The use of GENIOSIL® GF 80 as a coupling agent in mineral-filled plastics improves filler dispersibility, reduces its sedimentation tendency and greatly lowers the resin's viscosity. In addition, it leads to higher filler loading and a marked increase in water (vapor) resistance, as well as resistance to acids and bases. As a component of adhesives and sealants, GENIOSIL® GF 80 improves both adhesion to the substrate and mechanical properties such as flexural strength, tensile strength and modulus of elasticity.
GENIOSIL® GF 80 is an epoxy functional alkoxysilane. It´s a clear, colorless liquid with a characteristic odor. The silane hydrolyzes in the presence of moisture (methanol is released) to form silanols, which can then react with themselves to produce siloxanes. The epoxy group on GENIOSIL® GF 80 can undergo a ring-opening reaction with nucleophiles such as alcohols and amines. An acidic or basic catalyst may be required. As a bifunctional, organically unsaturated molecule, GENIOSIL® GF 80 is able to function as a molecular bridge between inorganic and organic substrates.

1. General processing information

GENIOSIL® GF 80 is highly miscible with standard organic solvents, such as alcohols, hydrocarbons and acetone.
GENIOSIL® GF 80 can be physically dissolved in neutral water to an extent upward of 5 wt %.
Much stronger homogeneous aqueous concentrations (up to 50% by weight) can be obtained by way of hydrolysis.
By incorporating a hydrolysis catalyst (e.g acetic acid), hydrolysis can be greatly accelerated at pH values of 3 to 4. However, at pH values below 4, the epoxy ring may start to open.

2. GENIOSIL® GF 80 as a surface modifier

Fillers are treated either with pure GENIOSIL® GF 80 or a solution thereof. It may be necessary to pretreat the substrate with water and/or a catalyst (e.g. ammonia). Subsequent binding of the treated filler, for example to epoxy resins, is preferably effected during the normal crosslinking process. In an alternative procedure referred to as blending, GENIOSIL® GF 80 is added directly to the polymer - either before the filler is incorporated or at the same time. A prerequisite for the blending process is that GENIOSIL® GF 80 and the polymer are compatible and that the resin and GENIOSIL® GF 80 do not react prematurely.

3. GENIOSIL® GF 80 as an adhesion promoter in formulations

Used as a primer, GENIOSIL® GF 80 is applied as an aqueous or organic solution to an inorganic substrate (e.g. metal or glass surfaces). Once GENIOSIL® GF 80 has dried and bonded to the surface, an organic coating may be applied using a standard technique (e.g. spraying or knife coating).
In adhesives and sealants GENIOSIL® GF 80 may be added to the formulation as an adhesion promoter. Processing is effected by means of standard mixing methods.

GENIOSIL® GF 80 is mainly used in the treatment of inorganic fillers (e.g. glass, mineral and glass wools, ATH, kaolin, mica, metallic oxides) for various polymer types, such as epoxy resins, urethane, melamine resins, EPDM, and for polysulfides, and an additive or primer in coatings, paints, adhesives and sealants.


Information on available container sizes is obtainable from WACKER subsidiaries.


The 'Best use before end' date of each batch is shown on the product label. Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.

Sales and support

Wacker Chemical Corporation
3301 Sutton Road
Adrian, MI 49221-9397
United States
+1  888  922-5374 (Phone)

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