JP2002294266A - Lubricant containing phosphazene compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant for hard disk having good CSS durability. SOLUTION: A lubricant contains a phosphazene compound represented by formula (1): A-OCH2 CF2 O(CF2 CF2 O)p (CF2 O)q CF2 CH2 O-A and formula (5): A-OCH2 CF2 O(CF2 CF2 O)p (CF2 O)q CF2 CH2 OH comprising a sequence wherein a perfluorooxyalkylene unit selected from -CF2 O- and -CF2 CF2 O- is randomly distributed and further having a functional end group A: [wherein A is a group represented by formula (a), herein R is a hydrogen atom, a 1-4C alkyl, a 1-4C alkoxy, a 1-4C haloalkyl, an aryl, a substituted aryl, an aryloxy, a substituted aryloxy, and p and q are each real number of 1-30].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lubricant containing a phosphazene compound. More specifically, the present invention relates to a lubricant for a recording medium such as a hard disk as a large-capacity recording medium or a metal-deposited tape used for an 8 mm video tape recorder or a digital video cassette.

[0002]

2. Description of the Related Art With the spread of the Internet, intranets, local area networks, and the like, information can be easily retrieved simply by accessing a network. One of the things that support the multimedia age is an external storage device. As an existing large-capacity external storage device, a recording medium layer is provided on a high-strength circular substrate (hard disk), and the hard disk is rotated at high speed to operate a recording / reproducing element (head), that is, a so-called CSS system. A hard disk includes a fixed magnetic disk, an optical disk, a magneto-optical disk, and the like. The most popular of these is an apparatus using a fixed magnetic disk.

[0003]

In order to increase the capacity without changing the size of these external storage devices, it is necessary to increase, for example, the areal recording density of a recording medium layer. To do this,
It is necessary to reduce the bit size and move the head as close to the recording medium as possible. In order to reduce the distance between the head and the disk, the irregularities on the disk surface must be reduced. For example, to reduce the distance to 100 nm or less, the irregularities must be reduced to 10 nm or less. When the smoothness of the disk surface is improved, on the other hand, the head is more easily attracted to the disk surface. Also, in order to obtain high-speed response, it is necessary to increase the bit transfer speed and, consequently, the rotation speed of the disk. For example, the maximum rotation speed of a 3.5-inch hard disk needs to be 5400 to 7200 rpm, and the head passing speed around the disk reaches 125 km / hr. However, any of the above changes greatly increases the probability of contact between the disk and the head, abrasion, etc., and lowers reliability.

To cope with these problems and protect the disk surface and the head, it is easiest to increase the amount of lubricant applied to the disk protective film surface. However, when the amount of the applied lubricant is increased, not only the sliding resistance of the lubricating film is increased, but also the action of adsorbing the lubricant is increased, and the spindle motor stops and burns. If a low-viscosity lubricant is used to reduce the sliding resistance, the lubricant moves and disappears from the protective film when the disk rotates at a high speed, causing contact between the disk and the head and breakage.

[0005] The lubricant can be formed very simply by forming a lubricant film having a uniform molecular thickness on a protective film provided on the hard disk so that the lubricant can be used when the hard disk rotates and when the apparatus is started up.
Friction and abrasion generated at the time of stopping are reduced. To protect the disk and head, the sliding resistance is low, the bonding strength with the protective film is large, the coefficient of friction is low, the chemical stability, thermal stability, corrosion resistance are large, and the temperature is low at -10 ° C or lower. A lubricant having a lubricating ability and capable of forming an ultrathin film at a low vapor pressure is required. The hard disk lubricant has a CSS durability of 50,000 times or more and has no change in friction coefficient. That is, in the CSS repetition test, it is required that there is no abnormality such as burn-in of the head and scratches on the disk at least up to 50,000 times.

For protecting the surface of the current hard disk, a diamond-like carbon (DLC) protective film is used from the viewpoints of chemical stability, strength, ultrathinness, smoothness and the like. As is apparent from the structure, the protective film is mostly composed of carbon, and therefore has a low chemical bonding property and a small adhesive force such as hydrogen bonding with hydrogen and nitrogen atoms and van der Waals force. There is nothing else due to the interaction.

