High-performance syringe rubber protective cap and preparation method thereof

Abstract

The invention relates to the field of medical rubber, in particular to a high-performance syringe rubber protective cap and a preparation method of the high-performance syringe rubber protective cap. The rubber material is prepared from the following components in parts by weight: 100 to 150 parts of modified polyisoprene, 5 to 10 parts of alkaline white carbon black, 30 to 50 parts of calcined kaolin, 1 to 2 parts of peroxide, 0.2 to 0.5 part of vulcanization accelerator, 1 to 3 parts of stearic acid, 5 to 15 parts of ultrahigh molecular weight polyethylene powder, 1 to 2 parts of carbon black and 5 to 10 parts of dimethyl silicone oil. The syringe rubber protective cap prepared by the invention has excellent puncture resistance, air tightness and environmental protection property, and does not easily generate adverse reaction with compound medicines.

Description

Technical Field

[0001] The invention relates to the field of medical rubber, and in particular to a high-performance syringe rubber protective cap and a preparation method thereof. Background Art

[0002] In the field of medical devices, such as gloves, condoms, catheters, and rubber caps, natural rubber has traditionally been used. However, due to the sensitization and allergic reactions that natural rubber may cause, the industry has begun to look for alternatives, and cis-polyisoprene synthetic rubber has become a major candidate because it does not contain proteins that may cause allergies. However, there are still some problems in the application of polyisoprene rubber caps, among which the most prominent problem is the problem of puncture debris.

[0003] Patent CN118791805A discloses a medical injection rubber stopper, which is composed of the following components: halogenated butyl rubber, polyisoprene rubber, active magnesium oxide, polytetrafluoroethylene, filler, lubricant, and antistatic coating; the rubber stopper prepared by the invention has better chemical stability and lower gas permeability, is not only acid and alkali resistant, but also can effectively reduce the reaction with drugs, and the rubber stopper itself has good lubrication performance and elasticity, so that the rubber stopper is not easy to produce debris during the puncture process; by adding lubricants to increase the self-lubricating performance of the rubber stopper raw material, the friction between the injection needle and the rubber stopper is greatly reduced during the puncture of the injection needle, thereby avoiding the generation of needle puncture debris; coating a layer of antistatic coating on the surface of the molded rubber stopper can reduce static electricity accumulation, thereby reducing pollution and debris. However, halogenated butyl rubber may release harmful gases during the high-temperature sterilization of the rubber stopper, affecting the safety of the drug.

[0004] Patent CN102731876B discloses a formula for a medical rubber stopper, and its components are as follows by weight: medical artificial rubber, medical zinc oxide, medical stearic acid, medical anti-aging agent, medical insoluble sulfur, medical thiazole accelerator, medical sulfonamide accelerator, medical tetrabenzylthiuram disulfide. The beneficial effects of this invention are: 1. Using medical tetrabenzylthiuram disulfide instead of rubber accelerator TMTD can prevent the rubber stopper from precipitating carcinogenic nitrosamines; 2. Using artificial polyisoprene can avoid allergic reactions caused by natural rubber containing plant proteases and other substances; 3. Using medical white carbon black and medical calcined kaolin can improve the needle resistance of the rubber stopper. However, the rubber stopper contains more additives, which may cause adverse reactions with compound drugs.

[0005] Therefore, there is an urgent need in the market for a syringe rubber protective cap that has good puncture resistance, good environmental protection, and is not prone to adverse reactions with compound drugs. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to obtain a syringe rubber protective cap which has good puncture resistance, good environmental protection, is not prone to adverse reactions with compound drugs and has good air tightness.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a high-performance syringe rubber cap, which includes the following raw materials, by weight, 100-150 parts of modified polyisoprene, 5-10 parts of basic white carbon black, 30-50 parts of calcined kaolin, 1-2 parts of peroxide, 0.2-0.5 parts of vulcanization accelerator, 1-3 parts of stearic acid, 5-15 parts of ultra-high molecular weight polyethylene powder, 1-2 parts of carbon black, and 5-10 parts of dimethyl silicone oil.

