Antibacterial flexible silica gel rubber compound and preparation method thereof

Abstract

The invention relates to the field of high polymer material processing, in particular to an antibacterial flexible silica gel rubber compound and a preparation method thereof. Comprising a belt body, the belt body is formed by vulcanizing an antibacterial tear-resistant silicone rubber material, and the antibacterial tear-resistant silicone rubber material is prepared from the following raw materials in percentage by weight: 70-90% of silicone rubber compound, 8-20% of EMH-carboxyl-terminated polycaprolactone blend and the balance of a processing aid. The EMH-carboxyl-terminated polycaprolactone blend and the silicone rubber compound are compounded and can be fully and uniformly mixed, and under the vulcanization action of the vulcanizing agent, the prepared antibacterial tear-resistant silicone rubber material, watchbands obtained after vulcanization molding and other products have relatively good biocompatibility, antibacterial property and flexibility, and the antibacterial tear-resistant silicone rubber material has the advantages of good mechanical properties, good wear resistance, good wear resistance, good wear resistance and the like. When the watchband is in contact with the human epidermis for a long time, the phenomena of bacterium breeding, allergy, dermatitis and the like can be reduced, so that the survival of human epidermis cells is maintained for a long time, and the practicability of the watchband is improved.

Description

Technical Field

[0001] The present application relates to the field of polymer material processing, and more specifically, to an antibacterial flexible silicone rubber compound and a preparation method thereof. Background Art

[0002] Silicone rubber has outstanding advantages, including resistance to high and low temperatures, resistance to chemical corrosion, good insulation, odorlessness, non-toxicity, softness, skin-friendliness, and excellent biocompatibility. It has a wide range of applications and is often used in electronics, medical care, automobiles, aerospace, and other fields. In areas that come into contact with the human body, especially in smart wearable devices, compounded silicone rubber can be used to make casings and seals for devices such as smart bracelets and smart watches. A watch strap refers to a band used to secure a watch to the wrist, and it does more than just secure the watch. Watch straps are usually made of metal materials, but metal materials have poor biocompatibility. Therefore, after contact with the skin, in vitro cells are prone to react and produce toxicity, reducing cell activity, and thus easily causing allergies, dermatitis, and other phenomena. Watch straps made of silicone rubber are widely used because of their softness, elasticity, and skin-friendliness.

[0003] Since silicone rubber watch straps are usually in close contact with human skin during use, sweat and oil on human skin will be adsorbed on the silicone rubber watch straps when worn for a long time, forming a humid environment, thereby promoting bacterial growth. When the watch strap with bacteria comes into contact with the surface of human skin, the microbial community on the surface of the human skin will be unbalanced, and then cause skin infections, allergies and other phenomena. These lesions will affect the normal function and activity of skin cells, especially for people with more sensitive skin or children, where the above phenomena are more obvious, and further research is needed. Summary of the Invention

[0004] In order to obtain better biocompatibility while achieving skin-friendly, soft and antibacterial properties, so that the manufactured watch strap is not prone to breeding bacteria or producing cytotoxic reactions after contacting the human skin surface, the watch strap can maintain cell survival for a long time during wearing, thereby improving the practicality of the watch strap, the present application provides an antibacterial and flexible silicone rubber compound and its preparation method.

[0005] In a first aspect, the present application provides an antibacterial flexible silicone rubber compound, which is composed of the following raw materials in percentage by weight: Silicone rubber compound 70-90% Antibacterial compound 8-25% The balance is processing aids; The antibacterial compound consists of an EMH-carboxyl-terminated polycaprolactone blend and nano silver, and the content of the nano silver in the antibacterial compound is less than or equal to 0.1 wt %.

[0006] Silicone rubber compound has excellent softness, skin affinity and biocompatibility, and can reduce skin scraping. The EMH-carboxyl-terminated polycaprolactone blend is obtained by blending and modifying EMH and carboxyl-terminated polycaprolactone. Among them, EMH is a ternary copolymer, that is, ethylene-acrylate-maleic anhydride copolymer with excellent compatibility. After blending with carboxyl-terminated polycaprolactone, it forms a material with good compatibility, antibacterial and biocompatibility, and promotes the uniform dispersion of nanosilver in its antibacterial composite system. The nanosilver and EMH-carboxyl-terminated polycaprolactone blend play a synergistic role, further improving the antibacterial properties. The EMH-carboxyl-terminated polycaprolactone blend is compounded with the silicone rubber compound and can be fully mixed. Under the vulcanization action of the vulcanizing agent, the antibacterial and tear-resistant silicone rubber material obtained is made. The watch strap obtained after vulcanization molding has better biocompatibility, antibacterial and softness. When the watch strap is in contact with the human epidermis for a long time, it can reduce the breeding of bacteria, allergies, dermatitis and other phenomena, thereby maintaining the survival of human epidermal cells for a long time and improving the practicality of the watch strap.

