JPH0985632A - Polishing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a polishing layer as corresponding to the characteristic of a thick carrier, regarding a head cleaning work via the use of a film tape. SOLUTION: A polishing layer 3 is formed on the surface of a carrier 2. The thickness of the carrier 2 is between 30μm and 100μm, and the center line mean surface roughness Ra of the polishing layer 3 is between 0.01μm and 0.1μm. According to the application of the range for surface roughness, contaminants on a magnetic head for recording long wavelength signals can be properly removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is mainly applied to magnetic signals.
The present invention relates to a polishing film used for removing stains on the surface of a magnetic head for recording or reproducing magnetic recording having a wavelength of 0 μm / bit or more.

[0002]

2. Description of the Related Art As an example of the above magnetic head,
There is a magnetic head built in a camera for recording photographing information by providing a magnetic layer on an emulsion-sensitive photographic film.
Further, a photographic film used for cleaning such a magnetic head or a cleaning film dedicated to cleaning has been proposed as seen in JP-A-6-148798.

In addition, various cleaning tapes, cleaning disks, etc. have been conventionally used for magnetic heads in video, audio, information equipment, etc., but these have a cleaning layer formed on a thin support like magnetic tapes. (JP-A-54-97001, JP-A-61)
-123012, Japanese Patent Publication No. 3-73047, etc.), a cleaning device having a cleaning layer formed on a disc-shaped support (Japanese Patent Laid-Open Publication No. 6-58242).
1-222716).

[0004]

However, in the various cleaning materials described above, the recording wavelength is 10 μm /
It is difficult to satisfactorily remove head contamination in a magnetic head that records and reproduces a long-wavelength signal of one bit or more.

That is, as described above, the long wavelength dirt is
You will not notice unless the amount of dirt is much larger than in the case of short wavelength signal recording. For this reason, it is necessary to give special consideration to the cleaning of the magnetic head, and in particular, it is necessary to minimize the polishing amount and enhance the cleaning power.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a polishing film suitable for removing dirt on a magnetic head for recording and reproducing a long wavelength signal.

[0007]

The polishing film of the present invention, which has solved the above problems, comprises a support and a polishing layer provided on the surface thereof. The support has a thickness of 30 to 100 .mu.m, and the center line of the polishing layer. Average surface roughness Ra (JIS-B-R0601
-1982) is 0.01 to 0.1 μm.

Further, the polishing film has perforations arranged on the film surface or has a coercive force Hc of 1 in the polishing layer.
A magnetic material of 9750 to 237,000 A / m is used as one of all polishing layers.
˜45% by weight. The magnetic substance of the polishing layer is magnetized in the dispersion process or the coating process, and a magnetic signal having a bit interval of 10 μm or more is recorded.
It is desirable that the magnetic signal is recorded from the support surface side.

When the center line average surface roughness Ra of the polishing layer is 0.01 to 0.1 μm, the Rp (height of the maximum protrusion from the average line) is 0.02 to 0.1 μm. It is preferable.

The center line average surface roughness Ra of this polishing layer is
It can be adjusted by adjusting the dispersion time and the kind of the binder for dispersion. That is, Ra can be lowered by extending the dispersion time, but it is difficult to lower Rp. Moreover, when a binder suitable for dispersibility is selected,
Ra can be lowered even with the same dispersion time. Ra and R
Compatibility of p can be achieved by dispersion conditions, binder type and addition amount, addition of alumina powder smaller than the main abrasive, and the like.

The above Ra was measured by using a three-dimensional surface inspection machine (manufactured by Kosaka Laboratory) with a needle tip of 0.1 rφ, a needle tip load of 10 mg, a sweep speed of 0.25 mm / sec and a sweep distance of 0.1.
Calculate in mm.

[0012]

According to the present invention as described above, the support has a thickness of 30 to 100 μm and the polishing layer has an Ra of 0.01.
By setting the thickness to be 0.1 μm, it is possible to satisfactorily remove head dirt in a magnetic head that records / reproduces a long wavelength signal having a recording wavelength of 10 μm / bit or more, with a minimum cleaning amount and a high cleaning power.

Further, as a method of further enhancing the effect, perforation is provided on the film surface, and a remarkable effect is exhibited particularly when it is heavily soiled. Coercive force in the polishing layer is 1975
A magnetic substance of 0 to 237,000 A / m is added to the total polishing layer of 1 to 45
When it is contained by weight% and polished while observing the magnetic signal,
Excessive polishing can be prevented. Further, when the magnetic substance of the polishing layer is magnetized in the dispersion process or the coating process, the polishing effect is enhanced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to embodiments of the polishing film of the present invention. FIG. 1 is a schematic view showing the usage of the polishing film of this example, FIG. 2 is a schematic view showing the structure of an example of the polishing film, and FIG. 3 is a schematic view showing the structure of another example.

The polishing film 1 of this example has a thickness of 30 to 1
The support 2 having a thickness of 00 μm has a polishing layer 3 on one surface thereof, and the polishing layer 3 is composed of an abrasive 4, a magnetic material, and a binder. The center line average surface roughness Ra of the polishing layer 3 is 0.01 to 0.1 μm.

The polishing film 1 is provided in the shape of a photographic film (for example, width 24 mm, length 1-2 m), and the surface of the support 2 opposite to the polishing layer 3 (see FIG. 2) or the same side. The surface (see FIG. 3) is provided with an emulsion layer 5 coated with a photosensitive emulsion. When the polishing layer 3 is formed on the surface without the emulsion layer 5 as shown in FIG. 2, it is formed on the entire surface or only on the upper and lower portions thereof, and is formed on the surface provided with the emulsion layer 5 as shown in FIG. Sometimes, it is formed only in the upper part and / or the lower part. Further, perforations 7 (perforations) are formed at predetermined intervals on the upper edge and the lower edge of the polishing film 1.

