An antibacterial flexible silicone rubber compound and a method for preparing the same

Abstract

The application relates to the field of polymer material processing, in particular to an antibacterial flexible silica rubber mixing material and a preparation method thereof. The application relates to a watchband, wherein the watchband is formed by vulcanization of antibacterial tear-resistant silica rubber material; the antibacterial tear-resistant silica rubber material is composed of the following raw materials in percentage by weight: 70-90% of silica rubber mixing material, 8-20% of EMH-carboxyl-terminated polycaprolactone blend, and the balance of processing aids. The EMH-carboxyl-terminated polycaprolactone blend is compounded with the silica rubber mixing material, can be fully mixed and uniform, and under the vulcanization of a vulcanizing agent, the prepared antibacterial tear-resistant silica rubber material can obtain better biocompatibility, antibacterial property and softness after being vulcanized and formed, so that when the watchband is in contact with the human skin for a long time, the watchband can reduce the breeding of bacteria, the occurrence of allergy and dermatitis and other phenomena, thereby maintaining the survival of the human skin cells for a long time and improving the practicability of the watchband.

Description

TECHNICAL FIELD

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

[0002] Silicone rubber has outstanding advantages, such as high and low temperature resistance, chemical corrosion resistance, good insulation, no odor and non-toxic, soft and skin-friendly, and good biocompatibility. It is widely used in electronics, medical, automotive, aerospace and other fields. In the field of contact with the human body, especially in smart wearable devices, mixing silicone rubber can be used to make the shell and sealing of smart wristbands, smart watches and other devices. The watchband refers to the band used to fix the watch on the wrist, which not only plays a role in fixing the watch. The watchband is usually made of metal material, but the biocompatibility of metal material is poor, so after contacting with the skin, the cells in the body can easily produce toxicity and reduce cell activity, thereby easily causing phenomena such as allergy and dermatitis. The watchband made of silicone rubber is widely used because of its softness, elasticity, and skin-friendly advantages.

[0003] Because the silicone watchband is usually in close contact with the human skin during use, and is worn for a long time, the sweat and oil on the human skin will be adsorbed on the silicone watchband, and a humid environment will be formed, thereby promoting the growth of bacteria. When the watchband with bacteria contacts the human skin surface, it will cause imbalance of the microbial community on the human skin surface, and further cause skin infection, allergy and other phenomena. These pathological changes will affect the normal function and activity of skin cells, especially for people with sensitive skin or children, the above phenomena are more obvious, so further research is needed. SUMMARY

[0004] In order to obtain better biocompatibility, at the same time, play the role of skin-friendly softness and antibacterial, so that the watchband made does not easily breed bacteria or produce cytotoxicity after contacting with the human skin surface, therefore, the watchband can maintain cell survival for a long time during wearing, and improve the practicability of the watchband, the present application provides an antibacterial flexible silicone rubber mixing compound and a preparation method thereof.

[0005] In the first aspect, the present application provides an antibacterial flexible silicone rubber mixing compound, which is composed of the following weight percentage of raw materials:

[0006] Silicone rubber mixing compound 70-90%

[0007] Antibacterial composite agent 8-25%

[0008] The balance is a processing aid;

[0009] The antibacterial composite agent is composed of EMH-carboxyl-terminated polycaprolactone blend and nano-silver, and the content of nano-silver in the antibacterial composite agent is ≦0.1wt%.

[0010] The silicone rubber compound has better softness, skin-friendliness and biocompatibility, and can reduce skin scratching. The EMH-carboxyl-terminated polycaprolactone blend is obtained by blending modification of EMH and carboxyl-terminated polycaprolactone. The EMH is a terpolymer, i.e. ethylene-acrylate-maleic anhydride copolymer, which has better compatibility. After blending with the carboxyl-terminated polycaprolactone, a material with good compatibility, antibacterial property and biocompatibility is formed, and the dispersion of nano-silver in the antibacterial composite system is promoted. The nano-silver and the EMH-carboxyl-terminated polycaprolactone blend have a synergistic effect, further improving the antibacterial property. The EMH-carboxyl-terminated polycaprolactone blend is compounded with the silicone rubber compound, which can be fully mixed and uniform, and under the vulcanization of the vulcanizing agent, the prepared antibacterial and tear-resistant silicone rubber material is vulcanized and formed, and the watchband obtained has better biocompatibility, antibacterial property and softness. When the watchband is in contact with the human skin for a long time, it can reduce the growth of bacteria, the occurrence of allergy and dermatitis, etc., thereby maintaining the survival of human skin cells for a long time and improving the practicality of the watchband.

[0011] In addition, the content of nano-silver in the antibacterial composite of the present application is ≦0.1wt%, which can form an antibacterial composite with good antibacterial property and biocompatibility with the EMH-carboxyl-terminated polycaprolactone blend of the present application. After blending with the silicone rubber compound and vulcanization, the watchband and other products obtained have better antibacterial property, biocompatibility and tear resistance and other mechanical properties, improving the practicality.

[0012] Preferably, the silicone rubber compound is prepared from methyl silicone oil, hydroxyl silicone oil, silazane, methyl vinyl gum, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyl disiloxane, and bis-3-methacryloyloxypropyl tetramethyl disiloxane.

[0013] The methyl vinyl silicone rubber compound is a non-crosslinked state compound, which is crosslinked and cured under the action of a vulcanizing agent. The methyl vinyl raw rubber has the advantages of high temperature resistance, good softness and good biocompatibility, and the silicone rubber compound prepared from the methyl vinyl raw rubber, methyl silicone oil, hydroxyl silicone oil, silazane, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyl disiloxane and bis-3-methyl methacryl oxy propyl tetramethyl disiloxane has good comprehensive performance. After the silicone rubber compound is blended and modified with an antibacterial composite agent (composed of EMH-carboxyl-terminated polycaprolactone blend and nano-silver, and the content of nano-silver in the antibacterial composite agent is ≤0.1wt%), the prepared antibacterial and tear-resistant silicone rubber material has good biocompatibility, and at the same time, has the effects of skin-friendly softness and antibacterial property. After the watchband prepared is in contact with the surface of human skin, bacteria are not easy to breed or cell toxicity reaction is not easy to occur, so that the watchband can maintain cell survival for a long time during wearing and is not easy to be torn and damaged, thereby improving the practicability of the watchband.

[0014] Preferably, the vulcanizing agent is silica platinum gold water.

[0015] The silica platinum gold water is prepared by the silicon hydrogen addition reaction of hydrogen-containing silicone oil and vinyl double bond in the presence of a catalyst. The silica platinum gold water is contacted with the silicone rubber compound, which not only has a catalytic effect, but also has a crosslinking effect, thereby improving the vulcanization forming efficiency of the antibacterial and tear-resistant silicone rubber material and making the antibacterial and tear-resistant silicone rubber material have good softness.

[0016] Preferably, the EMH-carboxyl-terminated polycaprolactone blend is prepared from the following raw materials in percentage by weight: EMH 10-20%

[0017] Carboxyl-terminated polycaprolactone 60-80%

[0018] Regenerated cellulose fiber powder 5-10%

[0019] Polyethylene glycol-polydimethylsiloxane-polyethylene glycol 1-3%.

[0020] The regenerated cellulose fiber powder has good water absorption, air permeability and antibacterial property, and has good biocompatibility. The polyethylene glycol-polydimethylsiloxane-polyethylene glycol (PEG-PDMS-PEG) is a three-block copolymer, which combines the advantages of polyethylene glycol (PEG) and polydimethylsiloxane (PDMS), and has the advantages of wetting, dispersing and biocompatibility, low surface tension and lubricity, which helps to reduce the adhesion and aggregation between filler particles, thereby improving the dispersibility of the regenerated cellulose fiber powder in the raw material system. In combination with the carboxyl-terminated polycaprolactone and EMH, the obtained EMH-carboxyl-terminated polycaprolactone blend has good biocompatibility, and at the same time, has good antibacterial property and air permeability.

