Aromatic and aromatic-like containing media lubricants for data storage devices

Abstract

A lubricant containing an aromatic or aromatic-like group configured to be adsorbed by a magnetic recording medium is formed from (Ar) m (R1oRfR2p) q where Ar is an aromatic group, a polyaromatic hydrocarbon (PAH), a rotaxene, a cycloalkane or a heterocyclic ring, m = 1-10, R1 and R2 are moieties containing a first polar group and a second polar group, respectively, Rf is a perfluorinated polyether, o = 1-10, p = 0-10, and q = 1-10. The first polar group or the second polar group may be independently a hydroxyl group, a phosphonic acid, a silanol, or a carboxylic acid. In one embodiment, the lubricant has the formula wherein Ar is a system formed from PAH, rotaxene, cycloalkane or heterocyclic ring, X, Y and Z may be independently a hydroxyl, phosphonic acid moiety, silanol or carboxylic acid moiety, and wherein Rf may be CF2O (CF2CF2) nCF2-wherein n is from 1 to 100. Synthetic lubricants may require the reaction of p-bromophenol with (Ar) m (R1oRfR2p) q. # imgabs0 #

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. non-provisional application No. 1 8 / 230,584, filed with the U.S. Patent and Trademark Office on August 4, 2023, entitled "AROMATIC AND AROMATIC-LIKE CONTAINING MEDIALUBRICANTS FOR DATASTORAGE DEVICES," and is incorporated herein by reference in its entirety for all purposes, which non-provisional application claims priority to U.S. Provisional Application No. 63 / 414,325, filed on October 7, 2022. Technical Field

[0003] The present disclosure relates to lubricants, and more particularly to lubricants incorporating aromatic moieties, wherein these lubricants are suitable for use in a variety of applications, including magnetic recording media. Background Art

[0004] The present disclosure relates to lubricants suitable for magnetic storage media, particularly media configured for high energy recording such as heat assisted magnetic recording (HAMR), energy assisted magnetic recording (EAMR) or microwave assisted magnetic recording (MAMR). Magnetic storage systems such as hard disk drive (HDD) systems are used in various devices in both stationary and mobile computing environments. Examples of devices including magnetic storage systems include data center storage systems, desktop computers, portable notebook computers, portable hard disk drives, network storage systems, high definition television (HDTV) receivers, vehicle control systems, cellular or mobile phones, television set-top boxes, digital cameras, digital video cameras, video game controllers, and portable media players.

[0005] A typical disk drive includes a magnetic storage medium in the form of one or more flat or circular disks. The disk is usually formed by two main components, namely a substrate material that forms its structure and rigidity, and a magnetic medium coating that maintains magnetic pulses or magnetic moments representing data in a recording layer within the coating. A typical disk drive also includes a read head and a write head, usually in the form of a magnetic transducer, which can sense and / or change the magnetic field stored on the recording layer of the disk. High energy recording such as HAMR uses high recording temperatures to write information to the medium to increase the surface density (AD) of written data on a magnetic storage medium with high coercivity. However, high recording energies, microwaves, or temperatures applied to the medium may pose challenges. Other examples of magnetic storage media include flexible tape media that can be used for tape recording.

[0006] One challenge comes from the layer of lubricant that separates the outer layer of the disk from the recording head. The slider (e.g., surrounding the recording head) is typically less than 10 nm away from the disk. Therefore, the lubricant must typically be low profile. However, as the molecular weight of the lubricant backbone is reduced to the range of 100 Da to 10,000 Da to achieve magnetic spacing and reduce the head-disk gap, the vapor pressure of the lubricant molecules increases exponentially. This will significantly increase the desorption rate of the molecules and the risk of lubricant loss, ultimately leading to great instability of sub-monolayer thick lubricant films.

[0007] That is, it is desirable that the lubricant remain stably bonded to the disk and not easily evaporate into the environment of the HDD. Such loss of media lubricant and / or reduced film stability will compromise the reliability, quality and durability of the disk media and head component integration, thereby reducing the overall performance of the actual HDD product. In addition, if the lubricant detaches from the disk surface, degrades and / or oxidizes, the loss of necessary mechanical and chemical robustness that undermines safety can cause the HDD to crash rapidly.

[0008] Due to the high temperatures of up to 300°C to 600°C associated with the head-media interface design in HAMR HDDs, suitable lubricants for use in the corresponding media may benefit from high thermal stability and high oxidation resistance. In addition, higher temperatures also increase the presence of contaminants, which may adversely affect the performance, reliability, and durability of HAMR drives. Therefore, there is a need in the art for high-temperature lubricants with properties suitable for HAMR drives, including the ability to sequester and / or remove contaminants before they interfere with data storage or other operating processes.

[0009] Typical HDD operating temperatures range from about 25°C to about 45°C. Standard HDD storage temperatures are between about 12°C and about 33°C. HDD temperatures above about 45°C result in higher failure rates. Temperatures below about 25°C also result in higher failure rates. In addition, aged HDD drives (3 years and older) are more likely to fail when their average operating temperatures are 40°C and higher.

[0010] The temperature dependence of the annual failure rate (AFR) is known in the art, as described by E. Pinheiro et al., Proc. th USENIX Conference on File and Storage Technologies (FAST'07), February 2007. Figure 6 The study's observations of the distribution of average temperature and failure rate are shown. It can be seen that when the average disk temperature is outside the range of about 25°C to about 45°C, the AFR increases, most significantly at lower temperatures. The age of the HDD is also a factor. Figure 7The AFR for the study based on age and temperature is shown. After the rupture, the AFR is relatively stable until the 3 year mark, then the AFR increases significantly, especially at high temperatures.

[0011]

[0006] Therefore, there is a need in the art to design thermally stable / oxidation resistant lubricant films having specific properties suitable for use in HDDs over a wide and extreme temperature range. Summary of the invention

[0012] In one aspect, the present disclosure provides a lubricant configured to be adsorbed by a magnetic recording medium, such as a disk of a hard drive, the lubricant comprising polyaromatic carbon moieties bonded to a perfluorinated polyether grafted with -OH-containing functional groups.

[0013] In one aspect, the lubricant is configured to be absorbed by the magnetic recording medium and may be formed from:

[0014] (Ar) m (R1 o R f R2 p ) q

[0015] in

[0016] Ar is an aromatic group, a polyaromatic hydrocarbon (PAH), an annulene, a cycloalkane or a heterocycle,

[0017] m is 1 to 10

[0018] R1 is a part containing the first polar group,

[0019] R2 is a part containing a second polar group,

[0020] R f It is a perfluorinated polyether.

[0021] o is 1 to 10

[0022] p is 0 to 10, and

[0023] q is 1 to 10.

