A process for dyeing polyester materials with isoparaffinic medium disperse dyes

Abstract

The application relates to a method for dyeing polyester materials with isoparaffin medium dispersed dyes, which comprises the following steps: S1, mixing the dispersed dyes with isoparaffin medium, adding zirconium beads for grinding to prepare a dye mother liquor; S2, preparing a dyeing solution by mixing the dye mother liquor with isoparaffin medium; S3, padding the polyester materials in a water bath for mordanting; S4, adding the pretreated polyester into the dyeing solution for dyeing; and S5, completing the dyeing through reduction cleaning and washing. The dyeing method uses isoparaffin as the dyeing medium, can greatly improve the dyeing rate of the polyester materials, reduces the use of dyeing water, and reduces the generation of dyeing wastewater.

Description

Technical Field

[0001] The invention relates to a dyeing method for polyester materials, in particular to a dyeing method for polyester materials using disperse dyes with an isoparaffin medium, and belongs to the technical field of dyeing and finishing. Background Art

[0002] Polyester fiber is a synthetic fiber made from polyester polymers. Its many excellent properties, such as abrasion resistance, fade resistance, wrinkle resistance, easy cleaning, high strength, and good elasticity, make it an ideal material for clothing, bedding, and outdoor products. Consequently, it is widely used in textiles, industrial materials, and other fields. Polyester fiber also exhibits excellent chemical resistance, making it resistant to corrosion from many chemicals. This makes it a popular material in industrial materials such as filters, insulation, and construction materials.

[0003] Traditionally, polyester fibers are dyed using disperse dyes in aqueous media. The main dyeing methods include high-temperature and high-pressure dyeing, high-temperature melt dyeing, and carrier dyeing. However, these dyeing processes consume significant amounts of water and energy. Furthermore, to ensure optimal dye dispersion and dyeing, large amounts of dispersants and dyeing auxiliaries are required. However, excess chemicals remain in the dyeing wastewater, placing a significant burden on subsequent wastewater treatment.

[0004] At present, waterless and low-water dyeing technology has become one of the important research directions of green ecological dyeing and finishing technology. A series of advanced technologies such as supercritical carbon dioxide dyeing and vacuum sublimation dyeing have been developed, but these dyeing methods have certain limitations in practical applications.

[0005] Therefore, it is necessary to develop a safe, environmentally friendly, green and low-carbon dyeing method to reduce energy consumption and wastewater discharge. Isoparaffin is a non-toxic, colorless, odorless liquid with good environmental compatibility, easy degradation, and low price. It has been widely used in fields such as energy, medicine, chemicals, and daily necessities. Using isoparaffin as the dyeing medium instead of traditional water-bath dyeing can effectively reduce the use of water resources and the generation of dyeing wastewater, while also achieving good dyeing results. Therefore, developing an isoparaffin-based disperse dyeing method for polyester materials has important practical significance. Summary of the Invention

[0006] The object of the present invention is to provide a method for dyeing polyester materials with disperse dyes using an isoparaffin medium. The dyeing method uses isoparaffin as a dyeing medium instead of a water bath for disperse dye dyeing, which can greatly improve the dyeing rate of the polyester material, while reducing the use of dyeing water and the generation of dyeing wastewater, thereby achieving green dyeing and finishing.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A method for dyeing polyester materials with disperse dyes using an isoparaffin medium, the method comprising the following steps:

[0009] S1. Preparation of dye mother liquor: Disperse dye and isoparaffin medium are mixed in a mass ratio of 1:(3-15), zirconium beads are added and ground for 2-6 hours to prepare dye mother liquor;

[0010] The isoparaffins are isoparaffins with a carbon number of C8-C20;

[0011] S2. Preparation of dye solution: prepare dye solution by taking 2-5% owf dye mother solution and isoparaffin medium at a bath ratio of 1:(10-60);

[0012] S3. Polyester pretreatment: Dip and pad the polyester material in a water bath to prepare the polyester for dyeing at a liquid rate of 30%-80%;

[0013] S4, dyeing: adding the pretreated polyester material to the dye solution according to the bath ratio described in S2, and starting dyeing;

[0014] S4.1. Heating: Dye at room temperature, increase the temperature to 90°C at 1-5°C / min, and then increase the temperature to 95-145°C at 1-3°C / min;

[0015] S4.2, heat preservation: keep at the highest dyeing temperature for 40-100 minutes;

[0016] S4.3. Cooling: After the insulation is completed, cool to 50-80°C at a rate of 1-5°C / min;

[0017] S5. After reduction cleaning and water washing, dyeing is completed.

