Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the present invention is directed to solving at least one or more of the problems of wastewater discharge, deep dyeing tone, blackness improvement of black cotton fabric, color fixation of a coordinated reactive dye composition, and improvement of the color fastness of waterless dyeing, especially the most common color fastness to rubbing and color fastness to washing.
Further, the invention aims to simultaneously solve the problems of waste water discharge, deep color dyeing, black degree improvement of black cotton fabrics and the like caused by water bath dyeing.
Furthermore, the invention aims to simultaneously solve the problems of waste water discharge, deep color dyeing, black degree improvement of black cotton fabrics, color fixation rate equivalent to that of the prior art and the like caused by water bath dyeing.
Still further, the invention aims to simultaneously solve the problems of waste water discharge, deep color dyeing, black degree improvement of black cotton fabrics, color fixation rate higher than that of the prior art and the like caused by water bath dyeing.
And, still further, the present invention is directed to simultaneously solve the problems of wastewater discharge, deep dyeing tone, improvement of blackness of black cotton fabric, coordination of fixation ratio of reactive dye composition, improvement of dyeing fastness of waterless dyeing, etc. caused by water bath dyeing.
In order to solve the problems, the invention adopts the following technical scheme: a waterless dyeing method for synchronously dyeing and fixing high-blackness cotton fabric comprises the following steps: placing the cotton fabric in an anhydrous dye bath, heating at a certain speed, keeping the temperature after reaching a target temperature, and dyeing for a certain time; cooling to room temperature after dyeing is finished, cleaning the dyed fabric by using an anhydrous solvent, and finally drying to obtain a dyed cotton fabric; the anhydrous dye bath is obtained by dissolving a reactive dye in an anhydrous solvent, wherein the anhydrous solvent consists of ethylene glycol monomethyl ether acetate and an aprotic polar solvent; characterized in that the method comprises the step of further adding an organic base into the anhydrous dye bath before the temperature rise is started.
The anhydrous dyeing method according to the present invention, wherein the aprotic polar solvent is selected from any one or more of dimethyl sulfoxide, dimethylformamide, dimethylacetamide, sulfolane, acetonitrile and acetone.
The anhydrous dyeing method according to the present invention, wherein the aprotic polar solvent is selected from any one or more of dimethylsulfoxide, dimethylformamide and dimethylacetamide.
The anhydrous dyeing method according to the present invention, wherein the aprotic polar solvent is selected from dimethylsulfoxide.
According to the anhydrous dyeing method, the volume ratio of the ethylene glycol monomethyl ether acetate to the dimethyl sulfoxide is (55-80): (45-20).
According to the anhydrous dyeing method, the volume ratio of the ethylene glycol monomethyl ether acetate to the dimethyl sulfoxide is (65-75): (35-25).
The anhydrous dyeing method according to the present invention, wherein the organic base is a mixture of triethylene diamine and tetramethyl guanidine.
According to the anhydrous dyeing method, the weight ratio of the triethylene diamine to the tetramethyl guanidine is (1.5-2): 1.
according to the anhydrous dyeing method, the adding amount of the organic base is 2-8 g/L.
According to the anhydrous dyeing method, the cotton fabric is swelled by dimethyl sulfoxide in advance.
Reactive dyes
The reactive dye of the present invention is selected from reactive black dye compositions.
Further, the reactive black dye composition comprises a dye compound A, wherein the dye compound A is selected from any one or more of dye compounds shown in a formula (I);
in the formula (I), R1-R4Each independently selected from H, C1-C4Alkyl radical, C1-C4Alkoxy and SO3M;Y1-Y2Each independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K.
Further, the reactive black dye composition also comprises a dye compound B and a dye compound C; wherein,
the dye compound B is selected from any one or more of dye compounds shown in a formula (II);
in the formula (II), R5-R8Each independently selected from H, C1-C4Alkyl radical, C1-C4Alkoxy and SO3M;Y3-Y4Each independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K;
the dye compound C is selected from any one or more of dye compounds shown in a formula (III);
in the formula (III), R9-R10Each independently selected from H, C1-C4Alkyl radical, C1-C4Alkoxy and SO3M;Y5Independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K.
