Wd Media (singapore) Pte. Ltd.

Hoya Corporation

Wd Media, LLC

Hoya Lens Thailand Ltd.

(singapore) Pte. Ltd.

Katsushi Hamakubo

Koichi Shimokawa

Kae Itoh

Kae Ito

Kota Suzuki

Eiichi Yajima

Takako Ishizaki

Natsumi Tasaki

Provided are [1] a coating composition containing inorganic oxide particles (A), an epoxy compound (b1) having an organosilane moiety, a polyglycerol polyglycidyl ether (b2) having three or more epoxy groups, and a photocationic polymerization initiator (C), [2] a spectacle lens including a hard coat layer obtainable by curing the coating composition described in [1] above and a substrate, and [3] a method for producing a spectacle lens, including a step of applying the coating composition described in [1] above onto a substrate and a step of curing the applied coating composition by irradiation with light.

Coating composition, eyeglass lens, and method for manufacturing eyeglass

A coating composition capable of forming an acrylic hard coat film contains (A) an acrylate component and (B) a metal oxide, wherein a mass ratio (B)/(A) of (B) the metal oxide to (A) the acrylate component is from 0.1 to 1.5, (A) the acrylate component comprises components (a-1), (a-2) and (a-3), and a content ratio X of the component (a-1), a content ratio Y of the component (a-2) and a content ratio Z of the component (a-3) satisfies the following conditions (1) and (2). Condition (1): in (A) the acrylate component, X is from 40 to 60% by mass, and a total of Y and Z is from 60 to 40% by mass, and condition (2): in the total of Y and Z, Z is 0% by mass or more and less than 100% by mass.

Coating composition

A magnetic disk of is provided, the magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. In an embodiment, the lubrication layer a film formed by a lubricant having a perfluoropolyether compound A having a perfluoropolyether main chain in the structure and also having a hydroxyl group at the end and a compound C obtained from a reaction between a compound B expressed by: [Chemical formula 1] CF(&#x2014;O&#x2014;CF)m-(O&#x2014;CF)n-OCF[m and n in the formula are natural numbers.] and aluminum oxide.

Magnetic disk and manufacturing method thereof

Coating composition containing (A) an acrylate component and (B) zirconia, wherein a mass ratio (B)/(A) of (B) to (A) is from 0.1 to 2.0, (A) contains components (a-1), (a-2) and (a-3), and a content ratio X of component (a-1), a content ratio Y of component (a-2) and content ratio Z of component (a-3) satisfies conditions (1) and (2), and optical member having hard coat film obtained by using coating composition.

A coating composition contains (A) an acrylate component and (B) a metal oxide. A mass ratio (B)/(A) is from 0.6 to 1.3, (A) contains the components (a-1), (a-2) and (a-3), and a content ratio X of (a-1), a content ratio Y of (a-2) and a content ratio Z of (a-3) satisfies the conditions (1) and (2): (a-1): a polyfunctional acrylate compound having 3 or more acrylate groups in one molecule; (a-2): a dendritic aliphatic compound having an acrylate group at an end thereof; and (a-3): a modified acrylate compound having been modified with an alkylene oxide or &#x3b5;-caprolactone. The condition (1): in (A), X is from 40 to 60% by mass, and a total of Y and Z is from 60 to 40% by mass, and the condition (2): in the total of Y and Z, Z is 30% by mass or more and less than 100% by mass.

A lubricant compound is contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, and the lubricant compound contains a component A represented by Chemical formula 1 and a component B represented by Chemical formula 2: wherein X in Chemical formula 1 represents OH wherein X in Chemical formula 2 represents OCHCH(OH)CHOH,and the lubricant compound further contains a component C made of a specific compound having a phosphezene ring in the structure thereof.

Lubricant compound for magnetic disk and magnetic disk

To provide a plastic lens having a &#x3bb;/4 layer exhibiting excellent adhesion between a plastic substrate and a hard coat layer, and a method for producing thereof. A plastic lens containing: a plastic substrate (A); a &#x3bb;/4 layer (B) that is formed on the plastic substrate, is formed by curing a composition comprising a bifunctional or higher functional acrylate compound, a dendritic aliphatic compound having an acrylate group at an end thereof, and metal oxide particles, and has a thickness of from 50 to 100 nm; and a hard coat layer (C) that is formed on the &#x3bb;/4 layer directly or through another layer.

Plastic lens and production method therefor

An aspect of the present invention relates to a polarizing lens, which comprises a polarizing layer comprising a dichroic dye and a functional film in this order on a lens substrate, and further comprises a waterborne resin layer between the polarizing layer and the functional film as a layer adjacent to both the polarizing layer and functional film, wherein the waterborne resin layer is greater than 0.50 &#x3bc;m in thickness and has been formed by coating and drying a waterborne resin composition comprising a polyether polyurethane resin and a water-based solvent.

Polarizing lens

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 () comprises a substrate () and at least a magnetic layer (), a carbon-based protective layer (), and a lubricating layer () provided in that order over the substrate (). The lubricating layer () 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.

Magnetic disk and method of manufacturing the same

A magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. 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 include 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. A content of the compound b in the two types of compounds is not more than 10%.

Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk () has at least a magnetic layer (), a carbon-based protective layer (), and a lubricating layer () provided in this order over a substrate (). The lubricating layer () contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.

A lubricant for a magnetic disk that is excellent in heat resistance and is suitably used in a magnetic disk to be mounted on a magnetic recording device of a thermally assisted magnetic recording system and a magnetic disk provided with a lubricant layer containing this lubricant. The lubricant for a magnetic disk contains a compound where perfluoropolyether groups each having a perfluoropolyether main chain in its structure and a phosphazene ring at an end are linked to each other through a linking group. The linking group is an aliphatic group or a phosphazene ring. In a magnetic disk having at least a magnetic recording layer, a protective layer, and a lubricant layer on a substrate, the lubricant layer contains the lubricant for a magnetic disk.

Lubricant for magnetic disk and magnetic disk

A method of manufacturing a magnetic disk in which at least a magnetic layer, a carbon protective layer, and a lubrication layer are sequentially formed on a substrate is provided. The method comprises forming a film of a lubricant composition on the protective layer, the lubricant comprising a lubricant compound having a perfluoropolyether main chain in the molecular structure and an aromatic group or a phosphazene ring. The method further comprises forming the lubrication layer, and subjecting the magnetic disk to ultraviolet irradiation under a nitrogen gas or an inert gas atmosphere having an oxygen concentration of 5 volume % or less by adjusting an atmospheric temperature to a range of 50 to 180&#xb0; C.

Method of producing a magnetic recording disc

On manufacturing a magnetic disk having at least a magnetic layer (), a protective layer (), and a lubricating layer () formed in this order over a substrate (), 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&#xb0; C. or more.

Method of manufacturing a magnetic disk

A magnetic disk in which at least a magnetic layer, a protective layer, and the lubrication layer are sequentially provided on a substrate, the lubrication layer contains a lubricant compound for a magnetic disk, having a perfluoropolyether main chain in the molecular structure and a structure indicated as follows at a position close to the center of the molecule:-0-CH&#x2014;CH(OH)&#x2014;CH&#x2014;CH&#x2014;CH(OH)&#x2014;CH-0-or-0-CH&#x2014;CH(OH)&#x2014;CH(OH)&#x2014;CH-0-.

Growing community of inventors

Tokyo, Japan

Katsushi Hamakubo