Modified dyes and their use

Abstract

The application discloses a modified dye and application thereof, and a preparation method of the modified dye. 1‑3 alkylene or hydroxyl-substituted C 1‑3 alkylene, R2, R3, R4 are independently selected from C 1‑2 alkyl; two quaternary ammonium centers spaced by R1 are formed in the molecule of the modified dye; the modified dye can realize simultaneous liquid coloring and functionalization, has little negative effect on physical properties of a product, has no wastewater discharge, meets high environmental protection standards, and avoids problems of insufficient high-temperature stability after addition of part of antibacterial agents, unexpected reaction of the antibacterial agents with the disperse dye, and difficulty in effective dispersion of part of the antibacterial agents, and has good and long-lasting antibacterial effect.

Description

[0001] This invention is a divisional application of Chinese invention patent application filed on August 13, 2024, with application number 2024111028362 and titled "A Nonwoven Fabric, Antibacterial Masterbatch, and Antibacterial Colored Fiber". Technical Field

[0002] This invention relates to the field of textile manufacturing technology, specifically to a modified dye and its application. Background Technology

[0003] When textiles are used, they inevitably need to have a certain color. Different colors may be needed in different scenarios. At the same time, with the continuous improvement of ecological and environmental protection requirements and the process of industrial upgrading, the application prospects and industrial scale of biodegradable polyester textiles are getting bigger and bigger. Functional biodegradable polyester textiles are even more favored. For example, biodegradable polyester textiles with antibacterial and flame retardant functions have ushered in rapid development. Currently, the main methods for preparing colored textiles or functionalized biodegradable polyester textiles include the following: The first method involves first preparing colored or functionalized fibers, and then using these fibers to create colored or functionalized textiles. The methods for imparting color or functionality include solution dyeing or functionalization, and fiber dyeing or functionalization. Solution dyeing or functionalization involves adding dyes or functional auxiliaries during fiber formation, meaning that the dyes or functional auxiliaries are directly added to the polymer during spinning, resulting in fibers that inherently possess color or functionality. Fiber dyeing or functionalization, on the other hand, is a process performed after the fibers have been formed, which involves impregnating the fibers with dyeing solutions or functional auxiliary dispersions to achieve dyeing or functionalization. The second method involves first producing textiles, and then dyeing them with dyeing solutions or functional auxiliary dispersions. In both methods, dyeing with dyeing solutions or functional auxiliary dispersions generates more wastewater and pollution, while solution dyeing or functionalization can be performed without generating wastewater, thus offering environmental advantages and achieving energy conservation and emission reduction.

[0004] Currently, based on the need for ecological and environmental protection, the preferred method is solution dyeing or functionalization. However, when it is desired to prepare biodegradable polyester textiles that have both color and antibacterial functions, it is necessary to add the dye masterbatch and antibacterial agent to the biodegradable polyester raw materials, such as biodegradable polypropylene terephthalate (PTT) and polybutylene succinate (PBS), and then melt-spun them together to make fibers or yarns before making textiles. However, in practice, it has been found that the above method has the following problems: (1) Some antibacterial agents (such as organic antibacterial agents) have insufficient high-temperature stability and decompose when melted with polyester raw materials, losing their antibacterial effect. There are also some antibacterial agents that are not fully functional. The interaction between the antibacterial agent and the disperse dye destroys the antibacterial effect. There is also the problem that the antibacterial agent (such as inorganic antibacterial agent) is not well dispersed in the polyester raw material and is easy to agglomerate, resulting in the antibacterial effect not meeting expectations. Especially when the antibacterial performance requirements are high, the amount of antibacterial agent added is too much. (2) Large color difference and poor color fastness. It is believed that after the addition of some antibacterial agents, under the action of environmental oxygen, light and other factors, the stability of the dye is affected, causing the dye to decompose or the adhesion to decrease. (3) The addition of antibacterial agents causes a decrease in the physical properties of the fiber, such as strength, elongation, and hand feel. Some antibacterial agents affect the interaction between the molecular chains of the resin polymer, affecting the crystallinity and orientation of the fiber, thereby affecting the physical properties of the fiber. Summary of the Invention

[0005] The purpose of this invention is to overcome one or more deficiencies in the prior art and to provide an improved nonwoven fabric that imparts color and antibacterial properties to the nonwoven fabric while having almost no negative impact on the physical properties of the product, and a method for preparing the same.

[0006] The present invention also provides antibacterial masterbatch or antibacterial colored fiber that can be used to prepare the above-mentioned nonwoven fabric.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A nonwoven fabric comprising a nonwoven structure made of antibacterial colored fibers using a nonwoven process;

[0009] The method for preparing the antibacterial colored fiber includes: reacting a disperse dye with a tertiary nitrogen structure with a compound shown in formula (Ⅰ) under alkaline conditions to generate a modified dye; wherein the pH value of the alkaline conditions is controlled to be greater than or equal to 10.

[0010] Then the modified dye and the first polyester resin are mixed and melt-extruded to obtain antibacterial masterbatch;

[0011] The antibacterial masterbatch and the second polyester resin are mixed and then spun to produce the antibacterial colored fiber in the form of short fibers.

[0012] In the text, R1 is selected from C. 1-3 alkyl or hydroxy substituted C 1-3 Alkyl groups, R2, R3, and R4 are independently selected from C1 and C2. 1-2 alkyl.

