Degumming and decoloring method for polyester woven fabric

Abstract

To provide a degumming and decoloring method for a polyester woven fabric, which can effectively remove a surface preparation agent, a gum film, and dye attached to the polyester woven fabric.SOLUTION: This method includes following steps: a step to provide a first polyester woven fabric to which dye and a gum film or a treatment agent are attached; a step to obtain a second polyester woven fabric by peeling off the gum film or the treatment agent in the first polyester woven fabric by compounding a combination of alkaline aqueous solution and catalysis; and a step to obtain a third polyester woven fabric by decoloring the second polyester woven fabric by combining a chemical reduction method and a chemical oxidation method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for decolorization, and in particular to a method for degumming and decolorizing polyester fabrics. [Background technology]

[0002] Generally, the dyed polyester fabric has a dye and at least one of a surface treatment and a gum film. The gum film is, for example, polyurethane (PU) gum, polymethyl methacrylate (PMMA, acrylic) gum, polyurethane (PU) film, thermoplastic polyurethane (TPU) film, or thermoplastic polyether ester elastomer (TPEE) film. The surface treatment is, for example, a water-repellent agent. For the recycled polyester fabric, the dye, the surface treatment, and the gum film attached to the recycled polyester fabric need to be removed.

[0003] Currently known decolorization methods for polyester fabrics include solvent extraction and chemical bleaching. For the solvent extraction method, see, for example, Taiwan Patent Publication No. I481762, which uses solvent vapor to extract dyes for dyeing polyester fibers. For the chemical bleaching method, see, for example, U.S. Pat. No. 5,261,925A1, which decolorizes polyester fabrics by ozone oxidation reaction, and U.S. Pat. No. 7,981,337B2, which decolorizes polyester fabrics by reduction reaction. However, the above decolorization methods usually only remove dyes, but cannot remove surface treatments or gum films. In addition, when the surface treatments and / or gum films on dyed polyester fabrics are not removed, subsequent dye removal may be difficult.

[0004] Therefore, it has become an important goal in the art to develop a method that can effectively remove dyes, surface treatments, and gum films from polyester fabrics. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a method for degumming and decolorizing polyester fabrics, which can effectively remove surface treatments, gum films, and dyes attached to the polyester fabrics. [Means for solving the problem]

[0006] The method for degumming and bleaching polyester fabrics of the present invention includes providing a first polyester fabric having a dye and a gum film or a surface treatment agent attached thereto, and sequentially performing degumming and bleaching operations. The degumming operation includes the following operations: mixing a catalyst into a first alkaline aqueous solution to prepare a catalyst solution; immersing the first polyester fabric in the catalyst solution to remove the gum film or the surface treatment agent and obtain a second polyester fabric having a dye attached thereto; and bleaching operation includes the following operations: providing a reductive bleaching solution and an oxidative bleaching solution; immersing the second polyester fabric in the reductive bleaching solution to carry out a reductive bleaching reaction; immersing the second polyester fabric in the oxidative bleaching solution to carry out an oxidative bleaching reaction to obtain a third polyester fabric.

[0007] In one embodiment of the present invention, the gum film is selected from at least one of a PU gum film, a TPU gum film, a TPEE gum film, and an acrylic gum, and the surface treatment agent is selected from at least one of a fluorine-containing water repellent agent and a fluorine-free water repellent agent.

[0008] In one embodiment of the invention, the alkaline aqueous solution comprises at least one selected from an alkali metal hydroxide solution, an alkaline earth metal hydroxide solution, an alkaline earth metal carbonate solution, and an alkaline earth metal bicarbonate solution.

[0009] In one embodiment of the invention, the catalyst comprises at least one selected from a quaternary ammonium salt, a quaternary ammonium base, a quaternary phosphonium salt, and a crown ether.

[0010] In one embodiment of the invention, the quaternary ammonium salt comprises at least one selected from benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, tricaprylmethylammonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride.

[0011] In one embodiment of the invention, the quaternary ammonium base comprises at least one selected from phenyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, triethylmethylammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0012] In one embodiment of the invention, the quaternary phosphonium salt comprises at least one selected from butyltriphenylphosphonium bromide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium bromide, and benzyltriphenylphosphonium chloride.

