Micro-copolymerization modified polyamide 66 fiber and preparation method thereof

Abstract

The invention relates to a micro-copolymerization modified polyamide 66 fiber and a preparation method thereof, in particular to a method for improving the dyeing performance of the high-strength polyamide 66 fiber by copolymerizing a trace nitrogen-containing six-membered heterocyclic ring to a polyamide 66 main chain. The preparation method is characterized by comprising the following steps: firstly, carrying out a salt forming reaction on a nitrogen-containing six-membered heterocyclic compound and aliphatic dibasic acid or diamine to obtain a nitrogen-containing six-membered heterocyclic amide salt, mixing the amide salt with nylon 66 salt, carrying out melt polycondensation to obtain nitrogen-containing six-membered heterocyclic copolymerized polyamide 66, and then carrying out melt spinning to obtain the micro-copolymerized modified polyamide 66 fiber. The micro-copolymerized modified polyamide 66 fiber prepared by the invention has excellent mechanical properties and dyeing properties.

Description

Technical Field

[0001] The present invention belongs to the field of polyamide fiber preparation, and relates to a micro-copolymerized modified polyamide 66 fiber and a preparation method thereof, and in particular to a method for obtaining polyamide 66 fiber by melt spinning after preparing micro-copolymerized modified polyamide 66 by introducing nitrogen-containing six-membered heterocycles into a polyamide 66 molecular chain. Background Art

[0002] Polyamide 66 fiber has excellent strength, wear resistance, and corrosion resistance, and is widely used in clothing, industrial use, and home textiles. With its excellent mechanical properties, high-strength polyamide 66 fiber has shown great application potential in high-end application markets such as soldier training uniforms and outdoor sportswear. However, the dyeing performance of high-strength polyamide 66 fiber is relatively poor, which limits its color diversity and aesthetics. Therefore, in-depth research on effective methods to improve the dyeing performance of high-strength polyamide 66 fiber is of great significance to broaden its application scope, enhance product competitiveness, and meet the diversified needs of the market.

[0003] High-strength polyamide 66 fiber has poor dyeing performance in practical applications. The main reasons are the following two aspects: On the one hand, acid dyes are currently used to dye polyamide 66 fibers, which are dyed by combining with the terminal amino groups in the fiber molecules. However, the preparation of high-strength polyamide 66 is to combine the terminal amino group with the terminal carboxyl group by terminal condensation reaction to generate polyamide 66 with higher molecular weight. This process significantly reduces the number of dyeable groups (i.e., terminal amino groups) in the fiber. The terminal amino group is the key "dyeing seat" for the dye molecule to bind, and the reduction in its number directly affects the dyeing performance of the fiber. On the other hand, the molecular crystallinity and orientation of high-strength polyamide 66 fibers are high. The crystalline region hinders the adsorption and diffusion of the dye. At the same time, the high orientation means that the fiber molecular chain is arranged more orderly, which further increases the difficulty of the dye molecules penetrating into the fiber.

[0004] Chinese patent CN117758525A discloses a dyeing method for high-strength polyamide 66 fabric, which completes the dyeing process through the steps of pretreatment, dyeing, soaping, color fixation and shaping. In the dyeing process, acid dyes with various molecular structures are used to cooperate with each other, and combined with the three-stage temperature rising dyeing technology, the dyeing is achieved, thereby obtaining better color fastness. However, this patent only improves the dyeing performance of high-strength polyamide 66 by optimizing the dyeing process, and fails to fundamentally solve the technical bottlenecks of high-strength polyamide 66 fiber dyeing difficulties, such as the insufficient number of "dyeing seats" and the limitations of high fiber crystallinity and high orientation. Summary of the invention

[0005] The present invention provides a micro-copolymerized modified polyamide 66 fiber and a preparation method thereof, and particularly relates to a method for obtaining the polyamide 66 fiber by preparing the micro-copolymerized modified polyamide 66 by introducing a nitrogen-containing six-membered heterocycle into a polyamide 66 molecular chain and then melt-spinning the prepared polyamide 66.