In a preferred embodiment, the dye compound a is selected from any one or more of the dye compounds represented by formula (I');
in the formula (I'), Y1-Y2Each independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K;
the dye compound B is selected from any one or more of dye compounds shown in a formula (II');
in the formula (II'), R6Selected from SO3M;R7-R8Each independently selected from C1-C4Alkyl and C1-C4An alkoxy group; y is3-Y4Each independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K;
the dye compound C is selected from any one or more of dye compounds shown in a formula (III');
in the formula (III), Y5Independently selected from SO2CH=CH2Or SO2CH2CH2OSO3M; m is selected from H, Na or K.
In a specific embodiment, the dye compound A is selected from the dye compounds represented by the formula (I-1),
in another embodiment, the dye compound A is selected from the dye compounds represented by the formula (I-2),
in a specific embodiment, the dye compound B is selected from the dye compounds represented by the formula (II-1),
in another embodiment, the dye compound B is selected from the dye compounds represented by the formula (II-2),
in a specific embodiment, the dye compound C is selected from the dye compounds represented by the formula (III-1),
in another embodiment, the dye compound C is selected from the dye compounds represented by the formula (III-2),
in the present invention, the dye compound is derived from a commercially known product, and can be prepared according to a known method.
Most preferably, the dye compound A, the dye compound B and the dye compound C of the present invention are selected from the dye compounds represented by the formula (I-1), the dye compounds represented by the formula (II-1) and the dye compounds represented by the formula (III-1).
Of course, those skilled in the art know that the dye compounds represented by the formula (I-2), the dye compounds represented by the formula (II-2), and the dye compounds represented by the formula (III-2) may be used instead of the above dye compounds because they can be converted into the dye compounds represented by the formula (I-1), the dye compounds represented by the formula (II-1), and the dye compounds represented by the formula (III-1) under basic conditions.
Advantageously, when the dye compound represented by the formula (I-2), the dye compound represented by the formula (II-2) or the dye compound represented by the formula (III-2) is used, a base is added to form a vinylsulfone dye compound before use, and then the mixture is precipitated under neutral conditions. And extracting the crude product by using an organic solvent, and distilling under reduced pressure to obtain the high-purity vinyl sulfone dye compound.
Further, as the reactive black dye composition of the present invention, a dye compound a, a dye compound B and a dye compound C are mainly included.
In the above embodiments, "mainly comprising" generally means that other dye components are optionally included in addition to the dye compound a, the dye compound B, and the dye compound C; however, the dye compound A, the dye compound B and the dye compound C account for more than 70%, preferably more than 80%, more preferably more than 90%, and most preferably more than 95% of the total weight of all the dye components.
In a preferred embodiment, "consisting essentially of means that the ratio of the total weight of the dye compound a, the dye compound B and the dye compound C to the weight of the reactive black dye composition is not less than 90%; preferably not less than 95%; more preferably not less than 97%; and, most preferably not less than 98%.
In a further preferred embodiment, the reactive black dye composition according to the invention consists of a dye compound a, a dye compound B and a dye compound C. That is, the reactive black dye composition of the present invention is obtained by mixing the dye compound a, the dye compound B and the dye compound C.
Advantageously, the mixing can be either dry or wet.
In the dry mixing embodiment, the dye compounds are dry mixed using dye granules obtained by extrusion granulation or spray drying granulation. Advantageously, the particle size of the dye particles is 100-2000 μm, preferably 150-1500 μm, more preferably 200-1000 μm, and most preferably 200-500 μm.
In the wet mixing embodiment, the dye compounds are slurried in a ratio, agitated in a kettle, blended, and then spray dried.
The weight percentage of the dye compound a is 45-85% based on the total weight of the reactive black dye composition.
Preferably, the dye compound a is present in an amount of 50 to 80% by weight, based on the total weight of the reactive black dye composition.
More preferably, the weight percentage of the dye compound a is 55-75% based on the total weight of the reactive black dye composition.
And, most preferably, the weight percentage of the dye compound a is 60 to 70% based on the total weight of the reactive black dye composition.
In a specific embodiment, the weight percentage of dye compound a is 65% based on the total weight of the reactive black dye composition.
The weight percentage of the dye compound B is 15-35% based on the total weight of the reactive black dye composition.
Preferably, the weight percentage of the dye compound B is 18-32% based on the total weight of the reactive black dye composition.
More preferably, the weight percentage of the dye compound B is 20-30% based on the total weight of the reactive black dye composition.
And, most preferably, the weight percentage of the dye compound B is 22-28% based on the total weight of the reactive black dye composition.
