30 - 35 min, wash it with deionized water 3 times again, and put it in an oven at 60 °C to dry for standby.

[0014] Preferably, the preparation of oxidized lyocell fiber in step (2) includes: Prepare a buffer solution, place the buffer solution and pretreated lyocell fiber in a three-necked flask, add TEMPO and NaClO2, stir evenly, then add NaClO to maintain the reaction, and then add absolute ethanol to terminate the reaction. Take out the fiber, wash it several times to obtain oxidized lyocell fiber (O-lyocell).

[0015] Preferably, the preparation of oxidized lyocell fiber: First, prepare 90 - 100 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 0.5 - 1 M, strictly control the pH = 6.8. Place the buffer solution and 1 - 3 g of pretreated lyocell fiber in a three-necked flask, add 0.05 - 0.1 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 1.73 - 2 g of NaClO2 thereto, stir tightly at 60 °C for 10 - 15 min, then add 1 g of NaClO and immediately plug the bottle stopper, maintain the reaction at 50 - 60 °C for 12 h; then add 5 mL of absolute ethanol to terminate the reaction; take out the fiber, wash the fiber 3 times with absolute ethanol to remove unreacted drugs, and finally obtain oxidized lyocell fiber (O-lyocell).

[0016] Preferably, the preparation of flame-retardant lyocell fiber: Put oxidized lyocell fiber and 20 - 30 ml of 85 wt% ethanol aqueous solution into a three-necked flask, slowly dropwise add 15 - 20 g of aluminum chloride solution (10 wt%) into it, and heat it in a water bath at 60 - 70 °C for 2 h; after the reaction is completed, wash the fiber 3 times with deionized water and dry it at 60 °C. Finally, obtain flame-retardant lyocell fiber (FR-lyocell).

[0017] Among them, TEMPO is a stable nitroxide radical, with functions such as selective oxidation and radical capture. During the oxidation process, TEMPO only oxidizes primary hydroxyl groups and has no effect on hydroxyl groups at other positions, with high selectivity, and the reaction conditions are mild and the oxidation yield is high. Use the mild TEMPO / NaClO2 / NaClO oxidation system to oxidize lyocell fiber, and then chelate with Al 3+ to obtain a flame-retardant cellulose fiber with a structure similar to sodium alginate and certain strength.

[0018] Preferably, first, cut the flame-retardant lyocell fiber into 15 cm lengths, ultrasonically treat it in an ethanol solution for 30 - 40 min to remove the residual organic solvent on the surface, repeatedly rinse it with deionized water, and then dry it in a 60 °C vacuum oven for later use. Prepare a 2 g / L dopamine solution with Tris-HCl buffer solution (pH = 8.5) as the solvent. Immerse the washed flame-retardant lyocell fiber in the newly prepared dopamine buffer solution, take it out after shaking and reacting in a 25 °C constant temperature water bath shaker for 24 h, repeatedly rinse it with deionized water, dry it and label it as flame-retardant lyocell-PDA.

[0019] Among them, during this process, covalent bonds and non-covalent bonds are established between dopamine and the flame-retardant lyocell fiber, making the PDA layer tightly adhere to the surface of the flame-retardant lyocell fiber. Moreover, as the reaction proceeds, the colors of the dopamine solution and the flame-retardant lyocell fiber change from colorless to light brown and finally to black. This characteristic can indirectly prove that polydopamine PDA is successfully coated on the surface of the flame-retardant lyocell fiber.

[0020] Preferably, the modification treatment device used in step (4) for anti-ultraviolet modification includes a fiber cutting machine, an ultrasonic treatment machine, a vacuum drying oven and a water bath shaker. The ultrasonic treatment machine is installed on the right side of the fiber cutting machine, the vacuum drying oven is installed on the right side of the ultrasonic treatment machine, and the water bath shaker is installed on the right side of the vacuum drying oven.

[0021] More preferably, the ultrasonic processor includes a vacuum pump, a feeding pipe, an ultrasonic treatment tank, a rotating motor and a scrambler. The vacuum pump is installed on the right side of the top of the ultrasonic treatment tank. A working chamber is arranged inside the ultrasonic treatment tank. The input end of the feeding pipe is connected to the output end of the fiber cutting machine, and the output end of the feeding pipe communicates with the left side of the top of the working chamber. The input end of the vacuum pump communicates with the right side of the top of the working chamber. The rotating motor is installed in the middle of the top of the ultrasonic treatment tank. A rotating hole is arranged in the middle of the top of the working chamber. The output end of the rotating motor passes through the rotating hole and is connected to the top of the scrambler.

[0022] More preferably, the modification treatment device further includes a receiving screen. A sliding groove is arranged at the bottom right of the working chamber, and the receiving screen is slidably connected to the sliding groove.

[0023] More preferably, the modification treatment device further includes a handle, and the handle is installed at the right end of the receiving screen.

[0024] More preferably, the modification treatment device further includes a sealing ring. A sealing groove is arranged on the outer side of the right part of the receiving screen, and the sealing ring is fitted and installed in the sealing groove.

