Natural plant-based batik pigment and batik process

Abstract

The invention discloses a batik pigment based on natural plants. The batik pigment comprises the following raw materials: a basic auxiliary agent and at least one color development plant, the basic auxiliary agent is prepared from the following components in parts by weight: 3 to 8 parts of gallnut and 2 to 6 parts of rhizoma curcumae longae; the color development plants comprise the following components in parts by weight: 10 to 20 parts of radix rubiae, 5 to 15 parts of radix scutellariae and 5 to 12 parts of indigo grass. The invention further discloses a batik process adopting the batik pigment. According to the batik pigment based on the natural plants, the problems that a traditional plant dye is single in chromatography and unstable in color matching are solved, the chromatography of the batik pigment is rich and controllable, and the requirement of the batik technology for rich colors is met; the dye is excellent in stability and long in storage life; a wax printing process is adapted, the dyeing effect is stable, and the color fastness is high.

Description

Technical Field

[0001] This invention relates to the field of printing and dyeing technology, specifically to a batik pigment and batik process based on natural plants. Background Technology

[0002] With the increasing global awareness of environmental protection and the deepening of the concept of sustainable development, the textile industry has an increasingly urgent need for green and environmentally friendly dyes. While traditional synthetic dyes offer a full color spectrum and high color fastness, their production process generates large amounts of toxic wastewater, and dyed textiles may contain residual carcinogenic aromatic amines and other harmful substances, posing a dual threat to the environment and human health. Against this backdrop, natural plant dyes, due to their advantages of being derived from renewable resources, having good biodegradability, and leaving no toxic residues, have once again become a research hotspot. Natural plant dyes have a long history of application, but single plant dyes have obvious limitations: on the one hand, most single dyes have a narrow color spectrum, such as madder mainly providing red and indigo only producing blue, which makes it difficult to meet the needs of the modern textile industry for rich colors; on the other hand, single plant dyes have low coloring rates, and their wash fastness and light fastness are generally insufficient (usually only grade 1-2), and their adaptability to different fibers varies greatly, especially their fixation effect on cellulose fibers such as cotton and linen is poor, which limits their industrial application.

[0003] Furthermore, existing plant-based dyes have limitations in their compatibility with traditional processes. Take batik as an example: its core principle is to utilize the resist-dyeing effect of wax to form patterns. This requires that the dye not damage the integrity of the wax film during dyeing at 60-70℃, while maintaining stable colorfastness after dewaxing. However, existing composite dyes either cause the wax film to melt due to excessively high dyeing temperatures (>80℃) or suffer severe fading after dewaxing and washing due to insufficient colorfastness (<3 grade), making it difficult to meet the technical requirements of traditional batik processes.

[0004] Therefore, developing a natural plant composite dye with scientific formulation, high extraction efficiency, good stability, high color fastness, and compatibility with a variety of fibers and traditional processes has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] Therefore, based on the shortcomings of the prior art, the present invention provides a batik pigment and batik process based on natural plants.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The first aspect of the present invention provides a batik pigment based on natural plants, wherein the raw materials of the batik pigment include a basic auxiliary agent and at least one color-developing plant; by weight, the basic auxiliary agent includes 3-8 parts of gallnut and 2-6 parts of turmeric; the color-developing plant includes madder, scutellaria, and indigo, wherein madder is 10-20 parts, scutellaria is 5-15 parts, and indigo is 5-12 parts.

[0007] The batik pigment based on natural plants in this invention does not have a fixed, single color. Instead, by adjusting the proportions of the core plant raw materials, it can achieve coverage of multiple color systems, including red, yellow, blue, and green. Furthermore, it can obtain transitional colors (such as orange, purple, and cyan) through precise control of the proportions. The specific color is determined by the raw material ratios, thus solving the problem of the limited color spectrum of traditional plant dyes. Different plant raw materials play different roles in the dyeing process and are the core factor determining the final color of the composite dye, as detailed below: Madder: Provides a base color for red tones. Its alizarin and alizarin are natural red hair coloring components and are the core source of warm tones such as red and orange.

[0008] Scutellaria baicalensis: Provides a basic yellow color, mainly relying on flavonoids such as baicalin. When used alone, it is bright yellow, and when mixed with other raw materials, the hue and brightness can be adjusted.

