Titanium-based flame-retardant polyester fiber and method for producing the same

Abstract

The present application relates to the technical field of polyester fiber preparation, and particularly relates to a titanium-based flame-retardant polyester fiber and a preparation method thereof, the polyester fiber contains the following raw materials in parts by weight: modified polyester resin 95-110 parts, modified titanium dioxide 0.5-1 part, flame retardant 0.5-1.5 parts, and antioxidant 0.5-1 part. The titanium-based flame-retardant polyester fiber prepared by the present application has good mechanical properties and extinction.

Description

Technical Field

[0001] This invention relates to the field of polyester fiber preparation technology, specifically to a titanium-based flame-retardant polyester fiber and its preparation method. Background Technology

[0002] Polyester fiber is a type of synthetic fiber, typically a polymer compound produced by the polymerization of terephthalic acid and ethylene glycol through an esterification reaction. Polyester fiber has advantages such as good elasticity, high strength, and excellent abrasion resistance, and is widely used in clothing, home textiles, and decorations, becoming one of the most widely used fibers in the textile industry today. However, traditional polyester fiber is a flammable fiber, and many fire accidents are caused or amplified by the combustion of textiles. Therefore, increasing the flame retardancy of polyester fiber is of great significance for eliminating fire hazards, delaying the spread of fire, and reducing harm to people's health.

[0003] Patent CN106521691B discloses a polyester fiber with flame-retardant and antibacterial properties, which is made of polyester resin, polyimide, nano-bentonite, basalt fiber, 8-hydroxyquinoline copper, flame retardant, starch ether, initiator, silane coupling agent, dispersant, and surfactant. The polyester fiber prepared by this invention has excellent antibacterial and flame-retardant properties. However, the flame retardant used in this invention contains halogens. Halogenated flame retardants will release harmful gases at high temperatures, which will endanger human health.

[0004] Patent CN112831863B discloses a flame-retardant polyester fiber and its preparation process, which is composed of 70-80 parts polyester chips, 18-30 parts flame-retardant masterbatch, and 2.0-5.0 parts anti-drip agent. The flame-retardant masterbatch is composed of a composite flame retardant, a synergistic flame retardant, urea, nano-titanium dioxide, nano-bamboo charcoal powder, an antioxidant, calcium stearate, ethylene bis(fatty acid amide), isopropyltris(dioctyl pyrophosphate) titanate, and polyester chips. Under the synergistic effect of these substances, the prepared polyester fiber has a superior flame-retardant effect. This invention uses a blending method to add the flame-retardant masterbatch to the polyester fiber, which typically requires adding a large amount of flame retardant, increasing the cost to some extent.

[0005] Therefore, there is an urgent need in the market for a polyester fiber that does not release toxic gases, has lower costs, and has good flame retardant properties. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a titanium-based flame-retardant polyester fiber that does not release toxic gases, can reduce costs to a certain extent, and has good matting and mechanical properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a titanium-based flame-retardant polyester fiber, which, by weight, comprises the following raw materials: 95-110 parts of modified polyester resin, 0.5-1 parts of modified titanium dioxide, 0.5-1.5 parts of flame retardant, and 0.5-1 parts of antioxidant.

[0009] In some embodiments, the method for preparing the modified polyester resin includes the following steps:

[0010] (1) Pentaerythritol phosphate, maleic anhydride, and phosphoric acid were added to dichloromethane and reacted at 70-80℃ for 5-6 h. The mixture was then rotary evaporated and dried to obtain the compound. The obtained compound was added to methanol with 4-vinylbenzoic acid and azobisisobutyronitrile and reacted at 70-80℃ for 0.5-1.5 h to obtain a copolymer with a number average molecular weight of 300-400.

