Extract of primula sieboldi eichl pigments and its use in dyeing fabrics

Abstract

The present application relates to a Rechun pigment extract and its application in fabric dyeing. The Rechun pigment extract can be used as a good plant dye, and when applied to fabric dyeing, a plant dyed fabric with high color fastness and stability can be prepared without using a chemical mordant. The Rechun pigment extract can also be used as an effective and natural environment-friendly color fastness improver for plant dyes in fabric dyeing. The Rechun color fastness improver can be used for post-treatment of fabric dyed by plant dyes with poor color fastness, effectively solving the problem of poor color fastness of plant dyes and effectively improving the color fastness of the obtained dyed fabric. The dyeing method using the Rechun pigment extract can prepare a plant dyed fabric with high color fastness, uniform color and environmental protection, and the dyeing method is green and environmentally friendly, and the wastewater generated in the dyeing process has less impact on the environment.

Description

Technical Field

[0001] This invention relates to the field of fabric dyeing technology, and in particular to a rehmannia glutinosa pigment extract and its application in fabric dyeing. Background Technology

[0002] Rejuvenating herb (Hemiberle sibthorpioides) is a perennial herb with high medicinal value as a traditional Chinese medicine. It is believed to have effects such as clearing the liver and improving eyesight, nourishing yin and yang, relaxing muscles and promoting blood circulation, and nourishing the five internal organs. Rejuvenating herb is a plant with both medicinal and edible uses; after harvesting, it can be eaten as a vegetable or dried for medicinal purposes. It can also be used to make medicinal wine, infused in water, or added to porridge, providing the body with rich nutrients. Currently, the most common applications of rejuvenating herb are as a traditional Chinese medicine to utilize its medicinal value and in the production of health-promoting teas and wines. There are no reports on its use as a natural dye in textile dyeing.

[0003] my country has a long tradition of using plant dyes to color fabrics. Plant dyes are not only naturally beautiful and fragrant, but also a renewable resource with good biodegradability and environmental compatibility. They are non-toxic, harmless, non-allergenic, and non-carcinogenic to the skin, and many also possess antibacterial and UV-protective properties. As more people prioritize their health and demand green products and green consumption, fabrics dyed with plant dyes are becoming increasingly popular. However, existing plant dyes suffer from problems such as inconsistent hue, poor adhesion, and poor colorfastness. To address the poor colorfastness of plant dyes, domestic textile companies currently typically use chemical materials as mordants or add chemical reagents to improve colorfastness, which generates large amounts of wastewater and severely pollutes the environment. Therefore, it is essential to develop new plant dyes with high colorfastness and to research and develop a green and environmentally friendly technology that can solve the aforementioned performance problems. Summary of the Invention

[0004] Based on this, the present invention provides a *Euphorbia lathyris* pigment extract, which has a high pigment concentration and can be used as a plant dye for fabric dyeing. It can achieve high color fastness in the dyed fabric without the use of chemical mordants. Furthermore, this *Euphorbia lathyris* pigment extract can also be used as a color fastness enhancer to treat fabrics dyed with plant dyes that have poor color fastness, effectively solving the problem of poor color fastness of plant dyes and significantly improving the color fastness of the resulting dyed fabric.

[0005] The specific technical solution is as follows:

[0006] A pigment extract of Rehmannia glutinosa is prepared by the following steps: adding Rehmannia glutinosa to water and steaming it at 90℃-100℃ for 25min-70min.

[0007] In some embodiments, the preparation method of the Rejuvenating Herb pigment extract includes the following steps: adding Rejuvenating Herb to water and steaming it at a temperature of 95℃-100℃ for 55min-65min to obtain the extract.

[0008] In some embodiments, the preparation method of the Rejuvenating Herb pigment extract includes the following steps: adding Rejuvenating Herb to water and steaming it at a temperature of 95℃-100℃ for 25min-35min to obtain the extract.

[0009] In some embodiments, the ratio of the rejuvenating herb to water is 15g / L-25g / L.

[0010] The present invention also provides the application of the above-mentioned Rehmannia glutinosa pigment extract.

[0011] The specific technical solution is as follows:

[0012] Application of Resveratrol or the above-mentioned Resveratrol pigment extract as a plant dye in fabric dyeing.

[0013] Application of Rejuvenating Grass or the above-mentioned Rejuvenating Grass pigment extract as a color fastness enhancer in fabric dyeing.

