Nylon 12 fiber and its preparation method and application

Abstract

The application belongs to the technical field of textile preparation, and particularly relates to a nylon 12 fiber and a preparation method and application thereof. The nylon 12 fiber comprises the following raw materials in mass fractions: 98-100 parts of nylon 12 resin and 0-2 parts of an additive; the nylon 12 resin is an amino-terminated polymer, and the content of terminal amino groups is 10-110 mmol / kg. The nylon 12 resin is an amino-terminated polymer, and the content of terminal amino groups satisfies the above range, so that dyeing sites can be increased, the regularity of molecular chains can be reduced, and the amorphous region can be increased, so that the dye, especially the acid dye, can be easily dyed, the dyeing rate is significantly improved, the dyeing rate can reach more than 95%, the color fastness to washing and the color fastness to perspiration can reach grades 4-5, good mechanical properties are maintained, the application requirements of high-end garment fabrics are met, and excellent long-acting antibacterial performance is achieved.

Description

Technical Field

[0001] This invention belongs to the field of textile preparation technology, specifically relating to a nylon 12 fiber, its preparation method, and its application. Background Technology

[0002] Nylon, also known as polyamide fiber, is a type of nylon. Nylon fibers possess excellent properties such as strength, abrasion resistance, elastic recovery, and moisture absorption. Nylon 6 and Nylon 66 are the most widely used varieties. Nylon 12 fiber is a new type of polyamide fiber. Compared to Nylon 6 and Nylon 66, it exhibits superior properties such as better low-temperature toughness, self-lubrication, low water absorption, and low density, making it a promising candidate for the textile industry. Acid dye systems are the most commonly used dyes for nylon dyeing. By combining with strong ionic bonds or electrostatically with the terminal amino groups of nylon, it achieves vibrant colors with excellent colorfastness, making it the preferred dye system for dyeing nylon fabrics. However, due to differences in molecular structure, Nylon 12 fiber exhibits significant differences from Nylon 6 and Nylon 66 in terms of crystallinity, melting point, hydrophilicity, amide bond density, and terminal amino group content. This results in poor dye uptake and low colorfastness when using traditional acid dye systems, becoming a major obstacle to its application in the textile industry.

[0003] Existing technologies address the issues of poor dyeing performance and low color fastness of nylon 12 fibers by adjusting the end-group composition ratio of the nylon 12 resin and introducing metal salt dyeing agents. While this approach can achieve good dyeing results, it is unsuitable for acidic dye systems, and the metal salts increase thermal degradation during spinning, hindering industrial application. Nylon, as a high-end fabric that comes into direct contact with the human body, requires good antibacterial properties. The antibacterial properties of nylon 12 fibers produced using the aforementioned methods do not meet these requirements. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is how to improve the dyeability of nylon 12, especially acid dyes, and improve its antibacterial properties, thereby providing a nylon 12 fiber, its preparation method and application.

[0005] To this end, the present invention provides the following technical solution.

[0006] The first aspect of the present invention provides a nylon 12 fiber, wherein, by weight parts, the nylon 12 fiber raw material comprises: 98-100 parts of nylon 12 resin and 0-2 parts of additives; The nylon 12 resin is amino-terminated, with an amino content of 10-110 mmol / kg.

[0007] This invention adjusts the terminal amino content of nylon 12 resin to improve dye uptake and color fastness. For example, the terminal amino content can be 10 mmol / kg, 20 mmol / kg, 30 mmol / kg, 40 mmol / kg, 50 mmol / kg, 60 mmol / kg, 70 mmol / kg, 80 mmol / kg, 90 mmol / kg, 100 mmol / kg, etc.

[0008] In one alternative embodiment, the amino end-capping is achieved by adding an end-capping agent during the polymerization process of nylon 12; the end-capping agent includes monoamine end-capping agents and / or polyamine end-capping agents.