[0013] In some embodiments of the present invention, the nonwoven process can be performed with reference to existing nonwoven processes. Further, the nonwoven process includes sequentially performing the following steps: opening, feeding, carding, web laying, needle punching, gluing, setting, and rolling.

[0014] Furthermore, the specific operations for each step in the above nonwoven process are as follows:

[0015] Opening: Sawtooth roller opener, beater speed 400-700 rpm; Feeding: Sawtooth roller speed 5-25 rpm, vane roller speed 5-30 rpm; Carding: Web longitudinal and transverse strength ratio 5-10:1; Web laying: Width 2.5-4.5m, web forming machine speed 150-250m / min; Needling: Needling depth 8-16mm, needle density 70-150 needles / cm². 2 ; Applying adhesive: Polyester hot melt adhesive is used. The polyester hot melt adhesive is mixed with pure water at a mass ratio of 1:0.9-1.1, stirred at high speed to form a slurry, and then coated onto the fiber mesh by a coating equipment. It is then hot-pressed at 145-155℃ and 0.05-0.15MPa, and the hot-pressing time is 3-8s; Setting: The heat setting temperature is 140-155℃ and the time is 30-60s; Rolling: The winding speed is 150-250m / min.

[0016] Further, by weight percentage, the raw materials of the polyester hot melt adhesive include: 67%-72% PES copolyester powder, 13%-16% ethylene glycidyl methacrylate copolymer, 13%-16% ethylene vinyl acetate copolymer, and 0.1%-1% antioxidant. According to a specific aspect of the invention, by weight percentage, the raw materials of the polyester hot melt adhesive include: 69.5% PES copolyester powder, 15% ethylene glycidyl methacrylate copolymer, 15% ethylene vinyl acetate copolymer, and 0.5% antioxidant MIANOX616.

[0017] According to some preferred aspects of the present invention, the disperse dye having a tertiary nitrogen structure has the following structure:

[0018]

[0019] According to some preferred aspects of the present invention, the modified dye has the following structure:

[0020]

[0021] In some embodiments of the present invention, the disperse dye having a tertiary nitrogen structure includes, but is not limited to, combinations of one or more compounds selected from the following:

[0022]

[0023] In some embodiments of the present invention, in formula (I), R1 is selected from methyl, ethyl, propyl, hydroxy-substituted methyl, hydroxy-substituted ethyl, or hydroxy-substituted propyl.

[0024] In some embodiments of the present invention, in formula (I), R2, R3, and R4 are independently selected from methyl groups.

[0025] In some embodiments of the present invention, the compound represented by formula (I) is selected from (2-chloroethyl)trimethylammonium chloride (structural formula: (3-Chloropropyl)trimethylammonium chloride, (3-chloro-2-hydroxypropyl)trimethylammonium chloride (structural formula: One or more combinations of )

[0026] According to some preferred aspects of the invention, the mass ratio of the disperse dye having a tertiary nitrogen structure to the compound represented by formula (I) is 1-10:1.

[0027] According to some preferred aspects of the invention, the reaction is controlled to be carried out at 20-30°C.

[0028] According to some preferred aspects of the present invention, an embodiment for preparing the modified dye includes: dissolving the disperse dye having a tertiary nitrogen structure in anhydrous ethanol to prepare a dye solution, then adding the compound shown in formula (Ⅰ) to the dye solution to obtain a pre-reaction solution; then adjusting the pH of the pre-reaction solution to greater than or equal to 10 with an alkaline hydroxide aqueous solution, reacting, and continuously adding the alkaline hydroxide aqueous solution during the reaction to maintain the pH value always greater than or equal to 10.

[0029] Furthermore, in some embodiments of the present invention, the mass concentration of the dye solution is controlled to be 0.5%-5%, and more particularly 0.8%-3%.

[0030] Furthermore, in some embodiments of the present invention, the molar concentration of the alkaline hydroxide aqueous solution is controlled to be 0.5-3 mol / L.

[0031] Furthermore, in some embodiments of the present invention, the alkaline hydroxide in the alkaline hydroxide aqueous solution is sodium hydroxide and / or potassium hydroxide, and the alkaline hydroxide aqueous solution is formed by dispersing the alkaline hydroxide in water.

[0032] Furthermore, in some embodiments of the present invention, the reaction time is controlled to be greater than or equal to 10 minutes. Even further, the reaction time is controlled to be 12-90 minutes.

[0033] Furthermore, in some embodiments of the present invention, after the reaction is completed, the pH value is adjusted to 7.0±0.2 with hydrochloric acid, and then the ethanol is removed by vacuum evaporation.

[0034] According to some preferred aspects of the present invention, the modified dye accounts for 5%-25% and the first polyester resin accounts for 75%-95% by mass percentage in the antibacterial masterbatch.

[0035] According to some preferred aspects of the invention, in the antibacterial colored fiber, the antibacterial masterbatch accounts for 1%-10% by weight, and the second polyester resin accounts for 90%-99%.

[0036] In some embodiments of the present invention, the first polyester resin and the second polyester resin are independently polypropylene terephthalate and / or polybutylene succinate.

[0037] In this invention, the first polyester resin and the second polyester resin are preferably bio-based polyester resins, as bio-based polyesters are biodegradable and environmentally friendly. In some embodiments of this invention, the first polyester resin and the second polyester resin are independently bio-based polypropylene terephthalate and / or bio-based polybutylene succinate.

