Polyurethane urea elastic fiber with long-acting unwinding property and preparation method thereof

Abstract

The invention provides a polyurethane urea elastic fiber with long-acting unwinding property and a preparation method thereof, the polyurethane urea elastic fiber is obtained by using polyurethane urea and a lubricant as spinning raw materials in the presence of a solvent through dry spinning, and the content of the lubricant is 0.3%-5% based on the total mass of the polyurethane urea elastic fiber; and the lubricating agent comprises a stearic acid amide lubricating agent. The special lubricant can be well dissolved in a polar organic solvent, the lubricant and a polyurethane urea system are good in compatibility and high in migration efficiency in the spinning preparation process of the polyurethane urea elastic fiber, the long-acting unwinding property of the fiber can be effectively improved, the lubricant does not need to be ground in advance, and the preparation process is simple. The spinnability and the uniformity of the spinning solution are ensured, and the production efficiency and the production stability of spinning are improved.

Description

Technical Field

[0001] The present invention belongs to polyurethane urea elastic fibers, and particularly relates to a polyurethane urea elastic fiber with long-term unwinding property and a preparation method thereof. Technical Background

[0002] Unwinding is a very important process in the application of polyurethane urea elastic fibers (spandex). However, when the spandex cake is stored for a long time, it will be accompanied by the volatilization of the oil agent and the change of its own physical and chemical properties, resulting in phenomena such as adhesion and broken filaments during the subsequent unwinding process, which affects production efficiency and quality. At present, the commonly used methods to improve the unwinding property include increasing the oil content on the fiber surface or adding unwinding aids. Among them, too high oil content on the fiber will cause problems such as uneven end face, overlapping filaments, and edge dropping of the cake, and the oil agent must be removed in the subsequent pretreatment and dyeing processes of the fabric, so the oil content on the fiber should not be too high; improving the unwinding property by adding unwinding aids, but too high content of conventional unwinding aids such as magnesium stearate will cause problems such as poor cake forming and low binding force, and most unwinding agents cannot be dissolved in the dry spinning system of spandex. High content of unwinding agents will damage the spinning equipment for spandex preparation and affect the normal operation of production. Summary of the Invention

[0003] Technical Problem: Aiming at the deficiencies of the existing technology, the present invention provides a polyurethane urea elastic fiber with long-term unwinding property and a preparation method thereof, effectively solving the problem of adhesion and broken filaments of the fiber during its subsequent application due to long-term placement.

[0004] Technical Solution: The present invention provides a polyurethane urea elastic fiber with long-term unwinding property. The polyurethane urea elastic fiber contains 0.3% - 5% of a lubricant, calculated based on the total mass of the polyurethane urea elastic fiber, and the lubricant is soluble in polar organic solvents.

[0005] Among them,

[0006] The lubricant includes a stearic acid amide lubricant or a combination of a stearic acid amide lubricant and a stearic acid ester lubricant; the mass ratio of the combination of the stearic acid amide lubricant and the stearic acid ester lubricant is 3:1 - 1:3; the lubricant is soluble in polar organic solvents.

[0007] The stearic acid amide lubricant includes at least one of ethylene bis-12-hydroxy stearic acid amide, ethylene bis-stearic acid amide, hydroxyethyl stearic acid amide, stearic acid diethanolamide, and oleic acid amide.

[0008] The stearic acid ester lubricant includes at least one of ethylene glycol distearate, glyceryl tristearate, pentaerythritol tetrastearate, and sorbitan monostearate.

[0009] The polar organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide and N-methyl-2-pyrrolidone.

[0010] The polyurethane urea comprises a reaction product of a polymer polyol, a polyisocyanate, a diamine chain extender and a terminator.

[0011] The polymer polyol includes polyester polyol and / or polyether polyol, and the polyether polyol includes one or more of polytetramethylene glycol, polyethylene glycol or polypropylene glycol; the number average molecular weight of the polymer polyol is 1000-2000 g / mol.

[0012] The polyisocyanate includes toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dimethylbiphenyl diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dicyclohexylmethane diisocyanate and / or one or more derivatives and / or modified polymers.

[0013] The diamine chain extender includes one or more of ethylenediamine, propylenediamine, 2-methyl-1,5-pentanediamine, pentanediamine, and hexamethylenediamine; the terminator independently includes one or more of dimethylamine, diethylamine, dipropylamine, n-butanol, and ethanolamine.