[0014] This invention also provides a method for dyeing fabrics using the above-mentioned *Eupatorium fortunei* pigment extract as a plant dye or color fastness improver. The dyed fabrics obtained by this method have high color fastness, effectively solving the problem of poor color fastness of plant dyes. Furthermore, this method is simple, environmentally friendly, and does not generate wastewater that causes significant environmental pollution.

[0015] The specific technical solution is as follows:

[0016] A method for dyeing fabric includes the following steps:

[0017] Fabric pretreatment: The fabric to be dyed is subjected to desizing and fiber modification in sequence;

[0018] Preparation of dye solution: According to the desired color depth of the fabric to be dyed, a certain amount of the rejuvenating grass pigment extract is measured, added to water, and stirred evenly to obtain the dye solution.

[0019] Fabric dyeing: The pretreated fabric to be dyed is placed in the dye solution for dyeing;

[0020] Fabric post-treatment: Wash and dry the dyed fabric.

[0021] In some embodiments, the desizing treatment includes: adding the fabric to be dyed to water, then adding 2 g / L-3 g / L sodium carbonate and 0.3 g / L-0.8 g / L BCN, and treating the fabric to be dyed at a temperature of 85℃-95℃ for 25 min-35 min.

[0022] In some embodiments, during the desizing process, the bath ratio of the fabric to be dyed to water is 1:60-80.

[0023] In some embodiments, the fiber modification includes: adding the desized fabric to be dyed to water, then adding 1g / L-2g / L sodium hydroxide or 2g / L-3g / L sodium carbonate, and adding the modifier FIXRESIN CTX at 3%-12% of the weight of the fabric to be dyed, and modifying the fabric to be dyed at a temperature of 75℃-85℃ for 15min-25min.

[0024] In some embodiments, during the fiber modification step, the bath ratio of the fabric to be dyed to water is 1:40-60.

[0025] In some embodiments, the temperature of the water in the step of preparing the dye solution is 30°C-40°C.

[0026] In some embodiments, in the step of preparing the dye solution, the mass ratio of the fabric to be dyed to the dye solution is 1:50-80, and the extract of *Euphorbia lathyris* pigment is 4-10% of the weight of the fabric to be dyed.

[0027] In some embodiments, the dyeing process involves dyeing the fabric at a temperature of 75°C-85°C for 50-70 minutes.

[0028] In some embodiments, the washing conditions in the fabric post-treatment step include: a fabric-to-water bath ratio of 1:100-150, a temperature of 30℃-35℃, and a time of 5min-10min.

[0029] In some embodiments, the drying conditions in the fabric post-treatment step include: a temperature of 50°C-60°C and a time of 10-20 minutes (the drying time varies depending on the thickness of the fabric).

[0030] A method for dyeing fabric includes the following steps:

[0031] Preparation of plant pigment extract: Extract pigments from natural plants with water to obtain plant pigment extract;

[0032] Fabric pretreatment: The fabric to be dyed is subjected to desizing and fiber modification in sequence;

[0033] Preparation of dye solution: According to the desired color depth of the fabric to be dyed, a certain amount of the plant pigment extract is measured, added to water, and stirred evenly to obtain the dye solution;

[0034] Preparation of color fastness improving treatment solution: Measure the pigment extract of the herb *Euphorbia hirta*, add it to water, stir evenly to obtain the color fastness improving treatment solution;

[0035] Fabric dyeing: The pretreated fabric to be dyed is placed in the dye solution for dyeing;

[0036] Fabric post-treatment: The dyed fabric is immersed in the color fastness improvement treatment solution, then washed and dried.

[0037] In some embodiments, the natural plant used in the step of preparing the plant pigment extract is one or more of the following: Lithospermum erythrorhizon, Cynomorium songaricum, and coffee leaves.

[0038] In some embodiments, in the step of preparing the plant pigment extract, the bath ratio of the natural plant to water is 1:40-60; the conditions for extracting the pigment include: a temperature of 90℃-100℃ and a time of 50min-70min.

[0039] In some embodiments, the desizing treatment includes: adding the fabric to be dyed to water, then adding 2 g / L-3 g / L sodium carbonate and 0.3 g / L-0.8 g / L BCN, and treating the fabric to be dyed at a temperature of 85℃-95℃ for 25 min-35 min.

