Modified polyester filament and preparation method thereof

Abstract

The invention discloses a modified polyester filament which comprises modified polyester and a delustering agent, the modified polyester comprises a terephthalic acid chain segment, an isophthalic acid chain segment, an ethylene glycol chain segment, a diethylene glycol chain segment and a 5-amino isophthalic acid bis-3-hydroxyethyl ester chain segment, and the delustering agent is inorganic mesoporous powder. The surface of the inorganic mesoporous powder contains amino functional groups. According to the modified polyester filament, the amino-containing inorganic mesoporous powder is introduced into a melt spinning system instead of a traditional delustering agent, the acetaldehyde removing effect and the delustering effect are achieved at the same time, industrial production is easy to achieve, release of acetaldehyde steam can be reduced in the spinning process, and the production efficiency is improved. The other purpose of the invention is to disclose a preparation method of the modified polyester filament. According to the preparation method, deterioration of acetaldehyde steam release to the environment in the spinning process is reduced, the content of acetaldehyde in the modified polyester filament is reduced, and the application safety of the modified polyester filament is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of spinning production, in particular 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 characteristics such as short bonding time, high strength, non-toxicity and pollution-free, and is known as "green adhesive". In the past ten years, hot melt adhesive has been widely used in the textile industry (such as adhesive interlining). The key to the manufacture of high-quality adhesive interlining is to have high-performance hot melt adhesive. Since copolyester hot melt adhesive is excellent in feel, price, and resistance to water washing, sand washing and steam pressing, it has a broader development prospect. Polyester hot melt adhesive is a new type of hot melt adhesive developed in recent decades. It is a modified low-melting point saturated copolyester, which is mostly made by copolymerization of two or more dibasic acids and diols, so that its crystallinity, glass transition temperature and melting point are greatly reduced to meet the special requirements of hot melt adhesive.

[0003] Thermal bonding low melting point fiber is one of the important raw materials for nonwoven fabrics. According to statistics, it accounts for about 28% of the total amount of nonwoven fabric fibers. In the current rapidly developing nonwoven fabric industry, the thermal bonding method has been given priority development because it uses a fiber-type adhesive processing method, which makes the processing simple, the production speed high, the energy consumption low, the application flexible, the product does not contain any chemical reagents, does not pollute the environment, and is 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 material, partially softens and melts the polymer fiber material, and then cools and solidifies the fibers to bond together. For the polyester nonwoven fabric industry, they need a polymer with a lower melting point than conventional polyester fibers and good compatibility with conventional polyester as a thermal bonding low melting point fiber. According to the "like dissolves like" principle, nonwoven fabrics with polyester as the main fiber should be bonded with polyester fibers of the same family. Practice has shown that bonding fibers spun from low-melting-point copolyester can make polyester flakes softer and fluffier, which provides a broad space for the application of polyester low-melting-point thermal bonding fibers.

[0004] However, a series of side reactions will occur during the esterification reaction of low-melting-point copolyesters, producing many by-products, among which acetaldehyde is the most influential by-product, which can cause facial flushing, palpitations, and decreased blood pressure. At the same time, acetaldehyde can cause eye, nose and upper respiratory tract irritation and bronchitis. Inhalation of high concentrations of acetaldehyde has an anesthetic effect. Acetaldehyde is extremely harmful to human health.

[0005] In the preparation process of low-melting-point copolyester filaments, the cooling and stretching temperatures involved are both low and the time is short, which makes it impossible to reduce the acetaldehyde content of the fiber to below the safe value. Therefore, a new technical solution is urgently needed to solve at least one of the above technical problems. Summary of the invention

[0006] In view of the above-mentioned deficiencies, one object of the present invention is to provide a modified polyester filament, wherein an inorganic mesoporous powder containing amino groups is introduced into a melt spinning system instead of a traditional matting agent, and simultaneously plays the role of scavenging acetaldehyde and matting, and is easy to realize industrial production, and can reduce the release of acetaldehyde vapor during the spinning process, thereby improving the production environment. Another object of the present invention is to provide a method for preparing a modified polyester filament, wherein a modified polyester containing amino groups in a side group is synthesized by an inorganic simple copolymerization method, and thermal oxidative degradation is suppressed during polymerization and processing, and the generation of acetaldehyde is suppressed, and the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process is reduced, and the acetaldehyde content in the modified polyester filament is reduced, which 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 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 an inorganic mesoporous powder having an amino functional group on its surface.

