JPS63306527A - Magnetic recording medium and its production - Google Patents

Abstract

PURPOSE:To adequately maintain the abrasion loss of a head and to improve the output of a luminance signal by using the surface-treated magnetic oxide powder added with specific elements in a magnetic recording medium contg. magnetic metal powder and/or magnetic iron nitride powder as well as the magnetic oxide powder. CONSTITUTION:This magnetic recording medium contains the magnetic metal powder and/or magnetic iron nitride powder as well as the magnetic oxide powder. The surface treated-magnetic oxide powder added with additives contg. at least one kind of the element selected from aluminum, titanium, zirconium, silicon, etc., in the components is used in said medium. The surface treatment in this case is executed by coating the respective elements or the org. compds. of the plural elements on the magnetic oxide, then calcining the same. The abrasion loss of the head is thereby maintained at the prescribed value without impairing the magnetic characteristics and the performance of the magnetic recording medium is additionally improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium using metal magnetic powder and/or iron nitride magnetic powder and a method for manufacturing the same.

PRIOR ART Magnetic recording media such as magnetic tapes and magnetic disks are widely used in the video field, audio field, combinator field, etc. Such magnetic recording media are made by using a ferromagnetic metal as a base material by vapor deposition, etc. Thin-film magnetic recording media that have been formed into a film, and coating-type magnetic recording media that have formed a magnetic coating by applying and drying a magnetic coating consisting of magnetic powder, resin, solvent, dispersant, and other additives onto a base material. is used.

This coated magnetic recording medium has a high coercive force (Hc) and a residual magnetic flux density (B
Metal magnetic powder with large s) (e.g. Fes Fe-Co,
magnetic powder such as Fe-N1-Go) and iron nitride magnetic powder (Fe-N1-Go etc.)
, nitrides such as Fe-Ni-Co) are used. These magnetic powders contain Zns A It % S1% Z
rs Mn, Crs Mo, Ba, h% Cas Mg
Some magnetic powders contain one or more of 5HaSCuSSr, etc., and some have the surface of the magnetic powder coated with an oxide film for rust prevention. The particle size of these magnetic powders has an average long axis of 0.05 to 1 μm and an average short axis of 0.00 μm.
The specific surface area is 20 to 65 rrr/g at about 5 to 0.3μ.
Moderate ones are often used.

However, magnetic paint made of metal magnetic powder or iron nitride as magnetic powder is coated on a plastic sheet base material and dried to form a magnetic coating, and then a magnetic tape is inserted into a tape recorder for recording and playback. If you do it repeatedly for a long time,
As a result of the surface of the ferrite head for recording and reproducing being rubbed by the magnetic tape, it changes to a non-magnetic amorphous material. When the tip of the ferrite head changes to a non-magnetic material in this way, the non-magnetic material becomes interposed between the magnetic tape and the magnetic ferrite head, causing a so-called spacing loss and deteriorating the electromagnetic conversion characteristics. There is a problem with making it happen.

In order to solve this problem, Cr2O3, Aj! 20
3. A magnetic paint is manufactured by adding non-magnetic inorganic powder such as α-Fe20B or SiC as an abrasive, and this is used to manufacture a magnetic tape.

By the way, the magnetic powder used in high-density recording media tends to be made finer, and in line with this trend, the inorganic powder of the abrasive is also made finer. As the inorganic powder becomes finer in this way, its effectiveness in polishing the ferrite head decreases. Therefore, the amount of inorganic powder added is increased to compensate for this decrease.

However, increasing the amount of non-magnetic inorganic powder added reduces the blending ratio of magnetic powder in the magnetic coating, which reduces the magnetic properties of the magnetic tape. It has also been attempted to provide a ferrite head polishing effect without degrading the magnetic properties by using a physical magnetic powder.

