A rubber piston and a method for treating a rubber piston body

Abstract

The present invention discloses a rubber piston and a treatment method for a rubber piston body, belonging to the technical field of medical rubber accessories. The treatment method for the rubber piston body includes the following steps: S1. The rubber piston body is subjected to surface treatment by using a low-temperature plasma surface modification technology; S2. The rubber piston body treated in step S1 is subjected to chemical vapor deposition treatment by using an evaporation material, and the evaporation material includes polytetrafluoroethylene powder. The present invention also provides a rubber piston obtained by the above treatment method. The rubber piston includes a rubber piston body and a polytetrafluoroethylene film. The rubber piston body includes a plug top and a plug body, and the polytetrafluoroethylene film covers the outer surface of the plug body. The rubber piston treated by the treatment method provided by the present invention can effectively prevent the components of the rubber piston from entering the medicine solution.

Description

Technical Field

[0001] The present invention relates to the technical field of medical rubber accessories, and particularly relates to a rubber piston and a processing method for a rubber piston body. Background Art

[0002] Halogenated butyl rubber is widely used in the packaging of drugs. Some pharmaceutical factories produce strong acid-base drugs, such as acyclovir, calf blood, sodium bicarbonate injection, etc. The development trend of these drugs has shifted to prefilled syringes and pen injectors that integrate drug storage and injection functions. Thus, it can be seen that there is a large market space for the demand of high-performance brominated butyl rubber pistons.

[0003] Halogenated butyl rubber stoppers are important sealing materials in pharmaceutical packaging materials. However, since they are in direct contact with drugs, cross-reactions may occur between the rubber stoppers and drugs through adsorption, absorption, or leaching, thereby affecting or contaminating the drugs. Currently, for many high-difficulty drugs or drugs with strong activity in the market, coated or film-coated rubber stoppers are used. The production processes of these rubber stoppers are complex or the costs are high. Moreover, the current vulcanization systems of halogenated butyl rubber stoppers on the market mainly include sulfur or sulfur carrier vulcanization systems, zinc oxide vulcanization systems, and resin vulcanization systems. Both sulfur and zinc oxide will have a certain impact on drugs. In addition, when a needle is inserted into a halogenated butyl rubber stopper, there is a problem of needle puncture debris. If the debris of the halogenated butyl rubber stopper enters the drug, it will contaminate the drug to a certain extent. In addition, if the drug is in contact with the halogenated butyl rubber stopper for a long time, it is very likely that the internal substances in the halogenated butyl rubber stopper will be leached out, thereby contaminating the drug.

[0004] In our previous research, by coating polyethylene tetrafluoroethylene and chlorinated polyethylene to form a double-layer coating, in addition to blocking the medicine or the rubber stopper respectively, the two coatings also form misaligned pores, which are not easy for the two to shuttle through each other. In addition, when a needle is inserted, the debris stabbed from the stopper body is borne by the double layers of the polyvinyl chloride layer and the polytetrafluoroethylene layer, avoiding entering the drug to contaminate the drug. However, the processes and raw materials for coating the two materials are relatively complex, and the problem of uneven coating is likely to occur. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies, and provide a rubber piston and a processing method for a rubber piston body, so as to solve the technical problem of how to effectively block the components of the rubber piston from entering the medicine water through relatively simple processes and raw materials in the prior art.

[0006] To achieve the above technical purpose, the technical solution of the present invention provides a processing method for a rubber piston body, including the following steps:

[0007] S1. Perform surface treatment on the rubber piston body by using a low-temperature plasma surface modification technology;

[0008] S2. Use an evaporation material to perform chemical vapor deposition treatment on the rubber piston body after the treatment in step S1. The evaporation material includes polytetrafluoroethylene powder.

[0009] Further, in step S2, the evaporation material further includes nano mica powder.

[0010] Further, the mass ratio of the nano mica powder to the polytetrafluoroethylene is 0.01 - 0.02:1.

[0011] Further, in step S1, the treatment temperature of the low-temperature plasma surface modification technology is 10 - 20°C, the treatment time is 1 - 2 min, and the treatment power is 5 KW - 10 KW.

[0012] Further, in step S2, the conditions for the chemical vapor deposition treatment include: placing the rubber piston body in a reaction chamber, evacuating the reaction chamber to 1×10 -3 ~10×10 -3 Pa, introducing a mixture of the evaporation material and oxygen into the coating vacuum chamber, controlling the flow rate of the evaporation material to be 5 - 20 sccm, the oxygen flow rate to be 400 - 500 sccm, the deposition pressure to be 20 - 30 Pa, and the deposition power to be 300 - 500 W.

[0013] Further, before step S1, it further includes pre-treating the rubber piston body: creating pores on the surface of the plug body of the rubber piston body.

[0014] Further, the pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.1 - 0.2 cm.

[0015] Further, the diameter of the needle is 0.5 - 0.7 mm.

[0016] Further, the rubber piston body is a bromobutyl rubber piston.

[0017] In addition, the present invention also provides a rubber piston obtained by the above treatment method. The rubber piston includes a rubber piston body and a polytetrafluoroethylene film. The rubber piston body includes a plug top and a plug body, and the polytetrafluoroethylene film covers the outer surface of the plug body.

[0018] Compared with the prior art, the beneficial effects of the present invention include: First, the surface of the rubber piston body is treated by the low-temperature plasma surface modification technology to open the chemical bonds of the surface molecules of the rubber piston body, combine with the free radicals in the plasma, form free radicals on the surface of the rubber piston body, and significantly improve the adhesion performance and reaction activity of the material surface. Then, a chemical vapor deposition treatment is carried out on the treated rubber piston body with an evaporation material including polytetrafluoroethylene (PTFE). The polytetrafluoroethylene powder is bombarded by the plasma in the chemical vapor deposition reaction chamber to generate a large number of PTFE fragment free radicals. These PTFE fragment free radicals are adsorbed on the surface of the rubber piston body and couple with the free radicals on its surface. During the continuous coupling process, PTFE is evenly deposited and coated on the surface of the bromobutyl rubber piston to form a firm polytetrafluoroethylene film, thereby effectively preventing the components of the rubber piston from entering the medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the rubber piston proposed in Embodiments 1-9 of the present invention.

[0020] Description of the reference numerals: 1. Rubber piston body; 11. Plug top; 12. Plug body; 2. Polytetrafluoroethylene film. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present specific embodiment provides a method for treating a rubber piston body, including the following steps:

[0022] S1. The surface of the rubber piston body is treated by the low-temperature plasma surface modification technology; the treatment temperature of the low-temperature plasma surface modification technology is 10-20 °C, the treatment time is 1-2 min, and the treatment power is 5 KW-10 KW;

[0023] S2. A chemical vapor deposition treatment is carried out on the rubber piston body treated in step S1 with an evaporation material, and the evaporation material includes polytetrafluoroethylene powder; the conditions of the chemical vapor deposition treatment include: putting the rubber piston body into the reaction chamber, evacuating the reaction chamber to 1×10 -3 ~10×10 -3 Pa, introducing a mixture of the evaporation material and oxygen into the coating vacuum chamber, controlling the flow rate of the evaporation material to be 5-20 sccm, the oxygen flow rate to be 400-500 sccm, the deposition pressure to be 20-30 Pa, and the deposition power to be 300-500 W.

[0024] In the above specific embodiments, we found that by being able to form a uniform and thin polytetrafluoroethylene film, and being able to effectively block the components of the rubber piston from entering the potion. However, in the drug compatibility test, after a long time, the clarity of the potion will deteriorate. We carefully studied the problems therein and found that this may be related to the existence of tiny and shallow pores on the surface of the rubber piston. These pores make it difficult for the polytetrafluoroethylene powder to fill in, resulting in voids between the polytetrafluoroethylene film and the rubber piston. The existence of these voids easily allows the active ingredients in the rubber piston to penetrate into the potion, leading to a deterioration in the clarity of the potion. Furthermore, we considered how to eliminate the influence brought by the pores. Based on this, we further proposed:

[0025] In some embodiments, in step S2, the evaporation material further includes nano-scale mica powder. Further, the mass ratio of the nano-scale mica powder to the polytetrafluoroethylene powder is 0.01 - 0.02:1. The particle size of the nano-scale mica powder is 1 - 100 nm. The particle size of the nano-scale mica powder is very small and it is easy to penetrate into the pores to fill the pores. Coupled with the mixing of the polytetrafluoroethylene powder and the nano-scale mica powder, there will also be a connection between them during the chemical vapor deposition treatment. Thus, under the action of the nano-scale mica powder, the adhesion between the polytetrafluoroethylene and the pores of the rubber piston body is improved, thereby avoiding the influence of the pores on the clarity.

[0026] In order to reduce the thickness of the polytetrafluoroethylene film without affecting the clarity performance, we further made the following improvements:

[0027] In some embodiments, before step S1, it further includes pre-treating the rubber piston body: creating pores on the surface of the plug body of the rubber piston body. Further, the pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.1 - 0.2 cm. Still further, the diameter of the needle is 0.5 - 0.7 mm.

[0028] Creating pores on the surface of the plug body, these pores have a certain size and the polytetrafluoroethylene can penetrate into them. The penetrated polytetrafluoroethylene is equivalent to being embedded in the surface of the plug body, thereby improving the bonding force between the polytetrafluoroethylene film and the plug body, making it more tightly combined with the plug body, and a thinner polytetrafluoroethylene film can also ensure the clarity of the treated piston.

[0029] In some embodiments, the rubber piston body is a bromobutyl rubber piston.

[0030] This specific embodiment also proposes a rubber piston obtained by the above treatment method. The rubber piston includes a rubber piston body and a polytetrafluoroethylene film. The rubber piston body includes a plug top and a plug body, and the polytetrafluoroethylene film covers the outer surface of the plug body.

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] It should be noted that the rubber piston body in the following embodiments is a bromobutyl rubber piston.

[0033] The rubber pistons obtained after the treatment of the following Examples 1-9 and Comparative Example 2, in combination with Figure 1 , include a rubber piston body 1 and a polytetrafluoroethylene film 2. The rubber piston body 1 includes a plug top 11 and a plug body 12, and the polytetrafluoroethylene film 2 is coated on the outer surface of the plug body 12.

[0034] Example 1

[0035] This example proposes a treatment method for a rubber piston body, including the following steps:

[0036] S1. The rubber piston body is surface-treated by using a low-temperature plasma surface modification technology; the treatment temperature of the low-temperature plasma surface modification technology is 15°C, the treatment time is 1 min, and the treatment power is 8 KW;

[0037] S2. The rubber piston body treated in step S1 is subjected to chemical vapor deposition treatment by using an evaporation material. The evaporation material includes polytetrafluoroethylene powder; the conditions for the chemical vapor deposition treatment are as follows: the rubber piston body is placed in a reaction chamber, the reaction chamber is evacuated to 5×10 -3 Pa, a mixture of the evaporation material and oxygen is introduced into the coating vacuum chamber, the flow rate of the evaporation material is controlled to be 15 sccm, the oxygen flow rate is 450 sccm, the deposition pressure is 25 Pa, and the deposition power is 500 W.

[0038] The thickness of the polytetrafluoroethylene film in the treated rubber piston is about 0.08 mm.

[0039] Example 2

[0040] This example proposes a treatment method for a rubber piston body, including the following steps:

[0041] S1. The rubber piston body is surface-treated by using a low-temperature plasma surface modification technology; the treatment temperature of the low-temperature plasma surface modification technology is 10°C, the treatment time is 1.5 min, and the treatment power is 5 KW;

[0042] S2. Perform chemical vapor deposition treatment on the rubber piston body after the treatment in step S1 using an evaporation material, where the evaporation material includes polytetrafluoroethylene powder; the conditions for the chemical vapor deposition treatment: Place the rubber piston body in a reaction chamber, evacuate the reaction chamber to 1×10 -3 Pa, introduce a mixture of the evaporation material and oxygen into the coating vacuum chamber, control the flow rate of the evaporation material to be 20 sccm, the oxygen flow rate to be 500 sccm, the deposition pressure to be 20 Pa, and the deposition power to be 400 W.

[0043] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.08 mm.

[0044] Example 3

[0045] This example proposes a method for treating a rubber piston body, including the following steps:

[0046] S1. Perform surface treatment on the rubber piston body using low-temperature plasma surface modification technology; the treatment temperature of the low-temperature plasma surface modification technology is 20°C, the treatment time is 2 min, and the treatment power is 10 KW;

[0047] S2. Perform chemical vapor deposition treatment on the rubber piston body after the treatment in step S1 using an evaporation material, where the evaporation material includes polytetrafluoroethylene powder; the conditions for the chemical vapor deposition treatment: Place the rubber piston body in a reaction chamber, evacuate the reaction chamber to 10×10 -3 Pa, introduce a mixture of the evaporation material and oxygen into the coating vacuum chamber, control the flow rate of the evaporation material to be 5 sccm, the oxygen flow rate to be 400 sccm, the deposition pressure to be 30 Pa, and the deposition power to be 300 W.

[0048] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.08 mm.

