CN108442149B - A cyclic dyeing method for fabrics by reactive dye colored microspheres - Google Patents

Abstract

The present invention provides a cyclic dyeing method for fabrics by reactive dye colored microspheres, comprising the following steps: S1, using polystyrene-acrylate cationic nano-microspheres to adsorb reactive dyes to obtain reactive dye colored microspheres, the reactive dyes The dosage of the dye relative to the nano-microspheres is 60-75%; S2, using the dispersion liquid of the reactive dye color microspheres as the dyeing liquid, the cationic modified cellulose fabric is first impregnated, and the reactive dye color microspheres are suitable for dyeing. The fabric weight c ₀ is 1% to 10%, the dyeing temperature is 25 to 50° C., the pH value is 3 to 5, and the dyeing time is 10 to 90 minutes to obtain the first dyed fabric and dyeing residue; S3, adjusting the dyeing residue Concentration cn = cn _{-1 +} 0.5%, and the primary dyeing process is used to cyclically dye the primary dyed fabric to obtain a dyed fabric. The fabric dyeing method provided by the invention has higher dye utilization rate, saves cost and is beneficial to environmental protection.

Description

A cyclic dyeing method for fabrics by reactive dye colored microspheres

technical field

The invention relates to the technical field of fabric dyeing, in particular to a cyclic dyeing method for fabrics by reactive dye colored microspheres.

Background technique

As one of the main dyes for dyeing cellulose fibers and fabrics, reactive dyes have the advantages of bright color and complete color spectrum. Reactive dyes are mainly divided into azo type, phthalocyanine type and anthraquinone type according to their parent dye color system, and can be divided into s-triazine type and vinyl sulfone type according to the type of active group. The dyeing of reactive dyes and fibers is a chemical reaction, which is a covalent bond between fibers and dyes. The commonly used reactive dye dyeing method is the dip dyeing method. The common process of dyeing cotton fabrics includes: first immersing the fabric in the dyeing solution, heating the temperature to 90 °C, adding electrolyte sodium sulfate in batches, and then adding an alkali agent such as sodium carbonate to fix the color. , the final wash. Reactive dyes are prone to hydrolysis during dyeing, resulting in low dye uptake and fixation rate. In actual production, a large amount of inorganic salts are usually added to promote dyeing, which makes the production wastewater of the textile printing and dyeing industry contain a large amount of electrolytes. Therefore, the treatment of printing and dyeing wastewater is still a difficult problem at present.

Colored polymer composite microspheres are a new type of functional composite materials that combine colorants in a specific way, and have broad application prospects in many fields such as textile printing and dyeing, leather manufacturing, electronic display, inkjet printing, and medicine. Colored polymer composite microspheres combine the advantages of polymer microspheres and colorants. They not only have the characteristics of large specific surface area of polymer microspheres, uniform particle size, diverse surface structure and morphology of microspheres, but also have excellent dye color. And organic pigments have the advantages of super durability.

Among them, color microspheres obtained by compounding reactive dyes and polymer microspheres are used as pigment materials to dye cotton fabrics, which can realize salt-free dyeing of cotton fabrics with reactive dyes and achieve the purpose of reducing wastewater discharge in the printing and dyeing industry. However, the dye utilization rate in this method still needs to be further improved.

SUMMARY OF THE INVENTION

In view of this, the present application provides a cyclic dyeing method for fabrics with reactive dye colored microspheres. The fabric dyeing method provided by the present invention has higher dye utilization rate, saves cost and is beneficial to environmental protection.

The invention provides a cyclic dyeing method for fabrics by reactive dye colored microspheres, comprising the following steps:

S1, using polystyrene-acrylate cationic nano-microspheres to adsorb reactive dyes to obtain reactive dye colored microspheres, and the amount of the reactive dyes relative to the nano-microspheres is 60-75wt%;

S2, using the dispersion of the reactive dye color microspheres as the dyeing solution, carry out primary dip dyeing on the cationic modified cellulose fabric, the reactive dye color microspheres have a weight c ₀ of 1% to 10% of the fabric, and the dyeing temperature is 25～50℃, the pH value of dyeing is 3～5, and the dyeing time is 10～90min to obtain the first dyed fabric and dyeing residue;

S3, adjusting the concentration of the dyeing residue according to formula 1, and adopting the process of the first dip dyeing to carry out cyclic dyeing on the first dyed fabric to obtain the dyed fabric;

c _n =c _n-1 +0.5% formula 1;

n is the number of dyeing cycles, and c _n is the dye concentration of the nth dyeing.

