A modified polyester filament and its preparation method

Abstract

The present invention discloses a modified polyester filament, which comprises a modified polyester and a delustering agent. The modified polyester comprises a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment and a 5-amino-isophthalic acid bis-3-hydroxyethyl ester segment. The delustering agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. The modified polyester filament of the present invention introduces an inorganic mesoporous powder containing amino groups into the melt spinning system instead of the traditional delustering agent, which simultaneously plays the role of acetaldehyde scavenging and delustering, and is easy to realize industrial production. During the spinning process, the release of acetaldehyde vapor can be reduced, and the production environment can be improved. Another object of the present invention is to disclose a preparation method of the modified polyester filament. The preparation method of the present invention reduces the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process, reduces the content of acetaldehyde in the modified polyester filament, and is beneficial to the safety of its application.

Description

Technical Field

[0001] The present invention relates to the technical field of spinning production, and particularly relates to a modified polyester filament and a preparation method thereof. Background Art

[0002] Hot melt adhesive is a new type of adhesive that has been developed rapidly at home and abroad in recent years. Compared with other types of adhesives, hot melt adhesive has excellent properties such as short bonding time, high strength, non-toxicity and no pollution, and is known as the "green adhesive". In the past decade or more, hot melt adhesive has been widely used in the textile industry (such as adhesive interlining). The key to manufacturing high-quality adhesive interlining lies in having high-performance hot melt adhesive. Since copolyester-based hot melt adhesive is excellent in terms of hand feeling, price, and resistance to washing, sand washing, and steam pressing, it has a broader development prospect. Polyester-based hot melt adhesive is a new variety of hot melt adhesive developed in recent decades. It is a modified low-melting-point saturated copolyester, mostly prepared by copolymerizing two or more dibasic acids and diols, so as to greatly reduce its crystallinity, glass transition temperature and melting point to meet the special requirements of hot melt adhesive.

[0003] Thermally bondable low-melting-point fiber is one of the important raw materials for non-woven fabrics. According to statistics, it accounts for about 28% of the total fiber consumption of non-woven fabrics. In the current rapidly developing non-woven fabric industry, the thermal bonding method has been given priority development because of its processing method using fiber-type adhesives, which makes the processing simple, the production speed high, the energy consumption low, the operation flexible, the product free of any chemical reagents, non-polluting to the environment and harmless to the human body. The thermal bonding method is a reinforcement method that utilizes the thermoplasticity of polymer materials, applies a certain amount of heat to the polymer fiber materials, makes the polymer fiber materials partially soften and melt, and then makes the fibers bond to each other after cooling and solidification. For the polyester non-woven fabric industry, they need a polymer with a melting point lower than that of conventional polyester fibers and good compatibility with conventional polyester as the thermally bondable low-melting-point fiber. According to the "like dissolves like" principle, non-woven fabrics with polyester as the main fiber should be bonded with polyester fibers of the same family. Practice has shown that the bonding fibers spun from low-melting-point copolyester can make polyester flocs softer and fluffier, which provides a broad space for the application of polyester-based low-melting-point thermally bondable fibers.

[0004] However, a series of side reactions will occur during the esterification reaction of low-melting-point copolyester, generating many by-products. The by-product with the greatest impact is acetaldehyde, which can cause discomfort symptoms such as flushing, palpitations and blood pressure drop. At the same time, acetaldehyde can cause irritation symptoms in the eyes, nose and upper respiratory tract and bronchitis. Inhalation of high-concentration acetaldehyde has an anesthetic effect, and acetaldehyde poses a great harm to human health.

[0005] During the preparation of low-melting copolyester filaments, the involved cooling and stretching temperatures are both relatively low, and the time is short, so the acetaldehyde content of the fibers cannot be reduced below the safety value. Therefore, there is an urgent need for a new technical solution to solve at least one of the above technical problems. Summary of the Invention

[0006] In view of the above deficiencies, one object of the present invention is to provide a modified polyester filament. An inorganic mesoporous powder containing amino groups is introduced into the melt spinning system instead of the traditional matting agent, which can simultaneously play the role of acetaldehyde scavenging and matting, and is easy to realize industrial production. During the spinning process, the release of acetaldehyde vapor can be reduced, and the production environment can be improved. Another object of the present invention is to provide a preparation method of a modified polyester filament. By simply copolymerizing inorganic substances, a modified polyester with amino groups in the side chain is synthesized, which inhibits thermal oxidative degradation during polymerization and processing, inhibits the generation of acetaldehyde, reduces the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process, reduces the acetaldehyde content in the modified polyester filament, and is beneficial to the safety of its application.

[0007] In order to achieve the above technical objectives and meet the above technical requirements, the technical solution adopted by the present invention is:

[0008] A modified polyester filament, comprising a modified polyester and a matting agent. The modified polyester includes a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment, and a 5-aminoisophthalic acid bis-3-hydroxyethyl ester segment. The matting agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups.

[0009] As a preferred technical solution, the inorganic mesoporous powder is a mesoporous titanium dioxide powder. The pore diameter of the mesoporous titanium dioxide powder is 2nm - 4nm, the specific surface area is 100m 2 / g - 300m 2 / g, the particle size is 200nm - 300nm, and the content of the amino functional group is 1wt% - 3wt%.

[0010] As a preferred technical solution, the melting point of the modified polyester is 110°C - 150°C, and the molecular weight of the modified polyester is 18,000 - 22,000.

[0011] The present invention also provides a preparation method of a modified polyester filament, comprising the following steps:

[0012] Prepare a matting agent and a modified polyester, mix the matting agent and the modified polyester to obtain a modified polyester chip, and the modified polyester chip is metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain a modified polyester filament.

