JPH0281318A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent information of sticking matters on a head surface and to obtain excellent characteristics by adding at least two kinds of specific compounds selected as additives. CONSTITUTION:At least one kind of compound selected from organic silicon compounds expressed by formula I is used as a lubricant with at least one kind of ester expressed by formula II, a combination of at least one of these esters and at least one kind of ester selected from those expressed by formula III, or at least one kind of glycerol ester expressed by formula IV. In formula I, R1 represents alkyl groups having 11-17 carbons, R2 and R3 are methyl groups or fluoroalkyl groups, (k) and (l) are respectively integers from 0 to 7, (m) is from 0 to 18, (n) is from 0 to 5, and 0<=m+n<=18. Thereby, adhesion of a nonmagnetic layer onto the head surface can be prevented and excellent characteristics of the medium can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium, and more specifically, it is particularly advantageous in that it does not form a non-magnetic layer on the head surface and has low sliding noise. The present invention relates to providing an improved magnetic recording medium, such as a magnetic tape for a VTR, which exhibits excellent characteristics.

[Prior Art] Magnetic recording media such as magnetic tapes are usually used under harsh conditions, such as sliding at high speed with strong contact pressure with a head, and sometimes rubbing the same spot thousands of times in still mode.

For example, for a 215-inch VTR tape, even for a home VTR, the relative speed between the tape head is 5.8 m/h.
see, and therefore the tape is required to have high durability. In addition to a high level of continuous durability, especially when used in the still mode, tape running stability is also required when used under various environmental conditions. Therefore, attempts have been made to use various lubricants to meet these demands.

For example, known materials include the use of silicone oil, squalane, paraffin, etc.
39081 and Japanese Patent Publication No. 59-39810, the combined use of two or more different types of lubricants such as fatty acid-fatty acid ester, fatty acid-fatty acid ester-fatty acid amide, various fatty acids, fatty acid esters, etc. , fatty acid amides, higher alcohols, etc., have also been attempted to be used alone.

[Problems to be Solved by the Invention] As mentioned above, in the research and development of improving magnetic recording media such as VTR tapes, compounds selected from various fatty acids, long-chain alcohols, fatty acid amides, etc. have been used alone or in combination as lubricants. Research has been conducted on its use as an antidote, and it has been shown to be quite effective. However, the use of these compounds has by no means solved all problems, and many difficult questions still remain unsolved. For example, after conducting numerous running tests on various tapes using these compounds as lubricants, we found that some lubricants crystallize and form deposits on the tape contact surface of the head, and that some lubricants It has been found that the agent may react with the metal in the material of the head to form a nonmagnetic layer. When a nonmagnetic layer is formed on the head surface in this way, the increase in sliding noise, especially in the high frequency range, becomes significant, causing another big problem.

In today's VTR technology field, where the trend toward higher bands is increasing, noise reduction in the high frequency range is an urgent need, but the formation of deposits on the nonmagnetic layer as described above causes an increase in noise. Therefore, there is a need to carefully reconsider the suitability of the above-mentioned various compounds as lubricants from a different angle.

The present inventors conducted research to find the most suitable lubricant for magnetic recording media while considering the relationship between the structural characteristics of the various lubricants mentioned above and their advantages and disadvantages as a lubricant. , at least two or three of the following:
A lubricant consisting of a combination of different types of compounds is V
The present invention was achieved by discovering that the lubricant is extremely effective as a lubricant for magnetic recording media such as TR tapes.