Therefore, as a lubricant, a perfluoroalkyl polyether oligomer (hereinafter abbreviated as “PFPE”) is generally used (Monthly Tribology, No. 99,
November, pp. 37-38, 1995). PFPE has low surface energy, chemical inertness, low vapor pressure, and thermal stability derived from fluorocarbon, but because of its low surface energy, the bonding force with the protective film surface is weak, and the lubricant is generated by the centrifugal force of disk rotation. However, there is a drawback that they move and disappear from the protective film. In order to suppress this, an additive of the second component is used (US Pat. No. 4,871,625), but due to the low compatibility derived from fluorocarbon of PFPE, phase separation is caused and sufficient effect is not obtained at present. is there.
Therefore, in order to impart a binding property to PFPE, a functional group such as a hydroxyl group or an acylamide group is introduced into the end or the center of the PFPE main chain (Aushimont, FOMBLIN, Inc.).
Z derivative), but these functional groups having active hydrogen may reduce chemical stability due to friction with the head.

Further, a perfluoroalkoxy phosphazene compound is disclosed as a treating agent for a magnetic recording medium (Japanese Patent Application Laid-Open No. 63-103428). Since the CSS durability cannot be obtained, a new lubricant is desired.

An object of the present invention is to provide, for example, a hard disk lubricant having good CSS durability.

[0010]

The present invention provides -CF ₂ O-,
The following formulas (1) and (5) comprising a sequence in which perfluorooxyalkylene units selected from —CF ₂ CF ₂ O— are randomly distributed and further having a functional terminal group A.
The present invention relates to a lubricant containing a phosphazene compound represented by the formula: _{A-OCH 2 CF 2 O (} CF 2 CF 2 O) p (CF 2 O) qCF 2 CH 2 O-A (1) A-OCH 2 CF 2 O (CF 2 CF 2 O) p (CF 2 O) qCF ₂ CH ₂ OH (5) wherein A is a group represented by the following formula (a). Here, R represents a hydrogen _{atom, C 1 to 4 alkyl,} a _{C 1 to 4 alkoxy,} a _{C 1 to 4} haloalkyl, aryl, substituted aryl, aryloxy, substituted aryloxy, p and q are 1 30 real numbers. ]

[0011]

Embedded image

[0012]

DETAILED DESCRIPTION OF THE INVENTION Here, the alkyl C _{1 to 4} for example, can be exemplified by methyl, ethyl, propyl, butyl and the like. Examples of C _1-4 alkoxy include methoxy, ethoxy, propoxy, butoxy and the like. The haloalkyl of C _{1 to 4} for example, fluoromethyl, trifluoromethyl, chloromethyl, fluoroethyl, trifluoroethyl, bromoethyl, iodopropyl, fluoro butyl, chlorobutyl, can be exemplified bromobutyl like. Examples of aryl include phenyl,
Examples include naphthyl. Examples of aryloxy include phenoxy, naphthoxy and the like. Examples of the substituent of the substituted aryl and the substituted aryloxy include the above-mentioned C _1-4 alkyl, C _1-4 alkoxy, C _1-4
And the like.

In the present invention, the phosphazene compound of the above formula (1) is a novel compound not described in the literature. For example, a phosphonitrile halide oligomer and a phenol or an alcohol having hydroxyl groups introduced at both ends of the PFPE main chain can be used. It is a manufactured substance. Here, examples of the oligomer of phosphonitrile halide include a cyclic trimer of phosphonitrile chloride, a cyclic tetramer of phosphonitrile chloride, and a mixture thereof. Examples of phenols include haloalkoxyphenols such as phenol and meta-trifluoromethylphenol, and alkoxyphenols such as meta-methoxyphenol. Further, as the alcohol having hydroxyl groups introduced at both ends of the PFPE main chain, a perfluoroalkyl polyether oligomer having an average molecular weight of the following formula (b) of 400 to 6000 (Zu derivative of Asimont Corporation)
Can be exemplified. HOCH ₂ CF ₂ O (CF ₂ CF ₂ O) r (CF ₂ O) sCF ₂ CH ₂ OH (b) [r = 1 to 30, s = 1 to 30]

The compound (1) of the present invention is produced, for example, as follows. That is, as described in JP-A-62-53996, alcohols and phenols are previously reacted with sodium or the like to form alcoholates and phenolates, and then reacted with a cyclic oligomer of phosphonitrile halide. . More specifically, phenols are dissolved in a solvent such as diethyl ether, diisopropyl ether, toluene or the like, and less than the equivalent required to convert all the phenols to phenolate, preferably 85 to 95% equivalent of metal sodium, hydrogen By reacting a base such as sodium chloride at the reflux temperature of the solvent until all of these bases have reacted,
Obtain the phenolate. 15-2 of the obtained phenolate
Reaction with 5% equivalents, preferably 18-21% equivalents, of the cyclotrimer of the phosphonitrile halide gives the aryloxy-substituted tricyclophosphonitrile halide. Separately,
An alcohol having a hydroxyl group introduced into both ends of PFPE (hereinafter abbreviated as “PFPE-DOH”) and a base selected from the above bases are added in the same equivalent amount, and solidified at room temperature to 120 ° C., preferably 40 to 100 ° C. The reaction is continued until the base is no longer visible.

The aryloxy-substituted tricyclophosphonitrile halide obtained above and the alcoholated PFP
E-DOH is reacted in an ether solvent such as diethyl ether, diisopropyl ether, perfluorohexyl methyl ether or the like for 1 to 10 days, preferably 2 to 5 days, from room temperature to the reflux temperature of the solvent.
The reaction mixture obtained in this reaction is added to an ether solvent solution containing a phenolate separately prepared by the above method, and the mixture is heated from room temperature to the reflux temperature of the solvent, preferably at the reflux temperature.
The reaction is allowed to complete for 5 to 15 days until no partially halogenated tricyclophosphonitrile is detected. After washing the reaction mixture several times with water,
After dehydration and drying, the solvent used is removed by distillation under reduced pressure. When the unreacted phenols, PFPE-DOH and hexaaryloxy-substituted tricyclophosphonitrile are present from the obtained reaction mixture, these compounds are distilled off by molecular distillation to remove the above compound ( 1) is manufactured.

In the present invention, in addition to the compound of the formula (1), compounds having a high molecular weight such as the following formulas (2) and (3) may be present in the reaction system. A small amount of such a compound may be present in the lubricant of the present invention. Here, B is a group represented by the formula (4).

[0017]

Embedded image

[0018]

Embedded image

—CH ₂ CF ₂ O (CF ₂ CF ₂ O) r (CF ₂ O) sCF ₂ CH ₂ — (4) [r = 1 to 30, s = 1 to 30]

Since the synthesis of the compound of the formula (1) takes a long time as described above, the reaction may not be completed and may be stopped at an appropriate place in consideration of economy. In this case, a compound represented by the following formula (5) may be, for example, 50
% Or more, but even if such a compound coexists with the compound (1), the object of the present invention is not inhibited. The ratio of the compound (1) to the compound (5) can be selected from a wide range, for example, the former / the latter (weight ratio) =
5-95 / 95-5, preferably 20-80 / 80-2
A range of 0 can be exemplified. A-OCH ₂ CF ₂ O (CF ₂ CF ₂ O) p (CF ₂ O) qCF ₂ CH ₂ OH (5) The compound of the present invention is used for nonflammable lubricating oils and hydraulic oils, especially for recording media. It is suitable for the use of the agent.

When the phosphazene compound of the present invention is used as a lubricant, the phosphazene compound can be used as a lubricant as it is, or may be used after being dissolved in an appropriate organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene, methylene chloride, chloroform, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichlorotrifluoroethane (Freon 113) and perfluorohexylmethyl. Ether (H
Halogenated hydrocarbons such as FE-7100), ethers such as diethyl ether, dimethoxyethane, dioxane, and tetrahydrofuran; esters such as ethyl acetate, butyl butyrate, and amyl acetate; cyclohexane, cycloheptane;
Examples thereof include alicyclic hydrocarbons such as cyclooctane, dimethylformamide, dimethylsulfoxide, and a mixed solvent of two or more of these. When the lubricant of the present invention is used as a lubricant for a recording medium, the total concentration of the compounds of the formulas (1) and (5) may be 0.1% by weight or more, usually 0.1%.
%, Preferably about 10 to 100% by weight, more preferably about 20 to 100% by weight.

In the present invention, the compounds of the formulas (1) and (5) and the formula (b) have an average molecular weight of 400 to 6000.
Can be used in combination. HOCH ₂ CF ₂ O (CF ₂ CF ₂ O) r (CF ₂ O) sCF ₂ CH ₂ OH (b) [r = 1 to 30, s = 1 to 30] In the present invention, the formulas (1) and (5) )) And the following perfluoroalkyl polyether oligomer (c) may be used in combination. _{X-CF 2 O (CF 2} CF 2 O) m (CF 2 O) nCF 2 -Y (c) [X, Y is _{HO (CH 2 CH 2 O)} tCH 2 -, HO
It represents at least one group selected from CH ₂ CH (OH) CH ₂ OCH ₂ —, HOOC— and a piperonyl group.
m = 1-80, n = 1-80, t = 1-30] Examples of the oligomer (c) include FOMBLIN
ZDol-TX, Z-TETRAOL, Z-DIAC,
AM3001 (both manufactured by Ausimont) and the like.

In the present invention, the compounds of formulas (1) and (5) can be used in combination with the following perfluoroalkyl polyether oligomer (d). F [CF (CF ₃ ) CF ₂ O] uCF (CF ₃ ) COOH (d) [u = 1-60] As an example of the oligomer (d), KRYTOX 1
57FS (DuPont) and the like. In the present invention, the compounds of the formulas (1) and (5) and the following phosphazene compound (e) can be used in combination.

[N = P {OCH ₂ CF ₂ CF ₃ } a {OCH ₂ (CF ₂ CF ₂ ) xH} b] y (e) wherein a and b are real numbers of 0 to 2, and a + b = 2, x is 1, 2, 3 or 4, and y is 3 or 4. Examples of the phosphazene compound (e) include Moresco phosphalol NF-100, NF-46 (Matsumura Petroleum Institute Co., Ltd.) and the like. Compound (b),
When (c), (d) and (e) are used in combination, the concentration of each compound is preferably at least 0.1% by weight, usually about 10 to 90% by weight. Compounds (b), (c),
At least two of (d) and (e) can be used in combination.

[0025]

The present invention will be described in more detail with reference to the following examples, but it should not be construed that the invention is limited thereto. The reactions described below were all performed in an argon gas atmosphere.

Example 1 A 2-L four-necked flask equipped with a reflux condenser, an argon gas inlet, a thermometer and a stirrer was charged with 282.1 g (1.74 mol) of meta-trifluoromethylphenol and dried and dehydrated. 1.2 L of diisopropyl ether purified by distillation was added, and 36.5 g of small pieces of metallic sodium were added with stirring.
(1.59 mol), and reacted for 2 days at a temperature at which diisopropyl ether was refluxed. After confirming that all the sodium metal had been consumed, the cyclotrimer of phosphonitrile chloride was added to the mixture while stirring the reaction mixture. 0.7 g (0.31 mol) was added and reacted at reflux temperature for 3 days to obtain about 1300 g of reaction mixture. After washing the reaction mixture 5 times with about 500 ml of purified water,
The diisopropyl ether layer was separated, dehydrated with molecular sieves, and the diisopropyl ether was distilled off under reduced pressure with a rotary evaporator to obtain a brown transparent liquid. This is referred to as (i).

In the same flask as above, PFPE-DO
H ｛A diol having an average value of r and s described in the above formula (b) of 1 and 10 respectively｝ 144.4 g (0.15
1 mol) and 3.5 g (0.151 mol) of small pieces of metallic sodium, and allowed to react at 50 ° C. to 100 ° C. for 12 days. After confirming that all metallic sodium was consumed in the reaction, perfluorohexyl was added. 450 g of methyl ether was added to reduce the viscosity of the reaction. In addition, 150.
A solution in which 5 g of (i) was dissolved in 140 g of diisopropyl ether was gradually added dropwise, and the mixture was stirred at a reflux temperature for 3 days, and then allowed to cool to room temperature. The obtained reaction mixture is (ii)
And

In the same manner as in the production of (i) above, meta-
192.7 g (1.19 mol) of trifluoromethylphenol and 24.8 g (1.08 mol) of small pieces of sodium metal
To a solution containing 1.19 mol of meta-trifluoromethylphenolate and 700 g of diisopropyl ether separately prepared from the above, quantitatively adding the whole amount of the reaction mixture of the above (ii) using 230 g of perfluorohexyl methyl ether, The mixture was stirred and reacted at the reflux temperature of the solvent for 9 days.
In this reaction mixture, it was confirmed by capillary gas chromatography that the cyclotrimer of phosphonitrile in which only the meta-trifluoromethylphenoxy group and the chlorine atom were both substituted in a mixed state, that is, no reaction intermediate was present. Thereafter, the contained solvent was distilled off from the reaction mixture under reduced pressure by a rotary evaporator, and the obtained residue was dissolved in 200 g of diethyl ether. This diethyl ether solution was washed three times with 200 g of a 1% aqueous nitric acid solution, and further washed four times with 200 g of purified water. After these operations, the diethyl ether layer was dehydrated and dried with molecular sieves, and the diethyl ether was distilled off under reduced pressure by a rotary evaporator to obtain 222.6 g of a slightly turbid oily liquid. It was confirmed by capillary gas chromatography that the reaction product also contained unreacted PFPE-DOH and a phosphonitrile cyclotrimer (by-product) substituted with six meta-trifluoromethylphenoxy groups. Therefore, these compounds were separated by a molecular distillation apparatus equipped with a diffusion pump to obtain 21 g of a pale yellow transparent liquid.

The substance obtained from the ratio of the methylene protons and the aromatic protons derived from the meta-trifluoromethylphenoxy group in 400 MHz proton NMR and the substance obtained from the FT-IR were compound (1-a) and compound (5-
It was a mixture of a) having a weight ratio of 47/53. (CF ₃ C ₆ H ₄ O) ₅ P ₃ N ₃ OCH ₂ CF ₂ (OCF ₂ CF ₂ ) (OCF ₂ ) ₁₀ OCF ₂ CH ₂ ON ₃ P ₃ (OC ₆ H ₄ CF ₃ ) ₅ [Compound (1 -a)] _{(CF 3 C 6 H 4 O} ) 5 P 3 N 3 OCH 2 CF 2 (OCF 2 CF 2) (OCF 2) 10 OCF 2 CH 2 OH [compound (5-a)] boiling point, 170 ° C or more / ^10-4 torr.

Example 2 A meta-phenoxyphenol was used in place of the meta-trifluoromethylphenol described in Example 1, and the same reaction as in Example 1 was carried out to obtain a phospho-substitute having six meta-phenoxyphenoxy groups. An oily liquid (270.6 g) was obtained which also contained the nitrile cyclotrimer (by-product) and unreacted PFPE-DOH. Toluene is added to this oily liquid
After adding 0 g and stirring, the mixture was placed in a separating funnel and allowed to stand overnight to separate into two layers. After confirming that most of the meta-phenoxyphenoxy group-substituted 6-substituted phosphonitrile cyclotrimers were extracted in the upper toluene layer,
The lower layer was subjected to molecular distillation equipped with a diffusion pump. By this operation, toluene, a cyclotrimer of phosphonitrile substituted with 6 meta-phenoxyphenoxy groups not extracted with toluene and unreacted PFPE-DOH
Was separated to obtain 55 g of a yellow transparent liquid.

In the 400 MHz proton NMR,
Tylene proton and meta-phenoxyphenoxy group
Derived from the aromatic proton ratio and FT-IR
Substance was the weight of compound (1-b) and compound (5-b).
It was a mixture having a quantitative ratio of 30/70. (C₆H₅OC₆H₄O)₅P₃N₃OCH₂CF₂(OCF₂CF₂) (OCF₂) ₁₀ OCF₂CH₂ON₃P₃(OC₆H₄OC₆H₅)₅[Compound (1-b)] (C₆H₅OC₆H₄O)₅P₃N₃OCH₂CF₂(OCF₂CF₂) (OCF₂) ₁₀ OCF₂CH₂OH [compound (5-b)] The boiling point is 200 ° C. or higher / 10^-4torr.