[0014] The polyurethane urea elastic fiber with long-term unwinding property of the present invention comprises polyurethane urea and lubricant as spinning raw materials, and is obtained by dry spinning in the presence of a solvent; the lubricant is added in the form of a solution, and specifically comprises the following steps:

[0015] Preparation of polyurethane urea: reacting the polymer polyol and polyisocyanate to obtain a prepolymer mixture, dissolving the prepolymer mixture in the presence of a solvent to obtain a prepolymer solution, and reacting the prepolymer solution with a mixed amine solution containing a diamine chain extender and a terminator to obtain a polyurethane urea stock solution;

[0016] Preparation of lubricant solution: adding the lubricant into a polar organic solvent and stirring sufficiently to obtain a lubricant solution, wherein the mass concentration of the lubricant solution is 10-30%;

[0017] Preparation of spinning solution: adding an organic solvent solution containing a lubricant to a polyurethane urea solution; fully mixing and aging to obtain a spinning solution;

[0018] Preparation of polyurethane urea elastic fiber: The spinning solution is transported by a metering pump, spun through a spinneret assembly, and then formed through a spinning tunnel, a false twisting device, and a winding machine to obtain a polyurethane urea elastic fiber with long-lasting unwinding properties.

[0019] Beneficial effects: The polyurethane-urea elastic fiber with long-term unwinding property of the present invention contains a specific lubricant, which can be well dissolved in polar organic solvents. During the spinning preparation process of the polyurethane-urea elastic fiber, the lubricant has good compatibility with the polyurethane-urea system and high migration efficiency, which can effectively improve the long-term unwinding property of the fiber. Moreover, it is not necessary to pre-grind the lubricant, ensuring the spinnability and uniformity of the spinning dope, and improving the production efficiency and production stability of spinning. Detailed implementation manners

[0020] For the polyurethane-urea elastic fiber with long-term unwinding property, the polyurethane-urea elastic fiber contains 0.3% - 5% of a lubricant, calculated based on the total mass of the polyurethane-urea elastic fiber, and the lubricant is soluble in polar organic solvents;

[0021] In the present invention, the term "dissolve" means that above 70 °C, the lubricant forms a homogeneous solution in polar organic solvents;

[0022] The polar organic solvents include at least one of N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP);

[0023] The lubricant includes stearic acid amide lubricants;

[0024] Further, the lubricant includes a combination of stearic acid amide lubricants and stearic acid ester lubricants; the mass ratio of the combination of stearic acid amide lubricants and stearic acid ester lubricants is 3:1 - 1:3

[0025] The stearic acid amide lubricants include at least one of ethylene bis-12-hydroxystearamide (EBH), ethylene bisstearamide (EBS), hydroxyethyl stearamide, stearic acid diethanolamide, and oleic acid amide; further, the stearic acid amide lubricants include at least one of ethylene bis-12-hydroxystearamide (EBH), ethylene bisstearamide (EBS), hydroxyethyl stearamide, and stearic acid diethanolamide; more preferably, the stearic acid amide lubricant includes ethylene bis-12-hydroxystearamide;

[0026] Further, the stearic acid ester lubricants include at least one of ethylene glycol distearate, glyceryl tristearate, pentaerythritol tetrastearate, and sorbitan monostearate.

[0027] More preferably, the stearic acid ester lubricant includes pentaerythritol tetrastearate;

[0028] Preferably, the fiber further contains at least one of a delustering agent, an ultraviolet absorber, and an antioxidant;

[0029] The mass content of the matting agent is 0.5% to 2%, calculated based on the total mass of the fibers;

[0030] The mass content of the ultraviolet absorber is 0.1% to 2%, calculated based on the total mass of the fibers;

[0031] The mass content of the antioxidant is 0.1% to 2%, calculated based on the total mass of the fibers;

[0032] The matting agent includes at least one of titanium dioxide and silicon dioxide;

[0033] The ultraviolet absorber includes at least one of UV622, UV1164, and UV320;

[0034] The antioxidant includes at least one of antioxidant 245, antioxidant 1790, and antioxidant 1010.