[0025] More preferably, the modification treatment device further includes an air intake net, and the air intake net is installed at the input end of the vacuum pump.

[0026] More preferably, the modification treatment device further includes a quick connector. A round hole is arranged at the bottom left of the working chamber, and the quick connector is fitted and installed in the round hole. A water outlet solenoid valve is arranged at the bottom left of the working chamber.

[0027] More preferably, a sliding groove is arranged at the front end of the vacuum drying box of the modification treatment device, and the receiving screen is slidably connected to the sliding groove.

[0028] When the present invention performs the modification treatment of the flame-retardant fiber, the fiber is put into the fiber cutting machine for sizing cutting, and then the vacuum pump is turned on to output and evacuate the working chamber and the feeding pipe. Under the negative pressure of the feeding pipe, the cut fiber will be driven into the working chamber and immersed in the ethanol solution in the working chamber. At the same time, the rotating motor can be turned on to output and drive the scrambler to scramble the inside of the working chamber, and timely break up the agglomerated fiber bundles. After the feeding is completed, the vacuum pump can be turned off. After breaking up the fiber bundles, the ultrasonic treatment tank is turned on to perform ultrasonic treatment on the fiber. After the treatment is completed, the ethanol solution can be discharged and replaced with deionized water to continuously rinse the fiber repeatedly. After the rinsing is completed, the fiber is taken out and put into the vacuum drying box for drying treatment, and then added to the water bath shaker for the last step of processing to obtain the flame-retardant fiber; through this device, the flame-retardant fiber can be scrambled after being cut, preventing the flame-retardant fiber from agglomerating and improving the soaking processing quality of the flame-retardant fiber.

[0029] Preferably, a mixed solution of 0.1 - 0.3 mol / L of (NH4)2TiF6 and 0.3 - 0.5 mol / L of H3BO3 is prepared, the pH value is adjusted to 3.88 - 4, and then the above-prepared flame-retardant lyocell fiber - PDA fiber is immersed in this mixed solution, and the reaction is carried out at room temperature for 1 - 12 h. After the reaction is completed, it is rinsed with deionized water multiple times, dried, and the flame-retardant lyocell - PDA - TiO2 fiber is obtained.

[0030] Among them, (NH4)2TiF6 will hydrolyze in the H3BO3 solution to generate TiO2 nanoparticles, and these nanoparticles will be reduced to the catechol groups of PDA, and promote the homogeneous deposition of TiO2 with this as the seed layer, and finally form a tight and irreversible TiO2 layer on the fiber surface.

[0031] The beneficial effects of the present invention are as follows: The TiO2 layer prepared by the specific method of the flame-retardant and ultraviolet-resistant fiber of the present invention endows the fiber with good ultraviolet protection performance; the TiO2 layer can effectively absorb and reflect ultraviolet rays, and at the same time endows the fiber with good ultraviolet protection performance; since the TiO2 nanoparticles are an effective ultraviolet shielding agent that can reflect and absorb ultraviolet rays, the flame-retardant lyocell - PDA - TiO2 fiber can convert ultraviolet rays into visible light and heat, thereby minimizing the transmitted ultraviolet rays; the flame-retardant lyocell - PDA - TiO2 fiber can capture the active free radicals generated by ultraviolet irradiation, so as to achieve the effect of ultraviolet protection. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the modification treatment device of the flame-retardant and ultraviolet-resistant fiber of the present invention;

[0033] Figure 2 It is a schematic top view structure diagram of the ultrasonic treatment box of the flame-retardant and ultraviolet-resistant fiber of the present invention;

[0034] Figure 3 It is a schematic right view structure diagram of the ultrasonic treatment box of the present invention;

[0035] Figure 4 It is a schematic top view structure diagram of the receiving screen of the present invention;

[0036] Figure 5 It is the preparation process flow of the flame-retardant and ultraviolet-resistant fiber of the present invention.

[0037] Markings in the drawings: 1. Fiber cutting machine; 2. Ultrasonic treatment machine; 3. Vacuum drying oven; 4. Water bath shaker; 5. Vacuum pump; 6. Feeding pipe; 7. Ultrasonic treatment box; 8. Rotating motor; 9. Stirrer; 10. Working chamber; 11. Receiving screen; 12. Handle; 13. Sealing ring; 14. Air intake net; 15. Quick connector; 16. Water outlet solenoid valve. Embodiment Example

[0038] Pretreatment of Lyocell fibers: Take 10 g of Lyocell fibers and place them in a beaker containing deionized water. Then add 15 ml of absolute ethanol to it. After washing at room temperature for 30 min, take them out, wash with deionized water three times, and put them in an oven at 60 °C to dry for later use.

[0039] Preparation of oxidized Lyocell fibers: First, prepare 90 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 0.5 M, and strictly control the pH = 6.8. Place the buffer solution and 1 g of pretreated Lyocell fibers in a three-necked flask, add 0.05 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 1.73 g of NaClO2 to it, and stir tightly at 60 °C for 10 min. Then add 1 g of NaClO and keep reacting at 50 °C for 12 h; then add 5 mL of absolute ethanol to terminate the reaction; after taking out the fibers, wash the fibers three times with absolute ethanol to obtain oxidized Lyocell fibers (O-lyocell).