In a specific embodiment, the dye compound B is present in an amount of 25% by weight, based on the total weight of the reactive black dye composition.
The dye compound C is present in an amount of 5 to 18% by weight, based on the total weight of the reactive black dye composition.
Preferably, the dye compound C is present in an amount of 6 to 16% by weight, based on the total weight of the reactive black dye composition.
More preferably, the weight percentage of the dye compound C is 7-14% based on the total weight of the reactive black dye composition.
And, most preferably, the weight percentage of the dye compound C is 8-12% based on the total weight of the reactive black dye composition.
In a specific embodiment, the dye compound C is present in an amount of 10% by weight, based on the total weight of the reactive black dye composition.
Anhydrous solvent
The anhydrous solvent of the invention mainly comprises ethylene glycol monomethyl ether acetate and an aprotic polar solvent.
In the present invention, "mainly consisting of …" means that the anhydrous solvent optionally includes other organic solvents in addition to ethylene glycol monomethyl ether acetate and the aprotic polar solvent, but the sum of the volumes of ethylene glycol monomethyl ether acetate and the aprotic polar solvent accounts for 90% or more, preferably 95% or more, more preferably 97% or more, and most preferably 98% or more of the sum of the volumes of all the solvents. In one embodiment, the volume of ethylene glycol monomethyl ether acetate is 65 units, the volume of the aprotic polar solvent is 30 units, and the volume of the other organic solvent is 5 units.
Advantageously, the volume ratio of ethylene glycol monomethyl ether acetate to aprotic polar solvent is (55-80): (45-20). Preferably, the volume ratio of the ethylene glycol monomethyl ether acetate to the aprotic polar solvent is (60-80): (40-20); more preferably, the volume ratio of ethylene glycol monomethyl ether acetate to aprotic polar solvent is (65-80): (35-20); and, most preferably, the volume ratio of ethylene glycol monomethyl ether acetate to aprotic polar solvent is (65-75): (35-25).
In a specific embodiment, the volume ratio of ethylene glycol monomethyl ether acetate to aprotic polar solvent is 70: 30.
in a preferred embodiment, the anhydrous solvent of the present invention consists of ethylene glycol monomethyl ether acetate and an aprotic polar solvent.
As the aprotic polar solvent of the present invention, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, sulfolane, acetonitrile, acetone and hexamethylphosphoramide are included.
Preferably, the aprotic polar solvent is selected from a mixture of any one or more of dimethyl sulfoxide, dimethylformamide, dimethylacetamide, sulfolane, acetonitrile and acetone.
More preferably, the aprotic polar solvent is selected from a mixture of any one or more of dimethyl sulfoxide, dimethylformamide, dimethylacetamide, sulfolane and acetonitrile.
And, most preferably, the aprotic polar solvent is selected from a mixture of any one or more of dimethyl sulfoxide, dimethylformamide and dimethylacetamide.
In a particular embodiment, the aprotic polar solvent is selected from dimethyl sulfoxide.
As other organic solvents of the present invention, there may be mentioned, but not limited to, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, halogenated hydrocarbon solvents, alcohol solvents, ether solvents, ester solvents, ketone solvents, polyol solvents and the like.
As the aromatic hydrocarbon solvent, for example, benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene, and the like can be cited.
As the aliphatic hydrocarbon solvent, for example, pentane, hexane, octane and petroleum ether having a boiling point of 60 to 90 ℃ and the like can be mentioned.
Examples of the alicyclic hydrocarbon solvent include cyclopentane, cyclohexane, cyclohexanone, tolucyclohexanone, and the like.
Examples of the halogenated hydrocarbon solvent include chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, bromobenzene, dichloromethane, and trichloromethane.
Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.
Examples of the ether solvent include methyl ether, ethyl ether, methylethyl ether, propylene oxide, tetrahydrofuran, dioxane, and the like.
Examples of the ester solvent include methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl n-butanone, methyl isobutyl ketone, and the like.
Examples of the polyhydric alcohol solvent include ethylene glycol, glycerol, ethylene glycol, monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, and ethylene glycol dibutyl ether.
As the remaining solvent, for example, dimethyl carbonate, phenol, and the like can be mentioned.
In view of the anhydrous solvent system and the dyeing and fixing mechanism of the present invention, as other organic solvents, it is preferable that the dyeing and fixing reaction is not disturbed. Such solvents may be considered inert solvents. In a particular embodiment, the inert solvent may be acetone. In another specific embodiment, the inert solvent may be dioxane.
However, as a most preferred embodiment, the anhydrous solvent of the present invention consists of ethylene glycol monomethyl ether acetate and dimethyl sulfoxide. That is, the anhydrous solvent of the present invention is a mixture of ethylene glycol monomethyl ether acetate and dimethyl sulfoxide.
Without wishing to be bound by any theory, the anhydrous solvent system of the present invention eliminates hydrolysis of the disperse black dye composition, and to some extent, improves dye uptake and fixation.
Advantageously, the volume ratio of ethylene glycol monomethyl ether acetate to dimethyl sulfoxide is (55-80): (45-20). Preferably, the volume ratio of the ethylene glycol monomethyl ether acetate to the dimethyl sulfoxide is (60-80): (40-20); more preferably, the volume ratio of ethylene glycol monomethyl ether acetate to dimethyl sulfoxide is (65-80): (35-20); and, most preferably, the volume ratio of ethylene glycol monomethyl ether acetate to dimethyl sulfoxide is (65-75): (35-25).
In a specific embodiment, the volume ratio of ethylene glycol monomethyl ether acetate to dimethyl sulfoxide is 70: 30.
the anhydrous solvent system with the specific composition further improves the dyeing fixation rate of the invention.
Color fixing base
In the process of the present invention, it is preferred to add a fixing base in view of fixing and improving dyeing properties.
The fixing base of the present invention may be theoretically an inorganic base or an organic base.
As the inorganic base, sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium hydroxide, potassium hydroxide, sodium tripolyphosphate, potassium tripolyphosphate, sodium hexametaphosphate, and potassium hexametaphosphate, and mixtures thereof can be mentioned.
Preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, and mixtures thereof.
More preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, and mixtures thereof.
And, most preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, and mixtures thereof.
The addition of the inorganic base can improve the dyeing fixation rate, but the solubility of the inorganic base in the anhydrous solvent system is limited; in addition, the inorganic bases have a limited degree of improvement in the dye fixation of the present invention at the same concentration. Thus, as the fixing base of the present invention, preference is given to organic bases; or primarily an organic base.
In one embodiment, as the fixing base of the present invention, an organic base is preferred.
As the organic base of the present invention, triethylene diamine, tetramethyl guanidine, hexamethylene tetramine, and mixtures thereof are selected.
In the invention, the addition of the organic alkali can obviously improve the dyeing fixation rate of the invention. In the case of not using organic alkali, although cotton fabrics with high degree of blackness can be obtained only depending on the used reactive dye and anhydrous solvent, the dyeing fixation rate is low and is only about 10%. This results in inefficient dyeing and significant waste of dye. Under the condition of using organic alkali, if only triethylene diamine is used, the dyeing fixation rate can reach about 65 percent at most; if only tetramethyl guanidine is used, the dyeing fixation rate can reach about 60 percent at most; whereas, if only hexamethylenetetramine is used, the dye fixation is generally around 30-40%.
Therefore, preferably, as the organic base of the present invention, triethylenediamine, tetramethylguanidine, and a mixture thereof are selected. When these organic bases are used, the dye fixation of the present invention is at least comparable to, or significantly higher than, existing aqueous dyeing processes.
In order to further improve the dyeing efficiency, the composition of an anhydrous solvent system needs to be optimized, and the mixture of triethylene diamine and tetramethyl guanidine is used as a color fixing base, so that the dyeing color fixing rate can be obviously improved. The inventor finds that the dye fixation rate of the invention can be optimized to 70-80% under the same other process parameters by adjusting the weight ratio of triethylene diamine and tetramethyl guanidine within a specific value range.
Advantageously, in the mixture of triethylenediamine and tetramethylguanidine, the weight ratio of triethylenediamine to tetramethylguanidine is (1.5-2): 1, preferably (1.5-1.9): 1, more preferably (1.5-1.8): 1, and, most preferably, (1.5-1.7): 1.
in a specific embodiment, the fixing base is selected from a mixture of triethylene diamine and tetramethyl guanidine, wherein the weight ratio of triethylene diamine to tetramethyl guanidine is 1.6: 1.
without wishing to be bound by any theory, since dyeing is carried out in an anhydrous solvent, the organic base of the specific composition of the present invention interacts with the dye compound a, the dye compound B and the dye compound C of the present invention, respectively, and finally promotes the nucleophilic addition or nucleophilic substitution reaction of the disperse black dye composition with the hydroxyl group on the cotton fiber. In contrast, triethylene diamine is more beneficial to improving the fixation rate of the dye compound A; and the tetramethylguanidine is more beneficial to improving the fixation rate of the dye compound B and the dye compound C.
