Method of using silica sol as a binder

surface treatment

The surface of the adhered object needs to be clean, dry, free of oil stains and dust. For metal surfaces, sandblasting can be performed to increase roughness; For ceramic or glass surfaces, surface impurities can be removed by acid or alkali washing.

Silica sol modulation

Direct use: Depending on the adhesive strength requirements, different solid content silica sol can be selected (such as 20% -50%). High solid content silica sol has higher bonding strength, but poorer flowability.

Add curing agent: To accelerate curing, a small amount of acidic or alkaline catalyst (such as hydrochloric acid, ammonia) or organotin compound can be added. The dosage of curing agent needs to be strictly controlled, as excessive dosage may affect the bonding performance.

Blending modification: Blending silica sol with organic resins (such as epoxy resin and polyurethane) can balance the high temperature resistance of inorganic adhesives and the flexibility of organic adhesives.

Coating and bonding

Uniformly coat the prepared silica sol onto the surface of the adhesive, with a thickness controlled between 0.1-0.5 mm. For large-area bonding, spraying or rolling coating processes can be used.

Align and press the two adhesives together, remove any bubbles, and fix them. After the silica sol has preliminarily solidified (about 2-4 hours at room temperature), subsequent processing or heating curing can be carried out.

solidification conditions

Room temperature curing: suitable for temperature sensitive adhesives, but the curing time is relatively long (24-72 hours for complete curing).

Heating curing: Heating at 80-150 ℃ for 1-2 hours can significantly shorten the curing time and improve the adhesive strength. The heating method can be hot air circulation, infrared heating, or oven heating.

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