Preferably, the reactive dye is a reactive dye containing a sulfonic acid group.

Preferably, the average particle size of the polystyrene-acrylate cationic nano-microspheres is 50 nm to 150 nm.

Preferably, the polystyrene-acrylate type cationic nano-microspheres are styrene-butyl acrylate copolymer type cationic nano-microspheres.

Preferably, in step S1, the adsorption of reactive dyes is carried out in the presence of sodium chloride.

Preferably, in step S1, the adsorption of the reactive dye is carried out under stirring conditions, and the stirring speed is preferably above 300 N/min.

Preferably, the cationically modified cellulose fabric is obtained by modifying the cellulose fabric with a modifier selected from the group consisting of polyepichlorohydrin amides, glycidyl trimethyl ammonium chloride and 3 - One or more of chloro-2-hydroxypropyltrimethylammonium chloride.

Preferably, the cellulosic fabric is selected from cotton fabric, linen fabric, Tencel fabric or modal fabric.

Preferably, in step S2, the bath ratio of the primary impregnation is 1:20-1:100, and the stirring speed is preferably 200-300 N/min.

Preferably, after the primary impregnation in step S2 is completed, the method further includes: washing the fabric with water, and then drying at 40-110° C. to obtain a dry primary dyed fabric.

In the present invention, reactive dyes/polystyrene-acrylate cationic microspheres with a dye dosage of 60-75 wt% are selected, and the dispersion liquid is used as the dyeing liquid, and the cationic modified cellulose fabric is dyed at room temperature by means of dip dyeing. After the dip dyeing is completed, adjust the dyeing residue concentration c _n =c _n-1 +0.5% (n is the number of cycles, c ₀ =1%-10%), and repeat the dyeing by the above dip dyeing process to obtain dyed fabrics. Compared with the prior art, the colored microspheres described in the present application have certain stability and better dyeability. By cyclic dyeing of the modified fabric, a darker and brighter dyed fabric can be obtained by using very few dyes. , saving dyes, significantly improving the utilization rate of dyes, environmental protection and low cost.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention provides a cyclic dyeing method for fabrics by reactive dye colored microspheres, comprising the following steps:

S1, using polystyrene-acrylate cationic nano-microspheres to adsorb reactive dyes to obtain reactive dye colored microspheres, and the amount of the reactive dyes relative to the nano-microspheres is 60-75wt%;

S2, using the dispersion of the reactive dye colored microspheres as the dyeing solution, carry out primary dip dyeing on the cationic modified cellulose fabric, the reactive dye colored microspheres have a weight c ₀ of 1% to 10% of the fabric, and the dyeing temperature is 25～50℃, the pH value of dyeing is 3～5, and the dyeing time is 10～90min to obtain primary dyed fabric and dyeing residue;

S3, adjusting the concentration of the dyeing residue according to formula 1, and adopting the process of the first dip dyeing to carry out cyclic dyeing on the first dyed fabric to obtain the dyed fabric;

c _n =c _n-1 +0.5% formula 1;

n is the number of dyeing cycles, and c _n is the dye concentration of the nth dyeing.

The fabric cyclic dyeing method provided by the invention has higher dye utilization rate, saves cost and is beneficial to environmental protection.

In the embodiments of the present invention, reactive dye colored microspheres are first provided, and polystyrene-acrylate cationic nanometer microspheres are used to adsorb reactive dyes to obtain reactive dye colored microspheres. Wherein, the reactive dyes are reactive dyes containing sulfonic acid groups, including but not limited to reactive red 4, 6, 195, reactive orange 19, 107, 202, reactive yellow 1, 95, 193, reactive blue 15, 19, 49 , one of active black 5 and 45. In a preferred embodiment of the present invention, the reactive dye used is a monochloro-s-triazine reactive dye such as reactive red 24 or reactive yellow 95.

