Silk glue protection process and high-sericin silk

Abstract

The invention provides a silk glue protection technology and high-sericin silk, and relates to the field of mulberry silk processing technologies, in particular to the field of mulberry silk processing technologies. The invention relates to a silk glue protection process, which comprises the following steps: immersing a raw silk white body into a treating fluid to fully fix sericin, and then sequentially washing, degumming and rinsing to obtain high-sericin silk, the treating fluid is prepared from 1 to 5 weight percent of waterborne acrylic resin, 0.5 to 3 weight percent of guanidine salt, 5 to 10 weight percent of silane modified polyurethane and the balance of water; a cross-linking agent is fully permeated into a raw silk white body through a chemical cross-linking method, and then acrylic resin and silane modified polyurethane are fully reacted with sericin under specific conditions to form a molecular winding structure to change the chemical structure and properties of the sericin, so that the fixation of the sericin is realized, the water solubility of the sericin is reduced, and the boiling resistance and alkali resistance of the sericin are improved; meanwhile, the hand feeling of raw silk white body products is improved.

Description

Technical Field

[0001] The invention relates to the field of mulberry silk processing technology, in particular to a silk rubber preservation technology and high-silk rubber silk. Background Art

[0002] Silk is mainly composed of fibroin and sericin. The sericin is coated on the outside of the fibroin, accounting for about 20-30% of the mass of silk. The sericin and fibroin are composed of 18 kinds of amino acids, containing about 97% pure protein. The fiber obtained by the silk finishing process is a high-grade fabric raw material. The chemical and physical properties of the fiber material directly affect the comfort and feel of the fabric, dyeing uniformity and other properties. Therefore, the functional processing and finishing of silk fibers has always been a key area of ​​concern in the silk industry.

[0003] The sericin layer in silk is prone to swelling, rupture and hydrolysis of protein fibers in weak acid and weak alkali aqueous solutions, and silk swells in water and becomes hard and hard after drying. In traditional silk weaving and dyeing processes, sericin is usually removed, and only the soft and elastic silk part is used, which leads to waste of sericin resources and environmental pollution. Therefore, it is of great significance to fix sericin on the surface of silk to retain it.

[0004] In recent years, the research, promotion and application of sericin fixation technology have not only solved this problem to a certain extent, but also given silk functional characteristics such as fullness, thickness and stiffness. The sericin fixation finishing agents currently studied at home and abroad mainly include chromium salts, small molecule aldehydes, tannic acid, synthetic resins, triazine compounds containing active chlorine, epoxy compounds and other types. There are many varieties, but the performance varies, and there are advantages and disadvantages to a certain extent.

[0005] Chromium salts have excellent solidifying effects, but they are colored, and trivalent chromium salts are easily oxidized into carcinogenic hexavalent chromium salts under high temperature and high pH conditions, so they are rarely used in solidifying treatments.

[0006] Formaldehyde is a traditional method in the early stage of the development of glue solidification, and the effect is good. However, formaldehyde substances are highly volatile, carcinogenic, and harmful to human health. With the requirements of eco-friendly silk fabrics, formaldehyde has gradually withdrawn from the glue solidification application process. Although glutaraldehyde has a good glue solidification effect (good cross-linking effect with protein), it is easy to yellow, which is not conducive to the processing of white and light-colored silk. It can only be used for the glue solidification treatment of dark silk products, which greatly limits the application scope of glutaraldehyde glue solidification.

[0007] Tannic acid lacks a certain amount of strong covalent bonding for the chemical cross-linking of silk protein, its cross-linking and solidifying effect is weak, and it itself has a darker color. Using it to finish silk will give the silk a darker color and have a great impact on the dyeing properties of silk. This method is rarely used.

[0008] Zhou Hongxiang et al. reported the use of three epoxy compounds for silk sericin fixation finishing. However, when these three compounds are used in the silk finishing process, a catalyst KSCN (toxic substance) needs to be added, and these three substances must be solidified in an organic solvent such as isopropyl alcohol. After treatment, unreacted epoxides on the silk need to be washed away with solvents such as acetone. This method is limited to laboratory theoretical research.

