Abstract: In manufacturing a magnetic recording disk, a magnetic film for a recording layer is deposited on a substrate of the magnetic recording disk in a magnetic-film deposition chamber, and the substrate is transferred from the magnetic-film deposition chamber to a lubricant-layer preparation chamber without exposing the substrate to the atmosphere. Then, a lubricant layer is prepared on the substrate in the lubricant-layer preparation chamber.

Abstract: A method and apparatus for depositing a protective film on a data recording disk, including the steps of depositing a magnetic film layer as a data recording layer on a surface of a substrate while the substrate is at a magnetic film deposition temperature; heating the substrate with the magnetic film layer thereon to a protective film deposition temperature; and depositing a protective film on the magnetic film layer while the substrate is at the protective film deposition layer; wherein the protective film deposition temperature is higher than the magnetic film deposition temperature.

Abstract: A method and apparatus for depositing a protective film on a data recording disk, including the steps of depositing a magnetic film layer as a data recording layer on a surface of a substrate while the substrate is at a magnetic film deposition temperature; heating the substrate with the magnetic film layer thereon to a protective film deposition temperature; and depositing a protective film on the magnetic film layer while the substrate is at the protective film deposition layer; wherein the protective film deposition temperature is higher than the magnetic film deposition temperature.

Abstract: This invention presents a method and an apparatus for manufacturing a magnetic recording disk, where steps from magnetic-film deposition to lubricant-layer preparation are carried out without vacuum breaking. The invention also presents a method and an apparatus for manufacturing a magnetic recording disk, where a substrate is cleaned prior to the lubricant-layer preparation. The invention also presents a method and an apparatus for manufacturing a magnetic recording disk, where burnishing is carried out in vacuum after the magnetic-film deposition. The invention also presents a method and an apparatus for manufacturing a magnetic recording disk, where post-preparation treatment to coordinate adhesive strength and surface lubricity of the lubricant layer is carried out in vacuum.

Abstract: The present invention relates to a method for producing an electrolytic solution containing a solute of lithium hexafluorophosphate. This method includes a step of (a) reacting lithium fluoride with phosphorus pentafluiride, in a nonaqueous organic solvent that is used for producing a lithium cell's electrolytic solution, thereby to form the lithium hexafluorophosphate dissolved in the solvent. According to this method, both yield and purity of the reaction product are sufficiently high, and the reaction can easily be managed. According to need, after the step (a), the nonaqueous organic solvent may be replaced with another nonaqueous organic solvent. The present invention further relates to a method for purifying an electrolytic solution used for a lithium cell. This electrolytic solution contains an acid impurity having at least one hydrogen atom in the molecule.

Abstract: A process of continuously crystalizing sodium percarbonate by the reaction of sodium carbonate with hydrogen peroxide using first and second reaction vessels includes the steps of: (a) continuously feeding a first feed solution containing sodium carbonate and a second feed solution containing hydrogen peroxide into the first reaction vessel, thereby to form therein a first slurry containing seed crystals of sodium percarbonate; (b) continuously discharging the first slurry from the first reaction vessel into the second reaction vessel while step (a) is performed; (c) continuously feeding at least one of hydrogen peroxide and sodium carbonate into the second reaction vessel while steps (a) and (b) are performed thereby to form therein a second slurry containing final sodium percarbonate crystals grown from the seed crystals; (d) continuously discharging the second slurry from the second reaction vessel while steps (a), (b) and (c) are performed; (e) continuously separating the second slurry into the final sodi

Abstract: The printing materials of the invention includes a film or sheet prepared from a chlorinated polyethylene containing 10 to 50 wt. % of chlorine and obtained by chlorinating a polyethylene having a molecular weight of 10,000 to 200,000, or from a polymer mixture containing the chlorinated polyethylene; a laminate comprising the film or sheet, and a base material; and a product prepared by impregnating or coating a base material with a solution of the chlorinated polyethylene or the polymer mixture. With the latter two printing materials, the surface of the film or sheet is used as the surface to be printed on. The image fixing method of the invention for use in producing copies by electrostatic printing comprises forming a toner image on one of these printing materials, and thereafter treating the printing material with heat at 160.degree. to 250.degree. C. for 5 to 30 seconds.

Abstract: The printing materials of the invention includes a film or sheet prepared from a chlorinated polyethylene containing 10 to 50 wt. % of chlorine and obtained by chlorinating a polyethylene having a molecular weight of 10,000 to 200,000, or from a polymer mixture containing the chlorinated polyethylene; a laminate comprising the film or sheet, and a base material; and a product prepared by impregnating or coating a base material with a solution of the chlorinated polyethylene or the polymer mixture. With the latter two printing materials, the surface of the film or sheet is used as the surface to be printed on. The image fixing method of the invention for use in producing copies by electrostatic printing comprises forming a toner image on one of these printing materials, and thereafter treating the printing material with heat at 160.degree. to 250.degree. C. for 5 to 30 seconds.

Abstract: The printing materials of the invention includes a film or sheet prepared from a chlorinated polyethylene containing 10 to 50 wt. % of chlorine and obtained by chlorinating a polyethylene having a molecular weight of 10,000 to 200,000, or from a polymer mixture containing the chlorinated polyethylene; a laminate comprising the film or sheet, and a base material; and a product prepared by impregnating or coating a base material with a solution of the chlorinated polyethylene or the polymer mixture. With the latter two printing materials, the surface of the film or sheet is used as the surface to be printed on. The image fixing method of the invention for use in producing copies by electrostatic printing comprises forming a toner image on one of these printing materials, and thereafter treating the printing material with heat at 160.degree. to 250.degree. C. for 5 to 30 seconds.

Abstract: Refining of either niobium hydroxide or tantalum hydroxide containing transition metals as impurities is accomplished easily and economically by dissolving the metal hydroxide in an aqueous solution of either hydrofluoric acid or oxalic acid, adjusting the pH of the solution to 1 to 4 and adding ammonium pyrrolidinedithiocarbamate (APDC) to the solution while maintaining the temperature of the solution below 60.degree. C. The addition of APDC causes the transition metals to simultaneously precipitate as coordination compounds. The minimum amount of APDC is 0.05 wt % of Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 that can be formed from Nb or Ta contained in the solution. After the treatment with APDC the pH of the solution is raised to 6 or above to precipitate the refined metal hydroxide.

Abstract: A process for producing hydrogen chloride and ammonia, comprising the steps of carrying out the reaction of ammonium chloride with ammonium hydrogen sulfate in the state of molten salt to produce hydrogen chloride, and heating the reaction system at the above-mentioned reaction carrying step at a temperature of 300.degree. C. or higher to produce ammonia gas, thereby hydrogen chloride and ammonia can be obtained in high yields, overcoming problems encountered in conventional corresponding processes.