Nylon / cotton fabric vat dye one-bath process homochromatic dyeing method

Abstract

The invention discloses a brocade / cotton fabric vat dye one-bath process homochromatic dyeing method which comprises the following steps: (1) weighing raw materials, and adding water to dilute and melt the materials; adding water into a dye vat, and then adding the molten raw materials; (2) after the dyeing machine runs for 3-5 minutes, putting the brocade / cotton fabric into the dyeing machine, heating to a set temperature at a speed of 1 DEG C / min for dyeing, and dyeing at a constant temperature for 30-40 minutes; (3) cooling to room temperature, and leaching with water for 5-10 minutes so as to carry out air oxidation color development; (4) feeding water into the dye vat again to a soap boiling bath ratio, adding a soap boiling agent, heating to 95 DEG C, and performing soap boiling for 10-15 minutes; and (5) cooling, discharging water, washing the brocade / cotton fabric with water, and drying. The method has the advantages of short flow, energy conservation, consumption reduction, pollution reduction, good homochromatism, excellent color fastness and the like.

Description

Technical Field

[0001] The invention relates to the technical field of dyeing and finishing, in particular to a one-bath homochromatic dyeing method for nylon / cotton fabrics using vat dyes. Background Art

[0002] Nylon / cotton fabrics are blended or interwoven nylon and cotton. They combine the strength and abrasion resistance of nylon with the comfort and breathability of cotton and are widely used in clothing, home textiles, and industrial fabrics. Nylon / cotton fabrics contain both nylon and cotton fibers, which have significant structural differences, resulting in significant differences in dyeing properties. Achieving isochromatic dyeing presents a technical challenge.

[0003] Currently, traditional dyeing methods for nylon / cotton fabrics primarily include two-bath dyeing with neutral or acid / reactive dyes, one-bath dyeing with acid / reactive dyes, and one-bath dyeing with reactive dyes. Each of these processes has its advantages and disadvantages. The two-bath dyeing process can handle deep, rich colors, but it suffers from complex processes, a lengthy dyeing process, and high water and energy consumption. The one-bath process, while offering a shorter process and energy savings, is more suitable for medium and light colors. However, when dyeing dark colors, color consistency deteriorates, and the dyeing technique is complex and difficult to control, impacting product quality and stability. Therefore, current nylon / cotton dyeing technologies have yet to fully meet the demand for high-quality, green, and ecological dyeing.

[0004] Vat dyes are a type of dye that can only be dyed after being reduced. They are insoluble in water and contain two or more carbonyl groups in their molecules. Under the action of alkaline solution of reducing agent, the carbonyl groups are reduced to hydroxyl groups, making the dye soluble in the alkaline solution, forming a leuco sodium salt with affinity for cellulose, thereby dyeing the fiber. After being oxidized by air or oxidant, it returns to the original insoluble dye and fixes on the fiber. The schematic diagram of the vat dye dyeing process is as follows Figure 1 shown.

[0005] Vat dyes can be divided into anthraquinone dyes and indigo dyes based on their structure. Anthraquinone dyes are the most numerous, accounting for nearly 80%. These dyes offer the highest fastness of all dyes, a full color spectrum, and vibrant hues, second only to basic dyes. They are suitable for dyeing and printing cotton, linen, and viscose fibers. Nylon fibers are generally dyed with weakly acidic, neutral, reactive, and disperse dyes; vat dyes are rarely used in actual production. Summary of the Invention

[0006] The invention aims to provide a one-bath homochromic dyeing method for brocade / cotton fabrics using vat dyes, which has a short process, the advantages of energy saving, consumption reduction and pollution reduction, and has good homochromic properties and excellent color fastness.

[0007] The technical solution adopted by the present invention to solve its technical problem is: A method for dyeing brocade / cotton fabric with vat dyes in one bath, comprising the following steps: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 3-5 minutes, brocade / cotton fabric is added, and the temperature is raised to the set temperature at a rate of 1°C / min for dyeing, and the dyeing is continued at a constant temperature for 30-40 minutes; (3) Cooling to room temperature, rinsing with water for 5-10 minutes to allow air oxidation and color development; (4) Add water to the dye vat again to the soap boiling bath ratio, add soap boiling agent, raise the temperature to 95℃, and soap boil for 10-15 minutes; (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it; In step (1), the raw material composition includes: Vat dye X% (owf) 0 <X≦5 Dispersant 1~2g / L Sodium hydrosulfite 10-15g / L Caustic soda 6~9g / L Anhydrous sodium sulfate 0-10g / L or sodium sulfate powder 0-3g / L.

