阅读说明：本技术 一种含pbt的双组分弹性纤维染色工艺 (PBT-containing bi-component elastic fiber dyeing process ) 是由 史连明 于 2020-12-24 设计创作，主要内容包括：本发明提供一种含PBT的双组分弹性纤维染色工艺,包括通过酯化反应和缩聚反应制备改性PET熔体,进而通过POY工艺制备PET POY丝和PBT POY丝,最终制成双组分弹性纤维；将制备好的双组分弹性纤维依次经过漂洗,除湿,第一次染色,第二次染色,水洗,脱水,干燥。通过本发明制成的双组分弹性纤维上染率高,匀染性达到5级,在耐皂洗色牢度达到5级,干摩擦牢度达到5级。(The invention provides a process for dyeing a dual-component elastic fiber containing PBT, which comprises the steps of preparing a modified PET melt through esterification reaction and polycondensation reaction, further preparing PET POY (polyester oriented yarn) and PBT POY (polybutylene terephthalate POY) through a POY (polyester oriented yarn) process, and finally preparing the dual-component elastic fiber; the prepared bi-component elastic fiber is sequentially subjected to rinsing, dehumidification, primary dyeing, secondary dyeing, washing, dehydration and drying. The bicomponent elastic fiber prepared by the invention has high dye-uptake, level-dyeing property reaching 5 grades, soaping-resistant color fastness reaching 5 grades, and dry friction fastness reaching 5 grades.)

1. A process for dyeing PBT-containing bicomponent elastic fiber is characterized in that the bicomponent elastic fiber comprises a PBT component and a PET component; the dyeing process method comprises the following steps:

preparing a modified PET melt: carrying out esterification reaction and polycondensation reaction on the PET melt to prepare a modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component filament bundles, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching, false twisting and deformation to prepare double-component DTY to prepare double-component elastic fibers;

rinsing, namely putting the prepared bi-component elastic fiber into a rinsing water solution at the temperature of 90-100 ℃, preserving heat and standing for 1-2h, and then washing in a water solution at the temperature of 50-70 ℃ to remove residues on the surface of the bi-component elastic fiber;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 50-55 ℃, preserving heat, soaking for 0.2-0.5h, standing for 0.5-1h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.2-0.5h, and naturally cooling;

and (3) dyeing for the second time: adding dyeing assistant into the dyeing solution which is naturally cooled to 30-40 ℃, fully mixing, then heating the dyeing solution to 70-80 ℃, soaking the bi-component elastic fiber for 0.3-0.5h in a heat preservation way, continuously heating the dyeing solution to a boiling state, and soaking for 0.5-1h in a heat preservation way;

washing with water: washing the dyed fabric with cold water at 15-20 ℃, and then washing with warm water at 35-40 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35-40%;

and (3) drying: drying the dehydrated fabric at 55-60 deg.C for 3-5h, and oven drying at 80-85 deg.C.

2. The dyeing process for bicomponent elastic fiber according to claim 1, wherein in the step of preparing the modified PET melt, terephthalic acid, heptanediol having a tertiary butyl side group with ethylene glycol and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol are mixed uniformly, and then the PET melt is subjected to esterification reaction and polycondensation reaction.

3. The two-component spandex dyeing process of claim 2, wherein the second hot box temperature of the DTY process is 130-150 ℃.

4. The process for dyeing bicomponent elastic fiber according to claim 2, wherein the 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol is synthesized by the following steps: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 10-15%, reacting for 3-4h at the temperature of 70-75 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.5-2.0: 0.015.

5. Dyeing process for bicomponent elastic fibers according to claim 2, characterized in that the esterification reaction comprises the following steps:

preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the temperature of the esterification reaction is 250-260 ℃, and the end point of the esterification reaction is determined when the water distillation amount in the esterification reaction reaches more than 90% of the theoretical value.

6. Dyeing process for bicomponent elastic fibers according to claim 5, characterized in that the esterification reaction is followed by a polycondensation reaction comprising the following steps:

the pressure in the stage is steadily pumped from normal pressure to below 500Pa absolute within 0.5-1h, the reaction temperature is 260-minus one DEG C, the reaction time is 0.5-1h, then the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is further reduced to below 100Pa absolute, the reaction temperature is 275-minus one DEG C, and the reaction time is 1-1.5 h.

