Hand feeling type acidic leveling agent and preparation method thereof

Abstract

The invention relates to the field of leveling agents, in particular to a hand feeling type acidic leveling agent and a preparation method thereof. The preparation method comprises the following steps: firstly, amidating long-chain fatty acid of which the carbon atom number is greater than 10 and hydroxyethyl ethylenediamine, and then carrying out ring-opening addition on the amidated long-chain fatty acid and EO under the catalysis of AlMe3-NH4Cl or Me2AlNH2 to prepare a hydrophobic-hydrophilic block copolymer; the obtained leveling agent is high-concentration transparent liquid and is free of gel; the dyeing agent has excellent retarding property, migration property and dye dispersibility in dyeing of acid dyes such as chinlon, wool and the like, and can form a flexible lubricating film on the surface of a fiber, so that the problem that a fabric becomes hard after high-temperature setting is remarkably solved, and a softening agent after-finishing procedure is omitted.

Description

Technical Field

[0001] This invention relates to the field of leveling agents, and more specifically, to a hand-feel type acidic leveling agent and its preparation method. Background Technology

[0002] In acid dyeing systems for nylon, wool, and other fibers, leveling agents are key auxiliaries for controlling dyeing rate and preventing uneven dyeing. Existing acid leveling agents mostly use short-chain fatty acids or their derivatives as hydrophobic units, primarily based on two considerations: first, the short-chain carbon skeleton has good water solubility and is less prone to gelation even at high concentrations or low temperatures, facilitating on-site mixing and pipeline transportation; second, the small molecular size of short chains allows for rapid diffusion to the fiber surface, resulting in a significant initial slowing effect and inhibiting uneven dyeing. For example, Chinese patent CN104141251B discloses a high-temperature leveling agent for microfiber fabrics, which uses fatty acids and polyethylene glycol as raw materials, undergoing an esterification reaction under a strong acid catalyst to synthesize high-temperature leveling agent component A. The fatty acid is any one of isooctanoic acid, isononanoic acid, and isodecanic acid. Under the action of the leveling agent, the dye can easily penetrate into the microfiber, achieving uniform dyeing. Therefore, short-chain fatty acids are considered a solution that balances processing convenience with basic leveling performance.

[0003] However, the above-mentioned solutions have certain drawbacks in terms of the final hand feel. After nylon fabrics are set at high temperatures of 180-200℃, the amorphous regions on the fiber surface rearrange. Short-chain fatty acid derivatives, due to insufficient carbon chain length and weak intermolecular forces, cannot form an effective flexible coating layer, nor can they offset the increase in rigidity brought about by high-temperature setting. As a result, the coefficient of friction on the fabric surface increases, and the touch becomes noticeably hard and dry, lacking the soft hand feel expected by traditional acid leveling agents. To compensate for the hand feel defect, additional softeners are often required for secondary finishing, which not only increases the number of processes and costs but also easily causes compatibility problems and reduces color fastness.

[0004] Therefore, there is an urgent need to develop an acidic leveling agent that combines excellent leveling properties with a good hand feel to meet the actual production needs of the printing and dyeing industry. Summary of the Invention

[0005] To address the aforementioned technical problems, the first aspect of this invention provides a method for preparing a hand-feel type acidic leveling agent, comprising:

[0006] S1. Under nitrogen atmosphere, ethylenediamine and inorganic base are mixed and heated to 160-180℃. Then ethylene oxide (EO) is added and reacted for 2-5 hours. After the reaction is completed, the product hydroxyethyl ethylenediamine is collected by vacuum distillation.

[0007] S2. Mix fatty acids and hydroxyethyl ethylenediamine and react them at 140-180℃ and pH < 3 to obtain the amide intermediate.

[0008] S3. Mix the amide intermediate, EO and catalyst, and react at 1-5 bar and 80-120℃ to obtain a hand-feeling acidic leveling agent.

[0009] As an implementable example, in step S1, the mass ratio of ethylenediamine to EO is (100-120):(40-50).

[0010] As an feasible example, in step S1, the inorganic base is 0.3-0.5% of the total mass of ethylenediamine and EO.

[0011] Furthermore, the inorganic base includes sodium hydroxide or potassium hydroxide.

[0012] Furthermore, the inorganic base is potassium hydroxide, and the reaction formula for step S1 is as shown in formula (1):

[0013]

[0014] As an example of implementation, the vacuum distillation is carried out at a temperature of 235-240°C and a pressure of 200-210 kPa.

[0015] As an feasible example, the fatty acid (R-COOH) has more than 10 carbon atoms, and the reaction formula for step S2 is as shown in formula (2):

[0016]

[0017] Furthermore, the fatty acids include one or more of lauric acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, or stearic acid.

[0018] Furthermore, the fatty acid mentioned is oleic acid.

