A strong protection type wool low temperature dyeing method based on guanidine salt stripping of wool lipids

Abstract

This invention discloses a high-strength, protective low-temperature dyeing method for wool based on guanidine salt removal of wool lipids, belonging to the application technology field of wool dyeing and finishing in the wool textile industry. Addressing the problems of significant fiber structure damage and strength reduction in existing high-temperature wool dyeing processes, and the limitations of existing low-temperature dyeing technologies in industrial application and poor dark-color dyeing effects, this invention employs a PHMB / SPHMB, sodium carbonate, and sodium sulfate composite system to degrease wool, followed by washing and low-temperature dyeing with wool reactive dyes. This invention can achieve low-temperature dyeing of wool at 70-75℃, with a maximum dye uptake of 99.12%, and the dyeing effect is superior to conventional boiling dyeing processes. The treated wool fibers retain their strength without loss and even show a slight increase, while also imparting excellent antibacterial properties. The process is short, energy-efficient, environmentally friendly, and suitable for industrial production needs.

Description

Technical Field

[0001] This invention relates to a powerful protective low-temperature dyeing method for wool based on guanidine salts to remove wool lipids, belonging to the application technology field of wool dyeing and finishing in the wool textile industry. Background Technology

[0002] Wool fiber, as a typical representative of natural protein fibers, possesses excellent elasticity and wrinkle resistance, superior softness and comfort, and outstanding warmth and temperature regulation properties, occupying an important position in the high-end textile industry. However, the dense scale layer and hydrophobic lipid layer composed of fatty acid mixtures on the surface of wool make it difficult for dye molecules to penetrate, diffuse, and dye into the fiber interior. Traditional wool dyeing processes typically require high temperatures of around 98°C, which severely damages the wool fiber structure, causing peptide bond hydrolysis and disulfide bond breakage. This not only results in a significant decrease in fiber strength and severe yellowing but also exacerbates felting deformation, damaging the fiber surface scales and leading to a surge in breakage rates during subsequent combing and spinning, seriously affecting its spinnability and the quality of the final product. Low-temperature dyeing, with its gentle dyeing conditions, avoids the damage to the fiber from high temperatures at the source. It fully preserves the natural characteristics of wool, such as its soft hand feel and warmth, while reducing fiber yellowing and felting, significantly improving product quality stability, and simultaneously reducing energy consumption and environmental impact.

[0003] To achieve low-temperature dyeing of wool, there are currently three main types of common and effective methods: The first type is the external field-assisted method, which aims to reduce the dye diffusion barrier through the special effects of physical external fields without altering the fiber structure or the core dye bath formulation. Typical technologies include ultrasound, low-temperature plasma, and ultraviolet radiation. However, due to limitations in production equipment, it is currently difficult to achieve industrial-scale mass production. The second type is the fiber modification method, which aims to pretreat wool fibers using chemical and biological methods to break down the dye mass transfer barrier in the scale layer at its source. This method is mainly divided into chemical modification and biological modification. There are two main categories of enzymatic modification, but these methods still have significant limitations. Enzymatic processes are costly and their activity is easily affected by temperature and humidity. Peroxyformic acid systems, on the other hand, suffer from strong reagent corrosivity and poor reaction controllability. The third category is the low-temperature dye bath auxiliary method. The core of this method is to improve the wettability of the wool surface and the dye diffusion performance by adding specific auxiliaries to the dye bath without changing the fiber structure, thereby achieving low-temperature dyeing. Although this method can achieve good low-temperature dyeing results, it has problems such as limited dyeing effect, high difficulty in dyeing dark-colored varieties, and high auxiliary cost, making it difficult to promote and apply on a large scale.

[0004] Low-temperature dyeing of wool faces numerous limitations. From a physical structure perspective, wool's scale layer comprises a surface layer, an outer layer, and an inner layer. The surface layer contains 25% lipid structures, primarily composed of fatty acids such as 18-methyleicosanoic acid (18-MEA), which can cross-link with cysteine ​​residues in the fiber via thioester bonds, forming a dense, hydrophobic barrier on the fiber surface. Furthermore, the outer layer has a high content of disulfide and isomer bonds; these lipid and disulfide structures provide the fiber with strong resistance to water, chemical reagents, and dyes. Therefore, developing a low-temperature wool dyeing process that avoids damaging the wool's surface scale layer to minimize strength loss while simultaneously increasing the wool's hydrophilicity, allowing dye molecules to diffuse more easily into the wool fiber, is a pressing technical challenge in this field. Summary of the Invention

[0005] To address the problem of damaged wool fiber structure and significant reduction in strength during conventional boiling dyeing processes, this invention aims to provide a low-temperature wool dyeing method based on the removal of wool lipids for enhanced strength protection. This invention selects polyhexamethylene biguanide hydrochloride or modified polyhexamethylene biguanide hydrochloride, along with a suitable alkali agent, to achieve wool dyeing at 70-75°C with dyeing results similar to or even better than conventional boiling dyeing.