[0024] The value of p may be 1 to 10. The first polar group may be at least one selected from hydroxyl, phosphonic acid, silanol, or carboxylic acid, and the second polar group may be at least one selected from hydroxyl, phosphonic acid, silanol, or carboxylic acid. f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s may be independently 1 to 100. Alternatively, R f Can be -CF 2 O(CF 2 CF 2 O) q CF 2 -, and q is 1 to 100. Ar can be selected from aromatic groups; polycyclic aromatic hydrocarbons (PAHs), such as naphthalene, phenanthene, phenanthrene, pyrene, triphenylene; annulene, such as cyclooctatetraene, cyclooctadecene; cycloalkanes, such as cyclohexane, cyclooctane, cyclodecane; and other heterocycles, such as triazine, cyclen, cycloamine or cyclotriphosphazene.

[0025] In one aspect, the lubricant may have a PAH aromatic central group and aromatic terminal groups of the formula:

[0026]

[0027] Where R f It is CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0028] In another aspect, the lubricant may have a PAH central group and aromatic end groups of the formula:

[0029]

[0030] Where R f It is CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0031] The present disclosure relates in part to a data storage device configured for magnetic recording, the data storage device comprising a magnetic recording medium formed by a substrate, a magnetic recording layer on the substrate, an outer coating on the magnetic recording layer; and a lubricant of one aspect of the present disclosure adsorbed by the outer coating. In the data storage device, R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF 2CF 2 O) s CF 2 -, and r and s are independently 1 to 100, or R f Can be -CF 2 O(CF 2 CF 2 O) q CF 2 -, and q is 1 to 100. Ar can be selected from aromatic groups; PAHs such as naphthalene, phenanthene, phenanthrene, pyrene, triphenylene; annulenes such as cyclooctatetraene, cyclooctadecene; cycloalkanes such as cyclohexane, cyclooctane, cyclodecane; and other heterocycles such as triazine, cyclocyclotoxin, cyclolamin or cyclotriphosphazene.

[0032] In data storage devices, the lubricant may have the formula:

[0033]

[0034] Where R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0035] In data storage devices, the lubricant may have the formula:

[0036]

[0037] Where R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -or-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0038] In another exemplary embodiment, a magnetic recording medium includes: a substrate; a magnetic recording layer on the substrate; an overcoat layer on the magnetic recording layer; and a lubricant according to an aspect of the present disclosure adsorbed by the overcoat layer.

[0039] In another exemplary embodiment, a data storage system includes: at least one magnetic head; a magnetic recording medium coated with a layer of a lubricant according to one aspect of the present disclosure; a drive mechanism for positioning the at least one magnetic head on the magnetic recording medium; and a controller electrically coupled to the at least one magnetic head for controlling the operation of the at least one magnetic head.

[0040] In another exemplary embodiment, a data storage system includes a slider having at least one magnetic head and an air bearing surface (ABS), wherein a thin film of a lubricant according to one aspect of the present disclosure is disposed on the ABS; and a magnetic recording medium including a magnetic recording layer. The slider is configured to write information to the magnetic recording layer using heat-assisted magnetic recording (HAMR), energy-assisted magnetic recording (EAMR), or microwave-assisted magnetic recording (MAMR).

[0041] In another exemplary embodiment, the lubricant is configured to be adsorbed by the magnetic recording medium, wherein the lubricant has the formula:

[0042]

[0043] wherein Ar is a polyaromatic hydrocarbon (PAH) ring system, X, Y and Z may independently be a hydroxyl group, a phosphonic acid moiety, a silanol or a carboxylic acid moiety, and wherein R f Can be CF 2 O(CF 2 CF 2 )nF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r, s are independently 1 to 100. The aromatic center can be an aromatic group; PAH, such as naphthalene, phenanthrenes, phenanthrenes, pyrenes, triphenylenes; annulenes, such as cyclooctatetraene, cyclooctadecene; cycloalkanes, cyclohexanes, cyclooctanes, cyclodecanes; and other heterocycles, such as triazines, cyclocyclotoxins, cyclolamides or cyclotriphosphazenes, or any of the aromatic and quasi-aromatic molecules listed in Table 1.

[0044] In one exemplary embodiment, the present disclosure is directed to a method of synthesizing a lubricant, the method comprising:

[0045] Make 4-bromophenol

[0046] (Ar) m (R1 o R f R2 p ) q reaction

[0047] in

[0048] Ar is an aromatic group, a polyaromatic hydrocarbon, an annulene, a cycloalkane or a heterocycle,

[0049] m is 1 to 10

[0050] R1 is a part containing the first polar group,

[0051] R2 is a part containing a second polar group,

[0052] R f It is a perfluorinated polyether.

[0053] o is 1 to 10,

[0054] p is 0 to 10, and

[0055] q is 1 to 10. p can also have a value of 1 to 10.

[0056] In this method, R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or Rf Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r, s are independently 1 to 100, and wherein the first polar group may be at least one selected from hydroxyl, phosphonic acid, silanol or carboxylic acid. In the present disclosure, p may be 1 to 10.

[0057] Other aspects and advantages of the present disclosure will become apparent from the following detailed description, which, when taken in conjunction with the accompanying drawings, illustrate by way of example the principles of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1a is a diagram schematically illustrating a data storage device including a slider and a magnetic recording medium according to one aspect of the present disclosure;

[0059] Figure 1b According to one aspect of the present disclosure Figure 1a A schematic side view of a slider and a magnetic recording medium;

[0060] Figure 2 is a schematic side view of a magnetic recording medium including a lubricant layer according to one aspect of the present disclosure;

[0061] Figure 3 A schematic diagram of the molecular design of a lubricant containing polyaromatic hydrocarbons (PAH) with improved thermal stability according to one aspect of the present disclosure is shown;

[0062] Figure 4 is a graph showing thermogravimetric analysis (TGA) results demonstrating improved thermal stability / oxidative resistance for aromatic or quasi-aromatic core-terminated / centered lubricant molecules according to one aspect of the present disclosure as a function of weight loss derivation and temperature;

[0063] Figure 5 is a TGA result showing thermal stability / antioxidant improvement by introducing aromatic rings and replacing the aromatic rings with PAH groups according to one aspect of the present disclosure;

[0064] Figure 6 shows the distribution of average temperature and annual failure rate (AFR); and

[0065] Figure 7 The annual failure rate (AFR) based on age and temperature is shown. DETAILED DESCRIPTION

[0066] Heat-assisted magnetic recording (HAMR) systems operate at much higher temperatures than conventional magnetic recording systems, which are also referred to herein as conventional magnetic recording (CMR) systems that do not employ heat or other energy to assist recording. Examples of CMR systems may include perpendicular magnetic recording disk drives and flexible tape media that can be used for magnetic tape recording, which do not employ heat or other energy to assist recording. HAMR is an example of magnetic recording within the energy-assisted magnetic recording (EAMR) technology category, where CMR is supplemented by other energy used in the system. Other examples of EAMR may include microwave-assisted magnetic recording (MAMR) and the application of current to various conductive structures and / or magnetic structures close to the main pole.

[0067] The thickness of lubricant on the outer coating of magnetic recording medium (its non-limiting example is the disk of HDD) is less than 10nm. Lubricant plays many roles at the head-disk interface, including interval / gap establishment, chemical integration, pollution prevention, head wear reduction, head-disk interaction control, etc. Ideally, the lubricant film stays on the disk and does not migrate to the environment of HDD. If it migrates, the mechanical and chemical integration of head and disk changes, thereby affecting performance. The loss of lubricating film protection caused by evaporation, depletion / migration, degradation and / or oxidation of molecules can even cause head collision and eventually cause HDD failure. When some functional groups of organic fluorocarbon main chain and / or lubricant molecule are degraded, decomposed, oxidized, exhausted and / or evaporated, if the surface adsorption of molecules is not greatly stabilized at elevated temperatures (particularly in an oxidizing environment), the functionality and performance loss of the lubricant film that causes the protection disk increase.

[0068] This problem is addressed by incorporating aromatic groups, PAHs, annulenes, cycloalkanes, and moieties of heterocycles into the structure of the lubricant to produce a more heat-resistant lubricant molecule that resists failure at temperatures outside the preferred operating range and unexpectedly extends the life of the magnetic recording media.

[0069] More specifically, the lubricant can be represented by the following formula:

[0070] (Ar) m (R1 o R f R2 p ) q

[0071] in

[0072] Ar is an aromatic group, polyaromatic hydrocarbon (PAH), annulene, cycloalkane or heterocycle, etc.,

[0073] m is 1 to 10,

[0074] R1 is a moiety containing a first polar group and optionally an aromatic group or a PAH,

[0075] R2 is a moiety containing a second polar group and optionally an aromatic group or a PAH,

[0076] R f It is a perfluorinated polyether.

[0077] o is 1 to 10

[0078] p is 0 to 10 or 1 to 10, and

[0079] q is 1 to 10.

[0080] The first polar group may be a hydroxyl group, a phosphonic acid group, a silanol group, or a carboxylic acid group, and the second polar group may be a hydroxyl group, a phosphonic acid group, a silanol group, or a carboxylic acid group. f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100. Or, R f Can be -CF 2 O(CF 2 CF 2 O) q CF 2 -, and q is 1 to 100. The PAH may be, but is not limited to, pyrene, naphthalene, phenanthene, phenanthrene or triphenylene.

[0081] definition

[0082] For purposes herein and the claims thereto, the new numbering scheme for the Periodic Table Groups is used as described in Chemical and Engineering News, 63(5), No. 27 (1985). Thus, a "Group 4 metal" is an element from Group 4 of the Periodic Table, such as Hf, Ti, or Zr. For purposes herein, molecular weight refers to number average molecular weight (Mn) and is expressed as grams per mole (g / mol), unless otherwise indicated.

[0083] As used herein, and unless otherwise indicated, the term “ n " means a hydrocarbon or perfluorocarbon having n carbon atoms per molecule, where n is a positive integer. Likewise, "C m -C y "A group or compound is a group or compound containing carbon atoms whose total number is in the range m to y. Thus, C 1 -C 4 Alkyl groups refer to alkyl groups containing a total number of carbon atoms ranging from 1 to 4 (eg, 1, 2, 3, and 4).

[0084] The term "moiety" refers to one or more covalently bonded atoms that form a portion of a molecule. The terms "group," "moiety," and "substituent" may be used interchangeably.

[0085] The term "hydrocarbyl group" or "hydrocarbyl" may be used interchangeably and is defined to mean a group containing only hydrogen and carbon atoms. Preferred hydrocarbyl groups are C 1 -C 20 Groups, which may be straight chain, branched, star-shaped, comb-shaped, dendritic or cyclic, and when cyclic, may be aromatic or non-aromatic. Examples of such groups include, but are not limited to, alkyl groups (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, octylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl and the like), aryl groups (such as phenyl, benzyl, naphthyl and the like).

[0086] For purposes herein, a heteroatom is any non-carbon atom selected from Groups 1 3 to 17 of the Periodic Table of Elements. In one or more aspects, the heteroatom is a non-metal atom selected from B, N, O, Si, P, S, As, Se, Te, and the halogens F, Cl, Br, I, and At.

[0087] Unless otherwise indicated, the term "substituted" means that at least one hydrogen atom has been replaced with at least one non-hydrogen atom or functional group.

[0088] For the purposes of this article, functional groups include Si(OH) 3 PO(OH) 2, COOH, a hydrocarbon group, a heteroatom or a heteroatom-containing group, such as a halogen (such as Br, Cl, F or I) or at least one functional group such as -NR* 2 , -NR*-CO-R*, -OR*, *-O-CO-R*, -CO-OR*, -SeR*, -TeR*, -PR* 2 、-PO-(OR*) 2 、-O-PO-(OR*) 2 , -AsR* 2 , -SbR* 2 、-SR*、-SO 2 -(OR*) 2 ,-BR* 2 、-SiR* 3 、-(CH 2 )q-SiR* 3 or a combination thereof, wherein q is 1 to 10, and each R* is independently hydrogen, a hydrocarbon group or a halogenated carbonyl group, and two or more R* can be joined together to form a substituted or unsubstituted fully saturated, partially unsaturated or aromatic ring or polycyclic structure, or wherein at least one heteroatom has been inserted into the hydrocarbon ring.

[0089] In one or more aspects, the functional groups may include: saturated C 1 -C 20 Group, unsaturated C 1 -C 20 Group, alicyclic C 3 -C 20 Group, heterocyclic C 3 -C 20 Group, aromatic C 5 -C 20 Group, heteroaromatic C 5 -C 20 group, cyclotriphosphazine group, halogen, -NR* 2 , -NR*-CO-R*, -OR*, -O-CO-R*, -CO-OR*, -SeR*, -TeR*, -PR* 2 、-PO-(OR*) 2 、-O-PO-(OR*) 2 、-N=P(NR* 2 ) 3 , -AsR* 2 、-SR*、-SO 2 -(OR*) 2 ,-BR* 2 、-SiR* 3 、-(CH2 )q-SiR* 3 ,-(CF 2 )q-SiR* 3 or a combination thereof, wherein q is 1 to 10, and each R* is independently hydrogen; halogen; saturated, unsaturated, aromatic and / or heterocyclic C 1 -C 20 Group.

