摘要:
Aqueous dispersion containing pyrogenically produced oxide particles of titanium, zinc, iron or cerium having an average particle size, expressed as a median value, in the dispersion of less than 200 nm, the particle sizes of the oxide particles are not distributed symmetrically in the dispersion, the dispersion contains as dispersing agent at least one (poly)phosphate corresponding to the general formula I and has a pH of 4.5 to 7.5. It is prepared by dispersing a stream of a preliminary dispersion by means of a high-energy mill. It can be used in sunscreen formulations.
摘要:
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 μm.
摘要:
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.
摘要:
Aqueous dispersion containing a hydrophilic metal oxide powder comprising a metal oxide and a surface modification of the metal oxide, wherein a) the metal oxide is selected from the group consisting of TiO2, ZrO2, SiO2, Al2O3, Fe2O3, Fe3O4, Sb2O3, WO3, CeO2 and mixed oxides thereof and b) the surface modification b1) comprises silicon atoms and aluminum atoms and b2) the silicon atoms are at least partly bonded to a hydrocarbon radical via a C atom and b3) the Al/Si molar ratio of the surface modification is 1:2-1:20.
摘要:
Process for the infiltration of porous ceramic components, in which a dispersion containing metal oxide particles and having a metal oxide content of at least 30% by weight, based on the dispersion, is used, where the particle size distribution d50 of the metal oxide particles is not more than 200 nm.
摘要:
Slurry which contains a) from (50) to (80) % by weight of refractory particles having an average particle size of from (0.5) m to (150) m, b) from (5) to (35) % by weight of aluminium oxide particles having an average particle diameter of less than (300) nm and c) from (5) to (35) % by weight of water and d) a pH of from (5) to (12). Process for producing the slurry using a dispersion, and also the dispersion itself. Process for producing a casting mould, and also the casting mould itself.
摘要:
Process for preparing an aqueous dispersion which has a pH of 9 to 14 and comprises particles of a pyrogenic titanium-silicon mixed oxide powder having a proportion of silicon dioxide of 75 to 99.99% by weight and of titanium dioxide of 0.01 to 25% by weight, whose mean aggregate diameter in the dispersion is not more than 200 nm, and at least one basic, quaternary ammonium compound.
摘要:
Process for preparing a dispersion of surface-modified silicon dioxide particles having an average particle diameter of not more than 100 nm by high-pressure milling of a preliminary dispersion comprising a) 10% to 50% by weight of surface-modified silicon dioxide particles, b) at least one glycol monoether of the general formula (A): H3C(CH2)m—O—(CH2)n—[O—(CH2)o]p—OH, c) at least one carboxylic ester of the general formula (B): H2x+1Cx—O—CH2—(CHR)—[O—CHR]y—O—C(═O)—CzH2z+1, d) the molar ratio A/B being 10:90 to 40:60 and m, n, o, p, x, y and z being independent of one another. Dispersion obtainable by this process. Process for producing granules of surface-modified silicon dioxide particles by separating off the liquid phase of the dispersion. Granules obtainable by this process. Use of dispersion and granules in coating materials.
摘要:
Process for preparing surface-modified silicon dioxide particles with a mean particle diameter of at most 100 nm, comprising the steps of: a) providing a predispersion b) high-pressure grinding of the predispersion to form a dispersion c) removing the liquid phase of the dispersion, the predispersion comprising a1) surface-modified silicon dioxide particles which are at least partly aggregated, are bonded to the surface-modifying component via Si—O—Si bonds and still have reactive groups on their surface, a2) one or more organosilicon compounds which have at least one silicon-carbon bond and at least one functional group which can react with the reactive groups to form a covalent Si—O—Si bond, and a3) one or more solvents. Redispersible, surface-modified silicon dioxide particles obtainable by this process. Use of these in toner powders, silicone rubber, adhesives and scratch-resistance surface coatings.
摘要:
Reactor for carrying out chemical and physical materials transformations, which comprises a reaction space enclosed by a reactor housing, where the reactor housing has at least two lateral fluid inlets having adjustably mounted nozzles which include an angle of about 20-160 degrees and through which fluid jets which impinge on one another at a common collision point within the reaction space are passed and the reactor has a fluid outlet at the bottom of the reaction space, which is characterized in that—an exchangeable bottom plate•which has a hole as fluid outlet and•on which moveably supported spheres are located so as to block the original path of the individual fluid jets in the unaligned state rests on the bottom of the reaction space and—a half shell standing upright on the bottom of the reaction space is located between each moveably supported sphere and the wall of the reactor space and—bottom plate, half shell and moveably supported spheres comprise one or more hard materials.