Silicon-free and solid-free afterstain and application thereof

Abstract

This invention relates to the field of cotton knitted fabric dyeing technology, specifically to a silicone-free and fixative-free re-dyeing agent and its application. The silicone-free and fixative-free re-dyeing agent comprises the following components by weight percentage: 1-20% cationic dispersant, 5-25% fatty amine polyoxyethylene ether, 5-20% anti-settling agent, 5-20% diethylene glycol monobutyl ether, and water as the balance. When using the re-dyeing agent of this invention to re-dye cotton knitted fabrics, there is no need for steps such as fixative stripping, silicone stripping, or resin stripping. Simply add the re-dyeing agent to the dye bath; no pretreatment step is required, and re-dyeing and color correction can be performed directly. Furthermore, the re-dyeing agent of this invention can prevent the decrease in strength of cotton knitted fabrics under high-temperature and acidic conditions, has a stronger ability to prevent the shedding of soft oil, silicone oil, or formaldehyde-free fixing agents, and can also prevent auxiliaries from solidifying in low-temperature environments, thus improving the quality of re-dyeing.

Description

Technical Field

[0001] This invention relates to the field of cotton knitted fabric dyeing technology, and in particular to a silicone-free and solid-free re-dyeing agent and its application. Background Technology

[0002] After cotton knitwear is bleached or dyed with reactive dyes, it requires finishing and setting processes. During these processes, human error or the negative effects of finishing auxiliaries can cause bleached cotton knitwear to yellow, resulting in a decrease in whiteness. Dyed cotton knitwear may experience changes in color or shade, such as a shift from red to blue, or a change in color from light to dark. To meet customer requirements, dyeing plants will re-bleach and re-dye yellowed white fabrics and correct colors for fabrics with altered color or shade. Furthermore, to meet sales needs for the following year or season, dyeing plants typically stock several popular or potentially popular colors. If cotton knitwear in these stocked colors experiences slow sales, they will be re-dyed, usually to reactive black or sulfur black, as black always has market demand.

[0003] In the finishing and setting process, formaldehyde-free color-fixing agents are added to improve color fastness, and non-silicone softening oils or organosilicone oils are added to improve the fabric's hand feel, making it softer, fluffier, smoother, and more elastic.

[0004] In response, Wang Taiyan et al. published a new environmentally friendly re-dyeing agent, Silcodi AD, in the proceedings of the National Symposium on Practical New Technologies and Environmentally Friendly and Efficient Chemicals in Printing and Dyeing. Using this AD re-dyeing agent eliminates the need for stripping, silicone stripping, and resin stripping; simply adding the AD re-dyeing agent to the dye bath allows for direct re-dyeing and color correction. However, when using this AD re-dyeing agent to dye cotton knitwear with reactive dyes, the pH needs to be adjusted to above neutral using 0.5 g / L of 98% glacial acetic acid (HAC) and 0.5-1 g / L of Na₂CO₃. The concentration of Na₂CO₃ is within a range of 0.5-1 g / L, requiring gradual addition of Na₂CO₃, pH measurement, and repeated pH measurements until the desired pH value is achieved. In other words, the use of this AD re-dyeing agent is cumbersome and inconvenient.

[0005] To address this, the applicant previously applied for a re-dyeing agent with silicone-free and solidification-free effects (publication number CN108396575A). This re-dyeing agent is composed of alkyl polyoxypropylene ether methyl ammonium halide, fatty alcohol polyoxyethylene ether, formic acid, acetic acid, oxalic acid, citric acid or benzoic acid, and deionized water. Although this re-dyeing agent overcomes the cumbersome use of the aforementioned AD re-dyeing agent, it still has the following shortcomings:

[0006] (1) The formula contains acidic substances such as formic acid, acetic acid, oxalic acid, citric acid or benzoic acid. Because cotton is a cellulose fiber, it has good alkali resistance but poor acid resistance. Under acidic conditions at a temperature ≥50℃, the acid can easily cause hydrolysis of cellulose molecules, resulting in a decrease in strength. Especially for knitted fabrics whose burst strength is close to the national standard threshold, it is no longer suitable to use this re-dyeing agent for repair.

[0007] (2) The alkyl polyoxypropylene ether methyl ammonium halide in the formula has only one cationic quaternary ammonium group in its molecular structure. Its charge repulsion is small, and its ability to prevent soft oil, silicone oil or formaldehyde-free fixing agent from falling off is still insufficient.

[0008] (3) If the auxiliary agent in the re-dyeing agent has poor freeze resistance, it will solidify when used in low-temperature environments such as winter, which will affect the re-dyeing quality of cotton knitted fabrics.