[0049] Example 4

[0050] This example proposes a method for treating a rubber piston body, including the following steps:

[0051] S1. Perform surface treatment on the rubber piston body using low-temperature plasma surface modification technology; the treatment temperature of the low-temperature plasma surface modification technology is 15°C, the treatment time is 1 min, and the treatment power is 8 KW;

[0052] S2. Use evaporation materials to perform chemical vapor deposition on the rubber piston body after the treatment in step S1. The evaporation materials include polytetrafluoroethylene powder and nano-scale mica powder; the mass ratio of the nano-scale mica powder to the polytetrafluoroethylene powder is 0.01:1; the conditions for the chemical vapor deposition treatment are as follows: Place the rubber piston body in the reaction chamber, evacuate the reaction chamber to 5×10 -3 Pa, introduce a mixture of evaporation materials and oxygen into the coating vacuum chamber, control the flow rate of the evaporation materials to be 15 sccm, the oxygen flow rate to be 450 sccm, the deposition pressure to be 25 Pa, and the deposition power to be 500 W.

[0053] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.08 mm.

[0054] Example 5

[0055] This example presents a method for treating a rubber piston body, including the following steps:

[0056] S1. Use low-temperature plasma surface modification technology to perform surface treatment on the rubber piston body; the treatment temperature of the low-temperature plasma surface modification technology is 10°C, the treatment time is 1.5 min, and the treatment power is 5 KW;

[0057] S2. Use evaporation materials to perform chemical vapor deposition on the rubber piston body after the treatment in step S1. The evaporation materials include polytetrafluoroethylene powder and nano-scale mica powder; the mass ratio of the nano-scale mica powder to the polytetrafluoroethylene powder is 0.02:1; the conditions for the chemical vapor deposition treatment are as follows: Place the rubber piston body in the reaction chamber, evacuate the reaction chamber to 1×10 -3 Pa, introduce a mixture of evaporation materials and oxygen into the coating vacuum chamber, control the flow rate of the evaporation materials to be 20 sccm, the oxygen flow rate to be 500 sccm, the deposition pressure to be 20 Pa, and the deposition power to be 400 W.

[0058] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.08 mm.

[0059] Example 6

[0060] This example presents a method for treating a rubber piston body, including the following steps:

[0061] S1. Use low-temperature plasma surface modification technology to perform surface treatment on the rubber piston body; the treatment temperature of the low-temperature plasma surface modification technology is 20°C, the treatment time is 2 min, and the treatment power is 10 KW;

[0062] S2. Perform chemical vapor deposition treatment on the rubber piston body processed in step S1 using evaporation materials. The evaporation materials include polytetrafluoroethylene powder and nanoscale mica powder; the mass ratio of the nanoscale mica powder to the polytetrafluoroethylene powder is 0.01:1; the conditions for the chemical vapor deposition treatment are as follows: Place the rubber piston body in the reaction chamber, evacuate the reaction chamber to 10×10 -3 Pa, introduce a mixture of the evaporation materials and oxygen into the coating vacuum chamber, control the flow rate of the evaporation materials to be 5 sccm, the oxygen flow rate to be 400 sccm, the deposition pressure to be 30 Pa, and the deposition power to be 300 W.

[0063] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.08 mm.

[0064] Example 7

[0065] The difference between the treatment method of the rubber piston body in this example and that in Example 4 is only that a pretreatment is performed on the rubber piston body before step S1: pores are created on the surface of the plug body of the rubber piston body (not shown in the figure but easy to understand). The pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.1 cm, and the diameter of the needle is 0.7 mm.

[0066] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.04 mm.

[0067] Example 8

[0068] The difference between the treatment method of the rubber piston body in this example and that in Example 4 is only that a pretreatment is performed on the rubber piston body before step S1: pores are created on the surface of the plug body of the rubber piston body (not shown in the figure but easy to understand). The pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.2 cm, and the diameter of the needle is 0.5 mm.

[0069] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.04 mm.

[0070] Example 9

[0071] The difference between the treatment method of the rubber piston body in this example and that in Example 4 is only that a pretreatment is performed on the rubber piston body before step S1: pores are created on the surface of the plug body of the rubber piston body (not shown in the figure but easy to understand). The pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.1 cm, and the diameter of the needle is 0.6 mm.

[0072] The thickness of the polytetrafluoroethylene film in the treated rubber piston is approximately 0.04 mm.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Example 4 is that the thickness of the polytetrafluoroethylene film in the processed rubber piston is about 0.04 mm.

[0075] Comparative Example 2

[0076] This comparative example is an unprocessed rubber piston body, that is, the outer surface of the rubber piston body is not coated with a polytetrafluoroethylene film.

[0077] Performance test:

[0078] Hermeticity test with the container

[0079] Experimental method: The method under [Rubber stopper and container hermeticity performance] in YBB00052005 - 2015 "Halogenated butyl rubber stoppers for sterile powders for injection". Take 8 processed rubber pistons of Examples 1 - 9 and Comparative Examples 1 - 2 respectively. The experimental results prove that the brominated butyl rubber pistons of Examples 1 - 9 and Comparative Examples 1 - 2 have good hermeticity with the container.

[0080] Drug compatibility test

[0081] Highly sensitive and active drugs are selected for the experimental drugs: 1. Cefotiam hydrochloride for injection, specification 1.0 g; 2. Ceftriaxone sodium for injection, specification 1.0 g. The above drugs are filled into the bottles covered with Examples 1 - 9 and Comparative Examples 1 - 2 and inverted, and the clarity at different time periods is observed. The results are shown in Tables 1 - 2.

[0082] Table 1 Drug compatibility test - Clarity of cefotiam hydrochloride for injection

[0083] Group 0 months 3 months 6 months 8 months Example 1 Clarification Clarification ＞1 ＞2 Example 2 Clarification Clarification ＞1 ＞2 Example 3 Clarification Clarification ＞1 ＞2 Example 4 Clarification Clarification Clarification Clarification Example 5 Clarification Clarification Clarification Clarification Example 6 Clarification Clarification Clarification Clarification Example 7 Clarification Clarification Clarification Clarification Example 8 Clarification Clarification Clarification Clarification Example 9 Clarification Clarification Clarification Clarification Comparative Example 1 Clarification Clarification ＞1 ＞2 Comparative Example 2 Clarification ＞0.5 ＞2 ＞3

[0084] Table 2 Drug compatibility test - Clarity of ceftriaxone sodium for injection

[0085]

[0086]

[0087] As can be seen from Tables 1 and 2, the processed rubber pistons of Examples 1 - 9 of the present invention have good drug compatibility.

[0088] Puncture debris test

[0089] Pierce the treated rubber pistons of Examples 1-9 and Comparative Examples 1-2 with a hypodermic needle. Each rubber stopper was pierced 100 times with a hypodermic needle, and the debris condition was recorded. The results are shown in Table 3. It can be seen from Table 3 that there was varying degrees of debris shedding in Examples 1-6 of the present invention, no debris shedding in Examples 7-9, and debris shedding in Comparative Examples 1-2. This may be related to the tightness of the bonding of the polytetrafluoroethylene film.

[0090] Table 3 Debris shedding of halogenated butyl rubber stoppers

[0091]

[0092]

[0093] The specific embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A processing method for a rubber piston body, characterized in that, It includes the following steps: S1. Perform surface treatment on the rubber piston body by using the low-temperature plasma surface modification technology; S2. Perform chemical vapor deposition treatment on the rubber piston body treated in step S1 by using an evaporation material, where the evaporation material includes polytetrafluoroethylene powder; the evaporation material also includes nano-scale mica powder; Before step S1, it also includes pre-treating the rubber piston body: creating pores on the surface of the plug body of the rubber piston body.

2. The processing method of the rubber piston body according to claim 1, characterized in that, In step S2, the mass ratio of the nano-scale mica powder to the polytetrafluoroethylene is 0.01 - 0.02:

1.

3. The processing method of the rubber piston body according to claim 1, characterized in that, In step S1, the treatment temperature of the low-temperature plasma surface modification technology is 10 - 20 °C, the treatment time is 1 - 2 min, and the treatment power is 5 KW - 10 KW.

4. The processing method of the rubber piston body according to any one of claims 1-3, characterized in that, In step S2, the conditions of the chemical vapor deposition process include: placing the rubber piston body into the reaction chamber, evacuating the reaction chamber to 1×10 -3 ~10×10 -3 Pa, introducing a mixture of evaporation material and oxygen into the coating vacuum chamber, controlling the flow rate of the evaporation material to be 5 - 20 sccm, the oxygen flow rate to be 400 - 500 sccm, the deposition pressure to be 20 - 30 Pa, and the deposition power to be 300 - 500 W.

5. The processing method of the rubber piston body according to claim 4, characterized in that, The pores are obtained by inserting a needle into the surface of the plug body to a depth of 0.1 cm - 0.2 cm.

6. The processing method of the rubber piston body according to claim 5, characterized in that, The diameter of the needle is 0.5 - 0.7 mm.

7. The processing method of the rubber piston body according to claim 1, characterized in that, The rubber piston body is a bromobutyl rubber piston.

8. A rubber piston, characterized in that, Obtained by the treatment method according to any one of claims 1 - 7, the rubber piston includes a rubber piston body and a polytetrafluoroethylene film, the rubber piston body includes a plug top and a plug body, and the polytetrafluoroethylene film is coated on the outer surface of the plug body.

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