[0009] The present application prepares a modified polyisoprene with low turbidity and compounds it with basic white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, ultra-high molecular weight polyethylene powder and carbon black to prepare a syringe rubber cap with excellent puncture resistance, good environmental protection, not easy to have adverse reactions with compound drugs and excellent air tightness.

[0010] In some embodiments, the method for preparing the modified polyisoprene comprises the following steps:

[0011] A1, adding diallyl diphenylsilane, tetrahydrofurfuryl methacrylate and azobisisobutyronitrile into a solvent, reacting at 70-80° C. for 3-6 hours, and drying to obtain a structure regulator;

[0012] A2. Under nitrogen protection, cyclohexane, isoprene and a structure regulator are added to a reaction vessel, the temperature is raised to 50-70° C., a cyclohexane solution of n-butyl lithium is added, and after reacting for 3-5 hours, ethanol is added and stirred for 20-30 minutes. After drying, modified polyisoprene is obtained.

[0013] The turbidity of polyisoprene affects the various properties of the rubber cap, so it is very necessary to prepare polyisoprene with low turbidity. However, in the prior art, in order to obtain polyisoprene with low turbidity, it is often necessary to perform an extraction operation after the polymerization reaction is completed, which consumes a large amount of solvent and does not meet the requirements of environmental protection. In response to this problem, the present application obtains a structure regulator containing a double benzene ring space structure and a cyclic ether group by reacting diallyl diphenyl silane with propylene oxide, and adds it to the synthesis process of polyisoprene. It is found that the turbidity of polyisoprene can be reduced and the air tightness and puncture resistance of the prepared rubber cap can be increased. This may be because the diallyl diphenyl silane segment in the structure regulator prepared by the present application can be complexed with a lithium catalyst, and its special spatial structure has a directional effect on the attack of isoprene, thereby increasing the proportion of cis-1,4-polyisoprene in polyisoprene and reducing the generation of by-products such as trans-1,4-polyisoprene and 3,4-polyisoprene. However, the present application found during the experiment that the turbidity of polyisoprene did not decrease significantly when only diallyldiphenylsilane was added. This may be because the steric hindrance effect of the diallyldiphenylsilane chain segment after complexing with the lithium catalyst makes it difficult for isoprene to be contacted by the active species, thereby reducing the polymerization reaction rate. The present application found that this problem can be solved after the introduction of cyclic ether groups. This may be because the cyclic ether groups can increase the polarity of the polymerization system and increase the catalytic activity of the lithium catalyst, thereby increasing the reaction rate. In addition, the present application found that the turbidity of modified polyisoprene was lowest after diallyldiphenylsilane and tetrahydrofurfuryl methacrylate were polymerized and then added. This may be because after diallyldiphenylsilane and tetrahydrofurfuryl methacrylate were polymerized, each diallyldiphenylsilane segment was isolated by the tetrahydrofurfuryl methacrylate segment, which can reduce the steric effect while improving the activity of the catalyst, achieving the effect of timely reacting the "oriented" isoprene, increasing the proportion of cis-1,4-polyisoprene in polyisoprene, and thus improving the puncture resistance, chemical resistance and air tightness of the rubber cap. In addition, the introduction of -Si- is also conducive to improving the lubricity of the rubber cap and thus improving its puncture resistance.

[0014] In some embodiments, the mass ratio of diallyldiphenylsilane to tetrahydrofurfuryl methacrylate is 1:(0.4-0.7).

[0015] In some embodiments, the mass ratio of isoprene to the structure regulator in step A2 is 1:(0.0002-0.0007).

[0016] The present application limits the ratio of diallyldiphenylsilane and tetrahydrofurfuryl methacrylate or isoprene and a structure regulator, thereby reducing the residual tetrahydrofurfuryl methacrylate in the system, preventing it from entering the synthesis process of polyisoprene to catalyze the chain extension reaction of isoprene and affecting it, thereby facilitating the improvement of the puncture resistance and air tightness of polyisoprene.

[0017] In some embodiments, the high-performance syringe rubber cap further comprises 3-5 parts by weight of modified polytetrafluoroethylene powder.

[0018] In some embodiments, the method for preparing the modified polytetrafluoroethylene powder comprises the following steps: adding polytetrafluoroethylene powder and methacrylic acid into a high-speed mixer, and stirring at a speed of 300-500 rpm for 20-40 minutes at room temperature to obtain the modified polytetrafluoroethylene powder.

[0019] Polytetrafluoroethylene micropowder is corrosion-resistant. Using polytetrafluoroethylene micropowder to prepare rubber caps can improve their corrosion resistance and make it difficult for compound drugs to react adversely with rubber caps. However, polytetrafluoroethylene micropowder is chemically inert, so it is easy to agglomerate during the blending process with polyisoprene. In response to this problem, the present application uses methacrylic acid with a filamentous fiber structure to modify polytetrafluoroethylene micropowder, so that filamentous fibers are attached to the surface of polytetrafluoroethylene micropowder, and each polytetrafluoroethylene micropowder can be separated. In the process of rubber vulcanization, methacrylic acid can participate in the vulcanization of rubber and react with double bonds, so that polytetrafluoroethylene micropowder is evenly dispersed in polyisoprene, which is beneficial to improving the corrosion resistance of rubber caps, making rubber caps less likely to react with drugs, ensuring the safety of drugs, and the introduction of fluorine atoms into the system is beneficial to improving the lubricity of rubber caps, and then it is beneficial to improve the puncture resistance of rubber caps.

[0020] In some embodiments, the mass ratio of the polytetrafluoroethylene powder to methacrylic acid is 1:(0.2-0.5).

[0021] Too much methacrylic acid remaining in the rubber cap may affect the vulcanization effect of the rubber. The present application limits the ratio of polytetrafluoroethylene powder and methacrylic acid to increase the loading amount of methacrylic acid while reducing the residual methacrylic acid, which is beneficial to improving the puncture resistance and air tightness of the rubber cap of the syringe.

[0022] In some embodiments, the peroxide is di-tert-butylcumene peroxide.

[0023] In some embodiments, the vulcanization accelerator is sodium dibutyl dithiocarbamate.

[0024] Another aspect of the present invention provides a method for preparing a high-performance syringe rubber protective cap, comprising the following steps:

[0025] S1. Mixing modified polyisoprene, alkaline white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, modified polytetrafluoroethylene powder, ultra-high molecular weight polyethylene powder and carbon black at 100-120° C. for 10-15 minutes to prepare a rubber compound;

[0026] S2, cutting the mixed rubber obtained in step S1 into strips, leaving them for 3-7 days to obtain mixed rubber strips;

[0027] S3, vulcanizing the mixed rubber strip obtained in step S2 for 20-40 minutes at a vulcanization temperature of 130-140° C. to prepare a vulcanized rubber sheet;

[0028] S4, punching the vulcanized rubber sheet obtained in step S3, siliconizing it with dimethyl silicone oil, and obtaining a high-performance syringe rubber protective cap after drying.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention prepares a modified polyisoprene with low turbidity and mixes it with basic white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, ultra-high molecular weight polyethylene powder, and carbon black to prepare a syringe rubber cap with excellent puncture resistance, good environmental protection, not easy to react adversely with compound drugs, and excellent air tightness.

[0031] (2) The present invention obtains a structure regulator containing a double benzene ring space structure and a cyclic ether group by reacting diallyl diphenylsilane with propylene oxide. It is found that adding the structure regulator to the synthesis process of polyisoprene can reduce the turbidity of the polyisoprene and increase the air tightness, puncture resistance and chemical resistance of the prepared rubber protective cap.

[0032] (3) The present invention uses methacrylic acid to modify polytetrafluoroethylene micropowder with a filamentous fiber structure, so that filamentous fibers are attached to the surface of the polytetrafluoroethylene micropowder, which can separate the polytetrafluoroethylene micropowders. In addition, during the vulcanization of the rubber, methacrylic acid can participate in the vulcanization of the rubber and react with double bonds, so that the polytetrafluoroethylene micropowder is evenly dispersed in the polyisoprene, which is beneficial to improving the corrosion resistance of the rubber protective cap, making it difficult for the rubber protective cap to react with drugs, thereby ensuring the safety of the drugs. DETAILED DESCRIPTION

[0033] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0034] In the following embodiments and comparative examples, except for modified polyisoprene and modified polytetrafluoroethylene powder, the other compounds and related reagents used can be purchased from the market, among which the particle size of polytetrafluoroethylene powder is 1-2 μm, purchased from Dongguan Zhengtao Plastic Co., Ltd.; the model of ultra-high molecular weight polyethylene powder is XM220, purchased from Dongguan Sancheng Plastic Raw Materials Co., Ltd.; the model of carbon black is n220, purchased from Jinan Delan Chemical Co., Ltd.

[0035] Preparation Example 1

[0036] The method for preparing modified polyisoprene-1 comprises the following steps:

[0037] A1, add 1g of diallyldiphenylsilane, 0.55g of tetrahydrofurfuryl methacrylate, and 0.01g of azobisisobutyronitrile to 10g of chloroform, react at 75°C for 4.5h, and dry to obtain a structure regulator;

[0038] A2. Under nitrogen protection, 300 g of cyclohexane, 100 g of isoprene and 0.05 g of a structure regulator were added to a reaction vessel, the temperature was raised to 60° C., 10 g of a 1 wt% n-butyl lithium cyclohexane solution was added, and after reacting for 4 h, 1000 g of anhydrous ethanol was added and stirred for 25 min. After drying, modified polyisoprene-1 was obtained.

[0039] Preparation Example 2

[0040] The preparation method of modified polyisoprene-2 ​​is the same as that of Preparation Example 1, except that the addition amount of tetrahydrofurfuryl methacrylate is 1 g.

[0041] Preparation Example 3

[0042] The preparation method of modified polyisoprene-3 is the same as that of Preparation Example 1, except that the amount of the structure regulator added is 0.1 g.

[0043] Preparation Example 4

[0044] The preparation method of modified polytetrafluoroethylene micropowder-1 comprises the following steps: adding 10g polytetrafluoroethylene micropowder and 3.5g methacrylic acid into a high-speed stirrer, and stirring at a speed of 400 rpm for 30 minutes at room temperature to obtain modified polytetrafluoroethylene micropowder-1.

[0045] Preparation Example 5

[0046] The preparation method of polytetrafluoroethylene powder-2 is the same as that of Preparation Example 4, except that the added amount of methacrylic acid is 0.7 g.

[0047] Preparation Example 6

[0048] The preparation method of polyisoprene comprises the following steps: adding 300 g of cyclohexane and 100 g of isoprene into a reaction container under nitrogen protection, heating to 60° C., adding 10 g of a 1 wt% n-butyl lithium cyclohexane solution, reacting for 4 h, adding 1000 g of anhydrous ethanol, stirring for 25 min, and obtaining polyisoprene after drying.

[0049] The turbidity of the polyisoprene obtained in Preparation Examples 1-3 and 6 was tested according to YBB00232004-2015 "Medicinal Synthetic Polyisoprene Gasket". The results are shown in Table 1:

[0050] Table 1

[0051] Group Turbidity of polyisoprene Preparation Example 1 <0.5 level Preparation Example 2 <Level 1 Preparation Example 3 <Level 1 Preparation Example 6 <Level 2

[0052] It can be seen from the data in Table 1 that the modified polyisoprene obtained in Preparation Example 1 has a higher purity. It can be seen from the comparison between Preparation Examples 2 and 3 and Preparation Example 1 that changing the ratio of diallyldiphenylsilane and tetrahydrofurfuryl methacrylate or isoprene and the structure regulator will reduce the purity of the polyisoprene; it can be seen from the comparison between Preparation Example 6 and Preparation Example 1 that the purity of the unmodified polyisoprene is lower.

[0053] Example 1

[0054] A high-performance syringe rubber protective cap comprises the following raw materials, measured by weight: 125 parts of modified polyisoprene-1, 7 parts of basic white carbon black, 40 parts of calcined kaolin, 1.5 parts of di-tert-butyl peroxide isopropylbenzene, 0.35 parts of sodium dibutyl dithiocarbamate, 2 parts of stearic acid, 10 parts of ultra-high molecular weight polyethylene powder, 1.5 parts of carbon black, and 7 parts of dimethyl silicone oil.

[0055] The method for preparing the high-performance syringe rubber protective cap of this embodiment comprises the following steps:

[0056] S1. Using a strong pressure internal mixer, modified polyisoprene-1, alkaline white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, ultra-high molecular weight polyethylene powder, and carbon black are mixed at 110° C. for 12 minutes to obtain a rubber compound;

[0057] S2, cutting the mixed rubber obtained in step S1 into strips on an open rubber mixer and leaving it for 5 days to obtain mixed rubber strips;

[0058] S3, placing the mixed rubber strip obtained in step S2 into an injection molding rubber vulcanizer, and vulcanizing it for 30 minutes using a high-temperature rapid injection molding vulcanization process at a vulcanization temperature of 135° C. to prepare a vulcanized rubber sheet;

[0059] S4. In a clean environment, a special punching machine and a matching mold are used to punch the vulcanized rubber sheet obtained in step S3, and dimethyl silicone oil is used for siliconization. After drying, a high-performance syringe rubber cap is obtained.

[0060] Example 2

[0061] A high-performance syringe rubber protective cap comprises the following raw materials, measured by weight: 100 parts of modified polyisoprene-1, 5 parts of basic white carbon black, 30 parts of calcined kaolin, 1 part of di-tert-butyl peroxide isopropylbenzene, 0.2 parts of sodium dibutyl dithiocarbamate, 1 part of stearic acid, 5 parts of ultra-high molecular weight polyethylene powder, 1 part of carbon black, and 5 parts of dimethyl silicone oil.

[0062] The method for preparing the high-performance syringe rubber protective cap of this embodiment comprises the following steps:

[0063] S1. Using a strong pressure internal mixer, modified polyisoprene-1, basic white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, ultra-high molecular weight polyethylene powder, and carbon black were mixed at 100° C. for 15 minutes to obtain a rubber compound;

[0064] S2, cutting the mixed rubber obtained in step S1 into strips on an open rubber mixer and leaving it for 3 days to obtain mixed rubber strips;

[0065] S3, placing the mixed rubber strip obtained in step S2 into an injection molding rubber vulcanizer, and vulcanizing it for 20 minutes using a high-temperature rapid injection molding vulcanization process at a vulcanization temperature of 140° C. to prepare a vulcanized rubber sheet;

[0066] S4. In a clean environment, a special punching machine and a matching mold are used to punch the vulcanized rubber sheet obtained in step S3, and dimethyl silicone oil is used for siliconization. After drying, a high-performance syringe rubber cap is obtained.

[0067] Example 3

[0068] A high-performance syringe rubber protective cap comprises the following raw materials, measured by weight: 150 parts of modified polyisoprene-1, 10 parts of basic white carbon black, 50 parts of calcined kaolin, 2 parts of di-tert-butyl peroxide isopropylbenzene, 0.5 parts of sodium dibutyl dithiocarbamate, 3 parts of stearic acid, 15 parts of ultra-high molecular weight polyethylene powder, 2 parts of carbon black, and 10 parts of dimethyl silicone oil.

[0069] The method for preparing the high-performance syringe rubber protective cap of this embodiment comprises the following steps:

[0070] S1. Using a strong pressure internal mixer, modified polyisoprene-1, alkaline white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, ultra-high molecular weight polyethylene powder, and carbon black are mixed at 120° C. for 10 min to obtain a rubber compound;

[0071] S2, cutting the mixed rubber obtained in step S1 into strips on an open rubber mixer, leaving the mixed rubber for 7 days to obtain mixed rubber strips;

[0072] S3, placing the mixed rubber strip obtained in step S2 into an injection molding rubber vulcanizer, and vulcanizing it for 30 minutes using a high-temperature rapid injection molding vulcanization process at a vulcanization temperature of 130° C. to prepare a vulcanized rubber sheet;

[0073] S4. In a clean environment, a special punching machine and a matching mold are used to punch the vulcanized rubber sheet obtained in step S3, and dimethyl silicone oil is used for siliconization. After drying, a high-performance syringe rubber cap is obtained.

[0074] Example 4

[0075] A high-performance syringe rubber protective cap and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified polyisoprene-1 is replaced by modified polyisoprene-2.

[0076] Example 5

[0077] A high-performance syringe rubber protective cap and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of modified polyisoprene-1 is replaced by modified polyisoprene-3.

[0078] Example 6

[0079] A high-performance syringe rubber protective cap comprises the following raw materials, measured by weight: 125 parts of modified polyisoprene-1, 7 parts of basic white carbon black, 40 parts of calcined kaolin, 1.5 parts of di-tert-butyl peroxide isopropylbenzene, 0.35 parts of sodium dibutyl dithiocarbamate, 2 parts of stearic acid, 10 parts of ultra-high molecular weight polyethylene powder, 1.5 parts of carbon black, 7 parts of dimethyl silicone oil, and 4 parts of modified polytetrafluoroethylene micropowder-1.

[0080] The method for preparing the high-performance syringe rubber protective cap of this embodiment comprises the following steps:

[0081] S1. Using a strong pressure internal mixer, modified polyisoprene-1, alkaline white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, modified polytetrafluoroethylene micropowder-1, ultra-high molecular weight polyethylene powder, and carbon black were mixed at 110° C. for 12 minutes to obtain a rubber compound;

[0082] S2, cutting the mixed rubber obtained in step S1 into strips on an open rubber mixer and leaving it for 5 days to obtain mixed rubber strips;

[0083] S3, placing the mixed rubber strip obtained in step S2 into an injection molding rubber vulcanizer, and vulcanizing it for 30 minutes using a high-temperature rapid injection molding vulcanization process at a vulcanization temperature of 135° C. to prepare a vulcanized rubber sheet;

[0084] S4. In a clean environment, a special punching machine and a matching mold are used to punch the vulcanized rubber sheet obtained in step S3, and dimethyl silicone oil is used for siliconization. After drying, a high-performance syringe rubber cap is obtained.

[0085] Example 7

[0086] A high-performance syringe rubber protective cap and a preparation method thereof. The specific implementation method is the same as Example 6, except that an equal amount of modified polytetrafluoroethylene micropowder-1 is replaced by modified polytetrafluoroethylene micropowder-2.

[0087] Comparative Example 1

[0088] A high-performance syringe rubber protective cap and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified polyisoprene-1 is replaced by polyisoprene.

[0089] Performance Testing

[0090] According to YBB00232004-2015 "Medicinal Synthetic Polyisoprene Gasket", the high-performance syringe rubber caps obtained in the above embodiments and comparative examples were subjected to the following performance tests:

[0091] 1. Puncture resistance and sealing performance

[0092] The test results are shown in Table 2:

[0093] Table 2

[0094] Group Puncture debris (grains) Sealing (4h) Example 1 1 No leakage Example 2 1 No leakage Example 3 1 No leakage Example 4 2 No leakage Example 5 3 There is a leak Example 6 0 No leakage Example 7 2 There is a leak Comparative Example 1 5 There is a leak

[0095] It can be seen from the data in Table 2 that the syringe rubber caps in Examples 1-3 of the present invention have good puncture resistance and air tightness. From the comparison between Examples 4 and 5 and Example 1, it can be seen that changing the ratio of diallyldiphenylsilane and tetrahydrofurfuryl methacrylate or isoprene and the structure regulator will affect the chain extension reaction of the modified polyisoprene, thereby reducing the puncture resistance and air tightness of the syringe rubber cap; from the comparison between Example 6 and Example 1, it can be seen that the puncture resistance and air tightness of the syringe rubber cap are further improved after adding modified polytetrafluoroethylene powder; from the comparison between Example 7 and Example 1, it can be seen that the change in the ratio of polytetrafluoroethylene powder and methacrylic acid will affect the vulcanization effect of the rubber, resulting in the deterioration of the puncture resistance and air tightness of the syringe rubber cap; from the comparison between Comparative Example 1 and Example 1, it can be seen that without modifying polyisoprene, the puncture resistance and air tightness of the syringe rubber cap are poor.

[0096] 2. Chemical property test of the rubber protective caps of syringes obtained in Examples 1 and 6

[0097] The results are shown in Table 3:

[0098] Table 3

[0099] project index The test results of Example 1 The test results of Example 6 heavy metal ≤ 1 part per million <1 in 1 million <1 in 1 million Ammonium ion ≤0.0002％ ＜0.0002％ ＜0.0002％ Zinc ion ≤0.0003 ＜0.0003％ ＜0.0003％

[0100] From the data in Table 3, it can be seen that the chemical properties of the rubber protective caps for syringes obtained in Examples 1 and 6 meet the requirements.

