JPH0633082A - Ester lubricant base - Google Patents

Abstract

(57) [Summary] [Structure] Trimethylolpropane or trimethylol-
A complex ester composed of an oxyethylene adduct of rupropane and a mixed carboxylic acid of a monocarboxylic acid and a polycarboxylic acid, wherein the mixed carboxylic acid is a polycarboxylic acid or a monocarboxylic acid having 12 or more carbon atoms. 40 mol% or more of carboxylic acid and
Kinematic viscosity at ℃ is 80 centistokes or more, pour point is 0
Ester-based lubricant bases at or below ° C. [Effect] In metalworking work, it has excellent thermal oxidation stability and lubricity, and is less affected by dirt on the machine.
It is possible to provide an ester-based lubricating base having excellent high temperature detergency and low temperature fluidity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ester-based lubricating base material, and more particularly, to a lubricating base material for metalworking, which has excellent thermal oxidation stability and lubricity, and high temperature detergency and low temperature fluidity. It relates to an excellent ester-based lubricant base.

[0002]

2. Description of the Related Art In recent years, as the performance and speed of metal working machines have increased, the conditions under which lubricants have been used have become more severe, and metal working oils such as wire drawing oil, cutting oil, press oil, rolling oil, etc. There is a strong demand for a lubricating oil having excellent lubricity and thermal oxidation stability. In addition, solid fats such as beef fat, which are widely used as a lubricant base, have a high melting point and adhere to a machine, which deteriorates maintenance and working environment, and there is a risk of fire due to oxidation of lubricant oil. Therefore,
Lubricating bases are required to have excellent thermal oxidative stability, excellent low temperature fluidity so as not to adhere to machines, and excellent thermal oxidative stability and cleanliness even at high temperatures due to high speed operation.

In order to obtain high lubricity in the ester type lubricant base, it is desirable that the fatty acid used has a long chain length. In addition, increasing the chain length of the fatty acid not only improves the lubricity but also the viscosity index, but has the drawback that the low temperature fluidity deteriorates. When an aliphatic branched acid is used, low temperature fluidity is improved, but lubricity and viscosity index are lowered.
When unsaturated fatty acids such as oleic acid are used, the low temperature fluidity and viscosity index are good, but the lubricity is inferior to the case where saturated fatty acids of the same chain length are used.

In order to improve these points, it has been proposed to use complex esters. For example, Japanese Examined Patent Publication No. 52-17516 discloses, as a rolling oil for stainless steel having a good finished surface of a rolled plate, a complex ester composed of pentaerythritol, dimer acid and oleic acid, and trimethylol. A complex ester composed of rupropane and succinic acid and caproic acid is described. However, the former has poor cleanability at high temperatures, and the latter has insufficient lubricity.

Japanese Patent Publication No. 61-57360, Japanese Patent Publication No. 6-6
No. 2-13495, Japanese Patent Publication No. 2-32315,
Japanese Examined Patent Publication (Kokoku) No. 3-4600 discloses a complex ester of diethylene glycol, dimer acid and stearic acid as a constituent of a rolling oil excellent in lubricity and surface cleanliness of a metal plate to be processed, and polyethylene. A complex ester consisting of glycol and dimer acid and palmitic acid is described. However, they have poor low temperature fluidity and insufficient thermooxidative stability.

Japanese Patent Publication No. 2-7354 discloses, as metalworking oils other than rolling oils excellent in extreme pressure lubricity, complex esters of pentaerythritol and adipic acid and stearic acid, and trimethylolpropane. And complex esters consisting of behenic acid and ethylene glycol diglycidyl ether are described, but these have poor low-temperature fluidity and insufficient thermal oxidative stability.

Japanese Patent Publication No. 40839/1988 discloses trimethylol as an automatic transmission oil and a two-cycle engine oil.
A complex ester consisting of rupropane and dimer acid, caprylic acid and capric acid is described.
Poor lubricity.