[0009] Indigo plant: Provides the basic blue color, indigo is produced by the oxidation of indigo glycosides, and is a key raw material for cool colors such as blue and green.

[0010] Gallnut: It is light brown in color and its main function is to fix and deepen the color without changing the base color, but it can make the color more intense and stable (such as making red darker and blue deeper). The tannins in gallnut form a hydrogen bond network with the phenolic hydroxyl groups in other plant materials, which can improve color fastness.

[0011] Turmeric: It helps adjust the color tone, enhances the brightness of yellow tones, and makes mixed colors (such as green and orange) more even, reducing color variations. The amphiphilic structure of curcumin solves the compatibility problem of different polar color-producing components, thus improving the uniformity of dyeing.

[0012] In some preferred embodiments of the present invention, the combination of color-producing plants includes: Red system: 10-20 parts madder root, 5-10 parts scutellaria root (optional); Yellow system: 8-15 parts of Scutellaria baicalensis; Blue system: 5-12 parts indigo, 3-8 parts of scutellaria baicalensis (optional), with the ratio of indigo to scutellaria baicalensis > 1:1; Green system: 5-10 parts indigo and 8-15 parts scutellaria, with the ratio of indigo to scutellaria < 1:1.

[0013] In some preferred embodiments of the present invention, the weight ratio of madder root to scutellaria root in the red system is 1:(0.3-0.8), and the dyed color ranges from brick red to dark red.

[0014] In some preferred embodiments of the present invention, the weight ratio of indigo to scutellaria in the green system is 1:(1.2-3), and the resulting color is grass green to dark green after dyeing.

[0015] In some preferred embodiments of the present invention, the dyeing temperature range of the batik dye is 60-65°C.

[0016] In some preferred embodiments of the present invention, the method for preparing the batik pigment includes the following steps: S1. Grind the raw materials to 80-100 mesh and dry them at 45-50℃ and a vacuum of 0.01-0.08MPa until the moisture content is ≤5%; S2. Mix the raw materials according to the formula, add 10-15 times the weight of deionized water, adjust the pH to 4.5-5.5, extract at a constant temperature of 70-85℃ for 2-3 hours, and filter to obtain the initial extract; add 8-10 times the weight of 60-70% ethanol solution to the residue, and extract ultrasonically at 50-60℃ and 100-300W power for 1-1.5 hours, and filter to obtain the secondary extract; S3. Combine the primary extract and secondary extract, centrifuge and filter through a 0.45μm microfiltration membrane, then concentrate under reduced pressure at 40-50℃ and a vacuum of 0.01-0.09MPa until the solid content is 20-30%; then add 0.5-1% chitosan and 0.3-0.5% sodium alginate, stir at 100-200r / min for 10-30 minutes, and then homogenize under 30-40MPa pressure 2-3 times. S4. After filtration through a 0.22μm polyethersulfone filter membrane, the product is dispensed and pasteurized to obtain the batik pigment.

[0017] In step S2 of this invention, a water-to-alcohol extraction stepwise process is employed, with differentiated extraction conditions designed for chromophores of different polarities—aqueous phase extraction (70-85℃, pH=4.5-5.5) efficiently dissolves water-soluble components such as flavonoids and anthraquinones; alcohol phase ultrasonic extraction (60-70% ethanol, 100-300W power) can specifically enrich indole lipid-soluble components. Compared with single water or alcohol extraction, the total active ingredient extraction rate is increased by 25-35%, with the extraction rate of indigo glycosides (lipid-soluble) increasing by more than 40%, and the retention rate of alizarin (water-soluble) reaching more than 90%.

[0018] In some preferred embodiments of the present invention, in step S3, the chitosan has a molecular weight of 50,000-100,000 Da. Introducing 0.5-1% low molecular weight chitosan during the concentration stage allows its amino groups to form dynamic covalent bonds with the phenolic hydroxyl groups in the dye. Simultaneously, the molecular chains encapsulate the color-producing components, solving the problems of easy oxidation and precipitation of natural dyes and greatly improving the storage stability of the dye. Experiments have shown that under light-protected storage conditions at 4-10℃, the shelf life of this batik pigment is extended from 3-6 months for traditional plant dyes to 12 months, with no significant decrease in dyeing performance.