[0013] As a preferred technical solution, the specific steps for preparing the matting agent are:

[0014] Using an alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, the template agent and the titanium source are added to ethanol and mixed and dissolved. Deionized water is added to form a precipitate. After aging, filtration, and extraction to remove part of the template agent, it is then washed and dried to obtain the matting agent, which is mesoporous titanium dioxide powder;

[0015] The specific steps for preparing the modified polyester are as follows:

[0016] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride under an ice-water bath condition, react for 3 h - 4 h, evaporate to remove methanol, add water to separate out the esterification product, and then extract the esterification product with ethyl acetate. After volatilizing to remove ethyl acetate, 5-aminoisophthalic acid dimethyl ester is obtained;

[0017] 5-Aminoisophthalic acid dimethyl ester and ethylene glycol carry out a transesterification reaction under the action of a first catalyst. The esterification temperature is 180 °C - 210 °C, and the esterification time is 2 h - 3 h until the transesterification reaction is complete, obtaining 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0018] After preparing a slurry of terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, and mesoporous titanium dioxide powder, an esterification reaction is carried out to obtain an esterification product. The pressure is 0.1 - 0.3 Mpa, and the temperature is 230 °C - 250 °C;

[0019] After the esterification reaction is completed, 5-aminoisophthalic acid bis-3-hydroxyethyl ester is added to the esterification product, and then a second catalyst and a stabilizer are added. Under a negative pressure condition, the polycondensation reaction in the low-vacuum stage is started. The pressure in the low-vacuum stage is smoothly reduced from normal pressure to below an absolute pressure of 500 Pa, the temperature is controlled at 260 °C - 270 °C, and the reaction time is 30 min - 50 min. Then, continue to evacuate to carry out the polycondensation reaction in the high-vacuum stage. The pressure in the high-vacuum stage is reduced to less than an absolute pressure of 70 Pa, the reaction temperature is controlled at 275 °C - 280 °C, and the reaction time is 50 min - 90 min to obtain the modified polyester.

[0020] As a preferred technical solution, the alkylamine is dodecylamine, tetradecylamine, hexadecylamine, or octadecylamine. The molar ratio of the alkylamine to the titanium source is 1:(2 - 3), the volume ratio of the ethanol to the deionized water is 1:(4 - 5), the concentration of the alkylamine is 2 wt% - 2.2 wt%, the aging condition is first at room temperature for 20 h - 24 h, then heated to 90 °C - 100 °C, and the heating time is 40 h - 48 h. The extraction condition is to treat in a nitric acid ethanol solution with pH = 2 at room temperature for 12 h - 15 h. The washing condition is to filter and wash with ethanol 3 - 5 times, and the drying condition is a drying temperature of 50 °C - 60 °C and a drying time of 24 h - 30 h.

[0021] As a preferred technical solution, the molar ratio of 5-aminoisophthalic acid, methanol, and thionyl chloride is 1:(35.0 - 37.5):(3 - 3.5), the volume of water added is 2 - 3 times that of methanol, the volume of ethyl acetate added is 1 - 1.2 times that of methanol, the molar ratio of dimethyl 5-aminoisophthalate to ethylene glycol is 1:(1.8 - 2.2), the addition amount of the first catalyst is 0.02% - 0.03% of the weight of dimethyl 5-aminoisophthalate, and the molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:(0.4 - 0.6):(0.08 - 0.12):(1.8 - 2.5).

[0022] As a preferred technical solution, the weight of the delustering agent is 0.20% - 0.25% of the weight of the modified polyester, and the molar ratio of bis(3-hydroxyethyl) 5-aminoisophthalate to terephthalic acid is 1:(0.02 - 0.03).

[0023] As a preferred technical solution, the stabilizer is triphenyl phosphate, trimethyl phosphate, or trimethyl phosphite, the addition amount of the stabilizer is 0.03% - 0.05% of the total weight of terephthalic acid, the second catalyst is antimony trioxide, antimony glycolate, or antimony acetate, and the addition amount of the second catalyst is 0.03% - 0.05% of the total weight of terephthalic acid.

[0024] As a preferred technical solution, the parameters for preparing the modified polyester filament are as follows: the extrusion temperature is 270°C - 280°C, the cooling temperature is 20°C - 25°C, the speed of the first roll is 2200 m / min - 2400 m / min, the temperature of the first roll is 65°C - 70°C, the speed of the second roll is 3000 m / min - 3200 m / min, the temperature of the second roll is 150°C - 180°C, the winding speed is 2960 m / min - 3230 m / min, the fineness of the modified polyester filament is 1.5 dtex - 3.0 dtex, the breaking strength is ≥3.5 cN / dtex, the elongation at break is 50.0 ± 5.0%, and the content of acetaldehyde in the modified polyester filament is <0.5 ppm.

[0025] Compared with the traditional technical solution, the beneficial effects of the present invention are as follows:

[0026] 1), The present invention introduces an inorganic mesoporous powder containing amino groups into the melt spinning system instead of the traditional delustering agent, which simultaneously plays the role of acetaldehyde scavenging and delustering, is easy to realize industrial production, can reduce the release of acetaldehyde vapor during the spinning process, improve the production environment, synthesize a modified polyester with amino groups in the side chain through a simple copolymerization method, inhibit thermal oxidative degradation during the polymerization and processing processes, inhibit the generation of acetaldehyde, reduce the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process, reduce the content of acetaldehyde in the modified polyester filament, and is beneficial to the safety of its application;

[0027] 2), Mesoporous titanium dioxide powder with a high refractive index needs to be added to the modified polyester filament. The mesoporous titanium dioxide powder is prepared into a mesoporous form containing amino functional groups, which has both a matting function and an acetaldehyde scavenging function;

[0028] 3), The preparation method of the modified polyester filament synthesizes a modified polyester with amino groups in the side chain by simple copolymerization through inorganic substances. During the polymerization and processing, thermal oxidative degradation is inhibited, the generation of acetaldehyde is inhibited, the environmental deterioration caused by the release of acetaldehyde vapor during the spinning process is reduced, the content of acetaldehyde in the modified polyester filament is reduced, which is beneficial to the safety of its application. Detailed implementation manners

[0029] The present invention will be further described below.

