Preparation method and application of cationic bio-based environmentally friendly sizing agent for nylon

Abstract

This invention discloses a method for preparing and applying a cationic bio-based environmentally friendly slurry for nylon. The method involves synthesizing a quaternary ammonium salt cationic modifier, then sizing the nylon fabric to introduce positive groups such as quaternary ammonium salt groups, thereby reducing the electrostatic repulsion between the fiber and the dye molecules. Finally, the method is applied to inkjet printing of nylon fabric. By rationally regulating the surface and interfacial properties between the functional nylon-slurry-ink droplets, the method reduces ink bleed-through on the nylon fabric surface, improves color vividness and pattern refinement, and reduces ink usage during digital inkjet printing, achieving energy conservation and emission reduction. This method is suitable for the large-scale production of high-quality nylon and functional nylon fabric products.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of a cationic bio-based environmentally friendly slurry used for nylon and functional nylon. Background Art

[0002] Nylon is the second most popular chemical fiber after polyester. Textiles made from it have a wide demand and market in everyday clothing, sportswear, and outdoor protection. Functional nylon is a graphene-nylon composite fiber. In addition to its excellent mechanical properties such as high strength, high modulus, and wear resistance, it also possesses multifunctional properties such as far-infrared thermal insulation, antibacterial and anti-mite properties, antistatic properties, and UV protection. As a functional material, it is widely used in sportswear, swimwear, down jackets, and mountaineering clothing, and is also used in uniforms for events such as the Olympics.

[0003] Compared to traditional printing and dyeing processes, textile inkjet printing technology is becoming increasingly popular and important due to its lower resource consumption, higher image quality, and reduced wastewater discharge. Inkjet printing produces liquid ink droplets, which are deposited on a substrate in a specific pattern. When the liquid contains a colorant, an image is created. However, the porosity, roughness, and thickness of the fabric significantly limit the quality of inkjet printing. Digital printing on functional nylon, which is inherently gray, suffers from insufficient color vividness. Furthermore, functional nylon fibers have a smooth surface and are relatively thin. If fabric treatment and ink control are not performed to perfection, post-processing such as steaming and washing can lead to surface bleed-through or a lack of vibrant color. This can also result in whitening and uneven coloring after digital printing. Therefore, to reduce ink bleed-through on the fabric surface and improve printing accuracy, color intensity, and fixation, the fabric requires sizing and cationic modification.

[0004] Conventional printing pretreatment agents currently used are mostly acrylic copolymers, sodium hydroxymethyl cellulose, and sodium alginate. However, in the process of preparing the slurry, additives such as urea, salt, and alkali are usually needed to help expand the fibers and help the dye develop or fix its color. For inkjet printing pretreatment processes, traditional sizing has certain disadvantages. For example, the use of thickeners in the slurry will change the physical properties and feel of the fabric to a certain extent. At the same time, when the slurry is applied to the fabric surface by padding, a large amount of waste liquid is generated, causing environmental pollution and waste of resources. Therefore, how to reduce the addition of salt and alkali additives, use clean production technology, and prepare environmentally friendly slurries for textile materials have become research and development focuses.

[0005] Currently, chitosan, as a high-tech green material, has been studied by many scholars due to its good biocompatibility, antibacterial and biodegradability. CN102409534A used chitosan solution to treat cotton fabric under acidic conditions and found that chitosan molecules can spontaneously transfer from the solution to the fiber, but it does not affect the internal structure of the fiber. The introduction of amino groups greatly improves the adsorption rate of pigments. CN105178063A constructed a pure bio-based coating by depositing chitosan and ammonium phytate layer by layer, giving the fabric certain antibacterial and flame retardant effects, and also improving the tensile properties of cotton fabrics. In recent years, some people have tried to apply chitosan to inkjet printing and have achieved certain results. CN108947346A used chitosan to prepare a slurry for inkjet printing fabric pretreatment. Experiments confirmed that chitosan can achieve better color performance when applied to fabric inkjet printing, but the use of chitosan will slightly reduce the tensile strength of the fabric. In existing research, chitosan has made progress in dye dyeing, but there is still a lot of room for exploration in its application in dye inkjet printing. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a preparation method and application of a cationic bio-based environmentally friendly slurry for nylon, so as to improve the problems of fabric surface penetration and low color vividness during inkjet printing of nylon fabric. When the slurry is used to size nylon fabric, the fabric surface penetration is reduced, the printing accuracy is improved, and the color fastness and color depth are improved.

