Brominated butyl rubber composite gasket and preparation method thereof

Abstract

The invention discloses a brominated butyl rubber composite gasket which comprises a medicine connection sealing layer and a puncture surface layer which are integrally overlapped in the thickness direction. The rubber raw materials of the medicine connection sealing layer mainly comprise 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.1-0.4 part of sulfur, 30-45 parts of calcined kaolin, 20-35 parts of montmorillonite, 0-5 parts of an inorganic coloring agent and 2-3 parts of polyethylene wax powder; the rubber raw materials of the puncture surface layer mainly comprise 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.2-0.5 part of sulfur, 40-70 parts of calcined kaolin, 20-40 parts of composite powder of white carbon black and organic silicon elastomer micro powder, 0-5 parts of an inorganic coloring agent and 0.1-0.5 part of a silane coupling agent. The brominated butyl rubber composite gasket with the two-layer laminated structure is reasonable in structure, and the compatibility and puncture resistance of the brominated butyl rubber composite gasket with drugs meet the use requirements of insulin pen test syringes.

Description

Technical Field

[0001] The invention relates to the technical field of rubber product production, and in particular to a brominated butyl rubber composite gasket and a preparation method thereof. Background Art

[0002] The brominated butyl rubber composite gasket used for insulin pen test syringes must be resistant to multiple punctures. The existing brominated butyl rubber gaskets use the same formula of rubber and use color to distinguish the packaging surface facing and away from the drug.

[0003] In order to improve the compatibility and safety of gaskets with pharmaceuticals, brominated butyl rubber gaskets usually adopt a formula with less ash, such as using high-density polyethylene micropowder to replace part of the ash filler. This method is beneficial to improve the density and hardness of the rubber plug, but the cost is high. At the same time, the probability of needle puncture and chip falling and the puncture force are increased, especially for gaskets with a consistent formula in the thickness direction. Summary of the invention

[0004] One of the purposes of the present invention is to overcome the defects existing in the prior art and provide a brominated butyl rubber composite gasket, which adopts a laminated structure of a drug-bonded sealing layer and a puncture surface layer, has both the safety of the drug-bonded sealing layer and the toughening and sealing performance of the puncture surface layer, and meets the use requirements of insulin pen test syringes.

[0005] In order to achieve the above technical effects, the technical solution of the present invention is: a brominated butyl rubber composite gasket, comprising a medical sealing layer and a puncture surface layer integrally laminated along the thickness direction;

[0006] The rubber raw material of the medical sealing layer is mainly composed of: 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.1-0.4 parts of sulfur, 30-45 parts of calcined kaolin, 20-35 parts of montmorillonite, 0-5 parts of inorganic colorant, and 2-3 parts of polyethylene wax powder;

[0007] The rubber raw material of the puncture surface layer is mainly composed of: 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.2-0.5 parts of sulfur, 40-70 parts of calcined kaolin, 20-40 parts of composite powder of white carbon black and silicone elastomer powder, 0-5 parts of inorganic colorant, and 0.1-0.5 parts of silane coupling agent.

[0008] Furthermore, the rubber raw material of the medical sealing layer is mainly composed of: 100 parts of brominated butyl rubber, 2.5-5 parts of magnesium oxide, 0.2-0.4 parts of sulfur, 30-40 parts of calcined kaolin, 25-35 parts of montmorillonite, 1-3 parts of inorganic colorant, and 2-3 parts of polyethylene wax powder;

[0009] The rubber raw material of the puncture surface layer is mainly composed of: 100 parts of brominated butyl rubber, 3-6 parts of magnesium oxide, 0.3-0.5 parts of sulfur, 50-70 parts of calcined kaolin, 20-30 parts of composite powder of white carbon black and silicone elastomer powder, 1-3 parts of inorganic colorant, and 0.1-0.3 parts of silane coupling agent.