[0009] Although the above-mentioned treatment process fixes sericin, its alkali resistance is limited and does not meet the formaldehyde content standard requirements; although the low-temperature reeling and low-temperature dyeing and finishing processes attempt to retain sericin, their essential problems are not solved, the product is troublesome to use and maintain, and the scope of application is limited. Summary of the invention

[0010] Purpose of the invention: The present invention provides a silk sericin preservation process and high sericin silk, which can retain most of the sericin in silk cocoons or raw silk blanks after processing, and the sericin is not easily dissolved in subsequent processes, while ensuring its soft feel, improving the utilization rate of silk and dyeing uniformity, reducing environmental pollution, and expanding the style and application range of silk fabrics.

[0011] Technical Solution

[0012] In the first aspect, the present application provides a silk glue preservation process: A silk glue preservation process comprises the following preparation steps: The raw silk blank is immersed in a treatment liquid, reacted in a water bath at 90-100°C for 1-2 hours to allow the sericin to be fully fixed, and then washed, degummed and rinsed in sequence to obtain high-sericin silk; the treatment liquid is 1-5wt% of aqueous acrylic resin, 0.5-3wt% of guanidine salt, 5-10wt% of silane-modified polyurethane and the balance of water.

[0013] Furthermore, the treatment liquid is 2-5wt% water-based acrylic resin, 0.5-3wt% guanidine salt, 5-8wt% silane-modified polyurethane and the balance water.

[0014] Furthermore, the treatment liquid is 2-4 wt% of water-based acrylic resin, 1-2 wt% of guanidine salt, 5-8 wt% of silane-modified polyurethane and the balance of water.

[0015] Furthermore, the bath ratio of the raw silk blank immersed in the treatment liquid is 1:(10-30).

[0016] Furthermore, the water-based acrylic resin includes a combination of one or more of hydroxyethyl acrylate copolymer, hydroxypropyl acrylate copolymer and polyethylene glycol-modified hydroxyethyl acrylate copolymer.

[0017] Furthermore, the water-based acrylic resin is a styrene-acrylic emulsion type water-based acrylic resin.

[0018] Furthermore, the silane-modified polyurethane includes one of SX3430E, SX6735D, S888E, GENIOSIL® STP~E15, STP~E35 of AGC Corporation; SPUR+* 1015, SPUR+* 3030, and SPUR+* 3040 of Momentive Corporation.

[0019] Furthermore, the guanidine salt includes one or a combination of guanidine hydrochloride, guanidine nitrate, guanidine carbonate, and guanidine nitrate.

[0020] Further, the degumming process is as follows: The washed and dried raw silk blank is placed in a 0.2% sodium carbonate solution and boiled at 95°C for 30-60 min, with a bath ratio of 1:(50-100).

[0021] Furthermore, the rinsing process is to boil the degummed raw silk blank in 100° C. boiling water for 10 to 30 minutes.

[0022] In a second aspect, the present application provides a high-silk silk: The high-silk rubber silk of the present application is prepared by the silk rubber preservation process of the present application.

[0023] Beneficial effects: 1. A silk sericin preservation process, comprising the following preparation steps: immersing raw silk blanks in a treatment liquid to allow the sericin to be fully fixed, and then washing, degumming and rinsing in sequence to obtain high-sericin silk; the treatment liquid comprises 1.5-3wt% water-based acrylic resin, 1-2wt% guanidine salt and 5-10wt% silane-modified polyurethane and the remainder water; the cross-linking agent is fully infiltrated into the raw silk blanks by a chemical cross-linking method, and then under specific conditions, the water-based acrylic resin and the silane-modified polyurethane react fully with the sericin to form a molecular entanglement structure to change the chemical structure and properties of the sericin, reduce its water solubility, and improve its boiling resistance and alkali resistance, thereby achieving the fixation of the sericin and improving the feel of the raw silk blank products.

[0024] 2. Further use of an appropriate amount of guanidine salt can reduce the sericin that is not combined with amino resin and silane-modified polyurethane during the sericin preservation process, further improve the feel of high sericin silk and reduce the uneven dyeing of high sericin silk (the second point highlights the role of guanidine salt in the combination of water-based acrylic resin, guanidine salt and silane-modified polyurethane). DETAILED DESCRIPTION

[0025] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments.

