JPH0349033A - Synthetic lubricating oil containing fluorine-contained ester - Google Patents

Abstract

PURPOSE:To assure an adhesive property and lubricity under any use conditions and to maintain a lubricating effect over a long period of time by compounding the resulted product of esterification of the perfluorodicarboxylic acid and fluorodiol expressed by prescribed formulas. CONSTITUTION:The synthetic lubricating oil is obtd. by compounding the resulted product of esterification of the perfluorodicarboxylic acid expressed by formula I and the fluorodiol expressed by formula II. In the formula I and the formula II, n is 2 to 10 integer; l, m, x, y are 1 to 3 integer. The perfluorodicarboxylic acid is preferably perfluorosuccinic acid, perfluoroadipic acid and perfluorosebacic acid. The fluorodiol is preferably the respective diols of n=4, 6, 8 or n=5, 7 in the formula II. The substitution of a part or the whole of the perfluorodicarboxylic acid of the formula I with aliphat. dicarboxylic acid and sulfurcontained dicarboxylic acid is possible as well.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a lubricant containing a fluorine-containing alkyl ester derivative that exhibits good lubricating action even in a low temperature range.

(bl) Conventional technology For example, in a ferromagnetic metal thin film type magnetic recording medium in which a ferromagnetic metal material is deposited on a polymer film by a method such as one-layer coating, and the ferromagnetic metal thin film is Because the smoothness is extremely good, the actual contact area is large, making it easier for adhesion phenomena (so-called sticking) to occur and increasing the coefficient of friction.There are many drawbacks in terms of durability and runnability, so we need to improve them. The use of various lubricants is being considered for this purpose.

In addition, there are various problems with surface lubricants for magnetic recording media, special lubricants used in molding thermoplastic resins, and special lubricants used in precision machinery.

That is, lubricants used for such special uses are required to have strict characteristics depending on the use, and it is currently difficult for well-known lubricants to meet these requirements satisfactorily.

(c) Problems to be Solved by the Invention A fluorine-containing oil agent can be considered as a solution to meet this demand. However, fluorine-containing oils generally lack polarity and have problems with solubility and compatibility with other resins, solvents, etc. For this reason, ester compounds of fluorinated alcohols and ester compounds of fluorinated carboxylic acids have been investigated, but they lack fluorine content, molecular weight, polarity, etc., and the desired lubricating properties have not been achieved as expected.

Therefore, the purpose of the present invention is to develop a new compound that maintains adhesion and lubricity under any conditions of use, and that maintains a lubricating effect for a long time simply by applying it to the surface. The object of the present invention is to provide a lubricant suitable for use in magnetic recording media of magnetic metal thin film type during the winter.

(dl Means for solving the problem, that is, the present invention is a synthetic lubricant prepared by blending an esterification product of a perfluorodicarboxylic acid represented by the general formula (1) and a fluorodiol represented by the general formula (2) or (3). It is related to oil.

HOOC(CF z)-COOH(11HO(CI-1
,)t(CFz),(CHz),OH(21CFz(C
Ft) n (CHz) Fluoroadipic acid and perfluorosebacic acid are preferred.

As the fluorodiol, diols of general formula (2) with n=4.6°8 and general formula (3) with n=5.7 are generally preferred.

In the present invention, it is also possible to replace part or all of the perfluorodicarboxylic acid of general formula (11) with an aliphatic dicarboxylic acid and/or a sulfur-containing dicarboxylic acid.

It is also possible to substitute part or all of the fluorodiol of general formula (2) or (3) with an aliphatic diol and/or a sulfur-containing diol and/or a nitrogen-containing diol.

However, the object of the present invention cannot be achieved unless at least one molecule of the perfluorodicarboxylic acid or fluorodiol is incorporated into the esterified product.