[0010] The preferred technical solution is that the composite powder of white carbon black and silicone elastomer powder is obtained by grinding and drying white carbon black and silicone elastomer powder in a silane coupling agent solution, and the mass ratio of white carbon black to silicone elastomer powder is (3.5-7): 1. Specifically, the mass ratio of white carbon black to silicone elastomer powder can be selected as 3.5: 1, 4: 1, 4.5: 1, 5: 1, 5.5: 1, 6: 1, 6.5: 1, 7: 1, and any two ratios as the interval value of the maximum value and the minimum value.

[0011] The preferred technical solution is that the particle size of the white carbon black is 7 to 40 nm, and the particle size of the organic silicon elastomer powder is 5 to 13 μm.

[0012] The preferred technical solution is that the particle size of the montmorillonite is 800-2000 mesh, and the diameter-thickness ratio is (10-20):1; the particle size of the calcined kaolin is 2000-4000 mesh. The above particle sizes are taken as the average particle size.

[0013] A preferred technical solution is that the silicone elastomer powder is a cross-linked polymer of polydimethylsiloxane and vinyl polydimethylsiloxane.

[0014] The preferred technical solution is that the silane coupling agent is a composition of a first silane coupling agent having a long-chain alkyl group of C12 or more and a mercaptosilane coupling agent, and the mass percentage of the first silane coupling agent in the silane coupling agent is 65% to 85%. The selection range of the silane coupling agent includes dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane, and more preferably at least one of dodecyltrimethoxysilane and hexadecyltrimethoxysilane. The mercaptosilane coupling agent can be selected from bis(triethoxypropylsilane) disulfide and bis-(γ-triethoxysilylpropyl) tetrasulfide.

[0015] The second object of the present invention is to provide a method for preparing a brominated butyl rubber composite gasket, comprising the following steps:

[0016] S1: grinding white carbon black and organic silicon elastomer powder in a silane coupling agent solution with a mass concentration of 5% to 10% for 2 to 5 hours, and drying to obtain a composite powder of white carbon black and organic silicon elastomer powder;

[0017] S2: refining, refining and calendering the rubber raw materials of the drug-bonded sealing layer and the puncture surface layer respectively to obtain a drug-bonded sealing layer film and a puncture surface layer film;

[0018] S3: vulcanizing the medical sealing layer film and the puncture surface film once respectively, then overlapping the medical sealing layer film and the puncture surface film, and performing secondary vulcanization to obtain a brominated butyl rubber composite gasket.

[0019] The preferred technical solution is that the primary vulcanization process parameters of the drug-bonded sealing layer film are: the vulcanization temperature is 155-168°C, the vulcanization pressure is 150-165kg / cm 2 , the vulcanization time is 160~190s.

[0020] The primary vulcanization process parameters of the puncture surface film are: vulcanization temperature is 165-178℃, and vulcanization pressure is 125-140kg / cm 2 , the vulcanization time is 160~190s.

[0021] The preferred technical solution is that the process parameters of the secondary vulcanization are: the vulcanization temperature is 175-185°C, the vulcanization pressure is 125-140kg / cm 2 , the vulcanization time is 200-250s.

[0022] The preferred technical solution is that the mixing of the rubber raw material for puncturing the surface layer includes the following steps:

[0023] S01, mixing bromobutyl rubber with an inorganic colorant, magnesium oxide and calcined kaolin to obtain a first mixed rubber, the mixing temperature being 80-90° C.;

[0024] S02, mixing and kneading the first rubber mix with the composite powder of white carbon black and silicone elastomer powder to obtain a second rubber mix, wherein the discharge temperature is not higher than 115° C.;

[0025] S03, mixing the second mixed rubber with sulfur and refining the mixture at a temperature of 65-75°C.

[0026] The advantages and beneficial effects of the present invention are:

[0027] The brominated butyl rubber composite gasket is a laminated structure of a drug-bonded sealing layer and a puncture surface layer;

[0028] The drug-bonded sealing layer is in direct contact with the drug, and a relatively small amount of calcined kaolin and montmorillonite are used as fillers to reduce the ash content of the drug-bonded sealing layer. Due to the calendering and vulcanization pressure, the montmorillonite part of the two-dimensional sheet structure is arranged in a plane orientation, which can effectively limit the movement of the rubber molecular chain and ensure that the drug-bonded sealing layer has a suitable hardness.