[0007] In addition, the content of nanosilver in the antibacterial composite of the present application is ≤0.1wt%, which can be combined with the EMH-carboxyl-terminated polycaprolactone blend of the present application to form an antibacterial composite with good antibacterial properties and good biocompatibility. After being blended with the silicone rubber compound, the watch strap and other products obtained after vulcanization have better antibacterial properties, biocompatibility and mechanical properties such as tear resistance, thereby improving its practicality.

[0008] Preferably, the silicone rubber compound is prepared from methyl silicone oil, hydroxy silicone oil, silazane, methyl vinyl rubber, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyldisiloxane, and bis-3-methacryloxypropylated tetramethyldisiloxane.

[0009] Methyl vinyl silicone rubber compound is an uncrosslinked compound that undergoes crosslinking and curing under the action of a vulcanizing agent. Methyl vinyl raw rubber has the advantages of high temperature resistance, good flexibility and good biocompatibility. The silicone rubber compound prepared by it with methyl silicone oil, hydroxy silicone oil, silazane, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyldisiloxane and bis-3-methylpropyleneoxypropylated tetramethyldisiloxane has good comprehensive performance. When the silicone rubber compound is blended and modified with an antibacterial composite agent (composed of an EMH-carboxyl-terminated polycaprolactone blend and nanosilver, with the content of nanosilver in the antibacterial composite agent ≤0.1wt%), the obtained antibacterial and tear-resistant silicone rubber material has better biocompatibility and at the same time plays the role of skin-friendly, soft and antibacterial. When the prepared watch strap comes into contact with the surface of human skin, it is not easy to breed bacteria or produce cytotoxic reactions. Therefore, the watch strap can maintain cell survival for a long time during wearing and is not prone to tearing and damage, thereby improving the practicality of the watch strap.

[0010] Preferably, the vulcanizing agent is silica gel platinum water.

[0011] Silicone platinum water is a catalyst-based process in which hydrogenated silicone oil reacts with vinyl double bonds to form a hydrosilylation reaction. When applied to silicone rubber compounds, this not only catalyzes but also crosslinks the rubber, improving the vulcanization efficiency of the antibacterial and tear-resistant silicone rubber. This also results in improved flexibility.

[0012] Preferably, the EMH-carboxyl terminated polycaprolactone blend is prepared from the following raw materials in percentage by weight: EMH 10-20% Carboxyl terminated polycaprolactone 60-80% Regenerated cellulose fiber powder 5-10% Polyethylene glycol-polydimethylsiloxane-polyethylene glycol 1-3%.

[0013] Regenerated cellulose fiber powder has excellent water absorption, air permeability, antibacterial properties, and good biocompatibility, while polyethylene glycol-polydimethylsiloxane-polyethylene glycol (PEG-PDMS-PEG) is a triblock copolymer that combines the advantages of polyethylene glycol (PEG) and polydimethylsiloxane (PDMS), and has wettability, dispersibility and biocompatibility. It can have low surface tension and lubricity, which helps to reduce the adhesion and aggregation between filler particles, thereby improving the dispersibility of regenerated cellulose fiber powder in the raw material system. Combined with carboxyl-terminated polycaprolactone and EMH, the obtained EMH-carboxyl-terminated polycaprolactone blend has excellent biocompatibility and better antibacterial and air permeability.

[0014] When EMH-carboxyl-terminated polycaprolactone blend is blended with silicone rubber compound, the watch strap can have better softness, antibacterial properties and breathability, reducing the growth of bacteria during use of the watch strap and avoiding the imbalance of bacterial colonies on the skin surface, which may cause the activity of skin cells.

[0015] Preferably, the regenerated cellulose fiber powder is chitin fiber powder and / or bamboo fiber powder.