[0008]

As described above, the complex ester is not only superior in terms of lubricity and thermo-oxidative stability to ordinary esters and natural fats and oils, but also has a wide range of viscosity. Can be adjusted. However, no one has been found that simultaneously satisfies lubricity, low temperature fluidity, thermo-oxidative stability and high temperature detergency.

Therefore, an object of the present invention is to provide an ester-based lubricating base for metal processing which is excellent in lubricity and is also excellent in thermal oxidation stability, low temperature fluidity and high temperature detergency. There is.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, consisted of a complex ester of a specific polyvalent alcohol and a specific mixed carboxylic acid, We have found that those with a kinematic viscosity at 40 ° C and a pour point within a specific range are ester-based lubricant bases for metal processing that have excellent lubricity, low-temperature fluidity, thermo-oxidative stability and high-temperature detergency. The present invention has been completed.

That is, the present invention provides a complex ester composed of trimethylolpropane or an oxyethylene adduct of trimethylolpropane and a mixed carboxylic acid of a monocarboxylic acid and a polycarboxylic acid, wherein The acid contains a polycarboxylic acid or a monocarboxylic acid having 12 or more carbon atoms in an amount of 40 mol% or more, and has a kinematic viscosity at 40 ° C. of 80 centistes.
And a pour point of 0 ° C. or lower.

[0012]

In the present invention, the polyhydric alcohol constituting the complex ester is trimethylolpropane or an oxyethylene adduct of trimethylolpropane. If polyalcohols other than these are used, lubricity will be insufficient, precipitation of crystallized substances will occur during long-term storage at high temperature due to high pour point, and amount of sludge and gelation due to thermal oxidative deterioration will occur. However, it is not preferable because it causes a lot of stains inside and around the machine.

In the oxyethylene adduct of trimethylolpropane, the number of moles of oxyethylene added is not particularly limited, but generally, trimethylolpropane 1
It is preferably 6 mol or less relative to the molecule. If the number of moles added is too large, the thermal oxidative stability at high temperature becomes poor and sludge and gelation may occur, which is not preferable.

The monocarboxylic acid having 12 or more carbon atoms constituting the complex ester is a monocarboxylic acid having a saturated or unsaturated hydrocarbon group, and the hydrocarbon group may be linear or branched. However, in the case of a monocarboxylic acid having a branched hydrocarbon group, it is preferable that the main chain has 12 or more carbon atoms.

Examples of such monocarboxylic acids having 12 or more carbon atoms include lauric acid, myristic acid,
Isomyristic acid, pentadecanoic acid, palmitic acid, isopalmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, linoleic acid, nonadecanoic acid, arachidic acid, behenic acid, erucic acid, unsaturated monocarboxylic acid olein Acid, linoleic acid, linolenic acid, arachidonic acid, etc. are polymerized, and isostearic acid, which is a by-product when producing polymerized acids such as dimer acid, trimer acid, etc. They may be used alone or in combination of two or more.

Examples of the polycarboxylic acid constituting the complex ester include adipic acid, 2.2-dimethylsuccinic acid, 2.3-ditylglutaric acid, suberic acid, azelaic acid, trimethyladipic acid, sebacic acid and isophthalic acid. Acids, dimer acids, trimer acids and the like can be used, and among these, one kind thereof can be used alone or two or more kinds can be mixed and used.

In the present invention, the mixed carboxylic acid constituting the complex ester contains the above polyvalent carboxylic acid or the above and the above monocarboxylic acid having 12 or more carbon atoms in an amount of 40 mol% or more of all carboxylic acids. If the proportion of monocarboxylic acids having less than 12 carbon atoms exceeds 60 mol% of all carboxylic acids, lubricity becomes insufficient. In addition, if isostearic acid, which is a by-product in the production of oleic acid, linoleic acid, linolenic acid, erucic acid, dimer acid, trimer acid, etc., is contained in an amount of 5 mol% or more of all carboxylic acids, lubricity is improved. It is also preferable because it has excellent low temperature fluidity.

The complex ester used in the present invention can be obtained by esterifying the above-mentioned polyhydric alcohol and mixed carboxylic acid by a conventional method.
The kinematic viscosity at 40 ° C. is adjusted to 80 centistokes or higher (usually up to 1,000 centistokes) and the pour point is 0 ° C. or lower (usually up to −40 ° C.) by combining the raw material components. Kinematic viscosity at 40 ℃ is 80 centist
If the porosity is less than 50 ° C, the lubricity is poor, and if the pour point exceeds 0 ° C, it adheres to the periphery of the machine, making it difficult to use.

In the ester type lubricant base of the present invention, the above complex ester can be used alone or in a mixture with mineral oil or other synthetic oil within a range not impairing the characteristics of the lubricant base. Further, additives such as an antioxidant and an extreme pressure additive which are usually used may be added to the lubricant base.

[0020]

The ester type lubricant base of the present invention has excellent lubricity and thermal oxidative stability, and also has good low temperature fluidity and high temperature detergency. For this reason, it can be used as metalworking oil such as wire drawing oil, cutting oil, press oil, rolling oil, etc., which has been increasing in speed in recent years, and it has excellent low temperature fluidity and high temperature cleanliness, so it does not stain the machine. Little impact.

[0021]

EXAMPLES Next, the present invention will be specifically described with reference to Examples.

Example 1 100 g (0.75 mol) of trimethylolpropane and 438 g of oleic acid were placed in a 1-liter four-necked flask equipped with a stirrer, a nitrogen blowing tube, a thermometer and a water separator equipped with a condenser. 1.85 mol) and 161 g of dimer acid
(0.28 mol) was charged, 2 g of paratoluenesulfonic acid was added as a catalyst, and the mixture was reacted at 160 ° C. under a nitrogen stream of 200 milliliter / min until the calculated amount of produced water was distilled. After completion of the reaction, remove the catalyst by washing with water,
It was dehydrated at 90 ° C. and 20 mmHg. Then, after adding 5 g of activated clay and stirring at 80 ° C. for 1 hour, the activated clay was filtered using 10 g of a filter aid [Radiolite 600, Showa Chemical Industry Co., Ltd.]. The obtained complex ester was used as the ester-based lubricant base of Sample No. 1.

Examples 2 to 9 The types and compositions of monocarboxylic acid and polycarboxylic acid are
The esterification reaction was carried out in the same manner as in Example 1 except that the changes were made as shown in Table 1 and Table 2, and after this reaction, Example 1 was performed.
Were treated in the same manner as above to obtain 8 kinds of complex esters, which were used as ester lubricant bases of sample numbers 2 to 9. For reference, Table 1 also shows the raw material composition of the ester-based lubricating base material of Sample No. 1 of Example 1.

Comparative Examples 1 to 11 Except that the kinds and compositions of polyhydric alcohol, monocarboxylic acid and polycarboxylic acid were changed as shown in Tables 3 and 4, respectively.
An esterification reaction was carried out in the same manner as in Example 1, and after this reaction, the same treatment as in Example 1 was carried out to obtain 11 kinds of complex esters, which were used as the ester-based lubricating base materials of sample numbers 10 to 20. did.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