[0019] In step S3 of this invention, by adding sodium alginate, a natural thickener, the viscosity of the dye solution can be increased, avoiding bleeding caused by tiny gaps in the wax film, thereby enhancing the clarity of the pattern edges.

[0020] In step S3 of this invention, the dye particle size is uniformized by high-pressure homogenization treatment at 30-40MPa, with a D50 of 1-2μm. The difference in affinity for different natural fibers such as cotton, linen, and silk is reduced to less than 10%, which solves the problem of traditional dyes being sensitive to fiber type.

[0021] In the above preparation method, all raw materials used are natural plants, and the preparation process uses water and food-grade ethanol as solvents. No toxic or harmful substances are used, and the ethanol can be recovered through distillation, reducing environmental pollution. No chemical auxiliaries are required in the dyeing and post-treatment processes, which aligns with the development trend of green textiles.

[0022] A second aspect of the present invention discloses a batik process, wherein the batik process uses the aforementioned batik pigment and includes the following steps: S1. Wax sealing: Applying wax to the surface of textiles to form a resist-dyeing wax film; S2. Pre-dyeing soaking: Soak the wax-sealed textiles in deionized water at 25-30℃ for 3-5 minutes; S3. Dye bath preparation: Dilute the dye at a liquor ratio of 1:20-1:30, add 0.5-2% of natural mordant equivalent to the weight of the fabric, and adjust the pH to 5.0-6.0; S4. Staining: Heat to 60-65℃ at a rate of ≤2℃ / min, and keep warm for 50-60 minutes with stirring at 100-150r / min. S5. Dewaxing and color fixing: After cooling to below 40℃, dewax in hot water at 60-70℃ for 15-20 minutes, then soak in 0.3-0.5% gallnut extract at 45-50℃ for 5-10 minutes; S6. Post-treatment: Rinse 2-3 times with deionized water at 40-50℃ and air dry naturally.

[0023] In some preferred embodiments of the present invention, in step S1, the textile is a natural fiber textile such as cotton, linen or silk.

[0024] In some preferred embodiments of the present invention, in step S1, the wax is one of beeswax, paraffin wax, wood wax, beeswax, or a mixture thereof.

[0025] In step S2 of this invention, the wax-sealed fabric is first soaked in deionized water at 25-30℃ for 3-5 minutes, and then placed in a dye bath and slowly heated to 60-65℃ (heating rate ≤2℃ / min). This can avoid the wax film from cracking due to excessive temperature difference.

[0026] In some preferred embodiments of the present invention, in step S3, the natural mordant is alum or ferrous sulfate; alum is selected when the textile is cotton fiber, and ferrous sulfate is selected when the textile is silk fiber.

[0027] In this invention, alum (potassium aluminum sulfate) is used as mordant for cotton fibers (mainly cellulose), through the formation of ternary coordination bonds between Al³⁺ and cellulose hydroxyl groups and dye phenolic hydroxyl groups; ferrous sulfate is used as mordant for silk fibers (mainly protein), through the formation of chelates between Fe²⁺ and protein amino groups and chromophores, thereby achieving targeted binding of fibers, mordant and dye.

[0028] In step S4 of this invention, the heat preservation and dyeing time is controlled at 50-60 minutes to ensure that the dye is fully applied to the area not covered by the wax film.

[0029] In step S5 of this invention, during dewaxing, the wax is soaked in hot water at 60-70℃ (the temperature is slightly lower than the melting point of the wax) and gently stirred to make the wax float to the surface of the water and remove it. After dewaxing, the wax is immediately soaked in 0.3-0.5% gallnut extract at 45-50℃ for 5-10 minutes to further consolidate the color of the unsealed area and improve the final color fastness.

[0030] After targeted mordant dyeing and soaking in gallnut extract, the color fastness to washing reaches level 3-4, the color retention rate after dewaxing is ≥90%, and there is no obvious fading or color bleeding after multiple washes.

[0031] In some preferred embodiments of the present invention, for dark color requirements, steps S3-S5 are repeated 2-3 times for dyeing. After each dyeing, the product must be completely dried to avoid wax film penetration caused by excessively concentrated dye solution in a single dyeing process.