[0016] Both chitin fiber powder and bamboo fiber powder have good biocompatibility, and have antibacterial and breathable properties. The EMH-carboxyl-terminated polycaprolactone blend prepared by combining EMH, carboxyl-terminated polycaprolactone, regenerated cellulose fiber powder, polyethylene glycol-polydimethylsiloxane-polyethylene glycol has good breathability, antibacterial properties, compatibility and biocompatibility. When used in the raw material system of antibacterial and tear-resistant silicone rubber materials, it is fully compatible with the silicone rubber compound, and further improves the biocompatibility, antibacterial properties and breathability of the antibacterial and tear-resistant silicone rubber material, reduces the bacterial growth of the watch strap during long-term use, or the occurrence of cytotoxic reactions, which may cause allergies, etc., so that the skin cells in contact with the watch strap can maintain their activity for a long time, thereby improving the practicality of the watch strap.

[0017] Preferably, the regenerated cellulose fiber powder has a particle size of 1-2 microns and a length of 5-10 microns.

[0018] The above particle size range can fully disperse the regenerated cellulose fiber powder in the raw material system, thereby achieving better air permeability and antibacterial properties. The watch strap made of antibacterial and tear-resistant silicone rubber material can reduce the growth of bacteria and the occurrence of allergies after long-term wear and contact with sweat, and can maintain cell survival for a long time, thereby improving the practicality of the watch strap.

[0019] Preferably, the average molecular weight of the carboxyl-terminated polycaprolactone is 5,000-10,000.

[0020] The above average molecular weight of carboxyl-terminated polycaprolactone is a weight average molecular weight. Within this range, it can be fully mixed with the silicone rubber compound and obtain better physical properties.

[0021] Preferably, the average molecular weight of the EMH is 20,000-50,000.

[0022] The average molecular weight of EMH can better promote the compatibility of silicone rubber compound and carboxyl-terminated polycaprolactone, so that the watch strap made of antibacterial and tear-resistant silicone rubber material has better antibacterial properties, softness and biocompatibility. The watch strap made of antibacterial and tear-resistant silicone rubber material can reduce the growth of bacteria and the occurrence of allergies after long-term wear and contact with sweat, and can maintain cell survival for a long time, thereby improving the practicality of the watch strap.

[0023] Preferably, the MH-carboxyl terminated polycaprolactone blend is prepared by the following method: According to weight percentage, regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol are weighed and mixed evenly to obtain a mixture A; carboxyl-terminated polycaprolactone and EMH are weighed and mixed evenly, crushed, dried, and sieved through 100-200 mesh to obtain a mixture B; then all of the mixture A is added to the mixture B, mixed evenly, and heated until the carboxyl-terminated polycaprolactone and EMH are melted, cooled, crushed, and sieved through 200-300 mesh to obtain an EMH-carboxyl-terminated polycaprolactone blend.

[0024] In the above preparation method, by mixing regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol, the regenerated cellulose fiber powder can be wetted and dispersed to avoid agglomeration, etc.; the carboxyl-terminated polycaprolactone and EMH are evenly mixed, crushed, dried, and sieved through 100-200 mesh to form a mixture B of small particles, which is easier to fully and evenly mix with the mixture A. After melting, cooling, crushing, and sieving through 200-300 mesh, the EMH-carboxyl-terminated polycaprolactone blend is obtained, which has excellent dispersibility, compatibility and biocompatibility, and has antibacterial properties and breathability. When it is compounded with silicone rubber compound, it can be fully mixed. The watch strap made of the obtained antibacterial and tear-resistant silicone rubber material has excellent performance. When worn for a long time, it is not easy to breed bacteria or cause dermatitis even after contact with sweat and oil, thereby reducing the phenomenon of reduced activity of epidermal cells at the position where the watch strap contacts the human body during long-term wear, thereby improving the practicality of the watch strap.

[0025] In a second aspect, the present application provides a method for preparing an antibacterial flexible silicone rubber compound, which is prepared by the following method: According to the percentage by weight, the silicone rubber compound, the processing aid and the antibacterial compound are weighed and mixed evenly to obtain the antibacterial and flexible silicone rubber compound.

[0026] The above process is simple to operate and has high production efficiency. It can fully mix the materials. After a vulcanization temperature of 130-175°C and a vulcanization time of 5-10 minutes, the resulting watch strap has excellent biocompatibility, antibacterial properties and softness. When the watch strap is in contact with the human epidermis for a long time, it can reduce the breeding of bacteria, allergies, dermatitis and other phenomena, thereby maintaining the survival of human epidermal cells for a long time and improving the practicality of the watch strap.

[0027] In summary, this application has the following beneficial effects: 1. Silicone rubber compounds exhibit excellent softness, skin affinity, and biocompatibility, reducing skin abrasion. EMH-carboxyl-terminated polycaprolactone blends are obtained by blending and modifying EMH with carboxyl-terminated polycaprolactone. EMH, a terpolymer of ethylene acrylate and maleic anhydride, exhibits excellent compatibility. When blended with carboxyl-terminated polycaprolactone, the EMH-carboxyl-terminated polycaprolactone blend is thoroughly mixed with the silicone rubber compound. Under the vulcanization action of a vulcanizing agent, the resulting antibacterial and tear-resistant silicone rubber material exhibits excellent biocompatibility, antibacterial properties, and softness. This reduces bacterial growth, allergies, and dermatitis associated with prolonged skin contact, thereby maintaining the survival of human epidermal cells and enhancing the watchband's practicality.

[0028] 2. The EMH-carboxyl-terminated polycaprolactone blend made from regenerated cellulose fiber, EMH, carboxyl-terminated polycaprolactone, regenerated cellulose fiber powder, polyethylene glycol-polydimethylsiloxane-polyethylene glycol has excellent air permeability, antibacterial properties, compatibility and biocompatibility. When used in the raw material system of antibacterial and tear-resistant silicone rubber materials, it is fully compatible with the silicone rubber compound and further improves the biocompatibility, antibacterial properties and air permeability of the antibacterial and tear-resistant silicone rubber materials, reduces the bacterial growth of the watch strap during long-term use, or the occurrence of cytotoxic reactions, which may cause allergies, etc., and enables the skin cells in contact with the watch strap to maintain activity for a long time, thereby improving the practicality of the watch strap. DETAILED DESCRIPTION

[0029] The present application is further described in detail below with reference to the embodiments.

[0030] Sources of some raw materials: Methyl vinyl silicone rubber compound, preferred manufacturer: Fuding Ruifeng Auto Parts Co., Ltd., model RF220; Silicone platinum water, the preferred manufacturer is Dongguan Zhongxin Silicone Material Co., Ltd., model ZX-BJ020, effective platinum content 1000-5000PPM; Molecular structure of carboxyl-terminated polycaprolactone: Polyethylene glycol-polydimethylsiloxane-polyethylene glycol, the molecular formula is [C2H4O]n[C2H6OSi]m[C2H4O]n, where m and n are both 10.

[0031] Preparation Example of EMH-Carboxyl-Terminated Polycaprolactone Blend Preparation Example 1 An EMH-carboxyl-terminated polycaprolactone blend is prepared by the following method: According to weight percentage, 5% regenerated cellulose fiber powder and 1% polyethylene glycol-polydimethylsiloxane-polyethylene glycol are weighed and mixed evenly to obtain a mixture A; 80% carboxyl-terminated polycaprolactone and 14% EMH are weighed and mixed evenly, crushed with a grinder, placed in an oven at 50°C for drying for 2 hours, and then sieved through 100 mesh to obtain a mixture B; then all of the mixture A is added to the mixture B and mixed evenly, and heated to 150°C to completely melt the carboxyl-terminated polycaprolactone and EMH, cooled to 35°C, crushed with a grinder, and sieved through 200 mesh to obtain an EMH-carboxyl-terminated polycaprolactone blend.

[0032] The regenerated cellulose fiber powder is chitin fiber powder. The particle size of the regenerated cellulose fiber powder is 1 micron and the length is 5 microns. The average molecular weight of the carboxyl-terminated polycaprolactone is 5000. The average molecular weight of EMH is 50,000.

[0033] Preparation Example 2 Preparation Example 2 differs from Preparation Example 1 in that the dosage and process parameters are different, as follows: According to weight percentage, 7% regenerated cellulose fiber powder and 2% polyethylene glycol-polydimethylsiloxane-polyethylene glycol are weighed and mixed evenly to obtain a mixture A; 70% carboxyl-terminated polycaprolactone and 21% EMH are weighed and mixed evenly, crushed with a grinder, placed in a 50° C. oven for drying for 2 hours, and then sieved through 150 mesh to obtain a mixture B; then all of the mixture A is added to the mixture B, mixed evenly, and heated to 150° C. to completely melt the carboxyl-terminated polycaprolactone and EMH, cooled to 35° C., crushed with a grinder, and sieved through 250 mesh to obtain an EMH-carboxyl-terminated polycaprolactone blend.