[0040] Preparation of flame-retardant Lyocell fibers: Place the oxidized Lyocell fibers and 20 ml of an 85 wt% ethanol aqueous solution in a three-necked flask, and slowly drop 15 g of an aluminum chloride solution (10 wt%) into it. Heat it in a water bath at 60 °C for 2 h; after the reaction is completed, wash the fibers three times with deionized water and dry them at 60 °C. Obtain flame-retardant Lyocell fibers.

[0041] Cut the flame-retardant Lyocell fibers into 15 cm lengths, ultrasonically treat them in an ethanol solution for 30 min, repeatedly rinse them, and then dry them in a vacuum oven at 60 °C for later use. Using Tris-HCl buffer (pH = 8.5) as a solvent, soak the washed flame-retardant Lyocell fibers in a newly prepared dopamine buffer solution, take them out after shaking and reacting in a constant temperature water bath shaker at 25 °C for 24 h, repeatedly rinse with deionized water, dry and label them as flame-retardant Lyocell-PDA.

[0042] Prepare a mixed solution of 0.1 mol / L (NH4)2TiF6 and 0.3 mol / L H3BO3, adjust the pH value to 3.88, and then immerse the above-obtained flame-retardant Lyocell-PDA fibers into this mixed solution and react at room temperature for 1 h. After the reaction is completed, wash them many times with deionized water, dry and obtain flame-retardant Lyocell-PDA-TiO2 fibers.

[0043] Example 2

[0044] Pretreatment of Lyocell fibers: Take 12 g of Lyocell fibers and place them in a beaker containing deionized water. Add 16 ml of absolute ethanol to it. After washing at room temperature for 31 min, take them out, then wash with deionized water three times, and put them in an oven at 60 °C to dry for later use.

[0045] Preparation of oxidized Lyocell fibers: First, prepare 92 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 0.6 M, and strictly control the pH = 6.8. Place the buffer solution and 1.5 g of pretreated Lyocell fibers in a three-necked flask, add 0.06 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 1.75 g of NaClO2 to it, stir tightly at 60 °C for 12 min, then add 1 g of NaClO, and keep reacting at 52 °C for 12 h; then add 5 mL of absolute ethanol to terminate the reaction; after taking out the fibers, wash the fibers three times with absolute ethanol to obtain oxidized Lyocell fibers (O-lyocell).

[0046] Preparation of flame-retardant Lyocell fibers: Place the oxidized Lyocell fibers and 22 ml of an 85 wt% ethanol aqueous solution in a three-necked flask, and slowly drop 16 g of an aluminum chloride solution (10 wt%) into it. Heat it in a water bath at 62 °C for 2 h; after the reaction is completed, wash the fibers three times with deionized water and dry them at 60 °C. Obtain flame-retardant Lyocell fibers.

[0047] Cut the flame-retardant Lyocell fibers into 15 cm lengths, ultrasonically treat them in an ethanol solution for 32 min, repeatedly rinse them, and then dry them in a vacuum oven at 60 °C for later use. Using Tris-HCl buffer solution (pH = 8.5) as a solvent, soak the washed flame-retardant Lyocell fibers in a newly prepared dopamine buffer solution, take them out after shaking and reacting in a constant temperature water bath shaker at 25 °C for 24 h, repeatedly rinse them with deionized water, dry them and label them as flame-retardant Lyocell-PDA.

[0048] Prepare a mixed solution of 0.15 mol / L (NH4)2TiF6 and 0.35 mol / L H3BO3, adjust the pH value to 3.9, and then immerse the above-obtained flame-retardant Lyocell fiber-PDA fibers in this mixed solution and react at room temperature for 4 h. After the reaction is completed, wash them many times with deionized water, dry them to obtain flame-retardant Lyocell-PDA-TiO2 fibers.

[0049] Example 3

[0050] Pretreatment of Lyocell fibers: Take 15 g of Lyocell fibers and place them in a beaker containing deionized water. Add 18 ml of absolute ethanol to it. After washing at room temperature for 33 min, take them out, wash with deionized water three times, and then put them in an oven at 60 °C to dry for later use.

[0051] Preparation of oxidized Lyocell fibers: First, prepare 94 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 0.7 M, and strictly control the pH = 6.8. Place the buffer solution and 2 g of pretreated Lyocell fibers in a three-necked flask, add 0.07 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 1.8 g of NaClO2 to it, and stir tightly at 60 °C for 13 min. Then add 1 g of NaClO and keep reacting at 55 °C for 12 h; then add 5 mL of absolute ethanol to terminate the reaction; after taking out the fibers, wash the fibers three times with absolute ethanol to obtain oxidized Lyocell fibers (O-lyocell).