[0038] In some embodiments of the present invention, the spinning process can be performed with reference to existing methods for producing short fibers. Further, the spinning process includes the following steps performed sequentially: pre-drying, melting, extrusion, cooling, bundling and oiling, drawing, cutting, and heat setting.

[0039] Furthermore, the pre-baking temperature is 100-130℃, and the time is 10-30h.

[0040] Furthermore, the melting temperature is 240-270°C.

[0041] Furthermore, the extrusion is screw extrusion, with the following parameters: main screw extrusion temperature of 240-255℃ and extrusion pressure of 6.5-7.2MPa.

[0042] Furthermore, the cooling is annular airflow cooling with the following parameters: wind speed 0.4-0.6 m / s, wind temperature 25-28℃, and relative humidity controlled at 65%-85%.

[0043] Furthermore, the parameters for oiling the bundles are: oiling amount 0.3%-0.8% (based on fiber mass percentage).

[0044] Furthermore, the drawing parameters are: a drawing ratio of 3-4 times, a drawing temperature of 65-70℃, and a drawing speed of 800-1200m / min.

[0045] Furthermore, the cutting involves cutting the long fibers into short fibers of 35-40 mm.

[0046] Furthermore, the parameters for heat setting are: heat setting temperature 150-160℃, time 20-40s.

[0047] Another technical solution provided by the present invention: a method for preparing a nonwoven fabric, the method comprising:

[0048] (1) Preparation of modified dyes

[0049] A disperse dye having a tertiary nitrogen structure is reacted with the compound shown in formula (Ⅰ) under alkaline conditions to generate a modified dye; wherein the pH value of the alkaline conditions is controlled to be greater than or equal to 10.

[0050] (2) Preparation of antibacterial masterbatch

[0051] The modified dye and the first polyester resin are mixed and melt-extruded to obtain antibacterial masterbatch;

[0052] (3) Preparation of antibacterial colored fibers in the form of short fibers

[0053] The antibacterial masterbatch and the second polyester resin are mixed and then spun to obtain short-fiber antibacterial colored fibers.

[0054] (4) Preparation of nonwoven fabric

[0055] Nonwoven fabrics are prepared using the aforementioned antibacterial colored fibers via a nonwoven process.

[0056] Another technical solution provided by the present invention: an antibacterial masterbatch, wherein the raw materials of the antibacterial masterbatch include modified dyes and a first polyester resin, wherein the antibacterial masterbatch is obtained by mixing and melt extruding the raw materials;

[0057] The method for preparing the modified dye includes: reacting a disperse dye having a tertiary nitrogen structure with a compound shown in formula (Ⅰ) under alkaline conditions to generate the modified dye; wherein the pH value of the alkaline conditions is controlled to be greater than or equal to 10.

[0058] In the text, R1 is selected from C. 1-3 alkyl or hydroxy substituted C 1-3 Alkyl groups, R2, R3, and R4 are independently selected from C1 and C2.1-2 alkyl.

[0059] Another technical solution provided by the present invention: an antibacterial colored fiber, wherein the antibacterial colored fiber is prepared by the following preparation method: the antibacterial masterbatch described above is mixed with the second polyester resin and then spun to form the antibacterial colored fiber in the form of short fibers.

[0060] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0061] This invention addresses the shortcomings of existing textiles that attempt to simultaneously possess color and antibacterial functions, such as insufficient antibacterial performance, large color differences, and decreased physical properties. It innovatively provides an improved nonwoven fabric that imparts both color and antibacterial properties while having virtually no negative impact on the product's physical properties. Specifically, this invention, for the first time, chemically modifies disperse dyes with tertiary nitrogen structures, causing each dye molecule to form two quaternary ammonium centers separated by alkyl groups. Typically, quaternary ammonium cations exert their antibacterial and bactericidal effects by interacting electrostatically with negatively charged bacterial cell membranes, thus affecting the function of the bacterial cell membrane. Practice has shown that the presence of this type of quaternary ammonium cation in this invention achieves unexpectedly excellent antibacterial effects. In particular, the introduction of antibacterial quaternary ammonium centers into the disperse dye not only avoids affecting the disperse dye but also avoids the problems of insufficient high-temperature stability, undesirable interactions with disperse dyes, and even difficulty in effective dispersion of some existing antibacterial agents. This allows the invention to simultaneously achieve solution coloring and functionalization, reducing wastewater discharge, meeting current high environmental standards, facilitating industrial applications, and providing long-lasting antibacterial effects. Attached Figure Description

[0062] Figure 1 The images show the antibacterial effects of the modified dyes prepared in Examples 1-4 of this invention.

[0063] Figure 2 The diagram shows the antibacterial effect of the modified dyes prepared in Comparative Examples 1 and 2 of this invention.

[0064] Figure 3 This is a diagram illustrating the antibacterial effect of the nonwoven fabric prepared in Comparative Example 2 of the present invention;

[0065] Figure 4 This is a diagram showing the antibacterial effect of the modified dye prepared in Comparative Example 3 of this invention.

[0066] Figure 5 This is a diagram showing the antibacterial effect of the nonwoven fabric prepared in Comparative Example 3 of the present invention. Detailed Implementation

[0067] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0068] Unless otherwise specified in the following examples, all raw materials can be obtained from commercial sources or prepared by conventional methods in the art.