[0030] In the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if terms such as "top", "bottom", "left", "right", "front", "rear", "inner", "outer", etc. are used to indicate the orientation or position relationship, it is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship are only used for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] A modified polyester filament provided by an embodiment of the present invention includes a modified polyester and a matting agent. The modified polyester includes a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment, and a 5-aminoisophthalic acid bis-3-hydroxyethyl ester segment. The matting agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. The present invention introduces an inorganic mesoporous powder containing amino groups into the melt spinning system instead of the traditional matting agent, which simultaneously plays the role of acetaldehyde scavenging and matting, is easy to realize industrial production, can reduce the release of acetaldehyde vapor during the spinning process, improve the production environment, synthesize a modified polyester with amino groups in the side chain by simple copolymerization, inhibit thermal oxidative degradation during the polymerization and processing, inhibit the generation of acetaldehyde, reduce the environmental deterioration caused by the release of acetaldehyde vapor during the spinning process, and reduce the content of acetaldehyde in the modified polyester filament, which is beneficial to the safety of its application.

[0032] In some of the embodiments, the inorganic mesoporous powder is mesoporous titanium dioxide powder, the pore diameter of the mesoporous titanium dioxide powder is 2nm - 4nm, and the specific surface area is 100m 2 / g - 300m 2 / g, with a particle size of 200 nm - 300 nm and an amino functional group content of 1 wt% - 3 wt%. In the modified polyester filament of the present invention, a mesoporous titanium dioxide powder with a high refractive index needs to be added. The mesoporous titanium dioxide powder is prepared into a mesoporous form containing amino functional groups, which has both a matting function and an acetaldehyde scavenging function. On the one hand, the porous structure can increase the number of light refractions, producing a better matting effect; on the other hand, the mesopores are beneficial for adsorbing acetaldehyde vapor molecules. Because the modified polyester becomes a modified polyester melt after heating and extrusion, acetaldehyde vapor molecules will be released, and the mesopores can well adsorb the acetaldehyde vapor molecules. Moreover, the mesoporous structure greatly increases the specific surface area of the mesoporous titanium dioxide powder and the adsorption sites of acetaldehyde molecules.

[0033] The present invention uses an inorganic mesoporous material to absorb acetaldehyde generated during the polymerization and spinning processes. The inorganic mesoporous material is mesoporous titanium dioxide powder, which not only has the function of absorbing acetaldehyde molecules but also has high matting ability. On the basis of not changing the existing production process of low-melting polyester filaments, the mesoporous titanium dioxide powder is added to the melt spinning system instead of the traditional matting agent.

[0034] In some of the embodiments, the melting point of the modified polyester is 110°C - 150°C, and the molecular weight of the modified polyester is 18,000 - 22,000. The low melting point of the modified polyester does not affect the absorption of acetaldehyde.

[0035] The present invention also provides a method for preparing a modified polyester filament, which includes the following steps:

[0036] Prepare a matting agent and a modified polyester, mix the matting agent and the modified polyester to obtain modified polyester chips, and the modified polyester chips are metered, melted, extruded, cooled, oiled, drawn, heat-set, and wound to obtain the modified polyester filament.

[0037] In some of the embodiments, the specific steps for preparing the matting agent are as follows:

[0038] Using an alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, add the template agent and the titanium source to ethanol and mix and dissolve them. This can form amino functional groups. Add deionized water to generate a precipitate, age, filter, and extract to remove part of the template agent, and then wash and dry to obtain the matting agent. The matting agent is mesoporous titanium dioxide powder. When preparing the mesoporous titanium dioxide powder containing amino groups in the present invention, an alkylamine is directly used as the template agent, which is different from the conventional preparation of mesoporous titanium dioxide powder that requires complete removal of the template agent. Instead, part of the template agent is retained, thereby reducing the step of reintroducing amino functional groups and lowering the production cost. Moreover, the amino functional groups are located on the inner wall of the mesopores, which does not affect the whiteness of the mesoporous titanium dioxide powder and the color of the final product.

[0039] The specific steps for preparing the modified polyester are as follows:

[0040] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride under an ice-water bath condition, react for 3 h - 4 h, evaporate to remove methanol, add water to separate out the esterification product, and then extract the esterification product with ethyl acetate. After volatilizing to remove ethyl acetate, dimethyl 5-aminoisophthalate is obtained;

[0041] Dimethyl 5-aminoisophthalate and ethylene glycol carry out a transesterification reaction under the action of a first catalyst. The esterification temperature is 180 °C - 210 °C, and the esterification time is 2 h - 3 h until the transesterification reaction is complete to obtain bis(3-hydroxyethyl) 5-aminoisophthalate. On the basis of introducing mesoporous titanium dioxide powder containing an amino functional group, the present invention also adds bis(3-hydroxyethyl) 5-aminoisophthalate to the comonomer. For bis(3-hydroxyethyl) 5-aminoisophthalate, on the one hand, the aniline group in the structure acts as an aromatic amine antioxidant to inhibit the thermal oxidative degradation of macromolecules; on the other hand, 5-aminoisophthalic acid destroys the regular structure of the polyester macromolecule, which is beneficial to reducing the melting point of the modified polyester. On the third hand, the amino group in the structure reacts with acetaldehyde to form a Schiff base reaction, in-situ chemically bonding the acetaldehyde generated by high-temperature pyrolysis to the macromolecular chain, reducing the content of acetaldehyde in the polyester melt, reducing the content of acetaldehyde in the modified polyester filament, and reducing the impact of acetaldehyde on the environment during the application of the modified polyester filament.