[0009] In one optional embodiment, the capping agent comprises at least one selected from guanidine amino capping agents, N-(3-aminopropyl)-1,4-butanediamine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, alkane carbon chain diamines, and aromatic diamines. In one optional embodiment, the guanidine-amino end-capping agent comprises polyhexamethylene guanidine hydrochloride and / or polyhexamethylene biguanide hydrochloride; polyhexamethylene guanidine hydrochloride (PHMG) has the structural formula H-[NH-(CH2)6-NH-C(=NH)] n -H. Polyhexamethylene biguanide hydrochloride (PHMB) H-[NH-(CH2)6-NH-C(=NH)-NH-C(=NH)] n –H, this capping agent can add a -NH2 as a staining site. The guanidino group (-NH-C(=NH)-) carries a positive charge after protonation. When stained with acid dyes, it binds to the negatively charged dye molecules and can serve as a staining site.

[0010] N-(3-aminopropyl)-1,4-butanediamine, also known as spermidine, contains one secondary amino group (-NH-) and two primary amino groups (-NH2), with the following structural formula: H2N-(CH2)4-NH-(CH2)3-NH2. N,N'-bis(3-aminopropyl)-1,4-butanediamine, also known as spermine, contains two secondary amino groups (-NH-) and two primary amino groups, with the following structural formula: (-NH2)H2N-(CH2)3-NH-(CH2)4-NH-(CH2)3-NH2. The NH2 groups in spermidine and spermine react with the -COOH terminal of the nylon 12 molecular chain, increasing the -NH2 group as an active site. Furthermore, the protonated secondary amino group (-NH-) carries a positive charge, which binds to negatively charged dye molecules during acid dyeing, serving as a staining site.

[0011] In one alternative embodiment, the alkane-carbon chain diamine has the structural formula: H2N-(CH2). n-NH2, where n ranges from 1 to 16, such as 2, 4, 6, 8, 10, 12, etc.; In one optional embodiment, the aromatic diamine includes at least one of p-phenylenediamine, m-phenylenediamine, and diphenyl ether diamine. The aromatic diamine contains two primary amino groups (-NH2) and a benzene ring structure, which can be one or more; for example, p-phenylenediamine, m-phenylenediamine, diphenyl ether diamine, etc.

[0012] In one optional embodiment, the nylon 12 resin has an end-amino content of 45-110 mmol / kg; In one optional embodiment, the nylon 12 resin has an end-amino content of 60-110 mmol / kg.

[0013] In one optional embodiment, the nylon 12 resin exhibits a melt flow rate of 1-60 g / 10 min, preferably 3-50 g / 10 min, under test conditions of 190°C and 2.16 kg. Exemplary melt flow rates include 1 g / 10 min, 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 50 g / 10 min, 55 g / 10 min, and 60 g / 10 min.

[0014] In one alternative embodiment, the additives include antioxidants and / or lubricants; In one optional embodiment, the antioxidant includes hindered phenolic antioxidants and / or phosphite antioxidants; In one alternative embodiment, the lubricant includes at least one of polyethylene wax, oxidized polyethylene wax, fluoropolymer additives, rare earth lubricants, EBS (ethylene bis-stearamide), erucamide, and sorbitamide.

[0015] In this invention, the fluoropolymer additives include PFAS (perfluorinated and polyfluoroalkyl substances), etc. Rare earth lubricants are lubricating materials with rare earth elements or their compounds as the core components, such as rare earth oxide nano-boronized rare earth, lanthanum fluoride (LaF3) nanoparticles, and lanthanum organic carboxylic acids (such as lanthanum oleate).

[0016] A second aspect of the present invention provides a method for preparing the above-mentioned nylon 12 fiber, comprising the following steps: (1) Obtain Nylon 12 resin; (2) Melt spinning.

[0017] In one optional embodiment, the melt spinning parameters are: temperature of 190-280℃; and / or spinning speed of 600-8000 m / min; and / or side-blowing air temperature of 0-20℃; and / or side-blowing air speed of 0.3-1 m / min; and / or cooling air relative humidity of 40-85%; and / or stretching ratio of 1.5-5 times; and / or heat setting temperature of 60-140℃; and / or number of spinnerets of 25-500.

[0018] In an optional embodiment, step (1) further includes the step of mixing nylon 12 resin and additives; In one alternative implementation, the mixing is followed by melt extrusion; In one alternative embodiment, the parameters of the melt extrusion are: a rotation speed of 300-600 r / min; and / or an extrusion temperature of 190-280°C.