As the aliphatic dicarboxylic acid to be substituted, succinic acid, maleic acid, phthalic acid, fumaric acid, adipic acid, sebacic acid, dodecanedioic acid, malic acid, tartaric acid, etc. can be used, and as the sulfur-containing dicarboxylic acid, thiodiglycolic acid, thiodiglycolic acid, etc. can be used. Thiodipropionic acid, dithiodipropionic acid, etc. can be used.

Further, as the aliphatic diol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butanediol, hexanediol, etc. can be used.

As the sulfur-containing diol, thiodiglycol, bisphenol S and its ethylene oxide adduct, propylene oxide adduct, etc. can be used. Further, as the nitrogen-containing diol, an amino alcohol having a tertiary nitrogen represented by the following general formula (4) can be used.

X However, R: an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, or a phenyl group p: an integer of 1 to 3 Either a paint type in which a magnetic paint containing magnetic powder or the like is applied onto a support, or a thin film type magnetic recording medium in which a ferromagnetic metal thin film is directly applied to the support by methods such as vapor deposition, sputtering, ion blating, etc. can also be applied, but the effect is remarkable in thin film type. Furthermore, it may be applied to the surface layer of a back coat layer containing non-magnetic fibers.

In addition to the above lubricant for magnetic recording media, it can also be used as a synthetic lubricant such as a special lubricant for precision machinery, a heat-resistant lubricant, and a special lubricant for molding thermoplastic resins.

Furthermore, the ester compound thus obtained is waterproof.

Fiber treatment agents for various fibers such as antifouling fibers, surface treatment agents for paper and leather, antifouling paints, various waxes such as car wax, printing ink additives, back treatment agents for adhesive tapes, and mold release agents. It is also useful as a fluidity improver, a boiling resistance improver, an antifogging agent, etc., which are often used in plastics.

Next, specific examples of the compounds according to the present invention will be given.

Esterification product 1 Perfluoroadipic acid C1100c(CF2)4CO
O11) 1 mole and C4 fluorinated diol Cll0CI
IzCLC4FaCllzCIIz011) 1.2 mol of reaction product (acid value 2.5) esterification product 2 1 mol of perfluoroadipic acid and 0.04 fluorinated diol.
5 moles of reaction product (acid number 129) Esterification product 3 Perfluorosuccinic acid C1100c (CFri2COOI
I) Reaction product of 1 mol and 1.1 mol of propylene glycol (acid value 5.7) Esterification product 4 Perfluorosebacic acid Cl100c (CF□)acO
Otl) Reaction product of 1 mol and 0165 mol of butyljetanolamine (acid value 56) Esterification product 5 Thiodipropionic acid (HOOCCHzCHzSCHzC
Reaction product of 1 mol of C4 fluorinated diol (oxidation 1.5) Esterification product 6 0.5 mol of barfluoroadipic acid, 0.5 mol of adipic acid
Mol and C1 fluorinated diol 11 3 Methyl 15 Bentanediol 110 clhcIl□CIt CII□CI+□011
0.3 mol 113 In the case of a lubricant for magnetic recording media, the total amount applied to the surface of the magnetic layer is 0.5 to 30 μ/d, preferably 1 to 15 μ/d. When used as an overcoat layer for rust prevention, etc., the cough membrane thickness is preferably 20 to 300. If it is 300 Å or more, spacing loss is large;
If it is thinner than 20, the effect on lubricity will be reduced.

The above-mentioned fluorine-containing ester may be used alone as a lubricant, but it can also be used in combination with a conventionally known lubricant.

The lubricants used include fatty acids or their metal salts, fatty acid amides, fatty acid esters, fatty alcohols or their alcocytosorbitan esters, sulfur compounds, fatty acid mercaptans, silicone oil, barfluoroalkyl ethylene oxide, graphite, and carbon black. graph]・Polymer, tungsten disulfide, etc.

reaction product (acid value 4.1) A layer surface containing a mixture of these compounds is formed by the application of a paint, which coats the mixture of said compounds at zero
．． It consists of an organic solvent solution containing 0.05% to 1% by weight. Organic solvents for this purpose include toluene, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, xylene, benzene, cyclohexanone, methanol, ethanol, propatool, impropatol, butanol, ethyl cellosolve, methyl cellosolve, freon, etc. Single or mixed solvents are used.