[0009] (4) Pretreatment steps: At room temperature, add silicone-free and solidification-free dyeing agent to the dyeing vat, then heat to 50-75℃ and keep warm for 20-40 minutes to obtain pretreated fabric; the pretreatment step takes time and is not conducive to improving production efficiency.

[0010] Therefore, it is necessary to further improve existing re-dyeing agents. Summary of the Invention

[0011] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a silicone-free and fixative-free dyeing agent, which can avoid the phenomenon of strength reduction of cotton knitted fabrics under high temperature and acid conditions, has a stronger ability to prevent the shedding of soft oil, silicone oil or formaldehyde-free fixing agent, and can prevent the auxiliaries from solidifying in low temperature environment. It can also eliminate the need for pretreatment steps and can be directly dyed without pretreatment steps.

[0012] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0013] A silicone-free and solid-free re-dyeing agent comprises the following components by weight percentage: 1-20% cationic dispersant, 5-25% fatty amine polyoxyethylene ether, 5-20% anti-precipitant, 5-20% diethylene glycol monobutyl ether, and water as the balance.

[0014] Preferably, the cationic dispersant is prepared by conventional modification of castor oil polyoxyethylene ether with 3-chloro-2-hydroxypropyltrimethylammonium chloride.

[0015] Preferably, the castor oil polyoxyethylene ether is prepared by reacting ricinoleic acid triglyceride with ethylene oxide.

[0016] Preferably, the fatty amine polyoxyethylene ether is selected from at least one of fatty amine polyoxyethylene ether 1815, fatty amine polyoxyethylene ether 1820, and fatty amine polyoxyethylene ether 1830.

[0017] Preferably, the anti-settling agent is prepared by compounding Pingpingjia O-25 and Pingpingjia O-30.

[0018] Preferably, it comprises the following components by weight percentage: 1-10% cationic dispersant, 15-25% fatty amine polyoxyethylene ether, 2.5-5% Pingpingjia O-25, 2.5-5% Pingpingjia O-30, 5-10% diethylene glycol monobutyl ether, and water as the balance.

[0019] Preferably, it comprises the following components by weight percentage: 7.5% cationic dispersant, 15% fatty amine polyoxyethylene ether 1830, 2.5% Pingpingjia O-25, 2.5% Pingpingjia O-30, 5% diethylene glycol monobutyl ether and 67.5% water.

[0020] The cationic dispersant in this invention is prepared by modifying castor oil polyoxyethylene ether with 3-chloro-2-hydroxypropyltrimethylammonium chloride. Castor oil polyoxyethylene ether is prepared by reacting ricinoleic acid triglyceride with ethylene oxide. Its molecular structure contains three polyoxyethylene molecular chains, each with three hydroxyl groups at the end, allowing for the attachment of up to three quaternary ammonium groups. Therefore, the cationic dispersant in this invention exhibits greater charge repulsion than the alkyl polyoxypropylene ether-based methyl ammonium halide in patent CN108396575A, resulting in superior ability to prevent the detachment of soft oils, silicone oils, or formaldehyde-free fixing agents.

[0021] The fatty amine polyoxyethylene ether in the formulation of this invention is both nonionic and slightly cationic, with a higher cloud point than the fatty alcohol polyoxyethylene ether in patent CN108396575A. Its high-temperature emulsification and dispersion capabilities are superior to those of fatty alcohol polyoxyethylene ether, as is its alkali resistance. Furthermore, for nonionic surfactants, when the cloud point temperature is exceeded, they precipitate from the water, losing their surface activity and thus their effectiveness, reducing their applicability. Therefore, the cationic dispersant can form mixed micelles with the fatty amine polyoxyethylene ether. These mixed micelles are cationic, solving the high-temperature cloud point problem and enhancing the emulsification and dispersion capabilities, especially under strong alkalinity and high temperature. During the re-dyeing process, the stability of any soft oil or silicone oil that may be shed after emulsification and dispersion by the mixed micelles is excellent; it will not aggregate, break down, or re-adhere to the fabric, thus preventing soft oil spots or silicone oil spots. This overcomes the limitation that the optimal usage conditions for AD counterstaining agents in the prior art are pH 4.5-6.5, which restricts their application.

[0022] The formula of this invention does not contain acidic substances such as formic acid, acetic acid, oxalic acid, citric acid or benzoic acid as described in patent CN108396575A; it will not cause hydrolysis of cellulose molecules or reduce strength when used under acidic conditions at a temperature ≥50℃, and is especially suitable for repairing knitted fabrics whose burst strength is close to the national standard critical value.

