Tea extract modified silk cotton and preparation method thereof

Abstract

The invention discloses tea extract modified silk floss and a preparation method thereof, the method comprising the following steps: 1) extracting green tea with water to obtain tea extract; 2) pre-treating mulberry silkworm cocoons to obtain silk floss; 3) soaking the silk floss with tea extract and performing heating modification treatment to obtain the silk floss; the preparation method is simple to operate, requires mild conditions, is low in cost, has great market potential, and the obtained modified silk floss contains tea polyphenols, metal minerals, vitamins, theanine and other effective ingredients, has excellent antibacterial and water-washing resistance, and also has good skin care and deodorizing effects.

Description

Technical Field

[0001] The technology of the present invention relates to silk floss, in particular to silk floss modified by tea extract, and also to a preparation method of silk fiber modified by tea extract, belonging to the field of textile technology. Background Art

[0002] Silk is a natural protein fiber that is light, soft and fine in nature. It has a pleasing luster, soft feel and excellent moisture absorption and breathability. It has always been used as a high-end textile raw material in the textile field. Silk fiber can not only be processed into clothing fabrics, but also used in home bedding and decoration, such as silk (silk floss) quilts, curtains, etc. In addition, in order to make full use of the excellent characteristics of silk protein, silk fiber is often processed into powder, which is widely used in many fields such as textiles, food, cosmetics and biomedicine.

[0003] Silk is mainly composed of 75-80% fibroin and 20-25% sericin. The right amount of sericin can make the monofilaments have good bundling during weaving, and can also make the refined fabric fluffy and comfortable. Most of the current silk scouring processes have the problems of poor cleanliness and high residual glue content. At the same time, because silk is a natural protein fiber, there is a situation of excessive microorganisms after long-term use. Studies have shown that tea polyphenols have antibacterial and anti-inflammatory, skin whitening and anti-aging effects. Introducing tea polyphenols into products can effectively resist the damage of ultraviolet rays and free radicals to the skin. For example, in Chinese patent CN113152083A, silk fibers are immersed in tea polyphenol solution, and silane coupling agents and catalysts are added to modify silk fibers under vacuum conditions, which can make silk fibers have good antibacterial effects. However, this method is complicated, and its tea polyphenols are obtained by using special ionic liquid-assisted ethanol / ammonium sulfate extraction. The extraction process mainly obtains tea polyphenols, and most of the other components are lost. In addition, the modification process requires the addition of silane coupling agents and catalysts, the reaction conditions are harsh, and the production cost is increased, which is not conducive to industrial production. Summary of the invention

[0004] In view of the defects of the prior art, the first object of the present invention is to provide a silk floss modified with tea extract. The silk floss modified with tea extract has a light tea fragrance, and introduces a variety of effective ingredients such as tea polyphenols, minerals, vitamins, theanine, trace metals, etc., which not only gives it excellent antibacterial, skin care and deodorizing effects, but also has good modification stability and excellent water-washing resistance. After multiple washings, it can still maintain its excellent performance.

[0005] The second object of the present invention is to provide a method for preparing tea extract modified silk cotton with simple operation, mild conditions and low production cost.

[0006] In order to achieve the above technical objectives, the present invention provides a method for preparing tea extract modified silk floss, which comprises the following steps:

[0007] 1) extracting green tea with water to obtain tea extract;

[0008] 2) pre-treating silkworm cocoons to obtain silk floss;

[0009] 3) The silk cotton is soaked in tea extract and subjected to heat modification treatment to obtain the silk cotton.

[0010] The key to the technical solution of the present invention is to use green tea water extract to modify silk floss. Green tea is rich in ingredients, including tea polyphenols, trace metal elements, vitamins, amino acids and other main ingredients. The active ingredients obtained by extracting with different solvents and under different conditions are very different. Water extraction can extract water-soluble tea polyphenols, trace metal ions, amino acids, vitamins and other effective ingredients. These ingredients are perfectly compounded and used to modify silk floss to obtain unexpected technical effects, which can give silk floss excellent antibacterial, skin care and deodorizing effects. In addition, the silk is made fluffy and soft by pre-treating the silkworm cocoons to remove part of the sericin, which is beneficial for full contact with the tea extract during the subsequent soaking process, so that the effective ingredients in the tea are loaded on the silk fibers. Then, the silk is subjected to a heat modification treatment, and the coordination and complexation between metal ions, amino acids, tea polyphenols and other components, as well as the physical and chemical bonding between the silk cotton and the silk fiber, are utilized to greatly improve the loading stability between the effective ingredients in the tea extract and the silk cotton. At the same time, the silk fiber itself has a large specific area, which can provide a large number of loading sites for the effective ingredients in the tea, thereby obtaining modified silk fibers with better water washing resistance and stability.