[0009] As a preferred technical solution, the inorganic mesoporous powder is mesoporous titanium dioxide powder, the pore size of the mesoporous titanium dioxide powder is 2nm-4nm, and 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 method for preparing modified polyester filaments, comprising the following steps:

[0012] 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.

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

[0014] Using 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 into ethanol to mix and dissolve, deionized water is added to generate a precipitate, and a portion of the template agent is removed by aging, filtering, and extraction, and then washed and dried to obtain the matting agent, which is a mesoporous titanium dioxide powder;

[0015] The specific steps of preparing the modified polyester are:

[0016] 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;

[0017] 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;

[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 an esterification product at a pressure of 0.1-0.3Mpa and a temperature of 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, 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.

[0020] As a preferred technical solution, the alkylamine is dodecaamine, tetradecaamine, hexadecane or octadecane, 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 room temperature, the room temperature time is 2h-24h, and then the temperature is raised to 90°C-100°C, and the heating time is 40h-48h, the extraction conditions are treated 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.

[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 5-aminoisophthalic acid dimethyl ester 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 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).

[0022] As a preferred technical solution, 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] As a preferred technical solution, the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and the added amount of the stabilizer is 0.03%-0.05% of the total weight of the terephthalic acid; the second catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, and the added amount of the second catalyst is 0.03%-0.05% of the total weight of the terephthalic acid.

[0024] As a preferred technical solution, 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, one roller speed is 2200m / min-2400m / min, one 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.

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

[0026] 1) 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 scavenging acetaldehyde and matting, is easy to realize industrial production, can reduce the release of acetaldehyde vapor during the spinning process, improve the production environment, and synthesize the modified polyester containing amino groups in the side groups by a simple copolymerization method, so as to achieve the inhibition of thermal oxidative degradation and the generation of acetaldehyde during the polymerization and processing process, reduce the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process, and reduce the acetaldehyde content in the modified polyester filament, which is beneficial to the safety of its application;

[0027] 2) High-refractive-index mesoporous titanium dioxide powder needs to be added to the modified polyester filament, and the mesoporous titanium dioxide powder is prepared into a mesoporous form containing amino functional groups, which has both extinction function and acetaldehyde removal function;

[0028] 3) The preparation method of modified polyester filaments is to synthesize modified polyesters containing amino groups in side groups through simple inorganic copolymerization, so as to inhibit thermal oxidative degradation and the generation of acetaldehyde during polymerization and processing, reduce the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process, reduce the acetaldehyde content in the modified polyester filaments, and benefit the safety of its application. DETAILED DESCRIPTION

[0029] The present invention is 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 the terms "top", "bottom", "left", "right", "front", "back", "inside", "outside" and the like indicate orientation or positional relationships, it is only for the convenience of describing the present invention, and does not indicate or imply 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 positional relationship are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, 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 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 an inorganic mesoporous powder, and the surface of the inorganic mesoporous powder contains an amino functional group. The present invention introduces the amino-containing inorganic mesoporous powder into the melt spinning system instead of the traditional matting agent, and simultaneously plays the role of acetaldehyde removal and matting, and is easy to realize industrial production. The release of acetaldehyde vapor can be reduced during the spinning process, and the production environment is improved. The modified polyester containing amino groups in the side groups is synthesized by a simple copolymerization method, and thermal oxidative degradation is suppressed during the polymerization and processing process, and the generation of acetaldehyde is suppressed, and the deterioration of the environment caused by the release of acetaldehyde vapor during the spinning process is reduced, and the acetaldehyde content in the modified polyester filament is reduced, which is beneficial to the safety of its application.

