阅读说明：本技术 植物染料栗子果皮染色制得的棕色莱赛尔面料及其制备方法 (Brown Lyocell fabric prepared by dyeing chestnut peels with vegetable dye and preparation method thereof ) 是由 周凡雨 彭雄义 邓健 董雄伟 李强 蔡亚军 刘仰硕 蔡映杰 于 2020-10-13 设计创作，主要内容包括：本发明涉及植物染料栗子果皮染色制得的棕色莱赛尔面料及其制备方法。本发明通过石油醚从栗子果皮中萃取提取棕色色素粉末,然后再将棕色色素粉末接枝1-氨基-2-硫酸酯乙基砜乙烷；制得改性棕色植物染料粉末；最后,将莱赛尔面料在改性棕色植物染料中进行染色,制得棕色莱赛尔面料。本发明使反应活性低的栗子果皮中的棕色色素变成具有高反应活性天然染料,此外,染色过程不需要加其它媒染剂和促染剂等染料助剂,简化了染色流程,节约了成本,同时减少了染色造成的环境污染；本发明制备的棕色莱赛尔面料具有较高的K/S值,其耐皂洗变色牢度和耐干摩擦色牢度均较高。(The invention relates to brown lyocell fabric prepared by dyeing chestnut peels with vegetable dye and a preparation method thereof. Extracting brown pigment powder from chestnut peels by using petroleum ether, and grafting the brown pigment powder with 1-amino-2-sulfate ethyl sulfone ethane; preparing modified brown plant dye powder; and finally, dyeing the lyocell fabric in a modified brown plant dye to obtain the brown lyocell fabric. The invention changes brown pigment in chestnut peel with low reactivity into natural dye with high reactivity, and in addition, other dye auxiliaries such as mordant, accelerant and the like are not needed in the dyeing process, thereby simplifying the dyeing process, saving the cost and simultaneously reducing the environmental pollution caused by dyeing; the brown lyocell fabric prepared by the method has a high K/S value, and has high soaping color change fastness and dry rubbing color fastness.)

1. The preparation method of the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye is characterized by comprising the following steps of:

(1) preparation of a dyeing solution: dissolving the modified brown plant dye in an aqueous solution to prepare a dyeing solution, and regulating the dyeing solution to 10-11% by using 30wt% NaOH alkali liquor;

(2) dyeing: putting the lyocell fabric and dyeing liquid into a dyeing machine for dyeing, wherein the bath ratio is 1: 20-30, the dyeing time is 20-30 minutes, the dyeing temperature is 50-60 ℃, and after dyeing is finished, cooling and taking out the lyocell fabric;

(3) and (3) post-treatment: and (3) washing the dyed lyocell fabric obtained in the step (2) with cold water, soap boiling, water washing and drying to obtain the brown lyocell fabric.

2. The preparation method of the brown lyocell fabric prepared by dyeing chestnut peels with the plant dye according to claim 1, wherein the ratio of the modified brown plant dye (g) to water (mL) in the step (1) is 1: 50-60.

3. The preparation method of the brown lyocell fabric prepared by dyeing chestnut peels with the plant dye according to claim 1, wherein the preparation method of the modified brown plant dye in the step (1) comprises the following steps: adding brown pigment powder, 5wt% of formaldehyde water solution and 1-amino-2-sulfuric ester ethyl sulfone ethane into ethanol-water mixed solution, adjusting the pH of reaction solution to 11-12 by using 30wt% of NaOH alkali liquor, continuously stirring, reacting for 90-120 minutes at the reaction temperature of 50-70 ℃, and spray drying after the reaction is finished to obtain the modified brown plant dye powder.

