Medical foamed silica gel material and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a medical foaming silica gel material and a preparation method thereof. The material is prepared from, by weight, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano-silver, 15-35 parts of reinforcing filler, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea. The medical foamed silica gel material prepared by the invention is a medical polymer material which is light, soft and good in compatibility with human bodies. A mixture composed of siloxane-based rubber, a reinforcing filler, a foaming aid and a platinum catalyst is vulcanized to form the porous foam elastomer. The material has the characteristics of high air permeability, excellent antibacterial property, high tensile strength and the like, so that the material has excellent performance in various medical applications.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a medical foamed silica gel material and a preparation method thereof. Background Art

[0002] Foamed silicone rubber material is a porous polymer elastic material made by foaming silicone rubber, also known as sponge silicone rubber or microporous silicone rubber. Foamed silicone rubber material not only retains the advantages of silicone rubber material itself, but also has the characteristics of lightness and excellent shock absorption performance. Foamed silicone rubber has high thermal stability, good thermal insulation, insulation, moisture resistance and shock resistance. It can be used in various electronic components, instruments, meters, and instrument wheels of flying bodies to play the "three-proof" protection role of moisture, shock and corrosion. In addition, it can also be used as a filling material for thermal insulation interlayers, floating materials in salt spray atmospheres, and sealing materials.

[0003] By introducing a microporous structure, foamed silicone rubber materials can further improve their elasticity, breathability and comfort while maintaining the excellent properties of silicone materials, thus giving them broad application prospects in the medical field.

[0004] The research and application of medical silicone rubber began in the 1960s. With the continuous advancement of science and technology, great progress has been made in the research of medical silicone rubber as a biocompatible material. In particular, in recent decades, as an important form of medical silicone rubber, medical foamed silicone rubber has been widely used in the fields of pacemakers, heart valves, artificial joints, artificial tendons, etc. At the same time, with the continuous development of medical technology, the application scope of medical foamed silicone rubber is also expanding.

[0005] With the continuous advancement of medical technology, medical materials are increasingly used in the medical field. Silicone materials are widely used in medical devices, artificial organs, implants, etc. due to their good biocompatibility, chemical stability and easy processing. Medical foam silicone rubber is also widely used in the medical field. It can replace bone or cartilage as a tissue filling or scaffold material; it can also replace human fat tissue to repair facial subcutaneous tissue defects and deformities; it can also be made into tendon sheath substitutes and intestinal fistula plugs and other medical supplies. In addition, medical foam silicone rubber is also widely used in the field of cosmetic surgery, such as breast augmentation, rhinoplasty and other surgeries.

[0006] As the production process and technical level of medical foam silicone rubber continue to improve, the application field of foam silicone rubber is becoming more and more extensive, and the market demand will continue to grow. However, traditional silicone materials have problems such as insufficient elasticity, poor air permeability and poor antibacterial properties in certain applications, which limits its application in some high-end medical fields.

[0007] Therefore, it is of great significance to develop a silicone rubber foam material with excellent mechanical properties, uniform pore size distribution, and excellent antibacterial properties. Summary of the invention

[0008] Based on the problems existing in the above background technology, the present invention proposes a medical foamed silicone material and a preparation method thereof, which are as follows:

[0009] A medical foamed silicone material comprises the following components, measured by weight: 60-75 parts of methyl vinyl silicone rubber, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano silver, 15-35 parts of reinforcing filler, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea.

[0010] Preferably, a medical foamed silicone material is made of the following components by weight: 70 parts of methyl vinyl silicone rubber, 20 parts of medium phenyl silicone rubber, 8 parts of high phenyl silicone rubber, 9 parts of modified nano silver, 22 parts of reinforcing filler, 6 parts of vulcanizing agent, 25 parts of foaming agent, 3 parts of platinum catalyst and 4 parts of urea. Urea is mainly used as a foaming aid and is usually used together with the foaming agent.