[0034] Preparation Example 3 Preparation Example 3 differs from Preparation Example 1 in that the dosage and process parameters are different, as follows: According to weight percentage, 10% regenerated cellulose fiber powder and 3% polyethylene glycol-polydimethylsiloxane-polyethylene glycol are weighed and mixed evenly to obtain a mixture A; 60% carboxyl-terminated polycaprolactone and 27% EMH are weighed and mixed evenly, crushed with a grinder, placed in a 50° C. oven for drying for 2 hours, and then sieved through 200 mesh to obtain a mixture B; then all of the mixture A is added to the mixture B, mixed evenly, and heated to 150° C. to completely melt the carboxyl-terminated polycaprolactone and EMH, cooled to 35° C., crushed with a grinder, and sieved through 300 mesh to obtain an EMH-carboxyl-terminated polycaprolactone blend.

[0035] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 2 is that the regenerated cellulose fiber powder is bamboo fiber powder.

[0036] Preparation Example 5 Preparation Example 5 is different from Preparation Example 2 in that the regenerated cellulose fiber powder is composed of chitin fiber powder and bamboo fiber powder in a weight ratio of 1:2.

[0037] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 5 is that the particle size of the regenerated cellulose fiber powder is 2 microns and the length is 10 microns.

[0038] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 5 is that the average molecular weight of the carboxyl-terminated polycaprolactone is 10,000.

[0039] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 5 is that the average molecular weight of EMH is 20,000.

[0040] Preparation Comparative Example Preparation Comparative Example 1 The difference between Preparation Comparative Example 1 and Preparation Example 1 is that an equal amount of regenerated cellulose fiber powder is replaced by carboxyl-terminated polycaprolactone.

[0041] Preparation Comparative Example 2 The difference between Preparation Comparative Example 2 and Preparation Example 1 is that an equal amount of polyethylene glycol-polydimethylsiloxane-polyethylene glycol is replaced by carboxyl-terminated polycaprolactone.

[0042] Preparation Comparative Example 3 The difference between Preparation Comparative Example 3 and Preparation Example 1 is that the regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol are replaced by carboxyl-terminated polycaprolactone in equal amounts. Example

[0043] Example 1 An antibacterial flexible silicone rubber compound is prepared by the following method: Silicone rubber compound: Methyl silicone oil, hydroxy silicone oil, silazane, methyl vinyl rubber, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyldisiloxane and bis-3-methacryloxypropylated tetramethyldisiloxane are put into a kneader at a weight ratio of 10:5:2:100:30:1:1, heated to 155°C at a stirring rate of 5°C / min and 50 r / min, and stirred for 2 h to prepare a silicone rubber compound.

[0044] According to weight percentage, 90% silicone rubber compound, 8% antibacterial compound, and 2% processing aid were weighed and put into a double-roll rubber mixer for mixing. The roller temperature of the double-roll rubber mixer was 120°C, and the mixture was fully mixed and uniformly mixed (until the surface of the material was smooth and there was no stratification, etc.) to obtain an antibacterial and tear-resistant silicone rubber material; wherein the processing aid was talcum powder for easy demolding; the antibacterial compound was composed of the EMH-carboxyl-terminated polycaprolactone blend in Preparation Example 1 and nanosilver, and the content of nanosilver in the antibacterial compound was 0.1wt%.

[0045] Example 2 The difference between Example 2 and Example 1 is that the amounts of raw materials used are different, as follows: According to weight percentage, 80% silicone rubber compound, 15% antibacterial compound, and 5% processing aid were weighed.

[0046] Example 3 The difference between Example 3 and Example 1 is that the amounts of raw materials used are different, as follows: According to weight percentage, 70% silicone rubber compound, 25% antibacterial compound, and 5% processing aid were weighed.

[0047] Examples 4-13 The difference between Example 4-13 and Example 2 is that the sources of the EMH-carboxyl-terminated polycaprolactone blend are different, as shown in Table 1; Table 1 Sources of EMH-carboxyl-terminated polycaprolactone blends of Example 2 and Examples 4-13 Example Sources of EMH-carboxyl-terminated polycaprolactone blends Example 2 Preparation Example 1 Example 4 Preparation Example 2 Example 5 Preparation Example 3 Example 6 Preparation Example 4 Example 7 Preparation Example 5 Example 8 Preparation Example 6 Example 9 Preparation Example 7 Example 10 Preparation Example 8 Example 11 Preparation Comparative Example 1 Example 12 Preparation Comparative Example 2 Example 13 Preparation Comparative Example 3 Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the EMH-carboxyl-terminated polycaprolactone blend is replaced by an equal amount of silicone rubber compound.

[0048] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the EMH-carboxyl-terminated polycaprolactone blend is replaced by carboxyl-terminated polycaprolactone in equal amounts.

[0049] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the EMH-carboxyl-terminated polycaprolactone blend is replaced by nanosilver in equal amounts.

[0050] Performance testing Detection method / test method The antibacterial and flexible silicone rubber compound obtained in Examples 1-13 and Comparative Examples 1-3 and the dipentadiene vulcanizing agent were placed in a double-roll mixer at a weight ratio of 100:3 and mixed evenly to obtain the antibacterial and flexible silicone rubber compound containing the vulcanizing agent; the antibacterial and flexible silicone rubber compound containing the vulcanizing agent was placed in a mold, and then the mold was placed in a flat-plate vulcanizing machine for vulcanization. After the flat-plate vulcanizing machine was subjected to a vulcanization temperature of 150°C and a vulcanization time of 8 minutes, vulcanization molding was performed, and the mold of the flat-plate vulcanizing machine was taken out, cooled to 30°C, and demolded to obtain test samples for the following performance tests.

[0051] 1. Hardness The hardness test is mainly used to evaluate its elasticity and flexibility. It is tested with reference to the national standard GB / T 531.1-2008 and a Shore A hardness tester is used.

[0052] 2. Elongation The test specimens were 1.5 mm thick and tested for breaking strength and elongation according to ASTM D412. The elongation test was used to assess the ductility and plasticity of the material under load.

[0053] 3. Antibacterial efficiency 1. Antibacterial activity: Antibacterial activity was tested according to ISO 22196-2011. The untreated sample was used as the blank group, and the antibacterial rate was calculated.

[0054] 2. Bacterial growth rate: The test sample was completely immersed in artificial sweat at a temperature of 37°C for 1 minute, taken out, and then placed parallel to the surface of artificial leather (the surface of the artificial leather was sprayed with 15g / m 2 Artificial sweat, and keep the humidity of the leather surface at 60%), and contact with the artificial skin surface, and keep the artificial skin temperature at 37°C, laboratory humidity 60%, laboratory temperature maintained at 37°C, and placed for 72 hours. After placement, the number of bacteria on the side of the test sample in contact with the artificial skin surface was detected. The detection method was the same as (1). The sample that was not treated with artificial sweat was the blank group, and the bacterial growth rate was calculated. The bacterial growth rate = |[(bacterial number of blank group - bacterial number after artificial sweat treatment) / bacterial number of blank group]| * 100.

[0055] Preparation of artificial sweat: 8 g of sodium chloride, 0.1 g of urea, 0.01 g of triglyceride, 0.01 g of wax, and 0.02 g of squalene were weighed and added to 1000 g of water. 85% by mass lactic acid was then added to adjust the pH to 5.8 to obtain artificial sweat.

[0056] Biocompatibility test: The test was conducted in accordance with GB / T 16886.5-2003, wherein the biotoxicity score was: no cytotoxicity (0), slight cytotoxicity (1), moderate cytotoxicity (2), and severe cytotoxicity (3).

[0057] Table 2 Experimental data of Examples 1-13 and Comparative Examples 1-3 Combining Example 1 and Comparative Examples 1-3 and Table 2, it can be seen that the antibacterial rates of Comparative Examples 1-2 are lower than that of Example 1, and the bacterial growth rate is higher than that of Example 1, while the biocompatibility of Example 1 is better than that of Comparative Example 3, indicating that the raw material ratio of the present application, the silicone rubber compound combined with the EMH-carboxyl-terminated polycaprolactone blend, can obtain better antibacterial effect and biocompatibility, and is not easy to breed bacteria in sweat and oil, and is not easy to cause allergies and the like, so that the skin in contact with the strap can maintain cell survival for a long time, thereby improving the practicality of the strap.

