Preparation of sealants and compounds

Sealants (sealing materials) and compounds (filling materials) are thickflowing pastes which solidify in the cold. They are prepared by mixing low-molecular silicone elastomers with mineral ingredients. Sealants and compounds are supplemented with special catalysts which help them to solidify in the cold. Before using sealants or compounds, the surface of the product is sometimes covered with a sub-layer to improve adhesion. 

Raw stock a) sealants are produced from elastomers SKTN, SKTN-A, SKTN-B, SKTN-C, or SKTNPh-50, titanium white TS (or zinc white M-l or M-2), iron oxide (Redoxide), silicone liquid GKZh-94 b) compounds are produced from elastomers SKTN, SKTN-A or SKTN-B, arbon white U-333, zinc or titanium white, pigment. 

The production process of sealants (Fig. 63, a) includes the sieving of the filler (white) through a metal mesh (No. 016 or No. 018) in closed 

Similarly to sealants, the compound paste is mixed before use with a metalorganic or silicone catalyst as a result, even at room temperature the paste switches from a thick-flowing to a rubberlike state and solidifies. The compound paste can be prepared with a catalyst, i.e. as a one-component system. In this case the equipment should be particularly airtight, especially the equipment used to load the compound into containers. 

The most important properties and applications of silicone sealants and compounds are given in Table 23. 

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