[0052] Preparation of flame-retardant Lyocell fibers: Place the oxidized Lyocell fibers and 25 ml of an 85 wt% ethanol aqueous solution in a three-necked flask, and slowly add 18 g of an aluminum chloride solution (10 wt%) dropwise to it. Heat it in a water bath at 65 °C for 2 h; after the reaction is completed, wash the fibers three times with deionized water and dry them at 60 °C. The flame-retardant Lyocell fibers are obtained.

[0053] Cut the flame-retardant Lyocell fibers into 15 cm lengths, ultrasonically treat them in an ethanol solution for 35 min, rinse them repeatedly, and then dry them in a vacuum oven at 60 °C for later use. Using Tris-HCl buffer solution (pH = 8.5) as a solvent, soak the washed flame-retardant Lyocell fibers in a newly prepared dopamine buffer solution, take them out after reacting in a constant temperature water bath shaker at 25 °C for 24 h, rinse them repeatedly with deionized water, dry them and label them as flame-retardant Lyocell-PDA.

[0054] Prepare a mixed solution of 0.2 mol / L (NH4)2TiF6 and 0.4 mol / L H3BO3, adjust the pH value to 3.92, and then immerse the above-obtained flame-retardant Lyocell-PDA fibers into this mixed solution and react at room temperature for 6 h. After the reaction is completed, wash them with deionized water many times, dry them to obtain flame-retardant Lyocell-PDA-TiO2 fibers.

[0055] Example 4

[0056] Pretreatment of Lyocell fibers: Take 20 g of Lyocell fibers and place them in a beaker containing deionized water. Then add 20 ml of absolute ethanol. After washing at room temperature for 35 min, take them out, wash with deionized water three times, and put them in an oven at 60 °C to dry for standby.

[0057] Preparation of oxidized Lyocell fibers: First, prepare 100 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 1 M, and strictly control the pH = 6.8. Place the buffer solution and 3 g of pretreated Lyocell fibers in a three-necked flask. Add 0.1 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 2 g of NaClO2, and stir tightly at 60 °C for 15 min. Then add 1 g of NaClO and keep reacting at 60 °C for 12 h. Then add 5 mL of absolute ethanol to terminate the reaction. After taking out the fibers, wash the fibers three times with absolute ethanol to obtain oxidized Lyocell fibers (O-lyocell).

[0058] Preparation of flame-retardant Lyocell fibers: Place the oxidized Lyocell fibers and 30 ml of an 85 wt% ethanol aqueous solution in a three-necked flask, and slowly drop 20 g of an aluminum chloride solution (10 wt%) into it. Heat in a water bath at 70 °C for 2 h. After the reaction is completed, wash the fibers three times with deionized water and dry at 60 °C. The flame-retardant Lyocell fibers are obtained.

[0059] Cut the flame-retardant Lyocell fibers into pieces 15 cm long, ultrasonically treat them in an ethanol solution for 40 min. After repeated rinsing, dry them in a vacuum oven at 60 °C for standby. Using Tris-HCl buffer solution (pH = 8.5) as the solvent, soak the washed flame-retardant Lyocell fibers in a newly prepared dopamine buffer solution, take them out after oscillating and reacting in a constant temperature water bath shaker at 25 °C for 24 h, rinse repeatedly with deionized water, dry and label them as flame-retardant Lyocell-PDA.

[0060] As Figures 1 to 4 shown, a modification treatment device for a flame-retardant fiber of the present invention includes a fiber cutting machine 1, an ultrasonic treatment machine 2, a vacuum drying oven 3, and a water bath shaker 4. The ultrasonic treatment machine 2 is installed on the right side of the fiber cutting machine 1, the vacuum drying oven 3 is installed on the right side of the ultrasonic treatment machine 2, and the water bath shaker 4 is installed on the right side of the vacuum drying oven 3.

[0061] A modification treatment device for flame-retardant fibers of the present invention. The ultrasonic treatment machine 2 includes a vacuum pump 5, a feeding pipe 6, an ultrasonic treatment tank 7, a rotating motor 8 and a stirrer 9. The vacuum pump 5 is installed on the right side of the top of the ultrasonic treatment tank 7. A working chamber 10 is arranged inside the ultrasonic treatment tank 7. The input end of the feeding pipe 6 is connected to the output end of the fiber cutting machine 1, and the output end of the feeding pipe 6 is communicated with the left side of the top of the working chamber 10. The input end of the vacuum pump 5 is communicated with the right side of the top of the working chamber 10. The rotating motor 8 is installed in the middle of the top of the ultrasonic treatment tank 7. A rotating hole is arranged in the middle of the top of the working chamber 10. The output end of the rotating motor 8 passes through the rotating hole and is connected to the top of the stirrer 9. When carrying out the modification treatment of the flame-retardant fibers, the fibers are put into the fiber cutting machine for sizing cutting, and then the vacuum pump is turned on to pump out the air in the working chamber and the feeding pipe. Under the negative pressure of the feeding pipe, the cut fibers will be driven into the working chamber and immersed in the ethanol solution in the working chamber. At the same time, the rotating motor can be turned on to drive the stirrer to stir the inside of the working chamber, and the agglomerated fiber bundles can be timely dispersed. After the feeding is completed, the vacuum pump can be turned off. After the fiber bundles are disrupted, the ultrasonic treatment tank is turned on to perform ultrasonic treatment on the fibers. After the treatment is completed, the ethanol solution can be drained and replaced with deionized water to continuously rinse the fibers repeatedly. After the rinsing is completed, the fibers are taken out and put into a vacuum drying oven for drying treatment, and then added to a water bath shaker for the last step of processing to obtain the flame-retardant fibers. Through this device, the flame-retardant fibers can be disrupted after being cut, preventing the flame-retardant fibers from agglomerating, improving the soaking processing quality of the flame-retardant fibers, and thus enhancing the practicability.