[0011] (2) Add terephthalic acid, ethylene glycol, catalyst and heat stabilizer to the first reaction vessel, remove the air in the reaction vessel, react at 235-245℃ and 0.2-0.4MPa, when the water output reaches 85-90% of the theoretical value, add polyethylene glycol under normal pressure, react at normal pressure for 50-70min, when the water output reaches 95-99% of the theoretical value, stop the reaction and obtain the reaction liquid;

[0012] (3) The reaction liquid obtained in step (2) is transported to the second reactor. The temperature reaches 240-250℃. While stirring, the copolymer obtained in step (1) is added. The pressure inside the reactor is reduced to -0.1KPa to 1KPa within 45-55 minutes. The temperature inside the reactor is controlled at 275-285℃. The reaction is carried out for 1-2 hours. Then the pressure inside the reactor is increased to 40-50Pa. The reaction time is 4-5 hours. The material is discharged, granulated, and dried to obtain the modified polyester resin.

[0013] Polyester fiber is a flammable material. To improve its flame retardancy, flame retardants are usually added. However, directly adding flame retardants may lead to uneven distribution and affect the flame retardant effect. This invention modifies polyester fiber to impart flame retardancy, reducing the amount of flame retardant required. This is likely because phosphate groups are added to the modified polyester fiber, giving it flame retardancy. Furthermore, copolymers containing alkane segments and benzene rings participate in the polyester polycondensation reaction, increasing the number of freely moving alkane segments. This increases the irregularity of the polyester fiber structure, improving its toughness. Additionally, the freely moving alkane segments increase the entanglement of the phosphate ester with the polyester fiber backbone, allowing the phosphate ester to bind tightly to the backbone, further enhancing flame retardancy. Simultaneously, the specific selection of a cage-like pentaerythritol phosphate increases the interaction with flame retardants and modified titanium dioxide, further improving compatibility with the polyester fiber. This results in a polyester fiber with uniform texture and good mechanical properties.

[0014] In some embodiments, the mass ratio of pentaerythritol phosphate to maleic anhydride in step (1) is (1.5-1.8):1.

[0015] In some embodiments, the mass ratio of the compound to 4-vinylbenzoic acid in step (1) is (1.8-2.1):1.

[0016] This invention limits the reaction of pentaerythritol phosphate to only one carboxyl group after the hydrolysis of maleic anhydride, thus retaining one carboxyl group to participate in the esterification reaction. Then, by limiting the mass ratio of the compound to 4-vinylbenzoic acid, it is made to have a certain alkane segment, while having enough carboxyl groups to participate in the esterification reaction, thereby increasing the toughness of polyester fibers.

[0017] In some embodiments, the mass ratio of terephthalic acid, ethylene glycol and polyethylene glycol in step (2) is 1:(0.2-0.4):(0.5-0.7).

[0018] In some embodiments, the mass ratio of the reaction solution to the copolymer in step (3) is 1:(0.1-0.2).

[0019] This invention increases the processability of polyester fibers by limiting the mass ratio of terephthalic acid, ethylene glycol, and polyethylene glycol, without reducing the water resistance of the polyester; and increases the flame retardancy of the modified polyester resin by limiting the mass ratio of the reaction solution to the copolymer, without reducing the original properties of the polyester resin.

[0020] In some embodiments, the method for preparing the modified titanium dioxide includes the following steps:

[0021] 1) Add 2-hydroxy-4-(methacryloyloxy)benzophenone, 10-hydroxy-2-decenoic acid and azobisisobutyronitrile to methanol, stir and react at 70-80℃ for 7-8h to obtain a prepolymer with a number average molecular weight of 500-600.

[0022] 2) Add titanium dioxide and silane coupling agent to ethanol, stir at 50-60℃ for 3-4 hours, then add the prepolymer obtained in step 1), stir and react at 70-80℃ for 1-2 hours to obtain modified titanium dioxide.

[0023] Preferably, the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

[0024] Titanium dioxide possesses certain matting and antibacterial properties. When added to polyester fibers as a filler, it can increase the strength of the polyester fibers. However, the small particle size of titanium dioxide makes it difficult to disperse evenly in polyester fibers, resulting in inconsistent quality. This invention modifies titanium dioxide to give it good dispersibility, allowing it to disperse evenly when blended with polyester resin. The resulting polyester fibers exhibit good matting properties. This may be because the modified titanium dioxide also has polar carboxyl groups, generating a negative charge and increasing the electrostatic repulsion between titanium dioxide particles, thus ensuring uniform dispersion. In addition, the modified titanium dioxide has better compatibility with polyester resin, which also increases the UV resistance of the polyester fibers. Furthermore, the addition of a silane coupling agent helps reduce surface tension, as it tends to migrate to the surface during heating. During combustion, the organosilicon dehydrates to form layered silica, which can increase the anti-dripping properties of the polyester fibers.

