JPS5898841A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To enhance traveling stability and durability, by adding a specified org. silicone compd. into a magnetic layer. CONSTITUTION:A magnetic layer consisting mainly of a magnetic powder and a binder contains an org. silicone compd. represented by the formula (R1, R2 are -CH3 or -R3ONO2, R3 is 1-26C hydrocarbon group, and n1, n2 are each an integer shown as follows: 0<=n1<1,000, 1<=n2<500, n1+n2<=1,000) having polar groups represented by -R3ONO2 superior in compatibility with the binder, on the main chainor on it and at both its ends.

Description

[Detailed description of the invention]

The present invention relates to a magnetic recording medium, and an object thereof is to provide a magnetic recording medium that improves the lubricity and wear resistance of a magnetic layer and has excellent running stability and durability. In general, M body J-Kff such as polyester film
Magnetic recording media such as magnetic tapes, which are made by applying magnetic paints made from four-property powders, binders, organic solvents, and their base materials, are made by applying magnetic paints such as powders, binders, organic solvents, and other materials. #'7 'l'!1
The friction coefficient of the layer is required to be small and the running stability is excellent, and the compatibility is a little difficult because the recording head is violently squeezed during recording [1]. <
It is required to have excellent durability. Because of this, the oil in the magnetic layer? Conventionally, lubricants such as silicone oil have been incorporated into the magnetic layer to improve the if properties and l111.11 flux properties. It has been proposed that a magnetic layer is modified with a fatty acid represented by (1) or (II) and/or mixed with a high quality silicone compound in the magnetic layer. Lucky number 7-21 saturated 1+ or unfi t1 differentiated hydrogen group, n 0-50
indicates an integer. ) 11 0 CH,. (However, in the formula, R1, R2 Muyo and R5 (! element 32" f7
~2] saturated or unsaturated hydrocarbon group, m is 1 to 10
An integer of 0, n an integer of 0 to 250, m + n≦
300, m≧n15. ) Regarding A, there is a problem that silicone oil has poor lubricity and compatibility with the recurved binder, which makes the magnetic layer inhomogeneous and causes pinholes or tends to leak excessively onto the surface of the magnetic layer. , 捷fc +i'l ;fr', 'I
Q A lipid-modified organosilicone complex represented by the formula (I) and r): fll) d, both ends; 11/
Since it has 7 acid residues, the compatibility with the binder is 0.
19th tl, Zhao Qingz 1 elephant (111 t1 te B (moth layer's lubricity j? Yohi abrasion resistance e! As a result of extensive investigation into this situation, the inventors found that the general formula (wherein R5 and R are -C[16-R5
(') NO2 and R3 represent a carbonyl hydrogen group with a prime number of 1 to 26, n and n2 digits 0≦n1, 1000, 1≦02
It is an integer of ≦500, n, +-n 2≦1000. ) When the organic silicone oil expressed as 4. The magnetism, lubricity and wear resistance of 5. 0, This invention & iJ? The modified organosilicone compound used in this invention has -R,ON(')2(
R,H hydrocarbon water VM) has strong polarity and has a modified group that is highly compatible with the binder, so it is easily compatible with the binder, and therefore, it exudes moderately on the surface of the outer layer. , excessive oozing or pinballing may occur on the surface of the magnetic layer. In addition, these highly polar modified groups have good lubricity and are made of organic silicone compounds with excellent lubricity. These modified groups as well as the main chain exhibit an excellent anti-oxidant effect, which further improves the lubricity and wear resistance of the magnetic layer.Especially, the lubricity and wear resistance of the magnetic layer are further improved. If the magnetic layer also has these modified 4<, the effect is significant, and therefore, according to the present invention, the 4゛4 slipping does not excessively ooze out on the surface of the magnetic layer or cause pinholes. The lubricity and wear resistance of the magnetic layer are sufficiently improved without causing any damage, and a magnetic@1 recording medium with excellent running stability and durability can be obtained. In the compound, a modified group compound represented by -R3ONo2 or a saturated or unsaturated hydrocarbon group represented by the general formula CnH2n or CnH2n -2 with a carbon number of 1
It is preferable that the number of carbon atoms be in the range of 26 to 26 and a concave shape. If the number of carbon atoms is less than 1, the improvement in Is wear resistance will not be sufficient, and if it exceeds 26, there is a risk that the P fll property will be reduced. Specific examples of such modifying groups include, for example, C2I
I 4ON() 2, Cs Summer J1oONO2
, -C1o)■2ooNO2, -C261-15□0N
O2, -C2■]2ON02, and the like. R1 and R2 are a methyl group or the same modified group as above,
When R1 and 1(2) are the same modified groups as mentioned above, the compatibility with the binder becomes even better and moderately high, and the lubricity and abrasion resistance of the magnetic layer are improved. -r> and direction -1-. Note that R1, L, and R2 may be the same or different /1.In addition, the degree of polymerization, that is, the general formula σ+n, jOi and n2
is O≦n 1<1000.1≦02≦500, n□
10n2≦100 (an integer of 1 (preferably 2, n
If □ and n2 are too large, 11 molecules will be dissolved in the solvent and φu<4

[The modified organosilicone compound of the present invention can be used alone as a coating material to improve lubricity and abrasion resistance. However, it is also possible to use a mixture of two or more.The effect is exhibited when it is contained in the magnetic layer in an amount of 0.1% by weight or more based on the magnetic powder, and the increase in the content However, if the Bi content exceeds 10% Bi based on the magnetic powder, it may slightly ooze out onto the surface of the magnetic layer, contaminating the magnetic head, and reducing the output. In order to form a gold layer, a polygonal organic silicone compound of 1973 was added to the layer. This can be carried out by mixing and dispersing the magnetic paint with -1 and the like, applying the paint onto a substrate such as a polyester film, and drying it. The silico compound compound is dissolved in a suitable solvent, and according to popular belief, the solution is first applied to a pre-formed magnetic cloth or sprayed onto a magnetic layer. V in the solution
C soak? It may be performed with 1ilL. Do you use Q7 here? For example, r-
Fe20, powder, Fes 04 powder, Co-containing r-Fe203 powder, CopiiFe, 04 powder, C
It includes a wide range of conventionally known 411, C-C, Fe powder, C (+ powder, Fe--Ni powder, etc.). 1. HX vinyl chloride as a binder
6'1-vinyl thread copolymer, vinyl 7 resin,
Acrylonitrile-butashigon compound, co↑[combined, vinylfunral thread resin, polyurethane thread resin, fiber thread resin, incyanate compound, etc., which are usually used as binders for magnetic powders, are all used. But vinyl chloride-vinyl acetate copolymer, cellulose resin, etc. Urethane thread resin and the like are preferably used. The organic solvent is not particularly limited, and solvents used to dissolve the modified organosilicone compound of the present invention and Ingu, for example, ketone solvents such as acetone, methyl isobutyl ketone, methyl ethyl ketone, and isochlorohexanone. , ester solvents such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as benzene, toluene, and xylene, alcohol solvents such as isopropyl alcohol, acid amide solvents such as dimethylformamide, and ether solvents such as tetrahydrofuran and dioxane. Solvents and the like may be used alone or in combination of two or more. Incidentally, commonly used persimmon additives such as dispersants, abrasives, antistatic agents, etc. may be optionally added to the magnetic paint. Next, I will explain the 74 actual cases of this invention. Example 1 Using a modified organic silicone compound expressed by a convex structure, f(
1, Co-containing Fe205 magnetic powder s (l n
E tri MISVAGHf United States U, C, C Nel-:
iiJ, cyclization 10 〃Hinyl-vinyl acetate-dinylalyl copolymer) Pantex"r-5250 (large 8 〃honingi'f+-'n, urethane elastomer) Coronate L (E1 polyurethane 2 〃industrial A magnetic paint was prepared by mixing and dispersing a mixture of composition 1 in a ball mill for 70 hours. Apply this magnetic paint to a polyester film of
1-, Ifc: 9', applied to a dry thickness of 5μ,
After drying and surface treatment, it was 3.8 mm [1
I cut it into pieces and made magnetic tape. Example 2 In the composition of the magnetic paint in Example 1, Jitsugi Example IK
A magnetic tape was prepared in the same manner as in Example 1, except that the modified organic silicone compound represented by the structural formula -F was used in the same amount as the modified organic silicone compound represented by the structural formula -F. 115 Comparative Example 1 Actual 11 Examples], [: Can it be done? N41'i: Paint) 1M1. l+Q, K-b E(, Real 1ij11
Example I Instead of a modified organosilicone compound of the structural formula K, a dimethylborisiloxane oil (represented by the structure i47 of F) is used (it f11!).
River left +, 6-+ tJ' Same as in Example 1, G
Make R sea tape. Comparative Example 2 Example 1. In the composition of the 6μ paint in Example 1, the same amount of myristic acid-modified silicone compound represented by the following structural formula was used in place of the modified organic silicone compound having the structural formula shown in Example 1. 1
I made magnetic tape in the same way. +1 1 0 CH5 The magnetic tapes obtained in each example and each comparative example were tested for durability, and the coefficient of friction was determined to be 11. Durability test '#↓1 was carried out under the conditions of 35°C and 180%RH.
Each magnet 1t5. Tape head load i'f [10g, travel M
Is it running at 4.8 cm/sec and generating FIF, output? The number of runs until the output drops by 3 dBfl from the 7J 191 output is measured.
The coefficient of friction with the magnetic head after running twice was measured. The table below shows the results. As is clear from the table, the magnetic tape obtained by the present invention (Examples 1 and 2) is different from that of the conventional magnetic tape (Comparative Example 1).
and 2), all of which have small coefficients of friction and good durability, which shows that the magnetic recording medium provided by the present invention has excellent stability and durability.

Claims (1)

[Claims] 1 General formula (wherein R and R2 are -CH3 or -R5ON
O2 and R3 represent a hydrogen group having 1 to 26 carbon atoms, and n
and n2 is 0≦n, <1000, 1≦n2≦500
, n1+02≦1000. ) A magnetic recording medium having a magnetic layer containing a silicone compound represented by