[0032] Comparative Example 1 (Compound of JP 6-220077 publication) reflux condenser, argon gas inlet tube, a 1-L four-necked flask equipped with a thermometer and _{stirrer, C 3 F 7 O (CF} 2
41.3 g (0.083 mol) of CF ₂ O) ₂ CF ₂ CH ₂ OH and 0.5 L of diisopropyl ether dried and dehydrated and purified by distillation were added, and while stirring, 1.73 g (0.075 g) of small pieces of metallic sodium was added. Mol), and reacted at 50 ° C. for 3 days. After reacting all the metallic sodium, 6.95 g of cyclotrimer of phosphonitrile chloride was added.
(0.02 mol) and 40 ml of diisopropyl ether were added and reacted at 60 to 70 ° C. for 2 days. Let the obtained reaction mixture be (iii).

In the same manner as in the above (iii), 18.8 g (0.198 mol) of phenol and 4.14 of metallic sodium
g (0.18 mol) in diisopropyl ether 250m
The reaction was carried out for 5 days in 1 L to obtain a solution of sodium phenolate in diisopropyl ether. This solution is referred to as (iv).

The whole amount of the solution (iv) is poured into the flask containing the (iii) at room temperature for about 5 minutes, and the mixture is reacted at 70 ° C. for 10 days. It was washed with an aqueous solution, then washed four times with an aqueous nitric acid solution, and further washed six times with purified water. The diisopropyl ether solution obtained in these washings was dehydrated and dried with molecular sieves, and diisopropyl ether was distilled off under reduced pressure using a rotary evaporator to remove the diisopropyl ether.
3.3 g of a pale yellow liquid were obtained.

In 400 MHz proton NMR,
Aromatic groups derived from tylene protons and phenoxy groups
The material obtained from the Roton ratio and the FT-IR shows ΔC₃
F₇O (CF₂CF₂O)₂CF₂CH₂O｝_1.6P₃
N₃(OC₆H₅) _3.4[Compound (2-a)],
The density is 1.6 g / cm³(15 ° C), viscosity (kinematic viscosity)
Is 50mm²/ Sec (40 ° C), the surface tension is 25.
It was 2 dyne / cm (25 ° C.).

Test Example 1 The compound (1-a) obtained in Example 1 and the compound (5-
The hard disk was immersed in a solution obtained by dissolving 1 g of the mixture of a) in 1000 ml of perfluorohexyl methyl ether (HFE-7100), and then taken out and taken out at 120 ° C.
For 30 minutes to form a film having a thickness of 10 ° on the hard disk. This was subjected to the following test. The performance test of the lubricant was carried out by measuring the change in the coefficient of friction by a CSS repetition test using an actual drive modified so that the coefficient of friction could be measured from the force applied to the head. The CSS cycle starts when the head is in contact with the disk surface, and when the head floats, the CSS cycle is performed a predetermined number of times.
After reaching 200 rpm, the process was repeated in 33 seconds until the head stopped again with the head in contact with the disk surface, which was defined as one cycle. The hard disk has a plasma CV on a recording medium made by 3.5 inch sputtering.
A DLC protective film of D to 100 ° to 200 ° was prepared. In order to enhance the surface smoothness, the texture was not used. The head is a monolithic MIG (metal in
gap) and the load was 7.5 g. The quality of the CSS test was determined based on the number of cycles (CSS life) until the head and the disk adhere (crash) and the state of the disk (whether worn or not). As a result, the CSS life is 50,000
After the cycle, the condition of the disk was normal.

Test Example 2 Test Example 1 was repeated except that 1 g of the mixture of the compound (1-b) and the compound (5-b) was used instead of 1 g of the mixture of the compound (1-a) and the compound (5-a). As a result, the CSS life was 50,000 cycles or more, and the disk condition was normal.

