Polyether amide block copolymer, fiber and preparation method thereof

Abstract

The invention relates to the field of high polymer materials, and discloses a polyether amide block copolymer, a fiber and a preparation method of the polyether amide block copolymer. The polyether amide block copolymer is prepared through melt copolymerization by taking a copolymer composed of polyamide 6 and long-carbon-chain polyamide as a hard segment and polyether or polyether amine as a soft segment, and the polyether amide block copolymer is low in raw material cost and simple in polymerization process. Meanwhile, compared with the existing polyether amide fiber, the polyether amide fiber prepared by taking the polyether amide block copolymer as a raw material through a melt spinning method has the advantages that the structural designability is high, the strength and the elasticity can be considered in different fields, the performance is stable, and the requirements of different fields on the material performance are met; the method can be widely applied to multiple fields of composite spinning, clothing, shoes, medical equipment and the like, and has a wide market prospect.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and specifically relates to a polyetheramide block copolymer, a fiber and a preparation method thereof. Background Art

[0002] Polyamide fibers, with their high strength, wear resistance and easy dyeing properties, have become the second largest variety of synthetic fibers. Polyamide fabrics have been widely used in the clothing field due to their sweat absorption, light weight, good toughness and acid and alkali resistance. However, polyamide fibers also have some inherent disadvantages, such as high modulus and poor elastic recovery, which limit their application in the pursuit of higher wearing comfort.

[0003] In order to improve these disadvantages of polyamide fibers, researchers have tried to introduce polyether segments into polyamide segments to form polyetheramide block copolymers. Through the melt spinning process, this copolymer can be prepared into polyetheramide elastic fibers, which not only have less environmental pollution, but also the thermal stability and chemical resistance of the spinning raw materials are better than those of traditional spandex and polyurethane (PU).

[0004] The long carbon chain polyamides have unique flexibility, good dimensional stability, hydrophobicity, chemical resistance, good low temperature toughness, etc., and are widely used in the hard segments of polyetheramide block copolymers, such as poly(ω-aminoundecanamide) (PA11), poly(dodecanolactam) (PA12), etc.; due to the limitation of monomer large-scale supply, the hard segments of domestic polyetheramides are mainly poly(decamethylene adipamide) (PA1010), poly(dodecanedioyl decanediamine) (PA1012), poly(dodecanedioyl dodecanediamine) (PA1212). However, the above long carbon chain polyamides as hard segments all have the problems of expensive monomers and complex preparation processes, which limit their wide application. For example, Chinese Patent Publication CN105839220B discloses an AABB type long carbon chain polyetheramide elastic fiber and its preparation method and application. It uses an AABB type long carbon chain polyamide as the hard chain segment and a block copolymer composed of alternating hard and soft chain segments with polyether as the soft chain segment as the raw material, and prepares polyetheramide elastic fibers by melt spinning. Its elastic recovery rate is only 80%, and the moisture regain is also low, and the wearing comfort is poor. In addition, the long carbon chain polyamide has a low melting point, poor heat resistance, and is expensive, and the production cost of elastic fibers is relatively high. Chinese Patent CN109208113A discloses a polyamide 6 elastic fiber and its preparation method, which uses a block copolymer with polyamide 6 as the polymer hard chain segment and polyether and / or polyetheramine as the polymer soft chain segment as the raw material, and the prepared polyamide 6 elastic fiber has poor mechanical strength. Chinese Patent CN111041592B discloses a preparation method of semi-aromatic polyetheramide elastomer fibers, which uses a block copolymer with semi-aromatic polyamide as the hard segment and polyether polyol as the soft segment as the raw material. The high-pressure polymerization process of this block copolymer is cumbersome and the raw material cost is relatively high.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a polyetheramide block copolymer and its fibers. Using the polyetheramide block copolymer as a raw material, polyetheramide fibers with excellent mechanical properties, good elastic recovery, and good dimensional stability are prepared by the melt spinning method.

[0007] To solve the above technical problems, the technical solution of the present invention is as follows:

[0008] The first object of the present invention is to provide a polyetheramide block copolymer, which includes: a hard segment composed of polyamide 6 and a long-chain polyamide, a soft segment composed of a polyether or a polyetheramine, and a dicarboxylic acid connecting the hard segment and the soft segment. The structural general formula of the polyetheramide block copolymer is shown in Formula I:

[0009]

[0010] Among them,

[0011] R 1 is a polyamide 6 chain segment;

[0012] R 2 is a long-chain polyamide chain segment;

[0013] R is a dicarboxylic acid;

[0014] R 3 is a polyether or polyetheramine chain segment.