On the other hand, for the effect on the fastness of dyeing, the organic bases of the specific composition according to the invention likewise have a greater effect on smooth cotton fabric fibers and on enhancing the dye-fiber interaction. The test result shows that the color fastness to rubbing and washing is improved.
In another embodiment, the fixing base of the present invention comprises primarily an organic base.
In the above embodiments, "consisting essentially of means that the fixation base optionally includes other organic and inorganic bases in addition to the organic base; but the weight of organic base is more than 90%, preferably more than 95%, more preferably more than 97%, and most preferably more than 98% of the sum of the weight of all fixing bases. Preferably, the fixing base optionally comprises an inorganic base as described above in addition to the organic base.
As the inorganic base, sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium hydroxide, potassium hydroxide, sodium tripolyphosphate, potassium tripolyphosphate, sodium hexametaphosphate, and potassium hexametaphosphate, and mixtures thereof can be mentioned.
Preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, and mixtures thereof.
More preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, sodium silicate, potassium silicate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, and mixtures thereof.
And, most preferably, the inorganic base is selected from the group consisting of sodium carbonate, sodium phosphate, potassium carbonate, potassium phosphate, and mixtures thereof.
In a particular embodiment, the fixing base is selected from a mixture of triethylenediamine, tetramethylguanidine and sodium carbonate.
Advantageously, in the mixture of triethylenediamine, tetramethylguanidine and sodium carbonate, the weight ratio of triethylenediamine, tetramethylguanidine and sodium carbonate is (1.5-2): 1: (0.01-0.3), preferably (1.5-1.9): 1: (0.01-0.25), more preferably (1.5-1.8): 1: (0.01-0.2), and, most preferably, (1.5-1.7): 1: (0.01-0.15).
In a more specific embodiment, the fixing base is selected from a mixture of triethylene diamine, tetramethyl guanidine and sodium carbonate in a weight ratio of 1.5: 1: 0.1.
dyeing method
The dyeing method of the invention comprises the steps of placing the cotton fabric in an anhydrous dye bath, heating at a certain speed, keeping the temperature after reaching the target temperature, and dyeing for a certain time; and cooling to room temperature after dyeing is finished, washing the dyed fabric by using an anhydrous solvent, and finally drying to obtain the dyed cotton fabric.
The anhydrous dye bath is obtained by dissolving the reactive dye (or the reactive black dye composition) in the anhydrous solvent.
In the present invention, the bath ratio of the cotton fabric (dry weight) to the anhydrous dye bath is 1: (8-25) g/mL.
Preferably, the bath ratio of the cotton fabric to the anhydrous dye bath is 1: (10-22) g/mL; more preferably, the bath ratio of the cotton fabric to the anhydrous dye bath is 1: (12-20) g/mL; and, most preferably, the bath ratio of the cotton fabric to the anhydrous dye bath is 1: (14-18) g/mL.
In a specific embodiment, the bath ratio of the cotton fabric to the anhydrous dye bath is 1: 16 g/mL.
In the present invention, the amount of the dye is 2 to 6 o.w.f..
Specifically, the dye amount is 2 o.w.f%, 3 o.w.f%, 4 o.w.f%, 5 o.w.f%, 6 o.w.f%.
Preferably, the dye is used in an amount of 2-5 o.w.f%; more preferably, the dye is used in an amount of 3-5 o.w.f..
In one embodiment, the dye is present in an amount of 4 o.w.f..
In the invention, the heating rate of dyeing is 0.5-5 ℃/min.
Preferably, the heating rate is 1-4.5 ℃/min; more preferably, the temperature rise rate is 1.5-4 ℃/min; and, most preferably, the rate of temperature rise is 2-3.5 ℃/min.
In a specific embodiment, the temperature ramp rate is 3 ℃/min.
In the present invention, the target temperature for dyeing is 70 to 100 ℃.
Preferably, the target temperature is 75-95 ℃; more preferably, the target temperature is 80-95 ℃; and, most preferably, the target temperature is 80-90 ℃.
In a specific embodiment, the target temperature is 85 ℃.
In the present invention, the dyeing time is 1 to 12 hours.