[0101] 3. Biological performance testing of syringe rubber caps

[0102] After testing, the rubber caps for syringes prepared in Examples 1-6 do not contain proteins that can cause allergic reactions, and will not release any substances that cause side effects on patients; there is no pyrogen; the hemolysis rate is 3.1%-3.7%, which is less than the standard 5%; and there is no systemic acute toxicity.

[0103] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-performance syringe rubber protective cap, characterized in that: The invention comprises the following raw materials by weight: 100-150 parts of modified polyisoprene, 5-10 parts of alkaline white carbon black, 30-50 parts of calcined kaolin, 1-2 parts of peroxide, 0.2-0.5 parts of vulcanization accelerator, 1-3 parts of stearic acid, 5-15 parts of ultra-high molecular weight polyethylene powder, 1-2 parts of carbon black and 5-10 parts of dimethyl silicone oil.

2. The high-performance syringe rubber protective cap according to claim 1, characterized in that: The preparation method of the modified polyisoprene comprises the following steps: A1, adding diallyl diphenylsilane, tetrahydrofurfuryl methacrylate and azobisisobutyronitrile into a solvent, reacting at 70-80° C. for 3-6 hours, and drying to obtain a structure regulator; A2. Under nitrogen protection, cyclohexane, isoprene and a structure regulator are added to a reaction vessel, the temperature is raised to 50-70° C., a cyclohexane solution of n-butyl lithium is added, and after reacting for 3-5 hours, ethanol is added and stirred for 20-30 minutes. After drying, modified polyisoprene is obtained.

3. The high-performance syringe rubber protective cap according to claim 2, characterized in that: The mass ratio of diallyldiphenylsilane to tetrahydrofurfuryl methacrylate is 1:(0.4-0.7).

4. The high-performance syringe rubber protective cap according to claim 2, characterized in that: The mass ratio of isoprene to the structure regulator in step A2 is 1:(0.0002-0.0007).

5. The high performance syringe rubber protective cap according to claim 1, characterized in that: The peroxide is di-tert-butyl peroxide isopropylbenzene.

6. The high performance syringe rubber protective cap according to claim 1, characterized in that: The vulcanization accelerator is sodium dibutyl dithiocarbamate.

7. The high performance syringe rubber protective cap according to claim 1, characterized in that: The high-performance syringe rubber protective cap also contains 5-15 parts by weight of modified polytetrafluoroethylene powder.

8. The high-performance syringe rubber protective cap according to claim 7, characterized in that: The preparation method of the modified polytetrafluoroethylene micropowder comprises the following steps: adding polytetrafluoroethylene micropowder and methacrylic acid into a high-speed stirrer, and stirring at a speed of 300-500 rpm for 20-40 minutes at room temperature to obtain the modified polytetrafluoroethylene micropowder.

9. The high performance syringe rubber protective cap according to claim 8, characterized in that: The mass ratio of the polytetrafluoroethylene powder to methacrylic acid is 1:(0.2-0.5).

10. A method for preparing the high-performance syringe rubber protective cap according to any one of claims 7 to 9, characterized in that: The following steps are involved: S1. Mixing modified polyisoprene, alkaline white carbon black, calcined kaolin, peroxide, vulcanization accelerator, stearic acid, modified polytetrafluoroethylene powder, ultra-high molecular weight polyethylene powder and carbon black at 100-120° C. for 10-15 minutes to prepare a rubber compound; S2, cutting the mixed rubber obtained in step S1 into strips, leaving them for 3-7 days to obtain mixed rubber strips; S3, vulcanizing the mixed rubber strip obtained in step S2 for 20-40 minutes at a vulcanization temperature of 130-140° C. to prepare a vulcanized rubber sheet; S4, punching the vulcanized rubber sheet obtained in step S3, siliconizing it with dimethyl silicone oil, and obtaining a high-performance syringe rubber protective cap after drying.