tertiary ammonium fatty acid salts, tertiary ammonium fatty acid salt compositions, lubricants for magnetic recording media, magnetic recording media, and manufacturing methods.

Abstract

To provide a lubricant capable of improving the durability of a magnetic recording medium, and to provide a magnetic recording medium with excellent durability when such a lubricant is applied. [Solution] A tertiary ammonium salt of fatty acid, represented by the following formula (1). TIFF2026145009000018.tif27131 (In formula (1), R represents a hydrocarbon group having 7 or more carbon atoms, and R1, R2, and R3 represent saturated hydrocarbon groups having 12 or fewer carbon atoms.) Also, a lubricant for magnetic recording media containing the fatty acid tertiary ammonium salt, and a magnetic recording media containing the lubricant for magnetic recording media.

Description

[Technical Field]

[0001] The present invention relates to tertiary ammonium fatty acid salts, tertiary ammonium fatty acid salt compositions, lubricants for magnetic recording media, magnetic recording media, and methods for producing them. [Background technology]

[0002] In magnetic recording systems using coated magnetic tape, such as LTO (Linear Tape-Open), lubricants are added to the magnetic recording medium to improve the coefficient of friction between the magnetic head and the magnetic tape, thereby enhancing durability. For the past 50 years or more, "long-chain hydrocarbon fatty acids and their esters" have been widely used as lubricants in coated magnetic tape (Non-Patent Literature 1). However, despite the dramatic increase in recording density of magnetic tape over the last 30 years—a 100-fold increase from LTO1 to LTO10 launched last year—the lubricant has remained unchanged for many years, still using "long-chain hydrocarbon fatty acids and their esters," with very few other lubricants being known. Technical responses to increasing recording density have been implemented through a combination of improvements to magnetic powder, base film, and process improvements to improve the dispersibility of magnetic powder, but all of these have reached their limits. Another method to improve electromagnetic conversion characteristics is to reduce spacing by smoothing the tape surface, but this increases friction and worsens durability. Therefore, the development of lubricants that reduce friction and improve durability is attracting attention. However, improving the properties of lubricants for coated magnetic tape applications has been difficult, and there has been little significant progress to date.

[0003] Among these, Patent Document 1 (Japanese Patent Publication No. 4-271012) discloses the use of a tertiary ammonium salt of a long-chain fatty acid as a lubricant for a coated magnetic recording medium. In the example of Patent Document 1, dimethylstearylammonium stearate is synthesized, and a composition obtained by mixing it with a magnetic material, resin component, and solvent is applied to a tape substrate to produce a magnetic layer containing the lubricant.

[0004] Patent Document 2 (Japanese Unexamined Patent Publication No. Hei 4-370520) discloses a long-chain fatty acid quaternary ammonium salt as a lubricant for magnetic recording media. In the example of Patent Document 2, a magnetic tape is produced by applying a long-chain fatty acid quaternary ammonium salt having 12 to 18 carbon atoms onto the surface of a ferromagnetic metal thin film with a film thickness of 200 nm.

[0005] Patent Document 3 (Japanese Unexamined Patent Publication No. Hei 4-372718) discloses a long-chain fatty acid ammonium salt (RCOO - HN + R1R2R3) for use as a lubricant for coating-type magnetic recording media. At least one of R, R1, R2 and R3 is a hydrocarbon having 10 or more carbon atoms or a halogen-containing hydrocarbon. In the example of Patent Document 3, a magnetic tape is produced with addition of dimethyl stearyl amine salt of stearic acid, primary amine salt of stearic acid and secondary amine salt of stearic acid. [Prior Art Documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Unexamined Patent Publication No. Hei 4-271012 [Patent Document 2] Japanese Unexamined Patent Publication No. Hei 4-370520 [Patent Document 3] Japanese Unexamined Patent Publication No. Hei 4-372718 [Non-Patent Documents]

[0007] [Non-Patent Document 1] NIKKEI MATERIALS & TECHNOLOGY Supplement: "Practical Encyclopedia of Materials", Nikkei BP Co., Ltd., August 1994, pp. 116-131 [Summary of the Invention] [Problem to be Solved by the Invention]

[0008] In recent years, the thinning of magnetic layers and the smoothing of tape surfaces have led to increased friction between the magnetic head and magnetic tape. Therefore, there is a need for a lubricant that can improve the coefficient of friction between the magnetic head and the magnetic recording medium, thereby enhancing the durability of the magnetic recording medium. One of the objectives of this invention is to provide a lubricant capable of improving the durability of a magnetic recording medium, and to provide a magnetic recording medium with superior durability when treated with such a lubricant. [Means for solving the problem]

[0009] Against the aforementioned background, the inventors focused on the molecular structure and composition of ammonium carboxylate salts and discovered that the frictional properties of magnetic tape could be greatly improved by optimizing the design. This disclosure relates to a tertiary ammonium salt of fatty acid represented by the following formula (1). [ka] (In formula (1), R represents a hydrocarbon group having 7 or more carbon atoms, and R1, R2, and R3 each represent a saturated hydrocarbon group having 12 or fewer carbon atoms.) The lubricant according to this disclosure is a lubricant for magnetic recording media that contains a tertiary ammonium fatty acid salt represented by formula (1) above.

[0010] This disclosure relates to a method for producing a composition, comprising reacting a fatty acid having 8 or more carbon atoms with a tertiary amine represented by formula (3) in a molar ratio of 1 to 10:1. TIFF2026145009000003.tif14163 (In formula (3), R1, R2, and R3 each represent saturated hydrocarbon groups with 12 or fewer carbon atoms.) [Effects of the Invention]

[0011] The tertiary ammonium fatty acid salt and the lubricant containing such tertiary ammonium fatty acid salt according to this disclosure provide a lubricant that suppresses crystallization of the lubricant and can improve the durability of magnetic recording media. Furthermore, a magnetic recording media with excellent durability is provided when such a lubricant is applied. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic cross-sectional view showing one embodiment of the magnetic recording medium according to this disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view showing one embodiment of the magnetic recording medium according to this disclosure. [Figure 3] Figure 3 is a schematic diagram showing a device for measuring high-speed friction characteristics. [Figure 4] Figure 4 shows microscopic images of the magnetic tape surfaces of Example 1 and Comparative Example 2. [Figure 5] Figure 5 is a schematic diagram showing a device for measuring friction characteristics. [Modes for carrying out the invention]

[0013] [Summary of the Embodiment] First, embodiments relating to this disclosure will be listed and described. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or greater and B or less". Embodiments combining different technical means are also included in the technical scope of the present invention.

[0014] This disclosure relates to a tertiary ammonium salt of fatty acid represented by the following formula (1). [ka] (In formula (1), R represents a hydrocarbon group having 7 or more carbon atoms, and R1, R2, and R3 each represent a saturated hydrocarbon group having 12 or fewer carbon atoms.)

[0015] Conventionally, it has been known to use organic ammonium salts of fatty acids as lubricants for magnetic recording media. On the other hand, with the thinning of the magnetic layer and the smoothing of the tape surface, friction between the magnetic head and the magnetic tape tends to increase. For this reason, conventional fatty acid salt-based lubricants have insufficient lubrication performance, and magnetic tapes coated with these lubricants sometimes exhibit insufficient practical characteristics, such as a decrease in playback output during tape running tests. In contrast, the fatty acid salt according to this disclosure is a salt of a long-chain fatty acid and a tertiary amine having a specific range of carbon chains. This compound can reduce the coefficient of friction of the magnetic tape compared to the prior art and improve the durability of the magnetic tape. Although not bound by theory, the compound according to this disclosure exhibits sufficient lubrication performance due to the balance of hydrocarbon groups present in the fatty acid and amine, and also suppresses crystallization of the lubricant on the magnetic tape. It is believed that the compound according to this disclosure maintains the affinity between the magnetic layer and the lubricant, resulting in a lower coefficient of friction.

[0016] In formula (1) above, R1 may be a saturated, straight-chain hydrocarbon group having 6 to 12 carbon atoms, and R2 and R3 may each be saturated hydrocarbon groups having 1 to 6 carbon atoms. When within this range, the effects of this disclosure are clearer.

[0017] This disclosure relates to a fatty acid tertiary ammonium salt compound represented by the following formula (2). [ka] (In formula (2), R represents a hydrocarbon group having 7 or more carbon atoms, and R4 represents a saturated hydrocarbon group having 6 to 12 carbon atoms.) Within this scope, the effects of this disclosure become clearer.

[0018] The fatty acid tertiary ammonium salt composition according to this disclosure comprises at least one of the fatty acid tertiary ammonium salts described in any of the above.

[0019] The lubricant for magnetic recording media according to this disclosure comprises at least one of the tertiary ammonium salts of fatty acids described in any of the above.

[0020] The magnetic recording medium according to this disclosure comprises a non-magnetic support and a magnetic layer laminated on the non-magnetic support, and includes a lubricant for the magnetic recording medium.

[0021] The magnetic recording medium may contain a lubricant for the magnetic recording medium in its magnetic layer.

[0022] The magnetic recording medium further comprises a lubricant layer laminated on the magnetic layer, and the lubricant layer may contain the lubricant for the magnetic recording medium.

[0023] This disclosure relates to a method for producing a composition, comprising reacting a fatty acid having 8 or more carbon atoms with a tertiary amine represented by formula (3) in a molar ratio of 1 to 10:1. TIFF2026145009000006.tif14163 (In formula (3), R1, R2, and R3 each represent saturated hydrocarbon groups with 12 or fewer carbon atoms.) This manufacturing method makes it possible to obtain a lubricant for magnetic recording media that has excellent lubrication performance and suppresses crystallization of the lubricant in magnetic tape.

[0024] [Specific examples of embodiments] The compounds, lubricants, and magnetic recording media related to this disclosure will be described in more detail below. [Tertiary ammonium salts of fatty acids] The fatty acid tertiary ammonium salt represented by formula (1) is a salt formed from a long-chain fatty acid and a tertiary ammonium compound. [ka] (In formula (1), R represents a hydrocarbon group having 7 or more carbon atoms, and R1, R2, and R3 each represent a saturated hydrocarbon group having 12 or fewer carbon atoms.)

[0025] In formula (1), R is a hydrocarbon group having 7 or more carbon atoms, and may be linear or branched. It may also be a saturated or unsaturated hydrocarbon group. R is preferably a saturated hydrocarbon. Furthermore, R is preferably a linear hydrocarbon. The number of carbon atoms in R may be 7 to 30, and from the viewpoint of frictional properties, 9 to 23 is preferred, and 11 to 23 is more preferred. Specifically, R can be a saturated hydrocarbon group such as n-heptyl group, n-octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, pentadecyl group, heptadecyl group and heneicosane group, or an unsaturated hydrocarbon group such as 8-heptadecenyl group and 8,11-heptadecadienyl group, with heptadecyl group, tridecyl group and pentadecyl group being preferred.

[0026] In other words, the fatty acids constituting the tertiary ammonium fatty acid salt according to this disclosure are fatty acids having 8 or more carbon atoms, and may be one or more selected from the group consisting of saturated fatty acids such as caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid, and unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, erucic acid, and elaidic acid. Preferably, at least one or more are selected from saturated fatty acids, more preferably saturated fatty acids having 7 to 30 carbon atoms, 9 to 23 carbon atoms, or 11 to 23 carbon atoms, even more preferably one or more are selected from the group consisting of stearic acid, myristic acid, and palmitic acid, and even more preferably fatty acids mainly composed of stearic acid. Note that "main component" means that stearic acid has the highest content among the fatty acids.

[0027] In formula (1), R1, R2, and R3 are each independently saturated hydrocarbon groups having 12 or fewer carbon atoms. R1, R2, and R3 may be the same or different from each other. R2 and R3 are preferably saturated hydrocarbon groups with fewer carbon atoms than R1, and having 12 or fewer carbon atoms. That is, of R1 to R3, R1 is preferably the longest hydrocarbon group, and R2 and R3 are preferably the same length as or shorter than R1. R1 preferably has 4 to 12 carbon atoms, more preferably 6 to 12, even more preferably 8 to 12, and particularly preferably 10 to 12, and is also preferably a saturated, linear hydrocarbon group. Examples of R1 include dodecyl, undecyl, decyl, nonyl, octyl, heptyl, hexyl, pentyl, butyl, and propyl groups, among which dodecyl, undecyl, decyl, nonyl, octyl, and hexyl groups are preferred.

[0028] The tertiary ammonium constituting the fatty acid tertiary ammonium salt according to this disclosure can be obtained from a tertiary amine represented by formula (3) as a raw material. TIFF2026145009000008.tif14163 (In formula (3), R1, R2, and R3 each represent saturated hydrocarbon groups with 12 or fewer carbon atoms.) Among tertiary amines, it is believed that by using a tertiary amine in which the longest hydrocarbon group has 12 or fewer carbon atoms, it is possible to achieve both high lubricity and dispersibility when applied to magnetic tape, suppress crystallization, and obtain a magnetic recording medium with excellent durability. When R is a hydrocarbon group with 17 or more carbon atoms, R1 preferably has 10 or fewer carbon atoms, and more preferably 9 or fewer.

[0029] R2 and R3 may be the same or different from each other. R2 and R3 are preferably saturated hydrocarbon groups having 1 to 6 carbon atoms. Examples of R2 and R3 include dodecyl, decyl, octyl, heptyl, hexyl, pentyl, butyl, propyl, ethyl, and methyl groups, among which butyl, propyl, ethyl, and methyl groups are preferred, and methyl groups are more preferred. From a manufacturing standpoint, it is preferable that both R2 and R3 are one of butyl, propyl, ethyl, or methyl groups, and it is even more preferable that both R2 and R3 are methyl groups.

[0030] The tertiary ammonium fatty acid salt according to this disclosure is more preferably a compound represented by the following formula (2). That is, the tertiary ammonium fatty acid salt according to this disclosure is more preferably a salt of a fatty acid and a dimethylalkyl (C6-C12)amine. Examples of tertiary amines include dimethyloctylamine, dimethyldecylamine, and dimethyldodecylamine. [ka] (In formula (2), R represents a hydrocarbon group having 7 or more carbon atoms, and R4 represents a saturated hydrocarbon group having 6 to 12 carbon atoms.) The compound represented by formula (2) is suitable as a lubricant for magnetic tape, reducing both the coefficient of friction during low-speed and high-speed tape operation. Furthermore, it is soluble in 2-butanone, which is commonly used as a solvent for forming the magnetic layer, and allows for the production of magnetic tape without significantly altering conventional magnetic tape manufacturing methods or conditions. In addition, crystallization of the lubricant on the surface of the magnetic tape is less likely to occur, and the lubricant can be applied at the desired concentration.

[0031] [Method for producing tertiary ammonium salts of fatty acids] The method for producing the tertiary ammonium salt of a fatty acid according to this disclosure is not particularly limited. For example, first, a tertiary amine compound having the target hydrocarbon group is synthesized. The tertiary amine compound can be synthesized from a secondary amine compound and an alkyl halide compound according to known methods. Alternatively, the tertiary amine compound may be a commercially available compound. Next, the tertiary amine compound and an equimolar amount of a fatty acid are dissolved in a solvent or without a solvent, heated under reflux, and then the solvent is removed to produce the salt. The tertiary amine compound and the fatty acid are usually mixed in equimolar amounts, but other ratios may be used, for example, the fatty acid and tertiary amine compound may be mixed in a molar ratio of 0.5 to 10:1. The solvent is not particularly limited as long as it can dissolve the tertiary amine compound and fatty acid used as raw materials, and may be, for example, ethanol, diethyl ether, 2-butanone, etc. Heating under reflux can be carried out, for example, at 35 to 80°C for 0.5 to 15 hours.

[0032] [Method for producing the composition] The composition according to this disclosure is a composition containing the aforementioned tertiary ammonium fatty acid salt, and can be produced by reacting a fatty acid having 8 or more carbon atoms with a tertiary amine represented by the aforementioned formula (3) in a molar ratio of 1 to 10:1. In producing the composition according to this disclosure, the fatty acid having 8 or more carbon atoms and the tertiary amine represented by formula (3) may be mixed in a molar ratio greater than 1 to 10:1, preferably in the range of 1.5 to 9:1, more preferably in the range of 2 to 8:1, and even more preferably in the range of 2 to 6:1. Except for the mixing ratio of the fatty acid and the tertiary amine, the composition according to this disclosure can be produced in the same manner as in the [Method for Producing Tertiary Ammonium Fatty Acid Salt]. When an excess amount of fatty acid is added to the tertiary amine compound, it is presumed that some of the fatty acid that did not directly react with the tertiary amine compound exists in an associated state around the tertiary ammonium fatty acid salt. The composition produced in this manner is suitable as a lubricant for magnetic recording media and has excellent lubricity.

[0033] The obtained compounds can be identified, for example, by nuclear magnetic resonance spectroscopy (NMR) or Fourier transform infrared spectroscopy (FTIR) measurements. When identifying compounds by NMR measurements, the methyl group of tetramethylsilane (TMS) is used as a standard. 1 The target compound can be identified by 1H-NMR measurement.

[0034] [Composition] The compositions according to this disclosure are compositions comprising at least one of the above-mentioned tertiary ammonium fatty acid salts. The compositions according to this disclosure may further contain components other than the above-mentioned tertiary ammonium fatty acid salts. When the composition contains components other than the above-mentioned tertiary ammonium fatty acid salts, the proportion of the tertiary ammonium fatty acid salt according to this disclosure to the whole composition is not limited as long as the effects according to this disclosure are obtained, but it is generally preferable to contain 10 wt% or more of the tertiary ammonium fatty acid salt represented by formula (1) or (2) above, more preferably 30 wt% or more, even more preferably 50 wt% or more, particularly preferably 80 wt% or more, and preferably substantially composed of the tertiary ammonium fatty acid salt represented by formula (1) or (2) above. The compositions according to this disclosure may also contain fatty acids and tertiary amines, which are raw materials for the above-mentioned tertiary ammonium fatty acid salts. The compositions according to this disclosure are solid, liquid or semi-solid at room temperature and may be provided as a powder or granular composition, or dissolved in a solvent and provided as a solution.

[0035] [Lubricant] The tertiary ammonium fatty acid salts and compositions described above according to this disclosure can be used as lubricants. The lubricants according to this disclosure include the tertiary ammonium fatty acid salts described above, or the tertiary ammonium fatty acid salt compositions described above. The lubricants according to this disclosure can be suitably used as lubricants for magnetic recording media, particularly as lubricants for magnetic tapes. Primary and secondary amines, which are sometimes used as lubricants for magnetic tapes, have active hydrogen and react with other components (e.g., isocyanates) used in the manufacture of magnetic recording media, reducing the strength of the magnetic layer coating and causing issues such as shedding of magnetic powder. On the other hand, the tertiary ammonium salts according to this disclosure are considered to have low reactivity and can maintain lubrication performance.

[0036] The tertiary ammonium salts or compositions described above are compounds that are solid, liquid, or semi-solid at room temperature, and may be provided as powders or granules, or as liquid lubricants. When applied to magnetic recording media (coated or added to a magnetic layer), it is preferable that the fatty acid tertiary ammonium salts or compositions described above be dissolved in a solvent as needed and used as a solution. Typically, when a lubricant is added to a magnetic layer, a magnetic powder, binder, and lubricant are mixed with a solvent, and this mixture is applied to a non-magnetic support and dried to form the magnetic layer. Examples of solvents used when applied to magnetic recording media include hydrocarbon solvents such as diisopropyl ether, n-hexane, 2-butanone (methyl ethyl ketone), toluene, and cyclohexanone, while examples of solvents used when coating include alcohol solvents such as isopropyl alcohol and ethanol. When used as a solution, the content of the tertiary ammonium salt compound according to this disclosure in the solvent-containing lubricant is not particularly limited as long as it does not impair the performance of the lubricant, but is preferably 0.001 to 40.0 g / L, and more preferably 0.05 to 20.0 g / L.

[0037] By using the lubricant according to this disclosure in a magnetic recording medium, excellent lubrication is maintained both during low-speed operation (e.g., at the start of magnetic tape operation) and high-speed operation. Furthermore, since the lubricant is less likely to precipitate on the surface of the magnetic recording medium, it can be mixed into the magnetic layer in a high-concentration solution or applied to the magnetic layer, and the lubricating effect is sustained even after long-term use. This provides excellent running performance and durability. While the lubricant according to this disclosure is suitable as a lubricant for magnetic recording media, it can also be applied as a lubricant to polymer films and other materials that do not contain a magnetic layer.

[0038] [Magnetic recording medium] The magnetic recording medium according to this disclosure comprises a non-magnetic support and a magnetic layer laminated on the non-magnetic support, and contains the above-mentioned lubricant. The magnetic layer may also contain the above-mentioned lubricant. The magnetic layer containing the lubricant means that the lubricant is internally added to the magnetic layer. When the lubricant is internally added, it seeps out onto the surface of the magnetic recording medium and exhibits lubricity. Furthermore, the magnetic recording medium according to this disclosure comprises a non-magnetic support and a magnetic layer laminated on the non-magnetic support, with a lubricant layer formed on the magnetic layer, and the lubricant layer may contain the above-mentioned lubricant. The non-magnetic support may also contain the above-mentioned lubricant. The lubricant in the non-magnetic layer plays a role in supplying lubricant to the magnetic layer. The lubricant may be contained in either the non-magnetic support or the magnetic layer, or in both.

[0039] Examples of magnetic recording media include magnetic tapes and magnetic disks. From the viewpoint of reducing the coefficient of friction and improving durability, magnetic tapes or magnetic disks are preferred as magnetic recording media.

[0040] Figure 1 is a schematic cross-sectional view showing the configuration of a magnetic tape according to this disclosure. Referring to Figure 1, the magnetic tape 1 is formed by laminating and integrating a magnetic layer 11, a non-magnetic layer 21, a base film 31, and a back coat layer 41 in this order. The non-magnetic layer and the base film constitute a non-magnetic support. In the magnetic tape of Figure 1, a lubricant is added to the magnetic layer 11. The lubricant may also be added to the magnetic layer 11, the non-magnetic layer 21, and / or the back coat layer. The magnetic layer 11 may be in the form of pigment and magnetic powder dispersed in an organic layer containing a binder and lubricant. The lubricant seeps from the inside of the magnetic layer 11 to the surface, thereby continuously maintaining a low coefficient of friction of the magnetic tape. The non-magnetic layer 21 may be in the form of pigment and / or non-magnetic powder dispersed in an organic layer containing a binder and lubricant. In addition, the magnetic layer 11 and the non-magnetic layer 21 may contain other additives. Examples of additives include dispersants, dispersing aids, fungicides, antistatic agents, and antioxidants.

[0041] The pigment contained in the magnetic layer 11 is not particularly limited as long as it is a component found in known magnetic tapes, and examples include abrasives such as alumina and carbon black powder. The magnetic powder contained in the magnetic layer 11 is not particularly limited as long as it is a component found in known magnetic tapes, and examples include ferromagnetic iron oxide particles such as γ-Fe2O3 and cobalt-coated γ-Fe2O3, ferromagnetic chromium dioxide particles, ferromagnetic metal particles made of metals such as Fe, Co, and Ni, and alloys containing these, and hexagonal plate-shaped hexagonal ferrite fine particles. Examples include hexagonal ferrite, epsilon-type iron oxide (ε-iron oxide), Co-containing spinel ferrite, gamma hematite, magnetite, chromium dioxide, and cobalt-coated iron oxide. The crystal structure of hexagonal ferrite is composed of at least iron atoms, divalent metal atoms, and oxygen atoms. Divalent metal atoms are metal atoms that can become divalent cations as ions, and examples include strontium atoms, barium atoms, alkaline earth metal atoms such as calcium atoms, and lead atoms. Examples of hexagonal ferrites include hexagonal strontium ferrite and hexagonal barium ferrite.

[0042] Examples of binders included in the organic layers constituting the magnetic layer 11 and the non-magnetic layer 21 include polymers such as vinyl chloride, vinyl acetate, vinyl alcohol, vinylidene chloride, acrylic acid esters, methacrylic acid esters, styrene, butadiene, and acrylonitrile, or copolymers combining two or more of these, polyurethane resins, polyester resins, epoxy resins, etc. Hydrophilic polar groups such as sulfonic acid groups, carboxyl groups, and phosphate groups may be introduced into the binder to improve the dispersibility of the magnetic powder. The binder is not particularly limited as long as it is generally used in magnetic tapes, and examples include crosslinked polyurethane resins or vinyl chloride resins, thermosetting resins, or reactive resins.

[0043] The base film 31 is a layer that functions as a support for the magnetic tape. Examples of materials for the base film 31 include polyester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polycyclohexylene dimethylene terephthalate (PCT), polyethylene-p-oxybenzoate (PEB), aramid (aromatic polyamide), polyethylene bisphenoxycarboxylate, etc., and one or more of these may be used in combination.

[0044] The back coat layer 41 is a layer for improving the running performance of the magnetic tape. The back coat layer 41 may contain a lubricant. Examples of materials for the back coat layer 41 include polyurethane resins containing carbon and calcium carbonate, nitrocellulose resins, polyester resins, etc.

[0045] Referring to Figure 2, in another embodiment of the present disclosure, the magnetic tape 2 has a lubricant layer 52, a magnetic layer 12, a non-magnetic layer 21, a base film 31, and a back coat layer 41 laminated in this order and integrated. In the magnetic tape 2 of Figure 2, the lubricant layer 52 is held on the surface of the magnetic layer 12, thereby reducing the coefficient of friction and maintaining the durability of the magnetic tape 2. The magnetic layer 12 may or may not contain a lubricant.

[0046] The specific dimensions of the magnetic tape are not particularly limited, but the thickness of the magnetic tape may be, for example, about 3 to 80 μm, and more specifically, about 3 to 10 μm. Generally, among the layers constituting the magnetic tape, the base film 31 has the greatest thickness. The thickness of the base film may be, for example, 3 to 80 μm, preferably 3 to 20 μm, and more preferably 3 to 10 μm.

[0047] The thickness of the magnetic layer 11 can be optimized according to the corresponding recording device and the bandwidth of the recording signal, and is not particularly limited, but from the viewpoint of high-density recording, it may be 10 nm to 150 nm, preferably 20 nm to 120 nm, and more preferably 30 nm to 100 nm. In a magnetic tape, at least one magnetic layer is sufficient, but two or more magnetic layers with different magnetic properties may be provided. If the magnetic layer includes multiple layers, the sum of the thicknesses of the multiple magnetic layers may be within the aforementioned range.

[0048] The thickness of the non-magnetic layer 21 is not particularly limited, but may be, for example, 10 nm to 500 nm, and preferably 50 nm to 300 nm. The thickness of the back coat layer 41 is not particularly limited, but may be, for example, 0.9 μm or less, and preferably 0.1 to 0.7 μm.

[0049] When a lubricant layer 52 is provided on the outermost surface of a magnetic tape, as shown in Figure 2 (magnetic tape 2), the thickness of the lubricant layer 52 may be, for example, about 0.1 to 10 nm, and preferably about 0.5 to 5 nm. Within this range, lubrication performance can be obtained while maintaining surface uniformity.

[0050] The thickness of each layer constituting a magnetic tape can be measured by known film thickness measurement methods. For example, the cross-section in the thickness direction of the magnetic tape can be exposed using known methods such as an ion beam or microtome, and then the exposed cross-section can be observed with a scanning electron microscope to determine the layer thickness from the obtained microscope image. Alternatively, the thickness of each layer can be determined as the design thickness calculated from the manufacturing conditions.

[0051] When the lubricant according to this disclosure is added to a magnetic layer, the content ratio of the lubricant in the magnetic layer is not limited as long as the effects according to this disclosure are obtained, but may be, for example, about 0.1 to 10 wt% or about 0.1 to 5.0 wt%, and preferably about 0.3 to 3.0 wt%. Within this range, lubrication performance can be obtained while maintaining surface uniformity.

[0052] When the lubricant according to this disclosure is applied as a lubricant layer to the surface of a magnetic tape, the amount of lubricant applied to the magnetic tape is not limited as long as the effects according to this disclosure are obtained, but for example, 0.1 to 5.0 mg / m² 2 It can be in the range of 0.5 to 3.0 mg / m². 2 It is preferable that the range be within this range. Within this range, lubrication performance can be obtained while maintaining surface uniformity.

[0053] [Examples] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0054] [Synthesis of compounds] The compounds of Examples 1-24 and Comparative Examples 1-3 were obtained by following the procedure below. Each compound was analyzed using the JEOL JNM-ECX400. 1 The structure was identified by 1H-NMR measurement. Chloroform-d was used as the solvent and TMS as the reference material.

[0055] <Amine Synthesis> As described below, an amine compound that is a raw material for a tertiary fatty acid ammonium salt was synthesized. • Compound 1 (dipropylhexylamine) (C3H7)2NH + C6H 13 Br → C6H 13 N(C3H7)2 Dipropylamine (4.43 g), 1-bromohexane (7.22 g), and potassium carbonate (6.87 g) were added to N,N-dimethylformamide (10 mL), and the mixture was heated and stirred at 60°C for 1 hour and at 70°C for 9 hours. After completion of the reaction, diethyl ether was added to the reaction mixture, the mixture was washed with water three times, the organic layer was dried over anhydrous sodium sulfate, and the solvent was removed. Thereafter, the obtained compound was dissolved in hexane, purified by short column chromatography using Wakogel 50NH2 with hexane as the eluent, and after removing the solvent, 7.00 g of Compound 1 was obtained. 1 1H NMR (400 MHz, CDCl3) δ (ppm): 2.375-2.325 (m, 6H), 1.459-1.403 (m, 6H), 1.281-1.251 (m, 6H), 0.883-0.833 (m, 9H)

[0056] • Compound 2 (dipropyloctylamine) (C3H7)2NH + C8H 17 Br → C8H 17 N(C3H7)2 Dipropylamine (3.79 g), 1-bromooctane (7.24 g), and potassium carbonate (6.21 g) were heated and stirred in N,N-dimethylformamide (10 mL) at 60°C for 30 minutes and at 70°C for 9 hours. After completion of the reaction, diethyl ether was added to the reaction mixture, the mixture was washed with water three times, the organic layer was dried over Na2SO4, and the solvent was removed. Thereafter, the obtained compound was dissolved in hexane, purified by short column chromatography using Wakogel 50NH2 with hexane as the eluent, and after removing the solvent, 7.46 g of Compound 2 was obtained. 1H NMR(400MHz,CDCl3) δ(ppm):2.393-2.326(m, 6H), 1.749-1.370(m, 6H), 1.301-1.254(m, 10H), 0.880-0.833(m, 9H)

[0057] Compound 3 (Dipropyldecylamine) (C3H7)2NH + C 10 H 21 Br → C 10 H 21 N(C3H7)2 Dipropylamine (3.65 g), 1-bromodecane (7.97 g), and potassium carbonate (5.78 g) were heated and stirred in N,N-dimethylformamide (10 mL) at 60°C for 1 hour and then at 70°C for 10 hours. After the reaction was complete, diethyl ether was added to the reaction mixture and washed three times with water. The organic layer was dried over anhydrous sodium sulfate to remove the solvent. The resulting compound was then dissolved in hexane and purified by short column chromatography using a Wako Gel 50NH2. After solvent removal, 8.23 ​​g of compound 3 was obtained. 1 H NMR(400MHz,CDCl3) δ(ppm):2.395-2.329(m, 6H), 1.481-1.388(m, 6H), 1.301-1.246(m, 14H), 0.881-0.835(m, 9H)

[0058] • Compound 4 (Dipropyldodecylamine) (C3H7)2NH + C 12 H 25 Br → C 12 H 25 N(C3H7)2 Dipropylamine (3.09 g), 1-bromododecane (7.61 g), and potassium carbonate (4.79 g) were added to N,N-dimethylformamide (10 mL), and the mixture was heated and stirred at 60°C for 1 hour, then at 70°C for 8 hours. After the reaction was complete, diethyl ether was added to the reaction mixture, and it was washed three times with water. The organic layer was dried over anhydrous sodium sulfate to remove the solvent. The mixture was then purified by short column chromatography using Wako Gel 50 NH2 in hexane, and after solvent removal, 7.49 g of compound 4 was obtained. 1 H NMR(400MHz,CDCl3) δ(ppm):2.392-2.325(m, 6H), 1.479-1.385(m, 6H), 1.283-1.204(m, 18H), 0.871-0.834(m, 9H)

[0059] Compound 5 (Dibutyldodecylamine) (C4H9)2NH + C 12 H 25 Br → C 12 H 25 N(C4H9)2 Dibutylamine (3.65 g), 1-bromododecane (7.03 g), and potassium carbonate (4.22 g) were added to N,N-dimethylformamide (10 mL), and the mixture was heated and stirred at 60°C for 1 hour, then at 70°C for 13 hours. After the reaction was complete, diethyl ether was added to the reaction mixture, and it was washed three times with water. The organic layer was dried over anhydrous sodium sulfate to remove the solvent. The mixture was then purified by short column chromatography using Wako Gel 50 NH2 in hexane, and after solvent removal, 7.67 g of compound 5 was obtained. 1 H NMR(400MHz,CDCl3) δ(ppm):2.388-2.340(m, 6H), 1.428-1.353(m, 6H), 1.298-1.240(m, 22H), 0.909-0.844(m, 9H)

[0060] • Compound 6 (ethylmethyldodecylamine) (C2H5)CH3NH + C 12 H 25 Br → C12 H 25 N(C2H5)CH3 N-ethylmethylamine (7.59 g), 1-bromododecane (19.37 g), and potassium carbonate (12.60 g) were heated and stirred at 60°C for 1 hour, then at 70°C for 1 hour, and finally at 90°C for 1 hour. After the reaction was complete, water and diethyl ether were added to the reaction mixture, and the organic layer was washed three times with water. The organic layer was then dried over anhydrous sodium sulfate to remove the solvent. Subsequently, the mixture was purified by distillation under reduced pressure (82-85°C / 50 Pa) using a rotary vacuum pump to obtain 11.57 g of compound 6. 1 H NMR(400MHz,CDCl3) δ(ppm):2.382 (q / 7.2Hz, 2H), 2.285(t / 7.8Hz, 2H), 2.186(s, 3H), 1.380-1.490(m, 2H), 1.180-1.290(m, 18H), 1.035(t / 7.2Hz, 3H), 0.865(7.6Hz, 3H)

[0061] <Example 1> Dimethyldodecylamine and an equivalent amount of stearic acid were dissolved in ethanol and heated under reflux for 1 hour. The solvent was then removed to obtain the desired dimethyldodecylammonium stearate. 1 H NMR (500MHz, CDCl3) δ(ppm): 2.606 (m, 2H), 2.469(s, 6H), 2.245(t / J=7.5Hz, 2H), 1.594(m, 4H), 1.304-1.245(m, 46H), 0.873(t / J=6.8Hz, 6H)

[0062] <Example 2> The desired dimethyldecylammonium stearate was obtained in the same manner as in Example 1, except that dimethyldodecylamine was replaced with dimethyldecylamine. 1H NMR (500MHz, CDCl3) δ(ppm): 2.601 (m. 2H), 2.471(s, 6H), 2.248(t / J=7.5Hz, 2H), 1.596(m, 4H), 1.300-1.248(m, 42H), 0.876(t / J=6.8Hz, 6H)

[0063] <Example 3> The desired dimethyloctylammonium stearate was obtained in the same manner as in Example 1, except that dimethyldodecylamine was replaced with dimethyloctylamine. 1 H NMR (500MHz, CDCl3) δ(ppm): 2.604 (m. 2H), 2.467(s, 6H), 2.248(t / J=7.5Hz, 2H), 1.597(m, 4H), 1.310-1.250(m, 38H), 0.874(t / J=6.8Hz, 6H)

[0064] <Example 4> Dimethylhexylamine and an equivalent amount of stearic acid were heated and stirred at 80°C for 1 hour to obtain dimethylhexylammonium stearate. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.759-2.684 (m. 2H), 2.549(s, 6H), 2.277(t / J=7.6Hz, 2H), 1.677-1.545(m, 4H), 1.373-1.174(m, 34H), 0.938-0.836(m, 6H)

[0065] <Example 5> Dimethyldodecylamine and an equivalent amount of octanoic acid were heated and stirred at 80°C for 1 hour to obtain dimethyldodecylammonium octanoate. 1H NMR (400MHz, CDCl3) δ(ppm): 2.644-2.574 (m. 2H), 2.465(s, 6H), 2.239(t / J=8.0Hz, 2H), 1.667-1.516(m, 4H), 1.360-1.200(m, 26H), 0.840-0.918(m, 6H)

[0066] <Example 6> Dimethyldodecylammonium decanoate was obtained in the same manner as in Example 5, except that octanoic acid was replaced with decanoic acid. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.652-2.534 (m. 2H), 2.451(s, 6H), 2.247(t / J=8.0Hz, 2H), 1.695-1.501(m, 4H), 1.376-1.196(m, 30H), 0.805-0.941(m, 6H)

[0067] <Example 7> Dimethyldodecylammonium undecanoate was obtained in the same manner as in Example 5, except that octanoic acid was replaced with undecanoic acid. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.630-2.546 (m. 2H), 2.451(s, 6H), 2.247(t / J=8.0Hz, 2H), 1.676-1.504(m, 4H), 1.376-1.196(m, 30H), 0.805-0.941(m, 6H)

[0068] <Example 8> Dimethyldodecylammonium dodecanoate was obtained in the same manner as in Example 5, except that octanoic acid was replaced with dodecanoic acid. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.644-2.525(m. 2H), 2.446(s, 6H), 2.30-2.28(m, 2H), 1.692-1.495(m, 4H), 1.386-1.161(m, 34H), 0.805-0.941(m, 6H)

[0069] <Example 9> Dimethyldodecylammonium myristate salt was obtained in the same manner as in Example 5, except that octanoic acid was replaced with myristic acid. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.648-2.564 (m. 2H), 2.463(s, 6H), 2.237(t / J=7.5Hz, 2H), 1.677-1.517(m, 4H), 1.373-1.171(m, 38H), 0.909-0.844(m, 6H)

[0070] <Example 10> Dimethyldodecylammonium eicosanoate was obtained in the same manner as in Example 5, except that octanoic acid was replaced with eicosanoic acid. 1 H NMR (400MHz, CDCl3) δ(ppm):2.591(t / J=8.2Hz, 2H), 2.422(s, 6H), 2.227(t / J=7.6Hz, 2H), 1.625-1.502(m, 4H), 1.269-1.235(m, 50H), 0.861(t / J=6.6Hz, 6H)

[0071] <Example 11> The reaction was carried out in the same manner as in Example 5, with octanoic acid replaced by docosahexaenoic acid and dimethyldodecylamine replaced by dimethylhexylamine, to obtain dimethylhexylammonium docosahexaenoic acid. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.666-2.605(m 2H), 2.484(s, 6H), 2.254(t / J=7.5Hz, 2H), 1.644-1.549(m, 4H), 1.348-1.224(m, 44H), 0.878(t / J=6.8Hz, 6H)

[0072] <Example 12> Octanoic acid was replaced with dodecanoic acid, and dimethyldodecylamine was replaced with compound 6 (ethylmethyldodecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain ethylmethyldodecylammonium dodecanoate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.827-2.773(q / J=7.3Hz, 2H), 2.693-2.650(m, 2H),2.466(s, 3H), 2.256-2.217(t / J=7.3Hz, 2H), 1.662-1.530(m, 4H), 1.373-1.211(m, 34H), 1.206-1.160(t / J=7.3Hz, 3H), 0.906-0.852(m, 6H)

[0073] <Example 13> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 6 (ethylmethyldodecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain ethylmethyldodecylammonium stearate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.813-2.758(q / J=7.3Hz, 2H), 2.678-2.637(m, 2H),2.455(s, 3H), 2.258-2.220(t / J=7.3Hz, 2H), 1.677-1.538(m, 4H), 1.371-1.208(m, 46H), 1.196-1.159(t / J=7.3Hz, 3H), 0.898-0.863(t / J=7.0Hz, 6H)

[0074] <Example 14> The reaction was carried out in the same manner as in Example 5, with octanoic acid replaced by dodecanoic acid and dimethyldodecylamine replaced by compound 2 (dipropyloctylamine), to obtain dipropyloctylammonium dodecanoate. 1H NMR (400MHz, CDCl3) δ(ppm):2.715-2.686(m, 6H), 2.226-2.221(m, 2H), 1.632-1.537(m, 8H), 1.276-1.236(m, 26H), 0.925-0.845(m, 12H)

[0075] <Example 15> Octanoic acid was replaced with dodecanoic acid, and dimethyldodecylamine was replaced with compound 3 (dipropyldecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyldecylammonium dodecanoate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.671-2.630(m, 6H), 2.239(t / J=7.6Hz, 2H), 1.597-1.519(m, 8H), 1.261-1.238(m, 30H), 0.919-0.845(m, 12H)

[0076] <Example 16> The reaction was carried out in the same manner as in Example 5, with octanoic acid replaced by myristic acid and dimethyldodecylamine replaced by compound 2 (dipropyloctylamine), to obtain dipropyloctylammonium myristate salt. 1 H NMR (400MHz, CDCl3) δ(ppm):2.715-2.607(m, 6H), 2.234(t / J=7.6Hz, 2H), 1.561(quintet / J=7.6Hz, 8H), 1.263-1.235(m, 30H), 0.920-0.846(m, 12H)

[0077] <Example 17> Octanoic acid was replaced with myristic acid, and dimethyldodecylamine was replaced with compound 3 (dipropyldecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyldecylammonium myristate salt. 1H NMR (400MHz, CDCl3) δ(ppm):2.691-2.621(m, 6H), 2.235(t / J=7.6Hz, 2H), 1.613-1.515(m, 8H), 1.318-1.236(m, 34H), 0.917-0.848(m, 12H)

[0078] <Example 18> Octanoic acid was replaced with palmitic acid, and dimethyldodecylamine was replaced with compound 2 (dipropyloctylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyloctylammonium palmitate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.723-2.652(m, 6H), 2.244(t / J=7.8Hz, 2H), 1.616-1.527(m, 8H), 1.265-1.235(m, 34H), 0.922-0.848(m, 12H)

[0079] <Example 19> Octanoic acid was replaced with palmitic acid, and dimethyldodecylamine was replaced with compound 3 (dipropyldecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyldecylammonium palmitate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.695-2.625(m, 6H), 2.237(t / J=7.8Hz, 2H), 1.614-1.518(m, 8H), 1.606-1.234(m, 38H), 0.882(quintet / J=7.3Hz, 12H)

[0080] <Example 20> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 1 (dipropylhexylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropylhexylammonium stearate. 1H NMR (400MHz, CDCl3) δ(ppm): 2.857-2.730 (m, 6H), 2.250(t / J=9.1Hz, 2H), 1.696-1.503(m, 8H), 1.367-1.191(m, 34H), 0.979-0.833(m, 12H)

[0081] <Example 21> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 2 (dipropyloctylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyloctylammonium stearate. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.804-2.684 (m, 6H), 2.238(t / J=7.5Hz, 2H), 1.664-1.500(m, 8H), 1.359-1.191(m, 38H), 0.960-0.827(m, 12H)

[0082] <Example 22> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 3 (dipropyldecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyldecylammonium stearate. 1 H NMR (400MHz, CDCl3) δ(ppm): 2.757-2.644 (m, 6H), 2.230(t / J=7.5Hz, 2H), 1.658-1.481(m, 8H), 1.361-1.193(m, 42H), 0.968-0.828(m, 12H)

[0083] <Example 23> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 4 (dipropyldodecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dipropyldodecylammonium stearate. 1H NMR (400MHz, CDCl3) δ(ppm): 2.756-2.647 (m, 6H), 2.236(t / J=7.5Hz, 2H), 1.661-1.489(m, 8H), 1.364-1.178(m, 46H), 0.953-0.833(m, 12H)

[0084] <Example 24> Octanoic acid was replaced with stearic acid, and dimethyldodecylamine was replaced with compound 5 (dibutyldodecylamine), and the reaction was carried out in the same manner as in Example 5 to obtain dibutyldodecylammonium stearate. 1 H NMR (400MHz, CDCl3) δ(ppm):2.746-2.695(m, 6H), 2.211(t / J=7.8Hz, 2H), 1.562-1.505(m, 8H), 1.298-1.236(m, 50H), 0.934-0.844(m, 12H)

[0085] <Comparative Example 1> The desired dimethyltetradecylammonium stearate was obtained in the same manner as in Example 1, except that dimethyldodecylamine was replaced with dimethyltetradecylamine.

[0086] <Comparative Example 2> The desired dimethyloctadecylammonium stearate was obtained in the same manner as in Example 1, except that dimethyldodecylamine was replaced with dimethyloctadecylamine.

[0087] <Comparative Example 3> Trimethyldodecylammonium stearate was synthesized from the corresponding trimethyldodecylammonium bromide by ion exchange, as described in reference to, for example, J. Porous Mater (2018) Vol. 25, pp. 935-943.

[0088] [Friction Characteristics Evaluation 1] [Preparation of evaluation samples (magnetic recording media)] The compounds obtained in Examples 1-3 and Comparative Examples 1-3 were dissolved in a solvent (isopropyl alcohol (IPA) or diisopropyl ether (DIPE)) to concentrations of 0.1 wt%, 0.5 wt%, and 1.0 wt%, respectively. The resulting solutions were coated onto the surface of a magnetic tape (Fujifilm Corporation, LTO Ultrium9) with a wet thickness of 4 μm, and the solvent was evaporated by natural drying for 2 hours to prepare magnetic recording media for evaluation. As a blank, a sample was prepared by coating only the surface of a magnetic tape with a solvent.

[0089] [Evaluation of magnetic recording media] (1) Surface precipitation The surface of each evaluation sample was observed under a microscope to check for the presence or absence of lubricant deposition on the tape surface. Lubricant deposition on the sample surface impairs the smoothness and uniformity of the magnetic tape surface. (2)Low speed friction characteristics Friction was measured using a friction and wear testing machine (Tribogear) TYPE 40 manufactured by Shinto Kagaku Co., Ltd. under the following test conditions. Test ball: SUJ2 (10mm diameter) Load capacity: 50gf Sliding speed: 1.0 mm / sec. Sliding distance: 5 mm, 5 reciprocating motions Tests were conducted at three different locations on the evaluation sample, and the arithmetic mean of the obtained friction coefficients was defined as the friction coefficient (u). The low-speed friction coefficient was defined as the value obtained by normalizing the friction coefficient (u) with respect to the blank friction coefficient (u0) (u std = u / u0). (3) High-speed friction characteristics Friction was measured using a friction measuring device equipped with a magnetic tape fixing part having a load sensor and a rotatable AlTiC cylinder (radius 3.0 cm) according to the following procedure. A schematic diagram of the friction measuring device is shown in Figure 3. In Figure 3, the friction measuring device 3 comprises a fixing part 31, a weight 32, and a rotating body 33, and the evaluation sample S is fixed at one end to the fixing part 31 and at the other end to the weight 32. 1. One end of the sample for evaluation was secured with the tape fixing part, the magnetic tape was hung over the outer circumference of the cylinder, and a weight (100g) was attached to the other end before it was placed on the measuring machine. 2. The test was started by rotating the cylinder at a sliding speed of 0.1 m / s under stable conditions of temperature: 21-25°C and relative humidity: 40-60%. 3. The average value of the coefficient of kinetic friction was measured between 90 and 100 seconds after the start of the test. 4. The average value of the kinetic friction coefficient of the blank was set to 1.0, and the relative value of the average kinetic friction coefficient of each evaluation sample was calculated. This value was defined as the high-speed friction coefficient.

[0090] Table 1 shows the structural formulas and evaluation results of the compounds in Examples 1-3 and Comparative Examples 1-3. In Table 1, "-" indicates that crystal precipitation occurred on the surface of the sample. For samples where crystal precipitation occurred, the coefficient of friction was not measured because the surface was not uniform. [Table 1]

[0091] As shown in Table 1, no surface deposition occurred on the magnetic recording media treated with the compounds of Examples 1 to 3, regardless of the concentration (0.1 wt%, 0.5 wt%, and 1.0 wt%). In contrast, surface deposition occurred on the magnetic recording media treated with the compounds of Comparative Examples 1 to 3 at concentrations of 0.5 wt% and 1.0 wt%. Figure 4 shows surface photographs of the magnetic recording media of Example 1 (0.5 wt%, 1.0 wt%) and Comparative Example 2 (0.5 wt%, 1.0 wt%). The scale bar in the photograph is 20 μm. As shown in Figure 4, no deposition was observed on the surface of the magnetic recording media in Example 1, whereas crystallized lubricant was observed in Comparative Example 2.

[0092] Regarding the low-speed friction coefficient, at 0.1 wt%, the magnetic recording media of Examples 1-3 showed reduced friction relative to the blank, achieving an effect equivalent to Comparative Examples 1-3. At 0.5 wt% and 1.0 wt%, precipitation occurred in all of Comparative Examples 1-3, and therefore the friction coefficient could not be reduced by increasing the concentration, whereas Examples 1-3 all showed a significant friction reduction effect. Regarding the high-speed friction coefficient, at 0.1 wt%, the magnetic recording media of Examples 1 to 3 exhibited reduced friction relative to the blank, achieving a greater friction reduction effect than Comparative Examples 1 to 3. At 0.5 wt% and 1.0 wt%, precipitation occurred in all of Comparative Examples 1 to 3, whereas no precipitation occurred in Examples 1 to 3, demonstrating a significant friction reduction effect.

[0093] In the above test, the evaluation was performed on a sample in which a lubricating layer was created on top of a magnetic layer. However, since the same solvent is used when the lubricant is added to the magnetic layer, it is expected that a similar trend will be observed.

[0094] [Friction Characteristics Evaluation 2] [Preparation of evaluation samples (magnetic recording media)] The compounds obtained in Examples 1-24 and Comparative Examples 1-3 were dissolved in isopropyl alcohol (IPA) to concentrations of 0.5 wt% and 1.0 wt%, respectively. Existing lubricants were removed from commercially available magnetic tape (Fujifilm Corporation, LTO Ultrium 9) by immersion in hexane at room temperature for 10 minutes. The solutions containing each compound were applied as a bar coat to the surface of the magnetic tape from which the existing lubricant had been removed, with a wet thickness of 4 μm. The solution was then allowed to air dry for 2 hours to evaporate the solvent, and a magnetic recording medium for evaluation was prepared. A commercially available magnetic tape was used as a blank sample.

[0095] [Evaluation of magnetic recording media] The friction characteristics were evaluated in accordance with ECMA-319. Friction was measured using a friction tester equipped with a load cell having a magnetic tape fixing part and a fixed AlTiC material slider (cylindrical, φ=7mm) following the procedure below. A schematic diagram of the friction measuring machine is shown in Figure 5. Referring to Figure 5, the friction measuring machine 7 comprises a load cell 71, a slider 75, and a cylinder 76, with the load cell 71 fixed to a ball screw 73 driven by a motor 72. Since the cylinder 76 rotates, the friction due to the cylinder 76 can be ignored. The evaluation sample S is fixed at one end to the load cell 71 and at the other end to a weight 77. 1. One end of the evaluation sample S was fixed to the load cell 71 with the tape fixing part, and the evaluation sample S was hung around the outer circumference of the slider 75 and cylinder 76 so that the wrapping angle with respect to the slider 75 was 180°, and a weight (50g) was attached to the other end and the measurement device was set up. 2. Under stable conditions of 21-25°C and 40-60% relative humidity, the load cell 71 was moved back and forth at a sliding speed of 0.5 mm / sec. over a one-way distance of 20 mm. 3. The average value of the kinetic friction coefficient was calculated for the 4th to 8th reciprocating motions out of 10. The average value of the kinetic friction coefficient of the blank sample (LTO9 tape) was set to 1.0, and the relative values ​​of each evaluation sample were calculated and evaluated as friction characteristics. Friction characteristics = (Average value of the dynamic friction coefficient of the evaluation sample) / (Average value of the dynamic friction coefficient of the blank sample)

[0096] Table 2 shows the structural formulas and evaluation results of the compounds in Examples 1-4 and Comparative Examples 1 and 2. In Table 2, "-" indicates that crystal precipitation occurred on the surface of the sample. For samples where crystal precipitation occurred, the coefficient of friction was not measured because the surface was not uniform. Note that the substituents R, R1, R2, and R3 in Tables 2 and 3 correspond to R, R1, R2, and R3 in formula (1). [ka]

[0097] [Table 2]

[0098] As shown in Table 2, no surface deposition occurred on the magnetic recording media treated with the compounds of Examples 1 to 4, regardless of whether the concentration was 0.5 wt% or 1.0 wt%. In contrast, surface deposition occurred on the magnetic recording media treated with the compounds of Comparative Examples 1 and 2, both at 0.5 wt% and 1.0 wt% concentrations. These results are consistent with those shown in Table 1. Furthermore, similar to the friction characteristic evaluation method 1 (a method in which the slider rotates relative to a fixed tape), it was confirmed that friction was significantly reduced in Examples 1 to 4 using the friction characteristic evaluation method 2 (a method in which the tape reciprocates relative to a fixed slider).

[0099] Table 3 summarizes the structural formulas and evaluation results of the compounds in Examples 5 to 24. Note that Table 3 also includes the results for Example 1, as shown in Table 2.

[0100] [Table 3]

[0101] As shown in Table 3, tertiary ammonium fatty acid salts in which R is 7 or greater and R1, R2, and R3 are saturated hydrocarbon groups with 12 or fewer carbon atoms each did not exhibit surface precipitation at either 0.5 wt% or 1.0 wt% concentrations. Furthermore, friction was reduced compared to the blank sample (commercially available magnetic tape). In particular, for R with 9 to 17 carbon atoms, the frictional properties at 1.0 wt% were 0.7 or less, indicating a significant reduction in friction and confirming superior frictional properties. Compounds with R1 having 10 or fewer carbon atoms were found to tend to exhibit reduced friction.

[0102] [Production of the composition] The fatty acids and amine compounds in the proportions listed in Table 4 were heated and stirred at 80°C for 1 hour to obtain the compositions of Examples 25 to 33. In Comparative Example 4, commercially available fatty acids were used as is. Each composition was prepared using a JEOL JNM-ECX400. 1The structure was identified by 1H-NMR measurement. Chloroform-d was used as the solvent and TMS as the reference material. For Examples 25-33 and Comparative Example 4, the method for preparing the evaluation sample (magnetic recording medium) and the method for evaluating the magnetic recording medium were the same as in [Friction Characteristic Evaluation 2] for friction characteristic evaluation.

[0103] Table 4 shows the evaluation results for Examples 1, 4, 5, 9, 11, 25-33 and Comparative Example 4. Note that Table 4 also includes the results for the examples shown in Tables 2 and 3. In Table 4, "-" indicates that crystal precipitation occurred on the surface of the sample. For samples with crystal precipitation, the friction coefficient was not measured due to the non-uniform surface. [Table 4]

[0104] As shown in Table 4, compositions were prepared by reacting fatty acids with 8 or more carbon atoms with alkyldimethylamines with 6 to 12 carbon atoms in a molar ratio of 1 to 8:1. All examples showed good lubricity compared to the blank sample. When a 0.5 wt% solution was applied to a magnetic tape, no surface precipitation occurred even in compositions prepared with an excess of fatty acid. Furthermore, comparisons between Example 5 and Example 25, Example 9 and Examples 26-28, Example 4 and Examples 29 and 30, Example 1 and Example 31, and Example 11 and Examples 32 and 33 confirmed that friction was significantly reduced and that the compositions exhibited superior frictional properties compared to the examples in which fatty acids and alkyldimethylamines were reacted in equimolar amounts.

[0105] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the present invention is defined by the claims and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of Symbols]

[0106] 1,2 Magnetic tape, 11,12 Magnetic layer, 21 Non-magnetic layer, 31 Base film, 41 Back coat layer, 51 Lubricant layer, 3 friction measuring device, 31 fixed part, 32 weight, 33 rotating body, 7 Friction measuring instrument, 71 Load cell, 72 Motor, 73 Ball screw, 75 Slider, 76 Cylinder, Weight, 77 S Sample for evaluation.

Claims

1. A tertiary ammonium salt of a fatty acid, represented by the following formula (1). 【Chemistry 1】 (In formula (1), R is a hydrocarbon group having 7 or more carbon atoms, R １ , R ２ and R ３ (Each of these represents a saturated hydrocarbon group with 12 or fewer carbon atoms.)

2. In the above formula (1), R １ R is a saturated, straight-chain hydrocarbon group having 6 to 12 carbon atoms. ２ and R ３ The fatty acid tertiary ammonium salt according to claim 1, wherein each of the groups is a saturated hydrocarbon group having 1 to 6 carbon atoms.

3. A tertiary ammonium salt of a fatty acid, represented by the following formula (2). 【Chemistry 2】 (In formula (2), R is a hydrocarbon group having 7 or more carbon atoms, R ４ (This indicates a saturated hydrocarbon group with 6 to 12 carbon atoms.)

4. A tertiary ammonium fatty acid salt composition comprising at least one of the tertiary ammonium fatty acid salts described in claim 1 or 3.

5. A lubricant for magnetic recording media comprising at least one of the tertiary ammonium salts of fatty acids described in claim 1 or 3.

6. A magnetic recording medium comprising a non-magnetic support and a magnetic layer laminated on the non-magnetic support, and containing the lubricant for magnetic recording media described in claim 5.

7. The magnetic recording medium according to claim 6, wherein the magnetic layer includes the lubricant for the magnetic recording medium.

8. The magnetic recording medium according to claim 6, further comprising a lubricant layer laminated on the magnetic layer, wherein the lubricant layer contains the lubricant for the magnetic recording medium.

9. A method for producing a composition obtained by reacting a fatty acid having 8 or more carbon atoms with a tertiary amine represented by formula (3) in a molar ratio of 1 to 10:

1. (In formula (3), R １ , R ２ and R ３ each represent a saturated hydrocarbon group having 12 or less carbon atoms)

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