4. The method for preparing the brown lyocell fabric by dyeing the chestnut peels with the vegetable dye according to claim 3, wherein the method for preparing the 1-amino-2-sulfate ethyl sulfone ethane comprises the following steps:

step 001, preparation of 2-chloroethanol sulfate: stirring 2-chloroethanol and chlorosulfonic acid in a three-neck flask for reaction for 1-3 hours at the temperature of 50-60 ℃; after the reaction is finished, cooling and crystallizing the reacted solution, wherein the cooling temperature is-5-0 ℃, and crystallizing the product to obtain 2-chloroethanol sulfate; the ratio of the 2-chloroethanol to the chlorosulfonic acid is 1mL to (1-2) mL;

step 002, preparation of 1-amino-2-sulfate ethyl thioether ethane: dissolving 2-chloroethanol sulfate and 2-aminoethanethiol in 10wt% sodium hydroxide aqueous solution, and reacting at room temperature for 1-3 hours to obtain reaction liquid containing 1-amino-2-sulfuric ester ethyl thioether ethane; the proportion of the 2-chloroethanol sulfate, the 2-aminoethanethiol and the 10wt% sodium hydroxide aqueous solution is 1g to (1-1.2) g to (20-40) mL;

step 003, preparation of 1-amino-2-sulfate ethyl sulfone ethane: at room temperature, dropwise adding 30wt% of aqueous hydrogen peroxide solution into the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane prepared in the step 002, wherein the dropwise adding time is 30-60 minutes, reacting for 1-3 hours after the dropwise adding is completed, and distilling under reduced pressure after the reaction is completed to prepare 1-amino-2-sulfuric ester ethyl sulfone ethane; the ratio of the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane to 30wt% of hydrogen peroxide water solution is 1mL to (0.1-0.3) mL.

5. The preparation method of the brown lyocell fabric prepared by dyeing chestnut peels with the plant dye according to claim 3, wherein the ratio of the brown pigment powder, 1-amino-2-sulfate ethyl sulfone ethane, 5wt% of formaldehyde aqueous solution and ethanol-water mixed solution is 1g to (0.1-0.3) g to (3-5) mL to (30-50) mL; the volume fraction of ethanol in the ethanol-water mixed solution is 5-15%.

6. The preparation method of the brown lyocell fabric prepared by dyeing chestnut peels with the plant dye according to claim 3, wherein the volume fraction of ethanol in the ethanol-water mixed solution is 5-15%.

7. The preparation method of the brown lyocell fabric prepared by the plant dye chestnut peel dyeing according to claim 3, characterized in that the preparation method of the brown pigment powder comprises the following steps: crushing chestnut peels, grinding the crushed chestnut peels to 100-200 meshes, adding petroleum ether under the ultrasonic condition for extraction, wherein the mass ratio of the chestnut peels to the petroleum ether is 1: 10-20, the ultrasonic power is 200-400W, the temperature is 30-40 ℃, and the extraction time is 50-70 min; filtering the extract, and collecting filtrate; and distilling the filtrate under reduced pressure to obtain powdery brown pigment.

8. The method for preparing the brown lyocell fabric by dyeing the chestnut peels with the vegetable dye according to claim 1, wherein the soaping conditions in the step (3) are as follows: 2g/L of soap flakes, 2g/L of sodium carbonate, 95 ℃ for 10min and a bath ratio of 1: 30.

9. The brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye is characterized by being prepared by adopting the preparation method of the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye according to any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of fabric preparation, and particularly relates to brown lyocell fabric prepared by dyeing chestnut peels with a vegetable dye and a preparation method thereof.

Background

Most of dyes used in the prior art are synthetic dyes, a large amount of pollutants can be generated in the production and processing processes, and some synthetic dyes are harmful to human bodies. The natural plant dye is safe and nontoxic, has environmental protection effect, and some of the natural plant dye also has the functions of antibiosis and ultraviolet resistance. The natural dye has better biodegradability and environmental compatibility. The natural dye is suitable for developing green products with high added value, and the development prospect of the fabric dyed by the natural dye is very good. Under the impact of the wave of people advocating green consumer goods at present, the method has wider development prospect.