[0035] The polyurethane-urea elastic fiber with long-term unwinding property will be obtained by dry spinning using polyurethane-urea and a lubricant as spinning raw materials in the presence of a solvent;

[0036] Preferably, the lubricant is added in the form of a solution;

[0037] The polyurethane-urea includes the reaction product of a polymer polyol, a polyisocyanate, a diamine chain extender, and a terminator;

[0038] The polymer polyol includes a polyester polyol and / or a polyether polyol. Further, the polymer polyol includes a polyether polyol, and the polyether polyol includes one or more of polytetrahydrofuran diol, polyethylene glycol, or polypropylene glycol;

[0039] As an example, the polymer polyol includes polytetrahydrofuran diol PTMEG;

[0040] The number-average molecular weight of the polymer polyol is 1000 to 2000 g / mol;

[0041] The polyisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dimethylbiphenyl diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dicyclohexylmethane diisocyanate, and / or derivatives and / or modified polymers;

[0042] As an example, the polyisocyanate includes diphenylmethane diisocyanate MDI;

[0043] The diamine chain extender described above includes one or more of ethylenediamine, propanediamine, 2-methyl-1,5-pentanediamine, pentanediamine, and hexanediamine;

[0044] The terminator independently includes one or more of dimethylamine, diethylamine, dipropylamine, n-butanol, and ethanolamine;

[0045] The solvent described above includes one or more of N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP);

[0046] As an example, the preparation method of the polyurethane-urea elastic fiber with long-term unwinding property is specifically as follows:

[0047] Add the lubricant solution to the polyurethane-urea stock solution, and obtain the spinning dope after sufficient mixing and curing;

[0048] Among them, at 70 °C, add the lubricant to the polar organic solvent and stir well to obtain the lubricant solution, and the mass concentration of the lubricant solution is 10-30%;

[0049] The lubricant is dissolved in DMAC, and the DMAC solution containing the lubricant is added to the polyurethane-urea stock solution;

[0050] The spinning dope is transported by a metering pump, extruded through a spinneret assembly to form filaments, and formed through a spinning channel, a false-twist device, and a winding machine respectively to obtain the polyurethane-urea elastic fiber with long-term unwinding property.

[0051] As an example, the preparation method of the polyurethane-urea is specifically as follows: React the polymer polyol and polyisocyanate described above to obtain a prepolymer mixture, dissolve it in the presence of a solvent to obtain a prepolymer solution, and react the prepolymer solution with a mixed amine solution containing a diamine chain extender and a terminator to obtain a polyurethane-urea spinning dope;

[0052] The NCO mass content of the prepolymer mixture is 2 wt% to 4 wt%;

[0053] The mass concentration of the prepolymer solution is 30 wt% to 60 wt%;

[0054] Control the molar ratio of the amine end group (A) in the mixed amine to the isocyanate end group (NCO) in the prepolymer mixture to be 1.01 to 1.10; the molar ratio of the diamine chain extender to the terminator is 1:1 to 30:1;

[0055] The mass concentration of the mixed amine solution is 3 wt% to 10 wt%;

[0056] The mass concentration of the polyurethane-urea stock solution is 25 wt% to 45 wt%.

[0057] The following examples are used to describe the production process of the present invention in detail, but these examples should not be construed as limiting the present invention in any sense.

[0058] Preparation of polyurethane-urea solution:

[0059] Mix 5 parts by weight of polytetrahydrofuran glycol (PTMEG, number average molecular weight 1800 g / mol) with 1.3 parts by weight of diphenylmethane diisocyanate (MDI), and react at 90 °C for 2 hours to obtain a polyurethane prepolymer mixture; dissolve the polyurethane prepolymer mixture in 10.8 parts by weight of N,N-dimethylacetamide (DMAC) solution, cool the prepolymer solution to below 15 °C, and gradually add a DMAC solution (mass content 7%) containing 0.092 parts by weight of ethylenediamine, 0.028 parts by weight of propylenediamine, and 0.018 parts by weight of diethylamine for chain extension reaction and chain termination reaction, and then add 0.5% antioxidant 245, 0.22% ultraviolet absorber UV-622, and 0.5% matting agent titanium dioxide to obtain a polyurethane-urea solution with a mass content of 35% (solution mass concentration = solute mass / total solution mass × 100%).

[0060] Preparation of lubricant solution:

[0061] Add the lubricant to DMAC and stir well at 70 °C to dissolve to obtain a lubricant solution with a mass content of 20% (solution mass concentration = solute mass / total solution mass × 100%).

[0062] Preparation of polyurethane-urea elastic fiber:

[0063] (1) Mix the polyurethane-urea solution and the lubricant solution and cure to obtain a spinning dope;

[0064] (2) Spin the spinning dope obtained in step (1) through a spinneret assembly to obtain 40D polyurethane-urea elastic fiber;

[0065] The spinning in step (2) is dry spinning, and the spinning dope is transported by a metering pump and spun through a spinneret hole assembly;

[0066] After the spinning and forming in step (2), it also includes the steps of drying and shaping in a spinning duct, false twisting, and winding and forming.

[0067] Example 1:

[0068] The lubricant is ethylene bis(12-hydroxystearamide) (EBH), and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.3% of the total fiber mass.

[0069] Example 2:

[0070] The difference from Example 1 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.5% of the total mass of the fiber.

[0071] Example 3:

[0072] The difference from Example 1 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 1% of the total mass of the fiber.

[0073] Example 4:

[0074] The difference from Example 1 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 3% of the total mass of the fiber.

[0075] Example 5:

[0076] The difference from Example 1 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 5% of the total mass of the fiber.

[0077] Example 6:

[0078] The difference from Example 1 is that the lubricant is ethylene bis-stearamide.

[0079] Example 7:

[0080] The difference from Example 1 is that the lubricant is oleamide.

[0081] Example 8:

[0082] The lubricant is ethylene bis(12-hydroxy stearamide) (EBH) and pentaerythritol tetrastearate with a mass ratio of 1:1, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.3% of the total mass of the fiber.

[0083] Example 9:

[0084] The difference from Example 8 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.5% of the total mass of the fiber.

[0085] Example 10:

[0086] The difference from Example 8 is that the lubricant in the prepared polyurethane-urea elastic fiber accounts for 1% of the total mass of the fiber.

[0087] Example 11:

[0088] The lubricant is ethylene bis(12-hydroxy stearamide) (EBH) and pentaerythritol tetrastearate with a mass ratio of 3:1, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 1% of the total mass of the fiber.

[0089] Example 12:

[0090] The lubricant is ethylene bis(12-hydroxystearamide) (EBH) and pentaerythritol tetrastearate with a mass ratio of 1:3, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 1% of the total mass of the fiber.

[0091] Example 13:

[0092] The lubricant is ethylene bis(12-hydroxystearamide) (EBH) and glyceryl tristearate with a mass ratio of 1:1, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 1% of the total mass of the fiber.

[0093] Example 14:

[0094] The lubricant is ethylene bis(12-hydroxystearamide) (EBH) and pentaerythritol tetrastearate with a mass ratio of 1:10, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.3% of the total mass of the fiber.

[0095] Example 15:

[0096] The lubricant is ethylene bis(12-hydroxystearamide) (EBH) and pentaerythritol tetrastearate with a mass ratio of 10:1, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.3% of the total mass of the fiber.

[0097] Example 16:

[0098] The lubricant is ethylene bis(12-hydroxystearamide) (EBH) and oleamide with a mass ratio of 1:1, and the lubricant in the prepared polyurethane-urea elastic fiber accounts for 0.3% of the total mass of the fiber.

[0099] Comparative Example 1:

[0100] The difference from Example 1 is that the lubricant is magnesium stearate.

[0101] Comparative Example 2:

[0102] The difference from Example 2 is that the lubricant is magnesium stearate.

[0103] Comparative Example 3:

[0104] The difference from Example 3 is that the lubricant is magnesium stearate.

[0105] Comparative Example 4:

[0106] The difference from Example 1 is that the lubricant is montan wax.

[0107] Comparative Example 5:

[0108] The difference from Example 6 is that the lubricant is ethylene bis(12-hydroxystearamide) (EBH) and montan wax with a mass ratio of 1:1.

[0109] The unwinding properties of the polyurethane urea fibers prepared in the examples and comparative examples were tested respectively, and the testing methods were as follows:

[0110] (1) Spinnability: refers to the consistency of product quality and the sustainability of production efficiency during the spandex production process. It is quantified by the number of failures that occur within 30 days. The more failures there are, the worse the spinnability.

[0111] (2) Unwinding test: The fiber was placed in an oven at 60°C for 72 h and 144 h, respectively, to simulate the aging of the silk cake after long-term storage.

[0112] Put the aged silk roll into the bearing, wind the ends of the aged 72h and 144h fibers onto the rollers in the unwinding direction, and put them into the air inlet to complete the hanging. Set the instrument input speed to 10m / min, and the output speed to be set according to the sample type and test purpose. Start the instrument, and when the silk roll sticks during unwinding and the reciprocating amplitude is large, the test is over, and the unwinding performance is recorded.

[0113] Unwinding (TR) = output roller speed / input roller speed

[0114] (3) Mechanical properties:

[0115] DS (breaking strength): The maximum force that a specimen can withstand when stretched to fracture under specified tensile test conditions.

[0116] DE (elongation at break): The ratio of the elongation of the specimen at breaking strength to the initial length, expressed as a percentage.

[0117] DE (%) = displacement / (clamp distance (50 mm)) × 100%

[0118] Test method: In a standard atmosphere with a temperature of 20±1℃ and a humidity of 65%±5%, use a constant-speed elongation tester to break the sample with the specified starting length, pre-tension and stretching speed, and record the breaking strength and breaking elongation. Specific implementation shall be in accordance with FZ / T 50006.

[0119] The performance test results of the polyurethane urea fibers prepared in the examples and comparative examples are shown in the following table:

[0120]

[0121]

Claims

1. A polyurethane urea elastic fiber with long-term unwinding properties, characterized in that: The polyurethane urea elastic fiber contains 0.3% to 5% of a lubricant, calculated based on the total mass of the polyurethane urea elastic fiber, and the lubricant can be dissolved in a polar organic solvent.

2. The polyurethane urea elastic fiber with long-term unwinding property according to claim 1, characterized in that: The lubricant includes a stearic acid amide lubricant or a combination of a stearic acid amide lubricant and a stearic acid ester lubricant; the mass ratio of the combination of the stearic acid amide lubricant and the stearic acid ester lubricant is 3:1 to 1:

3.

3. The polyurethane urea elastic fiber with long-term unwinding property according to claim 2, characterized in that: The stearic acid amide lubricant includes at least one of ethylene bis-12-hydroxy stearic acid amide, ethylene bis stearic acid amide, hydroxyethyl stearic acid amide, stearic acid diethanolamide, and oleic acid amide.

4. The polyurethane urea elastic fiber with long-term unwinding property according to claim 2, characterized in that: The stearate lubricant includes at least one of ethylene glycol distearate, glyceryl tristearate, pentaerythritol tetrastearate and sorbitan monostearate.

5. The polyurethane urea elastic fiber with long-term unwinding property according to claim 2, characterized in that: The polar organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide and N-methyl-2-pyrrolidone.

6. The polyurethane urea elastic fiber with long-term unwinding property according to claim 1, characterized in that: The polyurethane urea comprises a reaction product of a polymer polyol, a polyisocyanate, a diamine chain extender and a terminator.

7. The polyurethane urea elastic fiber with long-term unwinding property according to claim 6, characterized in that: The polymer polyol includes polyester polyol and / or polyether polyol, and the polyether polyol includes one or more of polytetramethylene glycol, polyethylene glycol or polypropylene glycol; the number average molecular weight of the polymer polyol is 1000-2000 g / mol.

8. The polyurethane urea elastic fiber with long-term unwinding property according to claim 6, characterized in that: The polyisocyanate includes toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dimethylbiphenyl diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dicyclohexylmethane diisocyanate and / or one or more derivatives and / or modified polymers.

9. The polyurethane urea elastic fiber with long-term unwinding property according to claim 6, characterized in that: The diamine chain extender includes one or more of ethylenediamine, propylenediamine, 2-methyl-1,5-pentanediamine, pentanediamine, and hexamethylenediamine; the terminator independently includes one or more of dimethylamine, diethylamine, dipropylamine, n-butanol, and ethanolamine.

10. The method for preparing the polyurethane urea elastic fiber with long-term unwinding property according to any one of claims 1 to 9, characterized in that: The polyurethane urea elastic fiber with long-term unwinding property comprises polyurethane urea and lubricant as spinning raw materials, and is obtained by dry spinning in the presence of a solvent; the lubricant is added in the form of a solution, and specifically comprises the following steps: Preparation of polyurethane urea: reacting the polymer polyol and polyisocyanate to obtain a prepolymer mixture, dissolving the prepolymer mixture in the presence of a solvent to obtain a prepolymer solution, and reacting the prepolymer solution with a mixed amine solution containing a diamine chain extender and a terminator to obtain a polyurethane urea stock solution; Preparation of lubricant solution: adding the lubricant into a polar organic solvent and stirring sufficiently to obtain a lubricant solution, wherein the mass concentration of the lubricant solution is 10-30%; Preparation of spinning solution: adding an organic solvent solution containing a lubricant to a polyurethane urea solution; fully mixing and aging to obtain a spinning solution; Preparation of polyurethane urea elastic fiber: The spinning solution is transported by a metering pump, spun through a spinneret assembly, and then formed through a spinning tunnel, a false twisting device, and a winding machine to obtain a polyurethane urea elastic fiber with long-lasting unwinding properties.

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