The polishing film 1 is wound in the film cartridge 10 and stored in the spool 11. The film cartridge 10 is loaded in a camera 20 (not shown in the whole), the polishing film 1 is pulled out from the film cartridge 10 in accordance with the photographing operation, and the polishing layer 3 is attached to the magnetic head 21 built in the camera 20. Are in sliding contact with each other to clean the surface. The emulsion layer 5 is not essential as the polishing film 1, and the polishing layer 3 may be formed on the support 2 having no emulsion layer 5.

The magnetic head 21 of the camera 20 is for recording photographic information and the like in a normal use condition with a photographic film having a magnetic recording surface being brought into sliding contact with each other in response to photographing, and the magnetic signal thereof is 10 μm / bit or more. It is configured to perform magnetic recording having a wavelength of.

In the polishing of the magnetic head 21, the polishing based on the magnetic signal recorded on the magnetic material of the polishing layer 3 is performed on the magnetic material of the polishing film 1 by a signal (for example, sound at 640 Hz).
Is recorded and reproduced while polishing the magnetic head 21, and the polishing is stopped when a desired reproduction output is obtained. As a result, excessive polishing can be prevented, and when the magnetic head 21 is initially dirty, the reproduction output drops due to spacing loss, but the reproduction output recovers with polishing cleaning time. When it has recovered, you can stop polishing and cleaning.

The magnetic substance of the polishing layer 3 is magnetized in the dispersion process or the coating process so that the bit interval is 10 μm.
The above magnetic signals are recorded from the support surface side.

Alumina is mainly used as the polishing agent in the polishing layer, but in addition, chromium oxide, silicon carbide,
Diamond particles and the like can be used alone or in combination.

As the polishing agent applicable to the polishing layer of the present invention, chromium oxide having an average particle size of 0.05 μm to 500 μm, α-alumina, silicon carbide, non-magnetic iron oxide, diamond, γ-alumina, α. γ-alumina, fused alumina, cerium oxide, corundum, artificial diamond, garnet, emery (main components: corundum and magnetite), garnet, silica stone, silicon nitride, boron nitride, molybdenum carbide, boron carbide, tungsten carbide, titanium carbide, etc. So, mainly for materials with a Mohs hardness of 6 or more, 1 to 4
Used in combination up to seed. The pH of these abrasives used in combination is 2 to 10, and particularly preferably 5 to 10. These abrasives are used as the main constituent material of the polishing layer.

The magnetic substance (ferromagnetic fine powder) that can be used in the polishing layer is γ-Fe ₂ O ₃ , Co-containing (deposited, modified, doped) γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Co-containing (deposited, modified, doped) Fe ₃ O ₄ , γ-FeOx,
Co-containing (deposition, modification, doping) γ-FeOx (X =
1.33 to 1.50), CrO ₂ , Fe-Co alloy, C
o-Ni-P alloy, Co-Ni-Fe-B alloy, Fe-
Known ferromagnetic fine powders such as Ni-Zn alloy, Ni-Co alloy, and Co-Ni-Fe alloy can be used.
Japanese Patent Publication No. 44-14090, Japanese Patent Publication No. 45-18372
Issue, Japanese Examined Patent Publication No. 47-22062, Japanese Examined Patent Publication No. 47-2251
No. 3, JP-B-46-28466, JP-B-46-387
No. 55, Japanese Patent Publication No. 47-4286, Japanese Patent Publication No. 47-124
No. 22, Japanese Patent Publication No. 47-17284, Japanese Patent Publication No. 47-18
No. 509, Japanese Patent Publication No. 47-18573, Japanese Patent Publication No. 39-1
0307, Japanese Patent Publication No. 48-29280, Japanese Patent Publication No. 48-
No. 39639, Japanese Patent Publication No. 58-29605, Japanese Patent Publication No. 60
-44254, JP-A-59-126605, U.S. Pat. Nos. 3,026,215, 3,031,341 and 3,100.
No. 194, No. 3242005, No. 3389014.

The particle size of these ferromagnetic fine powders is about 0.
With a length of 005 to 1 μm, the ratio of axial length / axial width is 1/1 to
It is about 50/1. The specific surface area of these ferromagnetic fine powders is preferably 1 to 80 m ² / g, more preferably 20 to 70.
m ² / g, coercive force (Hc) 19750-237,000
A / m, water content 0.1-2.0% by weight, pH 3-1
1 (5 g magnetic substance / 100 g water). The surface of these ferromagnetic fine powders may be impregnated with a surface treatment agent, a dispersant, a lubricant, an antistatic agent, etc., which will be described later, in a solvent for each purpose and adsorbed. Other 1
Elements other than those listed (Sr, P
b, Mn, Cd, Al, Si, Na, Ca, K, Ti,
Cu, Zn, S, etc.) for improving magnetic characteristics or as an impurity. In particular, the metal ferromagnetic fine powder contains Al or Si compound as a sintering inhibitor on the particle surface, and the amount thereof is 1 to 10% by weight of the metal component.

