Liquid silicone rubber (LSR) claims typically center on two-part platinum-cure systems fed through liquid injection molding, with vinyl siloxane polymers and hydride crosslinkers metered as separate streams, as in the representative filing US8198357B2. High-consistency silicone rubber (HCR) claims more often describe peroxide-cure or platinum-cure gum stocks processed by compression or transfer molding rather than liquid injection. Both routes appear together in this corpus because search terms for cure system, compression set and tear strength cover overlapping claim language. In practice, LSR filings skew toward feed and mixing methods while HCR filings skew toward the base polymer and filler composition itself.

The ranked leaders in this 771-record corpus are large industrial silicone producers with continuous filing histories going back well before the 2017 peak year. The top assignee alone holds 183 records, more than six times the fifth-place count of 28, and the top 5 combined account for 49.5% of all records in scope. Below the top 10 — which together hold 60.2% — the ranking thins into a long tail of companies with far fewer filings each, so competitive tracking should focus on the handful of large filers rather than the full 100-company list.

No — filing activity peaked in 2017 at 48 records and has declined since, with the 2022 midpoint at just 4. That is a sign of a mature, well-claimed field rather than an emerging one, though publication lag of roughly 18 months means the most recent one or two years in any trend chart will always look lower than they eventually turn out to be. Recent-year momentum data for the leading assignees also shows flat or zero activity, reinforcing the slowdown rather than contradicting it.

The technology composition data shows polymer composition (C08L, 53.6% of records) and additive use (C08K, 37.4%) carrying far more density than layered products (B32B, 9.2%) or textile treatment (D06M, 9.1%). Sub-areas like self-lubricating grade additives, food-grade certification claims, and silicone-to-metal laminate bonding sit in that thinner overlap territory. A new filing targeting one of those narrower intersections is more likely to clear prior art than one aimed at core cure-system composition, where the leading assignees have been filing for years.

US8198357B2, assigned to Bluestar Silicones USA Corp. and granted 2012-06-12, covers a method for producing molded silicone rubber products from a liquid silicone rubber base combined with a separately fed inhibitor master batch and catalyst master batch, rather than a single pre-mixed formulation. The claims center on the split-feed process and the compositions of the base, inhibitor batch and catalyst batch as used together in liquid injection molding. It does not claim peroxide-cure HCR processing or compression molding, so it constrains split-feed LSR injection methods specifically rather than silicone rubber molding broadly.