[0008] The present invention systematically studies the effects of factors such as temperature, electrolytes, dye molecular structure and auxiliaries on the homochromatic dyeing effect of vat dyes, and uses Gaussian computational chemistry software to calculate the dye structure parameters, revealing their influencing rules. This guides dye compatibility experiments and develops a method for regulating the homochromatic dyeing of nylon / cotton fabrics with vat dyes.

[0009] When the color of the nylon component is darker than that of the cotton component, anhydrous sodium sulfate needs to be added; when the color of the nylon component is lighter than that of the cotton component, opening powder needs to be added; and when the colors of the two components are similar, there is no need to add anhydrous sodium sulfate and opening powder.

[0010] From the analysis of the dyeing mechanism of vat dyes, the structural properties of soluble leuco bodies are similar to those of weak acid dyes, and they have a certain affinity for nylon fibers. In theory, vat dyes have the ability to dye nylon fibers.

[0011] Due to the different structures of nylon and cotton fibers, their sensitivity to various factors, such as temperature, electrolytes, vat dye molecular structure, and auxiliaries, varies during single-bath vat dyeing. For example, increasing temperature favors the absorption of vat dyes onto the nylon component, while increasing electrolyte concentration favors the absorption of vat dyes onto the cotton component. Vat dyes with different molecular structures also distribute differently across nylon and cotton bicomponent fabrics. Adding different auxiliaries can also alter the absorption of vat dyes across the nylon and cotton bicomponents. Therefore, systematic research has revealed the mechanism for regulating homochromic dyeing of nylon / cotton fabrics. By adjusting and controlling these various process factors during dyeing, homochromic absorption of vat dyes onto the nylon and cotton bicomponents can be achieved.

[0012] Preferably, in step (2), the temperature is set to 85°C.

[0013] Preferably, the bath ratio of dyeing is 5 to 20:1.

[0014] Preferably, the dispersant is selected from dispersant NNO, dispersant MF, dispersant Reax 85A, and lignin S-36.

[0015] Preferably, the bath ratio of soap boiling is 5 to 20:1.

[0016] Preferably, the composition of the soaping agent is: 2 g / L sodium carbonate and 1 g / L detergent.

[0017] Preferably, the vat dye is selected from one or a combination of CI Vat Black 8, CI Vat Yellow 1, CI Vat Red 10, and Vat Blue. The present invention has found that only these specific dyes and their combinations can achieve good homochromy in dyeing brocade / cotton fabrics.

[0018] Preferably, the vat blue is composed of vat blue 5508 and vat blue DMG in a mass ratio of 2:8.

[0019] The beneficial effects of the present invention are: short process, energy saving, consumption reduction and pollution reduction, good color consistency and excellent color fastness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the vat dyeing process; Figure 2 This is a comparison of dyeing samples at different temperatures and electrolyte concentrations; Figure 3 The effect of temperature and electrolyte (anhydrous sodium sulfate) concentration on the color depth of nylon / cotton fabrics: (a) nylon; (b) cotton Figure 4 The effect of pulling powder on the dyeing of brocade / cotton fabrics; Figure 5 It is a comparison chart of dyed fabric pictures and dye structure parameters; Figure 6 This is a photo of two kinds of vat blue dyes dyed together and a color difference performance chart; Figure 7 It is the improvement of Vat Blue 5508 and Vat Blue DMG in dyeing of nylon / cotton fabric blends; Figure 8 This is a comparison chart of dyeing samples and color difference performance of vat dyed nylon / cotton blended fabrics; Figure 9 This is a comparison chart of nylon / cotton blended fabric blending dyeing samples and color difference performance. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described in detail below through specific embodiments.