[Means for Solving the Problem] In other words, in the course of research to develop a VTR tape with low sliding noise in a high frequency range, the present inventors discovered that non-conformities on the head surface, which cause an increase in sliding noise, were discovered. They realized that the formation of the magnetic layer had some relationship with the type of lubricant used for magnetic tape, and as a result of further investigation, they discovered that a nonmagnetic layer is formed when lubricants such as fatty acids, long-chain alcohols, and fatty acid amides are used. I learned that it's easy. Therefore, we conducted an experiment in which a nonmagnetic layer was deliberately formed and adhered to the head surface using such a type of lubricant, and we were also successful in taking an electron microscope photo of the deposit. As a result of detailed analysis and examination from various angles of various materials obtained through these series of studies, we found that -COOH, -OH, contained in lubricants such as fatty acids, long-chain alcohols, and fatty acid amides.
, -NH and other polar groups cause these lubricants to crystallize on the tape contact surface of the head or react with the metal in the head material to form a nonmagnetic layer. I was convinced of this.

On the other hand, it has been confirmed that when a hydrocarbon such as silicone oil or squalane is used as a lubricant, the above-mentioned crystallization and reaction on the head surface are small, and therefore, it is difficult to form a nonmagnetic layer. However, these lubricants such as silicone oil and squalane have poor compatibility with the binder and have the disadvantage that it is difficult to form a sufficient lubricant film on the tape surface.

In addition, these materials tend to bleed at high temperatures, and there is concern that they may stick to the cylinder.

Therefore, the inventors conducted intensive research to find a new type of lubricant that takes advantage of the advantages of these various known lubricants and eliminates their drawbacks, and finally developed the following new type of lubricant.

That is, in addition to at least one kind selected from the group of organosilicon compounds represented by the general formula (A) below, the following (
At least one selected from the group of esters represented by the general formula B) or at least one ester of (B)
A combination of a species and at least one selected from the group of esters represented by the following general formula (C), or the following (D)
By using at least one member selected from the group of glycerin esters represented by the formula (A) as a lubricant for magnetic tape, it has good compatibility with the binder and is easy to adhere to the head. It was confirmed that a good magnetic recording medium with little kimono formation could be obtained. That is, the present invention provides the above magnetic recording medium.

(Group 1) General formula (A): [wherein R1 represents an alkyl having 11 to 17 carbon atoms, and R and R3 are each independently represented by a methyl group or the formula -C2H4(CF2)kCF3 represents a fluorinated alkyl group, k represents an integer of 0 to 7, g represents an integer of 0 to 7, m-0 to 18, n-0
5, and 0≦m+n≦18, and when n-0, at least one of R and R3 is -CH(CF2
), CF3. At least one member selected from the group of organosilicon compounds represented by ]; and (Group ■) - at least one member selected from the group consisting of (a), (0) and (c) above: (a) General formula (B): RCOOR5 [where R4 represents an alkyl or alkenyl having 13 to 17 carbon atoms, and R5 represents an alkyl having 1 to 8 carbon atoms or an alkyl having a side chain of 4 to 12 carbon atoms]. at least one member selected from the group of represents an alkyl group having a side chain]; and General formula (C): RBCOOR7 [wherein R and R7 each independently represent an alkyl group having a side chain of
-22 alkyl]; and (c) general formula (D): [wherein RR and Rlo are each 8'9 independently , alkyl having 1 to 21 carbon atoms or 11 carbon atoms
~21 alkenyl, alcadenyl, or alkyl having a side chain. ] (However, when the total number of carbon atoms in R8, R9 and R10 is 13 or more and R8, R9 and Rlo are all alkyl, it is included in the glycerin ester of formula (D) The total number of carbon atoms shall be 24 or less.) A magnetic recording medium comprising a magnetic layer simultaneously containing at least one lubricant selected from the group consisting of: .

Here, the preferred usage amount of the organosilicon compound shown in (A) above is 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, based on the amount of magnetic powder, and the amount used in the above (B) Similarly, the preferred amount of the ester represented by or the glycerin ester represented by (D) above is 0.1 based on the amount of magnetic powder.
-10% by weight, more preferably 0.5-5% by weight, and the preferred amount of the ester represented by (C) is 0.05-3% by weight, preferably 0.05% by weight, based on the amount of magnetic powder. 1-1
Ball amount%.

