Nylon 12 fiber and preparation method and application thereof

Abstract

The invention 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 is prepared from the following raw materials in parts by mass: 98 to 100 parts of nylon 12 resin and 0 to 2 parts of auxiliaries, the nylon 12 resin is amino-terminated, and the amino-terminated content is 10-110 mmol / kg. The nylon 12 resin is adopted as an amino-terminated polymer, and the amino-terminated content meets the range, so that dyeing sites can be increased, molecular chain regularity can be reduced, an amorphous region can be increased, dye, especially acid dye, can be conveniently dyed, the dye-uptake and color fastness can be remarkably improved, the dye-uptake can reach 95% or above, and the color fastness can reach 95% or above. The color fastness to washing and the color fastness to perspiration can reach grade 4-5 and the like, good mechanical properties are kept, the application requirements of high-end garment materials are met, and the long-acting antibacterial performance is excellent.

Description

Technical Field

[0001] The present invention belongs to the technical field of textile preparation, and in particular relates to a nylon 12 fiber and a preparation method and application thereof. Background Art

[0002] Nylon, also known as polyamide fiber, nylon, or nylon, boasts excellent properties such as strength, abrasion resistance, elastic recovery, and hygroscopicity. 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 offers superior low-temperature toughness, self-lubrication, low water absorption, and low density, offering broad application prospects in the textile industry. Acid dye systems are the most commonly used for dyeing nylon. They bind to the amino groups at the end of the nylon through strong ionic bonds or electrostatics, resulting in vibrant colors with excellent color fastness, making them the preferred dye system for dyeing nylon fabrics. However, due to differences in molecular structure, nylon 12 fiber exhibits significant differences in crystallinity, melting point, hydrophilicity, amide bond density, and amino group content compared to nylon 6 and nylon 66. This results in poor dye uptake and low color fastness when dyed with traditional acid dye systems, a major obstacle restricting its application in the textile industry.

[0003] Existing technologies address the poor dyeing properties and color fastness of nylon 12 fibers by adjusting the end group composition ratio of the nylon 12 resin and introducing metal salt dyes. While this approach achieves good dyeing results, it is not suitable for acid dye systems, as metal salts increase thermal degradation during spinning, making industrial application difficult. As a high-end fabric that comes into direct contact with the human body, nylon fibers require good antibacterial properties. However, the antibacterial properties of nylon 12 fibers produced by this method 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 the antibacterial properties, thereby providing a nylon 12 fiber and its preparation method and application.

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

[0006] A first aspect of the present invention provides a nylon 12 fiber, wherein the nylon 12 fiber raw material comprises, by weight: 98-100 parts of nylon 12 resin and 0-2 parts of an additive;

[0007] The nylon 12 resin is amino-terminated, and the terminal amino group content is 10-110 mmol / kg.

[0008] The present invention adjusts the terminal amino group content of nylon 12 resin to improve dye uptake and color fastness. Exemplarily, the terminal amino group content is 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.

[0009] In an optional 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 a monoamine end-capping agent and / or a polyamine end-capping agent.

[0010] In an optional embodiment, the end-capping agent includes at least one of a guanidine-containing amino end-capping agent, N-(3-aminopropyl)-1,4-butanediamine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, an alkane carbon chain diamine, and an aromatic diamine;

[0011] In an optional embodiment, the guanidine-containing amino end-capping agent includes polyhexamethyleneguanidine hydrochloride and / or polyhexamethylene biguanide hydrochloride; polyhexamethyleneguanidine hydrochloride (PHMG), the structural formula of which is 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, the capping agent can add a -NH2 as a dyeing site. The guanidine group (-NH-C(=NH)-) carries a positive charge after protonation. When dyeing with acidic dyes, it combines with the dye molecules with negative charges and can serve as a dyeing site.

[0012] N-(3-Aminopropyl)-1,4-butanediamine, also known as spermidine, contains one secondary amine group (-NH-) and two primary amine 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 amine groups (-NH-) and two primary amine groups, with the following structural formula: (-NH2)H2N-(CH2)3-NH-(CH2)4-NH-(CH2)3-NH2. The NH2 in spermidine and spermine reacts with the -COOH groups at the ends of nylon 12 molecules, creating additional -NH2 active sites. Furthermore, the protonated secondary -NH- groups carry a positive charge, which, when dyed with acidic dyes, binds to negatively charged dye molecules and serves as dyeing sites.

[0013] In an optional embodiment, the alkane carbon chain diamine has the structural formula: H2N-(CH2) n-NH2, wherein n ranges from 1 to 16, such as 2, 4, 6, 8, 10, 12, etc.;

[0014] In an 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 may be one or more benzene ring structures; for example, p-phenylenediamine, m-phenylenediamine, diphenyl ether diamine, etc.

