A high-strength polyamide 66 fiber material and its preparation method

Abstract

The present invention relates to a high-strength polyamide 66 fiber material and a preparation method thereof, and particularly to a method for improving the level dyeing property of a fine denier high-strength polyamide 66 fiber material by introducing a sulfonic acid group and a pyridine ring into the polyamide 66 molecular chain. The characteristics of the present invention are as follows: First, a compound containing a sulfonic acid group is subjected to a salt-forming reaction with an aliphatic diamine to obtain an amide salt containing a sulfonic acid group, and a compound containing a pyridine ring is subjected to a salt-forming reaction with an aliphatic dicarboxylic acid or a diamine to obtain an amide salt containing a pyridine ring. Then, the two are mixed with nylon 66 salt and subjected to melt polycondensation to obtain polyamide 66 containing a sulfonic acid group and a pyridine ring in the molecular chain. Subsequently, high-strength polyamide 66 fiber material is obtained by melt spinning. The high-strength polyamide 66 fiber material prepared by the present invention has high breaking strength, high dye uptake rate, and good dyeing uniformity.

Description

Technical Field

[0001] The present invention belongs to the field of polyamide fiber preparation, and relates to a high-strength polyamide 66 fiber material and a preparation method thereof, in particular to a method for obtaining a fine-denier high-strength polyamide 66 fiber material by introducing sulfonic acid groups and pyridine rings into the polyamide 66 molecular chain to prepare modified polyamide 66 and then performing melt spinning. Background Art

[0002] Polyamide 66 fibers have the characteristics of high strength, wear resistance, cold resistance, aging resistance, and comfort, and are widely used in the textile and clothing fields. Among them, fine-denier high-strength polyamide 66 fibers have good mechanical properties, softness, hygroscopicity, and air permeability, and can be used to manufacture high-performance end products such as sportswear, military clothing, and protective clothing. With the increase in the degree of refinement, the single-filament diameter of fine-denier fibers becomes smaller, and the specific surface area increases, which can endow fabrics with properties such as fluffiness, covering property, softness, heat preservation property, moisture permeability and waterproof property. However, due to the large specific surface area of fine-denier fibers, the dye uptake rate is fast, resulting in poor leveling property and easy occurrence of uneven dyeing. For polyamide 66 fibers with relatively poor leveling property, this is an even more severe test. Therefore, in-depth study of the leveling property of fine-denier high-strength polyamide 66 fibers and exploration of effective ways to improve their leveling effect are of crucial significance for broadening their application scope, enhancing product competitiveness, and meeting the diversified needs of the market.

[0003] Fine-denier polyamide 66 fibers have a relatively small diameter and a relatively large specific surface area, and dyes are more likely to be adsorbed on the surface, and the dye concentration inside the fiber is relatively low, resulting in problems such as color streaks, yin-yang surfaces, and segment differences in uneven dyeing during the dyeing process of fine-denier polyamide 66 fibers. Chinese Patent CN103132349A discloses a dyeing and finishing process for ultra-fine-denier polyamide fabrics. This method reduces the initial dyeing rate of dyes by using an anionic leveling agent to achieve a leveling effect. However, this patent only improves the dyeing performance of fine-denier polyamide by adding a leveling agent, and fails to fundamentally solve the technical bottleneck of difficult leveling of fine-denier polyamide 66 fibers. Summary of the Invention

[0004] The present invention provides a method for preparing a high-strength polyamide 66 fiber material. In particular, it relates to a method for obtaining a fine-denier high-strength polyamide 66 fiber material by introducing sulfonic acid groups and pyridine rings into the polyamide 66 molecular chain to prepare modified polyamide 66 and then performing melt spinning.

[0005] The high-strength polyamide 66 fiber prepared by the present invention copolymerizes sulfonic acid groups and pyridine ring structures into the main chain of the polyamide 66 molecule. A small amount of sulfonic acid groups combine with the terminal amino groups, increasing the resistance to acid dyes, appropriately slowing down the dyeing rate of acid dyes in the fiber, delaying the dyeing time, and facilitating the uniform diffusion and combination of dyes on the surface and inside of the fiber. The pyridine ring structure contains basic nitrogen atoms, increasing the number of "dyeing sites" in the molecular chain during the dyeing of polyamide 66, improving the dye uptake rate of the polyamide 66 fiber, and compensating to a certain extent for the defect of the reduced dye uptake rate caused by the decrease in the number of terminal amino groups.

