Polyester fiber as well as preparation method and application thereof

Abstract

The invention discloses a polyester fiber as well as a preparation method and application thereof, and relates to the technical field of fiber materials. The preparation raw materials of the polyester fiber comprise waste polyester and a silicon dioxide component dispersed by polyethylene glycol. According to the polyester fiber, a polyethylene glycol dispersed silicon dioxide component is introduced into the waste polyester, the mechanical property is improved, the obtained polyester fiber can realize normal-pressure boiling dyeing, has the advantages of easiness in normal-pressure dyeing of disperse dye, high dye uptake and high color fastness, and can realize rapid dyeing at 90-100 DEG C, the dye uptake is not lower than 92%, and the polyester fiber has the advantages of high color fastness, low cost and the like. The method is especially suitable for preparing textiles, such as clothes and household textiles.

Description

Technical Field

[0001] The invention relates to the technical field of fiber materials, and in particular to a polyester fiber and a preparation method and application thereof. Background Art

[0002] Polyester is an important variety of synthetic polymers, and polyester fiber prepared from polyester is an important basic raw material for textiles. However, a large amount of waste silk is inevitably produced during the production process of polyester fiber. These waste silks are fluffy in volume, which brings inconvenience to transportation and utilization. Generally, the production waste silk is processed into foam materials or friction materials and then sold. However, how to reuse the waste silk at a high level is still an industrial difficulty.

[0003] From the perspective of the schemes disclosed in the prior art, there are currently two main methods for recycling polyester fiber waste: physical method, chemical method and semi-chemical method. Among them, the physical method is to use waste polyester as part of the raw material, and blend it with high-viscosity polyester bottle flakes or virgin polyester to make up for the defects of low molecular weight and easy thermal degradation of waste polyester itself, but the fibers obtained by this method are mainly used for spinning short fibers, the quality indicators of the products are limited and the added value of the products is also low; the chemical method of recycling and reuse is to deeply depolymerize the waste polyester in a small molecule depolymerizer into monomers or other types of small molecules, and then re-esterify and polycondense after purification. This method has a long process, complex process, high actual operating cost, and is difficult to promote. In addition, the solvent used in the purification process has strong polarity, low boiling point, and high cost, and cannot be applied in industry; the semi-chemical recycling method is between physical recycling and chemical recycling. By introducing a chain extender into the waste polyester melt for viscosity increase, although the molecular weight can be increased, the increase in molecular weight based on the chain extension reaction will lead to a widening of the molecular weight distribution after viscosity increase, and a decrease in melt spinning performance. Summary of the invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the object of the present invention is to provide a polyester fiber, in which polyethylene glycol-dispersed silica is introduced into waste polyester to improve the mechanical properties, dye uptake and color fastness of the polyester fiber.

[0005] The second aspect of the present invention is to provide a method for preparing polyester fiber.

[0006] A third aspect of the present invention is to provide a textile product.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A first aspect of the present invention provides a polyester fiber, wherein the raw materials for preparing the polyester fiber include waste polyester and a silicon dioxide component dispersed in polyethylene glycol.

[0009] The invention introduces organic and inorganic components into the waste polyester in situ by mixing the waste polyester with the silicon dioxide component dispersed by polyethylene glycol, wherein the polyethylene glycol, as a component reacting with the waste polyester, also plays a role as a silicon dioxide dispersant, and the silicon dioxide thickens the polyethylene glycol, thereby facilitating production.

[0010] In the process of preparing polyester fiber, the polyethylene glycol-rich hydroxyl groups of the polyethylene glycol-dispersed silica component react with the terminal carboxyl groups of the waste polyester. Since the number of hydroxyl functional groups is originally higher than the number of carboxyl groups, the carboxyl functional groups of the waste polyester can be quickly converted into a hydroxyl-terminated structure, thereby inhibiting the thermal degradation process. At the same time, the introduced silica also catalyzes the reaction between the hydroxyl group and the carboxyl group.