[0006] The main chain of the polyamide 66 fiber molecule prepared by the present invention introduces a nitrogen-containing six-membered heterocyclic ring, and the basic nitrogen atoms contained in the nitrogen-containing six-membered heterocyclic ring increase the number of "dyeing seats" in the molecular chain during dyeing, thereby improving the dyeing rate of the polyamide 66 fiber. Unlike the terminal amino group of polyamide 66, the "dyeing seat" of the nitrogen-containing six-membered heterocyclic ring will not decrease with the increase of the molecular weight of polyamide 66, and it has obvious advantages in improving the dyeing performance of high-strength polyamide 66 fiber, and is suitable for the viscosity increase of polyamide 66 with different molecular weights and meets the requirements for improving the dyeing performance of polyamide 66 fibers with different strengths. In addition, the nitrogen-containing six-membered heterocyclic ring is a rigid group, and the introduction of a small amount of nitrogen-containing six-membered heterocyclic ring can moderately reduce the regularity of the polyamide 66 molecular chain, which is more conducive to the diffusion and binding of dyes inside the fiber.

[0007] The present invention provides a micro-copolymerized modified polyamide 66 fiber having the following structure:

[0008] Wherein, n is 4~10, x is 39~105, y is 1~43, and the structural formula of R is as follows:

[0009] The present invention also provides a method for preparing the above-mentioned micro-copolymerized modified polyamide 66 fiber, the specific steps of which are as follows: (1) A nitrogen-containing six-membered heterocyclic compound and an aliphatic dibasic acid or diamine are added to water or ethanol in a certain proportion, and stirred at 60-90°C for 1-12 hours to perform a salt-forming reaction. After the salt is precipitated, it is filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic compound; (2) Add 1-100 parts of nitrogen-containing six-membered heterocyclic amide salt, 75-105 parts of nylon 66 salt, and 60-80 parts of deionized water into a polymerization reactor, and replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 215-235°C, and maintain the pressure at 1.8-2.0 MPa for condensation for 2-3 hours; continue to raise the temperature to 245-255°C, and reduce the pressure to normal pressure 0 MPa after 0.5-1 hour; continue to raise the temperature to 270-280°C, evacuate to a pressure of -0.01-0.10 MPa, and maintain the temperature and pressure for 1-3 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66; (3) The nitrogen-containing six-membered heterocyclic copolymer polyamide 66 or the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 are mixed in a certain proportion and then spun in a melt spinning machine to obtain micro-copolymer modified polyamide 66 fibers.

[0010] The method for preparing a micro-copolymer modified polyamide 66 fiber as described above, in step (1), the nitrogen-containing six-membered heterocyclic compound includes a nitrogen-containing six-membered heterocyclic dibasic acid and a nitrogen-containing six-membered heterocyclic diamine, and the nitrogen-containing six-membered heterocyclic dibasic acid includes 2,6-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,3-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, 2,5-pyrimidinedicarboxylic acid, 2,3-pyrazinedicarboxylic acid, 2,6-pyrazinedicarboxylic acid, 2,5-pyrazinedicarboxylic acid, 4,5-pyridazinedicarboxylic acid, 3,6-pyridazinedicarboxylic acid One or more of the pyridine ring-containing diamines include one or more of 2,6-diaminopyridine, 2,5-diaminopyridine, 2,4-diaminopyridine, 2,3-diaminopyridine, 3,5-diaminopyridine, 3,4-diaminopyridine, 4,6-diaminopyrimidine, 2,4-diaminopyrimidine, 4,5-diaminopyrimidine, 2,6-diaminopyrazine, 4,5-diaminopyridazine, and 3,6-diaminopyridazine; the aliphatic dibasic acid is a straight-chain aliphatic dibasic acid having 4 to 12 carbon atoms; the aliphatic diamine is a straight-chain aliphatic diamine having 4 to 10 carbon atoms.

