316results about "Magnetic layer protection" patented technology

The magnetic tape device includes: a magnetic tape; and a servo head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the servo head is a TMR head, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes a servo pattern, the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.

Disclosed herein are blowing agents comprising fluorocarbons and/or hydrofluorocarbons useful in foamable compositions. Also disclosed are methods for forming a foam comprising the aforementioned blowing agents.

Disclosed is a magnetic disk that has excellent durability, particularly excellent LUL durability, and excellent alumina resistance and has a high level of reliability under a low flying height of a magnetic head involved in a recent tendency toward a rapid increase in recording density and a very severe environment resistance requirement due to diversified applications. A magnetic disk (10) comprises a substrate (1) and at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in that order over the substrate (1). The lubricating layer (8) contains a compound that has a perfluoropolyether main chain in the structure thereof and has an aromatic group and a polar group at the end of the molecule.

Provided are filtered cathodic vacuum arc systems useful for modifying a surface of a substrate (e.g. depositing a thin film of a material onto a surface of a substrate and/or implanting a material into the near-surface region of a substrate). The systems are configured to stabilize a do arc discharge plasma from an arc source. Also provided are methods for modifying a surface of a substrate, which in some cases includes depositing a material onto a surface of a substrate, in some cases includes implanting a material into the near-surface region of a substrate, and in some cases includes both depositing a material onto a surface of a substrate and implanting a material into the near-surface region of a substrate using the subject cathodic arc systems. In addition, magnetic recording media produced by the subject systems and methods are provided.

An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is improved by reducing noise thought to be due to an auxiliary recording layer so that a higher recording density can be achieved, and a method of manufacturing the same.

In order to achieve the above object, a representative configuration of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.

A magnetic disk includes a substrate on which a nonmagnetic metal layer, a magnetic layer, a carbon-based protection layer, an alcohol-based coupling layer, and a lubrication layer successively formed thereon. The lubrication layer contains a hydroxyl- or a carboxyl-modified compound as a lubricating material. The alcohol-based coupling layer contains, for example, lower alcohol as a main component and is deposited on the carbon-based protection layer, for example, by vapor deposition. The alcohol-based coupling layer may be replaced by a layer containing lower alcohol. The carbon-based protection layer may be deposited by plasma CVD.

A magnetic disk is provided which is excellent in durability of the magnetic disk or particularly in LUL durability and CFT characteristics and has high reliability under a decreased floating amount of the magnetic head accompanying the recent rapid increase in a recording density and extremely severe environmental resistance accompanying diversification of the applications.

The magnetic disk of the present invention is a magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate, and the lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.2, the two types of compounds including a compound a having a hydroxyl group at the end and a compound b having a number average molecular weight smaller than the number average molecular weight of the compound a and not more than 1500, and a content of the compound b in the two types of compounds being not more than 10%.

In a magnetic recording disk 1 including a magnetic layer 12, a protective layer 13, and a lubricating layer 14, the lubricating layer 14 is made from a lubricant prepared from a composition. The weight change of the lubricant ranges from −20% to −50% at 300° C. in the case where the lubricant is subjected to thermogravimetric analysis in such a manner that the lubricant is heated from 40° C. to 500° C. at a heating rate of 10° C./min. The lubricant has a maximum peak at about 300° C. in the case where the lubricant is subjected to differential thermal analysis in the same manner as described above. The lubricant can be quantitatively measured for heat resistance. Therefore, a magnetic recording disk exhibiting stable performance at high temperatures and a method for manufacturing such a magnetic recording disk can be obtained.

An evaluation method that can easily evaluate properties of a carbon protective film and a lubricant on a magnetic-disk surface or particularly, an evaluation method of a magnetic disk in which the properties of the magnetic-disk surface can be evaluated accurately so that a strict demand for interactions between the magnetic-disk surface and a head can be met is provided. In a state in which an element portion of the magnetic head provided with the head element portion that projects by thermal expansion is projected, after being brought into contact with a predetermined radial position on the surface of the rotating magnetic disk, the head is further made to perform seeking in a state in which the element portion is projected by a specified amount, whereby the properties of the carbon film or the lubricant formed on the magnetic-disk surface is evaluated.

A manufacturing method of a magnetic recording medium provided with a protective layer excellent in corrosion resistance, mechanical durability, adhesion with a lubrication layer, and floating stability of a head even if the film thickness is reduced is provided. This is a manufacturing method of a magnetic recording medium in which at least a magnetic layer, a carbon protective layer, and a lubrication layer are sequentially provided on a substrate, and said carbon protective layer is provided with a lower layer formed on the magnetic layer side and an upper layer formed on the lubrication layer side. The lower layer is formed by a chemical vapor deposition (CVD) method using hydrocarbon gas and then, the upper layer is formed by using mixed gas of hydrocarbon gas and nitrogen gas and then, treatment which nitridizes the surface of the upper layer is applied.

On manufacturing a magnetic disk having at least a magnetic layer (60), a protective layer (70), and a lubricating layer (80) formed in this order over a substrate (10), the lubricating layer is formed by using a coating solution in which a perfluoropolyether compound having a perfluoropolyether main chain and a hydroxyl group in a structure thereof is dispersed and dissolved in a fluorine-based solvent having a boiling point of 90° C. or more.

Disclosed is a perfluoropolyether (PFPE) lubricant comprising less than about 10 percent PFPE molecules having a molecular weight lower than about 2000 Daltons, and wherein the average molecular weight of the lubricant is greater than about 5000 Daltons. Such a lubricant comprises less than about 15 percent PFPE molecules having a moleuclar weight greater than about 10,000 Daltons. Also disclosed is a thin film magnetic disc comprising a recording surface and a PFPE lubricant in contact with the recording surface. The recording surface of such a thin film magnetic disc can be adapted to magnetically record information via an air bearing read/write head. The recording surface can be smooth. The disc can further comprise a rough-surfaced landing zone inward of the recording surface, wherein the PFPE lubricant is in contact with the landing zone. Also disclosed is a method of lubricating a thin film magnetic disc. The method can comprise applying a narrow, high molecular weight fractionated PFPE lubricant to the disc. In addition, a method of preparing a PFPE lubricant for use with a thin film magnetic disc is disclosed. The method can comprise fractionating a PFPE lubricant to include less than about 10 percent PFPE molecules having a molecular weight lower than about 2000 Daltons. The average molecular weight of such a lubricant after fractionation is greater than about 5000 Daltons.