When using a magnetic tape containing oxide magnetic powder as an abrasive agent in a magnetic coating film made of metal magnetic powder or iron nitride magnetic powder, if there is too little of this abrasive agent, the ferrite head becomes amorphous as described above. Insufficient polishing of the parts will result in spacing loss, while if too much abrasive is used, the amount of wear on the ferrite head will increase (which will negatively affect the durability of the ferrite head.Generally, it is the most preferable. Ferrite head wear amount is 0.5 to 2μ-71
00 hours, and the corresponding amount of abrasive compounded is 30% by weight or more based on the magnetic powder.

Problems to be Solved by the Invention However, such oxide magnetic powder has a coercive force (LIC) approximately equivalent to that of metal magnetic powder or iron nitride magnetic powder.
However, the saturation magnetic flux density (Bs) is inferior, so if 10 to 30% by weight is added to the metal magnetic powder or iron nitride magnetic powder, the saturation magnetic flux density (Bg) of the magnetic recording medium decreases, and the brightness signal There was a problem that the output (Yout) deteriorated.

The purpose of the present invention is to be able to maintain a moderate amount of wear on a recording/reproducing ferrite head during use, to have a high saturation magnetic flux density (BS), and to achieve a high brightness signal output (Yout).
The object of the present invention is to provide a magnetic recording medium that can maintain a high level of magnetic flux.

Means for Solving the Problems In order to solve the above problems, the present invention provides a magnetic recording medium containing metal magnetic powder and/or iron nitride magnetic powder and oxide magnetic powder. The present invention provides a magnetic recording medium characterized in that it uses surface-treated oxide magnetic powder to which an additive containing at least one element selected from the group of elements such as silicon is added.

There is also a step of obtaining a mixture of oxide magnetic powder and at least one organic compound of at least one element such as aluminum, titanium, zirconium, silicon, etc., and firing this mixture to form oxide magnetic powder. A small number of elements selected from the group of elements aluminum, titanium, zirconium, and silicon.
A surface treatment process for obtaining a surface-treated oxide magnetic powder to which an additive having a certain element as a component is added, and the surface-treated oxide magnetic powder is used together with a metal magnetic powder and/or an iron nitride magnetic powder to form a paint. The present invention provides a method for manufacturing a magnetic recording medium, which comprises the steps of:

In the present invention, the metal magnetic powder includes, for example, a ferromagnetic alloy powder, in which the metal content is 75% by weight or more, and 80% by weight or more of the metal content is Fe, Co5N.
15Fe-Co % Fe-Ni % Co-Ni or Co-Ni-Fe (both are one type, and the metal content is 20% by weight or less, preferably 0.5 to 5M amount % is Al)
5SiSS sSc, Ti, V, Cr, Mn
5Cus Zn, Y, MO% Rhs PdsA
glSns 5bSTe 1Bas Tax W%
Res Au 1Hys Pb5Bi, Las Ce
It has a composition such as 5PrSNdsBsP, and may also contain small amounts of water and hydroxide. The ferromagnetic alloy powder preferably has particles with a major axis of about 0.5 μm or less.

In addition, in the present invention, the iron nitride magnetic powder is Ni,
GO% ZaSAl, Sis Zr-, Mns C
rs MO% Has Ca5Mg, Tl5Has
CL1% Mainly composed of iron containing one or more types of Sr, etc., including those whose surface is oxidized to improve oxidation stability, and the average particle size is 0.05 to 1.0μ.
11 average short axis is 0.005 to 0.3μ.

In addition, in the present invention, the oxide magnetic powder has the general formula F
eOx, where 1.33 ≦
However, 1.33 < x < 1.50, and magnetic powders represented by ■ can be mentioned. A metal may be added to these ferromagnetic iron oxides, such as cobalt-added gamma iron oxide (Go-γFe20), and this metal may also be added, for example, f:, r, Mn5CO% N15CLI%
Divalent metals such as Zn have O to 10a to the above iron oxide.
To this ferromagnetic iron oxide, which may be added with tomic%, for example, spinel type ferrite ribs FFe203 (:2
Valence metal Mg.