[0015] In an optional embodiment, the nylon 12 resin has an amino group content of 45-110 mmol / kg;

[0016] In an optional embodiment, the nylon 12 resin has an amino group content of 60-110 mmol / kg.

[0017] In an optional embodiment, the nylon 12 resin has 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.

[0018] In an optional embodiment, the auxiliary agent includes an antioxidant and / or a lubricant;

[0019] In an optional embodiment, the antioxidant includes a hindered phenol antioxidant and / or a phosphite antioxidant;

[0020] In an optional embodiment, the lubricant includes at least one of polyethylene wax, oxidized polyethylene wax, fluoropolymer additives, rare earth lubricants, EBS (ethylene bisstearamide), erucamide, and sorbic acid amide.

[0021] In the present invention, the fluoropolymer additives include PFAS (per- and polyfluoroalkyl substances) and the like;

[0022] Rare earth lubricants refer to lubricating materials with rare earth elements or their compounds as core components, such as rare earth oxide nanoborides, lanthanum fluoride (LaF3) nanoparticles, organic lanthanum carboxylates (such as lanthanum oleate), etc.

[0023] A second aspect of the present invention provides a method for preparing the above-mentioned nylon 12 fiber, comprising the following steps:

[0024] (1) obtaining nylon 12 resin;

[0025] (2) Melt spinning.

[0026] In an optional embodiment, the parameters of the melt spinning are: temperature of 190-280°C; and / or, spinning speed of 600-8000 m / min; and / or, side blowing temperature of 0-20°C; and / or, side blowing 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°C; and / or, number of spinnerets of 25-500.

[0027] In an optional embodiment, the step (1) further comprises the step of mixing nylon 12 resin and an additive;

[0028] In an alternative embodiment, the mixing comprises melt extrusion;

[0029] In an optional embodiment, the melt extrusion parameters are: a rotation speed of 300-600 r / min; and / or an extrusion temperature of 190-280°C.

[0030] In the preparation method, the nylon 12 resin is first dried to a moisture content of less than 300 ppm before melt spinning, such as drying at 80° C. for 4-24 hours.

[0031] A third aspect of the present invention provides an application of the above-mentioned nylon 12 fiber in textile fabrics. The technical solution of the present invention has the following advantages:

[0032] 1. The nylon 12 fiber provided by the present invention comprises, by weight, 98-100 parts of nylon 12 resin and 0-2 parts of an auxiliary agent; the nylon 12 resin is amino-terminated, with a terminal amino group content of 10-110 mmol / kg. The present invention uses nylon 12 resin as an amino-terminated polymer, and the terminal amino group content meets the above-mentioned range. This can increase dyeing sites, reduce molecular chain regularity, increase amorphous regions, and facilitate dye uptake, especially of acid dyes. It significantly improves dye uptake and color fastness, with dye uptake reaching over 95%, and color fastness to washing and perspiration reaching grades 4-5. It maintains good mechanical properties, meets the application requirements of high-end clothing fabrics, and has excellent long-lasting antibacterial properties. Excessive terminal amino group content in nylon 12 resin affects the aging resistance and yellowing resistance of nylon 12 fiber, resulting in poor performance.

[0033] The nylon 12 resin provided by the present invention consumes terminal carboxyl sites and increases terminal amino sites, thereby increasing the terminal amino content without reducing the molecular chain length.

[0034] The nylon 12 fiber provided by the present invention can also have good dye uptake and color fastness without using auxiliaries, dye accelerators, and color-fixing crosslinking agents, avoiding the use of metal salts and the like as dye accelerators in the prior art to destroy the hydrogen bond network of nylon 12. Metal salts increase thermal degradation during spinning and weaken the mechanical properties of the fiber. The fiber has the advantages of simple formula and low cost.

[0035] 2. The nylon 12 fiber provided by the present invention uses at least one of polyhexamethyleneguanidine hydrochloride, polyhexamethylene biguanidine 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 improve the terminal amino group level of nylon 12 and introduce antibacterial groups into the molecular chain, which helps to improve the dyeing rate and color fastness of nylon 12 fiber and achieve long-lasting antibacterial properties. DETAILED DESCRIPTION

[0036] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0037] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0038] The raw materials used in the following examples and comparative examples are shown in Table 1:

[0039] Table 1 Source of raw materials

[0040]

[0041] The nylon 12 resin in Table 1 was prepared according to a preparation method known in the art. One method is listed here: laurolactam, water, and an amino end-capping agent were added to a stirring container, the temperature was raised to 250-280° C. and the temperature was kept for 2-4 hours. After the system was depressurized to normal pressure, vacuum was applied at 240-260° C. for 1-3 hours, with the vacuum degree maintained at -70 to -90 kPa. The system was cooled to 190-220° C., the material was discharged, and water-cooled and pelletized to obtain nylon 12 resin.