[Function] The organosilicon compound represented by the general formula (A) above is a preferable lubricant that has excellent lubricity and is less likely to cause deposits on the head surface or reactions with the head surface. However, when used alone, the lubricating layer may be destroyed by the impact caused by the head when running at high speed, and there is a risk that the magnetic layer may adhere to the head. However, this problem arises when using the ester represented by the formula (B), the combination of two esters represented by the formulas (B) and (C), or the glycerin ester represented by the formula (D) above ( This problem could be solved by using it in combination with the organosilicon compound in A). The reason why R1 is defined as an alkyl having 11 to 17 carbon atoms is because when R is represented by the general formula CnH2o+1■, the organosilicon compound of the general formula (^) when n-1l-17 has a melting point of 20 to 50°C. This is because the compound has the best lubricity. The compound (A) corresponding to nm 9 is a compound with a melting point of 5 to 10° C., and even when added to a magnetic paint, a sufficient effect of lowering friction cannot be obtained. When n further increases to n-13, the friction tends to rise slightly and reaches the allowable limit at n-17.

Therefore, as the compound of formula (A), those with n-11 to n-17 are preferred, and those with n-11 or n-12 are particularly preferred.

The reason why g of the alkyl fluoride represented by -CH(CF, , ), CF3 is determined to be 0 to 7 is because when g exceeds 7, the compatibility with the binder becomes significantly poor. Similarly m>
18. n>5. The case where m+n>18 is also not preferred because the compatibility with the binder becomes poor.

Ester represented by general formula (B), or general formula (B
) and an ester represented by the general formula (C), or a glycerin ester represented by the general formula (D), in combination with an organosilicon compound represented by the general formula (A). It has been found that the drawbacks of using (A) alone can be compensated for.

The ester of formula (B), or the combination of esters of formula (B) and (C), or the glycerin ester of formula (D) forms a homogeneous mixture with the binder on the magnetic surface to form a protective film with excellent impact resistance. It is presumed that it forms a compound that compensates for the drawbacks of organic silicon compounds and further enhances their effects.

R4 of the ester represented by general formula (B) is C-13-
The reason why 17 is alkyl or alkenyl is because if C is smaller than 13, sufficient durability cannot be obtained, whereas if C is larger than 17, the compatibility with the binder becomes significantly poor. In addition, when R5 represents alkyl, it is set to C-1 to C-8 in order to avoid leaving an OH group, and the lower limit is set to 1.
Moreover, if the number of C exceeds 8, the desired lubricating effect cannot be obtained, so the upper limit was set at 8. When R5 is an alkyl having a side chain, the above limit is 4 and the upper limit is 12.
Since it was recognized that it should be C-4 to C-12.

The reason why R6 and R7 of the ester represented by general formula (C) are C-13-22 alkyl is the same as the reason for R4 above.

R8′ R9′ R10 in general formula (D) is C-
The reason for choosing alkyl from 1 to 21 is that monoesters or diesters with even one OH group remaining have poor moisture resistance, and the polar group OH remains, which causes the disadvantages mentioned above. However, even if R8, R
Even if 9 or R10 is C-1 methyl (CH3-), the above-mentioned preferred effect of use as a lubricant can be obtained if the H of OH of glycerin is replaced by this instead of remaining as it is. This is because it has been confirmed that However, if 'R8'R9' R10 is a group containing an unsaturated bond such as alkenyl or alcadenyl, or an alkyl group having a side chain, it is recognized that the desired effect cannot be obtained unless the number of carbon atoms is larger. C-
11 was set as the lower limit. On the other hand, if the number of C is too large, the desired lubricating effect cannot be obtained, and it has been recognized that the upper limit is C-21, so the number of carbon atoms for R8゜R9, Rlo is set to 1 to 21 for alkyl, C-11 for alkenyl, alcadenyl and alkyl with a side chain
~21. In addition, when the total number of carbon atoms in R8'R9' Rlo is 13 or more and R8'R9' R10 is selected from alkyl, if the total number of C's contained in the glycerin ester exceeds 24, the compatibility with the binder may be affected. Since the number of carbon atoms becomes significantly worse, the total number of carbon atoms is limited to 24.

