Abstract:
The present invention involves a structure of a contactless ohmic resistance potentiometer. A current path between two exterior electrodes is provided by a photoconductor, and a means is provided for causing an exposure of a portion of the length of the photoconductor between one exterior electrode and a tapping electrode. This permits a voltage division between two exterior electrodes. The usable surface of the photoconductor layer is delimited by an exterior electrode and a tapping electrode having a definite geometric course between the exterior electrodes. The distance ratio from the tapping electrode to the two exterior electrodes is varied by means of displacing the exposure of the photoconductor which causes the active partial surface of the photoconductor to be varied at will.
Abstract:
A contactless conductance potentiometer is provided in which the total conductance between two electric terminals can be selectively divided, the two parts being equal to the total conductance. This can be accomplished by using a ring-shaped photoconductor on a substrate, the ring-shaped photoconductor being divided along a diametral line. One exterior electrode is located on the substrate in a position surrounding one portion of the ring-shaped photoconductor and being in contact with the marginal edge thereof. The remaining part of the ring-shaped photoconductor is in marginal contact with the second exterior electrode. A tapping electrode is mounted inside the ring-shaped photoconductor and is in marginal contact with the inner edge of the ring-shaped photoconductor. The construction is such that when the photoconductor is exposed to light falling on the combined ring-shaped parts, current will flow through the exposed part of the photoconductor between the tapping electrode and one of the two exterior electrodes.
Abstract:
Surface-modified, structurally modified fumed silicas Surface-modified, structurally modified fumed silicas are surface-modified with N-containing silicon compounds. They are used as fillers in resins and adhesives.
Abstract:
The invention relates to emulsifier systems comprising organomodified siloxane block copolymers, their use, in particular the preparation of cosmetic, dermatological or pharmaceutical formulations, and of care and cleaning compositions, and also the products themselves prepared with the help of emulsifier systems.
Abstract:
RTV two-component silicone rubber which contains structurally modified hydrophobic fumed silicas which have vinyl groups fixed on the surface, further hydrophobic groups, such as trimethylsilyl and/or dimethylsilyl and/or monomethylsilyl groups, additionally being fixed on the surface.
Abstract:
The present invention relates to a hydrophobic, fumed silica which is obtained by milling a fumed silica which has fixed dimethylsilyl and/or monomethylsilyl groups on the surface due to silanization; and to a process for the preparation of the silica according to the invention, and to silicone rubber materials containing the silica according to the invention.
Abstract:
Surface-modified, pyrogenically prepared silica is prepared by subjecting the pyrogenically prepared silica, which is in the form of aggregates of primary particles and possesses a BET surface area of 150±15 m2/g, the aggregates having an average area of 12 000-20 000 nm2, an average equivalent circle diameter (ECD) of 90-120 nm and an average circumference of 1150-1700 nm, to surface-modification in a known way. It can be used as a filler for thickening liquid systems.
Abstract:
The invention relates to a hydrophobic fumed silica which is obtained by grinding a fumed silica which, as a result of silanization, has octylsilyl groups fixed on the surface, to a process for preparing it, and to coating formulations comprising this silica.
Abstract:
Mixed oxide powder consisting of particles with the components zirconium dioxide, aluminium oxide and at least a third component selected from the group including yttrium oxide, magnesium oxide or calcium oxide, wherein mixed oxide powder has an aluminium oxide content 0.01 to 10 wt. % and is homogeneously distributed in the mixed oxide particles, the content of aluminium oxide, zirconium dioxide and yttrium oxide is at least 99.5 wt. %, based on the total quantity of the powder, and the BET surface area is 20 to 80 m2/g. It is obtained by atomising a solution containing at least one starting compound for each of aluminium oxide, zirconium dioxide and the third component, allowing the atomised solution to react with oxygen in a reaction chamber at a reaction temperature 700 to 15000° C., cooling the hot gases and the solid products and then separating the solid product from the gases. It can be used as a dental material.
Abstract:
The present invention relates to coating formulations comprising surface-modified silicon dioxides. The coating formulations are useful in applications such as architectural paints for buildings, windows and doors.