As other magnetic materials, plate-like hexagonal barium ferrite, modified barium ferrite, modified strontium ferrite and the like can be used. The particle size of barium ferrite is about 0.001 to 1 μm and the thickness is 1/2 to 1/20 of the diameter. Barium ferrite has a specific gravity of 4 to 6 g / cc and a specific surface area of 1 m.
² / g to 70 m ² / g. These barium ferrites contain rare earth elements in an amount of 10 wt% or less as necessary, and the remaining alkali metals and alkaline earth metals for improving magnetic characteristics or as impurities. The surface of each of these magnetic materials may be impregnated with a dispersant, a lubricant, an antistatic agent, etc., which will be described later, in a solvent prior to dispersion for the purpose of adsorbing them.

Particularly when a ferromagnetic alloy powder containing iron, cobalt or nickel is used as the magnetic material, the effect is remarkable, the specific surface area is 35 m ² / g or more, and the coercive force is 19750 to 237,000 A / m. Preferably 3
It is preferable to use a ferromagnetic alloy powder of 0000 to 142200 A / m. As a detailed example of this ferromagnetic alloy powder, the metal content in the ferromagnetic alloy powder is 60% by weight or more, and 70% by weight or more of the metal content is at least one ferromagnetic metal or alloy (for example, Fe , Co, N
i, Fe-Co, Fe-Ni, Co-Ni, Co-Ni
-Fe) and other components (for example, A) within the range of 40% by weight or less, more preferably 20% by weight or less of the metal content.
l, Si, S, Sc, Ti, V, Cr, Mn, Cu, Z
n, Y, Mo, Rh, Pd, Ag, Sn, Sb, Te,
Ba, Ta, W, Re, Au, Hg, Pb, Bi, L
a, Ce, Pr, Nd, B, P), alloys which may contain iron, iron nitride, iron carbide and the like. Further, the ferromagnetic metal may include a small amount of water, hydroxide or oxide, alkali metal element (Na, K, etc.), alkaline earth metal element (Mg, Ca, Sr), or the like.
Methods for producing these ferromagnetic metal powders are already known,
The ferromagnetic alloy powder, which is a typical example of the magnetic material used in the present invention, can also be manufactured by these known methods.

That is, the following method can be given as an example of the method for producing the ferromagnetic alloy fine powder. (A)
A method of reducing a complex organic acid salt (mainly oxalate) with a reducing gas such as hydrogen, (b) a method of reducing iron oxide with a reducing gas such as hydrogen to obtain Fe or Fe-Co particles, ( c) a method of thermally decomposing a metal carbonyl compound, (d) a method of adding a reducing agent such as sodium borohydride, hypophosphite or hydrazine to an aqueous solution of a ferromagnetic metal for reduction, and (e) a mercury cathode. Method to separate ferromagnetic metal powder from mercury after electrolysis of the ferromagnetic metal powder, (f)
There is a method of obtaining fine powder by evaporating a metal in a low pressure inert gas.

When the ferromagnetic fine powder is used, its shape is not particularly limited, but is usually needle-like, granular, dice-like,
Rice granules and plates are used. The specific surface area (S _BET ) of this ferromagnetic alloy powder is preferably 40 m ² / g or more, and more preferably 45 m ² / g or more. The coercive force (Hc) of these ferromagnetic materials is more preferably 79000 to 158000 A / m. The σs of these ferromagnetic materials is 100 to 200 em.
u / g is preferred. The crystallite size is preferably 150 to 300A. Examples of these ferromagnetic alloy fine powders include JP-A-53-70397, JP-A-58-119609, JP-A-58-130435, and JP-A-59-80901.
JP-A-59-16903, JP-A-59-4145
No. 3, Japanese Patent Publication No. 61-37761, and US Pat. No. 44472.
64, US Pat. No. 4,792,011, US Pat.
No. 198, for example. These ferromagnetic materials are used in an amount of 5 to 400 parts by weight based on 100 parts by weight of the abrasive. If it is less than this, magnetism cannot be obtained. If it is too large, the polishing ability will be reduced.

As the binder that can be used in the polishing layer, those having an inorganic salt of 0.1 wt% or less can be used. As the binder used in the polishing layer, in addition to vinyl chloride resin, urethane resin and polyisocyanate, conventionally known thermoplastic resins, thermosetting resins, reactive resins, electron beam curable resins, UV curable resins, visible A light curable resin, a mildewproof resin or a mixture thereof can be used.

The softening temperature of the thermoplastic resin is 150 ° C.
Hereinafter, those having an average molecular weight of 10,000 to 300,000 and a degree of polymerization of about 50 to 2,000, more preferably 200 to 2,000.
To about 700, for example, acrylic acid ester acrylonitrile copolymer, acrylic acid ester vinylidene chloride copolymer, acrylic acid ester styrene copolymer,
Methacrylate acrylonitrile copolymer, methacrylate vinylidene chloride copolymer, methacrylate styrene copolymer, urethane elastomer,
Nylon-silicon resin, nitrocellulose-polyamide resin, polyfucca vinyl, vinylidene chloride acrylonitrile copolymer, butadiene acrylonitrile copolymer, polyamide resin, polyvinyl butyral, cellulose derivative (cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, Cellulose propionate, nitrocellulose, ethyl cellulose, methyl cellulose, propyl cellulose, methyl ethyl cellulose, carboxymethyl cellulose, acetyl cellulose, etc.), styrene butadiene copolymer, polyester resin, polycarbonate resin, chlorovinyl ether acrylate copolymer, amino resin, Various synthetic rubber type thermoplastic resins and mixtures thereof are used.