As mentioned above, at least two compounds selected from each of the two groups (A) and (B) are combined, or at least one compound selected from each of the three groups (A), (B) and (C) is combined. under harsh conditions by using in a magnetic paint a combination of at least three compounds selected from the group (A) and (D) or a combination of at least two compounds selected from each of the two groups (A) and (D). A VT with excellent performance that does not form deposits on the head even when used, and therefore has low sliding noise in the high frequency range.
It was confirmed that R tape could be manufactured.

The present invention was researched and developed with the aim of solving the problem of head reaction and formation of young particles caused by lubricants, and is effective for all types of heads such as ferrite materials and metal materials. be.

The organosilicon compound represented by the general formula (^) used in carrying out the present invention is not limited to the following general formula (E) method.

Some synthesis examples are shown below.

Synthesis Example 400. and 800 g of toluene, heated to 80°C, and stirred to form a 5i-cn-containing organosilicon compound represented by the following formula [where R2r R3+ D + m+ n has the same meaning as above] and RCOO.
It can be easily synthesized by carrying out a dehydrochlorination reaction with a fatty acid represented by H (R1 is alkyl having 11 to 17 carbon atoms) in the presence of a hydrochloric acid scavenger such as pyridine or triethylamine. However, this is just an example, and the general formula (^
The 5l-CI-containing organosilicon compound represented by the synthesis of the compound 441sr7F4 was synthesized. After the dropwise addition was completed, the temperature was further increased, and a dehydrochlorination reaction was carried out for 5 hours under reflux of toluene. Next, after cooling, 101 g of triethylamine was added to neutralize the resulting amine hydrochloride, which was separated in a furnace, and the solution was distilled under reduced pressure to remove toluene, triethylamine, and other low-boiling substances, resulting in a melting point of 30"C. 727g of pale yellow solid
was gotten. When this product was examined by infrared absorption spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry, it was found to be an organosilicon compound represented by the following formula.

The following organic silicon compounds were synthesized according to the above method.

C2H4(CF2)7CF3 H30 CH(CF)CF Examples will be explained below.

Example 1 Acicular CO-containing γFe2O3 magnetic powder (BET 40r+f/g;, He 7600e)
100 parts by weight α-alumina (average particle size 0, 3u
n) 5 mm parts vinyl chloride-vinyl acetate copolymer 13 parts by weight polyurethane resin
8.7 parts by weight MEK:TL:ANON (5:3:
2) 260 weight weight solvent) The mixture of the above composition was mixed in a sand mill for 20 hours to uniformly disperse it, and then the following compounds 6 of the formulas <1), (N), and (Yama), respectively, were mixed. The specified amount was added as a lubricant, and the mixture was further mixed and dispersed for 30 minutes.

(i) 2 parts by weight [Compound of Synthesis Example [a]] CH(CH2), 6COOC4H 91 parts by weight [n-butyl stearate, that is, R in general formula (B) is C-17
, and R4 is C-4 alkyl] CH(CH) C00CR0.5 parts by weight [myristyl myristate, that is, R in the general formula (C) is c-ta alkyl, and Re is C- 14 alkyl compound] Next, 3.4 parts of an isocyanate crosslinking agent was added and mixed and dispersed for 30 minutes to prepare a magnetic paint.

The obtained magnetic paint was placed on a polyethylene terephthalate (PET) film with a thickness of 14 °C to a dry thickness of 5 tlra.
After coating, smoothing, orientation, and drying were performed, followed by mirror finishing and curing using a supercalender, and the film was cut into 1/2 inch width to produce a videotape.

With respect to the obtained tape, the sliding noise after running for 2 hours was measured using a predetermined sliding noise measuring system under the following conditions.

