Lubricants and methods to determine dewetting thickness thereof
AssigneeWestern Digital Technologies, Inc.
InventorsBala Krishna Pathem, Nicholas Ryan Conley, Bruno Jean Marchon
Life of this patent
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Abstract
A lubricant including a plurality of segments including a divalent center segment and two sidechain segments, each including a perfluoroalkyl ether moieties is provided in which a dewetting thickness of the lubricant may be determined based in-part on a segment weight average molecular weight of the segments. A magnetic recording medium and a magnetic data storage system including the lubricant are also provided.
Claims20
A lubricant comprising:
- a plurality of segments, each linked together by ether linkages according to a general formula:
- Re1-Rb1-Ri-Rc-Ri-Rb2-Re2;
- wherein Rc is a divalent center segment including a perfluoroalkyl ether moiety;
- wherein each of Rb1 and Rb2 is, independently, a sidechain segment including a perfluoroalkyl ether moiety;
- wherein each Ri is, independently, a divalent linking segment including a functional group including elements from Group 13-17 of the periodic table of the elements;
- wherein each of Re1 and Re2 is, independently, a monovalent end segment including a functional group including elements from Group 13-17 of the periodic table of the elements;
- wherein Rb1≠Rc≠Rb2;
- and
- wherein the lubricant has a bonding percentage of about 70% to about 100% corresponding to a total area of a surface on which the lubricant is located.
A lubricant comprising a plurality of segments linked together by ether linkages according to a formula:
- wherein each of x, y1, and y2 is an integer from 1 to 10;
- wherein y1≠x≠y2;
- and
- wherein the lubricant has a bonding percentage of about 70% to less than about 100% corresponding to a total area of a surface on which the lubricant is located.
A method to determine a dewetting thickness of a lubricant, comprising:
- (a) generating a chemical representation of the lubricant including a plurality of segments, each linked together through an ether linkage according to a general formula:
- Re1-Rb1-Ri-Rc-Ri-Rb2-Re2;
- wherein Rc is a divalent center segment including a perfluoroalkyl ether moiety;
- wherein each of Rb1 and Rb2 is, independently, a sidechain segment including a perfluoroalkyl ether moiety;
- wherein each Ri is, independently, a divalent linking segment including a functional group including elements from Group 13-17 of the periodic table of the elements;
- wherein each of Re1 and Re2 is, independently, a monovalent end segment including a functional group including elements from Group 13-17 of the periodic table of the elements;
- and
- wherein Rb1≠Rc≠Rb2;
- wherein the lubricant has a bonding percentage of about 70% to about 100% corresponding to a total area of a surface on which the lubricant is located;
- (b) determining a segment weight average molecular weight (α) according to the formula:
- α=[molecular weight of Rb1+molecular weight of Rb2+molecular weight of Rc]÷3;
- and
- (c) determining the dewetting thickness, Tdw, of the lubricant according to the formula:
- Tdw=0.0045(α)+8.0226.
Dependencies are inferred from the claim text.