Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Self-Treatment of Lubricants for Rigid Disks

IP.com Disclosure Number: IPCOM000036895D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 17K

Publishing Venue

IBM

Related People

Bowen, AJ: AUTHOR [+2]

Abstract

As a magnetic recording disk rotates at an elevated temperature, lubricants necessary for functional operation of this disk can spinoff to a point where mechanical durability is a concern. The spinoff tendency is lessened significantly by adding functional groups (like acids or alcohols) to the ends of the molecules used as the lubricant. These new structures attach to the disk under certain time and temperature conditions.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 91% of the total text.

Page 1 of 2

Self-Treatment of Lubricants for Rigid Disks

As a magnetic recording disk rotates at an elevated temperature, lubricants necessary for functional operation of this disk can spinoff to a point where mechanical durability is a concern. The spinoff tendency is lessened significantly by adding functional groups (like acids or alcohols) to the ends of the molecules used as the lubricant. These new structures attach to the disk under certain time and temperature conditions.

Perfluoro polyethers (PFPE) are used as a topical lubricant on disks in magnetic recording applications. As the operation temperature increases from 20 to 60 degrees Celsius, the viscosity of the lube decreases from 200 to 30 centistrokes. At typically high RPMs and typical lube thickness, the viscous shear rate causes spinoff to occur over a 1 to 5 year time period at the worst- case temperature of 60 degrees Celsius. The spinoff tendency is lessened by adding functional groups (like acids or alcohols) to the end(s) of the PFPE molecule. These new "functional PFPE" attach to the disk under certain time and temperature conditions. At the file's high operating temperature of 60 degrees Celsius, the typical attachment time is three days. In this attachment time, insignificant amounts of lube spin off. At the file's lower temperature ranges the attachment time is much longer, but the higher viscosity holds the lube in place for the required file life. The required attachment is done in the file as oppo...