CN115785696B - Vegetable dye and preparation method and application thereof - Google Patents

Abstract

The application provides a vegetable dye and a preparation method and application thereof, belonging to the technical field of natural-source dyes prepared from natural raw materials. 60-80 parts of plant extract, 5-10 parts of natural modifier and the balance of deionized water. The vegetable dye of the application uses natural modifier and natural dye as main components to carry out modification-dyeing one bath process, thereby improving the dyeing percentage and improving the color fastness. The application is applied to dyeing of fabrics, especially pure cotton fabrics, and has the advantages of high dye-uptake, high color fastness, low energy consumption and the like.

Description

Vegetable dye and preparation method and application thereof

Technical Field

The application relates to a vegetable dye and a preparation method and application thereof, belonging to the technical field of natural-source dyes prepared from natural raw materials.

Background

Along with the continuous improvement of the living standard of people, the importance of people on health is also increased. Synthetic dyes can impart vivid colors to fabrics, but there are unavoidable environmental problems in textile processing. In the textile processing process, if some additional functions are required to be given to the fabric, an auxiliary agent is inevitably required to be added for functional finishing. Under the influence of the background, natural vegetable dyes gradually return to the human field of vision.

In recent years, research on vegetable dyes is also increasing, but due to the problems of large molecular weight, low dye-uptake, poor color fastness and the like of most of natural vegetable dyes, a plurality of chemical auxiliary agents are required to be added in the application process of the natural vegetable dyes, so that the ecological processed textiles are caused, and the connection with the chemical auxiliary agents cannot be disconnected. In order to achieve the aim of leveling the application performance with the synthetic dye and solve the problem that the liquid vegetable dye is difficult to preserve for a long time, some manufacturers prepare the vegetable dye into powder for preservation in a spray drying mode, but the drastic changes of temperature and humidity in the powder preparation process can cause the structure of part of substances in the vegetable dye (mixture) to change, so that the color becomes dull or the color fastness is poor; and a large amount of energy is consumed in the drying and pulverizing process, so that the cost in the application process of the vegetable dye is increased.

For the above problems, many researchers have proposed different solutions, such as: CN1912012a mentions that pasty natural substances can be extracted from pomegranate peel and leaf to increase dye-uptake of vegetable dye and improve color fastness, but the extraction process is complicated and the cost is high, and the method is not suitable for mass industrial production. Regarding the problem of damage to active ingredients caused in the spray drying pulverizing process, the preparation of the vegetable dye into a highly concentrated paste form is a good solution, but has a lot of problems in the application process. For example: CN102041689a adopts ultrasonic extraction to obtain higher extraction rate in order to solve the problems of poor hydrophilicity and lower extraction rate of vegetable dye pigment molecules, which increases the processing cost of vegetable dye in intangible way; CN101914305a adds an emulsifier to uniformly disperse the plant dye with poor water solubility, so as to obtain uniform paste-like plant dye, which is contrary to the original purpose that the plant dye is natural and pollution-free.

Disclosure of Invention

In view of the above, the application firstly provides the vegetable dye, improves the dye-uptake and color fastness of the vegetable dye, and simultaneously maintains the natural pollution-free processing concept of the vegetable dye, thereby helping to better apply and develop the ecological textile.

Specifically, the application is realized by the following modes:

a yellow pasty antibacterial vegetable dye comprises the following components:

plant extract: 60-80 parts by mass of a lubricant,

natural modifier: 5-10 parts by mass of a metal alloy,

the balance of deionized water,

the plant extract is one or more of flos Sophorae Immaturus, rhizoma Polygoni Cuspidati, radix et rhizoma Rhei, pericarpium Granati, fructus Gardeniae, and cortex Phellodendri extract. The quercetin and rutin in the flos Sophorae Immaturus and flos Sophorae Immaturus extract belong to flavonoid substances, wherein the quercetin has small molecular weight, and can easily diffuse into fiber to reduce color difference between the inside and the outside of fiber. Rutin has the advantages of larger molecular weight, more phenolic hydroxyl groups, more complexing positions, stronger binding force and better color fastness. The emodin in the extractive solutions of rhizoma Polygoni Cuspidati and radix et rhizoma Rhei can destroy bacterial cell membrane, inhibit synthesis of protein in bacteria, and have excellent antibacterial effect. The pericarpium Granati extractive solution mainly contains polyphenols such as punicalagin, ellagic acid, and gallic acid, and has good color fastness and antibacterial property. The gardenia extract contains more crocin and flavonoid gardenia yellow pigment, the molecular structure is linear, the substantivity is strong, and the water solubility is good. The main component of the phellodendron extract is berberine, which is the only cationic vegetable dye.