[0006] This invention provides a method to improve the dyeing effect of wool at low temperatures by removing the lipid layer on the surface of wool. The wool is degreased in a targeted manner using a composite system of polyhexamethylene biguanide hydrochloride (PHMB) or modified polyhexamethylene biguanide hydrochloride (SPHMB), sodium carbonate and sodium sulfate. The wool is then cleaned with an alkali removal process to remove residual reagents. Finally, the wool is dyed at low temperature using a wool reactive dye, which simultaneously achieves strong protection and antibacterial functional modification of the wool fibers.

[0007] In one embodiment of the present invention, the modified polyhexamethylene biguanide hydrochloride is prepared by adding sodium vinyl sulfonate (SVS) to polyhexamethylene biguanide hydrochloride (PHMB) under alkaline conditions and obtaining modified polyhexamethylene biguanide hydrochloride (SPHMB) through a grafting reaction.

[0008] In one embodiment of the present invention, PHMB is a polymeric antibacterial agent developed by Hangzhou Luochuan Chemical Co., Ltd., whose main component is polyhexamethylene biguanide hydrochloride, and the content of effective active ingredient is 20%.

[0009] In one embodiment of the present invention, the concentration of PHMB in the reaction system is 200~250g / L, and the concentration of SVS is 5~10g / L.

[0010] In one embodiment of the present invention, the grafting reaction conditions are: reaction temperature of 40~60°C, time of 5~8h, and pH range of 7.5~9.

[0011] In one embodiment of the present invention, the wool is wool knitted fabric, wool woven fabric, or wool top.

[0012] In one embodiment of the present invention, a method for improving the dyeing effect of wool at low temperatures by removing the lipid layer on the surface of wool is provided, the method specifically including the following steps: (1) Wool degreasing treatment: PHMB or SPHMB, sodium carbonate and sodium sulfate are used to degrease the wool. The directional removal of lipids on the surface of the wool is completed through pretreatment. (2) Alkali removal and cleaning: SDS-CH3COOH pickling solution is used to pickle the wool treated in step (1), and then deionized water is used to wash the wool to remove the residual SPHMB and sodium carbonate on the surface of the wool. (3) Low-temperature dyeing treatment: The wool treated in step (2) is dyed at low temperature with wool reactive dye.

[0013] In one embodiment of the present invention, all the steps are performed in a rapid infrared high-temperature staining machine.

[0014] In one embodiment of the present invention, in step (1), the concentrations of PHMB and SPHMB in the composite treatment solution are both 2~10 g / L, the concentration of sodium carbonate is 1~2 g / L, and the concentration of sodium sulfate is 1~3 g / L.

[0015] In one embodiment of the present invention, in step (1), when treating wool with a composite treatment solution, the treatment temperature is 50~60°C, the pH range is 9~11, the bath ratio is 1:20~1:30, and the treatment time is 15~20min.

[0016] In one embodiment of the present invention, in step (1), when the concentrations of PHMB and SPHMB in the composite treatment solution are 2 g / L, a leveling agent needs to be added.

[0017] In one embodiment of the present invention, in step (2), the concentration of SDS in the pickling solution is 1~2 g / L and the concentration of acetic acid is 3~5 mL / L.

[0018] In one embodiment of the present invention, in step (2), the pickling process is carried out at a temperature of 50-60°C, a bath ratio of 1:20-1:30, and a processing time of 15-20 min.

[0019] In one embodiment of the present invention, in step (2), during the water washing treatment, the treatment temperature is 40~50°C, the bath ratio is 1:20~1:30, and the treatment time is 10~15min.

[0020] In one embodiment of the present invention, in step (3), the amount of wool reactive dye used is 2%~3 owf, the dyeing temperature is 70~75°C, the pH range is 4~5, and the liquor ratio is 1:20~1:30.