CalBaSMn5 Fe, Co5Ni5 C11%
Zn) alone or a composite ferrite consisting of a solid solution of two or more of these individual ferrites, magnetoplumbite ferrite or hexagonal ferrite MO/6F
e2 (15 (M: Ba % 5rSPb), ferrox planar fephite, that is, an intermediate structure between Spenel type and magnetoplumbite type, garnet type ferrite 3R20B/5Fe203 (R: trivalent rare earth element), perovskite type ferrite or Orthoferrite RFe03 may also be mentioned.Barium ferrite B
aO・6Fe203, strontium ferrite S″r
O.6Fe20B is preferred.

Also mentioned is ferromagnetic chromium dioxide (Cr 02),
This chromium dioxide includes those having a film of dichromium trioxide (Cr203) on the surface of CrO2 particles, and
NaS K s Tis V , Mns Fe
S Cos t'S TC-% Rus 5nsC
Chromium dioxide, which is obtained by adding metals such as E and Pb, semiconductors such as P, Sb, and Te, or oxides thereof to CrO2 in an amount of 0 to 20% by weight, can also be used. It is effective that the acicular ratio of the acicular chromium dioxide is about 2/1 to 20/1, preferably 571 or more, and the average length is in the range of 0.2 to 2.0 μm, preferably 0.2 to 1 .0 μl.

Note that the material is not limited to these, and any material having magnetic properties equivalent to these may be used.

In the present invention, the above-mentioned oxide magnetic powder may be used in combination, and conventionally known abrasives such as Af203 may also be used in combination.

In the present invention, the oxide magnetic powder is Az, Ti5St,
The surface is treated by adding an additive containing at least one element of Zr, such as an oxide,
To do this, an oxide magnetic powder is coated with an organic compound of each of the above elements or a plurality of the elements, and then fired.

In the present invention, as the organic compound of Af, general formula A
I (OR,)3, where R- is the same or different alkyl group, trialkoxyaluminum compound showing an allyl group, such as aluminum isoproplate<Al(OCH(CH5)2)3), mono5ec-
Butoxyaluminum diisopropylate CAR (OCR(CH3)2 )2 (OCH(CH3
)(CH2O)Is)], 7/L/minium ethylate (AI! (OC2Hs)3).

In addition, aluminum chelate compounds made by replacing part or all of the open groups of the above aluminum alcoholate with a chelating agent such as alkyl acetoacetate or acetylacetone, such as aluminum ethyl acetoacetate diisopropylate (see below), etc. Alkylacetoacetate aluminum diisopropylate, aluminum tris(ethylacetoacetate) aluminum tris(acetylacetonate) aluminum bisethylacetoacetate monoacetylacetonate.

Further, an aluminum coupling agent consisting of acetalkoxyaluminum diisopropylate represented by the general formula where R: is an alkyl group can also be used.

Also, the general formula R25tx3, where R2 is vinyl,
An organic functional group having a glucidoxy, methacryl, amino, or mercapto group, and X is a silane coupling agent mainly representing chlorine and an alkoxy group, such as BiQ)l/trichlorosilane CH25IC1lSiCj3 Vinyltris(2
-nmethoxyethoxy)silane CH2-CH5i (O
C2HaOCH3)5T, glycidoxypropyl trimethoxysilane OH3 ゛CH2-CC00C3i (CH3')5γ-(2
-aminoethyl)aminopropyltrimethoxysilane H2NG2114NHC5Si (OcH3)3T-
Chloropropifretrimethoxysilane Cj C3HsS
i (OCH3)3 T-mercaptopropyltrimethoxysilane 113C5
116Si (OCH3)3T-aminopropyltriethoxysilane H2NC3HsSi (OC2H5)3.