[0006] The present invention provides a high-strength polyamide 66 fiber material with the following structure:

[0007]

[0008] Where m is 4 - 10, n is 4 - 10, x is 1 - 35, y is 32 - 146, z is 1 - 35, and the structure of R' is as follows:

[0009]

[0010] The structure of R is as follows:

[0011]

[0012] The present invention also provides a preparation method of the high-strength polyamide 66 fiber material, and the specific steps are as follows:

[0013] (1) Add a dibasic acid containing sulfonic acid groups and an aliphatic diamine in a certain proportion to water or ethanol, carry out a salification reaction at room temperature, and after the salt precipitates, filter, wash, and dry to obtain an amide salt containing sulfonic acid groups;

[0014] (2) Add a pyridine ring structure compound and an aliphatic dibasic acid or diamine in a certain proportion to water or ethanol, stir at 60 - 90 °C for 1 - 12 h, and after the salt precipitates, filter, wash, and dry to obtain an amide salt containing a pyridine ring structure;

[0015] (3) Add 1 - 50 parts of the salt containing sulfonic acid groups, 1 - 50 parts of the amide salt containing a pyridine ring structure, 75 - 100 parts of nylon 66 salt, and 60 - 80 parts of deionized water to a polymerization reaction kettle, displace the air in the kettle with nitrogen 3 times; turn on the heating, slowly raise the temperature to 215 - 235 °C, keep the pressure at 1.8 - 2.0 MPa and carry out polycondensation for 2 - 3 h; continue to raise the temperature to 245 - 255 °C, reduce the pressure to normal pressure 0 MPa in 0.5 - 1 h; continue to raise the temperature to 270 - 280 °C, evacuate to a pressure of -0.01 - -0.10 MPa, and keep the temperature and pressure for 1 - 3 h to obtain polyamide 66 with sulfonic acid groups and pyridine ring structures in the molecular chain;

[0016] (4) Mix the polyamide 66 containing sulfonic acid groups and pyridine ring structures or the polyamide 66 containing sulfonic acid groups and pyridine ring structures with conventional polyamide 66 in a certain proportion and then carry out spinning in a melt spinning machine to obtain a high-strength polyamide 66 fiber material.

[0017] For the preparation method of a high-strength polyamide 66 fiber material as described above, in step (1), the compound containing sulfonic acid groups is sodium 5-sulfoisophthalate; the aliphatic diamine is a straight-chain aliphatic diamine with 4 to 10 carbon atoms.

[0018] For the preparation method of a high-strength polyamide 66 fiber material as described above, in step (1), the dibasic acid containing sulfonic acid groups and the aliphatic diamine carry out a salification reaction in a molar ratio of 1:1.02 to 1.05.

[0019] For the preparation method of a high-strength polyamide 66 fiber material as described above, in step (2), the compound containing pyridine ring structures includes a pyridine ring-containing dibasic acid and a pyridine ring-containing diamine. The pyridine ring-containing 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, and 3,4-pyridinedicarboxylic acid. The pyridine ring-containing diamine includes one or more of 2,6-diaminopyridine, 2,5-diaminopyridine, 2,4-diaminopyridine, 2,3-diaminopyridine, 3,5-diaminopyridine, and 3,4-diaminopyridine; the aliphatic dibasic acid is a straight-chain aliphatic dibasic acid with 4 to 12 carbon atoms; the aliphatic diamine is a straight-chain aliphatic diamine with 4 to 10 carbon atoms.

[0020] For the preparation method of a high-strength polyamide 66 fiber material as described above, in step (2), when the compound containing pyridine ring structures is a diamine structure, the pyridine ring-containing diamine and the aliphatic dibasic acid carry out a salification reaction in a molar ratio of 1.02 to 1.05:1; when the compound containing pyridine ring structures is a dibasic acid structure, the pyridine ring-containing dibasic acid and the aliphatic diamine carry out a salification reaction in a molar ratio of 1:1.02 to 1.05.

[0021] For the preparation method of a high-strength polyamide 66 fiber material as described above, in step (3), the number-average molecular weight of the polyamide 66 with a molecular chain containing sulfonic acid groups and pyridine ring structures is 17,000 to 24,000 g / mol.