(el Example Example 1 Co-N on polyethylene terephthalate with a thickness of 7 μm
1 (Ni 20% by weight) was deposited to a thickness of 1500 nm to form a metal thin film layer. At the same time as the vapor deposition, oxygen was blown onto the surface of the magnetic layer.

A lubricant as shown in Table 1 below is applied on this metal thin film layer.
．． Coating amount 1 of a solution diluted with Freon at a concentration of 0.05% by weight
The coating was coated at a rate of 0 .mu./rrl, dried, slit, and packed in a cassette to obtain a sample.

As is clear from the surface finish, all the products to which the present invention is applied have a small W friction coefficient, and have significantly improved running performance and durability.

Example 2 A two-batch type hard disk having a carbon layer on the top layer was immersed in a lubricant solution consisting of a 0.1% by weight trichlorotrifluoroethane solution of the esterification product 1 of the present invention, taken out, and then placed in an oven. Heat treatment was performed for 1 hour at 80'lll. The thickness of the lubricant film formed is 0.01μm
Met. I conducted an durability test on the hard disk using a CSS tester, but the μ value was 0 even after 20,000 cycles.
．． It was 5 or less. On the other hand, when perfluoropolyether oil was used in place of the esterification product of the present invention in the same method, the μ value exceeded 0.5 after 2000 cycles.

Example 3 The load bearing capacity of the fluorine-containing ester of the present invention was measured using a Soda type quaternary tester at a rotation speed of 22 Orpm, and a high-speed quaternary type friction tester at a chamber shaft rotation speed of 1500 rpm and a load of 1. The test was conducted under the conditions of 50 ktr and 30 minutes. The results are shown in Table-2.

As is clear from Table 2, the fluorine-containing ester of the present invention has better load-bearing capacity and wear resistance than conventional products, and can be used as a lubricant for various precision machines. Are better.

(f) Effects of the Invention The fluorine-containing esterified product of the present invention exhibits extremely excellent lubricity and is easy to synthesize and handle. Furthermore, by appropriately selecting the types and blending ratios of perfluorodicarboxylic acid and perfluorodiol,
The l and fluorine contents can be set in proportions as required, and desired properties can be obtained.

Therefore, if the fluorine-containing esterified product of the present invention is used alone or in combination with other components as a lubricant, it can be used not only in various machines but also in various machines.
In particular, it can be used as a lubricant for various materials such as metal, glass, silica gel, and graphite. Especially thin film magnetic tape,
Suitable as a lubricant for thin film magnetic disks, etc.

Claims (5)

[Claims] (1) A synthetic lubricating oil comprising an esterification product of a perfluorodicarboxylic acid represented by the general formula (1) and a fluorodiol represented by the general formula (2) or (3). HOOC(CF_2)_nCOOH(1) HO(CH_2)_l(CF_2)_n(CH_2)_
mOH (2) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ (3) However, n: An integer from 2 to 10 l, m, x, y: An integer from 1 to 3 (2) The synthetic lubricating oil according to claim 1, wherein part or all of the perfluorodicarboxylic acid is substituted with an aliphatic dicarboxylic acid and/or a sulfur-containing dicarboxylic acid. (3) The synthetic lubricating oil according to claim 1, wherein part or all of the fluorodiol is substituted with an aliphatic diol and/or a sulfur-containing diol and/or a nitrogen-containing diol. (4) a part of the perfluorodicarboxylic acid is substituted with an aliphatic dicarboxylic acid and/or a sulfur-containing dicarboxylic acid,
The synthetic lubricating oil according to claim 1, wherein a portion of the fluorodiol is substituted with an aliphatic diol and/or a sulfur-containing diol and/or a nitrogen-containing diol. (5) A magnetic recording medium comprising the esterification product according to claim 1 on the layer surface of the magnetic recording medium.