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| RTV31 |
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RTV31, RTV60, RTV88 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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RTV31, RTV60 and RTV88 silicone rubber compounds are high temperature two-part silicone elastomers. They are supplied ready-to-use with a base compound and DBT (dibutyl tin dilaurate) as the standard curing agent. DBT is suitable for most applications, however other catalysts are available to facilitate deep section cure, faster cure and automated mixing. RTV31, RTV60 and RTV88 silicone rubber compounds differ primarily in viscosity in the uncured state. |
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Typical high temperature applications for these products include, but are not limited to:
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Mixing Select a mixing container 4 to 5 times larger than the volume of RTV silicone rubber compound to be used. Weigh out the RTV silicone rubber base compound and add the appropriate amount of curing agent. 0.5% DBT by weight will provide a work time or pot life of about one hour and a cure time of 24 hours. 0.5% DBT is the most commonly used concentration of curing agent for RTV31, RTV60 and RTV88 silicone rubber compounds. The pot life may be lengthened by using less DBT (as little as 0.1% DBT). MEASURING GUIDE FOR CURING AGENT ADDITION
With clean tools, thoroughly mix the RTV base compound and the curing agent, scraping the sides and bottom of the container carefully to produce a homogeneous mixture. When using power mixers, avoid excessive speeds which could entrap large amounts of air or cause overheating of the mixture, resulting in shorter pot life. Deaeration Air entrapped during mixing should be removed to eliminate voids in the cured product. Expose the mixed material to a vacuum of 25mm (29 in.) of mercury. The material will expand, crest, and recede to about the original level as the bubbles break. Degassing is usually complete about two minutes after frothing ceases. When using the RTV silicone rubber compound for potting, a deaeration step may be necessary after pouring to avoid capturing air in complex assemblies. Curing Using DBT curing agent at a level of 0.5%, these RTV silicone rubber compounds will cure in 24 hours at 25° C (77° F) and 50% relative humidity to form durable, resilient rubbers. Under these conditions a pot life of about one hour will typically be available for pouring and working with the catalyzed material. Pot life may be increased by refrigerating the mixed material at 0° C (32° F) after catalyzing. Cure times may be shortened by using mild heat up to 93° C (200° F) maximum. A choice of curing agents is available for use with RTV31, RTV60 and RTV88 silicone rubber compounds.
Deep Section Cure If these RTV silicone rubber compounds are to be used in deep sections at temperatures over 150° C (302° F), the cured product should be properly conditioned prior to service. Following room temperature cure of 1-3 days, a typical program would be eight hours at 50° C intervals from 100° C (212° F) to the service temperature. Longer times at each temperature will be required for larger parts or very deep sections. Bonding If adhesion is an important application requirement, RTV31, RTV60 and RTV88 silicone rubber compounds require a primer to bond to non-silicone surfaces. Thoroughly clean the substrate with a non-oily solvent such as naphtha or methyl ethyl ketone (MEK) and let dry. Then apply a uniform thin film of a suitable silicone primer such as SS4004 silicone primer and allow the primer to air dry for one hour or more. Finally, apply freshly catalyzed RTV silicone rubber compound to the primed surface and cure as recommended. For more details on priming and adhesion refer to GE Silicones data sheet on silicone primers (1873). |
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Material Safety Data Sheets are available upon request from GE Silicones. Similar information for solvents and other chemicals used with GE products should be obtained from your suppliers. When solvents are used, proper safety precautions must be observed. |
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These products may be shipped at ambient temperature up to 110°F for 7 days maximum. They must be stored at -18°C (0°F) or below.The warranty period is 12 months from the date of shipment from GE Silicones if stored in the original unopened container at these conditions. |
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RTV31, RTV60 and RTV88 silicone rubber compounds may be ordered from GE Silicones, Waterford, NY, 12188, the GE Silicones sales office nearest you or an authorized GE silicone product distributor. |
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Prior to considering use of a GE Silicones product in fulfilling any Government requirement, please contact the Government and Trade Compliance office at 413-448-4624. CDS1868 |
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LEGAL DISCLAIMER | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||