[0013] In one embodiment of the invention, the crown ether comprises at least one selected from 12-crown-4-ether, 15-crown-5-ether, 18-crown-6-ether, dibenzo-18-crown-6-ether, and diaza-18-crown-6-ether.

[0014] In one embodiment of the present invention, the concentration of the catalyst solution is 0.5 g / L to 20 g / L, and the weight ratio of the catalyst solution to the first polyester fabric is 5:1 to 50:1.

[0015] In one embodiment of the present invention, the reaction conditions for removing the gum film or the surface treatment agent are a reaction temperature of 60° C. to 140° C. and a reaction time of 5 minutes to 60 minutes.

[0016] In one embodiment of the present invention, the reducing and decolorizing solution comprises a reducing agent and water, and the reducing agent is at least one selected from ammonium dodecylpoly(oxyethylene) sulfate, sodium dithionite, sodium thiosulfate, sodium hydroxymethanesulfinate, and thiourea dioxide.

[0017] In one embodiment of the present invention, the concentration of the reducing and bleaching solution is 0.5 g / L to 15 g / L, and the weight ratio of the reducing and bleaching solution to the second polyester fabric is 5:1 to 50:1.

[0018] In one embodiment of the present invention, the conditions for the reductive decolorization reaction are a reaction temperature of 90° C. to 140° C. and a reaction time of 5 minutes to 60 minutes.

[0019] In one embodiment of the present invention, the oxidative bleaching solution comprises an oxidizing agent and water, and the oxidizing agent is at least one selected from hydrogen peroxide, sodium nitrate, sodium nitrite, chlorite, hypochlorite, ammonium persulfate, and sodium persulfate.

[0020] In one embodiment of the present invention, the concentration of the oxidative bleaching solution is 0.5 g / L to 15 g / L, and the weight ratio of the oxidative bleaching solution to the second polyester fabric is 5:1 to 50:1.

[0021] In one embodiment of the present invention, the conditions for the oxidative decolorization reaction are a reaction temperature of 60° C. to 120° C. and a reaction time of 5 minutes to 60 minutes.

[0022] In one embodiment of the present invention, the bleaching process is carried out in the following order: first, a reductive bleaching reaction is carried out on the second polyester fabric, and then an oxidative bleaching reaction is carried out on the second polyester fabric that has been subjected to the reductive bleaching reaction.

[0023] In one embodiment of the present invention, the bleaching process is carried out in the following order: first, an oxidative bleaching reaction is carried out on the second polyester fabric, and then, a reductive bleaching reaction is carried out on the second polyester fabric that has been subjected to the oxidative bleaching reaction.

[0024] In one embodiment of the present invention, the degumming and bleaching method further includes drying the third polyester fabric, the drying conditions being a drying temperature of 120° C. and a drying time of 2 to 4 hours. Effect of the Invention

[0025] As described above, the method for degumming and bleaching polyester fabrics of the present invention uses a combination of an alkaline aqueous solution and a catalyst to peel off various kinds of surface treatment agents or gum films on the surface of polyester fabrics, and then bleaches the polyester fabrics through a combination of chemical reduction and chemical oxidation. In this way, the surface treatment agents or gum films and dyes on the polyester fabric materials can be effectively removed. Furthermore, compared with the solvent extraction method using organic solvents, the present invention performs degumming and bleaching on polyester fabrics through aqueous solutions (i.e., aqueous catalyst solution, reduction bleaching solution, oxidation bleaching solution), which is obviously more environmentally friendly. [Brief description of the drawings]

[0026] [Figure 1] 1 is a flow chart of the method for degumming and decolorizing polyester fabric of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are merely illustrative and do not limit the present invention.

[0028] Here, ranges expressed as "one value to another value" are a summary method to avoid listing every value in the range in the specification. Thus, the description of a particular numerical range includes any value in that numerical range and smaller numerical ranges defined by any value in that numerical range, and is the same as if the any value and the smaller numerical range were specified in the specification.