[0011] Preferably, the reinforcing filler is at least one of modified white carbon black, glass powder, calcium carbonate, montmorillonite, graphene, and silicon powder. The addition of reinforcing materials can improve the thermal stability of silicone rubber foam and make the whole system have a higher thermal decomposition temperature; the vulcanizing agent is at least one of sulfur, dicumyl peroxide (DCP), and benzoyl peroxide; the foaming agent is at least one of ammonium bicarbonate, sodium bicarbonate, azobisisobutyronitrile, azodicarbonamide, and 1,1-azo (1-acetoxy-1-phenylethane). The foaming agent can improve the foaming ratio and prepare silicone rubber foam materials with smooth surface, small and uniform pores, and small compression permanent deformation.

[0012] Preferably, the preparation method of the modified nanosilver is as follows:

[0013] S1: First, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.15-0.25 mol / L, and a dispersant is added and stirred to obtain a silver nitrate dispersion solution;

[0014] S2, adding a reducing agent to deionized water, and then adding a pH adjusting agent to obtain a reducing agent solution;

[0015] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0016] S4, adding a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0017] S5, let the suspension stand for 4-6h, centrifuge at 3500-4500r / min, then add anhydrous ethanol, centrifuge at 2000-3500r / min, stand, and obtain a precipitate, which is dried in a vacuum drying oven at 45°C for 6-12h to obtain modified nano silver. The antibacterial properties of the foamed silica gel material can be significantly improved by applying the modified nano silver to the foamed silica gel material. At the same time, the modified nano silver powder prepared by the present invention has high purity and good dispersibility, and the preparation method is relatively simple. It can effectively prevent the agglomeration of the nano silver powder.

[0018] Preferably, the dispersant in S1 is one or a mixture of benzyltrimethylammonium bromide, tetramethylammonium hydroxide, sodium laurate, polyethylene glycol, polyvinyl alcohol, and allyl alcohol, and the silver nitrate and the dispersant are mixed in a molar ratio of 2-3:1;

[0019] The reducing agent in S2 is one or more of triethanolamine, diethanolamine, ferrous sulfate, citric acid, formaldehyde, hydrogen peroxide, and hydrazine hydrate, and the molar ratio of the silver nitrate to the reducing agent is 2:(3-5);

[0020] The pH regulator in S2 is one of ammonia water and sodium hydroxide or a mixture of the two, and the pH value of the pH regulator in S2 is adjusted to 8-9;

[0021] The accelerator in S4 is one of hydrogen peroxide, sodium hydroxide or ammonia water.

[0022] Preferably, the reinforcing filler is modified silica, and the modified silica is obtained by the following steps:

[0023] First, add the fumed silica to be modified into a three-necked flask, add 60-100 mL of anhydrous ethanol, put the three-necked flask into a constant temperature water bath at 70-85°C and stir for 1-3 hours, mix the silane coupling agent, anhydrous ethanol and water in a volume ratio of 1:(2-5):(0.5-1) to obtain a silane coupling agent modified liquid; use a separatory funnel to dropwise add the prepared silane coupling agent modified liquid into the three-necked flask, stop stirring after 1-12 hours to obtain a modified silica suspension, filter and transfer the fumed silica to a tray, put it into a 50-75°C drying oven for drying for 1-2 hours, and crush it to obtain modified silica.

[0024] Silane coupling agent is used to modify the surface of reinforcing filler white carbon black to improve its dispersibility in the silicone rubber matrix and enhance its interface bonding with silicone rubber. After being heated, the alkoxy group in the silane coupling agent is hydrolyzed in anhydrous ethanol solution to generate silanol, which undergoes a dehydration condensation reaction with the silanol in SiO2. The active group at the other end undergoes a chemical reaction and mechanical entanglement with the silicone rubber matrix, thereby connecting the inorganic reinforcing filler and the polymer through the silane coupling agent, that is, the silane coupling agent is used to connect the "bridge structure" between the SiO2 surface and the silicone rubber matrix, thereby improving the compatibility between SiO2 and the silicone rubber matrix, and obtaining a foamed silicone rubber with high tensile strength and uniform open porosity.

[0025] Preferably, the silane coupling agent is selected from one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane.

[0026] Preferably, the medical foamed silicone material is made by mixing the following components: 60-75 parts of methyl vinyl silicone rubber, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano silver, 15-35 parts of modified white carbon black, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea.

[0027] Preferably, a medical foamed silicone material is made of the following components, by weight: 60-75 parts of methyl vinyl silicone rubber, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano silver, 15-35 parts of modified white carbon black, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea.