[0032] In some embodiments, the inorganic mesoporous powder is mesoporous titanium dioxide powder, the pore size of the mesoporous titanium dioxide powder is 2nm-4nm, and the specific surface area is 100m 2 / g-300m 2 / g, the particle size is 200nm-300nm, the content of amino functional groups is 1wt%-3wt%, and the present invention needs to add high refractive index mesoporous titanium dioxide powder to the modified polyester filament, and prepare the mesoporous titanium dioxide powder into a mesoporous form containing amino functional groups, which has both extinction function and acetaldehyde removal function. On the one hand, the porous structure can increase the number of refractions of light and produce a better extinction effect; on the other hand, the mesopores are conducive to the adsorption of acetaldehyde vapor molecules, because the modified polyester becomes a modified polyester melt after heating and extrusion, which will release acetaldehyde vapor molecules, and the mesopores can well adsorb acetaldehyde vapor molecules, and 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 adopts an inorganic mesoporous material to absorb acetaldehyde generated in the polymerization and spinning process. The inorganic mesoporous material is mesoporous titanium dioxide powder, which has the function of absorbing acetaldehyde molecules and has efficient extinction ability. The mesoporous titanium dioxide powder is added to the melt spinning system instead of the traditional extinction agent without changing the existing low-melting point polyester filament production process.

[0034] In some embodiments, 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. 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 modified polyester filaments, comprising the following steps:

[0036] 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.

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

[0038] Alkylamine is used as a template agent, isopropyl titanate or n-butyl titanate is used as a titanium source, the template agent and the titanium source are added into ethanol and mixed and dissolved, so that amino functional groups can be formed, deionized water is added to generate precipitation, and part of the template agent is removed through aging, filtering and extraction, and then the matting agent is obtained through washing and drying. The matting agent is mesoporous titanium dioxide powder. In the preparation of amino-containing mesoporous titanium dioxide powder, the alkylamine is directly used as a template agent. Different from the conventional preparation of mesoporous titanium dioxide powder, which requires complete removal of the template agent, a part of the template agent is retained, thereby reducing the step of reintroducing the amino functional group and reducing the production cost. Moreover, the amino functional group is located on the inner wall of the mesopore, 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 modified polyester are:

[0040] 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;

[0041] 5-aminoisophthalic acid dimethyl ester and ethylene glycol undergo an ester exchange reaction under the action of a first catalyst, the esterification temperature is 180-210 DEG C, the esterification time is 2h-3h, until the ester exchange reaction is complete, and 5-aminoisophthalic acid bis-3-hydroxyethyl ester is obtained. On the basis of introducing mesoporous titanium dioxide powder containing amino functional groups, the present invention further adds 5-aminoisophthalic acid bis-3-hydroxyethyl ester into the comonomer. For 5-aminoisophthalic acid bis-3-hydroxyethyl ester, on the one hand, the aniline group in the structure acts as an aromatic amine antioxidant to inhibit the thermal oxidation degradation of macromolecules; on the other hand, 5-aminoisophthalic acid destroys the regular structure of polyester macromolecules, which is beneficial to reducing the melting point of the modified polyester. The third aspect is that the amino group in the structure reacts with acetaldehyde to undergo Schiff base reaction, and the acetaldehyde generated by high-temperature cracking is in-situ chemically bonded to the macromolecular chain, thereby reducing the content of acetaldehyde in the polyester melt, reducing the content of acetaldehyde in the modified polyester filaments, and reducing the impact of acetaldehyde on the environment in the application of the modified polyester filaments.

[0042] 5-aminoisophthalic acid, methanol, and thionyl chloride react in an ice-water bath to form dimethyl 5-aminoisophthalate. In the reaction, methanol and thionyl chloride first generate the intermediate methyl chloride sulfite. The -OSOCl group in methyl chloride sulfite is easily separated from the methyl group and reacts with the free H + The generated sulfurous acid chloride is very 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 5-aminoisophthalic acid dimethyl ester is then subjected to an ester exchange reaction with ethylene glycol at 180℃-210℃ to obtain the third monomer 5-aminoisophthalic acid bis-3-hydroxyethyl ester. Methanol is produced as a by-product, and its boiling point is much lower than the reaction temperature, so it is easy to evaporate and remove.