[0042] 5-Aminoisophthalic acid, methanol, and thionyl chloride undergo an esterification reaction in an ice-water bath to form dimethyl 5-aminoisophthalate. During this reaction process, methanol and thionyl chloride first generate the intermediate methyl chlorosulfite. The -OSOCl group in methyl chlorosulfite is easily detached from the methyl group and combines with the free H of the carboxylic acid + to generate chlorosulfurous acid. Chlorosulfurous acid is extremely easy to decompose, so that the reaction has a high yield and reaction rate, and the detached methyl group combines with the carboxylate to form an ester. In addition, due to the steric effect, the amino group on the benzene ring does not participate in the amidation reaction of the carboxylic acid group, and the amino group remains unchanged. The synthesized dimethyl 5-aminoisophthalate then undergoes a transesterification reaction with ethylene glycol at 180 °C - 210 °C to obtain the third monomer bis(3-hydroxyethyl) 5-aminoisophthalate, and the by-product is methanol, whose boiling point is much lower than the reaction temperature and is easily evaporated and removed.

[0043] Prepare a slurry from terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, and mesoporous titanium dioxide powder, and then carry out an esterification reaction to obtain an esterification product. The pressure is 0.1 - 0.3 Mpa, and the temperature is 230 °C - 250 °C;

[0044] After the esterification reaction is completed, bis(3-hydroxyethyl) 5-aminoisophthalate is added to the esterification product, and then a second catalyst and a stabilizer are added. The polycondensation reaction in the low-vacuum stage is started under negative pressure. The pressure in the low-vacuum stage is smoothly reduced from atmospheric pressure to below an absolute pressure of 500 Pa, the temperature is controlled at 260°C - 270°C, the reaction time is 30 min - 50 min, and then the vacuum is continuously pumped to carry out the polycondensation reaction in the high-vacuum stage. The pressure in the high-vacuum stage is reduced to an absolute pressure of less than 70 Pa, the reaction temperature is controlled at 275°C - 280°C, and the reaction time is 50 min - 90 min to obtain the modified polyester.

[0045] In some of these embodiments, the alkylamine is dodecylamine, tetradecylamine, hexadecylamine or octadecylamine. The molar ratio of the alkylamine to the titanium source is 1:(2 - 3), the volume ratio of ethanol to deionized water is 1:(4 - 5), the concentration of the alkylamine is 2 wt% - 2.2 wt%, the aging conditions are first at room temperature of 20°C - 26°C for 20 h - 24 h, and then the temperature is raised to 90°C - 100°C with a heating time of 40 h - 48 h. The extraction conditions are treatment in a nitric acid ethanol solution with pH = 2 at room temperature for 12 h - 15 h, the washing conditions are filtration and washing with ethanol 3 - 5 times, and the drying conditions are a drying temperature of 50°C - 60°C and a drying time of 24 h - 30 h.

[0046] In some of these embodiments, the molar ratio of 5-aminoisophthalic acid, methanol, and thionyl chloride is 1:(35.0 - 37.5):(3 - 3.5). The volume of water added is 2 - 3 times that of methanol, the volume of ethyl acetate added is 1 - 1.2 times that of methanol. The molar ratio of dimethyl 5-aminoisophthalate to ethylene glycol is 1:(1.8 - 2.2). The addition amount of the first catalyst is 0.02% - 0.03% of the weight of dimethyl 5-aminoisophthalate. The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:(0.4 - 0.6):(0.08 - 0.12):(1.8 - 2.5). Within the above ranges, the controllability of the reaction process is good, and the properties and stability of the finally obtained modified polyester filaments are better.

[0047] In some of these embodiments, the weight of the delustering agent is 0.20% - 0.25% of the weight of the modified polyester. The molar ratio of bis(3-hydroxyethyl) 5-aminoisophthalate to terephthalic acid is 1:(0.02 - 0.03). If the weight of the delustering agent is less than 0.20% of the weight of the modified polyester, the delustering effect is poor and the effect of absorbing acetaldehyde is not good. If the weight of the delustering agent is greater than 0.25% of the weight of the modified polyester, it will instead affect the properties and stability of the modified polyester, and the improvement of the acetaldehyde absorption effect is not obvious.

[0048] In some of these embodiments, the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and the addition amount of the stabilizer is 0.03%-0.05% of the total weight of terephthalic acid. The second catalyst is antimony trioxide, antimony glycolate or antimony acetate, and the addition amount of the second catalyst is 0.03%-0.05% of the total weight of terephthalic acid, which improves the stability and reaction rate of the reaction process. If there is no mention of mass percentage, molar ratio or volume for the components in the present invention, it indicates that it has little impact on the technical effects of the present invention and is not specifically limited.

[0049] In some of these embodiments, the spinning process of the modified polyester filament is as follows: the modified polyester chips are metered and melted to obtain a modified polyester melt, and the modified polyester melt is extruded through a spinneret hole, cooled, oiled, stretched, heat-set and wound to produce the modified polyester filament. The modified polyester filament passes through a first roller and a second roller to be wound. The speed difference between the first roller and the second roller forms stretching. The first roller heats the fiber, and the second roller performs heat setting. The parameters for preparing the modified polyester filament are as follows: the extrusion temperature is 270°C - 280°C, the cooling temperature is 20°C - 25°C, the speed of the first roller is 2200 m / min - 2400 m / min, the temperature of the first roller is 65°C - 70°C, the speed of the second roller is 3000 m / min - 3200 m / min, the temperature of the second roller is 150°C - 180°C, the winding speed is 2960 m / min - 3230 m / min, the fineness of the modified polyester filament is 1.5 dtex - 3.0 dtex, the breaking strength is ≥3.5 cN / dtex, the breaking elongation is 50.0 ± 5.0%, and the content of acetaldehyde in the modified polyester filament is <0.5 ppm.