[0029] Composite powders of white carbon black and organic silicon elastomer powder are added to the puncture surface layer. The composite powders are evenly dispersed, which is beneficial to enhancing the elastic toughness of the puncture surface layer and the sealing performance after multiple punctures.

[0030] The brominated butyl rubber composite gasket with a two-layer laminated structure has a reasonable structure, and its compatibility with drugs and puncture resistance meet the use requirements of insulin pen test syringes. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0034] Main components and purchasers:

[0035] Silane coupling agent: bis(triethoxypropylsilane) disulfide (sulfur-containing silane coupling agent), dodecyltrimethoxysilane;

[0036] Inorganic colorant: carbon black, particle size 3000 mesh, Mitsubishi, Japan;

[0037] White carbon black: particle size is 20-40nm, from Rhodia, France;

[0038] Silicone elastomer powder: cross-linked polymer of polydimethylsiloxane and vinyl polydimethylsiloxane, particle size of 5 to 10 μm, Cosmethicone SF-606.

[0039] Montmorillonite: particle size is 1000 mesh, diameter-to-thickness ratio is (10-20):1, Nanocor Company, USA;

[0040] Calcined kaolin: particle size 1250 mesh, Sanxin, Inner Mongolia;

[0041] Bromobutyl rubber: ExxonMobil 2222;

[0042] Polyethylene wax powder: PEWO-0520, Nanjing Tianshi.

[0043] Example 1

[0044] The rubber raw material composition of the brominated butyl rubber composite gasket of Example 1 is as follows:

[0045] The rubber raw materials of the medical sealing layer are mainly composed of: 100 parts of brominated butyl rubber, 3 parts of magnesium oxide, 0.35 parts of sulfur, 35 parts of calcined kaolin, 30 parts of montmorillonite, 2 parts of inorganic colorant, and 2.4 parts of polyethylene wax powder;

[0046] The rubber raw materials for puncturing the surface layer are mainly composed of: 100 parts of brominated butyl rubber, 3.5 parts of magnesium oxide, 0.4 parts of sulfur, 60 parts of calcined kaolin, 24 parts of composite powder of white carbon black and silicone elastomer powder, 2 parts of inorganic colorant, and 0.2 parts of silane coupling agent.

[0047] The preparation method of the brominated butyl rubber composite gasket comprises the following steps:

[0048] S1: placing white carbon black and organic silicon elastomer powder in a mass ratio of 5:1 in a 5% mass concentration bis(triethoxypropylsilane) disulfide ethanol solution, grinding for 3 hours, and drying to obtain a composite powder of white carbon black and organic silicon elastomer powder;

[0049] S2: Rubber mixing and calendering of the puncture surface layer and the drug-bonded sealing layer.

[0050] Mixing of rubber raw materials for puncturing the surface layer: Bromobutyl rubber is mixed with inorganic colorant, magnesium oxide and calcined kaolin for 600 seconds to obtain a first mixed rubber, and the mixing temperature is 85°C; then the first mixed rubber is mixed with a composite powder of white carbon black and silicone elastomer powder and mixed for 320 seconds to obtain a second mixed rubber, and the discharge temperature is controlled not to be higher than 115°C; finally, the second mixed rubber is mixed with sulfur and mixed at a mixing temperature of 70°C.

[0051] Rubber raw material mixing of the medical sealing layer: bromobutyl rubber is first mixed with inorganic colorant and magnesium oxide and kneaded for 640s at a kneading temperature of 95°C; then calcined kaolin, montmorillonite and polyethylene wax powder are added to the rubber mixture and kneaded for 320s at a kneading temperature of 95°C; finally, sulfur is added to the rubber mixture and the mixture is kneaded at a kneading temperature of 70°C.