The natural dye includes mineral dye, animal dye, plant dye, etc., and the plant dye is used as main component. The vegetable dye dyeing is characterized in that: besides natural color, some dyed fabrics of plants such as India madder blue, turmeric root-tuber and the like have insect prevention and sterilization effects, and the dyed fabric of the plant dye has an uninteresting interest in color and luster and natural fragrance, and is naturally appreciated by some consumers. The plant dyes commonly used in ancient times are numerous, and the dyeing process created by ancient people according to different dye characteristics comprises the following steps: direct dyeing, mordant dyeing, reduction dyeing, resist dyeing, chromatography dyeing and the like. The variety of dyes and technological methods makes the color spectrum of ancient printing and dyeing industry rich, and there are hundreds of ancient books recorded, especially dozens of similar colors clearly distinguished in one color tone, which needs to be achieved by skillfully mastering the combination and formula of various dyes and changing technological conditions. The Chinese chestnut originates from China, is distributed in 26 provinces (cities and autonomous regions) in China, is rich in China, and mainly comprises the variety of the King mountain red oil chestnut, the Xinyang Chinese chestnut and the like. The use of Chinese chestnut as a medicine is recorded in medical ancient books of all ages, and the medicine used parts comprise roots, barks, leaves, flowers, epicarp, endocarp, involucre, and the like of the Chinese chestnuts. The chestnut shell is the epicarp of chestnut, has sweet, astringent and mild properties, has the efficacy of lowering adverse qi and stopping bleeding, and is mainly used for treating stomach regurgitation, epistaxis, hematochezia and other symptoms. Chestnut peels are abandoned by people at present and are still to be developed in the field of textile dyeing. Chestnut peels are brown in color, which has good potential for brown vegetable dyes. However, when the brown pigment of chestnut peels is applied to natural dyes, the color fastness is low, and particularly the color fastness to washing and weather is low. Aiming at the limitation that the brown pigment of the chestnut peel is applied to natural dye, the performance of the brown pigment needs to be further improved.

Lyocell is a new type of renewable cellulose fiber that has many advantages, such as: good drapability, high strength, easy dyeing, thick hand feeling, simple production process, renewable raw material sources, no environmental pollution in the production process and the like, and the shape retention and the wrinkle resistance of the viscose are superior to those of common viscose fiber products. Therefore, it is known as the novel environment-friendly fiber with the most development potential in the 21 st century, and has wide development space. Lyocell fabric is a fabric woven by lyocell fibers, and currently, the fabric is mainly dyed by chemically synthesized dyes. Literature research and market research find that lyocell fabric dyed by natural dye is only reported and needs to be further developed.

Disclosure of Invention

The chemical synthetic dye has strong reactivity, is combined with the lyocell fabric through chemical bonds, is relatively stable in brown pigment of the chestnut peel of the plant dye without chemical modification, is poor in reactivity, is relatively weak in binding force with the lyocell fabric, and is low in color fastness, washing resistance and weather fastness of the lyocell fabric dyed by the brown pigment in the chestnut peel without chemical modification. The invention aims to overcome the defects of the prior art and provides brown lyocell fabric prepared by dyeing chestnut peels with vegetable dye and a preparation method thereof.

The invention aims to provide the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye, and the fabric has high K/S value, high soaping-resistant color-changing fastness level and high dry-rubbing color fastness level and has good application prospect.

The invention aims to provide a brown lyocell fabric prepared by dyeing chestnut peels with a vegetable dye, and the fabric can be prepared by the following preparation method: extracting brown pigment powder from chestnut peel by using petroleum ether, and grafting 1-amino-2-sulfate ethyl sulfone ethane to the brown pigment powder; preparing modified brown plant dye powder; and finally, dyeing the lyocell fabric in the modified brown plant dye.