Further, as an organic compound of Ti, general formula tetraalkoxytitanium, for example, tetraisopropoxytitanium (Ti
(0-ic3B?)4), tetra-n-butoxytitanium (Ti(0-aCaH9)4, tetrakis-2-ethylhexoxytitanium [Ti(OCH2CH(C2H5)
) C4H9) Tetrastearoxytitanium (Ti (0-
CI8H37)a, also titanium acylates with the general formula =Ti-0-Rλ, where R3 is an acyl group, and also titanium chelate compounds, such as di-iso-propoxy bis(acetylacetonato)titanium, Ti (0-ic3H7)2 (QC(CH3)CHC
OCH3)2iso-propoxy(2-ethylhexanediolato)titaniumTi(0-ic311t)n-(OCH2CH(C2H
5) CB(OH)C3Hy)4-n゛sheetbutoxybis(triethanolaminate)titaniumTi(0-nC4H9)2
0H)2)2, hydroxy bis(lactato)titanium T
i(OH)2(OCR(CH3)CGON)2.

Also, the general formula (RO)+m-Ti-X1, where RO
is an alkoxy group, l is 1 to 4. X is a fatty acid group, an alkyl group, a phenol group, a hydrocarbon group, a phosphite group, a phosphate group, etc., and n is 1 to 5 (when n is 2 or more, X may be the same or different). It will be done. Specifically, for example, isopropyl triisostearoyl titanate tetra (
2,2 diallyloxymethyl-1-butoxy) di(di-tridecyl) phosphite titanate di(dioctyl pyrophosphate) oxyacetate titanate and the following may also be mentioned.

Isopropyl tridecyl benzenesulfonyl titanate isopropyl tris (dioctyl pyrophosphate)
Titanate tetraisopropyl bis(dioctyl phosphite) titanate tetraoctyl bis(ditridecyl phosphite) titanate.

Tetra(2,2diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite Titaniumbis(dioctylpyrophosphate)ethylene titanate Isopropyltrioctanoyl titanate Isopropyl dimethacrylylisostearoyl titanate Isoprobyl isostearoyl diacryl titanate Isopropyl Tri(dioctyl phosphate) titanate Isopropyl tricumylphenyl titanate Isopropyl tri (N-aminoethyl-aminoel) titanate These titanium compounds can also be used in the form of a polymer, such as a dimer.

In addition, as organic compounds of Zr, zirconium stearate (Zr-3tearate), zirconium alkoxide carboxylate (Zr-Alkoxi
de-Carboxylate), zirconium alkoxide (Zr-Alk-, □xide).

Additionally, Zr-A 12 type coupling agents can also be used, specifically product numbers A and B manufactured by CAVfiDON CHEMICAL.

Examples include those from FSIll.

Further, in the above example, an organic compound of Al5T1%5ISZr alone or in combination is used, but it is also possible to use a plurality of organic compounds such as butyl titanate dimer.

The organic compounds of the above elements such as Aj can be used singly or in combination, but in order to add additives such as oxides containing these 11 elements as components to the surface of the oxide magnetic powder, these compounds must first be added. An organic compound of an element such as AI is dissolved in a solvent or water and mixed with magnetic powder. At this time, the mixing ratio of the organic compound of elements such as AI to the magnetic powder is 10 to 10.
200% by weight is suitable. It is then preferably filtered under pressure, dried at 100°C, and allowed to cool naturally. This magnetic powder is preferably transferred to another furnace and fired at 400 to 600°C in the atmosphere.

Incidentally, the calcination may be performed in an inert gas such as N2 or H2 gas or a reducing gas, or may be pressurized if necessary.

If you do this, the above Aj! Additives having elements such as Affi as a component, which are produced from organic compounds of elements such as
For example, surface-treated magnetic powder having oxides mainly on the surface of the magnetic powder particles can be produced.

At this time, the above elements such as At attached to the magnetic powder can be detected by fluorescent X-ray analysis, but the amount of the attached to the magnetic powder is preferably 2 to 20%.

The oxide magnetic powder obtained in this way is mixed with the above metal magnetic powder and/or iron nitride magnetic powder, and is further mixed with an abrasive, a binder, a solvent, a dispersant, an abrasive, a filler, an antistatic agent, and an antistatic agent. A magnetic paint is prepared by appropriately selecting and mixing each component such as a rust agent and a fungicide.

Methods for applying the above-mentioned magnetic paint to supports such as plastics include known application methods such as doctor blades, reverse rolls, gravure rolls, and spinner coats. Processing is performed to form a magnetic recording medium.