[0023] In this invention, diethylene glycol monobutyl ether is used as an organic solvent. Considering that if the additive has poor freeze resistance in low winter temperatures, it may solidify, the addition of diethylene glycol monobutyl ether can improve the freeze resistance of the additive.

[0024] Furthermore, considering that some dyeing plants have poor water quality and high hardness, it is necessary to add anionic macromolecular propylene polymer chelating dispersants to improve water quality and prevent adverse effects of water quality on dyeing. However, some cotton knitwear, especially dark-colored cotton knitwear dyed with reactive dyes, is treated with strong cationic formaldehyde-free fixing agents. This may lead to a "precipitation reaction" between the chelating dispersant and the formaldehyde-free fixing agent, thus adversely affecting the dyeing process. To avoid the "precipitation reaction" problem, this invention uses a compound of nonionic surfactants Pingpingjia O-25 and Pingpingjia O-30 as an anti-precipitant, combined with a cationic dispersant and aliphatic amine polyoxyethylene ether.

[0025] Another object of the present invention is to provide an application of the above-mentioned silicone-free and solids-free re-dyeing agent, specifically, to apply the above-mentioned silicone-free and solids-free re-dyeing agent to the re-dyeing process of cotton knitted fabrics. The above-mentioned silicone-free and solids-free re-dyeing agent is internally named YK-606 by the applicant.

[0026] Preferably, the re-dyeing process includes the following steps: at room temperature, the fabric is first placed in a dyeing vat, then a silicone-free and solid-free re-dyeing agent is added, then dye and dyeing auxiliaries are added to the dyeing vat, then the temperature is raised to 60-98℃ and kept warm for 30-90 minutes to obtain the re-dyed fabric.

[0027] Preferably, the amount of the silicon-free and solid-free dyeing agent is 1-4% (owf).

[0028] Preferably, during dyeing, for fabrics that require re-boiling for whitening, reactive dye color correction, and reactive dye color modification during re-dyeing, the dyeing temperature is 60-98℃ and the dyeing time is 30-90 minutes.

[0029] As a further implementation method, during dyeing, for both white fabrics that require sulfur black color conversion during re-dyeing and reactive dye-dyed fabrics that require sulfur black color conversion, the dyeing temperature is 80-98℃ and the dyeing time is 60-90 minutes.

[0030] For fabrics treated with softening oil during finishing, the dosage of YK-606 is 1-1.5% (owf); for fabrics treated with both softening oil and formaldehyde-free fixing agent, the dosage is 1.5-2% (owf); for fabrics treated with silicone oil, the dosage is 2-2.5% (owf); for fabrics treated with both silicone oil and softening oil, the dosage is 2.5-3% (owf); for fabrics treated with both silicone oil and formaldehyde-free fixing agent, the dosage is 2.5-3% (owf); and for fabrics treated with both silicone oil, softening oil, and formaldehyde-free fixing agent, the dosage is 3-4% (owf). In general, the more auxiliaries added during finishing and the higher the dosage of auxiliaries, the higher the dosage of YK-606 needs to be, and vice versa.

[0031] As is well known in this field (“Fundamentals of Textile Organic Chemistry”, 1st ed., Sui Weimin et al., Shanghai Jiaotong University Press, p. 232, June 1992): Quaternary ammonium salt cationic surfactants have cationic groups as their surface-active components. When mixed with anionic surfactants or some dyes that can generate large anions in aqueous solutions (such as acid dyes, direct dyes, etc.), precipitation occurs. The dyeing and printing industry utilizes this property to use cationic surfactants as fixing agents for direct dyes, improving wash fastness.

[0032] It is well known in this field that "Fundamentals of Organic Chemistry in Textiles" was published in 1992. More than 30 years have passed since then. During this period, the synthesis and application technology of surfactants has continued to develop and be updated, and their types have become more diverse. In addition, direct dyes in the printing and dyeing industry, due to their problems with color fastness, especially their poor wash fastness, can no longer meet the increasingly high requirements for color fastness of textiles, and are therefore gradually being phased out and replaced by reactive dyes.

[0033] Quaternary ammonium salt cationic surfactants are divided into alkyl quaternary ammonium salt surfactants and alkyl polyether quaternary ammonium salt surfactants. For example, in the well-known ("Fundamentals of Textile Organic Chemistry", 1st edition, Sui Weimin et al., Shanghai Jiaotong University Press, p. 232, June 1992): dimethyl dodecyl benzyl ammonium chloride and trimethyl octadecyl ammonium chloride belong to alkyl quaternary ammonium salt surfactants, and their molecular structures do not contain polyoxyethylene hydrophilic chains. However, the cationic dispersant in this invention is prepared by modifying castor oil polyoxyethylene ether with 3-chloro-2-hydroxypropyltrimethylammonium chloride. The cationic dispersant has polyoxyethylene hydrophilic chains in its molecular structure. Therefore, under the dispersing effect of polyoxyethylene hydrophilic chains, even if it encounters anionic substances, it will not undergo a "precipitation reaction".

