Nylon 12 fiber easy to dye and preparation method thereof

Abstract

The invention provides a nylon 12 fiber easy to dye and a preparation method thereof. The fiber comprises nylon 12 resin and a dyeable agent, and the content of amino-terminated groups of the nylon 12 resin is 2-5 times of the molar content of carboxyl-terminated groups. The preparation method comprises the following steps: mixing, extruding and granulating, melting and spinning, stretching and shaping and post-processing. The nylon 12 fiber is easy to dye and high in color fastness.

Description

Technical Field

[0001] The invention belongs to the technical field of fiber materials, and in particular relates to an easily dyeable nylon 12 fiber and a preparation method thereof. Background Art

[0002] As an important synthetic fiber, nylon fiber is widely used in many fields such as textiles and engineering plastics. Nylon fiber has excellent mechanical properties, wear resistance, chemical corrosion resistance and other characteristics, but it has certain shortcomings in dyeing performance. Traditional nylon fiber usually needs to be dyed under high temperature and high pressure. Not only is the dyeing process complicated and energy-intensive, but the equipment requirements are also high. At the same time, the fastness after dyeing is not high, and it is easy to fade and other problems, which to a certain extent limits the application of nylon fiber in high-end fields.

[0003] In order to improve the dyeing performance of nylon fibers, researchers have conducted a lot of research. In the prior art, copolymerization, blending and other methods are usually used to introduce hydrophilic groups or dyeable groups. For example, CN105780179A: discloses a polyamide fiber and a preparation method thereof, which is melt-spinned by mixing a specific content of amino-terminated polyether with polyamide in a screw extruder under an inert gas flow, and the obtained polyamide fiber has the characteristics of high relative viscosity of polyamide resin, high fiber strength, excellent color, easy processing, low cost, etc., and the preparation method is simple in process, low in spinning temperature, and small change in relative viscosity of resin before and after spinning. However, there are relatively few studies on nylon fibers that are easy to dye, and the problems existing in the prior art are mainly the following: First, the tinting power is insufficient, and many color systems are not easy to dye; second, the color fastness is not high and it is easy to fade; third, the dyeing process is complicated, needs to be carried out under high temperature and high pressure, and has high energy consumption and high requirements for equipment. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, one of the objects of the present invention is to provide a nylon 12 fiber which is easy to dye and has high color fastness.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0006] A nylon 12 fiber, comprising the following raw materials:

[0007] Nylon 12 resin 92–98 parts,

[0008] Dyeable agent 1-5 parts;

[0009] Wherein, the terminal amino group content of the nylon 12 resin is 2-5 times the molar content of the terminal carboxyl group.

[0010] The inventors have found that the content of nylon 12 resin terminal amino groups is 2-5 times that of terminal carboxyl groups, which has good technical effects. The principle is that the increase of terminal amino groups changes the fiber structure and enhances the binding force between the fiber and the dye. The terminal amino groups can interfere with the regular arrangement of the molecular chain, reduce the crystallinity, increase the amorphous area, facilitate the entry of the dye, and improve the dyeing amount and dyeing uniformity. It also enhances the surface hydrophilicity, facilitates the penetration of the dye solution, and improves the dyeing uniformity and fastness. During acid dyeing, the terminal amino groups are protonated to form ionic bonds with anionic dyes, and the high content has strong binding force. At the same time, it can form hydrogen bonds with the polar groups of the dye to strengthen the interaction. However, the terminal amino group content cannot be too high, otherwise it will affect the mechanical properties and heat stability of the fiber.

[0011] In the present invention, the fiber further comprises: 0.1-1.5 parts of antioxidant and 0.1-1.5 parts of lubricant.

[0012] The antioxidant is a combination of one or more of a hindered phenol antioxidant and a phosphite antioxidant. The lubricant includes one or more of polyethylene waxes, esters, metal soaps, stearic acid complex esters, amide waxes, montan waxes and bisphenol A epoxy resins. The above-mentioned additives are all commonly used additives in the art, and their selection and content are well known in the art.

[0013] In one embodiment of the present invention, the dyeable agent is a cationic dye dyeable agent and / or an anionic dye dyeable agent, preferably a cationic dye dyeable agent. For example, the cationic dye dyeable agent includes but is not limited to one or more of sodium chloride, magnesium chloride, zinc chloride, calcium chloride, lithium chloride, lithium bromide, aluminum chloride, ferric chloride, stannous chloride, and cobalt chloride. The anionic dye dyeable agent includes but is not limited to one or more of sodium sulfate, naphthalenesulfonic acid formaldehyde condensate, sodium lignin sulfonate, and aromatic polyether sulfonate.

[0014] Another object of the present invention is to provide a method for preparing nylon 12 fiber that is easy to dye.

[0015] A method for preparing the above-mentioned nylon 12 fiber that is easy to dye, the preparation method comprises the following steps: mixing, extrusion granulation, melt spinning, stretching and shaping, and post-treatment.

[0016] In one embodiment of the present invention, in the mixing step, nylon 12 resin, dyeable agent and optional auxiliary agent are mixed according to proportion; preferably, the mixing temperature is 20-90° C., the mixing speed is 1000-1200 r / min, and the mixing time is 10-15 min.