[0011] Polyethylene glycol is introduced into the polyester main chain in a chemically combined manner, and its own crystallization performance and thermal temperature will be affected. The silicon dioxide introduced synchronously in the present invention plays a role of heterogeneous nucleation, ensuring that the crystallization performance and thermal performance do not decrease after the polyethylene glycol is copolymerized into the polyester. Polyethylene glycol is distributed in the amorphous region of the polyester, increasing the amorphous region content of the fiber, and can make the final spun fiber disperse dye easier to dye. Compared with the high energy consumption problem caused by the high temperature and high pressure conditions required for conventional polyester fiber disperse dye dyeing, the present invention can achieve normal pressure boiling dyeing, that is, it can be quickly dyed under 90-100°C. At the same time, silicon dioxide refines the grain size of the crystalline region and the size of the amorphous region structure, acts as a physical "rivet" in the amorphous region, limits the movement of the amorphous region chain segment, and to a certain extent suppresses the problem of the glass transition temperature of the polyester falling due to the introduction of polyethylene glycol, so that the dyes enriched in the amorphous region are not easy to migrate out, ensuring the requirements of high color fastness.

[0012] Preferably, the polyethylene glycol is liquid at room temperature.

[0013] Preferably, in the polyethylene glycol-dispersed silicon dioxide component, the mass ratio of polyethylene glycol to silicon dioxide is (9-99):1.

[0014] Preferably, in the polyethylene glycol-dispersed silicon dioxide component, the mass ratio of polyethylene glycol to silicon dioxide is (90-99):(10-1).

[0015] Preferably, the addition amount of the polyethylene glycol dispersed silicon dioxide component is 3 to 25 wt % of the mass of the waste polyester.

[0016] More preferably, the addition amount of the polyethylene glycol dispersed silicon dioxide component is 5 to 20 wt % of the mass of the waste polyester.

[0017] More preferably, the added amount of the polyethylene glycol dispersed silicon dioxide component is 10 to 20 wt % of the mass of the waste polyester.

[0018] Preferably, the number average molecular weight of the polyethylene glycol is 1000-4000 g / mol.

[0019] More preferably, the number average molecular weight of the polyethylene glycol is 1000-2000 g / mol.

[0020] Preferably, the average particle size of the polyethylene glycol is 50 to 150 nm.

[0021] More preferably, the average particle size of the polyethylene glycol is 90 to 110 nm.

[0022] The size of silica is nanometer, which is more favorable for catalyzing the reaction between hydroxyl and carboxyl groups.

[0023] Preferably, the polyethylene glycol dispersed silicon dioxide component is a polyethylene glycol dispersed silicon dioxide slurry.

[0024] Polyethylene glycol-dispersed silica is added in the form of slurry during production, which can solve the problem that silica particles are small and difficult to disperse.

[0025] More preferably, the polyethylene glycol dispersed silica slurry is prepared by a method comprising the following steps:

[0026] The polyethylene glycol is heated to 80-100°C and silicon dioxide is added under stirring.

[0027] More preferably, the stirring rate is 10 to 50 r / min; and the stirring time is 20 to 40 min.

[0028] Preferably, the waste polyester satisfies at least one of the following (a) to (d):

[0029] (a) the number average molecular weight of the waste polyester is 10000 to 20000 g / mol;

[0030] (b) the waste polyester has an intrinsic viscosity of 0.5 to 0.7 dL / g at 25°C;

[0031] (c) the terminal carboxyl content of the waste polyester is 8 to 20 mol / t;

[0032] (d) The waste polyester includes waste polyester foam or friction material; the waste polyester foam or friction material is processed from waste silk generated in the production of polyester fibers.

[0033] More preferably, the number average molecular weight of the waste polyester is 12000-20000 g / mol.

[0034] More preferably, the number average molecular weight of the waste polyester is 16000-20000 g / mol.

[0035] More preferably, the waste polyester has an intrinsic viscosity of 0.6 to 0.7 dL / g at 25°C.

[0036] More preferably, the waste polyester has an intrinsic viscosity of 0.6 to 0.65 dL / g at 25°C.

[0037] More preferably, the terminal carboxyl content of the waste polyester is 10 to 20 mol / t.

[0038] More preferably, the terminal carboxyl content of the waste polyester is 10 to 17 mol / t.

