Abstract: A compound of the formula wherein R is alkyl or aralkyl of up to 18 carbon atoms, the amine function being optionally protected are used to prepare compounds of the formula in which R retains its previous meaning and the amine is optionally protected.

Abstract: The single-use camera has a main body in which is housed the film cartridge and around which a cover member is formed. On the main body of the camera is a closure and a spring which are used to close the light-shield cover in the film gate of the cartridge when the cover is opened to remove the film cartridge.

Abstract: Magnetite particles containing a silicon component inside, and having the silicon component exposed on the surface in a proportion of 0.05 to 2.0% by weight as silicon which have improved moisture resistance as indicated by moisture content of magnetite (% by weight), measured under high-temperature, high-humidity conditions (200.degree. C., Karl Fischer technique), and given by the equation (1)moisture content (% by weight).ltoreq.0.5+A/2 (1),where A represents the amount (% by weight) of presence of the silicon component, expressed in terms of silicon, contained in magnetite, i.e., the total amount (% by weight) of silicon in magnetite, provided that 0.3.ltoreq.A.ltoreq.3.0;an electrical resistance of 1.times.10.sup.3 .OMEGA..multidot.cm or more; a degree of aggregation of 40 or less; and low residual magnetization whereby the particles are excellent in operating efficiency, flowability and environmental resistance, without lowering the electrical resistance compared with the current standard.

Abstract: A compound of the formula ##STR1## wherein the substituents are as defined in the specification.

Abstract: Solid adsorbents for soaking up or binding adsorbates from the group comprising mineral oils, ester oils, liquid hydrocarbons and other liquid inert organic compounds or mixtures thereof which comprise, as adsorptive components, a finely disperse to granular polyvinyl acetal insoluble in water and in the adsorbates, preferably polyvinyl butyral.Use of the adsorbents for soaking up or adsorptive binding and, as appropriate, for subsequent disposal or reprocessing of products, which may acutely pollute the environment, from the group comprising crude oil, tar oil, lubricating oil, lubricating grease, mineral oil, petroleum, hydraulic oil, paraffin oil, spindle oil, light and heavy fuel oil, diesel oil, kerosene, gasoline, benzene, liquid organic pesticides or pesticide solutions, vegetable oils and fats, animal oils and fats and, if appropriate, aqueous emulsions or suspensions of the said products.