The present invention has no special limitation on the source of the polystyrene-acrylate cationic nano-microspheres, which can be prepared or commercially available. In the embodiment of the present invention, the average particle size of the polystyrene-acrylate cationic nano-microspheres is 50 nm to 150 nm. The polystyrene-acrylate type cationic nano-microspheres are preferably styrene-butyl acrylate copolymer type cationic nano-microspheres, more preferably poly(styrene-butyl acrylate-p-vinylbenzyltrimethyl chloride) ammonium chloride) microspheres, namely P(St-BA-VBT) microspheres. Specifically, the average particle size of the undyed P(St-BA-VBT) microspheres was 67 nm, the polydispersity index PDI=0.076, the particle size distribution was narrow, and the monodispersity was good.

In the embodiment of the present invention, the aqueous dispersion of the polymer nano-microspheres can be mixed with a reactive dye solution for adsorption. The amount of the reactive dye relative to the nano-microspheres is 60-75 wt%, and purified by dialysis to obtain reactive dyes. Dye polymer composite microspheres, namely reactive dye color microspheres. The invention utilizes the electrostatic effect and hydrophobic effect between reactive dyes and cationic copolymer microspheres to obtain color copolymer microspheres with high reactive dye content. The microspheres not only have excellent color properties of dyes, but also copolymer microspheres Large specific surface, special effects on light absorption and scattering.

Wherein, the amount of the dye is 60-75wt%, the average particle size of the colored microsphere copolymer can be 83nm-93nm; the amount of the dye is preferably 75%, the particle size distribution is narrow, the monodispersity is better, and the amount of the dye is Below 60%, if the dosage is 30%, the average particle size of reactive yellow 95/copolymer microspheres is 117nm, PDI=0.195, and the particle size distribution is the widest, which is unfavorable for application.

Preferably, the adsorption of reactive dyes is carried out in the presence of sodium chloride, which is more conducive to the adsorption of dyes. The adsorption of reactive dyes is preferably carried out under stirring conditions, and the stirring speed is preferably above 300N/min (that is, the rotation speed of the engine per minute), such as 300-500N/min, and the dye adsorption capacity is high. In the embodiment of the present invention, the dye adsorption can be carried out at a pH value of 4 to 6 and a room temperature of 25° C. to 40° C. After 120 minutes, conventional purification can be performed to obtain reactive dye colored microspheres with high dye adsorption capacity and stable performance. In the embodiment of the present invention, the adsorption capacity of the obtained reactive dye colored microspheres is generally above 300 mg/g, such as 350-600 mg/g, specifically 530 mg/g, 580 mg/g and the like.

The invention adopts the above-mentioned polymer composite microspheres as the pigment material, and the fabric is modified and then dyed, which can not only solve the problems of poor dye depth of dyes and pigments on the fabric, sluggish color, etc., but also realize salt-free dyeing and reduce sewage. Emissions and cost savings.

In the embodiment of the present invention, the cellulose fabric can be modified by placing it in a solution of a modifier, and the modifier is preferably selected from polyepichlorohydrin amides, glycidyl trimethyl ammonium chloride and one or more of 3-chloro-2-hydroxypropyltrimethylammonium chloride (EPTAC) to obtain a cationically modified cellulose fabric. Wherein, the cellulose fabric can be selected from cotton fabrics, hemp fabrics, tencel fabrics or modal fabrics, preferably cotton fabrics; it can be woven fabrics or knitted fabrics, and the technical indicators such as the structure and basic properties of the fabrics are not adjusted according to the present invention. No special restrictions. In the embodiment of the present invention, the cellulose fabric is a cotton knitted fabric, and the grammage is 100-120 g/m ² .