[0040] In some embodiments, the fiber modification includes: adding the desized fabric to be dyed to water, then adding 1g / L-2g / L sodium hydroxide or 2g / L-3g / L sodium carbonate, and adding the modifier FIXRESIN CTX at 3%-12% of the weight of the fabric to be dyed, and modifying the fabric to be dyed at a temperature of 75℃-85℃ for 15min-25min.

[0041] In some embodiments, the temperature of the water in the step of preparing the dye solution is 30°C-40°C.

[0042] In some embodiments, in the step of preparing the dye solution, the mass ratio of the fabric to be dyed to the dye solution is 1:50-80, and the plant pigment extract is 5-8% of the weight of the fabric to be dyed.

[0043] In some embodiments, in the step of preparing the color fastness improving treatment solution, the ratio of the amount of the color fastness improving treatment solution to the fabric to be dyed is 45-55:1, and the concentration of the rejuvenating grass pigment extract in the color fastness improving treatment solution is 55mL / L-65mL / L.

[0044] In some embodiments, the dyeing process involves dyeing the fabric at a temperature of 75°C-85°C for 50-70 minutes.

[0045] In some embodiments, during the fabric post-treatment step, the soaking temperature is 75°C-85°C and the time is 50-70 minutes.

[0046] In some embodiments, the washing conditions in the fabric post-treatment step include: a fabric-to-water bath ratio of 1:100-150, a temperature of 30℃-35℃, and a time of 5min-10min.

[0047] In some embodiments, the drying conditions in the fabric post-treatment step include: a temperature of 50°C-60°C and a time of 10-20 minutes (the drying time varies depending on the thickness of the fabric).

[0048] The present invention also provides a dyed fabric. This dyed fabric has high color fastness.

[0049] The specific technical solution is as follows:

[0050] Dyed fabrics prepared by the above-mentioned methods for dyeing any fabric.

[0051] This invention, through extensive research on natural plants, has discovered that *Euphorbia lathyris* and its pigment extracts can serve as excellent plant dyes. Applying them to fabric dyeing allows for the preparation of plant-dyed fabrics with high and stable colorfastness without the use of chemical mordants. While enriching the hues of plant dyes, this application of *Euphorbia lathyris* effectively improves the colorfastness of plant-dyed fabrics, resulting in plant-dyed fabrics with high colorfastness, uniform color, and environmental friendliness. Furthermore, the dyeing method is green and environmentally friendly, with minimal wastewater impact during the dyeing process.

[0052] Furthermore, this invention also discovers that *Euphorbia hirta* and its pigment extract can be used as an effective, natural, and environmentally friendly color fastness enhancer for plant dyes in fabric dyeing. Using this *Euphorbia hirta* color fastness enhancer to post-treat fabrics dyed with plant dyes that have poor color fastness can effectively solve the problem of poor color fastness of plant dyes, effectively improve the color fastness of the resulting dyed fabrics, and this method does not require the addition of chemical reagents, is green and environmentally friendly, and the wastewater generated during the dyeing process has a small impact on the environment.

[0053] The fabric dyeing method provided by this invention is simple, environmentally friendly, and does not generate wastewater that causes significant environmental pollution. The dyed fabrics obtained by this method have high color fastness, effectively solving the problem of poor color fastness of plant dyes. By using Resveratrol extract as a plant dye or color fastness enhancer, combined with fiber modification and other pretreatment steps, and by optimizing the process parameters in each step, the color fastness of the obtained dyed fabrics can be further improved. Attached Figure Description

[0054] Figure 1The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Example 1.

[0055] Figure 2 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Example 2.

[0056] Figure 3 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Example 3.

[0057] Figure 4 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Example 4.

[0058] Figure 5 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared by the dyeing method provided in Example 5.

[0059] Figure 6 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 1.

[0060] Figure 7 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 2.

[0061] Figure 8 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 3.

[0062] Figure 9 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 4.

[0063] Figure 10 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 5.

[0064] Figure 11 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 6.

[0065] Figure 12 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 7.

[0066] Figure 13 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 8.

[0067] Figure 14The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 9.

[0068] Figure 15 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 10.

[0069] Figure 16 The dyeing effect (left) and sun exposure effect (right) of the dyed fabric prepared using the dyeing method provided in Comparative Example 11. Detailed Implementation

[0070] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be construed as limiting the invention.

[0071] Unless otherwise defined, all technical and scientific terms used in this invention 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 limit the invention.

[0072] The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps is not limited to the steps or modules listed, but may optionally include steps not listed, or may optionally include other steps inherent to such process, method, product, or device.

