Modified polyester filament and preparation method therefor

Abstract

Disclosed in the present invention is a modified polyester filament, comprising a modified polyester and a matting agent. The modified polyester comprises terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and bis(3-hydroxyethyl) 5-aminoisophthalate segments. The matting agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups. In the modified polyester filament in the present invention, the amino-containing inorganic mesoporous powder is introduced into a melt spinning system as a substitute for conventional matting agents, achieving the effects of both acetaldehyde scavenging and matting, thereby reducing the release of acetaldehyde vapor during the spinning process and improving a production environment. The preparation method in the present invention reduces the environmental deterioration caused by the release of acetaldehyde vapor during the spinning process, lowers the content of acetaldehyde in the modified polyester filament, and enhances the safety of use of the modified polyester filament.

Description

A modified polyester filament and its preparation method Technical Field

[0001] This invention relates to the field of spinning production technology, and in particular to a modified polyester filament and its preparation method. Background Technology

[0002] Thermal bonding low-melting-point fibers are one of the important raw materials for nonwoven fabrics. Thermal bonding utilizes the thermoplasticity of polymer materials, applying heat to polymer fibers to partially soften and melt them, which then solidifies upon cooling, bonding the fibers together. For the polyester nonwoven fabric industry, a polymer with a lower melting point than conventional polyester fibers and good compatibility with conventional polyesters is needed as a thermal bonding low-melting-point fiber. According to the principle of "like dissolves like," nonwoven fabrics with polyester as the main fiber should be bonded with polyester fibers of the same family. Practice shows that bonding fibers spun from low-melting-point copolyesters can make polyester wadding softer and more fluffy, providing broad application prospects for polyester low-melting-point thermal bonding fibers.

[0003] However, a series of side reactions occur during the esterification of low-melting-point copolyesters, producing many byproducts. Among these, acetaldehyde is the most significant byproduct, causing discomfort such as facial flushing, palpitations, and a drop in blood pressure. Acetaldehyde can also cause irritation to the eyes, nose, and upper respiratory tract, as well as bronchitis. Inhalation of high concentrations of acetaldehyde has an anesthetic effect, posing a significant threat to human health.

[0004] In the preparation process of low-melting-point copolyester filaments, the cooling and stretching temperatures involved are both low, and the time is short, making it impossible to reduce the acetaldehyde content of the fiber below a safe level. Therefore, a new technical solution is urgently needed to solve at least one of the above technical problems. Summary of the Invention

[0005] In view of the above shortcomings, one object of the present invention is to provide a modified polyester filament that introduces an amino-containing inorganic mesoporous powder into the melt spinning system to replace the traditional matting agent, thereby simultaneously achieving acetaldehyde removal and matting effects. This is easy to implement in industrial production, and can reduce the release of acetaldehyde vapor during the spinning process, thus improving the production environment.

[0006] Another objective of this invention is to provide a method for preparing modified polyester filaments, which synthesizes modified polyesters with amino-containing side groups through simple inorganic copolymerization. This method inhibits thermal oxidative degradation during polymerization and processing, suppresses the generation of acetaldehyde, reduces the release of acetaldehyde vapor during spinning, thus reducing the environmental impact and lowering the acetaldehyde content in the modified polyester filaments, thereby improving the safety of its application.

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

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

[0009] Preferably, the inorganic mesoporous powder is mesoporous titanium dioxide powder, wherein the pore size of the mesoporous titanium dioxide powder is 2nm-4nm and the specific surface area is 100m². 2 / g -300m 2 / g, with a particle size of 200nm-300nm, and the content of the amino functional group is 1wt%-3wt%.

[0010] Preferably, the modified polyester has a melting point of 110℃-150℃ and a molecular weight of 18000-22000.

[0011] This invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0012] A matting agent and a modified polyester are prepared. The matting agent and the modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

[0013] Preferably, the specific steps for preparing the matting agent are as follows:

[0014] Using alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol, and deionized water is added to generate a precipitate. After aging, filtration, and extraction to remove part of the template agent, the precipitate 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] 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 3-4 hours. The methanol was evaporated to remove the methanol, and water was added to separate the esterification product. The esterification product was then extracted with ethyl acetate, and the ethyl acetate was evaporated to remove the ester to obtain dimethyl 5-amino-isophthalate.

