# US 11,898,117 B2 · High temperature lubricants for magnetic media

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- Number: US 11,898,117 B2
- Document ID: US11898117B2
- Status: Granted
- Kind: B2
- Application number: 18/105,368
- Filed: 2023-02-03
- Published: 2023-08-10
- Granted: 2024-02-13
- Earliest claimed: 2021-03-05
- Assignees: Western Digital Technologies, Inc.
- Applicants: Western Digital Technologies, Inc.
- Inventors: Xingliang He; Bala Krishna Pathem
- Web page: https://patentgrep.com/patent/US11898117B2

## CPC

- C10M 105/54: containing carbon, hydrogen, halogen and oxygen
- C10M 107/38: containing halogen
- C08G 65/007: {containing fluorine}
- C08G 65/2612: {containing aromatic or arylaliphatic hydroxyl groups}
- C08G 65/32: Polymers modified by chemical after-treatment
- C08L 71/00: Compositions of polyethers obtained by reactions forming an ether link in the main chain (of polyacetals C08L59/00; of epoxy resins C08L63/00; of polythioether-ethers C08L81/02; of polyether-sulfones C08L81/06); Compositions of derivatives of such polymers
- G11B 5/012: Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence)
- G11B 5/255: comprising means for protection against wear {(in thin film structures G11B5/3106)}
- G11B 5/7257: {Perfluoropolyether lubricant}
- C10M 2213/043: used as base material
- C10N 2020/04: Molecular weight; Molecular weight distribution
- C10N 2030/06: Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
- C10N 2040/18: in connection with recordings on magnetic tape or disc
- C10N 2050/023: {Multi-layer lubricant coatings}
- C10N 2050/08: Solids
- G11B 2005/0021: {Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal}
- C10M: LUBRICATING COMPOSITIONS (well drilling compositions C09K8/02); USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION (mould release, i.e. separating, agents for metals B22C3/00, for plastics or substances in a plastic state, in general B29C33/56, for glass C03B40/02; textile lubricating compositions D06M11/00, D06M13/00, D06M15/00; immersion oils for microscopy G02B21/33)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- C10N: INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS

## Abstract

High temperature lubricants for magnetic media are provided. One such lubricant includes fluoroalkyl, fluoroalkenyl, perfluoroalkyl, or perfluoroalkyl ether segments, anchoring functional groups engageable with a protective overcoat of a magnetic recording media, and cyclic functional groups. The lubricants can be used in conjunction with a magnetic recording medium and/or a magnetic data storage system.

## Claims

### Claim 1

A lubricant comprising: a plurality of segments according to general formula (I), (II), or (III):
Re1—Rb1—Rc—Rb2—Re2 (I);
Re1—Rb1—Re2 (II); or
Re1—Rb1-(Rc-Rb2)m—Re2 (III);
wherein Rc, when present, is a divalent linking segment comprising an anchoring functional group engageable with a protective overcoat of a magnetic recording media;
wherein each Rb1 and Rb2, when present, independently comprises a chain segment comprising at least one of a fluoroalkyl ether moiety, a fluoroalkenyl ether moiety, a perfluoroalkyl ether moiety, a perfluoroalkenyl ether moiety, or a combination thereof;
wherein each of Re1 and Re2 independently comprises a substituted or unsubstituted cyclic anchoring functional group engageable with the protective overcoat of a magnetic recording media;
wherein one or more of Re1, Re2, and Rc, independently comprises a cyclic functional group comprising at least one of an alicyclic C3-C50 alkyl radical, an alicyclic C3-C50 alkenyl radical, a heterocyclic C3-C50 radical, an aromatic C5-C50 radical, a polycyclic aromatic C10-C50 radical, a heteroaromatic C5-C50 radical, a cyclotriphosphazine radical, or a combination thereof;
wherein m is from 1 to 20; and
wherein the unsubstituted cyclic anchoring functional group is selected from the group consisting of:

### Claim 2 (depends on 1)

The lubricant of claim 1, wherein at least one anchoring functional group, at least one cyclic functional group, or a combination thereof, further comprises at least one of B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, and wherein two or more R* may join together to form a ring structure.

### Claim 3 (depends on 1)

The lubricant of claim 1, wherein at least one anchoring functional group comprises a hydroxyl (—OH) moiety.

### Claim 4 (depends on 1)

The lubricant of claim 1, wherein at least one cyclic functional group independently comprises a substituted or unsubstituted monovalent moiety comprising a formula selected from the group consisting of:
or a combination thereof, wherein the moiety is bonded to a respective segment “A” at any substitutable position.