[0007] For functional nylon fabrics, we have researched and developed a cationic bio-based environmentally friendly sizing system to regulate the interface relationship between nylon, sizing and ink droplets, promote the adsorption and fixation of dye molecules, ensure the color vividness and color uniformity of digitally printed functional nylon fabrics, improve the color fixation rate, reduce the number of washing times, and achieve the goal of saving water and energy.

[0008] The invention uses chitosan as raw material, grafts amide groups, and then introduces quaternary ammonium groups on the grafted chitosan to prepare chitosan-acrylamide-quaternary ammonium salt copolymers with different grafting rates. The copolymers are subjected to a double-dipping and double-padding sizing treatment on nylon fabrics, and then used for inkjet printing of functional nylon fabrics.

[0009] The preparation and application of a functional nylon special environmentally friendly slurry includes the following steps:

[0010] (1) Weigh a certain amount of chitosan and place it in a flask. Add an appropriate amount of acetic acid solution, stir mechanically and heat under a nitrogen atmosphere.

[0011] (2) Subsequently, the oxidant solution, the reducing agent solution, and the acrylamide monomer were added to the flask simultaneously, and the reaction was stirred under nitrogen for 3-6 hours. Finally, the terminator was added and stirred for 20-30 minutes. The suspension was filtered, washed and filtered repeatedly with ethanol, and dried in a vacuum oven until the quality was stable, thereby obtaining grafted chitosan.

[0012] (3) Add the grafted chitosan to a flask and soak it in isopropyl alcohol to fully swell it. Dissolve 3-chloro-2-hydroxypropyldimethylbutane ammonium chloride in deionized water and slowly pour it into the flask while stirring continuously. Stir and react at 80°C for 20-24 hours. After the reaction is complete, filter the liquid, soak the remaining solid in ethanol, wash it, filter it, and dry it in a vacuum oven until the quality is stable to obtain chitosan quaternary ammonium salt.

[0013] (4) Chitosan quaternary ammonium salt, acetic acid and urea are added to deionized water and stirred uniformly to obtain a functional nylon-specific environmentally friendly slurry. The present invention first synthesizes a quaternary ammonium salt cationic modifier, then performs a sizing treatment on nylon fabric to introduce positive groups such as quaternary ammonium salt groups to reduce the electrostatic repulsion between the fiber and the dye molecules; and finally applies the slurry to nylon fabric inkjet printing.

[0014] The acetic acid solution has a concentration of 0.5-3%, the stirring speed of the mechanical stirring paddle is 600-1200 rpm, and the nitrogen is introduced for 15-30 minutes. More preferably, the acetic acid solution has a concentration of 1-2%, the stirring speed of the mechanical stirring paddle is 1000-1200 rpm, and the nitrogen is introduced for 30 minutes.

[0015] The oxidizing agent is any one of potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, permanganate, and sodium perborate. The oxidizing agent is any one of potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, permanganate, and sodium perborate. The terminator is any one of hydroquinone and p-tert-butylcatechol. More preferably, the oxidizing agent is any one of potassium persulfate, sodium persulfate, and sodium perborate; the reducing agent is any one of sodium bisulfite and sodium sulfite; and the terminator is hydroquinone.

[0016] More preferably, the acrylamide accounts for 10%-50% of the chitosan.

[0017] More preferably, the amount of the oxidant is 0.02-0.05 mol / L, the molar ratio of the oxidant to the reducing agent is 1:1.5-3 (most preferably 1:1.5), and the mass percentage of the terminator to the chitosan is 2-5% (most preferably 3%).

[0018] The isopropyl acetone soaking time is 20-24 hours, the ethanol washing number is 2-6 times, and the chitosan quaternary ammonium salt is placed in a vacuum oven at 75-85° C. and dried until the mass is constant. Further preferably, the isopropyl acetone soaking time is 24 hours, the ethanol washing number is 3 times, and the chitosan quaternary ammonium salt is placed in a vacuum oven and dried at 80° C. until the mass is constant.

[0019] Further preferably, the functional nylon special environmentally friendly slurry contains 1-5% chitosan quaternary ammonium salt, 1-3% acetic acid, 2-5% urea, 87-96% deionized water, and a bath ratio of fabric to aqueous solution of 1:30-50.

[0020] The nylon fabric is subjected to a two-dip, two-pad sizing treatment. The bath ratio of the nylon fabric to the cationic bio-based environmentally friendly sizing agent is 1:15-50. Each immersion time is 20-30 minutes, and the liquid pick-up rate is 70%-80%. The fabric is then dried at 70-80°C for 5-10 minutes. Furthermore, the nylon fabric is further preferably subjected to a two-dip, two-pad sizing treatment. The immersion time is 20 minutes, and the pick-up rate is 70%-80%. The fabric is then dried at 70°C for 10 minutes.