Measurement conditions Temperature, humidity 23℃, 10%RH Play mode SP Input IMΩ Resolution bandwidth 10kllz Video bandwidth 10011z Sweep time 65 seconds VH3VTR (BR3711 manufactured by Victor Japan Co., Ltd.)
, determine the system noise using a spectrum analyzer (Hyutread Packard Corporation HP-3585A), then determine the noise when playing each demagnetized sample tape, and calculate the difference between the noise during playback and the system noise. It was taken as sliding noise.

Furthermore, after measuring the sliding noise, the surface of the magnetic head was observed under a microscope to check for any deposits.If no deposits were observed on the tape contact surface of the head, it would be ``no'', and if no deposits were observed. Those that were recorded as “existing” were recorded. These test results, together with the results of other Examples and Comparative Examples, are the first
Shown in the table.

Example 2 Instead of (1) used in Example 1 as the organosilicon compound, 3 parts by weight of a compound represented by the following formula (lv) was used: (iv) [Compound of Synthesis Example [d]]; Ester In place of the compound of formula (li) used in Example 1, 0.5 parts by weight of a compound represented by the following formula (v) was used.

(v) CH3(CH2)14C00CH2CH(C2H5)(
CH2)3CH3[2-ethylhexyl palmitate, that is, R in general formula (B) is C-15 alkyl and R
Compound where 4 is C-7 alkyl having a side chain]
Furthermore, as another ester, 0.1 ffiffi part of a compound represented by the following formula (vl) was used in place of the compound of formula (iii) used in Example 1: (vi) CH3(CH2)2oCOOC22H45 [ Behenylbehenate, that is, a compound in which R5 in general formula (C) is C-21 alkyl and Re is C-22 alkyl]
: The same procedure as in Example 1 was repeated except for the above. The results are summarized in Table 1.

Example 3 Instead of (1) used in Example 1 as an organosilicon compound, a compound represented by the following formula (vll) (synthesis example [h
using 1 part by weight of the compound): (vii) [That is, R1 in the general formula (A) is C-15 alkyl, R and R3 are each methyl, and l, m
, n are 5. 5. 2]; Instead of (11) used in Example 1 as the ester, 1 part by weight of the compound represented by the following formula (viii) was used (
X: (viii) CH3 (CH2) 7CH fable CH (CH2) 7C00C1
8H35 [Oleyl oleate, that is, a compound in which R4 of the general formula (B) is C-17 alkenyl and R5 is C-18 alkenyl]: The formula used in Example 1 as another ester for Sara (
In place of the compound iii), 1 part by weight of a compound represented by the following formula (Lx) was used: (ix) CH(CH) C00C16H3 [
Stearyl stearate, that is, R in the general formula (C) is C
-17 Alkylalkyl Compound] The same procedure as in Example 1 was repeated except for the above. The results are summarized in Table 1.

Example 4 In place of (1) used in Example 1 as an organosilicon compound, 1.5 parts by weight of a compound represented by the following formula (x) (compound of Synthesis Example [c]) was used: (x) [ That is, in the general formula (A) (7;)R, is C-13 alkyl, R2 and R3 are -0 fluorinated alkyl, (1, m, and n are 0 and 0.2, respectively). A certain compound] ; Instead of (Ii) used in Example 1 as an ester, 0.5 parts by weight of a compound represented by the following formula (xi) was used: (xi) CH (CH2), 6COOCH3 [methyl stearate That is, R in general formula (B) is C-
A compound in which I7 is alkyl and R5 is C-1 alkyl] ; As yet another ester, the compound used in Example 1 (
In place of iii), 0.8 parts by weight of a compound represented by the following formula (xli) was used: (xii) CH (CH2) 12COOC14
H29 [Myristyl myristate, general formula (C)
Compound in which R is C-13 alkyl and R7 is C-14 alkyl] The same procedure as in Example 1 was repeated except for the above. The results are summarized in Table 1.

