Soft tensile all-cotton spunlace fabric and preparation method and application thereof

Abstract

The application discloses a kind of soft tensile full cotton water jet cloth and preparation method and application thereof, it is related to non-woven fabric technical field.The preparation method of the soft tensile full cotton water jet cloth includes the following steps:S1: (1) carboxylation modification is carried out to defatted cotton;Then using N,N-dimethyl-1,3-diamino propane is modified to tertiary amine;Finally, it is quaternary ammonium salt, and modified defatted cotton is obtained;(2) modified defatted cotton, pure cotton is mixed according to proportion, is laid, once water jet treatment, drying;Defatting, drying again, and defatted cotton non-woven fabric is obtained;S2: defatted cotton non-woven fabric, cotton paper is alternately laminated, and the two sides of outermost layer are both defatted cotton non-woven fabric;Second water jet treatment, drying, and the soft tensile full cotton water jet cloth is obtained.The soft tensile full cotton water jet cloth prepared by the application has high tensile strength, strong liquid absorption, good softness, and certain bacteriostatic effect.

Description

Technical Field

[0001] This invention relates to the field of nonwoven fabric technology, specifically to a soft, tensile-resistant all-cotton spunlace fabric, its preparation method, and its application. Background Technology

[0002] With the improvement of living standards, textiles, as materials that people frequently come into contact with, have placed higher demands on their performance and comfort. Among them, in the field of nonwoven fabrics, all-cotton spunlace nonwoven fabric, as an important non-manufacturing material, has been widely used due to its advantages such as being all-natural, comfortable, and breathable. However, in the current technology, all-cotton spunlace fabric still has shortcomings. For example, the tensile strength of all-cotton spunlace fabric itself is generally low, and adding high-strength synthetic fibers will destroy the all-cotton properties of the material. On the other hand, using methods to increase the spunlace strength will reduce the softness of all-cotton spunlace fabric.

[0003] In conclusion, solving the above problems and preparing a soft, tensile-resistant all-cotton spunlace fabric is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a soft, tensile-resistant all-cotton spunlace fabric, its preparation method, and its application, in order to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for preparing a soft, tensile-resistant, all-cotton spunlace fabric includes the following steps:

[0007] S1: (1) Carboxylation modification of degreased cotton; then N,N-dimethyl-1,3-diaminopropane is used to modify it into a tertiary amine; finally, it is quaternized to obtain modified degreased cotton; (2) Modified degreased cotton and pure cotton are mixed in proportion, laid flat, hydroentangled once, and dried; degreased and dried again to obtain degreased cotton nonwoven fabric;

[0008] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper, with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; perform a second hydroentangling treatment and dry to obtain a soft, tensile-resistant all-cotton hydroentangled fabric.

[0009] Preferably, in step S2, the number of alternating layers is ≥3; the basis weight of the degreased cotton nonwoven fabric is 15~50g / m². 2 The weight of cotton paper is 15~25g / m³. 2 .

[0010] Preferably, the ratio of modified degreased cotton to pure cotton in the raw materials of the degreased cotton nonwoven fabric is (2~3):10.

[0011] The preferred method for preparing modified degreased cotton is as follows: (1) Add degreased cotton and chloroacetic acid to sodium hydroxide solution, stir at 60~70℃ for 7~8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton;

[0012] (2) Add carboxyl-modified degreased cotton, N,N-dimethyl-1,3-diaminopropane, N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine to tetrahydrofuran and mix evenly. Stir at 20~25℃ for 4~5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton.

[0013] (3) Add N,N-dimethyl modified degreased cotton, triethylamine and bromoethane to an ethanol aqueous solution, stir at 60~65℃ for 30~40h, filter, wash and dry to obtain modified degreased cotton.

[0014] Preferably, the carboxyl-modified degreased cotton comprises the following raw materials, by mass parts: 100 parts degreased cotton, 9-10 parts chloroacetic acid, and 180-200 parts 15-20 wt% sodium hydroxide solution;

[0015] The N,N-dimethyl modified degreased cotton comprises the following raw materials, by mass parts: 100 parts carboxyl modified degreased cotton, 10-12 parts N,N-dimethyl-1,3-diaminopropane, 21-23 parts N,N'-dicyclohexylcarbodiimide, 11-13 parts 4-dimethylaminopyridine, and 130-150 parts tetrahydrofuran;

[0016] The modified degreased cotton comprises the following raw materials, by mass: 100 parts N,N-dimethyl modified degreased cotton, 10-11 parts triethylamine, 11-12 parts bromoethane, and 35-40 wt% ethanol aqueous solution.

[0017] Preferably, the water pressure for the first hydroentangling treatment is 80-100 bar; the specific process for the second hydroentangling treatment is as follows: first, low-pressure hydroentangling treatment at a water pressure of 35-50 bar, and then high-pressure hydroentangling treatment at a water pressure of 120-150 bar.

[0018] More preferably, the method for preparing the cotton paper is as follows: a fluoroacrylamide copolymer is prepared into a solution, uniformly sprayed onto the surface of absorbent cotton paper, and dried to obtain cotton paper; wherein, the concentration of the fluoroacrylamide copolymer is 200~300mg / L, and the solvent is a 50~70wt% aqueous ethanol solution.

[0019] Preferred method for preparing the fluorinated acrylamide copolymer includes the following steps: (1) adding acrylamide and 2-acrylamido-2-methylpropanesulfonic acid to deionized water and stirring until homogeneous, adjusting the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) adding perfluorooctyl ethyl acrylate and polyethylene glycol monoallyl ether to deionized water and stirring until homogeneous to obtain reaction monomer solution B; (3) mixing reaction monomer solution A and reaction monomer solution B until homogeneous under a nitrogen atmosphere, adding 0.1~0.2wt% of initiator, stirring at 25~30℃ for 4~4.5h, filtering, washing, and drying to obtain the fluorinated acrylamide copolymer.

[0020] Preferredly, the raw materials for the fluorinated acrylamide copolymer include, by weight, 14-16 parts acrylamide, 2-3 parts 2-acrylamido-2-methylpropanesulfonic acid, 0.15-0.2 parts perfluorooctyl ethyl acrylate, 0.3 parts polyethylene glycol monoallyl ether, and 0.05-0.1 parts initiator; wherein the polyethylene glycol monoallyl ether has a molecular weight of 400-1000.

[0021] Preferably, the soft, tensile-resistant cotton spunlace fabric can be functionalized by adding RO pure water or natural plant extracts for use in wet wipe production.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention obtains degreased cotton nonwoven fabric by spunlace using pure cotton and modified degreased cotton as pure cotton raw materials, obtains cotton paper by spraying a fluoroacrylamide copolymer solution onto the surface of absorbent cotton paper and drying it, and prepares the all-cotton spunlace fabric by alternating layers of cotton paper and degreased cotton nonwoven fabric with the outermost layer being pure cotton degreased cotton nonwoven fabric. This all-cotton spunlace fabric has high tensile strength, strong liquid absorption, good softness, and a certain antibacterial effect.

[0023] The modified degreased cotton is prepared by etherifying the hydroxyl groups in the degreased cotton with vinyl chloride under alkaline conditions, followed by acidification to obtain carboxylated degreased cotton. Further, under the catalysis of N,N'-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP), the carboxyl groups of the carboxylated degreased cotton undergo a coupling reaction with the primary amine of N,N-dimethyl-1,3-diaminopropane to obtain N,N-dimethyl modified degreased cotton. Further, under the catalysis of triethylamine, the tertiary amine groups in the N,N-dimethyl modified degreased cotton are alkylated with bromoethane to obtain modified degreased cotton containing quaternary ammonium salts. The introduction of modified degreased cotton, with its quaternary ammonium salt groups, significantly improves the fabric's hydrophilicity, enhances contact comfort, and imparts antibacterial properties. Furthermore, because the hydroxyl groups in pure cotton fibers carry a negative charge, the nonwoven fabric after spunlace treatment is more robust, has a lower fuzzing rate, is softer, and has higher tensile strength.