The invention also aims to provide a preparation method of brown lyocell fabric prepared by dyeing chestnut peels with vegetable dye, which comprises the following steps:

(1) extraction of brown pigment: crushing chestnut peels, grinding the crushed chestnut peels to 100-200 meshes, adding petroleum ether under the ultrasonic condition for extraction, wherein the mass ratio of the chestnut peels to the petroleum ether is 1: 10-20, the ultrasonic power is 200-400W, the temperature is 30-40 ℃, and the extraction time is 50-70 min; filtering the extract, and collecting filtrate; and distilling the filtrate under reduced pressure to obtain powdery brown pigment.

(2) Chemical modification: adding the brown pigment powder prepared in the step (1), 5wt% of formaldehyde water solution and 1-amino-2-sulfuric ester ethyl sulfone ethane into an ethanol-water mixed solution, adjusting the pH of a reaction solution to 11-12 by using 30wt% of NaOH alkali liquor, continuously stirring, reacting for 90-120 minutes at the temperature of 50-70 ℃, and performing spray drying after the reaction is finished to obtain the modified brown plant dye powder.

Preferably, the ratio of the brown pigment powder, the 1-amino-2-sulfuric ester ethyl sulfone ethane, the 5wt% formaldehyde water solution and the ethanol-water mixed solution is 1g to (0.1-0.3) g to (3-5) mL to (30-50) mL; the volume fraction of ethanol in the ethanol-water mixed solution is 5-15%.

Preferably, the preparation method of the 1-amino-2-sulfate ethyl sulfone ethane comprises the following steps:

step 001, preparation of 2-chloroethanol sulfate: stirring 2-chloroethanol and chlorosulfonic acid in a three-neck flask for reaction for 1-3 hours at the temperature of 50-60 ℃; after the reaction is finished, cooling and crystallizing the reacted solution, wherein the cooling temperature is-5-0 ℃, and crystallizing the product to obtain 2-chloroethanol sulfate; the ratio of the 2-chloroethanol to the chlorosulfonic acid is 1mL to (1-2) mL; the main chemical reaction equations involved in this step are shown below.

Step 002, preparation of 1-amino-2-sulfate ethyl thioether ethane: dissolving 2-chloroethanol sulfate and 2-aminoethanethiol in 10wt% sodium hydroxide aqueous solution, and reacting at room temperature for 1-3 hours to obtain reaction liquid containing 1-amino-2-sulfuric ester ethyl thioether ethane; the proportion of the 2-chloroethanol sulfate, the 2-aminoethanethiol and the 10wt% sodium hydroxide aqueous solution is 1g to (1-1.2) g to (20-40) mL; the main chemical reaction equations involved in this step are shown below.

Step 003, preparation of 1-amino-2-sulfate ethyl sulfone ethane: at room temperature, dropwise adding 30wt% of aqueous hydrogen peroxide solution into the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane prepared in the step 002, wherein the dropwise adding time is 30-60 minutes, reacting for 1-3 hours after the dropwise adding is completed, and distilling under reduced pressure after the reaction is completed to prepare 1-amino-2-sulfuric ester ethyl sulfone ethane; the ratio of the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane to 30wt% of aqueous hydrogen peroxide solution is 1mL to (0.1-0.3) mL; the main chemical reaction equations involved in this step are shown below.

The chemical reaction equation involved in the step (2) is as follows, wherein R-C₆H₄-OH represents the molecular structure of the brown pigment.

(3) Dyeing: dissolving a proper amount of modified brown plant dye in an aqueous solution to prepare a dyeing solution, and regulating the pH value of the dyeing solution to 10-11 by using 30wt% NaOH alkali liquor; and (3) putting the Lyocell fabric and the dyeing liquid into a dyeing machine for dyeing, wherein the bath ratio is 1 to (20-30), the dyeing time is 20-30 minutes, the dyeing temperature is 50-60 ℃, and the Lyocell fabric is taken out after dyeing is finished.

Preferably, the ratio of the brown plant dye (g) to water (mL) is 1: 50-60.