[0022] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0023] Example 1: A method for dyeing brocade / cotton fabric with vat dyes in one bath, comprising the following steps: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 4 minutes, brocade / cotton fabric (brocade: cotton = 1:1 mass ratio) is added, and the temperature is raised to 85°C at a rate of 1°C / min for dyeing, and the dyeing is carried out at a constant temperature for 35 minutes; the dyeing bath ratio is 10:1; (3) Cooling to room temperature, rinsing with water for 8 minutes to perform air oxidation color development; (4) The dye vat was filled with water again to a soap bath ratio of 10:1, and a soap boiling agent was added. The composition of the soap boiling agent was as follows: sodium carbonate 2 g / L, detergent (detergent 6501, purchased from Jiangsu Haian Petrochemical Plant) 1 g / L, and the temperature was raised to 95°C and soap boiling was carried out for 10 min. (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it; In step (1), the raw material composition is: Vat dye (CI Vat Black 8) 3% (owf) Dispersant (dispersant NNO) 1.5g / L Hydrosulfite 12g / L Caustic soda 7g / L.

[0024] Example 2: A method for dyeing brocade / cotton fabric with vat dyes in one bath, comprising the following steps: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 3 minutes, brocade / cotton fabric (brocade: cotton = 9:1 mass ratio) is added, and the temperature is raised to 85°C at a rate of 1°C / min for dyeing, and the dyeing is carried out at a constant temperature for 30 minutes; the dyeing bath ratio is 5:1; (3) Cooling to room temperature, rinsing with water for 5 minutes to perform air oxidation color development; (4) Add water to the dye vat again to a soap bath ratio of 5:1, add soap boiling agent, the composition of the soap boiling agent is: sodium carbonate 2g / L, detergent 1g / L, heat to 95℃, and soap boiling for 12 minutes; (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it; In step (1), the raw material composition is: Vat dye (CI Vat Red 10) 0.1% (owf) Dispersant (Dispersant Reax 85A) 1g / L Sodium hydrosulfite 10g / L Caustic soda 6g / L Anhydrous sodium sulfate 10g / L.

[0025] Example 3: A method for dyeing brocade / cotton fabric with vat dyes in one bath, comprising the following steps: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 5 minutes, brocade / cotton fabric (brocade:cotton = 1:9 mass ratio) is added, and the temperature is raised to 85°C at a rate of 1°C / min for dyeing, and the dyeing is carried out at a constant temperature for 40 minutes; the dyeing bath ratio is 20:1; (3) Cooling to room temperature, rinsing with water for 10 min to allow air oxidation and color development; (4) Add water to the dye vat again to a soap bath ratio of 20:1, add soap boiling agent, the composition of the soap boiling agent is: sodium carbonate 2g / L, detergent 1g / L, heat to 95℃, and soap boiling for 15 minutes; (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it; In step (1), the raw material composition is: Vat dye (CI Vat Yellow 1, Vat Blue 5508 and Vat Blue DMG in a mass ratio of 2:8) 5% (owf) Dispersant (lignin S-36, purchased from Jiangjiefa Technology Co., Ltd.) 2g / L Hydrosulfite 15g / L Caustic soda 9g / L Lakai powder 3g / L.

[0026] Example 4: The difference between this embodiment and embodiment 1 is that the vat dye is a mixed dye consisting of vat blue 5508 and vat blue DMG (purchased from Jiangsu World Chemical Co., Ltd.) in a mass ratio of 2:8, and the rest is the same as embodiment 1.

[0027] (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; One-bath homochromatic dyeing method for nylon / cotton fabrics using vat dyes: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 3 minutes, brocade / cotton fabric (brocade: cotton = 1:1 mass ratio) is added, and the temperature is raised to the set temperature at a rate of 1°C / min for dyeing, and the dyeing is carried out at a constant temperature for 35 minutes; the dyeing bath ratio is 10:1; (3) Cooling to room temperature, rinsing with water for 10 min to allow air oxidation and color development; (4) Add water to the dye vat again to a soap bath ratio of 10:1, add soap boiling agent, the composition of the soap boiling agent is: sodium carbonate 2g / L, detergent (detergent 6501) 1g / L, heat to 95℃, and soap boiling for 10 minutes; (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it Example 5: Temperature and electrolyte regulation CI Vat Red 10 was selected, the dye concentration was set to 2% (owf), hydrosulfite 15g / L, caustic soda 9g / L, dispersant MF 1g / L, the temperature was varied to 70, 80, and 90°C, and the holding time was 30 minutes. Then, at the same temperature, the sodium sulfate concentration was varied to 0, 5, 10, 15, 20, 25, and 30g / L, and a mixture of nylon and cotton fabric (mass ratio 50 / 50) was dyed. The effects of temperature and electrolyte dosage on the nylon / cotton color matching were observed. The fabric K / S value test results are shown below. Figure 3 As shown in the figure, the color difference ΔE value of the dyed fabric photo and brocade / cotton dyed sample is as follows Figure 2 shown.