[0025] In some embodiments, the mass ratio of 2-hydroxy-4-(methacryloyloxy)benzophenone to 10-hydroxy-2-decenoic acid in step 1) is 1:(0.66-0.80).

[0026] In some embodiments, the mass ratio of titanium dioxide, silane coupling agent and prepolymer in step 2) is 1:(0.5-0.7):(0.6-0.8).

[0027] This invention limits the mass ratio of 2-hydroxy-4-(methacryloyloxy)benzophenone to 10-hydroxy-2-decenoic acid to obtain a prepolymer containing a certain amount of carboxyl groups, thereby increasing the dispersibility of modified titanium dioxide and providing good compatibility with polyester resin. In addition, limiting the mass ratio of titanium dioxide, silane coupling agent and prepolymer allows some hydroxyl groups on the surface of titanium dioxide to react with the silane coupling agent, reducing agglomeration while still maintaining good matting properties.

[0028] A second aspect of this invention provides a method for preparing titanium-based flame-retardant polyester fibers, comprising the following steps:

[0029] S1. Add the modified polyester resin, modified titanium dioxide, flame retardant, and antioxidant to the mixer and stir for 20-30 minutes to obtain the mixture.

[0030] S2. The mixture obtained in step S1 is added to a twin-screw extruder for extrusion. The feed speed of the twin-screw extruder is 550-650 rpm, the extrusion temperature is 240-250℃, and then melt spinning is performed. The feed rate of the spinning metering pump is controlled at 700-800 g / min, the spinning temperature is 275-285℃, and the spinning speed is 840-860 m / min. Then, the drawing process is performed with a drawing ratio of 1.5-2.5 times and a winding speed of 650-750 m / min to obtain titanium-based flame-retardant polyester fiber.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. This invention incorporates copolymers and modified titanium dioxide, which exhibit excellent flame retardancy, matting properties, and UV resistance. Furthermore, it does not release toxic gases during the preparation process, thus reducing costs to some extent and providing good mechanical properties.

[0033] 2. This invention modifies polyester fibers to impart flame retardancy, reducing the amount of flame retardant required. Furthermore, the copolymer containing alkane segments and benzene rings participates in the polyester polycondensation reaction, increasing the number of freely moving alkane segments. This increases the irregularity of the polyester fiber structure, improving its toughness. Simultaneously, the freely moving alkane segments increase the entanglement of the phosphate ester with the polyester fiber backbone, allowing the phosphate ester to bind tightly to the backbone, further enhancing its flame retardancy. The specific selection of pentaerythritol phosphate with a cage-like structure increases its interaction with other substances and its compatibility with polyester fibers, resulting in a more uniform texture in the obtained polyester fibers.

[0034] 3. This invention modifies titanium dioxide to give it good dispersibility, allowing it to be evenly dispersed when blended with polyester resin. The resulting polyester fiber has good matting properties. In addition, the modified titanium dioxide has better compatibility with polyester resin, which also increases the UV resistance of the polyester fiber. Furthermore, the addition of silane coupling agent helps to reduce surface tension, and it tends to migrate to the surface when heated. During combustion, the organosilicon dehydrates to form layered silica, which can increase the anti-dripping properties of the polyester fiber. Detailed Implementation

[0035] The present invention will be described below with reference to specific embodiments. It should be noted that the examples and comparative examples below are for illustrative purposes only and are not intended to limit the invention. Other combinations and various modifications within the scope of the invention can be made without departing from its spirit or scope.

[0036] To facilitate implementation of this invention by those skilled in the art, some raw materials and manufacturers of the embodiments and comparative examples are described below:

[0037] The compounds and related reagents used in the following examples and comparative examples are all commercially available. The titanium dioxide was purchased from Shanghai Maoguo Nanotechnology Co., Ltd., and the particle size was 20 nm.