[0039] The characteristic viscosity of polyester chips used for conventional fibers is above 0.65dL / g, and the terminal carboxyl content is within 30mol / t (generally 5-30mol / t). During melt spinning, the viscosity will decrease and the terminal carboxyl content will increase due to heat, shear and other effects. This change is not conducive to the reuse of waste silk. In the process of making waste polyester into foam or friction material, the viscosity will further decrease and the terminal carboxyl content will further increase, which can reach more than 100mol / t. The low viscosity of waste polyester is not conducive to the mechanical properties of polyester fiber after forming, and the increase in the terminal carboxyl content will significantly deteriorate the color of the melt and aggravate the reduction of molecular weight. The present invention uses waste polyester with low viscosity and high terminal carboxyl content as raw material, introduces polyethylene glycol dispersed silica to react, inhibits the thermal degradation process, improves the performance of the obtained polyester fiber, and realizes the high-value reuse of waste polyester.

[0040] Preferably, the L value of the waste polyester is ≥80; and the b value of the waste polyester is ≤6.

[0041] More preferably, the waste polyester foam material or friction material is obtained by mechanical processing of waste fibers generated in the production of polyester fibers.

[0042] The existing technologies for utilizing foam or friction materials formed from waste fibers in polyester fiber production focus on mixing them into raw materials of better quality in a certain proportion to make up for their own deficiencies, or deeply depolymerizing them into repolymerized monomers, etc. These recycling methods have problems such as reduced quality or high costs caused by long chemical processes.

[0043] The present invention is based on the characteristics of the foam material or friction material formed by polyester fiber waste, fully considering its molecular weight and molecular chain functional groups, taking it as the main body, introducing organic and inorganic components in situ for modification, and forming a high value-added functional polyester fiber raw material. The waste silk formed in the production process of polyester fiber is heated and melted, resulting in a decrease in molecular weight, while its reactive activity is also improved to a certain extent. The present invention makes full use of this feature to use waste polyester and polyethylene glycol-dispersed silica to prepare polyester fiber, without deep depolymerization and repolymerization, which not only avoids the problem of quality degradation during reuse, but also further improves its added value of reuse, realizing high-value reuse of waste resources.

[0044] Preferably, the preparation raw material further comprises an auxiliary agent; the added mass of the auxiliary agent relative to the waste polyester is 100 to 500 ppm.

[0045] More preferably, the additive is added in an amount of 100 to 200 ppm relative to the waste polyester.

[0046] Preferably, the auxiliary agent includes an antioxidant.

[0047] Preferably, the polyester fiber can be colored with disperse dyes at 90-100° C.; the fiber strength of the polyester fiber is ≥3.5 cN / dtex; the dye uptake rate of the polyester fiber is ≥92%; and the color fastness of the polyester fiber is ≥level 4.

[0048] The second aspect of the present invention provides a method for preparing the polyester fiber according to the first aspect of the present invention, comprising the following steps:

[0049] The components are blended and extruded under vacuum suction conditions to obtain polyester chips; solid phase viscosity enhancement and melt spinning are performed to obtain the polyester fibers.

[0050] The preparation method of the invention introduces organic and inorganic components (polyethylene glycol dispersed silicon dioxide) into waste polyester in situ to prepare modified polyester chips, and then obtains polyester fibers with disperse dyes that are easy to dye at normal pressure and high color fastness through melt spinning.

[0051] Preferably, the extrusion is carried out in a twin-screw extruder.

[0052] More preferably, the twin-screw extruder comprises a vacuum suction device.

[0053] More preferably, the preparation method comprises the following steps:

[0054] The components are mixed, added into a twin-screw extruder with a vacuum suction device, blended under vacuum suction, and extruded through a twin-screw extruder to obtain low-viscosity polyester chips; solid phase viscosity enhancement is performed to obtain high-viscosity polyester chips; and melt spinning is performed to obtain the polyester fiber.

[0055] Preferably, the vacuum suction pressure is 500-1000Pa.

[0056] More preferably, the vacuum suction pressure is 900-1000Pa.

[0057] Preferably, the blending temperature is 250-280° C. and the blending time is 60-180 s.

[0058] More preferably, the blending temperature is 270-280° C. and the blending time is 160-180 s.

[0059] Preferably, the temperature of the solid phase thickening is 200-230° C.; the time of the solid phase thickening is 10-15 hours.

[0060] More preferably, the temperature of the solid phase thickening is 220-230° C.; the time of the solid phase thickening is 14-15 hours.

[0061] Preferably, the vacuum degree of the solid phase thickening is 0-50Pa, more preferably 40-50Pa.

[0062] Preferably, the intrinsic viscosity of the polyester chips at 25° C. is 0.3-0.5 dL / g.