[0043] 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;

[0044] 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 condensation 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 condensation 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 a modified polyester.

[0045] In some embodiments, the alkylamine is dodecaamine, tetradecaamine, hexadecane or octadecane, 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 first at room temperature of 20°C-26°C, the room temperature time is 20h-24h, then the temperature is raised to 90°C-100°C, the heating time is 40h-48h, the extraction conditions are treated in a nitric acid ethanol solution with pH=2 at room temperature for 12h-15h, the washing conditions are filtered and washed with ethanol for 3-5 times, and the drying conditions are drying temperature of 50°C-60°C, and drying time of 24h-30h.

[0046] 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 5-aminoisophthalic acid dimethyl ester 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 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). Within the above range, the reaction process has good controllability, and the modified polyester filament finally obtained has better performance and better stability.

[0047] 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 is poor and the acetaldehyde absorption effect is not good. 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 acetaldehyde absorption effect will not be significantly improved.

[0048] In some embodiments, 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, 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, which improves the stability of the reaction process and the reaction rate. If the mass percentage, molar ratio or volume of a component in the present invention is not mentioned, it means that the technical effect of the present invention is less affected and no specific limitation is made.

[0049] In some embodiments, the spinning process of the modified polyester filament is: the modified polyester chips are measured and melted to obtain a modified polyester melt, the modified polyester melt is extruded through a spinneret, cooled, oiled, stretched, heat-set and wound to obtain a modified polyester filament, the modified polyester filament is passed through a 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 heats the fiber. 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 2 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.

[0050] Example 1

[0051] A modified polyester filament 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, the matting agent is an inorganic mesoporous powder, the surface of the inorganic mesoporous powder contains an amino functional group, the inorganic mesoporous powder is a mesoporous titanium dioxide powder, the pore diameter of the mesoporous titanium dioxide powder is 2nm, and the specific surface area is 100m 2 / g, the particle size is 200nm, the content of amino functional groups is 1wt%, 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 modified polyester filaments, comprising the following steps:

[0053] 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.

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

[0055] Alkylamine is used as a template agent and isopropyl titanate is used as a titanium source. The template agent and the titanium source are added into ethanol to mix and dissolve, and deionized water is added to generate precipitation. A part of the template agent is removed by aging, filtering, and extraction, and then a matting agent is obtained by washing and drying. The matting agent is mesoporous titanium dioxide powder.

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

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

[0058] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride in an ice-water bath, react for 3 hours, 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;

[0059] 5-aminoisophthalic acid dimethyl ester and ethylene glycol are subjected to an ester exchange reaction under the action of a first catalyst, the esterification temperature is 180° C., the esterification time is 2 h, until the ester exchange reaction is complete, to obtain 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0060] 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 MPa and a temperature of 230°C. When the amount of water distilled in the esterification reaction reaches more than 95% of the theoretical value, the esterification reaction ends and an esterification product is obtained;

[0061] 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 condensation reaction is started under negative pressure conditions. The pressure in the low vacuum stage is steadily reduced from normal pressure to an absolute pressure of 450Pa, the temperature is controlled at 260°C, and the reaction time is 30min. Then, vacuuming is continued to carry out a high vacuum stage condensation reaction. The pressure in the high vacuum stage is reduced to an absolute pressure of 60Pa, the reaction temperature is controlled at 275°C, and the reaction time is 50min to obtain a 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, and 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 twice that of methanol, the volume of ethyl acetate added is 1 time that of methanol, the molar ratio of 5-aminoisophthalic acid dimethyl ester to ethylene glycol is 1:1.8, the amount of the first catalyst added is 0.02% of the weight of 5-aminoisophthalic acid dimethyl ester, 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, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester to terephthalic acid is 1:0.02.