[0018] Isoparaffins are non-toxic, colorless, odorless, transparent, oily liquids with stable properties, safety, environmental friendliness, and low price. Preferably, the isoparaffins are selected from one or more of isodecane, isododecane, isotridecane, isotetradecane, or isohexadecane. Using these isoparaffins for dyeing results in better dyeing effects and improved dye uptake.

[0019] Compared with traditional polyester disperse dye dyeing methods, the dyeing method described in the present invention uses an isoparaffin medium instead of a water bath dyeing method. The dyeing process does not require pH adjustment or the addition of dyeing auxiliaries. At the same time, the medium can be recycled and reused. This dyeing method not only greatly reduces the use of dyeing water and dyeing auxiliaries, but also achieves excellent dyeing properties for the polyester fabric after dyeing.

[0020] The inventors find that the direct dyeing of polyester with pure isomeric alkanes has poor dyeing effect and low dyeing rate, the present application can obtain good dyeing effect by pretreating polyester before S4 dyeing, and impregnating in water bath to make polyester enter dyeing with suitable liquor rate.

[0021] In the present application, in S1, the dye particle size is reduced by grinding to make the dye uniformly dispersed in the medium, so as to improve the dispersibility of the dye in the medium and the level dyeing of the dyed fabric. In S2, isomeric alkanes are used as dyeing medium to prepare a dispersion dyeing solution. In S3, pretreatment and impregnation with a small amount of water can effectively reduce the glass transition temperature of the fiber, and has a plasticizing effect on the fiber, so as to promote the dyeing of the dye. In S4, the temperature rising rate is controlled to reduce the dyeing rate of the dye, and the level dyeing is improved, and at a suitable temperature, the glass transition temperature of the fiber is reached to open the amorphous region of the fiber, and the dyeing of the fiber is promoted. In S5, reduction cleaning is used to fix the dyeing of the fabric, and the fastness is improved.

[0022] As preferred, the dispersion dye in S1 is one or more of high-temperature dispersion dye, medium-temperature dispersion dye and low-temperature dispersion dye. The inventors have verified that some commonly used dispersion dyes, such as dispersion red 167, dispersion orange 30, dispersion blue 79, dispersion red 60, dispersion yellow 23 and dispersion blue 56, are all suitable for the dyeing method of the present application.

[0023] As preferred, the dispersion dye in S1 is mixed with the isomeric alkane medium at a mass ratio of 1:(8-12), and is ground for 3-5h.

[0024] As preferred, the dyeing bath ratio in S2 is 1:(20-40). Under this dyeing bath ratio, good level dyeing can be obtained while reducing the use of dyeing medium.

[0025] As preferred, the polyester material in S3 is a fiber, yarn or fabric of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polycaprolactone (PCL), polylactic acid (PLA), polyhydroxyalkanoate (PHA), polyhydroxybutyrate-co-valerate (PHBV) or polybutylene succinate (PBS).

[0026] As preferred, in S4.1, when the temperature of the dyeing solution is lower than 90℃, the temperature is raised at a rate of 1-3℃ / min; when the temperature of the dyeing solution is higher than 90℃, the temperature is raised at a rate of 1-2℃ / min, and the temperature is raised to 110-140℃. Reducing the temperature rising rate can reduce the dyeing rate of the dye, which is beneficial to improve the level dyeing of the fabric.

[0027] As preferred, in S4.3, the temperature lowering rate is 1-3℃ / min, and the temperature is lowered to 60-80℃. Reducing the temperature lowering rate is beneficial to improve the level dyeing of the fabric.