[0073] In this invention, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0074] All commonly used chemical reagents and experimental materials used in the examples and comparative examples were commercially available products. The modifier FIXRESIN CTX was purchased from Shanghai Zhanhe Industrial Co., Ltd.; the leaching agent BCN, a surfactant compound, was purchased from Guangzhou Changli Chemical Industry Co., Ltd.

[0075] The following are specific examples.

[0076] Example 1

[0077] In this embodiment, the fabric to be dyed is a silk satin fabric. The fabric dyeing method provided in this embodiment is as follows:

[0078] Step (1): Extract pigments from Rejuvenating Grass.

[0079] Add *Euphorbia lathyris* to water at a ratio of 20 g / L, and steam at 100°C for 60 minutes to obtain *Euphorbia lathyris* pigment extract.

[0080] Step (2): Fabric pretreatment.

[0081] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:80, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0082] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 3g / L sodium carbonate and 3% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20 minutes.

[0083] Step (3): Prepare the dye solution.

[0084] Add 8% (equivalent to the weight of the fabric to be dyed) of the extract of *Euphorbia lathyris* pigment to water at 35°C and stir until homogeneous to obtain the dye solution. The weight of the obtained dye solution is 60 times the weight of the fabric to be dyed.

[0085] Step (4): Fabric dyeing.

[0086] The pretreated fabric to be dyed is placed in the dye solution prepared in step (3) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0087] Step (5): Fabric post-treatment.

[0088] Washing: Wash the dyed fabric with water at a liquor ratio of 1:50, a temperature of 30℃, and a time of 5 minutes.

[0089] Drying: Dry the washed fabric. Set the dryer temperature to 50℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0090] Example 2

[0091] In this embodiment, the fabric to be dyed is pure linen. The fabric dyeing method provided in this embodiment is as follows:

[0092] Step (1): Extract pigments from Rejuvenating Grass.

[0093] Add *Euphorbia lathyris* to water at a ratio of 20 g / L, and steam at 100°C for 60 minutes to obtain *Euphorbia lathyris* pigment extract.

[0094] Step (2): Fabric pretreatment.

[0095] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:60, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0096] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 2g / L sodium hydroxide and 10% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20min.

[0097] Step (3): Prepare the dye solution.

[0098] Add 5% (equivalent to the weight of the fabric to be dyed) of the extract of *Euphorbia humifusa* pigment to water at 35°C and stir until homogeneous to obtain the dye solution. The weight of the obtained dye solution is 50 times the weight of the fabric to be dyed.

[0099] Step (4): Fabric dyeing.

[0100] The pretreated fabric to be dyed is placed in the dye solution prepared in step (3) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0101] Step (5): Fabric post-treatment.

[0102] Washing: Wash the dyed fabric with water at a liquor ratio of 1:100, a temperature of 30℃, and a time of 5 minutes.

[0103] Drying: Dry the washed fabric. Set the dryer temperature to 60℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0104] Example 3

[0105] In this embodiment, the fabric to be dyed is a pure cotton fabric. The fabric dyeing method provided in this embodiment is as follows:

[0106] Step (1): Prepare the color fastness enhancer for Rejuvenating Grass.

[0107] Add the herb to water at a ratio of 20g / L and boil at 100℃ for 30 minutes to obtain the herb color fastness enhancer.

[0108] Step (2): Extracting comfrey pigment.

[0109] Add the comfrey root to water at a bath ratio of 1:50, and steam at 100℃ for 60 minutes to obtain the comfrey pigment extract.

[0110] Step (3): Fabric pretreatment.

[0111] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:60, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0112] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 2g / L sodium hydroxide and 10% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20min.

[0113] Step (4): Prepare the dye solution.

[0114] Add 5% (equivalent to the weight of the fabric to be dyed) of comfrey pigment extract to water at 35℃ and stir well to obtain the dye solution. The weight of the obtained dye solution is 50 times the weight of the fabric to be dyed.

[0115] Step (5): Prepare color fastness improvement treatment solution.

[0116] Measure out 60 mL / L of the color fastness enhancer for *Euphorbia humifusa*, add it to water, stir well to obtain a color fastness enhancement treatment solution. The weight of the obtained color fastness enhancement treatment solution is 50 times the weight of the fabric to be dyed.

[0117] Step (6): Fabric dyeing.

[0118] The pretreated fabric to be dyed is placed in the dye solution prepared in step (4) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0119] Step (7): Fabric post-treatment.

[0120] Color fastness improvement treatment: Immerse the dyed fabric in the color fastness improvement treatment solution prepared in step (5) at a temperature of 80°C for 60 minutes.

[0121] Washing: Wash the fabric after the color fastness improvement treatment with a liquor ratio of 1:100, a temperature of 30℃, and a time of 5 minutes.

[0122] Drying: Dry the washed fabric. Set the dryer temperature to 60℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0123] Example 4

[0124] In this embodiment, the fabric to be dyed is pure linen. The fabric dyeing method provided in this embodiment is as follows:

[0125] Step (1): Prepare the color fastness enhancer for Rejuvenating Grass.

[0126] Add the herb to water at a ratio of 20g / L and boil at 100℃ for 30 minutes to obtain the herb color fastness enhancer.

[0127] Step (2): Extracting Cynomorium pigment.

[0128] Add Cynomorium songaricum to water at a bath ratio of 1:50, and boil at 100℃ for 60 minutes to obtain Cynomorium songaricum pigment extract.

[0129] Step (3): Fabric pretreatment.

[0130] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:60, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0131] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 2g / L sodium hydroxide and 10% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20min.

[0132] Step (4): Prepare the dye solution.

[0133] Add 5% (equivalent to the weight of the fabric to be dyed) of Cynomorium songaricum extract to 35°C water and stir until homogeneous to obtain the dye solution. The weight of the obtained dye solution is 50 times the weight of the fabric to be dyed.

[0134] Step (5): Prepare color fastness improvement treatment solution.

[0135] Measure out 60 mL / L of the color fastness enhancer for *Euphorbia humifusa*, add it to water, stir well to obtain a color fastness enhancement treatment solution. The weight of the obtained color fastness enhancement treatment solution is 50 times the weight of the fabric to be dyed.

[0136] Step (6): Fabric dyeing.

[0137] The pretreated fabric to be dyed is placed in the dye solution prepared in step (4) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0138] Step (7): Fabric post-treatment.

[0139] Color fastness improvement treatment: Immerse the dyed fabric in the color fastness improvement treatment solution prepared in step (5) at a temperature of 80°C for 60 minutes.

[0140] Washing: Wash the fabric after the color fastness improvement treatment with a liquor ratio of 1:100, a temperature of 30℃, and a time of 5 minutes.

[0141] Drying: Dry the washed fabric. Set the dryer temperature to 60℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0142] Example 5

[0143] In this embodiment, the fabric to be dyed is a silk-cotton fabric. The fabric dyeing method provided in this embodiment is as follows:

[0144] Step (1): Prepare the color fastness enhancer for Rejuvenating Grass.

[0145] Add the herb to water at a ratio of 20g / L and boil at 100℃ for 30 minutes to obtain the herb color fastness enhancer.

[0146] Step (2): Extract coffee leaf pigments.

[0147] Coffee leaves are added to water at a bath ratio of 1:50 and boiled at 100°C for 60 minutes to obtain coffee leaf pigment extract.

[0148] Step (3): Fabric pretreatment.

[0149] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:60, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0150] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 2g / L sodium hydroxide and 10% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20min.

[0151] Step (4): Prepare the dye solution.

[0152] Add 5% (equivalent to the weight of the fabric to be dyed) of coffee leaf pigment extract to water at 35°C and stir well to obtain the dye solution. The weight of the obtained dye solution is 50 times the weight of the fabric to be dyed.

[0153] Step (5): Prepare color fastness improvement treatment solution.

[0154] Measure out 60 mL / L of the color fastness enhancer for *Euphorbia humifusa*, add it to water, stir well to obtain a color fastness enhancement treatment solution. The weight of the obtained color fastness enhancement treatment solution is 50 times the weight of the fabric to be dyed.

[0155] Step (6): Fabric dyeing.

[0156] The pretreated fabric to be dyed is placed in the dye solution prepared in step (4) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0157] Step (7): Fabric post-treatment.

[0158] Color fastness improvement treatment: Immerse the dyed fabric in the color fastness improvement treatment solution prepared in step (5) at a temperature of 80°C for 60 minutes.

[0159] Washing: Wash the fabric after the color fastness improvement treatment with a liquor ratio of 1:100, a temperature of 30℃, and a time of 5 minutes.