(4) Post-treatment of the lyocell fabric: and (4) washing the dyed lyocell fabric obtained in the step (3) with cold water, soap boiling, water washing and drying to obtain the brown lyocell fabric.

Preferably, the soaping conditions are: 2g/L of soap flakes, 2g/L of sodium carbonate, 95 ℃ for 10min and a bath ratio of 1: 30.

The chemical modification and dyeing mechanism analysis of the invention:

the molecular structure of the brown pigment extracted from the chestnut peels contains a large number of phenolic hydroxyl groups, and active hydrogen atoms at the ortho-position of the phenolic hydroxyl groups are easy to perform condensation reaction, so that 1-amino-2-sulfate ethyl sulfone ethane is introduced at the ortho-position of the phenolic hydroxyl groups.

The chemically modified brown pigment molecule contains beta-ethyl sulfone sulfate which is a characteristic group of the reactive dye, and the modification is equivalent to the modification of the brown pigment extracted from the chestnut peels into the reactive dye; the lyocell fabric mainly comprises cellulose, and the dyeing of the cellulose fiber is mainly realized by adopting reactive dye. Therefore, the chemically modified brown pigment can be well chemically reacted with the lyocell fabric, so that the two are firmly combined.

The invention has the following remarkable advantages:

(1) through chemical modification, a characteristic group beta-ethyl sulfone sulfate of a reactive dye is grafted on brown pigment molecules in chestnut peels, and the reactive dye is converted into a vinyl sulfone group in an alkaline medium to have high reactivity and form stable covalent bond combination with cellulose fibers; so that the brown pigment in the chestnut peel with low reactivity is changed into natural dye with high reactivity.

(2) Aiming at the problem that a large amount of printing and dyeing auxiliary agents are needed in the dyeing process of the synthetic dye, in the dyeing process, the affinity between the modified brown pigment molecules and the fabric is good, so that the brown pigment molecules are easy to approach the surface of the fabric, and therefore, other dye auxiliary agents such as mordants, accelerating agents and the like are not needed to be added, the dyeing process is simplified, the cost is saved, and the environmental pollution caused by dyeing is reduced.

(3) Aiming at the problem of great difficulty in extracting brown pigment from chestnut peels, the invention adopts a petroleum ether extraction method to extract the brown pigment from the chestnut peels, and the extraction method has the characteristics of simplicity, practicability, high efficiency and the like.

(4) Aiming at the problem that the synthetic route of the modifier 1-amino-2-sulfate ethyl sulfone ethane is complex, the invention obtains a simple synthetic route by refining a synthetic scheme.

(5) The dyed brown lyocell fabric has a high K/S value and high soaping color change fastness and dry rubbing color fastness.

Detailed Description

The examples described below illustrate the invention in detail.

Example 1

The preparation method of the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye comprises the following steps:

(1) extraction of brown pigment: crushing chestnut peels, grinding the crushed chestnut peels to 150 meshes, adding petroleum ether under the ultrasonic condition for extraction, wherein the mass ratio of the chestnut peels to the petroleum ether is 1: 15, the ultrasonic power is 300W, the temperature is 35 ℃, and the extraction time is 60 min; filtering the extract, and collecting filtrate; and distilling the filtrate under reduced pressure to obtain powdery brown pigment.

(2) Chemical modification: and (2) adding 5g of brown pigment powder prepared in the step (1), 20mL of 5wt% aqueous formaldehyde solution and 1g of 1-amino-2-sulfuric ester ethyl sulfone ethane into 200mL of 10% ethanol-water mixed solution, adjusting the pH of the reaction solution to 11.5 by using 30wt% NaOH alkaline solution, continuously stirring, reacting for 105 minutes at the reaction temperature of 60 ℃, and spray drying after the reaction is finished to obtain the modified brown plant dye powder.