[0021] The obtained functional nylon fabric was then subjected to inkjet printing.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The preparation and application of a functional nylon special environmentally friendly slurry of the present invention promotes the adsorption and fixation of anionic dye molecules, reduces the amount of ink used in the digital printing inkjet process, ensures the color vividness and color uniformity of the digitally printed functional nylon fabric, improves the color fixation rate, reduces the number of water washings, and achieves the goal of saving water and energy.

[0024] (2) The raw material chitosan used in the present invention is a green and environmentally friendly material with good biocompatibility, biodegradability and antibacterial properties. Not only is the raw material easy to obtain, but the prepared nylon-specific environmentally friendly slurry is durable and durable when coated on the fabric surface, thereby improving the inkjet printing performance of the dye and the antibacterial properties of the fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the infrared spectrum of the chitosan-acrylamide-quaternary ammonium salt copolymer prepared in Example 1. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described in detail below through specific embodiments.

[0027] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0028] Example 1:

[0029] A method for preparing a slurry suitable for functional nylon fabrics comprises the following steps:

[0030] (1) Weigh 20 g of chitosan and place it in a flask. Add 40 ml of 1% acetic acid solution and stir evenly with a mechanical stirrer at a speed of 1100 rpm. Pass nitrogen into the flask for 30 min to expel the air.

[0031] (2) When the temperature in the flask reaches 60°C, 5 ml of a 0.045 mol / L oxidizing agent potassium persulfate solution, 5 ml of a 0.0657 mol / L reducing agent sodium bisulfite solution, and 5 g of acrylamide monomer are added to the flask simultaneously, with the mass ratio of acrylamide to chitosan being 25%. The mixture is stirred for 4 h while maintaining nitrogen flow. 0.06 g of a terminator, hydroquinone, is added, the nitrogen flow is turned off, and stirring is continued for 30 min. The reaction is completed. The suspension is filtered, repeatedly washed and filtered with ethanol, and dried in a vacuum oven until the mass is stable to obtain grafted chitosan.

[0032] (3) Add the grafted chitosan into a flask, pour in 50 ml of isopropyl ketone and soak for 24 hours to fully swell it. Dissolve 23.32 g of 3-chloro-2-hydroxypropyldimethylbutane ammonium chloride in deionized water, slowly pour it into the flask and stir continuously, and stir the reaction at a constant speed of 80°C for 24 hours. After the reaction is completed, filter the liquid, soak the remaining solid in ethanol, wash, and filter, repeat three times, and place it in a vacuum oven at 80°C to dry until the quality is stable to obtain chitosan quaternary ammonium salt, which is chitosan-acrylamide-quaternary ammonium salt copolymer. The infrared spectrum of the chitosan-acrylamide-quaternary ammonium salt copolymer prepared in Example 1 is shown as follows: Figure 1 As shown, at 3406cm -1 The broad peaks at 1657 cm are the stretching vibration peaks of -COOH, -CONH-, and -CONH2. -1 The absorption peak intensity at 1380-1430 cm -1 The bending vibration peak intensity of the -NH- group increases, indicating that acrylamide has been connected to the chitosan main chain to form a graft copolymer. -1 A strong absorption peak of CH bending vibration of -CH3 appeared, which indicated that quaternary ammonium salt side chains were introduced into the copolymer.

[0033] (4) Add 2.554 g of chitosan quaternary ammonium salt, 1.276 g of acetic acid and 3.83 g of urea to 120 ml of deionized water and stir evenly to obtain a functional nylon special environmentally friendly slurry.

[0034] Weigh 6g of nylon fabric (with a 1:20 ratio of fabric to functional nylon environmentally friendly sizing agent) and perform a two-dip and two-roll sizing treatment, with each immersion lasting 20 minutes and ensuring a roll-off ratio of 70%-80%. The fabric is then dried in an oven at 70°C for 10 minutes.

[0035] The fabric after sizing is ready for subsequent inkjet printing.

[0036] Example 2:

[0037] A method for preparing a slurry suitable for functional nylon fabrics comprises the following steps:

[0038] (1) Weigh 20 g of chitosan and place it in a flask. Add 40 ml of 1% acetic acid solution and stir evenly with a mechanical stirrer at a speed of 1100 rpm. Pass nitrogen into the flask for 30 min to expel the air.