[0062] The modification treatment device of the present invention further includes a receiving screen 11. A sliding groove is arranged at the bottom right of the working chamber 10. The receiving screen 11 is slidably connected to the sliding groove. When taking out the fibers from the ultrasonic treatment tank, the liquid in the working chamber can be drained first, and then the fibers can be left on the top of the screen through the filtration of the receiving screen. At this time, the receiving screen can be taken out, thus realizing more convenient material taking and enhancing the practicability.

[0063] The modification treatment device of the present invention further includes a handle 12. The handle 12 is installed at the right end of the receiving screen 11. The handle can make the pulling operation of the receiving screen more convenient, thus enhancing the practicability.

[0064] The modification treatment device of the present invention further includes a sealing ring 13. A sealing groove is arranged on the outer side of the right part of the receiving screen 11. The sealing ring 13 is fitted and installed in the sealing groove. The sealing ring can effectively improve the sealing performance between the receiving screen and the sliding groove, preventing the solution from leaking out, and thus enhancing the practicability.

[0065] The modified treatment device of the present invention further includes an intake net 14, which is installed at the input end of the vacuum pump 5; the intake net can filter fibers to a certain extent when the vacuum pump is working, preventing the fibers from being drawn into the vacuum pump and causing damage to the pump body, thereby enhancing the practicability.

[0066] The modified treatment device of the present invention further includes a quick connector 15. There is a round hole at the bottom left end of the working chamber 10, and the quick connector 15 is fitted and installed in the round hole. A water outlet solenoid valve 16 is arranged on the left side at the bottom end of the working chamber 10; the quick connector can more conveniently connect the deionized water and ethanol solution pipelines to the working chamber, further facilitating the operation of fiber modification treatment, thereby enhancing the practicability.

[0067] In the modified treatment device of the present invention, a sliding groove is provided at the front end of the vacuum drying oven 3, and the material receiving screen 11 is slidably connected to the sliding groove; after the material receiving screen is pulled out, the material receiving screen can be directly placed into the vacuum drying oven for drying, so that the washing and drying of the fibers are more convenient, thereby enhancing the practicability.

[0068] When the modified treatment device of the present invention is working, when performing the modification treatment of flame-retardant fibers, the fibers are put into the fiber cutting machine for sizing cutting, and then the vacuum pump is turned on to output and evacuate the working chamber and the feeding pipe. Under the negative pressure of the feeding pipe, the cut fibers will be driven into the working chamber and immersed in the ethanol solution in the working chamber. At the same time, the rotating motor can be turned on to output and drive the stirrer to stir the inside of the working chamber to timely disperse the agglomerated fiber bundles. After the feeding is completed, the vacuum pump can be turned off. After the fiber bundles are disrupted, the ultrasonic treatment box is turned on to perform ultrasonic treatment on the fibers. After the treatment is completed, the ethanol solution can be discharged and replaced with deionized water to continuously wash the fibers repeatedly. After the washing is completed, the material receiving screen is pulled out and slid into the vacuum drying oven for drying treatment, and then added to the water bath shaker for the last step of processing to obtain the flame-retardant fibers.

[0069] Prepare a mixed solution of 0.3 mol / L (NH4)2TiF6 and 0.5 mol / L H3BO3, adjust the pH value to 4, and then immerse the obtained flame-retardant lyocell fiber-PDA fiber in this mixed solution and react at room temperature for 12 h. After the reaction is completed, wash with deionized water multiple times, dry and obtain the flame-retardant lyocell-PDA-TiO2 fiber.

[0070] Comparative Example 1

[0071] Pretreatment of Lyocell fibers: Take 10 - 20 g of lyocell fibers and place them in a beaker filled with deionized water, and add 15 - 20 ml of absolute ethanol thereto. After washing at room temperature for 30 - 35 min, take them out, wash with deionized water 3 times, and put them in an oven at 60 °C for drying for later use.

[0072] Preparation of carboxymethylated lyocell fiber: Put 2 g of pretreated lyocell fiber, 2.5 g of sodium chloroacetate and an appropriate amount of 85 wt% ethanol aqueous solution into a three-necked flask, heat it in a water bath at 60 °C for 2 h, then add 30 ml of 85 wt% ethanol aqueous solution and 1.5 g of sodium hydroxide to it, and then raise the water bath temperature to 70 °C and keep it for 3 h; finally, wash the reacted fiber with absolute ethanol 3 times until neutral to obtain carboxymethylated lyocell fiber (CM-lyocell).