Test Example 3 Instead of 1 g of the mixture of the compound (1-a) and the compound (5-a), 0.2 g of a mixture of the compound (1-a) and the compound (5-a) and an average molecular weight of 2,000 The test was conducted in the same manner as in Test Example 1 except for using 0.8 g of a perfluoroalkyl polyether oligomer (Zu derivative of Ausimont Co.), and as a result, the CSS life was 50,000 cycles or more, and the condition of the disk was normal.

Test Example 4 Test Example 1 was repeated except that 1 g of the compound (2-a) was used instead of 1 g of a mixture of the compound (1-a) and the compound (5-a).
As a result, the CSS life was 28,000.
It was a cycle and the disk was worn. As a compound similar to the compound of the formula (1) of the present invention, the compound having the chemical structure obtained in Comparative Example 1 is disclosed in JP-A-6-2200.
No. 77 discloses this. Although this publication does not disclose the usefulness as a lubricant for a recording medium, a comparison between the above Examples 3 and 4 and Comparative Example 2 reveals that JP-A-6-2
It is apparent that the compound described in JP 2007077 is not useful in terms of performance as a lubricant for recording media.

[0040]

According to the present invention, for example, a hard disk lubricant having good CSS durability can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10N 40:18 C10N 40:18 (72) Inventor Eiyoshi Kobayashi 10-33 Ashiharacho, Nishinomiya City, Hyogo Prefecture Matsumura Corporation Petroleum Research Institute (72) Inventor Rie Fujimoto 10-33 Ashiharacho, Nishinomiya City, Hyogo Prefecture Matsumura Petroleum Research Institute Co., Ltd. F-term (reference) 4H104 BD06A BD07A BH14A CD04A LA03 PA16 5D006 AA01

Claims (6)

[Claims] 1. A _{-CF 2 O -, - CF 2} CF 2 O-,
A lubricant containing a phosphazene compound represented by the following formulas (1) and (5), which has a sequence in which perfluorooxyalkylene units selected from the above are randomly distributed and further has a functional terminal group A. _{A-OCH 2 CF 2 O (} CF 2 CF 2 O) p (CF 2 O) qCF 2 CH 2 O-A (1) A-OCH 2 CF 2 O (CF 2 CF 2 O) p (CF 2 O) qCF ₂ CH ₂ OH (5) wherein A is a group represented by the following formula (a). Here, R represents a hydrogen _{atom, C 1 to 4 alkyl,} a _{C 1 to 4 alkoxy,} a _{C 1 to 4} haloalkyl, aryl, substituted aryl, aryloxy, substituted aryloxy, p and q are 1 30 real numbers. ] 2. The lubricant according to claim 1, further comprising a perfluoroalkyl polyether oligomer of the formula (b) having an average molecular weight of 400 to 6000. HOCH ₂ CF ₂ O (CF ₂ CF ₂ O) r (CF ₂ O) sCF ₂ CH ₂ OH (b) [r = 1 to 30, s = 1 to 30] 3. The lubricant according to claim 1, further comprising a perfluoroalkyl polyether oligomer of the formula (c). _{X-CF 2 O (CF 2} CF 2 O) m (CF 2 O) nCF 2 -Y (c) [X, Y is _{HO (CH 2 CH 2 O)} tCH 2 -, HO
_{CH 2 CH (OH) CH 2} OCH 2 -, represents at least one group selected from HOOC- or piperonyl group.
m = 1-80, n = 1-80, t = 1-30] 4. The lubricant according to claim 1, further comprising a perfluoroalkyl polyether oligomer of the formula (d). _{F [CF (CF 3) CF} 2 O] uCF (CF 3) COOH (d) [u = 1~60] 5. The lubricant according to claim 1, further comprising a phosphazene compound of the formula (e). [N = P {OCH ₂ CF ₂ CF ₃ } a {OCH ₂ (CF ₂ CF ₂ ) xH} b] y (e) wherein a and b are real numbers from 0 to 2 and a + b = 2 , X is 1, 2, 3 or 4, and y is 3 or 4. ] 6. The lubricant according to claim 1, wherein the lubricant is a lubricant for a recording medium.