[0028] Temperature has a significant effect on the distribution and dyeing of vat dyes on nylon / cotton two-component fabrics. At a lower temperature (70°C), the color depth of cotton fabrics is higher than that of nylon fabrics. This is because the glass transition temperature of nylon is 50-60°C and its orientation is relatively high. At 70°C, the nylon fibers fail to fully swell, making it difficult for the dye to diffuse into the interior of the nylon fibers, and more dye tends to be dyed onto the cotton fabric. As the dyeing temperature increases, the nylon fibers gradually swell, the voids inside the fibers become larger, and the dye diffusion capacity gradually increases, gradually deepening the color of the nylon component fabric. Therefore, when the dyeing temperature reaches 90°C, the dye tends to dye the nylon fibers more, increasing the color depth (K / S) of the nylon fabric and decreasing the color depth (K / S) of the cotton fabric. Under the same electrolyte concentration, the K / S value of the nylon fabric dyed sample is higher than that of the cotton fabric dyed sample.

[0029] At the same dyeing temperature, as the amount of electrolyte increases, the color depth of the cotton fabric increases, while the color depth of the nylon fabric does not change much. This shows that the electrolyte has a more obvious dyeing effect on the vat dye cotton fabric, while the dyeing effect on the nylon fabric is very small. This may be because there are more hydroxyl groups in cellulose fibers, which ionize to Cell-0 under alkaline conditions. - The absolute value of the kinetic layer potential is larger, the repulsion effect on the sodium salt of the leucosome is greater, and the electrolyte effect is more sensitive.

[0030] Therefore, when dyeing at medium and low temperatures, the dyed fabric exhibits the appearance of a lighter brocade and darker cotton. Increasing the amount of electrolyte accelerates the dye's transfer to the cotton fibers, resulting in a gradual increase in color difference and a decrease in the homochromic effect. When dyeing at high temperatures, the dyed fabric exhibits the appearance of a dark brocade and a lighter cotton. Increasing the amount of electrolyte increases the color depth of the cotton component, gradually reduces the color difference, and improves the homochromic effect.

[0031] These experimental results demonstrate that increasing the dyeing temperature facilitates the vat dye's uptake onto the nylon component, while increasing the electrolyte dosage facilitates the vat dye's uptake onto the cotton component. In actual dyeing, temperature and electrolyte concentration can be adjusted based on the distribution of the vat dye onto the nylon / cotton components to achieve optimal tonal matching. Based on the above data, it can be inferred that when dyeing with CI Vat Red 10, a temperature of 85°C and no electrolyte addition yields optimal tonal matching between nylon and cotton fibers.

[0032] Example 6: Effect of auxiliaries on brocade / cotton fabric dyeing CI Vat Red 10 was selected, with a dye dosage of 2% (owf), hydrosulfite dosage of 15 g / L, caustic soda dosage of 9 g / L, dispersant MF of 1 g / L, a holding time of 30 minutes, and a dyeing temperature of 90°C. Sixteen surfactants were added at 1 g / L each to dye a 50 / 50 mixture of nylon and cotton fabric. Their effects on the color depth of the dyed fabric were observed. The results are shown in Table 1.

[0033] Table 1 Effect of auxiliaries on dyeing of brocade / cotton fabrics

[0034] When CI Vat Red 10 is used to dye a nylon / cotton blend (50 / 50 by mass) under high temperature conditions, the dyeing results in a dark nylon color and a light cotton color. The data in the table above demonstrates that various auxiliaries have significantly different effects on the distribution and dyeing of two-component fabrics. Dispersants, such as Reax 85A, lignin S-36, Tilo-6405, and hyperdispersant 20000, effectively disperse and stabilize leuco-body salts, promoting dyeing of two components. However, these agents are more effective at promoting dyeing of the nylon component than the cotton component, such as leuco-body sodium salts. Anionic surfactants, however, compete with leuco-body sodium salts, reducing dyeing of either the nylon or cotton component to varying degrees, ultimately affecting the distribution and dyeing of two-component fabrics. Examples include sodium dodecylbenzene sulfonate, sizing powder, and AOS, with sizing powder effectively enhancing the isochromatic effect. Polyoxyethylene ether phosphates or fatty acid esters, such as penetrants AEP and LAE-9, significantly improve dye uptake on the nylon component while slightly reducing it on the cotton component. Nonionic surfactants have varying effects. Equivalent additives like PEGA O and TX-10 reduced dye uptake on both fabrics, likely due to their strong solubilizing properties. Other nonionic surfactants, such as OP-15, Tween 80, AEO-9, and OP-10, improve dye uptake on nylon fabrics while having little effect on the cotton component.

[0035] We selected the auxiliary agent Lakai powder with better homochromic effect, changed its concentration, and observed its effect on homochromic dyeing of vat dye brocade / cotton fabrics. The results are as follows: Figure 4 As shown. Figure 4 The data shows that with increasing the amount of sizing powder, the K / S ratio of nylon fiber gradually decreases, while the K / S ratio of cotton fiber gradually increases. The color difference ΔE between the nylon and cotton components also decreases, indicating that the color-matching effect of the dyed fabric is significantly enhanced. Sizing powder is a sodium salt of alkylnaphthalenesulfonic acid with a similar structure to the sodium salt of leuco. After addition, it can be well adsorbed to the nylon component, forming a competitive dyeing effect with the sodium salt of leuco, inhibiting the sodium salt's dyeing of the nylon component, thereby increasing the dyeing of the cotton component fabric.

[0036] From the above results, it can be seen that when the color of the nylon component is darker than that of the cotton component, the addition of the opening powder can reduce the dyeing of the nylon component and increase the dyeing of the cotton component, which plays a better regulatory role in the dyeing of the same color.

[0037] Example 7: Effect of vat dye structure on homochromic dyeing of brocade / cotton fabrics The dye concentration was set at 2% (owf), hydrosulfite 15g / L, caustic soda 9g / L, dispersant MF 1g / L, and the holding time was 30min. A nylon / cotton fabric mixture (mass ratio 50 / 50) was dyed. The homochromatic properties of nylon / cotton fabrics with 20 different vat dyes were evaluated at 80°C. A mathematical function affecting the partitioning of vat dyes on nylon / cotton bicomponent fabrics was constructed using two molecular structure parameters: dye molecular weight and CLogP (calculated n-octanol / water partition coefficient). This function is called the partition factor. Photos of the dyed fabrics and related parameters are shown in the figure below. Figure 5 shown.

[0038] from Figure 5 As can be seen from the images and data, the distribution of vat dyes on nylon / cotton bicomponent fabrics varies depending on the dye structure. Most dyes tend to dye the cotton component more. Only a few vat dyes produce a darker color on the nylon component than on the cotton component.

[0039] Observing the color values of nylon / cotton two-component dye samples and comparing them with molecular structure parameters revealed that molecular weight and CLogP significantly influence the distribution of vat dyes in nylon / cotton two-component fabrics. Because nylon has a tighter structure and is more hydrophobic than cotton fibers, the lower the molecular weight of the dye, the greater its ClogP value, indicating a greater tendency to dye the nylon component.

[0040] According to the influence law, a function (distribution factor) reflecting the distribution of vat dyes in nylon and cotton two-component dyeing is constructed. The function is shown in formula (1).

[0041] In formula (1), M is the molecular weight.

[0042] Depend on Figure 5 It can be seen that, with the exception of CI Vat Yellow 33, as the partition factor increases, the dye's uptake on the nylon component increases, while its uptake on the cotton component gradually decreases. When the partition factor is close to 1.60 (1.55-1.61), the dyed nylon and cotton fabrics have good color-matching. When the partition factor is less than 1.60, the dyed fabrics exhibit a light nylon and dark cotton appearance. When the partition factor is greater than 1.60, the dyed fabrics exhibit a dark nylon and light cotton appearance.