7. Dyeing process for bicomponent elastic fibers according to claim 1, characterized in that in the rinsing step the concentration of the aqueous rinsing solution is comprised between 10 and 20 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide to the hydrogen peroxide to the stabilizer to the second penetrating agent to the chelating agent is 4-6: 5-8: 4-6: 1-2: 1.

8. the dyeing process for the bi-component elastic fibers according to claim 1, wherein the dyeing solution comprises a pigment, a dyeing assistant, a penetrating agent and water, the mass ratio of the pigment, the dyeing assistant, the penetrating agent and the water is 15-25:10-15:5-10:50-100, the solid is completely dissolved by stirring, and the pH value of the dyeing solution is 7.5-8.

9. The dyeing process for bi-component elastic fibers according to claim 8, wherein the dyeing assistant is prepared from the following raw materials in parts by weight: 3-5 parts of poloxamer/chitosan oligosaccharide compound, 1-2 parts of polyglutamic acid, 1-2 parts of crospovidone, 0.5-1 part of hydrolyzed polymaleic anhydride, 0.5-1 part of disodium ethylene diamine tetraacetate, 0.3-0.5 part of allyl glycidyl ether and 0.1-0.3 part of bis (trifluoromethanesulfonyl) imide, and the preparation method comprises the following steps: adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into the cross-linked polyvidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, continuing the microwave treatment, adding the poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, adding boiling water into the obtained mixture under stirring until the mixture is completely dissolved, naturally cooling the obtained mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant.

10. The process for dyeing bicomponent elastic fiber according to claim 1, wherein the content ratio of the PET component to the PET component in the bicomponent elastic fiber is 1:1, the dye uptake of the bi-component elastic fiber at 120 ℃ is 88.7-94.3%, the K/S value is 22.62-25.74, the soaping resistance color fastness reaches 5 grade, and the dry rubbing fastness reaches 5 grade.

Technical Field

The invention relates to the technical field of composite fibers, in particular to a process for dyeing a dual-component elastic fiber containing PBT.

Background

The history of the composite fiber can trace back to the bicomponent glass fiber appearing in the nineteenth century, and people begin the research of the bicomponent chemical fiber by the thirty-four decades of the twentieth century. By the fifty years, DuPont developed a polyamide bicomponent composite fiber "Cantresse" and used it commercially. By the seventies of the last century, bicomponent fibers began to rise in asian countries, and many companies such as eastern japan, korea, etc. had been invested in research, development, and commercial applications, and employed highly complex, expensive spinneret assemblies. In the eighty and ninety years of the last century, in order to meet the requirements of people on the research and development and production of composite fibers, the improvement research on a spinneret plate assembly is hot, the developed spinneret plate assembly with a thin flat plate structure endows the composite fibers with the advantages of flexibility and low cost of key equipment, and at the moment, more than 4 machine companies can provide related equipment and technologies of bicomponent fibers.

At present, a new technical revolution of the global chemical fiber industry is developing, the era of 'large fiber' is coming, functionalization, differentiation, intellectualization and greening become development trends of the chemical fiber industry, the field of high-performance fiber is the scientific and technological high point of the global competition, and the composite fiber technology is more and more paid attention by the industry as one of key realization technologies of the high-performance fiber. The united states announced the establishment of the "research center for revolutionary fiber and fabric manufacturing" (RFT MII) in 2016, and the close integration of new revolutionary fabrics and fibers with various areas of national economy has led to a number of new applications that soon became the focus of research and development in various well-known colleges and scientific institutions in the united states.

The PBT fiber has excellent dyeing property and elastic recovery rate, lower modulus, softness and comfort; while PET fibers have poor dyeability, they have high modulus and excellent dimensional stability, and the combination of both fibers can exert their advantages to the greatest extent.

However, since terylene is hydrophobic fiber, the molecule thereof does not contain hydrophilic groups, and the molecular structure thereof lacks active groups which can be combined with dye, such as cellulose or protein fiber, and the dyeing performance of terylene fiber is not good. In addition, the finished product of the polyester fiber is a partially crystallized supermolecular structure, molecular chains of the crystallized parts of the polyester fiber are mutually parallel and mostly in a trans-conformation, while an amorphous region is mostly in a cis-conformation, and the molecular arrangement of the amorphous region is quite tight, so that the dyeing difficulty of the polyester fiber is further increased. At present, the conventional Polyester (PET) fiber is generally dyed by using disperse dyes at high temperature (130 ℃) and high pressure, the dye-uptake of the fiber can be ensured only by dyeing at high temperature and high pressure, the requirements of high temperature and high pressure on equipment are higher, the energy consumption is higher, meanwhile, the dyeing difficulty is high, the dyeing required time is longer, the cost of the process is higher, and the application of the colorful PET/PBT fiber is limited to a certain extent.

Therefore, how to overcome the defect of poor dyeing property of PET fibers and prepare the PBT-containing two-component elastic yarn becomes the problem to be solved urgently at present

Disclosure of Invention

The invention solves the technical problem of providing a process for dyeing the dual-component elastic fiber containing the PBT, and the process enables dye molecules to enter the fiber more easily in the dyeing process by modifying the PET and combining the PET with the PBT, thereby improving the dyeing performance of the PET to a certain extent, and having simple dyeing process and low dyeing cost.

In order to solve the technical problems, the invention provides a process for dyeing a PBT-containing bicomponent elastic fiber, wherein the bicomponent elastic fiber comprises a PBT component and a PET component; the dyeing process method comprises the following steps:

preparing a modified PET melt: carrying out esterification reaction and polycondensation reaction on the PET melt to prepare a modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component filament bundles, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching, false twisting and deformation to prepare double-component DTY to prepare double-component elastic fibers;

rinsing, namely putting the prepared bi-component elastic fiber into a rinsing water solution at the temperature of 90-100 ℃, preserving heat and standing for 1-2h, and then washing in a water solution at the temperature of 50-70 ℃ to remove residues on the surface of the bi-component elastic fiber;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 50-55 ℃, preserving heat, soaking for 0.2-0.5h, standing for 0.5-1h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.2-0.5h, and naturally cooling;

and (3) dyeing for the second time: adding dyeing assistant into the dyeing solution which is naturally cooled to 30-40 ℃, fully mixing, then heating the dyeing solution to 70-80 ℃, soaking the bi-component elastic fiber for 0.3-0.5h in a heat preservation way, continuously heating the dyeing solution to a boiling state, and soaking for 0.5-1h in a heat preservation way;

washing with water: washing the dyed fabric with cold water at 15-20 ℃, and then washing with warm water at 35-40 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35-40%;

and (3) drying: drying the dehydrated fabric at 55-60 deg.C for 3-5h, and oven drying at 80-85 deg.C.

Preferably, in the step of preparing the modified PET melt, terephthalic acid, ethylene glycol heptanediol with tertiary butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol are mixed uniformly, and then esterification reaction and polycondensation reaction are carried out on the PET melt.

Preferably, the temperature of the second hot box of the DTY process is 130-150 ℃.

Preferably, the synthesis method of the 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol comprises the following steps: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 10-15%, reacting for 3-4h at the temperature of 70-75 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.5-2.0: 0.015.

Preferably, the esterification reaction comprises the following steps:

preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the temperature of the esterification reaction is 250-260 ℃, and the end point of the esterification reaction is determined when the water distillation amount in the esterification reaction reaches more than 90% of the theoretical value.

Preferably, after the esterification reaction is finished, a polycondensation reaction is performed, and the polycondensation reaction includes the following steps:

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the condition of negative pressure, wherein the pressure in the stage is stably pumped from normal pressure to below 500Pa absolute pressure within 0.5-1h, the reaction temperature is 260-285 ℃, the reaction time is 0.5-1h, then continuing to pump vacuum to perform the polycondensation reaction in the high vacuum stage, and further reducing the reaction pressure to below 100Pa absolute pressure, the reaction temperature is 275-285 ℃, and the reaction time is 1-1.5 h.

Preferably, in the rinsing step, the concentration of the rinsing aqueous solution is 10-20 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide to the hydrogen peroxide to the stabilizer to the second penetrating agent to the chelating agent is 4-6: 5-8: 4-6: 1-2: 1.

preferably, the dyeing liquid comprises pigment, dyeing assistant, penetrating agent and water, the mass ratio of the pigment, the dyeing assistant, the penetrating agent and the water is 15-25:10-15:5-10:50-100, the solid is completely dissolved by stirring, and the pH value of the dyeing liquid is 7.5-8.

