A method for antibacterial finishing of silk

Abstract

The invention belongs to the field of textile engineering and discloses a method for antibacterial finishing of silk. The method comprises: wetting the silk with an ergothioneine (EGT) solution, spraying with a hexamethylphosphoric acid triamide (HMPA) solution containing an acylating agent and a silver salt, and after reaction, washing and drying. After the surface of the silk is grafted and modified by the method, the antibacterial property of the fabric is improved.

Description

Technical Field

[0001] The invention belongs to the field of textile engineering, and particularly relates to a method for antibacterial finishing of silk. Background Art

[0002] The natural protein structure of silk fabrics makes them an important textile material with good affinity to the human body, but it also becomes a suitable place for bacteria to breed, multiply and spread. Therefore, the research and development of silk fabrics with antibacterial properties has social significance and economic benefits.

[0003] Silver-based antimicrobial agents have a strong antimicrobial effect in fabric antimicrobial finishing and dominate the inorganic antimicrobial market. Currently, the application of silver-based antimicrobial agents in silk fabrics is primarily through fabric post-finishing, whereby the surface of the silk fabric is coated or impregnated with an antimicrobial agent to form an antimicrobial layer. However, this process is complex, costly, and results in poor bonding strength, which does not meet environmental standards and limits its applicability. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method for antibacterial finishing of silk, which improves the antibacterial properties of the fabric after surface grafting modification of the silk.

[0005] In order to solve the above technical problems, the technical solutions provided by the present invention are as follows:

[0006] A method for antibacterial finishing of silk, comprising the following steps:

[0007] S1: The silk is washed and dried, and then double-dipped and double-rolled with thioneine ergot (EGT) solution;

[0008] S2: spraying the silk obtained in step S1 with a hexamethylphosphoramide (HMPA) solution containing an acylating agent and a silver salt for reaction;

[0009] S3: Washing and drying the silk in step S2.

[0010] Preferably, in step S1, the concentration of the EGT solution is 10-15 g / L.

[0011] Preferably, in step S1, the bath ratio of the second dipping and the second rolling is 30:1-50:1, and the rolling rate is 80-85%.

[0012] Preferably, in step S2, the acylating agent is one of malonyl chloride, 1,4-cyclohexanediyl chloride or oxalyl chloride.

[0013] Preferably, in step S2, the silver salt is one of silver chloride, silver cyanide and silver thiosulfate.

[0014] Preferably, in step S2, in the hexamethylphosphoric triamide (HMPA) solution containing the acylating agent and the silver salt, the concentration of the acylating agent is 25-38 g / L, and the concentration of the silver salt is 460-850 mg / L.

[0015] Preferably, in step S2, the spraying amount is 15-20 mL / m 2 silk.

[0016] Preferably, in step S2, the reaction temperature is 8-15° C. and the reaction time is 5-8 min.

[0017] Compared with the prior art, the finishing method of the present invention utilizes the hydroxyl, sulfhydryl, amino groups of serine, cysteine, tyrosine, lysine and other residues on the surface of silk to graft EGT through acylation reaction to form N + -COO - layer, which can enhance the hydrophilicity of silk and selectively adsorb negatively charged bacteria on the surface. The thioimidazole group can + The formation of coordination bonds can kill bacteria adsorbed on the surface in situ without causing the loss of silver. Therefore, this finishing method can maintain the antibacterial effect for a long time. In addition, the acylation reaction bridging itself also requires Ag. + It participates in the reaction as a catalyst and accelerates the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The silk surface obtained by the antibacterial finishing method of the present invention forms N + -COO - Schematic diagram of the layer structure. DETAILED DESCRIPTION

[0019] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0020] The present invention provides a method for antibacterial finishing of silk, comprising: washing and drying the silk, then dipping and rolling it with an EGT solution, then spraying it with an HMPA solution of an acylating agent and a silver salt, and reacting it. After the reaction is complete, washing it with water and drying it to obtain silk with antibacterial properties. The hydroxyl, sulfhydryl, and amino groups of serine, cysteine, tyrosine, lysine, and other residues on the surface of the silk are grafted with EGT through an acylation reaction to form N + -COO - Layer, such as Figure 1 As shown. + -COO -The layer can enhance the hydrophilicity of silk and selectively adsorb negatively charged bacteria on the surface. The thioimidazole group can + It forms a coordination bond to kill bacteria adsorbed on the surface in situ without causing the loss of silver.

[0021] Example 1

[0022] A method for antibacterial finishing of silk, comprising the following steps:

[0023] The silk was washed and dried, then double-dipped and double-rolled with 13g / L EGT solution at a bath ratio of 40:1 and a rolling rate of 83%. The silk was then sprayed with HMPA solution containing 28g / L oxalyl chloride and 750mg / L silver cyanide at a spray rate of 18mL / m 2 Silk, react at 10℃ for 6 minutes; finally wash and dry.

[0024] Example 2

[0025] A method for antibacterial finishing of silk, comprising the following steps:

[0026] The silk was washed and dried, and then double-dipped and double-rolled with 10g / L EGT solution, with a bath ratio of 30:1 and a rolling rate of 85%. Then, the silk was sprayed with HMPA solution containing 38g / L malonyl chloride and 460mg / L silver chloride at a spraying rate of 15mL / m 2 Silk, react at 8℃ for 8 minutes; finally wash and dry.

[0027] Example 3

[0028] A method for antibacterial finishing of silk, comprising the following steps:

[0029] The silk was washed and dried, then double-dipped and double-rolled with 15 g / L EGT solution at a bath ratio of 50:1 and a rolling rate of 80%. The silk was then sprayed with HMPA solution containing 25 g / L 1,4-cyclohexanediyl chloride and 850 mg / L silver thiosulfate at a spray rate of 20 mL / m 2 Silk, react at 15℃ for 5 minutes; finally wash and dry.

[0030] Comparative Example 1 (no EGT)

[0031] The silk was washed and dried, and then sprayed with HMPA solution containing 28 g / L oxalyl chloride and 750 mg / L silver cyanide at a spraying rate of 18 mL / m 2 Silk, react at 10℃ for 6 minutes; finally wash and dry.

[0032] Comparative Example 2 (without oxalyl chloride)

[0033] The silk was washed and dried, then dipped and rolled twice with 13g / L EGT solution, with a bath ratio of 40:1 and a rolling rate of 83%. The silk was then sprayed with HMPA solution containing 750mg / L silver cyanide at a spray rate of 18mL / m 2 Silk, react at 10℃ for 6 minutes; finally wash and dry.

[0034] Comparative Example 3 (Silver Cyanide-Free)

[0035] The silk was washed and dried, and then dipped and rolled twice with 13g / L EGT solution, with a bath ratio of 40:1 and a rolling rate of 83%. Then, the silk was sprayed with HMPA solution containing 28g / L oxalyl chloride at a spraying rate of 18mL / m 2 Silk, react at 10℃ for 6 minutes; finally wash and dry.

[0036] Antimicrobial testing methods

[0037] The antibacterial effects of the silk fabrics treated with the methods of Examples 1-3 and Comparative Examples 1-3 on Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans were tested using the AATCC 100-2004 standard. The results are shown in Table 1.

[0038] Table 1

[0039]

[0040] From the data in Table 1, we can know that compared with the comparative example, the silk treated by the method of the present invention has better antibacterial and bactericidal properties against Gram-positive bacteria, Gram-negative bacteria and fungi. + It is effectively retained on the surface of silk, but has poor binding force and will be lost in large quantities after washing. However, the finishing method of comparative example 3 does not have Ag + The acylation reaction is not complete and there is almost no antibacterial effect.

[0041] Silver Release

[0042] According to GB / T 3921-2008 "Textiles - Tests for Colour Fastness - Colour Fastness to Washing with Soap", the silks treated by the methods of Examples 1-3 and Comparative Examples 1-2 were washed five times in a standardized manner. The washing liquids were collected and the silver content therein was determined. The silver loss rate was calculated based on the total amount of silver in the silk. The results are shown in Table 2.

[0043] Table 2

[0044] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Silver loss rate (%) 0.13±0.01 0.18±0.02 0.15±0.02 21.31±1.28 35.92±1.88

[0045] As shown in Table 2, after five standardized washes, the silver loss rate for silk treated according to the methods of Examples 1-3 was less than 0.2%. However, the silver loss rate for silk treated according to the methods of Comparative Examples 1 and 2 exceeded 20%, more than 100 times that of the examples. Because silver doesn't form a coordination compound, its bond to the silk relies on weak adsorption and is easily washed away in a washing environment. Consequently, the antibacterial effect decreases with increasing wash cycles.

[0046] The present invention provides a method and concept for antibacterial finishing of silk. There are many methods and approaches to realize the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention. All components not specified in this embodiment can be realized by existing technologies.

[0047] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for antibacterial finishing of silk, characterized in that: The steps include: S1: Wash and dry the silk and then dip and roll it with thioneine EGT solution; S2: spraying the silk obtained in step S1 with a hexamethylphosphoric acid triamide (HMPA) solution containing an acylating agent and a silver salt for reaction; S3: washing and drying the silk obtained in step S2.

2. A method for antibacterial finishing of silk according to claim 1, characterized in that: In step S1, the concentration of the EGT solution is 10-15 g / L.

3. The method for antibacterial finishing of silk according to claim 1, characterized in that: In step S1, the bath ratio of the second dipping and the second rolling is 30:1-50:1, and the rolling rate is 80-85%.

4. The method for antibacterial finishing of silk according to claim 1, characterized in that: In step S2, the acylating agent is one of malonyl chloride, 1,4-cyclohexanediyl chloride and oxalyl chloride.

5. The method for antibacterial finishing of silk according to claim 1, characterized in that: In step S2, the silver salt is one of silver chloride, silver cyanide and silver thiosulfate.

6. The method for antibacterial finishing of silk according to claim 1, characterized in that: In step S2, in the HMPA solution containing the acylating agent and the silver salt, the concentration of the acylating agent is 25-38 g / L, and the concentration of the silver salt is 460-850 mg / L.

7. The method for antibacterial finishing of silk according to claim 6, characterized in that: In step S2, the spraying amount is 15-20 mL / m 2 silk.

8. The method for antibacterial finishing of silk according to claim 1, characterized in that: In step S2, the reaction temperature is 8-15°C and the reaction time is 5-8 minutes.

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