[0021] When the EMH-carboxyl-terminated poly (caprolactone) blend is blended with the silicone rubber compound, the watchband can have better softness, antibacterial property and air permeability, and can reduce the breeding of bacteria during use, avoid the imbalance of bacterial colonies on the skin surface, and cause the activity of skin cells.

[0022] Preferably, the regenerated cellulose fiber powder is chitin fiber powder and / or bamboo fiber powder.

[0023] The chitin fiber powder and the bamboo fiber powder both have good biocompatibility, and also have antibacterial property and air permeability. Furthermore, the EMH-carboxyl-terminated poly (caprolactone) blend prepared by combining the EMH, the carboxyl-terminated poly (caprolactone), the regenerated cellulose fiber powder and the polyethylene glycol-polydimethylsiloxane-polyethylene glycol has good air permeability, antibacterial property, compatibility and biocompatibility. When the EMH-carboxyl-terminated poly (caprolactone) blend is used in the raw material system of the antibacterial and tear-resistant silicone rubber material, the silicone rubber compound can be fully compatible, and the biocompatibility, the antibacterial property and the air permeability of the antibacterial and tear-resistant silicone rubber material can be further improved. The watchband prepared by the antibacterial and tear-resistant silicone rubber material can reduce the breeding of bacteria during long-term use, can avoid the occurrence of cell toxicity and allergy, can maintain the activity of skin cells for a long time, and can improve the practicability of the watchband.

[0024] Preferably, the particle size of the regenerated cellulose fiber powder is 1-2 microns, and the length is 5-10 microns.

[0025] The above particle size range can make the regenerated cellulose fiber powder fully dispersed in the raw material system, so as to have good air permeability and antibacterial property. The watchband prepared by the antibacterial and tear-resistant silicone rubber material can reduce the breeding of bacteria after long-term wearing and contact with sweat, can avoid the occurrence of allergy, can maintain cell survival for a long time, and can improve the practicability of the watchband.

[0026] Preferably, the average molecular weight of the carboxyl-terminated poly (caprolactone) is 5000-10000.

[0027] The average molecular weight of the carboxyl-terminated poly (caprolactone) is the weight average molecular weight. In the above range, the carboxyl-terminated poly (caprolactone) can be fully mixed with the silicone rubber compound, and good physical properties can be obtained.

[0028] Preferably, the average molecular weight of the EMH is 20-50 thousand.

[0029] The EMH with the above average molecular weight can better promote the compatibility of the silicone rubber compound and the carboxyl-terminated poly (caprolactone), so that the watchband prepared by the antibacterial and tear-resistant silicone rubber material can have good antibacterial property, softness and biocompatibility. The watchband prepared by the antibacterial and tear-resistant silicone rubber material can reduce the breeding of bacteria after long-term wearing and contact with sweat, can avoid the occurrence of allergy, can maintain cell survival for a long time, and can improve the practicability of the watchband.

[0030] Preferably, the MH-carboxyl-terminated polycaprolactone blend is prepared by the following method:

[0031] According to the weight percentage, the regenerated cellulose fiber powder and the polyethylene glycol-polydimethylsiloxane-polyethylene glycol are mixed uniformly to obtain mixture A; the carboxyl-terminated polycaprolactone and EMH are mixed uniformly, crushed, dried, and sieved to 100-200 meshes to obtain mixture B; then mixture A is added to mixture B and mixed uniformly, and heated to melt the carboxyl-terminated polycaprolactone and EMH, cooled, crushed, and sieved to 200-300 meshes to obtain the EMH-carboxyl-terminated polycaprolactone blend.