Preferably, the dyeing assistant is prepared from the following raw materials in parts by weight: 3-5 parts of poloxamer/chitosan oligosaccharide compound, 1-2 parts of polyglutamic acid, 1-2 parts of crospovidone, 0.5-1 part of hydrolyzed polymaleic anhydride, 0.5-1 part of disodium ethylene diamine tetraacetate, 0.3-0.5 part of allyl glycidyl ether and 0.1-0.3 part of bis (trifluoromethanesulfonyl) imide, and the preparation method comprises the following steps: adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into the cross-linked polyvidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, continuing the microwave treatment, adding the poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, adding boiling water into the obtained mixture under stirring until the mixture is completely dissolved, naturally cooling the obtained mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant.

Preferably, in the bicomponent elastic fiber, the content ratio of the PET component to the PET component is 1:1, the dye uptake of the bi-component elastic fiber at 120 ℃ is 88.7-94.3%, the K/S value is 22.62-25.74, the soaping resistance color fastness reaches 5 grade, and the dry rubbing fastness reaches 5 grade.

Compared with the related art, the cleaning device for processing the metal product provided by the invention has the following beneficial effects:

(1) the PBT-containing bicomponent elastic fiber has excellent dyeing property, the dye-uptake rate is 88.7-94.3% under the temperature condition of 120 ℃, the K/S value is 22.62-25.74, the soaping color fastness (polyester staining and cotton staining) reaches 5 grades, and the dry friction fastness reaches 5 grades, which is far higher than the level of the prior art;

(2) the preparation method of the PBT-containing two-component elastic yarn is simple in process, and the dyeing property of PET fibers is remarkably improved by introducing 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol and heptanediol with a tert-butyl side group into a PET molecular chain, so that the comprehensive property of the PBT-containing two-component elastic yarn is improved.

(3) The purity and the moisture content of the composite fiber are controlled by rinsing and dehumidifying the composite fiber in the dyeing process so as to ensure the dye concentration of the dyeing solution; the problem that the concentration of the dyeing solution suddenly changes due to water evaporation of the dyeing solution caused by long-time boiling dyeing is solved by a step-by-step heating dyeing mode;

(4) the level-dyeing property and the color fastness are improved by adding a dyeing assistant in the secondary dyeing process; the dyeing process disclosed by the invention has the advantages that the excellent dyeing effect on the PBT-containing bi-component elastic fiber is ensured, the dye-uptake is high, the level-dyeing property reaches 5 grades, the penetrability is good, and the washing fastness, the perspiration fastness, the light fastness, the ironing fastness, the sublimation fastness and the rubbing fastness can reach 5 grades, so that the use quality of the dyed textile fabric is ensured.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Example 1:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 10%, reacting for 4 hours at the temperature of 70 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.5:0.015, uniformly mixing terephthalic acid, heptanediol with ethylene glycol having tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 260 ℃, and the esterification reaction end point is determined when the water distillation amount in the esterification reaction reaches more than 90% of a theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to below 500Pa absolute within 0.5h, wherein the reaction temperature is 260 ℃ and the reaction time is 1h, then continuously pumping vacuum to perform the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to below 100Pa absolute, the reaction temperature is 285 ℃ and the reaction time is 1h, and preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 130 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 10 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide, the hydrogen peroxide, the stabilizer, the second penetrating agent and the chelating agent is 4: 5: 6: 2: 1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at 100 ℃, preserving heat and standing for 1.5h, and then washing in an aqueous solution at 60 ℃ to remove the surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises pigment, dyeing assistant, penetrant and water, the mass ratio of the pigment to the dyeing assistant to the penetrant to the water is 15:10:8:67, stirring the mixture to completely dissolve solid matters, and the pH value of the dyeing solution is 7.5. Soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 55 ℃, preserving heat, soaking for 0.5h, standing for 1h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.3h, and naturally cooling;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 40 ℃, fully mixing, then heating the dyeing solution to 80 ℃, soaking the bi-component elastic fiber for 0.3h under the condition of heat preservation, continuously heating the dyeing solution to a boiling state, and soaking for 0.6h under the condition of heat preservation;

washing with water: washing the dyed fabric with cold water at 20 ℃, and then washing with warm water at 40 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35%;

and (3) drying: drying the dehydrated fabric at 60 ℃ for 3h, and then drying at 85 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 89.3 percent under the temperature condition of 120 ℃, K/S value of 23.64, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