[0011] In the method for preparing a micro-copolymer modified polyamide 66 fiber as described above, in step (1), when the nitrogen-containing six-membered heterocyclic compound is a diamine structure, the nitrogen-containing six-membered heterocyclic diamine and the aliphatic dibasic acid are subjected to a salt-forming reaction at a molar ratio of 1.02 to 1.05:1; when the nitrogen-containing six-membered heterocyclic compound is a dibasic acid structure, the nitrogen-containing six-membered heterocyclic dibasic acid and the aliphatic diamine are subjected to a salt-forming reaction at a molar ratio of 1:1.02 to 1.05.

[0012] In the method for preparing the micro-copolymerized modified polyamide 66 fiber as described above, in step (2), the number average molecular weight of the nitrogen-containing six-membered heterocyclic copolymerized polyamide 66 is 17000-24000 g / mol.

[0013] In the method for preparing a micro-copolymer modified polyamide 66 fiber as described above, in step (3), when x is 66-105 and y is 1-7, the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 can be directly spun; when x is 39-66 and y is 7-43, the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 can be mixed with conventional polyamide 66 in a ratio of 1:18-98 and then spun.

[0014] In the method for preparing the micro-copolymer modified polyamide 66 fiber as described above, the melt spinning conditions in step (3) are a temperature of 280-290° C., a winding speed of 2500-3500 m / min, and a stretching multiple of 5-5.5.

[0015] The micro-copolymer modified polyamide 66 fiber as described above has a breaking strength of 6.5-8.2 cN / dtex, a breaking elongation of 17.4-26.8%, and the woven fabric has a washing color fastness of grade 4-5, a dyeing rate of 98.3-99.9%, and a K / S value of 22.0-26.5.

[0016] After the fibers are knitted into long and thin socks by a hosiery machine, the color uptake rate is determined using acid red N-2RBL or NAVY MPA acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to soaping", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0017] The technical solution of the present invention can achieve the following beneficial effects: (1) Significantly improve the dyeing performance of high-strength polyamide 66 fiber: By introducing a nitrogen-containing six-membered heterocyclic structure into the main chain of the polyamide 66 fiber molecule, the number of "dyeing sites" in the molecular chain during dyeing is increased. This innovative design significantly improves the dyeing rate of high-strength polyamide 66 fiber, overcoming the problem of poor dyeing performance of traditional polyamide 66 fiber due to insufficient number of "dyeing sites".

[0018] (2) Expanding the application scope of polyamide 66 fiber: Due to the improvement of dyeing performance, high-strength polyamide 66 fiber can present richer colors and higher aesthetics, thereby meeting the demand for color diversity in more fields. This helps to expand the application scope of polyamide 66 fiber, especially in the fields of textiles, clothing, home decoration, etc. that require high color expression.

[0019] (3) Adapting to the requirements of different molecular weight polyamide 66 and different strength polyamide 66 fibers: The "dyeing seat" of the nitrogen-containing six-membered heterocyclic structure will not decrease as the molecular weight increases during the polyamide viscosity increasing process. This feature makes the present invention suitable for dyeing polyamide 66 fibers with different strength requirements, providing greater flexibility and adaptability. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0021] Example 1 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,6-pyridinedicarboxylic acid and 1,6-hexanediamine were added to water in a molar ratio of 1:1.02, and stirred at 90°C for 1 hour to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 1 part of nitrogen-containing six-membered heterocyclic amide salt, 75 parts of nylon 66 salt, and 60 parts of deionized water into a polymerization reactor, replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 215°C, maintain the pressure at 1.8 MPa for condensation for 2 hours; continue to raise the temperature to 245°C, and reduce the pressure to normal pressure 0 MPa after 0.5 hours; continue to raise the temperature to 275°C, evacuate to a pressure of -0.01 MPa, and maintain the temperature and pressure for 1 hour to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 17100 g / mol and the molecular structure is:

[0022] (3) The nitrogen-containing six-membered heterocyclic copolymer polyamide 66 was spun in a melt spinning machine at a spinning temperature of 280°C, a winding speed of 2500 m / min, and a stretching ratio of 5.0 to obtain micro-copolymer modified polyamide 66 fibers.