Specifically, in the embodiment of the present invention, the cellulose fabric is placed in a modifier solution with a concentration of 1 to 50 g/L, and the bath ratio can be 1:20 to 1:100; the modification temperature is preferably 20 to 70 ° C, and the stirring The speed can be 200N/min, and the time is 10min～120min. After the modification, it can also be treated with sodium hydroxide solution, and finally washed with water, neutralized, etc., to obtain a cationically modified cellulose fabric. Here, the liquor ratio refers to the ratio of the dyed fabric to the dye liquor. For example, 1:20 means that 1 g of cellulose fabric corresponds to 19 g of water.

Taking cotton fabric as an example, cotton fiber is cellulose fiber, which is ionized into Cell-O ^- in solution, cationic modifier is ionized into cation in solution, and the two are combined with each other through electrostatic attraction, and a large amount of cationic modifier Adsorbed on the surface of cotton fiber, and finally the surface of cotton fiber is positively charged; due to the negative charge on the surface of reactive dye/copolymer microspheres, there is a strong electrostatic attraction between it and the cationically modified cotton fabric, which changes the color of the fabric. Cotton fibers are cellulose fibers with obvious grooves on the surface, but the cationic modifier does not change the surface morphology of cotton fibers.

After obtaining the reactive dye colored microspheres and the cationically modified cellulose fabric, in the embodiment of the present invention, the aqueous dispersion of the reactive dye colored microspheres is used as the dyeing solution, and the modified cellulose fabric is dyed on an infrared dyeing machine at room temperature by means of dip dyeing. , to obtain the first dyed fabric and dyeing residue.

In the embodiment of the present invention, color microsphere dispersions of different mass concentrations are prepared with water, and the reactive dye color microspheres have a weight c ₀ of 1% to 10%, preferably 2% to 9%, and more preferably 3% to 5%. %; the concentration of the prepared reactive dye color microsphere dispersion liquid is one of 2%, 4%, 6%, 8%, 10%, etc. of the composite microspheres to the fabric weight. In addition, the bath ratio of the fabric to the dye liquor prepared with the colored microspheres can be 1:20-1:100, preferably 1:30-1:80. In the embodiment of the present invention, the parameters of the infrared dyeing machine are set: the stirring speed is 200-300 N/min, the dyeing temperature is 25-50°C, the dyeing time is 10-90 min, preferably 20-80 min, and the pH value is 3-5 under the condition Do initial dip.

After the dyeing is completed, the embodiment of the present invention further includes: washing the fabric with water, and then drying at 40-110° C. to obtain a dry primary dyed fabric. Among them, the drying time can be 30min to 60min, which can be adjusted according to the specific conditions of different fabrics.

The invention uses colored microspheres to dye cationic modified fabrics, and has the following advantages: (1) the polymer composite microspheres have large specific surface area and uniform particle size, so that the fabrics are more bright and bright; (2) under the condition of the same amount of dyes, polymerization Compared with the traditional dip-dyeing process, the dyeing with compound microspheres can significantly improve the K/S of dyed fabrics and the color is darker; (3) The method is simple and easy to operate, no need to add electrolytes, and the colored microspheres can dye the fabrics at room temperature without salt dyeing. Reduce sewage discharge, save energy, environmental protection, and cost, and the dyed fabric has good color fastness, and each fastness index meets the application standards of dyed fabrics.

After obtaining the first dyed fabric and the dyeing residue, in the embodiment of the present invention, the pH value of the residue is adjusted to be consistent with the original dye liquor, and the microsphere concentration of the residue is adjusted to be c _n =c _n-1 +0.5%, where n is cyclic dyeing times, cn is the dye liquor concentration of the _nth dyeing, after repeated dyeing with the same dip dyeing process, the dyed fabric after cyclic dyeing is obtained. In the embodiment of the present invention, 1≤n≤4, c ₀ =1%-10%, preferably 3%-5%, and finally the nth fabric is dyed.

The results show that the color copolymer microspheres dyed fabric of the present invention has deeper color, higher color saturation and vividness, and can obtain deeper and brighter colors by using less dyes (the prepared color microspheres), and the color Copolymer microspheres can be recycled and reused. The cyclic dyeing method provided by the invention is of great significance for the innovation of the current basic theory of fiber dyeing, the improvement of the utilization rate of reactive dyes, and the reduction of printing and dyeing wastewater discharge.