The natural modifier is one or more selected from collagen, animal gelatin, sodium caseinate, soybean protein, betaine and quaternary ammonium salt chitosan. Cellulose fiber shows negative electricity in water, dye molecules are negatively charged after being dissolved in water, and the resistance of dye dyeing fiber is larger and the dye-uptake is lower due to the action of electrostatic repulsive force. The natural modifier is mainly protein and cation matters, and has strong electropositivity, dye and fiber after being dissolved in water. The polycation of the quaternary ammonium salt chitosan not only can increase the dye uptake of the dye, but also has good antibacterial and antiseptic properties. Firstly, the functional groups are easy to act on groups with negative charges on the surfaces of fungal cells to change the fluxion of fungal cell membranes; secondly, the DNA has high affinity to DNA, can enter the nucleus of pathogenic bacteria, and interfere the replication and transcription of DNA; thirdly, it can inhibit the growth of spoilage bacteria such as bacillus subtilis, escherichia coli, pseudomonas and staphylococcus aureus.

In the scheme of the plant dye, the applicant selects polyhydroxy plant dyes such as pagodatree flower, pagodatree flower bud, giant knotweed, rhubarb, pomegranate rind, gardenia, phellodendron bark extract and the like as dyeing components, the plant dyes have larger molecular weight and conjugated system, and also have good water solubility, the plant dyes, natural proteins or cationic modifiers are mixed, the natural modifiers can form yellow pasty antibacterial dye-modifier temporary storage bodies with hydroxyl groups contained in quercetin, rutin, emodin, punicalagin and the like in a manner of hydrogen bond, electrostatic adsorption and the like, and the temporary storage bodies enable the plant dyes to be stored in paste form, so that the phenomenon that the structures of pigments and other effective components are irreversibly changed due to severe changes of temperature and humidity in the powder processing process is effectively improved. When the temporary storage body is added with the dye liquor, the electropositivity of the natural modifier molecules can promote the combination of the natural modifier molecules and the cellulose fibers with electronegativity to form a dye-modifier-fiber structure, so that the dye uptake of the dye to the cellulose fibers is improved, the binding force between the cellulose fibers and the dye is enhanced, and the original dyeing effect of the vegetable dye is reserved to the greatest extent.

Further, as preferable:

the plant extract is a mixture of flos Sophorae Immaturus extract and pericarpium Granati extract. More preferably, in the plant extract, the weight ratio of the mixture of the pagodatree flower bud extract, the pagodatree flower extract and the pomegranate rind extract is 1:1:3. The plant extract is obtained by the following steps: any one of flos Sophorae Immaturus, rhizoma Polygoni Cuspidati, radix et rhizoma Rhei, pericarpium Granati, fructus Gardeniae, and cortex Phellodendri is used as plant material, and the plant material is pulverized, concentrated with water, and optionally added to obtain plant extractive solution.

The natural modifier is a mixture of animal gelatin, sodium caseinate and quaternary ammonium salt chitosan, and more preferably, the mass ratio of the animal gelatin to the sodium caseinate to the quaternary ammonium salt chitosan is 3:1:0.2.

The plant dye also comprises natural preservative, the addition amount of which is 0.1-0.5 part by mass, and the plant dye comprises the following components in parts by mass: 60-80 parts by mass of plant extract, 5-10 parts by mass of natural modifier, 0.1-0.5 part by mass of natural preservative and the balance of water, more preferably, the natural preservative is selected from one or more of nisin, natamycin and tea polyphenol. Nisin is a natural polypeptide produced by fermentation of streptococcus lactis, and mainly causes outflow of small molecular substances in cells and inflow of extracellular water molecules by changing the permeability of cell membranes, so that the cells are subjected to autolysis and death, and the bacteria are obviously inhibited. The natamycin is a natural polypeptide substance separated from various mould biological fermentation, and mainly causes cell membrane deformation, changes cell membrane permeability, reduces cytoplasmic pH value, finally causes cell death, has obvious inhibition effect on mould and saccharomycetes, and has about 50 times stronger inhibition effect than potassium sorbate. Tea polyphenols have broad-spectrum antibacterial effect, mainly by destroying cell membrane function, inhibiting specific target protein of bacteria, and inhibiting oxidation. More preferably, the natural preservative is a mixture of nisin, natamycin and tea polyphenol, and the mass ratio is 1:1:0.5. The natural preservative is introduced into the natural plant dye for the first time, so that the problem of short storage time caused by easy deterioration and mildew of the natural plant dye in a liquid state is solved.

Meanwhile, the applicant also provides a preparation method of the vegetable dye, which comprises the following steps:

(1) Treating a natural modifier: one or more of a certain amount of collagen, animal gelatin, sodium caseinate, soybean protein and quaternary ammonium salt chitosan powder are weighed, added into 40-60 ℃ aqueous solution while stirring, and fully stirred for 24 hours to obtain the natural modifier.