In Tables 1 to 4 above, each component is as follows. <Polyvalent alcohol> NPG: Neopentyl glycol [manufactured by Koei Chemical Co., Ltd.] TMP: Trimethyl propane [manufactured by Koei Chemical Co., Ltd.] PE: Pentaerythritol [manufactured by Koei Chemical Co., Ltd.] <Monocarboxylic acid> Oleic acid: myristic acid 3.8 mol%, palmitic acid 4.7 mol%, hexadecenoic acid 9.0 mol%, stearic acid 1.2 mol%, oleic acid 72.0 mol%, linoleic acid
Acid 7.3 mol%, Linoleic acid 2.0 mol% Palm FA: Caprylic acid 7.3 mol%, Capric acid 7.
3 mol%, lauric acid 50.1 mol%, myristic acid 1
8.3 mol%, palmitic acid 8.2 mol%, stearic acid 3.0 mol%, oleic acid 5.2 mol%, and others.
6 mol% beef tallow FA: myristic acid 4.8 mol%, palmitic acid 31.9 mol%, stearic acid 25.9 mol%, oleic acid 36.6 mol%, other 0.8 mol% C ₈ : caprylic acid C ₁₀ : capric acid C ₁₂ : lauric acid bC ₁₈ : isostearic acid [Emazol 871, manufactured by Emery Co.] <polycarboxylic acid> C ₄ : succinic acid [manufactured by Kawasaki Chemicals Co., Ltd.] C ₆ : adipic acid [Sumitomo Chemical Co., Ltd.] C ₁₀ : Sebacic Acid [Toyokuni Oil Co., Ltd.] C ₁₂ : Dodecanedioic Acid [Reagent First Grade, Tokyo Chemical Industry Co., Ltd.]
Ltd.] C _36: dimer - acid [Ba - Sadaimu 216, manufactured by Henkel Hakusui Co.]

Further, in Tables 1 to 4, each number in the table indicates the mol% of each alcohol with respect to the total alcohol in the case of polyvalent alcohol, and in the case of monocarboxylic acid and polyvalent carboxylic acid. , And mol% of each monocarboxylic acid and each polyvalent carboxylic acid with respect to the total raw material carboxylic acid, respectively.

Of the monocarboxylic acids, oleic acid and beef tallow FA are composed of mixed fatty acids having 12 or more carbon atoms, and therefore the numbers in the table correspond to the total mol% of monocarboxylic acids having 12 or more carbon atoms. . On the other hand, Palm FA
Since it is composed of a mixed fatty acid of a fatty acid having less than 12 carbon atoms and a fatty acid having 12 or more carbon atoms, the fatty acid having 12 or more carbon atoms is the total mol% of monocarboxylic acids having 12 or more carbon atoms.
Is displayed in parentheses.

Sample Nos. 1-9 obtained in Examples 1-9 above
The acid value, the hydroxyl value, and the complex number of each of the complex esters of sample numbers 10 to 20 obtained in Comparative Examples 1 to 11,
The pour point (JIS K2269) and kinematic viscosity at 40 ° C. (JIS K2283) were examined. The results are summarized in Table 5 below.

[0033]

[Table 5]

Example 10 Trimethylolpropane 1 containing 3 mol of oxyethylene added to a 1-liter four-necked flask equipped with a stirrer, a nitrogen blowing tube, a thermometer and a water separator equipped with a condenser.
74.7 g (0.66 mol), oleic acid 383.9 g
(1.39 mol) and 140.7 g (0.24) of dimer acid
Mol) and charged with para-toluenesulfonic acid 2 as a catalyst.
16 g under a nitrogen stream of 200 milliliter / min.
The reaction was carried out at 0 ° C. until the calculated amount of produced water was distilled off. After the reaction is completed, the catalyst is removed by washing with water,
It was dehydrated at 20 mmHg. Then, after adding 5 g of activated clay and stirring at 80 ° C. for 1 hour, the activated clay was filtered using 10 g of a filter aid [Radiolite 600, Showa Chemical Industry Co., Ltd.]. The obtained complex ester was used as the ester-based lubricating base material of Sample No. 21.

Examples 11 to 18 The types and compositions of monocarboxylic acid and polycarboxylic acid are
Esterification reaction was carried out in the same manner as in Example 10 except that the changes were made as shown in Table 6 and Table 7, and after this reaction, the same treatment as in Example 10 was carried out to obtain 8 kinds of complex esters. Were used as the ester-based lubricant bases of sample numbers 22 to 29. In addition, in Table 6, as a reference, Example 10
The raw material composition of the ester-based lubricating base of Sample No. 21 was also shown.