Example 2:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 15%, reacting for 3 hours at the temperature of 75 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:2:0.015, uniformly mixing terephthalic acid, ethylene glycol heptanediol with tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 260 ℃, and the esterification reaction end point is determined when the water distillation amount in the esterification reaction reaches more than 90% of a theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to below 500Pa absolute within 1h, controlling the reaction temperature to be 270 ℃ and the reaction time to be 1h, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to below 100Pa absolute, controlling the reaction temperature to be 280 ℃ and the reaction time to be 1.5h, thus preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 150 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 20 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide, the hydrogen peroxide, the stabilizer, the second penetrating agent and the chelating agent is 6: 5: 4: 2: 1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at 100 ℃, preserving heat and standing for 2 hours, and then washing in an aqueous solution at 50 ℃ to remove surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises a pigment, a dyeing assistant, a penetrating agent and water, the mass ratio of the pigment to the dyeing assistant to the penetrating agent to the water is 25:10:5:60, stirring the mixture to completely dissolve solid matters, and the pH value range of the dyeing solution is 8. Soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 55 ℃, preserving heat, soaking for 0.2h, standing for 1h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.2h, and naturally cooling;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 30 ℃, fully mixing, then heating the dyeing solution to 80 ℃, soaking the bi-component elastic fiber for 0.3h under the condition of heat preservation, continuing heating the dyeing solution to a boiling state, and soaking for 1h under the condition of heat preservation;

washing with water: washing the dyed fabric with cold water at 20 ℃, and then washing with warm water at 40 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35%;

and (3) drying: drying the dehydrated fabric at 60 ℃ for 5h, and then drying at 80 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 88.7 percent under the temperature condition of 120 ℃, K/S value of 24.92, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

Example 3:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 20%, reacting for 3 hours at the temperature of 75 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.8:0.015, uniformly mixing terephthalic acid, heptanediol with ethylene glycol having tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 250 ℃, and the esterification reaction end point is determined when the water distillation amount in the esterification reaction reaches more than 90% of a theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the condition of negative pressure, stably pumping the pressure in the stage from normal pressure to below 500Pa absolute within 1h, controlling the reaction temperature to be 270 ℃, performing the reaction for 0.5h, then continuously pumping vacuum, performing the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to below 100Pa absolute, controlling the reaction temperature to be 275 ℃ and the reaction time to be 1.5h, and preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 150 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 20 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide, the hydrogen peroxide, the stabilizer, the second penetrating agent and the chelating agent is 6: 8: 4: 1:1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at the temperature of 90 ℃, preserving heat and standing for 1h, and then washing in an aqueous solution at the temperature of 70 ℃ to remove surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises pigment, dyeing assistant, penetrant and water, the mass ratio of the pigment to the dyeing assistant to the penetrant to the water is 25:15:5:55, stirring the mixture to completely dissolve solid matters, and the pH value of the dyeing solution is 8. Soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 50 ℃, preserving heat, soaking for 0.2h, standing for 0.5h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.2h, and naturally cooling;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 30 ℃, fully mixing, then heating the dyeing solution to 70 ℃, soaking the bi-component elastic fiber for 0.5h in a heat preservation way, continuously heating the dyeing solution to a boiling state, and soaking for 0.5h in a heat preservation way;

washing with water: washing the dyed fabric with cold water at 15 ℃ and then with warm water at 35 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 40%;

and (3) drying: drying the dehydrated fabric at 55 ℃ for 5h, and then drying at 80 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 91.5 percent under the temperature condition of 120 ℃, K/S value of 25.74, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

