(1) Table drying time
It refers to the time it takes for a single component room temperature vulcanized silicone rubber to lose its adhesion by touching the surface with fingers during the curing process in the atmospheric environment. Normal refers to the time distance during which silicone rubber flat sealant is extruded and air dried under standard conditions, without touching the surface.

(2) Curing depth
It refers to the thickness of the adhesive layer of silicone rubber flat sealant that solidifies from the outside to the inside within a certain period of time after being applied in a fixed mold under standard conditions, such as 2-3mm/24h, 0.6mm/h, etc.

(3) Extrudability (defined according to the specifications of ASTMC1183)
According to the ASTM C1183 specification, the extrusion weight per unit time under specific pressure conditions using Semco tubing and a specific nozzle (diameter 3.2mm) is called extrusion performance.

(4) Instant sealing pressure
It refers to applying silicone rubber flat sealant with a certain diameter to the flange surface, then immediately closing it to control the reasonable thickness of the adhesive layer, and then applying air pressure at a certain rate. The maximum pressure it receives is the instant sealing pressure.

(5) Curing characteristics in oil
It refers to applying silicone rubber flat sealant into a fixed mold, then placing the mold into oil and recording the thickness of the silicone rubber flat sealant that solidifies from the outside to the inside within a certain period of time to characterize the oil curing characteristics of the silicone rubber flat sealant.

(6) Drying time shear strength persistence rate
It refers to placing the previously glued shear test piece under specific high temperature and high humidity conditions for a certain period of time, then stopping the closure and bonding, stopping the curing under standard conditions for 168 hours, testing its shear strength, and comparing it with the shear strength tested under standard conditions for direct bonding and curing for 168 hours to calculate the strength persistence rate.

(7) Thermal stability before curing
It refers to placing uncured silicone rubber flat sealant in a high-temperature environment for a certain period of time, and then still being able to cure under standard conditions, elucidating that silicone rubber flat sealant is stable under this temperature condition. If the thermal stability temperature of the sealant is ≥ 100 ℃, it means that the uncured sealant can still be cured after heating at 100 ℃.

According to the different phenyl content (phenyl: silicon atom) in silicone rubber, it can be divided into low phenyl, medium phenyl, and high phenyl silicone rubber. When rubber crystallizes or approaches the glass transition point, or when these two situations overlap, it will cause the rubber to appear stiff. Introducing an appropriate amount of large volume functional groups can disrupt the regularity of polymer chains, thereby reducing the crystallization temperature of the polymer. At the same time, the introduction of large volume functional groups can change the intermolecular forces of the polymer, thus also altering the glass transition temperature. Low phenyl silicone rubber (C6H5/Si=6-11%) has excellent low-temperature resistance due to the above reasons, and is independent of the type of phenyl monomer used. The brittle temperature of vulcanized rubber is -120 ℃, making it the rubber with the best low-temperature performance today. Low phenyl silicone rubber combines the advantages of vinyl silicone rubber and its cost is not very high, so there is a trend to replace vinyl silicone rubber. When the phenyl content is greatly increased, it will increase the rigidity of the molecular chain, thereby