[0034] Direct dyes and reactive dyes are two types of dyes with different structures. Currently, quaternary ammonium salt polymer fixing agents, especially quaternary ammonium salt polymer formaldehyde-free fixing agents, are used in the printing and dyeing industry as fixing agents for reactive dyes, thereby meeting higher color fastness requirements.

[0035] This study found that the cationic dispersant (prepared from castor oil polyoxyethylene ether modified with 3-chloro-2-hydroxypropyltrimethylammonium chloride) has a greater charge repulsion than the alkyl polyoxypropylene ether-based methyl ammonium halide in patent CN108396575A, and its ability to prevent the shedding of soft oil, silicone oil, or formaldehyde-free fixing agents is superior. In addition, the nonionic surfactants Pingpingjia O-25 and Pingpingjia O-30 are compounded as anti-precipitating agents, and after being compounded with the cationic dispersant and fatty amine polyoxyethylene ether, cationic mixed micelles are formed, which solves the problem of high-temperature cloud point resistance. The compounding also enhances the effect, especially the emulsification and dispersion ability under strong alkalinity and high temperature. Therefore, the pretreatment step can be eliminated, the re-dyeing time can be reduced, and the production efficiency can be improved. Moreover, it does not react with anionic auxiliaries, such as anionic macromolecular methylpropene polymer chelating dispersants, nor with anionic reactive dyes, and will not cause problems such as "color spots" or "lakes".

[0036] The mechanism of action of YK-606 is as follows: On the one hand, during the re-dyeing process, it prevents the strong cationic macromolecular polymer formaldehyde-free fixing agent from falling off the fabric. This prevents uneven distribution of the formaldehyde-free fixing agent on the fabric due to uneven re-adhesion after falling off, and thus prevents uneven adsorption of anionic reactive dyes on the fabric, avoiding color spot problems. On the other hand, during the re-dyeing process, the softening oil finishing agent or organosilicon finishing agent that falls off the fabric will not aggregate or break down under the action of emulsification and dispersion, and will not re-adhere to the fabric, thus avoiding the problem of soft oil spots or silicone oil spots.

[0037] Compared with the prior art, the present invention has the following advantages: when using the re-dyeing agent of the present invention to re-dye cotton knitted fabrics, there is no need to go through steps such as stripping solids, stripping silicone, and stripping resin. Simply add the re-dyeing agent to the dye bath and you can directly re-dye and repair the color.

[0038] Furthermore, the re-dyeing agent of this invention can be used under strongly alkaline conditions and at high temperatures, thus offering a wider range of application conditions. The re-dyeing agent of this invention eliminates the need for a pretreatment step under high-temperature acidic conditions, avoiding the strength reduction of cotton knitwear under such conditions. It also has a stronger ability to prevent the shedding of softening oil, silicone oil, or formaldehyde-free fixing agents, and can prevent auxiliaries from solidifying at low temperatures, improving re-dyeing quality. The re-dyeing agent of this invention eliminates the need for a pretreatment step, reduces re-dyeing time, and improves production efficiency. Detailed Implementation

[0039] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited to the scope described in the embodiments.

[0040] Prepare the silicon-free and solid-free re-dyeing agents of Examples 1-4 according to the formulations in Table 1.

[0041] Table 1. Formulation of Silicone-Free and Solid-Free Re-dyeing Agents for Examples 1-4 (%)

[0042]

[0043] The preparation method of the silicone-free and solid-free re-dyeing agent in Examples 1-4 above is as follows: Weigh each component according to the proportion, heat deionized water to 50°C, add diethylene glycol monobutyl ether, stir for 10 minutes, then heat to 60°C, add Pingpingjia O-25 and Pingpingjia O-30, stir for 20 minutes, then heat to 70°C, add fatty amine polyoxyethylene ether, stir for 30 minutes, then heat to 80°C, add cationic dispersant, stir for 40 minutes, and cool to 30°C to obtain the corresponding silicone-free and solid-free re-dyeing agent.

[0044] Comparative Example 1: Compared with Example 3, the difference is that alkyl polyoxypropylene ether methyl ammonium halide is used instead of the cationic dispersant in this invention. The other components and contents, as well as the preparation method, are the same as in Example 3.