[0073] Preparation of flame-retardant lyocell fiber: Put carboxymethylated lyocell fiber and 20 - 30 ml of 85 wt% ethanol aqueous solution into a three-necked flask, slowly drop 15 - 20 g of aluminum chloride solution (10 wt%) into it, and heat it in a water bath at 60 - 70 °C for 2 h; after the reaction is completed, wash the fiber with deionized water 3 times and dry it at 60 °C. The flame-retardant lyocell fiber is obtained.

[0074] Cut the flame-retardant lyocell fiber into 15 cm lengths, ultrasonically treat it in an ethanol solution for 30 - 40 min, repeatedly rinse it, and then dry it in a vacuum oven at 60 °C for later use. Using Tris-HCl buffer solution (pH = 8.5) as the solvent, soak the washed flame-retardant lyocell fiber in the newly prepared dopamine buffer solution, take it out after shaking and reacting in a constant temperature water bath shaker at 25 °C for 24 h, repeatedly rinse it with deionized water, dry it and label it as flame-retardant lyocell-PDA.

[0075] Prepare a mixed solution of 0.1 - 0.3 mol / L (NH4)2TiF6 and 0.3 - 0.5 mol / L H3BO3, adjust the pH value to 3.88 - 4, and then immerse the above-obtained flame-retardant lyocell fiber-PDA fiber into this mixed solution and react at room temperature for 1 - 12 h. After the reaction is completed, wash it with deionized water many times, dry it and obtain flame-retardant lyocell-PDA-TiO2 fiber.

[0076] Comparative Example 2

[0077] Pretreatment of Lyocell fiber: Take 10 - 20 g of lyocell fiber and put it into a beaker containing deionized water, add 15 - 20 ml of absolute ethanol to it, take it out after washing at room temperature for 30 - 35 min, then wash it with deionized water 3 times, and put it into an oven at 60 °C to dry for later use.

[0078] Preparation of carboxymethylated lyocell fiber: 2 g of pretreated lyocell fiber, 3 g of sodium chloroacetate and an appropriate amount of 85 wt% ethanol aqueous solution were placed in a three-necked flask, heated in a water bath at 60 °C for 2 h, then 25 ml of 85 wt% ethanol aqueous solution and 2 g of sodium hydroxide were added thereto, and then the water bath temperature was raised to 70 °C and maintained for 3 h; finally, the reacted fiber was washed 3 times with absolute ethanol until neutral to obtain carboxymethylated lyocell fiber (CM-lyocell).

[0079] Preparation of flame-retardant lyocell fiber: The carboxymethylated lyocell fiber and 20 - 30 ml of 85 wt% ethanol aqueous solution were placed in a three-necked flask, and 15 - 20 g of aluminum chloride solution (10 wt%) was slowly added dropwise thereto, and heated in a water bath at 60 - 70 °C for 2 h; after the reaction was completed, the fiber was washed 3 times with deionized water and dried at 60 °C. The flame-retardant lyocell fiber was obtained.

[0080] The flame-retardant lyocell fiber was cut into 15 cm lengths, ultrasonically treated in an ethanol solution for 30 - 40 min, repeatedly rinsed, and then dried in a vacuum oven at 60 °C for later use. Using Tris-HCl buffer solution (pH = 8.5) as a solvent, the washed flame-retardant lyocell fiber was immersed in a newly prepared dopamine buffer solution, shaken and reacted in a constant temperature water bath shaker at 25 °C for 24 h, then taken out, repeatedly rinsed with deionized water, dried and labeled as flame-retardant lyocell-PDA.

[0081] A mixed solution of 0.1 - 0.3 mol / L (NH4)2TiF6 and 0.3 - 0.5 mol / L H3BO3 was prepared, the pH value was adjusted to 3.88 - 4, and then the above-obtained flame-retardant lyocell fiber-PDA fiber was immersed in this mixed solution and reacted at room temperature for 1 - 12 h. After the reaction was completed, it was repeatedly rinsed with deionized water, dried to obtain flame-retardant lyocell-PDA-TiO2 fiber.

[0082] The flame-retardant and ultraviolet-resistant fibers obtained in Examples 1 to 4 and Comparative Product 1 and 2 were tested. The specific test methods are as follows:

[0083] Combustion test

[0084] Under air conditions, the flame-retardant treated fibers (0.5 g each) were exposed to a stable flame of an alcohol lamp, and the combustion phenomenon of the fibers was observed, and the whole process was recorded by a digital camera.

[0085] Single fiber strength test

[0086] The tensile properties of the fibers before and after flame retardant modification were tested using an electronic single fiber strength tester (Laizhou Yuanmao Instrument, model YM-06A) at 25 °C and 60% relative humidity. The initial grip distance for all samples was 10 mm, and the tensile speed was 10 mm / min. Ten single fibers were tested for each sample, and the average value was taken as the final result.

[0087] Ultraviolet protection performance test

[0088] The fibers before and after modification were treated by ultraviolet irradiation. The intensity of the ultraviolet lamp was 80 W / m2, which is much higher than the ultraviolet intensity in sunlight. The main wavelength of ultraviolet light was 360 nm. The distance between the fiber and the ultraviolet light source was fixed at 25 cm, and the treatment time was 24 h.

[0089] The ultraviolet protection factor (UPF) and the transmittance of UVA and UVB of the non-woven fabrics before and after modification were tested using a Labsphere UV2000 ultraviolet transmittance analyzer. This experiment was carried out in accordance with the evaluation of the anti-ultraviolet performance of textiles GB / T18830-2002. In order to reduce errors, four different regions were selected for testing each sample, and the average value of the data was taken as the final transmittance of the sample.

[0090]

[0091] As can be seen from Table 1, the best flame retardant effect of Example 4 reached 86%, and the worst effect of Comparative Example 2 was 36%. The char residue of the fiber after flame retardant modification was significant, and the flame retardancy was greatly improved. The reason is that the introduction of carboxylic acid groups and aluminum ions can promote the dehydration and carbonization of the fiber, and then form a physical barrier to isolate the transfer of oxygen and heat, thereby preventing the combustion from proceeding. Metallic aluminum undergoes a thermal oxidation reaction at high temperature to generate metal oxides, which adhere to the fiber surface to form a physical barrier, protecting the fiber and inhibiting the combustion behavior. The non-combustible gases (such as H2O and CO2) released by the flame retardant fiber can effectively dilute the combustible gas and reduce the temperature in the combustion zone, further reducing the possibility of combustion.

[0092]

[0093]

[0094] In Examples 1-4 in Table 2, the breaking strength only fluctuated slightly, and it can be considered that the breaking strength of the fiber remained basically unchanged before and after modification. The breaking strength of Example 4 was the highest, the maximum breaking elongation was 27.4%, and that of Comparative Example 2 was the lowest at 20.5%. This is because when the original fiber underwent an oxidation reaction in the TEMPO / NaClO2 / NaClO reaction system, a certain degree of degradation occurred, resulting in a decrease in the mechanical properties of the fiber, that is, the breaking strength and breaking elongation of the flame-retardant modified fiber decreased. Even so, due to the high dry and wet strength characteristics of lyocell fiber, the flame-retardant modified fiber maintained the breaking strength of the original fiber. Therefore, the flame-retardant fiber still has good practicality. However, the breaking elongation of the flame-retardant fiber decreased, indicating that the fiber was affected by oxidation, resulting in poor fiber toughness.

[0095]

[0096] As can be seen from Table 3, according to the provisions of GB / T18830-2002, when the UPF value is greater than 50, it is considered that the fabric has good ultraviolet protection ability. The effect of Example 4 was the best, reaching 1125, indicating that the TiO2 coating imparted good ultraviolet protection performance to the fiber. The TiO2 coating can effectively absorb and reflect ultraviolet rays, and at the same time impart good ultraviolet protection performance to the fiber. Since TiO2 nanoparticles are an effective ultraviolet shielding agent that can reflect and absorb ultraviolet rays, the TiO2 coating can convert ultraviolet rays into visible light and heat, thereby minimizing the transmitted ultraviolet rays. PDA can capture the active free radicals generated by ultraviolet irradiation, thereby achieving the effect of ultraviolet protection. Since the chemical structure of PDA is similar to that of natural melanin, it can capture the free radicals generated by ultraviolet irradiation, thus being able to play a role in resisting ultraviolet rays, indicating that the non-woven fabric has excellent ultraviolet resistance.

[0097] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A flame-retardant and ultraviolet-resistant fiber, characterized in that The preparation process includes the following steps: (1) Pretreat the Lyocell fiber; (2) Prepare the oxidized Lyocell fiber; (3) Preparation of the flame-retardant Lyocell fiber: Mix the oxidized Lyocell fiber with an appropriate amount of ethanol aqueous solution, slowly add an aluminum trichloride solution dropwise, heat in a water bath, wash and dry to obtain the flame-retardant Lyocell fiber; (4) Anti-ultraviolet modification: Cut the Lyocell fiber, perform ultrasonic treatment, dry for later use. Immerse the washed fiber in a newly prepared dopamine buffer solution, react with constant temperature water bath oscillation, take it out, rinse, dry and label it as flame-retardant Lyocell-PDA. Prepare a mixed solution of (NH4)2TiF6 and H3BO3, adjust the pH, immerse the flame-retardant Lyocell-PDA fiber in this mixed solution, react at room temperature, rinse and dry after completion to obtain the flame-retardant Lyocell-PDA-TiO2 fiber; Step (1) Pretreatment of the Lyocell fiber: Take 10 - 20 g of Lyocell fiber and place it in a beaker containing deionized water, add 15 - 20 ml of absolute ethanol thereto, take it out after washing at room temperature for 30 - 35 min, then wash it 3 times with deionized water, and put it in an oven at 60 °C to dry for later use; Step (2) Preparation of the oxidized Lyocell fiber includes: Prepare a buffer solution, place the buffer solution and the pretreated Lyocell fiber in a three-necked flask, add TEMPO and NaClO2, stir evenly, then add NaClO to maintain the reaction, and then add absolute ethanol to terminate the reaction. Take out the fiber, wash it several times to obtain the oxidized Lyocell fiber; Step (2) Preparation of the oxidized Lyocell fiber includes: First, prepare 90 - 100 mL of a buffer solution of disodium hydrogen phosphate and sodium dihydrogen phosphate with a concentration of 0.5 - 1 M, strictly control the pH = 6.