[0029] It should be understood that terms such as "first", "second", "third", etc. may be used herein to describe various elements or signals, but these elements or signals should not be limited by these terms. These terms are mainly used to distinguish one element from another element or one signal from another signal. Also, the term "or" used herein should include any one or combination of the associated listed items according to actual circumstances.

[0030] Figure 1 is a flow chart of the method for degumming and decolorizing polyester fabric of the present invention. Referring to Figure 1, step S100 is carried out to provide a first polyester fabric having a dye and a gum film or a surface treatment attached thereto. To be more specific, polyester fabric generally refers to objects woven from polyester fiber, such as clothing, bags, bed sheets, etc. Polyester fibers are man-made fibers and may include polyethylene terephthalate (PET) fibers, polybutylene terephthalate (PBT) fibers, polytrimethylene terephthalate (PTT) fibers, poly(1,4-cyclohexanedimethylene terephthalate) (PCT) fibers, and poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) fibers, etc. (however, the present invention is not limited thereto). The type of polyester fiber is not particularly limited in the present invention.

[0031] In this embodiment, the dye may be, for example, a disperse dye, but the present invention is not limited thereto. In some embodiments, the gum film may be, for example, a fluorine-containing water repellent (e.g., perfluorooctanoic acid and its salts, perfluorooctane sulfonyl compounds, alkylphenol polyoxyethylene ethers, perfluoroethane sulfonyl compounds, or sulfonates), a fluorine-free water repellent (e.g., organic silicone water repellent and long-chain hydrocarbon water repellent, such as 3M PM-3705, PM-3888, Ruco-dry ECO Plus, etc.), or a combination thereof, but the present invention is not limited thereto. The gum film may be, for example, a polyurethane gum film, a thermoplastic polyurethane film, a thermoplastic polyether ester elastomer gum film, a polymethyl methacrylate (acrylic) gum, or a combination thereof, but the present invention is not limited thereto.

[0032] Next, step S110 is carried out to perform a degumming process on the first polyester fabric. The degumming process includes the following operations. First, a catalyst is mixed in an alkaline aqueous solution to prepare a catalyst solution. Then, the first polyester fabric is immersed in the catalyst solution to remove the gum film or surface treatment agent, and a second polyester fabric with a dye attached thereto is obtained. Here, the second polyester fabric refers to the polyester fabric after the degumming process. That is, the dye is attached to the second polyester fabric, but the gum film and surface treatment agent are not attached, or only a trace amount of the gum film and / or surface treatment agent is attached. To be specific, at this stage, the catalyst and the alkaline aqueous solution are mixed and blended to remove the surface treatment agent and gum film on the polyester fabric material.

[0033] In the present invention, the catalyst may be, for example, at least one of quaternary ammonium salt, quaternary ammonium base, quaternary phosphonium salt, and crown ether, but the present invention is not limited thereto.In some embodiments, the quaternary ammonium salt may comprise at least one selected from benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, tricaprylmethylammonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride (but the present invention is not limited thereto).In some embodiments, the quaternary ammonium base may comprise at least one selected from phenyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, triethylmethylammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide (but the present invention is not limited thereto). In some embodiments, the quaternary phosphonium salt may comprise at least one selected from butyltriphenylphosphonium bromide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium bromide, and benzyltriphenylphosphonium chloride (although the invention is not limited thereto). In some embodiments, the crown ether may comprise at least one selected from 12-crown-4-ether, 15-crown-5-ether, 18-crown-6-ether, dibenzo-18-crown-6-ether, and diaza-18-crown-6-ether (although the invention is not limited thereto).

[0034] In the present invention, the alkaline aqueous solution may be, for example, an alkali metal hydroxide solution, an alkaline earth metal hydroxide solution, an alkaline earth metal carbonate solution, an alkaline earth metal bicarbonate solution, or a combination thereof, but the present invention is not limited thereto. In some embodiments, the alkali metal hydroxide may include at least one selected from sodium hydroxide (NaOH) and potassium hydroxide (KOH) (but the present invention is not limited thereto). In some embodiments, the alkaline earth metal hydroxide may include at least one selected from calcium hydroxide (Ca(OH)2), barium hydroxide (Ba(OH)2), and magnesium hydroxide (Mg(OH)2) (but the present invention is not limited thereto). In some embodiments, the alkaline earth metal carbonate may include at least one selected from magnesium carbonate and calcium carbonate (but the present invention is not limited thereto). In some embodiments, the alkaline earth metal bicarbonate may include at least one selected from magnesium bicarbonate and calcium bicarbonate (but the present invention is not limited thereto). Here, the alkaline aqueous solution functions as a solvent, so that environmental pollution by organic solvents can be prevented.