Examples of vinyl chloride resins include vinyl chloride vinyl acetate vinyl alcohol copolymer, vinyl chloride vinyl alcohol copolymer, vinyl vinylidene chloride copolymer, vinyl acrylonitrile copolymer, and the like. , A vinyl chloride copolymer-
_{(CHClCH 2) n - (CHXCH} 2) m - (X is terminal or middle _{thereof, -SO 3 Na, -SO 3 H} , -PO
It is desirable that the basic unit is an organic group having a polar group such as ₄ H) from the viewpoint of the strength of the polishing layer and the dispersibility of the abrasive particles. Among vinyl chloride-based resins, MR110 manufactured by Nippon Zeon Co., Ltd., is particularly preferable in terms of dispersibility and coating film strength.
For example, 400 × 110A.

Further, the thermosetting resin or the reactive resin has a molecular weight of 200,000 or less in the state of the coating liquid,
By heating and humidifying after coating and drying, the molecular weight becomes infinite due to reactions such as condensation and addition. Further, among these resins, those which are not softened or melted before the resin is thermally decomposed are preferable. Specifically, for example, phenol resin, phenoxy resin, epoxy resin, polyurethane resin, polyester resin, polyurethane polycarbonate resin, urea resin, melamine resin, alkyd resin, silicone resin, acrylic reaction resin (electron beam curing resin), epoxy-polyamide Resin, nitrocellulose melamine resin, mixture of high molecular weight polyester resin and isocyanate prepolymer, mixture of methacrylate copolymer and diisocyanate prepolymer, mixture of polyester polyol and polyisocyanate, urea formaldehyde resin, low molecular weight glycol / high molecular weight A mixture of diol / triphenylmethane triisocyanate,
And polyamine resins, polyimine resins, and mixtures thereof.

In particular, the urethane resin is not particularly limited, and a conventionally known binder resin can be used. For example, 100% modulus is 50 ~
Glass transition temperature (Tg) of 300 kg / mm ²
Is preferably in the range of -30 to 50 ° C., because it gives the ability to hold the abrasive in the polishing layer and imparts appropriate elasticity to the coating film.

Specifically, C- manufactured by Dainippon Ink and Chemicals, Inc.
7209, Pandex, N-2301, N-2302, N-2304, N-3 manufactured by Nippon Polyurethane Co., Ltd.
107, UR-8200, UR-8 manufactured by Toyobo Co., Ltd.
300, UR-8600, and the like. Among them, those having a polar group for promoting dispersion of abrasive particles in the molecule are preferable. These thermoplastic resins, thermosetting resins,
The reactive resin has carboxylic acid (COOM) as a functional group,
Sulfinic acid, sulfenic acid, sulfonic acid (SO
₃ M), phosphoric acid (PO (OM) (OM)), phosphonic acid,
Sulfuric acid (OSO ₃ M) and acidic groups (M is H, alkali metal, alkaline earth metal, hydrocarbon group) such as ester groups thereof, amino acids; aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols, Amphoteric groups such as sulfobetaine, phosphobetaine, alkylbetaine type, amino group, imino group, imide group, amide group, etc.
Hydroxyl group, alkoxyl group, thiol group, alkylthio group, halogen group (F, Cl, Br, I), silyl group, siloxane group, epoxy group, isocyanato group, cyano group,
One or more nitrile groups, oxo groups, acryl groups, and phosphine groups may generally be contained. Each functional group may be contained in an amount of 1 × 10 ⁻⁶ eq to 1 × 10 ⁻² eq per 1 g of the resin in order to promote the dispersion of the abrasive particles and improve the strength of the polishing layer coating film.

The mixing ratio of the polishing agent and the binder resin of the polishing layer is 5 to 700 parts by weight of the binder resin with respect to 100 parts by weight of the polishing agent.

The polyisocyanate used in the present invention is not particularly limited, and those conventionally known as binder resins can be used. For example, isocyanates such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine diisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate. , A product of the isocyanates and polyalcohols, 2 to 2 produced by condensation of the isocyanates
In the case of a 10-mer polyisocyanate, a product of polyisocyanate and polyurethane, the end functional group may be isocyanate, etc. Among them, if there are three or more isocyanate groups (-NCO) in one molecule, the crosslinking is three-dimensionally. It is desirable because it is done.

The polyisocyanates preferably have an average molecular weight of 100 to 20,000. Commercially available trade names of these polyisocyanates include Coronate L, Coronate HL, Coronate 2030, Coronate 2031, Millionate MR, Millionate MT
L (manufactured by Nippon Polyurethane Co., Ltd.), Takenate D-102,
Takenate D-110N, Takenate D-200, Takenate D-202, Takenate 300S, Takenate 5
00 (manufactured by Takeda Pharmaceutical Co., Ltd.), Sumidur T-80, Sumidur 44S, Sumidur PF, Sumidur L, Sumidur N, Death Module L, Death Module I
L, DeathModule N, DeathModule HL, DeathModule T65, DeathModule 15, DeathModule R, DeathModule RF, DeathModule SL, DeathModule Z4273 (manufactured by Sumitomo Bayer Co., Ltd.), and the like. Can be used in combination of two or more utilizing the difference between the two. Further, for the purpose of accelerating the curing reaction, hydroxyl groups (butanediol, hexanediol, molecular weight of 1000-10
000 polyurethane, water, etc.), a compound having an amino group (monomethylamine, dimethylamine, trimethylamine, etc.), a metal oxide catalyst, and a catalyst such as iron acetylacetonate can also be used in combination. It is desirable that these compounds having a hydroxyl group or an amino group are polyfunctional.

Among the above-mentioned polyisocyanates, particularly desirable are those for promoting and improving the three-dimensional crosslink density.
Trifunctional polyisocyanate is preferable, and examples include Coronate 3040 manufactured by Nippon Polyurethane Co., Ltd.

