US 9,005,782 B2Granted

Magnetic disk and method of manufacturing the same

AssigneeWD Media, LLC

InventorsKatsushi Hamakubo, Kae Itoh

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Abstract

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 (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) 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.

Claims11

Dependent claims

A magnetic disk comprising:

a substrate, and
a magnetic layer, a protective layer, and a lubricating layer provided in this order over the substrate,
wherein said lubricating layer contains a compound having a perfluoropolyether main chain in a structure thereof and having at least three hydroxyl groups other than at ends of a molecule thereof, and wherein the ends of the molecule of the compound do not contain polar groups such that the ends are in a free state,
wherein the compound having a perfluoropolyether main chain is obtained by reacting a perfluorodiol compound represented by the following formula (II) and a diepoxy compound:
CF3CF2(OC2F4)m(OCF2)nOCF2CH2OH formula (II)
wherein m and n are each an integer of 1 or more, and
wherein the diepoxy compound is represented by one of the following formulas:

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/744,829Filed 27 Mar 2009
Priority: JP 2008-08895130 Mar 2008
Published: US 2011/0026162 A13 Feb 2011
Granted: 14 Apr 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G11B 5/725
Protective coatings, e.g. anti-static or antifriction: containing a lubricant , e.g. organic compounds
C10M 107/38
Lubricating compositions characterised by the base-material being a macromolecular compound: containing halogen
G11B 5/8408
Processes or apparatus specially adapted for manufacturing record carriers: protecting the magnetic layer
C10M 2213/043
Obtained from monomers containing carbon, hydrogen, halogen and oxygen: used as base material

Family

US 2011/0026162 A1Pre-grant publication · published 3 Feb 2011
US 9,005,782 B2This patent

From the US filing history. Foreign family members aren’t listed.

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