Methoxysilane Based Sealants
 In recent years, Cray Valley has developed two new CRAYVALLAC® rheology modifiers for use in one-component moisture cured methoxysilane sealants. These two 100% active amide products, CRAYVALLAC SL and CRAYVALLAC SLX, are specifically designed to impart excellent sag and slump resistance to methoxysilane based sealants without detrimentally effecting their other performance benefits e.g. adhesion, non-staining, UV stability, flexibility and storage stability. Also, the relatively high bulk densities of CRAYVALLAC SLX and CRAYVALLAC SL results in less dusting during use compared to fumed silica. The following product bulletins have been provided to differentiate the performance benefits of our CRAYVALLAC® rheology modifiers:
| CRAYVALLAC PA5 GA 25: Pre-activated paste
independant on temperature. NEW! |
| CRAYVALLAC PA5 DA 25: Pre-activated paste
independant on temperature. NEW! |
The following technical paper contains information regarding the basic chemistry of one-component moisture cured methoxysilane sealants and their production processes. In addition, a comparison of the rheological performances of CRAYVALLAC SLX and CRAYVALLAC SL is also provided:
 Methoxysilane Based Sealants
General Sealant Applications
In addition to methoxysilane based sealants, Cray Valley's micronised rheology modifiers are also used in Butyl Rubber and 2K Polyurethane based sealants for the control of sag and slump:
The dispersion and activation of these rheology modifiers is generally achieved during the pigment and filler grind phase of the sealant process. The heat generated during this phase facilitates the activation process. However, the suitability of castor based rheology modifiers is influenced by the processing temperature. Too high a temperature will result in the melting of the castor and a decrease in the final sag and slump properties. Typically, a process temperature of 60 - 65°C should not be exceeded with ANTISETTLE CVP. Should temperatures in excess of this be encountered then it is recommended to shift to an amide, or amide modified castor modifier. The tolerance of these products towards higher processing temperatures is CRAYVALLAC SUPER > CRAYVALLAC SF > CRAYVALLAC MT, with FLOWTONE GST being essentially equivalent to CRAYVALLAC MT yet easier to disperse due to its modification with micronised kaolin.
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