[0028] Preferably, the liquid carrying rate in S3 is 40%-60%. Different liquid carrying rates affect the dyeing depth of the fabric, and the optimal liquid carrying rate is 50%.

[0029] Preferably, in S4.2, the holding time is 45-70 min.

[0030] Preferably, in S5, the reduction cleaning method is to add the dyed polyester material to the reduction cleaning solution at a bath ratio of 1:50, and perform reduction cleaning at 65-90° C. for 5-15 minutes.

[0031] Preferably, the reducing cleaning solution is composed of 2g / L sodium hydroxide, 2g / L hydrosulfite and 2g / L soap flakes, and the solvent is water.

[0032] The present invention utilizes isoparaffin as a dyeing medium to dye polyester with disperse dyes. The dyeing method first grinds the disperse dye and the medium to prepare a dye mother liquor, which is then prepared with the isoparaffin medium to prepare a dye liquor. The polyester is pretreated and padded in a water bath for dyeing, then placed in the dye liquor for dyeing, and finally, reduced and cleaned to complete the dyeing process. The polyester disperse dye dyeing method provided by the present invention eliminates the need for pH adjustment or the addition of dyeing auxiliaries, and the medium is recyclable. This method significantly reduces dyeing water consumption and wastewater discharge, thus having important practical significance for the development of ecological dyeing and finishing.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. Dyeing polyester fabrics with isoparaffin as the medium. At high temperatures, oil-soluble isoparaffin can reduce the formation of oligomers on the surface of polyester fibers, thereby achieving higher levelness during the dyeing process without adjusting pH and adding dyeing auxiliaries. At the same time, it reduces the use of auxiliaries and the solutes in the medium, which is beneficial to the medium recovery.

[0035] 2. When dyeing polyester fabrics with isoparaffin as the medium, only a small liquid rate (40%-60%) is required. Trace amounts of water can plasticize the polyester fibers, lowering their glass transition temperature. At relatively low temperatures, the amorphous regions of the fibers are opened, promoting the diffusion of the dye solution into the fibers, thereby obtaining better dyeing effects. This method has significant water-saving and wastewater discharge reduction effects, and is in line with the development direction of ecological dyeing and finishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the sample after dyeing in Example 1;

[0037] Figure 2 This is the sample after dyeing in Comparative Example 1;

[0038] Figure 3 This is the sample after dyeing in Example 2;

[0039] Figure 4 This is the sample after dyeing in Comparative Example 2;

[0040] Figure 5 This is the sample after dyeing in Example 3;

[0041] Figure 6 This is the sample after dyeing in Comparative Example 3;

[0042] Figure 7 This is the sample after dyeing in Example 4;

[0043] Figure 8 This is the sample after dyeing in Comparative Example 4. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further described in detail below through specific examples. It should be understood that the implementation of the present invention is not limited to the following examples, and any form of modification and / or change made to the present invention will fall within the scope of protection of the present invention.

[0045] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. The methods in the following examples are all conventional methods in the art unless otherwise specified.

[0046] The polyester material used for dyeing in the following embodiments is polyester (polyethylene terephthalate) fabric or yarn.

[0047] Example 1:

[0048] A method for dyeing polyester material with disperse red 167 using an isoparaffin medium, the method comprising the following specific steps:

[0049] S1. Preparation of dye master liquor: Disperse Red 167 and isoparaffin medium were mixed at a mass ratio of 1:10, zirconium beads were added and ground for 3 hours to prepare isoparaffin medium disperse dye master liquor;

[0050] The isoparaffin medium is isohexadecane, and its physical parameters are shown in Table 1.

[0051] S2. Preparation of dye solution: prepare dye solution by mixing 2% owf dye mother solution with isoparaffin medium at a bath ratio of 1:30;

[0052] S3. Polyester pretreatment: Dip the polyester fabric in a water bath to prepare it for dyeing with a liquid rate of 50%;

[0053] S4, dyeing: adding the pretreated polyester to the dye liquor according to the bath ratio described in S2, and starting dyeing;

[0054] S4.1. Heating: Start dyeing at room temperature, then increase the temperature to 90°C at 3°C / min, then increase the temperature to 130°C at 1°C / min;

[0055] S4.2, heat preservation: keep at the highest dyeing temperature for 60 minutes;

[0056] S4.3. Cooling: After the holding period, cool to 70°C at a rate of 2°C / min.

[0057] S5. After reduction cleaning and water washing, dyeing is completed. The composition of the reduction cleaning solution is 2g / L sodium hydroxide, 2g / L hydrosulfite and 2g / L soap flakes, the bath ratio is 1:50, and the reduction cleaning is carried out at 80℃ for 10 minutes (the same below).

[0058] Table 1 Related parameters of isoparaffins used in Example 1

[0059]

[0060] The dyed sample is red, see Figure 1 .

[0061] Example 2:

[0062] A method for dyeing polyester material with isoparaffin medium Disperse Orange 30, the method comprising the following specific steps:

[0063] S1. Preparation of dye master liquor: Disperse Orange 30 and isoparaffin medium were mixed at a mass ratio of 1:10, zirconium beads were added and ground for 3 hours to prepare isoparaffin medium disperse dye master liquor;

[0064] S2. Preparation of dye solution: prepare dye solution by mixing 2% owf dye mother solution with isoparaffin medium at a bath ratio of 1:30;

[0065] S3. Polyester pretreatment: Dip the polyester fabric in a water bath to prepare it for dyeing with a liquid rate of 50%;

[0066] S4, dyeing: adding the pretreated polyester to the dye liquor according to the bath ratio described in S2, and starting dyeing;

[0067] S4.1. Heating: Start dyeing at room temperature, then increase the temperature to 90°C at 3°C / min, then increase the temperature to 130°C at 1°C / min;

[0068] S4.2, heat preservation: keep at the highest dyeing temperature for 60 minutes;

[0069] S4.3. Cooling: After the holding period, cool to 70°C at a rate of 2°C / min.

[0070] S5. After reduction cleaning and water washing, dyeing is completed. The composition of the reduction cleaning solution is 2g / L sodium hydroxide, 2g / L hydrosulfite and 2g / L soap flakes, the bath ratio is 1:50, and the reduction cleaning is carried out at 80℃ for 10 minutes (the same below).

[0071] The species of isohexadecane is the same as that in Example 1.

[0072] The dyed sample is orange, see Figure 3 .

[0073] Example 3:

[0074] A method for dyeing polyester material with isoparaffin-based disperse blue 79, the method comprising the following specific steps:

[0075] S1. Preparation of dye master liquor: Disperse Blue 79 and isoparaffin medium were mixed at a mass ratio of 1:10, and zirconium beads were added and ground for 3 hours to prepare isoparaffin medium disperse dye master liquor;

[0076] S2. Preparation of dye solution: prepare dye solution by mixing 2% owf dye mother solution with isoparaffin medium at a bath ratio of 1:30;

[0077] S3. Polyester pretreatment: Dip the polyester fabric in a water bath to prepare it for dyeing with a liquid rate of 50%;

[0078] S4, dyeing: adding the pretreated polyester to the dye liquor according to the bath ratio described in S2, and starting dyeing;

[0079] S4.1. Heating: Start dyeing at room temperature, then increase the temperature to 90°C at 3°C / min, then increase the temperature to 130°C at 1°C / min;

[0080] S4.2, heat preservation: keep at the highest dyeing temperature for 60 minutes;

[0081] S4.3. Cooling: After the holding period, cool to 70°C at a rate of 2°C / min.

[0082] S5. After reduction cleaning and water washing, dyeing is completed. The composition of the reduction cleaning solution is 2g / L sodium hydroxide, 2g / L hydrosulfite and 2g / L soap flakes, the bath ratio is 1:50, and the reduction cleaning is carried out at 80℃ for 10 minutes (the same below).

[0083] The species of isohexadecane is the same as that in Example 1.

[0084] The dyed sample is blue, see Figure 5 .