[0011] As a preferred solution, the water is soft water. Soft water is used as the extraction solvent mainly because tap water or mineral water will react with the active ingredients in the tea leaves, resulting in unstable effects. Soft water can extract the active ingredients in the tea leaves to a greater extent and avoid unnecessary side reactions.

[0012] As a preferred solution, the extraction conditions are: the mass ratio of green tea to water is 1:40-50, the extraction temperature is 80-100°C, and the time is 20-30 minutes. Further preferably, the mass ratio of green tea to water is 1:45-50. The amount of green tea has a great influence on the performance of silk fiber. When the amount of green tea is too high, it will not only affect the appearance and color of silk cotton, but also the content of the extracted tea active ingredients loaded on the silk fiber will not increase significantly; when the amount of green tea is too low, the prepared silk fiber has poor anti-washing and antibacterial effects. If the extraction temperature is too high, the active ingredients in the tea are easily destroyed, and if the extraction temperature is too low, it cannot be fully extracted.

[0013] As a preferred solution, the pretreatment includes silking cotton, beating cotton, boiling cotton and washing cotton.

[0014] As a preferred solution, the silk floss is sprayed with a NaOH solution having a mass percentage concentration of 0.4-0.5%, and the silk floss temperature is 60-70°C. Alkaline spraying can make the silkworm cocoons looser, which is conducive to winding the cocoons on the roller of the silk floss machine. The concentration of the NaOH solution and the silk floss temperature directly affect the quality of the silk floss. When the concentration of the NaOH solution is too high or the silk floss temperature is too low, the strength and toughness of the silk floss decrease, and degumming and pupa skin phenomena will occur. When the concentration of the NaOH solution is too low or the silk floss temperature is too high, the silkworm cocoons are not loose enough, which is not conducive to the preparation of silk floss.

[0015] As a preferred solution, during the beating process, the wet weight of each piece of silk cotton is controlled to be between 2 and 2.5 kg.

[0016] As a preferred solution, the cotton boiling liquid used in the cotton boiling process includes the following mass percentage components: NaOH 5-15%; hydrogen peroxide 5-15%; mercerizing soap 1-8%; sodium silicate 1-5%; water is the balance; the conditions in the cotton boiling process are controlled as follows: temperature is 90-100°C; time is 90-100min; the mass ratio of the silk cotton sheet to the cotton boiling liquid is 1:40-50. In the present invention, the mercerizing soap can be hydrolyzed in water to generate free alkali and fatty acids; and the free alkali gradually reacts with sericin to form salt, promotes the hydrolysis of sericin, and then improves the solubility of sericin to achieve the purpose of degumming. The alkalinity of some mercerizing soap after hydrolysis gradually disappears, which promotes the further hydrolysis of mercerizing soap, keeps the pH value of the cotton boiling liquid within a certain range, and reduces the damage to the silk fibroin. At the same time, adding a certain concentration of hydrogen peroxide can oxidize colored substances and salts, promote the dissociation of cocoon silk, and make the silk color white. If the concentration exceeds the range, the oxidation is too strong and damages the quality of the silk. By adding a certain amount of weakly alkaline sodium silicate, the pH value of the cotton boiling liquid can be stabilized and the rapid decomposition of hydrogen peroxide can be inhibited.

[0017] As a preferred solution, 5-10% tartaric acid is added during the cotton boiling process. Tartaric acid is an organic acid degumming agent. Adding tartaric acid can further reduce the residual glue content, ensure the silk sericin dissolution rate, and thus improve the mechanical properties of silk.

[0018] As a preferred solution, the cleaning solvent is soft water and the cleaning instrument is an ultrasonic instrument. After the silk floss is cleaned with soft water and ultrasonic waves, the sericin on the silk floss can be better stripped off, so that the silk floss and the tea extract can fully react with each other.

[0019] As a preferred solution, the mass ratio of the tea extract to the mulberry cotton is 1:6 to 10, and more preferably 1:8 to 10. When the mass of the mulberry cotton is too high, the rinsing times will be high, while when the mass of the mulberry cotton is too low, the color of the mulberry cotton will be affected.

[0020] As a preferred solution, the soaking time is 5 to 10 minutes; the conditions for the heating modification treatment are: the temperature is 70 to 85°C and the time is 5 to 10 minutes. Soaking and heating can help the silk to fully absorb the effective ingredients in the tea extract. After soaking, the silk floss is dehydrated and then dried at a temperature of 60 to 75°C for 2 to 3 hours. When the silk floss is completely dried, the silk floss containing tea extract is obtained.