[0021] In one embodiment of the present invention, in step (3), after dyeing for 30-60 minutes, soda ash is added to fix the color. After adding soda ash, the concentration of soda ash is 1.5-3 g / L, and the fixing time is 10-20 minutes. Finally, the dyed wool is soaped with soap solution at 70-75°C for 5-10 minutes.

[0022] The present invention also provides wool that has been processed and dyed according to the above method.

[0023] Beneficial effects of the present invention (1) PHMB / SPHMB guanidine salts can target carbonyl carbon atoms of ester and thioester bonds that connect keratin and lipid layers in wool fibers, and achieve directional breakage of ester and thioester bonds through nucleophilic addition-elimination reactions, hydrolyzing them into water-soluble 18-MEA carboxylate to achieve degreasing, completing the efficient removal of lipid layers on the surface of wool, greatly improving the wettability of fibers, and thus solving the problem of difficult dye diffusion at low temperatures; the sulfonate anions on the SPHMB molecular chain after PHMB modification neutralize some of the positive charge of guanidine groups, weakening the overall positive charge, and changing the electrostatic adsorption force on the wool surface from strong adsorption to moderate adsorption, slowing down the surface adsorption rate, avoiding the formation of a dense barrier, and allowing alkali and water molecules to penetrate smoothly into the fiber interior, making the wool change from only surface swelling to full-layer uniform swelling. The fully swollen fiber provides a diffusion channel for SPHMB, making it easier for it to enter the fiber interior. In addition, the deep degreasing and uniform swelling caused by SPHMB to wool provide a double guarantee for the penetration of dye in the subsequent dyeing process, making the dyeing effect of using SPHMB better.

[0024] (2) No loss of strength. The reaction conditions of wool degreasing are mild and will not cause etching or damage to the wool cuticle layer during the degreasing process; at the same time, PHMB / SPHMB can cross-link with wool protein molecules, which slightly improves the fiber strength and preserves the original strength, hand feel and natural luster of wool fibers to the greatest extent.

[0025] (3) Enhanced Functionality. PHMB itself is an antibacterial agent. Introducing it into the degreasing process not only helps with dyeing but also endows wool with antibacterial properties, thus streamlining the dyeing and functional finishing process and increasing the added value of the product.

[0026] (4) High color depth and high color fastness. After treatment with SPHMB-Na2CO3-Na2SO4 composite solution, the lipid content on the surface of wool fibers is reduced and the hydrophilicity is significantly improved, which is conducive to the diffusion of dye into the wool fibers, so that a high dyeing percentage can be achieved under low temperature conditions; at the same time, SPHMB, which cross-links with wool fibers, also adds dyeing sites for dyeing, further improving the dyeing effect.

[0027] (5) Green, environmentally friendly, and energy-saving production. This invention significantly reduces the activation energy of dye diffusion by directionally removing the lipid barrier on the surface of wool, allowing the dyeing process to be carried out at 70-75°C or even lower temperatures. The dyeing effect is comparable to or even better than that of conventional boiling dyeing processes, greatly reducing the consumption of steam and electricity during the dyeing process, which meets the industrial demand for energy conservation and emission reduction. This system does not use any toxic or harmful substances or organic solvents, and both PHMB / SPHMB and sodium carbonate have good biocompatibility and wastewater treatability, effectively reducing the treatment load of dyeing and finishing wastewater, which is in line with the development trend of green textile chemicals and dyeing and finishing technology. Detailed Implementation

[0028] 1. Wetting Time Test Method The wetting time of the samples was determined using a JC2000 DM contact angle tester, which is the time required for a water droplet to completely penetrate the surface of the wool fabric. Each sample was tested in parallel 10 times.

[0029] 2. Dyeing rate test method The absorbance of the original solution and the residual solution after staining were measured using a UV-5500PC ultraviolet spectrophotometer.

[0030] The specific calculation formula is as follows: Dyeing rate (%) =

[0031] 3. K / S value testing method Using the Color-Eye7000A computer colorimeter, the apparent color depth (K / S) of dyed wool was measured under a standard observer angle (10°) and a D65 light source. Three points were randomly selected for testing, and the average value was taken.

[0032] 4. Soap wash fastness test method The color fastness to soap washing of dyed wool was determined in accordance with GB / T 3921-2008 "Textiles - Tests for color fastness to soap washing".

[0033] 5. Fracture strength test method The strength of wool bundle fibers was tested using a YG162A electronic fiber strength tester. The fiber bundles were combed to remove coarser impurities and some short fibers, making them more uniform, smooth, and straight. The combed sample was then cut into bundles of fibers 40 mm in length and 1.5 mg in weight. The test was repeated 10 times, and the average value was taken.

[0034] 6. Antibacterial rate test method The antibacterial properties of treated wool against Escherichia coli were determined according to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method".

[0035] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0036] In the following implementation, the wool fiber fineness was 25 μm, purchased from Wuxi Xiexin Wool Textile Co., Ltd.; the wool reactive dye was Lanasol Red CE, provided by Huntsman Corporation, USA; PHMB was purchased from Hangzhou Luochuan Chemical Co., Ltd., with an effective active ingredient content of 20%; SVS was purchased from Suzhou Great Pharmaceutical Technology Co., Ltd.; sodium carbonate, sodium sulfate and sodium dodecyl sulfate were purchased from Sinopharm Chemical Reagent Co., Ltd.

[0037] All liquor ratios mentioned below are in g / mL.

[0038] Example 1 A high-protection low-temperature dyeing method for wool based on modified guanidine salts for removing wool lipids specifically includes the following steps: (1) PHMB modification: PHMB was modified with SVS in an alkaline environment. The specific process was as follows: 50g of PHMB was put into a three-necked flask, deionized water was added to make the total volume of the solution 200mL, the pH was adjusted to 8.5, 1g of SVS was added, and the mixture was stirred until completely dissolved. The temperature was raised to 40°C, and the reaction was carried out under constant temperature and stirring for 8h. After the reaction was completed, the mixture was cooled to room temperature by natural cooling. 0.5mol / L dilute hydrochloric acid was added dropwise with stirring to adjust the pH of the system to 7.0 and terminate the reaction to obtain SPHMB.

[0039] (2) Wool degreasing treatment: Wool was degreased using SPHMB, sodium carbonate, and sodium sulfate. Specifically, the wool was added to a SPHMB-Na2CO3-Na2SO4 composite treatment solution and treated at 60°C for 15 minutes. The concentration of SPHMB was 10 g / L, the concentration of Na2CO3 was 1.6 g / L, the concentration of Na2SO4 was 2.5 g / L, the bath ratio was 1:20, and the pH was 10. The entire process was carried out in a rapid infrared high-temperature dyeing machine.

[0040] (3) Alkali removal and washing: The wool treated in step (2) was acid-washed with SDS-CH3COOH acid washing solution, and then washed with deionized water. The acid washing process was carried out at a temperature of 60°C for 15 min, with a liquor ratio of 1:30. The concentration of SDS in the acid washing solution was 2 g / L, and the concentration of acetic acid was 5 mL / L. The washing process was carried out at a temperature of 40°C for 10 min, with a liquor ratio of 1:30. The whole process was carried out in a rapid infrared high-temperature dyeing sample machine.

[0041] (4) Low-temperature dyeing treatment: The wool fabric treated in step (3) is dyed with the wool reactive dye Lanasol Red CE; wherein the concentration of Lanasol Red CE is 2% owf, the dyeing temperature is 75°C, the pH is 4.7, and the liquor ratio is 1:20; after dyeing for 30 min, soda ash is added for color fixing, wherein the concentration of soda ash after addition is 2g / L, and the color fixing time is 15 min; finally, the dyed wool is soaped in soap solution at 75°C for 5 min.

[0042] Example 2 A high-protection low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids, referring to Example 1, the difference is that in step (2), the concentration of SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution is adjusted to 2g / L, and 1g / L of Abaco B is added.

[0043] Example 3 A high-protection low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids, referring to Example 1, the difference is that in step (2), the concentration of SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution is adjusted to 2g / L, and 2g / L of lauric acid imidazoline is added.

[0044] Example 4 A powerful protective low-temperature dyeing method for wool based on guanidine salt stripping of wool lipids, referring to Example 1, the difference being that step (1) PHMB modification is omitted, and the SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with unmodified PHMB, with the concentration remaining unchanged.

[0045] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the wool was not treated in any way.

[0046] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the wool is only processed in step (4) and not in steps (1) to (3).