[0019] In the preparation method, before melt spinning, the nylon 12 resin is first dried to a water content of less than 300 ppm, such as drying at 80°C for 4-24 hours.

[0020] A third aspect of this invention provides an application of the aforementioned nylon 12 fiber in textile fabrics. The technical solution of this invention has the following advantages: 1. The nylon 12 fiber provided by this invention, by weight, comprises the following raw materials: 98-100 parts nylon 12 resin and 0-2 parts auxiliaries; the nylon 12 resin is amino-terminated, with an amino content of 10-110 mmol / kg. This invention uses nylon 12 resin as an amino-terminated polymer, and the amino content meets the above range, which can increase dyeing sites, reduce molecular chain regularity, increase amorphous regions, facilitate dye uptake, especially acid dyes, significantly improve dyeing rate and color fastness, achieving an uptake rate of over 95%, and achieving washing fastness and perspiration fastness grades of 4-5, maintaining good mechanical properties, meeting the requirements of high-end apparel fabric applications, and possessing excellent long-lasting antibacterial properties. Excessive amino content in the nylon 12 resin affects the aging resistance and yellowing resistance of the nylon 12 fiber, resulting in poor performance.

[0021] The nylon 12 resin provided by this invention can increase the content of terminal amino groups without reducing the molecular chain length by consuming terminal carboxyl sites and increasing terminal amino sites.

[0022] The nylon 12 fiber provided by this invention can achieve good dyeing rate and color fastness without the use of auxiliaries, dyeing accelerators, and color-fixing crosslinking agents. This avoids the damage to the nylon 12 hydrogen bond network caused by the use of metal salts as dyeing accelerators in the prior art. Metal salts will increase thermal degradation during spinning and weaken the mechanical properties of the fiber. It has the advantages of simple formulation and low cost.

[0023] 2. The nylon 12 fiber provided by the present invention uses at least one of polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanide hydrochloride, N-(3-aminopropyl)-1,4-butanediamine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, alkane carbon chain diamine, and aromatic diamine as a capping agent to increase the terminal amino level of nylon 12 and introduce antibacterial groups on the molecular chain, which helps to improve the dyeing rate and color fastness of nylon 12 fiber, while achieving long-lasting antibacterial properties. Detailed Implementation

[0024] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0025] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0026] The raw materials used in the following examples and comparative examples are shown in Table 1: Table 1. Sources of raw materials

[0027] The nylon 12 resin in Table 1 was prepared according to a well-known preparation method in the art. One method is described here: Dodecanolactam, water, and amino end-capping agent are added to a stirring container. The mixture is heated to 250-280°C and held for 2-4 hours. After the system is depressurized to atmospheric pressure, it is evacuated at 240-260°C for 1-3 hours, with the vacuum degree maintained at -70 to -90 kPa. After the system temperature drops to 190-220°C, it is discharged, water-cooled, and pelletized to obtain nylon 12 resin.

[0028] Example 1 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: PA12-3# resin was dried at 80℃ for 24 hours until the moisture content was 45ppm. The dried PA12-3# resin was then fed into a melt spinning system to produce PA12-3# fiber. The spinning process parameters were: spinning temperature 230℃, spinning speed 1600m / min, side-blowing air temperature 17℃, cooling air relative humidity 60%, side-blowing air speed 0.6m / min, stretch ratio 2, and heat setting temperature 120℃; the spinneret used for spinning had 48 spinneret holes.

[0029] Example 2 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: By mass, 99.5 parts of dried PA12-4# were mixed with 0.5 parts of EBS and melt-blended. The screw speed was set to 600 r / min and the extrusion temperature was 190℃ to obtain PA12-4# resin material.

[0030] The above resin was dried at 80℃ for 24 hours until the water content was 37ppm. The dried PA12-4# resin was fed into a melt spinning system to produce PA12-4# fiber. The spinning process parameters were: spinning temperature 245℃, spinning speed 1600m / min, side-blowing air temperature 16℃, cooling air relative humidity 50%, side-blowing air speed 0.5m / min, stretch ratio 3, heat setting temperature 120℃; the spinneret used for spinning had 48 spinneret holes.

[0031] Example 3 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: PA12-5# resin was dried at 80℃ for 24 hours until the moisture content was 36ppm. The dried PA12-5# resin was then fed into a melt spinning system to produce PA12-5# fiber. The spinning process parameters were: spinning temperature 232℃, spinning speed 1800m / min, side-blowing air temperature 15℃, cooling air relative humidity 45%, side-blowing air speed 0.6m / min, stretch ratio 2.5 times, and heat setting temperature 120℃; the spinneret used for spinning had 96 spinneret holes.

[0032] Example 4 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: PA12-6# resin was dried at 80℃ for 24 hours until the moisture content was 43ppm. The dried PA12-6# resin was then fed into a melt spinning system to produce PA12-6# fiber. The spinning process parameters were: spinning temperature 225℃, spinning speed 1600m / min, side-blowing air temperature 16℃, cooling air relative humidity 65%, side-blowing air speed 0.7m / min, stretch ratio 3, and heat setting temperature 120℃; the spinneret used for spinning had 48 spinneret holes.

[0033] Example 5 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: By mass, 98 parts of dried PA12-7# were mixed with 2 parts of EBS and melt-blended. The screw speed was set to 500 r / min and the extrusion temperature to 220℃ to obtain PA12-7# resin material.

[0034] The above resin was dried at 80℃ for 24 hours until the water content was 39ppm. The dried PA12-7# resin was fed into a melt spinning system to obtain PA12-7# fiber. The spinning process parameters were: spinning temperature 232℃, spinning speed 2400m / min, side-blowing air temperature 15℃, cooling air relative humidity 45%, side-blowing air speed 0.6m / min, stretch ratio 2.5 times, heat setting temperature 120℃; the spinneret used for spinning had 96 spinneret holes.

[0035] Example 6 This embodiment provides a method for preparing nylon 12 fibers, including the following steps: PA12-8# resin was dried at 80℃ for 24 hours until the moisture content was 41ppm. The dried PA12-8# resin was then fed into a melt spinning system to produce PA12-8# fiber. The spinning process parameters were: spinning temperature 225℃, spinning speed 3200m / min, side-blowing air temperature 20℃, cooling air relative humidity 65%, side-blowing air speed 0.4m / min, stretch ratio 2, and heat setting temperature 120℃; the spinneret used for spinning had 48 spinneret holes.

[0036] Example 7 This embodiment provides a method for preparing nylon 12 fiber, which is basically the same as that in embodiment 2, except that PA12-9# resin is used.

[0037] Comparative Example 1 This comparative example provides a method for preparing nylon 12 fibers, which is basically the same as that in Example 3, except that PA12-1# resin is used.

[0038] Comparative Example 2 This comparative example provides a method for preparing nylon 12 fibers, which is basically the same as that in Example 5, except that PA12-2# resin is used.

[0039] Comparative Example 3 This embodiment provides a method for preparing nylon 12 fibers, which is basically the same as that in Example 2, except that PA12-10# resin is used.

[0040] Test Example 1 The test examples provide the properties of the nylon 12 fibers obtained in each embodiment and comparative example, as follows: Tensile strength test method: The test shall be conducted in accordance with the national standard GB / T14344-2008, with a clamping distance of 200 mm and a tensile speed of 200 mm / min.

[0041] Dyeability test method: The fiber was rinsed in a 2 g / L sodium dodecyl sulfate solution for 1 h (80℃), 1% acetic acid was added to adjust the pH, and 2% (owf) dye (dye type: Acid Black 1 CAS: 1064-48-8) was added. Dyeing was carried out at 80℃ for 2 h with a liquor ratio of 1:12. T% represents the dye uptake rate, which is the percentage of dye adsorbed onto the fiber during the dyeing process relative to the initial total amount of dye added. The calculation formula is: T (%) = (amount of dye adsorbed onto the fiber / total amount of dye initially added) × 100%. K / S value is the color depth of the fiber after dyeing. The larger the value, the better the dyeing performance. It is obtained by spectrophotometry. The tensile strength of the dyed fiber was tested according to the national standard GB / T14344-2008.

[0042] The test method for color fastness is as follows: GB / T 3921-2008. The test method for color fastness to perspiration is as follows: GB / T3922. The color fastness to washing and color fastness to perspiration are obtained.