[0069] Of the following, (2-chloroethyl)trimethylammonium chloride (CAS No.: 999-81-5) and (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CAS No.: 3327-22-8) were purchased from Hubei Jiufenglong Chemical Co., Ltd. 2-Dimethylaminochloroethane hydrochloric acid (CAS No.: 4584-46-7) was purchased from Hubei Dali Chemical Co., Ltd.

[0070] Disperse Yellow 49 dye, structural formula:

[0071] Disperse Red 1 dye, structural formula:

[0072] Disperse Blue 148 dye, structural formula:

[0073] Disperse Orange 25 dye, structural formula: All of the dyes mentioned above were purchased commercially.

[0074] The bio-based PTT resin is produced by our company; the PES copolyester powder, grade WT-51, is from Jiangyin Weitao Plastic New Material Co., Ltd.; the ethylene glycidyl methacrylate copolymer, grade AX8750, is from Shanghai Chaoqi Plastic Co., Ltd.; the ethylene vinyl acetate copolymer, grade UE647-04, is from Shanghai Chaoqi Plastic Co., Ltd.

[0075] Example 1:

[0076] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom. The preparation method includes:

[0077] (1) Preparation of modified dye: Disperse Yellow 49 dye was dissolved in anhydrous ethanol to prepare a dye solution with a mass fraction of 2%. (2-chloroethyl)trimethylammonium chloride was added to the dye solution at a dry weight ratio of Disperse Yellow 49 / (2-chloroethyl)trimethylammonium chloride of 4:1 to obtain a pre-reaction solution. The pH of the pre-reaction solution was then adjusted to 12.0 with 1 mol / L sodium hydroxide aqueous solution, and this pH was maintained dropwise continuously during the reaction. The reaction was carried out at room temperature for 30 min. After the reaction, the pH was adjusted to 7.0 ± 0.2 with 1 mol / L hydrochloric acid. Finally, the ethanol was removed by vacuum evaporation at 50 °C to obtain the modified dye.

[0078] The reaction formula for Disperse Yellow 49 with (2-chloroethyl)trimethylammonium chloride is as follows:

[0079]

[0080] (2) Preparation of antibacterial masterbatch: Modified dye and bio-based PTT resin were mixed in a high-speed mixer at a mass ratio of 10:90, pre-dried (temperature 120℃, time 24h), melted at high temperature (temperature 255℃), extruded by screw extrusion (extrusion temperature 245℃, extrusion pressure 6.5MPa), cooled, and pelletized to obtain antibacterial masterbatch.

[0081] (3) Preparation of nonwoven fabrics:

[0082] Weigh out the antibacterial masterbatch and bio-based PTT resin at a mass ratio of 4:96, mix them, and spin them on a melt spinning machine according to the spinning process of PTT solution-dyed fibers to obtain short-fiber antibacterial colored fibers; then process them according to the polyester nonwoven fabric processing process to obtain nonwoven fabric.

[0083] The spinning process of PTT solution-dyed fiber is as follows: pre-drying → high-temperature melting → twin-screw extrusion → ring air cooling → bundling and oiling → drawing → cutting → heat setting; the pre-drying temperature is 120℃ and the time is 24h; the high-temperature melting temperature is 255℃; the twin-screw extrusion parameters are: extrusion temperature 250℃ and extrusion pressure 7.0MPa; the ring air cooling parameters are: air velocity 0.5m / s, air temperature 26℃, and relative humidity 72%; the bundling and oiling parameters are: Chuanhua polyester fiber special oil agent TF-701A, oiling amount 0.5%; the drawing parameters are: draw ratio 3.5 times, drawing temperature 67℃, and drawing speed 1000m / min; cutting is: cutting long fibers into short fibers of about 38mm; the heat setting parameters are: heat setting temperature 155℃ and setting time 30s.

[0084] The processing technology for polyester nonwoven fabric is as follows: opening → feeding → carding → web laying → needle punching → gluing → setting → rolling; Opening: sawtooth roller opening machine, beater speed 520 rpm; Feeding: sawtooth roller speed 15 rpm, vane roller speed 18 rpm; Carding: web longitudinal and transverse strength ratio 7.5:1; Web laying: width 3.5m, web forming machine speed 220m / min; Needle punching: needle punching depth 12mm, needle punching density 110 needles / cm². 2 ; Adhesive application: Polyester hot melt adhesive, which is mixed with pure water at a mass ratio of 1:1, stirred at high speed to form a slurry, and then coated onto the fiber mesh by a coating device, and hot-pressed at 150℃ and 0.1MPa for 5s; Setting: Heat setting temperature 145℃, time 35s; Rolling: Winding speed 230m / min. The polyester hot melt adhesive used for adhesive application, by mass percentage, includes: 69.5% PES copolyester powder, 15% ethylene methacrylate glycidyl copolymer, 15% ethylene vinyl acetate copolymer, and 0.5% antioxidant MIANOX616. These are mixed evenly to form the hot melt adhesive.