[0028] Preferably, a method for preparing a medical foamed silicone material is characterized by comprising the following steps:

[0029] Step 1, weighing a certain amount of methyl vinyl silicone rubber, medium phenyl silicone rubber, high phenyl silicone rubber, modified nano silver, reinforcing filler, vulcanizing agent, foaming agent, platinum catalyst and urea respectively according to proportion;

[0030] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0031] Step 3, mixing the medium phenyl silicone rubber and the high phenyl silicone rubber on an open mill, with a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20-45 min to obtain a mixed rubber B;

[0032] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0033] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0034] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0035] Preferably, the phenyl content of the medium phenyl silicone rubber is 15-25 mol%, and the medium phenyl silicone has ablation-resistant silicon performance; the phenyl content of the high phenyl silicone rubber is 30-50 mol%, and the high phenyl silicone rubber has radiation resistance, and the γ-ray radiation resistance value of the high phenyl silicone rubber is 2.58×104C / kg.

[0036] Compared with the prior art, the present invention has the following beneficial effects: 1) The medical foamed silicone material of the present invention is a light, soft, and human body compatible medical polymer material. It is a mixture of silicone rubber, reinforcing filler, foaming aid, and platinum catalyst, and forms a porous white foamed elastic body after vulcanization. This material has the characteristics of high air permeability, excellent antibacterial property, and high tensile strength, so that it performs well in various medical applications.

[0037] 2) Phenyl silicone rubber is made by introducing diphenylsiloxane segments (or methylphenylsiloxane segments) into the molecular chain of vinyl silicone rubber. This is achieved by introducing large-volume phenyl groups to destroy the regularity of the dimethylsiloxane structure and reduce the crystallization temperature and glass transition temperature of the polymer. As the phenyl content increases, the rigidity of the molecular chain increases, and its crystallization temperature rises instead. When the phenyl content is 15-25%, it is generally called medium phenyl silicone, which has flame retardant characteristics. When the phenyl content is above 30%, it is generally called high phenyl silicone, which has excellent radiation resistance. Phenyl silicone rubber is used in occasions that require low temperature resistance, ablation resistance, high-energy radiation resistance, heat insulation, etc. The present invention prepares silicone rubber with excellent biomedical properties by mixing silicone rubbers with different phenyl contents, which can be widely used in various medical scenarios.

[0038] 3) The foamed silicone material prepared by the present invention is light in weight and has good elasticity, and can be used as a filler for human organs. The silicone foam with an open-pore structure can replace the non-healable biological tissue in the human body; and it is easy to process and carve into a shape, making it more convenient and flexible in the manufacture of various complex medical devices.

[0039] 4) After the present invention uses a silane coupling agent to modify the gas phase carbon black, its dispersibility is significantly improved, and the modification effect is good. The mechanical properties of the foamed silica material prepared using the modified silica are better than those of the foamed silica material prepared using the unmodified silica.

[0040] In summary, medical foam silicone materials can be widely used in the medical field due to their good biocompatibility, stability of physical and chemical properties, high temperature resistance and sterilizability, convenient processing and molding, softness and elasticity, good sealing performance, and environmental protection and non-toxicity. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] Example 1

[0043] First, the nanosilver is modified, the steps are as follows:

[0044] S1: firstly, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.2 mol / L, and tetramethylammonium hydroxide is added to the silver nitrate and the dispersant tetramethylammonium hydroxide in a molar ratio of 2-3:1, and then stirred to obtain a silver nitrate dispersion solution;

[0045] S2, weighing a certain amount of reducing agent at a molar ratio of silver nitrate and reducing agent of 2:4, adding reducing agent diethanolamine into deionized water, and then adding pH adjusting agent sodium hydroxide to adjust the pH value to 9 to obtain reducing agent solution;

[0046] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0047] S4, adding sodium hydroxide as a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0048] S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

[0049] Then the fumed silica is modified as follows:

[0050] First, add the fumed silica to be modified into a three-necked flask, add 60-100 mL of anhydrous ethanol, put the three-necked flask into a constant temperature water bath at 70-85°C and stir for 1-3 hours, mix the silane coupling agent γ-(2,3-epoxypropoxy)propyltrimethoxysilane, anhydrous ethanol and water in a volume ratio of 1:3:0.7 to obtain a silane coupling agent modified liquid; use a separatory funnel to add the prepared silane coupling agent modified liquid dropwise into the three-necked flask, stop stirring after 1-12 hours to obtain a modified silica suspension, filter and transfer the fumed silica to a tray, put it into a drying oven at 50-75°C for drying for 1-2 hours, and crush it to obtain modified silica.