Al s Sis Ti, Zr on the surface of the active oxide magnetic powder
When using a magnetic recording medium that uses these additives in combination with metal magnetic powder and/or iron nitride magnetic powder, it is necessary to polish the ferrite head with oxide magnetic powder. can be performed better and maintain high magnetic properties.

Example Next, the present invention will be explained in detail.

Example 1 Hexagonal plate-shaped barium ferrite magnetic powder (average diameter 0.15
μen, coercive force Hc=9000e) 100g and pure water 300g
1117! After mixing, the zircoaluminate coupling agent CAVCOMOD, A (CAVEDON
After adding 100 g of CHEMICAL (manufactured by CHEMICAL) and mixing again, the mixture was filtered. The resulting mixture was heat treated in air at 600°C for 1 hour.

The amount of ZrxAl in the magnetic powder obtained above was measured by X-ray fluorescence analysis and was found to be 4.1%.

Next, 11 parts by weight of vinyl chloride-vinyl acetate copolymer, 11 parts by weight of polyurethane elastomer, and 13 parts by weight of toluene.
0 parts by weight, 282 parts by weight of a binder solution consisting of 130 parts by weight of methyl ethyl ketone, and az2o3 as an inorganic lubricant.
5 parts by weight of powder, 3 parts by weight of fatty acid ester as an organic lubricant, 25 parts by weight of the surface-treated barium ferrite magnetic powder obtained above, and acicular metal iron magnetic powder (major axis average 0.2
After mixing 100 parts by weight (4 μ scale, short axis average 0.04 μm) in a sand mill for about 20 hours, 4 parts by weight of polyisocyanate was added and further mixed to prepare a magnetic paint.

This magnetic paint is applied onto a polyethylene terephthalate film by gravure printing, oriented in a magnetic field, dried, and then subjected to calendaring, hardening reaction treatment, and slitting to produce a 172-inch wide video magnetic tape. did.

This tape was measured using a sample vibrating magnetometer (manufactured by Riken Denshi Co., Ltd.) to determine the saturation magnetic flux density B3, squareness ratio Br/as, and coercive force He.
The results are shown in Table 1.

Next, a videotape recorder (BR- made by Japan Victor Co., Ltd.
The side surface of the ferrite head of 7000) was photographed using an optical microscope, and after running the magnetic tape for 100 hours, the side surface of the ferrite head was photographed again and the wear dimensions of the ferrite head were measured and expressed as the amount of head wear. Shown in 1.

Furthermore, the video tape recorder, oscilloscope, and spectrum analyzer were connected, and the magnetic tape obtained above and a commercially available magnetic master tape were set in the video tape recorder, and the output ratio at 4 MHz was determined from the output of the commercially available magnetic master tape. It was calculated as OdB, and the results are shown in Table 1.

Example 2 A magnetic paint was prepared in the same manner as in Example 1 except that 50 parts by weight of the barium ferrite magnetic powder treated with the zircoaluminate coupling agent CAVCO-1'1OD SA was used instead of 25 parts by weight. A magnetic tape was prepared using the same, and the results were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 Surface-treated barium ferrite magnetic powder was prepared in the same manner as in Example 1 except that aluminum ethylate (aluminum alcoholate coupling agent) was used instead of the zircoaluminate coupling agent CAVCO-MOD. A magnetic paint was prepared from steel in the same manner as in Example 1, and a magnetic tape was made using the same. Table 1 shows the results of measurements on this in the same manner as in Example 1.
Shown below.

Example 4 In Example 1, instead of using hexagonal plate-shaped barium ferrite powder, Co-coated Fe203 acicular magnetic powder (major axis average 0.24 μm, short axis average 0.03 μm) was used, and Zirco Aluminate cuff pulling agent CAVCO
-MOD, surface-treated Co-coated γ-Fe203 magnetic powder was prepared in the same manner except that aluminum monoacetylacetonate bisethyl acetoacetate (aluminum chelate coupling agent) was used instead of A, and the following examples were prepared. A magnetic coating material was prepared in the same manner as in Example 1, and a magnetic tape was prepared using the same. Table 1 shows the results of measurements made on this tape in the same manner as in Example 1.

