JPH0548529B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic storage body used in a magnetic storage device (such as a magnetic disk device or a magnetic drum device).

(Prior Art) In general, there are the following methods for recording and reproducing a magnetic storage device comprising a recording and reproducing magnetic head (hereinafter referred to as a head) and a magnetic storage body. In other words, at the start of operation, the head and the magnetic storage surface are set in contact, and then a space corresponding to an air layer is created between the head and the magnetic storage surface by giving the magnetic storage the required rotation, and recording and playback are performed in this state. (contact start-stop method, hereinafter referred to as CSS). In this method, at the end of the operation, the magnetic storage body stops rotating, and at this time the head and the magnetic storage body surface are in a frictional state of contact, as at the beginning of the operation.

The frictional force generated between the head and the magnetic storage material under these contact friction conditions can wear out the head and the magnetic storage material and may eventually cause scratches on the head and the magnetic medium.

Further, in the contact friction state, a slight change in the posture of the head may cause the load applied to the head to become uneven, causing scratches on the surface of the head and the magnetic storage body.

Furthermore, if the head and the magnetic storage body are in contact for a long time, they will attract each other and become difficult to separate.

In order to prevent the magnetic memory from being destroyed or adsorbed due to contact and sliding with the head, a lubricant such as perfluoroalkyl polyether is applied to the surface of the magnetic memory as seen in Japanese Patent Application Laid-Open No. 52-49805. It was covered with a drug.

(Problems to be Solved by the Invention) However, such lubricants have poor load resistance and cannot prevent the occurrence of scratches on the magnetic memory when sliding with the head or repeating CSS many times. Another drawback was that the removed lubricant was thickly localized on the contact sliding surface between the magnetic storage body and the head and was attracted to it, making it difficult to separate.

An object of the present invention is to provide a magnetic memory that solves this problem.

(Means for solving the problem) The magnetic storage body of the present invention has a partial cross-sectional view (first
As shown in the figure, a magnetic medium 2 is coated on a base body 1, and a lubricant 4 made of ladder-type polysiloxane is further coated on the medium.

The base body 1 is made of metal such as aluminum alloy, titanium alloy, or stainless steel, or polyester, polyimide, polyamideimide, polyether sulfon, polysulfon, aromatic polyether, epoxy resin, urea resin, melamine resin, polycarbonate, diallyl phthalate resin. , acrylic resin, phenolic resin, polyphenylene sulfide, polyphenylene ether, polyacetal resin, polybutylene terephthalate, bismaleimide triazine resin, polyoxybenzylene resin,
Plastics such as polyamino bismaleimide resin, polyphenylene oxide, polyphenylene sulfide, ceramics such as glass, silicon, germanium, alumina, silica, diamond, anodized alumite coated aluminum alloy, Ni-P plating film, Cr,
A laminated alloy substrate such as an aluminum alloy, titanium alloy, or stainless steel coated with a metal such as FeNi, stainless steel, Mo, or W, or the above plastic, or the above ceramic, or the above plastic substrate coated with the above metal or the above ceramic, or the above metal or A ceramic substrate coated with the plastic.

Next, this base body 1 is coated with a magnetic medium 2 made of Fe ₃ O ₄ , γ-Fe ₂ O ₃ , Fe ₃ N ₄ , ceramics such as iron oxide or iron nitride such as barium ferrite, or Co. , Co-Ni, Co-Ni-P,
Co-Mn-P, Co-Mn-Ni-P, Co-Re, Co
−Ni−Re, Co−Mn−Re−P, Co−Cr, Co−
Fe-Cr, Co-V, Co-Ru, Co-Os, Co-Pt,
Co-Ni-Pt, Co-Pt-Cr, Co-Pt-V, Co-
Rh, Co−Cr−Rh, Co−Ni−Mo, Co−Ni−
Metals containing cobalt such as Cr, Co-Ni-W, Co-Sm, or Fe-Mg, Fe-Nd, Fe-Ag,
Metals containing iron such as Fe-Pd, Fe-Tb or Mn
Metals containing manganese such as -Al and Mn-Cu-Al are used.

The lubricant 4 is represented by the following general formula.

Here R, R′, R″, R, R′′′′, R′′′′
′ is −C _n
H _2n+1 , −C _n F _2n+1 (m is an integer greater than or equal to 1) or
C ₆ H ₆ , C ₆ H ₆ CH ₂ C1, C ₆ H ₆ CH ₂ OOCH ₃ ,
_C2H4C6H6 , _{C6H6CH3 , C6H6Si ( CH3 ) 3 , -X (} X
is -H, -COOH, -NCO, -M(OR) _-3o Rn (n is 0, 1 or 2, M is a metal or metalloid such as Si, Ti, Zr, Ge, Sn), -CN, - NH ₂ , −NRH, −
NH−, −CH−CH ₂ , −SO ₃ H, −NO, −OH, −
COOR, −NHCONH−, −NHCO−, −NCS, −
SH, −CONH ₂ , −PO(OH) ₂ , =PO(OH), =PO
-, =P-, -O-, -S- (R is -C _n H _2n+1 , _n is 1
or larger integer), -CH ₂ -O-O-CH ₂ -, -CH=
CH ₂ , -C≡CH, and other functional groups).