[0019] In this invention, long-chain fatty acids with more than 10 carbon atoms are selected as raw materials and subjected to amidation reaction with hydroxyethyl ethylenediamine. Long-chain hydrophobic alkyl groups are introduced at the end of the amide intermediate molecule. These long-chain hydrophobic alkyl groups are chemically anchored to the surface of nylon fibers via amide bonds, forming a flexible lubricating layer through hydrophobic-van der Waals forces. This significantly reduces the coefficient of friction between fibers, giving the finished nylon fabric a soft and smooth hand feel. At the same time, the long-chain hydrophobic segments and the hydrophilic polyether segments formed by subsequent EO addition constitute a hydrophobic-hydrophilic block structure. While maintaining high concentration non-gelling and leveling properties, this makes the hand feel durable and wash-resistant, overcoming the defect of traditional acidic leveling agents causing the fabric hand feel to harden.

[0020] As an implementable example, the molar ratio of the fatty acid to hydroxyethyl ethylenediamine is 1:

[0021] (1-1.2).

[0022] As an feasible example, in step S3, the molar ratio of the amide intermediate to EO is 1:(10-30), and the reaction formula for step S3 is as shown in formula (3):

[0023]

[0024] Furthermore, in step S3, the molar ratio of the amide intermediate to EO is 1:25.

[0025] This invention strictly limits the molar ratio of amide intermediate to ethylene oxide to 1:25. By precisely controlling the polyether chain length, the molecule possesses both appropriate hydrophilicity and hydrophobicity: ensuring no gelation and uniform dye dispersion at high concentrations, while also ensuring effective binding of amide bonds and nylon hydrogen bonds, resulting in excellent slow dyeing and migration properties; at the same time, it imparts a soft, smooth, and wash-resistant feel to the fabric, avoiding the problems of excessive hydrophilicity and decreased binding force due to an excessively high ratio, or insufficient water solubility and poor leveling properties due to an excessively low ratio. Thus, a stable, process-adaptable, and hand-feeling acidic leveling agent is obtained under high-pressure reaction conditions.

[0026] As an example of implementation, the catalyst includes AlMe3-NH4Cl or Me2AlNH2.

[0027] This application selects AlMe3-NH4Cl or Me2AlNH2 as catalysts for the S3 step ring-opening addition reaction because both can activate ethylene oxide via Al–N bonds, enabling efficient ring-opening at 80-120℃ and 1-5 bar, resulting in a fast reaction rate and few byproducts. The AlMe3-NH4Cl system also exhibits a Lewis acid-base synergistic effect, further reducing the activation energy and inhibiting polyether segment degradation, while Me2AlNH2 has less steric hindrance, which is beneficial for controlling chain growth during EO addition. Both are oil-soluble and readily soluble in the reaction system; after the reaction, hydrolysis completely deactivates them and converts them into soluble aluminum salts, eliminating the need for additional separation steps and ensuring high product purity, low color, and no residual metal contamination. This approach balances process simplicity, low cost, and stable performance.

[0028] Furthermore, the amount of catalyst used is 0.5-1% of the total molar amount of amide intermediate and EO.

[0029] A second aspect of the present invention provides a hand-feeling acidic leveling agent prepared by the above-described method for preparing a hand-feeling acidic leveling agent.

[0030] Beneficial effects

[0031] (I) By selecting fatty acid oleic acid with a suitable chain length as the reaction raw material, the leveling agent prepared by this invention can form a flexible lubricating film on the surface of nylon after use, which significantly improves the stiff feel after high temperature setting and realizes the integration of leveling and softness.

[0032] (ii) By limiting the molar ratio of amide intermediate to EO to 1:(10-30), this invention can ensure that high solids content products remain transparent and flowing liquids, which facilitates storage, transportation and measurement.

[0033] (III) In this invention, AlMe3-NH4Cl or Me2AlNH2 is selected as the catalyst for the ring-opening addition reaction. The ring-opening addition can be completed rapidly at 80-120℃ and 1-5 bar. There are few side reactions and low energy consumption. At the same time, the catalyst is converted into soluble aluminum salt after hydrolysis, with no heavy metal residue, which meets the requirements for ecological textile processing.

[0034] (iv) The leveling agent provided by the present invention is applicable to acid dye systems and is suitable for various fibers such as nylon and wool and their blended fabrics. It has a wide process window and good reproducibility.

[0035] (v) The leveling agent provided by the present invention has a balanced ratio of hydrophilic to hydrophobic blocks, and its slow dyeing, migration and dye dispersibility are all at or above those of commercially available acidic leveling agents. Detailed Implementation

[0036] Example 1

[0037] The first aspect of this example provides a method for preparing a hand-feeling acid leveling agent, specifically as follows:

[0038] S1. Under nitrogen atmosphere, 112 parts of ethylenediamine and 0.8 parts of KOH were mixed, heated to 160℃ and held for 1 hour; then heated to 180℃ and held for 2 hours; then, under 0.60 MPa pressure, 22.2 parts of EO were added to each of the two batches and reacted for 3 hours. After the reaction was completed, the unreacted ethylenediamine was recovered by distillation, and then the product hydroxyethyl ethylenediamine was collected by vacuum distillation at 235℃ and 204.41 kPa.