[0043] The above conclusions indicate that vat dyes with different structures exhibit different distribution patterns when used to dye nylon / cotton bicomponent fibers. CI Vat Black 8 and CI Vat Yellow 1 exhibit excellent color-matching. However, the color-matching of red and blue dyes is less than ideal. This can be achieved through comprehensive control based on the influence of factors such as dyeing temperature, electrolytes, and auxiliaries, or through dye compounding.

[0044] Example 8: Compounding of blue vat dyes The above research revealed that there is still a lack of blue vat dyes with good homochromic properties among the three primary colors. Therefore, two compound commercial dyes (Vat Blue 5508 and Vat Blue DMG) were selected to dye a nylon / cotton fabric blend. Their distribution and dyeing behavior on the two component fibers were further explored, providing a basis for the subsequent compounding of dyes suitable for homochromic dyeing of nylon / cotton fabrics.

[0045] The dye concentration was set to 2% (owf), hydrosulfite 15g / L, caustic soda 9g / L, dispersant MF1g / L, the temperature was changed to 70, 80, and 90℃, the holding time was 30min, and a nylon / cotton mixed fabric (mass ratio: 50 / 50) was dyed to observe the effect of temperature on the nylon / cotton isochromaticity. The results are shown below. Figure 6 shown.

[0046] Depend on Figure 6 It can be seen that when vat blue 5508 is used to dye a brocade / cotton fabric mixture (mass ratio is 50 / 50), the dyed fabric generally presents the apparent characteristics of brocade being light and cotton being dark; while vat blue DMG generally presents the apparent characteristics of brocade being dark and cotton being light. Based on the complementarity of the dyeing distribution of the two, the two dyes are mixed in different proportions to achieve the same color effect of brocade / cotton fabrics.

[0047] The total dye dosage was set to 2% (owf), the hydrosulfite dosage was 15 g / L, the caustic soda dosage was 9 g / L, the dispersant MF was 1 g / L, the dyeing temperature was 85°C, the holding time was 30 min, the mass dosage ratio of the two was changed, and the brocade / cotton fabric (50 / 50) was dyed to observe its homochromic effect. The results are shown in Table 2.

[0048] Table 2 Color depth and color difference performance of mixed dyeing in different proportions

[0049] From the data in the table above, we can see that when the dosage ratio of the two is 2:8, the K / S value of nylon / cotton is similar, the ΔE value is the smallest, and the homochromic effect is the best. Therefore, using a 2:8 ratio and changing the total concentration of the dyes, we observe whether the two dyes improve the nylon / cotton components in the same way. The test results are as follows: Figure 7 As shown. Figure 7As can be seen, as the dye concentration gradually increases, at a ratio of 2:8, the lifting properties of Vat Blue 5508 and Vat Blue DMG on nylon / cotton fabrics remain basically the same. This shows that the combination of these two commercial dyes can achieve good homochromic dyeing, and a blue vat dye with good homochromic dyeing properties has been successfully obtained.

[0050] Example 9: Dye compatibility test The above research shows that the vat dyes suitable for homochromic dyeing are CI Vat Black 8, CI Vat Yellow 1, and a composite blue dye (Blue 5508 / Blue DMG ratio of 2:8). Furthermore, Example 5 shows that CI Vat Red 10 exhibits a light-blue-cotton-dense color at 80°C, while exhibiting a dark-blue-cotton-light color at 90°C. Therefore, a dyeing temperature of 85°C achieves excellent homochromic properties. A three-primary color compatibility test can be performed.

[0051] The total dye dosage was set at 2% (owf), the hydrosulfite dosage was 15 g / L, the caustic soda dosage was 9 g / L, the dispersant MF was 1 g / L, the dyeing temperature was 85°C, the holding time was 30 min, the mass ratios of the three dye components were changed, and a brocade / cotton fabric mixture was dyed. The color properties of the dyed samples were measured. The results are shown in Table 3.