[0032] In the above preparation method, the regenerated cellulose fiber powder and the polyethylene glycol-polydimethylsiloxane-polyethylene glycol are mixed to wet and disperse the regenerated cellulose fiber powder, avoiding agglomeration; the carboxyl-terminated polycaprolactone and EMH are mixed uniformly, crushed, dried, and sieved to 100-200 meshes to form a small particle mixture B, which is more easily mixed uniformly with mixture A; after melting, cooling, crushing, and sieving to 200-300 meshes, the EMH-carboxyl-terminated polycaprolactone blend has better dispersibility, compatibility, and biocompatibility, and has antibacterial properties, air permeability, etc. When it is compounded with a silicone rubber compound, it can be fully mixed and uniform, and the watchband produced by the antibacterial and tear-resistant silicone rubber material has better performance. When worn for a long time, even after contact with sweat and oil, bacteria are not easy to breed, or skin inflammation is not easy to occur, thereby reducing the phenomenon of reduced activity of epidermal cells at the position of the watchband in contact with the human body during long-term wearing, and improving the practicality of the watchband.

[0033] In a second aspect, the application provides a preparation method of an antibacterial flexible silicone rubber compound, which is prepared by the following method:

[0034] According to the weight percentage, the silicone rubber compound, processing aid, and antibacterial composite are mixed uniformly to obtain the antibacterial flexible silicone rubber compound.

[0035] The above process is simple, has high production efficiency, and can fully mix the materials uniformly. After vulcanization at a temperature of 130-175℃ for 5-10min, the watchband obtained has better biocompatibility, antibacterial properties, and softness, and can reduce the breeding of bacteria, allergic reactions, and skin inflammation when the watchband is in contact with the human epidermis for a long time, thereby maintaining the survival of human epidermal cells for a long time and improving the practicality of the watchband.

[0036] In summary, the application has the following beneficial effects:

[0037] 1、Silicone rubber mixing rubber has better softness, skin and biocompatibility, can reduce the skin scraping, and EMH-carboxyl terminated poly (caprolactone) blend is obtained by blending modification of EMH and carboxyl terminated poly (caprolactone), wherein EMH is a terpolymer, i.e. ethylene-acrylate-maleic anhydride copolymer has better compatibility, and after blending with carboxyl terminated poly (caprolactone), a material with good compatibility, antibacterial and biocompatibility is formed. The EMH-carboxyl terminated poly (caprolactone) blend is compounded with the silicone rubber mixing rubber, which can be fully mixed and uniform, and under the vulcanization of the vulcanizing agent, the prepared antibacterial and tear-resistant silicone rubber material is vulcanized to form a watchband with good biocompatibility, antibacterial and softness, which can reduce the growth of bacteria, allergic reactions, dermatitis and other phenomena when the watchband is in contact with the human skin for a long time, thereby maintaining the survival of human skin cells for a long time and improving the practicability of the watchband.

[0038] 2、regenerated cellulose fiber, EMH, carboxyl terminated poly (caprolactone), regenerated cellulose fiber powder, polyethylene glycol-polydimethylsiloxane-polyethylene glycol to prepare EMH-carboxyl terminated poly (caprolactone) blend has good air permeability, antibacterial, compatibility and biocompatibility, when it is used in the raw material system of antibacterial and tear-resistant silicone rubber material, it can fully compatible with silicone rubber mixing rubber, and further improve the biocompatibility, antibacterial and air permeability of antibacterial and tear-resistant silicone rubber material, reduce the growth of bacteria or cell toxicity reaction of the prepared watchband in long-term use, and cause allergic reactions, so that the skin cells in contact with the watchband can maintain activity for a long time, and the practicability of the watchband is improved. DETAILED DESCRIPTION

[0039] The application will be further described in detail below in combination with examples.

[0040] Part of the source of raw materials:

[0041] Methyl vinyl silicone rubber mixing rubber, preferably the manufacturer Fuding Ruifeng Automobile Parts Co., Ltd., model RF220;

[0042] Silica platinum gold water, preferably the manufacturer Dongguan Zhongxin Organic Silicon Material Co., Ltd., model ZX-BJ020, effective platinum content 1000-5000PPM;

[0043] Molecular structure of carboxyl terminated poly (caprolactone):

[0044]

[0045] Polyethylene glycol-polydimethylsiloxane-polyethylene glycol, molecular formula [C2H4O]n[C2H6OSi]m[C2H4O]n, wherein m, n are both 10.