In order to further understand the present application, the cyclic dyeing method for fabrics by reactive dye colored microspheres provided by the present application will be specifically described below with reference to the examples.

In the following examples, the cotton fabric involved is cotton weft plain knitted fabric (40s, 110g/m ² , purchased from Zibo Tianluo Textile Printing and Dyeing Co., Ltd.); the average particle size of P(St-BA-VBT) microspheres is 67nm , the polydispersity index PDI=0.076.

Example 1

The cotton fabric is placed in the modifier 3-chloro-2-hydroxypropyltrimethylammonium chloride solution with a concentration of 20g/L (the bath ratio is 1:50), and modified in an infrared dyeing machine; set Parameters of infrared dyeing machine: rotating speed 200N/min, temperature 70℃, heating rate 3℃/min, time 30min. After the modification, 5g/L NaOH solution was added to the modifier solution, and the treatment was continued for 30min. Then, the treated fabric was washed with water for 5 times, and 2 g/L of glacial acetic acid solution was used to neutralize the lye on the fabric, and finally washed with water until neutral, to obtain a cationic modified cotton fabric.

Example 2

The P(St-BA-VBT) microsphere dispersion was added dropwise to the reactive red 24 solution, the amount of dye relative to the nano-microspheres was 75wt%, 2.9mM/L (millimoles per liter) NaCl was added, and the concentration was 500N/L. Stir at a rotating speed for 1 min, and carry out dye adsorption at pH 5 and room temperature of 25 °C. After 120 min, dialysis and purification are performed to obtain reactive red 24 colored microspheres (dye adsorption capacity 363 mg/g, average particle size 85 nm).

The reactive red 24 color microsphere dispersion liquid was selected as the dyeing liquid, and the modified fabric in Example 1 was dyed by means of dip dyeing on an infrared dyeing machine. The specific operations are as follows: use distilled water to prepare reactive red 24 color microsphere dispersion with a concentration of 5%, and the bath ratio of the color microsphere dye solution to the modified fabric is 50:1; set the parameters of the infrared dyeing machine: rotating speed 200N/min, temperature 25°C, staining at pH 4.70 for 30 min. After dyeing, the fabric was washed with distilled water, placed flat in a blast drying oven for drying, and then placed in an oven at 40° C. for 30 min to obtain a dry primary dyed fabric.

Adjust the pH value of the residual liquid after the initial dyeing to be consistent with the original dyeing solution, and adjust its concentration to be c _n =c _n-1 +0.5%, and repeat the dyeing of the initially dyed fabric by using the same dyeing process to obtain the dyeing after cyclic dyeing fabric, see Table 1 for its color index. In Table 1, fabric 0 is the modified cotton fabric dyed with the original solution, and fabrics 1 to 4 are the cotton fabrics dyed by the microsphere dispersion for 1 to 4 times, respectively.

Table 1 Color index of cyclic dyeing modified cotton fabric in Example 2 of the present invention

As shown in Table 1, among all the fabrics, the K/S value of fabric 0 is the largest of 14.8, and the K/S value of fabric 3 is the smallest of 14.2, and the difference between the two is only 0.6, that is, the K/S value of fabrics 0 to 4 varies greatly. small, indicating that the recycling of reactive dye/copolymer microsphere dispersions has no effect on the apparent color depth of the fabric. In addition, the other color values of fabrics 0 to 4 are similar, and there is almost no color difference between fabrics, which indicates that the reactive dye/copolymer microsphere cyclic dyeing process is feasible. Since the color index of the fabric is closely related to the stability of the reactive dye/copolymer microspheres, the absence of color difference also indicates that the reactive dye/copolymer microspheres still maintain the same stability and dyeing performance after recycling.

The above-mentioned color index test method is: fold the colored fabric into 4 layers, place it in the test hole of the Datacolor SF-600plus colorimeter, and set the test parameters: D65 light source, 6mm measuring aperture, 10° viewing angle; Color indicators L*, a*, b*, C* and h°. Each layer of the fabric is tested twice and the average is taken.

