Abstract: The method produces powder particles that are uniformly coated with functional groups. It includes homogenizing, in an agitator mill, a suspension of glass, quartz, glass ceramic, and/or ceramic particles in a suspending agent together with a coating agent, so that the particles in the suspension react with the coating agent in the agitator mill to form the uniformly coated powder particles with functional groups. Preferably a weight ratio of the suspending agent to the particles is from 0.5:1 to 5:1. The suspending agent is preferably an aqueous solvent and the coating agent is preferably a silane. The uniformly coated powder particles have a particle size (d50) of less than 2 ?m, have a specific surface of 5 to 40 m2/g, and are free of agglomerates.

Abstract: The invention relates to a method for producing powder particles that are uniformly coated with functional groups. According to said method, a suspension of particles of a crude powder is reacted with a coating reagent that contains at least one functional group. The suspension is homogenised in an agitation mill, where the particles are reacted with the coating reagent. The powder thus obtained is suitable for use as a filler in dental materials, cosmetic compositions, pharmaceutical compositions, paints, coatings, rubber mixtures and adhesives.

Abstract: To hermetically seal a fiber optic light guide (1) in a stripped or de-coated state, I.e. the bare optical fiber (2), in a feedthrough sleeve (5) the bare optical fiber (2) is sealed together with the feedthrough sleeve (5) by composite-glass solder with local heating. To make a permanent hermetic glass seal, the feedthrough sleeve (5) is made from an Invar alloy with very low thermal expansion and the composite-glass solder is low-melting with thermal expansion properties adapted to the alloy. The composite-glass solder is molded into prefabricated half-cylinder-shaped pressed parts (7) in a press/sinter technology process, The stripped optical fiber (2) is inserted between the pressed parts (7) arranged in the feedthrough sleeve (5) and sealed by melting the pressed parts together with each other and with the stripped optical fiber and feedthrough sleeve.

Abstract: To hermetically seal a fiber optic light guide (1) in a stripped or de-coated state, i.e. the actual optical fiber (2), in a feedthrough sleeve (5) the actual optical fiber (2) is sealed together with the feedthrough sleeve (5) by means of glass solder with local heating. In order to make a permanent hermetic glass seal, the feedthrough sleeve (5) is made from an Invar alloy, i.e. an alloy with very low thermal expansion during heating and the glass solder employed is a low-melting glass solder with thermal expansion properties adapted to the metallic material. The glass solder is molded into prefabricated half-cylinder-shaped pressed parts (7), in which the stripped optical fiber (2) is inserted and sealed.