[0039] S2. Oleic acid and hydroxyethyl ethylenediamine are mixed in a molar ratio of 1:1. The mixture is kept at 140°C for 2 hours in an acidic environment with pH 2.5 to carry out the first dehydration. Then the temperature is raised to 180°C and kept for 2 hours to carry out the second dehydration, thus obtaining the amide intermediate.

[0040] S3. Mix 1 mol of amide intermediate, 25 mol of EO and 0.13 mol of AlMe3-NH4Cl, and react at 80°C for 1 h under 2 bar pressure. Then raise the temperature to 100°C and react for 1 h. Finally, raise the temperature to 120°C and react for 1 h to obtain a hand-feel type acidic leveling agent.

[0041] In this example, EO was purchased from Weifang Puxin Chemical Co., Ltd., with CP-grade purity.

[0042] The second aspect of this example provides a hand-feeling acidic leveling agent prepared by the above-described method for preparing a hand-feeling acidic leveling agent.

[0043] Example 2

[0044] The specific implementation method in this example is the same as in Example 1, except that:

[0045] 1. In step S2, palmitic acid is used instead of oleic acid;

[0046] 2. In step S3, the reaction raw materials are 1 mol of amide intermediate, 20 mol of EO and 0.105 mol of AlMe3-NH4Cl.

[0047] Example 3

[0048] The specific implementation method of this example is the same as that of Example 1, except that in step S3, the reaction raw materials are 1 mol of amide intermediate, 10 mol of EO and 0.055 mol of AlMe3-NH4Cl.

[0049] Example 4

[0050] The specific implementation method of this example is the same as that of Example 1, except that in step S3, the reaction raw materials are 1 mol of amide intermediate, 20 mol of EO and 0.105 mol of AlMe3-NH4Cl.

[0051] Comparative Example 1

[0052] The specific implementation method in this example is the same as in Example 1, except that decanoic acid is used instead of oleic acid in step S2.

[0053] Comparative Example 2

[0054] The specific implementation method in this example is the same as in Example 1, except that the reaction temperature in step S2 is 130°C.

[0055] Comparative Example 3

[0056] The specific implementation method of this example is the same as that of Example 1, except that in step S3, the reaction raw materials are 1 mol of amide intermediate, 8 mol of EO and 0.045 mol of AlMe3-NH4Cl.

[0057] Comparative Example 4

[0058] The specific implementation method of this example is the same as that of Example 1, except that in step S3, the reaction raw materials are 1 mol of amide intermediate, 35 mol of EO and 0.18 mol of AlMe3-NH4Cl.

[0059] Comparative Example 5

[0060] A commercially available leveling agent, model CMP-1, was purchased from Zhejiang Huasheng Textile Technology Co., Ltd.

[0061] Performance testing

[0062] 1. Transmissibility test

[0063] Test method: Colored fabric and undyed fabric of the same specification and weight were sewn together with undyed polyester thread. The product from Examples 1-4 and Comparative Examples 1-5 was applied at a rate of 0.5 g / L, acetic acid (50 wt%) at 0.8 g / L, with a liquor ratio of 1:20. The fabric was then dyed at 40°C, with the temperature increased to 98°C at a rate of 1.5°C / min, held for 30 min, and then cooled to 60°C. The fabric was then washed, dried, and ready for testing. After regaining moisture, the K / S values ​​of the colored and white fabrics were tested, and the migration rate was calculated using the following method.

[0064]

[0065] Among them, the higher the migration rate, the better the migration performance.

[0066] 2. Slow-release test

[0067] Test Method: Prepare 10 identical dye solutions using 1.5 wt% Acid Blue 2037, 0.25 g / L of the products from Examples 1-4 and Comparative Examples 1-5, and 0.8 g / L of acetic acid (50 wt%) at a liquor ratio of 1:20. Run the solutions at room temperature (25°C) for 10 min, increasing the temperature at a rate of 1°C / min. Run the solutions at 50°C, 60°C, 70°C, 80°C, 90°C, 98°C for 15 min, 98°C for 30 min, 98°C for 45 min, and 98°C for 60 min, retaining the residual water. After washing, drying, and rehydration, the solutions are mounted on the samples. The K / S value is measured at different temperatures. A slower increase in the K / S value indicates better dyeing performance. The K / S values ​​are ranked from slowest to fastest as follows: very good, good, relatively good, slightly poor, poor, and very poor.

