摘要:
A room temperature crosslinking, one component (RTV 1C) silicone rubber formulation with hydrophobic, silica featuring extremely low water absorption, a high level of whiteness, and fine-tunable, storage-stable rheological properties with a high reinforcing action in the silicone rubber vulcanizate contains A) from 0.5 to 60% by weight of a hydrophobic silica having the following properties: a carbon content of >3.1%; a methanol wettability of >60%; a reflectance of >94%; a BET/CTAB ratio of from >1 to 30 m2/g; a water vapor absorption at 30° C. at an ambient humidity of 30 of
摘要:
The invention relates to silicone rubber formulations comprising organopolysiloxanes and hydrophobicized silicas, which possess an extremely high level of whiteness.
摘要:
The present invention provides a hydrophobic precipitated silica having the following properties: carbon content1.0-8.0% methanol wettability 20-55% reflectance>94% BET/CTAB ratio ≦1 DBP absorption
摘要:
A precipitated silica having an SiOHisolated absorbance ratio of greater than or equal to 1.5, a silanol group density of 1 to 3.0 SiOH/nm2, a modified tapped density of 1 to 50 g/l, and a pH of 3-5, when measured as a aqueous suspension of 5.00 g of the precipitated silica in 100 ml. of deionized water allows preparation of storage-stable RTV-1 silicone rubber formulations without stabilizer. A process for preparing the precipitated silica and its use in thickening sealants is provided.
摘要:
Hydrophilic precipitated silicas which combine a particularly low initial moisture content with low moisture absorption over time, a low tapped density and a low silanol group density, have the following physicochemical parameters: equilibrium moisture content (at 70% relative humidity/20° C.) of 0.5%-5.0% by weight, based on the weight of the hydrophilic precipitated silica, BET surface area of 50-250 m2/g, CTAB surface area of 50-250 m2/g, and DBP (anhydrous) of 200-350 g/100 g.
摘要:
Precipitated silicas having an SiOHisolated absorbance ratio of greater than or equal to 1, may be used as reinforcers and thickeners for sealants.
摘要:
A precipitated silica having an SiOHisolated absorbance ratio of greater than or equal to 1.5, a silanol group density of 1 to 3.0 SiOH/nm2, a modified tapped density of 1 to 50 g/l, and a pH of 3-5, when measured as a aqueous suspension of 5.00 g of the precipitated silica in 100 ml. of deionized water allows preparation of storage-stable RTV-1 silicone rubber formulations without stabilizer. A process for preparing the precipitated silica and its use in thickening sealants is provided.
摘要:
Hydrophilic precipitated silicas which combine a particularly low initial moisture content with low moisture absorption over time, a low tapped density and a low silanol group density, have the following physicochemical parameters: equilibrium moisture content (at 70% relative humidity/20° C.) of 0.5%-5.0% by weight, based on the weight of the hydrophilic precipitated silica, BET surface area of 50-250 m2/g, CTAB surface area of 50-250 m2/g, and DBP (anhydrous) of 200-350 g/100 g.
摘要:
A precipitated silica having a d50-value of from 150 to 2000 nm, a d90-value of from 500 to 7000 nm, a silanol group density of from 2.5 to 8 OH/nm2, and a modified tapped density of less than or equal to 70 g/l is useful for thickening and providing thixotropy in liquid systems and shows superior efficiency at thickening and creating thixotropy compared to existing grades of precipitated silica. The precipitated silica functions best as a thixotrope in non-polar or intermediate polar liquid systems such as unsaturated polyester (UPE) resin systems.
摘要:
A precipitated silica having a d50-value of from 150 to 2000 nm, a d90-value of from 500 to 7000 nm, a silanol group density of from 2.5 to 8 OH/nm2, and a modified tapped density of less than or equal to 70 g/l is useful for thickening and providing thixotropy in liquid systems and shows superior efficiency at thickening and creating thixotropy compared to existing grades of precipitated silica. The precipitated silica functions best as a thixotrope in non-polar or intermediate polar liquid systems such as unsaturated polyester (UPE) resin systems.