Example 4:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 13%, reacting for 3.5 hours at the temperature of 73 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:2:0.015, uniformly mixing terephthalic acid, heptanediol with ethylene glycol having tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the temperature of the esterification reaction is 255 ℃, and the end point of the esterification reaction is determined when the water distillation amount in the esterification reaction reaches more than 90% of the theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to below 500Pa absolute within 1h, controlling the reaction temperature to be 265 ℃ and the reaction time to be 1h, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to below 100Pa absolute, controlling the reaction temperature to be 280 ℃ and the reaction time to be 1h, thus preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 140 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 18 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide to the hydrogen peroxide to the stabilizer to the second penetrating agent to the chelating agent is 5: 7: 5: 1:1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at the temperature of 98 ℃, preserving heat and standing for 2 hours, and then washing in an aqueous solution at the temperature of 60 ℃ to remove surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises pigment, a dyeing assistant, a penetrating agent and water, the pigment, the dyeing assistant, the penetrating agent and the water are stirred according to a mass ratio of 20:10:10:60 to completely dissolve solid matters, the pH value of the dyeing solution is 7.7, the dehumidified bi-component elastic fibers are soaked in the dyeing solution, the temperature of the dyeing solution is raised to 55 ℃, the bi-component elastic fibers are soaked for 0.3h and kept stand for 1h, the temperature is raised to a boiling state at the raising speed, the bi-component elastic fibers are soaked for 0.5h, and the bi-component elastic fibers are naturally cooled;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 35, fully mixing, heating the dyeing solution to 78 ℃, soaking the bi-component elastic fiber for 0.5h in a heat preservation way, continuously heating the dyeing solution to a boiling state, and soaking for 0.5h in a heat preservation way;

washing with water: washing the dyed fabric with cold water at 20 ℃, and then washing with warm water at 35 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35%;

and (3) drying: the dehydrated fabric is dried for 3 hours at 560 ℃ and then dried at 85 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 90 percent under the temperature condition of 120 ℃, K/S value of 24.44, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

Example 5:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 12%, reacting for 4 hours at the temperature of 75 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.5:0.015, uniformly mixing terephthalic acid, heptanediol with ethylene glycol having tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 250 ℃, and the esterification reaction end point is determined when the water distillation amount in the esterification reaction reaches more than 90% of a theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to the absolute pressure of below 500Pa within 0.5h, wherein the reaction temperature is 260 ℃ and the reaction time is 1h, then continuously pumping vacuum to perform the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to the absolute pressure of below 100Pa, the reaction temperature is 280 ℃ and the reaction time is 1h, and preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 130 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 17 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide to the hydrogen peroxide to the stabilizer to the second penetrating agent to the chelating agent is 5:5: 6: 1:1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at 100 ℃, preserving heat and standing for 1h, and then washing in an aqueous solution at 55 ℃ to remove surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises pigment, dyeing assistant, penetrant and water, the mass ratio of the pigment to the dyeing assistant to the penetrant to the water is 20:15:10:55, stirring the mixture to completely dissolve solid matters, and the pH value of the dyeing solution is 8. Soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 55 ℃, preserving heat, soaking for 0.2h, standing for 0.5h, continuously heating to a boiling state at the heating speed, preserving heat, soaking for 0.5h, and naturally cooling;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 40 ℃, fully mixing, then heating the dyeing solution to 70 ℃, soaking the bi-component elastic fiber for 0.5h in a heat preservation way, continuously heating the dyeing solution to a boiling state, and soaking for 0.5h in a heat preservation way;

washing with water: washing the dyed fabric with cold water at 20 ℃, and then washing with warm water at 35 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 38%;

and (3) drying: drying the dehydrated fabric at 60 ℃ for 4h, and then drying at 80 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 88.7 percent under the temperature condition of 120 ℃, K/S value of 25.44, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

Example 6:

preparing a modified PET melt: uniformly mixing palladium acetate and dimethyl di-tert-butyl ethylene, adding a hydrogen peroxide solution with the mass concentration of 10%, reacting for 4 hours at the temperature of 70 ℃, cooling, crystallizing and refining to obtain 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, wherein the mass ratio of the dimethyl di-tert-butyl ethylene to the hydrogen peroxide solution to the palladium acetate is 1:1.5:0.015, uniformly mixing terephthalic acid, heptanediol with ethylene glycol having tert-butyl side groups and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol, and then carrying out esterification reaction on a PET melt; preparing terephthalic acid, ethylene glycol, heptanediol with tertiary butyl side group and 2,2,3,4,5, 5-hexamethyl-3, 4-hexanediol into slurry, adding a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the temperature of the esterification reaction is 255 ℃, and the end point of the esterification reaction is determined when the water distillation amount in the esterification reaction reaches more than 90% of the theoretical value.

