Flame-retardant polyester fabric and preparation method thereof

Abstract

The invention belongs to the field of polyester fibers, and particularly relates to a flame-retardant polyester fabric, a preparation method of which comprises the following steps: uniformly mixing 100 parts of modified polyester master batch, 5-15 parts of mica powder, 1-5 parts of antioxidant, 1-3 parts of ultraviolet screening agent and 8-10 parts of polyethylene glycol 20000, and then carrying out melt spinning on a spinning machine to obtain polyester fibers, and finally, spinning the polyester fibers into the flame-retardant polyester fabric through a textile machine. The prepared polyester fabric has excellent flame retardant property, the initial limit oxygen index of the polyester fabric reaches 39.5%, the vertical combustibility UL-94 of the polyester fabric reaches the V0 level, and after the polyester fabric is washed 100 times, the polyester fabric still has the high limit oxygen index and has good washing fastness.

Description

Technical Field

[0001] The present invention belongs to the field of polyester fibers, and particularly relates to a flame-retardant polyester fabric and a preparation method thereof. Background Art

[0002] Polyester fabric, commonly known as polyester fiber and PET, is a synthetic fiber fabric obtained by esterification or transesterification of terephthalic acid and ethylene glycol, followed by polycondensation to obtain a linear structure high molecular polymer, and then through a series of processing techniques such as melt spinning and weaving. Polyester is currently the synthetic fiber with the largest production and widest application range in the world. It has many excellent practical properties such as strong resistance, good resilience, good wrinkle resistance, good heat resistance, and solid durability. It is widely used in fields such as clothing manufacturing, decorative supplies, automotive interiors, industrial textiles, and other special-purpose textiles. Polyester fiber was first developed in a laboratory in the UK in 1941 and began large-scale industrial production in the US in 1953, and since then has been rapidly applied and developed worldwide. Since 1972, the world production of polyester fiber has exceeded that of polyamide fiber and has since become the world's largest synthetic fiber.

[0003] There are only benzene rings, ester bonds, and short-chain alkanes on the molecular chain of PET, and there are no flame-retardant elements. Therefore, the limiting oxygen index of polyester fabric is generally about 9 - 22, belonging to flammable materials. It is easily ignited when encountering a flame, and a large amount of heat and flaming droplets will be released during the combustion process, causing the rapid spread of the fire and secondary burns to people or animals, posing a great threat to people's lives and property safety. In order to improve the fire safety of polyester fabric during use, it needs to be flame-retardant modified. As a synthetic fiber, there are many ways to improve polyester fabric. Starting from the synthesis stage of PET molecules, by means of copolymerization, etc., directly introduce flame retardants into the PET molecular chain to change its molecular structure to obtain flame-retardant PET polymers; it is also possible to directly blend flame retardants with ordinary PET raw materials during the melt spinning stage of the fiber, and obtain flame-retardant PET fibers through spinning; and post-treatment methods such as flame-retardant liquid padding and baking, flame-retardant coating, and flame-retardant liquid impregnation are used to flame-retard polyester fabrics. The flame retardants exist on the surface of PET fibers through physical adsorption, deposition, physical entanglement, intermolecular hydrogen bonding, etc.

[0004] In summary, while the excellent use performance of polyester fabric brings great convenience to people's production and life, its flammability also threatens people's property and personal safety. It is very urgent and necessary to improve the flame-retardant performance of polyester fabric. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a polyester fabric with excellent flame-retardant performance and good wash resistance and a preparation method thereof. The present invention is achieved through the following technical solutions: A preparation method of a flame-retardant polyester fabric, comprising the following steps: Step 1: Preparation of a modified polyester masterbatch Add terephthalic acid, ethylene glycol, and catalyst Sb2O3 into a reaction kettle and mix evenly. Obtain a prepolymer through esterification and pre-polycondensation; then add flame-retardant modification monomer A to the prepolymer, and prepare a modified polyester through polycondensation reaction and final polycondensation reaction. The modified polyester is extruded, granulated, and dried to obtain a modified polyester masterbatch; Among them, the structure of the flame-retardant modification monomer A is: ; Step 2: Preparation of a modified polyester masterbatch By weight, mix 100 parts of the modified polyester masterbatch, 5 - 15 parts of mica powder, 1 - 5 parts of antioxidant, 1 - 3 parts of ultraviolet absorber, and 8 - 10 parts of polyethylene glycol 20000 evenly, then carry out melt spinning on a spinning machine to obtain polyester fibers, and finally weave the polyester fibers into a flame-retardant polyester fabric through a textile machine.

[0006] In some embodiments, the antioxidant is selected from one or more of triphenyl phosphite, triphenyl phosphate, antioxidant HP-136, antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 1068.

[0007] In some embodiments, the ultraviolet absorber is selected from one or more of zirconia, silica, calcium oxide, antimony pentoxide, cerium dioxide, yttrium oxide, zinc oxide, nickel oxide, chromium oxide, and titanium dioxide.

[0008] In some embodiments, the molar ratio of terephthalic acid to ethylene glycol is 1:(1 - 1.5); the molar ratio of terephthalic acid to flame-retardant modification monomer A is 1: (0.05 - 0.2); the molar ratio of terephthalic acid to catalyst Sb2O3 is 1: (0.01 - 0.1).

[0009] In some embodiments, the esterification temperature is 230 - 250 °C, the esterification pressure is 0.1 - 0.5 MPa, and the esterification time is 1 - 3 h; In some embodiments, the pre-polycondensation temperature is 250 - 270 °C, the pre-polycondensation pressure is -0.02 - -0.01 MPa, and the pre-polycondensation time is 30 - 60 min; In some embodiments, the polycondensation temperature is 270 - 290 °C, the polycondensation vacuum degree is 1 - 5 kPa, and the polycondensation time is 30 - 60 min; In some embodiments, the final polycondensation temperature is 280 - 300 °C, the final polycondensation vacuum degree is 100 - 200 Pa, and the final polycondensation time is 60 - 90 min.

[0010] In some embodiments, the rotation speed of the extruder is 20 - 50 r / min, the temperature of the first zone of the extruder is 265 °C, the temperature of the second zone is 290 °C, the temperature of the third zone is 280 °C, and the temperature of the fourth zone is 270 °C.

[0011] In some embodiments, in step 2, the spinning temperature of the spinning machine is 250 - 280 °C, the screw rotation speed is 500 - 800 r / min, and the winding speed is 1000 - 1200 r / min.

[0012] The present invention also protects the flame - retardant polyester fabric prepared by the above - mentioned method.

[0013] The present invention has achieved the following beneficial effects: 1) The polyester fabric prepared by the present invention has excellent flame - retardant properties. Its initial limiting oxygen index reaches 39.5%, the vertical burning property UL - 94 reaches V0 level, and after 100 washes, the polyester fabric still has a relatively high limiting oxygen index, showing good wash - fastness.

[0014] 2) The flame - retardant modified monomer A of the present invention has two carboxyl groups and can participate in the polycondensation reaction as a polymerization monomer to embed the flame - retardant structure into the polymer, endowing it with excellent wash - fastness. On the other hand, the flame - retardant modified monomer A of the present invention contains triazine and borate ester structures, and such structures themselves have good flame - retardant properties. Introducing them into the polyester fabric can achieve synergistic and efficient flame retardancy. Specific embodiments: The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0016] The endpoints and any values of the ranges described in the present invention are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0017] Unless otherwise specified, all raw materials and reagents of the present invention are raw materials and reagents available in the conventional market.

[0018] Preparation Example 1 Synthesis of Flame - Retardant Modified Monomer A Step 1: Synthesis of Intermediate Compound III (refer to the method disclosed in CN116640126A)

[0019] Under nitrogen protection, compound I (0.1 mol), compound II (0.2 mol), KOAc (0.3 mol), Pd(dppf)Cl2 (0.005 mol) and THF (500 mL) were added to a reactor. The mixed solution of the above reactants was heated to reflux for 7 hours. After the reaction was completed, it was cooled to room temperature, distilled water was added, and the filter cake was obtained by suction filtration and dried in a vacuum oven. It was separated and purified by silica gel column chromatography (n-hexane:ethyl acetate = 1:1) to obtain intermediate compound III with a yield of 83.5% and an HPLC purity of 99.8%.

[0020] LC-MS (ESI): [M+H] + = 368.2

[0021] Step 2: Synthesis of flame retardant modified monomer A

[0022] Step S1: Sodium pieces (0.1 mol) were added to a reactor, and anhydrous ethanol (200 mL) was immediately added. It was stirred at room temperature until the sodium pieces completely disappeared. Diethyl malonate (0.1 mol) was added, and the reaction was stirred at room temperature for 1 h. Subsequently, compound III (0.12 mol) was added, and the temperature was raised to 80 °C and stirred for 2 h. The reaction progress was monitored by TLC plate (petroleum ether:ethyl acetate = 8:1). After the reaction was completed, the solid impurities were removed by suction filtration, and the reaction solution was rotary evaporated to obtain intermediate compound V, which was directly used in the next step of the reaction.

[0023] Step S2: The compound V obtained in Step S1 was added to a reactor, and then a mixed solvent of dichloromethane:methanol (V:V = 9:1) (200 mL) and sodium hydroxide (0.4 mol) were added. It was stirred at room temperature for 6 h. The reaction progress was monitored by TLC plate (petroleum ether:ethyl acetate = 8:1). After the reaction was completed, the reaction solution was rotary evaporated to obtain intermediate compound VI; Step S3: Water (100 mL) was added to the intermediate compound VI obtained in Step S2, and 1 M hydrochloric acid was slowly added dropwise to adjust the pH to 2. Then water (100 mL) was added, and it was extracted with ethyl acetate (200 mL × 3). The organic phases were combined, washed with saturated sodium chloride solution (100 mL × 3), dried over anhydrous sodium sulfate, then filtered and rotary evaporated to obtain the crude product. The crude product was separated and purified by silica gel column chromatography to obtain compound A with a total yield of 60.8% and an HPLC purity of 99.6%.

[0024] 1 H-NMR (400 MHz, DMSO- d6): δ (ppm): 11.5 (s, 2H), 4.68 - 4.61 (m, 1H), 1.25 (s, 24H).

[0025] Example 1 A method for preparing a flame - retardant polyester fabric, the specific steps are as follows: Step 1: Preparation of modified polyester masterbatch Add terephthalic acid, ethylene glycol and catalyst Sb2O3 into the reaction kettle and mix evenly. Check the airtightness of the system, fill with nitrogen to remove the air in the reaction kettle, and obtain a prepolymer through esterification and pre - polycondensation; then add flame - retardant modified monomer A (obtained from Preparation Example 1) to the prepolymer, and prepare the required modified polyester through polycondensation reaction and final polycondensation reaction. Finally, extrude, pelletize and dry to obtain the modified polyester masterbatch.

[0026] The molar ratio of terephthalic acid to ethylene glycol is 1:1.15; The molar ratio of terephthalic acid to flame - retardant modified monomer A is 1:0.15; The molar ratio of terephthalic acid to catalyst Sb2O3 is 1:0.02; The esterification temperature is 230 °C, the esterification pressure is 0.2 MPa, and the esterification time is 2.0 h; The pre - polycondensation temperature is 250 °C, the pre - polycondensation pressure is - 0.01 MPa, and the pre - polycondensation time is 45 min; The polycondensation temperature is 270 °C, the polycondensation vacuum degree is 1 kPa, and the polycondensation time is 60 min; The final polycondensation temperature is 280 °C, the final polycondensation vacuum degree is 200 Pa, and the final polycondensation time is 90 min.

[0027] The rotation speed of the extruder is 50 r / min, the temperature of the first zone of the extruder is 265 °C, the temperature of the second zone is 290 °C, the temperature of the third zone is 280 °C, and the temperature of the fourth zone is 270 °C.

[0028] Step 2: Preparation method of flame - retardant polyester fabric By weight, mix 100 parts of modified polyester masterbatch (obtained in Step 1), 10 parts of mica powder (produced by Tuolin Mineral Products Processing Factory in Lingshou County, particle size is 10 μm, sand content < 3%), 2 parts of antioxidant 1010, 3 parts of ultraviolet absorber zinc oxide, and 10 parts of polyethylene glycol 20000 evenly. Then carry out melt spinning on a spinning machine, the spinning temperature in the spinning machine is 265 °C, the screw rotation speed is 600 r / min, the winding speed is 1200 r / min to obtain polyester fibers, and finally weave the polyester fibers into a flame - retardant polyester fabric through a textile machine.

[0029] Example 2 A preparation method of a flame-retardant polyester fabric, and the specific steps are as follows: Step 1: Preparation of modified polyester masterbatch Add terephthalic acid, ethylene glycol and catalyst Sb2O3 into the reaction kettle and mix evenly. Check the airtightness of the system, fill with nitrogen to remove the air in the reaction kettle, and obtain a prepolymer through esterification and pre-polycondensation; then add flame-retardant modified monomer A (obtained in Preparation Example 1) to the prepolymer, and prepare the required modified polyester through polycondensation reaction and final polycondensation reaction. Finally, extrude, pelletize and dry to obtain the modified polyester masterbatch.

[0030] The molar ratio of terephthalic acid to ethylene glycol is 1:1.2; The molar ratio of terephthalic acid to flame-retardant modified monomer A is 1:0.1; The molar ratio of terephthalic acid to catalyst Sb2O3 is 1:0.01; The esterification temperature is 240°C, the esterification pressure is 0.2 MPa, and the esterification time is 1.5 h; The pre-polycondensation temperature is 260°C, the pre-polycondensation pressure is -0.02 MPa, and the pre-polycondensation time is 30 min; The polycondensation temperature is 280°C, the polycondensation vacuum degree is 1 kPa, and the polycondensation time is 40 min; The final polycondensation temperature is 290°C, the final polycondensation vacuum degree is 200 Pa, and the final polycondensation time is 60 min.

[0031] The rotation speed of the extruder is 50 r / min, the temperature of the first zone of the extruder is 265°C, the temperature of the second zone is 290°C, the temperature of the third zone is 280°C, and the temperature of the fourth zone is 270°C.

[0032] Step 2: Preparation method of flame-retardant polyester fabric By weight, mix 100 parts of modified polyester masterbatch (obtained in Step 1), 8 parts of mica powder (produced by Tuolin Mineral Products Processing Factory in Lingshou County, with a particle size of 10 μm and a sand content of <3%), 3 parts of antioxidant 168, 2 parts of ultraviolet-resistant agent titanium dioxide, and 10 parts of polyethylene glycol 20000 evenly, and then carry out melt spinning on a spinning machine. The spinning temperature in the spinning machine is 265°C, the screw rotation speed is 600 r / min, and the winding speed is 1200 r / min to obtain polyester fibers. Finally, the polyester fibers are woven into a flame-retardant polyester fabric by a weaving machine.

[0033] Example 3 A preparation method of a flame-retardant polyester fabric, and the specific steps are as follows: Step 1: Preparation of modified polyester masterbatch Add terephthalic acid, ethylene glycol and catalyst Sb2O3 into a reaction kettle and mix them evenly. Check the airtightness of the system, fill it with nitrogen to remove the air in the reaction kettle, and obtain a prepolymer through esterification and prepolycondensation; then add flame retardant modified monomer A (obtained in Preparation Example 1) into the prepolymer, and prepare the required modified polyester through polycondensation reaction and final polycondensation reaction. Finally, obtain the modified polyester masterbatch through extrusion granulation and drying.

[0034] The molar ratio of terephthalic acid to ethylene glycol is 1:1.15; The molar ratio of terephthalic acid to flame retardant modified monomer A is 1:0.15; The molar ratio of terephthalic acid to catalyst Sb2O3 is 1:0.02; The esterification temperature is 230 °C, the esterification pressure is 0.2 MPa, and the esterification time is 2.0 h; The prepolycondensation temperature is 250 °C, the prepolycondensation pressure is -0.01 MPa, and the prepolycondensation time is 45 min; The polycondensation temperature is 270 °C, the polycondensation vacuum degree is 1 kPa, and the polycondensation time is 60 min; The final polycondensation temperature is 280 °C, the final polycondensation vacuum degree is 200 Pa, and the final polycondensation time is 90 min.

[0035] The rotation speed of the extruder is 50 r / min, the temperature of the first zone of the extruder is 265 °C, the temperature of the second zone is 290 °C, the temperature of the third zone is 280 °C, and the temperature of the fourth zone is 270 °C.

[0036] Step 2: Preparation method of flame retardant polyester fabric By weight, mix 100 parts of the modified polyester masterbatch (obtained in Step 1), 15 parts of mica powder (produced by Tuolin Mineral Products Processing Factory in Lingshou County, with a particle size of 10 μm and a sand content < 3%), 5 parts of antioxidant 1076, 3 parts of ultraviolet resistant agent titanium dioxide, and 10 parts of polyethylene glycol 20000 evenly, and then carry out melt spinning on a spinning machine. The spinning temperature in the spinning machine is 265 °C, the screw rotation speed is 600 r / min, and the winding speed is 1200 r / min to obtain polyester fibers. Finally, weave the polyester fibers into a flame retardant polyester fabric through a textile machine.

[0037] Comparative Example 1 Replace the flame retardant modified monomer A in Example 1 with , and keep other operations and parameters the same as in Example 1 to prepare the corresponding polyester fabric.

[0038] Flame retardancy test Test the flame retardancy of the flame retardant polyester fabrics obtained in Examples 1 - 3 and Comparative Example 1 respectively. The test method is as follows: Limiting oxygen index: The limiting oxygen index of the polyester fabric was detected according to GB / T 5454-1997 "Textiles - Burning performance - Determination of oxygen index". At the same time, the UL-94 rating of vertical flammability (tested with a CZF-5 vertical burning tester) was used to assist in the judgment. In addition, according to "GB / T 17596-1998 Textiles - Commercial laundering procedures before fabric flammability testing", the limiting oxygen index of the fabric after 100 washes was tested. The results are shown in Table 1.