In addition, compounds having various functions are added to the polishing layer as additives. For example, a dispersant, a lubricant, an antistatic agent, an antioxidant, a fungicide, a coloring agent, a solvent, and the like are added.

The dispersant and dispersion aid may be added for the purpose of assisting the dispersion of the abrasive in the binder. Dispersants and dispersing aids include caprylic acid, capric acid, lauric acid,
2 carbon atoms such as myristic acid, palmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, stearolic acid, behenic acid, maleic acid and phthalic acid
~ 40 fatty acids (R ₁ COOH, R ₁ has 1 to 3 carbon atoms)
Nine alkyl groups, phenyl groups, aralkyl groups), alkali metals (Li, Na, K, NH) of the above fatty acids
₄ ⁺ etc.) or alkaline earth metals (Mg, Ca, Ba)
Etc.), metal soap (copper oleate) composed of Cu, Pb, etc., fatty acid amide; lecithin (soybean oil lecithin) and the like are used. In addition to these, higher alcohols having 4 to 40 carbon atoms (butanol, octyl alcohol, myristyl alcohol, stearyl alcohol) and their sulfates, sulfonic acids, phenylsulfonic acids, alkylsulfonic acids, sulfonic acid esters, phosphoric acid monoesters, phosphoric acid diesters , Phosphoric acid triester, alkylphosphonic acid, phenylphosphonic acid, amine compounds and the like can also be used.
Further, polyethylene glycol, polyethylene oxide, sulfosuccinic acid, metal sulfosuccinate, sulfosuccinate, and the like can also be used. These dispersants are usually used in one or more kinds, and one kind of the dispersant is the binder 10.
It is added in the range of 0.005 to 20 parts by weight with respect to 0 parts by weight. The method of using these dispersants may be such that they are pre-deposited on the surface of the ferromagnetic fine powder or non-magnetic fine powder, or they may be added during dispersion.

As the powdery lubricant, graphite, molybdenum disulfide, boron nitride, graphite fluoride, calcium carbonate, barium sulfate, silicon oxide, titanium oxide, zinc oxide,
Inorganic fine powders such as tin oxide and tungsten disulfide, acrylic styrene resin fine powder, benzoguanamine resin fine powder, melamine resin fine powder, polyolefin resin fine powder, polyester resin fine powder, polyamide resin fine powder, polyimide Resin fine powders such as fine resin powder and polyhooker ethylene resin fine powder.

The following organic compound type lubricants may be added to the polishing layer, expecting the effects of further reducing the friction coefficient and controlling the elasticity of the coating film. The amount added in that case is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the weight of the abrasive particles.
It is.

As the organic compound type lubricant, silicone oil (dialkyl polysiloxane, dialkoxy polysiloxane, phenyl polysiloxane, fluoroalkyl polysiloxane (KF96, KF69 manufactured by Shin-Etsu Chemical Co., Ltd.) is used.
Etc.)), fatty acid modified silicone oil, fluorine alcohol, polyolefin (polyethylene wax, polypropylene etc.), polyglycol (ethylene glycol, polyethylene oxide wax etc.), tetrafluoroethylene oxide wax, polytetrafluoroglycol, perfluoroalkyl ether, perfluoro Compounds in which fluorine or silicon is introduced, such as fatty acids, perfluoro fatty acid esters, perfluoroalkyl sulfates, perfluoroalkyl sulfonates, perfluoroalkylbenzene sulfonates, perfluoroalkyl phosphates, alkyl sulfates, alkyl sulfonates , Alkylphosphonic acid triester,
Organic acids and organic acid ester compounds such as alkyl phosphonic acid monoesters, alkyl phosphonic acid diesters, alkyl phosphate esters, succinate esters, triazaindolizine, tetraazaindene, benzotriazole, benzotriazine, benzodiazole, EDTA, etc. Heterocyclic compounds containing nitrogen and sulfur, C10-4
It is composed of 0 monobasic fatty acid and one or more monohydric alcohols having 2 to 40 carbon atoms, dihydric alcohols, trihydric alcohols, tetrahydric alcohols, and hexahydric alcohols. Fatty acid esters, carbon number 10
Or more monobasic fatty acids and fatty acid esters consisting of monohydric to hexahydric alcohols having 11 to 70 carbon atoms in total with the carbon number of the fatty acids, fatty acids having 8 to 40 carbon atoms or fatty acid amides , Fatty acid alkylamides, and fatty alcohols can also be used.

Specific examples of these compounds include butyl caprylate, octyl caprylate, ethyl laurate, butyl laurate, octyl laurate, ethyl myristate, butyl myristate, octyl myristate, 2-ethylhexyl myristate, Ethyl palmitate, butyl palmitate, octyl palmitate, 2-ethylhexyl palmitate, ethyl stearate, butyl stearate, isobutyl stearate, octyl stearate, 2-ethylhexyl stearate, amyl stearate, isoamyl stearate, 2 stearate.
Ethylpentyl, 2-hexyldecyl stearate, isotridecyl stearate, stearic acid amide, alkyl stearate, butoxyethyl stearate,
Anhydrosorbitan monostearate, anhydrosorbitan distearate, anhydrosorbitan tristearate, anhydrosorbitan tetrastearate, oleyl oleate, oleyl alcohol, lauryl alcohol, montan wax, carnauba wax,
Can be used alone or in combination.