### Claim 5 (depends on 4)

The lubricant of claim 4, wherein the cyclic functional group is further substituted with one or more functional groups comprising one or more of B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, and wherein two or more R* may join together to form a ring structure.

### Claim 6 (depends on 1)

The lubricant of claim 1, wherein at least one cyclic functional group comprises at least one of a monovalent anisolyl radical, phenolic radical, resorcinolyl radical, catecholyl radical, hydroquinonyl radical, phloroglucinolyl radical, pyrogallolyl radical, phenalenyl radical, indolyl radical, adamantanyl radical, or a combination thereof.

### Claim 7 (depends on 1)

The lubricant of claim 1, wherein Rc, when present, comprises general formula (IV):
wherein each Y independently comprises:
(i) —CH2—;
(ii) —CF2—;
(iii) —CHF—;
(iv) —CF2CF2CF2O(CF2CF2CF2CF2O)aCF2CF2CF2—;
(v) —CF2CF2O(CF2CF2CF2O)aCF2CF2—;
(vi) —CF2CF2O[CF(CF3)CF2O]aCF2CF2—;
(vii) —CF2O(CF2CF2O)a(CF2O)bCF2—;
(viii) —CF2O(CF2CF2O)aCF2—;
or a combination thereof;
wherein each a, when present, is independently from 1 to 20,
wherein each b, when present, is independently from 1 to 20;
wherein p is from 1 to 20; and
wherein R1 is an anchoring functional group engageable with a protective overcoat of a magnetic recording media, comprising B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, and wherein two or more R* may join together to form a ring structure.

### Claim 8 (depends on 7)

The lubricant of claim 7, wherein R1 is a cyclic functional group comprising an alicyclic C3-C50 alkyl radical, an alicyclic C3-C50 alkenyl radical, a heterocyclic C3-C50 radical, an aromatic C5-C50 radical, a polycyclic aromatic C10-C50 radical, a heteroaromatic C5-C50 radical, a cyclotriphosphazine radical, or a combination thereof.

### Claim 9 (depends on 8)

The lubricant of claim 8, wherein at least one cyclic functional group further comprises B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, and wherein two or more R* may join together to form a ring structure.

### Claim 10 (depends on 8)

The lubricant of claim 8, wherein R1 comprises a hydroxyl moiety (—OH).

### Claim 11 (depends on 1)

The lubricant of claim 1, wherein Rc, when present, comprises general formula (V):
wherein each Q independently comprises:
(i) —CH2—;
(ii) —CF2—;
(iii) —CHF—;
(iv) —CF2CF2CF2O(CF2CF2CF2CF2O)aCF2CF2CF2—;
(v) —CF2CF2O(CF2CF2CF2O)aCF2CF2—;
(vi) —CF2CF2O[CF(CF3)CF2O]aCF2CF2—;
(vii) —CF2O(CF2CF2O)a(CF2O)bCF2—;
(viii) —CF2O(CF2CF2O)aCF2—;
or a combination thereof;
wherein each a, when present, is independently from 1 to 20,
wherein each b, when present, is independently from 1 to 20;
wherein n is from 1 to 20; and
wherein R1 is an anchoring functional group engageable with a protective overcoat of a magnetic recording media, comprising —OH, B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, wherein two or more R* may join together to form a ring structure, or R1 is a cyclic functional group including at least one of an alicyclic C3-C50 alkyl radical, an alicyclic C3-C50 alkenyl radical, a heterocyclic C3-C50 radical, an aromatic C5-C50 radical, a polycyclic aromatic C10-C50 radical, a heteroaromatic C5-C50 radical, a cyclotriphosphazine radical, or a combination thereof.

### Claim 12 (depends on 11)

The lubricant of claim 11, wherein at least one cyclic functional group further comprises B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, and wherein two or more R* may join together to form a ring structure.

### Claim 13 (depends on 1)

The lubricant of claim 1, wherein Rc, when present, comprises an ester functional group comprising general formula (VI), (VII), or a combination thereof:
wherein t, when present, is from 1 to 20; and
wherein s, when present, is from 1 to 20.