[0024] The preparation method of the fluorinated acrylamide copolymer involves using acrylamide and 2-acrylamido-2-methylpropanesulfonic acid as hydrophilic monomers, perfluorooctyl ethyl acrylate as a hydrophobic monomer, and polyethylene glycol monoallyl ether as an amphiphilic monomer. After initiation with an initiator, the fluorinated acrylamide copolymer is obtained. When the fluorinated acrylamide copolymer solution is sprayed onto the surface of absorbent paper and dried, a film with discontinuous island-like hydrophobic regions is formed on the surface of the absorbent paper through hydrophobic association. These locally hydrophobic regions serve two purposes: firstly, during hydroentangling, the discontinuous hydrophobic region structure can disperse the impact of water pressure, reducing fiber loss from the absorbent paper, and also preventing excessive hydroentangling from causing the fibers to become too tightly compressed, thus preventing a decrease in the fluffiness and softness of the nonwoven fabric; secondly, the areas not covered by fluorinated islands retain the capillary channels of the absorbent paper, therefore not hindering liquid absorption, but rather preventing liquid backflow and increasing the absorbency. The sulfonic acid groups in 2-acrylamido-2-methylpropanesulfonic acid not only improve the absorbency of the fabric but also form bonds with the quaternary ammonium salt groups used in pure cotton nonwoven fabrics, increasing the integrity of the spunlace fabric and thus improving tensile strength. However, due to its large steric hindrance, perfluorooctyl ethyl acrylate cannot be further increased in the polymer even with increased monomer addition. Therefore, this invention uses polyethylene glycol monoallyl ether with a molecular weight of 400-1000 as the second hydrophobic monomer. This effectively wets the perfluorooctyl ethyl acrylate monomer, reduces the local chain segment density, and increases the content of the perfluorooctyl ethyl acrylate monomer in the polymer. At the same time, it can also participate in the polymerization reaction, improving the wetting and spreading properties of the fluoroacrylamide copolymer, thereby increasing the tensile strength of the fabric. However, the concentration of the fluoroacrylamide copolymer solution needs to be controlled. If the concentration is too low, it is difficult to trigger hydrophobic association. If the concentration is too high, the local hydrophobic areas are too large and may even merge together, which seriously affects the hydroentangling effect and reduces the liquid absorption. Therefore, the mass ratio of perfluorooctyl ethyl acrylate and polyethylene glycol monoallyl ether is controlled at 3~4:6.

[0025] The hydroentangling process employs a stepped hydraulic pressure technique. Low-pressure hydroentangling pre-wets and pre-entangles the fabric, preventing drastic fiber displacement. High-pressure hydroentangling then effectively improves the overall strength of the fabric. Furthermore, the degreasing process is placed after hydroentangling because degreased cotton exhibits reduced mechanical properties and higher hydrophilicity after degreasing. Hydroentangling requires greater pressure to achieve the same effect, resulting in higher energy consumption. Additionally, the inclusion of degreased cotton in the pure cotton fibers promotes uniformity in hydroentangling. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that the following quantities are by weight. There are no special restrictions on the manufacturers from which the raw materials involved in this invention can be purchased. Exemplary examples include: chloroacetic acid (CAS number: 79-11-8); N,N-dimethyl-1,3-diaminopropane (CAS number: 109-55-7); N,N'-dicyclohexylcarbodiimide (CAS number: 538-75-0); 4-dimethylaminopyridine (CAS number: 1122-58-3); triethylamine (CAS number: 121-44-8); and bromoethane (CAS number: ). : 74-96-4; Acrylamide CAS number: 79-06-1; 2-Acrylamido-2-methylpropanesulfonic acid CAS number: 15214-89-8; Perfluorooctyl ethyl acrylate CAS number: 27905-45-9; Polyethylene glycol monoallyl ether has a molecular weight of 800; Pure cotton, impurity content <1%, fiber length 30mm, fineness 1.2dtex; Degreased cotton is pure cotton prepared by a degreasing process; Absorbent cotton paper, model FF-390, basis weight 20g / m² 2 Provided by Shenzhen Renshan Technology Co., Ltd.

[0028] In the following examples, parts refer to parts by weight, and all raw materials mentioned above and others not mentioned are commercially available; wherein, the degreasing process is carried out according to the method provided by patent CN113529402A.

[0029] Example 1: A method for preparing a soft, tensile-resistant all-cotton spunlace fabric includes the following steps:

[0030] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0031] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0032] Step 3: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0033] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0034] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2.5, laid flat, and subjected to a hydroentangling treatment at a water pressure of 90 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0035] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with a water pressure of 40 bar, and then perform a second hydroentangling treatment with a water pressure of 130 bar, and dry to obtain a soft and tensile-resistant all-cotton hydroentangled fabric.

[0036] Example 2: A method for preparing a soft, tensile-resistant all-cotton spunlace fabric includes the following steps:

[0037] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0038] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0039] Step 3: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0040] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0041] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2, laid flat, and subjected to a hydroentangling treatment at a water pressure of 100 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0042] S2: Alternately stack degreased cotton nonwoven fabric and cotton paper (the number of alternating stacking layers is three times), with the outermost layer having degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with water pressure of 50 bar, and then perform a second hydroentangling treatment with high-pressure hydroentangling treatment with water pressure of 120 bar, and dry to obtain soft and tensile-resistant all-cotton hydroentangled fabric.

[0043] Example 3: A method for preparing a soft, tensile-resistant all-cotton spunlace fabric includes the following steps:

[0044] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0045] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0046] Step 3: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0047] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0048] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:3, laid flat, and subjected to a hydroentangling treatment at a water pressure of 80 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0049] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment at 35 bar, then perform a second hydroentangling treatment at 150 bar, and dry to obtain a soft, tensile-resistant all-cotton hydroentangled fabric.

[0050] Comparative Example 1: Based on Example 1, the degreased cotton was not modified, and the remaining processes remained unchanged, as follows:

[0051] Step 1: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0052] Step 2: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0053] Step 3: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0054] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2.5, laid flat, and subjected to a hydroentangling treatment at a water pressure of 90 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0055] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with a water pressure of 40 bar, and then perform a second hydroentangling treatment with a water pressure of 130 bar, and dry to obtain a soft and tensile-resistant all-cotton hydroentangled fabric.

[0056] Comparative Example 2: Based on Example 1, without the addition of polyethylene glycol monoallyl ether, the remaining processes remain unchanged, as follows:

[0057] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0058] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts sodium dodecyl sulfonate to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0059] Step 3: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0060] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0061] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2.5, laid flat, and subjected to a hydroentangling treatment at a water pressure of 90 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0062] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with a water pressure of 40 bar, and then perform a second hydroentangling treatment with a water pressure of 130 bar, and dry to obtain a soft and tensile-resistant all-cotton hydroentangled fabric.

[0063] Comparative Example 3: Based on Example 1, the ratio of perfluorooctyl ethyl acrylate and polyethylene glycol monoallyl ether was changed, while the rest of the process remained unchanged, as follows:

[0064] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0065] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.3 parts perfluorooctyl ethyl acrylate and 0.18 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0066] Step 3: Preparation of cotton paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 250mg / L, which is then evenly sprayed onto the surface of absorbent cotton paper and dried to obtain cotton paper.

[0067] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0068] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2.5, laid flat, and subjected to a hydroentangling treatment at a water pressure of 90 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0069] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with a water pressure of 40 bar, and then perform a second hydroentangling treatment with a water pressure of 130 bar, and dry to obtain a soft and tensile-resistant all-cotton hydroentangled fabric.

[0070] Comparative Example 4: Based on Example 1, the concentration of the fluoroacrylamide copolymer was increased, while the rest of the process remained unchanged, as follows:

[0071] Step 1: Preparation of modified degreased cotton: (1) Add 100 parts of degreased cotton and 9.5 parts of chloroacetic acid to 200 parts of 20wt% sodium hydroxide solution, stir at 65℃ for 8h, wash, acidify and dry to obtain carboxyl-modified degreased cotton; (2) Add 100 parts of carboxyl-modified degreased cotton, 11 parts of N,N-dimethyl-1,3-diaminopropane, 22 parts of N,N'-dicyclohexylcarbodiimide and 12 parts of 4-dimethylaminopyridine to 150 parts of tetrahydrofuran and mix evenly, stir at 25℃ for 4.5h, filter, wash and dry to obtain N,N-dimethyl-modified degreased cotton; (3) Add 100 parts of N,N-dimethyl-modified degreased cotton, 10.5 parts of triethylamine and 11.5 parts of bromoethane to 40wt% ethanol aqueous solution, stir at 60℃ for 32h, filter, wash and dry to obtain modified degreased cotton;