The preparation method of the 1-amino-2-sulfate ethyl sulfone ethane comprises the following steps:

step 001, preparation of 2-chloroethanol sulfate: stirring 10mL of 2-chloroethanol and 15mL of chlorosulfonic acid in a three-neck flask for reaction, wherein the reaction time is 2 hours and the reaction temperature is 55 ℃; after the reaction is finished, cooling and crystallizing the reacted solution at-3 ℃ to obtain a crystallized product, namely 2-chloroethanol sulfate;

step 002, preparation of 1-amino-2-sulfate ethyl thioether ethane: dissolving 5g of 2-chloroethanol sulfate and 5g of 2-aminoethanethiol in 150mL of 10wt% sodium hydroxide aqueous solution, and reacting at room temperature for 2 hours to obtain a reaction solution containing 1-amino-2-sulfate ethyl thioether ethane;

step 003, preparation of 1-amino-2-sulfate ethyl sulfone ethane: at room temperature, 2mL of 30wt% aqueous hydrogen peroxide solution is dropwise added into 10mL of the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane prepared in the step 002, the dropwise adding time is 5 minutes, the reaction is carried out for 2 hours after the dropwise adding is finished, and reduced pressure distillation is carried out after the reaction is finished, so as to prepare the 1-amino-2-sulfuric ester ethyl sulfone ethane.

(3) Dyeing: dissolving 2g of modified brown plant dye in 110mL of aqueous solution to prepare a dyeing solution, and regulating the pH value of the dyeing solution to 10.5 by using 30wt% NaOH alkali liquor; and (3) putting the lyocell fabric and the dyeing liquid into a dyeing machine for dyeing, wherein the bath ratio is 1: 25, the dyeing time is 25 minutes, the dyeing temperature is 55 ℃, and the lyocell fabric is taken out after dyeing is finished.

(4) Post-treatment of the lyocell fabric: washing the dyed lyocell fabric obtained in the step (3) with cold water, soap boiling, water washing and drying to obtain brown lyocell fabric; the soap boiling conditions are as follows: 2g/L of soap flakes, 2g/L of sodium carbonate, 95 ℃ for 10min and a bath ratio of 1: 30.

Example 2

The preparation method of the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye comprises the following steps:

(1) extraction of brown pigment: pulverizing chestnut peel, grinding to 100 mesh, extracting with petroleum ether under ultrasonic condition at 200W/30 deg.C for 50min, wherein the mass ratio of chestnut peel to petroleum ether is 1: 10; filtering the extract, and collecting filtrate; and distilling the filtrate under reduced pressure to obtain powdery brown pigment.

(2) Chemical modification: and (2) adding 5g of brown pigment powder prepared in the step (1), 20mL of 5wt% aqueous formaldehyde solution and 0.5g of 1-amino-2-sulfuric ester ethyl sulfone ethane into 200mL of 5% ethanol-water mixed solution, adjusting the pH of the reaction solution to 11 by using 30wt% NaOH alkaline solution, continuously stirring, reacting for 90 minutes at the reaction temperature of 50 ℃, and spray drying after the reaction is finished to obtain the modified brown plant dye powder.

The preparation method of the 1-amino-2-sulfate ethyl sulfone ethane comprises the following steps:

step 001, preparation of 2-chloroethanol sulfate: stirring 10mL of 2-chloroethanol and 15mL of chlorosulfonic acid in a three-neck flask for reaction, wherein the reaction time is 2 hours and the reaction temperature is 55 ℃; after the reaction is finished, cooling and crystallizing the reacted solution at-3 ℃ to obtain a crystallized product, namely 2-chloroethanol sulfate;

step 002, preparation of 1-amino-2-sulfate ethyl thioether ethane: dissolving 5g of 2-chloroethanol sulfate and 5g of 2-aminoethanethiol in 150mL of 10wt% sodium hydroxide aqueous solution, and reacting at room temperature for 2 hours to obtain a reaction solution containing 1-amino-2-sulfate ethyl thioether ethane;

step 003, preparation of 1-amino-2-sulfate ethyl sulfone ethane: at room temperature, 2mL of 30wt% aqueous hydrogen peroxide solution is dropwise added into 10mL of the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane prepared in the step 002, the dropwise adding time is 5 minutes, the reaction is carried out for 2 hours after the dropwise adding is finished, and reduced pressure distillation is carried out after the reaction is finished, so as to prepare the 1-amino-2-sulfuric ester ethyl sulfone ethane.