[0015] Optionally, in Formula I, x = 20 - 150; y = 6 - 25; n = 5 - 45. x, y, and n represent the degree of polymerization of each chain segment in the polyetheramide block copolymer. By adjusting the values of x, y, and n, the hardness, elasticity, and heat resistance of the material can be adjusted.

[0016] PA6 has a high crystallinity and a relatively high melting point. When applied to the hard segment of the polyetheramide block copolymer, its compatibility with the non-crystalline polyether soft segment is low, so that the hard segment and the soft segment each maintain their unique properties in the copolymer.

[0017] The polyetheramide block copolymer provided by the present invention is a random copolymer composed of the hard segment polyamide 6 (PA6) and a long-chain polyamide, which combines the double advantages of the long-chain polyamide and polyamide 6. The hydrogen bond density of the hard segment structure is reduced, increasing the flexibility of the polyetheramide block copolymer and facilitating the improvement of its fiber-forming property. At the same time, the raw material cost is relatively low, which is beneficial to large-scale production.

[0018] In the above technical solution, the content of the hard segment is 30-95 wt.% of the total mass of the polyetheramide block copolymer.

[0019] It should be noted that the total mass of the polyetheramide block copolymer includes the hard segment and the soft segment. The dicarboxylic acid only serves as a chemical linking group and has no substantial influence on the ratio of the hard segment to the soft segment. Its dosage should be determined according to the comprehensive ratio of the hard segment and the soft segment, and the addition amount is not large, so there is no need to consider it additionally here.

[0020] In the above technical solution, the content of the long-chain polyamide in the hard segment is 5-30 wt.% of the total mass of the hard segment.

[0021] In the present invention, by introducing long-chain polyamide into the PA6 chain segment, a unique copolymer hard segment is formed, significantly improving the tensile strength of the fiber. First, the introduction of long-chain polyamide leads to a decrease in the hydrogen bond density of the PA6 chain segment, thereby enhancing the flexibility of the hard segment. This change further weakens the microphase separation phenomenon between the hard segment and the soft segment, enabling the PA6 chain segment to be more easily oriented and shaped during the stretching and fiber formation of the polyetheramide block copolymer. This structural optimization improves the fiber breaking strength. In order to balance the hydrogen bond density, microphase separation, chain segment orientation, etc., the present invention precisely controls the content of the long-chain polyamide within the range of 5-30 wt.% of the total mass of the hard segment, so that the hard segment retains good mechanical strength while obtaining high tensile strength.

[0022] In addition, the introduction of long-chain polyamide also slightly increases the elastic recovery rate of the polyetheramide fiber. This means that the fiber can recover to its original shape faster after being subjected to an external force, thereby enhancing the durability and recovery performance of the material.

[0023] Furthermore, the long-chain polyamide is selected from one or more of polyamide 510, polyamide 512, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212, and polyamide 1214.

[0024] In the above technical solution, the content of the soft segment is 5-70 wt.% of the total mass of the polyetheramide block copolymer.

[0025] The soft segment polyether is a flexible chain segment, which weakens the intermolecular force and enhances the movement ability of the molecular chain. The introduction of the soft segment polyether reduces the breaking strength of the fiber and increases the elongation at break. At the same time, due to the high water absorption of the polyether chain segment structure, after it is introduced into the PA6 chain segment, the moisture regain of the copolymer increases significantly and increases with the increase of the soft segment content.

[0026] In the above technical solution, the soft segment is selected from polyether or polyetheramine, and the number average molecular weight of the polyether or polyetheramine is 400-2000 g / mol.

[0027] Furthermore, the polyether is selected from one or more of linear or branched polyalkylene glycols with 2-5 carbon atoms.

[0028] Furthermore, the polyetheramine is selected from one or more of linear or branched polyalkylene oxides with 2-5 carbon atoms and terminal amino groups.

[0029] In the polyetheramide block copolymer, the flexibility and elasticity of the soft segment are mainly determined by the molecular weight of the polyether or polyetheramine.

[0030] High molecular weight polyethers or polyetheramines usually endow the copolymer with higher flexibility and elasticity. The high molecular weight polyether or polyetheramine segments in the copolymer can more effectively absorb and disperse stress, thereby improving the impact resistance and fatigue resistance of the material. However, high molecular weight polyethers or polyetheramines may also increase the processing difficulty of the copolymer because the longer segments may reduce the fluidity of the copolymer in the molten state, increasing the complexity of processing such as extrusion and injection molding. In contrast, low molecular weight polyethers or polyetheramines may make the copolymer have better processability and fluidity. The shorter segments make the copolymer easier to flow and shape in the molten state, thus improving the processing efficiency. However, low molecular weight polyethers or polyetheramines may sacrifice some flexibility and elasticity because the shorter segments have weaker ability to absorb and disperse stress.

[0031] Therefore, in order to balance the flexibility, elasticity and processability of the copolymer, the present invention controls the molecular weight of the polyether or polyetheramine within the range of 400-2000 g / mol.

[0032] In the above technical solution, the dicarboxylic acid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid.

[0033] The second object of the present invention is to provide a preparation method of the above polyetheramide block copolymer, which includes mixing caprolactam, long-chain polyamide salt, dicarboxylic acid, polyether or polyetheramine, antioxidant, catalyst, deionized water, removing oxygen in the system by nitrogen replacement, then heating up for polymerization reaction, and after the reaction is completed, discharging, pelletizing, extracting and drying to obtain the polyetheramide block copolymer.

[0034] Furthermore, the conditions of the polymerization reaction include:

[0035] First, heat up to 210-250 °C, the pressure is 0.1-0.5 Mpa, and react for 1-5 h;

[0036] After reducing to normal pressure within 0.5-1.5 h, continue to heat up to 230-260 °C and react for 2-5 h;

[0037] Continue to heat up to 240 - 265 °C and react for 1 - 2 h under vacuum conditions.

[0038] In the present invention, a polyetheramide block copolymer with PA6 and long-chain polyamide as hard segments and polyether or polyetheramine as soft segments is prepared by a "one-pot method". First, caprolactam, long-chain polyamide salt, dicarboxylic acid, polyether or polyetheramine, antioxidant, catalyst, and deionized water are mixed. To ensure the purity of the reaction environment, nitrogen replacement is used to effectively remove oxygen in the system, thereby avoiding product oxidation, reducing unnecessary oxidation reactions, and maintaining the efficient progress of the polymerization reaction.

[0039] Subsequently, gradually raise the temperature of the system to 90 - 115 °C and continuously stir during this process to ensure that all materials can be evenly mixed. While maintaining the stirring state, continue to heat up to trigger the polymerization reaction. The role of stirring is crucial. It can not only promote the uniform mixing of materials but also enhance mass transfer and heat transfer effects, ensuring that the polymerization reaction proceeds evenly throughout the system.

[0040] During the polymerization reaction, it is best to always maintain the stirring state, which can increase mass transfer and heat transfer, not only ensuring uniform mixing but also ensuring the uniformity of the polymerization reaction. During the polymerization reaction, the pressure drops from 0.1 - 0.5 Mpa to atmospheric pressure within 0.5 - 1.5 h. This slow pressure relief process is to maintain the stability of the system. If the pressure is rapidly relieved, water is rapidly discharged, which may cause the system viscosity to rapidly increase, resulting in uneven molecular weight distribution, and may also cause the exclusion of small molecule substances, having an adverse impact on the polymerization reaction.

[0041] Furthermore, the antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010, and SEED.

[0042] Furthermore, the catalyst is selected from one or more of phosphoric acid, sodium hypophosphite, sodium dihydrogen phosphate, tetrabutyl titanate, antimony trioxide, and antimony glycolate.

[0043] Furthermore, the long-chain polyamide salt is selected from one or more of polyamide 510 salt, polyamide 512 salt, polyamide 610 salt, polyamide 612 salt, polyamide 1010 salt, polyamide 1012 salt, polyamide 1212 salt, and polyamide 1214 salt.

[0044] The third object of the present invention is to provide a polyetheramide fiber prepared from the above polyetheramide block copolymer.

[0045] Furthermore, the strength of the polyetheramide fiber is 1.1 - 4.9 cN / dtex, the 30% fixed elongation elastic recovery rate ≥ 85%, and the moisture regain rate ≥ 3.68%.

[0046] Further, the polyether amide fiber is selected from one of virgin fiber, fiber filament, POY fiber, drawn textured yarn, FDY fiber or staple fiber.

[0047] The fourth object of the present invention is to provide a method for preparing a polyether amide fiber, comprising: subjecting the above polyether amide block copolymer to vacuum drying and then obtaining the polyether amide fiber through melt spinning.

[0048] Further, the conditions for vacuum drying include: vacuum drying at 80-110°C until the moisture content ≤ 500 ppm.

[0049] In the above technical solution, during melt spinning, the spinning temperature is 200-280°C;

[0050] Further, the spinning temperature is 220-260°C.

[0051] Further, during melt spinning, the wind speed of the ring blower is 0.2-0.5 m / s, the temperature of the ring blower is 26-53°C, the spinning distance is 2-8 m, and the spinning speed is 100-2000 m / s.

[0052] Further, the melt spinning also includes a cold drawing and / or heat setting process.

[0053] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0054] The present invention uses a copolymer of polyamide 6 and long-chain polyamide as the hard segment, combined with polyether or polyetheramine as the soft segment, and prepares a polyether amide block copolymer through melt copolymerization. The hard segment of this copolymer combines the dual advantages of long-chain polyamide and polyamide 6. By reducing the hydrogen bond density of the hard segment structure, the flexibility of the polyether amide block copolymer is significantly enhanced, and thus its fiber-forming performance is optimized.