[0045] Comparative Example 2: Compared with Example 3, the difference is that fatty alcohol polyoxyethylene ether is used instead of fatty amine polyoxyethylene ether in this invention, while the other components and contents, and the preparation method are the same as in Example 3.

[0046] Comparative Example 3: Compared with Example 3, the difference is that alkyl polyoxypropylene ether-based methyl ammonium halide is used instead of the cationic dispersant in this invention, and fatty alcohol polyoxyethylene ether is used instead of fatty amine polyoxyethylene ether in this invention. The remaining components and contents, and the preparation method are the same as in Example 3.

[0047] Comparative Example 4: Compared with Example 3, the difference is that dimethyl dodecyl benzyl ammonium chloride is used instead of the cationic dispersant in this invention. The other components and contents, as well as the preparation method, are the same as in Example 3.

[0048] Comparative Example 5: Compared with Example 3, the difference is that trimethyloctadecylammonium chloride is used instead of the cationic dispersant in this invention. The other components and contents, as well as the preparation method, are the same as in Example 3.

[0049] Comparative Example 6: Compared with Example 3, the difference is that deionized water is used instead of diethylene glycol monobutyl ether in this invention, while the other components and contents, and the preparation method are the same as in Example 3.

[0050] Comparative Example 7: The re-dyeing agent prepared in Example 3 of the applicant's earlier application (publication number CN108396575A).

[0051] Application Example 1

[0052] Fabric type: Bright red cotton knitted fabric, finished with the addition of softening oil, silicone oil and color-fixing agent; Dyeing type: Reactive dye color correction.

[0053] The silicone-free and solids-free re-dyeing agents of Examples 1-4 and Comparative Examples 1-6 are applied in the re-dyeing process of cotton knitted fabrics. The steps include:

[0054] At room temperature, the fabric is first placed in the dyeing vat, then M (owf) (M is set to 1%, 2%, 4% respectively) of the silicone-free and solid-free re-dyeing agent is added, followed by reactive dyes, salt and alkali, and then the temperature is raised to N (N is set to 60℃, 75℃, 90℃ respectively), the dyeing time is 90 minutes, and then the liquid is drained to obtain the re-dyed fabric.

[0055] Effect evaluation and performance testing

[0056] 1) Cloud point test method: Prepare a 10 g / L dispersion of surfactant, Examples 1-4, and Comparative Examples 1-3, and prepare a mixed dispersion of sodium chloride, i.e., 10 g / L + 50 g / L sodium chloride. Then take 100 g and heat it in an induction cooker until the dispersion becomes cloudy. The temperature at which the dispersion becomes cloudy is the cloud point.

[0057] Table 2 Comparison of cloud spots

[0058]

[0059] For nonionic surfactants, above the cloud point temperature, they precipitate out of water, losing their surface activity and thus their effectiveness, thereby reducing their application range. Table 2 shows that the cloud points of commonly used fatty alcohol polyoxyethylene ethers AEO-7 and AEO-9 are <90℃, especially when mixed with sodium chloride to form a dispersion, the cloud point further decreases to <70℃. When dyeing with reactive dyes, especially dark colors, more sodium chloride and other salt-based dyeing accelerators are needed, and the dyeing temperature is 60-90℃. Therefore, if the cloud point of a mixed dispersion of fatty alcohol polyoxyethylene ether and sodium chloride is <60-90℃, its application range will inevitably be reduced. Furthermore, when mixed with sodium chloride, cationic dispersants have a better ability to raise the cloud point temperature than alkyl ammonium polyoxypropylene ethers, thus ensuring better performance at high temperatures.

[0060] 2) Compatibility test method with anionic macromolecular malonic acid polymer: Weigh 1 gram of the auxiliary agent and add 98 grams of water, stir well, then add 1 gram of anionic macromolecular malonic acid polymer, stir well, and observe the initial stability and the stability after different standing times. If the initial mixture is turbid, it indicates poor stability. If precipitation occurs after standing, it indicates very poor stability. Conversely, if it is transparent, it indicates good stability. If it is transparent and there is no precipitation after standing, it indicates very good stability.