[0051] A method for preparing a medical foamed silicone material, characterized in that it comprises the following steps:

[0052] Step 1, weigh 70 parts of methyl vinyl silicone rubber, 20 parts of medium phenyl silicone rubber, 7 parts of high phenyl silicone rubber, 10 parts of modified nano silver, 20 parts of modified white carbon black, 7 parts of vulcanizing agent dicumyl peroxide, 20 parts of blowing agent sodium bicarbonate, 3 parts of platinum catalyst and 5 parts of urea respectively according to proportion;

[0053] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0054] Step 3, mixing a medium phenyl silicone rubber having a phenyl content of 15 to 25 mol% and a high phenyl silicone rubber having a phenyl content of 30 to 50 mol% on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20 to 45 min to obtain a mixed rubber B;

[0055] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0056] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0057] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0058] Example 2

[0059] First, the nanosilver is modified, the steps are as follows:

[0060] S1: firstly, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.2 mol / L, and benzyltrimethylammonium bromide is added according to the molar ratio of silver nitrate to dispersant benzyltrimethylammonium bromide of 2-3:1, and then stirred to obtain a silver nitrate dispersion solution;

[0061] S2, weighing a certain amount of reducing agent at a molar ratio of 2:3 with silver nitrate and reducing agent, adding the reducing agent ferrous sulfate into deionized water, and then adding the pH adjusting agent hydrogen peroxide to adjust the pH value to 8 to obtain a reducing agent solution;

[0062] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0063] S4, adding hydrogen peroxide as a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0064] S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

[0065] Then the fumed silica is modified as follows:

[0066] First, add the fumed silica to be modified into a three-necked flask, add 60-100 mL of anhydrous ethanol, put the three-necked flask into a constant temperature water bath at 70-85°C and stir for 1-3 hours, mix the silane coupling agent vinyltrimethoxysilane, anhydrous ethanol and water in a volume ratio of 1:2:0.5 to obtain a silane coupling agent modified liquid; use a separatory funnel to add the prepared silane coupling agent modified liquid dropwise into the three-necked flask, stop stirring after 1-12 hours to obtain a modified silica suspension, filter and transfer the fumed silica to a tray, put it into a 50-75°C drying oven for drying for 1-2 hours, and crush it to obtain modified silica.

[0067] A method for preparing a medical foamed silicone material, characterized in that it comprises the following steps:

[0068] Step 1, weigh 60 parts of methyl vinyl silicone rubber, 15 parts of medium phenyl silicone rubber, 5 parts of high phenyl silicone rubber, 6 parts of modified nano silver, 15 parts of modified white carbon black, 5 parts of vulcanizing agent benzoyl peroxide, 15 parts of blowing agent sodium bicarbonate, 1 part of platinum catalyst and 1 part of urea respectively according to proportion;

[0069] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0070] Step 3, mixing a medium phenyl silicone rubber having a phenyl content of 15 to 25 mol% and a high phenyl silicone rubber having a phenyl content of 30 to 50 mol% on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20 to 45 min to obtain a mixed rubber B;

[0071] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0072] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0073] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0074] Example 3

[0075] First, the nanosilver is modified, the steps are as follows:

[0076] S1: firstly, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.2 mol / L, and polyvinyl alcohol is added in a molar ratio of silver nitrate to polyvinyl alcohol of 2-3:1 and stirred to obtain a silver nitrate dispersion solution;

[0077] S2, weighing a certain amount of reducing agent at a molar ratio of silver nitrate and reducing agent of 2:5, adding reducing agent citric acid into deionized water, and then adding pH adjusting agent hydrogen peroxide to adjust the pH value to 9 to obtain a reducing agent solution;

[0078] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0079] S4, adding ammonia water as a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0080] S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

[0081] Then the fumed silica is modified as follows:

[0082] First, add the fumed silica to be modified into a three-necked flask, add 60-100 mL of anhydrous ethanol, put the three-necked flask into a constant temperature water bath at 70-85°C and stir for 1-3 hours, mix the silane coupling agent γ-aminopropyltriethoxysilane, anhydrous ethanol and water in a volume ratio of 1:5:1 to obtain a silane coupling agent modified liquid; use a separatory funnel to add the prepared silane coupling agent modified liquid dropwise into the three-necked flask, stop stirring after 1-12 hours to obtain a modified silica suspension, filter and transfer the fumed silica to a tray, put it into a drying oven at 50-75°C to dry for 1-2 hours, and crush it to obtain modified silica.

[0083] A method for preparing a medical foamed silicone material, characterized in that it comprises the following steps:

[0084] Step 1, weigh 75 parts of methyl vinyl silicone rubber, 25 parts of medium phenyl silicone rubber, 10 parts of high phenyl silicone rubber, 15 parts of modified nano silver, 35 parts of modified white carbon black, 10 parts of sulfur as a vulcanizing agent, 35 parts of azodicarbonamide as a blowing agent, 5 parts of platinum catalyst and 10 parts of urea respectively according to proportion;

[0085] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0086] Step 3, mixing a medium phenyl silicone rubber having a phenyl content of 15 to 25 mol% and a high phenyl silicone rubber having a phenyl content of 30 to 50 mol% on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20 to 45 min to obtain a mixed rubber B;

[0087] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0088] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0089] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0090] Example 4

[0091] First, the nanosilver is modified, the steps are as follows:

[0092] S1: firstly, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.2 mol / L, and polyvinyl alcohol is added to the silver nitrate and the dispersant polyvinyl alcohol in a molar ratio of 2-3:1, and then stirred to obtain a silver nitrate dispersion solution;

[0093] S2, weighing a certain amount of reducing agent at a molar ratio of silver nitrate and reducing agent of 2:3, adding the reducing agent diethanolamine into deionized water, and then adding the pH adjusting agent sodium hydroxide to adjust the pH value to 8 to obtain a reducing agent solution;

[0094] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0095] S4, adding sodium hydroxide as a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0096] S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

[0097] A method for preparing a medical foamed silicone material, characterized in that it comprises the following steps:

[0098] Step 1, weigh 72 parts of methyl vinyl silicone rubber, 22 parts of medium phenyl silicone rubber, 6 parts of high phenyl silicone rubber, 11 parts of modified nano silver, 32 parts of glass powder, 10 parts of vulcanizing agent benzoyl peroxide, 30 parts of foaming agent azodicarbonamide, 3 parts of platinum catalyst and 2 parts of urea respectively according to proportion;

[0099] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0100] Step 3, mixing a medium phenyl silicone rubber having a phenyl content of 15 to 25 mol% and a high phenyl silicone rubber having a phenyl content of 30 to 50 mol% on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20 to 45 min to obtain a mixed rubber B;

[0101] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0102] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0103] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0104] Example 5

[0105] First, the nanosilver is modified, the steps are as follows:

[0106] S1: First, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.2 mol / L, and silver nitrate and dispersant acryl alcohol are added in a molar ratio of 2-3:1 and stirred to obtain a silver nitrate dispersion solution;

[0107] S2, weighing a certain amount of reducing agent at a molar ratio of silver nitrate and reducing agent of 2:5, adding the reducing agent hydrazine hydrate into deionized water, and then adding the pH adjusting agent sodium hydroxide to adjust the pH value to 9 to obtain a reducing agent solution;

[0108] S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution;

[0109] S4, adding hydrogen peroxide as a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension;

[0110] S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

[0111] A method for preparing a medical foamed silicone material, characterized in that it comprises the following steps:

[0112] Step 1, weigh 68 parts of methyl vinyl silicone rubber, 17 parts of medium phenyl silicone rubber, 8 parts of high phenyl silicone rubber, 7 parts of modified nano silver, 18 parts of montmorillonite, 6 parts of vulcanizing agent diisopropylbenzene peroxide, 17 parts of foaming agent 1,1-azo (1-acetoxy-1-phenylethane), 2 parts of platinum catalyst and 7 parts of urea respectively according to proportion;

[0113] Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A;

[0114] Step 3, mixing a medium phenyl silicone rubber having a phenyl content of 15 to 25 mol% and a high phenyl silicone rubber having a phenyl content of 30 to 50 mol% on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20 to 45 min to obtain a mixed rubber B;

[0115] Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside;

[0116] Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes;

[0117] Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

[0118] Comparative Example 1

[0119] Nanosilver is added directly without modification, fumed silica is improved according to the method in Example 1, and the rest of the preparation method is the same as in Example 1.