[0055] Taking this as the raw material, the present invention further prepares polyether amide fibers through the melt spinning method, significantly improving the comprehensive performance of the fibers and breaking through the bottleneck of the mutual exclusion of strength and elasticity of traditional polyamide fibers. Compared with the existing polyether amide fibers, the fibers prepared by the present invention have stronger structural design flexibility, can balance strength and elasticity for different fields, show stable performance, and perfectly meet the diverse material performance requirements of various fields. Therefore, these fibers have broad application potential in many fields such as composite spinning, clothing manufacturing, shoe production, medical equipment, etc., and the market prospect is very broad.

[0056] In addition, the raw material cost of the present invention is relatively low, the polymerization process is simple, and there is no need to rely on high-temperature and high-pressure equipment, thus achieving a high cost performance and being conducive to large-scale production. This innovation not only promotes the innovation of polyether amide fiber technology, but also injects new vitality into the upgrading and development of related industries. Detailed implementation manners

[0057] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0058] The performance test method is as follows:

[0059] Determine the tensile strength, elongation at break and elastic recovery rate of the polyetheramide fiber of the present invention according to GBT14344-2022 "Test Method for Tensile Properties of Chemical Fiber Filaments";

[0060] Determine the moisture regain of the polyetheramide fiber of the present invention according to CB / T 6503-2017 "Test Method for Moisture Regain of Chemical Fibers".

[0061] In the present invention, the term "polyetheramine Dx" is used to represent polyetheramines with different molecular weights, where "x" represents the specific value of the molecular weight, and the unit is g / mol. For example:

[0062] Polyetheramine D1000: represents a polyetheramine with a molecular weight of 1000 g / mol.

[0063] Polyetheramine D2000: represents a polyetheramine with a molecular weight of 2000 g / mol.

[0064] And so on, other polyetheramines with different molecular weights can be named and represented in the form of "polyetheramine Dx".

[0065] Example 1

[0066] A preparation method of a polyetheramide fiber, comprising the following steps:

[0067] a): Place 126 kg of caprolactam, 14 kg of polyamide 1012 salt, 4.4 kg of adipic acid, 0.2 kg of sodium hypophosphite, 60 kg of polyetheramine D2000, 0.2 kg of antioxidant 1098, and 2.8 kg of deionized water in a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95°C, start stirring, after the temperature rises to 210°C, carry out pressure-maintaining polymerization at 0.4 Mpa for 3 h; raise the temperature to 250°C for atmospheric-pressure polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 250°C for 1 h, stop stirring, and discharge to obtain a polyetheramide block copolymer; wherein the mass ratio of the hard segment PA6 to polyamide 1012 is 9:1, and the mass ratio of the hard segment to the soft segment is 7:3.

[0068] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 236 °C, the spinneret temperature is 245 °C, the wind speed of the annular air blast is 0.3 m / s, the temperature of the annular air blast is 38 °C, the spinning speed is 800 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0069] Example 2

[0070] A method for preparing polyetheramide fibers, comprising the following steps:

[0071] a): Put 72 kg of caprolactam, 8 kg of polyamide 1012 salt, 8.8 kg of adipic acid, 0.2 kg of sodium hypophosphite, 120 kg of polyetheramine D2000, 0.3 kg of antioxidant 168, and 2.8 kg of deionized water into a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 210 °C, carry out pressure maintaining polymerization for 3 h at 0.2 Mpa; raise the temperature to 250 °C for atmospheric pressure polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 250 °C for 1 h, stop stirring, and discharge to obtain polyetheramide block copolymer; the mass ratio of the hard segment PA6 to polyamide 1012 is 9:1, and the mass ratio of the hard segment to the soft segment is 4:6.

[0072] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 207 °C, the spinneret temperature is 215 °C, the wind speed of the annular air blast is 0.3 m / s, the temperature of the annular air blast is 41 °C, the spinning speed is 600 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0073] Example 3

[0074] A method for preparing polyetheramide fibers, comprising the following steps:

[0075] a): Put 126 kg of caprolactam, 14 kg of polyamide 1012 salt, 4.4 kg of adipic acid, 0.1 kg of tetrabutyl titanate, 60 kg of polyethylene glycol D2000, 0.3 kg of antioxidant 168, and 2.8 kg of deionized water into a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 210 °C, carry out pressure maintaining polymerization for 3 h at 0.2 Mpa; raise the temperature to 240 °C for atmospheric pressure polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 240 °C for 3 h, stop stirring, and discharge to obtain polyetheramide block copolymer; the mass ratio of the hard segment PA6 to 1012 is 9:1, and the mass ratio of the hard segment to the soft segment is 7:3.