[0022] A preparation method of the high-strength polyamide 66 fiber material as described above. In step (4), when x is 1 to 4, y is 70 to 146, and z is 1 to 4, the polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain can be spun alone. When x is 4 to 35, y is 32 to 70, and z is 4 to 35, the polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain is mixed with conventional polyamide 66 in a ratio of 1:36 to 196 and then spun.

[0023] A preparation method of the high-strength polyamide 66 fiber material as described above. In step (4), the conditions for melt spinning are a temperature of 280 to 295 °C, a winding speed of 2500 to 3500 m / min, and a draw ratio of 4.5 to 5.5.

[0024] A preparation method of the high-strength polyamide 66 fiber material as described above. The single filament fineness of the prepared high-strength polyamide 66 fiber material is 0.9 - 1.4 dtex, the breaking strength is 6.5 - 8.2 cN / dtex, and the elongation at break is 16.4 - 24.7%. After the fiber is knitted into a slender stocking tube by a hosiery machine, the dye uptake rate is measured using Acid Red N-2RB or LNAVY MPA acid dyes according to "GB / T 23976.1-2009 Dyes - Determination of the dye-uptake rate curve - Method for determination of the percentage of dye-uptake", and the levelness is evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness". The levelness of the stocking tube knitted by the present invention is 5, the dye uptake rate is 98.1 - 99.2%, and the K / S value is 24.5 - 28.5.

[0025] Adopting the technical solution of the present invention can achieve the following beneficial effects:

[0026] (1) Significantly improve the levelness performance of fine denier high-strength polyamide 66 fiber: By introducing a sulfonic acid group into the main chain of the polyamide 66 fiber molecule, the dye-uptake rate of acid dyes is effectively reduced, and the dyeing time is delayed. This design significantly improves the levelness effect of the fine denier high-strength polyamide 66 fiber, overcoming the problem of uneven dyeing caused by the too fast dye-uptake rate of traditional fine denier polyamide 66 fiber. At the same time, by introducing a pyridine ring into the main chain of the polyamide 66 fiber molecule, the number of "dyeing seats" in the molecular chain during the dyeing of polyamide 66 is increased, compensating to a certain extent for the defect of the reduced dye-uptake rate caused by the decrease in the number of terminal amino groups. The sulfonic acid group and the pyridine ring work together to improve the levelness performance of the fine denier high-strength polyamide 66 fiber.

[0027] (2)Widen the application scope of fine-denier high-strength polyamide 66 fiber: Due to the improved level dyeing performance, the fine-denier high-strength polyamide 66 fiber can exhibit richer colors and higher aesthetics, thus meeting the demand for color diversity in more fields. This helps to widen the application scope of the fine-denier high-strength polyamide 66 fiber, especially in textiles, clothing, home decoration and other fields that require high color expressiveness. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with the detailed implementation manners. It should be understood that these embodiments are only used to illustrate the present invention and not 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 also fall within the scope defined by the appended claims of this application.

[0029] Example 1

[0030] Use the method described in the present invention to produce high-strength polyamide 66 fiber materials. The specific steps are as follows:

[0031] (1)Add sodium 5-sulfoisophthalate and 1,6-hexanediamine to water at a molar ratio of 1:1.02, react at room temperature, filter, wash and dry after salt precipitation to obtain an amide salt containing a sulfonic acid group;

[0032] (2)Add 2,4-pyridinedicarboxylic acid and 1,6-hexanediamine to water at a molar ratio of 1:1.02, stir at 60 °C for 1 h, filter, wash and dry after salt precipitation to obtain an amide salt containing a pyridine ring structure;

[0033] (3)Add 1 part of the salt containing a sulfonic acid group, 1 part of the amide salt containing a pyridine ring structure, 75 parts of nylon 66 salt, and 60 parts of deionized water to the polymerization reactor, and displace the air in the reactor with nitrogen 3 times; turn on the heating, slowly raise the temperature to 215 °C, keep the pressure at 2.0 MPa and carry out polycondensation for 2 h; continue to raise the temperature to 255 °C, reduce the pressure to normal pressure 0 MPa in 0.5 h; continue to raise the temperature to 270 °C, evacuate to a pressure of -0.01 MPa, and keep the temperature and pressure for 1 h to obtain polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain, the number average molecular weight of which is 17400 g / mol, and the molecular structural formula is:

[0034]

[0035] (4)Spun the polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain, the spinning temperature is 280 °C, the winding speed is 3500 m / min, and the draw ratio is 4.5 to obtain high-strength polyamide 66 fiber materials.

