JP2001089781A - Extreme pressure additive, its production method, cutting fluid and grinding fluid - Google Patents

Abstract

(57) [Summary] [Problem] Completely water-soluble without using a surfactant, odor,
Provided is an extreme pressure additive having a good hue, excellent defoaming properties and rust prevention properties, and also having high load-bearing performance and lubricating performance equivalent to oil-based oils. An extreme pressure additive comprising a salt of a condensate of a sulfurized hydroxyunsaturated fatty acid, wherein the condensate comprises:
An extreme pressure additive, characterized by having a sulfur content of 8 to 15% by weight (mass), a hue of 6 or less, and an acid value of 80 to 200;
A cutting fluid or a grinding fluid comprising this and water. After reacting the hydroxyunsaturated fatty acid with sulfur and hydrogen sulfide under heat and pressure to sulfurize and condense the hydroxyunsaturated fatty acid, the resulting reaction product is neutralized with a base to obtain an extreme pressure additive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a water-soluble extreme pressure additive and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various oils have been used to prepare liquids for cutting or grinding metals, and in particular, the advantages of using water as a medium, namely, cooling effects, noncombustibility, economy and environmental pollution. Water soluble oil agents have been preferably used because of their small size. However, water-soluble oils have insufficient load-bearing performance,
In addition, there are problems in metal working performance such as a decrease in finished surface accuracy and tool life due to insufficient lubrication performance such as a friction reduction effect. Further, there are problems specific to the water-soluble oil agent, such as foaming during use, generation of rust, decay, and deterioration of odor. Various attempts have been made to improve these specific problems.

[0003] In order to impart load resistance, extreme pressure additives which are almost insoluble in water, for example, chlorine-based extreme pressure additives such as chlorinated paraffins and chlorinated fatty acid esters, or JP-A-7-157793. As described in the above, emulsion type oils are used in which sulfur-based extreme pressure additives such as sulfurized oils and fats, sulfurized olefins, and dialkyl polysulfides are dispersed in water using a large amount of a surfactant. However, the extreme pressure performance of emulsion type oils is not sufficient, and the management of the liquid in the emulsion state is complicated, so that the oil is contaminated when the emulsion is destroyed and the processed product needs to be washed with a solvent. There is also a problem in terms of aspects.

[0004] As an example of water-solubilization with a sulfur-based extreme pressure additive, an attempt has been made for a soluble oil agent using a sulfurized long-chain unsaturated fatty acid salt such as an alkanolamine salt of sulfurized oleic acid. However, although the extreme pressure performance is high, there is a major drawback that it is difficult to completely solubilize water without using a surfactant, the odor is strong, and the foaming is severe.

US Pat. No. 4,425,0046 discloses the use of di (2-hydroxyethyl) disulfide as a soluble oil agent using other sulfur-based extreme pressure additives.
JP-A-63-284294 discloses the use of alkanolamine salts of 3-mercaptopropionic disulfide, and JP-A-5-43886 describes the use of alkanolamine salts of alkylthiopropionic acid. Although the extreme pressure performance and lubrication performance are improved, they are not sufficient.

[0006] Soluble type oil containing no sulfur is disclosed in JP-B-60-49677 and JP-B-2-57.
There is an alkali metal or amine salt of a condensate of ricinoleic acid described in JP-A-99-99, and an alkali metal salt or amine salt of a condensate of a hydroxy long-chain fatty acid described in JP-A-7-97590. Excellent in odor, defoaming property, rot resistance and rust prevention. However, there is a disadvantage that the extreme pressure performance is considerably lower than that of the sulfur type extreme pressure additive.

[0007]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an extreme pressure additive which is completely water-soluble, has excellent load-bearing performance and lubricating performance, and has good odor, defoaming properties and rust prevention properties. The purpose was to.

[0008]

The inventors of the present invention have conducted various studies to achieve this object. As a result, the salt of the condensate of hydroxyunsaturated fatty acid is not used as an extreme pressure additive, By cross-linking the intramolecular unsaturated double bond of sulfur with sulfur and introducing a sulfur cross-linking structure into the molecule to form a salt of a sulfurized and condensed hydroxy unsaturated fatty acid,
It has been found that it is an extreme pressure additive with better performance.

When ricinoleic acid is used as the hydroxyunsaturated fatty acid, a salt of condensed ricinoleic acid having a sulfur cross-linking structure in the molecule obtained by reacting ricinoleic acid with sulfur and hydrogen sulfide at a relatively low temperature is a water-soluble extreme pressure. The present inventors have found that the additives have the most excellent properties, that is, excellent load-bearing performance, lubricating performance, complete water solubility, odor, defoaming properties, and rust-preventive properties, and have completed the present invention.

That is, the present invention is an extreme pressure additive comprising a salt of a condensate of a sulfurized hydroxyunsaturated fatty acid having a specific sulfur content, a specific color and a specific acid value.

In the present invention, typical examples of the salt of the condensate of the sulfurized hydroxyunsaturated fatty acid include those having all of the following structures in chemical structure.

(X) The hydroxy unsaturated fatty acid has a condensed structure (ester bond). (Y) having a sulfur crosslinked structure in which a sulfur atom is added to an intramolecular carbon-carbon unsaturated double bond based on a hydroxyunsaturated fatty acid; (Z) Carboxyl groups based on hydroxyunsaturated fatty acids are included in the condensate molecule as a salt structure.