Comparative Examples 12 to 21 Except that the kinds and compositions of polyhydric alcohol, monocarboxylic acid and polycarboxylic acid were changed as shown in Tables 8 and 9,
An esterification reaction was carried out in the same manner as in Example 10, and after this reaction, the same treatment as in Example 10 was carried out to obtain 10 kinds of complex esters, which were sample Nos. 30 to 39.
Was used as an ester-based lubricant base.

[0037]

[Table 6]

[0038]

[Table 7]

[0039]

[Table 8]

[0040]

[Table 9]

In Tables 6 to 9 above, the polyvalent alcohol
Each component in the column of "Le" is as follows. DEG: Diethylene glycol [Reagent first grade, manufactured by Tokyo Chemical Industry Co., Ltd.] TMP-E03: Trimethylolpropane oxyethylene 3 mol adduct [Polyol TP-30, manufactured by Perstorp Polyols] PE-E05: Pentaerythritol Le Oxyethylene 5
Molar adduct (Polyol PP-50, Perstorp Polyols)

The components in the columns of monocarboxylic acid and polycarboxylic acid are the same as those in the above Tables 1 to 4, and each number in the table and the value in parentheses are as follows. This is the same as the case of Tables 1 to 4 above.

Sample No. 2 obtained in Examples 10 to 18 above
1 to 29 and sample numbers 30 to 30 obtained in Comparative Examples 12 to 21.
For each complex ester of 39, its acid value,
Hydroxyl value, pour point (JIS K2269) and 40 ° C
The kinematic viscosity (JIS K2283) was examined. The results are summarized in Table 10 below.

[0044]

[Table 10]

Next, sample numbers 1 to 9 and sample numbers 21 to 29 of the examples and sample numbers 10, 13, 1 of the comparative example.
4, 18 to 20 and sample numbers 30, 33, 34, 3
A hot-tube test and a friction coefficient (lubricity) test were carried out for Nos. 8 and 39 in the following manner. The results are shown in Tables 11 and 12.

<Hot-tube tester> A hot-tube tester manufactured by Komatsu Equipment Co., Ltd. was used. Insert the glass tube into the electric furnace and push up the oil with air.
The oil deteriorates by being subjected to heat and oxidation as it passes through the glass tube. The test was carried out at 260 ° C. for 16 hours to examine the thermooxidative stability and high temperature detergency of the oil. The state of deposits on the inner wall of the glass tube was evaluated based on the standard color scale. There were 10 points for no deposit and 0 point for black.
When the tube was clogged with a gel-like sludge, it was added as a remark after the score.

<Friction Coefficient (Lubricity) Test> The friction coefficient (μ) was measured using a Soda type pendulum type oil friction tester to evaluate lubricity.

[0048]

[Table 11]

[0049]

[Table 12]

Table 5, Table 10, Table 11 and Table 12 above
As is clear from the results, the products of the present invention all have a pour point of 0 ° C. or lower and a kinematic viscosity at 40 ° C. of 80 centistokes or higher. Good cleanliness, low coefficient of friction,
Excellent lubricity. On the other hand, the comparative product is inferior in any of the above characteristics.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area C10N 30:10 40:22 40:24 Z 8217-4H

Claims (1)

[Claims] 1. A complex ester composed of trimethylolpropane or an oxyethylene adduct of trimethylolpropane and a mixed carboxylic acid of a monocarboxylic acid and a polyvalent carboxylic acid, wherein the mixed carboxylic acid is a polyvalent one. 40 mol% or more of carboxylic acid or monocarboxylic acid having 12 or more carbon atoms and
An ester lubricant base material having a kinematic viscosity of 40 centigrade or more at 40 ° C. and a pour point of 0 ° C. or less.