[0035] In some embodiments, the concentration of the catalyst in the catalyst solution may be, for example, 0.5 grams / liter (g / L) to 20 g / L, and preferably, for example, 2 g / L to 10 g / L. In some embodiments, the bath ratio (weight ratio) of the catalyst solution to the first polyester fabric may be, for example, 5:1 to 50:1, and preferably, for example, 8:1 to 20:1. In some embodiments, the reaction conditions for removing the gum film may be, for example, a reaction temperature of 60°C to 140°C, and a reaction time of 5 minutes to 60 minutes, and preferably, a reaction temperature of 100°C to 130°C, and a reaction time of 20 minutes to 40 minutes. After the degumming operation is completed, the second polyester fabric may be filtered and washed.

[0036] Next, step S120 is carried out to perform the bleaching operation. The bleaching operation includes at least the following operations: providing a reductive bleaching solution and an oxidative bleaching solution; immersing a second polyester fabric in the reductive bleaching solution to perform a reductive bleaching reaction; immersing the second polyester fabric that has undergone the reductive bleaching reaction in an oxidative bleaching solution to perform an oxidative bleaching reaction; removing the dye to obtain a third polyester fabric. Here, the third polyester fabric refers to the polyester fabric that has undergone the degumming and dye removal operations. That is, the third polyester fabric has no dye or gum film attached thereto, or only a trace amount of gum film and / or dye attached thereto. To be more specific, at this stage, the dye on the polyester fabric material is removed by the reductive bleaching and oxidative bleaching reactions.

[0037] In the present invention, the reducing and decolorizing solution is a reducing agent aqueous solution. In some embodiments, the reducing agent may include at least one selected from ammonium dodecylpoly(oxyethylene) sulfate, sodium dithionite, sodium thiosulfate, sodium hydroxymethanesulfinate, and thiourea dioxide (although the present invention is not limited thereto). Here, the aqueous solution functions as a solvent, and therefore can prevent environmental pollution caused by organic solvents.

[0038] Specifically, the second polyester fabric after degumming is immersed in a reduction bleaching solution. The reducing agent can reduce dye molecules, for example, by reducing the N=N double bond of the azo dye to a NH2 single bond, thereby removing a part of the dye (i.e., the dye removed by the reduction reaction). In some embodiments, the concentration of the reducing agent in the reduction bleaching solution may be, for example, 0.5 g / L to 15 g / L, and preferably, for example, 2 g / L to 10 g / L. In some embodiments, the bath ratio (weight ratio) of the reduction bleaching solution to the second polyester fabric may be, for example, 5:1 to 50:1, and preferably, for example, 8:1 to 20:1. In some embodiments, the conditions of the reduction bleaching reaction may be, for example, a reaction temperature of 90°C to 140°C, and a reaction time of, for example, 5 minutes to 60 minutes. Preferably, the reaction temperature may be, for example, 120°C to 140°C, and the reaction time may be, for example, 20 minutes to 40 minutes. When within the above temperature and time ranges, the reducing agent has excellent reactivity and can effectively remove dye from polyester fabric.

[0039] In the present invention, the oxidizing decolorizing solution is a combination of an oxidizing agent and water. In some embodiments, the oxidizing agent may include at least one selected from hydrogen peroxide, sodium nitrate, sodium nitrite, sodium chlorite, calcium chlorite, sodium hypochlorite, calcium hypochlorite, ammonium persulfate, and sodium persulfate (although the present invention is not limited thereto). Here, the aqueous solution functions as a solvent, and therefore can prevent environmental pollution caused by organic solvents.