[0042] Example 1

[0043] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0044] PA12-3# resin was dried at 80°C for 24 hours until the moisture content reached 45 ppm. The dried PA12-3# resin was fed into a melt spinning system to produce PA12-3# fiber. The spinning process parameters were: spinning temperature 230°C, spinning speed 1600 m / min, cross-blowing temperature 17°C, cooling air relative humidity 60%, cross-blowing speed 0.6 m / min, draw ratio 2x, heat setting temperature 120°C; and the number of spinnerets used was 48.

[0045] Example 2

[0046] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0047] 99.5 parts of PA12-4# were dried and mixed with 0.5 parts of EBS for melt blending. The screw speed was set to 600 r / min and the extrusion temperature was set to 190°C to obtain PA12-4# resin material.

[0048] The resin was dried at 80°C for 24 hours until the moisture content reached 37 ppm. 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°C, spinning speed 1600 m / min, cross-blowing temperature 16°C, cooling air relative humidity 50%, cross-blowing speed 0.5 m / min, draw ratio 3x, heat setting temperature 120°C; and the number of spinnerets used was 48.

[0049] Example 3

[0050] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0051] PA12-5# resin was dried at 80°C for 24 hours until the moisture content reached 36 ppm. The dried PA12-5# resin was fed into a melt spinning system to produce PA12-5# fiber. The spinning process parameters were: spinning temperature 232°C, spinning speed 1800 m / min, cross-blowing temperature 15°C, cooling air relative humidity 45%, cross-blowing speed 0.6 m / min, stretching ratio 2.5x, heat setting temperature 120°C, and the number of spinnerets used was 96.

[0052] Example 4

[0053] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0054] PA12-6# resin was dried at 80°C for 24 hours until the moisture content reached 43ppm. The dried PA12-6# resin was fed into a melt spinning system to produce PA12-6# fiber. The spinning process parameters were: spinning temperature 225°C, spinning speed 1600m / min, cross-blowing temperature 16°C, cooling air relative humidity 65%, cross-blowing speed 0.7m / min, draw ratio 3x, heat setting temperature 120°C. The spinneret used for the spinning process had 48 spinnerets.

[0055] Example 5

[0056] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0057] 98 parts of PA12-7# were dried and melt-blended with 2 parts of EBS. The screw speed was set to 500 r / min and the extrusion temperature was set to 220°C to obtain PA12-7# resin material.

[0058] The resin was dried at 80°C for 24 hours until the moisture content reached 39 ppm. The dried PPA12-7# resin was fed into a melt spinning system to produce PA12-7# fiber. The spinning process parameters were: spinning temperature 232°C, spinning speed 2400 m / min, cross-blowing temperature 15°C, cooling air relative humidity 45%, cross-blowing speed 0.6 m / min, draw ratio 2.5x, heat setting temperature 120°C. The spinneret used for spinning had 96 spinnerets.

[0059] Example 6

[0060] This embodiment provides a method for preparing nylon 12 fiber, comprising the following steps:

[0061] PA12-8# resin was dried at 80°C for 24 hours until the moisture content reached 41ppm. The dried PA12-8# resin was fed into a melt spinning system to produce PA12-8# fiber. The spinning process parameters were: spinning temperature 225°C, spinning speed 3200m / min, cross-blowing temperature 20°C, cooling air relative humidity 65%, cross-blowing speed 0.4m / min, draw ratio 2x, heat setting temperature 120°C. The spinneret used for the spinning process had 48 spinnerets.

[0062] Example 7

[0063] This embodiment provides a method for preparing nylon 12 fiber, which is basically the same as that of Example 2, except that PA12-9# resin is used.

[0064] Comparative Example 1

[0065] This comparative example provides a preparation method of nylon 12 fiber, which is basically the same as Example 3, except that PA12-1# resin is used.

[0066] Comparative Example 2

[0067] This comparative example provides a preparation method of nylon 12 fiber, which is basically the same as Example 5, except that PA12-2# resin is used.

[0068] Comparative Example 3

[0069] This embodiment provides a method for preparing nylon 12 fiber, which is basically the same as that of Example 2, except that PA12-10# resin is used.

[0070] Test Example 1

[0071] The test examples provide the properties of nylon 12 fibers prepared in various embodiments and comparative examples, as follows:

[0072] Tensile strength test method: Tested in accordance with national standard GB / T14344-2008, with a clamping distance of 200 mm and a tensile speed of 200 mm / min.