[0090] For the purposes of this article, a functional group capable of attaching to the surface of a magnetic recording medium refers to a functional group that has a completely changed affinity for the same surface relative to the affinity of a perfluoroalkyl ether to the surface. Completely different affinities may include chemical adsorption other than chemical bonding and conventional physical bonding, such as hydrogen bonding, van der Waals forces, weak London dispersion forces, dipole-dipole interactions and / or the like with the surface of the magnetic recording medium, preferably with a protective outer coating of the recording medium, and / or one or more types of bonds and / or coordination bonds. In one or more aspects, a functional group capable of attaching to the surface of a magnetic recording medium refers to a functional group that has a chemically activated affinity for the carbon outer coating (COC) of the magnetic recording medium relative to the affinity of a perfluoroalkyl ether to the same surface.

[0091] A heterocycle, also referred to herein as a heterocyclic group, is a ring having a heteroatom in the ring structure, as distinct from a heteroatom-substituted ring in which a hydrogen on a ring atom is replaced by a heteroatom. For example, tetrahydrofuran is a heterocycle, and 4-N,N-dimethylamino-phenyl is a heteroatom-substituted ring. A substituted heterocycle is a heterocycle in which a hydrogen of one of the ring atoms is replaced, such as by a hydrocarbyl or heteroatom-containing group.

[0092] The polyaromatic hydrocarbons (PAHs) of the present disclosure include naphthalene, phenanthene, phenanthrene, pyrene, and triphenylene. However, as listed in Table 1, there is a wide range of PAHs that can be used in the present disclosure.

[0093] Table 1 Polyaromatic hydrocarbons, their chemical formulas and their Chemical Abstracts Services (CAS) numbers.

[0094]

[0095]

[0096]

[0097] A "compound" refers to a substance composed of two or more separate chemical elements. A "derivative" refers to a compound in which one or more of the atoms or functional groups of a precursor compound has been replaced by another atom or functional group, usually by means of a chemical reaction having one or more steps.

[0098] For the purposes of this document, unless otherwise specified, the medium lubricant comprises a plurality of segments and each segment is connected to another segment via an ether bond (e.g., a -COC bond). For the purposes of this document, a segment comprising a perfluoropolyalkyl ether portion may have the general formula:

[0099] -(CF 2 ) a O-;

[0100] wherein each a is 1 to 100. The segment comprising a perfluoroalkyl ether portion has the following general formula:

[0101] -(CF 2 ) a O) b -;

[0102] wherein each a is 1 to 100, and b is the number of repeating units in the segment.

[0103] The perfluoroalkyl ether moieties present in a particular segment are bonded together to form a perfluoropolyalkyl ether chain. Unless otherwise specified, each perfluoroalkyl ether moiety present in a perfluoropolyalkyl ether segment may be the same or different. For example, the following are each example of a perfluoropolyalkyl ether segment:

[0104] i)-(CF 2 CF 2 O) b -, perfluoropolyethyl ether segment;

[0105] ii)-(CF 2 CF 2 CF 2 O) b -, perfluoropolypropyl ether segment;

[0106] iii)-(---CF(CF 3 )CF 2 O) b -, perfluoropolybutyl ether segment;

[0107] iv)-(CF 2 CF 2 CF 2 CF 2 O) b -, perfluoropolybutyl ether segment; and

[0108] v)-(CF 2 CF 2 O) b -(CF 2 O) b -, perfluoropolyethyl ether-perfluoropolymethyl ether segment, also known as Z-chain segment in the art.

[0109] For purposes herein, a segment, such as a divalent core segment comprising a perfluoroalkyl ether moiety Rc and / or a divalent core segment comprising a perfluoroalkyl ether moiety Rb′ and Rb 2 The molecular weight of a divalent side chain segment is defined as the molecular weight of the perfluoroalkyl ether moiety present in the segment.

[0110] Unless otherwise indicated, a divalent central segment (abbreviated herein as Rc) refers to a divalent chemical moiety optionally comprising a perfluoroalkyl ether moiety or optionally formed from one or more perfluoroalkyl ether moieties, which is chemically bonded to the connecting segment moieties on either side via an ether bond.

[0111] The intermediate or linking segment, abbreviated herein as Ri, refers to a chemical moiety bonded between the central segment and the side chain segments through an ether linkage and contains at least one functional group, which is preferably selected to attach to a protective layer of a magnetic recording medium.

[0112] The side chain segment (abbreviated herein as Rb) refers to a divalent chemical moiety comprising a perfluoroalkyl ether moiety or formed of one or more perfluoroalkyl ether moieties, which is chemically bonded to the linking segment moiety and the terminal segment via an ether bond.

[0113] A terminal segment, abbreviated herein as Re, refers to a monovalent group comprising at least one functional group preferably selected to attach to a protective layer of a magnetic recording medium.The terminal moiety is located at either end of a side chain of a lubricant molecule.

[0114] For any particular compound disclosed herein, unless otherwise stated, any general or specific structure presented also encompasses all conformational isomers, regioisomers, and stereoisomers that may result from a particular set of substituents. Similarly, unless otherwise stated, the general or specific structure also encompasses all enantiomers, diastereomers, and other optical isomers (whether enantiomeric or racemic forms), as well as mixtures of stereoisomers, as will be recognized by the skilled artisan.

[0115] As used herein, the term "aromatic" also refers to pseudoaromatic heterocycles, which are heterocyclic substituents having similar properties and structure (almost planar) as aromatic heterocyclic ligands but which are not aromatic by definition; likewise, the term aromatic also refers to substituted aromatic compounds.

[0116] As used herein, a moiety that is chemically identical to another moiety is defined as being identical in overall composition except for isotopic abundance and / or distribution, and / or except for stereochemical arrangements such as optical isomers, conformers, steric isomers and / or the like.

[0117] As used herein, the term "adsorption" refers to individual molecules, atoms or ions that collect on a surface. In contrast, the term "adsorption" refers to the situation where a material is immersed in a large amount of another phase or material, such as a sponge, cloth, filter, etc.