[0032] In some preferred embodiments of the present invention, the dyed textiles have a wash fastness of 3-4 and a light fastness of 4 or higher.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses gallnut and turmeric as basic auxiliaries, scientifically compounded with color-producing plants such as madder, scutellaria, and indigo, to form a multi-color dye system including red, yellow, blue, and green. Specifically, the red system achieves a range of shades from brick red to deep red by adjusting the ratio of madder to scutellaria, while the green system achieves a hue transition from grass green to dark green by controlling the ratio of indigo to scutellaria. This solves the problems of limited color spectrum and unstable color matching in traditional plant dyes, meeting the demand for rich colors in batik processes.

[0034] 2. This invention employs a water-to-alcohol extraction stepwise extraction process to specifically dissolve water-soluble (e.g., flavonoids) and fat-soluble (e.g., indoles) active ingredients, significantly improving the overall extraction rate compared to single extraction methods. Specifically, the extraction rate of indigofera tinctoria from indigofera tinctoria is increased by over 40%, and the retention rate of alizarin from madder root reaches over 90%, significantly improving the utilization rate of plant raw materials and reducing production costs.

[0035] 3. This invention, by adding chitosan with a specific molecular weight, utilizes the dynamic covalent bonding and molecular chain entanglement between chitosan and dye components, combined with high-pressure homogenization treatment, to achieve uniform dispersion of the dye system with a particle size controlled at 1-2 μm, effectively solving the problems of easy oxidation and precipitation of natural dyes.

[0036] 4. The dyeing temperature range of the batik dye of this invention is 60-65℃, which forms a safe difference of 5-10℃ compared with commonly used batik waxes (beeswax, paraffin, etc., melting point 60-70℃). This ensures that the dye molecules fully penetrate the fiber while preventing the wax film from melting at high temperatures and causing the pattern to become blurred. Simultaneously, the addition of sodium alginate increases the viscosity of the dye liquor, reduces bleeding, lowers the edge clarity error of the wax-sealed pattern, and improves the fineness of the batik product.

[0037] 5. In the batik process of this invention, through targeted mordant dyeing and the binding effect of tannins in the gallnut solution with the fibers, the wash fastness of the dyed textiles reaches grade 3-4, and the light fastness reaches grade 4 or above. After batik dewaxing and washing processes, the color retention rate is ≥90%, solving the problem of insufficient color fastness of traditional natural dyes in batik processes. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Example 1: Red batik pigments and their application in batik

[0041] This embodiment provides a red batik pigment based on natural plants. By weight, its raw materials include: 15 parts madder root, 7 parts scutellaria root, 5 parts gallnut, and 3 parts turmeric.

[0042] The preparation method of the red batik pigment based on natural plants in this embodiment includes the following steps: S1. Grind the raw materials to 100 mesh and dry them at 45℃ and 0.08MPa vacuum until the moisture content is 4.2%; S2. Mix the raw materials according to the formula, add 12 times the weight of deionized water, adjust the pH to 5.0 with citric acid, and extract in an 80℃ constant temperature water bath for 2.5 hours, stirring once every 30 minutes at 150 r / min. Filter through a 300 mesh filter cloth to obtain the initial extract; add 8 times the weight of 65% ethanol solution to the residue, place in an ultrasonic extractor at 55℃, and ultrasonically extract at 300W power for 1.2 hours. Filter to obtain the secondary extract. S3. Combine the initial extract and the secondary extract, centrifuge at 4000 r / min for 15 minutes, take the supernatant and filter it through a 0.45 μm microfiltration membrane, then transfer it to a rotary evaporator and concentrate it under reduced pressure at 45℃ and a vacuum of 0.09 MPa to a solid content of 25%; add 0.8% (relative to the weight of the concentrate) of chitosan (molecular weight 80000 Da) and 0.4% of sodium alginate, stir at 200 r / min for 30 minutes, and then homogenize twice under high pressure at 35 MPa; S4. After filtration through a 0.22μm polyethersulfone membrane, dispense into brown glass bottles and pasteurize at 65℃ for 30 minutes to obtain the finished dye.

[0043] The batik dyeing process, which utilizes a red batik pigment based on natural plants as described in this embodiment, involves the following steps: S1. Wax sealing: Select a 10cm×10cm pure cotton fabric, use a traditional wax knife to apply beeswax (melting point 65℃) to the surface of the fabric, and draw a straight line pattern with a width of 2mm; S2. Pre-dyeing soaking: Soak the wax-sealed cotton fabric in 30℃ deionized water for 5 minutes, then remove and drain the surface moisture. S3. Dye bath preparation: Dilute the compound dye stock solution at a liquor ratio of 1:25, add 1.0% (relative to the weight of the fabric) of alum as a mordant, and adjust the pH to 5.5 with acetic acid. S4. Dyeing: Place the fabric in the dye bath and heat it to 62°C at a rate of 2°C / min. Keep it at the temperature for 55 minutes and gently stir it at a speed of 120r / min during the process. S5. Dewaxing and color fixing: After dyeing, let it cool naturally to below 40℃, then soak it in 65℃ hot water for 18 minutes and stir to remove the floating wax; then transfer it to 50℃ 0.5% gallnut extract solution and soak it for 10 minutes. After taking it out, rinse it 3 times with 45℃ deionized water and let it air dry naturally. Example 2: Green batik pigments and their applications in batik

[0044] This embodiment provides a green batik pigment system based on natural plants. By weight, its raw materials include: 8 parts indigo, 12 parts scutellaria, 4 parts gallnut, and 2 parts turmeric.

[0045] The preparation method of the green batik pigment based on natural plants in this embodiment includes the following steps: S1. Grind the raw materials to 90 mesh and dry them at 50℃ and 0.08MPa vacuum until the moisture content is 3.8%; S2. Mix the raw materials according to the formula, add 15 times the weight of deionized water, adjust the pH to 4.8 with citric acid, extract in a 75℃ constant temperature water bath for 3 hours, stirring once every 30 minutes at 150 r / min, filter through a 300 mesh filter cloth to obtain the initial extract; add 10 times the weight of 70% ethanol solution to the residue, place in an ultrasonic extractor at 60℃, ultrasonically extract at 300W power for 1 hour, filter to obtain the secondary extract; S3. Combine the initial extract and the secondary extract, centrifuge at 4000 r / min for 15 minutes, take the supernatant and filter it through a 0.45 μm microfiltration membrane, then transfer it to a rotary evaporator and concentrate it under reduced pressure at 45℃ and a vacuum of 0.09 MPa to a solid content of 28%; add 0.6% (relative to the weight of the concentrate) of chitosan (molecular weight 100000 Da) and 0.3% of sodium alginate, stir at 200 r / min for 30 minutes, and then homogenize twice under high pressure at 30 MPa; S4. After filtration through a 0.22μm polyethersulfone membrane, dispense into brown glass bottles and pasteurize at 65℃ for 30 minutes to obtain the finished dye.

[0046] The batik dyeing process using the green batik pigment system based on natural plants, as described in this embodiment, involves the following specific steps: S1. Wax sealing: Select a 10cm×10cm silk fabric, use a traditional wax knife to apply wood wax (melting point 68℃) to the surface of the fabric, and draw a straight line pattern with a width of 2mm; S2. Pre-dyeing soaking: Soak the wax-sealed cotton fabric in 30℃ deionized water for 5 minutes, then remove and drain the surface moisture. S3. Dye bath preparation: Dilute the compound dye stock solution at a bath ratio of 1:25, add 0.8% (relative to the weight of the fabric) of ferrous sulfate as a mordant, and adjust the pH to 5.2 with acetic acid; S4. Dyeing: Place the fabric in the dye bath and heat it to 65°C at a rate of 2°C / min. Keep it warm for 60 minutes and gently stir it at 120r / min during the process. S5. Dewaxing and color fixing: After dyeing, let it cool naturally to below 40℃, then soak it in 68℃ hot water for 15 minutes and stir to remove the floating wax; then transfer it to 0.5% gallnut extract at 50℃ and soak it for 10 minutes. After taking it out, rinse it three times with 45℃ deionized water and let it air dry naturally. Example 3: Blue batik pigments and their applications in batik

[0047] This embodiment provides a blue batik pigment based on natural plants. By weight, its raw materials include: 12 parts indigo, 5 parts scutellaria, 6 parts gallnut, and 2 parts turmeric.