[0038] Preparation Example 1

[0039] The preparation method of modified polyester resin-1 includes the following steps:

[0040] (1) 16g of pentaerythritol phosphate, 10g of maleic anhydride, and 0.2g of 75wt% phosphoric acid solution were added to 100ml of dichloromethane and reacted at 75℃ for 5.5h. The mixture was then rotary evaporated and dried to obtain the compound. 20g of the obtained compound, 10g of 4-vinylbenzoic acid, and 1g of azobisisobutyronitrile were added to 1000g of anhydrous methanol and reacted at 75℃ for 1h to obtain a copolymer with a number average molecular weight of 367.

[0041] (2) Add 10g terephthalic acid, 3g ethylene glycol, 0.1g antimony glycolate and 0.1g triphenyl phosphate to the first reaction vessel, remove the air in the reaction vessel, and react at 240℃ and 0.3MPa. When the water output reaches 87% of the theoretical value, add 6g polyethylene glycol-600 under normal pressure and react at normal pressure for 60min. When the water output reaches 98% of the theoretical value, stop the reaction and obtain the reaction solution.

[0042] (3) 10g of the reaction liquid obtained in step (2) is transported to the second reactor. The temperature reaches 245℃. While stirring, 1.5g of the copolymer obtained in step (1) is added. The pressure inside the reactor is reduced to -0.1KPa within 50min. The temperature inside the reactor is controlled at 280℃. The reaction is carried out for 1.5h. Then the pressure inside the reactor is increased to 46Pa. The reaction time is 4.5h. The material is discharged, granulated, and dried to obtain modified polyester resin-1.

[0043] Preparation Example 2

[0044] The preparation method of modified polyester resin-2 is the same as that of preparation example 1, except that the amount of pentaerythritol phosphate added in step (1) is 20g.

[0045] Preparation Example 3

[0046] The preparation method of modified polyester resin-3 is the same as that of preparation example 1, except that the amount of compound added in step (1) is 15g.

[0047] Preparation Example 4

[0048] The preparation method of modified polyester resin-4 is the same as that of preparation example 1, except that the amount of polyethylene glycol added in step (2) is 3g.

[0049] Preparation Example 5

[0050] The preparation method of modified polyester resin-5 is the same as that of preparation example 1, except that the amount of copolymer added in step (3) is 3g.

[0051] Preparation Example 6

[0052] The preparation method of polyester resin includes the following steps:

[0053] (1) 16g of pentaerythritol phosphate, 10g of maleic anhydride, and 75wt% phosphoric acid solution were added to 100ml of dichloromethane and reacted at 75℃ for 5.5h. The mixture was then rotary evaporated and dried to obtain the compound. 20g of the obtained compound, 10g of 4-vinylbenzoic acid, and 1g of azobisisobutyronitrile were added to 1000g of anhydrous methanol and reacted at 75℃ for 1h to obtain a copolymer with a number average molecular weight of 367.

[0054] (2) Add 10g terephthalic acid, 3g ethylene glycol, 0.1g antimony glycolate and 0.1g triphenyl phosphate to the first reaction vessel, remove the air in the reaction vessel, and react at 240℃ and 0.3MPa. When the water output reaches 87% of the theoretical value, add 6g polyethylene glycol-600 under normal pressure and react at normal pressure for 60min. When the water output reaches 98% of the theoretical value, stop the reaction and obtain the reaction solution.

[0055] (3) 10g of the reaction liquid obtained in step (2) is transported to the second reactor. The temperature reaches 245℃. The pressure inside the reactor is reduced to -0.1Kpa within 50min. The temperature inside the reactor is controlled at 280℃. The reaction is carried out for 1.5h. Then the pressure inside the reactor is increased to 46Pa. The reaction time is 4.5h. The material is discharged, granulated, and dried to obtain polyester resin.

[0056] Preparation Example 7

[0057] The preparation method of modified titanium dioxide-1 includes the following steps:

[0058] 1) Add 10g of 2-hydroxy-4-(methacryloyloxy)benzophenone, 7.5g of 10-hydroxy-2-decenoic acid, and 0.1g of azobisisobutyronitrile to 100ml of anhydrous methanol and stir at 75℃ for 7.5h to obtain a prepolymer with a number average molecular weight of 587.