[0118] Data storage devices

[0119] Figure 1a FIG. 1 is a schematic top view of a data storage device 100 (e.g., a disk drive or a magnetic recording device) configured for magnetic recording according to one or more aspects of the present disclosure, the data storage device including a slider 108 and a magnetic recording medium 102 having a lubricant layer. A laser specifically for heat-assisted magnetic recording (HAMR) (in Figure 1a Not visible in , but in Figure 1b 114) is positioned with a head / slider 108. The disk drive 100 may include one or more disks / media 102 to store data. The disks / media 102 reside on a spindle assembly 104 mounted to a drive housing. Data may be stored along tracks in the magnetic recording layer of the disks 102. Reading and writing of data is accomplished with a head 108 (slider) that may have both a read element and a write element (108a and 108b). The write element 108a is used to change the properties of the magnetic recording layer of the disk 102 and thereby write information to it. In one aspect, the head 108 may have a magnetoresistive (MR), giant magnetoresistive (GMR), or tunnel magnetoresistive (TMR) element. In an alternative aspect, the head 108 may be another type of head, such as a Hall effect head. In operation, a spindle motor (not shown) rotates the spindle assembly 104, and thus the disks 102, to position the head 108 at a specific location along a desired disk track 107. The position of the head 108 relative to the disk 102 may be controlled by control circuitry 110 (eg, a microcontroller).

[0120] Figure 1b yes Figure 1a 1 and 102. According to one or more aspects of the present disclosure, the magnetic recording medium 102 includes a lubricant layer (see Figure 3 ). The slider 108 may include a submount 112 attached to an upper surface of the slider 108. The laser 114 may be attached to the submount 112 and may be attached to the slider 108. The slider 108 includes a writing element (e.g., a writer) 108a and a reading element (e.g., a reader) 108b, which are positioned along an air bearing surface (ABS) 108c of the slider for writing information to the medium 102 and reading information from the medium 102, respectively. In other aspects, the slider may also include a layer of lubricant (not shown).

[0121] In operation, the laser 114 used in HAMR is configured to generate and direct optical energy to a waveguide in the slider (e.g., along the dashed line), which directs the light to a near field transducer (NFT) proximate to the air bearing surface (e.g., bottom surface) 108c of the slider 108. Upon receiving light from the laser 114 via the waveguide, the NFT generates localized thermal energy that heats a portion of the medium 102 within or proximate to the writing element 108a and proximate to the reading element 108b. The expected recording temperature is in the range of about 300°C to 500°C. Figure 1b In the illustrated aspect, the laser directed light is disposed within the writer 108a and proximate the trailing edge of the slider. In other aspects, the laser directed light may instead be positioned between the writer 108a and the reader 108b. Figure 1b A specific example of a HAMR system is shown. In other examples, the magnetic recording medium 102 with a lubricant layer according to aspects of the present disclosure can be used in other suitable HAMR systems (e.g., with other sliders configured for HAMR). The media can also be used in EAMR and MAMR systems, or other non-HAMR systems.

[0122] Magnetic recording media

[0123] Figure 2 2 is a schematic side view of a magnetic recording medium 200 configured, for example, for heat-assisted magnetic recording and having a lubricant layer according to one or more aspects of the present disclosure. In one aspect, the magnetic recording medium 200 can be used in a data storage system (e.g., a disk drive 100) configured for HAMR, EAMER, or MAMR. The magnetic recording medium 200 has a stacked structure, wherein a substrate 202 is at the bottom / base layer, an adhesion layer 204 is located on the substrate 202, a heat sink layer 206 is located on the adhesion layer 204, an interlayer 208 is located on the heat sink layer 206, a magnetic recording layer (MRL) 210 is located on the interlayer 208, a capping layer 212 is located on the MRL 210, an outer coating layer 214 is located on the capping layer 212, and a lubricant layer 216 is located on the outer coating layer 214. In one aspect, the magnetic recording medium 200 can have a soft magnetic underlayer (SUL) located between the adhesion layer 204 and the heat sink layer 206. In one aspect, the magnetic recording medium 200 can have a thermal resistance layer (TRL) between the interlayer 208 and the heat sink layer 206. In non-HAMR recording media, some layers such as the TRL and the heat sink layer may not be present or may be replaced by different layers. In one aspect, the substrate 202 can be made of one or more materials such as Al alloy, Al plated with NiP, glass, glass ceramic, and / or combinations thereof. In some aspects, the magnetic recording medium 200 can have a plurality of layers in various stacking orders. Figure 2 Some or all of the layers shown in and / or additional layers. It should also be noted that Figure 2Each layer shown in can include one or more sub-layers. For example, in some embodiments, the magnetic recording layer can have multiple layers.

[0124] Lubricants

[0125] In one aspect, the lubricants disclosed herein can be used as lubricating molecular layers that can be used in various mechanical devices, including data storage systems configured for magnetic recording (e.g., hard disk drives, tape drives, etc.) and other micro-electromechanical systems. When one or more functional groups of the lubricant adsorb to the lubricated surface or otherwise connect to the surface, the polymer or macromolecular lubricant can form a lubricant layer. For example, a lubricant layer 216 is formed on a magnetic recording medium 200 (e.g., a disk including a magnetic recording layer 210) that moves relative to other components in a mechanical device. This lubricant layer 216 helps protect the magnetic recording medium from friction, wear, contamination and / or damage caused by interactions between the magnetic recording medium and other components in the mechanical device (e.g., interactions between a slider and a magnetic recording medium in some cases, such as contact, friction, wear, erosion). In other words, this interfacial polymer and / or molecular layer helps to achieve reliable, robust and durable chemical / mechanical integration of magnetic recording media and read / write heads.

[0126] Figure 3 is a schematic diagram showing the molecular design of a lubricant incorporating aromatic rings. Bonding to the recording media substrate is via polar groups, which can be located near the ends of the PFPE chains or closer to the center of the aromatic core. The aromatics can be selected from aromatic rings or different PAH cores. A non-exhaustive list of PAH rings includes the following:

[0127] The present disclosure is not limited to these PAH rings, but may include any suitable PAH ring, such as listed in Table 1.

[0128] The general structure of the PAH-containing lubricant of the present disclosure can be given by the following formula:

[0129]

[0130] wherein Ar is a polycyclic aromatic hydrocarbon (PAH) ring system, X, Y and Z may independently be a hydroxyl group, a phosphoric acid moiety, a silanol group or a carboxylic acid moiety, and wherein R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, wherein n is 1 to 100. f Can also be -CF 2 CF 2O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r, s are independently 1 to 100. The aromatic PAH center can be naphthalene, phenalene, phenanthrene, triphenylene or any aromatic material listed in Table 1.

[0131] In one aspect, the lubricant can have the formula:

[0132]

[0133] Where R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )-CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0134] In one aspect, the lubricant can have the formula:

[0135]

[0136] wherein X and Y are independently hydroxyl, phosphoric acid moiety, silanol or carboxylic acid moiety, and wherein R f It is CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can also be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r, s are independently 1 to 100. The aromatic center is not limited to pyrene, but can also be naphthalene, phenalene, phenanthrene, triphenylene or any aromatic material listed in Table 1.