As the antistatic agent, the polishing layer preferably contains carbon black for the purpose of preventing electrostatic breakdown due to static electricity generated between the polishing layer and the object to be ground. As carbon black, furnace for rubber, thermal for rubber, black for color, acetylene black and the like can be used. These carbon blacks are used for the purpose of improving anti-static properties, light-shielding agents, friction coefficient adjusting agents and durability of the film. Specific examples of the abbreviations of these carbon blacks in the United States are SAF, ISAF, IISAF,
T, HAF, SPF, FF, FEF, HMF, GPF,
APF, SRF, MPF, ECF, SCF, CF, F
There are T, MT, HCC, HCF, MCF, LFF, RCF and the like, and those classified in D-1765-82a of American ASTM standard can be used. Among these carbon blacks, in order to effectively achieve the object of the present invention, it is preferable to use furnace black having a particle size satisfying the above conditions.

The average particle size of these carbon blacks used in the present invention is 5 to 1000 nm (electron microscope),
Nitrogen adsorption method Specific surface area 10-800 m ² / g, pH 4
-11 (JIS standard K-6221-1982 method), dibutyl phthalate (DBP) oil absorption is 10-800 ml /
It is 100 g (JIS standard K-6221-1982 method). The average particle size of the carbon black used in the present invention is 5 to 100 n for the purpose of lowering the surface electric resistance of the coating film.
m of carbon black, and when controlling the strength of the coating film, carbon black of 50 to 1000 nm is used.

The type and amount of carbon black added may be selected depending on the purpose of the polishing film. Further, these carbon blacks may be surface-treated with a dispersant described below or the like, or may be used after being grafted with a resin. Also, the temperature of the furnace when producing carbon black is set to 20
It is also possible to use a material which is treated at a temperature of 00 ° C. or higher and is partially graphitized. Also, hollow carbon black can be used as a special carbon black. In the case of the polishing layer, these carbon blacks are preferably used in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the inorganic powder. For usable carbon black, for example, "Carbon Black Handbook" edited by Carbon Black Association (published in 1972) can be referred to. Regarding the powders other than alumina used in the present invention, each powder preferably has a Na content of 0.1 wt% or less.

As the antistatic agent other than carbon black, conductive powder such as graphite, modified graphite, carbon black graft polymer, tin oxide-antimony oxide, tin oxide, titanium oxide-tin oxide-antimony oxide; saponin, etc. Natural surfactant; alkylene oxide type, glycerin type, glycidol type, polyhydric alcohol, polyhydric alcohol ester, alkylphenol EO
Nonionic surfactants such as adducts; higher alkyl amines, cyclic amines, hydantoin derivatives, amido amines,
Cationic surfactants such as ester amides, quaternary ammonium salts, pyridine and other heterocycles, phosphonium or sulfonium; carboxylic acid, sulfonic acid, phosphonic acid, phosphoric acid, sulfate group, phosphonate group, phosphonate group, etc. Anionic surfactants containing an acidic group of the following; amino acids; aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohol, and amphoteric surfactants such as alkyl betaine type are used.

Some examples of these surfactant compounds that can be used as antistatic agents are described in Ryohei Oda et al., "Synthesis of Surfactants and Their Applications" (Maki Shoten 1972 edition); W. Bailey's "Surfs Active Agents" (Interscience Publications Corporation 1985 edition); P. Sisley, "Encyclopedia of Surf Esactive Agents,
Volume 2 "(Chemical Publishing Company, 1964 edition);" Surfactant Handbook ", 6th printing (Sangyo Tosho Co., Ltd.,
December 20, 1966); Hideo Marumo, "Antistatic Agent"
It is described in written books such as Koshobo (1968). These surfactants may be added alone or as a mixture. Although these are used as antistatic agents, they are sometimes used for other purposes such as dispersion, improvement of lubricity, coating aids, wetting agents, curing accelerators and dispersion accelerators.

As the antioxidant, alkylphenol, benzotriazine, tetraazaindene, sulfamide, guanidine, which are generally known as rust preventives,
Nucleic acids, pyridines, amines, hydroquinones, metal chelators such as EDTA, rust inhibitors naphthenic acid, alkenyl succinic acid, phosphoric acid, dilauryl phosphate, and the like, rapeseed oil known as an oil agent, lauryl alcohol, and the like, Extreme pressure agents such as dibenzyl sulfide, tricresyl phosphate, and tributyl phosphite are used. These are also used as detergents / dispersants, viscosity index improvers, pour point depressants, foaming agents and the like. These lubricants are added in the range of 0.01 to 30 parts by weight based on 100 parts by weight of the binder.

As the fungicide, 2- (4-thiazolyl) -benzimidazole, N- (fluorodichloromethylthio) -phthalimide, 10.10'-oxybisphenoxarcin, 2,4,5,6 tetra- Examples include chloroisophthalonitrile, P-tolyldiiodomethylsulfone, triiodoallyl alcohol, dihydroacetate, mercury phenyloleate, bis (tributyltin) oxide, and saltylanilide. Such a thing is shown, for example, in "Microbial Hazard and Prevention Technology", 1972 Engineering Book, "Chemistry and Industry" 32, 904 (1979) and the like.

As the colorant, industrial dyes used for dyes and pigments such as phthalocyanine dyes, cyanine dyes and chelate dyes can be used.

The solvent is used at the time of dispersion, kneading and coating, and it is a ketone system such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone and tetrahydrofuran in an arbitrary ratio; methanol, ethanol,
Alcohols such as propanol, butanol, isobutyl alcohol, isopropyl alcohol, and methylcyclohexanol; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, ethyl lactate;
Ester systems such as glycol acetate monoethyl ether; ether systems such as diethyl ether, glycol dimethyl ether, glycol monoethyl ether and dioxane; tar systems (aromatic hydrocarbons) such as benzene, toluene, xylene, cresol, chlorobenzene and styrene; Chlorinated hydrocarbons such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, ethylene chlorohydrin and dichlorobenzene, NN-dimethylformaldehyde, hexane, water and the like can be used. Further, these solvents are usually used in two or more kinds at an arbitrary ratio. Also one
Trace amounts of impurities (polymers of the solvent itself, moisture, raw material components, etc.) may be contained in an amount of not more than% by weight. These solvents are used in an amount of 100 to 20 relative to 100 parts by weight of the total solid content of the coating solution.
Used at 000 parts by weight. The preferred solid content of the coating solution is 1 to 70% by weight.