[0076] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 230 °C, the spinneret temperature is 240 °C, the wind speed of the ring blower is 0.4 m / s, the temperature of the ring blower is 36 °C, the spinning speed is 800 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0077] Example 4

[0078] A method for preparing polyetheramide fibers, comprising the following steps:

[0079] a): Place 126 kg of caprolactam, 14 kg of polyamide 1012 salt, 4.4 kg of adipic acid, 0.1 kg of tetrabutyl titanate, 60 kg of polyethylene glycol D1000, 0.3 kg of antioxidant 168, and 2.8 kg of deionized water in a reaction vessel. Replace the nitrogen 3 times to remove the oxygen in the reactor. Start heating. When the temperature reaches 95 °C, start stirring. After the temperature rises to 210 °C, carry out pressure polymerization at 0.2 Mpa for 3 h. Raise the temperature to 240 °C and carry out normal pressure polymerization for 4 h. Then evacuate and carry out vacuum polymerization reaction at 240 °C for 3 h. Stop stirring and discharge to obtain the polyetheramide block copolymer. The mass ratio of the hard segment PA6 to 1012 is 9:1, and the mass ratio of the hard segment to the soft segment is 7:3.

[0080] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 230 °C, the spinneret temperature is 240 °C, the wind speed of the ring blower is 0.4 m / s, the temperature of the ring blower is 36 °C, the spinning speed is 1200 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0081] Example 5

[0082] A method for preparing polyetheramide fibers, comprising the following steps:

[0083] a): Place 162 kg of caprolactam, 18 kg of polyamide 612 salt, 4.4 kg of adipic acid, 0.1 kg of antimony trioxide, 20 kg of polyethylene glycol D800, 0.3 kg of antioxidant SEED, and 2.8 kg of deionized water in a reaction vessel. Replace the nitrogen 3 times to remove the oxygen in the reactor. Start heating. When the temperature reaches 95 °C, start stirring. After the temperature rises to 240 °C, carry out pressure polymerization at 0.5 Mpa for 4 h. Raise the temperature to 240 °C and carry out normal pressure polymerization for 2.5 h. Then evacuate and carry out vacuum polymerization reaction at 250 °C for 2 h. Stop stirring and discharge to obtain the polyetheramide block copolymer. The mass ratio of the hard segment PA6 to 612 is 9:1, and the mass ratio of the hard segment to the soft segment is 9:1.

[0084] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 235 °C, the spinneret temperature is 242 °C, the wind speed of the ring blower is 0.5 m / s, the temperature of the ring blower is 42 °C, the spinning speed is 500 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0085] Example 6

[0086] A method for preparing polyetheramide fibers, comprising the following steps:

[0087] a): Place 128 kg of caprolactam, 32 kg of polyamide 512 salt, 8.1 kg of sebacic acid, 0.1 kg of antimony trioxide, 40 kg of polypropylene glycol D1000, 0.3 kg of antioxidant SEED, and 2.8 kg of deionized water in a reaction vessel. Replace the nitrogen 3 times to remove the oxygen in the reactor. Start heating. When the temperature reaches 95 °C, start stirring. After the temperature rises to 240 °C, carry out pressure-holding polymerization at 0.5 Mpa for 2.5 h. Raise the temperature to 240 °C for atmospheric-pressure polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 250 °C for 3 h. Stop stirring and discharge to obtain the polyetheramide block copolymer. The mass ratio of the hard segment PA6 to 512 is 8:2, and the mass ratio of the hard segment to the soft segment is 8:2.

[0088] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 225 °C, the spinneret temperature is 235 °C, the wind speed of the ring blower is 0.2 m / s, the temperature of the ring blower is 47 °C, the spinning speed is 500 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0089] Example 7

[0090] A method for preparing polyetheramide fibers, comprising the following steps:

[0091] a): Place 98 kg of caprolactam, 42 kg of polyamide 1010 salt, 8.8 kg of sebacic acid, 0.2 kg of sodium hypophosphite, 60 kg of polyetheramine D1000, 0.3 kg of antioxidant 1010, and 2.8 kg of deionized water in a reaction vessel. Replace the nitrogen 3 times to remove the oxygen in the reactor. Start heating. When the temperature reaches 95 °C, start stirring. After the temperature rises to 230 °C, carry out pressure-holding polymerization at 0.4 Mpa for 3 h. Raise the temperature to 245 °C for atmospheric-pressure polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 250 °C for 1 h. Stop stirring and discharge to obtain the polyetheramide block copolymer. The mass ratio of the hard segment PA6 to 1010 is 7:3, and the mass ratio of the hard segment to the soft segment is 7:3.