[0048] The preparation method of the blue batik pigment based on natural plants in this embodiment includes the following steps: S1. Grind the raw materials to 80 mesh and dry them at 48℃ and 0.08MPa vacuum until the moisture content is 4.5%; S2. Mix the raw materials according to the formula, add 10 times the weight of deionized water, adjust the pH to 5.2 with citric acid, extract in a constant temperature water bath at 85℃ for 2 hours, stirring once every 30 minutes at 150 r / min, filter through a 300 mesh filter cloth to obtain the initial extract; add 9 times the weight of 60% ethanol solution to the residue, place in an ultrasonic extractor at 50℃, ultrasonically extract at 300W power for 1.5 hours, filter to obtain the secondary extract; S3. Combine the initial extract and the secondary extract, centrifuge at 4000 r / min for 15 minutes, take the supernatant and filter it through a 0.45 μm microfiltration membrane, then transfer it to a rotary evaporator and concentrate it under reduced pressure at 45℃ and a vacuum of 0.09 MPa to a solid content of 22%; add 1.0% (relative to the weight of the concentrate) of chitosan (molecular weight 60000 Da) and 0.5% of sodium alginate, stir at 200 r / min for 30 minutes, and then homogenize twice under high pressure at 40 MPa; S4. After filtration through a 0.22μm polyethersulfone membrane, dispense into brown glass bottles and pasteurize at 65℃ for 30 minutes to obtain the finished dye.

[0049] The batik dyeing process using the natural plant-based blue batik pigment of this embodiment involves the following specific steps: S1. Wax sealing: Select a 10cm×10cm linen fabric, use a traditional wax knife to apply paraffin wax (melting point 62℃) to the surface of the fabric, and draw a straight line pattern with a width of 2mm; S2. Pre-dyeing soaking: Soak the wax-sealed cotton fabric in 30℃ deionized water for 5 minutes, then remove and drain the surface moisture. S3. Dye bath preparation: Dilute the compound dye stock solution at a liquor ratio of 1:25, add 1.2% (relative to the weight of the fabric) of alum as a mordant, and adjust the pH to 5.8 with acetic acid. S4. Dyeing: Place the fabric in the dye bath and heat it to 60°C at a rate of 2°C / min. Keep it warm for 50 minutes and gently stir it at 120r / min during the process. S5. Dewaxing and color fixing: After dyeing, let it cool naturally to below 40℃, then soak it in 62℃ hot water for 20 minutes and stir to remove the floating wax; then transfer it to 0.5% gallnut extract at 50℃ and soak it for 10 minutes. After taking it out, rinse it three times with 45℃ deionized water and let it air dry naturally.

[0050] The dyed fabrics were tested for colorfastness to washing, colorfastness to light, and pattern edge error. The results are shown in Table 1. Among them: Color testing was conducted using a computer colorimeter. Wash fastness testing was performed according to GB / T 3921-2008 "Textiles - Tests for color fastness to soaping" and light fastness testing was performed according to GB / T 8427-2019 "Textiles - Tests for color fastness to artificial light: xenon arc". The edge error of the pattern was determined using a high-precision microscope. Five feature points of the wax-sealed straight line pattern were selected, and the distance between the actual pattern edge and the designed edge (design line width 2mm) was measured. The maximum deviation value was then calculated as the edge error.

[0051] Table 1

[0052] As can be seen from the results in Table 1, the batik pigments of the present invention have a rich and controllable color spectrum, stable dyeing effect, high color fastness, and the fabric pattern edge error obtained by the batik process of the present invention is small. Comparative Example 1

[0053] The difference between this comparative example and Example 1 is that this example only uses the water extraction process, that is, after mixing the raw materials, 12 times the weight of deionized water is added, and the mixture is extracted at 80°C for 3.7 hours (the total extraction time is the same as the water extraction + alcohol extraction time of Example 1). The rest of the preparation process and batik process are exactly the same as those of Example 1.

[0054] The batik pigments and batik fabrics of Comparative Example 1 were tested, and the results are shown in Table 2.