[0039] Table 1 Test results of flame retardancy performance

[0040] As can be seen from Table 1, the modified polyester fabric has excellent flame retardancy performance. Its initial limiting oxygen index reaches 39.5%, and the vertical flammability UL-94 reaches V0 level. Moreover, after 100 washes, the polyester fabric still has a relatively high limiting oxygen index and good wash resistance. The reasons are as follows: On the one hand, the flame retardant modified monomer A of the present invention has two carboxyl groups, which can participate in the polycondensation reaction as a polymerization monomer to embed the flame retardant structure into the polymer, making it have excellent water wash resistance; on the other hand, the flame retardant modified monomer A of the present invention contains triazine and borate ester structures, and such structures themselves have good flame retardancy performance. Introducing them into the polyester fabric can achieve synergistic and efficient flame retardancy. In addition, from Example 1 and Comparative Example 1, it can be seen that the introduction of element B significantly improves the flame retardancy performance of the polyester fabric.

[0041] The above examples are only for clearly illustrating the examples and not for limiting the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications thus derived are still within the protection scope of the present invention.

Claims

1. A preparation method of a flame-retardant polyester fabric, comprising the following steps: Step 1: Preparation of modified polyester masterbatch Add terephthalic acid, ethylene glycol and catalyst Sb2O3 into a reaction kettle and mix evenly. Obtain a prepolymer through esterification and pre-polycondensation; then add flame-retardant modification monomer A into the prepolymer, and prepare modified polyester through polycondensation reaction and final polycondensation reaction. The modified polyester is extruded into pellets and dried to obtain modified polyester masterbatch; Among them, the structure of the flame retardant modified monomer A is: ; Step 2: Preparation of modified polyester masterbatch By weight, mix 100 parts of modified polyester masterbatch, 5 - 15 parts of mica powder, 1 - 5 parts of antioxidant, 1 - 3 parts of ultraviolet absorber, and 8 - 10 parts of polyethylene glycol 20000 evenly, then carry out melt spinning on a spinning machine to obtain polyester fibers, and finally weave the polyester fibers into a flame-retardant polyester fabric through a textile machine.

2. The preparation method according to claim 1, characterized in that, The antioxidant is selected from one or more of triphenyl phosphite, triphenyl phosphate, antioxidant HP-136, antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1068.

3. The preparation method according to claim 1, characterized in that, The ultraviolet absorber is selected from one or more of zirconium oxide, silicon dioxide, calcium oxide, antimony pentoxide, cerium dioxide, yttrium oxide, zinc oxide, nickel oxide, chromium oxide, titanium dioxide.

4. The preparation method according to claim 1, wherein The molar ratio of terephthalic acid to ethylene glycol is 1:(1 - 1.5); the molar ratio of terephthalic acid to flame-retardant modification monomer A is 1:(0.05 - 0.2); the molar ratio of terephthalic acid to catalyst Sb2O3 is 1:(0.01 - 0.1).

5. According to the preparation method described in claim 1, characterized in that: The esterification temperature is 230 - 250 °C, the esterification pressure is 0.1 - 0.5 MPa, and the esterification time is 1 - 3 h; The pre-polycondensation temperature is 250 - 270 °C, the pre-polycondensation pressure is -0.02 - -0.01 MPa, and the pre-polycondensation time is 30 - 60 min; The polycondensation temperature is 270 - 290 °C, the polycondensation vacuum degree is 1 - 5 kPa, and the polycondensation time is 30 - 60 min; The final polycondensation temperature is 280 - 300 °C, the final polycondensation vacuum degree is 100 - 200 Pa, and the final polycondensation time is 60 - 90 min.

6. The preparation method according to claim 1, wherein, In step 1, the rotation speed of the extruder is 20 - 50 r / min, the temperature of the first zone of the extruder is 265 °C, the temperature of the second zone is 290 °C, the temperature of the third zone is 280 °C, and the temperature of the fourth zone is 270 °C.

7. The preparation method according to claim 1, characterized in that, In step 2, the spinning temperature of the spinning machine is 250 - 280 °C, the screw rotation speed is 500 - 800 r / min, and the winding speed is 1000 - 1200 r / min.

8. A flame-retardant polyester fabric prepared by the method according to any one of claims 1 - 7.

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