[0085] Example 4:

[0086] A method for dyeing polyester material with isoparaffin medium Disperse Orange 30, the method comprising the following specific steps:

[0087] S1. Preparation of dye master liquor: Disperse Orange 30 and isoparaffin medium were mixed at a mass ratio of 1:10, zirconium beads were added and ground for 3 hours to prepare isoparaffin medium disperse dye master liquor;

[0088] S2. Preparation of dye solution: prepare dye solution by mixing 2% owf dye mother solution with isoparaffin medium at a bath ratio of 1:30;

[0089] S3. Polyester pretreatment: Dip the polyester yarn in a water bath to prepare the yarn for dyeing at a liquid rate of 50%;

[0090] S4, dyeing: adding the pretreated polyester to the dye liquor according to the bath ratio described in S2, and starting dyeing;

[0091] S4.1. Heating: Start dyeing at room temperature, then increase the temperature to 90°C at 3°C / min, then increase the temperature to 130°C at 1°C / min;

[0092] S4.2, heat preservation: keep at the highest dyeing temperature for 60 minutes;

[0093] S4.3. Cooling: After the holding period, cool to 70°C at a rate of 2°C / min.

[0094] S5. After reduction cleaning and water washing, dyeing is completed. The composition of the reduction cleaning solution is 2g / L sodium hydroxide, 2g / L hydrosulfite and 2g / L soap flakes, the bath ratio is 1:50, and the reduction cleaning is carried out at 80℃ for 10 minutes (the same below).

[0095] The species of isohexadecane is the same as that in Example 1.

[0096] The dyed sample is orange, see Figure 7 .

[0097] Comparative Example 1:

[0098] The specific dyeing method and process conditions are the same as those in Example 1, except that the dyeing medium isoparaffin is replaced by water.

[0099] The dyed sample is red, see Figure 2 .

[0100] Comparative Example 2

[0101] The specific dyeing method and process conditions are the same as those in Example 1, except that the dyeing medium isoparaffin is replaced by water.

[0102] The dyed sample is orange, see Figure 4 .

[0103] Comparative Example 3

[0104] The specific dyeing method and process conditions are the same as those of Example 1, and the dyeing medium isomeric alkanes is replaced by water.

[0105] The dyed sample is blue, see Figure 6 .

[0106] Comparative Example 4

[0107] The specific dyeing method and process conditions are the same as those of Example 1, and the dyeing medium isomeric alkanes is replaced by water.

[0108] The dyed sample is orange, see Figure 8 .

[0109] Comparative Example 5

[0110] Referring to Example 1, the S3 polyester pretreatment is omitted, and the other dyeing method and process conditions are the same.

[0111] The dyed samples obtained in each of the above examples are subjected to color fastness, rubbing fastness, and fabric dyeing performance testing, and the test results are shown in Tables 2 and 3.

[0112] ① Rubbing fastness test method: according to GB / T 3920—2008 "Textile color fastness test rubbing fastness";

[0113] ② Color fastness test method: according to GB / T 3921—2008 "Textile color fastness test soaping fastness";

[0114] ③ K / S value test method: after the dyed polyester fabric is dried and conditioned, it is folded to be opaque, and the K / S values of 10 different positions are tested under D65 and 10° viewing angle, and the average is taken;

[0115] ④ Unevenness test method: the standard deviation of the dyed fabric is calculated according to the measured K / S value, and the unevenness of the dyed fabric is calculated according to the formula

[0116] In the formula: S λ is the standard deviation; λ is the maximum absorption wavelength of the corresponding dye, nm; n is the number of sampling points. The smaller the unevenness, the better the level dyeing; the greater the unevenness, the worse the level dyeing.

[0117] Table 2 Fabric dyeing fastness

[0118]

[0119] Table 3 Fabric dyeing performance test

[0120]

[0121] Comparative Example 6

[0122] ​With reference to Example 1, the influence of different liquid carrying rates on the dyeing effect in the pretreatment of S3 polyester is discussed. Other dyeing methods and process conditions are the same as those in Example 1.

[0123] The dyeing performance of the fabrics treated with different liquid pick-up rates was tested according to the aforementioned test method. The test results are shown in Table 4.