[0068] 3. Dispersion test

[0069] Test method: Take 0.5 g / L each of Disperse Ruby S-2GFL and Disperse Brilliant Blue 2BLM, and add 0.5 g / L of the products from Examples 1-4 and Comparative Examples 1-5 to the working solution at pH=5. Heat to 98℃ at a rate of 2℃ / min and run for 30 min. Then cool to 60℃ at a rate of 2℃ / min and filter. Dry the filter paper and observe the dye diffusion on the filter paper surface. A high concentration of dye on the filter paper surface indicates poor dispersion performance, and vice versa. Based on a self-made test card, the minimum residue is rated as level 5.

[0070] 4. Hydrogel addition test

[0071] Test method: Weigh 20g of the product from Examples 1-4 and Comparative Examples 1-5 into a beaker, add 10g of water and stir. After stirring evenly, observe the state of the solution. If the solution is transparent and fluid, it is non-gelling. If it is viscous and requires heating to become fluid, it is gelling.

[0072] 5. Hand feel test

[0073] Test method: A blind test was conducted by five people using pinching, touching, grasping, and visual inspection to rank the softness and smoothness of the textiles treated with the products of Examples 1-4 and Comparative Examples 1-5. The products were ranked according to their softness, with smaller numbers indicating better feel, i.e., number 1 being the softest sample.

[0074] 6. Dyeing percentage test

[0075] Calculate the dye uptake percentage E according to the formula:

[0076] E = (1 - A1 / A0) × 100% A1 — Absorbance of the residual solution after staining;

[0077] A0 – Absorbance of the pre-dye solution (625nm).

[0078] The results of the above tests are detailed in Table 1-2.

[0079] 7. Solubility

[0080] Test method: At room temperature (25℃), if more than 10g of leveling agent can be dissolved in 100mL of water, it is considered easily soluble; if more than 5g but less than 10g can be dissolved, it is considered slightly soluble; and if less than 5g can be dissolved, it is considered poorly soluble.

[0081] The experimental results are detailed in Table 1-2.

[0082] Table 1

[0083]

[0084] Table 2

[0085] Finished product appearance Solubility Migration rate / % feel Comparative Example 1 transparent liquid Easily soluble 57.45 3 Comparative Example 2 transparent liquid Easily soluble 53.48 4 Comparative Example 3 transparent liquid Insoluble 53.19 1 Comparative Example 4 Turbid liquid Easily soluble 58.13 2

[0086] As can be seen from the experimental results in Table 1-2, the acidic leveling agent provided in Example 1 of the present invention has excellent leveling effect, and due to the use of suitable fatty acids, the amount of EO added in the ring-opening addition reaction is limited, and the treated fabric has a good hand feel.

[0087] However, Comparative Example 1, due to its lower amidation reaction temperature, the shorter carbon chain of the fatty acid in Comparative Example 2, and the excessive or insufficient EO addition in the ring-opening addition reaction in Comparative Examples 3-4, will have a certain negative impact on the leveling effect of the leveling agent and the hand feel of the fabric, resulting in a decrease in the practicality of the product.

Claims

1. A method for preparing a hand-feel type acidic leveling agent, characterized in that, include: S1. Under nitrogen atmosphere, ethylenediamine and inorganic base are mixed and heated to 160-180℃. Then ethylene oxide is added and reacted for 2-5 hours. After the reaction is completed, the product hydroxyethyl ethylenediamine is collected by vacuum distillation. S2. Mix fatty acids and hydroxyethyl ethylenediamine and react them at 140-180℃ and pH < 3 to obtain the amide intermediate. S3. Mix the amide intermediate, ethylene oxide and catalyst, and react at 1-5 bar and 80-120℃ to obtain a hand-feel type acidic leveling agent.

2. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, In step S1, the mass ratio of ethylenediamine to EO is (100-120):(40-50).

3. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, The inorganic base mentioned includes sodium hydroxide or potassium hydroxide.

4. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, The vacuum distillation is carried out at a temperature of 235-240℃ and a pressure of 200-210 kPa.

5. The method for preparing a hand-feel type acidic leveling agent according to any one of claims 1-4, characterized in that, The fatty acid has more than 10 carbon atoms.

6. The method for preparing the hand-feel type acidic leveling agent according to claim 5, characterized in that, The fatty acids mentioned include one or more of lauric acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, or stearic acid.

7. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, The molar ratio of the fatty acid and hydroxyethyl ethylenediamine is 1:(1-1.2).

8. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, In step S3, the molar ratio of the amide intermediate to EO is 1:(10-30).

9. The method for preparing the hand-feel type acidic leveling agent according to claim 1, characterized in that, The catalysts include AlMe3-NH4Cl or Me2AlNH2.

10. A hand-feeling acidic leveling agent prepared by the method according to any one of claims 1-9.

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