[0085] Results Analysis: The modified dye was prepared into a 1.0 g / L solution using deionized water, and its average particle size was measured at 25℃ using a Nano ZS90 nanoparticle size potentiometric analyzer. Using *E. coli* as the test strain, the antibacterial properties of the modified dye were evaluated according to GB / T20944.1-2007 "Evaluation of Antibacterial Properties of Textiles - Part 1: Agar Blood Diffusion Method" (with the improvement that a paper disc adsorbed with 0.2 mL of 1.0 mg / mL modified dye was flatly placed on the culture medium after bacterial inoculation). The antibacterial properties of the nonwoven fabric were tested according to GB / T20944.2-2007 "Evaluation of Antibacterial Properties of Textiles - Part 2: Absorption Method". The fiber strength was tested according to GB / T 14337-2008 "Test Method for Tensile Properties of Short Chemical Fibers".

[0086] See Figure 1 As shown in Table 1, the modified dye obtained in this example exhibits an inhibition zone of 19.1 mm against *Escherichia coli*, demonstrating excellent antibacterial properties. The solution-dyed functional nonwoven fabric obtained in this example showed a 100% inhibition rate against both *Staphylococcus aureus* and *Escherichia coli*, significantly higher than that of pure nonwoven fabric without the modified dye of this invention (inhibition rates of 35% and 39%, respectively). The average particle size of the obtained modified dye is approximately 208 nm, which is relatively small, and the strength of the resulting fibers is 3.22 cN·tex. -1 The difference between the modified dye and the blank fiber is not significant, indicating that the modified dye of this invention has almost no negative impact on the physical properties of the fiber. It is evident that both the modified dye and the nonwoven fabric produced in this example exhibit excellent antibacterial properties, and the fiber possesses good mechanical properties (higher fiber strength contributes to a longer service life for the textiles).

[0087] Example 2:

[0088] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom. The preparation method includes:

[0089] (1) Preparation of modified dye: Disperse Red 1 dye was dissolved in anhydrous ethanol to prepare a 2% (w / w) dye solution. (2-Chloroethyl)trimethylammonium chloride was added to the dye solution at a dry weight ratio of 9:1 (Disperse Red 1 / (2-chloroethyl)trimethylammonium chloride) to obtain a pre-reaction solution. The pH of the pre-reaction solution was then adjusted to 10.3 with 1 mol / L sodium hydroxide aqueous solution, and this pH was maintained dropwise continuously during the reaction. The reaction was carried out at room temperature for 12 min. After the reaction, the pH was adjusted to 7.0 ± 0.2 with 1 mol / L hydrochloric acid. Finally, the ethanol was removed by vacuum evaporation at 50 °C to obtain the modified dye.

[0090] (2) Preparation of antibacterial masterbatch: Modified dye and bio-based PTT resin were mixed in a high-speed mixer at a mass ratio of 15:85, pre-dried (temperature 120℃, time 24h), melted at high temperature (temperature 255℃), extruded by screw extrusion (extrusion temperature 245℃, extrusion pressure 6.5MPa), cooled, and pelletized to obtain antibacterial masterbatch.

[0091] (3) Preparation of nonwoven fabrics:

[0092] Weigh the antibacterial masterbatch and bio-based PTT resin at a mass ratio of 6:94, mix them, and spin them on a melt spinning machine according to the spinning process of PTT solution-dyed fibers (parameters are the same as in Example 1) to obtain short-fiber antibacterial colored fibers; then process them according to the polyester nonwoven fabric processing process (parameters are the same as in Example 1) to obtain nonwoven fabric.

[0093] Results Analysis: Based on the above antibacterial performance testing methods, the test results are as follows: Figure 1 As shown in Table 1, the modified dye obtained in this example exhibits an inhibition zone of 18.6 mm against *Escherichia coli*, demonstrating excellent antibacterial properties. The nonwoven fabric processed in this example showed a 100% inhibition rate against both *Staphylococcus aureus* and *Escherichia coli*. The average particle size of the obtained modified dye is approximately 194 nm, which is relatively small, and the strength of the resulting fiber is 3.18 cN·tex. -1 The difference between the modified dye and the blank fiber is not significant, indicating that the modified dye of this invention has almost no negative impact on the physical properties of the fiber. Therefore, both the modified dye and the nonwoven fabric prepared in this example exhibit excellent antibacterial properties, and the fiber also possesses good mechanical properties.

[0094] Example 3:

[0095] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom. The preparation method includes:

[0096] (1) Preparation of modified dye: Disperse Blue 148 dye was dissolved in anhydrous ethanol to prepare a 2% (w / w) dye solution. (3-chloro-2-hydroxypropyl)trimethylammonium chloride was added to the above dye solution at a dry weight ratio of Disperse Blue 148 / (3-chloro-2-hydroxypropyl)trimethylammonium chloride of 6:1 to obtain a pre-reaction solution. The pH of the pre-reaction solution was then adjusted to 11.5 with 1 mol / L sodium hydroxide aqueous solution, and this pH was maintained dropwise continuously during the reaction. The reaction was carried out at room temperature for 60 min. After the reaction, the pH was adjusted to 7.0 ± 0.2 with 1 mol / L hydrochloric acid, and finally, the ethanol was removed by vacuum evaporation at 50 °C to obtain the modified dye.

[0097] (2) Preparation of antibacterial masterbatch: Modified dye and bio-based PTT resin were mixed in a high-speed mixer at a mass ratio of 6:94, pre-dried (temperature 120℃, time 24h), melted at high temperature (temperature 255℃), extruded by screw extrusion (extrusion temperature 245℃, extrusion pressure 6.5MPa), cooled, and pelletized to obtain antibacterial masterbatch.