[0137] In one aspect, the lubricant can also be represented by the formula:

[0138] (Ar) m (R1 o R f R2 p ) q

[0139] in

[0140] Ar is an aromatic group, polyaromatic hydrocarbon (PAH), annulene, cycloalkane or heterocycle, etc.,

[0141] m is 1 to 10

[0142] R1 is a part containing the first polar group,

[0143] R2 is a part containing a second polar group,

[0144] R f It is a perfluorinated polyether.

[0145] o is 1 to 10

[0146] P is 0 to 10 or 1 to 10, and

[0147] q is 1 to 10.

[0148] The first polar group may be a hydroxyl group, a phosphonic acid group, a silanol group, or a carboxylic acid group, and the second polar group may be a hydroxyl group, a phosphonic acid group, a silanol group, or a carboxylic acid group. f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )-CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100. Or, R f Can be -CF 2 O(CF 2 CF 2 O) q CF 2 -, and q is 1 to 100.

[0149] The X, Y and Z components (all of which include an -OH group capable of bonding to the magnetic recording medium) may be non-exclusively selected from the following:

[0150]

[0151]

[0152] In one embodiment, the lubricant may have the formula:

[0153]

[0154] Where R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Yes - CF 2 CF 2 O(CF 2 CF2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0155] In one embodiment, the lubricant may have the formula:

[0156]

[0157] Where R f Can be CF 2 O(CF 2 CF 2 ) n CF 2 -, where n is 1 to 100, or R f Can be -CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) s CF 2 CF 2 -、-CF 2 CF 2 O(CF 2 CF 2 CF 2 O) sCF 2 CF 2 -、-CF 2 CF 2 O[CF(CF 3 )CF 2 O] s CF 2 CF 2 -、-CF 2 O(CF 2 CF 2 O) r (CF 2 O) s CF 2 -、-CF 2 O(CF 2 CF 2 O) s CF 2 -, and r and s are independently 1 to 100.

[0158] Aromaticity and stability

[0159] The degree of aromaticity in a lubricant has been found to have a profound effect on thermal stability. Figures 4 to 5 An exemplary embodiment of the weight loss derivative as a function of temperature in a TGA test of an aromatic or quasi-aromatic group-terminated / centered lubricant molecule is shown. Figure 4 As shown, the lubricants evaluated include Lubricant 1 (no aromatic part with polar middle and terminal groups), Lubricant 2 (aromatic part with polar middle and terminal groups at the terminal), Lubricant 3 (aromatic center with polar groups at the center and terminal of 3 perfluoroalkyl ether chains), and Lubricant 4 (PAH center with polar groups near the center and at the terminal of 4 perfluoroalkyl ether chains). The aromatic properties of these four lubricants are as follows:

[0160] Lubricant 1 < Lubricant 2 < Lubricant 3 < Lubricant 4.

[0161] That is, Lubricant 1 is the least aromatic and Lubricant 4 is the most aromatic. It can be seen that as the degree of aromaticity increases, the degradation / oxidation regime indicated by the peak derivative of weight loss during the TGA test occurs at higher temperatures. Additionally, as aromaticity increases, the severity of derivatization (i.e., decomposition) tends to decrease.

[0162] The trend of thermal stability / antioxidant properties increasing with increasing aromaticity is Figure 5 Further elaboration in Figure 5In the example, lubricant A has no aromaticity and is formed by a perfluoroalkyl ether chain terminated with a polar component at the end. Lubricant B is a perfluoroalkyl ether chain terminated with both an aromatic component and a polar component. Lubricant C, which has the most aromatic characteristics, is a perfluoroalkyl ether chain terminated with both a PAH component and a polar component. Comparative aromaticity is as follows:

[0163] Lubricant A < Lubricant B

[0164] Lubricant B<Lubricant C.

[0165] That is, lubricant A has the lowest aromatic properties, while lubricant C has the highest aromatic properties.

[0166] exist Figure 5 For N 2 The results of the derivative of weight loss as a function of temperature are clear from TGA measurements in both N and air. When aromatic or quasi-aromatic groups are incorporated into the molecular structure, the onset of significant weight loss is at higher temperatures. This is true for N 2 The results under atmosphere are particularly clear. Figure 4 and Figure 5 The results shown in demonstrate the unexpected advantages obtained by increasing the aromatic properties of a lubricant, particularly when the aromatic properties are provided by incorporating a PAH component into the lubricant.

[0167] Synthetic pathway

[0168] There are several synthetic routes to obtain PAH-containing lubricants. Among them, the following examples are substitution reactions with halogenated PAH compounds. One example is the synthesis of halogenated pyrenes from perfluoroalkylated compounds with hydroxyl terminal groups:

[0169]

[0170] R f :-CF 2 O(CF 2 CF 2 O) n CF 2 -, where n is 1 to 100

[0171]

[0172]

[0173] The PAH group is not limited to pyrene, but can be naphthalene, phenanthene, phenanthrene, triphenylene, or other aromatic materials listed in Table 1.

[0174] Using halogenated PAHs as a non-limiting example, there are many halogenated PAH compounds that are commercially available, and some examples are:

[0175]

[0176] The present disclosure is not limited to brominated compounds, and other halogenated compounds such as chloride or iodide may be used. The above brominated compounds may therefore also be substituted with some of these halides.

[0177] An exemplary approach for placing an aromatic moiety at the end of the perfluoroalkyl ether chain of a PAH-centric lubricant can also be accomplished by substitution, as shown in this example:

[0178]

[0179] R f :-CF 2 O(CF 2 CF 2 O) n CF 2 -, where n is 1 to 100

[0180]

[0181] The PAH group is not limited to pyrene, but can be naphthalene, phenanthene, phenanthrene, triphenylene or other aromatic materials listed in Table 1. The alcohol is not limited to 4-bromophenol, but any suitable aromatic halohydrin can be used, including 4-fluorophenol, 4-chlorophenol and 4-iodophenol. Other benzyl alcohols can also be used, including 4-fluorobenzyl alcohol, 4-chlorobenzyl alcohol, 4-bromobenzyl alcohol and 4-iodobenzyl alcohol.