Example 5 In Example 1, Co-coated r-Fe205 acicular magnetic powder was used instead of the hexagonal plate-shaped barium ferrite powder, and the zircoaluminate coupling agent CA
A surface-treated Co-coated γ-Fe203 magnetic powder was prepared in the same manner as in Example 1, except that butyl titanate dimer (titanate coupling agent) was used instead of VCO-MOD, A. A coating material was prepared, a magnetic tape was produced using the coating material, and the results were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 6 In Example 1, Co-γ-Fe2O3 powder was used instead of the hexagonal plate-shaped barium ferrite magnetic powder, and methyltrimethoxysilane was used instead of the zircoaluminate coupling agent. ,400 in air
Surface treatment C was carried out in the same manner except that heat treatment was performed for 1 hour at °C.
o-γ-Fe203 magnetic powder was prepared, a magnetic paint was prepared in the same manner as in Example 1, and a magnetic tape was made using this, and the results were measured in the same manner as in Example 1, and the results are shown in Table 1. Shown below.

Comparative Example 1 In Example 1, the barium ferrite magnetic powder was mixed with a zircoaluminate camping agent CAVCO-Moo,
A magnetic paint was prepared in the same manner except that it was used as it was without surface treatment according to A, and a magnetic tape was made using this, and the results were measured in the same manner as in Example 1, and the results are shown in Table 1. .

Example 7 A magnetic paint was produced in the same manner as in Example 1 except that iron nitride magnetic powder was used instead of metallic iron magnetic powder in Example-1, and a magnetic tape was further produced using this. However, this was measured in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 A magnetic paint was prepared in the same manner as in Example 1, except that iron nitride magnetic powder was used instead of barium ferrite powder and the zircoaluminate camping agent was not used. A magnetic tape was prepared by using the magnetic tape, and the results were measured in the same manner as in Example 1, and the results are shown in Table 2.

From the above results, the magnetic properties of the comparative example are the same as those of the above example, but the head wear amount is small and it is not practical, whereas the example example has good saturation magnetic flux density Bs, brightness output, and head wear amount. It shows the value.

Effects of the Invention According to the present invention, an oxide magnetic powder containing an additive, such as an oxide, containing at least one element of Aj%T1%5iSZr as a component is used together with a metal magnetic powder and/or an iron nitride magnetic powder. Since it is possible to provide a magnetic recording medium with a high temperature, the excellent magnetic properties of metal magnetic powder and iron nitride magnetic powder are not impaired, and the amount of wear on the head of a recording/reproducing device can be maintained at a predetermined value during use. This allows the performance of the magnetic recording medium to be further improved.

Furthermore, by firing the organic compound of ^l s Tis Sis Zr and the oxide magnetic powder, additives containing these elements as components are added to the oxide magnetic powder, so the manufacturing method is simple.

Claims (3)

[Claims] (1) In a magnetic recording medium containing metal magnetic powder and/or iron nitride magnetic powder and oxide magnetic powder, aluminum,
A magnetic recording medium characterized by using surface-treated oxide magnetic powder to which an additive containing at least one element selected from the group of elements such as titanium, zirconium, and silicon is added. (2) The magnetic recording medium according to claim 1, wherein the additive is an oxide. (3) A step of obtaining a mixture of oxide magnetic powder and at least one organic compound of at least one element such as aluminum, titanium, zirconium, silicon, etc., and firing this mixture to convert aluminum into oxide magnetic powder. , titanium, zirconium, and silicon.
A surface treatment process for obtaining a surface-treated oxide magnetic powder to which an additive having a certain element as a component is added, and the surface-treated oxide magnetic powder is used together with a metal magnetic powder and/or an iron nitride magnetic powder to form a paint. 1. A method of manufacturing a magnetic recording medium, comprising the step of: