摘要:
A two part sealant cures rapidly in deep sections when the two parts are mixed together. A first part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, diacetamidosilane chain extender of the general formula
and aminoxysilicone compound having from 1 to 100 silicone atoms per molecule and from 3 to 10 aminoxy groups per molecule. A second part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler and hydroxyl endblocked polydiorganosiloxane having a degree of polymerization of from 1 to 50.
摘要:
A two part sealant cures rapidly in deep sections when the two parts are mixed together. A first part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, diacetamidosilane chain extender of the general formula
and aminoxysilicone compound having from 1 to 100 silicone atoms per molecule and from 3 to 10 aminoxy groups per molecule. A second part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler and hydroxyl endblocked polydiorganosiloxane having a degree of polymerization of from 1 to 50.
摘要:
A silicone sealant composition which bonds to dolomite containing concrete after exposure to moisture is obtained by adding a silicone fluid having greater than 2 mole percent epoxy functionality to a sealant of the type containing a hydroxyl endblocked polydiorganosiloxane, acetamidosilane chain extender and cross linking agent selected from the group consisting of triacetamidosilane and aminoxysilicon compound.
摘要:
A silicone sealant composition which bonds to dolomite containing concrete after exposure to moisture is obtained by adding a silicone fluid having greater than 2 mole percent epoxy functionality to a sealant of the type containing a hydroxyl endblocked polydiorganosiloxane, acetamidosilane chain extender and cross linking agent selected from the group consisting of triacetamidosilane and aminoxysilicon compound.
摘要:
A self leveling silicone sealant composition is obtained by combining 100 parts by weight of a hydroxyl endblocked polydiorganosiloxane having a viscosity of from 1.8 to 125 Pa·s; from 0 to 150 parts by weight of non-acidic, non-reinforcing filler, from 95 to 5 percent of the filler being treated; from 2.5 to 10 parts of diacetamidosilane; a crosslinker consisting of either from 0.3 to 4.2 parts of a triacetamidosilane or 1 to 6 parts of an aminoxysilicon compound; and from 1 to 50 parts of a diluent. The composition, when cured, has an elongation of at least 600 percent, a durometer on the Shore A scale of from 5 to 20 inclusive and a modulus at 150 percent elongation of less than 50 pounds per square inch.
摘要:
A process is disclosed of making a polydiorganosiloxane-silica universal mixture from a free-flowing, powdered, surface-modified, reinforcing silica-polydiorganosiloxane composition used to make, for example, RTV silicone sealant compositions which are non-sag. These mixtures are made by combining, mixing and heating a reinforcing silica filler and a diol surface modifying agent at 20°C. to 180°C. using 0.05 to 0.5 part by weight of the diol per one part by weight of the silica. Polydiorganosiloxane is added gradually to the resulting fluidized filler over a time period of less than 10 minutes to obtain the free flowing powdered reinforcing silica-polydiorganosiloxane. The foundation mixture is obtained by massing the above composition and adding more polydiorganosiloxane to obtain a mixture which has from 5 to 20 weight percent of silica filler. The product mixtures have a plateau stress of greater than 700 dynes/cm 2 and a shear-thinned viscosity of no more than 1,000 Pa·s at a shear stress of 50,000 dynes/cm 2 . RTV silicone sealant compositions are obtained in 10 to 15 minutes from the start of making the surface modified silica filler to the final sealant composition.
摘要:
A process is disclosed of making a pumpable, stable, polydiorganosiloxane-silica universal mixture by mixing and heating a polydiorganosiloxane, a reinforcing silica filler and a diol surface modifying agent at 50°C. to 180°C. using 0.05 to 0.5 part by weight of the diol per one part by weight of the silica. The mixture is used to make RTV silicone sealant compositions which are non-sag.