[0092] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 218 °C, the spinneret temperature is 225 °C, the wind speed of the ring blowing is 0.2 m / s, the temperature of the ring blowing is 35 °C, the spinning speed is 900 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0093] Example 8

[0094] A method for preparing polyetheramide fibers, comprising the following steps:

[0095] a): Put 133 kg of caprolactam, 7 kg of polyamide 1212 salt, 20 kg of terephthalic acid, 0.2 kg of sodium hypophosphite, 60 kg of polyetheramine D500, 0.25 kg of antioxidant 168, and 2.8 kg of deionized water into a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 240 °C, carry out pressure maintaining polymerization for 3 h at 0.5 Mpa; raise the temperature to 250 °C for atmospheric pressure polymerization for 3.5 h, then evacuate and carry out vacuum polymerization reaction at 250 °C for 3 h, stop stirring, and discharge to obtain a polyetheramide block copolymer; wherein the mass ratio of the hard segment PA6 to 1212 is 95:5, and the mass ratio of the hard segment to the soft segment is 7:3.

[0096] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 240 °C, the spinneret temperature is 245 °C, the wind speed of the ring blowing is 0.3 m / s, the temperature of the ring blowing is 30 °C, the spinning speed is 1000 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0097] Example 9

[0098] A method for preparing polyetheramide fibers, comprising the following steps:

[0099] a): Put 162 kg of caprolactam, 18 kg of polyamide 610 salt, 4.4 kg of adipic acid, 0.1 kg of antimony trioxide, 20 kg of polytetramethylene ether glycol D800, 0.3 kg of antioxidant SEED, and 2.8 kg of deionized water into a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 240 °C, carry out pressure maintaining polymerization for 4 h at 0.5 Mpa; raise the temperature to 240 °C for atmospheric pressure polymerization for 2.5 h, then evacuate and carry out vacuum polymerization reaction at 250 °C for 2 h, stop stirring, and discharge to obtain a polyetheramide block copolymer; wherein the mass ratio of the hard segment PA6 to 610 is 9:1, and the mass ratio of the hard segment to the soft segment is 9:1.

[0100] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 242 °C, the spinneret temperature is 250 °C, the wind speed of the ring blower is 0.35 m / s, the temperature of the ring blower is 38 °C, the spinning speed is 900 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0101] Example 10

[0102] A method for preparing polyetheramide fibers, comprising the following steps:

[0103] a): Place 102 kg of caprolactam, 18 kg of polyamide 1012 salt, 4.4 kg of adipic acid, 0.1 kg of ethylene glycol antimonate, 80 kg of polyethylene glycol D1000, 0.3 kg of antioxidant 1098, and 2.8 kg of deionized water in a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 250 °C, carry out pressure-holding polymerization at 0.5 Mpa for 2.5 h; raise the temperature to 260 °C for atmospheric polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 260 °C for 3 h, stop stirring, and discharge to obtain the polyetheramide block copolymer; the mass ratio of the hard segment PA6 to 1012 is 85:15, and the mass ratio of the hard segment to the soft segment is 6:4.

[0104] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 235 °C, the spinneret temperature is 242 °C, the wind speed of the ring blower is 0.3 m / s, the temperature of the ring blower is 52 °C, the spinning speed is 1050 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0105] Comparative Example 1

[0106] A method for preparing polyetheramide fibers, comprising the following steps:

[0107] a): Place 140 kg of caprolactam, 4.4 kg of adipic acid, 0.2 kg of sodium hypophosphite, 60 kg of polyetheramine D2000, 0.2 kg of antioxidant 1098, and 2.8 kg of deionized water in a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 210 °C, carry out pressure-holding polymerization at 0.4 Mpa for 3 h; raise the temperature to 250 °C for atmospheric polymerization for 4 h, and then evacuate and carry out vacuum polymerization reaction at 250 °C for 1 h, stop stirring, and discharge to obtain the polyetheramide block copolymer; the hard segment is PA6, and the mass ratio of the hard segment to the soft segment is 7:3.

[0108] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 245 °C, the spinneret temperature is 255 °C, the wind speed of the annular air blowing is 0.3 m / s, the temperature of the annular air blowing is 38 °C, the spinning speed is 800 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0109] It should be noted that the polymerization process of Comparative Example 1 is the same as that of Example 1. However, in the spinning stage, due to the differences in raw material properties (especially the change in melting point after PA6 is modified by long-chain polyamide), process conditions such as spinning temperature and spinneret temperature need to be appropriately adjusted according to the actual melting point of the copolymer.