[0055] Table 2

[0056] The results in the table above show that alcohol extraction can specifically dissolve fat-soluble alizarin. In contrast, the use of water extraction alone in Comparative Example 1 resulted in a 32% decrease in alizarin extraction rate, leading to insufficient dissolution of the active ingredients and a 40% reduction in solid content compared to Example 1. Due to insufficient color-developing components, the color brightness increased while the saturation decreased; furthermore, the binding force between the active ingredients and the fiber was weak, resulting in a 1-grade reduction in color fastness. Comparative Example 2

[0057] The difference between this comparative example and Example 1 is that only 0.4% sodium alginate is added in the composite treatment stage, and chitosan is not added. The rest of the preparation process and batik process are exactly the same as in Example 1.

[0058] The batik pigments and batik fabrics of Comparative Example 2 were tested, and the results are shown in Table 3.

[0059] Table 3

[0060] The results in the table above show that the amino groups of chitosan form covalent bonds with the phenolic hydroxyl groups of the dye, which helps improve storage stability. In Comparative Example 2, the dye dispersion decreased and stability worsened after the chitosan was removed. Furthermore, the addition of chitosan improves the uniformity of the dye system, thus the dyeing uniformity decreased after its removal. Additionally, chitosan can assist the dye in binding to the fiber; the color fastness was reduced compared to Example 1 after its removal. Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that gallnuts are removed from the raw material formula, while the rest of the preparation process and batik process are exactly the same as in Example 1.

[0062] The batik pigments and batik fabrics of Comparative Example 3 were tested, and the results are shown in Table 4.

[0063] Table 4

[0064] Please refer to Table 4. The tannins in gallnut can form a ternary complex with dyes and fibers. Their absence will lead to a decrease in binding force and easy detachment of dyes. Therefore, the wash fastness of Comparative Example 3 is only grade 2, which is 2 grades lower than that of Example 1. After 5 washes, the color retention rate is only 65%, which is much lower than that of Example 1 (the retention rate of Example 1 is ≥90%). Comparative Example 4

[0065] The difference between this comparative example and Example 1 is that only 0.8% chitosan is added in the composite treatment stage, and sodium alginate is not added. The rest of the preparation process and batik process are exactly the same as in Example 1.

[0066] The batik pigments and batik fabrics of Comparative Example 4 were tested, and the results are shown in Table 5.

[0067] Table 5

[0068] Please refer to Table 5. In Example 1, the dye viscosity was 12.5 mPa·s, while in Comparative Example 4, the viscosity decreased by 58.4% after the sodium alginate was omitted, indicating that sodium alginate can significantly increase the viscosity of the dye solution. Low-viscosity dye solutions are prone to seeping through the tiny gaps in the wax film, resulting in a significant decrease in edge clarity. Therefore, the edge error of the pattern in Comparative Example 4 is significantly greater than that in Example 1.

[0069] In addition, the staining uniformity of Comparative Example 4 was grade 3-4, with local bleeding marks; while Example 1 was grade 5, indicating that sodium alginate can inhibit the penetration of the dye solution, and local bleeding occurs after its absence. Comparative Example 5

[0070] The difference between this comparative example and Example 1 is that the batik process does not involve soaking in gallnut extract after dewaxing, while the rest of the preparation and batik processes are exactly the same as in Example 1.

[0071] The batik pigments and batik fabrics of Comparative Example 5 were tested, and the results are shown in Table 6.

[0072] Table 6

[0073] Please refer to Table 6. The color fastness of the fabric in Comparative Example 5 was grade 3 after the first wash, and dropped to grade 2 after 5 washes. In contrast, the color fastness of the fabric in Example 1 was grade 4 after the first wash and remained at grade 3-4 after 5 washes, indicating that soaking in the gallnut extract can further enhance the binding of the dye to the fiber, and the color fastness decreases significantly after the extract is removed.

[0074] The fabric in Comparative Example 5 had a color retention rate of 72% after 5 washes, while the retention rate in Example 1 was ≥90%, indicating that the tannins in the gallnut extract can fill the gaps between the fiber and the dye, reducing dye loss during washing.

[0075] After 5 washes, the color parameters of Example 1 were L*=46.5, a*=30.2, and b*=17.8. After 55 washes, the color parameters of the comparative example were L*=50.3, a*=26.8, and b*=16.4. This shows that the absence of the color fixing step led to an increase in color brightness and a significant decrease in color saturation.

[0076] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A natural plant based wax printing pigment, characterized in that, The raw materials of the wax dye pigment include a basic auxiliary and at least one color-producing plant; the basic auxiliary includes 3-8 parts of Chinese gall by weight, and 2-6 parts of turmeric by weight; the color-producing plant includes madder, radix scutellariae and indigo, wherein the madder is 10-20 parts by weight, the radix scutellariae is 5-15 parts by weight, and the indigo is 5-12 parts by weight.

2. A natural plant based wax printing pigment as claimed in claim 1, wherein, The combination of the color-producing plant includes: The red system: 10-20 parts of madder, and optionally 5-10 parts of radix scutellariae; The yellow system: 8-15 parts of radix scutellariae; The blue system: 5-12 parts of indigo, and optionally 3-8 parts of radix scutellariae; The green system: 5-10 parts of indigo, and 8-15 parts of radix scutellariae.

3. A natural plant based wax printing pigment as claimed in claim 2, wherein, In the red system, the weight ratio of madder to radix scutellariae is 1:(0.3-0.8); and / or, In the green system, the weight ratio of indigo to radix scutellariae is 1:(1.2-3).

4. A natural plant based wax printing pigment as claimed in claim 1, wherein, The dyeing temperature range of the wax dye is 60-65℃.

5. The natural plant based wax printing pigment as claimed in claim 1, wherein, The preparation method of the wax dye pigment includes the following steps: S1. The raw materials are respectively crushed to 80-100 mesh, and dried to a water content of ≤5% under the conditions of 45-50℃ and a vacuum degree of 0.01-0.08MPa; S2. The raw materials are mixed according to the formula, 10-15 times of deionized water by weight is added first, the pH is adjusted to 4.5-5.5, and then extracted at 70-85℃ for 2-3 hours to obtain a primary extract; the residue is added with 8-10 times of 60-70% ethanol solution by weight, and then ultrasonically extracted at 50-60℃ under a power of 100-300W for 1-1.5 hours to obtain a secondary extract; S3. The primary extract and the secondary extract are combined, and then filtered through centrifugation and a 0.45μm microfiltration membrane; and then concentrated under reduced pressure to a solid content of 20-30% under the conditions of 40-50℃ and a vacuum degree of 0.01-0.09MPa; then 0.5-1% of chitosan and 0.3-0.5% of sodium alginate are added, and stirred at a speed of 100-200r / min for 10-30 minutes, and then homogenized 2-3 times under a pressure of 30-40MPa; S4. Filtered through a 0.22μm polyether sulfone filter membrane, and then pasteurized after being divided into small portions, to obtain the wax dye pigment.

6. A natural plant based wax printing pigment as claimed in claim 5, wherein, In step S3, the molecular weight of the chitosan is 50000-100000Da.

7. A batik process characterized by The wax dyeing process uses the wax dye pigment according to any one of claims 1-6, and includes the following steps: S1. Wax sealing: coating a wax on the surface of a textile to form a resist wax film; S2. Pre-dyeing soaking: soaking the wax-sealed textile in deionized water at 25-30℃ for 3-5 minutes; S3. Preparation of dye bath: diluting the dye by 1:20-1:30, adding a natural mordant corresponding to 0.5-2% of the weight of the fabric, and adjusting the pH to 5.0-6.0; S4. Dyeing: heating to 60-65℃ at a rate of ≤2℃ / min, and dyeing for 50-60 minutes under stirring at a speed of 100-150r / min. S5, dewaxing and fixing: after cooling to 40°C or below, dewaxing in 60-70°C hot water for 15-20 minutes, and then soaking in 0.3-0.5% extract of Chinese gallnut at 45-50°C for 5-10 minutes; S6, post-treatment: washing in 40-50°C deionized water for 2-3 times, and then air-drying.

8. A batik process according to claim 7, characterised in that In step S1, the wax is one of beeswax, paraffin wax, wood wax, and Chinese wax, or a mixture thereof.

9. A batik process according to claim 7, characterized in that In step S3, the natural mordant is alum or soap alum; when the textile is cotton fiber, alum is selected; when the textile is silk fiber, soap alum is selected.

10. A batik process according to claim 7, characterized in that For deep color requirement, steps S3-S5 are repeated for 2-3 times of dyeing, and the textile is completely air-dried after each dyeing.

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