[0023] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using acid red N-2RBL acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0024] Example 2 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,4-pyridinedicarboxylic acid and 1,6-hexanediamine were added to water in a molar ratio of 1:1.03, and stirred at 80°C for 12 hours to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 2 parts of nitrogen-containing six-membered heterocyclic amide salt, 100 parts of nylon 66 salt, and 70 parts of deionized water into a polymerization reactor, and replace the air in the reactor with nitrogen for 3 times; turn on the heating, slowly raise the temperature to 225°C, and maintain the pressure at 1.9 MPa for condensation for 3 hours; continue to raise the temperature to 250°C, and reduce the pressure to normal pressure 0 MPa after 0.7 hours; continue to raise the temperature to 270°C, evacuate to a pressure of -0.05 MPa, and maintain the temperature and pressure for 2 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 23000 g / mol and the molecular structure is:

[0025] (3) The nitrogen-containing six-membered heterocyclic copolymer polyamide 66 was spun in a melt spinning machine at a spinning temperature of 282°C, a winding speed of 3500 m / min, and a stretching multiple of 4.5 to obtain micro-copolymer modified polyamide 66 fibers.

[0026] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using acid red N-2RBL acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0027] Example 3 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,5-pyridinedicarboxylic acid and 1,6-hexanediamine were added to water in a molar ratio of 1:1.04, and stirred at 70°C for 4 hours to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 3 parts of nitrogen-containing six-membered heterocyclic amide salt, 105 parts of nylon 66 salt, and 80 parts of deionized water into a polymerization reactor, replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 235°C, maintain the pressure at 2.0 MPa for condensation for 2.5 hours; continue to raise the temperature to 255°C, and reduce the pressure to normal pressure 0 MPa after 0.8 hours; continue to raise the temperature to 278°C, evacuate to a pressure of -0.08 MPa, and maintain the temperature and pressure for 2 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 24300 g / mol and the molecular structure is:

[0028] (3) The nitrogen-containing six-membered heterocyclic copolymer polyamide 66 was spun in a melt spinning machine at a spinning temperature of 285°C, a winding speed of 3000 m / min, and a stretching multiple of 5.2 to obtain micro-copolymer modified polyamide 66 fibers.

[0029] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using NAVY MPA acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0030] Example 4 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,6-diaminopyridine and 1,6-hexanedioic acid were added to water in a molar ratio of 1:1.05, and stirred at 60°C for 6 hours to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 74 parts of nitrogen-containing six-membered heterocyclic amide salt, 80 parts of nylon 66 salt, and 80 parts of deionized water into a polymerization reactor, replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 225°C, and maintain the pressure at 1.9 MPa for condensation for 3 hours; continue to raise the temperature to 250°C, and reduce the pressure to normal pressure 0 MPa after 1 hour; continue to raise the temperature to 280°C, evacuate to a pressure of -0.02 MPa, and maintain the temperature and pressure for 2 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 17800 g / mol and the molecular structure is:

[0031] (3) Nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 were mixed in a ratio of 1:48 and spun in a melt spinning machine at a spinning temperature of 286°C, a winding speed of 3100 m / min, and a stretching multiple of 5.3 to obtain micro-copolymer modified polyamide 66 fibers.

[0032] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using NAVY MPA acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0033] Example 5 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,6-diaminopyridine and 1,6-hexanedioic acid were added to water in a molar ratio of 1:1.03, and stirred at 90°C for 5 hours to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 76 parts of nitrogen-containing six-membered heterocyclic amide salt, 78 parts of nylon 66 salt, and 80 parts of deionized water into a polymerization reactor, replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 235°C, maintain the pressure at 2.0 MPa for condensation for 2.5 hours; continue to raise the temperature to 250°C, reduce the pressure to normal pressure 0 MPa after 0.5 hours; continue to raise the temperature to 275°C, evacuate to a pressure of -0.04 MPa, and maintain the temperature and pressure for 2 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 17100 g / mol and the molecular structure is:

[0034] (3) Nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 were mixed in a ratio of 1:18 and spun in a melt spinning machine at a spinning temperature of 288°C, a winding speed of 3000 m / min, and a stretching multiple of 5.3 to obtain micro-copolymer modified polyamide 66 fibers.

[0035] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using acid red N-2RBL acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0036] Example 6 A method for preparing micro-copolymerized modified polyamide 66 fiber, the specific steps are as follows: (1) 2,6-diaminopyridine and 1,6-hexanedioic acid were added to water in a molar ratio of 1:1.03, and stirred at 80°C for 6 hours to perform a salt-forming reaction. After the salt was precipitated, it was filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic ring; (2) Add 86 parts of nitrogen-containing six-membered heterocyclic amide salt, 80 parts of nylon 66 salt, and 70 parts of deionized water into a polymerization reactor, replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 230°C, and maintain the pressure at 1.8 MPa for condensation for 3 hours; continue to raise the temperature to 255°C, and reduce the pressure to normal pressure 0 MPa after 1 hour; continue to raise the temperature to 273°C, evacuate to a pressure of -0.05 MPa, and maintain the temperature and pressure for 3 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66, whose number average molecular weight is 18400 g / mol and the molecular structure is:

[0037] (3) Nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 were mixed in a ratio of 1:98 and spun in a melt spinning machine at a spinning temperature of 290°C, a winding speed of 3000 m / min, and a stretching multiple of 5.5 to obtain micro-copolymer modified polyamide 66 fibers.

[0038] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using NAVY MPA acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0039] Comparative Example 1 Polyamide 66 with a number average molecular weight of 17000 g / mol was spun in a melt spinning machine at a spinning temperature of 285° C., a winding speed of 2500 m / min, and a stretching multiple of 5.0 to obtain polyamide 66 fibers.

[0040] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using acid red N-2RBL acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0041] Comparative Example 2 Polyamide 66 with a number average molecular weight of 24000 g / mol was spun in a melt spinning machine at a spinning temperature of 295° C., a winding speed of 3000 m / min, and a stretching multiple of 5.5 to obtain polyamide 66 fibers.

[0042] After the fibers are woven into long and thin socks by a hosiery machine, the color uptake rate is determined using NAVY MPA acid dye according to "GB / T23976.1-2009 Determination of dye uptake rate curve - Color uptake rate determination method", the color fastness to washing is tested according to "GB / T3921-2008 Textiles - Color fastness to soaping - Tests for color fastness - Color fastness to washing", and the fastness grade is determined according to "GB / T251-2008 Textiles - Color fastness - Grey scale for assessment of staining".

[0043] The mechanical properties and dyeing properties of the micro-copolymer modified polyamide 66 fibers of various embodiments and comparative examples are shown in Table 1 below: Table 1 Mechanical properties and dyeing properties of micro-copolymer modified polyamide 66 fiber

[0044] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A micro-copolymer modified polyamide 66 fiber, characterized in that: The raw material is nitrogen-containing six-membered heterocyclic copolymer polyamide 66, and its structural formula is as follows: ； Wherein, n is 4~10, x is 39~105, y is 1~43, and the structural formula of R is as follows: 。 2. A method for preparing micro-copolymerized modified polyamide 66 fiber, characterized in that: The following steps are involved: (1) A nitrogen-containing six-membered heterocyclic compound and an aliphatic dibasic acid or diamine are added to water or ethanol in a certain proportion, and stirred at 60-90°C for 1-12 hours to perform a salt-forming reaction. After the salt is precipitated, it is filtered, washed, and dried to obtain an amide salt of a nitrogen-containing six-membered heterocyclic compound; (2) Add 1-100 parts of nitrogen-containing six-membered heterocyclic amide salt, 75-105 parts of nylon 66 salt, and 60-80 parts of deionized water into a polymerization reactor, and replace the air in the reactor with nitrogen three times; turn on the heating, slowly raise the temperature to 215-235°C, and maintain the pressure at 1.8-2.0 MPa for condensation for 2-3 hours; continue to raise the temperature to 245-255°C, and reduce the pressure to normal pressure 0 MPa after 0.5-1 hour; continue to raise the temperature to 270-280°C, evacuate to a pressure of -0.01-0.10 MPa, and maintain the temperature and pressure for 1-3 hours to obtain nitrogen-containing six-membered heterocyclic copolymer polyamide 66; (3) The nitrogen-containing six-membered heterocyclic copolymer polyamide 66 or the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 are mixed in a certain proportion and then spun in a melt spinning machine to obtain micro-copolymer modified polyamide 66 fibers.

