Solid silicone rubber—technically known as high-temperature vulcanizing (HTV) silicone rubber—is the oldest and most widely used variety within the silicone rubber family. Its origins date back to the 1940s, when the urgent wartime need for high-temperature-resistant sealing materials drove its early development. Over more than eight decades of evolution, it has expanded from a single initial formulation into a vast system comprising dozens of varieties—including general-purpose, high-temperature-resistant, oil-resistant, conductive, and flame-retardant types—establishing itself as an indispensable, fundamental elastomeric material in modern industry.



In terms of chemical composition, solid silicone rubber utilizes high-molecular-weight polyorganosiloxane as its base polymer—typically methyl vinyl silicone rubber (VMQ)—and incorporates fumed silica as a reinforcing filler. It employs peroxides or platinum compounds as vulcanizing agents, along with various additives such as processing aids, retarders, and colorants, to produce the final product through the three key stages of compounding, molding, and vulcanization. Unlike liquid silicone rubber, which consists of two components ready for immediate use, solid silicone rubber exists as a solid or paste at room temperature and requires mechanical processing and heat vulcanization to achieve its final properties; this characteristic gives it unparalleled advantages in terms of processing flexibility and product form diversity.

The most outstanding characteristic of solid silicone rubber is its exceptional temperature resistance. General-purpose grades are suitable for long-term use within a temperature range of -60°C to 200°C, while specialized formulations can withstand extreme heat exceeding 300°C. At the same time, the material retains good elasticity and flexibility in low-temperature environments, avoiding the hardening and cracking typical of ordinary rubber in the cold. This ability to perform across a wide temperature range makes it the preferred sealing material for extreme environments, such as those found in aerospace, oil exploration, and polar equipment. Furthermore, solid silicone rubber boasts excellent weather and UV resistance; it shows no significant signs of aging, chalking, or discoloration even after years of outdoor exposure—performance capabilities far beyond the reach of conventional organic rubbers.

Solid silicone rubber also excels in electrical performance. With a volume resistivity on the order of 10¹⁴ Ω·cm, a low and stable dielectric constant, and low dielectric loss, it is an ideal material for high-voltage insulation, cable accessories, and the sealing of power equipment. Notably, in the field of ultra-high voltage (UHV) power transmission, solid silicone rubber composite insulators have almost entirely replaced traditional porcelain insulators, becoming the standard choice for power grid construction.

Solid silicone rubber possesses another often-overlooked advantage: immense flexibility in formulation. By adjusting the type of raw rubber, the variety and dosage of fillers, the vulcanization system, and the combination of additives, key performance metrics—such as hardness, strength, elasticity, oil resistance, thermal conductivity, and electrical conductivity—can be precisely tuned across a wide range. Shore hardness can span from an ultra-soft 10 to a very hard 80, while tensile strength can be boosted from 2 MPa to over 10 MPa; this versatility allows solid silicone rubber to suit virtually any elastomer application, ranging from soft sealing rings to rigid structural components.