[0072] Step 2: Preparation of fluorinated acrylamide copolymer: (1) Add 15 parts acrylamide and 2.5 parts 2-acrylamido-2-methylpropanesulfonic acid to 100 parts deionized water and stir evenly. Adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add 0.18 parts perfluorooctyl ethyl acrylate and 0.3 parts polyethylene glycol monoallyl ether to 10 parts deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and hydrophilic reaction monomer solution B evenly, add 0.1 wt% of initiator NaHSO3-K2S2O8 (molar ratio of oxidant to reducing agent is 1:2), stir at 25℃ for 4 h, filter, wash and dry to obtain fluorinated acrylamide copolymer;

[0073] Step 3: Preparation of absorbent paper: Fluoroacrylamide copolymer is added to 60wt% ethanol aqueous solution to prepare a solution with a concentration of 600mg / L, which is then evenly sprayed onto the surface of absorbent paper and dried to obtain absorbent paper;

[0074] Step 4: Preparation of soft, tensile-resistant spunlace cotton fabric:

[0075] S1: Modified degreased cotton and pure cotton are mixed at a mass ratio of 10:2.5, laid flat, and subjected to a hydroentangling treatment at a water pressure of 90 bar, followed by drying; degreasing and further drying are then performed to obtain degreased cotton nonwoven fabric (weight 30 g / m²). 2 );

[0076] S2: Alternately layer degreased cotton nonwoven fabric and cotton paper (the number of alternating layers is three times), with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; first, perform low-pressure hydroentangling treatment with a water pressure of 40 bar, and then perform a second hydroentangling treatment with a water pressure of 130 bar, and dry to obtain a soft and tensile-resistant all-cotton hydroentangled fabric.

[0077] Performance Test 1: The performance of the sample from Example 1 was tested according to GB / T 40276-2021. The experimental data are shown in Table 1.

[0078] Table 1

[0079]

[0080] As shown in Table 1, this invention obtains degreased cotton nonwoven fabric by spunlace using pure cotton and modified degreased cotton as pure cotton raw materials, obtains cotton paper by spraying a fluoroacrylamide copolymer solution onto the surface of absorbent cotton paper and then drying it, and prepares the all-cotton spunlace fabric by alternating layers of cotton paper and degreased cotton nonwoven fabric with the outermost layer being pure cotton degreased cotton nonwoven fabric. This all-cotton spunlace fabric has high tensile strength, strong liquid absorption, good softness, and a certain antibacterial effect.

[0081] Performance test 2: (1) The fracture strength of the samples of each embodiment and comparative example was tested according to GB / T 24218.3-2010. The sample width was 50 mm and the tensile rate was 100 mm / min. (2) The absorption of the samples of each embodiment and comparative example was tested according to GB / T 24218.6-2010. The sample size was 100 mm × 100 mm. The experimental data are shown in Table 2.

[0082] Table 2

[0083]

[0084] As shown in Table 2, in Comparative Example 1, the unmodified absorbent cotton had reduced hydrophilicity and lacked chemical bonding, resulting in decreased tensile strength and liquid absorption. In Comparative Example 2, without the addition of polyethylene glycol monoallyl ether, the lack of wetting effect from polyethylene glycol monoallyl ether led to greater steric hindrance. With the same amount of perfluorooctyl ethyl acrylate, sodium dodecyl sulfonate was insufficient to promote its increase in polymer content, thus reducing tensile strength and liquid absorption. In Comparative Example 3, by changing the ratio of perfluorooctyl ethyl acrylate to polyethylene glycol monoallyl ether, the performance was clearly inferior to Example 1. In Comparative Example 4, increasing the concentration of fluoroacrylamide copolymer resulted in excessively large local hydrophobic regions, which even merged, severely affecting the hydroentangling effect, significantly reducing tensile strength, and decreasing liquid absorption.