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

[0065] The spinning process of modified polyester filament is as follows: modified polyester chips are measured 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 passed through a first roller and a second roller to be wound, the speed difference between the first roller and the second roller forms stretching, a first roller heats the modified polyester filament, and a second roller heat-sets. The parameters for preparing the modified polyester filament are as follows: extrusion temperature is 270°C, cooling temperature is 20°C, first roller speed is 2200m / min, first roller temperature is 65°C, second roller speed is 3000m / min, second roller temperature is 150°C, and winding speed is 2960m / min.

[0066] The test results show that the fineness of the modified polyester filament is 1.5 dtex, the breaking strength is 3.76 cN / dtex, the breaking elongation is 50.0%, and the acetaldehyde content in the modified polyester filament is 0.43 ppm.

[0067] Example 2

[0068] A modified polyester filament 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, the matting agent is an inorganic mesoporous powder, the surface of the inorganic mesoporous powder contains an amino functional group, the inorganic mesoporous powder is a mesoporous titanium dioxide powder, the pore diameter of the mesoporous titanium dioxide powder is 4nm, and the specific surface area is 300m 2 / g, the particle size is 300nm, the content of amino functional groups is 3wt%, 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 modified polyester filaments, comprising the following steps:

[0070] 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.

[0071] The specific steps for preparing the matting agent are:

[0072] Alkylamine is used as a template agent and n-butyl titanate is used as a titanium source. The template agent and the titanium source are added into ethanol to mix and dissolve, and deionized water is added to generate precipitation. A part of the template agent is removed by aging, filtering, and extraction, and then a matting agent is obtained by washing and drying. The matting agent is mesoporous titanium dioxide powder.

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

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

[0075] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride in an ice-water bath, react for 4 hours, 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;

[0076] 5-aminoisophthalic acid dimethyl ester and ethylene glycol are subjected to an ester exchange reaction under the action of a first catalyst, the esterification temperature is 210° C., the esterification time is 3 hours, and the ester exchange reaction is completed to obtain 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0077] 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 0.3 MPa and a temperature of 250°C. When the amount of water distilled in the esterification reaction reaches more than 95% of the theoretical value, the esterification reaction ends and an esterification product is obtained;

[0078] 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 condensation reaction is started under negative pressure conditions. The pressure in the low vacuum stage is steadily reduced from normal pressure to an absolute pressure of 450Pa, the temperature is controlled at 270°C, and the reaction time is 50min. Then, vacuuming is continued to carry out a high vacuum stage condensation reaction. The pressure in the high vacuum stage is reduced to an absolute pressure of 65Pa, the reaction temperature is controlled at 280°C, and the reaction time is 90min to obtain a 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 2.2wt%, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester 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, the volume of ethyl acetate added is 1.2 times that of methanol, the molar ratio of 5-aminoisophthalic acid dimethyl ester to ethylene glycol is 1:2.2, the amount of the first catalyst added is 0.03% of the weight of 5-aminoisophthalic acid dimethyl ester, 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, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester to terephthalic acid is 1:0.03.

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

[0082] The spinning process of modified polyester filament is as follows: modified polyester chips are measured 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 passed through a first roller and a second roller to be wound, the speed difference between the first roller and the second roller forms stretching, a first roller heats the modified polyester filament, and a second roller heat-sets. The parameters for preparing the modified polyester filament are as follows: extrusion temperature is 280°C, cooling temperature is 25°C, first roller speed is 2400m / min, first roller temperature is 70°C, second roller speed is 3200m / min, second roller temperature is 180°C, and winding speed is 3230m / min.

[0083] The test results show that the modified polyester filament has a fineness of 3.0 dtex, a breaking strength of 3.82 cN / dtex, an elongation at break of 55.0%, and an acetaldehyde content of 0.38 ppm.