[0046] Preparation Example of EMH-carboxyl-terminated polycaprolactone blend

[0047] Preparation Example 1

[0048] An EMH-carboxyl-terminated polycaprolactone blend is prepared by the following method:

[0049] According to the weight percentage, 5% of regenerated cellulose fiber powder and 1% of polyethylene glycol-polydimethylsiloxane-polyethylene glycol are mixed uniformly to obtain mixture A; 80% of carboxyl-terminated polycaprolactone and 14% of EMH are mixed uniformly, crushed by a crusher, placed in an oven at 50°C for drying for 2h, and then sieved to 100 meshes to obtain mixture B; then mixture A is added to mixture B, mixed uniformly, heated to 150°C, and the carboxyl-terminated polycaprolactone and EMH are completely melted, cooled to 35°C, crushed by a crusher, and sieved to 200 meshes to obtain the EMH-carboxyl-terminated polycaprolactone blend.

[0050] 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 the EMH is 50,000.

[0051] Preparation Example 2

[0052] Preparation Example 2 differs from Preparation Example 1 in that the amount and process parameters are different, as follows:

[0053] According to the weight percentage, 7% of regenerated cellulose fiber powder and 2% of polyethylene glycol-polydimethylsiloxane-polyethylene glycol are mixed uniformly to obtain mixture A; 70% of carboxyl-terminated polycaprolactone and 21% of EMH are mixed uniformly, crushed by a crusher, placed in an oven at 50°C for drying for 2h, and then sieved to 150 meshes to obtain mixture B; then mixture A is added to mixture B, mixed uniformly, heated to 150°C, and the carboxyl-terminated polycaprolactone and EMH are completely melted, cooled to 35°C, crushed by a crusher, and sieved to 250 meshes to obtain the EMH-carboxyl-terminated polycaprolactone blend.

[0054] Preparation Example 3

[0055] Preparation Example 3 differs from Preparation Example 1 in that the amount and process parameters are different, as follows:

[0056] Take 10% regenerated cellulose fiber powder and 3% polyethylene glycol-polydimethylsiloxane-polyethylene glycol by weight percentage, mix uniformly to obtain mixture A; take 60% carboxyl-terminated polycaprolactone and 27% EMH, mix uniformly, crush with a crusher, put into a 50℃ oven for drying for 2h, then sieve 200 meshes to obtain mixture B; then add all the mixture A into the mixture B, mix uniformly, heat to 150℃, make the carboxyl-terminated polycaprolactone and EMH completely melt, cool to 35℃, then crush with a crusher, sieve 300 meshes to obtain the EMH-carboxyl-terminated polycaprolactone blend.

[0057] Preparation Example 4

[0058] Preparation Example 4 is different from Preparation Example 2 in that the regenerated cellulose fiber powder is bamboo fiber powder.

[0059] Preparation Example 5

[0060] 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.

[0061] Preparation Example 6

[0062] Preparation Example 6 is different from Preparation Example 5 in that the particle size of the regenerated cellulose fiber powder is 2 microns and the length is 10 microns.

[0063] Preparation Example 7

[0064] Preparation Example 7 is different from Preparation Example 5 in that the average molecular weight of the carboxyl-terminated polycaprolactone is 10,000.

[0065] Preparation Example 8

[0066] Preparation Example 8 is different from Preparation Example 5 in that the average molecular weight of the EMH is 20,000.

[0067] Preparation Comparative Example

[0068] Preparation Comparative Example 1

[0069] Preparation Comparative Example 1 is different from Preparation Example 1 in that the regenerated cellulose fiber powder is replaced by an equal amount of carboxyl-terminated polycaprolactone.