[0017] In one embodiment of the present invention, in the extrusion granulation step, the mixed material is added into a twin-screw extruder for extrusion granulation; preferably, the extrusion granulation temperature is 180-280° C., and the extrusion granulation speed is 200-600 r / min.

[0018] In one embodiment of the present invention, the melt spinning has a temperature of 190-260° C., a pressure of 1-7 MPa, and a line speed of 1000-6000 m / min.

[0019] In one embodiment of the present invention, in the stretching and shaping step, the stretching ratio is 2-5 times and the stretching temperature is 100-150°C.

[0020] In the present invention, the post-treatment steps include cleaning, drying and oiling. The post-treatment can improve the surface finish and softness of the fiber. The above processes are all conventional and general processing processes in the art.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) In terms of coloring power, the high content of terminal amino groups enhances the binding force between nylon and dyes, and the dyeing agent improves the dyeing efficiency and dye dispersibility, making dyeing easier, thereby solving the problems of traditional dyeing that requires high temperature and pressure, high energy consumption and high equipment requirements.

[0023] (2) In terms of color fastness, the fiber of the present invention is not easy to fade due to its high terminal amino content, and the dyeing agent also increases the color fastness, effectively solving the problem of easy fading of traditional dyeing.

[0024] (3) In terms of dyeing process, the nylon 12 fiber in the present invention can be dyed at room temperature and pressure, which has a simple process, low energy consumption and low equipment requirements. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific embodiments:

[0026] Table 1 Raw materials used and their information

[0027]

[0028]

[0029] Table 2 Raw material formula and fiber performance test results

[0030]

[0031]

[0032] Example 1

[0033] 1. Raw material preparation: See Table 2 for the raw material ratio

[0034] 2. Mixing:

[0035] Add 100 kg of nylon 12 resin, dyeable agent, antioxidant and lubricant into a high-speed mixer and mix for 10 minutes at 80°C and 1000 r / min to ensure that all components are fully mixed.

[0036] 3. Extrusion granulation:

[0037] The mixed materials were added into a twin-screw extruder and extruded and granulated under the conditions of 200°C in zone 1, 220°C in zone 2, 230°C in zone 3, 230°C in zone 4, 220°C in zone 5, 210°C in zone 6, 200°C in die head temperature, 200r / min in rotation speed and 10MPa in pressure.

[0038] 4. Melt spinning:

[0039] The prepared nylon 12 particles were added into a melt spinning machine and melt spinning was carried out under the conditions of 240°C in zone 1, 250°C in zone 2, 250°C in zone 3, 240°C in zone 4, 5MPa pressure and a spinning speed of 1000m / min.

[0040] 5. Stretch and shape:

[0041] The spun nylon 12 fibers were stretched and shaped, with a stretching ratio of 4 times and a stretching temperature of 120°C.

[0042] 6. Post-processing:

[0043] The stretched and shaped nylon 12 fiber is cleaned, dried and oiled to improve the surface smoothness and softness of the fiber.

[0044] Example 2

[0045] 1. Raw material preparation: See Table 2 for the raw material ratio

[0046] 2. Mixing:

[0047] Add 100 kg of nylon 12 resin, dyeable agent, antioxidant and lubricant into a high-speed mixer and mix for 15 minutes at 90°C and 1200 r / min to ensure that all components are fully mixed.

[0048] 3. Extrusion granulation:

[0049] The mixed materials were added into a twin-screw extruder and extruded and granulated under the conditions of 190°C in zone 1, 210°C in zone 2, 220°C in zone 3, 220°C in zone 4, 210°C in zone 5, 200°C in zone 6, 190°C in die head, 250r / min in rotation speed and 12MPa in pressure.

[0050] 4. Melt spinning:

[0051] The prepared nylon 12 particles were added into a melt spinning machine and melt spinning was carried out under the conditions of 230°C in zone 1, 240°C in zone 2, 240°C in zone 3, 230°C in zone 4, 6MPa in pressure and 1200m / min in spinning speed.

[0052] 5. Stretch and shape:

[0053] The spun nylon 12 fibers were stretched and shaped, with a stretching ratio of 3.5 times and a stretching temperature of 110°C.

[0054] 6. Post-processing:

[0055] The stretched and shaped nylon 12 fiber is cleaned, dried and oiled to improve the surface smoothness and softness of the fiber.

[0056] Example 3

[0057] 1. Raw material preparation: See Table 2 for the raw material ratio

[0058] 2. Mixing:

[0059] Add 100 kg of nylon 12 resin, dyeable agent, antioxidant and lubricant into a high-speed mixer and mix for 12 minutes at 85°C and 1100 r / min to ensure that all components are fully mixed.

[0060] 3. Extrusion granulation:

[0061] The mixed materials were added into a twin-screw extruder and extruded and granulated under the conditions of zone 1 temperature of 210°C, zone 2 temperature of 230°C, zone 3 temperature of 240°C, zone 4 temperature of 240°C, zone 5 temperature of 230°C, zone 6 temperature of 220°C, die head temperature of 210°C, rotation speed of 220r / min, and pressure of 11MPa.

[0062] 4. Melt spinning:

[0063] The prepared nylon 12 particles were added into a melt spinning machine and melt spinning was carried out under the conditions of 250°C in zone 1, 260°C in zone 2, 260°C in zone 3, 250°C in zone 4, 7MPa in pressure and 1100m / min in spinning speed.

[0064] 5. Stretch and shape:

[0065] The spun nylon 12 fibers were stretched and shaped, with a stretching ratio of 4.5 times and a stretching temperature of 130°C.

[0066] 6. Post-processing:

[0067] The stretched and shaped nylon 12 fiber is cleaned, dried and oiled to improve the surface smoothness and softness of the fiber.

[0068] Comparative Example 1

[0069] Compared with Example 1, the difference is that the terminal amino group content of nylon 12 resin P2021102 is 1 times the terminal carboxyl group content.

[0070] The steps of mixing, extrusion granulation, melt spinning, stretching and shaping and post-treatment are the same as those in Example 1.

[0071] Comparative Example 2

[0072] Compared with Example 1, the difference is that the terminal amino group content of nylon 12 resin P2121102 is 6 times the terminal carboxyl group content.

[0073] The steps of mixing, extrusion granulation, melt spinning, stretching and shaping and post-treatment are the same as those in Example 1.

[0074] Performance Testing

[0075] 1. Dyeing performance test:

[0076] The nylon 12 fibers prepared in Example 1-3 and Comparative Example 1-2 were dyed with cationic dyes and anionic dyes at room temperature and pressure for 30 minutes, and then rinsed with clean water and dried.

[0077] The color depth (K / S value) of the dyed fiber is measured using a spectrophotometer. The larger the K / S value, the better the dyeing performance.

[0078] 2. Color fastness test:

[0079] The dyed nylon 12 fiber was tested for color fastness to washing, color fastness to rubbing and color fastness to sunlight.

[0080] The color fastness to washing test is carried out in accordance with GB / T 3921-2008 "Textiles - Tests for color fastness - Color fastness to washing with soap", the color fastness to rubbing test is carried out in accordance with GB / T 3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing", and the color fastness to sunlight test is carried out in accordance with GB / T 8427-2008 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc fading lamp".

[0081] 3. Test results and analysis:

[0082] Dyeing performance test results

[0083] After the nylon 12 fibers prepared in Examples 1-3 were dyed with cationic dyes and anionic dyes at room temperature and pressure, the K / S values ​​were 9.7, 9.8 and 10.4, respectively, which were significantly higher than those in Comparative Example 1 (K / S value was 5.7) and Comparative Example 2 (K / S value was 7.6). This shows that the nylon 12 fibers of the present invention are easy to dye and have good dyeing properties. The nylon 12 resin having a terminal amino group content that is 2-5 times the terminal carboxyl group content cooperates with the dyeable agent, so that the fiber can be fully combined with the dye molecules at room temperature and pressure, thereby improving the dyeing effect.

[0084] Color fastness test results

[0085] The nylon 12 fibers prepared in Examples 1-3 all showed high color fastness in the tests of color fastness to washing, color fastness to rubbing, and color fastness to sunlight, which were significantly better than those in Comparative Examples 1 and 2. This shows that the nylon 12 fibers of the present invention have high color fastness and are not easy to fade. The addition of dyeable agents increases the adsorption and diffusion speed of the dye on the fiber, and at the same time makes the distribution of the dye molecules in the fiber more stable, thereby improving the color fastness.

[0086] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and these modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A nylon 12 fiber, characterized in that: The fiber comprises raw materials consisting of: Nylon 12 resin 92–98 parts, Dyeable agent 1-5 parts; Wherein, the terminal amino group content of the nylon 12 resin is 2-5 times the molar content of the terminal carboxyl group.

2. The fiber according to claim 1, characterized in that The dyeable agent is a cationic dyeable agent and / or an anionic dyeable agent, preferably a cationic dyeable agent.

3. A method for preparing the easily dyeable nylon 12 fiber according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: mixing, extrusion granulation, melt spinning, stretching and shaping, and post-treatment.

4. The preparation method according to claim 3, characterized in that: In the mixing step, nylon 12 resin, a dyeable agent, and an optional auxiliary agent are mixed according to a proportion; Preferably, the mixing temperature is 20-90° C., the mixing speed is 1000-1200 r / min, and the mixing time is 10-15 min.

5. The preparation method according to claim 3 or 4, characterized in that: In the extrusion granulation step, the mixed material is added into a twin-screw extruder for extrusion granulation; Preferably, the extrusion granulation temperature is 180-280°C, and the extrusion granulation speed is 200-600r / min.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The melt spinning has a temperature of 190-260° C., a pressure of 1-7 MPa, and a line speed of 1000-6000 m / min.

7. The preparation method according to any one of claims 3 to 6, characterized in that: In the stretching and shaping step, the stretching ratio is 2-5 times and the stretching temperature is 100-150°C.

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