[0050] Example 1

[0051] A modified polyester filament, comprising a modified polyester and a delustering agent. The modified polyester comprises a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment and a 5-aminoisophthalic acid bis-3-hydroxyethyl ester segment. The delustering agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. The inorganic mesoporous powder is a mesoporous titanium dioxide powder. The pore diameter of the mesoporous titanium dioxide powder is 2 nm, the specific surface area is 100 m 2 / g, the particle size is 200 nm, the content of amino functional groups is 1 wt%, the melting point of the modified polyester is 110°C, and the molecular weight of the modified polyester is 18000.

[0052] The present invention also provides a method for preparing a modified polyester filament, comprising the following steps:

[0053] Prepare a delustering agent and a modified polyester, mix the delustering agent and the modified polyester to obtain modified polyester chips, and the modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to produce the modified polyester filament.

[0054] The specific steps for preparing the matting agent are as follows:

[0055] Using alkylamine as the template agent and isopropyl titanate as the titanium source, the template agent and the titanium source are added to ethanol and mixed and dissolved. Deionized water is added to form a precipitate, which is aged, filtered, and extracted to remove part of the template agent, and then washed and dried to obtain the matting agent, which is mesoporous titanium dioxide powder;

[0056] The aging conditions are first at room temperature of 20 °C for 20 h, then heated to 90 °C with a heating time of 40 h. The extraction conditions are treatment in a nitric acid ethanol solution with pH = 2 at room temperature for 12 h. The washing conditions are filtering and washing with ethanol 3 times. The drying conditions are a drying temperature of 50 °C and a drying time of 24 h.

[0057] The specific steps for preparing the modified polyester are as follows:

[0058] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride under ice-water bath conditions, react for 3 h, evaporate to remove methanol, add water to separate the esterification product, and then extract the esterification product with ethyl acetate. After volatilizing to remove ethyl acetate, 5-aminoisophthalic acid dimethyl ester is obtained;

[0059] 5-aminoisophthalic acid dimethyl ester and ethylene glycol carry out a transesterification reaction under the action of the first catalyst. The esterification temperature is 180 °C and the esterification time is 2 h until the transesterification reaction is complete, obtaining 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0060] After preparing a slurry of terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, and mesoporous titanium dioxide powder, carry out an esterification reaction to obtain an esterification product. The pressure is 0.1 Mpa and the temperature is 230 °C. When the distillate of water in the esterification reaction reaches more than 95% of the theoretical value, it is the end point of the esterification reaction to obtain the esterification product;

[0061] After the esterification reaction is completed, add 5-aminoisophthalic acid bis-3-hydroxyethyl ester to the esterification product, then add the second catalyst and stabilizer, and start the polycondensation reaction in the low vacuum stage under negative pressure. The pressure in the low vacuum stage is smoothly reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature is controlled at 260 °C, and the reaction time is 30 min. Then continue to evacuate to carry out the polycondensation reaction in the high vacuum stage. The pressure in the high vacuum stage is reduced to an absolute pressure of 60 Pa, the reaction temperature is controlled at 275 °C, and the reaction time is 50 min to obtain the modified polyester.

[0062] The alkylamine is dodecylamine. The molar ratio of the alkylamine to the titanium source is 1:2. The volume ratio of ethanol to deionized water is 1:4. The concentration of the alkylamine is 2 wt%.

[0063] The molar ratio of 5 - aminoisophthalic acid, methanol, and thionyl chloride is 1:35.0:3. The volume of water added is 2 times that of methanol, and the volume of ethyl acetate added is 1 time that of methanol. The molar ratio of dimethyl 5 - aminoterephthalate to ethylene glycol is 1:1.8. The addition amount of the first catalyst is 0.02% of the weight of dimethyl 5 - aminoterephthalate. The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.4:0.08:1.8. The weight of the delustering agent is 0.20% of the weight of the modified polyester. The molar ratio of bis - 3 - hydroxyethyl 5 - aminoterephthalate to terephthalic acid is 1:0.02.

[0064] The stabilizer is triphenyl phosphate, and the addition amount of the stabilizer is 0.03% of the total weight of terephthalic acid. The second catalyst is antimony trioxide, and the addition amount of the second catalyst is 0.03% of the total weight of terephthalic acid.

[0065] The spinning process of the modified polyester filament is as follows: The modified polyester chips are metered and melted to obtain a modified polyester melt. The modified polyester melt is extruded through spinneret holes, cooled, oiled, drawn, heat - set, and wound to obtain the modified polyester filament. The modified polyester filament passes through the first roll and the second roll to be wound. The speed difference between the first roll and the second roll forms the draw. The first roll heats the modified polyester filament, and the second roll performs heat - setting. The parameters for preparing the modified polyester filament are as follows: The extrusion temperature is 270 °C, the cooling temperature is 20 °C, the speed of the first roll is 2200 m / min, the temperature of the first roll is 65 °C, the speed of the second roll is 3000 m / min, the temperature of the second roll is 150 °C, and the winding speed is 2960 m / min.

[0066] Through tests, the fineness of the modified polyester filament is 1.5 dtex, the breaking strength is 3.76 cN / dtex, the breaking elongation rate is 50.0%, and the content of acetaldehyde in the modified polyester filament is 0.43 ppm.

[0067] Example 2

[0068] A modified polyester filament, comprising a modified polyester and a delustering agent. The modified polyester includes terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and bis - 3 - hydroxyethyl 5 - aminoterephthalate segments. The delustering agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. The inorganic mesoporous powder is mesoporous titanium dioxide powder. The pore diameter of the mesoporous titanium dioxide powder is 4 nm, the specific surface area is 300 m 2 / g, the particle size is 300 nm, the content of amino functional groups is 3 wt%, the melting point of the modified polyester is 150 °C, and the molecular weight of the modified polyester is 20000.