[0040] Specifically, the second polyester fabric after the reduction bleaching reaction is immersed in an oxidation bleaching solution. At this time, the oxidizing agent oxidizes the dye and destroys the conjugated structure, thereby removing a part of the dye (i.e., the dye removed by the oxidation reaction). In some embodiments, the concentration of the oxidizing agent in the oxidation bleaching solution may be, for example, 0.5 g / L to 15 g / L, and preferably, for example, 1 g / L to 5 g / L. In some embodiments, the weight ratio (weight ratio) of the oxidation bleaching solution to the second polyester fabric may be, for example, 5:1 to 50:1, and preferably, for example, 8:1 to 20:1. In some embodiments, the conditions of the oxidation bleaching reaction may be, for example, a reaction temperature of 60° C. to 120° C., and a reaction time of, for example, 5 minutes to 60 minutes. Preferably, the reaction temperature may be, for example, 70° C. to 100° C., and a reaction time of, for example, 20 minutes to 40 minutes. When within the above temperature and time ranges, the oxidizing agent has good reactivity and can remove dye from polyester fabric.

[0041] In the bleaching operation, the second polyester fabric can be subjected to a reductive bleaching reaction first, and then an oxidative bleaching reaction. In another embodiment, the second polyester fabric can be subjected to an oxidative bleaching reaction first, and then a reductive bleaching reaction. The present invention does not limit the order of the bleaching reactions. It should be noted that in some cases, the bleaching effect of the first reductive bleaching reaction is better than that of the first oxidative bleaching reaction.

[0042] Next, step S130 is carried out to dry the third polyester fabric. In some embodiments, the drying conditions may be, for example, a drying temperature of 120° C. and a drying time of, for example, 2 to 4 hours, but the present invention is not limited thereto. At this point, the degumming and decolorization of the polyester fabric of the present invention is substantially completed.

[0043] The actual effect of the method for degumming and decolorizing polyester fabrics of the present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments.

[0044] Embodiment <Examples 1-12> Examples 1-12 include the following steps for degumming and bleaching polyester fabrics with gum films or surface treatments of different types of materials (see Table 1) and dyes. Each step is briefly described below.

[0045] (1) Degumming

[0046] A catalyst (see Table 1) is mixed into an aqueous sodium hydroxide solution to prepare an aqueous catalyst solution with a concentration of 0.5 g / L to 20 g / L. Next, 10 grams of polyester fabric is added to carry out the degumming reaction. At this time, the bath ratio of the catalyst solution to the polyester fabric is 5:1 to 50:1, the reaction temperature is 60°C to 140°C, and the reaction time is 5 minutes to 60 minutes. After that, the polyester fabric that has undergone the degumming operation is subjected to a filtration and drainage step.

[0047] (2) Bleaching

[0048] Sodium dithionite is mixed with water to prepare a reduction and decolorization solution with a concentration of 0.5 g / L to 15 g / L. Next, the polyester fabric that has been subjected to the degumming process is added to carry out the reduction and decolorization reaction. In this case, the reaction temperature is 90°C to 140°C, and the reaction time is 5 minutes to 60 minutes. Then, the polyester fabric that has been subjected to the degumming process and the reduction and decolorization reaction is subjected to a filtration and drainage step.

[0049] Next, an aqueous solution of ammonium peroxide with a concentration of 0.5 g / L to 15 g / L is added to carry out an oxidative decolorization reaction. At this time, the reaction temperature is 60°C to 120°C, and the reaction time is 5 minutes to 60 minutes. After that, the polyester fabric that has been subjected to the degumming and decolorization process is subjected to a filtration and drainage step.

[0050] (3) Drying

[0051] The polyester fabric that has been subjected to the degumming and decolorizing operations is dried at a drying temperature of 120° C. for a drying time of 2 to 4 hours.

[0052] <Comparative Example> Comparative examples include a gum film or surface treatment and a bleaching step of a dyed polyester fabric.

[0053] (1) Bleaching

[0054] Sodium dithionate is mixed with water to prepare a reduction decolorization solution with a concentration of 0.5 g / L to 15 g / L. Then, 10 grams of polyester fabric is added to carry out the reduction decolorization reaction. At this time, the reaction temperature is 90°C to 140°C, and the reaction time is 5 minutes to 60 minutes. After that, the polyester fabric that has undergone the reduction decolorization reaction is subjected to a filtration and drainage step.