[0039] (2) When the temperature in the flask reaches 60°C, 5 ml of a 0.045 mol / L oxidizing agent potassium persulfate solution, 5 ml of a 0.0657 mol / L reducing agent sodium bisulfite solution, and 5 g of acrylamide monomer are added to the flask simultaneously, with the mass ratio of acrylamide to chitosan being 25%. The mixture is stirred for 4 h while maintaining nitrogen flow. 0.06 g of a terminator, hydroquinone, is added, the nitrogen flow is turned off, and stirring is continued for 30 min. The reaction is completed. The suspension is filtered, repeatedly washed and filtered with ethanol, and dried in a vacuum oven until the mass is stable to obtain grafted chitosan.

[0040] (3) Add the grafted chitosan to a flask and pour in 50 ml of isopropyl ketone to soak for 24 hours to allow it to fully swell. Dissolve 23.32 g of 3-chloro-2-hydroxypropyldimethylbutane ammonium chloride in deionized water, slowly pour it into the flask while stirring continuously, and react at 80°C at a constant speed for 24 hours. After the reaction is completed, filter the liquid, soak the remaining solid in ethanol, wash, and filter, repeat three times, and place it in a vacuum oven at 80°C to dry until the quality is stable, thereby obtaining chitosan quaternary ammonium salt.

[0041] (4) Add 3.831 g of chitosan quaternary ammonium salt, 1.914 g of acetic acid and 5.745 g of urea to 180 ml of deionized water and stir evenly to obtain a functional nylon special environmentally friendly slurry.

[0042] Weigh 6g of nylon fabric (with a 1:30 ratio of fabric to functional nylon environmentally friendly sizing agent) and perform a two-dip and two-roll sizing treatment, with each immersion lasting 20 minutes and ensuring a roll-off ratio of 70%-80%. The fabric is then dried in an oven at 70°C for 10 minutes.

[0043] Example 3:

[0044] A method for preparing a slurry suitable for functional nylon fabrics comprises the following steps:

[0045] (1) Weigh 20 g of chitosan and place it in a flask. Add 40 ml of 1% acetic acid solution and stir evenly with a mechanical stirrer at a speed of 1100 rpm. Pass nitrogen into the flask for 30 min to expel the air.

[0046] (2) When the temperature in the flask reaches 60°C, 5 ml of a 0.045 mol / L oxidizing agent potassium persulfate solution, 5 ml of a 0.0657 mol / L reducing agent sodium bisulfite solution, and 5 g of acrylamide monomer are added to the flask simultaneously, with the mass ratio of acrylamide to chitosan being 25%. The mixture is stirred for 4 h while maintaining nitrogen flow. 0.06 g of a terminator, hydroquinone, is added, the nitrogen flow is turned off, and stirring is continued for 30 min. The reaction is completed. The suspension is filtered, repeatedly washed and filtered with ethanol, and dried in a vacuum oven until the mass is stable to obtain grafted chitosan.

[0047] (3) Add the grafted chitosan to a flask and pour in 50 ml of isopropyl ketone to soak for 24 hours to allow it to fully swell. Dissolve 23.32 g of 3-chloro-2-hydroxypropyldimethylbutane ammonium chloride in deionized water, slowly pour it into the flask while stirring continuously, and react at 80°C at a constant speed for 24 hours. After the reaction is completed, filter the liquid, soak the remaining solid in ethanol, wash, and filter, repeat three times, and place it in a vacuum oven at 80°C to dry until the quality is stable, thereby obtaining chitosan quaternary ammonium salt.

[0048] (4) Add 6.39 g of chitosan quaternary ammonium salt, 3.18 g of acetic acid and 9.57 g of urea to 300 ml of deionized water and stir evenly to obtain a functional nylon special environmentally friendly slurry.

[0049] Weigh 6g of nylon fabric and apply it to a two-dip and two-roll sizing treatment (with a bath ratio of 1:50 for fabric and functional nylon special environmentally friendly sizing agent). Each immersion lasts 20 minutes, ensuring a roll-off ratio of 70%-80%. The fabric is then dried in an oven at 70°C for 10 minutes.

[0050] Comparative Example 1

[0051] Commercially available polyvinyl alcohol sizing agent, acetic acid, and urea were added to 300 ml of deionized water and stirred evenly to obtain a sizing solution.

[0052] 6 g of fabric was weighed and subjected to a two-immersion and two-rolling sizing treatment (the ratio of fabric to deionized water bath was 1:50). The immersion time was 20 min and the rolling rate was 70%-80%.

[0053] After the nylon fabric was subjected to a double-dipping and double-padding sizing treatment, the fabric was placed in an oven for drying at a temperature of 70°C for 10 minutes.

