The core composition of silicone release agents includes multiple key components, each undertaking different functions that work together to achieve the release effect. Here is a detailed introduction:
This is the most critical component that imparts release performance.
Common Types
- Silicone: Mainly vinyl silicone oil, which is currently the most widely used, stable, and reliable main body of release agents.
It undergoes a chemical reaction (crosslinking reaction) with the main film-forming substance to form a three-dimensional network structure, converting the coating from a liquid to a solid state.
Common Types
- Hydrogen-containing silicone oil: Used in addition-cured (platinum-catalyzed) silicone systems.
- Silane-based: Such as crosslinking agents for condensation-cured silicone systems (e.g., methyltrimethoxysilane, tetramethoxysilane, etc.).
It is used to accelerate the curing reaction between the crosslinking agent and the main film-forming substance.
Common Types
- Platinum catalyst: Used in addition-cured silicone systems (highly efficient, with no odorous by-products).
- Organotin catalysts: Such as dibutyltin dilaurate (DBTL) and stannous octoate, used in condensation-cured silicone systems (lower cost but with odor and poor environmental friendliness, gradually being replaced).
It adjusts the effective components (base agent, crosslinking agent, catalyst, etc.) into a viscosity suitable for coating, helping the effective components to be evenly applied to the surface of the substrate.
Common Types
- Organic solvents: Toluene, xylene, heptane, ethyl acetate, acetone, isopropanol, etc. (used in solvent-based systems).
- Water: Used in emulsion-type or water-soluble systems.
- Reactive monomers/diluents: Used in solvent-free (100% solid content) systems, such as UV-cured or EB-cured systems. These monomers themselves participate in the curing reaction, becoming part of the final coating, with almost no VOC emissions.
There are various types, with relatively small dosage but critical roles.
Common Types
- Anchoring agent: Improves the adhesion between the release coating and specific substrates (e.g., PET film, PE film, paper), preventing transfer or peeling. Usually, it is a specially modified silane or titanate.
- Inhibitor: (Mainly used in platinum-cured silicones) Delays the curing reaction, extends the operating time (pot life), and prevents premature curing during mixing or coating.
- Release force regulator: Precisely adjusts the magnitude and stability of release force. It can be a silicone oil with a specific structure or a modified polymer.
- Leveling agent: Improves the leveling property of the coating on the substrate, reduces defects such as orange peel and pinholes, and forms a smoother and more uniform surface.
Therefore, a release agent formula is a careful combination and balance of these components to meet the strict requirements of specific applications. The choice of system (solvent-based silicone, solvent-free silicone, emulsion silicone) depends on various factors such as cost, performance, environmental regulations, and equipment conditions.
Topwin is one of the leading professional manufacturers and solution providers with more than 20 years of experience, and has domestic top-level engineers in the silicone surfactant industry. Specializing in research and development, production, sales, and marketing of silicone-based special functional performance materials, Topwin also serves as a professional provider of technical services. Our products are mainly used in Polyurethane Foam, Corp Protection, Coatings and Inks, Leather & Textile, Silicone Release Coating for Paper and Film, Personal Care, and others.