The polishing layer is formed by dissolving, kneading and dispersing in an organic solvent by arbitrarily combining the above-mentioned compositions and the like, coating it on a support as a coating solution, drying, cutting and cleaning.

The method of dissolution, dispersion and kneading is not particularly limited, and the addition order of each component (resin, powder, lubricant, solvent, etc.), addition position during dissolution, dispersion and kneading, dispersion temperature (0 ~
80 ° C.) can be appropriately set. For preparation of the abrasive coating, a usual stirrer, disperser, kneader such as a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a tron mill, a sand grinder, a teg burr (S
zegvari) Attritor, high speed impeller, high speed stone mill, high speed impact mill, disper, kneader, high speed mixer, ribbon blender, cokneader, intensive mixer, tumbler, blender, disperser, homogenizer, single screw extruder, twin screw An extruder, an ultrasonic disperser, or the like can be used. Usually, a plurality of these machines are provided for dissolving, dispersing and kneading, and the treatment is performed continuously. For details of the technique regarding kneading and dispersion, see T.W. C. Written by Patton (Te,
See, Patton) "Paint Flow and P
IGMENT DISPERSION ”(Paint Flow and Pigment Dispersion) 196
It is described in John Wiley & Sons, Inc. (John Willy and Sons) for 4 years, Shinichi Tanaka, "Industrial Materials," Vol. 25, 37 (1977), and in the references cited in the book. In order to efficiently promote dispersion and kneading as an auxiliary material for these dispersion and kneading, the equivalent spherical diameter is 10 cm.
Steel balls, steel beads, ceramic beads, glass beads, and organic polymer beads having a diameter of φ to 0.05 mmφ can be used. Also, these materials are not limited to spherical shapes. It is also described in the specifications such as US Pat. Nos. 2,581,414 and 2,855,156. Also in the present invention, the polishing layer coating material can be prepared by kneading and dispersing according to the method described in the above-mentioned book or the cited document of the book.

As a method of providing the coating solution for the polishing layer on the support, there are coating, spraying and the like. In the case of coating, the viscosity of the coating liquid is adjusted to 1 to 20000 centistokes (25 ° C), and an air doctor coater, a blade coater, an air knife coater, a squeeze coater, an impregnation coater, a reverse roll coater, a transfer roll coater, a gravure coater, a kiss coater, A cast coater, a spray coater, a rod coater, a forward rotation roll coater, a curtain coater, an extrusion coater, a bar coater, a lip coater, etc. can be used, and other methods are also available, and a detailed explanation of these can be found in "Coating Engineering" published by Asakura Shoten. Pp. 253-277 (Showa 46.3.2)
0. Issuance). Before applying the desired liquid, a corona discharge treatment or the like may be performed to improve the adhesion to the undercoat layer or the support. When it is desired to form the polishing layer and the magnetic layer in multiple layers, simultaneous multilayer coating, sequential multilayer coating and the like may be performed. These are disclosed, for example, in JP-A-5
7-123532, JP-B-62-37451, JP-A-59-142741, JP-A-59-1.
No. 65239, and the like.

By such a method, 30 to 1 is formed on the support.
Immediately after providing the polishing coating layer with a thickness of about 00 μm, 20 to 1
After the treatment of drying at 30 ° C., the formed polishing coating layer is dried to a thickness of 0.1 to 100 μm. The transport speed of the support at this time is usually 10 m / min to 900 m / min, and the drying temperature is 20 ° C. to 1 in a plurality of drying zones.
The residual solvent amount of the coating film is controlled at 30 ° C to 0.1-40 mg.
/ M ² . If necessary, the remaining layer may be provided by the same procedure, and then the surface is smoothed, and then cut into a desired shape to produce the polishing film of the present invention. These production methods include powder pretreatment / surface treatment, kneading / dispersion, coating / orientation / drying, smoothing treatment, heat treatment, and EB.
It is desirable to continuously perform the steps of treatment, surface cleaning treatment, cutting and winding.

The polishing film thus prepared is cut and then wound on a desired plastic or metal reel.
It is desirable to burnish and / or clean the polishing film immediately before or before winding. In order to control the surface roughness and polishing power of the polishing film, the burnish is specifically sapphire blades, razor blades, cemented carbide blades, diamond blades, ceramic blades, etc. Make it even or smooth. The Mohs hardness of these materials is preferably 8 or more, but is not particularly limited as long as protrusions can be removed. The shape of these materials does not have to be a blade in particular, and a shape such as a square shape, a round shape, or a wheel (these materials may be provided around a rotating cylindrical shape) can also be used. Cleaning of the polishing film is performed by wiping the polishing film surface layer with a non-woven fabric or the like for the purpose of removing dirt on the polishing film surface and excess lubricant. As such a wiping material, for example, various Vileen made in Japan Vilene or Toray made Toray, Exeine, product name Kimwipe, and non-woven fabric made of nylon, non-woven fabric made of polyester, non-woven fabric made of rayon, non-woven fabric made of acrylonitrile, blended non-woven fabric, etc. Tissue paper etc. can be used.

