Abstract: The production of copper phthalocyanine in accordance with German Offenlegungsschrift No. 2,432,564 is improved by the process which is characterized in that the reaction product formed at 130.degree.-300.degree. C from optionally substituted phthalic anhydride, reaction products of optionally substituted phthalic anhydride with ammonia, or the dehydration products thereof, urea and, optionally, a catalyst is reacted with a copper salt and, optionally, a catalyst at temperatures of 150.degree.-350.degree. C and preferably 170.degree.-300.degree. C with the proviso that the catalyst is added either during the preparation of the starting material or during the reaction with the copper salt.

Abstract: A process and apparatus for conditioning crude copper phthalocyanine pigment prepared in a solvent-free process which comprises kneading at a shear gradient of 300-20,000 sec..sup.-1 for 10 seconds to 15 minutes and with an energy comsumption of 0.4-50 KWH/Kg. of copper phthalocyanine, a mixture of1. 1.0 part crude copper phthalocyanine which has not previously been subjected to extractive boiling;2. 0.1-20 parts of a salt which is soluble in water or in aqueous acids or bases; and3. 0.3-5 parts of an organic or inorganic solvent or mixture thereof which does not have significant amounts of the pigment or the salt.

Abstract: An electrical device having arc-prone electrical contacts within a container and an arc-resistant dielectric halogenated gas within the container. Also within the container is a filled resin electrical insulator. The filled resin comprises a cured epoxy resin and a filler of particles of calcium-aluminum glass.

Abstract: Transparent, colorless glass ceramic having a low coefficient of expansion, a high absorptivity for X-rays and which is useful in dental filling compositions, has the following ingredients, expressed as percent by weight of oxides: SiO.sub.2 40-55%, Al.sub.2 O.sub.3 15-25%, Li.sub.2 O 3-5%, P.sub.2 O.sub.5 3-10%, MgO 0-3%, ZnO 0-5%, ZrO.sub.2 2-7%, Ta.sub.2 O.sub.5 0-7% and La.sub.2 O.sub.3 10-20%.

Abstract: The effluent produced in the production of copper phthalocyanine according to the usual methods, containing by-products of the reaction and copper and molybdenum salts is advantageously purified by bringing it to a pH of between 3 and 9 and separating off the precipitate. The precipitate can be added to the starting components of the copper phthalocyanine production.

Abstract: Colorless, transparent glass ceramic with a linear thermal expansion which is smaller than 15 .times. 70.sup.-.sup.7 /.degree.C in the temperature range from 20.degree. to 300.degree.C, produced from a glass, which has been melted and shaped and thereafter subjected to a heat treatment for the controlled crystallization of innumerable, irregularly oriented, minute crystals of the structural type of .beta.-quartz, characterized in that it has, to at least 85% by weight, the following composition based on oxides:______________________________________ SiO.sub.2 45 to 68% by weight Al.sub.2 O.sub.3 15 to 30% by weight P.sub.2 O.sub.5 0 to 10% by weight Li.sub.2 O 2 to 6% by weight MgO 0 to 3% by weight ZnO 0 to 8% by weight ZrO.sub.2 2 to 7% by weight Ta.sub.2 O.sub.5 1 to 7% by weight ______________________________________The contents of Li.sub.2 O, MgO, ZnO and P.sub.2 O.sub.5 being such that the existing Al.sub.2 O.sub.3 content, to within a residue or a deficit of Al.sub.2 O.sub.

Abstract: Transparent, colorless, particulate glass ceramic having a low coefficient of expansion, a high absorptivity for X-rays and which is useful in dental filling compositions, has the following ingredients, expressed as percent by weight of oxides: SiO.sub.2 40-55%, Al.sub.2 O.sub.3 15-25%, Li.sub.2 O 3-5%, P.sub.2 O.sub.5 3-10%, MgO 0-3%, ZnO 0-5%, ZrO.sub.2 2-7%, Ta.sub.2 O.sub.5 0-7% and La.sub.2 O.sub.3 >12-20%.