[0052] The mixed rubber material is introduced into a calendering device, and calendered to preform to obtain a drug-bonded sealing layer film and a puncture surface layer film;

[0053] S3: A flat vulcanizing machine is used to vulcanize the sealing layer film and the puncture surface film at one time. The process parameters for the primary vulcanization of the sealing layer film are: vulcanization temperature is 165°C, and the vulcanization pressure is 160kg / cm 2 , the curing time is 180s; the primary curing process parameters of the puncture surface film are: curing temperature is 172℃, curing pressure is 130kg / cm 2 , the vulcanization time is 180s;

[0054] The drug-sealed sealing film and the puncture surface film are overlapped and subjected to secondary vulcanization. The process parameters of the secondary vulcanization are: vulcanization temperature is 180°C, vulcanization pressure is 130kg / cm 2 , the vulcanization time is 230s, and the brominated butyl rubber composite gasket is obtained.

[0055] Comparative Example 1

[0056] Based on the composite gasket preparation method of Example 1, the rubber raw material for puncturing the surface layer of Comparative Example 1 contains 25 parts of white carbon black and does not contain silicone elastomer powder.

[0057] Comparative Example 2

[0058] Based on the composite gasket preparation method of Example 1, the white carbon black and silicone elastomer powder in Comparative Example 2 are directly added to the brominated butyl rubber and mixed in the same step.

[0059] Example 2

[0060] Based on the composite gasket preparation method of Example 1, the mass ratio of white carbon black to silicone elastomer powder in Example 2 is 3:1.

[0061] Example 3

[0062] Based on the composite gasket preparation method of Example 1, the silane coupling agent used in preparing the composite powder of white carbon black and silicone elastomer micropowder in Example 3 is dodecyltrimethoxysilane.

[0063] Example 4

[0064] Based on the composite gasket preparation method of Example 1, the silane coupling agent used in preparing the composite powder of white carbon black and silicone elastomer powder in Example 4 is a combination of dodecyltrimethoxysilane and bis(triethoxypropylsilane) disulfide, and the mass percentage of dodecyltrimethoxysilane in the silane coupling agent is 70%.

[0065] Example 5

[0066] Based on the composite gasket preparation method of Example 4, the mass percentage of dodecyltrimethoxysilane in the silane coupling agent is 78%.

[0067] The composite gasket samples of the embodiment and the comparative example all meet the following gasket technical requirements and reach the qualified standards:

[0068] 1. Ash content: the remaining residue is less than 50%;

[0069] 2. Volatile sulfide: less than 50μg / 20cm 2 (measured in sodium sulfide);

[0070] 3. Clarity and color: clear and colorless;

[0071] 4. The maximum absorbance in the absorbance range of 220-360nm is less than 0.1;

[0072] 5. Heavy metals: less than one part per million;

[0073] 6. Ammonium ion: less than 0.0002%;

[0074] 7. Zinc ion: less than 0.0003%;

[0075] 8. Conductivity: less than 40μS / cm.

[0076] The composite gaskets of the embodiment and the comparative example were tested for puncture resistance and sealing properties of simulated insulin, and the testing method was as follows:

[0077] 1. Connect the gasket to the sample cartridge via the aluminum cover seal, and install the cartridge into the matching insulin injection pen;

[0078] 2. Take the insulin injection pen, open the pen cap, screw the injection needle into the injection pen until it is tightened, then loosen the injection needle and withdraw it to complete a composite gasket puncture;

[0079] 3. After each puncture, use filter paper to contact the gasket to check for leakage; if there is leakage, terminate the puncture test of the composite gasket.

[0080] A single composite gasket is qualified if it is punctured 65 times without leakage. 20 parallel samples are randomly selected for testing, and the average number of chips after 65 punctures is recorded.

[0081] 4. A puncture surface layer is produced separately according to the process of the embodiment, and the elongation at break of the puncture surface layer is tested.