[0017] Dimethyl 5-aminoisophthalate was subjected to transesterification with ethylene glycol under the action of a first catalyst at an esterification temperature of 180℃-210℃ and an esterification time of 2h-3h until the transesterification reaction was complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate.

[0018] 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 the esterification product. The pressure is 0.1-0.3 MPa and the temperature is 230℃-250℃.

[0019] After the esterification reaction is completed, bis-3-hydroxyethyl 5-aminoisophthalic acid is added to the esterification product, followed by a second catalyst and a stabilizer. A low-vacuum polycondensation reaction is then initiated under negative pressure. The pressure in the low-vacuum stage is steadily reduced from atmospheric pressure to below 500 Pa, the temperature is controlled at 260℃-270℃, and the reaction time is 30-50 min. Then, vacuum is continued to carry out a high-vacuum polycondensation reaction. The pressure in the high-vacuum stage is reduced to below 70 Pa, the reaction temperature is controlled at 275℃-280℃, and the reaction time is 50-90 min, thus obtaining the modified polyester.

[0020] Preferably, the alkylamine is dodecyl, tetradecyl, hexadecyl, 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 2wt%-2.2wt%, the aging conditions are: first at room temperature for 20-24 hours, then heated to 90℃-100℃ for 40-48 hours, the extraction conditions are: treatment in a nitric acid ethanol solution at pH=2 at room temperature for 12-15 hours, the washing conditions are: washing 3-5 times with ethanol filtration, and the drying conditions are: drying temperature 50℃-60℃ for 24-30 hours.

[0021] Preferably, 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 amount of the first catalyst added 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] Preferably, 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).

[0023] Preferably, 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 the terephthalic acid. The first catalyst is zinc acetate, and the second catalyst is antimony trioxide, antimony glycolate, or antimony acetate, and the amount of the second catalyst added is 0.03%-0.05% of the total weight of the terephthalic acid.

[0024] Preferably, the parameters for preparing the modified polyester filament are as follows: extrusion temperature of 270℃-280℃, cooling temperature of 20℃-25℃, first roll speed of 2200m / min-2400m / min, first roll temperature of 65℃-70℃, second roll speed of 3000m / min-3200m / min, second roll temperature of 150℃-180℃, winding speed of 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.

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

[0026] 1) This invention introduces amino-containing inorganic mesoporous powder into the melt spinning system to replace the traditional matting agent, which simultaneously plays the roles of acetaldehyde removal and matting. It is easy to implement in industrial production. During the spinning process, it can reduce the release of acetaldehyde vapor, improve the production environment, and synthesize modified polyester with amino-containing side groups through simple copolymerization. During polymerization and processing, it can inhibit thermal oxidative degradation, inhibit the generation of acetaldehyde, reduce the environmental degradation caused by the release of acetaldehyde vapor during spinning, reduce the acetaldehyde content in modified polyester filaments, and benefit the safety of its application.

[0027] 2) High-refractive-index mesoporous titanium dioxide powder 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 matting function and acetaldehyde removal function.

[0028] 3) The preparation method of modified polyester filament involves inorganically synthesizing modified polyester with amino-containing side groups through simple copolymerization. This process inhibits thermal oxidative degradation during polymerization and processing, suppresses the generation of acetaldehyde, reduces the release of acetaldehyde vapor during spinning, thus reducing the environmental degradation caused by acetaldehyde vapor and lowering the acetaldehyde content in the modified polyester filament, which is beneficial to the safety of its application. Detailed Implementation

[0029] The present invention will be further described below with reference to embodiments.

[0030] An embodiment of this invention provides a modified polyester filament comprising a modified polyester and a matting agent. The modified polyester includes terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester segments. The matting agent is an inorganic mesoporous powder containing amino functional groups on its surface. This invention introduces an amino-containing inorganic mesoporous powder into the melt spinning system instead of a traditional matting agent, simultaneously achieving acetaldehyde removal and matting effects. This is easily implemented in industrial production, reduces the release of acetaldehyde vapor during spinning, and improves the production environment. By synthesizing a modified polyester with amino-containing side groups through simple copolymerization, it inhibits thermal oxidative degradation during polymerization and processing, suppresses acetaldehyde production, reduces the environmental degradation caused by acetaldehyde vapor release during spinning, and lowers the acetaldehyde content in the modified polyester filament, thus improving its safety in application.

[0031] In some embodiments, the inorganic mesoporous powder is mesoporous titanium dioxide powder, with a pore size of 2nm-4nm and a specific surface area of ​​100m². 2 / g-300m 2 The titanium dioxide powder, with a particle size of 200nm-300nm and an amino functional group content of 1wt%-3wt%, is added to the modified polyester filaments in this invention. The mesoporous titanium dioxide powder is prepared into a mesoporous form containing amino functional groups, possessing both exfoliation and acetaldehyde removal functions. On one hand, the porous structure increases the number of light refractions, producing a better exfoliation effect; on the other hand, the mesopores are beneficial for adsorbing acetaldehyde vapor molecules. Because the modified polyester, after heating and extrusion, becomes a modified polyester melt, it releases acetaldehyde vapor molecules, which the mesopores can effectively adsorb. Furthermore, the mesoporous structure greatly increases the specific surface area of ​​the mesoporous titanium dioxide powder and the adsorption sites for acetaldehyde molecules.

[0032] This invention employs an inorganic mesoporous material to absorb acetaldehyde generated during polymerization and spinning. The inorganic mesoporous material is mesoporous titanium dioxide powder, which has both the function of absorbing acetaldehyde molecules and the ability to effectively remove dullness. The mesoporous titanium dioxide powder is added to the melt spinning system in place of traditional dulling agents without changing the existing low-melting-point polyester filament production process.

[0033] In some embodiments, the modified polyester has a melting point of 110°C-150°C and a molecular weight of 18,000-22,000. The low melting point of the modified polyester does not affect the absorption of acetaldehyde.

[0034] This invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0035] A matting agent and modified polyester are prepared. The matting agent and modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

[0036] In some embodiments, the specific steps for preparing the matting agent are as follows:

[0037] Using alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol to form amino functional groups. Deionized water is added to generate a precipitate. After aging, filtration, and extraction to remove part of the template agent, the product is washed and dried to obtain a matting agent, which is the mesoporous titanium dioxide powder. In preparing amino-containing mesoporous titanium dioxide powder, this invention directly uses alkylamine as a template agent, unlike conventional methods that require complete removal of the template agent. Instead, a portion of the template agent is retained, thereby reducing the steps of reintroducing amino functional groups and lowering production costs. Moreover, the amino functional groups are located on the inner wall of the mesopores and do not affect the whiteness of the mesoporous titanium dioxide powder or the color of the final product.

[0038] The specific steps for preparing modified polyester are as follows:

[0039] 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 3-4 hours. The methanol was evaporated to remove the methanol, and water was added to separate the esterification product. The esterification product was then extracted with ethyl acetate, and the ethyl acetate was evaporated to remove the ester to obtain dimethyl 5-amino-isophthalate.

[0040] Dimethyl 5-aminoisophthalate and ethylene glycol undergo transesterification under the action of a first catalyst at an esterification temperature of 180℃-210℃ for 2-3 hours until the transesterification reaction is complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate. Based on the introduction of mesoporous titanium dioxide powder containing amino functional groups, this invention also adds bis-3-hydroxyethyl 5-aminoisophthalate to the comonomer. For bis-3-hydroxyethyl 5-aminoisophthalate, firstly, the aniline group in its structure acts as an aromatic amine antioxidant, inhibiting the thermal oxidative degradation of macromolecules; secondly, 5-aminoisophthalic acid disrupts the regular structure of polyester macromolecules, which is beneficial for lowering the melting point of modified polyester; and thirdly, the amino group in its structure undergoes a Schiff base reaction with acetaldehyde, chemically bonding the acetaldehyde generated from high-temperature pyrolysis to the macromolecular chain in situ, reducing the acetaldehyde content in the polyester melt, lowering the acetaldehyde content in the modified polyester filament, and mitigating the environmental impact of acetaldehyde in the application of modified polyester filaments.

