Abstract:
A method for the preparation of reactive metal surfaces whereby the finished surfaces are in a reactive, essentially reduced condition and controlled oxidation reactions are employed to chemically bond a film on the metal surface to protect the surface or to provide a selected surface characteristic. During preparation the surface is covered by a working fluid that is inert with respect to the metal being worked and which is a solvent for film forming molecules which are being applied to the surface. The film forming molecules are thus readily chemically bonded to the reactive metal under controlled conditions essentially simultaneously with surface preparation to form a chemically uniform film on the reactive metal surface. The film is thus formed in the absence substances which may also react with the substrate metal to form undesirable reaction by-products which interfere with creation of a uniform, chemically bonded film on the substrate and which can result in pitting of the metal surface. The working fluid comprises a solvent for film forming monomers which is inert with respect to the metal being finished and may include halogenated liquid hydrocarbons and water as the solvent. Among the materials used to form the films of the method of the present invention good results have been achieved with hydroxyl and carboxyl terminated perfluoroalkylpolyethers. In addition inorganic film forming molecules such as phosphates, sulfates or chromates are used where water is the solvent for the working fluid. Articles produced by the method of the invention are claimed.
Abstract:
Procédé de préparation de surfaces métalliques réactives selon lequel les surfaces finies se trouvent dans un état réactif essentiellement réduit, et des réactions d'oxydation contrôlées sont utilisées pour lier chimiquement un film sur la surface métallique dans le but de protéger la surface ou de lui donner des caractéristiques désirées. Lors de la préparation, la surface est recouverte par un fluide de travail qui est inerte par rapport au métal à traiter et qui est un solvant pour des molécules filmogènes qui sont appliquées sur la surface. Les molécules filmogènes se lient chimiquement à la surface réactive dans des conditions contrôlées essentiellement simultanément avec la préparation de la surface pour former un film chimiquement uniforme sur la surface métallique réactive. Le film est ainsi formé en l'absence de substances qui peuvent également réagir avec le métal du substrat et former des sous-produits de réaction indésirables qui nuisent à la création d'un film uniforme chimiquement lié sur le substrat et qui peuvent former des piqûres à la surface du métal. Le fluide de travail consiste en un solvant pour des monomères filmogènes, qui est inerte par rapport au métal à finir et peut comprendre des hydrocarbures liquides halogénés et de l'eau comme le solvant. Parmi les matériaux utilisés pour former les films du procédé de la présente invention, de bons résultats ont été obtenus avec des perfluoroalkylpolyéthers à terminaison hydroxyle et carboxyle. De plus, des molécules inorganiques filmogènes telles que des phosphates, des sulfates ou des chromates sont utilisées lorsque l'eau est le solvant du fluide de travail. Des articles produits par le procédé de la présente invention sont revendiqués.
Abstract:
Improved recording medium and method for producing the same in which a thin lubricant film is applied directly to the surface of the recording medium without the necessity of intermediate layers or additional decomposition steps. The lubricant coating, which is a single monolayer of between about 30 and about 300 angstroms in thickness, is chemically bonded to the surface of the recording medium and the molecules of the film are oriented substantially normal to the surface of the recording medium. The backbone of the molecule of the film is selected from a number of different polymeric materials to provide a desired characteristic to the film surface, such as lubricity, and the distal end of the molecule is preferably provided with a strong electronegative group so that the surface of the magnetic medium is strongly electronegative which further protects against head crash and abrasion due to contact with the magnetic slider head. The film is applied directly to a reactive magnetizable metal surface of the media. The molecules of the film to be applied to the surface are brought to the surface in solubilized form since in this form the molecules are more soluble in the solution than they are in themselves thus promoting orientation of the molecule when the terminal bonding group of the molecule reacts with the surface of the recording medium.
Abstract:
The combination of a metal substrate and a thin surface film of a reaction product of the metal substrate and the film forming material. The molecules of the film are oriented essentially normal to the reactive metal substrate surface. The film molecules comprise a monofunctional or a polyfunctional terminal bonding group for chemically bonding with the metal substrate surface. It is preferred that a terminal bonding group be located at a terminus of the molecular backbone to insure that the desired molecular orientation is achieved. Additional sites may be provided for reaction with other molecules or for crosslinking to provide a film on the substrate surface having the desired characteristics. The terminal bonding group is selected from the group consisting of carbonyl, carboxy, carbonate, sulfide, sulfonate, amine, oxime, nitrate, phosphate, thiophosphate, epoxy, vinyl, benzyl, and ring systems capable of donating pi electrons. The backbone of is selected from the group of molecules having the formula [CX3 - (CX2O)m - (C2X4O)n - CX2] [CX3 - (CX2)n] - wherein X comprises fluorine, chlorine, iodine or hydrogen, m and n are integers of between 1 and about 32, and where X is hydrogen the hydrocarbon groups may be ethylenically unsaturated. A method for producing the article is provided.