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Room temperature vulcanizing compounds

Dibutyltin and dioctyltin diacetate, dilaurate, and di-(2-ethylhexanoate) are used as catalysts for the curing of room-temperature-vulcanized (RTV) sihcone elastomers to produce flexible siUcone mbbers used as sealing compounds, insulators, and in a wide variety of other appHcations. Diorganotin carboxylates also catalyze the curing of thermosetting siHcone resins, which are widely used in paper-release coatings. [Pg.74]

Another major use of organotin compounds is as curing agents for the room temperature vulcanization of silicones the 3 most commonly used compounds are Bu2SnX2, where X is acetate, 2-ethylhexanoate or laurate. The same compounds are also used to catalyse the addition of alcohols to isocyanates to produce polyurethanes. [Pg.400]

Dibutyltin diacetate, dilaurate, and di-(2-ethylhexanoate) are used as homogeneous catalysts for room-temperature-vulcanizing (RTV) silicones. The dialkyltin compounds bring about the cross-linking of the oligomeric siloxanes, to produce flexible, silicone rubbers having a host of different uses, such as electrical insulators and dental-impression molds. Recent work has also shown (560) that various dibutyltin dicar-boxylates catalyze both the hydrolysis and gelation of ethyl silicate under neutral conditions. [Pg.60]

Medium-molecular-weight PMTFPS with vinyl or hydroxyl end blocks are used for adhesives and sealants. They are cured either at ambient temperature (RTV-room temperature vulcanization) or at elevated temperature. One-part moisture-activated RTV sealants have been available commercially for many years. Because of then-very high resistance to jet engine fuels, excellent flexibility at very low temperatures, and high thermal stability, they have been used in both military and civilian aerospace applications.78 Two-part, heat-cured fluorosilicone sealants have been used in military aircraft applications and for sealing automotive fuel systems.79 Special class of fluorosilicone sealants are channel sealants or groove injection sealants, sticky, puttylike compounds, which do not cure. They are used to seal fuel tanks of military aircraft and missiles.75... [Pg.118]

Sealing Compound, One Part Silicone, Aircraft Firewall Adhesive/Sealant, Fluorosilicone Aromatic Fuel Resistant, One Part Room Temperature Vulcanizing... [Pg.522]

These are silicones in liquid or paste form that can be transformed into cross-linked elastomers at or near room temperature. There are two basic types, one component and two component. The one-component room temperature vulcanizing (RTV) elastomers cure upon exposure to air. A typical material of this type is synthesized from a dihydroxy-terminated siloxane oligomer and methyltriacetoxysilane (Scheme 2). The resulting tetraacetoxy compound will flow as a paste and so can be molded into shape. Hydrolysis of the acetoxy groups takes place over a period of hours. Condensation of the resulting silanols gives a highly cross-linked end product. [Pg.3990]

The spectral dispersion for organosilicones may be considerable for certain families of compounds. This is reflected in the Si chemical shifts of siloxanes, -(SiRR 0) -, an important class of compounds which includes resins, fluids, room-temperature vulcanized and heat-cured rubber consumer products. The first, Si NMR results (5,78) reported on polydimethylsiloxanes showed that individual resonance... [Pg.245]

Their main field of application are sealing compounds (silicone rubber) for which they are sold in the form of reactive one-component systems (mainly in cartridges) (RTV-l-systems, room-temperature vulcanization). Just like the one-component polyurethanes described in Section 4.2.2, they cure under the influence of moisture from the ambient air. In certain formulations, this reaction leads to the separation of acetic acid perceptible by its characteristic odor. Adhesive and sealing layers on a silicone basis show the following characteristics ... [Pg.40]

Leaving aside room-temperature-vulcanizing one-component silicones (RTV-IK), which are used largely as jointing compounds, there are three different types of silicone rubbers ... [Pg.702]

Silicones go into many different products (see Figs. 6-22 and 6-23). The so-called room temperature vulcanizing (RTV) system is an example of a specialty silicone compound that is very popular. All kinds of products are made in SI, such as complex molds in artistically designed shapes. The RTVs come in one- and two-component systems and... [Pg.455]

Room-temperature vulcanizing silicone rubbers (RTV) are also available commercially and are used as adhesives, caulks, and coatings [67]. The RTV systems usually improve the reaction of silanols with ethyl silicate catalyzed by tin compounds (dibutyltin dilaurate) to eliminate ethyl alcohol with the formation of the resin [Eq. (29)]. The time required for the final cure is about an hour at 150°C or 24 hr at room temperature. [Pg.147]

Sealant, ablative, silicone base, room temperature curing and primer Sealant, silicone rubber, room temperature vulcanizing Sealing compound, high tear strength Sealant, electrically conductive... [Pg.635]

RTV silicone adhesive is a rubberlike polymer called polydimethsiloxane. RTV stands for room temperature vulcanizing, or simply a rubber that cures at room temperature. Silicone rubber adhesives are made using a complicated process that turns elemental silicon metal made from sand (silica) into a rubbery polymer. When cured, silicone rubber adhesives/sealants have excellent resistance to heat (500—600 °F) and moisture that makes them exceptionally suited for outdoor weathering applications such as sealant and caulking compounds in the construction industry. Because of its exceptional properties, silicone adhesive has been used in some exotic applications such as the soles of the boots worn by the first astronauts to walk on the moon. Silicone adhesive/sealants are used to seal windows, doors, and portholes on the space shuttle and many satellite missiles. A special silicone adhesive is used to bond the heat shield tiles on space shuttles. [Pg.139]

Two main types of siUcone elastomer systems are used in biomedical prosthetics polysiloxanes terminated with hydroxyl groups and their subsequent polycondensation is the basis of room-temperature vulcanizing (RTV) systems in which tin compounds are used as catalysts. Another RTV or heat-cured system is based on unsaturated (vinyl) terminated polysiloxanes that undergo polyaddition reactions with the aid of a platinum catalyst. [Pg.253]


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See also in sourсe #XX -- [ Pg.185 ]




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