[0182] The overall synthetic route to PAH-centric lubricants may involve reacting epoxides with alcohols, wherein a reactive nucleophile reacts with the epoxide in the presence of an alcohol. N The reaction is carried out in a type 2 reaction. The reactive nucleophile is usually an anion, so the reaction conditions are essentially basic. The leaving group is the oxygen atom of the epoxide in the form of an alkoxide, which is converted to an alcohol upon acidic workup. In this case, a perfluorinated diol is reacted with an epoxidized PAH to obtain a perfluorinated lubricant centered on the PAH:

[0183] R f :-CF 2 O(CF 2 CF 2 O) n CF 2 -, where n is 1 to 100

[0184]

[0185] Another exemplary substitution reaction with an alkylated aromatic compound can produce a lubricant with aromatic character at the end of the perfluoroalkyl ether side chain:

[0186]

[0187]

[0188] The PAH group is not limited to pyrene, but can be naphthalene, phenanthrenes, phenanthrenes, triphenylenes, or other aromatic compounds listed in Table 1. The alcohol is not limited to 4-bromophenol, but any suitable aromatic halohydrin can be used, including 4-fluorophenol, 4-chlorophenol, and 4-iodophenol. Other benzyl alcohols can also be used, including 4-fluorobenzyl alcohol, 4-chlorobenzyl alcohol, 4-bromobenzyl alcohol, and 4-iodobenzyl alcohol.

[0189] Application of lubricant

[0190] In various aspects, a lubricant layer can be formed on a magnetic recording medium, particularly on a protective outer coating, via a dip coating method. For example, in one aspect, the magnetic recording medium can be immersed in a lubricant bath, which contains a lubricant based on perfluoropolyether (PFPE) and a special solvent, such as VERTREL-XF (1,1,1,2,3,4,4,5,5,5-decafluoropentane) according to one or more aspects of the present disclosure. After a predetermined amount of time, the magnetic recording medium can be taken out of the lubricant bath at a controlled rate. The solvent is then evaporated, leaving a lubricant layer containing a molecular thin lubricant according to an aspect of the present disclosure. The percentage of lubricant remaining on the surface of the magnetic recording medium after the lubricant is arranged can be referred to as a bonding percentage. By exposing a lubricated magnetic recording medium with a solvent used in a lubricant bath, the bonding percentages of different time periods can be quantified.

[0191] In one aspect, the thickness of the lubricant layer can be adjusted by controlling the immersion duration of the magnetic recording medium in the lubricant bath, the rate at which the magnetic recording medium is removed from the coating solution, and / or the concentration of the lubricant according to one or more aspects of the present disclosure in the lubricant bath.

[0192] In one or more aspects, the concentration of the lubricant in the lubricant bath can range from about 0.0001 g / L to about 100 g / L. In other aspects, the concentration of the lubricant in the lubricant bath can be selected to obtain a resulting lubricant layer with a thickness down to the nanometer level.

[0193] It is important to note that forming a lubricant layer on the surface of the magnetic recording medium, particularly on the surface of the protective overcoat, is not limited to dip coating, but may also involve spin coating, spray coating, vapor deposition, combinations thereof, or any other suitable coating process as will be understood by those skilled in the art after reading this disclosure. In addition, the magnetic recording layer, the protective overcoat, and / or any other layer of the medium (e.g., including for Figure 2 Each layer shown in medium 200 in FIG. 1 may be formed using any of a variety of deposition methods known in the art.

[0194] It should be noted that the methods presented herein for at least some of the various aspects may be implemented in whole or in part by computer hardware, manually, using professional equipment, etc., and combinations thereof.

[0195] Furthermore, any of the structures and / or steps may be implemented using known materials and / or techniques as will become apparent to one skilled in the art after reading this disclosure.

[0196] The above description is for the purpose of illustrating the general principles of the present disclosure and is not meant to limit the inventive concepts claimed herein.In addition, specific features described herein may be used in combination with other described features in each of the various possible combinations and permutations.

[0197] It should be noted that in the development of any such practical aspects, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which vary from implementation to implementation. In addition, it should be understood that such development work may be complex and time-consuming, but will still be routine work for those of ordinary skill in the art who benefit from this disclosure. In addition, the devices, systems and / or methods used / disclosed herein may also include some components other than those cited.

[0198] Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretations, including the implicit meanings in this specification as well as the meanings understood by those skilled in the art and / or as defined in dictionaries, treatises, and the like.

[0199] It must also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless otherwise indicated.

[0200] As also used herein, the term "about" represents an interval of precision that ensures the technical effect of the feature in question. In various methods, when combined with a value, the term "about" refers to plus or minus 20% of the reference value. For example, a thickness of about 10 nm refers to a thickness of 10 nm ± 2 nm, such as 8 nm to 12 nm, in this example.

[0201] In the thickness and this specific embodiment, each numerical value should be read once modified by the term "about" (unless it has been explicitly modified as such), and then read again without modification, unless the context otherwise indicates. In addition, in the Summary of the Invention and this specific embodiment, it should be understood that the physical range listed or described as useful, suitable or the like means that any and every value within the range, including the endpoints, will be considered to have been described. For example, "a range of 1 to 10" will be read as representing every possible number in the continuum between about 1 and about 10. Therefore, even if a specific data point within the range or even no data point within the range is clearly identified or only refers to a few specific data points, it should be understood that the inventors understand and understand that any and all data points within the range should be considered to have been specified, and the inventors have an understanding of the entire range and all points within the range.

[0202] As used in the specification and claims, "close to" includes "at". The term "and / or" refers to an inclusive "and" case as well as an exclusive "or" case, and such terms are used herein for brevity. For example, a composition formed by "A and / or B" can be A alone, B alone, or both A and B.

[0203] Various components described in this specification may be described as "comprising" and / or being made of and / or having certain materials, properties, or combinations of materials. In one aspect, this may mean that the component has certain materials, properties, or combinations of materials. In another aspect, this may mean that the component has certain materials, properties, or combinations of materials.

[0204] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any specific implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term "aspect" does not require that all aspects of the disclosure include the discussed feature, advantage, or mode of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, then object A and object C may still be considered to be coupled to each other (even if they are not directly in physical contact with each other).

[0205] It should also be noted that the term "over" and / or the term "on" as used in the present disclosure in the context of one component being over another component or in the context of one component being on another component may be used to indicate that one component is directly on the surface of another component (e.g., arranged in physical contact with the surface of another component) and / or in another component (e.g., directly embedded in the component). Thus, for example, a first component being over or on a second component may mean that (1) the first component is over or on the second component but not directly contacting the second component, (2) the first component is directly on (e.g., directly on the surface of) the second component, and / or (3) the first component is in (e.g., embedded in) the second component.