[0026] Embodiment 1, a silk glue preservation process, comprising the following preparation steps: Sericin preservation process: The raw silk blank (using golden silk, 22.5 momme) and the treating liquid are reacted in a water bath ratio of 1:20 in a 95 ℃ water bath for 1.5 hours to fully fix the sericin. The treating liquid is 2.5 wt% water-soluble styrene acrylic emulsion type water-based acrylic resin (average molecular weight is 8600), 2wt% guanidine hydrochloride and 8wt% silane-modified polyurethane (using SPUR+*1015 from Momentive) and the balance is water.

[0027] Washing process: The raw silk blank after the water bath reaction is washed with water for 5 times to remove the unreacted cross-linking reactants on the surface of the raw silk blank.

[0028] Degumming process: The washed and fully dried raw silk blank is placed in a 0.2% sodium carbonate solution and boiled at 95 °C for 50 min, with a bath ratio of 1:80.

[0029] Rinsing process: Boil the degummed raw silk in 100 ℃ boiling water for 10 min, repeat 3 times to remove residual alkali, and then dry to obtain high-sericin silk.

[0030] Embodiment 2, a silk glue preservation process, comprising the following preparation steps: Sericin preservation process: The raw silk blank and the treatment liquid are reacted in a water bath ratio of 1:10 in a 90 ℃ water bath for 2 hours to fully fix the sericin. The treatment liquid is 1.5wt% water-soluble styrene acrylic emulsion type water-based acrylic resin, 1wt% guanidine carbonate and 10wt% silane-modified polyurethane (using SPUR+* 3030 from Momentive) and the balance water.

[0031] Washing process: The raw silk blank after the water bath reaction is washed with water for 3 times to remove the cross-linking reactants that have not completely reacted on the surface of the raw silk blank.

[0032] Degumming process: The washed and fully dried raw silk blank is placed in a 0.5% sodium carbonate solution and boiled at 90 °C for 60 min, with a bath ratio of 1:100.

[0033] Rinsing process: Boil the degummed raw silk in 100 ℃ boiling water for 10 minutes, repeat twice to remove residual alkali, and then dry to obtain high-sericin silk.

[0034] Embodiment 3, a silk glue preservation process, comprising the following preparation steps: Sericin preservation process: The raw silk blank and the treatment liquid are reacted in a water bath ratio of 1:30 in a 90 ℃ water bath for 1 hour to fully fix the sericin. The treatment liquid is 3wt% water-soluble styrene acrylic emulsion type water-based acrylic resin, 2wt% guanidine carbonate and 5wt% silane-modified polyurethane (using SPUR+* 3030 from Momentive) and the balance water.

[0035] Washing process: The raw silk blank after the water bath reaction is washed with water for 5 times to remove the unreacted cross-linking reactants on the surface of the raw silk blank.

[0036] Degumming process: Place the washed and fully dried raw silk blank in a 0.1% sodium carbonate solution and boil it at 98°C for 30 minutes, with a bath ratio of 1:50.

[0037] Rinsing process: Boil the degummed raw silk in 100℃ boiling water for 10 minutes, repeat 3 times to remove residual alkali, and then dry to obtain high-sericin silk.

[0038] Example 4, a silk rubber preservation process, is different from Example 1 in that the amount of styrene acrylic emulsion type water-based acrylic resin in the treatment liquid is 1wt%.

[0039] Example 5, a silk rubber preservation process, is different from Example 1 in that the amount of styrene acrylic emulsion type water-based acrylic resin in the treatment liquid is 3wt%.

[0040] Example 6, a silk rubber preservation process, is different from Example 1 in that the amount of styrene acrylic emulsion type water-based acrylic resin in the treatment liquid is 4wt%.

[0041] Example 7, a silk rubber preservation process, is different from Example 1 in that the amount of styrene acrylic emulsion type water-based acrylic resin in the treatment liquid is 5wt%.