Example 5 As an organosilicon compound, 2 parts by weight of a compound represented by the following formula (xiii) (synthesis example [compound nl)] was used instead of (+) used in Example 1: (xiii) [i.e. , R1 in general formula (A) is a C-17 alkyl group, R2 and Ra are methyl groups, and g.

m and n are respectively 0 and 14. Compound that is 4]
;Other than that, the same procedure as in Example 1 was repeated.

The results were as shown in Table 1.

Example 6 As an organosilicon compound, instead of O) used in Example 1, a compound represented by the following formula (xlv) (synthesis example [f
using 1.5 parts by weight of the compound of f ]: (xiv) [That is, R1 of the general formula (A) is a C-13 alkyl, R is methyl, and R3 is a fluorinated alkyl of Ic -0 , and l, m, and n are each 0. 5.
Compound which is O] ; Furthermore, the compound of the formula (1
The following formula (X
Using 1 part by weight of the glycerin ester represented by V): (XV) Compound which is the alkyl of 1]; The same procedure as in Example 1 was repeated except for the above.

The results were as shown in Table 1.

Example 7 As an organosilicon compound, 0.7 parts by weight of a compound represented by the following formula (xvi) (synthesis example [compound of kl) was used instead of (xiv) used in Example 6 = (xvl) [That is, R8 in the general formula (D) is a C-17 alkenyl, and each of R9 and Rlo is C- [That is, R in the general formula (A) is a C-17 alkyl group,
R and R3 are methyl groups, and 0, m, and n are each 7. 6. Compound 2]; Instead of (XV) used in Example 6 as the glycerin ester, the following formula (xv
0.7 parts by weight of the compound represented by ii) was used.

(xvil) [That is, R8'R9' R10 of general formula (B)
[Compound where each is C-8 alkyl] The same procedure as in Example 6 was repeated except for the above. The results are summarized in Table 1.

Example 8 Instead of (xlv) used in Example 6 as an organosilicon compound, 3 parts by weight of a compound represented by the following formula (xviii) (compound of synthesis example [d]) was used = (xviil) [A compound in which R and R3 are methyl, and gm and n are each 0.1.0] Instead of (XV) used in Example 6 as a glycerin ester, the following formula (x
ix) 05 parts by weight of the compound represented by: (xix) [i.e.] In general formula (D), R8 is C-21 alkyl, and R9 and Rlo are each C-1 alkyl. A certain compound]; The same procedure as in Example 6 was repeated except for the above.

The results were as shown in Table 1.

Example 9 2 parts by weight of an organosilicon compound having the following formula as a lubricant: [i.e., R1 in general formula (A) is C-13 alkyl]
Compound of synthesis ρi [a]]; and n-butyl stearate Cl-13(CH2) 16COOC4H9 [i.e., R4 in general formula (B) is C-17 alkyl, R
Compound where 5 is C-4 alkyl] The same procedure as in Example 1 was repeated except that 1 part by weight of the combination was used. The results are summarized in Table 1.

Comparative Example 1 Same as Example 1 except that a combination of 2fflu parts of myristic acid (Cl3 (CH2) 1°C00H) and 1 part by weight of n-butyl stearate [CH3(CH2)16COoc4H9] was used as a lubricant. I repeated this. The results are summarized in Table 1.

Comparative Example 2 Autoorganic silicon compound 1.5 having the following formula as a lubricant
Parts by weight: [Synthesis example [compound of kl] and myristyl myristate [CH3(CH2)1゜C00C14H29] 0.5
Example 1 was repeated except that parts by weight were used.

The results are summarized in Table 1.

Table 1 [Effects of the Invention] It is clear from Table 1 that the magnetic recording medium of the present invention has at least two selected specific compounds as additives as explained above. As mentioned above, it is a recording medium that has excellent properties such that it does not form deposits on the head surface even when used for a long time under harsh conditions, and the sliding noise in the high frequency range of 10M1lz is extremely low. It was confirmed that there is.

