Abstract: This invention pertains to the polyurethane composition with hydrophilicity and hydrolysis resistance. The purpose of this invention is achieved by:1) A polyurethane molecule containing at least one acidic hydrophilic group in the molecule which is neutralized with piperidine derivatives and piperazinone derivatives, or2) A mixture containing polyurethane and compounds(s) having at least one acidic hydrophilic group which is neutralized with piperidine derivatives and piperazinone derivatives.The invention polyurethane compositions which have excellent hydrolysis resistance and rupture strength are useful for adhesives, paints, and bonding agents for magnetic recording media.

Abstract: A magnetic coating formulation is composed principally of magnetic particles and a binder. At least a portion of the binder is a polyurethane resin synthesized from a reactant mixture of specific phosphorus compound, epoxy compound, isocyanate compound and polyfunctional hydroxy compounds. The reactant mixture may optionally contain a chain extender. The polyurethane resin contains one phosphoric acid group or one residual group derived from phosphoric acid per 3,000-200,000 number average molecular weight of the polyurethane resin, and has a number average molecular weight of 4,000-150,000. A magnetic recording medium with a magnetic coating layer formed from the magnetic coating formulation is also disclosed. The magnetic coating layer features not only excellent dispersion of magnetic particles, in other words, excellent magnetic characteristics but also superb durability.

Abstract: An electromagnetic relay is provided with a movable contact sloped at a prescribed angle relative to an attracted face of an armature and a fixed contact sloped at a prescribed angle relative to an attracting face of a core. In this electromagnetic relay, it is possible to contact the movable and fixed contacts slidingly each other even when the armature is attached so as to be in contact with a frame.