[0021] The present invention also provides a tea extract modified silk cotton, which is obtained by the preparation method. The tea extract modified silk cotton of the present invention uses tea extract to modify silk cotton, and introduces the effective ingredients in the tea extract into silk cotton through chemical modification and physical loading. The effective ingredients such as tea polyphenols, minerals, vitamins and theanine in the tea extract, which are water-soluble, give the silk cotton good antibacterial, skin care and deodorizing effects. For example, tea polyphenols have bactericidal and anti-inflammatory effects, and adding them to silk cotton can improve the antibacterial and antibacterial functions of silk cotton, and have good skin care effects; the minerals contain more than 20 kinds, mainly iron, manganese, and calcium, and also contain selenium, zinc, germanium, etc. These elements are essential trace elements for the human body, such as iron, manganese, calcium, etc., and vitamins added to silk cotton also have a certain effect on preventing acne and pimples. Theanine is the main component of the fragrance in tea. Adding it to silk cotton can make the silk cotton have a fresh tea flavor, thereby playing a deodorizing effect, and at the same time modifying the silk cotton to make its surface more silky.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0023] 1) The silk floss material containing tea extract of the present invention contains tea polyphenols, minerals, vitamins, and theanine, among which tea polyphenols have bactericidal and anti-inflammatory effects, and can make the silk floss have excellent antibacterial and antifungal functions. Adding minerals and vitamins to the silk floss also has a certain effect on preventing acne and pimples. Theanine is the main component of the fragrance of tea. Adding it to the silk floss can make the silk floss have a fresh tea flavor, thereby playing a deodorizing effect.

[0024] 2) The silk cotton material containing tea extract of the present invention has excellent water-washing resistance. After being washed many times, the material still contains relatively high contents of tea polyphenols and trace elements.

[0025] 3) The preparation method of silk cotton containing tea extract of the present invention is simple to operate, mild in conditions and low in preparation cost. The soap-alkali method and tartaric acid are used in combination to greatly reduce the content of residual glue, thereby ensuring the mechanical and chemical properties of silk. At the same time, soft water and ultrasonic cleaning can not only fully remove the sericin on the glass silk, but also save 20% of water. DETAILED DESCRIPTION

[0026] The following examples are only specific descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. For ordinary technicians in the technical field, any improvements made without departing from the present invention should be deemed to be within the scope of protection of the present invention.

[0027] The silkworm cocoons used in the following examples and comparative examples are all high-quality silkworm cocoons with a grade of 5A or above after drying.

[0028] Embodiment 1:

[0029] Green tea with a tea polyphenol content of 32.3 wt.% was selected and mixed with soft water in a mass ratio of 1:50 and heated at 90°C for 30 minutes. The tea leaves were precipitated and filtered to obtain a tea extract.

[0030] The silkworm cocoons are placed in a silk floss machine and sprayed with an alkaline solution of 0.5% by mass concentration of NaOH solution. The temperature is set to 70°C. After the silk layer of the cocoons becomes loose, the cocoons are wound on the drum of the silk floss machine for silk floss treatment. The silkworm cocoons treated with silk floss are placed in a cotton beating machine to obtain a cotton floss with a wet weight of 2.5 kg. The cut cotton floss is placed in a cotton boiling liquid composed of 5% NaOH, 10% hydrogen peroxide, 8% mercerizing soap, 3% sodium silicate, and the remainder is water. The mass ratio of the cotton floss to the cotton boiling liquid is 1:40. At the same time, 5wt.% tartaric acid is added, and the cotton boiling liquid is kept in a slightly boiling state at 90°C for 90 minutes. The silk floss after cotton degumming is cleaned with soft water and ultrasonic washing equipment, and the sericin on the silk is peeled off to obtain silk floss.

[0031] After soaking the tea extract and mulberry cotton at a mass ratio of 1:10 for 10 minutes, the solution was heated to 80°C and boiled for 10 minutes. After soaking, the silk cotton was dehydrated and then dried at 75°C for 3 hours. When the silk cotton was completely dried, the tea extract modified silk cotton was obtained.

[0032] Embodiment 2:

[0033] Green tea with a tea polyphenol content of 32.3 wt.% was selected and mixed with soft water in a mass ratio of 1:45 and heated at 95°C for 30 minutes. The tea leaves were precipitated and filtered to obtain a tea extract.

[0034] The silkworm cocoons are placed in a silk floss machine and sprayed with an alkaline solution of 0.4% by mass concentration of NaOH solution. The temperature is set to 60°C. After the cocoon silk layer becomes loose, the cocoon silk is wound on the drum of the silk floss machine for silk floss treatment. The silkworm cocoons treated with silk floss are placed in a cotton beating machine to obtain a cotton floss with a wet weight of 2.5kg. The cut cotton floss is placed in a cotton boiling liquid composed of 10% NaOH, 5% hydrogen peroxide, 5% mercerizing soap, 5% sodium silicate, and the remainder is water. The mass ratio of the cotton floss to the cotton boiling liquid is 1:50. At the same time, 8wt.% tartaric acid is added, and the cotton boiling liquid is kept in a slightly boiling state at 90°C for 90 minutes. The silk floss after cotton degumming is cleaned with soft water and ultrasonic washing equipment, and the sericin on the silk is peeled off to obtain silk floss.