The layer structure of the polishing film of the present invention may be provided with a peeling preventive layer, that is, an undercoat layer between the layers, in addition to the support and the polishing layer.

As the material of the support, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, vinyl resins such as polyvinyl chloride, polycarbonate, polyimide, Polyamide, polysulfone,
In addition to plastics such as polyphenyl sulfone and polybenzoxazole, metals such as aluminum and copper and ceramics such as glass can be used. Prior to coating, these supports may be subjected to corona discharge treatment, plasma treatment, undercoating treatment, heat treatment, dust removal treatment, metal deposition treatment, and alkali treatment. Regarding these supports, for example, West German Patent 3338854A, JP-A-59-116926,
Japanese Unexamined Patent Publication No. 61-129731, US Pat.
88368; Yukio Mitsuishi, "Fiber and Industry," Vol. 31, p.
50-55, 1975 and the like. In the case of an abrasive film, the center line average surface roughness of these supports is 0.
001 to 1.5 μm (cutoff value 0.25 mm) is preferable. The support preferably has a thickness of 30 to 100 μm.
0 to 90 μm is particularly desirable. Further, it is desirable that the Young's modulus of either the longitudinal direction or the width direction of the support is 400 kg / mm ² or more.

Regarding the method for producing the polishing film of the present invention,
Further, the magnetic recording media described in JP-B-56-26890 can be referred to.

[0062]

EXAMPLES Examples and comparative examples of the present invention will be shown below to evaluate the polishing characteristics. The term "parts" in the examples means "parts by weight".

<Examples 1 to 5> 90 μm thick as a support
m of polyethylene naphthalate (PEN) is used, and an undercoat layer made of a polyester polyurethane resin is applied on this support to a layer thickness of 0.1 μm. Then, a polishing layer coating solution prepared by dispersing and adjusting the following composition for 4 hours with a glass bead dispersion medium using a sand grinder is bar-coated so that the thickness after drying is 5 μm, and dried. To prepare a sample of the polishing film.

Each example is constructed by changing the ratio of the abrasive (alumina) to the magnetic substance (iron oxide) in the polishing layer and adjusting the surface roughness Ra, and the average particle size is 0.3 μm. The abrasive ratio was 95% in Example 1, 90% in Example 2, 80% in Example 3, and 50% in Example 4.
In Example 5, it was set to 20% and the surface roughness Ra was 0.04 μm, 0.04 μm, 0.03 μm and 0.02, respectively.
.mu.m, 0.02 .mu.m.

Table 1 shows the results of the polishing test and the reproduction output measurement using the prepared polishing film. In the polishing test, the polishing amount of the magnetic head was converted into time, and the relative value was shown. The reproduction output was measured by recording 640 Hz and examining the reproduction output.

Comparative Examples 1 to 4 Table 1 shows Comparative Examples 1 to 4
The test results of are also shown. In this comparative example, an undercoat layer is applied to the same support as in the above-mentioned example, and a coating solution having the same composition is applied thereto, but the particle size of the abrasive and the abrasive ratio are changed, Average particle size is 1.5μ
The alumina of m was 99% in Comparative Example 1 and 15% in Comparative Example 2, and the surface roughness Ra was adjusted to 0.4 μm and 0.2 μm, respectively.

[Coating Liquid Composition] Abrasive particles (alumina, Mohs hardness 9, particle size 0.3 μm): X part Magnetic substance Co-deposited γ iron oxide (S _BET 45 m ² / g, Hc 54000 A / m): Y part Binder resin (polyester resin, sodium sulfonate 1 × 10 ^-3 equivalent / g resin content, Mw 70000): 10 parts Polyisocyanate (trimethylolpropane (1 mol) TDI (3 mol) adduct): 2 parts Lubricant (Oleic acid / oleyl oleate): 0.1 part Diluent (methyl ethyl ketone / cyclohexanone = 2/1): 200 parts Diluent (toluene / MIBK): 150 parts Additive (carbon black): 1 part

[0068]

[Table 1]

As a result of the above Table 1, in the polishing film according to the comparative example in which the abrasive particle size is large and the surface roughness Ra is large and the surface is rough, the polishing amount is excessive and a good cleaning action is obtained. Not not. On the other hand, according to the surface roughness Ra of the present invention, good polishing property is obtained, and cleaning is completed in a short time.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of use of a polishing film in one embodiment of the present invention.

FIG. 2 is a schematic view showing the structure of an example polishing film.

FIG. 3 is a schematic view showing the structure of a polishing film of another example.

[Explanation of symbols]

 1 Abrasive Film 2 Support 3 Abrasive Layer 4 Abrasive 5 Emulsion Layer 7 Perforation 10 Film Cartridge 11 Spool 20 Camera 21 Magnetic Head

Claims (6)

[Claims] 1. A polishing film comprising a support and a polishing layer provided on the surface thereof, wherein the support has a thickness of 30 to 100 μm.
and the center line average surface roughness Ra of the polishing layer is 0.01.
A polishing film having a thickness of 0.1 μm. 2. The polishing film according to claim 1, which has perforations arranged on the film surface. 3. The coercive force Hc is 1975 in the polishing layer.
A magnetic substance of 0 to 237,000 A / m is added to 1 to 4 of all polishing layers.
The polishing film according to claim 1, wherein the polishing film contains 5% by weight. 4. The polishing film according to claim 3, wherein the polishing layer is magnetized in a dispersion process or a coating process. 5. The polishing film according to claim 3, wherein a magnetic signal having a bit interval of 10 μm or more is recorded. 6. The polishing film according to claim 3, 4 or 5, wherein a magnetic signal is recorded from the side of the support surface.