[0073] Dyeability test method: Rinse the fiber in a 2g / L sodium dodecyl sulfate solution for 1 hour at 80°C, add 1% acetic acid to adjust the pH, add 2% (owf) dye (dye type: Acid Black 1 CAS: 1064-48-8), and dye at 80°C for 2 hours, using a bath ratio of 1:12. T% represents dye uptake, which is the percentage of dye absorbed onto the fiber during the dyeing process compared to the total amount of dye initially applied. The calculation formula is: T(%) = (amount of dye absorbed onto the fiber / total amount of dye initially applied) × 100%. The K / S value represents the color depth of the dyed fiber; a larger value indicates better dyeing performance. This value is measured using a spectrophotometer. The tensile strength of the dyed fiber is tested in accordance with the national standard GB / T14344-2008.

[0074] Color fastness test method: According to GB / T 3921-2008, color fastness to perspiration test is carried out according to GB / T3922 to obtain color fastness to washing and color fastness to perspiration.

[0075] 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 the test bacteria.

[0076] Antibacterial rate (%) = [(AB) / A] × 100%

[0077] A: Average colony count of antibacterial sample before shaking (cfu / mL)

[0078] B: Average colony count of antibacterial sample after shaking (cfu / mL)

[0079] Table 2 Test results of dyeing performance of nylon 12 fiber in various embodiments and comparative examples

[0080]

[0081]

[0082] Table 3 Antibacterial performance test results of nylon 12 fibers in various embodiments and comparative examples

[0083]

[0084] The above results demonstrate that, at the same melt flow rate, the nylon 12 fiber produced by the present invention can significantly improve dye uptake and color fastness while maintaining the same level of tensile strength or no degradation, as the amino group content increases. This effectively expands the application areas of nylon 12 fiber clothing. Furthermore, the nylon 12 fiber produced by the present invention also exhibits a strong antibacterial effect, making it suitable for use in the production of high-end antibacterial fabrics.

[0085] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present 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 an additive; The nylon 12 resin is amino-terminated, and the terminal amino group content is 10-110 mmol / kg.

2. The nylon 12 fiber according to claim 1, characterized in that The amino end-capping is achieved by adding an end-capping agent during the polymerization process of nylon 12; the end-capping agent includes a monoamine end-capping agent and / or a polyamine end-capping agent.

3. The nylon 12 fiber according to claim 2, characterized in that The end-capping agent includes at least one of a guanidine-containing amino end-capping agent, N-(3-aminopropyl)-1,4-butanediamine, N,N'-bis(3-aminopropyl)-1,4-butanediamine, an alkane carbon chain diamine, and an aromatic diamine; Preferably, the guanidine-containing amino end-capping agent comprises polyhexamethyleneguanidine hydrochloride and / or polyhexamethylene biguanidine hydrochloride; Preferably, the alkane carbon chain diamine has the structural formula: H2N-(CH2) n -NH2, wherein n ranges from 1 to 16; Preferably, the aromatic diamine includes at least one of p-phenylenediamine, m-phenylenediamine, and diphenyl ether diamine.

4. The nylon 12 fiber according to any one of claims 1 to 3, characterized in that The nylon 12 resin has a terminal amino group content of 45-110 mmol / kg; Preferably, the nylon 12 resin has an amino group content of 60-110 mmol / kg.

5. The nylon 12 fiber according to any one of claims 1 to 4, characterized in that: The nylon 12 resin has 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.

6. The nylon 12 fiber according to any one of claims 1 to 5, characterized in that The auxiliary agent includes an antioxidant and / or a lubricant; Preferably, the antioxidant comprises a hindered phenol antioxidant and / or a phosphite antioxidant; Preferably, the lubricant includes at least one of polyethylene wax, oxidized polyethylene wax, fluorine-containing polymer additives, rare earth lubricants, ethylene bisstearamide, erucamide, and sorbic acid amide.

7. The method for preparing nylon 12 fiber according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) obtaining nylon 12 resin; (2) Melt spinning.

8. The preparation method according to claim 7, characterized in that The melt spinning parameters are: temperature of 190-280°C; and / or, spinning speed of 600-8000 m / min; and / or, side blowing temperature of 0-20°C; and / or, side blowing 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°C; and / or, number of spinnerets of 25-500.

9. The preparation method according to claim 7 or 8, characterized in that The step (1) further comprises the step of mixing nylon 12 resin and an auxiliary agent; Preferably, the mixing comprises melt extrusion; Preferably, the melt extrusion parameters are: a rotation speed of 300-600 r / min; and / or an extrusion temperature of 190-280°C.

10. Use of the nylon 12 fiber according to any one of claims 1 to 6 or the nylon 12 fiber prepared by the preparation method according to any one of claims 7 to 9 in textile fabrics.

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