[0035] After soaking the tea extract and mulberry cotton at a mass ratio of 1:8 for 10 minutes, the solution was heated to 85°C and boiled for 10 minutes. After soaking, the silk cotton was dehydrated and then dried at 75°C for 3 hours. When the silk cotton was completely dried, the tea extract modified silk cotton was obtained.

[0036] Comparative Example 1

[0037] The difference from Example 1 is that commercially available tea polyphenols are directly used to replace tea leaves, wherein the amount of tea polyphenols used is measured according to the amount of tea polyphenols in the tea leaves.

[0038] Performance Test:

[0039] 1) Determination method of tea polyphenols content in modified silk cotton (GB / T8313-2018):

[0040] Testing instrument: UV spectrophotometer

[0041] Test process: The sample is extracted twice with 70% methanol aqueous solution in a 70°C water bath for 10 min. The extract is colorized with Folin phenol reagent and the absorbance is measured with a spectrophotometer. The absorbance of the sample is washed and tested.

[0042] 2) Determination method of metal element content in modified silk floss:

[0043] Test instrument: Inductively coupled plasma optical emission spectrometer

[0044] Test process: Take 0.2g sample and digest it with microwave, then analyze the metal elements with inductively coupled plasma spectrometer:

[0045] 3) Determination method of main components in tea polyphenols (GB / T20944.3-2008 10.1.2):

[0046] Testing instrument: high performance liquid chromatograph;

[0047] Test method: After the sample is extracted with an organic solvent, the extract is concentrated by low-temperature vacuum rotary evaporation, fixed to volume, filtered, and the filtrate is measured by high performance liquid chromatography.

[0048] The composition of commercially available tea polyphenols was determined, and the main component it contained was epigallocatechin, as well as a small amount of epicatechin and epicatechin gallate (catechin and epigallocatechin gallate were not detected). The main trace metal elements it contained were iron and calcium.

[0049] Table 1 Comparison of test data of green tea extract modified silk cotton and tea polyphenol modified silk cotton (before washing)

[0050]

[0051]

[0052] Table 2 Comparison of tea polyphenol detection data in green tea extract modified silk cotton and tea polyphenol modified silk cotton (after washing 10 times)

[0053] sample Tea polyphenols before washing (mg / kg) After tea polyphenols washing (10 times) Example 1 45378 20％ Example 2 40029 18％ Comparative Example 1 399.42 Not detected

[0054] Table 3 Comparison of metal ion detection data in green tea extract modified silk cotton and tea polyphenol modified silk cotton (after washing 10 times)

[0055]

Claims

1. A method for preparing tea extract modified silk floss, characterized in that: The following steps are involved: 1) Extracting green tea with soft water to obtain tea extract; 2) Pre-treating silkworm cocoons to obtain silk floss; 3) The silk floss is soaked in tea extract and subjected to heat modification treatment to obtain the silk floss; The extraction conditions are as follows: the mass ratio of green tea to soft water is 1:40-50, the extraction temperature is 80-100°C, and the extraction time is 20-30 minutes; The pretreatment includes silking cotton, beating cotton, boiling cotton and washing cotton, and tartaric acid with a mass percentage of 5-10% of silk cotton is added during the boiling process; The mass ratio of the tea extract to the silk floss is 1:6-10; The cotton-boiling process is to put the silk cotton pieces into the cotton-boiling liquid for boiling treatment, and the cotton-boiling liquid includes the following components in percentage by weight: the cotton-boiling liquid is in a slightly boiling state; NaOH 5~15%; Hydrogen peroxide 5~15%; Mercerizing soap 1~8%; Sodium silicate 1~5%; The balance is water; the mass ratio of silk floss to boiled floss liquid is 1:40~50; The conditions during the cooking process are controlled as follows: temperature is 90-100° C. and time is 90-100 min.

2. The method for preparing a tea extract modified silk floss according to claim 1, characterized in that: In the process of making the silk floss, a NaOH solution with a mass percentage concentration of 0.4-0.5% is used for spraying, and the temperature of the silk floss is 60-70°C.

3. The method for preparing a tea extract modified silk floss according to claim 2, characterized in that: During the beating process, the wet weight of each piece of silk cotton is controlled to be 2-2.5 kg.

4. The method for preparing tea extract modified silk floss according to claim 1, characterized in that: The soaking time is 5 to 10 minutes; The conditions of the heating modification treatment are: temperature of 70-85° C. and time of 5-10 min.

5. A tea extract modified silk floss, characterized in that: Obtained by the preparation method according to any one of claims 1 to 4.

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