[0070] Preparation Comparative Example 2

[0071] Preparation Comparative Example 2 is different from Preparation Example 1 in that the polyethylene glycol-polydimethylsiloxane-polyethylene glycol is replaced by an equal amount of carboxyl-terminated polycaprolactone.

[0072] Preparation Comparative Example 3

[0073] Preparation of Comparative Example 3 is different from Preparation Example 1 in that the regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol are replaced by carboxyl-terminated polycaprolactone in equal amounts.

[0074] Example

[0075] Example 1

[0076] An antibacterial flexible silicone rubber compound was prepared by the following method:

[0077] The silicone rubber compound was prepared by placing methyl silicone oil, hydroxyl silicone oil, silazane, methyl vinyl rubber, white carbon black, 1,1,3,3-tetramethoxy-1,3-divinyl disiloxane, and bis-3-methacryloyloxypropyl tetramethyl disiloxane in a weight ratio of 10:5:2:100:30:1:1 into a kneader, heating to 155°C at a rate of 5°C / min, stirring at a rate of 50 r / min, and stirring for 2 h.

[0078] The antibacterial and tear-resistant silicone rubber material was obtained by placing 90% silicone rubber compound, 8% antibacterial composite, and 2% processing aid in a two-roll rubber mixer, mixing them well (until the surface of the material was smooth and there were no stratification phenomena), and setting the roller temperature of the two-roll rubber mixer to 120°C; wherein the processing aid was talc to facilitate demolding, and the antibacterial composite was composed of the EMH-carboxyl-terminated polycaprolactone blend in Preparation Example 1 and nano-silver, and the content of nano-silver in the antibacterial composite was 0.1 wt%.

[0079] Example 2

[0080] Example 2 is different from Example 1 in that the amounts of raw materials are different, as follows:

[0081] The antibacterial and tear-resistant silicone rubber material was obtained by placing 90% silicone rubber compound, 8% antibacterial composite, and 2% processing aid in a two-roll rubber mixer, mixing them well (until the surface of the material was smooth and there were no stratification phenomena), and setting the roller temperature of the two-roll rubber mixer to 120°C; wherein the processing aid was talc to facilitate demolding, and the antibacterial composite was composed of the EMH-carboxyl-terminated polycaprolactone blend in Preparation Example 1 and nano-silver, and the content of nano-silver in the antibacterial composite was 0.1 wt%.

[0082] Example 3

[0083] Example 3 is different from Example 1 in that the amounts of raw materials are different, as follows:

[0084] The antibacterial and tear-resistant silicone rubber material was obtained by placing 90% silicone rubber compound, 8% antibacterial composite, and 2% processing aid in a two-roll rubber mixer, mixing them well (until the surface of the material was smooth and there were no stratification phenomena), and setting the roller temperature of the two-roll rubber mixer to 120°C; wherein the processing aid was talc to facilitate demolding, and the antibacterial composite was composed of the EMH-carboxyl-terminated polycaprolactone blend in Preparation Example 1 and nano-silver, and the content of nano-silver in the antibacterial composite was 0.1 wt%.

[0085] Examples 4-13

[0086] Examples 4-13 are different from Example 2 in that the sources of the EMH-carboxyl-terminated polycaprolactone blend are different, as shown in Table 1.

[0087] Table 1 Sources of EMH-carboxyl terminated polycaprolactone blends for Examples 2, 4-13

[0088] Example Source of EMH-carboxyl terminated polycaprolactone blend 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

[0089] Comparative Example 1

[0090] Comparative Example 1

[0091] Comparative Example 1 differs from Example 1 in that the EMH-carboxyl terminated polycaprolactone blend is replaced with an equal amount of silicone rubber masterbatch.

[0092] Comparative Example 2

[0093] Comparative Example 2 differs from Example 1 in that the EMH-carboxyl terminated polycaprolactone blend is replaced with an equal amount of carboxyl terminated polycaprolactone.

[0094] Comparative Example 3

[0095] Comparative Example 3 differs from Example 1 in that the EMH-carboxyl terminated polycaprolactone blend is replaced with an equal amount of nano-silver.

[0096] Performance Test

[0097] Test Method

[0098] The antibacterial flexible silicone rubber compounds obtained from Examples 1-13 and Comparative Examples 1-3 and bis-triazole vulcanizing agent were placed in a double roll mixer in a weight ratio of 100:3 and mixed uniformly to obtain an antibacterial flexible silicone rubber compound containing a vulcanizing agent. The antibacterial flexible silicone rubber compound containing a vulcanizing agent was placed in a mold, and the mold was placed in a flat vulcanization machine. After the flat vulcanization machine was subjected to a vulcanization temperature of 150°C and a vulcanization time of 8 min, vulcanization and molding were performed. After the mold of the flat vulcanization machine was removed and cooled to 30°C, demolding was performed, and test samples for the following performance tests were obtained.

[0099] 1. Hardness

[0100] The hardness test is mainly used to evaluate the elasticity and flexibility, and is tested according to the national standard GB / T 531.1-2008, using a Shore A hardness tester.

[0101] II. Elongation

[0102] The test sample has a thickness of 1.5 mm, and the breaking strength and elongation are tested according to the test method ASTM D412. The elongation test is used to evaluate the ductility and plasticity under stress.

[0103] III. Antibacterial Efficiency

[0104] 1. Antibacterial property: The antibacterial property was tested according to ISO 22196-2011, the untreated sample was blank group, and the antibacterial rate was calculated.

[0105] 2. Bacterial growth rate: The test sample was completely immersed in artificial sweat at 37℃ for 1 min, taken out, and then placed in parallel on the surface of artificial leather (the artificial leather surface was sprayed with 15g / m 2 artificial sweat, and the humidity of the leather surface was maintained at 60%), and the artificial skin surface was contacted, and the temperature of the artificial skin was maintained at 37℃, the laboratory humidity was 60%, the laboratory temperature was maintained at 37℃, and the placement time was 72h. After placement, the number of bacteria on the surface of the test sample in contact with the artificial skin was detected by the same method as (1), the sample without artificial sweat treatment was blank group, and the bacterial growth rate was calculated. The bacterial growth rate = | [(blank group bacterial number - artificial sweat treated bacterial number) / blank group bacterial number] | * 100.

[0106] Preparation of artificial sweat: 8g of sodium chloride, 0.1g of urea, 0.01g of triglyceride, 0.01g of wax, and 0.02g of squalene were added to 1000g of water, and then 85% by mass of lactic acid was added to adjust the pH value to 5.8 to obtain artificial sweat.

[0107] Biocompatibility test: The test was performed according to GB / T 16886.5-2003, wherein the biological toxicity score: no cytotoxicity (0), mild cytotoxicity (1), moderate cytotoxicity (2), and severe cytotoxicity (3).

[0108] Table 2 Experimental data of examples 1-13 and comparative examples 1-3

[0109]

[0110]

[0111] According to the combination of examples 1 and comparative examples 1-3 and table 2, it can be seen that the antibacterial rate of comparative examples 1-2 is lower than that of example 1, and the bacterial growth rate is higher than that of example 1, and the biocompatibility of example 1 is better than that of comparative example 3, which shows that the raw material ratio of the silicone rubber compound combined with EMH-carboxyl terminated polycaprolactone blend can obtain better antibacterial effect, biocompatibility, and is not easy to breed bacteria in sweat and grease, thereby not easy to cause allergic reactions and other phenomena, so that the skin in contact with the watchband can maintain cell survival for a long time, and the practicality of the watchband is improved.

[0112] It can be seen from the combination of Embodiment 3 and Embodiment 7 and Table 2 that the elongation and antibacterial property of Embodiment 7 are higher than those of Embodiment 3, and the bacterial growth rate is lower than that of Embodiment 3, indicating that the chitin fiber powder and the bamboo fiber powder are compounded to have a synergistic antibacterial effect and have better biocompatibility, and can reduce the breeding of bacteria in the sweat and grease environment, maintain the activity of the skin in contact with the watchband for a long time, and improve the practicability of the watchband.

[0113] It can be seen from the combination of Embodiment 2 and Embodiments 11-13 and Table 2 that the elongation and antibacterial property of Embodiments 11-13 are lower than those of Embodiment 2, and the hardness and bacterial growth rate are higher than those of Embodiment 2, indicating that the EMH-carboxyl-terminated polycaprolactone blend prepared from the regenerated cellulose fiber, EMH, carboxyl-terminated polycaprolactone, regenerated cellulose fiber powder, and polyethylene glycol-polydimethylsiloxane-polyethylene glycol is used in the raw material system of the antibacterial and tear-resistant silicone rubber material, and can be fully compatible with the silicone rubber compound, and further improve the biocompatibility, antibacterial property, and air permeability of the antibacterial and tear-resistant silicone rubber material, reduce the breeding of bacteria or the occurrence of cytotoxicity reaction in the long-term use of the watchband, cause allergic reactions, and maintain the activity of the skin cells in contact with the watchband for a long time, and improve the practicability of the watchband.

[0114] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An antibacterial and flexible silicone rubber compound, characterized in that, It consists of the following raw materials in parts by weight percentage: Silicone rubber compound 70-90% Antibacterial compound 8-25% The remainder is processing aids; The antibacterial compound is composed of EMH-carboxyl-terminated polycaprolactone blend and nano-silver, wherein the content of nano-silver in the antibacterial compound is ≤0.1wt%; The EMH-carboxyl-terminated polycaprolactone blend was prepared from the following raw materials in parts by weight percentage: EMH10-20% Carboxyl-terminated polycaprolactone 60-80% 5-10% regenerated cellulose fiber powder Polyethylene glycol-polydimethylsiloxane-polyethylene glycol 1-3.

2. The antibacterial and 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 raw rubber, silica, 1,1,3,3-tetramethoxy-1,3-divinyldisiloxane, and bis-3-methylpropenyloxypropyltetramethyldisiloxane.

3. The antibacterial and flexible silicone rubber compound according to claim 1, characterized in that: The regenerated cellulose fiber powder is chitin fiber powder and / or bamboo fiber powder.

4. The antibacterial and flexible silicone rubber compound according to claim 3, characterized in that: The regenerated cellulose fiber powder has a particle size of 1-2 micrometers and a length of 5-10 micrometers.

5. The antibacterial and flexible silicone rubber compound according to claim 1: characterized in that: The average molecular weight of the carboxyl-terminated polycaprolactone is 5000-10000.

6. The antibacterial and flexible silicone rubber compound according to claim 1: the average molecular weight of the EMH is 20,000-50,000.

7. The antibacterial and flexible silicone rubber compound according to claim 1, characterized in that, EMH-carboxyl-terminated polycaprolactone blends were prepared by the following method: Weigh out the regenerated cellulose fiber powder and polyethylene glycol-polydimethylsiloxane-polyethylene glycol by weight percentage, mix them evenly to obtain mixture A; weigh out the carboxyl-terminated polycaprolactone and EMH, mix them evenly, pulverize them, dry them, and sieve them through a 100-200 mesh to obtain mixture B; then add all of mixture A to mixture B and mix evenly, and heat until the carboxyl-terminated polycaprolactone and EMH melt, cool them, pulverize them, and sieve them through a 200-300 mesh to obtain the EMH-carboxyl-terminated polycaprolactone blend.

8. A method for preparing an antibacterial and flexible silicone rubber compound as described in any one of claims 1-7, characterized in that, Includes the following steps: Weigh out the silicone rubber compound, processing aids, and antibacterial compound according to the percentage by weight, and mix them evenly to obtain an antibacterial and flexible silicone rubber compound.

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