Butyl rubber is a synthetic rubber made of isobutylene and a small amount of isoprene <3%) polymerized at ultra-low temperature (←95°C). Its unique chemical stability and excellent sealing properties ensure quality and improve safety. , It also reduces the process of hot waxing, padding and film process required for the production of natural rubber stoppers. Butyl rubber stopper is much better than natural rubber stopper in terms of product standard, production level, performance and product quality. Halogenated butyl rubber stopper is the introduction of active halogen atoms into the molecular structure of butyl rubber, while preserving the isoprene double bond, so that it not only has the excellent performance of butyl rubber, but also reduces the pollution of antioxidants. The purity is improved, the vulcanization speed is accelerated, and sulfur-free vulcanization and zinc-free vulcanization can be realized, which greatly reduces the pollution and side effects of harmful substances on substances.

The characteristics of butyl rubber stoppers are as follows:

1. Butyl rubber stopper has excellent air tightness and water absorption. The infiltration of gas and water vapor during the storage process of the substances encapsulated by the bottle plug is extremely harmful, which is an important cause of mildew and deterioration. The air permeability coefficient of butyl rubber is 1/20 of that of natural rubber, and it has better air tightness than natural rubber. In addition, during the production and processing of rubber and its compounding agents for bottle stoppers, some impurities, such as hydrophilic proteins and resins of natural rubber, will inevitably remain, which will inevitably cause water absorption. Due to the characteristics of molecular structure, butyl rubber has a compact structure, and has few hydrophilic impurities and low water absorption, which is usually only 1/4-1/3 of natural rubber.

2. The chemical stability of butyl rubber stopper. Most of the bottle stoppers are in direct contact with the items, and the change of the items cannot be caused in the process of contacting the items, which requires that the bottle stopper must have good chemical stability. The degree of unsaturation of butyl rubber is 0.5%-3%, which is only 1/50 of that of natural rubber, so the chemical stability of butyl rubber is better than that of natural rubber. It has better chemical stability, is less likely to interact with the article and affect the quality, can prevent degradation, avoid the reaction between the material and the rubber, and has better stability to the external environment.

3. The butyl rubber stopper has good heat aging resistance. The stopper should be sterilized by steam, ethylene oxide and radiation before packaging the items. High temperature sterilization may sometimes be repeated, so it must have good heat aging resistance. The main chain structure and vulcanized crosslinks of butyl rubber are better than those of natural rubber in thermal aging resistance. The temperature range of butyl rubber is generally 130℃～160℃, the suitable vulcanization temperature is 170℃, and the highest temperature can reach 200℃-220℃, while the temperature range of natural rubber is generally 70℃-100℃, and the suitable vulcanization temperature is 140℃. Serious aging begins when it exceeds 160°C. In order to improve heat aging resistance, natural rubber must be added with antioxidants, which greatly increases the unsafety.
4. Butyl rubber stopper has high cleanliness and low extractability. Butyl stoppers should have high cleanliness and low extractability to ensure the purity of the item. During the contact process of the bottle stopper with the material, the impurities and compounding agents in the rubber will migrate to the surface of the bottle stopper or be extracted, contaminating or destroying the material and reducing the effect. The cleanliness of butyl rubber is about 10 times higher than that of natural rubber, the impurities contained in it are 1/8 of that of natural rubber, and the formula mixture is less, so the extractability is much lower than that of natural rubber. The UV absorbance of the butyl rubber stopper (checking the organic content) is only 1/11 of that of natural rubber, and the conductivity (checking the metal ion content) is only 1/48. The extractable organic compounds and metal ions in the natural rubber stopper are respectively It is 11 times and 4.3 times that of butyl rubber.
5. The butyl rubber stopper is easy to use. The stopper should be easy to package and use, and it is convenient and simple in clinical application. The butyl rubber stopper can avoid the chlorination and wax sealing process of the natural rubber stopper when the antibiotics are packaged, and the process of capping the polyester film during the infusion package, which simplifies the packaging process. Correspondingly, the aluminum cap matched with the butyl rubber stopper is an aluminum-plastic composite cap, which is extremely convenient for clinical use. The aluminum cap of the traditional natural rubber bottle stopper needs to be scratched with an auxiliary device, which is extremely inconvenient and easy to scratch. The rubber stopper will fall off, causing damage or pollution. Gently open the plastic cap on the aluminum cap, and the rubber stopper will be exposed, which is convenient for injection.