(2) Preparing a plant extract: pulverizing one or more of flos Sophorae Immaturus, rhizoma Polygoni Cuspidati, radix et rhizoma Rhei, pericarpium Granati, fructus Gardeniae, and cortex Phellodendri, soaking a certain amount of plant dye raw material powder in water solution at a bath ratio of 1:10-20, and stirring at 60-100deg.C for 30-60 min at constant speed, extracting for several times such as three or more times, filtering to obtain residue, mixing the extractive solutions, and concentrating to obtain plant extractive solution.

(3) Preparing a vegetable dye: heating the plant extract to 40-60 ℃ to be used as a solution; weighing a certain amount of natural modifier, heating to 40-60 ℃, slowly and uniformly adding the solution, fully stirring and uniformly cooling to obtain the yellow pasty plant dye with antibacterial property.

According to the preparation method, the prepared plant extract is weak acid, and selected polyhydroxy plant dyes such as pagodatree flower, pagodatree flower bud, giant knotweed rhizome, rhubarb, pomegranate rind, gardenia, cortex phellodendri extract and the like are combined with selected protein and cation natural modifier to form a temporary storage body, so that the temporary storage body is easier to combine with fabrics in dyeing, and the color fastness and the dye uptake are improved; meanwhile, the two components are matched, so that the prepared vegetable dye is pasty, the original dyeing property of the vegetable raw material is well reserved, the dye is endowed with antibacterial property, and the production cost is reduced.

Further, as preferable:

in the step (2), the weight of the solution after the concentration process is the same as the quality of the extracted raw materials.

In the step (3), a certain mass of natural preservative is added before the natural modifier solution is added, and the natural preservative is slowly and uniformly added into the solution after being weighed. The natural preservative and the natural modifier solution may be added sequentially or simultaneously.

The third aspect of the applicant aims to provide a process for applying the vegetable dye to dyeing of fabrics containing cellulose fibers such as cotton and viscose, wherein a natural modifier and a vegetable extract are dyed in one bath, and the method comprises the following specific steps of:

(1) Sample preparation: the fabric is flatly wound on a roller shaft of a jig dyeing machine, water is added according to the bath ratio of 1:10-20, and the fabric is fully wetted after 5-10 times of operation.

(2) Feeding: adding water (water with the temperature of 40-45 ℃) into the vegetable dye, and uniformly stirring to form the dye liquor with the concentration of o.w.f. 1-15%.

(3) Dyeing: placing the wet fabric in a dye liquor, setting the heating rate to be 1-3 ℃/min, heating to 60 ℃, and keeping the temperature for 30-60 min; alum is added in 1-5 g/L, and the heat preservation is continued for 30-60 min.

(4) Washing: washing with clear water (60 ℃ C. X20 min+normal temperature x 20 min), soaping (60 ℃ C. X20 min), washing with clear water (normal temperature x 20 min), sampling and drying.

According to the scheme, the dye not only comprises a dyeing component, but also comprises a modifying component, and when the dye is added into a fabric containing components such as cellulose fibers, a temporary storage body formed by the two components is combined with the fabric to form a firm dye-modifier-fiber structure, so that the dye uptake and color fastness of the vegetable dye are obviously improved. The dyeing processing of the fabric by the one-bath method of the vegetable dye and the natural modifier is realized, the dyeing cost of the vegetable dye is reduced, the dye-uptake is increased, the color fastness is improved, and the problems of lower dye-uptake and poor color fastness of the traditional vegetable dye are effectively solved.

The scheme also provides another application mode of the plant dye, wherein the natural modifier and the plant extract are in different baths, and the dyeing adopts a mode of modifying before coloring, and the specific steps are as follows:

(1) Pre-modification: weighing 5-10 parts by mass of natural modifier, adding water (water at 40 ℃ can be adopted) into the mixture according to the ratio of o.w.f. 3-5%, placing the fabric in the mixture, and heating to 60 ℃ and preserving heat for 20-30 min to complete pre-modification, wherein the natural modifier is one or more of collagen, animal gelatin, sodium caseinate, soybean protein and quaternary ammonium chitosan;

(2) Preparing materials: flatly winding the pre-modified fabric onto a roll shaft of a jig dyeing machine, wherein the fabric is wet at the moment and does not need to be wetted again;

(3) Feeding: 60-80 parts by mass of plant extract is added with water (water with the temperature of 40-45 ℃ can be adopted) and stirred uniformly to form o.w.f. 1-15% dye liquor;

(4) Dyeing: placing the fabric subjected to the pre-modification in the step (2) in a dye liquor, setting the heating rate to be 1-3 ℃/min, heating to 60 ℃, and keeping the temperature for 30-60 min; alum 1-5 g/L is added, and the heat preservation is continued for 30-60 min;

(5) Washing: cleaning (at normal temperature×20min+60deg.C×20min), soaping (at 60deg.C×20min), cleaning (at normal temperature×20min), sampling, and oven drying.

The application is further described below in connection with the following detailed description.

Detailed Description

The application will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application.

In the embodiments described in the following description of the embodiments,

(1) The preparation process of the plant extract comprises the following steps:

taking pagodatree flower, pagodatree flower bud, giant knotweed, rhubarb, pomegranate rind, gardenia and cortex phellodendri as plant raw materials, respectively crushing the plant raw materials into powder, respectively soaking the same amount of each powder in aqueous solution, and carrying out the following operations to obtain respective plant extract: the bath ratio is 1:10, the temperature is 80 ℃, the temperature is kept for 30min, the extraction is carried out for three times, the residual residues are filtered out, and the three extraction solutions are mixed and concentrated to obtain the plant extraction solution.

(2) Dyeing property and color fastness test:

(1) the dyeing process comprises the following steps: dyeing (2 ℃/min, 60 ℃ for 30 min) -sampling-adding mordant (2 g/L alum) -mordant (2 ℃/min, 60 ℃ for 30 min).

(2) The water washing process comprises the following steps: washing with hot water (3 ℃ C./min, 60 ℃ C., 20 min), washing with cold water (normal temperature, 20 min), and drying (50 ℃ C.).

(3) And (3) testing: cutting and sewing lining cloth on the dyed pure cotton woven fabric, and respectively testing and grading perspiration resistance color fastness, water-soaking resistance color fastness and friction resistance color fastness according to the national standard GB 31701-2015. And (3) testing the dyeing depth K/S value, testing by using a Datacolor-400 type color measuring and matching instrument, measuring four times, and taking an average value.

Example 1

The screening test of plant materials was carried out in this example, and the procedure was as follows:

(1) Preparing a natural modifier solution:

weighing 10g of natural modifier (namely 2g of each natural modifier) by the mass ratio of collagen, animal gelatin, sodium caseinate, soybean protein and quaternary ammonium salt chitosan of 1:1:1:1; after blending, the mixture was slowly and uniformly dissolved in an aqueous solution at 40℃to prepare 2L of a natural modifier solution (i.e., 5g/L of a natural modifier solution).

(2) Preparing a dyeing solution:

taking flos Sophorae Immaturus, rhizoma Polygoni Cuspidati, radix et rhizoma Rhei, pericarpium Granati, fructus Gardeniae and cortex Phellodendri as plant materials, and taking two parts of plant extractive solutions corresponding to each plant material, 1g each part, and 14 groups in total; adding one part into 100ml deionized water, and uniformly mixing to obtain experiment group dyeing solutions (seven groups in total); the other group is added into 100ml of the natural modifier solution prepared in the step (1) and uniformly mixed, and the mixture is stirred for 24 hours at the constant temperature of 40 ℃ to obtain a dyeing solution of a comparison group (seven groups in total).

(3) Dyeing:

cutting 5g of pure cotton woven fabric to obtain 14 pieces, respectively immersing the pure cotton woven fabric into dyeing solutions of an experimental group and a comparison group, putting a dyeing cup into a small sample color testing machine, controlling the temperature (3 ℃/min, 60 ℃ and 30 min), and performing dyeing treatment to obtain the experimental group 1-7 and the comparison group 1-7 respectively.

(4) The test groups 1 to 7 and the comparative groups 1 to 7 were respectively subjected to dyeing depth K/S and dyeing fastness test to obtain Table 1.

Table 1: color fastness contrast of dyed cotton fabrics

As can be seen from Table 1, the natural plant extracts of flos Sophorae Immaturus, rhizoma Polygoni Cuspidati, radix et rhizoma Rhei and pericarpium Granati have good dyeing property after being mixed with natural modifier, wherein the color fastness of rhizoma Polygoni Cuspidati and radix et rhizoma Rhei after dyeing is poor. After mixing the natural vegetable dye of gardenia and phellodendron with the natural modifier, the color depth is reduced to some extent, and the color fastness is poor. And (3) screening out the flos sophorae, flos sophorae and pericarpium sophorae as main components of the yellow pasty antibacterial vegetable dye by combining the dyeing depth and the dyeing fastness.

Example 2

In this example, an optimization experiment of the proportion of plant raw material components was performed as follows:

the proportion of plant extracts corresponding to the three plant raw materials of pagodatree flower bud, pagodatree flower and pomegranate rind has a direct influence on the dyeing depth, a three-factor three-level orthogonal test (table 2) is designed, and the mixing proportion of the three plant raw materials in the plant extracts is optimized.