3. The method for preparing a micro-copolymerized modified polyamide 66 fiber according to claim 2, characterized in that: In step (1), the nitrogen-containing six-membered heterocyclic compound includes a nitrogen-containing six-membered heterocyclic dibasic acid and a nitrogen-containing six-membered heterocyclic diamine, the nitrogen-containing six-membered heterocyclic dibasic acid includes one or more of 2,6-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,3-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, 2,5-pyrimidinedicarboxylic acid, 2,3-pyrazinedicarboxylic acid, 2,6-pyrazinedicarboxylic acid, 2,5-pyrazinedicarboxylic acid, 4,5-pyridazinedicarboxylic acid, and 3,6-pyridazinedicarboxylic acid, and the nitrogen-containing six-membered heterocyclic compound includes one or more of 2,6-pyridinedicarboxylic acid, 2,5-pyrazinedicarboxylic acid, 4,5-pyridazinedicarboxylic acid, and 3,6-pyridazinedicarboxylic acid. The diamines include one or more of 2,6-diaminopyridine, 2,5-diaminopyridine, 2,4-diaminopyridine, 2,3-diaminopyridine, 3,5-diaminopyridine, 3,4-diaminopyridine, 4,6-diaminopyrimidine, 2,4-diaminopyrimidine, 4,5-diaminopyrimidine, 2,6-diaminopyrazine, 4,5-diaminopyridazine, and 3,6-diaminopyridazine; the aliphatic dibasic acid is a straight-chain aliphatic dibasic acid having 4 to 12 carbon atoms; and the aliphatic diamine is a straight-chain aliphatic diamine having 4 to 10 carbon atoms.

4. The method for preparing a micro-copolymerized modified polyamide 66 fiber according to claim 2, characterized in that: In step (1), when the nitrogen-containing six-membered heterocyclic compound is a diamine structure, the nitrogen-containing six-membered heterocyclic diamine and the aliphatic dibasic acid are subjected to a salt-forming reaction at a molar ratio of 1.02 to 1.05:1; when the nitrogen-containing six-membered heterocyclic compound is a dibasic acid structure, the nitrogen-containing six-membered heterocyclic dibasic acid and the aliphatic diamine are subjected to a salt-forming reaction at a molar ratio of 1:1.02 to 1.

05.

5. The method for preparing a micro-copolymerized modified polyamide 66 fiber according to claim 2, characterized in that: In step (2), the number average molecular weight of the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 is 17000-24000 g / mol.

6. The method for preparing a micro-copolymerized modified polyamide 66 fiber according to claim 2, characterized in that: In step (3), when x is 66-105 and y is 1-7, the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 can be directly spun; when x is 39-66 and y is 7-43, the nitrogen-containing six-membered heterocyclic copolymer polyamide 66 and conventional polyamide 66 can be mixed in a ratio of 1:18-98 and then spun.

7. The method for preparing a micro-copolymerized modified polyamide 66 fiber according to claim 2, characterized in that: The melt spinning conditions in step (3) are a temperature of 280-290° C., a winding speed of 2500-3500 m / min, and a stretching ratio of 5-5.

5.

8. The micro-copolymer modified polyamide 66 fiber according to claim 2 has a breaking strength of 6.5-8.2 cN / dtex, an elongation at break of 17.4-26.8%, a washing color fastness of grade 4-5, a dyeing rate of 98.3-99.9%, and a K / S value of 22.0-26.5.

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