[0058] Combining Example 3 and Example 7 with Table 2, it can be seen that the elongation and antibacterial property of Example 7 are higher than those of Example 3, while the bacterial growth rate is lower than that of Example 3, indicating that the compounding of chitin fiber powder and bamboo fiber powder has a synergistic antibacterial effect and has better biocompatibility. At the same time, it can reduce the growth of bacteria in a sweat and oil environment, thereby maintaining the activity of the skin that the strap contacts for a long time, thereby improving the practicality of the strap.

[0059] Combining Example 2 and Examples 11-13 and Table 2, it can be seen that the elongation and antibacterial properties of Examples 11-13 are lower than those of Example 2, while the hardness and bacterial growth rate are higher than those of Example 2, indicating that the EMH-carboxyl-terminated polycaprolactone blend prepared by the application using regenerated cellulose fiber, EMH, carboxyl-terminated polycaprolactone, regenerated cellulose fiber powder, polyethylene glycol-polydimethylsiloxane-polyethylene glycol is used in the raw material system of antibacterial and tear-resistant silicone rubber materials. It is fully compatible with the silicone rubber compound and further improves the biocompatibility, antibacterial properties and breathability of the antibacterial and tear-resistant silicone rubber material, reduces the bacterial growth of the manufactured strap during long-term use, or the occurrence of cytotoxic reactions, and causes allergies and the like, so that the skin cells in contact with the strap can maintain activity for a long time, thereby improving the practicality of the strap.

[0060] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An antibacterial and flexible silicone rubber compound, characterized in that: It is composed of the following raw materials in parts by weight: Silicone rubber compound 70-90% Antibacterial compound 8-25% The balance is processing aids; The antibacterial composite consists of an EMH-carboxyl-terminated polycaprolactone blend and nanosilver, and the content of the nanosilver in the antibacterial composite is less than or equal to 0.1 wt%.

2. The antibacterial flexible silicone rubber compound according to claim 1, characterized in that: The silicone rubber compound is prepared from methyl silicone oil, hydroxy silicone oil, silazane, methyl vinyl rubber, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyldisiloxane and bis-3-methylpropyleneoxypropylated tetramethyldisiloxane.

3. The antibacterial flexible silicone rubber compound according to claim 1, characterized in that: The amount of the EMH-carboxyl-terminated polycaprolactone blend in the EMH-carboxyl-terminated polycaprolactone blend-coated nanosilver antibacterial agent is 75-86 wt %.

4. The antibacterial flexible silicone rubber compound according to claim 1, characterized in that: The EMH-carboxyl-terminated polycaprolactone blend is prepared from the following raw materials in parts by weight: EMH10-20% Carboxyl terminated polycaprolactone 60-80% Regenerated cellulose fiber powder 5-10% Polyethylene glycol-polydimethylsiloxane-polyethylene glycol 1-3%.

5. The antibacterial flexible silicone rubber compound according to claim 4, characterized in that: The regenerated cellulose fiber powder is chitin fiber powder and / or bamboo fiber powder.

6. The antibacterial flexible silicone rubber compound according to claim 5, characterized in that: The regenerated cellulose fiber powder has a particle size of 1-2 microns and a length of 5-10 microns.

7. The antibacterial flexible silicone rubber compound according to claim 4, characterized in that: The average molecular weight of the carboxyl-terminated polycaprolactone is 5,000-10,000.

8. The antibacterial flexible silicone rubber compound according to claim 4, wherein the average molecular weight of the EMH is 20,000-50,000.

9. The antibacterial flexible silicone rubber compound according to claim 4, characterized in that: EMH-carboxyl terminated polycaprolactone blends were prepared by the following method: According to weight percentage, regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol are weighed and mixed evenly to obtain a mixture A; carboxyl-terminated polycaprolactone and EMH are weighed and mixed evenly, crushed, dried, and sieved through 100-200 mesh to obtain a mixture B; then all of the mixture A is added to the mixture B, mixed evenly, and heated until the carboxyl-terminated polycaprolactone and EMH are melted, cooled, crushed, and sieved through 200-300 mesh to obtain an EMH-carboxyl-terminated polycaprolactone blend.

10. A method for preparing the antibacterial flexible silicone rubber compound according to any one of claims 1 to 9, characterized in that: The following steps are involved: According to the percentage by weight, the silicone rubber compound, the processing aid and the antibacterial compound are weighed and mixed evenly to obtain the antibacterial and flexible silicone rubber compound.

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