[0059] 2) Add 10g of titanium dioxide and 6g of γ-methacryloxypropyltrimethoxysilane to 300g of anhydrous ethanol, stir at 55℃ for 3.5h, then add 7g of the prepolymer obtained in step 1), stir at 75℃ for 1.5h to obtain modified titanium dioxide-1.

[0060] Preparation Example 8

[0061] The preparation method of modified titanium dioxide-2 is the same as that in preparation example 7, except that the amount of 10-hydroxy-2-decenoic acid added in step 1) is 9g.

[0062] Preparation Example 9

[0063] The preparation method of modified titanium dioxide-3 is the same as that in preparation example 7, except that the amount of prepolymer added in step 2) is 10g.

[0064] Example 1

[0065] A titanium-based flame-retardant polyester fiber, by weight, comprises the following raw materials: 100 parts of modified polyester resin-1, 0.8 parts of modified titanium dioxide-1, 1 part of tricresyl phosphate, and 0.8 parts of antioxidant 1010.

[0066] The preparation method of titanium-based flame-retardant polyester fiber in this embodiment includes the following steps:

[0067] S1. Add modified polyester resin-1, modified titanium dioxide-1, tricresyl phosphate, and antioxidant 1010 to a mixer and stir for 25 minutes to obtain a mixture.

[0068] S2. The mixture obtained in step S1 is added to a twin-screw extruder for extrusion. The feed speed of the twin-screw extruder is 600 rpm and the extrusion temperature is 245℃. Then, melt spinning is performed, with the spinning metering pump supply controlled at 750 g / min, the spinning temperature at 280℃, and the spinning speed at 850 m / min. After that, the drawing process is performed with a drawing ratio of 2 times and a winding speed of 700 m / min to obtain titanium-based flame-retardant polyester fiber.

[0069] Example 2

[0070] A titanium-based flame-retardant polyester fiber, by weight, comprises the following raw materials: 95 parts of modified polyester resin-1, 0.5 parts of modified titanium dioxide-1, 0.5 parts of tricresyl phosphate, and 0.5 parts of antioxidant 1010.

[0071] The preparation method of titanium-based flame-retardant polyester fiber in this embodiment includes the following steps:

[0072] S1. Add modified polyester resin-1, modified titanium dioxide-1, tricresyl phosphate, and antioxidant 1010 to a mixer and stir for 20 minutes to obtain a mixture.

[0073] S2. The mixture obtained in step S1 is added to a twin-screw extruder for extrusion. The feed speed of the twin-screw extruder is 550 rpm, the extrusion temperature is 240℃, and then melt spinning is performed. The feed rate of the spinning metering pump is controlled at 700 g / min, the spinning temperature is 275℃, and the spinning speed is 840 m / min. Then, the drawing process is performed with a drawing ratio of 1.5 times and a winding speed of 650 m / min to obtain titanium-based flame-retardant polyester fiber.

[0074] Example 3

[0075] A titanium-based flame-retardant polyester fiber, by weight, comprises the following raw materials: 110 parts of modified polyester resin-1, 1 part of modified titanium dioxide-1, 1.5 parts of tricresyl phosphate, and 1 part of antioxidant 1010.

[0076] The preparation method of titanium-based flame-retardant polyester fiber in this embodiment includes the following steps:

[0077] S1. Add modified polyester resin-1, modified titanium dioxide-1, tricresyl phosphate, and antioxidant 1010 to a mixer and stir for 30 minutes to obtain a mixture.

[0078] S2. The mixture obtained in step S1 is added to a twin-screw extruder for extrusion. The feed speed of the twin-screw extruder is 650 rpm, the extrusion temperature is 250℃, and then melt spinning is performed. The feed rate of the spinning metering pump is controlled at 800 g / min, the spinning temperature is 285℃, and the spinning speed is 860 m / min. Then, the drawing process is performed with a drawing ratio of 2.5 times and a winding speed of 750 m / min to obtain titanium-based flame-retardant polyester fiber.

[0079] Example 4

[0080] A titanium-based flame-retardant polyester fiber and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified polyester resin-1 is replaced with modified polyester resin-2 in an equal amount.

[0081] Example 5

[0082] A titanium-based flame-retardant polyester fiber and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified polyester resin-1 is replaced with modified polyester resin-3 in an equal amount.

[0083] Example 6

[0084] A titanium-based flame-retardant polyester fiber and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified polyester resin-1 is replaced with modified polyester resin-4 in equal amounts.

[0085] Example 7

[0086] A titanium-based flame-retardant polyester fiber and its preparation method are described. The specific implementation method is the same as that in Example 1, except that modified polyester resin-1 is replaced with modified polyester resin-5 in equal amounts.

[0087] Example 8

[0088] A titanium-based flame-retardant polyester fiber and its preparation method are described. The specific implementation method is the same as that in Example 1, except that modified titanium dioxide-1 is replaced with modified titanium dioxide-2 in equal amounts.

[0089] Example 9

[0090] A titanium-based flame-retardant polyester fiber and its preparation method are described. The specific implementation method is the same as that in Example 1, except that modified titanium dioxide-1 is replaced with modified titanium dioxide-3 in equal amounts.

[0091] Comparative Example 1

[0092] A titanium-based flame-retardant polyester fiber and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the modified polyester resin-1 is replaced with an equal amount of polyester resin.

[0093] Comparative Example 2

[0094] A titanium-based flame-retardant polyester fiber and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified titanium dioxide-1 is replaced with an equal amount of titanium dioxide.

[0095] Performance testing

[0096] 1. Mechanical properties

[0097] The mechanical properties of the titanium-based flame-retardant polyester fibers prepared in the above embodiments and comparative examples were tested using a multifilament tensile tester with a pre-tension of 3cN, a stretching speed of 200mm / min, and a clamping distance of 200mm.

[0098] 2. Flame retardancy

[0099] Using a high-temperature oxygen index tester, the polyester fibers obtained in each embodiment and comparative example were wound 40m of fiber on a yarn length measuring instrument, twisted with a twist number of 130±20, folded in half along the middle to form a strand, and fixed at the end. The limiting oxygen index was tested in accordance with the "Test Method for Flame Retardant Properties of Polyester Fibers - Oxygen Index Method FZT 50017-2001".

[0100] 3. Extinction properties

[0101] Using barium sulfate as a reference sample, the diffuse reflectance signals of visible light obtained from the polyester fibers in each embodiment and comparative example were collected using an integrating sphere attachment. The greater the diffuse reflectance of visible light, the better the extinction performance.