[0206] In the present disclosure, various value ranges may be specified, described and / or claimed. It should be noted that any time when a range is specified, described and / or claimed in the specification and / or claims refers to including end values ​​(at least in one aspect). In another aspect, the range may not include end values ​​of the range. In the present disclosure, various values ​​(e.g., value X) may be specified, described and / or claimed. In one aspect, it should be understood that value X may be exactly equal to X. In one aspect, it should be understood that value X may be "about X" with the above meaning. Similarly, when determining a value according to an equation, it should be understood that in one aspect, the value is equal to the value calculated according to the equation, and in another aspect, the value is approximately equal to the value calculated according to the equation according to the above meaning, or as clearly provided, such as plus or minus (±) a specific amount.

[0207] Although various aspects have been described above, it should be understood that they are presented by way of example only and not limitation. Therefore, the breadth and scope of aspects of the present invention should not be limited by any of the above exemplary aspects, but should only be defined in accordance with the following claims and their equivalents.

Claims

1. A lubricant configured to be adsorbed by a magnetic recording medium, the lubricant comprising: (Ar) m (R1 o R f R2 p ) q in Ar is an aromatic group, a polyaromatic hydrocarbon, an annulene, a cycloalkane or a heterocycle, m is 1 to 10, R1 is a part containing a first polar group, R2 is a part containing a second polar group, R f It is a perfluorinated polyether. o is 1 to 10, p is 0 to 10, and q is 1 to 10. 2 . The lubricant according to claim 1 , wherein the first polar group comprises at least one selected from the group consisting of a hydroxyl group, a phosphonic acid, a silanol, and a carboxylic acid. 3 . The lubricant according to claim 1 , wherein the second polar group comprises at least one selected from the group consisting of a hydroxyl group, a phosphonic acid, a silanol, and a carboxylic acid.

4. The lubricant according to claim 1, wherein R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

5. The lubricant according to claim 1, wherein R f -CF2O(CF2CF2O) q CF2-, and q is 1 to 100.

6. The lubricant according to claim 1, wherein Ar is selected from the group consisting of aromatic groups, polycyclic aromatic hydrocarbons, naphthalene, phenanthene, phenanthrene, pyrene, triphenylene, annulene, cyclooctatetraene, cyclooctadecene, cycloalkanes, cyclohexane, cyclooctane, cyclodecane, heterocycles, triazines, cyclocyclotoxin, cyclolamin, or cyclotriphosphazene.

7. The lubricant according to claim 1, having the formula: Where R f It is CF2O(CF2CF2) n CF2-, wherein n is 1 to 100, or R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

8. The lubricant of claim 1, having the formula: Where R f It is CF2O(CF2CF2) n CF2-, wherein n is 1 to 100, or R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

9. The lubricant according to claim 1, wherein p is 1 to 10.

10. A data storage device configured for magnetic recording, the data storage device comprising: A magnetic recording medium, comprising: substrate; a magnetic recording layer on the substrate; an overcoat layer disposed on the magnetic recording layer; and The lubricant according to claim 1 is absorbed by the outer coating.

11. The data storage device according to claim 10, wherein R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

12. The data storage device according to claim 10, wherein R f -CF2O(CF2CF2O) q CF2-, and q is 1 to 100.

13. The data storage device of claim 10, wherein Ar is selected from the group consisting of aromatic groups, polycyclic aromatic hydrocarbons, naphthalene, phenanthene, phenanthrene, pyrene, triphenylene, annulene, cyclooctatetraene, cyclooctadecene, cycloalkanes, cyclohexane, cyclooctane, cyclodecane, heterocycles, triazines, cyclocyclotoxin, cyclolamine, and cyclotriphosphazene.

14. The data storage device of claim 10, wherein the lubricant has the formula: Where R f It is CF2O(CF2CF2) n CF2-, wherein n is 1 to 100, or R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

15. The data storage device of claim 10, wherein the lubricant has the formula: Where R f It is CF2O(CF2CF2) n CF2-, wherein n is 1 to 100, or R f Yes - CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2- or -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

16. A magnetic recording medium, comprising: substrate; a magnetic recording layer on the substrate; an outer coating layer, the outer coating layer being disposed on the magnetic recording layer; as well as The lubricant according to claim 1 is absorbed by the outer coating.

17. A data storage system, the data storage system comprising: at least one magnetic head; A magnetic recording medium coated with a layer of the lubricant according to claim 1; a drive device for positioning the at least one magnetic head above the magnetic recording medium; and A controller is electrically coupled to the at least one magnetic head to control the operation of the at least one magnetic head.

18. A data storage system, comprising: a slider comprising at least one magnetic head and an air bearing surface, wherein a thin film of the lubricant according to claim 1 is disposed on the air bearing surface; and A magnetic recording medium comprising a magnetic recording layer; and The slider is configured to write information to the magnetic recording layer using heat-assisted magnetic recording, energy-assisted magnetic recording, or microwave-assisted magnetic recording.

19. A lubricant configured to be adsorbed by a magnetic recording medium, the lubricant comprising: wherein Ar is a polyaromatic hydrocarbon ring system, X, Y and Z are independently hydroxyl, phosphoric acid moiety, silanol or carboxylic acid moiety, and wherein R f It is CF2O(CF2CF2) n CF2-, wherein n is 1 to 100, or Rf is -CF2CF2O (CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2-, -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

20. The lubricant of claim 19, wherein Ar is selected from the group consisting of aromatic groups, polyaromatic hydrocarbons, naphthalene, phenanthene, phenanthrene, pyrene, triphenylene, annulene, cyclooctatetraene, cyclooctadecene, cycloalkanes, cyclohexane, cyclooctane, cyclodecane, heterocycles, triazines, cyclocyclotoxin, cyclolamin, and cyclotriphosphazene.

21. A method of synthesizing a lubricant, the method comprising: Make 4-bromophenol and (Ar) m (R1 o R f R2 p ) q reaction in Ar is an aromatic group, a polyaromatic hydrocarbon, an annulene, a cycloalkane or a heterocycle, m is 1 to 10, R1 is a part containing a first polar group, R2 is a part containing a second polar group, R f It is a perfluorinated polyether. o is 1 to 10, p is 0 to 10, and q is 1 to 10.

22. The method according to claim 21, wherein R f CF2O(CF2CF2) n CF2-, wherein n is 1 to 100.

23. The method according to claim 21, wherein R f -CF2CF2O(CF2CF2CF2CF2O) s CF2CF2-,-CF2CF2O(CF2CF2CF2O) s CF2CF2-,-CF2CF2O[CF(CF3)CF2O] s CF2CF2-, -CF2O(CF2CF2O) r (CF2O) s CF2-, -CF2O(CF2CF2O) s CF2-, and r and s are independently 1 to 100.

24. The method of claim 21, wherein the first polar group is selected from the group consisting of hydroxyl, phosphonic acid, silanol, or carboxylic acid.

25. The method of claim 21, wherein p is 1 to 10.

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