### Claim 14 (depends on 1)

The lubricant of claim 1, wherein Rb1, and Rb2 when present, comprises the formula:
(iv) —CF2CF2CF2O(CF2CF2CF2CF2O)aCF2CF2CF2—;
(v) —CF2CF2O(CF2CF2CF2O)aCF2CF2—;
(vi) —CF2CF2O[CF(CF3)CF2O]aCF2CF2—;
(vii) —CF2O(CF2CF2O)a(CF2O)bCF2—;
(viii) —CF2O(CF2CF2O)aCF2—;
or a combination thereof;
wherein each a is, independently from 1 to 20, and
wherein each b, when present, is independently from 1 to 20.

### Claim 15 (depends on 1)

The lubricant of claim 1, wherein each of Re1 and Re2 independently comprises general formula (VIII):
wherein R1 is an anchoring functional group engageable with a protective overcoat of a magnetic recording medium, comprising —OH B, Si, a pnictogen, a chalcogen, a halogen, —OR*, —NR*2, —NR*—CO—R*, —O—CO—R*, —CO—O—R*, —SeR*, —TeR*, —PR*2, —PO—(OR*)2, —O—PO—(OR*)2, —N═P(NR*2)3, —AsR*2, —SR*, —SO2—(OR*)2, —BR*2, —SiR*3, —(CH2)q-SiR*3, —(CF2)q-SiR*3, or a combination thereof, wherein q is 1 to 10 and each R* is, independently, a hydrogen, B, Si, a pnictogen, a chalcogen, a halogen, a saturated C1-C50 radical, an unsaturated C2-C50 radical, an aromatic C4-C50 radical, a polycyclic aromatic C5-C50 radical, a heteroaromatic C5-C50 radical, an alicyclic C3-C50 radical, and/or a heterocyclic C2-C50 radical, wherein two or more R* may join together to form a ring structure; or
wherein R1 is a cyclic functional group comprising an alicyclic C3-C50 alkyl radical, an alicyclic C3-C50 alkenyl radical, a heterocyclic C3-C50 radical, an aromatic C5-C50 radical, a polycyclic aromatic C10-C50 radical, a heteroaromatic C5-C50 radical, a cyclotriphosphazine radical, or a combination thereof.

### Claim 16 (depends on 1)

The lubricant of claim 1, comprising general formula (IX):
wherein a is from 1 to 20; b is from 1 to 20; and c is from 1 to 20.

### Claim 17 (depends on 1)

The lubricant of claim 1, comprising general formula (X):
wherein a is from 1 to 20; b is from 1 to 20; and c is from 1 to 20.

### Claim 18 (depends on 1)

A magnetic recording medium, comprising:
a magnetic recording layer on a substrate;
a protective overcoat on the magnetic recording layer; and
a lubricant layer comprising the lubricant according to claim 1 on the protective overcoat,
wherein the lubricant has a bonding percentage of about 20% to less than about 100%, corresponding to a degree of bonding of the lubricant to the total area of an upper surface of the protective overcoat.

### Claim 19 (depends on 1)

The lubricant according to claim 1, comprising a weight average molecular weight from about 0.1 to 20 kiloDaltons (kDa), a polydispersity of greater than or equal to about 1 and less than or equal to about 2 and a dewetting thickness of less than or equal to about 10 nanometers.

### Claim 20

A method of synthesizing a lubricant comprising:
reacting a perfluoroalkyl compound with an aromatic compound, to yield a compound comprising a plurality of segments according to general formula (I), (II), or (III):
Re1—Rb1—Rc—Rb2—Re2 (I);
Re1—Rb1—Re2 (II); or
Re1—Rb1-(Rc-Rb2)m—Re2 (III);
wherein Rc, when present, is a divalent linking segment comprising an anchoring functional group engageable with a protective overcoat of a magnetic recording medium;
wherein each Rb1 and Rb2, when present, independently comprises a chain segment comprising at least one of a fluoroalkyl ether moiety, a fluoroalkenyl ether moiety, a perfluoroalkyl ether moiety, a perfluoroalkenyl ether moiety, or a combination thereof;
wherein each of Re1 and Re2 independently comprises a substituted or unsubstituted cyclic anchoring functional group engageable with a protective overcoat of a magnetic recording media;
wherein one or more of Re1, Re2 and Rc independently comprises a cyclic functional group comprising at least one of an alicyclic C3-C50 alkyl radical, an alicyclic C3-C50 alkenyl radical, a heterocyclic C3-C50 radical, an aromatic C5-C50 radical, a polycyclic aromatic C10-C50 radical, a heteroaromatic C5-C50 radical, a cyclotriphosphazine radical, or a combination thereof;
wherein m is from 1 to 20; and
wherein the unsubstituted cyclic anchoring functional group is selected from the group consisting of: