Neutral Silicone Sealant

Neutral cure silicone sealant derives its name from its curing chemistry: unlike acetoxy silicone that releases acetic acid during cross-linking, neutral silicone uses oxime or alkoxy cure mechanisms that produce non-corrosive byproducts. This distinction is not merely academic — it determines substrate compatibility. Acetoxy cure silicone corrodes copper, brass, and zinc surfaces, attacks the silver backing on mirrors (causing black-edge deterioration), and reacts adversely with alkaline substrates such as concrete and marble. Neutral cure removes the acid attack, which is why it is the default choice for professional construction and industrial sealing applications. It describes the curing chemistry, not a guarantee for every substrate: mirror backings, natural stone and structural applications require a grade and test evidence suitable for that specific use.

The two primary neutral cure chemistries — oxime and alkoxy — each have specific performance characteristics. Oxime cure (also called ketoximino) sealants are the most common, offering good adhesion to most construction materials, moderate cure speed, and broad compatibility. Alkoxy cure sealants produce alcohol (typically methanol) as a byproduct and provide superior adhesion to porous substrates like concrete and masonry. Our manufacturing line produces both oxime and alkoxy formulations, allowing buyers to select the optimal chemistry for their project requirements. Both types deliver service temperature performance from -40 to +150 degrees Celsius and UV stability exceeding 20 years in exterior weathering exposure.

From a performance standpoint, our neutral silicone sealant achieves Shore A hardness of 18-25 (indicating a flexible, rubber-like cure), tensile strength above 0.8 MPa, and elongation at break exceeding 400 percent. The high elongation is critical for construction joint sealing, where thermal expansion and contraction, building settlement, and wind load deflection create constant movement in sealed joints. With a rated movement capability of plus or minus 25 percent, the sealant accommodates joint width changes without adhesive failure or cohesive tearing — meeting the requirements of ASTM C920, EN 15651, and GB/T 14683 standards.

Key Features

• Non-acidic cure — no acetic acid to corrode metals or attack mirror backing; mirror coatings and porous stone still need a compatibility check
• Excellent weathering resistance — UV stable for 20+ years
• Operating temperature range: -40°C to +150°C
• Strong adhesion to glass, aluminum, ceramic, wood, and most building materials
• Mildew-resistant formula available for wet areas
• Available in 12+ standard colors plus custom color matching

Technical Specifications

Indicative values for the series. Figures move with the grade, the substrate pair, coat weight and cure conditions, so treat them as a basis for comparison rather than a specification — the technical data sheet for the grade you are supplied states the values that apply to it, and the conditions they were measured under.

Applications

• Window and door frame sealing — interior and exterior perimeter joints
• Curtain wall and structural glazing — weatherproofing and sealing
• Bathroom and kitchen — sanitaryware, countertop, and backsplash sealing
• HVAC and ductwork — joint sealing and vibration damping
• General construction — expansion joints and movement joints

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Available Packaging

Neutral silicone sealant is available in 280ml and 300ml cartridges compatible with standard caulking guns, 590ml sausage packs for high-output professional use, and 20L pails for large-scale industrial application. Cartridges are available in white, clear, black, grey, and brown as standard stock colors. Custom RAL color matching and private label packaging services are available for qualified orders with minimum quantities.

Certifications & Compliance