After the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to the absolute pressure of below 500Pa within 0.5h, wherein the reaction temperature is 255 ℃ and the reaction time is 1h, then continuously pumping vacuum to perform the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to the absolute pressure of below 100Pa, the reaction temperature is 280 ℃ and the reaction time is 1h, and preparing the modified PET melt;

preparing PET POY (polyester pre-oriented yarn): preparing the prepared modified PET melt into PET POY yarns by a POY process;

preparing PBT POY yarn: preparing PBT POY yarns from the PBT melt through a POY process;

preparing a bicomponent elastic fiber: extruding and compounding PET POY yarns and PBT POY yarns at a spinneret micropore opening through a DTY process to form single-component yarns, stretching, cooling, solidifying, winding and forming to prepare double-component POY yarns, and then performing stretching false-twist texturing to prepare double-component DTY, wherein the temperature of a second hot box of the DTY process is 140 ℃ to prepare double-component elastic fibers;

rinsing to prepare a rinsing water solution with the concentration of 15 g/l; the active ingredients of the rinsing water solution comprise sodium hydroxide, hydrogen peroxide, a stabilizer, a second penetrating agent and a chelating agent, and the weight and dosage ratio of the sodium hydroxide to the hydrogen peroxide to the stabilizer to the second penetrating agent to the chelating agent is 5: 7: 4: 2: 1, putting the prepared bi-component elastic fiber into a rinsing aqueous solution at 100 ℃, preserving heat and standing for 2 hours, and then washing in an aqueous solution at 60 ℃ to remove surface residues;

dehumidifying, namely drying and dehumidifying the rinsed bi-component elastic fiber;

first dyeing: preparing a dyeing solution, wherein the dyeing solution comprises pigment, dyeing assistant, penetrating agent and water, the mass ratio of the pigment to the dyeing assistant to the penetrating agent to the water is 25:10:10:55, stirring the mixture to completely dissolve solid matters, and the pH value range of the dyeing solution is 7.5. Soaking the dehumidified bi-component elastic fiber in a dyeing solution, heating the dyeing solution to 55 ℃, preserving heat, soaking for 0.2h, standing for 1h, continuously heating at the heating speed to a boiling state, preserving heat, soaking for 0.2h, and naturally cooling;

and (3) dyeing for the second time: preparing a dyeing assistant, namely adding hydrolyzed polymaleic anhydride and allyl glycidyl ether into crospovidone, fully mixing, performing microwave treatment, standing for 0.5h, adding polyglutamic acid and bis (trifluoromethanesulfonimide), uniformly mixing, performing microwave treatment, adding poloxamer/chitosan oligosaccharide compound and disodium ethylenediamine tetraacetate, stirring, adding boiling water into the mixture until the mixture is completely dissolved, naturally cooling the mixed solution to room temperature under stirring, and finally preparing micro powder to obtain the dyeing assistant; adding a dyeing assistant into the dyeing solution which is naturally cooled to 30 ℃, fully mixing, then heating the dyeing solution to 80 ℃, soaking the bi-component elastic fiber for 0.3h under the condition of heat preservation, continuing heating the dyeing solution to a boiling state, and soaking for 1h under the condition of heat preservation;

washing with water: washing the dyed fabric with cold water at 15 ℃ and then with warm water at 40 ℃;

and (3) dehydrating: squeezing and dehydrating the washed fabric, and controlling the water content of the dehydrated fabric to be 35%;

and (3) drying: drying the dehydrated fabric at 60 ℃ for 3h, and then drying at 85 ℃.

The prepared bi-component elastic fiber has high dye-uptake, level-dyeing property reaching 5 grade, dye-uptake of 94.3 percent under the temperature condition of 120 ℃, K/S value of 23.688, soaping resistance color fastness reaching 5 grade, and dry friction fastness reaching 5 grade.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.