(1) Preparing a natural modifier solution:

weighing 5g of natural modifier (namely 1g of each natural modifier) by the mass ratio of collagen, animal gelatin, sodium caseinate, soy protein and quaternary ammonium salt chitosan of 1:1:1:1; after blending, the mixture was slowly and uniformly dissolved in an aqueous solution at 40℃to prepare 1L of a natural modifier solution (i.e., 5g/L of a natural modifier solution).

(2) Preparation of the dyeing solution

10% (o.w.f.) dye extracts were weighed according to the proportions in Table 3, added to 100ml of the natural modifier solutions, respectively, and 100ml of each of the dyeing solutions in different proportions was prepared, and stirred at a constant temperature of 40℃for 24 hours to prepare the dyeing solutions.

(3) Dyeing

The pure cotton woven fabric was cut into 5g cloth sample, after wetting, immersed in the dyeing solution, the dyeing cup was put into a sample color tester, after dyeing, the dyeing depth K/S and the color fastness were tested, and the results are shown in Table 3 and Table 4.

Table 2: orthogonal test table for optimal proportion of natural plant dye

Horizontal level	Sophora flower extract	Sophora flower bud extract	Pomegranate rind extract
				1	1	1	1
2	2	2	2
				3	3	3	3

Table 3: orthogonal experimental result and analysis of optimal proportion of natural plant dye

Sequence number	Sophora flower extract	Sophora flower bud extract	Pomegranate rind extract	K/S
					3-1	1	1	1	6.19
3-2	1	2	2	6.83
					3-3	1	3	3	7.36
3-4	2	2	3	7.59
					3-5	2	3	1	6.79
3-6	2	1	2	6.81
					3-7	3	3	1	7.68
3-8	3	1	3	7.43
					3-9	3	2	2	6.29
K1	6.79	6.81	6.88
					K2	7.06	6.90	6.64
K3	7.13	7.27	7.46
					R	0.34	0.46	0.82

Table 4: color fastness contrast of dyed cotton fabrics

As is clear from Table 4, the effect of the pomegranate rind on the dyeing depth K/S of the pure cotton woven fabric is greatest by taking the dyeing depth K/S as an evaluation standard, and then the effect is the pagodatree flower bud and the pagodatree flower bud. The color fastness after mixing is improved, and the improvement degree is not greatly different. And (3) combining factors such as dyeing depth K/S, dyeing fastness and raw material cost, and finally selecting the sophora flower extracting solution: pagodatree flower bud extracting solution: the weight ratio of the pomegranate rind extract is 2:2:3.

Example 3

The screening experiment of the natural modifier type is carried out in the embodiment, and the specific process is as follows:

(1) Preparing a dyeing solution:

mixing the extracting solutions corresponding to the three plant raw materials of the pagodatree flower bud, the pagodatree flower and the pomegranate rind according to the mass ratio of 2:2:3; 0.5L of the staining solution was formulated at 10% (o.w.f.).

(2) Preparing a natural modifier solution:

1g of collagen, animal gelatin, sodium caseinate, soybean protein and quaternary ammonium salt chitosan are respectively weighed and slowly and uniformly dissolved into a dyeing solution at 40 ℃ to prepare 100ml of modified dyeing solution.

(3) 5g of pure cotton woven fabric was cut out, wetted and immersed in the modified dyeing solution, the dyeing cup was put into a sample color tester, and after dyeing, the dyeing depth K/S color fastness test was performed, and the results are shown in Table 5.

Table 5: color fastness contrast of dyed cotton fabrics

As can be seen from table 5: the effect of the animal gelatin, the sodium caseinate and the quaternary ammonium salt chitosan on improving the dyeing color depth is obvious.

Example 4

In this example, an optimization experiment of the component proportion of the natural modifier was performed as follows:

different mixing ratios of three natural modifiers of quaternary ammonium salt chitosan, sodium caseinate and animal gelatin have direct influence on dyeing depth, three-factor three-level orthogonal tests (Table 6) are designed, and the mixing ratio of the three modifier raw materials in the natural modifiers is optimized.

(1) Preparing a dyeing solution:

mixing the extracting solutions corresponding to the three plant raw materials of the pagodatree flower bud, the pagodatree flower and the pomegranate rind according to the mass ratio of 2:2:3; 1L of the staining solution was prepared according to 8% (o.w.f.).

(2) Preparing a natural modifier solution:

5% (o.w.f.) of the components required for the natural modifier were weighed according to the proportions shown in Table 7, and slowly and uniformly dissolved in 100ml of the above-mentioned dyeing solution at 40℃to prepare a modified dyeing solution.

(3) Dyeing

The pure cotton woven fabric was cut into 5g cloth sample, after wetting, immersed in the dyeing solution, the dyeing cup was put into a sample color tester, after dyeing, the dyeing depth K/S and the color fastness were tested, and the results are shown in Table 7 and Table 8.

Table 6: orthogonal test table for optimal proportion of natural modifier

Horizontal level	Quaternary ammonium salt chitosan	Casein acid sodium salt	Animal gelatin
				1	0.1	1	1
2	0.2	2	2
				3	0.3	3	3

Table 7: orthogonal experimental result and analysis of optimal proportion of natural modifier

Table 8: color fastness contrast of dyed cotton fabrics

As is clear from Table 7, animal gelatin has the greatest effect on the depth of dyeing K/S of pure cotton woven fabric, followed by sodium caseinate and quaternary ammonium salt chitosan, using the depth of dyeing K/S as an evaluation criterion. The color fastness after mixing is improved, and the improvement degree is not greatly different. And (3) combining factors such as dyeing depth K/S, dyeing fastness and raw material cost, and finally selecting animal gelatin: sodium caseinate: the mass ratio of the quaternary ammonium salt chitosan is as follows: 3:1:0.3.

Example 5

The applicant carried out the following experiments with respect to the effect of the natural preservative on the dye of the present case:

(1) Mixing the extracting solutions corresponding to the three plant raw materials of the pagodatree flower bud, the pagodatree flower and the pomegranate rind according to the mass ratio of 2:2:3 to obtain a mixed extracting solution.

(2) Mixing animal gelatin, sodium caseinate and quaternary ammonium salt chitosan according to the mass ratio of 3:1:0.3 to obtain the natural modifier solution. Mixing the vegetable dye extract with a natural modifier solution to obtain a dye solution, and uniformly dividing the dye solution into A, B, C, D parts.

(3) Nisin (0.01%/1) was added to A, natamycin (0.01%/1) was added to B, tea polyphenol (0.01%/1) was added to C, and no substance was added to D.

(4) And (3) placing the four groups of dye solutions in the step (3) into a constant temperature incubator at 25 ℃ for heat preservation, and observing the bacterial growth state on the surface of the mixed extracting solution after heat preservation for 1, 4, 7, 10 and 13 days respectively. The colony count was observed and recorded to give Table 9.

Table 9: colony count of extract

As shown in table 9, compared with the blank group D, the effect of the three A, B, C groups on the quality guarantee effect of the dye is more obvious, and the deterioration and mildew phenomena of the dye are obviously reduced; A. b, C compared with three groups, nisin has better antibacterial and antiseptic properties than natamycin and tea polyphenol, so nisin: natamycin: the mass ratio of the tea polyphenols is 1:1:0.5.

In the following dyeing process, the dyeing liquid takes a natural modifier, a natural preservative and a plant extract as main dyeing components, and experiments of the dyeing process are carried out.

Example 6

The embodiment carries out the same bath dyeing mode of the natural modifier and the dye, and the specific process is as follows:

(1) Dye liquor is composed of: the yellow pasty antibacterial vegetable dye comprises a vegetable extract which is prepared by mixing 160g of pagodatree flower bud extract, 160g of pagodatree flower extract and 240g of pomegranate rind extract; the natural modifier is prepared by mixing 90g of animal gelatin, 30g of sodium caseinate and 9g of quaternary ammonium salt chitosan, the natural preservative is prepared by mixing 3.2g of nisin, 3.2g of natamycin and 1.6g of tea polyphenol, the plant extract, the natural modifier and the preservative are uniformly mixed at 40 ℃ to form a plant dye paste, the plant dye paste is weighed according to 20% (o.w.f.), a warm water material at 40 ℃ is stirred uniformly and then is used as a dye solution to be left for standby.

(2) Putting 4kg of pure cotton woven fabric into a jig dyeing machine, and adjusting parameters of the jig dyeing machine to be as follows: the bath ratio is 1:15, the rotating speed is 20r/min, and the heating rate is 2 ℃/min. The dyeing process comprises the following steps: after normal temperature charging, heating to 60 ℃ and preserving heat for 30min, adding 3g/L mordant alum, and preserving heat for 30min. The water washing process comprises the following steps: cleaning (normal temperature is multiplied by 20min+60 ℃ is multiplied by 20min), sampling and drying.

Comparative example 1

This embodiment is identical to the arrangement of embodiment 6, except that:

the content of natural dye in the vegetable dye paste is calculated according to the weight of the vegetable dye paste in the embodiment 6, the vegetable dye extract with the same content is weighed and spray-dried to prepare vegetable dye powder, and then warm water is used for dyeing according to the process in the embodiment 6.

Comparative example 2

This embodiment is identical to the arrangement of embodiment 6, except that:

(1) Taking 4kg of pure cotton woven fabric, placing the pure cotton woven fabric into a jig dyeing machine, firstly carrying out modification treatment, namely melting a natural modifier (the natural modifier is prepared by mixing 90g of animal gelatin, 30g of sodium caseinate and 9g of quaternary ammonium salt chitosan) with warm water at 40 ℃, and heating to 60 ℃ and preserving heat for 20min.

(2) The content of natural dye in the vegetable dye paste is calculated according to the weight of the vegetable dye paste in the embodiment 6, the vegetable dye extract with the same content is weighed and spray-dried to prepare vegetable dye powder, and then warm water is used for dyeing according to the process in the embodiment 6.

Example 7

The dye of the embodiment does not add a natural modifier, but uses a different bath mode of the natural modifier and the dye that the natural modifier is used for modifying and then dyeing the fabric, and the specific process is as follows:

(1) Dye liquor is composed of: the plant extract is prepared by mixing 160g of pagodatree flower bud extract, 160g of pagodatree flower extract and 240g of pomegranate rind extract; the natural preservative is prepared by mixing 3.2g of nisin, 3.2g of natamycin and 1.6g of tea polyphenol, uniformly mixing the plant extract and the preservative at 40 ℃ to form a plant dye paste, weighing the plant dye paste according to 20% (o.w.f.), uniformly stirring the plant dye paste with warm water at 40 ℃ for standing, and uniformly stirring the plant dye paste to serve as a dye solution for standing.

(2) Taking 4kg of pure cotton woven fabric, melting natural modifier (the natural modifier is prepared by mixing 90g of animal gelatin, 30g of sodium caseinate and 9g of quaternary ammonium salt chitosan) with warm water at 40 ℃, heating to 60 ℃, preserving heat for 20min, and placing the modified cotton woven fabric in a jig dyeing machine with the parameters of: the bath ratio is 1:15, the rotating speed is 20r/min, and the heating rate is 2 ℃/min. The dyeing process comprises the following steps: after normal temperature charging, heating to 60 ℃ and preserving heat for 30min, adding 3g/L mordant alum, and preserving heat for 30min. The water washing process comprises the following steps: cleaning (normal temperature is multiplied by 20min+60 ℃ is multiplied by 20min), sampling and drying.

Comparative example 3

This embodiment is identical to the arrangement of embodiment 7, except that:

the content of natural dye in the plant dye paste is calculated according to the weight of the plant dye paste in the embodiment 7, the plant extract with the same content is weighed and spray-dried, the plant extract is prepared into plant dye powder, and the plant dye powder is used as dye liquor after warm water treatment.

The pure cotton woven fabrics of the example 6, the example 7, the comparative example 1 and the comparative example 2 are cut and sewn into lining cloth, and perspiration fastness, blister fastness and rubbing fastness are respectively rated after being tested according to the national standard GB 31701-2015; the K/S value of the dyeing depth was measured, and the K/S value of the dyed pure cotton fabric was evaluated by using a Datacolor-400 type color measuring and matching instrument, and the result is shown in Table 10.

Table 10: table for comparing different dyeing effects and color fastness of cotton fabrics

The data in Table 10 shows that:

(1) Comparative example 6 and comparative example 1: when the paste vegetable dye is adopted for dyeing, the K/S value of the fabric is 6.3; when the powder vegetable dye is used for dyeing, the K/S value of the fabric is only 5.3, and the acid perspiration resistance and the color fastness are weakened. Under the condition of the plant dye with the same quality, the pasty plant dye has better effect on color depth than powder. This trend also exhibited the same trend in the comparison of example 7 and comparative example 3.

(2) Comparative example 6 and example 7: example 6, in which the modifier is co-bathed with the vegetable dye, under the same ingredients and parameters, the fabric K/S value is 6.3; in example 7, where the modifier and the vegetable dye are in different baths, the K/S value of the fabric is 6.5, and the color depth K/S effect of the different baths is better, but the color fastness difference is not great. This trend also shows the same trend in comparative example 2 and comparative example 3.

(3) Comparative example 1 compares with comparative example 2: although all the powder agents are adopted, the K/S of the comparative example 2 modified by the modifier is reduced from 5.3 to 3.4, and the color depth is obviously reduced; the color fastness is superior to that of the fabric of comparative example 2 modified without adding the natural modifier.

(4) Comparative example 1 compares with comparative example 3: the K/S value of comparative example 3 is slightly higher than that of comparative example 1 because: the adsorption capacity of the unmodified pure cotton woven fabric (comparative example 1) to the powdery vegetable dye was lower than that of the modified pure cotton woven fabric (comparative example 3), resulting in a slightly inferior dyeing depth relative to the modified pure cotton woven fabric.

