Abstract: An aqueous dispersion, comprising: a silicon dioxide powder having a silicon dioxide content of 10 to 60 wt. %, wherein the aqueous dispersion is stable in the pH range of 2 to 6, the aqueous dispersion additionally contains at least one compound, which is at least partially soluble in aqueous solution in the pH range 2 to 6 in the form of polyvalent cations, these being stable in a silicate-like environment as an anionic component of the particle surface of the silicon dioxide powder, the quantity of cation-providing compound in relation to the surface of the silicon dioxide is 0.001 to 0.1 mg cation-providing compound/m2 silicon dioxide surface, the cation-providing compound being calculated as the oxide, and the zeta potential of the aqueous dispersion has values of less than or equal to zero.

Abstract: A stable, aqueous dispersion, which includes:

Abstract: The present invention provides an aqueous dispersion containing at least two powder types selected from one or more metal oxide powders and/or one or more non-metal oxide powder. The present invention also provides a coating composition containing this dispersion, an inkjet recording medium containing the coating composition, and methods of making the same.

Abstract: A pyrogenic process is used to prepare alkali-doped silica particles. Particles produced by this process exhibit homogeneous doping, reduced agglomeration, greater stability and higher removal rates. Aqueous dispersions containing alkali-doped pyrogenic silica with average particle size less than 100 nm are used for polishing surfaces (CMP).

Abstract: A finely divided, stable dispersion of a solid is produced by: spraying at least two streams of a preliminary dispersion, each through a separate nozzle by pumps, onto a collision point in a reactor chamber enclosed by a reactor housing; passing water vapor through an opening into the reactor chamber so that a vaporous atmosphere consisting mainly of water vapor prevails in the reactor chamber; and removing the finely divided dispersion and a) vapor, b) partially condensed vapor consisting mainly of water or c) a combination of a) and b) from the reactor chamber by excess pressure of an incoming water vapor on the gas inlet side; wherein the solid has an average particle size of from 10 nm to 10 &mgr;m.

Abstract: An aqueous dispersion containing a cerium oxide-doped, pyrogenically produced silicon dioxide, wherein the cerium oxide is introduced through an aerosol of a cerium salt solution or suspension and the average particle size in the dispersion is less than 100 nm. The dispersion is produced by dispersing the cerium oxide-doped, pyrogenically produced silicon dioxide in aqueous solution by means of a high energy input. The aqueous dispersion can be used for chemical-mechanical polishing.

Abstract: Aqueous dispersions comprising microfine metal oxide particles and dispersion auxiliaries, wherein, as dispersion auxiliaries, at least one of the compounds of the general formula (I) 1

Abstract: Aqueous dispersions comprising:

Abstract: The present invention relates to an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide. In addition, the present invention provides a method of producing an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide and methods of using this aqueous dispersion for chemical-mechanical polishing.

Abstract: An aqueous dispersion is used in the chemical mechanical polishing of surfaces, particularly oxidic surfaces, such as silicon dioxide. The aqueous dispersion contains a powder of pyrogenically produced silicon dioxide doped with 0.01 and 3 wt. % aluminium oxide, relative to the total amount of powder, said powder having an average particle diameter in the dispersion of not more than 0.1 &mgr;m.

Abstract: Process for the production of yellow bis(3-[triethoxysilyl]propyl)polysulfane with an average sulfur chain length of less than 4 and an iodine colour value of ≦10 mg iodine/100 ml, wherein neutral chloropropyltriethoxysilane is mixed with chloropropyltrichlorosilane and then reacted with sodium sulfide (Na2S) and sulfur, disodium tetrasulfide (Na2S4) and Na2S or disodium trisulfide (Na2S3) and Na2S in ethanol.

Abstract: A process is disclosed for the preparation of anhydrous sodium sulfide by heating sodium sulfide having a water content of from 38 to 40% in a contact drier in vacuo, the temperature of the solid to be dried being increased from approximately 20° C. at the solid inlet to ≧180° C. at the solid outlet.

Abstract: Propyl silanes functionalized in 3-position are produced by catalytically reacting allyl compounds of the formula H2C═CH—CH2X with silanes of the formula R2R3R4SiH and using a 3- to 100-fold excess of silane.

Abstract: A pyrogenic process is used to prepare alkali-doped silica particles. Particles produced by this process exhibit homogeneous doping, reduced agglomeration, greater stability and higher removal rates. Aqueous dispersions containing alkali-doped pyrogenic silica with average particle size less than 100 nm are used for polishing surfaces (CMP).

Abstract: An aqueous dispersion containing a cerium oxide-doped, pyrogenically produced silicon dioxide, wherein the cerium oxide is introduced through an aerosol of a cerium salt solution or suspension and the average particle size in the dispersion is less than 100 nm. The dispersion is produced by dispersing the cerium oxide-doped, pyrogenically produced silicon dioxide in aqueous solution by means of a high energy input. The aqueous dispersion can be used for chemical-mechanical polishing.

Abstract: The invention relates to a process for the preparation of organosilylalkylpolysulfanes, of the general formula I (R1R2R3SiR4)2Sx (I) by reaction of organosilylalkylpolysulfanes of the general formula II (R1R2R3SiR4)2Sy (II) with an ionic sulfide of the general formula M+2S2− (III) and an organosilylalkyl halide of the general formula R1R2R3SiR4X (IV), the long-chain organosilylalkylpolysulfane of the general formula (II) and the organosilylalkyl halide of the general formula (IV) being initially introduced into the reaction vessel and the ionic sulfide of the general formula (III) being added to this solution in several portions.

Abstract: Organosilicon compounds of general formula (I) R1R2R3Si—R4—S—Zn—S—R4—SiR1R2R3  (I) wherein R1, R2, R independently, represent H, a halogen, alkyl or alkoxy and R4 represents an alkylidene group, their preparation and their use in rubber mixtures.

Abstract: The invention relates to a process for the preparation of organosilylalkylpolysulfanes, of the general formula I (R1R2R3SiR4)2SX (I) by reaction of organosilylalkylpolysulfanes of the general formula II (R1R2R3SiR4)2Sy (II) with an ionic sulfide of the general formula M+2S2− (III) and an organosilylalkyl halide of the general formula R1R2R3SiR4X (IV), the long-chain organosilylalkylpolysulfane of the general formula (II) and the organosilylalkyl halide of the general formula (IV) being initially introduced into the reaction vessel and the ionic sulfide of the general formula (III) being added to this solution in several portions.

Abstract: Organosilicon compounds of the formula I 1

Abstract: Process for the production of yellow bis(3-[triethoxysilyl]propyl)polysulfane with an average sulfur chain length of less than 4 and an iodine color value of ≦10 mg iodine/100 ml, wherein neutral chloropropyltriethoxysilane is mixed with chloropropyltrichlorosilane and then reacted with sodium sulfide (Na2S) and sulfur, disodium tetrasulfide (Na2S4) and Na2S or disodium trisulfide (Na2S3) and Na2S in ethanol.