Hoechst Aktiengesellschaft

Hoechst Celanese Corporation

Hiecgst Aktiengesellshat

Werner Groh

Peter Herbrechtsmeier

Rudolf Heumuller

Jurgen Theis

Gerhard Wieners

Jochen Coutandin

Hans-Tobias Macholdt

Gunter Siegemund

Thomas Stehlin

Andreas Brockmeyer

Roland Stern

Jorg Dahringer

Gerald Schutze

Richard Neuert

Clinton Dale Felton

Holger Jung

Hans Vowinkel

Baylor D Gibson

Peter Boening

James Robert Walden

Manfred Fleissner

Dieter Eichenauer

Electret fibers having improved charge stability are described which are composed of a material which predominantly contains a fiber-forming polymer or polycondensate and 0.01 to 30% by weight (preferably 0.01 to 10, in particular 0.1 to 5%, by weight), based on the weight of the material, of organic or organometallic charge control compounds, as contained in toners for electrophotographic processes, and a process for the production thereof. In addition, textile materials containing these electret fibers are described.

Electret fibers having improved charge stability, process for the

The use of additives to produce polymer electrets with improved charge stability. In particular, the invention relates to the use of specific charge control agents used for toners that are blended with various polymers at suitable concentrations to enhance the charge lifetime of the electrets. The charge control agents include a triphenylmethane compound, a polymeric ammonium compound, and arylsulfide compound and azochromium complex.

Polymer electrets with improved charge stability

Aromatic polyamide compositions with improved electrostatic properties, formed structures produced therefrom, and use and production thereof. Described are compositions comprising an aromatic polyamide which is soluble in organic solvents and from 0.01 to 30% by weight, based on the weight of the composition, of an organic or organometallic charge control agent. The compositions can be used for producing formed structures, in particular fibers; these fibers are preferably used for producing webs which can be used for producing dust filters.

Aromatic polyamide compositions with improved electrostatic properties,

Esters of .alpha.-fluoroacrylic acid are accessible by hydrolysis of an .alpha.-hydroxymethyl-.alpha.-fluoromalonic acid ester, decarboxylation and dehydration of the hydrolysis product and subsequent esterification of the resulting .alpha.-fluoroacrylic acid with an alcohol. The esters are polymerizable and are suitable for use as a starting material for preparing fluoropolymers which in turn are usable as materials for manufacturing transparent articles. The polymers are high-molecular and non-crystalline and have softening temperatures of above 100.degree. C.

.alpha.-fluoroacrylic acid esters and polymers thereof

In a process for the production of an optical coupler for polymeric optical fibers using ultrasound welding, the fibers are warmed, before the welding, to a temperature of from 50.degree. to 250.degree. C. for from 0.2 to 3 hours. The polymeric optical fibers are introduced into a plastic tube which melts with the fibers during the welding operation to form a unit. In another embodiment, a connector bar which has the same refractive index as the core material of the polymeric optical fibers can be inserted into the plastic tube, the polymeric optical fibers are brought into contact with the connector, and the plastic tube, the connector bar and the fibers are welded to one another under the action of ultrasound.

Process for the production of an optical coupler for polymeric optical

A thermoplastic molding compound consisting of units of 2,3-difluoroacrylic acid esters or their deuterated derivatives, or containing units of these esters, is distinguished by a high glass transition temperature and a high transparency. It is therefore suitable for the manufacture of beam waveguides for long transmission distances and high continuous use temperatures.

Transplant thermoplastic molding compound made of 2,3-difluoroacrylic

A detector for detecting invisible radiation and charged particles is composed of at least one radiation-absorbing panel and at least one optical waveguide arranged parallel to the surface of said panel and containing a fluorescent dyestuff. The luminescent light produced in the panel by the absorbed radiation is converted into a fluorescent radiation in the optical waveguide conducted to a photosensitive semiconductor component by total reflection and measured at that point.

Radiation detector

Certain esters of .alpha.-fluoroacrylic acid are accessible by hydrolyzing .alpha.-hydroxymethyl .alpha.-fluoromalonic acid esters and subsequently decarboxylating the hydrolysis product. The phenyl .alpha.-fluoroacrylates which are substituted on the phenyl radical can be prepared by hydroxymethylating dimethyl .alpha.-fluoromalonate, decarboxylating and dehydrating the resuiting dimethyl .alpha.-hydroxymethyl-.alpha.-fluoromalonate and esterifying the resuiting .alpha.-fluoroacrylic acid with substituted phenols. The substituted phenyl .alpha.-fluoroacrylates are colorless liquids or colorless solids which can be polymerized. They are suitable for use as a starting material for the preparation of fluorine polymers.

Substituted phenyl .alpha.-fluoroacrylates

Transparent thermoplastic molding composition of a polymer containing

Transparent thermoplastic molding composition, process for its

A process for the production of optical couplers from polymers in which the coupler structure is produced by injection molding and the polymers employed are preferably amorphous polymers, in particular PMMA, polystyrenes, polycarbonates, polyolefins, polyesters, polysulfones, polyether sulfones, polyether imides, polyarylates, polyamides or polyester carbonates. The coupler element is solid and may be coated with a polymer which has a lower refractive index than the coupler, so that the light propagation takes place in the coupler itself.

New multicompatible optical coupler produced by injection molding

Process for producing an optical coupler for polymer optical waveguides by arranging the optical waveguides in the same sense and bundling them by means of a plastic shrink-on sleeve. In this process, two to 10.sup.5 polymer optical waveguides are arranged in the same sense and bundled and a plastic tube is put over the mixing region. Then a piece of plastic shrink-on sleeve is pushed over the plastic tube and the shrink-on sleeve is heated to a temperature at which it contracts. The shrinkage temperature of the shrink-on sleeve is inside the thermoelastic temperature range of the plastic tube. The optical waveguide bundle may be stretched during or after heating.

Optical coupler for polymer optical waveguides

Transparent thermoplastic molding compound made of 2,3-difluoroacrylic

A light detector consists of a plate-like light-absorbing body and at least one optical waveguide connected thereto. Both parts of the light detector contain a fluorescent dye, whereby the irradiated light is converted into a fluorescence radiation. This radiation is guided by total reflection to a light-sensitive semiconductor element and is measured there. The light detector is suitable as light barrier, fiber-optic revolution counter or UV detector.

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Werner Groh