Polysiloxane Release Coating Low-Temperature Curing

The patent changes the curing temperature parameter from traditional high temperature (at least 130°C) to low temperature (70°C to 90°C, e.g., 85°C) by modifying the chemical composition of the release coating, specifically using a polysiloxane compound with terminal vinyl groups and a crosslinking agent with Si-H groups that can cure at lower temperatures without compromising substrate integrity

The patent creates a composite curing system combining multiple components: polysiloxane compound (A) with terminal vinyl groups, crosslinking agent (B) with Si-H groups, catalyst (C) from platinum group metals, and inhibitors (D1, D2). This composite material system enables low-temperature curing while maintaining coating performance and preventing substrate damage

The patent incorporates inhibitors (D1) maleimide and (D2) from the group of acetylenic compounds, ethylenically unsaturated isocyanates, acetylenically unsaturated silanes and unsaturated dicarboxylic acid diesters or maleate compounds) into the coating composition before application. These inhibitors preliminarily block the catalytic activity of the platinum group metal catalyst, preventing premature curing during storage and transport, and can be activated or removed during the controlled low-temperature curing process

The inhibitors act as intermediary substances that temporarily interfere with the curing reaction. They bind to the platinum group metal catalyst to form inactive complexes, mediating between the reactive components (polysiloxane A and crosslinking agent B) and the catalyst (C), thereby controlling the timing and location of the curing reaction to occur only when and where intended

The patent creates a dynamic system where the curing behavior changes with temperature. At ambient temperature, the inhibitors maintain stability and prevent curing. When heated to the curing temperature range (70°C to 90°C), the system dynamically transitions to an active curing state. The catalyst and inhibitor interaction is temperature-dependent, allowing the system to adapt its reactivity to the operating conditions

The curing process follows a periodic pattern: during storage and transport, the composition remains in a stable, inactive state due to inhibitor presence. During the curing cycle at elevated temperature (70°C to 90°C), the composition transitions to an active curing state. This periodic switching between stable and reactive states allows the composition to maintain stability when needed and cure efficiently when required