[0041] 5-Aminoisophthalic acid, methanol, and thionyl chloride undergo an esterification reaction in an ice-water bath to form dimethyl 5-aminoisophthalate. During this reaction, methanol and thionyl chloride first form the intermediate methyl sulfite. The -OSOCl group in methyl sulfite readily detaches from the methyl group and reacts with the free H+ of the carboxylic acid. + The reaction produces sulfurous chloride, which decomposes readily, resulting in high yields and reaction rates. The released methyl group combines with the carboxylate group to form an ester. Furthermore, due to steric hindrance, the amino group on the benzene ring does not participate in the amidation reaction of the carboxylate group, and the amino group remains unchanged. The synthesized dimethyl 5-aminoisophthalate then undergoes an transesterification reaction with ethylene glycol at 180℃-210℃ to yield the third monomer, bis-3-hydroxyethyl 5-aminoisophthalate. Methanol is a byproduct, but its boiling point is much lower than the reaction temperature, allowing it to be easily evaporated and removed.

[0042] 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 the esterification product. The pressure is 0.1-0.3 MPa and the temperature is 230℃-250℃.

[0043] After the esterification reaction is completed, bis-3-hydroxyethyl 5-aminoisophthalic acid is added to the esterification product, followed by a second catalyst and a stabilizer. The low-vacuum stage of polycondensation reaction is started under negative pressure. The pressure in the low-vacuum stage is steadily reduced from atmospheric pressure to below 500 Pa absolute pressure, the temperature is controlled at 260℃-270℃, and the reaction time is 30-50 min. Then, the vacuum is continued to carry out the high-vacuum stage of polycondensation reaction. The pressure in the high-vacuum stage is reduced to below 70 Pa absolute pressure, the reaction temperature is controlled at 275℃-280℃, and the reaction time is 50-90 min, thus obtaining the modified polyester.

[0044] In some embodiments, the alkylamine is dodecyl, tetradecyl, hexadecyl, or octadecylamine, the molar ratio of alkylamine to titanium source is 1:(2-3), the volume ratio of ethanol to deionized water is 1:(4-5), the concentration of alkylamine is 2wt%-2.2wt%, the aging conditions are: first at room temperature (20℃-26℃) for 20h-24h, then heated to 90℃-100℃ for 40h-48h, the extraction conditions are: treatment in nitric acid ethanol solution at pH=2 at room temperature for 12h-15h, the washing conditions are: washing with ethanol by vacuum filtration 3-5 times, and the drying conditions are: drying temperature 50℃-60℃ for 24h-30h.

[0045] In some 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 amount of the first catalyst added 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). Within the above range, the reaction process is well controllable, and the modified polyester filament obtained has better performance and stability.

[0046] In some embodiments, 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). If the weight of the matting agent is less than 0.20% of the weight of the modified polyester, the matting effect will be poor and the acetaldehyde absorption effect will be poor. If the weight of the matting agent is greater than 0.25% of the weight of the modified polyester, it will affect the performance and stability of the modified polyester, and the improvement in acetaldehyde absorption effect will not be significant.

[0047] In some embodiments, the stabilizer is triphenyl phosphate, trimethyl phosphate, or trimethyl phosphite, and the amount of 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, antimony glycolate, or antimony acetate, and the amount of the second catalyst added is 0.03%-0.05% of the total weight of terephthalic acid, thereby improving the stability and reaction rate of the reaction process. If any component in this invention is not mentioned in terms of mass percentage, molar ratio, or volume, it indicates that it has little impact on the technical effect of this invention and is not specifically limited.

[0048] In some embodiments, the spinning process of modified polyester filament is as follows: modified polyester chips are metered and melted to obtain modified polyester melt; the modified polyester melt is extruded through a spinneret, cooled, oiled, stretched, heat-set, and wound to obtain modified polyester filament; the modified polyester filament is wound through a first roller and a second roller, with the speed difference between the first and second rollers forming the stretch; the first roller heats the fiber, and the second roller heats it. The parameters for preparing the modified polyester filament are as follows: extrusion temperature is 270℃-280℃, cooling temperature is 20℃-25℃, and the first roller speed is 2... The winding speed is 200m / min-2400m / min, the temperature of the first roller is 65℃-70℃, the speed of the second roller is 3000m / min-3200m / min, the temperature of the second roller is 150℃-180℃, the 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.