In addition, the present invention tests the color fastness of dyed fabrics, and the color fastness to rubbing and washing of the colored fabrics are respectively in accordance with GB/T 3920-2008 "Color Fastness Test of Textiles" and GB/T3921-2008 The test was carried out according to the method described in "Color fastness to soaping of textile color fastness test". The result is as follows:

Table 2 Color fastness index of cyclic dyeing modified cotton fabric in Example 2 of the present invention

As can be seen from Table 2, the dry rubbing fastness of fabric 0-1 is grade 5, and the wet rubbing fastness is 4-5; the dry rubbing fastness of fabric 2-4 is 4-5 grade, and the wet rubbing fastness is fast. The color fastness of fabric 0 dyed by the original solution is grade 3-4, and the color fastness of fabric 1-4 is grade 3; the staining fastness of all fabrics is grade 5. Despite the increased number of dyeing cycles of the microsphere dispersion, the excellent color fastness can still meet the application standards for dyed fabrics. The color fastness of the fabric depends on the electrostatic attraction and hydrophobic interaction between the copolymer microspheres and the cationically modified cotton fabric, therefore, the excellent color fastness indicates that the interaction between the two is not affected by the recycling process. These results demonstrate that the recycling and cyclic dyeing of reactive dye/copolymer microspheres is feasible, and the process can potentially achieve zero emissions.

Example 3

The P(St-BA-VBT) microsphere dispersion was added dropwise to the reactive yellow 95 solution, the amount of dye relative to the nanospheres was 75wt%, 2.9mM/L NaCl was added, and the stirring speed was 500N/min. The value was 5, the dye was adsorbed at room temperature of 25°C, and purified by dialysis after 120 min to obtain reactive yellow 95 colored microspheres (dye adsorption amount 580 mg/g, average particle size 83 nm).

The reactive yellow 95 color microsphere dispersion liquid was selected as the dyeing liquid, and the modified fabric in Example 1 was dyed by means of dip dyeing on an infrared dyeing machine. The specific operations are as follows: use distilled water to prepare reactive yellow 95 color microsphere dispersion with a concentration of 5%, and the bath ratio of color microsphere dye solution and modified fabric is 50:1; set the parameters of the infrared dyeing machine: rotating speed 500N/min, temperature Dyeing at pH 5.0 at 25°C for 30 min. After dyeing, the fabric was washed with distilled water, placed flat in a blast drying oven for drying, and then placed in an oven at 40° C. for 30 min to obtain a dry primary dyed fabric.

Adjust the pH value of the residual liquid after the initial dyeing to be consistent with the original dyeing solution, and adjust its concentration to be c _n =c _n-1 +0.5%, and repeat the dyeing of the initially dyed fabric by using the same dyeing process to obtain the dyeing after cyclic dyeing For fabrics, see Table 3 for color index and Table 4 for color fastness index. In Tables 3 and 4, fabric 0 is the modified cotton fabric dyed with the original solution, and fabrics 1 to 4 are cotton fabrics dyed with the microsphere dispersion liquid for 1 to 4 times, respectively.

Table 3 The color index of the cyclic dyeing modified cotton fabric in Example 3 of the present invention

Table 4 The color fastness index of the cyclic dyeing modified cotton fabric in Example 3 of the present invention

Example 4

The P(St-BA-VBT) microsphere dispersion was added dropwise to the reactive yellow 95 solution, the amount of dye relative to the nanospheres was 60wt%, 2.9mM/L NaCl was added, and the stirring speed was 500N/min. The value was 5, the dye was adsorbed at room temperature of 25°C, and purified by dialysis after 120 min to obtain reactive yellow 95 colored microspheres (dye adsorption amount of 530 mg/g, average particle size of 93 nm).