(3) Dyeing: dissolving 2g of modified brown plant dye in 100mL of aqueous solution to prepare a dyeing solution, and regulating the pH value of the dyeing solution to 10.2 by using 30wt% NaOH alkali liquor; and (3) putting the lyocell fabric and the dyeing liquid into a dyeing machine for dyeing, wherein the bath ratio is 1: 25, the dyeing time is 20 minutes, the dyeing temperature is 50 ℃, and the lyocell fabric is taken out after dyeing is finished.

(4) Post-treatment of the lyocell fabric: washing the dyed lyocell fabric obtained in the step (3) with cold water, soap boiling, water washing and drying to obtain brown lyocell fabric; the soap boiling conditions are as follows: 2g/L of soap flakes, 2g/L of sodium carbonate, 95 ℃ for 10min and a bath ratio of 1: 30.

Example 3

The preparation method of the brown lyocell fabric prepared by dyeing the chestnut peels with the vegetable dye comprises the following steps:

(1) extraction of brown pigment: crushing chestnut peels, grinding the crushed chestnut peels to 200 meshes, adding petroleum ether under the ultrasonic condition for extraction, wherein the mass ratio of the chestnut peels to the petroleum ether is 1: 20, the ultrasonic power is 400W, the temperature is 40 ℃, and the extraction time is 70 min; filtering the extract, and collecting filtrate; and distilling the filtrate under reduced pressure to obtain powdery brown pigment.

(2) Chemical modification: and (2) adding 5g of brown pigment powder prepared in the step (1), 20mL of 5wt% aqueous formaldehyde solution and 1.5g of 1-amino-2-sulfuric ester ethyl sulfone ethane into 200mL of 15% ethanol-water mixed solution, adjusting the pH of the reaction solution to 12 by using 30wt% NaOH alkaline solution, continuously stirring, reacting for 120 minutes at the reaction temperature of 70 ℃, and spray drying after the reaction is finished to obtain the modified brown plant dye powder.

The preparation method of the 1-amino-2-sulfate ethyl sulfone ethane comprises the following steps:

step 001, preparation of 2-chloroethanol sulfate: stirring 10mL of 2-chloroethanol and 15mL of chlorosulfonic acid in a three-neck flask for reaction, wherein the reaction time is 2 hours and the reaction temperature is 55 ℃; after the reaction is finished, cooling and crystallizing the reacted solution at-3 ℃ to obtain a crystallized product, namely 2-chloroethanol sulfate;

step 002, preparation of 1-amino-2-sulfate ethyl thioether ethane: dissolving 5g of 2-chloroethanol sulfate and 5g of 2-aminoethanethiol in 150mL of 10wt% sodium hydroxide aqueous solution, and reacting at room temperature for 2 hours to obtain a reaction solution containing 1-amino-2-sulfate ethyl thioether ethane;

step 003, preparation of 1-amino-2-sulfate ethyl sulfone ethane: at room temperature, 2mL of 30wt% aqueous hydrogen peroxide solution is dropwise added into 10mL of the reaction solution containing 1-amino-2-sulfuric ester ethyl thioether ethane prepared in the step 002, the dropwise adding time is 5 minutes, the reaction is carried out for 2 hours after the dropwise adding is finished, and reduced pressure distillation is carried out after the reaction is finished, so as to prepare the 1-amino-2-sulfuric ester ethyl sulfone ethane.