[0049] Example 1

[0050] A modified polyester filament comprises a modified polyester and a matting agent. The modified polyester includes terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester segments. The matting agent is an inorganic mesoporous powder containing amino functional groups on its surface. The inorganic mesoporous powder is mesoporous titanium dioxide powder with a pore size of 2 nm and a specific surface area of ​​100 m². 2 / g, particle size of 200nm, amino functional group content of 1wt%, melting point of modified polyester at 110℃, and molecular weight of modified polyester of 18000.

[0051] This invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0052] A matting agent and modified polyester are prepared. The matting agent and modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

[0053] The specific steps for preparing a matting agent are as follows:

[0054] Using alkylamine as a template agent and isopropyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol, and deionized water is added to generate a precipitate. After aging, filtration and extraction to remove part of the template agent, the precipitate is then washed and dried to obtain a matting agent, which is mesoporous titanium dioxide powder.

[0055] The aging conditions were: first, room temperature 20℃ for 20 hours, then the temperature was increased to 90℃ for 40 hours; the extraction conditions were: treatment in nitric acid ethanol solution at pH=2 for 12 hours at room temperature; the washing conditions were: washing three times with ethanol by vacuum filtration; and the drying conditions were: drying temperature 50℃ for 24 hours.

[0056] The specific steps for preparing modified polyester are as follows:

[0057] 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 3 hours. The methanol was evaporated to remove the esterification product. Water was added to separate the esterification product. The esterification product was then extracted with ethyl acetate. After evaporation to remove the ethyl acetate, dimethyl 5-amino-isophthalate was obtained.

[0058] Dimethyl 5-aminoisophthalate was subjected to transesterification with ethylene glycol under the action of a first catalyst at an esterification temperature of 180°C for 2 hours until the transesterification reaction was complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate.

[0059] 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 the esterification product. The pressure is 0.1 MPa and the temperature is 230℃. The esterification reaction ends when the amount of water distilled out in the esterification reaction reaches more than 95% of the theoretical value.

[0060] After the esterification reaction was completed, bis-3-hydroxyethyl 5-aminoisophthalic acid was added to the esterification product, followed by a second catalyst and a stabilizer. The low-vacuum stage of polycondensation was initiated under negative pressure. The pressure in the low-vacuum stage was steadily reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature was controlled at 260 °C, and the reaction time was 30 min. Then, the vacuum was continued to carry out the high-vacuum stage of polycondensation. The pressure in the high-vacuum stage was reduced to an absolute pressure of 60 Pa, the reaction temperature was controlled at 275 °C, and the reaction time was 50 min, thus obtaining the modified polyester.

[0061] The alkylamine was dodecylamine, the molar ratio of alkylamine to titanium source was 1:2, the volume ratio of ethanol to deionized water was 1:4, and the concentration of alkylamine was 2wt%.

[0062] The molar ratio of 5-aminoisophthalic acid, methanol, and thionyl chloride is 1:35.0:3. The volume of water added is twice that of methanol, and the volume of ethyl acetate added is once that of methanol. The molar ratio of dimethyl 5-aminoisophthalate to ethylene glycol is 1:1.8. The amount of the first catalyst added is 0.02% of the weight of dimethyl 5-aminoisophthalate. The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.4:0.08:1.8. The weight of the matting agent is 0.20% of the weight of the modified polyester. The molar ratio of bis-3-hydroxyethyl 5-aminoisophthalate to terephthalic acid is 1:0.02.

[0063] The stabilizer is triphenyl phosphate, and the amount of stabilizer added is 0.03% of the total weight of terephthalic acid. The first catalyst is zinc acetate, and the second catalyst is antimony trioxide, and the amount of the second catalyst added is 0.03% of the total weight of terephthalic acid.

[0064] The spinning process of modified polyester filament is as follows: modified polyester chips are metered and melted to obtain modified polyester melt. The modified polyester melt is extruded through a spinneret, cooled, oiled, stretched, heat-set, and wound to obtain modified polyester filament. The modified polyester filament is wound through a first roller and a second roller. The speed difference between the first and second rollers forms the stretch. The first roller heats the modified polyester filament, and the second roller heats it. The parameters for preparing modified polyester filament are as follows: extrusion temperature is 270℃, cooling temperature is 20℃, first roller speed is 2200m / min, first roller temperature is 65℃, second roller speed is 3000m / min, second roller temperature is 150℃, and winding speed is 2960 m / min.

[0065] The modified polyester filament was tested and found to have a fineness of 1.5 dtex, a breaking strength of 3.76 cN / dtex, a breaking elongation of 50.0%, and an acetaldehyde content of 0.43 ppm.

[0066] Example 2

[0067] A modified polyester filament comprises a modified polyester and a matting agent. The modified polyester includes terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester segments. The matting agent is an inorganic mesoporous powder containing amino functional groups on its surface. The inorganic mesoporous powder is mesoporous titanium dioxide powder with a pore size of 4 nm and a specific surface area of ​​300 m². 2 / g, particle size of 300nm, amino functional group content of 3wt%, the melting point of the modified polyester is 150℃, and the molecular weight of the modified polyester is 20000.

[0068] This invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0069] A matting agent and modified polyester are prepared. The matting agent and modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

[0070] The specific steps for preparing a matting agent are as follows:

[0071] Using alkylamine as a template agent and tetrabutyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol, and deionized water is added to generate a precipitate. After aging, filtration and extraction to remove part of the template agent, the precipitate is obtained by washing and drying. The precipitate is mesoporous titanium dioxide powder.

[0072] The aging conditions were: first, room temperature 23℃ for 24 hours, then heated to 100℃ for 48 hours; extraction conditions were: treatment in nitric acid ethanol solution at pH=2 for 15 hours at room temperature; washing conditions were: washing 5 times with ethanol filtration; and drying conditions were: drying temperature 60℃ for 30 hours.

[0073] The specific steps for preparing modified polyester are as follows:

[0074] 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 4 hours, methanol was evaporated to remove it, water was added to separate the esterification product, the esterification product was extracted with ethyl acetate, and ethyl acetate was evaporated to remove it to obtain dimethyl 5-amino-isophthalate.

[0075] Dimethyl 5-aminoisophthalate was subjected to transesterification with ethylene glycol under the action of a first catalyst at an esterification temperature of 210°C for 3 hours until the transesterification reaction was complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate.

[0076] 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 the esterification product. The pressure is 0.3 MPa and the temperature is 250℃. The esterification reaction ends when the amount of water distilled out in the esterification reaction reaches more than 95% of the theoretical value.

[0077] After the esterification reaction, bis-3-hydroxyethyl 5-aminoisophthalic acid was added to the esterification product, followed by a second catalyst and a stabilizer. The low-vacuum stage of polycondensation was initiated under negative pressure. The pressure in the low-vacuum stage was steadily reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature was controlled at 270 °C, and the reaction time was 50 min. Then, the vacuum was continued to carry out the high-vacuum stage of polycondensation. The pressure in the high-vacuum stage was reduced to an absolute pressure of 65 Pa, the reaction temperature was controlled at 280 °C, and the reaction time was 90 min, thus obtaining the modified polyester.

[0078] The alkylamine is tetradecylamine, the molar ratio of alkylamine to titanium source is 1:3, the volume ratio of ethanol to deionized water is 1:5, the concentration of alkylamine is 2.2wt%, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester to terephthalic acid is 1:0.025.

[0079] 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 amount of the first catalyst added 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 matting 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.

[0080] The stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and the amount of stabilizer added is 0.05% of the total weight of terephthalic acid. The first catalyst is zinc acetate, and the second catalyst is antimony trioxide, antimony glycolate or antimony acetate, and the amount of the second catalyst added is 0.05% of the total weight of terephthalic acid.

[0081] The spinning process of modified polyester filament is as follows: modified polyester chips are metered and melted to obtain modified polyester melt. The modified polyester melt is extruded through a spinneret, cooled, oiled, stretched, heat-set, and wound to obtain modified polyester filament. The modified polyester filament is wound through a first roller and a second roller. The speed difference between the first and second rollers forms the stretching. The first roller heats the modified polyester filament, and the second roller heats it. The parameters for preparing modified polyester filament are as follows: extrusion temperature is 280℃, cooling temperature is 25℃, first roller speed is 2400m / min, first roller temperature is 70℃, second roller speed is 3200m / min, second roller temperature is 180℃, and winding speed is 3230 m / min.

[0082] The modified polyester filament was tested and found to have a fineness of 3.0 dtex, a breaking strength of 3.82 cN / dtex, a breaking elongation of 55.0%, and an acetaldehyde content of 0.38 ppm.

[0083] Example 3

[0084] A modified polyester filament comprises a modified polyester and a matting agent. The modified polyester includes terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester segments. The matting agent is an inorganic mesoporous powder containing amino functional groups on its surface. The inorganic mesoporous powder is mesoporous titanium dioxide powder with a pore size of 3 nm and a specific surface area of ​​200 m².2 / g, particle size of 260nm, amino functional group content of 2wt%, the melting point of the modified polyester is 130℃, and the molecular weight of the modified polyester is 22000.

[0085] This invention also provides a method for preparing modified polyester filaments, comprising the following steps:

[0086] A matting agent and modified polyester are prepared. The matting agent and modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

[0087] The specific steps for preparing a matting agent are as follows:

[0088] Using alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol, and deionized water is added to generate a precipitate. After aging, filtration and extraction to remove part of the template agent, the precipitate is then washed and dried to obtain a matting agent, which is mesoporous titanium dioxide powder.

[0089] The aging conditions were: room temperature 25℃ for 24 hours, followed by heating to 95℃ for 45 hours; extraction conditions were: treatment in nitric acid ethanol solution at pH=2 for 13 hours at room temperature; washing conditions were: washing four times with ethanol by vacuum filtration; and drying conditions were: drying temperature 55℃ for 25 hours.

[0090] The specific steps for preparing modified polyester are as follows:

[0091] 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 4 hours, methanol was evaporated to remove it, water was added to separate the esterification product, the esterification product was extracted with ethyl acetate, and ethyl acetate was evaporated to remove it to obtain dimethyl 5-amino-isophthalate.

[0092] Dimethyl 5-aminoisophthalate was subjected to transesterification with ethylene glycol under the action of a first catalyst at an esterification temperature of 200°C for 3 hours until the transesterification reaction was complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate.

[0093] 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 the esterification product. The pressure is 0.2 MPa and the temperature is 240℃. The esterification reaction ends when the amount of water distilled out in the esterification reaction reaches more than 95% of the theoretical value.

[0094] After the esterification reaction, bis-3-hydroxyethyl 5-aminoisophthalic acid was added to the esterification product, followed by a second catalyst and a stabilizer. The low-vacuum stage of polycondensation was initiated under negative pressure. The pressure in the low-vacuum stage was steadily reduced from atmospheric pressure to an absolute pressure of 450 Pa, the temperature was controlled at 265 °C, and the reaction time was 40 min. Then, the vacuum was continued to carry out the high-vacuum stage of polycondensation. The pressure in the high-vacuum stage was reduced to an absolute pressure of 65 Pa, the reaction temperature was controlled at 280 °C, and the reaction time was 80 min, thus obtaining the modified polyester.

[0095] The alkylamine is octadecylamine, the molar ratio of alkylamine to titanium source is 1:3, the volume ratio of ethanol to deionized water is 1:5, and the concentration of alkylamine is 2.1 wt%.

[0096] 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, 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. The amount of the first catalyst added 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 matting agent is 0.22% of the weight of the modified polyester. The molar ratio of bis-3-hydroxyethyl 5-aminoisophthalate to terephthalic acid is 1:0.03.

[0097] The stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and the amount of stabilizer added is 0.04% of the total weight of terephthalic acid. The first catalyst is zinc acetate and the second catalyst is antimony glycolate, and the amount of the second catalyst added is 0.04% of the total weight of terephthalic acid.

[0098] The parameters for preparing modified polyester filaments are as follows: extrusion temperature is 275℃, cooling temperature is 24℃, first roll speed is 2300m / min, first roll temperature is 70℃, second roll speed is 3100m / min, second roll temperature is 160℃, and winding speed is 3200m / min.

[0099] The modified polyester filament was tested and found to have a fineness of 2.0 dtex, a breaking strength of 3.78 cN / dtex, a breaking elongation of 52.0%, and an acetaldehyde content of 0.46 ppm.

[0100] Examples 1, 2 and 3 show that the acetaldehyde content is very low, the acetaldehyde elimination effect is good, and the mechanical properties are good.

[0101] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A modified polyester filament characterized in that, The product includes a modified polyester and a matting agent. The modified polyester comprises terephthalic acid segments, isophthalic acid segments, ethylene glycol segments, diethylene glycol segments, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester segments. The matting agent is an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains amino functional groups.

2. The modified polyester filament according to claim 1, characterized in that, The inorganic mesoporous powder is mesoporous titanium dioxide powder, and the pore size of the mesoporous titanium dioxide powder is 2nm-4nm, with a specific surface area of ​​100m². 2 / g-300m 2 / g, with a particle size of 200nm-300nm, and the content of the amino functional group is 1wt%-3wt%.

3. The modified polyester filament of claim 2, wherein, The modified polyester has a melting point of 110℃-150℃ and a molecular weight of 18000-22000.

4. The method of making a modified polyester filament according to any one of claims 2-3, characterized in that, Includes the following steps: A matting agent and a modified polyester are prepared. The matting agent and the modified polyester are mixed to obtain modified polyester chips. The modified polyester chips are metered, melted, extruded, cooled, oiled, stretched, heat-set and wound to obtain modified polyester filaments.

5. The production method according to claim 4, characterized by, The specific steps for preparing the matting agent are as follows: Using alkylamine as a template agent and isopropyl titanate or n-butyl titanate as a titanium source, the template agent and titanium source are mixed and dissolved in ethanol, and deionized water is added to generate a precipitate. After aging, filtration, and extraction to remove part of the template agent, the precipitate is then washed and dried to obtain the matting agent, which is mesoporous titanium dioxide powder. The specific steps for preparing the modified polyester are as follows: 5-Amino-isophthalic acid was dissolved in methanol, and thionyl chloride was added under ice-water bath conditions. The reaction was carried out for 3-4 hours. The methanol was evaporated to remove the methanol, and water was added to separate the esterification product. The esterification product was then extracted with ethyl acetate, and the ethyl acetate was evaporated to remove the ester to obtain dimethyl 5-amino-isophthalate. Dimethyl 5-aminoisophthalate was subjected to transesterification with ethylene glycol under the action of a first catalyst at an esterification temperature of 180℃-210℃ and an esterification time of 2h-3h until the transesterification reaction was complete, yielding bis-3-hydroxyethyl 5-aminoisophthalate. 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 the esterification product. The pressure is 0.1-0.3 MPa and the temperature is 230℃-250℃. After the esterification reaction is completed, bis-3-hydroxyethyl 5-aminoisophthalic acid is added to the esterification product, followed by a second catalyst and a stabilizer. A low-vacuum polycondensation reaction is then initiated under negative pressure. The pressure in the low-vacuum stage is steadily reduced from atmospheric pressure to below 500 Pa, the temperature is controlled at 260℃-270℃, and the reaction time is 30-50 min. Then, vacuum is continued to carry out a high-vacuum polycondensation reaction. The pressure in the high-vacuum stage is reduced to below 70 Pa, the reaction temperature is controlled at 275℃-280℃, and the reaction time is 50-90 min, thus obtaining the modified polyester.

6. The production method according to claim 5, characterized by The alkylamine is dodecyl, tetradecyl, hexadecyl, 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 2wt%-2.2wt%, the aging conditions are: first at room temperature for 20-24 hours, then heated to 90℃-100℃ for 40-48 hours, the extraction conditions are: treatment in a nitric acid ethanol solution at pH=2 at room temperature for 12-15 hours, the washing conditions are: washing 3-5 times with ethanol filtration, and the drying conditions are: drying temperature 50℃-60℃ for 24-30 hours.

7. The production method according to claim 5, characterized by, 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, and 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 amount of the first catalyst added 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).

8. The production method according to claim 5, characterized by, 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).

9. The production method according to claim 5, characterized by, The stabilizer is triphenyl phosphate, trimethyl phosphate, or trimethyl phosphite, and the amount of 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, antimony glycolate, or antimony acetate, and the amount of the second catalyst added is 0.03%-0.05% of the total weight of terephthalic acid.

10. The production method according to claim 4, characterized by, The parameters for preparing the modified polyester filament are as follows: extrusion temperature of 270℃-280℃, cooling temperature of 20℃-25℃, first roll speed of 2200m / min-2400m / min, first roll temperature of 65℃-70℃, second roll speed of 3000m / min-3200m / min, second roll temperature of 150℃-180℃, winding speed of 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.