[0082] The test results of the embodiments and comparative examples are as follows:

[0083]

[0084]

[0085] It can be seen from the above table that the addition of silicone elastomer powder to the puncture surface layer in the form of composite powder is beneficial to improving the puncture resistance of the composite gasket. The optimization of silane coupling agent in the composite powder is beneficial to improving the elongation at break of the puncture surface layer, and the chip shedding of the composite gasket after 65 punctures is also reduced accordingly.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A brominated butyl rubber composite gasket, characterized in that: It includes a drug-jointed sealing layer and a puncture surface layer integrally laminated along the thickness direction; The rubber raw material of the medical sealing layer is mainly composed of: 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.1-0.4 parts of sulfur, 30-45 parts of calcined kaolin, 20-35 parts of montmorillonite, 0-5 parts of inorganic colorant, and 2-3 parts of polyethylene wax powder; The rubber raw material of the puncture surface layer is mainly composed of: 100 parts of brominated butyl rubber, 2.5-6 parts of magnesium oxide, 0.2-0.5 parts of sulfur, 40-70 parts of calcined kaolin, 20-40 parts of composite powder of white carbon black and silicone elastomer powder, 0-5 parts of inorganic colorant, and 0.1-0.5 parts of silane coupling agent.

2. The brominated butyl rubber composite gasket according to claim 1, characterized in that: The composite powder of white carbon black and silicone elastomer powder is obtained by grinding and drying white carbon black and silicone elastomer powder in a silane coupling agent solution, and the mass ratio of white carbon black to silicone elastomer powder is (3.5-7):

1.

3. The brominated butyl rubber composite gasket according to claim 1, characterized in that: The particle size of the white carbon black is 7-40 nm, and the particle size of the organic silicon elastomer powder is 5-13 μm.

4. The brominated butyl rubber composite gasket according to claim 1, characterized in that: The particle size of the montmorillonite is 800-2000 meshes, and the diameter-thickness ratio is (10-20):1; the particle size of the calcined kaolin is 2000-4000 meshes.

5. The brominated butyl rubber composite gasket according to claim 1, characterized in that: The organic silicon elastomer powder is a cross-linked polymer of polydimethylsiloxane and vinyl polydimethylsiloxane.

6. The brominated butyl rubber composite gasket according to claim 2, characterized in that: The silane coupling agent is a composition of a first silane coupling agent having a long-chain alkyl group of C12 or more and a mercaptosilane coupling agent, and the mass percentage of the first silane coupling agent in the silane coupling agent is 65% to 85%.

7. A method for preparing a brominated butyl rubber composite gasket, characterized in that: The following steps are involved: S1: Place white carbon black and organic silicon elastomer powder in a silane coupling agent solution with a mass concentration of 5% to 10%, grind for 2 to 5 hours, and dry to obtain a composite powder of white carbon black and organic silicon elastomer powder; S2: refining, refining and calendering the rubber raw materials of the drug-bonded sealing layer and the puncture surface layer respectively to obtain a drug-bonded sealing layer film and a puncture surface layer film; S3: vulcanizing the medical sealing layer film and the puncture surface film once respectively, then overlapping the medical sealing layer film and the puncture surface film, and performing secondary vulcanization to obtain a brominated butyl rubber composite gasket.

8. The method for preparing the brominated butyl rubber composite gasket according to claim 7, characterized in that: The primary vulcanization process parameters of the medical sealant film are: vulcanization temperature is 155-168℃, and vulcanization pressure is 150-165kg / cm 2 , the vulcanization time is 160~190s; The primary vulcanization process parameters of the puncture surface film are: vulcanization temperature is 165-178℃, and vulcanization pressure is 125-140kg / cm 2 , the vulcanization time is 160~190s.

9. The method for preparing the brominated butyl rubber composite gasket according to claim 7, characterized in that: The process parameters of secondary vulcanization are: vulcanization temperature is 175-185℃, vulcanization pressure is 125-140kg / cm 2 , the vulcanization time is 200-250s.

10. The method for preparing a brominated butyl rubber composite gasket according to claim 7, characterized in that: The mixing of the rubber raw material for puncturing the surface layer includes the following steps: S01, mixing bromobutyl rubber with an inorganic colorant, magnesium oxide and calcined kaolin to obtain a first mixed rubber, the mixing temperature being 80-90° C.; S02, mixing and kneading the first rubber mix with the composite powder of white carbon black and silicone elastomer powder to obtain a second rubber mix, wherein the discharge temperature is not higher than 115° C.; S03, mixing the second mixed rubber with sulfur and refining the mixture at a temperature of 65-75°C.

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