[0061] Table 3 Comparison of compatibility with anionic macromolecular malathion polymers

[0062]

[0063] As shown in Table 3, alkyl quaternary ammonium salt surfactants such as dimethyl dodecyl benzyl ammonium chloride and trimethyl octadecyl ammonium chloride will undergo a precipitation reaction with the anionic macromolecular arsenic polymer. However, alkyl polyether quaternary ammonium salt surfactants, such as the cationic dispersant or alkyl polyoxypropylene ether methyl halide ammonium in this invention, will not undergo a precipitation reaction with the anionic macromolecular arsenic polymer. This indicates that the molecular structures of dimethyl dodecyl benzyl ammonium chloride and trimethyl octadecyl ammonium chloride do not contain a polyoxyethylene hydrophilic chain, but only a quaternary ammonium group. In contrast, the molecular structures of the cationic dispersant and alkyl polyoxypropylene ether methyl halide ammonium contain both a quaternary ammonium hydrophilic group and a polyoxyethylene hydrophilic chain hydrophilic group. Therefore, even if they encounter anionic substances, they will not undergo a precipitation reaction under the dispersing effect of the polyoxyethylene hydrophilic chain.

[0064] 3) Compatibility test method with anionic reactive dyes: Prepare 5 cups of each group of working solutions (the formulas of each group are shown in Table 4 below, and the unit of components is grams). After initial preparation, filter with filter paper. After 4H, 8H, 12H, and 24H, filter with filter paper respectively. Observe whether there are precipitates on the filter paper. If there are precipitates, it indicates that a "precipitation reaction" has occurred with the anionic reactive dye. If there are no precipitates, it indicates that a "precipitation reaction" has not occurred with the anionic reactive dye.

[0065] Table 4 Comparison of compatibility with anionic reactive dyes

[0066]

[0067] As shown in Table 4, alkyl quaternary ammonium salt surfactants such as dimethyl dodecyl benzyl ammonium chloride and trimethyl octadecyl ammonium chloride will undergo a "precipitation reaction" with anionic reactive dyes, while alkyl polyether quaternary ammonium salt surfactants, such as the cationic dispersant or alkyl polyoxypropylene ether methyl halide ammonium in this invention, will not undergo a "precipitation reaction" with anionic reactive dyes.

[0068] 4) High-temperature emulsification and dispersion ability test method: Weigh 50 grams of additive and 50 grams of No. 5 mineral oil, mix them in a beaker, and then place the beaker in an 80℃ water bath. Let it stand until the mixture in the beaker reaches 80℃. Stir with a stirrer for 5 minutes while keeping it at the temperature, and then quickly pour it into a 100mL graduated cylinder and start timing. When the water layer separates to 20mL on the graduated cylinder, stop timing. This time is the emulsification and dispersion time. Each group is tested in parallel 5 times, and the average emulsification and dispersion time is taken. The longer the emulsification and dispersion time, the better the emulsification and dispersion ability, and vice versa.

[0069] Table 5 Comparison of emulsifying and dispersing abilities

[0070]

[0071] As shown in Table 5, the emulsifying and dispersing ability of fatty amine polyoxyethylene ether is better than that of fatty alcohol polyoxyethylene ether AEO-7 and AEO-9, and the emulsifying and dispersing ability of Example 3 is better than that of Comparative Examples 1-5. In addition, the emulsifying and dispersing ability of the cationic dispersant and fatty amine polyoxyethylene ether in this invention is better than that of alkyl polyoxypropylene ether methyl ammonium halide, dimethyl dodecyl benzyl ammonium chloride and trimethyl octadecyl ammonium chloride.

[0072] 5) Caustic soda resistance test method: Prepare a 5 g / L dispersion of the additive and weigh 50 g of it. Then mix it with 50 g of 10 g / L caustic soda solution. After mixing, the concentration of the additive is 2.5 g / L and the concentration of caustic soda is 5 g / L. Let it stand for 10 min and observe the stability. If there is no floating matter, no flocculent matter, and no precipitation, it is considered stable. Otherwise, it is considered unstable, and the caustic soda resistance is 5 g / L. Using the caustic soda concentration of 5 g / L as a gradient, increase the concentration sequentially until instability occurs. The previous stable caustic soda concentration is the caustic soda resistance.

[0073] Table 6 Comparison of Caustic Soda Resistance

[0074]

[0075] As shown in Table 6, the caustic alkali resistance of fatty amine polyoxyethylene ether is better than that of fatty alcohol polyoxyethylene ether AEO-7 and AEO-9. The caustic alkali resistance of Example 3 is better than that of Comparative Examples 1-3. This also shows that the cationic dispersant in this invention is better than alkyl polyoxypropylene ether methyl ammonium halide in improving the caustic alkali resistance of nonionic surfactants.