[0069] The present invention also provides a method for preparing a modified polyester filament, comprising the following steps:

[0070] Prepare an anti-glare agent and a modified polyester, mix the anti-glare agent and the modified polyester to obtain modified polyester chips, and the modified polyester chips are metered, melted, extruded, cooled, oiled, drawn, heat-set and wound to produce modified polyester filaments.

[0071] The specific steps for preparing the anti-glare agent are as follows:

[0072] Using an alkylamine as a template agent and tetrabutyl titanate as a titanium source, add the template agent and the titanium source to ethanol and mix and dissolve them, add deionized water to form a precipitate, age, filter, and extract to remove part of the template agent, and then wash and dry to obtain the anti-glare agent, which is mesoporous titanium dioxide powder;

[0073] The aging conditions are first at room temperature of 23 °C for 24 h, then heated to 100 °C with a heating time of 48 h. The extraction conditions are treatment in a nitric acid-ethanol solution with pH = 2 at room temperature for 15 h. The washing conditions are filtering and washing with ethanol 5 times. The drying conditions are a drying temperature of 60 °C and a drying time of 30 h.

[0074] The specific steps for preparing the modified polyester are as follows:

[0075] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride under ice-water bath conditions, react for 4 h, evaporate to remove methanol, add water to separate the esterification product, and then extract the esterification product with ethyl acetate. After volatilizing to remove ethyl acetate, 5-aminoisophthalic acid dimethyl ester is obtained;

[0076] 5-aminoisophthalic acid dimethyl ester and ethylene glycol carry out a transesterification reaction under the action of a first catalyst. The esterification temperature is 210 °C and the esterification time is 3 h until the transesterification reaction is complete to obtain 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0077] After preparing a slurry of terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol and mesoporous titanium dioxide powder, carry out an esterification reaction to obtain an esterification product. The pressure is 0.3 Mpa and the temperature is 250 °C. When the distillate of water in the esterification reaction reaches more than 95% of the theoretical value, it is the end point of the esterification reaction to obtain the esterification product;

[0078] After the esterification reaction is completed, add 5-aminoisophthalic acid bis-3-hydroxyethyl ester to the esterification product, then add a second catalyst and a stabilizer, and start the polycondensation reaction in the low-vacuum stage under negative pressure. The pressure in the low-vacuum stage is smoothly reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature is controlled at 270 °C, and the reaction time is 50 min. Then continue to evacuate to carry out the polycondensation reaction in the high-vacuum stage. The pressure in the high-vacuum stage is reduced to an absolute pressure of 65 Pa, the reaction temperature is controlled at 280 °C, and the reaction time is 90 min to obtain the modified polyester.

[0079] The alkylamine is tetradecylamine, the molar ratio of the alkylamine to the titanium source is 1:3, the volume ratio of ethanol to deionized water is 1:5, the concentration of the alkylamine is 2.2 wt%, and the molar ratio of bis(3-hydroxyethyl)-5-aminoisophthalate to terephthalic acid is 1:0.025.

[0080] The molar ratio of 5-aminoisophthalic acid, methanol, and thionyl chloride is 1:37.5:3.5. The volume of water added is 3 times that of methanol, and the volume of ethyl acetate added is 1.2 times that of methanol. The molar ratio of dimethyl 5-aminoisophthalate to ethylene glycol is 1:2.2. The addition amount of the first catalyst is 0.03% of the weight of dimethyl 5-aminoisophthalate. The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.6:0.12:2.5. The weight of the delustering agent is 0.25% of the weight of the modified polyester. The molar ratio of bis(3-hydroxyethyl)-5-aminoisophthalate to terephthalic acid is 1:0.03.

[0081] The stabilizer is triphenyl phosphate, trimethyl phosphate, or trimethyl phosphite. The addition amount of the stabilizer is 0.05% of the total weight of terephthalic acid. The second catalyst is antimony trioxide, antimony glycolate, or antimony acetate. The addition amount of the second catalyst is 0.05% of the total weight of terephthalic acid.

[0082] The spinning process of the modified polyester filament is as follows: The modified polyester chips are metered and melted to obtain a modified polyester melt. The modified polyester melt is extruded through a spinneret hole, cooled, oiled, stretched, heat-set, and wound to obtain the modified polyester filament. The modified polyester filament passes through a first roller and a second roller to be wound. The speed difference between the first roller and the second roller forms stretching. The first roller heats the modified polyester filament, and the second roller performs heat setting. The parameters for preparing the modified polyester filament are as follows: the extrusion temperature is 280 °C, the cooling temperature is 25 °C, the speed of the first roller is 2400 m / min, the temperature of the first roller is 70 °C, the speed of the second roller is 3200 m / min, the temperature of the second roller is 180 °C, and the winding speed is 3230 m / min.

[0083] Through tests, the fineness of the modified polyester filament is measured to be 3.0 dtex, the breaking strength is 3.82 cN / dtex, the breaking elongation is 55.0%, and the content of acetaldehyde in the modified polyester filament is 0.38 ppm.

[0084] Example 3

[0085] A modified polyester filament, comprising a modified polyester and a delustering agent. The modified polyester includes a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment, and a bis(3-hydroxyethyl)-5-aminoisophthalate segment. The delustering agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. The inorganic mesoporous powder is a mesoporous titanium dioxide powder. The pore diameter of the mesoporous titanium dioxide powder is 3 nm, and the specific surface area is 200 m 2 / g, with a particle size of 260 nm, the content of amino functional groups is 2 wt%, the melting point of the modified polyester is 130 °C, and the molecular weight of the modified polyester is 22,000.

[0086] The present invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0087] Prepare a matting agent and a modified polyester, mix the matting agent and the modified polyester to obtain a modified polyester chip, and the modified polyester chip is metered, melted, extruded, cooled, oiled, drawn, heat-set and wound to obtain modified polyester filaments.

[0088] The specific steps for preparing the matting agent are:

[0089] Using an alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, add the template agent and the titanium source to ethanol and mix and dissolve them, add deionized water to form a precipitate, age, filter, and extract to remove part of the template agent, and then wash and dry to obtain the matting agent, and the matting agent is mesoporous titanium dioxide powder;

[0090] The aging conditions are at room temperature of 25 °C for 24 h, then heated to 95 °C with a heating time of 45 h, the extraction conditions are treatment in a nitric acid ethanol solution with pH = 2 at room temperature for 13 h, the washing conditions are filtering and washing with ethanol 4 times, and the drying conditions are a drying temperature of 55 °C and a drying time of 25 h.

[0091] The specific steps for preparing the modified polyester are:

[0092] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride under ice-water bath conditions, react for 4 h, evaporate to remove methanol, add water to separate the esterification product, and then extract the esterification product with ethyl acetate, and volatilize to remove ethyl acetate to obtain dimethyl 5-aminoisophthalate;

[0093] Dimethyl 5-aminoisophthalate and ethylene glycol carry out a transesterification reaction under the action of a first catalyst, the esterification temperature is 200 °C, and the esterification time is 3 h until the transesterification reaction is complete to obtain bis-3-hydroxyethyl 5-aminoisophthalate;

[0094] Prepare a slurry from terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol and mesoporous titanium dioxide powder, and then carry out an esterification reaction to obtain an esterification product, with a pressure of 0.2 Mpa and a temperature of 240 °C. When the distillate of water in the esterification reaction reaches more than 95% of the theoretical value, it is the end point of the esterification reaction to obtain the esterification product;

[0095] After the esterification reaction is completed, bis(3-hydroxyethyl) 5-aminoisophthalate is added to the esterification product, and then a second catalyst and a stabilizer are added. The polycondensation reaction in the low-vacuum stage is started under negative pressure. The pressure in the low-vacuum stage is smoothly reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature is controlled at 265 °C, the reaction time is 40 min, and then the vacuum is continuously pumped to carry out the polycondensation reaction in the high-vacuum stage. The pressure in the high-vacuum stage is reduced to an absolute pressure of 65 Pa, the reaction temperature is controlled at 280 °C, and the reaction time is 80 min to obtain the modified polyester.

[0096] The alkylamine is octadecylamine, the molar ratio of the alkylamine to the titanium source is 1:3, the volume ratio of ethanol to deionized water is 1:5, and the concentration of the alkylamine is 2.1 wt%.

[0097] The molar ratio of 5-aminoisophthalic acid, methanol, and thionyl chloride is 1:36:3.5. The volume of water added is 3 times that of methanol, the volume of ethyl acetate added is 1.2 times that of methanol, the molar ratio of dimethyl 5-aminoisophthalate to ethylene glycol is 1:2, the addition amount of the first catalyst is 0.03% of the weight of dimethyl 5-aminoisophthalate, the molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.5:0.1:2, the weight of the delustering agent is 0.22% of the weight of the modified polyester, and the molar ratio of bis(3-hydroxyethyl) 5-aminoisophthalate to terephthalic acid is 1:0.03.

[0098] The stabilizer is triphenyl phosphate, trimethyl phosphate, or trimethyl phosphite. The addition amount of the stabilizer is 0.04% of the total weight of terephthalic acid. The second catalyst is antimony glycolate, and the addition amount of the second catalyst is 0.04% of the total weight of terephthalic acid.

[0099] The parameters for preparing the modified polyester filaments are as follows: the extrusion temperature is 275 °C, the cooling temperature is 24 °C, the speed of the first roll is 2300 m / min, the temperature of the first roll is 70 °C, the speed of the second roll is 3100 m / min, the temperature of the second roll is 160 °C, and the winding speed is 3200 m / min.

[0100] Through tests, the fineness of the modified polyester filaments is measured to be 2.0 dtex, the breaking strength is 3.78 cN / dtex, the breaking elongation rate is 52.0%, and the content of acetaldehyde in the modified polyester filaments is 0.46 ppm.

[0101] It can be seen from Example 1, Example 2, and Example 3 that the content of acetaldehyde is very small, the elimination effect on acetaldehyde is good, and the mechanical properties are good.

[0102] Any numerical value recited herein includes all values from the lower value to the upper value incremented by one unit therebetween, provided that there is a separation of at least two units between any lower value and any higher value. For example, if a value for the number of components or for a process variable (such as temperature, pressure, time, etc.) is recited as being from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc. are also expressly recited in this specification. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples of what is meant to be specified, and it is considered that all possible combinations of numerical values between the lowest value and the highest value are expressly set forth in this specification in a similar manner.

[0103] Unless otherwise indicated, all ranges include the endpoints and all numbers therebetween. The term “about” or “approximate” when used in connection with a range is to be construed as appropriate for the two endpoints of that range. Thus, “about 20 to 30” is intended to cover “about 20 to about 30”, including at least the recited endpoints.

[0104] All articles and references, including patent applications and publications, are incorporated herein by reference for various purposes. The term “consisting essentially of” in describing a combination shall include the identified elements, ingredients, components or steps as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms “comprising” or “including” to describe the combinations of elements, ingredients, components or steps herein also contemplates embodiments consisting essentially of these elements, ingredients, components or steps. By use of the term “may” herein, it is meant that anything so described is optional.

[0105] A plurality of elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step can be divided into separate plural elements, ingredients, components or steps. The disclosure of “a” or “an” to describe an element, ingredient, component or step is not intended to exclude other elements, ingredients, components or steps.