[0047] Comparative Example 3 A conventional high-temperature dyeing method for wool, the difference between Comparative Example 3 and Example 1 is that the steps of (1) PHMB modification, (2) wool degreasing treatment and (3) alkali removal washing are omitted, and only step (4) is performed. In step (4), the dyeing temperature is adjusted to 98°C, and Abacus B is added to the dye bath at a concentration of 1g / L.

[0048] Comparative Example 4 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids. The difference between Comparative Example 4 and Example 1 is that step (3) alkali removal and washing is omitted, and only steps (1), (2), and (4) are performed.

[0049] Comparative Example 5 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids. The difference between Comparative Example 5 and Example 1 is that the concentration of SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is adjusted to 2g / L.

[0050] Comparative Example 6 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool grease. The difference between Comparative Example 6 and Example 1 is that the SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with hexadecyltrimethylammonium bromide (CTAB) with a concentration of 2 g / L.

[0051] Comparative Example 7 A high-protection low-temperature dyeing method for wool based on modified guanidine salt to remove wool grease. The difference between Comparative Example 7 and Example 1 is that the SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with polyethyleneimine (PEI) with a concentration of 2g / L.

[0052] Comparative Example 8 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids. The difference between Comparative Example 8 and Example 1 is that the SPHMB in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with chitosan quaternary ammonium salt with a concentration of 2g / L.

[0053] Comparative Example 9 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids. The difference between Comparative Example 9 and Example 1 is that the sodium carbonate in the cation exchange SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with trisodium phosphate, while the concentration remains unchanged.

[0054] Comparative Example 10 A powerful protective low-temperature dyeing method for wool based on modified guanidine salt to remove wool lipids. The difference between Comparative Example 10 and Example 1 is that the sodium carbonate in the SPHMB-Na2CO3-Na2SO4 composite treatment solution used in step (2) wool degreasing treatment is replaced with sodium hydroxide, while the concentration remains unchanged.

[0055] The wool samples obtained in Examples 1-4 and Comparative Examples 1-10 were tested for wetting time, dyeing rate, K / S value, washing fastness, breaking strength and antibacterial rate. The results are shown in Table 1.

[0056] Table 1 Performance Test Results

[0057] As shown in Table 1: (1) The wool prepared by the methods described in Examples 1 to 3 of this invention has a wetting time of less than 6s, a dyeing rate of more than 90%, a K / S value of more than 16, and color fastness to soaping, wool staining fastness, and cotton staining fastness all reach grade 4-5 or above. The fiber breaking strength is higher than 1650cN, and the antibacterial rate is close to or exceeds 90%. All core properties are significantly better than conventional high-temperature boiling dyeing processes. Among them, the optimal solution Example 1 has a dyeing rate of 99.12% and a K / S value of 21.94, both of which far exceed those of conventional high-temperature boiling dyeing processes; the wetting time is 5.9s, the breaking strength is 1767.6cN, which is 34.1% higher than that of conventional boiling dyeing processes; and the antibacterial rate is as high as 98.52%, with the best overall performance. Compared to Example 1, Examples 2 and 3 significantly reduced the amount of SPHMB used and incorporated a low-concentration leveling agent. Although the overall performance was somewhat inferior to Example 1, it was still significantly superior to the conventional 98°C boiling dyeing process. Hydrophilicity was greatly improved, and raw material input costs were lower, resulting in better economic efficiency for industrial-scale production. These results demonstrate that the method of this invention can achieve efficient low-temperature dyeing of wool at 75°C, simultaneously achieving multiple core objectives: no strength loss or even strength enhancement, excellent color fastness, and long-lasting antibacterial properties. Furthermore, the process parameters have a wide adjustable range, making it adaptable to industrial production scenarios with different performance requirements and cost control needs.

[0058] (2) The sample in Example 4, with step (1) omitted and the SPHMB in the composite treatment solution in step (2) replaced with unmodified PHMB, showed little difference in overall effect from Example 1. The main differences were that the wetting time, dyeing rate, and K / S value were all lower than those in Example 1. The main reason is that after PHMB was modified, the sulfonate anions on the SPHMB molecular chain neutralized some of the positive charge of the guanidine group, weakening the overall positive charge. The electrostatic adsorption force with the wool surface changed from strong adsorption to moderate adsorption, slowing down the surface adsorption rate and avoiding the formation of a dense barrier. The alkali solution and water molecules could then penetrate smoothly into the fiber, causing the wool to swell from only the surface to the entire layer. The fully swollen fiber provided a diffusion channel for SPHMB, making it easier for it to enter the fiber. In addition, the deep degreasing and uniform swelling caused by SPHMB to the wool provided a double guarantee for the penetration of dye in the subsequent dyeing process, making the dyeing effect of Example 1 better than that of Example 4.

[0059] (3) The sample (Comparative Example 2) that only underwent low-temperature dyeing treatment without degreasing and alkali removal cleaning processes had a dyeing rate of only 43.20% and a K / S value of only 5.59, which was far lower than the sample that underwent degreasing treatment under the same conditions. This is because there is a hydrophobic lipid barrier on the surface of wool, which has poor hydrophilicity. Under low-temperature conditions, dye molecules have difficulty penetrating and diffusing into the fiber interior, resulting in extremely poor dyeing effect. Only the color fastness to soaping meets the standard, which is completely unable to meet the processing requirements of low-temperature dyeing of wool.

[0060] (4) The sample (Comparative Example 3) which used the conventional 98°C high-temperature boiling dyeing process and did not undergo degreasing and alkali removal cleaning process, had a dyeing rate of 97.96%, but the K / S value was only 17.08, and the dyeing depth was significantly lower than the optimal solution of the present invention; at the same time, the fiber breaking strength was only 1317.7cN, which was a serious loss of strength compared with the undyed raw wool. This is because the high temperature caused the peptide bonds and disulfide bonds of the wool fiber to break, resulting in serious damage to its structure and a significant loss of strength.

[0061] (5) The sample (Comparative Example 4) that underwent degreasing and low-temperature dyeing but omitted the alkali removal and cleaning process, although the wetting time reached 5.5s and the dyeing rate reached 99.96%, the K / S value was only 11.74, and the actual dyeing depth was extremely poor; the color fastness to soap washing was only grade 4, and the color fastness of wool and cotton both dropped sharply, which could not meet the requirements for the color fastness of the finished product; at the same time, the fiber breaking strength was only 1542.5cN, with no strong protective effect, and the antibacterial rate was only 28.13%, with extremely poor antibacterial performance. This fully demonstrates that the alkali removal and cleaning process is a necessary step to ensure the dyeing effect, color fastness, strength and antibacterial performance of wool.

[0062] (6) The sample (Comparative Example 5) that underwent the complete process but with the SPHMB concentration adjusted to 2 g / L during degreasing had a wetting time of only 12.2 s, a dyeing rate of only 88.48%, and a K / S value of only 14.72. The hydrophilicity and low-temperature dyeing effect were significantly reduced compared to Example 1. At the same time, the fiber breaking strength was reduced to 1652.9 cN, the strength enhancement effect was significantly weakened, and the antibacterial rate was only 60.94%, with a significant decline in antibacterial performance. This proves that the preferred SPHMB concentration of the present invention is a key process parameter to ensure degreasing efficiency, dyeing effect, strength protection and antibacterial performance.

[0063] (7) It should be noted that the concentration of SPHMB used in the process of this invention is 10 g / L, while the concentration of CTAB, PEI, and chitosan quaternary ammonium salt used in the control sample is 2 g / L. The reason is that the effective active ingredient content of the PHMB product used in the test is only 20%, and the other reference reagents are all high-purity active ingredients. After conversion according to the effective active ingredient, the test concentration levels of the two are consistent, ensuring the scientific nature and comparability of the control test. The samples (comparative examples 6-8) that have undergone the complete process but have replaced SPHMB with the above three types of reagents in the degreasing treatment have significantly lower comprehensive performance in terms of hydrophilicity, low-temperature dyeing effect, fiber strength protection performance, and antibacterial performance than the SPHMB-Na2CO3-Na2SO4 composite system of this invention. They cannot simultaneously achieve the core objectives of efficient low-temperature dyeing, fiber strength enhancement, and long-term antibacterial modification, which fully proves that SPHMB has irreplaceable core advantages in this process.

[0064] (8) Samples (Comparative Examples 9-10) that underwent the complete process but had sodium carbonate replaced with trisodium phosphate and sodium hydroxide in the degreasing treatment, respectively, showed little difference in dyeing effect compared to the SPHMB-Na2CO3-Na2SO4 composite system of the present invention, but the fiber breaking strength decreased significantly. The main reason for this is that the pH value of the SPHMB-Na2CO3-Na2SO4 composite treatment solution was too high after replacing the alkali agent, which easily caused hydrolysis damage to the peptide bonds and disulfide bonds of the keratin macromolecules of wool fibers, resulting in irreversible reduction in fiber strength. The above results indicate that the preferred SPHMB-Na2CO3-Na2SO4 composite system of the present invention can precisely control the pH value of the treatment system, achieving efficient degreasing and dyeing while maximizing the preservation of the mechanical properties of wool fibers. Other alkali agents cannot achieve the same comprehensive treatment effect.