The reactive yellow 95 color microsphere dispersion liquid was selected as the dyeing liquid, and the modified fabric in Example 1 was dyed by means of dip dyeing on an infrared dyeing machine. The specific operations are as follows: use distilled water to prepare reactive yellow 95 color microsphere dispersion with a concentration of 3%, and the bath ratio of color microsphere dye solution and modified fabric is 30:1; set the parameters of the infrared dyeing machine: rotating speed 500N/min, temperature Dyeing at pH 5.0 at 25°C for 30 min. After dyeing, the fabric was washed with distilled water, placed flat in a blast drying oven for drying, and then placed in an oven at 40° C. for 50 min to obtain a dry primary dyed fabric.

Adjust the pH value of the residual liquid after the initial dyeing to be consistent with the original dyeing solution, and adjust its concentration to be c _n =c _n-1 +0.5%, and repeat the dyeing of the initially dyed fabric by using the same dyeing process to obtain the dyeing after cyclic dyeing Fabric, its color index, color fastness results are as follows:

Table 5 The color index of the cyclic dyeing modified cotton fabric in Example 4 of the present invention

Table 6 Color fastness index of cyclic dyeing modified cotton fabric in Example 4 of the present invention

It can be seen from the above examples that the colored microspheres described in the present application have a certain stability. By cyclically dyeing the modified fabric, a darker and brighter dyed fabric can be obtained by using very few dyes, which saves dyes and significantly improves the dyeing performance. The utilization rate of dyes is environmentally friendly and the cost is low. Compared with the traditional dip-dyeing process dyed fabric, the microsphere cyclic dyeing fabric of the invention has significantly higher K/S and darker color; and the dyed fabric has better color fastness, and various fastness indexes meet the application standards of dyed fabrics.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present invention, various modifications to these embodiments can be realized, while These modifications should also be regarded as the scope of protection of the present invention.

Claims (7)

1. A method for circularly dyeing fabric by using reactive dye colored microspheres comprises the following steps:

s1, adsorbing the reactive dye by using polystyrene-acrylate cation nano microspheres to obtain reactive dye colorful microspheres, wherein the use amount of the reactive dye relative to the nano microspheres is 60-75 wt%; the reactive dye is reactive red 24 or reactive yellow 95; the adsorption of the reactive dye is carried out in the presence of sodium chloride under the stirring condition;

s2, taking the dispersion liquid of the reactive dye color microspheres as a dye solution, and carrying out primary dip dyeing on the cationic modified cellulose fabric, wherein the reactive dye color microspheres have the weight c on the fabric₀1 to 10 percent, the dyeing temperature is 25 to 50 ℃, and the dyeing pH value is 3 to 5Dyeing for 10-90 min to obtain a primary dyed fabric and dyeing residual liquid;

s3, adjusting the concentration of the dyeing residual liquid according to the formula 1, and circularly dyeing the primarily dyed fabric by adopting the primary dip dyeing process to obtain a dyed fabric;

c_n＝c_n-1+ 0.5% of formula 1;

n is the number of dyeing cycles, c_nThe dye liquor concentration of the nth dyeing is shown.

2. The cyclic dyeing method according to claim 1, wherein the polystyrene-acrylate cationic nanospheres have an average particle size of 50nm to 150 nm.

3. The cyclic dyeing method according to claim 1, wherein the polystyrene-acrylate cationic nanospheres are styrene-butyl acrylate copolymer cationic nanospheres.

4. The cyclic dyeing process according to claim 1, characterized in that the cationic modified cellulose fabric is obtained by modifying a cellulose fabric with a modifier selected from one or more of polyepichlorohydrin amide, epoxypropyltrimethylammonium chloride and 3-chloro-2-hydroxypropyltrimethylammonium chloride.

5. The cyclic dyeing process according to claim 4, characterized in that the cellulose fabric is selected from cotton, hemp, tencel or modal.

6. The cyclic dyeing method according to claim 1, wherein in step S2, the bath ratio of the primary dip dyeing is 1:20 to 1: 100.

7. The cyclic dyeing method according to claim 1, wherein the step S2 further comprises, after the completion of the primary exhaust dyeing: and washing the fabric, and drying at 40-110 ℃ to obtain the dry primarily dyed fabric.