[0042] Example 8, a silk rubber preservation process, is different from Example 1 in that the amount of guanidine hydrochloride used in the treatment solution is 0.5wt%.

[0043] Example 9, a silk rubber preservation process, is different from Example 1 in that the amount of guanidine hydrochloride used in the treatment solution is 3wt%.

[0044] Comparative Example 1 is a silk rubber preservation process, which is different from Example 1 in that styrene acrylic emulsion type water-based acrylic resin is not used in the treatment liquid.

[0045] Performance Testing sample: Test sample: the silk sample after degumming treatment in Examples 1 to 9; Comparative example sample: a degummed silk sample of the comparative example; Control sample: silk sample without degumming treatment.

[0046] 1. Dissolution rate: The dissolution loss rate is calculated by the following formula: Dissolution loss rate = (W1~W2) / W1*100%; Wherein, W1 is the dry weight of the untreated silk sample, and W2 is the dry weight of the silk sample after degumming treatment according to the embodiment or the comparative example; the negative sign indicates that the dry weight increases after degumming treatment after the glue-preserving treatment, and the smaller the dissolution loss rate, the better the glue-preserving effect. The experimental results are shown in Table 1.

[0047] 2. In case of boiling water or weak alkali: The test samples, comparative samples and blank samples were placed in boiling water for 10 minutes respectively, and the state changes of the samples and the mass loss before and after treatment were observed and felt. The experimental results are shown in Table 2.

[0048] The test samples, comparative samples and blank samples were placed in a sodium carbonate solution with a concentration of 2 g / L for 10 min, and the state changes of the samples and the mass loss before and after treatment were observed and felt. The experimental results are shown in Table 2.

[0049] Table 1. Test results of silk sample dissolution loss rate obtained by using Examples 1 to 9 and Comparative Example 1 Group Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Dissolution rate (%) 21.28 1.69 16.76 2.06 6.81 -1.12 -1.35 -1.83 4.37 6.65 As shown in Table 1, the larger the dissolution loss rate, the more sericin is dissolved and the worse the sericin preservation effect. Therefore, Examples 1, 3, 5, 6, and 7 have relatively good sericin preservation effects, while Comparative Example 1 has a dissolution loss of more than 20%, indicating that the sericin is almost completely removed and can hardly be preserved.

[0050] Table 2. Changes of silk samples obtained from Examples 1 to 9 and Comparative Example 1 and control silk samples after being treated with boiling water and alkali solution Performance Indicators Embodiments 1 to 9 Comparative sample Control samples Boiling water situation No change in softness or hardness, basically no loss in quality Hardening, quality loss 3~8% Sericin falls off and becomes hard after drying, with a mass loss of 10~15% In case of weak alkali No change in softness or hardness, basically no loss in quality Sericin falls off, becomes soft after drying, and loses 10~20% of its quality After the sericin is completely removed and dried, it becomes soft and loses 20~25% of its quality. The performance of the example samples, comparative example samples and blank samples were tested.

[0051] 3. Warp Slippage: GB / T 21294~2024 was used to test the warp slippage of silk fabrics. The test results are shown in Table 3.

[0052] 4. Softness and color According to the factory inspection process, factory inspectors manually evaluate the softness of silk fabrics by touching and observing them.

[0053] The inspection method is as follows: The inspection staff has more than 2 years of inspection experience and can grade silk fabrics.

[0054] Each inspector randomly checks each roll of silk fabric 10 times, and each inspection takes an area of ​​30×30cm as the unit inspection area to evaluate the softness and color of the test sample. Two inspectors evaluate according to the above evaluation method, and the average score is taken. The results are shown in Table 3; the scoring criteria are as follows: 1 point: The softness and color are obviously inferior to the original silk fabric, which has a significant impact on sales. The fabric cannot be sold even after being downgraded.

[0055] 1~2 points (excluding 2): The soft feel and color are not as good as the original silk fabric, and the fabric can be sold after being downgraded.

[0056] 2~3 points (excluding 3): The softness and color are slightly inferior to the original silk fabric, but there is no need to downgrade.