[0098] (3) Preparation of nonwoven fabrics:

[0099] Weigh the antibacterial masterbatch and bio-based PTT resin at a mass ratio of 8:92, mix them, and spin them on a melt spinning machine according to the spinning process of PTT solution-dyed fibers (parameters are the same as in Example 1) to produce short-fiber antibacterial colored fibers; then process them according to the polyester nonwoven fabric processing process (parameters are the same as in Example 1) to obtain nonwoven fabric.

[0100] Results Analysis: The results, evaluated using the above antibacterial performance testing methods, are as follows: Figure 1 As shown in Table 1, the modified dye obtained in this example exhibits an inhibition zone of 18.8 mm against *Escherichia coli*, demonstrating excellent antibacterial properties. The nonwoven fabric processed in this example showed a 100% inhibition rate against both *Staphylococcus aureus* and *Escherichia coli*. The average particle size of the obtained modified dye is approximately 215 nm, which is relatively small, and the strength of the resulting fiber is 3.20 cN·tex. -1 The difference between the modified dye and the blank fiber is not significant, indicating that the modified dye of this invention has almost no negative impact on the physical properties of the fiber. Therefore, both the modified dye and the nonwoven fabric prepared in this example exhibit excellent antibacterial properties, and the fiber also possesses good mechanical properties.

[0101] Example 4:

[0102] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom. The preparation method includes:

[0103] (1) Preparation of modified dye: Disperse Orange 25 dye was dissolved in anhydrous ethanol to prepare a 2% (w / w) dye solution. (3-chloro-2-hydroxypropyl)trimethylammonium chloride was added to the above dye solution at a dry weight ratio of Disperse Orange 25 / (3-chloro-2-hydroxypropyl)trimethylammonium chloride of 2:1 to obtain a pre-reaction solution. The pH of the pre-reaction solution was then adjusted to 13.5 with 1 mol / L sodium hydroxide aqueous solution, and this pH was maintained dropwise continuously during the reaction. The reaction was carried out at room temperature for 90 min. After the reaction, the pH was adjusted to 7.0 ± 0.2 with 1 mol / L hydrochloric acid. Finally, the ethanol was removed by vacuum evaporation at 50 °C to obtain the modified dye.

[0104] (2) Preparation of antibacterial masterbatch: Modified dye and bio-based PTT resin were mixed in a high-speed mixer at a mass ratio of 22:78, pre-dried (temperature 120℃, time 24h), melted at high temperature (temperature 255℃), extruded by screw extrusion (extrusion temperature 245℃, extrusion pressure 6.5MPa), cooled, and pelletized to obtain antibacterial masterbatch.

[0105] (3) Preparation of nonwoven fabrics:

[0106] Weigh the antibacterial masterbatch and bio-based PTT resin at a mass ratio of 2:98, mix them, and spin them on a melt spinning machine according to the spinning process of PTT solution-dyed fibers (parameters are the same as in Example 1) to obtain short-fiber antibacterial colored fibers; then process them according to the polyester nonwoven fabric processing process (parameters are the same as in Example 1) to obtain nonwoven fabric.

[0107] Results Analysis: Based on the above antibacterial performance testing methods, the test results are as follows: Figure 1 As shown in Table 1, the modified dye obtained in this example exhibits an inhibition zone of 27.5 mm against *Escherichia coli*, demonstrating excellent antibacterial properties. The nonwoven fabric processed in this example showed a 100% inhibition rate against both *Staphylococcus aureus* and *Escherichia coli*. The average particle size of the obtained modified dye is approximately 241 nm, which is relatively small, and the strength of the resulting fiber is 3.21 cN·tex. -1 The difference between the modified dye and the blank fiber is not significant, indicating that the modified dye of this invention has almost no negative impact on the physical properties of the fiber. Therefore, both the modified dye and the nonwoven fabric prepared in this example exhibit excellent antibacterial properties, and the fiber also possesses good mechanical properties.

[0108] Table 1

[0109]

[0110] Comparative Example 1:

[0111] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom, wherein: (2-chloroethyl)trimethylammonium chloride (structural formula: ) from Example 1 is used. Replace with 2-dimethylaminochloroethane hydrochloride (structural formula: The rest is the same as in Example 1.

[0112] Results analysis: such as Figure 2 As shown, the modified dye obtained in this example exhibits an inhibition zone diameter of approximately 18.8 mm against *Escherichia coli*, demonstrating similar antibacterial activity to the modified dye obtained in Example 1. The nonwoven fabric obtained in this example shows a 100% inhibition rate against both *Staphylococcus aureus* and *Escherichia coli*, with antibacterial properties similar to the product obtained in Example 1, meeting the national standard requirements for antibacterial textiles (inhibition rates against *Staphylococcus aureus* and *Escherichia coli* both greater than or equal to 85%). However, the average particle size of the modified dye obtained in this example is approximately 1076 nm, significantly larger than the particle size of the modified dye obtained in Example 1; the strength of the fiber obtained in this example is only 2.85 cN·tex. -1 Compared to Example 1, the strength decreased by 11.5%, indicating poor fiber strength. Poor fiber strength severely affects the service life of nonwoven fabrics. Analysis suggests that this is because 2-dimethylaminochloroethane hydrochloride not only reacts with the tertiary nitrogen structure of the dye to form a quaternary ammonium structure, but the alkyl chlorides between 2-dimethylaminochloroethane hydrochloride molecules can also undergo electrophilic addition with their own tertiary nitrogen structure to form a cationic polymer. This results in a very large molecular size of the modified dye. When large dye particles are mixed into PTT fibers, they form large structural voids and stress concentration points within the fiber body, significantly and adversely affecting the fiber strength.

[0113] The reaction formula for cationic polymers is:

[0114]

[0115] Comparative Example 2:

[0116] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom, wherein: the method of adjusting the pH value of the pre-reaction solution to 10.3 in Example 2 is changed to adjusting the pH value of the pre-reaction solution to 9.1, that is, the pH value of the pre-reaction solution after adjustment does not meet the range required by the present invention, and the rest is the same as in Example 2.

[0117] Results analysis: such as Figure 2 and Figure 3 As shown, the diameter of the inhibition zone against Escherichia coli obtained in this example is 13.0 mm, which is significantly smaller than the diameter of the inhibition zone of the quaternized dye obtained in Example 2 (18.6 mm), indicating that the antibacterial activity of the obtained modified dye is low. The average particle size of the obtained modified dye is approximately 221 nm, and the strength of the obtained fiber is 3.20 cN·tex. -1In this example, the nonwoven fabric obtained exhibited inhibition rates of 80.3% and 85.5% against Staphylococcus aureus and Escherichia coli, respectively, significantly lower than the product obtained in Example 2. Analysis suggests this is because the pH of the reaction system was too low, making the quaternization reaction of the dye difficult to proceed, resulting in a lower amount of quaternized dye produced. Consequently, the modified dye exhibited lower antibacterial activity, leading to poorer antibacterial performance of the PTT nonwoven fabric containing this dye.

[0118] Comparative Example 3:

[0119] This example provides a method for preparing a nonwoven fabric and the nonwoven fabric made therefrom, wherein: (2-chloroethyl)trimethylammonium chloride (structural formula: ) from Example 1 is used. Replace with chloromethyltrimethylsilane (structural formula: Furthermore, in the preparation process of the antibacterial masterbatch, the mass ratio of modified dye to bio-based PTT resin is 20:80, and the rest is the same as in Example 1.

[0120] Results analysis: such as Figure 4 and Figure 5 As shown, the modified dye obtained in this example exhibits an inhibition zone diameter of 13.4 mm against *Escherichia coli*, which is significantly smaller than the antibacterial activity of the quaternized dye obtained in Example 1. The PTT nonwoven fabric obtained in this example shows inhibition rates of 83.6% and 88.2% against *Staphylococcus aureus* and *Escherichia coli*, respectively, and its antibacterial performance does not meet the national standard requirements for antibacterial textiles (inhibition rates against *Staphylococcus aureus* and *Escherichia coli* both greater than or equal to 85%). The average particle size of the obtained modified dye is approximately 211 nm, which is relatively small, and the strength of the obtained fiber is 3.13 cN·tex. -1 Analysis suggests that although the alkyl chloride of chloromethyltrimethylsilane can also undergo an electrophilic addition reaction with the tertiary nitrogen structure of the dye to form a quaternary ammonium center, the modified dye only has one quaternary ammonium center. Moreover, even if the number of quaternary ammonium centers in the system is increased to the same number as in the examples, the antibacterial activity is far inferior to that of the dyes obtained in the examples, based on practical results. This demonstrates that the two quaternary ammonium centers in the same dye molecule of the present invention have a synergistic effect.

[0121] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0122] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A modified dye, characterized in that, The method for preparing the modified dye includes: reacting a disperse dye having a tertiary nitrogen structure with a compound shown in formula (I) under alkaline conditions to generate the modified dye; wherein the pH value of the alkaline conditions is controlled to be greater than or equal to 10. In equation (Ⅰ), R1 is selected from C 1-3 alkylene or hydroxyl-substituted C 1-3 Alkylenes, R2, R3, and R4 are independently selected from C10. 1-2 alkyl; The modified dye molecule has two quaternary ammonium centers separated by R1. The disperse dye having a tertiary nitrogen structure has the following structure: ; The modified dye has the following structure: 。 2. The modified dye according to claim 1, characterized in that, The disperse dye having a tertiary nitrogen structure includes one or more combinations selected from the following compounds: 、 、 、 ； And / or, In formula (I), R1 is selected from methylene, ethylene, propylene, hydroxylated methylene, hydroxylated ethylene or hydroxylated propylene, and R2, R3 and R4 are independently selected from methyl.

3. The modified dye according to claim 1, characterized in that, The compound represented by formula (I) is a combination of one or more selected from (2-chloroethyl)trimethylammonium chloride, (3-chloropropyl)trimethylammonium chloride, and (3-chloro-2-hydroxypropyl)trimethylammonium chloride; and / or, the mass ratio of the disperse dye having a tertiary nitrogen structure to the compound represented by formula (I) is 1-10:

1.

4. The modified dye according to claim 1, characterized in that, The preparation of the modified dye includes: dissolving the disperse dye having a tertiary nitrogen structure in anhydrous ethanol to prepare a dye solution; then adding the compound shown in formula (Ⅰ) to the dye solution to obtain a pre-reaction solution; then adjusting the pH of the pre-reaction solution to greater than or equal to 10 with an alkaline hydroxide aqueous solution; reacting at 20-30°C; and continuously adding the alkaline hydroxide aqueous solution during the reaction to maintain the pH value at least greater than or equal to 10.

