Easily-dyed wear-resistant polypropylene fiber and preparation method thereof

Abstract

The invention discloses an easy-to-dye wear-resistant polypropylene fiber and a preparation method thereof.The polypropylene fiber is prepared from polypropylene and amino-modified polypropylene according to the mass ratio of 100: 10-20, the amino-modified polypropylene is obtained by reacting maleic anhydride grafted polypropylene serving as a precursor with polyethyleneimine, and the mass ratio of the maleic anhydride grafted polypropylene to the polyethyleneimine is 100: 10-20. The mass ratio of the maleic anhydride grafted polypropylene to the polyethyleneimine is 10: (0.8-1.3); the polypropylene fiber is prepared by melt spinning, cooling, oiling, drafting, curling and heat setting, the oiling adopts a diluent oil emulsion, and the diluent oil emulsion contains 1-3 wt% of water-soluble metal salt; the water-soluble metal salt is selected from zinc salt or copper salt. On the basis that the dyeing performance of the polypropylene fiber is improved, the good strength performance and wear resistance of the fiber can be kept.

Description

Technical Field

[0001] The present application relates to the field of polypropylene fiber manufacturing, and in particular to an easy-to-dye and wear-resistant polypropylene fiber and a preparation method thereof. Background Art

[0002] Polypropylene fiber is widely used in interior decoration materials (such as carpets, car interiors, sofa mattress spring packs), industrial protective nets, ropes and medical non-woven fabrics due to its light weight, chemical corrosion resistance and excellent water repellency. Its molecular chain is composed of non-polar carbon-hydrogen structure, with high crystallinity and weak intermolecular forces. Although this characteristic gives polypropylene good hydrophobicity and chemical stability, it makes its dyeing performance significantly inferior to natural fibers such as cotton and silk, as well as polar synthetic fibers such as polyester and nylon. Ultimately, it leads to problems such as low dyeing fastness and dull color, which seriously limits the application of polypropylene in high value-added textiles.

[0003] In order to improve the dyeing performance of polypropylene, the existing technology mainly introduces polar resin as a "dyeing seat" to improve the dyeing efficiency by using the interaction between its polar groups and dye molecules. For example, the Chinese patent with publication number CN1464082A proposes a method for manufacturing dyeable polypropylene, by blending polyester (such as polyethylene terephthalate) and polypropylene for spinning, and enhancing the dye adsorption capacity with the help of polar groups such as ester groups in polyester. However, the molecular structures of polypropylene and polyester are significantly different, and the compatibility of the two is poor. Macroscopic phase separation is easily formed during the melt blending process, resulting in weak interface bonding force inside the fiber. This defect not only reduces the breaking strength and wear resistance of the fiber, but also causes interface peeling due to stress concentration during subsequent processing or use, exacerbating fiber fuzzing, breakage and other problems. Other methods to improve dyeing include surface modification of polypropylene (such as corona treatment, plasma treatment) or coating with a treatment agent containing polar functional groups, but these methods have limitations such as short-lasting treatment effects, complex processes or high costs, and are difficult to meet the needs of industrial production. Summary of the invention

[0004] The present application provides an easy-to-dye and wear-resistant polypropylene fiber and a preparation method thereof, which can maintain good strength and wear resistance of the fiber on the basis of improving the dyeing performance of the polypropylene fiber.

[0005] In a first aspect, the present application provides an easy-to-dye and wear-resistant polypropylene fiber, whose raw materials include polypropylene and amino-modified polypropylene in a mass ratio of 100:10-20, wherein the amino-modified polypropylene is obtained by reacting maleic anhydride grafted polypropylene with polyethyleneimine as a precursor, and the mass ratio of maleic anhydride grafted polypropylene to polyethyleneimine is 10:0.8-1.3.

[0006] In any of the above technical solutions, the grafting rate of the maleic anhydride grafted polypropylene is 1-2%.

[0007] In any of the above technical solutions, the molecular weight of the polyethyleneimine is 800-2000.

[0008] In any of the above technical solutions, the reaction temperature is 180-210°C.