[0124] Table 4 Effect of liquid carrying rate on dyeing performance

[0125]

[0126]

[0127] in conclusion

[0128] from Figure 1-8 As shown in the table, polyester dyeing with different disperse dyes using isoparaffin as the dyeing medium under the same dyeing method and process conditions demonstrates good dye uptake and levelness for both polyester fabrics and yarns. Therefore, isoparaffin dyeing is suitable for different dyes and polyester fabrics. Table 2 demonstrates that dyeing polyester with isoparaffin as the dyeing medium achieves superior color fastness compared to traditional waterbath dyeing. Table 3 demonstrates that dyeing with a certain dyeing ratio effectively improves the K / S ratio of the fabric, while the isoparaffin medium also improves the levelness of the dyed fabric. Table 4 shows that a dyeing ratio of 50% achieves a high K / S ratio, while increasing the dyeing ratio further decreases the levelness of the fabric. This dyeing method achieves excellent dyeing results while also being more energy-efficient and emission-reducing, in line with the development trend of green and ecological dyeing and finishing technologies.

[0129] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0130] The above describes in detail the isoparaffin-medium disperse dye dyeing method for polyester materials provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The above examples are merely intended to facilitate understanding of the present invention's method and its core concepts. It should be noted that those skilled in the art will appreciate that various improvements and modifications may be made to the present invention without departing from the principles of the present invention, and such improvements and modifications fall within the scope of the claims.

Claims

1. A method for dyeing polyester material with isoparaffin-based disperse dyes, characterized in that The method comprises the following steps: S1. Preparation of dye mother liquor: Disperse dye and isoparaffin medium are mixed in a mass ratio of 1:(8-12), zirconium beads are added and ground for 3-5 hours to prepare dye mother liquor; The isoparaffin is selected from one or more of isodecane, isododecane, isotridecane, isotetradecane or isohexadecane; S2. Preparation of dye liquor: 2-5% owf dye mother liquor and isoparaffin medium are prepared into dye liquor at a bath ratio of 1:(10-60); S3. Polyester pretreatment: Dip and pad the polyester material in a water bath to prepare the polyester for dyeing at a liquid rate of 40%-60%; S4, dyeing: adding the pretreated polyester material to the dye solution according to the bath ratio described in S2, and starting dyeing; S4.

1. Heating: Start dyeing at room temperature, then increase the temperature to 90°C at 1-5°C / min, then increase the temperature to 95-145°C at 1-3°C / min; S4.2, heat preservation: keep at the highest dyeing temperature for 40-100 minutes; S4.

3. Cooling: After the insulation is completed, cool to 50-80°C at a rate of 1-5°C / min; S5. After reduction cleaning and water washing, dyeing is completed.

2. The dyeing method according to claim 1, wherein: The disperse dye in S1 is one or more of high-temperature disperse dye, medium-temperature disperse dye and low-temperature disperse dye.

3. The dyeing method according to claim 1, wherein: The polyester material described in S3 is a fiber, yarn or fabric of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polycaprolactone (PCL), polylactic acid (PLA), polyhydroxyalkanoate (PHA), polyhydroxybutyrate valerate (PHBV) or polybutylene succinate (PBS).

4. The dyeing method according to claim 1, wherein: In S4.1, when the dyeing solution temperature is lower than 90 ℃, the temperature is increased at a rate of 1-3 ℃ / min; when the dyeing solution temperature is higher than 90 ℃, the temperature is increased at a rate of 1-2 ℃ / min to 110-140 ℃.

5. The dyeing method according to claim 1, wherein: In S4.3, the cooling rate is 1-3°C / min, and the temperature is lowered to 60-80°C.

6. The dyeing method according to claim 1, wherein: In S5, the reduction cleaning method is to add the dyed polyester material to the reduction cleaning solution at a bath ratio of 1:50, and perform reduction cleaning at 65-90° C. for 5-15 minutes.

7. The dyeing method according to claim 6, wherein: The composition of the reducing cleaning solution is 2 g / L sodium hydroxide, 2 g / L hydrosulfite and 2 g / L soap flakes, and the solvent is water.

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