[0057] 3~4 points: The soft feel and color are slightly similar to the original silk fabric and no need to downgrade.

[0058] Table 3. Evaluation results of warp slippage, softness and color performance of silk fabrics of Examples 1 to 9 and Comparative Example 1 Group Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Control group Warp Slippage (mm) 1.75 1.88 1.78 1.80 1.72 1.71 1.68 1.77 1.81 1.90 1.91 Hand feel and color 4 2.5 4 3.6 4 4 4 3.8 3.5 2 - In the present application, high-sericin silk is treated with a treatment liquid, in which a water-based acrylic resin, guanidine salt and silane-modified polyurethane are used, and the dosage of the water-based acrylic resin, guanidine salt and silane-modified polyurethane is further optimized, so that the obtained silk retains a higher level of sericin, and at the same time the obtained silk and silk fabrics have higher mechanical properties, softness, dyeing gloss and more uniform dyeing properties, so that the obtained silk and silk fabrics have excellent comprehensive properties.

[0059] As shown in Table 3, the data of different embodiments show that when the sericin retention effect is good, the adhesion between the silk threads is enhanced, making the silk threads less likely to slip. In this case, the fabric's slippage data will be reduced, that is, the anti-slippage performance will be enhanced. In addition, when the sericin is completely removed, the silk fabric will lose its original color and become soft. If the sericin is retained without the sericin retention treatment, the hand feel will become harder. After the sericin retention treatment, the sericin is retained while maintaining a soft hand feel, the higher the score; therefore, embodiments 1, 3, 5, 6, and 7 have relatively good sericin retention effects; more preferred are embodiments 1, 3, 5, and 6.

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A silk glue preservation process, characterized in that: The method comprises the following preparation steps: The raw silk blank is immersed in a treatment liquid, reacted in a water bath at 90-100°C for 1-2 hours to allow the sericin to be fully fixed, and then washed, degummed and rinsed in sequence to obtain silk with a high sericin content; the treatment liquid is 1-5wt% of an aqueous acrylic resin, 0.5-3wt% of a guanidine salt, 5-10wt% of a silane-modified polyurethane and the remainder is water.

2. The silk glue preservation process according to claim 1, characterized in that: The treatment liquid comprises 2-5 wt% of water-based acrylic resin, 0.5-3 wt% of guanidine salt, 5-8 wt% of silane-modified polyurethane and the balance of water.

3. The silk glue preservation process according to claim 2, characterized in that: The treatment liquid comprises 2-4 wt% of water-based acrylic resin, 1-2 wt% of guanidine salt, 5-8 wt% of silane-modified polyurethane and the balance of water.

4. The silk glue preservation process according to claim 1, characterized in that: The bath ratio of the raw silk blank immersed in the treatment liquid is 1: (10-30).

5. The silk glue preservation process according to claim 1, characterized in that: The acrylic resin includes one or more of a hydroxyethyl acrylate copolymer, a hydroxypropyl acrylate copolymer and a polyethylene glycol-modified hydroxyethyl acrylate copolymer.

6. The silk glue preservation process according to claim 5, characterized in that: The acrylic resin is a styrene acrylic emulsion type water-based acrylic resin.

7. The silk glue preservation process according to claim 1, characterized in that: The silane-modified polyurethane includes SX3430E, SX6735D, S888E, GENIOSIL® STP E15, STP E35 of AGC Corporation; SPUR+* 1015, SPUR+* 3030, SPUR+* 3040 of Momentive Corporation; and the guanidine salt includes guanidine hydrochloride, guanidine nitrate, guanidine carbonate, guanidine nitrate, or a combination of the above.

8. The silk glue preservation process according to claim 1, characterized in that: The degumming process is as follows: The washed and dried raw silk blank is placed in a 0.1~0.5% sodium carbonate solution and boiled at 90~98 ℃ for 30~60 min, with a bath ratio of 1:(50~100).

9. The silk glue preservation process according to claim 1, characterized in that: The rinsing process is to boil the degummed raw silk blank in 100°C boiling water for 10 to 30 minutes.

10. Silk prepared by the silk glue preservation process according to any one of claims 1 to 9.