[0085] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a soft, tensile-resistant, all-cotton spunlace fabric, characterized in that: Includes the following steps: S1: (1) Carboxylation modification of degreased cotton; then N,N-dimethyl-1,3-diaminopropane is used to modify it into a tertiary amine; finally, it is quaternized to obtain modified degreased cotton; (2) Modified degreased cotton and pure cotton are mixed in proportion, laid flat, hydroentangled once, and dried; degreased and dried again to obtain degreased cotton nonwoven fabric; S2: Alternately layer degreased cotton nonwoven fabric and cotton paper, with the outermost layer consisting of degreased cotton nonwoven fabric on both sides; perform secondary hydroentanglement treatment and dry to obtain soft, tensile-resistant all-cotton hydroentangled fabric. The preparation method of modified degreased cotton is as follows: (1) Add degreased cotton and chloroacetic acid to sodium hydroxide solution, stir at 60~70℃ for 7~8h, wash, acidify and dry to obtain carboxyl modified degreased cotton; (2) Add carboxyl modified degreased cotton, N,N-dimethyl-1,3-diaminopropane, N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine to tetrahydrofuran and mix evenly, stir at 20~25℃ for 4~5h, filter, wash and dry to obtain N,N-dimethyl modified degreased cotton; (3) Add N,N-dimethyl modified degreased cotton, triethylamine and bromoethane to an ethanol aqueous solution, stir at 60~65℃ for 30~40h, filter, wash and dry to obtain modified degreased cotton.

2. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 1, characterized in that: In step S2, the alternating layering is performed ≥3 times; the basis weight of the degreased cotton nonwoven fabric is 15~50 g / m². 2 The weight of cotton paper is 15~25g / m³. 2 .

3. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 1, characterized in that: The raw materials of the degreased cotton nonwoven fabric are modified degreased cotton and pure cotton in a ratio of (2~3):

10.

4. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 1, characterized in that: The carboxyl-modified degreased cotton comprises the following raw materials, by mass: 100 parts degreased cotton, 9-10 parts chloroacetic acid, and 180-200 parts 15-20 wt% sodium hydroxide solution; The N,N-dimethyl modified degreased cotton comprises the following raw materials, by mass parts: 100 parts carboxyl modified degreased cotton, 10-12 parts N,N-dimethyl-1,3-diaminopropane, 21-23 parts N,N'-dicyclohexylcarbodiimide, 11-13 parts 4-dimethylaminopyridine, and 130-150 parts tetrahydrofuran; The modified degreased cotton comprises the following raw materials, by mass: 100 parts N,N-dimethyl modified degreased cotton, 10-11 parts triethylamine, 11-12 parts bromoethane, and 35-40 wt% ethanol aqueous solution.

5. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 1, characterized in that: The water pressure for the first hydroentangling treatment is 80~100 bar; the specific process for the second hydroentangling treatment is as follows: first, low-pressure hydroentangling treatment at a water pressure of 35~50 bar, and then high-pressure hydroentangling treatment at a water pressure of 120~150 bar.

6. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 1, characterized in that: The method for preparing the cotton paper is as follows: a fluoroacrylamide copolymer is prepared into a solution, uniformly sprayed onto the surface of absorbent cotton paper, and dried to obtain cotton paper; wherein, the concentration of the fluoroacrylamide copolymer is 200~300mg / L, and the solvent is a 50~70wt% aqueous ethanol solution.

7. The method for preparing a soft, tensile-resistant spunlace cotton fabric according to claim 6, characterized in that: The preparation method of the fluorinated acrylamide copolymer includes the following steps: (1) Add acrylamide and 2-acrylamido-2-methylpropanesulfonic acid to deionized water and stir evenly, adjust the pH to 6.5±0.3 to obtain reaction monomer solution A; (2) Add perfluorooctyl ethyl acrylate and polyethylene glycol monoallyl ether to deionized water and stir evenly to obtain reaction monomer solution B; (3) Under a nitrogen atmosphere, mix reaction monomer solution A and reaction monomer solution B evenly, add 0.1~0.2wt% of initiator, stir at 25~30℃ for 4~4.5h, filter, wash and dry to obtain fluorinated acrylamide copolymer.

8. The method for preparing a soft, tensile-resistant, all-cotton spunlace fabric according to claim 7, characterized in that: The raw materials for the fluorinated acrylamide copolymer include, by weight, 14-16 parts acrylamide, 2-3 parts 2-acrylamido-2-methylpropanesulfonic acid, 0.15-0.2 parts perfluorooctyl ethyl acrylate, 0.3 parts polyethylene glycol monoallyl ether, and 0.05-0.1 parts initiator; wherein the polyethylene glycol monoallyl ether has a molecular weight of 400-1000.

9. A soft, tensile-resistant, all-cotton spunlace fabric, characterized in that: The soft, tensile-resistant spunlace cotton fabric is prepared by the preparation method according to any one of claims 1 to 8.

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