JPS59148132A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium having superior lubricity, wear resistance, traveling performance, durability and electromagnetic transducing characteristics by incorporating a specified mercapto modified organosilicon compound into a magnetic layer. CONSTITUTION:A mercapto modified organosilicon compound represented by the formula (where X is a 1-30C hydrocarbon residue, 0<=m<1,000, 1<=n<=300, and m+n<=1,000) is used as a lubricant. The lubricant is added to a magnetic coating material contg. a dispersant for magnetic powder, a wear resistance providing agent, an antistatic agent, etc. besides ferromagnetic powder and a binder resin. The amount of the lubricant added is 0.2-20pts.wt. per 100pts.wt. binder. The coating material is coated on a substrate, dried, and cured. The hydrocarbon residues each having an SH group improve the compatibility of the lubricant with the binder and prevents the bleeding-out of the lubricant to the surface of a magnetic layer and the formation of pinholes. The lubricant shows a significant lubricating effect and improves the wear resistance of the magnetic layer without deteriorating the uniform dispersibility of the magnetic powder. A layer contg. the lubricant may be further formed on the rear side of the substrate opposite to the magnetic layer so as to improve the wear resistance furthermore.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of application of the invention: The present invention relates to improvements in magnetic recording media, and more specifically,
This invention relates to improvements in the lubricity, wear resistance, runnability, durability, and electromagnetic conversion characteristics of magnetic layers of magnetic recording media.

(b) Prior Art: The magnetic layer of a magnetic recording medium is generally made by coating a magnetic paint obtained by mixing and dispersing magnetic powder and its binder onto a support such as a polyester film.

The thus obtained magnetic recording medium travels while contacting the magnetic head, guide member, etc. during recording and reproduction, so it is required that the magnetic layer has a small coefficient of friction and has excellent running properties. During playback, the magnetic layer comes into intense sliding contact with a magnetic head, etc., so the magnetic layer is required to have little wear and excellent durability.

[21 Also, the magnetic properties or electromagnetic conversion properties of the magnetic layer are
It mainly depends on the dispersion state of the magnetic powder.

To meet the former requirement, that is, to improve lubricity and wear resistance, attempts have been made to incorporate various lubricants into the magnetic layer. method was being done.

However, although silicone oil has excellent lubricity, it has poor compatibility with binders, and although it can sufficiently reduce the frictional resistance of the magnetic layer, it may make the magnetic layer inhomogeneous, causing pinholes or The problem was that it oozed out on the surface.

In order to eliminate such drawbacks, in the past, ■ JP-A No. 57-37731, the general formula (however,
In the formula, R1 and R2 are -0H3 or -R50H, R3
represents a hydrocarbon group having 1 to 26 carbon atoms, nl and R
2 is O≦n1 < 1000.1≦n2≦500, n1
+n2 is an integer of 1000. ) When the alcohol-modified organosilicone compound shown in ) is contained in the magnetic layer, it has good compatibility with the binder, eliminates oozing or pinholes on the surface of the magnetic layer, and improves the lubricity of the magnetic layer. It is disclosed that wear resistance can be improved. In addition, ■ As shown in JP-A No. 57-37732, general formula (wherein R1 and R2 are -CH3 or -R5
000HXR5 represents a hydrocarbon group having 1 to 26 carbon atoms, and nl and R2 are 0≦n1<1000.1≦n2
It is an integer of ≦500 and n1+n2≦1000. ) can be realized by including a carboxyl-modified organic silicone compound shown in the magnetic layer.

In addition, ■ As proposed in JP-A No. 57-37733, (wherein R1 and R2 are -cu5 or -R5
NH2 and R5 represent a hydrocarbon group having 1 to 26 carbon atoms,
nl and R2 are 0≦n1<1000.1≦n2≦
It is an integer of 500Xn1 +n2≦1000. ) can also be realized by incorporating an amino-modified organosilicone compound shown in the magnetic layer, as disclosed in ■ JP-A-57-3
As proposed in No. 77a4, the general formula (wherein R1 and R2 are -OH!, t or -
R5C00R4, R3 and R4 represent a hydrocarbon group having 1 to 26 carbon atoms, and nl and R2 are 0≦n1<100
It is an integer of 0°1≦n2≦500 and n1+n2≦1000. ) can also be achieved by including an organic silicone compound shown in the formula in the magnetic layer.

These measures have a large lubrication effect and excellent compatibility with the binder, and although they improve the defects of making the magnetic layer inhomogeneous and causing pinholes and bleeding on the surface of the magnetic layer, they do not provide sufficient electromagnetic conversion characteristics. Not.

Furthermore, for the latter purpose, that is, to improve the dispersion state of magnetic powder, attempts have been made to add various dispersants to the magnetic layer.

For example, adding a dialkyl sulfosuccinate results in
It is known that it acts effectively as a dispersant, improves the degree of filling and orientation of magnetic powder, and imparts excellent magnetic properties or electromagnetic conversion properties.

However, when such a dispersant is used, the bonding strength between the magnetic powder and the binder decreases, and the dispersant tends to ooze out onto the surface of the magnetic layer, resulting in phenomena such as powder falling, output fluctuations, and tape noise. Durability becomes inferior.

Further, polyalkylene oxide alkyl phosphate esters also act effectively as dispersants in the same way as the above-mentioned dispersants, but they have the same drawbacks. For this reason,■ Unexamined Japanese Patent Publication No. 57-1
In No. 52535, a fatty acid-modified silicone compound 1 represented by the following general formula is used as a lubricant in a magnetic layer using a dialkyl sulfosuccinate as a dispersant for magnetic powder (where yl and y2 are -0H5 or -QC). !OR,R
is a saturated or unsaturated hydrocarbon group having 7 to 21 carbon atoms,
nl is an integer from θ to 1000, n2 is an integer from 1 to 500,
It has been clarified that the durability of the magnetic layer can be improved without impairing the dispersibility by adding (n1+n2 is 1001 or less) and coating it on the support. In addition, ■ Unexamined Japanese Patent Publication No. 57-1
No. 52537 is a magnetic layer using dialkyl sulfosuccinate as a dispersant for magnetic powder, and as a lubricant, the following general formula: saturated or unsaturated hydrocarbon group, n
l is an integer from 0 to 1000, n2 is an integer from 1 to 500, n
1+n2 is 1001 or less).

However, these measures have a poor lubrication effect and excellent compatibility with the binder, and although they improve the disadvantages of making the magnetic layer inhomogeneous, causing pinholes, and easily leaking onto the surface of the magnetic layer, It is difficult to say that running performance, durability, and electromagnetic conversion characteristics are sufficient.

In view of the above circumstances, the present inventors have conducted various studies and found that the general formula, where X represents a hydrocarbon residue of C1 to ago, and m is 0≦m<1000.1≦n≦300, m+n
When a mercapto-modified organosilicon compound with a formula of First, it was discovered that the electromagnetic conversion characteristics could be sufficiently improved, and the present invention was achieved.

(C) Object of the invention: That is, the present invention provides a magnetic recording medium in which a magnetic layer contains a mercapto-modified organosilicon compound to improve the lubricity, abrasion resistance, running properties, and electromagnetic conversion characteristics of the magnetic layer. The purpose is to

(d) Structure of the invention: The object of the present invention is to prepare the structure of a magnetic recording medium on a support by the general formula, where X represents a hydrocarbon residue of C1 to ago, and m is 0≦m<1000.1≦n≦300, m+n
This is achieved by providing a magnetic layer containing a mercapto-modified organosilicon compound having a molecular weight of ≦1000.

The magnetic layer of the magnetic recording medium according to the present invention can be formed by mixing and dispersing ferromagnetic powder together with a binder in a solvent to form a magnetic paint, and applying the paint onto a support.

When producing a magnetic paint, a dispersant, lubricant, abrasive, antistatic agent, etc. may be added as necessary.

Regarding the manufacturing method of magnetic paint, Japanese Patent Publication No. 35-15, No. 3
No. 9-26794, No. 43-186, No. 47-280
No. 43, No. 47-28045, No. 47-28046, No. 47-28048, No. 47-31445, No. 4
No. 8-111862, No. 48-21331, No. 448-
Specifications of each publication No. 33683, West German Published Patent Publication No. 206 (
It is described in detail in Publication No. 4655.

Magnetic powders that can be used in the magnetic layer of the magnetic recording medium of the present invention include γ-Fθ203, CO-containing -Fe205, CO
O-wear 7 FB20x,, Fe3O4, Co-containing Fe3
Iron oxide magnetic powder such as O4; Fe, Ni, Co, Fe-Nj
, -Co alloy, Fe-Mn-Zn alloy, Fe-Ni-Z
n alloy, Fe-co-Ni-Or gold alloy Fe-Co-N
Examples include various ferromagnetic powders such as metal magnetic powders containing Fθ, N1, and CO as main components, such as 1-P alloy and Co-Ni alloy.