[0054] The fabric after sizing is ready for subsequent inkjet printing.

[0055] Comparative Example 2

[0056] (1) Weigh 10.1 g of N,N-dimethylbutylamine and add it to 45 ml of 15% hydrochloric acid solution. Deoxygenate the mixture for 20 min and stir evenly at 60°C for 2 h.

[0057] (2) The resulting solution was injected into 20.35 g of epichlorohydrin at a rate of 36 ml / h at 25°C and allowed to react for 2 h. 5 g of acrylamide monomer was added to the flask and stirred at 80°C for 4 h under nitrogen. After the reaction, the liquid was filtered and the remaining solid was soaked, washed, and filtered with ethanol three times. The solid was then dried in a vacuum oven at 80°C until the mass was stable.

[0058] (3) Add 6.39 g of sizing agent, 3.18 g of acetic acid, and 9.57 g of urea to 300 ml of deionized water and stir evenly to obtain a sizing solution.

[0059] Weigh 6g of fabric and perform two-dip and two-roll sizing treatments (fabric to deionized water bath ratio 1:50), with each immersion time of 20 minutes, ensuring a roll-off rate of 70%-80%. Then place the fabric in an oven to dry at 70°C for 10 minutes.

[0060] The fabric after sizing is ready for subsequent inkjet printing.

[0061] Table 1 Properties of various slurries and inkjet printed fabrics

[0062]

[0063] As can be seen from Table 1, the slurry prepared in Example 1 is used for functional nylon inkjet printing, and its performance is better than that of other comparison groups. The slurry has moderate viscosity, and the inkjet printed fabric has high color vividness, good color fastness, good washing and abrasion fastness, and good anti-bleeding effect.

[0064] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing a cationic bio-based environmentally friendly slurry for nylon, characterized in that: The following steps are involved: (1) chitosan and acetic acid were weighed and mixed, mechanically stirred and heated under a nitrogen atmosphere to obtain a chitosan acetic acid solution; (2) then adding an oxidizing agent, a reducing agent, and an acrylamide monomer to the chitosan acetic acid solution, stirring the reaction under nitrogen for 3-6 hours, finally adding a terminator and stirring for 20-30 minutes, filtering the suspension, repeatedly washing and filtering with ethanol, and drying in a vacuum oven to obtain grafted chitosan; (3) adding the grafted chitosan to the reactor, pouring isopropyl ketone into the reactor to soak and fully swell, dissolving 3-chloro-2-hydroxypropyldimethylbutane ammonium chloride in deionized water, pouring it into the reactor and stirring continuously, stirring and reacting at 70-90° C. for 20-24 hours, filtering the liquid after the reaction is completed, soaking the remaining solid in ethanol, washing, filtering, and drying in a vacuum oven to obtain chitosan quaternary ammonium salt; (4) Chitosan quaternary ammonium salt, acetic acid and urea are added to deionized water and stirred evenly to obtain a cationic bio-based environmentally friendly slurry used for nylon.

2. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (1), the stirring speed of the mechanical stirring paddle is 600-1200 rpm.

3. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (2), the oxidant is any one of potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, permanganate, and sodium perborate.

4. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (2), the reducing agent is any one of ferrous sulfate, sodium hypophosphite, oxalic acid, sodium thiosulfate, sodium bisulfite, and sodium sulfite.

5. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (2), the terminator is any one of hydroquinone and p-tert-butylcatechol.

6. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (2), the molar ratio of the oxidant to the reducing agent is 1:1.5-3, the amount of acrylamide added is 10%-50% of the mass of chitosan, and the amount of the terminator added is 0.2-0.5% of the mass of chitosan.

7. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (3), the soaking time in isopropyl tone is 20-24 hours.

8. The method for preparing a cationic bio-based environmentally friendly slurry for nylon according to claim 1, characterized in that: In step (4), the cationic bio-based environmentally friendly slurry used for nylon adopts the following raw materials in percentage by mass:

9. Use of the cationic bio-based environmentally friendly slurry for nylon prepared by the preparation method according to any one of claims 1 to 8 in inkjet printing of nylon fabric.

10. The use according to claim 9, characterized in that include: The nylon fabric is subjected to a double-immersion and double-rolling sizing treatment, the bath ratio of the nylon fabric to the cationic bio-based environmentally friendly sizing agent is 1:15-50, the immersion time for each time is 20-30 minutes, the liquid carrying rate is 70%-80%, and then it is dried at 70-80°C for 5-10 minutes.

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