Easily-dyed cotton fiber underwear fabric and preparation method thereof
By using epoxy quaternary ammonium salt and microwave treatment technology in textile cotton fibers, the problems of poor hygroscopicity and uneven dyeing are solved, the dyeing performance and color fastness of the fibers are improved, and the environmentally friendly and clean dyeing process is achieved.
Patent Information
- Application Number
- CN202411256531.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-27
AI Technical Summary
The existing impurities in the dyeing process of textile cotton fibers lead to poor hygroscopicity and uneven dyeing. In addition, traditional chemical modification methods use toxic chemical reagents to pollute the environment, making it difficult to achieve environmental protection and clean production.
The modified cotton fibers were treated with epoxy quaternary ammonium salt under microwave conditions, and impurities were removed in supercritical carbon dioxide medium by sonication of cetaceanol polyoxyethylene ether-10 and alkaline pectin lyase, and Epoxy quaternary ammonium salt is used to promote the hydrophilicity and color fastness of cellulose under microwave.
It achieves the easy dyeing effect of fibers and improves color fastness, avoids environmental pollution, and meets the requirements of green processing and clean production.
Smart Images
Figure BDA0005034261550000071
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of textiles, in particular to an easily dyeable cotton fiber underwear fabric and a preparation method thereof. Background Art
[0002] Skin is the largest organ of the human body. It can resist most viruses and bacteria in the external environment and is the first line of defense for the human body. Underwear, as clothing that is in direct contact with the skin, still becomes the second layer of skin for the human body and a barrier to protect the safety of the human body. Its health, safety, and skin care effects undoubtedly add a protective lock to people's health. Underwear made of cotton fibers is undoubtedly very comfortable, but in addition to 94% of cellulose fibers, cotton fibers also contain 6% impurities (cellulose symbionts such as pectin, wax, and ash). When using cotton fibers, it is necessary to remove impurities such as wax and pectin as much as possible. If the above impurities exist, it will bring difficulties to the dyeing and finishing of cotton fabrics, such as uneven dyeing. The presence of these impurities makes the cotton fibers poor in hygroscopicity and difficult to dye in the later stage. Mechanical methods are mainly used for pre-dyeing and finishing of cotton fibers, and the commonly used means are to apply pressure or grinding. A more effective solution is to increase the amorphous region content of the fiber during grinding to achieve an increase in the dyeing and adsorption performance of the fiber, but doing so will inevitably damage the strength of the fiber. The main means of chemical modification is to react with the surface of cotton fibers through various oxidants, acids, alkalis, etc., so that the active groups on the surface of cotton fibers change, thereby affecting the subsequent dyeing and finishing process. We know that traditional chemical modification sometimes has to use some highly toxic chemical reagents, which causes environmental pollution; in today's advocacy of "green" processing and "clean" production, this is obviously not advisable. In order to focus on environmental protection, scientific and sustainable development, it is necessary to use mild modification methods such as biological enzymes to treat cotton fibers. Summary of the invention
[0003] The object of the present invention is to provide an easily dyeable cotton fiber underwear fabric and a preparation method thereof, so as to solve the problems existing in the prior art.
[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: an easily dyeable cotton fiber underwear fabric, wherein the easily dyeable cotton fiber underwear fabric is prepared by treating modified cotton fiber with epoxy quaternary ammonium salt under microwave conditions.
[0005] Furthermore, a method for preparing an easily dyeable cotton fiber underwear fabric comprises the following preparation steps:
[0006] (1) Cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, subjected to 21kHz ultrasound for 10 to 30 minutes, added to cotton fibers, and processed in a supercritical carbon dioxide fluid medium, and then washed with deionized water for 3 times, and dried at 60 to 90°C for 1 to 2 hours to obtain modified cotton fibers;
[0007] (2) Epoxy quaternary ammonium salt, sodium hydroxide and deionized water are mixed, ultrasonicated at 21 kHz for 10 to 30 minutes, added to modified cotton fiber, subjected to microwave treatment, then washed with deionized water for 3 times, dried at 30 to 48° C. for 6 to 10 hours, and finally woven to obtain easily dyeable cotton fiber underwear fabric.
[0008] Furthermore, the specification of the alkaline pectin lyase in step (1) is 500u / mg.
[0009] Furthermore, the process conditions of step (1) are as follows: temperature of 50°C, pressure of 20 MPa, dynamic / static cycle time distribution ratio of 1 min / 4 min, and time of 60 min.
[0010] Furthermore, in step (1), the mass ratio of the cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase mixture, and cotton fiber is 0.5-1:8-15:0.02-0.05:13.
[0011] Furthermore, the preparation method of the epoxy quaternary ammonium salt in step (2) is as follows: under a nitrogen atmosphere, N,N,N',N",N"-pentamethyldiethylenetriamine and ethanol are mixed in a mass ratio of 6 to 10:6, placed in an ice-water bath, stirred at 200 to 500 rpm, and epichlorohydrin with a mass of 2 to 3 times that of N,N,N',N",N"-pentamethyldiethylenetriamine is added dropwise at 0.1 to 0.8 mL / s, and stirring is continued for 20 to 50 min. At 20 to 30° C., the reaction is carried out for 3 to 6 h. Under the conditions of 40 to 70° C., a vacuum degree of 0.09 MPa, and a rotation speed of 100 to 300 rpm, the solvent is removed by rotary evaporation until the solution becomes viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30° C. for 24 h.
[0012] Furthermore, in step (2), the microwave power is 400-600 W and the time is 10-30 min.
[0013] Furthermore, in step (2), the ratio of the epoxy quaternary ammonium salt, sodium hydroxide, deionized water, and modified cotton fiber is 1:0.1-0.4:10-15:3.
[0014] Furthermore, the temperature of the deionized water used for washing in step (2) is 5 to 20°C.
[0015] Furthermore, the weight of the easily dyeable cotton fiber underwear fabric in step (2) is 50 to 80 g / m 2 .
[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention utilizes cetearyl alcohol polyoxyethylene ether-10 to reduce the surface tension of cotton fibers when alkaline pectin lyase is used to pretreat cotton fibers, and does not bind to enzyme proteins or interfere with the three-dimensional structure of the enzyme, thereby helping enzyme molecules to penetrate into micropores and cracks on the surface of cotton fibers, thereby promoting the decomposition and removal of pectin impurities on the surface and inside of the cotton fibers, and orienting itself toward a position that is favorable for catalysis, and at the same time, in a supercritical carbon dioxide fluid medium, more thoroughly removes fine impurities adhering to the surface of the cotton fibers, thereby exposing cellulose to the atmosphere. Then, under the action of microwave irradiation, short carbon chain epoxy quaternary ammonium salt is effectively infiltrated into the fiber. Under alkaline conditions, the hydroxyl groups on the fiber are promoted to generate negatively charged oxygen anions, which react with the epoxy groups on the epoxy quaternary ammonium salt to produce nucleophilic reactions, thereby cationizing the cellulose and enhancing the hydrophilicity of the fiber. The grafted quaternary nitrogen cations or protonated amine groups can adsorb some negatively charged substances, and the high temperature environment generated by microwaves causes the cellulose to swell, which promotes the penetration of the active substances into the fiber, thereby enhancing the color fastness of the dyed fabric. DETAILED DESCRIPTION
[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0018] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the test methods of various indicators of the easily dyeable cotton fiber underwear fabrics prepared in the following examples are as follows:
[0019] Dyeability: Take the embodiment and comparative example of the same size, immerse them completely in deionized water at a ratio of 1:50, heat to 40°C, add Levafix reactive blue dye (dye dosage is 3.4% (owf)) and sodium sulfate (40 g / L) in sequence, heat to 60°C at a rate of 1°C / min, add soda ash (20 g / L), keep warm for 60 min, take out the sample, wash with deionized water for 5 min, then soak in 80°C, 2g / L soap solution for 10 min, wash with deionized water for 5 min, and dry at 90°C for use; use spectrophotometer UltrascanPRO to test the dyeing effect and record its color index.
[0020] Color fastness: The dyed embodiments and comparative examples were used, with reference to GB / T3920, and the dry and wet rubbing color fastness were tested by Y571 electric friction fastness tester, and rated with gray sample cards; and with reference to GB / T3921, the sample and a soap solution containing 5 g / L soap flakes and 2 g / L sodium carbonate were added into the washing cup of SW-12 washing color fastness tester at a bath ratio of 1:50, washed at 40°C for 30 min, and then rated with gray sample cards for staining.
[0021] Example 1
[0022] (1) Cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, subjected to 21kHz ultrasound for 10 minutes, added to cotton fibers, and processed in a supercritical carbon dioxide fluid medium, wherein the process parameters are as follows: temperature of 50°C, pressure of 20MPa, dynamic / static cycle time distribution ratio of 1min / 4min, time of 60min, and then washed with deionized water for 3 times, and dried at 60°C for 1h to obtain modified cotton fibers; the mass ratio of the mixture of cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase, and cotton fibers is 0.5:8:0.02:13;
[0023] (2) Under nitrogen atmosphere, N,N,N',N",N"-pentamethyldiethylenetriamine and ethanol were mixed in a mass ratio of 6:6, placed in an ice water bath, stirred at 200 rpm, and epichlorohydrin (twice the mass of N,N,N',N",N"-pentamethyldiethylenetriamine) was added dropwise at 0.1 mL / s, and stirred for 20 min. The mixture was reacted at 20°C for 3 h. The mixture was heated at 40°C, vacuum degree of 0.09 MPa, and rotation speed of 100 rpm. Under the condition of 100 ° C, the solvent was evaporated until the solution became viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30 ° C for 24 hours to obtain epoxy quaternary ammonium salt; epoxy quaternary ammonium salt, sodium hydroxide and deionized water were mixed, ultrasonicated at 21kHz for 10 minutes, modified cotton fiber was added, and microwave treatment was performed with a power of 400 W and a time of 10 minutes, and then washed with deionized water at 5 ° C for 3 times, dried at 30 ° C for 6 hours, and finally woven to obtain a gram weight of 50g / m 2 Easy-to-dye cotton fiber underwear fabric; the epoxy quaternary ammonium salt, sodium hydroxide, deionized water, and modified cotton fiber are in a ratio of 1:0.1:10:3.
[0024] Example 2
[0025] (1) Cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, subjected to 21kHz ultrasound for 20 minutes, added to cotton fibers, and processed in a supercritical carbon dioxide fluid medium, wherein the process parameters are as follows: temperature of 50°C, pressure of 20MPa, dynamic / static cycle time distribution ratio of 1min / 4min, time of 60min, and then washed with deionized water for 3 times, and dried at 80°C for 1.5h to obtain modified cotton fibers; the mass ratio of the mixture of cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase, and cotton fibers is 0.75:12:0.04:13;
[0026] (2) Under nitrogen atmosphere, N,N,N',N",N"-pentamethyldivinyltriamine and ethanol were mixed in a mass ratio of 8:6, placed in an ice water bath, stirred at 400 rpm, and epichlorohydrin (2.5 times the mass of N,N,N',N",N"-pentamethyldivinyltriamine) was added dropwise at 0.4 mL / s, and stirred for 30 min. The mixture was reacted at 25°C for 4 h, and then heated at 50°C, a vacuum degree of 0.09 MPa, and a rotation speed of 200 rpm. Under the conditions, the solvent was evaporated until the solution became viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30°C for 24 hours to obtain epoxy quaternary ammonium salt; epoxy quaternary ammonium salt, sodium hydroxide, and deionized water were mixed, ultrasonicated at 21kHz for 20 minutes, modified cotton fiber was added, and microwave treatment was performed with a power of 500W and a time of 20 minutes, and then washed with deionized water at 10°C for 3 times, dried at 39°C for 8 hours, and finally woven to obtain a gram weight of 60g / m 2 Easy-to-dye cotton fiber underwear fabric; the epoxy quaternary ammonium salt, sodium hydroxide, deionized water, and modified cotton fiber are in a ratio of 1:0.2:13:3.
[0027] Example 3
[0028] (1) Cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, subjected to 21kHz ultrasound for 30 minutes, added to cotton fibers, and processed in a supercritical carbon dioxide fluid medium, wherein the process parameters are as follows: temperature of 50°C, pressure of 20MPa, dynamic / static cycle time distribution ratio of 1min / 4min, time of 60min, and then washed with deionized water for 3 times, and dried at 90°C for 2h to obtain modified cotton fibers; the mass ratio of the mixture of cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase, and cotton fibers is 1:15:0.05:13;
[0029] (2) Under nitrogen atmosphere, N,N,N',N",N"-pentamethyldiethylenetriamine and ethanol were mixed in a mass ratio of 10:6, placed in an ice water bath, stirred at 500 rpm, and epichlorohydrin (3 times the mass of N,N,N',N",N"-pentamethyldiethylenetriamine) was added dropwise at 0.8 mL / s, and stirred for 50 min. The mixture was reacted at 30°C for 6 h. The mixture was heated at 70°C, vacuum degree of 0.09 MPa, and rotation speed of 300 rpm. Under the condition of 100%, the solvent was evaporated until the solution became viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30°C for 24 hours to obtain epoxy quaternary ammonium salt; epoxy quaternary ammonium salt, sodium hydroxide and deionized water were mixed, ultrasonicated at 21kHz for 30 minutes, modified cotton fiber was added, and microwave treatment was performed with a power of 600W and a time of 30 minutes, and then washed with deionized water at 20°C for 3 times, dried at 48°C for 10 hours, and finally woven to obtain a gram weight of 80g / m 2 Easy-to-dye cotton fiber underwear fabric; the epoxy quaternary ammonium salt, sodium hydroxide, deionized water, and modified cotton fiber are in a ratio of 1:0.4:15:3.
[0030] Comparative Example 1
[0031] The difference between Comparative Example 1 and Example 2 is that step (1) is different. Step (1) is changed to: ethanol and alkaline pectin lyase are mixed, 21kHz ultrasound is applied for 20 minutes, cotton fibers are added, and process treatment is carried out in a supercritical carbon dioxide fluid medium. The process parameters are: temperature of 50°C, pressure of 20MPa, dynamic / static cycle time distribution ratio of 1min / 4min, time of 60min, and then washed with deionized water 3 times, and dried at 80°C for 1.5h to obtain modified cotton fibers; the mass ratio of the ethanol, alkaline pectin lyase mixture and cotton fibers is 12:0.04:13; the remaining steps are the same as in Example 2.
[0032] Comparative Example 2
[0033] The difference between Comparative Example 2 and Example 2 is that step (1) is different. Step (1) is changed to: mix cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase, ultrasonicate at 21kHz for 20min, add cotton fiber, react in a water bath at 50°C for 60min, then wash with deionized water 3 times, and dry at 80°C for 1.5h to obtain modified cotton fiber; the mass ratio of the cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase mixture and cotton fiber is 0.75:12:0.04:13; the remaining steps are the same as Example 2.
[0034] Comparative Example 3
[0035] The difference between Comparative Example 3 and Example 2 is that step (1) is omitted; the remaining steps are the same as those of Example 2.
[0036] Comparative Example 4
[0037] The difference between Comparative Example 4 and Example 2 is that step (2) is different. Step (2) is changed to: sodium hydroxide and deionized water are mixed, 21kHz ultrasound is applied for 20 minutes, modified cotton fiber is added, and microwave treatment is performed at a power of 500W for 20 minutes, and then washed three times with deionized water at 10°C, dried at 39°C for 8 hours, and finally woven to obtain a gram weight of 60g / m 2 Easy-to-dye cotton fiber underwear fabric; the sodium hydroxide, deionized water, and modified cotton fiber are 0.2:13:3; the remaining steps are the same as Example 2.
[0038] Comparative Example 5
[0039] The difference between Comparative Example 5 and Example 2 is that step (2) is different. Step (2) is changed to: Under a nitrogen atmosphere, N,N,N',N",N"-pentamethyldiethylenetriamine and ethanol are mixed in a mass ratio of 8:6, placed in an ice water bath, stirred at 400 rpm, and epichlorohydrin (2.5 times the mass of N,N,N',N",N"-pentamethyldiethylenetriamine) is added dropwise at 0.4 mL / s, and stirring is continued for 30 min. The reaction is carried out at 25 ° C for 4 h, and the mixture is heated at 50 ° C and vacuum for 1 h. Under the conditions of 0.09MPa and a rotation speed of 200rpm, the solvent is evaporated until the solution becomes viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30℃ for 24h to obtain epoxy quaternary ammonium salt; epoxy quaternary ammonium salt, sodium hydroxide, and deionized water are mixed, 21kHz ultrasound is used for 20min, modified cotton fiber is added, the temperature is raised to 60℃, the reaction is carried out for 30min, and then washed with deionized water at 10℃ for 3 times, dried at 39℃ for 8h, and finally woven to obtain a gram weight of 60g / m 2 Easy-to-dye cotton fiber underwear fabric; the epoxy quaternary ammonium salt, sodium hydroxide, deionized water, and modified cotton fiber are 1:0.2:13:3; the remaining steps are the same as Example 2.
[0040] Comparative Example 6
[0041] The difference between Comparative Example 6 and Example 2 is that there is no step (2), and step (1) is changed to: cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, 21kHz ultrasound is applied for 20min, cotton fibers are added, and process treatment is carried out in a supercritical carbon dioxide fluid medium. The process parameters are: temperature of 50°C, pressure of 20MPa, dynamic / static cycle time distribution ratio of 1min / 4min, time of 60min, and then washed with deionized water 3 times, dried at 80°C for 1.5h, and finally woven to obtain a gram weight of 60g / m 2 Easy-to-dye cotton fiber underwear fabric; the mass ratio of cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase mixture, and cotton fiber is 0.75:12:0.04:13; the remaining steps are the same as Example 2.
[0042] Effect example
[0043] Table 1 below shows the performance analysis results of the easily dyeable cotton fiber underwear fabrics of Examples 1 to 3 of the present invention and Comparative Examples 1 to 6.
[0044] Table 1
[0045]
[0046] From the comparison of the experimental data of the embodiment and the comparative example in Table 1, it can be found that the present invention uses cetearyl alcohol polyoxyethylene ether-10 to reduce the surface tension of cotton fibers when alkaline pectin lyase is used to pretreat cotton fibers, and does not bind to the enzyme protein or interfere with the three-dimensional structure of the enzyme, thereby helping the enzyme molecules to penetrate into the micropores and cracks on the surface of the cotton fibers, thereby promoting the decomposition and removal of pectin impurities on the surface and inside of the cotton fibers, and orienting itself toward a position that is favorable for catalysis. At the same time, in the supercritical carbon dioxide fluid medium, the fine impurities adhering to the surface of the cotton fibers are removed more thoroughly, so that the cellulose is exposed. Then, under the action of microwave irradiation, short carbon chain epoxy quaternary ammonium salt is effectively infiltrated into the fiber. Under alkaline conditions, the hydroxyl groups on the fiber are promoted to generate negatively charged oxygen anions, which react with the epoxy groups on the epoxy quaternary ammonium salt to produce nucleophilic reactions, thereby cationizing the cellulose and enhancing the hydrophilicity of the fiber. The grafted quaternary nitrogen cations or protonated amine groups can adsorb some negatively charged substances, and the high temperature environment generated by microwaves causes the cellulose to swell, which promotes the penetration of the active substances into the fiber, thereby enhancing the color fastness of the dyed fabric.
[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.
Claims
1. An easily dyeable cotton fiber underwear fabric, characterized in that: The easily dyeable cotton fiber underwear fabric is prepared by treating modified cotton fiber with epoxy quaternary ammonium salt under microwave conditions.
2. A method for preparing easily dyeable cotton fiber underwear fabric, characterized in that: The method comprises the following preparation steps: (1) Cetearyl alcohol polyoxyethylene ether-10, ethanol, and alkaline pectin lyase are mixed, subjected to 21kHz ultrasound for 10 to 30 minutes, added to cotton fibers, and processed in a supercritical carbon dioxide fluid medium, and then washed with deionized water for 3 times, and dried at 60 to 90°C for 1 to 2 hours to obtain modified cotton fibers; (2) Epoxy quaternary ammonium salt, sodium hydroxide and deionized water are mixed, ultrasonicated at 21 kHz for 10 to 30 minutes, added to modified cotton fiber, subjected to microwave treatment, then washed with deionized water for 3 times, dried at 30 to 48° C. for 6 to 10 hours, and finally woven to obtain easily dyeable cotton fiber underwear fabric.
3. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The specification of the alkaline pectin lyase in step (1) is 500u / mg.
4. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The process conditions of step (1) are as follows: temperature of 50° C., pressure of 20 MPa, dynamic / static cycle time distribution ratio of 1 min / 4 min, and time of 60 min.
5. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: In step (1), the mass ratio of the cetearyl alcohol polyoxyethylene ether-10, ethanol, alkaline pectin lyase mixture and cotton fiber is 0.5-1:8-15:0.02-0.05:
13.
6. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The preparation method of the epoxy quaternary ammonium salt in step (2) is as follows: under a nitrogen atmosphere, N,N,N',N",N"-pentamethyldiethylenetriamine and ethanol are mixed in a mass ratio of 6 to 10:6, placed in an ice-water bath, stirred at 200 to 500 rpm, and epichlorohydrin with a mass of 2 to 3 times that of N,N,N',N",N"-pentamethyldiethylenetriamine is added dropwise at 0.1 to 0.8 mL / s, and stirring is continued for 20 to 50 min. At 20 to 30° C., the reaction is carried out for 3 to 6 h. Under the conditions of 40 to 70° C., a vacuum degree of 0.09 MPa, and a rotation speed of 100 to 300 rpm, the solvent is removed by rotary evaporation until the solution becomes viscous, and then washed with petroleum ether and filtered, repeated three times, and dried at 30° C. for 24 h.
7. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The microwave power in step (2) is 400-600W and the time is 10-30min.
8. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The epoxy quaternary ammonium salt, sodium hydroxide, deionized water and modified cotton fiber in step (2) are in a ratio of 1:0.1-0.4:10-15:
3.
9. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The temperature of the deionized water used for washing in step (2) is 5 to 20°C.
10. The method for preparing an easily dyeable cotton fiber underwear fabric according to claim 2, characterized in that: The weight of the easily dyeable cotton fiber underwear fabric in step (2) is 50 to 80 g / m 2 .