The binder that can be used in the magnetic layer of the magnetic recording medium of the present invention includes thermoplastic resins, thermosetting resins, reactive resins, electron beam curable resins, and mixtures thereof.

The thermoplastic resin has a softening temperature of 150°C or less, an average molecular weight of 10,000 to 200,000, and a degree of polymerization of about 2.
00 to 2,000, such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylic ester-acrylonitrile copolymer, acrylic ester- Vinylidene chloride copolymer, acrylic ester-styrene copolymer, methacrylic ester-acrylonitrile copolymer, methacrylic ester-vinylidene chloride copolymer, methacrylic ester-styrene copolymer, urethane elastomer, polyvinyl fluoride , vinylidene chloride-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyamide resin, polyvinyl butyral, cellulose derivatives (cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, nitrocellulose, etc.), styrene-butadiene Copolymers, polyester resins, chlorovinyl ether-acrylic acid ester copolymers, amine resins, various synthetic rubber-based thermoplastic resins, and mixtures thereof are used.

These resins are disclosed in Japanese Patent Publications Nos. 37-6877 and 39-1.
No. 2528, No. 39-19282, No. 40-5349
No. 40-20907, No. 41-9463, No. 4
1-11-14059, 41-16985, 42-642
No. 8, No. 42-11621, No. 43-4623, No. 43-15206, No. 44-2889, No. 44-1
No. 7947, No. 44-18232, No. 45-1402
No. 0, No. 45-14500, No. 47-18573,
No. 47-22063, No. 47-22064, No. 47
-22068, 47-22069, 47-22
No. 070, No. 48-27886, U.S. Patent No. 3.
No. 144.352, No. 3,419,420, No. 3
, No. 499,789 and No. 3,713,887.

The thermosetting resin or reactive resin has a molecular weight of 200,000 or less in the state of a coating solution, and after coating and drying, the molecular weight becomes infinite due to reactions such as condensation and addition. Moreover, among these resins, those which do not soften or melt before the resin is thermally decomposed are preferable. Specifically, for example, a mixture of phenol resin, epoxy resin, polyurethane curable resin, urea resin, melamine resin, alkyd resin, silicone resin, acrylic reaction resin, high molecular weight polyester resin and isocyanate prepolymer 1
2- products, mixtures of methacrylate copolymers and diisocyanate prepolymers, mixtures of polyester polyols and polyisocyanates, urea formaldehyde resins, mixtures of low molecular weight glycols/high molecular weight diols/triphenylmethane triisocyanate, polyamine resins and A mixture, etc.

These resins are disclosed in Japanese Patent Publications Nos. 39-8103 and 40-97.
No. 79, No. 41-7192, No. 41-8016, No. 41-14275, No. 42-18179, No. 43-
No. 12081, No. 44-28023, No. 45-145
No. 01, No. 45-24902, No. 46-13103, No. 47-22067, No. 47-22072, No. 4
No. 7-22073, No. 47-28045, No. 47-2
No. 8048, No. 47-28922, U.S. Patent No. 3
．． No. 144.353, No. 3.320,090, No. 3,437,510, No. 3.597,273, No. 3,781,210, No. 3.781,211 It is written in the book.

Examples of electron beam irradiation-curable resins include unsaturated prepolymers,
For example, maleic anhydride type, urethane acrylic type, epoxy acrylic type, polyester acrylic type, polyether acrylic type, polyurethane acrylic type, polyamide acrylic type, etc. There are still polyfunctional monomers such as ether acrylic type, urethane acrylic type, epoxy acrylic type. , phosphate ester acrylic type, aryl type, hydrocarbon type, etc.

These binders may be used alone or in combination, and other additives may be added as required.

The mixing ratio of the ferromagnetic powder and the binder is 10 to 400 parts by weight of the binder to 100 parts by weight of the ferromagnetic powder,
It is preferably used in an amount of 30 to 200 parts by weight. If the amount of binder is too large, the recording density of the magnetic recording medium will be reduced, and if it is too small, the strength of the magnetic layer will be poor, resulting in undesirable situations such as decreased durability and powder falling off.

Furthermore, in order to improve the durability of the magnetic recording medium, the magnetic layer can contain various hardening agents, such as polyinsyanate.

As the polyisocyanate, an adduct of diisocyanate and trivalent polyol, or an adduct of diisocyanate
There are 3 moles of diisocyanate and a decarboxylating compound of water.

Examples of these include an adduct of 3 moles of tolylene diisocyanate and 1 mole of trimethylolpropane, an adduct of 3 moles of metaxylylene diisocyanate and 1 mole of trimethylolpropane, a pentamer of tolylene diisocyanate,
There are a pentamer consisting of 3 moles of tolylene diisocyanate and 2 moles of hexamethylene diisocyanate, and a decarboxylated product obtained by reacting 3 moles of hexamethylene diisocyanate with 1 mole of water, and these can be easily obtained industrially.

In addition to the magnetic powder according to the present invention, the binder, and the curing agent, additives such as a dispersant, a lubricant, an abrasive, and an antistatic agent may be added to the magnetic layer.

15- Dispersants used include caprylic acid, capric acid,
Fatty acids having 8 to 18 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, lylunic acid (represented by R-000H, where R is 7 to 7 carbon atoms) 17 saturated or unsaturated alkyl groups): alkali metals (Li, N
a, K, etc.) or alkaline earth metals (Mg, 0aX
A metal soap consisting of Ba, etc.) such as lecithin is used.

In addition to these, higher alcohols having 12 or more carbon atoms and sulfuric esters may also be used. These dispersants may be used alone or in combination of two or more. These dispersants are added in an amount of 1 to 20 parts by weight per 100 parts by weight of the binder.

These dispersants are described in Japanese Patent Publication Nos. 39-28369 and 44-
No. 17945, US Pat. No. 48-15001, US Pat. No. 3,587,993, and US Pat. No. 3,470,021.

Examples of lubricants include silicone oil, car pump 17-16-lac, graphite, carbon black graft polymer, molybdenum disulfide, tungsten disulfide, monobasic fatty acids having 12 to 16 carbon atoms, and the total number of carbon atoms in the fatty acids. Fatty acid esters (so-called waxes) made of monohydric alcohols having 21 to 23 carbon atoms can also be used.

These lubricants contain 0.00 parts by weight per 100 parts by weight of binder.
It is added in an amount of 2 to 20 parts by weight. Regarding these, publications such as Japanese Patent Publication No. 43-23889 and Japanese Patent Publication No. 43-81543, U.S. Patent No. 3,470,021, U.S. Pat.
No. 492,235, No. 3,497,411, No. 3
．． No. 523,086, No. 3,625,760, No. 3,630,772, No. 3,634,253, No. 3,642,539, No. 3,687,725. Each specification, M Technical Disc
'1osure Bulletin Vo19, N
o, 7. Page 779 (December 1966)
:F! Ll! 1KTRON Engineering K 1961 No. 1
2. It is described in Page 380 etc.

The abrasives used are commonly used materials such as fused alumina, silicon carbide chromium oxide, golantum, artificial corundum, diamond, artificial diamond, garnet, and emery (main components: corundum and magnetite). These abrasives have an average particle size of 0.05-5
μ is used, particularly preferably 0.1 to
It is 2μ.

These abrasives are used in an amount of 2 to 100 parts by weight of the binder.
It is added in an amount of zO parts by weight. These abrasive materials are disclosed in Japanese Patent Application Laid-Open No. 49-115510 and U.S. Patent No. 3,000.
7, No. 807, No. 3,041,196, No. 3.
No. 687,725, British Patent No. 1,145,349;
It is described in West German Patent (DT-PS) No. 853,211.

Antistatic agents used include conductive powders such as graphite, carbon black, tin oxide-antimony oxide compounds, tin oxide-titanium oxide-antimony oxide compounds, carbon black graft polymers, and natural surfactants such as saponin. : Nonionic surfactants such as alkylene oxide, glycerin, and glycidol:
Cationic surfactants such as higher alkyl amines, quaternary ammonium salts, pyridine, other heterocycles, phosphoniums or sulfoniums; Ampholytic surfactants such as anionic surfactants, amino acids, amino sulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols, etc. are used.

These surfactants that can be used as antistatic agents are disclosed in U.S. Patent Nos. 2,271,623 and 2,240,47
No. 2, No. 2,288,226, No. 2,676.1
No. 22, No. 2.676.924, No. 2,676.
No. 975, No. 2,691,566, No. 2,727
, No. 860, No. 2,730,498, No. 2.74
No. 2,379, Old No. 2,739.8, No. 3,06
No. 8,101, No. 3,158,484, No. 3,2
No. 01,253, No. 3.210,191, No. 3,
No. 294,540, No. 3,415,649, No. 3
, No. 441,413, No. 3,442,654, No. 3,475,174, No. 3,545,974, OLS No. 1,942,665, British Patent No. 1 .077.317, same No. 1, 198,
Including specifications such as No. 450, Ryohei Oda et al. [Synthesis of surfactants and their applications] (Maki Shoten 1964 edition):
A. W. Paley [Surface Active Agents] (Interscience Haflication Inc. 1958 edition): T. P. Sisley [Encyclopedia of Surface Active Agents Volume 2 J (Chemical Publications Company 1964 edition) ): “Surfactant Handbook” 6th edition (
Sangyo Tosho Co., Ltd. (December 20, 1966) and other publications.

These surfactants may be added alone or in combination. Although these are used as antistatic agents, they are sometimes applied for other purposes, such as dispersion, improving magnetic properties, improving lubricity, and as coating aids.

Solvents for magnetic paint or solvents used when applying magnetic paint include: Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Alcohols such as methanol, ethanol, propatool, and butanol; Methyl acetate, ethyl acetate, Ester systems such as butyl acetate, ethyl lactate, and glycol monoethyl acetate ether, glycol dimethyl ether, glycol monoethyl ether, and glycol ether systems such as dioxane: Aromatic hydrocarbons such as benzene, toluene, and xylene: Methylene chloride , ethylene chloride, carbon tetrachloride, chloroform, ethylene chlorohydrin, dichlorobenzene, and other halogenated hydrocarbons.

Materials for the support include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, plastics such as polycarbonate, Ou, and At.

Non-magnetic metals such as Zn, ceramics such as glass, porcelain, and earthenware are used.

The thickness of these supports is about 3 to 100 μm in the case of a film or sheet, preferably 5 to 50 μm,
In the case of a disk or card shape, the length is approximately 30 μm to 10 m, and in the case of a drum shape, the length is cylindrical, and the shape is determined depending on the recorder used.

The above-mentioned support has a so-called back coat (back coat) on the side opposite to the side on which the magnetic layer is provided for the purpose of preventing static electricity, preventing transfer, etc.
kcoat) may be performed.

Regarding backcoats, for example, U.S. Patent No. 2.804
, No. 401, No. 3,293,066, No. 3.61
No. 7,378, No. 3,062,676, No. 3.7
No. 34,772, No. 3,476.596, No. 2.
No. 643,048, No. 2,803,556, No. 2
．． No. 887,462, No. 2,923,642, No. 2.997,451, No. 3,007, 892, No. 3.041,196, No. 3,115,420
No. 3,166,688, etc.

Further, the support may be in any form such as a tape, sheet, card, disk, or drum, and various materials may be selected as necessary depending on the form.

The magnetic powder, binder, dispersant, lubricant, abrasive, antistatic agent, solvent, etc. according to the present invention are kneaded to form a magnetic paint.

For cross-talk, the magnetic powder and each of the components are fed into the cross-wire machine either simultaneously or individually one after another. For example, there is a method in which the magnetic powder is first added to a solution containing a dispersant and kneaded for a predetermined period of time, and then the remaining components are added and mixing is continued to obtain a magnetic paint.

Various types of crosstalk devices are used to disperse crosstalk. For example, two roll mill, three roll mill, ball mill, pebble mill, sand grinder, 8zegvari attritor, high speed impeller disperser, high speed stone mill,
High speed impact mill, Disper Kneader 1 high speed mixer,
There are homogenizers, ultrasonic dispersers, etc.

When the magnetic paint according to the present invention is dispersed by these methods, extremely good dispersion is achieved, and as a result of the dispersibility evaluation described below, the number of aggregates when observed with an electron microscope was lower than that of conventional magnetic paints. There were very few.

The technology related to crosstalk dispersion is written by T. O. PATTON.
a1nt Flow and Pigment Dis
persion (1964 John Willey
& 5ons). Also, U.S. Patent Nos. 2,581,414 and 2.855,156.
It is also stated in each specification of the issue.

Coating methods for forming a magnetic layer by applying the magnetic paint onto a support include gravure roll coating, Meyer bar coating, doctor blade coating, reverse roll coating, dip coating, air knife coating, calendar coating, and squeegee coating. Coating, kiss coating, fan tin coating, etc. can be used, and other methods are also possible, and detailed explanations of these can be found in "Coating Engineering" published by Asakura Shoten (published by Asakura Shoten: March 1971, 25
3 pages~) and “Plastic Films – Processing and Applications”
(published by Gihodo: July 1971) is described in detail.

The magnetic layer coated on the support by such a method is optionally treated to orient the ferromagnetic powder according to the present invention in the layer, and then the formed magnetic layer is dried. Further, if necessary, the magnetic recording body of the present invention is manufactured by subjecting it to surface smoothing processing or cutting it into a desired shape.

In this case, the orientation magnetic field is approximately 50025-3500 Gauss in alternating current or direct current, and the drying temperature is approximately 50-100 Gauss.
It is preferable that the temperature is about 0°C and the drying time is about 3 to 10 minutes.

The method for orienting the magnetic powder according to the present invention may be the method described in the following patents.

For example, U.S. Patent No. 1.949.840, U.S. Pat.
796, 359, 3,001,891, 3,172,776, 3,416,949, 3,473,960, 3,681,138. Specifications, Japanese Patent Publication No. 32-3427, No. 39-2836
No. 8, No. 40-23624, No. 40-23625,
No. 41-13181, No. 48-13043, No. 48
-39722, etc.

The orientation direction of the magnetic powder according to the present invention is determined depending on its use.

(θ) Effect: The magnetic recording medium according to the present invention has a hydrocarbon residue in the main chain having a mercapto group that has excellent affinity with the binder, as shown in the general formula described above. Because of this, it is well compatible with the binder and does not ooze out or form pinholes on the surface of the magnetic layer. In addition, these hydrocarbon residues having mercapto groups have lubricity, and together with the main chain consisting of an organic silicone compound with excellent lubricity, these hydrocarbon residues having mercapto groups also exert a lubricating effect. Therefore, the lubricity and wear resistance of the magnetic layer are further improved.

Furthermore, the magnetic paint using the above-mentioned mercapto-modified organosilicon compound can be used without impairing the dispersibility of the magnetic powder.
The durability and wear resistance of the magnetic layer can be improved.

(f) Examples Hereinafter, the content of the present invention will be specifically explained with reference to Examples and Comparative Examples. In addition, in the following Examples and Comparative Examples, "parts" means "parts by weight."

Example 1 ■ Magnetic paint containing CO-F+3205 magnetic powder 90 parts Polyurethane resin 16 parts cyclohexanone
60 parts methyl ethyl ketone 4
A mixture having a composition of 0 parts structural formula was placed in a ball mill, thoroughly mixed and dispersed, and then 4 parts of an isocyanate curing agent were added to obtain a black magnetic paint.

■ Magnetic tape Apply the above magnetic paint to one side of a polyethylene terephthalate film with a film thickness of 15 μm to a dry film thickness of 5 μm while applying a magnetic field.
It was coated so that it was μ.

The sample thus obtained was supercalendered and slit to produce a videotape with a width of 12.65 m.

This tape will be referred to as tape 1.

Example 2 In the composition of the magnetic paint in Example 1, vinyl chloride
Instead of vinyl acetate copolymer, nitrocellulose H-(
Tape 2 was a videotape obtained by the same treatment as in Example 1 except that the same amount of Asahi Kasei Corporation m (nitrocellulose) was used.

Example 3 In the composition of the magnetic paint in Example 1, the mixing ratio of the partially hydrolyzed vinyl chloride-vinyl acetate copolymer was set to 3 parts, and 5 parts of nitrocellulose H- (manufactured by Mukasei Co., Ltd.: Nitrocellulose) was added. A videotape treated in the same manner as in Example 1 was used as Tape 3.

Example 4 The same treatment as in Example 1 was carried out, except that in the composition of the magnetic paint in Example 1, the same amount of mercapto-modified organosilicon compound H represented by the following structural formula was used. A video tape was prepared by applying the following steps, and this was designated as Tape 4.

Example 5 The same treatment as in Example 4 was performed except that in the composition of the magnetic paint in Example 4, the same amount of nitrocellulose H- was used instead of the partially hydrolyzed vinyl chloride-vinyl acetate copolymer. The resulting video tape was designated as Tape 5.

Example 6 In the composition of the magnetic paint in Example 4, 8 parts of partially hydrolyzed vinyl chloride-vinyl acetate copolymer was used as 3 parts,
Tape 6 was a videotape obtained by carrying out the same treatment as in Example 1 except that 5 parts of nitrocellulose Hi was newly added.

Example 7 (1) Back layer The following composition was coated as a back layer on one side of a polyethylene terephthalate film with a thickness of 15 μm to form a layer with a dry thickness of 1 μm.

〔Composition〕

Polyurethane resin 2.5 parts Nitrocellulose H-0.5 parts Methyl ethyl ketone 50 parts (MIBK)
Methyl isobutyl ketone 50 parts Organosilicon compound polyisocyanate 0.3 parts Magnetic layer Next, a composition having the same composition as the magnetic paint in Example 1 was treated in the same manner as in Example 1 to prepare a magnetic paint. After that, this magnetic paint was applied to the polyethylene terephthalate film on which the back layer had been formed in step (2) above, while applying a magnetic field to the surface opposite to the back layer until the dry film thickness was 5 μm.
It was applied so that

(2) Magnetic tape Thereafter, the obtained sample was subjected to the same treatment as in step (2) of Example 1 to produce a video tape, which was designated as tape 7.

Example 8 A videotave was produced using a magnetic paint having the same composition as in Example 7, except that the mercapto-modified organosilicon compound was removed from the composition of the magnetic paint in Example 7, and by performing the same treatment as in Example 7. , this was designated as Tape 8.

Example 9 A videotape was prepared by applying a magnetic paint having the same composition as that of the magnetic paint in Example 4 and performing the same treatment as in Example 4, and on top of the magnetic layer, the back layer in Example 7 was applied. A composition similar to the composition to be formed was applied to form an overcoat layer with a dry film thickness of 1 μm, and the resulting tape was designated as Tape 9.

Example 10 In the composition of the magnetic paint in Example 9, a composition having the same composition as in Example 9 was used, except that the mercapto-modified organosilicon compound was removed, and the following treatment was the same as in Example 9. A video tape having an overcoat layer was prepared, and this was designated as tape 10.

Comparative Examples 1 to 6 In the composition of the magnetic paint in Example 1, the mercapto-modified organosilicon compound having the structural formula shown in Example 1 was replaced with a silicon compound having the structural formula listed in the second column of Table 1 below, respectively. Comparative tapes 1, 2, 3, 4, 5 and 6 were video tapes obtained by performing the same treatment as in Example 1, except that the following were used.

Table-1 Comparative Examples 7 to 12 In the composition of each magnetic paint in Comparative Examples 1 to 6,
Comparative tape 7. Comparative tapes were obtained by performing the same treatment as in Comparative Examples 1 to 6, except that the same amount of nitrocellulose Hi was used in each case instead of the partially hydrolyzed vinyl chloride-vinyl acetate copolymer. 8.9.10, 11 and 12.

Comparative Example 13 In the composition of the magnetic paint and the composition of the back layer coating in Example 7, the same amount of the compound of Comparative Example 2 was used in place of the mercapto-modified organic silicone compound in Example 7. A Pidio tape was prepared by performing the same treatment as in No. 7, and this was used as Comparative Tape No. 13.

Comparative Example 14 The same treatment as in Example 8 except that the same amount of the silicone compound in Comparative Example 2 was used in place of the mercapto-modified organosilicon compound in Example 8 in the composition of the back layer coating in Example 8. A videotape was prepared by applying the following steps, and this was designated as Comparative Tape 14.

Comparative Example 15 The same treatment as in Example 9 was performed, except that the same amount of the mercapto-modified organosilicon compound in Example 9 was used in the composition of the magnetic paint and the composition of the top coat layer in Example 9. Make a videotape,
The obtained tape was designated as Comparative Tape 15.

Comparative Example 16 In the composition of the coating of the top coat υ layer in Example 10,
A videotape was prepared in the same manner as in Example 10, except that the same amount of the siliconized metal of Comparative Example 6 was used in place of the mercapto-modified organosilicon compound in Example 10, and this was designated as Comparative Tape 16. .

The results of measurements of chroma S/N ratios according to Examples 1 to 10 and Comparative Examples 1 to 16 are shown in Table 2 below.

However, a) Running properties after 200 runs After the sample tape is repeatedly slid back and forth 200 times using a simulated head, it is placed on a VTR deck, and the disturbance of the TV screen due to poor running properties of the tape is measured by the magnitude of the skew value Δ
It is shown as B (absolute value). The skew value is the amount of timing deviation during image playback relative to the reference signal (a signal that takes 60 microseconds to scan from one end to the other on a CRT screen). In Table 2, ΔB<3μ8eQ.

3≦Δs<5psee.

5≦ΔS<8μsec.

and Δ≦8μ8eC The cases are indicated by ◎, ○, Δ and X marks, respectively.

(b) Chroma S/N ratio Chroma signal (3,58MW2) 0.714Vp-p
After recording on a luminance signal, it is played back, only the chroma signal is taken out, and the ratio of its effective value (S) to the noise level (N) from which the chroma signal is removed is expressed.

However, in Table 2, the values of the comparative sample (silicon oil) are used as the standard, and the values of other samples are expressed as relative values to this standard (indicated by 0).

Margin Table 2 below From the results in Table 2, it can be seen that the magnetic recording medium having a magnetic layer containing a mercapto-modified organosilicon compound according to the present invention has a magnetic layer containing other silicon compounds and other dispersants. Compared to other magnetic recording media, the running performance and Chroma S
It can be seen that both the /N ratio is excellent.

In particular, it was confirmed that running properties were further improved when the mercapto-modified organosilicon compound of the present invention was contained not only in the magnetic layer but also in the back layer or overcoat layer (Tape 7.9). Patent applicant Roku Konishi Photo Industry Co., Ltd. 39- Procedural amendment (voluntary) 158...3.1 8 Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case 1982 Patent application No. 23636 2, Title of the invention Magnetism Recording medium 3, Relationship with the case of the person making the amendment Patent application Person No. 2 Sasa, 1-26 Nishi-Shinjuku, Shinjuku-ku, Tokyo (Name) (127) Konishiroku Photo Industry Co., Ltd. 5, Amendment order Date None 6, Number of inventions increased by amendment None Column 8, [Detailed description of the invention], Contents of amendment 40-8, Contents of amendment (1) The scope of claims in the description was corrected as follows. do.

(1) On the support, the general formula, where X represents a hydrocarbon residue of O8-C8o, m is 0'-m≦1000, Ifin≦300, m+n
1. A magnetic recording medium comprising a mercapto-modified Yoiki silicon compound having a molecular weight of ≦1000.

1- (2) The statement "magnetic layer containing a con compound" on page 10, line 6 of the specification is corrected to "layer containing a con compound."

(3) The statements on page 22, lines 1 to 8 of the specification are corrected as follows.

Ester threads such as propyl, ethylene glycol monoacetate, diethylene glycol dimethyl ether, 2-
Ethers such as ethoxyethanol, tetrahydrofuran, and dioxane; Aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, and dichlorobenzene. reactor.

2- (4) The statement “Non-magnetic metals such as Zn, glass, porcelain, ceramics, etc.” on page 22, line 15 of the specification has been changed to “Z
n metals, glass, so-called new ceramics, etc.''

(5) Structural formula on page 28, line 8 of the specification, [ ” A certain description, [ 8HJ I am corrected.

3- (6) Structural formula on page 31, line 11 of the specification, [ 8H” of, " ” I am corrected.

(7) On page 36, line 13 of the specification, the statement ``The same lukabuto-modified organosilicon compounds, respectively'' was changed to ``In place of the lukabuto-modified organosilicon compounds, the silicon compounds of Comparative Example 6 were the same.'' do.

(8) "60 microseconds" on page 37, line 17 of the specification
A certain description has been corrected to "64 microseconds."

Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 23636 2 Name of the invention Magnetic recording medium 3 Person making the amendment Relationship to the case Patent applicant address Mr. 26-2 Nishi-Shinjuku 1-chome, Shinjuku-ku, Tokyo
Name) (127) Roku Konishi Photo Industry Co., Ltd. 6. Number of inventions increased by amendment N/A 7. "Detailed explanation of the invention" column of the specification subject to amendment (1) Specification page 15, 13- The description in the 14th line "...binder 10-400 parts by weight, preferably 30-200 parts by weight..." has been changed to "...binder 5-400 parts by weight..."
parts by weight, preferably 10 to 200 parts by weight...''

(2) On page 17, lines 13-14 of the specification, the description “...binder 100...” was replaced with “...ferromagnetic powder 1.
00...''.

(3) “…Binder 10” on page 18, line 7 of the specification
0..." is replaced with "...Ferromagnetic powder 100..."
・”.

(4) Specification Homare page 19 line 6 “...Binder 10
0..." is replaced with "...Ferromagnetic powder 100..."
・”.

Above 8. Contents of the amendment As shown in the attached document Procedural amendment (voluntary) September 30, 1980 Patent Application No. 23636 3. Relationship with the case of the person making the amendment Patent applicant 6. Inventions increased by the amendment No. 7. Subject of amendment (1) The statement on page 4, paragraph 6 of the procedural amendment review submitted on March 31, 1980 regarding the patent application in question is corrected to the following statement.

Record (6) Structural formula on page 31, line 11 of the specification, 8HJ of.

H I am corrected.

that's all

Claims (1)

[Scope of Claims] (]) On a support, a compound of the general formula, where X represents a hydrocarbon residue of 01 to σ3o, m is 0≦m<1000.1≦n≦300, m+n
1. A magnetic recording medium comprising a magnetic layer containing a mercapto-modified organosilicon compound of ≦1000.