[0160] Drying: Dry the washed fabric. Set the dryer temperature to 60℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0161] Comparative Example 1

[0162] The fabric dyeing method provided in Comparative Example 1 differs from that in Example 1 in that the plant privet is used instead of rehmannia root; the remaining steps and process conditions are the same as in Example 1.

[0163] Comparative Example 2

[0164] The fabric dyeing method provided in Comparative Example 2 differs from that in Example 2 in that the plant Coptis chinensis is used instead of Rehmannia glutinosa; the remaining steps and process conditions are the same as in Example 2.

[0165] Comparative Example 3

[0166] The fabric dyeing method provided in Comparative Example 3 differs from that in Example 3 in that it omits the color fastness improvement treatment in steps (1), (5), and (7) of Example 3. All other steps and process conditions are the same as in Example 3. Specifically:

[0167] Step (1): Extracting comfrey pigment.

[0168] Add the comfrey root to water at a bath ratio of 1:50, and steam at 100℃ for 60 minutes to obtain the comfrey pigment extract.

[0169] Step (2): Fabric pretreatment.

[0170] Desizing: Add the fabric to be dyed to water at a bath ratio of 1:60, then add 2 g / L of sodium carbonate and 0.5 g / L of scouring agent BCN, and treat the fabric to be dyed at 90℃ for 30 min.

[0171] Modification: Add the desized fabric to be dyed to water at a bath ratio of 1:50, then add 2g / L sodium hydroxide and 10% modifier FIXRESIN CTX (equivalent to the weight of the fabric to be dyed), and modify the fabric to be dyed at 80℃ for 20min.

[0172] Step (3): Prepare the dye solution.

[0173] Add 5% (equivalent to the weight of the fabric to be dyed) of comfrey pigment extract to water at 35℃ and stir well to obtain the dye solution. The weight of the obtained dye solution is 50 times the weight of the fabric to be dyed.

[0174] Step (4): Fabric dyeing.

[0175] The pretreated fabric to be dyed is placed in the dye solution prepared in step (4) for dyeing. The water bath is kept at a constant temperature of 80°C for 60 minutes.

[0176] Step (5): Fabric post-treatment.

[0177] Washing: Wash the dyed fabric with water at a liquor ratio of 1:100, a temperature of 30℃, and a time of 5 minutes.

[0178] Drying: Dry the washed fabric. Set the dryer temperature to 60℃ and the time to 10-20 minutes, depending on the thickness of the fabric.

[0179] Comparative Example 4

[0180] The fabric dyeing method provided in Comparative Example 4 differs from that in Example 3 in that in step (1), Polygonum multiflorum is used instead of Rehmannia glutinosa to prepare Polygonum multiflorum color fastness enhancer, and in step (5), Polygonum multiflorum color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 3.

[0181] Comparative Example 5

[0182] The fabric dyeing method provided in Comparative Example 5 differs from that in Example 3 in that in step (1), the plant Sichuan pepper is used instead of Rehmannia glutinosa to prepare the Sichuan pepper color fastness enhancer, and in step (5), the Sichuan pepper color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 3.

[0183] Comparative Example 6

[0184] The fabric dyeing method provided in Comparative Example 6 differs from that in Example 4 in that it omits the color fastness improvement treatment in steps (1), (5), and (7) of Example 4. All other steps and process conditions are the same as in Example 4. Specifically:

[0185] Comparative Example 7

[0186] The fabric dyeing method provided in Comparative Example 7 differs from that in Example 4 in that in step (1), Polygonum multiflorum is used instead of Rehmannia glutinosa to prepare Polygonum multiflorum color fastness enhancer, and in step (5), Polygonum multiflorum color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 4.

[0187] Comparative Example 8

[0188] The fabric dyeing method provided in Comparative Example 8 differs from that in Example 4 in that in step (1), the plant Sichuan pepper is used instead of Rehmannia glutinosa to prepare the Sichuan pepper color fastness enhancer, and in step (5), the Sichuan pepper color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 4.

[0189] Comparative Example 9

[0190] The fabric dyeing method provided in Comparative Example 9 differs from that in Example 5 in that it omits the color fastness improvement treatment in steps (1), (5), and (7) of Example 5. All other steps and process conditions are the same as in Example 5. Specifically:

[0191] Comparative Example 10

[0192] The fabric dyeing method provided in Comparative Example 10 differs from that in Example 5 in that in step (1), Polygonum multiflorum is used instead of Rehmannia glutinosa to prepare Polygonum multiflorum color fastness enhancer, and in step (5), Polygonum multiflorum color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 5.

[0193] Comparative Example 11

[0194] The fabric dyeing method provided in Comparative Example 11 differs from that in Example 5 in that in step (1), the plant Sichuan pepper is used instead of Rehmannia glutinosa to prepare the Sichuan pepper color fastness enhancer, and in step (5), the Sichuan pepper color fastness enhancer is used instead of Rehmannia glutinosa color fastness enhancer. The remaining steps and process conditions are the same as in Example 5.

[0195] The color fastness properties of the dyed fabrics obtained by the dyeing methods provided in Examples 1-5 and Comparative Examples 1-11 were tested, and the results are shown in Table 1. Figure 1-16 As shown.

[0196] Table 1. Test results of color fastness performance of dyed fabrics

[0197]

[0198]

[0199] From Table 1 and Figures 1-16The results show that the color fastness of the dyed fabric prepared in Example 1 is better than that of Comparative Example 1; the color fastness of the dyed fabric prepared in Example 2 is better than that of Comparative Example 2. It can be seen that using the pigment extract of *Ligustrum lucidum* as a plant dye can effectively improve the color fastness of the dyed fabric, and the color fastness of the dyed fabric obtained is better than that of other plants such as *Ligustrum lucidum* and *Coptis chinensis*. The dyed fabric prepared in Example 3 exhibits better color fastness than the dyed fabrics prepared in Comparative Examples 3, 4, and 5; the dyed fabric prepared in Example 4 exhibits better color fastness than the dyed fabrics prepared in Comparative Examples 6, 7, and 8; and the dyed fabric prepared in Example 5 exhibits better color fastness than the dyed fabrics prepared in Comparative Examples 9, 10, and 11. It is evident that post-treatment of plant-dyed fabrics with the *Polygonum multiflorum* color fastness enhancer can significantly improve the color fastness of the resulting fabrics, making the color fastness of the dyed fabrics better than that of fabrics not treated with the *Polygonum multiflorum* color fastness enhancer, and better than fabrics treated with color fastness enhancers prepared from other plants such as *Polygonum multiflorum* and *Zanthoxylum bungeanum* under the same process conditions. In other words, the *Polygonum multiflorum* color fastness enhancer provided by this invention can effectively improve the color fastness of plant dyes.

[0200] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0201] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for dyeing fabrics, characterized in that, Includes the following steps: Fabric pretreatment: The fabric to be dyed is subjected to desizing and fiber modification in sequence; Preparation of dye solution: According to the desired color depth of the fabric to be dyed, measure a certain amount of Rehmannia glutinosa pigment extract, add it to water, stir evenly, and the dye solution is obtained. Fabric dyeing: The pretreated fabric to be dyed is placed in the dye solution for dyeing; Fabric post-treatment: Wash and dry the dyed fabric; The preparation method of the herb extract includes the following steps: adding herb to water and steaming at 90℃-100℃ for 25min-70min to obtain the extract; The fiber modification includes: adding the desized fabric to be dyed to water, then adding 1g / L-2g / L sodium hydroxide or 2g / L-3g / L sodium carbonate, and adding the modifier FIXRESIN CTX at 3%-10% of the weight of the fabric to be dyed, and modifying the fabric to be dyed at a temperature of 75℃-85℃ for 15min-25min.

2. The fabric dyeing method according to claim 1, characterized in that, The preparation method of the *Huaichuncao* pigment extract includes the following steps: adding *Huaichuncao* to water and steaming at 95℃-100℃ for 55-65 minutes to obtain the extract; or, The preparation method of the herb extract includes the following steps: adding herb to water and steaming at 95℃-100℃ for 25min-35min to obtain the extract.

3. The fabric dyeing method according to claim 1 or 2, characterized in that, In the preparation of the pigment extract of Rehmannia glutinosa, the ratio of Rehmannia glutinosa to water is 15g / L-25g / L.

4. The fabric dyeing method according to claim 1 or 2, characterized in that, The desizing treatment includes: adding the fabric to be dyed to water, then adding 2 g / L-3 g / L sodium carbonate and 0.3 g / L-0.8 g / L LBCN, and treating the fabric at a temperature of 85℃-95℃ for 25 min-35 min; and / or, In the step of preparing the dye solution, the temperature of the water is 30℃-40℃; and / or, In the step of preparing the dye solution, the mass ratio of the fabric to be dyed to the dye solution is 1:50-80, and the *Euphorbia lathyris* pigment extract is 4-10% of the weight of the fabric to be dyed; and / or, In the fabric dyeing process, the dyeing temperature is 75℃-85℃, and the dyeing time is 50min-70min; and / or, In the fabric post-treatment steps, the washing conditions include: a fabric-to-water bath ratio of 1:100-150, a temperature of 30℃-35℃, and a time of 5-10 minutes; and / or, In the fabric post-treatment step, the drying conditions include: a temperature of 50℃-60℃ and a time of 10min-20min.

5. A method for dyeing fabrics, characterized in that, Includes the following steps: Preparation of plant pigment extract: Extract pigments from natural plants with water to obtain plant pigment extract; Fabric pretreatment: The fabric to be dyed is subjected to desizing and fiber modification in sequence; Preparation of dye solution: According to the desired color depth of the fabric to be dyed, a certain amount of the plant pigment extract is measured, added to water, and stirred evenly to obtain the dye solution; Preparation of color fastness improvement treatment solution: Measure out the pigment extract of Rehmannia glutinosa, add it to water, stir evenly to obtain the color fastness improvement treatment solution; Fabric dyeing: The pretreated fabric to be dyed is placed in the dye solution for dyeing; Fabric post-treatment: Immerse the dyed fabric in the color fastness improvement treatment solution, then wash and dry; The preparation method of the herb extract includes the following steps: adding herb to water and steaming at 90℃-100℃ for 25min-70min to obtain the extract; The fiber modification includes: adding the desized fabric to be dyed to water, then adding 1g / L-2g / L sodium hydroxide or 2g / L-3g / L sodium carbonate, and adding the modifier FIXRESIN CTX at 3%-10% of the weight of the fabric to be dyed, and modifying the fabric to be dyed at a temperature of 75℃-85℃ for 15min-25min.

6. The method for dyeing fabrics according to claim 5, characterized in that, The preparation method of the *Huaichuncao* pigment extract includes the following steps: adding *Huaichuncao* to water and steaming at 95℃-100℃ for 55-65 minutes to obtain the extract; or, The preparation method of the herb extract includes the following steps: adding herb to water and steaming at 95℃-100℃ for 25min-35min to obtain the extract.

7. The method for dyeing fabrics according to claim 5 or 6, characterized in that, In the preparation of the pigment extract of Rehmannia glutinosa, the ratio of Rehmannia glutinosa to water is 15g / L-25g / L.

8. The method for dyeing fabrics according to claim 5 or 6, characterized in that, In the step of preparing the plant pigment extract, the natural plant is one or more of the following: Lithospermum erythrorhizon, Cynomorium songaricum, and coffee leaves; and / or, In the step of preparing the plant pigment extract, the bath ratio of the natural plant to water is 1:40-60, and the extraction conditions include: a temperature of 90℃-100℃ and a time of 50min-70min; and / or, The desizing treatment includes: adding the fabric to be dyed to water, then adding 2 g / L-3 g / L sodium carbonate and 0.3 g / L-0.8 g / L LBCN, and treating the fabric at a temperature of 85℃-95℃ for 25 min-35 min; and / or, In the step of preparing the dye solution, the temperature of the water is 30℃-40℃; and / or, In the step of preparing the dye solution, the mass ratio of the fabric to be dyed to the dye solution is 1:50-80, and the plant pigment extract is 5-8% of the weight of the fabric to be dyed; and / or, In the step of preparing the color fastness improving treatment solution, the ratio of the amount of the color fastness improving treatment solution to the fabric to be dyed is 45-55:1, and the concentration of the *Euphorbia lathyris* pigment extract in the color fastness improving treatment solution is 55 mL / L-65 mL / L; and / or, In the fabric dyeing process, the dyeing temperature is 75℃-85℃, and the dyeing time is 50min-70min; and / or, In the fabric post-treatment step, the soaking temperature is 75℃-85℃, and the time is 50min-70min; and / or, In the fabric post-treatment steps, the washing conditions include: a fabric-to-water bath ratio of 1:100-150, a temperature of 30℃-35℃, and a time of 5-10 minutes; and / or, In the fabric post-treatment step, the drying conditions include: a temperature of 50℃-60℃ and a time of 10min-20min.

9. A dyed fabric prepared by the fabric dyeing method according to any one of claims 1-8.

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