5. The modified dye according to claim 4, characterized in that, The mass concentration of the dye solution is controlled to be 0.5%-5%; and / or, The molar concentration of the alkaline hydroxide aqueous solution is controlled to be 0.5-3 mol / L; and / or, The alkaline hydroxide in the alkaline hydroxide aqueous solution is sodium hydroxide and / or potassium hydroxide, and the alkaline hydroxide aqueous solution is formed by dispersing the alkaline hydroxide in water; and / or, The reaction time is controlled to be greater than or equal to 10 min; and / or, After the reaction was completed, the pH was adjusted to 7.0±0.2 with hydrochloric acid, and then the ethanol was removed by vacuum evaporation.

6. The modified dye according to claim 4, characterized in that, The mass concentration of the dye solution is controlled to be 0.8%-3%.

7. The modified dye according to claim 4, characterized in that, The reaction time is controlled to be 12-90 min.

8. The use of any one of the modified dyes according to claims 1-7 in the preparation of antibacterial masterbatches or antibacterial colored fibers.

9. A method for preparing a nonwoven fabric, characterized in that, The preparation method includes: (1) Preparation of modified dyes A disperse dye having a tertiary nitrogen structure is reacted with the compound shown in formula (I) under alkaline conditions to generate a modified dye; wherein the pH value of the alkaline conditions is controlled to be greater than or equal to 10. In equation (Ⅰ), R1 is selected from C 1-3 alkylene or hydroxyl-substituted C 1-3 Alkylenes, R2, R3, and R4 are independently selected from C10. 1-2 alkyl; The modified dye molecule has two quaternary ammonium centers separated by R1. The disperse dye having a tertiary nitrogen structure has the following structure: ; The modified dye has the following structure: ； (2) Preparation of antibacterial masterbatch The modified dye and the first polyester resin are mixed and melt-extruded to produce an antibacterial masterbatch; (3) Preparation of antibacterial colored fibers in the form of short fibers The antibacterial masterbatch and the second polyester resin are mixed and then spun to produce short-fiber antibacterial colored fibers. (4) Preparation of nonwoven fabric Nonwoven fabrics are prepared using the aforementioned antibacterial colored fibers via a nonwoven process.

10. The method for preparing the nonwoven fabric according to claim 9, characterized in that, The first polyester resin and the second polyester resin are both bio-based polyester resins; and / or, in step (2), by mass percentage, the modified dye accounts for 5%-25% of the antibacterial masterbatch, and the first polyester resin accounts for 75%-95%; and / or, in step (3), by mass percentage, the antibacterial colored fiber contains 1%-10% of the antibacterial masterbatch and the second polyester resin accounts for 90%-99%; and / or, In step (3), the spinning process includes the following steps performed in sequence: pre-drying, melting, extrusion, cooling, bundling and oiling, drawing, cutting and heat setting; in, The pre-drying temperature is 100-130℃, and the time is 10-30h; The melting temperature is 240-270℃; The extrusion is a screw extrusion with the following parameters: main screw extrusion temperature of 240-255℃ and extrusion pressure of 6.5-7.2MPa; The cooling method is annular airflow cooling, with the following parameters: air velocity 0.4-0.6 m / s, air temperature 25-28℃, and relative humidity controlled at 65%-85%. The parameters for oiling the bundled fibers are: oiling amount of 0.3%-0.8% by fiber mass percentage; The drawing parameters are: drawing ratio 3-4 times, drawing temperature 65-70℃, and drawing speed 800-1200m / min; The cutting process involves cutting long fibers into short fibers of 35-40mm. The parameters for heat setting are: heat setting temperature 150-160℃, time 20-40s.

11. The method for preparing the nonwoven fabric according to claim 9, characterized in that, The first polyester resin and the second polyester resin are independently bio-based polypropylene terephthalate and / or bio-based polybutylene succinate.

12. The method for preparing the nonwoven fabric according to claim 9, characterized in that, In step (4), the nonwoven process includes the following steps performed sequentially: Opening: Sawtooth roller opening machine, beater speed 400-700 rpm; Feeding: serrated roller speed 5-25 rpm, vane roller speed 5-30 rpm; Combing: The ratio of longitudinal to transverse strength of the fiber web is 5-10:1; Net laying: width 2.5-4.5m, net forming machine operation 150-250m / min; Acupuncture: Acupuncture depth 8-16mm, acupuncture density 70-150 needles / cm 2 ; Adhesive application: A polyester hot melt adhesive is used. The polyester hot melt adhesive is mixed with pure water at a mass ratio of 1:0.9-1.1, stirred at high speed to form a slurry, and then coated onto the fiber mesh by a coating device. The mixture is then hot-pressed at 145-155℃ and 0.05-0.15MPa. The raw materials of the polyester hot melt adhesive, by mass percentage, include: 67%-72% PES copolyester powder, 13%-16% ethylene-methyl methacrylate copolymer, 13%-16% ethylene-vinyl acetate copolymer, and 0.1%-1% antioxidant. Heat setting: 140-155℃, 30-60s; Rolling: Rewinding speed 150-250m / min.

13. The method for preparing the nonwoven fabric according to claim 12, characterized in that, The hot pressing time is 3-8 seconds.

Images