[0063] More preferably, the intrinsic viscosity of the polyester chips at 25° C. is 0.3 to 0.4 dL / g.

[0064] Preferably, the number average molecular weight of the polyester chips after solid phase viscosity enhancement is 24000-32000 g / mol.

[0065] More preferably, the number average molecular weight of the polyester chips after solid phase viscosity enhancement is 30,000 to 32,000 g / mol.

[0066] Preferably, the PDI of the polyester chips after solid phase viscosity enhancement is 2-3.

[0067] More preferably, the PDI of the polyester chips after solid phase viscosity enhancement is 2.2 to 2.5.

[0068] Preferably, the melt spinning temperature is 280-290°C.

[0069] In the preparation method of the present invention, the waste polyester and the silicon dioxide component dispersed by polyethylene glycol are homogeneously mixed during the blending process, and the combination of polyethylene glycol and polyester chemical bonds can be further improved by vacuum suction without phase separation. The properties of the extruded low-viscosity polyester slices can be changed by regulating the number average molecular weight, addition amount and silicon dioxide content of polyethylene glycol. Solid phase thickening is carried out below the melting point of the low-viscosity polyester slices. Compared with the liquid phase thickening reaction, the molecular weight distribution is more concentrated, which is conducive to spinning and improving the strength of the fiber. At the same time, solid phase thickening ensures that the yellowing degree of the slices after thickening is controlled.

[0070] The third aspect of the present invention provides a textile, wherein the raw materials for preparing the textile include the polyester fiber described in the first aspect of the present invention or the polyester fiber obtained by the preparation method described in the second aspect of the present invention.

[0071] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0072] (1) In the polyester fiber of the present invention, waste polyester is recycled in a high-value manner, and a polyethylene glycol-dispersed silica component is introduced to achieve synergistic effect and improve the mechanical properties of the polyester fiber. Not only is the processability of the recycled waste polyester and the quality of the product improved, but the obtained polyester fiber can also be dyed at normal pressure, and has the advantages of easy dyeing with disperse dyes at normal pressure, high dyeing rate, and high color fastness. Compared with the conventional high-temperature and high-pressure dyeing process of polyester fibers, the energy consumption and material consumption are significantly reduced, which is in line with the concept of green and low-carbon development.

[0073] (2) The preparation method of the present invention makes full use of the characteristics of waste polyester, especially waste polyester foam or friction material, which has low molecular weight but enhanced reactivity, avoiding low-value recycling, and realizes chemical bond between polyethylene glycol and polyester in the preparation process, avoiding phase separation, and improving the quality of polyester fiber products. The preparation method of the present invention has a short process, and the equipment used is all industrial equipment, without the need to add additional equipment, and has strong operability and is easy to promote.

[0074] (3) The polyester fiber of the present invention has the advantages of being easy to dye with disperse dyes under normal pressure, having a high dye uptake rate and high color fastness, and can be quickly dyed at 90 to 100° C., with a dye uptake rate of not less than 92%. It is particularly suitable for preparing textiles, such as clothing, household textiles, etc. DETAILED DESCRIPTION

[0075] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0076] Some of the raw materials used in the following examples and comparative examples of the present invention are described as follows:

[0077] The waste polyester is waste polyester foam, and the preparation method comprises the following steps: using oil-free waste silk formed in the production of polyester fibers as raw materials, and preparing the waste polyester foam by conventional mechanical processing; the obtained waste polyester foam has an L value of ≥80 and a b value of ≤6.

[0078] The preparation method of polyethylene glycol dispersed silicon dioxide slurry comprises the following steps: heating polyethylene glycol to 95° C. in a stirring and heating device, slowly adding silicon dioxide powder at a stirring rate of 35 r / min, and controlling the stirring time to 30 min.

[0079] Example 1

[0080] This embodiment provides a polyester fiber, including waste polyester, polyethylene glycol dispersed silica slurry and antioxidant 1010. The parameters and dosage of each component are shown in Table 1, where the dosage is based on 100 parts by mass of the waste polyester.