[0102] The experimental results are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] Comparison of experimental data from Examples 1-3 in Table 1 shows that the polyester fiber exhibits good mechanical properties, flame retardancy, and matting properties. Comparison of Example 4 with Example 1 shows that the change in the ratio of pentaerythritol phosphate to maleic anhydride in modified polyester resin-2 may reduce the active groups of the copolymer, affecting the formation of the polyester resin and leading to a decrease in the mechanical properties of the polyester fiber. Comparison of Example 5 with Example 1 shows that the change in the ratio of the compound to 4-vinylbenzoic acid in modified polyester resin-3 may reduce the number of phosphate esters, leading to a decrease in the mechanical properties and flame retardancy of the polyester fiber. Comparison of Example 6 with Example 1 shows that the change in the ratio of terephthalic acid, ethylene glycol, and polyethylene glycol in modified polyester resin-4 may lead to a decrease in the processability of the polyester fiber, resulting in a decrease in all properties. Comparison of Example 7 with Example 1 shows that the modified polyester... The change in the ratio of reaction solution to copolymer in Resin-5 may be due to excessive irregularity of polyester resin, leading to a decrease in the mechanical properties of polyester fiber. A comparison of Example 8 and Example 1 shows that the change in the ratio of 2-hydroxy-4-(methacryloyloxy)benzophenone to 10-hydroxy-2-decenoic acid in modified titanium dioxide-2 may lead to a decrease in the compatibility between modified titanium dioxide and polyester resin, resulting in a decrease in both the mechanical properties and matting properties of the polyester resin. A comparison of Example 9 and Example 1 shows that the change in the ratio of titanium dioxide, silane coupling agent, and prepolymer in modified titanium dioxide-3 leads to a decrease in the matting properties of polyester fiber. A comparison of Comparative Example 1 and Example 1 shows that using unmodified polyester resin results in a decrease in both mechanical properties and flame retardancy. A comparison of Comparative Example 2 and Example 1 shows that using unmodified titanium dioxide results in a decrease in the mechanical properties of polyester fiber.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A titanium-based flame-retardant polyester fiber, characterized by, By weight, comprising the following raw materials: modified polyester resin 95-110 parts, modified titanium dioxide 0.5-1 parts, flame retardant 0.5-1.5 parts, antioxidant 0.5-1 parts; the preparation method of the modified polyester resin, comprising the following steps: (1) the pentaerythritol phosphate and maleic anhydride, phosphoric acid is added to dichloromethane, reaction at 70-80℃ for 5-6h, rotary evaporation, drying to obtain the compound; the compound obtained with 4-vinyl benzoic acid, azobisisobutyronitrile is added to methanol, reaction at 70-80℃ for 0.5-1.5h, to obtain the number average molecular weight of 300-400 copolymer; (2) terephthalic acid, ethylene glycol, catalyst, thermal stabilizer is added to the first reactor, remove the air in the reactor, at 235-245℃, 0.2-0.4MPa reaction, when the water output reaches 85-90% of the theoretical value, under normal pressure, polyethylene glycol is added, under normal pressure reaction for 50-70min, when the water output reaches 95-99% of the theoretical value, the reaction is finished, to obtain the reaction liquid; (3) the reaction liquid obtained in step (2) is transported to the second reactor, the temperature reaches 240-250℃, step (1) is added to the copolymer, the pressure in the kettle is extracted to-0.1KPa~1KPa within 45-55min, the kettle temperature is controlled at 275-285℃, reaction for 1-2h, then the kettle pressure reaches 40-50Pa, the reaction time is 4-5h, discharge, granulation, drying, to obtain the modified polyester resin; The mass ratio of pentaerythritol phosphate and maleic anhydride in step (1) is (1.5-1.8):1; The mass ratio of compound and 4-vinyl benzoic acid in step (1) is (1.8-2.1):1; The mass ratio of terephthalic acid, ethylene glycol and polyethylene glycol in step (2) is 1:(0.2-0.4):(0.5-0.7); The mass ratio of reaction liquid and copolymer in step (3) is 1:(0.1-0.2).

2. The titanium-based flame retardant polyester fiber according to claim 1, characterized by, The preparation method of the modified titanium dioxide, comprising the following steps: 1) 2-hydroxy-4-(methacryloyloxy) benzophenone, 10-hydroxy-2-decenoic acid, azobisisobutyronitrile is added to methanol, 70-80℃ stirring reaction for 7-8h, to obtain the number average molecular weight of 500-600 prepolymer; 2) titanium dioxide, silane coupling agent is added to ethanol, stirring at 50-60℃ for 3-4h, then the prepolymer obtained in step 1) is added, stirring at 70-80℃ for 1-2h, to obtain the modified titanium dioxide.

3. The titanium-based flame-retardant polyester fiber according to claim 2, characterized by, The mass ratio of 2-hydroxy-4-(methacryloyloxy) benzophenone and 10-hydroxy-2-decenoic acid in step 1) is 1:(0.66-0.80).

4. The titanium-based flame retardant polyester fiber according to claim 2, characterized by, The mass ratio of titanium dioxide, silane coupling agent and prepolymer in step 2) is 1:(0.5-0.7):(0.6-0.8).

5. A process for the production of the titanium-based flame-retardant polyester fiber as claimed in any one of claims 1 to 4, characterized by, Comprising the following steps: S1, the modified polyester resin, modified titanium dioxide, flame retardant, antioxidant is added to the mixer, stirring for 20-30min, to obtain the mixture; S2, the mixture obtained in step S1 is added into a double screw extruder for extrusion, the feeding rotation speed of the double screw extruder is 550-650 rpm, the extrusion temperature is 240-250 ℃, then melt spinning is carried out, the control of the spinning metering pump supply is 700-800 g / min, the spinning temperature is 275-285 ℃, the spinning speed is 840-860 m / min, then drawing processing is carried out, the drawing multiple is 1.5-2.5 times, the winding speed is 650-750 m / min, and titanium-based flame-retardant polyester fiber is obtained.

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