FIG. 2 is a partial cross-sectional view of another magnetic storage body of the present invention. In FIG. 2, the base body 1, magnetic medium 2, and lubricant 4 are the same as in FIG. 1, but a protective film 3 is coated between the magnetic medium 2 and the lubricant 4. The protective film 3 is made of SiO ₂ , Si ₃ N ₄ , SiC, or a silicic acid compound such as a silicic acid polymer, or Al ₂ O ₃ , CoO,
_{Co3O4 , Co2O3} , α- _{Fe2O3 , Cr2O3 , CrO3 ,
TiO2} , _ZrO2 , Zno, PbO, NiO, _MoO2 or
Metal oxides such as _SnO2 or TiN, ZrN, CrN,
Metal nitrides such as TaN, BN or _MoS2 , _WS2 ,
Metal sulfides such as TaS ₂ or TiC, ZrC,
Metal carbides such as CrC, TaC, metal fluorides such as graphite fluoride, or W, Cr, Ir, NiB,
NiP, FeCr, NiCr, Sn, Pb, Zn, Tl, Au,
Ag, Cu, Ga, Ru, Rh, Mn, Mo, Os or
metals or alloys such as Ta or their alloys; semiconductors such as Si, Ge, B, C (amorphous or diamond-like or mixtures thereof); or polytetrafluoroethylene, phenolic resins;
Plastics such as polyimide are used. The most suitable material for the surface modification layer 4 coated on the protective film 3 is determined depending on the protective film used. The surface modification layer 4 is a compound containing functional groups as explained in _FIG .
_NH2 , -CN is optimal. Furthermore, when the protective film 3 is made of ceramics such as the above-mentioned silicon compounds, metal oxides, metal nitrides, metal sulfides, metal carbides, semiconductors, etc., among the above-mentioned functional groups, -Si(OR) _3-o Rn is most suitable. There is. When the protective film 3 is made of plastic, -CH-CH ₂ , -NH ₂ , -CN, -CH=CH-,
-C≡C-, _-CH2 -O-O- _CH2- is optimal.

(Function) The lubricant 4 has a high load-bearing capacity, excellent wear resistance, and high heat resistance due to the ladder-shaped SiO bonds contained in its molecules. Also, the polarity is R, R', R'', R', R''''', R'''''
Since it is shielded by a magnetic recording medium, it has excellent properties such as low surface tension and resistance to adhesion between the head and the magnetic memory.

(Example) The present invention will be explained below with reference to Examples. Here, the following samples and comparative samples were prepared and their characteristics were measured.

Sample 1 A cobalt-nickel-phosphorus alloy with a thickness of 0.05 um was placed as a magnetic medium 2 on the base body 1, which was an aluminum alloy substrate coated with a nickel-phosphorus plating film and mirror-finished to a surface roughness of 0.02 um. I glared. Next, as a protective film 3 on this magnetic medium 2,
Polysilicic acid (silicic acid polymer) as disclosed in Japanese Patent No. 20804 was coated to a thickness of 500A by a spin coating method and baked at 250°C. Next, on this protective film 3, R, R', R'', R, R in general formula (1),
R′′′′ and R′′′′′ are CH ₃ and n is 10 to 2
Magnetic disks were made by coating a ladder-type polysiloxane with a thickness of 20 angstroms.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 2 Same as sample 1, but with the general formula as lubricant 4.
(1) R, R', R'', R, R''''' and R''
'''but
A magnetic disk was made by coating a ladder type polysiloxane of C ₆ H ₅ and n=5.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 3 Same as Sample 1, except that nickel-phosphorus was applied as a protective film 3 on the magnetic medium 2 by electroless plating.
R and R in the general formula (1) are CH ₃ and R' and R''''' are C ₂ H ₄ C ₆ F ₁₃
, R′′′′′, R″ is CH ₂ COOH, and n is 5
A magnetic disk was made by coating a ladder-type polysiloxane with a thickness of 20 angstroms.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 4 Same as Sample 1, except that 200 angstroms of carbon was coated as a protective film on the magnetic medium 2 by sputtering method, and then the general formula was applied as lubricant 4.
R and R in (1) are CH ₃ , and R and R′′′′ are
C ₂ H ₄ C ₆ F ₁₃ , R′′′′′, R″ is CH ₃ , n
A magnetic disk was made by coating it with a ladder-type polysiloxane having a diameter of 10.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 5 Same as Sample 1, except that R, R, R', and R''''' in general formula (1) are
A magnetic disk was made by coating a ladder-type polysiloxane in which CH 3 was CH ₃ , R′′′′′, R″ was H, and n was 20.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 6 Same as sample 1 except that Cr was used as the base body 1.
The NiP plating layer is coated with a thickness of 1 um by a sputtering method, and then a CoNi alloy is coated as a magnetic medium 2 with a thickness of 0.05 um by a sputtering method. After coating 200 angstroms, the general formula as lubricant 4
R, R, R′, R′′′′ in (1) are CH ₃ , and R′
′′′′,
R'' is CH ₂ NH ₂ and a magnetic disk was made by coating a ladder-type polysiloxane with n=20.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 7 Same as Sample 1, except that 500 angstroms of NiP was coated on the magnetic medium 2 as a protective film 3 by electroless plating, and then baked at 300°C for 2 hours to form 100 angstroms of NiO on the surface. On top of that, as a lubricant 4, R, R' in general formula (1),
R, R′′′′ is CH ₃ , R′′′′′, R″ is CH
_2Si
A magnetic disk was made by coating a ladder-type polysiloxane with (OCH ₃ ) ₃ and n=20.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 8 Same as Sample 1 except that γFe ₂ O ₃ was coated as the magnetic medium 2 to a thickness of 0.1 um by sputtering, and R and R in general formula (1) were coated as the lubricant 4 on the magnetic medium. ″, R, R′′″, R′′″ are CH ₃ ;
A magnetic disk was made by coating a ladder type polysiloxane where R' is OCH ₃ and n is 20.

Sample 9 Same as sample 1, but as magnetic medium 2
A CoCr alloy is coated with a thickness of 0.1 um by a sputtering method, and the lubricant 4 is coated on the magnetic medium using the general formula (1).
R, R″, R, R′′′′, R′′′′′ in it are CH ₃ ,
A magnetic disk was made by coating a ladder-type polysiloxane in which R' was CH ₂ COOH and n was 20.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 10 Same as sample 1, except that Sn was coated on the magnetic medium 2 to a thickness of 0.05 um as a protective film 3 by electroless plating method and baked at 250°C to form SnO ₂ . On the film 3, as a lubricant 4, the general formula (1)
R and R are CH ₃ , and R′ and R′′′′ are
C ₂ H ₄ CF ₃ and R′′′′′, R” is CH ₂ Si(OCH ₃ ) ₃
A magnetic disk was made by coating a ladder-type polysiloxane with n=20.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 11 Same as sample 1 except that BN was coated as a protective film 3 with a thickness of 0.1 um by sputtering method, and on top of the protective film, R and R in the general formula (1) were used as a lubricant 4.
CH ₃ , R′, R′′′′ are C ₂ H ₄ CF ₃ , R
′′′′′, R″ is CH ₂ OOCCH ₂ (CF ₂ ) (CF ₃ ) CF ₂ O) _n
A magnetic disk was made by coating a ladder-type polysiloxane of CF ₃ with n=20 and m=10.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Sample 15 Same as Sample 1 except that TiC was coated with a thickness of 0.1 um as a protective film 3 by a sputtering method, and on top of the protective film, R and R in the general formula (1) were used as a lubricant 4.
CH ₃ , R′, R′′′′ are C ₂ H ₄ CF ₃ , R
′′′′′, R″ is CH ₂ OOCCH ₂ (C ₂ F ₄ O) _p (CF ₂ O) _q
A magnetic disk was made by coating a ladder-type polysiloxane of COOH with n=20, p=10, and q=8.

When the wear resistance of this magnetic disk was evaluated by CSS testing 100,000 times, no scratches were observed on the surface of the head or magnetic disk. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, the increase was only 1.2 times compared to when it was not left.

Comparative Sample 1 A magnetic disk was prepared in the same manner as Sample 1 except that a perfluoroalkyl polyether having the following structure was coated as lubricant 4.

Perfluoroalkyl polyether F (C ₂ F ₄ O) _p (CF ₂ O) _q CF _3The wear resistance of this magnetic disk was evaluated through 20,000 CSS tests, and the magnetic medium reached the surface of the head and magnetic disk. A wound occurred. In addition, when the head and magnetic disk were left for 70 hours and the adhesion force acting during that time was measured, it was found to have increased tenfold compared to when it was not left.

Comparative Sample 2 A magnetic disk was fabricated in the same manner as Sample 3, except that dimethyl silicone oil having the following structure was coated on the protective film 3 as a lubricant 4.

Dimethyl silicone oil H ₃ C (Si (CH ₃ ) ₂ O) _o Si (CH ₃ ) ₃ When the wear resistance of this magnetic disk was evaluated through 20,000 CSS tests, the magnetic medium reached the surface of the head and magnetic disk. A wound occurred. In addition, when the head and magnetic disk were left for 70 hours and the adsorption force acting during that time was measured, it was found to have increased 15 times compared to when it was not left.

(Effects of the Invention) As described above, it has been found that the magnetic storage body of the present invention has excellent wear resistance and is less likely to cause adhesion between the head and the disk, and can dramatically improve the reliability of the magnetic disk.

In the embodiments of the present invention, magnetic disks have been described, but it is clear that the present invention is also effective for floppy disks, magnetic tapes, and magnetic cards.

[Brief explanation of drawings]

1 and 2 are partial cross-sectional views showing the present invention. 1... Base body, 2... Magnetic medium, 3... Protective film, 4... Lubricant.

Claims (1)

[Claims] 1. A magnetic memory having a structure in which a magnetic medium is coated on a base body, and a wetting agent made of ladder-type polysiloxane is further coated on the medium directly or through a protective film.