[0081] The preparation method of the polyester fiber of this embodiment refers to the following steps:

[0082] The dried waste polyester foam or friction material, the silica slurry dispersed with polyethylene glycol and the antioxidant 1010 are mixed according to the proportions in Table 1, added into a twin-screw extruder with a vacuum suction device, and extruded after vacuum suction processing for 180 seconds under the conditions of a blending temperature of 275° C. and a suction pressure of 1000 Pa to obtain the corresponding low-viscosity polyester chips; the obtained low-viscosity polyester chips are solid-phase thickened for 15 hours under the conditions of 230° C. and 50 Pa to obtain high-viscosity polyester chips; the high-viscosity polyester chips are melt-spun at 288° C. to prepare polyester fibers.

[0083] The intrinsic viscosity of the low viscosity polyester chips and the molecular weight of the high viscosity polyester chips are shown in Table 2.

[0084] Embodiments 2 to 10

[0085] Examples 2 to 10 provide a polyester fiber. The differences from Example 1 are shown in Table 1. The preparation method is the same as that of Example 1.

[0086] Comparative Examples 1 to 3

[0087] Comparative Examples 1 to 3 provide a polyester fiber. The differences from Example 1 are shown in Table 1. The preparation method is the same as that of Example 1.

[0088] Table 1 Amounts of each component and parameters of polyester fiber in Examples and Comparative Examples

[0089]

[0090] In Table 1, the addition amounts of polyethylene glycol (PEG) dispersed silicon dioxide (SiO2) slurry and antioxidants are expressed as percentages by mass relative to the waste polyester.

[0091] Results

[0092] The property testing methods of the waste polyester, low-viscosity polyester chips and high-viscosity polyester chips in the above embodiments and comparative examples are as follows:

[0093] Intrinsic viscosity: Tested in accordance with GB / T 14190-2017.

[0094] Terminal carboxyl content: Tested in accordance with GB / T 14190-2017.

[0095] Lab value: Refer to GB / T 14190-2017 test.

[0096] PDI: The number average molecular weight and PDI (molecular weight distribution) of the samples were tested using a GPC-50 gel permeation chromatograph produced by PL Company of the United Kingdom. The equipment was equipped with a differential refractometer and a PL gel column (5μm mixed-C), with 1,1,1,3,3,3-hexafluoro-2-propanol as the eluent and a flow rate of 1mL / min. During the test, the sample was dried and dissolved in hexafluoroisopropanol to prepare a solution with a concentration of 1.0mg / mL. The test was carried out when the column temperature reached 40±1℃, and the number average molecular weight and the weight-average molecular weight leaving Mycobacterium tuberculosis were obtained. The calculation formula of PDI is: PDI=weight-average molecular weight / number-average molecular weight.

[0097] The test results of low viscosity polyester chips and high viscosity polyester chips are shown in Table 2.

[0098] The polyester fibers obtained in the above examples and comparative examples were tested for mechanical properties, and were dyed with disperse dyes at 100°C to test their dye uptake and color fastness. The test method is as follows:

[0099] Fiber mechanical strength: Tested in accordance with GB / T 14344-2022.

[0100] Dye uptake: Tested in accordance with GB / T 9337-2009.

[0101] Color fastness: Tested in accordance with GB / T 42223-2022.

[0102] The test results are shown in Table 3.

[0103] Table 2 Test results of low viscosity polyester chips and high viscosity polyester chips in the examples and comparative examples

[0104]

[0105]

[0106] Table 3 Test results of polyester fiber properties obtained in Examples and Comparative Examples

[0107] Fiber mechanical properties (cN / dtex) Dyeing rate (%) Color fastness (grade) Example 1 3.5 93 4.5 Example 2 3.6 93 4.5 Example 3 3.7 93 4.5 Example 4 3.8 93 4.5 Example 5 4.0 94 4.5 Example 6 4.2 96 5.0 Example 7 4.3 97 5.0 Example 8 4.5 92 4.5 Example 9 4.5 92 4.5 Example 10 4.4 92 4.5 Comparative Example 1 4.0 93 3.0 Comparative Example 2 3.8 45 3.0 Comparative Example 3 4.3 45 3.5

[0108] It can be seen from Table 2 and Table 3 that the polyester fiber of the present invention has excellent mechanical properties, dye uptake and color fastness, with a fiber strength of not less than 3.5 cN / dtex, a dye uptake of not less than 92%, and a color fastness of not less than Grade 4. In Comparative Example 1, since no silicon dioxide is added, the silicon dioxide lacks the effect of regulating the crystallization and thermal properties of the polyethylene glycol copolymerized into the polyester, and the inhibitory effect on the migration of the dye in the amorphous region is reduced, and the color fastness is reduced; in Comparative Examples 2 and 3, no silicon dioxide component dispersed with polyethylene glycol is added or the component lacks polyethylene glycol, and the dye uptake of the obtained polyester fiber is greatly reduced to only 45%, and the color fastness is also reduced to below Grade 4.