Claims (10)

1. The vegetable dye is characterized by comprising the following components in parts by weight:

plant extract: 60-80 parts by mass of a lubricant,

natural modifier: 5-10 parts by mass of a metal alloy,

the balance of deionized water,

the plant extract is selected from flos Sophorae Immaturus extract, rhizoma Polygoni Cuspidati extract, radix et rhizoma Rhei extract, pericarpium Granati extract, fructus Gardeniae extract, and cortex Phellodendri extract,

the natural modifier is a mixture of collagen, animal gelatin, sodium caseinate, soy protein and quaternary ammonium salt chitosan.

2. A vegetable dye according to claim 1, characterized in that: the plant extract is a mixture of pagodatree flower bud extract, pagodatree flower extract and pomegranate rind extract, and the weight ratio of the pagodatree flower bud extract to the pagodatree flower extract to the pomegranate rind extract is 2:2:3.

3. A vegetable dye according to claim 1, characterized in that: the natural modifier is a mixture of animal gelatin, sodium caseinate and quaternary ammonium salt chitosan, and the mass ratio of the animal gelatin to the sodium caseinate to the quaternary ammonium salt chitosan is 3:1:0.3.

4. A vegetable dye according to claim 1, characterized in that: also comprises natural preservative with the addition amount of 0.1-0.5 parts by mass.

5. A vegetable dye according to claim 4, characterized in that: the natural preservative is selected from one or more of nisin, natamycin and tea polyphenol.

6. A vegetable dye according to claim 4, characterized in that: the natural preservative is a mixture of nisin, natamycin and tea polyphenol, and the mass ratio of nisin to natamycin to tea polyphenol is 1:1:0.5.

7. A method for preparing the vegetable dye according to claim 1, which comprises the following steps:

(1) Preparing a plant extract: pulverizing plant raw materials into powder, soaking the powder in water at a bath ratio of 1:10-20 and a temperature of 60-100 ℃, stirring at a constant speed for 30-60 min, extracting, and concentrating to obtain plant extract;

(2) Preparing a natural modifier solution: weighing a natural modifier, and adding the natural modifier into a 40-60 ℃ aqueous solution in a stirring state to obtain a natural modifier solution;

(3) Preparing a vegetable dye: and heating the plant extract to 40-60 ℃, adding the natural modifier solution, fully and uniformly stirring, and cooling to obtain the yellow pasty plant dye.

8. A method of dyeing a cellulose-containing fabric using the vegetable dye of claim 1, comprising the steps of:

(1) Sample preparation: adding water into the fabric containing cellulose fibers according to a bath ratio of 1:10-20 for full wetting;

(2) Feeding: weighing the vegetable dye according to claim 1, adding water at 40-45 ℃ and uniformly stirring to obtain an o.w.f. 1-15% dye liquor;

(3) Dyeing: placing the wet fabric in a dye liquor, wherein the heating rate is 1-3 ℃/min, the temperature is increased to 60 ℃, and the heat preservation time is 30-60 min; alum 1-5 g/L is added, and the heat preservation is continued for 30-60 min;

(4) Washing with water and drying.

9. The method for dyeing a cellulose-containing fabric using a vegetable dye according to claim 8, wherein the washing with water in step (4) is performed by: cleaning with water, washing with soap at normal temperature of 20min plus 60 ℃ of 20min, cleaning with water at 60 ℃ of 20min, sampling and drying at normal temperature of 20min.

10. A dyeing method of applying the vegetable dye of claim 1 to cellulose-containing fiber fabrics, which is characterized by respectively weighing a natural modifier and a vegetable extract:

(1) Pre-modification: adding a hydration material into a fabric containing cellulose fibers according to the weight of o.w.f. 3-5%, heating to 60 ℃, and preserving heat for 20-30 min to finish pre-modification, wherein the natural modifier is one or more selected from collagen, animal gelatin, sodium caseinate, soybean protein and quaternary ammonium salt chitosan;

(2) Feeding: adding water into the plant extract to form dye liquor with the concentration of o.w.f. 1-15%;

(3) Dyeing: placing the pre-modified fabric in a dye liquor, wherein the heating rate is 1-3 ℃/min, the temperature is increased to 60 ℃, and the heat preservation time is 30-60 min; alum 1-5 g/L is added, and the heat preservation is continued for 30-60 min;

(4) Washing: cleaning with water, washing with soap at normal temperature of 20min plus 60 ℃ of 20min, cleaning with water at 60 ℃ of 20min, sampling and drying at normal temperature of 20min.