[0009] In any of the above technical solutions, the preparation method of the amino-modified polypropylene is: adding maleic anhydride grafted polypropylene and polyethyleneimine into a twin-screw extruder, melt blending, kneading for 5 to 10 minutes, and extruding and granulating to obtain.

[0010] This application introduces amino-modified polypropylene (PP-NH2) into the polypropylene matrix, and utilizes the strong interactions between the amino groups (-NH2) on its molecular chain and the dye molecules, such as hydrogen bonding, ion coordination, and electrostatic effects, to significantly improve the dyeing performance of the fiber. The polar properties of the amino group break the chemical inertness of the non-polar molecular chain of polypropylene, provide a stable binding site for the dye, and increase the dyeing rate of acidic or reactive dyes to more than twice that of traditional polypropylene. At the same time, amino-modified polypropylene is produced by melt reaction with polyethyleneimine (PEI) with high amino density using maleic anhydride grafted polypropylene (PP-g-MAH) as a precursor. Its molecular chain contains both a polypropylene main chain and polar side chains, ensuring compatibility with the matrix polypropylene. Compared with the solution of introducing polyester in the prior art, the molecular structure of amino-modified polypropylene is more similar to that of the polypropylene matrix, and the interfacial bonding strength is improved during melt blending, which effectively avoids the decrease in fiber strength caused by phase separation and the wear and fuzzing caused by interfacial peeling.

[0011] It should be noted that polyethyleneimine has a higher amino density and reactivity than small molecular weight polyamine compounds such as polyethylene polyamine, which is conducive to introducing more amino dyeing sites at a low addition amount, ensuring the balance between the dyeability and mechanical properties of polypropylene. It is preferred to use polyethyleneimine with a molecular weight of 800 to 1000 in order to further improve the reaction efficiency and help increase the amino content in polypropylene fibers.

[0012] In any of the above technical solutions, the polypropylene fiber is obtained by melt spinning, cooling, oiling, drawing, curling, and heat setting. The oiling is performed using a diluent oil emulsion, which contains 1 to 3 wt% of a water-soluble metal salt.

[0013] In any of the above technical solutions, the water-soluble metal salt is selected from zinc salt or copper salt.

[0014] Exemplarily, the zinc salt is selected from zinc sulfate, zinc chloride or zinc acetate.

[0015] Exemplarily, the copper salt is selected from copper sulfate, copper chloride or copper acetate.

[0016] In any of the above technical solutions, the diluted oil emulsion contains 20-40wt% oil agent, 1-2wt% antistatic agent, 2-3wt% emulsifier, 1-3wt% water-soluble metal salt, and the balance is water.

[0017] Exemplarily, the emulsifier is selected from one or more of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, and hydrogenated castor oil polyoxyethylene ether.

[0018] Exemplarily, the oil agent is selected from one or more of mineral oil, synthetic ester, and silicone oil.

[0019] Exemplarily, the antistatic agent is selected from one or more of cationic quaternary ammonium salts, fatty alcohol polyoxyethylene ether phosphates, alkyl sulfonates, and alkylphenol polyoxyethylene ether sulfates.

[0020] Zinc salt or copper salt is introduced in the oiling process, and metal ions are loaded onto the fiber surface by diluting the oil emulsion. Under the high-temperature stretching action of the stretching process, the metal ions diffuse into the amorphous region of the fiber and form a stable coordination complex with the -NH2 group in the amino-modified polypropylene. This process can enhance the molecular chain interaction force in the amorphous region of the fiber and increase the glass transition temperature (Tg), thereby inhibiting the wear of the fiber caused by chain segment slippage during friction and improving the wear resistance of the polypropylene fiber.

[0021] In any of the above technical solutions, pre-networking is performed between oiling and drawing, and the pre-networking air pressure is 0.03-0.05 MPa.