[0109] By comparing Examples 1 to 3, Examples 4 to 7, and Examples 8 to 10, it can be seen that changes in the molecular weight, intrinsic viscosity, terminal carboxyl content in the waste polyester, and changes in the mass ratio of polyethylene glycol to silica will lead to changes in the intrinsic viscosity of the low-viscosity polyester chips and the molecular weight and molecular weight distribution of the high-viscosity polyester chips. This change will affect the fiber strength of the polyester fiber, thereby affecting the application scenario or service life of the polyester fiber; the addition amount of polyethylene glycol-dispersed silica slurry will affect the mechanical properties, dye uptake and color fastness of the polyester fiber.

[0110] In summary, the polyester fiber of the present invention introduces a polyethylene glycol-dispersed silica component into waste polyester, thereby improving mechanical properties, and the obtained polyester fiber can be dyed at normal pressure, has the advantages of easy dyeing with disperse dyes at normal pressure, high dyeing rate, and high color fastness, can be dyed quickly at 90-100° C., and the dyeing rate is not less than 92%, and is particularly suitable for preparing textiles, such as clothing, household textiles, etc. At the same time, the preparation method of the polyester fiber has a short process, and the equipment used is all industrial equipment, no additional equipment is required, and the operability is strong and easy to promote.

[0111] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A polyester fiber, characterized in that: The raw materials for preparing the polyester fiber include waste polyester and a silicon dioxide component dispersed in polyethylene glycol.

2. The polyester fiber according to claim 1, characterized in that In the polyethylene glycol-dispersed silicon dioxide component, the mass ratio of polyethylene glycol to silicon dioxide is (9-99):

1.

3. The polyester fiber according to claim 1 or 2, characterized in that: The amount of the polyethylene glycol dispersed silicon dioxide component added is 3-25wt% of the mass of the waste polyester.

4. The polyester fiber according to claim 1 or 2, characterized in that: The number average molecular weight of the polyethylene glycol is 1000 to 4000 g / mol; And / or, the average particle size of the silicon dioxide is 50 to 150 nm.

5. The polyester fiber according to claim 1, characterized in that The waste polyester satisfies at least one of the following (a) to (d): (a) the number average molecular weight of the waste polyester is 10000 to 20000 g / mol; (b) the waste polyester has an intrinsic viscosity of 0.5 to 0.7 dL / g at 25°C; (c) the terminal carboxyl content of the waste polyester is 8 to 20 mol / t; (d) The waste polyester includes waste polyester foam or friction material; the waste polyester foam or friction material is processed from waste silk generated in the production of polyester fibers.

6. The polyester fiber according to claim 1, characterized in that The preparation raw material also includes an auxiliary agent; the added mass of the auxiliary agent relative to the waste polyester is 100 to 500 ppm; And / or, the auxiliary agent includes an antioxidant.

7. A method for preparing the polyester fiber according to any one of claims 1 to 6, characterized in that: The steps include: The components are blended and extruded under vacuum suction conditions to obtain polyester chips; solid phase viscosity enhancement and melt spinning are performed to obtain the polyester fibers.

8. The preparation method according to claim 7, characterized in that: The vacuum suction pressure is 500-1000 Pa; And / or, the blending temperature is 250-280°C; the blending time is 60-180s; And / or, the temperature of the solid phase thickening is 200-230° C.; the time of the solid phase thickening is 10-15 hours.

9. The preparation method according to claim 7 or 8, characterized in that: The intrinsic viscosity of the polyester chips at 25° C. is 0.3 to 0.5 dL / g; And / or, the number average molecular weight of the polyester chips after solid phase viscosity enhancement is 24000 to 32000 g / mol; And / or, the PDI of the polyester chips after solid phase viscosity enhancement is 2-3.

10. A textile, characterized in that: The preparation raw material includes the polyester fiber described in any one of claims 1 to 6 or the polyester fiber obtained by the preparation method described in any one of claims 7 to 9.

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