Claims (1)

[Claims] 1. (Group I) General formula (A) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, in the formula, R_1 represents an alkyl having 11 to 17 carbon atoms, and R_2 and R_3 each independently represents a methyl group or a fluorinated alkyl group represented by the formula -C_2H_4(CF_2)_kCF_3, k represents an integer of 0 to 7, l represents an integer of 0 to 7, m = 0 to
18, n=0 to 5, and 0≦m+n≦1
8, and when n=0, at least one of R_2 and R_3 is -C_2H_4(CF_2)_lCF_3. ]; and (Group II) at least one member selected from the group consisting of the following (a), (b) and (c): (a) General formula ( B): R_4COOR_5 [where R_4 represents an alkyl or alkenyl having 13 to 17 carbon atoms, and R_5 represents an alkyl having 1 to 8 carbon atoms or an alkyl having a side chain having 4 to 12 carbon atoms]
At least one kind selected from the group of esters represented by Represents an alkyl having a side chain of numbers 4 to 12]
At least one member selected from the group of esters represented by; and from the group of esters represented by the general formula (C): R_6COOR_7 [where R_6 and R_7 each independently represent an alkyl having 13 to 22 carbon atoms] Combination with at least one selected type; and (c) General formula (D): ▲ Numerical formulas, chemical formulas, tables, etc. represents an alkyl group, an alkenyl group having 11 to 21 carbon atoms, an alkadienyl group, or an alkyl group having a side chain. ] (However, the total number of carbon atoms of R_8, R_9 and R_1_0 is 13 or more, and R_8R_9 and R
When all of _1_0 are alkyl, the total number of carbon atoms contained in the glycerin ester of formula (D) shall be 24 or less. 1. A magnetic recording medium comprising a magnetic layer simultaneously containing at least one lubricant selected from the group of: 2. The content of the organosilicon compound having the general formula (A) is 0.1 to 10% by weight based on the amount of magnetic powder, and the content of the ester having the general formula (B) is 0.1 to 10% by weight based on the amount of magnetic powder. The magnetic recording medium according to claim 1, wherein the amount is 0.1 to 10% by weight based on the amount of magnetic powder. 3. The content of the organosilicon compound having the general formula (A) is 0.5 to 5% by weight based on the amount of magnetic powder, and the content of the ester having the general formula (B) is 0.5 to 5% by weight based on the amount of magnetic powder. 3. The magnetic recording medium according to claim 2, wherein the amount is 0.5 to 5% by weight based on the amount of magnetic powder. 4. The content of the organosilicon compound having the general formula (A) is 0.1 to 10% by weight based on the amount of magnetic powder, and the content of the ester having the general formula (B) is magnetic. The content of the ester having the general formula (C) is 0.1 to 10% by weight based on the amount of magnetic powder, and the content is 0.05% based on the amount of magnetic powder.
The magnetic recording medium according to claim 1, wherein the amount is 3% by weight. 5. The content of the organosilicon compound having the general formula (A) is 0.5 to 5% by weight based on the amount of magnetic powder, and
The content of the ester having the general formula B) is 0.5 to 5% by weight based on the amount of the magnetic powder, and the amount of the ester having the general formula (C) is 0.5% to 5% by weight based on the amount of the magnetic powder. .1-1% by weight
The magnetic recording medium according to claim 4. 6. The content of the organosilicon compound having the above general formula (A) is 0.1 to 10% by weight based on the amount of magnetic powder, and the content of the glycerin ester having the above general formula (D) The magnetic recording medium according to claim 1, wherein the amount is 0.1 to 10% by weight based on the amount of magnetic powder. 7. The content of the organosilicon compound having the above general formula (A) is 0.5 to 5% by weight based on the amount of magnetic powder, and the content of the glycerin ester having the above general formula (D) 7. The magnetic recording medium according to claim 6, wherein the amount is 0.5 to 5% by weight based on the amount of magnetic powder.