[0120] Comparative Example 2

[0121] Without adding modified nano silver, the fumed silica was improved and treated according to the method in Example 1, and the rest of the preparation method was the same as in Example 1.

[0122] Comparative Example 3

[0123] The nanosilver was modified according to the method in Example 1, the reinforcing filler was replaced with one of glass powder, calcium carbonate, montmorillonite, graphene, and silicon powder, and the rest of the preparation method was the same as in Example 1.

[0124] Comparative Example 4

[0125] The nanosilver was modified according to the method in Example 1, without adding reinforcing filler, and the rest of the preparation method was the same as in Example 1.

[0126] Comparative Example 5

[0127] No modified nanosilver or any reinforcing filler is added, and the rest of the preparation method is the same as in Example 1.

[0128] The medical foamed silicone materials prepared in Example 1 to Comparative Example 5 were subjected to the following tests, and the test results are shown in the following table.

[0129] Table 1 Test results of medical foamed silicone materials

[0130]

[0131] It can be concluded from the table that the antibacterial rate of the medical foamed silica gel material added with modified nano-silver can reach more than 99%, and the antibacterial performance is excellent; in Comparative Examples 3 and 4, modified nano-silver is still used. Compared with Comparative Example 1 adding unmodified nano-silver, Comparative Example 2 and Comparative Example 5 not adding modified nano-silver, the antibacterial rate of the foamed silica gel material added with modified nano-silver can reach more than 90%, which shows the superiority of the modified nano-silver in antibacterial performance. When reinforcing materials are added to the medical foamed silica gel material, the mechanical properties of the foamed silica gel material can be greatly improved, especially after the modification of white carbon black, the mechanical properties are significantly improved.

[0132] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A medical foamed silicone material, characterized in that: The invention comprises the following components by weight: 60-75 parts of methyl vinyl silicone rubber, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano silver, 15-35 parts of reinforcing filler, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea.

2. A medical foamed silicone material according to claim 1, characterized in that: The reinforcing filler is at least one of modified white carbon black, glass powder, calcium carbonate, montmorillonite, graphene, and silicon micropowder; the vulcanizing agent is at least one of sulfur, diisopropylbenzene peroxide, and benzoyl peroxide; and the foaming agent is at least one of ammonium bicarbonate, sodium bicarbonate, azobisisobutyronitrile, azodicarbonamide, and 1,1-azo(1-acetoxy-1-phenylethane).

3. The medical foamed silicone material according to claim 1, characterized in that: The preparation method of the modified nano silver is as follows: S1: First, a certain amount of silver nitrate is dissolved in deionized water to prepare a silver nitrate solution with a concentration of 0.15-0.25 mol / L, and a dispersant is added and stirred to obtain a silver nitrate dispersion solution; S2, adding a reducing agent to deionized water, and then adding a pH adjusting agent to obtain a reducing agent solution; S3, adding the reducing agent solution obtained in step S2 dropwise to the silver nitrate dispersion solution in step S1, and performing a reduction reaction at 80-105° C. for 4-6 hours to obtain a reaction solution; S4, adding a promoter to the reaction solution in step S3, stirring evenly and reacting again for 1-3 hours to obtain a suspension; S5. The suspension was allowed to stand for 4-6 hours, centrifuged at 3500-4500 r / min, and then anhydrous ethanol was added, and the mixture was centrifuged at 2000-3500 r / min. The mixture was allowed to stand to obtain a precipitate, which was dried in a vacuum drying oven at 45° C. for 6-12 hours to obtain modified nanosilver.

4. The medical foamed silicone material according to claim 3, characterized in that: The dispersant in S1 is one or a mixture of benzyltrimethylammonium bromide, tetramethylammonium hydroxide, sodium laurate, polyethylene glycol, polyvinyl alcohol, and allyl alcohol, and the silver nitrate and the dispersant are mixed in a molar ratio of 2-3:1; The reducing agent in S2 is one or more of triethanolamine, diethanolamine, ferrous sulfate, citric acid, formaldehyde, hydrogen peroxide, and hydrazine hydrate, and the molar ratio of the silver nitrate to the reducing agent is 2:(3-5); The pH regulator in S2 is one of ammonia water and sodium hydroxide or a mixture of the two, and the pH value of the pH regulator in S2 is adjusted to 8-9; The accelerator in S4 is one of hydrogen peroxide, sodium hydroxide or ammonia water.

5. The medical foamed silicone material according to claim 1, characterized in that: The reinforcing filler is modified white carbon black, and the modified white carbon black is obtained by the following steps: First, add the fumed silica to be modified into a three-necked flask, add 60-100 mL of anhydrous ethanol, put the three-necked flask into a constant temperature water bath at 70-85°C and stir for 1-3 hours, mix the silane coupling agent, anhydrous ethanol and water in a volume ratio of 1:(2-5):(0.5-1) to obtain a silane coupling agent modified liquid; use a separatory funnel to add the prepared silane coupling agent modified liquid dropwise into the three-necked flask, stop stirring after 1-12 hours to obtain a modified silica suspension, filter and transfer the fumed silica to a tray, put it into a 50-75°C drying oven for drying for 1-2 hours, and crush it to obtain modified silica.

6. The medical foamed silicone material according to claim 5, characterized in that: The silane coupling agent is selected from one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane.

7. A medical foamed silicone material according to any one of claims 1 to 6, characterized in that: The medical foamed silica gel material is prepared by mixing the following components: 60-75 parts of methyl vinyl silicone rubber, 15-25 parts of medium phenyl silicone rubber, 5-10 parts of high phenyl silicone rubber, 6-15 parts of modified nano silver, 15-35 parts of modified white carbon black, 5-10 parts of vulcanizing agent, 15-35 parts of foaming agent, 1-5 parts of platinum catalyst and 1-10 parts of urea.

8. A method for preparing a medical foamed silicone material according to any one of claims 1 to 6, characterized in that: The following steps are included: Step 1, weighing a certain amount of methyl vinyl silicone rubber, medium phenyl silicone rubber, high phenyl silicone rubber, modified nano silver, reinforcing filler, vulcanizing agent, foaming agent, platinum catalyst and urea respectively according to proportion; Step 2, placing the methyl vinyl silicone rubber on an open mill, with the roller temperature less than 45°C and the roller spacing of 4mm to 6mm for open milling, adding reinforcing fillers and mixing evenly, and then sheeting, mixing for 15min to 40min to obtain a mixed rubber A; Step 3, mixing the medium phenyl silicone rubber and the high phenyl silicone rubber on an open mill at a roller temperature of less than 45° C. and a roller spacing of 4 mm to 6 mm for 20-45 min to obtain a mixed rubber B; Step 4: The obtained rubber mix A is placed at room temperature for 12-24 hours, placed on an open mill and rolled, and the rubber mix B is added and mixed for 10-45 minutes, and the modified nano silver, the vulcanizing agent, and the platinum catalyst are added in batches and mixed for another 15-35 minutes. After mixing evenly, the foaming agent and urea are added, and mixed evenly again, and the sheet is set aside; Step 5: Put the uniformly blended rubber into the preheated mold and vulcanize it on a flat vulcanizer at 80-105°C for 8-25 minutes; Step 6: Place the rubber material in step 5 in an oven at 120-160° C. for 20-60 minutes. After it is fully foamed, take it out of the oven and cool it naturally to obtain a medical foamed silicone material.

9. The method for preparing a medical foamed silicone material according to claim 8, characterized in that: The phenyl content of the medium phenyl silicone rubber is 15-25 mol%, and the medium phenyl silicone has ablation-resistant silicon performance; the phenyl content of the high phenyl silicone rubber is 30-50 mol%, and the high phenyl silicone rubber has radiation resistance, and the γ-ray radiation resistance value of the high phenyl silicone rubber is 2.58×104C / kg.

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