8. Place the buffer solution and 1 - 3 g of the pretreated Lyocell fiber in a three-necked flask, add 0.05 - 0.1 g of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) and 1.73 - 2 g of NaClO2 thereto, stir tightly at 60 °C for 10 - 15 min, then add 1 g of NaClO, immediately stopper the flask, and maintain the reaction at 50 - 60 °C for 12 h; then add 5 mL of absolute ethanol to terminate the reaction; after taking out the fiber, wash the fiber 3 times with absolute ethanol to remove the unreacted drugs, and finally obtain the oxidized Lyocell fiber; Step (3) Preparation of the flame-retardant Lyocell fiber: Place the oxidized Lyocell fiber and 20 - 30 ml of 85 wt% ethanol aqueous solution in a three-necked flask, slowly add 15 - 20 g of 10 wt% aluminum trichloride solution dropwise thereto, heat in a water bath at 60 - 70 °C for 2 h; after the reaction is completed, wash the fiber 3 times with deionized water and dry at 60 °C; finally obtain the flame-retardant Lyocell fiber; Step (4) of the anti-ultraviolet modification includes: First, cut the flame-retardant lyocell fibers into lengths of 15 cm, ultrasonically treat them in an ethanol solution for 30 - 40 min, repeatedly rinse them with deionized water, and then dry them in a vacuum oven at 60 °C for later use; prepare a 2 g / L dopamine solution with a Tris-HCl buffer solution at pH = 8.5 as the solvent; soak the washed flame-retardant lyocell fibers in the newly prepared dopamine buffer solution, take them out after reacting in a constant-temperature water bath shaker at 25 °C for 24 h, repeatedly rinse them with deionized water, dry them and label them as flame-retardant lyocell-PDA; prepare a mixed solution of 0.1 - 0.3 mol / L (NH4)2TiF6 and 0.3 - 0.5 mol / L H3BO3, adjust the pH value to 3.88 - 4, and then immerse the obtained flame-retardant lyocell-PDA fibers in this mixed solution and react at room temperature for 1 - 12 h; after the reaction is completed, rinse them with deionized water multiple times, dry them to obtain flame-retardant lyocell-PDA-TiO2 fibers.

2. A flame-retardant and ultraviolet-resistant fiber according to claim 1, characterized in that: A modification treatment device used in step (4) of the anti-ultraviolet modification includes a fiber cutting machine (1), an ultrasonic treatment machine (2), a vacuum drying oven (3), and a water bath shaker (4). The ultrasonic treatment machine (2) is installed on the right side of the fiber cutting machine (1), the vacuum drying oven (3) is installed on the right side of the ultrasonic treatment machine (2), and the water bath shaker (4) is installed on the right side of the vacuum drying oven (3).

3. The flame-retardant and ultraviolet-resistant fiber according to claim 2, wherein: The ultrasonic treatment machine (2) includes a vacuum pump (5), a feeding pipe (6), an ultrasonic treatment tank (7), a rotating motor (8), and a stirrer (9). The vacuum pump (5) is installed on the upper right side of the ultrasonic treatment tank (7). A working chamber (10) is provided inside the ultrasonic treatment tank (7). The input end of the feeding pipe (6) is connected to the output end of the fiber cutting machine (1), and the output end of the feeding pipe (6) communicates with the upper left side of the top of the working chamber (10). The input end of the vacuum pump (5) communicates with the upper right side of the top of the working chamber (10). The rotating motor (8) is installed in the middle of the top of the ultrasonic treatment tank (7). A rotating hole is provided in the middle of the top of the working chamber (10). The output end of the rotating motor (8) passes through the rotating hole and is connected to the top of the stirrer (9).

4. The flame-retardant and ultraviolet-resistant fiber according to claim 3, characterized in that: The modification treatment device further includes a receiving screen (11), a sealing ring (13), and an air intake screen (14). A sliding groove is provided at the bottom right end of the working chamber (10), and the receiving screen (11) is slidably connected to the sliding groove; a sealing groove is provided on the outer side of the right part of the receiving screen (11), and the sealing ring (13) is fitted and installed in the sealing groove; the air intake screen (14) is installed at the input end of the vacuum pump (5).

5. The flame-retardant and ultraviolet-resistant fiber according to claim 4, characterized in that: The modification treatment device further includes a quick connector (15). A circular hole is provided at the bottom left end of the working chamber (10), and the quick connector (15) is fitted and installed in the circular hole. A water outlet solenoid valve (16) is provided at the bottom left end of the working chamber (10); a sliding groove is provided at the front end of the vacuum drying oven (3), and the receiving screen (11) is slidably connected to the sliding groove.

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