[0036] After the fiber is knitted into a slender sock tube by a hosiery machine, the dye uptake rate is measured using Acid Red N-2RBL acid dye according to "GB / T 23976.1-2009 Dyes - Determination of dyeing rate curve - Dye uptake rate determination method", and the evenness is evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0037] Example 2

[0038] The method for producing high-strength polyamide 66 fiber material described in the present invention is adopted, and the specific steps are as follows:

[0039] (1) Sodium 5-sulfoisophthalate and 1,6-hexanediamine are added to water in a molar ratio of 1:1.03, and the reaction is carried out at room temperature. After the salt precipitates, it is filtered, washed, and dried to obtain an amide salt containing a sulfonic acid group;

[0040] (2) 2,5-Pyridinedicarboxylic acid and 1,6-hexanediamine are added to water in a molar ratio of 1:1.03, stirred at 70 °C for 5 h. After the salt precipitates, it is filtered, washed, and dried to obtain an amide salt containing a pyridine ring structure;

[0041] (3) 3 parts of the salt containing a sulfonic acid group, 3 parts of the amide salt containing a pyridine ring structure, 100 parts of nylon 66 salt, and 70 parts of deionized water are added to a polymerization reactor, and the air in the reactor is replaced with nitrogen 3 times; heating is started, and the temperature is slowly raised to 220 °C, and the pressure is maintained at 1.8 MPa for polycondensation for 2.5 h; the temperature is further raised to 250 °C, and the pressure is reduced to atmospheric pressure 0 MPa in 0.8 h; the temperature is further raised to 275 °C, and the vacuum is pumped to a pressure of -0.05 MPa, and heat preservation and pressure maintenance are carried out for 2 h to obtain polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain, with a number average molecular weight of 24200 g / mol, and the molecular structural formula is:

[0042]

[0043] (4) The polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain is spun, the spinning temperature is 282 °C, the winding speed is 3200 m / min, and the drawing ratio is 4.5 to obtain a high-strength polyamide 66 fiber material.

[0044] After the fiber is knitted into a slender sock tube by a hosiery machine, the dye uptake rate is measured using NAVY MPA acid dye according to "GB / T 23976.1-2009 Dyes - Determination of dyeing rate curve - Dye uptake rate determination method", and the evenness is evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0045] Example 3

[0046] The method for producing high-strength polyamide 66 fiber material according to the present invention is as follows:

[0047] (1) Sodium 5-sulfoisophthalate and 1,6-hexanediamine are added to water at a molar ratio of 1:1.04, and the reaction is carried out at room temperature. After the salt precipitates, it is filtered, washed, and dried to obtain an amide salt containing a sulfonic acid group;

[0048] (2) 2,6-Pyridinedicarboxylic acid and 1,6-hexanediamine are added to water at a molar ratio of 1:1.04, and stirred at 80 °C for 6 h. After the salt precipitates, it is filtered, washed, and dried to obtain an amide salt containing a pyridine ring structure;

[0049] (3) 1 part of the salt containing a sulfonic acid group, 2 parts of the amide salt containing a pyridine ring structure, 100 parts of nylon 66 salt, and 80 parts of deionized water are added to a polymerization reactor, and the air in the reactor is replaced with nitrogen 3 times; heating is started, and the temperature is slowly raised to 225 °C, and the pressure is maintained at 1.9 MPa for polycondensation for 3 h; the temperature is further raised to 250 °C, and the pressure is reduced to atmospheric pressure of 0 MPa in 1 h; the temperature is further raised to 280 °C, and the vacuum is pumped to a pressure of -0.08 MPa, and kept warm and under pressure for 2 h to obtain polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain, the number average molecular weight of which is 23,300 g / mol, and the molecular structural formula is:

[0050]

[0051] (4) The polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain is spun at a spinning temperature of 285 °C, a winding speed of 3000 m / min, and a draw ratio of 4.5 to obtain a high-strength polyamide 66 fiber material.

[0052] After the fiber is knitted into a slender stocking tube by a hosiery machine, the dye uptake rate is measured with Acid Red N-2RBL acid dye according to "GB / T 23976.1-2009 Dyes - Determination of dye uptake rate curve - Method for determination of dye uptake rate", and the levelness is evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0053] Example 4

[0054] The method for producing high-strength polyamide 66 fiber material according to the present invention is as follows:

[0055] (1) Sodium 5-sulfoisophthalate and 1,6-hexanediamine are added to water at a molar ratio of 1:1.05, and the reaction is carried out at room temperature. After the salt precipitates, it is filtered, washed, and dried to obtain an amide salt containing a sulfonic acid group;

[0056] (2) Add 2,6-pyridinedicarboxylic acid and 1,6-hexanediamine to water at a molar ratio of 1:1.05, stir at 90 °C for 9 h, filter, wash and dry after the salt precipitates to obtain an amide salt containing a pyridine ring structure;

[0057] (3) Add 50 parts of a salt containing a sulfonic acid group, 50 parts of an amide salt containing a pyridine ring structure, 100 parts of nylon 66 salt, and 70 parts of deionized water to a polymerization reactor, and displace the air in the reactor with nitrogen 3 times; Turn on the heating, slowly raise the temperature to 235 °C, keep the pressure at 2.0 MPa and carry out polycondensation for 2 h; Continue to raise the temperature to 255 °C, reduce the pressure to atmospheric pressure of 0 MPa in 0.5 h; Continue to raise the temperature to 273 °C, evacuate to a pressure of -0.10 MPa, keep the temperature and pressure for 1 h to obtain polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain, its number average molecular weight is 17100 g / mol, and the molecular structural formula is:

[0058]

[0059] (4) Mix polyamide 66 with a sulfonic acid group and a pyridine ring structure in the molecular chain and conventional polyamide 66 at a ratio of 1:36 and then carry out spinning. The spinning temperature is 288 °C, the winding speed is 3000 m / min, and the draw ratio is 5.0 to obtain a high-strength polyamide 66 fiber material.

[0060] After knitting the fiber into a slender sock tube by a hosiery machine, measure the dye uptake rate with NAVY MPA acid dye according to "GB / T 23976.1-2009 Dyes - Determination of dyeing rate curve - Method for determination of dye uptake rate", and evaluate according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0061] Example 5

[0062] Use the method described in the present invention to produce a high-strength polyamide 66 fiber material, and the specific steps are as follows:

[0063] (1) Add sodium 5-sulfoisophthalate and 1,6-hexanediamine to water at a molar ratio of 1:1.03, react at room temperature, filter, wash and dry after the salt precipitates to obtain an amide salt containing a sulfonic acid group;

[0064] (2) Add 2,6-pyridinedicarboxylic acid and 1,6-hexanediamine to water at a molar ratio of 1:1.03, stir at 80 °C for 12 h, filter, wash and dry after the salt precipitates to obtain an amide salt containing a pyridine ring structure;

[0065] (3) Add 50 parts of salts containing sulfonic acid groups, 50 parts of amide salts containing pyridine ring structures, 100 parts of nylon 66 salt, and 70 parts of deionized water into the polymerization reactor, and displace the air in the reactor with nitrogen 3 times; turn on the heating, slowly raise the temperature to 225 °C, maintain the pressure at 1.8 MPa and carry out polycondensation for 2.5 h; continue to raise the temperature to 250 °C, and reduce the pressure to atmospheric pressure 0 MPa in 0.8 h; continue to raise the temperature to 278 °C, evacuate to a pressure of -0.05 MPa, and keep the temperature and pressure for 2 h to obtain polyamide 66 with sulfonic acid groups and pyridine ring structures in the molecular chain. Its number-average molecular weight is 17,800 g / mol, and the molecular structural formula is:

[0066]

[0067] (4) Mix polyamide 66 with sulfonic acid groups and pyridine ring structures in the molecular chain and conventional polyamide 66 in a ratio of 1:145, and then carry out spinning. The spinning temperature is 292 °C, the winding speed is 2900 m / min, and the draw ratio is 5.2 to obtain a high-strength polyamide 66 fiber material.

[0068] After the fiber is woven into a slender stocking tube by a hosiery machine, the dye uptake rate is measured with Acid Red N-2RBL acid dye according to "GB / T 23976.1-2009 Dyes - Determination of dye-uptake rate curves - Method for determination of dye-uptake rate", and the levelness is evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0069] Example 6

[0070] Use the method described in the present invention to produce a high-strength polyamide 66 fiber material. The specific steps are as follows:

[0071] (1) Add sodium 5-sulfoisophthalate and 1,6-hexanediamine into water at a molar ratio of 1:1.04, carry out the reaction at room temperature, filter, wash, and dry after the salt precipitates to obtain an amide salt containing sulfonic acid groups;

[0072] (2) Add 2,6-pyridinedicarboxylic acid and 1,6-hexanediamine into water at a molar ratio of 1:1.04, stir at 90 °C for 8 h, filter, wash, and dry after the salt precipitates to obtain an amide salt containing pyridine ring structures;

[0073] (3) Add 50 parts of salts containing sulfonic acid groups, 50 parts of amide salts containing pyridine ring structures, 100 parts of nylon 66 salt, and 80 parts of deionized water into the polymerization reactor, and displace the air in the reactor with nitrogen 3 times; turn on the heating, slowly raise the temperature to 235 °C, keep the pressure at 1.9 MPa and carry out polycondensation for 3 h; continue to raise the temperature to 245 °C, and reduce the pressure to atmospheric pressure 0 MPa in 1 h; continue to raise the temperature to 275 °C, evacuate to a pressure of -0.10 MPa, keep the temperature and pressure for 3 h to obtain polyamide 66 with a molecular chain containing sulfonic acid groups and pyridine ring structures, whose number average molecular weight is 18300 g / mol, and the molecular structural formula is:

[0074]

[0075] (4) Mix polyamide 66 with a molecular chain containing sulfonic acid groups and pyridine ring structures and conventional polyamide 66 in a ratio of 1:97 and then carry out spinning. The spinning temperature is 295 °C, the winding speed is 3000 m / min, and the draw ratio is 5.5 to obtain high-strength polyamide 66 fiber material.

[0076] After the fiber is woven into a slender stocking tube by a hosiery machine, use NAVY MPA acid dye to measure the dye uptake rate according to "GB / T 23976.1-2009 Dyes - Determination of dye uptake rate curve - Dye uptake rate determination method", and evaluate according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0077] Comparative Example 1

[0078] Spinning of polyamide 66 with a number average molecular weight of 13000 g / mol is carried out on a melt spinning machine. The spinning temperature is 285 °C, the winding speed is 2500 m / min, and the draw ratio is 3.0 to obtain polyamide 66 fiber. After the fiber is woven into a slender stocking tube by a hosiery machine, use acid red N-2RBL acid dye to measure the dye uptake rate according to "GB / T 23976.1-2009 Dyes - Determination of dye uptake rate curve - Dye uptake rate determination method", and evaluate according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0079] Comparative Example 2

[0080] Polyamide 66 with a number-average molecular weight of 24,000 g / mol was spun on a melt spinning machine at a spinning temperature of 300 °C, a winding speed of 3,000 m / min, and a draw ratio of 5.5 to obtain a high-strength polyamide 66 fiber material. After the fiber was knitted into a slender stocking tube by a hosiery knitting machine, the color uptake rate was measured using NAVY MPA acid dye according to "GB / T 23976.1-2009 Dyes - Determination of the dyeing rate curve - Method for the determination of the color uptake rate", and the levelness was evaluated according to "GB / T 21881-2015 Acid dyes - Determination of levelness".

[0081] The data tables of the mechanical properties and dyeing properties of the high-strength polyamide 66 fiber materials in each example and comparative example are shown in Table 1 below:

[0082] Table 1 Data tables of the mechanical properties and dyeing properties of high-strength polyamide 66 fiber materials

[0083]

[0084] The above examples only represent several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, 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 appended claims.

Claims

1. A high-strength polyamide 66 fiber material, characterized in that, The raw material is polyamide 66 containing sulfonic acid groups and pyridine rings in the molecular chain, and its structural formula is as follows: or ； where m is 4 - 10, n is 4 - 10, x is 1 - 35, y is 32 - 146, z is 1 - 35, and the structure of R’ is as follows: The structure of R is as follows: 。 2. A method for preparing a high-strength polyamide 66 fiber material, for preparing the high-strength polyamide 66 fiber material as described in claim 1, characterized in that, It includes the following steps: (1) Add a dibasic acid containing sulfonic acid groups and an aliphatic diamine in a certain proportion to water or ethanol, carry out a salification reaction at room temperature. After the salt precipitates, filter, wash, and dry to obtain an amide salt containing sulfonic acid groups. The dibasic acid containing sulfonic acid groups is sodium m-phthalate-5-sulfonate; (2) Add a pyridine ring structure compound and an aliphatic dibasic acid or diamine in a certain proportion to water or ethanol, stir at 60 - 90 °C for 1 - 12 h. After the salt precipitates, filter, wash, and dry to obtain an amide salt containing a pyridine ring structure. The pyridine ring structure compound includes a pyridine ring-containing dibasic acid and a pyridine ring-containing diamine. The pyridine ring-containing 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. The pyridine ring-containing diamine includes one or more of 2,6-diaminopyridine, 2,5-diaminopyridine, 2,4-diaminopyridine, 2,3-diaminopyridine, 3,5-diaminopyridine, 3,4-diaminopyridine; (3) Add 1 - 50 parts of the salt containing sulfonic acid groups, 1 - 50 parts of the amide salt containing a pyridine ring structure, 75 - 100 parts of nylon 66 salt, and 60 - 80 parts of deionized water to a polymerization reactor, and displace the air in the reactor with nitrogen 3 times; Start heating, slowly raise the temperature to 215 - 235 °C, and keep the pressure at 1.8 - 2.0 MPa for polycondensation for 2 - 3 h; Continue to raise the temperature to 245 - 255 °C, and reduce the pressure to atmospheric pressure in 0.5 - 1 h; Continue to raise the temperature to 270 - 280 °C, evacuate to a pressure of -0.01 - -0.10 MPa, and keep the temperature and pressure for 1 - 3 h to obtain polyamide 66 with sulfonic acid groups and pyridine ring structures in the molecular chain; (4) Mix polyamide 66 containing sulfonic acid groups and pyridine ring structures or polyamide 66 containing sulfonic acid groups and pyridine ring structures with conventional polyamide 66 in a certain proportion and carry out spinning in a melt spinning machine to obtain a high-strength polyamide 66 fiber material.

3. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, In step (1), the aliphatic diamine is a straight-chain aliphatic diamine with 4 - 10 carbon atoms.

4. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, In step (1), the dibasic acid containing sulfonic acid groups and the aliphatic diamine carry out a salification reaction according to a molar ratio of 1:1.02 - 1.

05.

5. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, In step (2), the aliphatic dibasic acid is a straight-chain aliphatic dibasic acid with 4 - 12 carbon atoms; the aliphatic diamine is a straight-chain aliphatic diamine with 4 - 10 carbon atoms.

6. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, In step (2), when the pyridine ring structure-containing compound is a diamine structure, the pyridine ring-containing diamine and the aliphatic dicarboxylic acid are subjected to a salt-forming reaction in a molar ratio of 1.02 to 1.05:1; when the pyridine ring structure-containing compound is a dicarboxylic acid structure, the pyridine ring-containing dicarboxylic acid and the aliphatic diamine are subjected to a salt-forming reaction in a molar ratio of 1:1.02 to 1.

05.

7. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, wherein, In step (3), the number-average molecular weight of the polyamide 66 with a molecular chain containing a sulfonic acid group and a pyridine ring structure is 17,000 to 24,000 g / mol.

8. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, In step (4), when x is 1 to 4, y is 70 to 146, and z is 1 to 4, the polyamide 66 with a molecular chain containing a sulfonic acid group and a pyridine ring structure is spun alone. When x is 4 to 35, y is 32 to 70, and z is 4 to 35, the polyamide 66 with a molecular chain containing a sulfonic acid group and a pyridine ring structure is mixed with conventional polyamide 66 in a ratio of 1:36 to 196 and then spun.

9. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, wherein, In step (4), the conditions for melt spinning are a temperature of 280 to 295 °C, a winding speed of 2,500 to 3,500 m / min, and a draw ratio of 4.5 to 5.

5.

10. The preparation method of a high-strength polyamide 66 fiber material according to claim 2, characterized in that, The prepared high-strength polyamide 66 fiber material has a single-filament fineness of 0.9 - 1.4 dtex, a breaking strength of 6.5 - 8.2 cN / dtex, an elongation at break of 16.4 - 24.7%, a dyeing uniformity of 5 grades for the woven fabric, a coloring rate of 98.1 - 99.2%, and a K / S value of 24.5 - 28.5.

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