(3) Dyeing: dissolving 2g of modified brown plant dye in 120mL of aqueous solution to prepare a dyeing solution, and regulating the pH value of the dyeing solution to 10.9 by using 30wt% NaOH alkali liquor; and (3) putting the lyocell fabric and the dyeing liquid into a dyeing machine for dyeing, wherein the bath ratio is 1: 25, the dyeing time is 30 minutes, the dyeing temperature is 60 ℃, and the lyocell fabric is taken out after dyeing is finished.

(4) Post-treatment of the lyocell fabric: washing the dyed lyocell fabric obtained in the step (3) with cold water, soap boiling, water washing and drying to obtain brown lyocell fabric; the soap boiling conditions are as follows: 2g/L of soap flakes, 2g/L of sodium carbonate, 95 ℃ for 10min and a bath ratio of 1: 30.

Comparative example 1

In this comparative example, the dyeing process was changed and the other preparation was carried out as in example 1, with example 1 as a comparison, the dyeing process after the change being:

dissolving 2g of modified brown plant dye in 110mL of aqueous solution to prepare a dyeing solution, and regulating the pH value of the dyeing solution to 10.6 by using 30wt% NaOH alkali liquor; placing the Lyocell fabric and dyeing liquor into a dyeing machine for dyeing, wherein the bath ratio is 1: 25, dyeing is carried out for 15min at 60 ℃, then sodium chloride is added, dyeing is carried out for 15min at 60 ℃, soda is added after the temperature is raised to 90 ℃, and color fixing is carried out for 30min at 90 ℃, wherein the concentration of sodium chloride is 40 g/L, and the concentration of soda is 10 g/L; and taking out the lyocell fabric after dyeing is finished.

Comparative example 2

By way of comparison with example 1, in this comparative example, instead of preparing 1-amino-2-sulfate ethylsulfone ethane, the dyeing is carried out directly with the extracted brown pigment, the other preparation being carried out as in example 1.

Comparative example 3

In this comparative example, the conventional dyeing method and the reactive dye available on the market, reactive brown ED-P, were used. The preparation method of the brown lyocell fabric dyed by the reactive dye reactive brown ED-P comprises the following steps:

selecting a Lyocell fabric and a reactive dye, namely reactive brown ED-P, dyeing the Lyocell fabric and the reactive dye by a conventional method, adding salt after dyeing for 15min at 60 ℃, continuing dyeing for 15min at 60 ℃, heating to 90 ℃, adding soda ash, fixing color for 30min at 90 ℃, wherein the experimental formula is as follows: the dosage of the reactive dye reactive brown ED-P is 2 percent (owf), the salt is 40 g/L, the soda is 10 g/L, and the bath ratio is 1: 50; and cooling after dyeing is finished, taking out a sample, washing with cold water, soap boiling (2 g/L of soap flakes and 2g/L of sodium carbonate, 95 ℃, 10min, bath ratio of 1: 30), washing with water, and drying to obtain the brown lyocell fabric.

Performance evaluation:

the properties of the brown lyocell fabrics obtained in examples 1 to 3 and comparative examples 1 to 3 were evaluated. The K/S value is measured by adopting a color measuring and matching instrument SF600X of DataColor company in America; the soaping-resistant color change fastness value test refers to GB/T3921-2008 'textile color fastness test soaping-resistant color fastness'; the dry rubbing resistance color fastness value test refers to GB/T3920-2008 'textile color fastness test rubbing color fastness', and specific data are shown in Table 1.

TABLE 1

	K/S value	Fastness to soaping change/grade	Color fastness to dry rubbing/grade
				Example 1	16.23	5	5
Example 2	16.32	5	5
				Example 3	16.79	5	4-5
Comparative example 1	7.23	4	4
				Comparative example 2	6.89	4-5	4-5
Comparative example 3	14.78	4	4-5

As can be seen from Table 1, the K/S values, the soaping discoloration resistance fastnesses and the dry rubbing fastness of examples 1 to 3 were all better than those of comparative examples 1 to 3.