[0055] Next, an aqueous solution of ammonium peroxide with a concentration of 0.5 g / L to 15 g / L is added to carry out an oxidative decolorization reaction. At this time, the reaction temperature is 60°C to 120°C, and the reaction time is 5 minutes to 60 minutes. After that, the polyester fabric that has been subjected to the decolorization operation is subjected to a filtration and drainage step.

[0056] (2) Drying

[0057] The polyester fabric after the decolorization is dried at a temperature of 120° C. for a period of 2 to 4 hours.

[0058] <Evaluation of bleaching effect> Optical tests were carried out on the polyester fabrics before and after the bleaching treatment in Examples 1 to 12 and the Comparative Example.

[0059] A colorimeter is used to measure the L*a*b color system (JIS Z8729 method is used). The higher the L value, the whiter the hue, the higher the a value, the redder the hue, and the higher the b value, the yellower the hue. The measurement results are shown in Table 1.

[0060] [Table 1]

[0061] As can be seen from the results of the Comparative Example and Example 1, compared with the Comparative Example in which the polyester fabric is directly bleached, Example 1 of the present invention in which the polyester fabric is degummed before bleaching can achieve a better bleaching effect during the bleaching operation. As can be seen from the results of Examples 1 to 6, the degumming treatment of the present invention can be applied to various kinds of gum films or surface treatment agents, such as PU gum, TPU gum, acrylic gum, TPEE film, fluorine-free water repellent, and fluorine-containing water repellent. Furthermore, as can be seen from the results of Examples 1 and 7 to 12, various catalysts (e.g., tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium hydroxide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, 18-crown-6-ether, and 12-crown-4-ether) can all be used in the degumming operation of the present invention, and all of them are helpful in improving the bleaching effect of the subsequent bleaching treatment.

[0062] As described above, the degumming and bleaching method of the present invention uses a combination of an alkaline aqueous solution and a catalyst to peel off various kinds of gum films or treatments on the surface of the polyester fabric, and then bleaches the polyester fabric through a combination of a chemical reduction method and a chemical oxidation method. In this way, the surface treatment or back film material and dye on the polyester fabric material can be effectively removed. Furthermore, compared with the solvent extraction method using an organic solvent, the present invention performs degumming and bleaching on the polyester fabric through an aqueous solution (i.e., catalytic alkaline aqueous solution, reduction bleaching solution, oxidation bleaching solution), which is obviously more environmentally friendly.

[0063] Although the present invention has been described in detail with reference to the above embodiments, they are not intended to limit the present invention. Those skilled in the art will understand that changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the following claims. [Industrial Applicability]

[0064] To provide a method for degumming and decolorizing polyester fabrics, which can effectively remove surface treatments or back film materials and dyes on polyester fabric materials. [Explanation of symbols]

[0065] 100, 110, 120, 130 steps

Claims

1. 1. A method for degumming and decolorizing polyester fabrics, comprising: providing a first polyester fabric having a dye and a gum film or surface treatment attached thereto; mixing a catalyst into an alkaline aqueous solution to prepare a catalyst solution; immersing the first polyester fabric in the catalyst solution to remove the gum film or the surface treatment agent, thereby obtaining a second polyester fabric having the dye attached thereto; carrying out a degumming operation including Providing a reducing bleaching solution and an oxidizing bleaching solution; Immersing the second polyester fabric in the reductive bleaching solution to carry out a reductive bleaching reaction; immersing the second polyester fabric in the oxidative bleaching solution to carry out an oxidative bleaching reaction; removing the dye to obtain a third polyester fabric; carrying out a bleaching operation including 2. A method for degumming and decolorizing comprising the steps of:

2. 2. The degumming and bleaching method of claim 1, wherein the gum film is selected from at least one of a polyurethane gum film, a thermoplastic polyurethane gum film, a thermoplastic polyether ester elastomer gum film, and an acrylic gum, and the surface treatment agent is selected from at least one of a fluorine-containing water repellent agent and a non-fluorine-containing water repellent agent.