[0076] 6) Freeze resistance test method: Take 100 grams of the additive into a 150-gram transparent plastic bottle and place it in a temperature-controlled freezer. Control the temperature at 0-3℃. Then observe the appearance of the additive in the freezer at time intervals of 0.5H, 1H, 2H, 4H, 12H, and 24H. If it is transparent and stable, it indicates good freeze resistance. If it becomes cloudy, viscous, or even solidifies, it indicates poor freeze resistance.

[0077] Table 7 Comparison of Freeze Resistance

[0078]

[0079] As shown in Table 7, the freeze resistance of Comparative Example 7 (the applicant's earlier application for a dyeing agent with model number YK-303, publication number CN108396575A) is worse than that of Examples 1-4. In addition, the freeze resistance of Examples 1-4 is better than that of Comparative Example 6. This indicates that the addition of diethylene glycol monobutyl ether in this invention can improve freeze resistance. Therefore, the requirements for the storage environment temperature of the auxiliary agent are relatively wide, and it is more convenient to use at low temperatures.

[0080] The fabric conditions of the re-dyed cotton knitted fabrics were compared with those of Examples 1-4 and Comparative Examples 1-6 in four aspects: dyeing uniformity, fabric smoothness, presence of soft oil spots, and presence of silicone oil spots. The results are shown in Tables 8-10 below:

[0081] Table 8 Fabric condition of Examples 1-4 and Comparative Examples 1-6

[0082]

[0083] As shown in Table 8, the silicone-free and fixative-free re-dyeing agents of Examples 1-4 of this invention have a stronger ability to prevent the removal of soft oil, silicone oil, or formaldehyde-free fixing agents compared to the silicone-free and fixative-free re-dyeing agents of Comparative Examples 1-3. A comparison of Example 3 with Comparative Examples 1-3 shows that the cationic dispersant in this invention has a better ability to prevent the removal of soft oil, silicone oil, or formaldehyde-free fixing agents compared to alkyl polyoxypropylene ether-based methyl halide ammonium. The fatty amine polyoxyethylene ether in this invention has better emulsifying and dispersing ability and alkali resistance stability compared to fatty alcohol polyoxyethylene ether. Furthermore, replacing the cationic dispersant in this invention with dimethyl dodecyl benzyl ammonium chloride or trimethyl octadecyl ammonium chloride not only results in color unevenness and stains after re-dyeing, but also in soft oil spots and silicone oil spots.

[0084] Table 9 Fabric condition of Examples 1-4 and Comparative Examples 1-6 (Table II)

[0085]

[0086] As can be seen from Tables 8-9, the fatty amine polyoxyethylene ether in this invention has better high-temperature emulsification and dispersion ability and alkali resistance compared with the fatty alcohol polyoxyethylene ether.

[0087] Table 10 Fabric condition of Examples 1-4 and Comparative Examples 1-3 (Table III)

[0088]

[0089] As can be seen from Tables 8-10, the cationic dispersant in this invention can be compounded with fatty amine polyoxyethylene ether, which solves the problem of high-temperature cloud point resistance and enhances the effect through compounding, especially the emulsification and dispersion ability under strong alkalinity and high temperature. During the re-dyeing process, the stability of soft oil or silicone oil that may fall off after being emulsified and dispersed by mixed micelles is excellent. It will not aggregate, break the emulsion, or re-adhere to the fabric, thus avoiding the problem of soft oil spots or silicone oil spots.

[0090] Application Example 2

[0091] Fabric type: white cotton knitted fabric, with softening oil added during finishing; dyeing type: bleached and dyed.

[0092] The silicone-free and solids-free re-dyeing agent of Example 3 and the silicone-free and solids-free re-dyeing agents of Comparative Examples 1-3 are applied in the re-dyeing process of cotton knitted fabrics. The steps include:

[0093] At room temperature, the fabric is first placed in the dyeing vat, then 3% (owf) of a silicone-free and solid-free re-dyeing agent is added, followed by whitening agent, caustic soda and hydrogen peroxide. The temperature is then raised to 98°C and the dyeing time is 30 minutes. The temperature is then lowered and the liquid is drained to obtain the re-dyed fabric.

[0094] The re-dyeing agent from Comparative Example 7 was applied to the re-dyeing process of cotton knitted fabrics. The steps included:

[0095] Pretreatment steps: At room temperature, first put the fabric into the dyeing vat, then add 3% (owf) of silicone-free and solids-free re-dyeing agent, then heat to 50℃ and keep it at that temperature for 30 minutes to obtain the pretreated fabric.

[0096] Dyeing steps: Add whitening agent, caustic soda and hydrogen peroxide to the dyeing vat, then heat to 98℃, dye for 30 minutes, then cool down and drain the liquid to obtain the re-dyed fabric;

[0097] In the pretreatment step, the pretreatment temperature is 50℃ and the pretreatment time is 30 minutes; in the staining step, the staining temperature is 98℃ and the staining time is 30 minutes.