[0043] Test method for antibacterial rate: Refer to GB / T20944.3-2008, use the shaking flask method to test the antibacterial performance of the sample, and select Escherichia coli and Staphylococcus aureus as test strains.

[0044] Antibacterial rate (%) = [(A - B) / A] × 100% A: Average colony count (cfu / mL) of the antibacterial sample before shaking. B: Average colony count (cfu / mL) after shaking the antibacterial sample. Table 2. Dyeing performance test results of nylon 12 fibers in each example and comparative example.

[0045] Table 3. Test results of antibacterial properties of nylon 12 fiber in each example and comparative example.

[0046] The results show that, at the same melt flow rate, the nylon 12 fiber prepared by this invention can significantly improve dyeing rate and color fastness with increasing terminal amino content, while maintaining the same or no reduction in tensile strength, effectively broadening the application fields of nylon 12 fiber in clothing. Furthermore, the nylon 12 fiber prepared by this invention also has good antibacterial effects and can be used to make high-grade antibacterial fabrics.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A nylon 12 fiber, characterized in that, The nylon 12 fiber raw material comprises, by weight, 98-100 parts of nylon 12 resin and 0-2 parts of additives; The nylon 12 resin is amino-terminated, with an amino-terminated content of 69-110 mmol / kg. The amino end-capping is achieved by adding an end-capping agent during the polymerization process of nylon 12; the end-capping agent includes monoamine end-capping agents and / or polyamine end-capping agents; The end-capping agent includes at least one of the following: guanidinyl amino end-capping agent, N-(3-aminopropyl)-1,4-butanediamine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, alkane carbon chain diamine, and aromatic diamine.

2. The nylon 12 fiber according to claim 1, characterized in that, The guanidine-containing amino end-capping agent includes polyhexamethylene guanidine hydrochloride and / or polyhexamethylene biguanide hydrochloride.

3. The nylon 12 fiber according to claim 1, characterized in that, The alkane-carbon chain diamine has the structural formula: H2N-(CH2) n -NH2, where n ranges from 1 to 16.

4. The nylon 12 fiber according to claim 1, characterized in that, The aromatic diamine includes at least one of p-phenylenediamine, m-phenylenediamine, and diphenyl ether diamine.

5. The nylon 12 fiber according to any one of claims 1-4, characterized in that, The nylon 12 resin exhibits a melt flow rate of 1-60 g / 10 min under test conditions of 190°C and 2.16 kg.

6. The nylon 12 fiber according to claim 5, characterized in that, The nylon 12 resin exhibits a melt flow rate of 3-50 g / 10 min under test conditions of 190°C and 2.16 kg.

7. The nylon 12 fiber according to any one of claims 1-4, characterized in that, The additives include antioxidants and / or lubricants.

8. The nylon 12 fiber according to claim 7, characterized in that, The antioxidants include hindered phenolic antioxidants and / or phosphite antioxidants.

9. The nylon 12 fiber according to claim 8, characterized in that, The lubricant includes at least one of polyethylene wax, oxidized polyethylene wax, fluoropolymer additives, rare earth lubricants, ethylene bis-stearamide, erucamide, and sorbitamide.

10. A method for preparing nylon 12 fiber according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Obtain Nylon 12 resin; (2) Melt spinning.

11. The preparation method according to claim 10, characterized in that, The parameters for melt spinning are: temperature of 190-280℃; and / or spinning speed of 600-8000 m / min; and / or side-blowing air temperature of 0-20℃; and / or side-blowing air speed of 0.3-1 m / min; and / or cooling air relative humidity of 40-85%; and / or stretching ratio of 1.5-5 times; and / or heat setting temperature of 60-140℃; and / or number of spinnerets of 25-500.

12. The preparation method according to claim 10 or 11, characterized in that, Step (1) also includes the step of mixing nylon 12 resin and additives.

13. The preparation method according to claim 12, characterized in that, The mixing process includes melt extrusion.

14. The preparation method according to claim 13, characterized in that, The parameters for the melt extrusion are: rotation speed of 300-600 r / min; and / or extrusion temperature of 190-280℃.

15. The use of the nylon 12 fiber according to any one of claims 1-9 or the nylon 12 fiber prepared by the preparation method according to any one of claims 10-14 in textile fabrics.

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