[0084] Example 3

[0085] A modified polyester filament 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, the matting agent is an inorganic mesoporous powder, the surface of the inorganic mesoporous powder contains an amino functional group, the inorganic mesoporous powder is a mesoporous titanium dioxide powder, the pore diameter of the mesoporous titanium dioxide powder is 3nm, and the specific surface area is 200m 2 / g, the particle size is 260nm, the content of amino functional groups is 2wt%, the melting point of the modified polyester is 130°C, and the molecular weight of the modified polyester is 22000.

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

[0087] 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.

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

[0089] Using 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 into ethanol to mix and dissolve, deionized water is added to generate precipitation, part of the template agent is removed by aging, filtering and extraction, and then washed and dried to obtain a matting agent, which is mesoporous titanium dioxide powder;

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

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

[0092] Dissolve 5-aminoisophthalic acid in methanol, add thionyl chloride in an ice-water bath, react for 4 hours, 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;

[0093] 5-aminoisophthalic acid dimethyl ester and ethylene glycol are subjected to an ester exchange reaction under the action of a first catalyst, the esterification temperature is 200° C., the esterification time is 3 hours, and the ester exchange reaction is completed to obtain 5-aminoisophthalic acid bis-3-hydroxyethyl ester;

[0094] 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 0.2 MPa and a temperature of 240°C. When the amount of water distilled in the esterification reaction reaches more than 95% of the theoretical value, the esterification reaction ends and an esterification product is obtained;

[0095] 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 condensation reaction is started under negative pressure conditions. The pressure in the low vacuum stage is steadily reduced from normal pressure to an absolute pressure of 450Pa, the temperature is controlled at 265°C, and the reaction time is 40min. Then, vacuuming is continued to carry out a high vacuum stage condensation reaction. The pressure in the high vacuum stage is reduced to an absolute pressure of 65Pa, the reaction temperature is controlled at 280°C, and the reaction time is 80min to obtain a 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 5-aminoisophthalic acid dimethyl ester to ethylene glycol is 1:2, the amount of the first catalyst added is 0.03% of the weight of 5-aminoisophthalic acid dimethyl ester, 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, and the molar ratio of 5-aminoisophthalic acid bis-3-hydroxyethyl ester to terephthalic acid is 1:0.03.

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

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

[0100] The test results show that the fineness of the modified polyester filament is 2.0 dtex, the breaking strength is 3.78 cN / dtex, the breaking elongation is 52.0%, and the acetaldehyde content in the modified polyester filament is 0.46 ppm.

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

[0102] Any numerical value cited herein includes all values ​​of lower and upper values ​​that increase by one unit from the lower limit to the upper limit, and there is at least a two-unit interval between any lower value and any higher value. For example, if the value of the quantity of a component or a process variable (such as temperature, pressure, time, etc.) is stated to be from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in the specification. For values ​​less than 1, one unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly stated in the specification in a similar manner.

[0103] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0104] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." to describe a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to indicate that any attribute described that "may" include is optional.

[0105] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0106] It should be understood that the above description is not intended to be limiting. Upon reading the above description, many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by these claims. For the purpose of comprehensiveness, all articles and references, including the disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the inventors did not consider the 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 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, the pore size of the mesoporous titanium dioxide powder is 2nm-4nm, and 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%.

3. The modified polyester filament according to claim 2, 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.

4. The method for preparing modified polyester filament according to any one of claims 2 to 3, 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.

5. The preparation method according to claim 4, characterized in that: The specific steps of preparing the matting agent are: Using 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 into ethanol to mix and dissolve, deionized water is added to generate a precipitate, and a portion of the template agent is removed by aging, filtering, and extraction, and then washed and dried to obtain the matting agent, which is a mesoporous titanium dioxide powder; 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.

6. The preparation method according to claim 5, characterized in that: The alkylamine is dodecaamine, tetradecaamine, hexadecane or octadecane, 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 room temperature, the room temperature time is 2h-24h, and then the temperature is raised to 90°C-100°C, and the heating time is 40h-48h, the extraction conditions are treated 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.

7. 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).

8. 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).

9. 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 the 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 the terephthalic acid.

10. 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 less than 0.5ppm.