[0106] It should be understood that the foregoing description is not intended to be limiting. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the present teachings should not be determined with reference to the foregoing description, but should be determined with reference to the appended claims and the full scope of equivalents to which such claims are entitled. For the sake of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the foregoing claims is not intended to abandon such subject matter, nor should it be considered that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A modified polyester filament, characterized in that: The invention comprises a modified polyester and a matting agent, wherein the modified polyester comprises a terephthalic acid segment, an isophthalic acid segment, an ethylene glycol segment, a diethylene glycol segment and a 5-aminoisophthalic acid bis-3-hydroxyethyl ester segment, and the matting agent is a mesoporous titanium dioxide powder having an amino functional group on the surface; the pore size of the mesoporous titanium dioxide powder is 2nm-4nm, and the specific surface area is 100m 2 / g-300m 2 / g, a particle size of 200nm-300nm, and an amino functional group content of 1wt%-3wt%; wherein the matting agent is prepared by the following steps: using alkylamine as a template agent, isopropyl titanate or n-butyl titanate as a titanium source, adding the template agent and the titanium source into ethanol for mixed dissolution, adding deionized water to generate a precipitate, removing part of the template agent through aging, filtering, and extraction, and then washing and drying to obtain the matting agent.

2. The modified polyester filament according to claim 1, characterized in that: The melting point of the modified polyester is between 110° C. and 150° C., and the molecular weight of the modified polyester is between 18,000 and 22,000.

3. The method for preparing modified polyester filament according to claim 1 or 2, characterized in that: The following steps are involved: A matting agent and modified polyester are prepared, the matting agent and modified polyester are mixed to obtain modified polyester chips, and the modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

4. The preparation method according to claim 3, characterized in that: The specific steps of preparing the modified polyester are: Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride in an ice-water bath, react for 3h-4h, evaporate to remove methanol, add water to separate the esterification product, extract the esterification product with ethyl acetate, evaporate to remove ethyl acetate, and obtain 5-aminoisophthalic acid dimethyl ester; 5-aminoisophthalic acid dimethyl ester and ethylene glycol undergo an ester exchange reaction under the action of a first catalyst, the esterification temperature is 180° C.-210° C., the esterification time is 2 h-3 h, until the ester exchange reaction is complete, to obtain 5-aminoisophthalic acid bis-3-hydroxyethyl ester; After terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol and mesoporous titanium dioxide powder are prepared into a slurry, an esterification reaction is carried out to obtain an esterification product at a pressure of 0.1-0.3Mpa and a temperature of 230°C-250°C; After the esterification reaction is completed, 5-aminoisophthalic acid bis-3-hydroxyethyl ester is added to the esterification product, and then a second catalyst and a stabilizer are added, and a low vacuum stage polycondensation reaction is started under negative pressure conditions, the pressure in the low vacuum stage is steadily reduced from normal pressure to an absolute pressure below 500Pa, the temperature is controlled at 260°C-270°C, the reaction time is 30min-50min, and then vacuuming is continued to carry out a high vacuum stage polycondensation reaction, the pressure in the high vacuum stage is reduced to an absolute pressure of less than 70Pa, the reaction temperature is controlled at 275°C-280°C, and the reaction time is 50min-90min, to obtain the modified polyester.

5. The preparation method according to claim 4, characterized in that: The alkylamine is dodecaamine, tetradecaamine, hexadecaneamine or octadecaneamine, the molar ratio of the alkylamine to the titanium source is 1:(2-3), the volume ratio of ethanol to deionized water is 1:(4-5), the concentration of the alkylamine is 2wt%-2.2wt%, the aging conditions are room temperature for 20h-24h, then heating to 90°C-100°C for 40h-48h, the extraction conditions are treatment in a nitric acid ethanol solution with pH=2 at room temperature for 12h-15h, the washing conditions are filtration and washing with ethanol for 3-5 times, and the drying conditions are drying temperature of 50°C-60°C and drying time of 24h-30h.

6. The preparation method according to claim 5, characterized in that: The molar ratio of 5-aminoisophthalic acid, methanol and thionyl chloride is 1: (35.0-37.5): (3-3.5), the volume of water added is 2-3 times that of methanol, the volume of ethyl acetate added is 1-1.2 times that of methanol, the molar ratio of 5-aminoisophthalic acid dimethyl ester and ethylene glycol is 1: (1.8-2.2), the amount of the first catalyst added is 0.02%-0.03% of the weight of 5-aminoisophthalic acid dimethyl ester, and the molar ratio of terephthalic acid, isophthalic acid, ethylene glycol and diethylene glycol is 1: (0.4-0.6): (0.08-0.12): (1.8-2.5).

7. The preparation method according to claim 5, characterized in that: The weight of the matting agent is 0.20%-0.25% of the weight of the modified polyester, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester to terephthalic acid is 1:(0.02-0.03).

8. The preparation method according to claim 5, characterized in that: The stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and the amount of the stabilizer added is 0.03%-0.05% of the total weight of terephthalic acid. The first catalyst is zinc acetate, and the second catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, and the amount of the second catalyst added is 0.03%-0.05% of the total weight of terephthalic acid.

9. The preparation method according to claim 4, characterized in that: The parameters for preparing the modified polyester filament are as follows: extrusion temperature is 270°C-280°C, cooling temperature is 20°C-25°C, first roller speed is 2200m / min-2400m / min, first roller temperature is 65°C-70°C, second roller speed is 3000m / min-3200m / min, second roller temperature is 150°C-180°C, winding speed is 2960m / min-3230m / min, the fineness of the modified polyester filament is 1.5dtex-3.0dtex, the breaking strength is ≥3.5cN / dtex, the breaking elongation is 50.0±5.0%, and the acetaldehyde content in the modified polyester filament is <0.5ppm.