Preferably, the dyeing time is 2-10 h; more preferably, the dyeing time is 3-8 h; and, most preferably, the dyeing time is 4-6 h.
In a specific embodiment, the staining time is 5 h.
In the invention, the method further comprises the step of adding a fixing alkali for fixing.
As the fixing base of the present invention, organic bases are preferred; or primarily an organic base.
After cooling to room temperature at the end of dyeing, the washing is advantageously carried out more than once, preferably more than twice, each with ethylene glycol monomethyl ether acetate and with aprotic polar solvents, respectively, until the last wash is colorless.
In a specific embodiment, after the dyeing is finished and cooled to room temperature, the washing is respectively carried out more than once, preferably more than twice by using ethylene glycol monomethyl ether acetate and dimethyl sulfoxide until the washing liquid at the last time is colorless.
More advantageously, the washing is carried out alternately with hot ethylene glycol monomethyl ether acetate and hot dimethyl sulfoxide more than once, preferably more than twice, each until the last washing is colorless.
In the above, "hot" means a temperature between 40 and 60 c, preferably between 45 and 55 c.
In a specific embodiment, "hot" means 50 ℃.
Advantageously, the cotton fabric used as the above-mentioned method is previously subjected to dimethyl sulfoxide swelling. Preferably, the swelling degree of the cotton fabric is between 10 and 30%, more preferably between 15 and 30%, and, most preferably between 20 and 30%.
In a particular embodiment, the cotton fabric has a swelling degree of 22%.
The swelling of the cotton fabric is preferably obtained by soaking at 60-90 deg.C, preferably 70-90 deg.C for 0.5-12h, preferably 1-6 h.
On swelling, the bath ratio is advantageously 1: (10-50); preferably, the bath ratio is advantageously 1: (15-45); more preferably, the bath ratio is advantageously 1: (20-40); and, most preferably, the bath ratio is advantageously 1: (25-35).
In a specific embodiment, the swelling of the cotton fabric is obtained by soaking for 4h at 80 ℃ with a bath ratio of 1: 30. the swelling degree of the product is 22% according to a centrifugal weighing method.
In a preferred embodiment, when a fixing base is used and when the fixing base is the aforementioned organic base, the invention also provides a dyeing process for simultaneous fixing of cotton fabric on dyeing, said process comprising the further addition of the aforementioned organic base to the aforementioned anhydrous dye bath before the start of the temperature increase.
In the present invention, the organic base is added in an amount of 2 to 8 g/L. Preferably, the addition amount of the organic base is 3-8 g/L; more preferably, the addition amount of the organic base is 4-8 g/L; and, most preferably, the organic base is added in an amount of 5 to 8 g/L.
In a specific embodiment, the organic base is added in an amount of 6 g/L.
Advantageously, the cotton fabric used as the above-mentioned method is previously subjected to dimethyl sulfoxide swelling. Preferably, the swelling degree of the cotton fabric is between 10 and 30%, more preferably between 15 and 30%, and, most preferably between 20 and 30%.
In a particular embodiment, the cotton fabric has a swelling degree of 22%.
Swelling of the cotton fabric was carried out as described above.
In another preferred embodiment, when a fixing base is used and when the fixing base mainly comprises the aforementioned organic base, the present invention also provides a dyeing process for fixing cotton fabrics by dyeing in steps, which comprises further adding the aforementioned fixing base in the aforementioned anhydrous dye bath after reaching the target temperature.
In the present invention, the fixing base is added in an amount of 2-8 g/L. Preferably, the addition amount of the fixing base is 3-8 g/L; more preferably, the fixing base is added in an amount of 4-8 g/L; and, most preferably, the fixing base is added in an amount of 5 to 8 g/L.
In a specific embodiment, the fixing base is added in an amount of 6 g/L.
Advantageously, the cotton fabric used as the above-mentioned method is previously subjected to dimethyl sulfoxide swelling. Preferably, the swelling degree of the cotton fabric is between 10 and 30%, more preferably between 15 and 30%, and, most preferably between 20 and 30%.
In a particular embodiment, the cotton fabric has a swelling degree of 22%.
Swelling of the cotton fabric was carried out as described above.
Without wishing to be bound by any theory, swelling contributes to an improved interaction between the cotton fabric fibers and the reactive dyes, thereby increasing the dye fixation of the present invention, while also contributing to further improvement of the fastness to washing.