[0110] Comparative Example 2

[0111] A method for preparing polyetheramide fibers, comprising the following steps:

[0112] a): Place 140 kg of caprolactam, 4.4 kg of adipic acid, 0.1 kg of tetrabutyl titanate, 60 kg of polyethylene glycol D2000, 0.3 kg of antioxidant 168, and 2.8 kg of deionized water in a reaction vessel, displace with nitrogen 3 times to remove the oxygen in the reactor; start heating, when the temperature reaches 95 °C, start stirring, after the temperature rises to 210 °C, keep the pressure at 0.2 Mpa for 3 h; raise the temperature to 240 °C for normal pressure polymerization for 4 h, and then evacuate to carry out vacuum polymerization reaction at 240 °C for 3 h, stop stirring, and discharge to obtain polyetheramide block copolymer; the hard segment is PA6, and the mass ratio of the hard segment to the soft segment is 7:3.

[0113] b): After extracting and drying the polyetheramide block copolymer, melt spinning is carried out. The spinning temperature is set at 245 °C, the spinneret temperature is 250 °C, the wind speed of the annular air blowing is 0.3 m / s, the temperature of the annular air blowing is 38 °C, the spinning speed is 800 m / s. After the spinning process reaches stability, winding is carried out, and then cold drawing and heat setting are carried out to obtain polyetheramide fibers.

[0114] It should be noted that the polymerization process of Comparative Example 2 is the same as that of Example 3. However, in the spinning stage, due to the differences in raw material properties (especially the change in melting point after PA6 is modified by long-chain polyamide), process conditions such as spinning temperature and spinneret temperature need to be appropriately adjusted according to the actual melting point of the copolymer.

[0115] Comparative Example 3

[0116] A method for preparing polyetheramide fibers, comprising the following steps:

[0117] a): Place 84 kg of caprolactam, 56 kg of polyamide 1010 salt, 8.8 kg of sebacic acid, 0.2 kg of sodium hypophosphite, 60 kg of polyetheramine D1000, 0.3 kg of antioxidant 1010, and 2.8 kg of deionized water into a reaction vessel. Replace the air with nitrogen three times to remove the oxygen in the reactor. Start heating up. When the temperature reaches 95°C, start stirring. After the temperature rises to 230°C, carry out pressure polymerization at 0.4 Mpa for 3 h. Raise the temperature to 245°C and carry out atmospheric polymerization for 4 h. Then evacuate and carry out vacuum polymerization reaction at 250°C for 1 h. Stop stirring and discharge to obtain the polyetheramide block copolymer. The mass ratio of the hard segment PA6 to 1010 is 6:4, and the mass ratio of the hard segment to the soft segment is 7:3.

[0118] b): After the polyetheramide block copolymer is extracted and dried, carry out melt spinning. Set the spinning temperature at 215°C, the spinneret temperature at 221°C, the wind speed of the annular air draft at 0.2 m / s, the temperature of the annular air draft at 35°C, and the spinning speed at 900 m / s. After the spinning process reaches stability, carry out winding. Then, through cold drawing and heat setting, obtain the polyetheramide fiber.

[0119] Comparative Example 4

[0120] Comparative Example 4 uses the same polymerization process as Example 1, except that the soft segment polyetheramine D2000 is replaced with polyetheramine D2500.

[0121] Performance Test:

[0122] Carry out performance tests on the polyetheramide fibers prepared in Examples 1 - 10 and Comparative Examples 1 - 4. The test results are shown in Table 1, where the elastic recovery rate is the elastic recovery rate at a specified elongation of 30%.

[0123] Table 1

[0124]

[0125]

[0126] Conclusion: Both Comparative Example 1 and Comparative Example 2 use PA6 as the hard segment of the copolymer. By comparing Comparative Example 1 with Example 1 and Comparative Example 2 with Example 3, it can be seen that introducing long-chain polyamide into the PA6 chain segment, and using the copolymer as the hard segment can effectively improve the tensile strength of the fiber. This is because the hydrogen bond density of the PA6 chain segment decreases, the flexibility of the hard segment increases, and the microphase separation phenomenon with the soft segment weakens. During the process of stretching the polyetheramide block copolymer into fibers, the PA6 chain segment is easy to orient and fix, resulting in an increase in its breaking strength. At the same time, due to the high water absorption of the polyether chain segment structure, after it is introduced into the PA6 chain segment, the moisture regain of the copolymer increases significantly and increases with the increase of the soft segment content. The introduction of long-chain polyamide in the hard segment slightly improves the elastic recovery rate of the polyetheramide fiber.

[0127] The polyetheramide fiber was prepared in the same manner as in Example 7 for Comparative Example 3, except that in Comparative Example 3, the mass ratio of the hard segment PA6 to 1010 was 6:4, and the strength of the fiber decreased significantly. This is because the increase in the long carbon chain structural units in the hard segment increased the flexibility of the chain segments and the entanglement degree of the molecular chains in the hard segment structure. During the spinning process, the hard segment of the copolymer was less likely to be oriented, resulting in a significant decrease in mechanical strength.

[0128] Comparative Example 4 used the same polymerization process as in Example 1, except that the soft segment polyetheramine D2000 was replaced with polyetheramine D2500. It was found during the polymerization that the viscosity of the copolymer was relatively low. This is because the molecular weight of the soft segment was relatively high, resulting in a large difference in the molecular weight between the polymerization product of the soft segment and the hard segment, and poor compatibility between the two. Under the same process conditions, the viscosity of the product prepared by polymerization was relatively low, leading to a decrease in the strength of the fiber.

[0129] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content within the scope of the technical solution of the present invention to obtain equivalent embodiments with equivalent changes. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A polyetheramide block copolymer, characterized in that: The polyetheramide block copolymer comprises: a hard segment composed of polyamide 6 and a long carbon chain polyamide, a soft segment composed of polyether or polyetheramine, and a dicarboxylic acid connecting the hard segment and the soft segment. The general structural formula of the polyetheramide block copolymer is shown in Formula I: in, R1 is a polyamide 6 segment; R2 is a long carbon chain polyamide segment; R is a dicarboxylic acid; R3 is a polyether or polyetheramine segment.

2. A polyetheramide block copolymer according to claim 1, characterized in that: The content of the hard segment is 30 to 95 wt.% of the total mass of the polyether amide block copolymer.

3. A polyetheramide block copolymer according to claim 1, characterized in that: The content of the long carbon chain polyamide in the hard segment is 5 to 30 wt.% of the total mass of the hard segment; Preferably, the long carbon chain polyamide is selected from one or more of polyamide 510, polyamide 512, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212 and polyamide 1214.

4. A polyetheramide block copolymer according to any one of claims 1 to 3, characterized in that: The content of the soft segment is 5 to 70 wt.% of the total mass of the polyether amide block copolymer.

5. A polyetheramide block copolymer according to any one of claims 1 to 3, characterized in that: The soft segment is selected from polyether or polyetheramine, and the number average molecular weight of the polyether or polyetheramine is 400 to 2000 g / mol; Preferably, the polyether is selected from one or more linear or branched polyoxyalkylene diols having a carbon number of 2 to 5; Preferably, the polyetheramine is selected from one or more linear or branched polyoxyalkylenes having 2 to 5 carbon atoms and containing terminal amino groups.

6. A polyetheramide block copolymer according to any one of claims 1 to 3, characterized in that: The dicarboxylic acid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid.

7. A method for preparing the polyether amide block copolymer according to any one of claims 1 to 6, comprising: Caprolactam, long-chain polyamide salt, dicarboxylic acid, polyether or polyether amine, antioxidant, catalyst and deionized water are mixed, oxygen in the system is removed by nitrogen replacement, and then the temperature is raised to carry out polymerization reaction, and after the reaction is completed, the material is discharged, pelletized, extracted and dried to obtain a polyether amide block copolymer; Preferably, the polymerization conditions include: First, heat to 210-250℃, pressure to 0.1-0.5Mpa, and react for 1-5h; After the pressure drops to normal pressure within 0.5 to 1.5 hours, continue to heat up to 230 to 260°C and react for 2 to 5 hours; Continue to raise the temperature to 240-265°C and react for 1-2 hours under vacuum; Preferably, the antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010, and SEED; Preferably, the catalyst is selected from one or more of phosphoric acid, sodium hypophosphite, sodium dihydrogen phosphate, tetrabutyl titanate, antimony trioxide, and ethylene glycol antimony.

8. A polyetheramide fiber, characterized in that: Prepared by using the polyether amide block copolymer according to any one of claims 1 to 6; Preferably, the polyetheramide fiber has a strength of 1.1 to 4.9 cN / dtex, an elastic recovery rate of 30% fixed elongation ≥ 85%, and a moisture regain ≥ 3.68%; Preferably, the polyetheramide fiber is selected from one of spun fiber, fiber filament, POY fiber, textured fiber, FDY fiber or staple fiber.

9. A method for preparing a polyetheramide fiber, comprising: The polyetheramide block copolymer according to any one of claims 1 to 6 is vacuum dried, and then melt-spinned to obtain polyetheramide fiber; Preferably, the vacuum drying conditions include: vacuum drying at 80-110° C. to a moisture content of ≤500 ppm.

10. The preparation method according to claim 9, characterized in that: During melt spinning, the spinning temperature is 200-280°C; Preferably, the spinning temperature is 220-260°C; Preferably, during melt spinning, the wind speed of the annular blowing is 0.2-0.5 m / s, the temperature of the annular blowing is 26-53° C., the spinning distance is 2-8 meters, and the spinning speed is 100-2000 m / s.

Images