[0098] Table 11 Fabric condition and bursting strength of Examples 3, 1-3 and 7

[0099]

[0100] Note: (1) The bursting strength is tested according to the method in the standard "FZ / T 73020-2019 Knitted Casual Clothing", which requires the bursting strength to be ≥250N; (2) The bursting strength of white cotton knitted fabric before re-dyeing is 272N.

[0101] As shown in Table 11, Examples 3 and Comparative Examples 1-3 do not contain acidic substances such as formic acid, acetic acid, oxalic acid, citric acid or benzoic acid as in Comparative Example 7, and do not require a pretreatment step. The bursting strength after re-dyeing can meet the standard requirements. However, the solid-free re-dyeing agent YK-303 in patent CN108396575A (i.e., Comparative Example 7) contains acidic substances and requires a pretreatment step. The bursting strength after re-dyeing cannot meet the standard requirements. This shows that the present invention can not only save the pretreatment step, but also has little impact on the bursting strength of the fabric after re-dyeing.

[0102] Application Example 3

[0103] Fabric type: White cotton knitted fabric, with silicone oil added during finishing; Dyeing type: Color-modified sulfur black.

[0104] The silicone-free and solids-free re-dyeing agent of Example 3 above is applied to the re-dyeing process of cotton knitted fabrics. The steps include:

[0105] At room temperature, the fabric is first placed in the dyeing vat, then 3% (owf) of a silicone-free and solid-free re-dyeing agent is added, followed by caustic soda, sodium sulfide and salt. The temperature is then raised to 98°C and kept at that temperature for 30 minutes. The temperature is then lowered to 80°C, sodium sulfide and sulfur black are added, and the temperature is raised to 98°C again. The dyeing time is 60 minutes, and the temperature is then lowered and the liquid is drained to obtain the re-dyed fabric.

[0106] The results showed that the re-dyed cotton knitted fabric obtained in Example 3 had uniform dyeing, no color spots, good fabric smoothness, and no silicone oil spots.

[0107] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A silicon-free and solid-free dyeing agent, characterized in that, It includes the following components by weight percentage: 1-20% cationic dispersant, 5-25% fatty amine polyoxyethylene ether, 5-20% anti-precipitant, 5-20% diethylene glycol monobutyl ether and water as balance; The cationic dispersant was prepared by modifying castor oil polyoxyethylene ether with 3-chloro-2-hydroxypropyltrimethylammonium chloride; The anti-settling agent is prepared by compounding Pingpingjia O-25 and Pingpingjia O-30.

2. The silicon-free and solid-free dyeing agent according to claim 1, characterized in that, The castor oil polyoxyethylene ether is prepared by reacting castor oil triglyceride with ethylene oxide.

3. The silicon-free and solid-free dyeing agent according to claim 1, characterized in that, The fatty amine polyoxyethylene ether is selected from at least one of fatty amine polyoxyethylene ether 1815, fatty amine polyoxyethylene ether 1820, and fatty amine polyoxyethylene ether 1830.

4. The silicon-free and solid-free dyeing agent according to claim 1, characterized in that, It includes the following components by weight percentage: 1-10% cationic dispersant, 15-25% fatty amine polyoxyethylene ether, 2.5-5% Pingpingjia O-25, 2.5-5% Pingpingjia O-30, 5-10% diethylene glycol monobutyl ether and water as balance.

5. The silicon-free and solid-free dyeing agent according to claim 1, characterized in that, It comprises the following components by weight percentage: 7.5% cationic dispersant, 15% fatty amine polyoxyethylene ether 1830, 2.5% Pingpingjia O-25, 2.5% Pingpingjia O-30, 5% diethylene glycol monobutyl ether and 67.5% water.

6. The application of the silicon-free and solid-free dyeing agent according to any one of claims 1-5, characterized in that, The aforementioned silicone-free and solids-free re-dyeing agent is applied to the re-dyeing process of cotton knitted fabrics. The re-dyeing process includes the following steps: at room temperature, the fabric is first placed in a dyeing vat, then the silicone-free and solids-free re-dyeing agent is added, then dye and dyeing auxiliaries are added to the dyeing vat, then the temperature is raised to 60-98℃ and kept at that temperature for 30-90 minutes to obtain the re-dyed fabric.

7. The application of the silicon-free and solid-free dyeing agent according to claim 6, characterized in that, The amount of the silicon-free and solid-free re-dyeing agent used is 1-4% (owf).