Abstract: A rechargeable electrochemical cell having a negative electrode, whose electrochemically active material comprises an intermetallic compound having the CaCu.sub.5 -structure which forms a hydride with hydrogen, obtains a high loadability and a long life cycle by virtue of the fact that the intermetallic compound comprises a non-stoichiometric metastable phase. The intermetallic compound is, preferably, of the type having the composition AB.sub.m, where m exceeds 5.4.

Abstract: Optically readable information disc having a substrate plate manufactured by an injection moulding process or a compression moulding process and composed of a mixture of 40-90% by weight of polymethylmethacrylate and 10-60% by weight of polyvinylchloride or chlorinated polyvinylchloride.

Abstract: An optically readable information disc having a substrate plate which on at least one side comprises an information layer of a lacquer cured by irradiation for example by ultraviolet light, said layer carrying an optically readable information track in which the lacquer is a monocomponent lacquer which, in addition to 0.1-5% by weight of auxiliary substances, comprises only one radiation cross-linkable compound in a quantity by weight from 95-99.9% selected from the group consisting of alkanedioldiacrylates, alkanedioldimethacrylates, alkeneglycoldiacrylates and alkeneglycoldimethacrylates having the acrylate or methacrylate groups in end position, of which the alkane moiety and alkene moiety comprise from 4 to 12 carbon atoms, and in which the cured lacquer apart from the auxiliary substances comprises no or substantially no extractable material.

Abstract: The invention relates to a method of reproducing plastics record carriers, in particular duplicating video records. According to the invention, a metal die is used which is provided with a thin-liquid molding resin of a particular composition which can be polymerized by radiation. A radiation-pervious substrate which is manufactured from synthetic material, for example polymethylmethacrylate, is provided on the molding resin. The molding resin is exposed to light via the substrate after which the cured molding resin together with the substrate connected thereto is removed from the die. The molding resin used in the process comprises low-molecular monomers or oligomers which contain on an average 25-70% by weight of hydrocarbon groups and/or phenyl groups. The molding resin is aprotic and has a functionality as regards unsaturatedness which is between the values 2 and 6. A suitable molding resin contains mono-, tri- or tetra esters of acrylic acid.

Abstract: A method of manufacturing an optically readable information carrier in which a substrate 1 which is provided on at least one surface with a material which is sensitive to deep ultraviolet light having a wavelength from 190-300 nm, is exposed to deep ultraviolet light via a contact mask 2 which on one side has a layer 4 of a material which is not permeable to deep ultraviolet light in which an information track 5, 6 has been provided, after which the exposed plate is developed and if desired is provided with a reflection layer.

Abstract: The invention relates to a method of reproducing plastics record carriers, in particular duplicating video records. According to the invention, a metal die is used which is provided with a thin-liquid molding resin of a particular composition which can be polymerized by radiation. A radiation-pervious substrate which is manufactured from synthetic material, for example polymethylmethacrylate, is provided on the molding resin. The molding resin is exposed to light via the substrate after which the cured molding resin together with the substrate connected thereto is removed from the die. The molding resin used in the process comprises low-molecular monomers or oligomers which contain on an average 25-70% by weight of hydrocarbon groups and/or phenyl groups. The molding resin is aprotic and has a functionality as regards unsaturatedness which is between the values 2 and 6. A suitable molding resin contains mono-, tri- or tetra esters of acylic acid.

Abstract: The invention relates to an information disc having a laminated structure which can be read optically. The information disc comprises a transparent substrate which is preferably manufactured from a synthetic resin, for example plexiglass, having thereon a radiation-cured lacquer layer in which the information track is present. The lacquer layer used comprises a radiation-cross linkable protic compound which after curing is aprotic. The lacquer layer preferably comprises a polythiol compound as well as a polyene compound in an equivalent ratio of 1:1.

Abstract: The invention relates to a disk-shaped record carrier, for example a video plate, which is provided on one side or on both sides with a radiation-reflecting surface structure in the form of an information track consisting of blocks and pits on which a reflecting layer of metal is provided. The plate can be read optically. According to the invention the reflecting metal layer is provided with a cover layer which is formed by a transparent plate which is connected to the metal surface by means of a radiation-curable lacquer. The lacquer is preferably a U.V. curing lacquer and contains a protic mixture of acrylic acid esters. The transparent plate is also preferably manufactured from a transparent synthetic resin and has a thickness of 200 .mu.m.