3. 2. The degumming and bleaching method of claim 1, wherein the alkaline aqueous solution comprises at least one selected from an alkali metal hydroxide solution, an alkaline earth metal hydroxide solution, an alkaline earth metal carbonate solution, and an alkaline earth metal bicarbonate solution.

4. 2. The degumming and bleaching process of claim 1, wherein the catalyst comprises at least one selected from a quaternary ammonium salt, a quaternary ammonium base, a quaternary phosphonium salt, and a crown ether.

5. 5. The degumming and bleaching method of claim 4, wherein the quaternary ammonium salt comprises at least one selected from benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, tricaprylmethylammonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride.

6. 5. The degumming and bleaching method of claim 4, wherein the quaternary ammonium base comprises at least one selected from phenyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, triethylmethylammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

7. 5. The degumming and bleaching method of claim 4, wherein the quaternary phosphonium salt comprises at least one selected from butyltriphenylphosphonium bromide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium bromide, and benzyltriphenylphosphonium chloride.

8. 5. The degumming and bleaching method of claim 4, wherein the crown ether comprises at least one selected from 12-crown-4-ether, 15-crown-5-ether, 18-crown-6-ether, dibenzo-18-crown-6-ether, and diaza-18-crown-6-ether.

9. 2. The degumming and decolorizing method according to claim 1, wherein the concentration of the catalyst solution is 0.5g / L to 20g / L, and the weight ratio of the catalyst solution to the first polyester fabric is 5:1 to 50:

1.

10. 2. The degumming and bleaching method according to claim 1, wherein the reaction conditions for removing the gum film or the surface treatment agent are a reaction temperature of 60° C. to 140° C. and a reaction time of 5 minutes to 60 minutes.

11. 2. The degumming and bleaching method of claim 1, wherein the reducing and bleaching solution comprises a reducing agent and water, and the reducing agent comprises at least one selected from ammonium dodecylpoly(oxyethylene) sulfate, sodium dithionite, sodium thiosulfate, sodium hydroxymethanesulfinate, and thiourea dioxide.

12. 2. The degumming and bleaching method according to claim 1, wherein the concentration of the reducing and bleaching solution is 0.5g / L to 15g / L, and the weight ratio of the reducing and bleaching solution to the second polyester fabric is 5:1 to 50:

1.

13. The degumming and decolorizing method according to claim 1, wherein the conditions of the reductive decolorizing reaction are a reaction temperature of 90° C. to 140° C. and a reaction time of 5 minutes to 60 minutes.

14. 2. The degumming and bleaching method of claim 1, wherein the oxidizing bleaching solution comprises an oxidizing agent and water, and the oxidizing agent is at least one selected from hydrogen peroxide, sodium nitrate, sodium nitrite, sodium chlorite, calcium chlorite, sodium hypochlorite, calcium hypochlorite, ammonium persulfate, and sodium persulfate.

15. 2. The degumming and bleaching method according to claim 1, wherein the concentration of the oxidative bleaching solution is 0.5 g / L to 15 g / L, and the weight ratio of the oxidative bleaching solution to the second polyester fabric is 5:1 to 50:

1.

16. 2. The method for degumming and bleaching according to claim 1, wherein the conditions of the oxidative bleaching reaction are a reaction temperature of 60° C. to 120° C. and a reaction time of 5 minutes to 60 minutes.

17. 2. The method for degumming and bleaching according to claim 1, wherein the order of the bleaching steps is to first carry out the reductive bleaching reaction on the second polyester fabric, and then carry out the oxidative bleaching reaction on the second polyester fabric that has been subjected to the reductive bleaching reaction.

18. 2. The method for degumming and bleaching according to claim 1, wherein the bleaching steps are carried out in the order of first carrying out an oxidative bleaching reaction on the second polyester fabric, and then carrying out a reductive bleaching reaction on the second polyester fabric that has been subjected to the oxidative bleaching reaction.

19. The degumming and decolorizing method according to claim 1, further comprising the step of drying the third polyester fabric under conditions of a drying temperature of 120° C. and a drying time of 2 to 4 hours.

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