[0065] Therefore, wool treated by the method described in this invention not only achieves a dyeing effect at a low temperature of 75°C that far exceeds that of undegreased dyeing at the same temperature and even surpasses that of conventional 98°C boiling dyeing, but also solves the industry pain point of significant reduction in fiber strength in traditional wool dyeing processes. Simultaneously, it endows wool with excellent antibacterial properties, realizing a short-process integrated processing of degreasing and dyeing aid, strong protection, and functional modification. The process is short, energy-efficient, and environmentally friendly, with comprehensive performance far exceeding existing technical solutions.

[0066] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for improving the dyeing effect of wool at low temperatures by removing the lipid layer on the surface of wool, characterized in that, Wool is degreased in a targeted manner using polyhexamethylene biguanide hydrochloride or a composite system of modified polyhexamethylene biguanide hydrochloride, sodium carbonate and sodium sulfate. After removing residual reagents through an alkali removal and washing process, the wool is finally dyed at low temperature using wool reactive dyes, which simultaneously achieves strong protection and antibacterial functional modification of wool fibers.

2. The method according to claim 1, characterized in that, The modified polyhexamethylene biguanide hydrochloride is prepared by adding sodium vinyl sulfonate to polyhexamethylene biguanide hydrochloride under alkaline conditions and obtaining modified polyhexamethylene biguanide hydrochloride through a grafting reaction.

3. The method according to claim 2, characterized in that, In the reaction system, the concentration of polyhexamethylene biguanide hydrochloride is 200~250 g / L, and the concentration of sodium vinyl sulfonate is 5~10 g / L.

4. The method according to claim 2, characterized in that, The grafting reaction conditions are: reaction temperature of 40~60°C, time of 5~8h, and pH range of 7.5~9.

5. The method according to claim 1, characterized in that, The method specifically includes the following steps: (1) Wool degreasing treatment: Polyhexamethylene biguanide hydrochloride or modified polyhexamethylene biguanide hydrochloride, together with sodium carbonate and sodium sulfate, are used to degrease the wool. The directional removal of lipids on the surface of the wool is completed through pretreatment. (2) Alkali removal and cleaning: Sodium dodecyl sulfate-acetic acid pickling solution is used to pickle the wool treated in step (1), and then the wool is washed with deionized water. (3) Low-temperature dyeing treatment: The wool treated in step (2) is dyed at low temperature with wool reactive dye.

6. The method according to claim 5, characterized in that, In step (1), the concentration of polyhexamethylene biguanide hydrochloride or modified polyhexamethylene biguanide hydrochloride in the composite treatment solution is 2~10 g / L, the concentration of sodium carbonate is 1~2 g / L, and the concentration of sodium sulfate is 1~3 g / L.

7. The method according to claim 5, characterized in that, In step (1), when treating wool with the composite treatment solution, the treatment temperature is 50~60°C, the pH range is 9~11, the bath ratio is 1:20~1:30, and the treatment time is 15~20min.

8. The method according to claim 5, characterized in that, In step (2), the concentration of sodium dodecyl sulfate in the pickling solution is 1~2 g / L, and the concentration of acetic acid is 3~5 mL / L; during pickling, the treatment temperature is 50~60°C, the bath ratio is 1:20~1:30, and the treatment time is 15~20 min; during water washing, the treatment temperature is 40~50°C, the bath ratio is 1:20~1:30, and the treatment time is 10~15 min.

9. The method according to claim 5, characterized in that, In step (3), the amount of reactive dye used for wool is 2%~30.wf, the dyeing temperature is 70~75°C, the pH range is 4~5, and the liquor ratio is 1:20~1:30; after dyeing for 30~60 minutes, soda ash is added for color fixing. After adding soda ash, the concentration of soda ash is 1.5~3g / L, and the color fixing time is 10~20 minutes; finally, the dyed wool is soaped with soap solution at 70~75°C for 5~10 minutes.

10. Wool processed and dyed by any one of the methods described in claims 1 to 9.

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