[0052] Table 3 Color parameters of mixed dyed brocade / cotton fabrics

[0053] From the data in the above table, we can see that the K / S values of the brocade / cotton fabric mixed samples dyed with the three groups of recipes are relatively close, and the color parameter performance such as brightness value is also relatively close, and ΔE is less than 3, indicating that the dyes of these three color systems have good compatibility and are suitable for the dyeing of brocade / cotton fabrics.

[0054] Example 10: Application of vat dye one-bath dyeing of nylon / cotton blended fabric Based on the above research on the mechanism of homochromy, CI Vat Red 10, CI Vat Yellow 1, a mixed blue dye (blue 5508 / blue DMG ratio of 2 / 8) and CI Vat Black 8 were selected to dye nylon / cotton blended fabrics. The concentration of CI Vat Black 8 was set to 5% (owf), the concentration of other dyes was 2% (owf), the amount of hydrosulfite was 15g / L, the amount of caustic soda was 9g / L, the dispersant MF was 1g / L, the dyeing temperature was 85℃, the holding time was 30min, and the nylon / cotton blended fabric was dyed. The results are as follows: Figure 8 As shown. Figure 8 It can be seen that the dyed fabrics have excellent levelness and the ΔE values are all lower than 0.3, which indicates that the selected dyes have excellent levelness effect on nylon / cotton blended fabrics at a dyeing temperature of 85°C.

[0055] CI Vat Red 10, CI Vat Yellow 1 and a mixed blue dye (Blue 5508 / Blue DMG: 2 / 8) were used to dye nylon / cotton blended fabrics. The compatibility of the dyes was observed. The total dye concentration was 2% (owf). The ratio of the three dyes was changed (mass ratio see Figure 9 ), the results are shown in Figure 9 As shown. Figure 9 It can be seen that the brocade / cotton blended fabrics dyed with the three groups of formulas have good levelness and the ΔE values are all less than 0.25, indicating that the dyes of these three color systems have good compatibility and are suitable for the dyeing of brocade / cotton blended fabrics.

[0056] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A method for dyeing brocade / cotton fabric with vat dyes in one bath, characterized in that: The steps include: (1) Weigh the raw materials and add water to dilute them; add water to the dyeing vat, and then add the diluted raw materials; (2) After the dyeing machine has been running for 3-5 minutes, brocade / cotton fabric is added, and the temperature is raised to the set temperature at a rate of 1°C / min for dyeing, and the dyeing is continued at a constant temperature for 30-40 minutes; (3) Cooling to room temperature, rinsing with water for 5-10 minutes to allow air oxidation and color development; (4) Add water to the dye vat again to the soap boiling bath ratio, add soap boiling agent, raise the temperature to 95℃, and soap boil for 10-15 minutes; (5) Cool down and drain water, wash the brocade / cotton fabric and then dry it; In step (1), the raw material composition includes: Vat dye X% (owf) 0 <X≦5 Dispersant 1~2g / L Sodium hydrosulfite 10-15g / L Caustic soda 6~9g / L Anhydrous sodium sulfate 0-10g / L or sodium sulfate powder 0-3g / L.

2. The method for dyeing brocade / cotton fabric with vat dyes in one bath, characterized in that: In step (2), the temperature was set to 85°C.

3. The method for dyeing brocade / cotton fabric with vat dyes in one bath, characterized in that: The bath ratio for dyeing is 5 to 20:

1.

4. The method for dyeing nylon / cotton fabric with vat dyes in one bath, characterized in that: The dispersant is selected from one of dispersant NNO, dispersant MF, dispersant Reax 85A and lignin S-36.

5. The method for dyeing nylon / cotton fabric with vat dyes in one bath, characterized in that: The bath ratio of soap boiling is 5 to 20:

1.

6. The method for dyeing brocade / cotton fabric with vat dyes in one bath, characterized in that: The composition of the soap boiling agent is: sodium carbonate 2g / L, detergent 1g / L.

7. The method for dyeing nylon / cotton fabric with vat dyes in one bath, characterized in that: The vat dye is selected from one or a combination of CI vat black 8, CI vat yellow 1, CI vat red 10 and vat blue.

8. The method for dyeing brocade / cotton fabric with vat dyes in one bath, characterized in that: The vat blue is composed of vat blue 5508 and vat blue DMG in a mass ratio of 2:8.

Images