[0022] After the oil coating and before the drawing, a pre-networking step (air pressure 0.03-0.05MPa) is added. The low-pressure air flow disturbance causes the diluted oil emulsion to evenly coat the surface of the monofilament to avoid local aggregation or insufficient penetration of the oil. The low-pressure design ensures that the fiber is only slightly disturbed and does not form periodic nodes in the traditional network process, thereby maintaining the mechanical uniformity of the fiber. The evenly distributed oil layer can accelerate the directional migration of metal ions during high-temperature drawing, making it more efficient to coordinate with amino groups. At the same time, the lubricating effect of the oil reduces the friction coefficient between the fiber and the guide roller during the drawing process, reduces the generation of surface hairiness, and further synergistically improves wear resistance.

[0023] In any of the above technical solutions, the stretching includes one stretching and two stretchings, the temperature of the first stretching is 60-80°C, the temperature of the second stretching is 100-120°C, and the total stretching multiple is 3-4.

[0024] In a second aspect, the present application provides a method for preparing easy-to-dye and wear-resistant polypropylene fiber, which comprises blending and melting the raw materials according to any of the raw material ratios of the polypropylene fiber described above to obtain a melt, and the melt is obtained by spinning, cooling, oiling, drawing, curling, and heat setting.

[0025] In any of the above technical solutions, the spinning box has a temperature of 245-265°C, a ring blowing speed of 0.6-0.8 mmin, a wind temperature of 20-25°C, and a spinning speed of 800-1000 m / min.

[0026] In any of the above technical solutions, the heat setting temperature is 120-130°C.

[0027] In summary, this application has the following beneficial effects: This application achieves a synergistic improvement in the dyeability and wear resistance of polypropylene fibers through the molecular design of amino-modified polypropylene, metal ion coordination enhancement, and pre-network process optimization. The introduction of amino groups gives the fiber an efficient dyeing seat function, and the dyeing rate is significantly improved compared to traditional polypropylene, and the high compatibility with the polypropylene matrix ensures the fiber's breaking strength. The high-temperature penetration and coordination of metal ions in the amorphous region increase the glass transition temperature and effectively improve the wear resistance. At the same time, the low-pressure pre-network process optimizes the oil distribution and coordination efficiency, further reducing friction damage. This solution achieves a simultaneous improvement in its dyeing performance and wear resistance while retaining the lightweight and water-repellent properties of polypropylene fibers. DETAILED DESCRIPTION

[0028] Preparation Example

[0029] Preparation Example 1, amino-modified polypropylene, is prepared according to the following steps: 1kg of maleic anhydride grafted polypropylene (grafting rate 1.5%, OREVAC® 18729) was mixed with 0.1kg of polyethyleneimine (molecular weight 1800, Bio-Toda) and put into a co-rotating twin-screw extruder (length-to-diameter ratio 40:1). The extruder temperature zones were set as follows: zone 1 180°C, zone 2 190°C, zone 3 200°C, zone 4 200°C, zone 5 200°C, and die head 200°C. The screw speed was 200rpm, the melt mixing time was 8min, and the amino-modified polypropylene was obtained by extrusion granulation.

[0030] Preparation Example 2, amino-modified polypropylene, was prepared according to the following steps: 1kg of maleic anhydride grafted polypropylene (grafting rate 2.0%, Coace®PP-g-MAH B1) was mixed with 0.13kg of polyethyleneimine (molecular weight 800, McLean) and put into a co-rotating twin-screw extruder. The extruder temperature zones were set as follows: zone 1 190℃, zone 200℃, zone 3 210℃, zone 4 210℃, zone 5 210℃, and die head 210℃. The screw speed was 220rpm, the melt mixing time was 5min, and the amino-modified polypropylene was obtained by extrusion granulation.

[0031] Preparation Example 3, amino-modified polypropylene, was prepared according to the following steps: 1kg of maleic anhydride grafted polypropylene (grafting rate 1.0%, BONDYRAM®PP-g-MAH 1010) was mixed with 0.08kg of polyethyleneimine (molecular weight 2000, Biotuoda) and put into a co-rotating twin-screw extruder. The extruder temperature zones were set as follows: zone 1 185℃, zone 2 195℃, zone 3 205℃, zone 4 205℃, zone 5 205℃, and die head 205℃. The screw speed was 200rpm, the melt mixing time was 10min, and the amino-modified polypropylene was obtained by extrusion granulation.

[0032] Preparation Example 4, amino-modified polypropylene, is different from Preparation Example 1 in that the molecular weight of polyethyleneimine is 2500 (McLean).

[0033] Preparation Example 5, amino-modified polypropylene, is different from Preparation Example 1 in that the molecular weight of polyethyleneimine is 600 (McLean).

[0034] Preparation Example 6, amino-modified polypropylene, is different from Preparation Example 1 in that polyethyleneimine (molecular weight 1800, Bio-Total) is replaced by an equal amount of triethylenetetramine.

[0035] Preparation Example 7, amino-modified polypropylene, is different from Preparation Example 1 in that polyethyleneimine (molecular weight 1800, Biotoda) is replaced by an equal amount of tetraethylenepentamine.

[0036] Example

[0037] Example 1, an easy-to-dye and wear-resistant polypropylene fiber is prepared according to the following steps: 10kg of polypropylene (Sico PP S2040) and 1.5kg of amino-modified polypropylene obtained in Preparation Example 1 were added to a twin-screw extruder, mixed at 220°C, extruded and water-cooled, and cut into composite slices using a granulator. The obtained composite slices were placed in a vacuum dryer at 95°C for 10 hours, transported to a melt spinning machine to melt, and the melt was ejected from the spinning spinneret at a spinning temperature of 260°C to obtain a monofilament. The monofilament was then cooled in a ring wind at a wind temperature of 21±1°C and a wind speed of 0.8m / min, and a diluent oil emulsion was supplied to the monofilament with an oil nozzle for bundling. The monofilament had an oil content of 0.7% after oiling, and the oiling temperature was 50°C. The bundled tow entered the pre-network device, and the pre-network air pressure was 0.04MPa. After leaving the pre-network device, the tow is drawn by the godet roller and enters the first and second drawing stages in sequence. The first drawing temperature is 72°C, the drawing multiple is 1.6, and the second drawing temperature is 110°C, the drawing multiple is 2. After drawing, the tow passes through the godet roller and enters the winder for winding. Finally, it is heat-set at 122-126°C for 10 minutes to obtain an easy-to-dye and wear-resistant polypropylene fiber with a fineness of 1.2dtex.

[0038] The diluted oil emulsion contains 35 wt % of silicone oil (Dow Corning DC-200), 1.5 wt % of antistatic agent (cationic quaternary ammonium salt, Akzo Nobel Armostat 600), 2.5 wt % of emulsifier (nonylphenol polyoxyethylene ether NP-10), 2.0 wt % of zinc sulfate, and 59 wt % of water.

[0039] Example 2, an easy-to-dye and wear-resistant polypropylene fiber is prepared according to the following steps: 10kg of polypropylene (Sico PP S2040) and 1.0kg of amino-modified polypropylene obtained in Preparation Example 2 were added to a twin-screw extruder, mixed at 230°C, extruded and water-cooled, and cut into composite slices using a granulator. The obtained composite slices were placed in a vacuum dryer at 90°C for 10 hours, transported to a melt spinning machine to melt, and the melt was ejected from the spinning spinneret at a spinning temperature of 265°C to obtain a monofilament. The monofilament was then cooled in a ring wind at a wind temperature of 24±1°C and a wind speed of 0.6m / min, and a diluent oil emulsion was supplied to the monofilament with an oil nozzle for bundling. The monofilament had an oil content of 0.6% after oiling, and the oiling temperature was 50°C. The bundled tow entered the pre-network device, and the pre-network air pressure was 0.03MPa. After leaving the pre-network device, the tow is drawn by the godet roller and enters the first and second drawing stages in sequence. The first drawing temperature is 80°C, the drawing multiple is 1.5, and the second drawing temperature is 120°C, the drawing multiple is 2. After drawing, the tow passes through the godet roller and enters the winder for winding. Finally, it is heat-set at 122-126°C for 10 minutes to obtain an easy-to-dye and wear-resistant polypropylene fiber with a fineness of 1.2dtex.

[0040] The above-mentioned diluent oil emulsion contains 35wt% of synthetic ester, 1.0wt% of antistatic agent (fatty alcohol polyoxyethylene ether phosphate, BASF Lutensit A-EP), 3.0wt% of emulsifier (hydrogenated castor oil polyoxyethylene ether EL-40), 3.0wt% of copper sulfate, and 68wt% of water.

[0041] Example 3, an easy-to-dye and wear-resistant polypropylene fiber is prepared according to the following steps: 10kg of polypropylene (Sico PP S2040) and 2.0kg of amino-modified polypropylene obtained in Preparation Example 3 were added to a twin-screw extruder, mixed at 220°C, extruded and water-cooled, and cut into composite slices using a granulator. The obtained composite slices were placed in a vacuum dryer at 95°C for 12 hours, transported to a melt spinning machine to melt, and the melt was ejected from the spinning spinneret at a spinning temperature of 245°C to obtain a monofilament. The monofilament was then cooled in a ring wind at a wind temperature of 21±1°C and a wind speed of 0.5m / min, and a diluent oil emulsion was supplied to the monofilament with an oil nozzle for bundling. The monofilament had an oil content of 0.8% after oiling, and the oiling temperature was 50°C. The bundled tow entered the pre-network device, and the pre-network air pressure was 0.05MPa. After leaving the pre-network device, the tow is drawn by the godet roller and enters the first and second drawing stages in sequence. The first drawing temperature is 60°C, the drawing multiple is 2, and the second drawing temperature is 100°C, the drawing multiple is 2. After drawing, the tow passes through the godet roller and enters the winder for winding. Finally, it is heat-set at 120-124°C for 13 minutes to obtain a 1.2dtex easy-to-dye and wear-resistant polypropylene fiber.

[0042] The diluted oil emulsion contains 40 wt % of mineral oil, 2.0 wt % of antistatic agent (sodium alkyl sulfonate, Dow Triton X-100), 2.5 wt % of emulsifier (fatty alcohol polyoxyethylene ether AEO-9), 1.0 wt % of zinc chloride, and 55 wt % of water.

[0043] Example 4, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 1 in that it is directly stretched without pre-networking after oiling.

[0044] Example 5, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 1 in that the amino-modified polypropylene obtained in Preparation Example 1 is replaced by an equal amount of the amino-modified polypropylene obtained in Preparation Example 4.

[0045] Example 6, an easy-to-dye and wear-resistant polypropylene fiber, differs from Example 1 in that the amino-modified polypropylene obtained in Preparation Example 1 is replaced by an equal amount of the amino-modified polypropylene obtained in Preparation Example 5.

[0046] Comparative Example

[0047] Comparative Example 1, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 1 in that an equal amount of maleic anhydride grafted polypropylene (grafting rate 1.5%, OREVAC® 18729) is used to replace the amino-modified polypropylene obtained in Preparation Example 1.

[0048] Comparative Example 2, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 4 in that the amino-modified polypropylene obtained in Preparation Example 1 is replaced by an equal amount of maleic anhydride-grafted polypropylene (grafting rate 1.5%, OREVAC® 18729).

[0049] Comparative Example 3, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 4 in that an equal amount of polypropylene (Secco PPS2040) is used to replace the amino-modified polypropylene obtained in Preparation Example 1.

[0050] Comparative Example 4 is an easy-to-dye and wear-resistant polypropylene fiber. The difference from Example 6 is that the raw materials of the polypropylene fiber are 10 kg polypropylene (Secco PP S2040) and 1.5 kg polyethylene terephthalate (intrinsic viscosity 0.4 dL / g, melting point 220-230°C).

[0051] Comparative Example 5, an easy-to-dye and wear-resistant polypropylene fiber, is different from Example 1 in that the amino-modified polypropylene obtained in Preparation Example 1 is replaced by an equal amount of the amino-modified polypropylene obtained in Preparation Example 6.

[0052] Comparative Example 6, an easily dyeable and wear-resistant polypropylene fiber, is different from Example 1 in that the amino-modified polypropylene obtained in Preparation Example 1 is replaced with an equal amount of the amino-modified polypropylene obtained in Preparation Example 7.

[0053] Comparative Example 7, an easy-to-dye and wear-resistant polypropylene fiber, differs from Example 1 in that zinc sulfate is not added to the diluent oil emulsion, and an equal amount of water replaces zinc sulfate.

[0054] Comparative Example 8 is an easy-to-dye and wear-resistant polypropylene fiber. The difference from Example 1 is that zinc sulfate is not added to the diluent oil emulsion, and an equal amount of water replaces zinc sulfate; and after oiling, no pre-networking is performed, and the fiber is directly stretched.

[0055] Performance testing

[0056] 1. Dyeing rate test Sample preparation: The fibers of the examples and comparative examples were made into yarns (yarn count 40 Ne, twist 650 twist / m) by ring spinning, woven in plain weave, with a fabric density of 120 strands / 10cm in warp and 80 strands / 10cm in weft, and a gram weight of 150 g / m 2 The fabric was washed three times according to GB / T8629-2017 "Household Washing and Drying Procedure for Textile Testing" to remove surface oil and impurities.

[0057] Test method: Refer to GB / T 23976.1-2009 "Textiles - Tests for colour fastness - Part 1: Colour fastness to washing", and test in combination with the dyeing process of acid dyes. Specifically, immerse the fiber sample (1.0 g) in a dye bath containing 2% (owf) acid dye (C.1.Acid Red57), with a bath ratio of 1:50 and pH = 4.5 (adjusted with acetic acid). Heat to 95°C at 2°C / min, keep warm for 60 minutes, cool to room temperature, take out the fiber, and wash with cold water. Use an ultraviolet spectrophotometer (UV-2600, Shimadzu) to measure the absorbance of the dyeing residue at λ = 520nm, and calculate the dye uptake: Dyeing rate (%) = (1-A1 / A0) × 100% Among them, A0 is the absorbance of blank dye solution, and A1 is the absorbance of residual solution after dyeing.

[0058] 2. Wear resistance test With reference to GB / T 21196.3-2007 "Determination of the abrasion resistance of textiles by the Martindale method", polypropylene fibers were tested. The fiber monofilaments were fixed in a reciprocating friction tester (YG401E), with a loading pressure of 0.5 cN / dtex, a friction head of 400-mesh sandpaper, and a friction frequency of 60 times / min. The number of frictions when obvious fuzzing or breakage appeared on the fiber surface was recorded, and the average value was taken for each group of 10 tests.

[0059] 3. Breaking strength test The test was conducted in accordance with GB / T 14344-2008 "Test Method for Tensile Properties of Chemical Fiber Filaments". A universal material testing machine (Instron 3365) was used with a clamping distance of 20 mm and a tensile speed of 20 mm / min to test the breaking strength of the single filament. Each group of samples was tested 30 times and the average value was taken, and the breaking strength (cN / dtex) was calculated based on the fineness.

[0060] Table 1. Performance test results

[0061] Analysis of test results: (1) The dye uptake rates of Examples 1 to 3 are all higher than 80%, indicating that amino-modified polypropylene significantly improves the dye uptake rate. However, in Comparative Examples 1 to 3, no amino modification was performed, and the dye uptake rates were significantly reduced, verifying the key role of amino groups as "dyeing sites".

[0062] (2) The wear resistance times of Examples 1 to 3 are significantly higher than those of the comparative examples, which is attributed to the coordination between metal ions and amino groups, which enhances the inter-molecular force in the amorphous region. In addition, amino-modified polypropylene has good compatibility with the polypropylene matrix compared to polar polymers such as polyester, which is beneficial to ensure the strength and wear resistance of polypropylene fiber. The wear resistance of Comparative Example 7 (no metal salt in the oil) decreased by about 28%, the wear resistance of Comparative Example 1 (no amino modification, but metal ions in the oil) decreased by about 30%, and the wear resistance of Comparative Example 2 (no amino modification and no metal ions in the oil) decreased by about 30.5%, proving the contribution of the coordination between metal ions and amino groups to wear resistance. The decrease in Example 5 (no pre-network) was about 13%, and the decrease in Comparative Example 8 (no metal salt and no pre-network) was about 37%, proving the contribution of the pre-network process to wear resistance.

[0063] (3) The breaking strength of Example 1 is higher than 3.8 cN / dtex, which is significantly better than that of Comparative Example 4 (2.3 cN / dtex), which proves that amino-modified polypropylene has good compatibility with the matrix compared with polyester, avoiding mechanical degradation caused by phase separation. The strength of Comparative Example 7 (no metal salt), Comparative Example 1 (no amino modification, but the oil contains metal ions), Comparative Example 2 (no amino modification, and the oil does not contain metal ions), Example 5 (no pre-network) and Comparative Example 8 (no pre-network and no metal salt) decreased, indicating that the metal salt in the oil coordinates with the amino group in the fiber, and the pre-network process can reduce fiber damage during the drawing process by uniformly distributing the oil.

[0064] (4) The dyeing performance of Example 1 (83.2%) is slightly higher than that of Examples 5 and 6 (79.7%, 80.6%), which proves that the use of polyethyleneimine with a molecular weight Mn of 800 to 2000 is helpful to improve the dyeing rate of polypropylene fiber. The reason may be that the reaction efficiency of polyethyleneimine in this molecular weight range with maleic anhydride grafted polypropylene is relatively high, which helps to increase the amino density in the fiber and increase the dyeing site content.

[0065] (5) The dye uptake rate of Example 1 (83.2%) is significantly higher than that of Comparative Examples 5-6 (60.7%, 64.3%), indicating that using polyethyleneimine as the amino grafted compound can produce polypropylene with a higher amino grafting rate compared to small molecular weight polyethylene polyamines, thereby obtaining polypropylene fibers with a high dye uptake rate.

[0066] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An easy-to-dye and wear-resistant polypropylene fiber, characterized in that: The invention comprises polypropylene and amino-modified polypropylene in a mass ratio of 100:10-20, wherein the amino-modified polypropylene is obtained by reacting maleic anhydride-grafted polypropylene as a precursor with polyethyleneimine, and the mass ratio of maleic anhydride-grafted polypropylene to polyethyleneimine is 10:0.8-1.3; the polypropylene fiber is obtained by melt spinning, cooling, oiling, drawing, curling and heat setting, wherein the oiling adopts a diluent oil emulsion, and the diluent oil emulsion contains 1-3wt% of a water-soluble metal salt; the water-soluble metal salt is selected from zinc salt or copper salt.

2. The polypropylene fiber according to claim 1, characterized in that The grafting rate of the maleic anhydride grafted polypropylene is 1-2%.

3. The polypropylene fiber according to claim 1, characterized in that The molecular weight of the polyethyleneimine is 800-2000.

4. The polypropylene fiber according to claim 1, characterized in that The reaction temperature is 180-210°C.

5. The polypropylene fiber according to claim 1, characterized in that The diluent oil emulsion comprises 20-40 wt% of oil agent, 1-2 wt% of antistatic agent, 2-3 wt% of emulsifier, 1-3 wt% of water-soluble metal salt, and the balance is water.

6. The polypropylene fiber according to claim 1, characterized in that Pre-networking is performed between the oiling and the drawing, and the pre-networking air pressure is 0.03-0.05 MPa.

7. The polypropylene fiber according to claim 1, characterized in that The stretching process includes one stretching process and two stretching processes, the temperature of the first stretching process is 60-80° C., the temperature of the second stretching process is 100-120° C., and the total stretching multiple is 3-4.

8. A method for preparing easy-to-dye and wear-resistant polypropylene fiber, characterized in that: According to the raw material ratio of the polypropylene fiber according to any one of claims 1 to 7, the raw materials are blended and melted to obtain a melt, and the melt is produced by spinning, cooling, oiling, drawing, curling and heat setting.

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