The term "hydroxy unsaturated fatty acid" means a compound having a hydroxyl group, a carbon-carbon unsaturated double bond and a carboxyl group in the molecule.

The salt of the condensate of the sulfurized hydroxyunsaturated fatty acid may be obtained by performing the reaction in any order.
It is preferable to obtain a condensate of a previously unsaturated hydroxyunsaturated fatty acid and convert it to a salt. In order to obtain the condensate of the sulfided hydroxyunsaturated fatty acid in the former stage, there is a method of condensing and sulphidizing the hydroxyunsaturated fatty acid to introduce an ester bond structure and a sulfur crosslinked structure into the molecule.

This method is preferable because the number of manufacturing steps and the like can be reduced, productivity can be further improved, and a sulfur crosslinked structure can be more easily introduced into the molecule.

Further, as a specific method, the hydroxyunsaturated fatty acid, sulfur and hydrogen sulfide can be sulfided at a relatively low temperature under heating and pressurization at a relatively low temperature in the presence of a catalyst, if necessary. A method of condensation can be adopted.

In this method, it is easier to control the reaction, including the sulfur content, and the resulting product is:
This is preferable since coloring is less and odor is less. It is preferable to select the reaction temperature in the range of more than 100 ° C to 150 ° C and the reaction time in the range of 1 to 20 hours.
The fact that the reaction can be carried out at a relatively low pressure and a relatively low temperature is preferable because the energy consumption per unit production can be reduced and the reaction can be carried out in a general pressure-resistant reactor.

The condensate of the sulfurized hydroxyunsaturated fatty acid has an acid value of 80 to 200 mgKOH / g, and
It is preferable that it is 0 to 160 mgKOH / g in that excellent lubricating performance and stable water solubility can be achieved without using a surfactant. This is the same in the case of the optimal sulfided ricinoleic acid condensate described below. The condensate of the sulfided hydroxyunsaturated fatty acid may be converted to a water-dispersible water-soluble solution by converting it into a salt, but the water-soluble water is more stable.

Next, raw materials for obtaining a condensate of a sulfided hydroxyunsaturated fatty acid will be described.

In the hydroxy unsaturated fatty acid, the number of hydroxyl groups and the number of carboxyl groups in the molecule are not limited, but may be 1 to 3 in each case. The chain length of the carbon of the hydroxyunsaturated fatty acid is preferably a long chain, for example, 12 to 3 including the carbon of the unsaturated double bond.
0, preferably 14-20.

Examples of such hydroxy unsaturated fatty acids include monohydroxy unsaturated fatty acids such as 12-hydroxy oleic acid (ricinoleic acid), 13-hydroxy oleic acid, and 15-hydroxy oleic acid;
10-dihydroxyoleic acid, 9,10-dihydroxylinoleic acid, 12,13-dihydroxyoleic acid,
Examples thereof include dihydroxy unsaturated fatty acids such as 15,16-dihydroxylinoleic acid and 9,10-dihydroxypalmitoleic acid. These may be used alone or in combination of two or more. Considering the performance and economy as an oil agent, the most preferred is 12-hydroxyoleic acid (ricinoleic acid).

In the present invention, commercially available hydroxyunsaturated fatty acids and hydrogen sulfide can be used. As the sulfur, either solid or molten sulfur may be used.

The catalyst used in the production method of the present invention is usually a basic catalyst. As the basic catalyst, an amine is suitable, and an alkylamine, an arylamine, a polyamine, or an alkanolamine having good reactivity is used. Examples include, for example, butylamine, dibutylamine, tributylamine, n-octylamine, tert-octylamine, dioctylamine, tert-dodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine, dicyclohexylamine , Arylamine, hexamethylenetetramine, triethanolamine and the like.

The sulfur content in the extreme pressure additive of the present invention is, for example, 8 to 15% by weight (mass). 9-11 weight (mass) in combination with excellent extreme pressure performance and low corrosiveness
% Is preferred. The raw material charge ratio [weight (mass) conversion]
Although it can be freely changed depending on the required sulfur content, etc., the sulfur content is 9 to 11%, the hydroxyunsaturated fatty acid is 80 to 90%, the sulfur is 6 to 7%, the hydrogen sulfide is 3 to 4%, and the catalyst is 0. 2 to 0.6% is preferred.

The reaction mode according to the production method of the present invention includes a method in which hydrogen sulfide gas is blown into a hydroxyunsaturated fatty acid, sulfur, and a catalyst in an autoclave, and a method in which hydroxyunsaturated fatty acid, sulfur, liquefied hydrogen sulfide, and a catalyst are simultaneously charged. Any of these methods may be used, but the former method, which allows a reaction under a relatively low pressure, is preferred. The pressure conditions for this reaction are:
Although not particularly limited, for example, 98 to 2940 kPa (1
-30 kg / cm ² ), but in the former method of blowing hydrogen sulfide gas, 98-980 kPa
(1 to 10 kg / cm ² ), which is more preferable from the viewpoint of safety.

The reaction temperature in the production method of the present invention is relatively low as compared with the method of sulfurizing only with sulfur using the same hydroxy unsaturated fatty acid. The reaction temperature in the production method of the present invention is not particularly limited by the type of hydroxyunsaturated fatty acid to be sulfurized and esterified, but can be usually selected from the range of 100 to 200 ° C. In the method of blowing hydrogen sulfide, the hydrogen sulfide is blown so as to be consumed as much as possible in the system by successive reactions. In the production method of the present invention, it is not preferable to employ high-temperature reaction conditions under which the condensation reaction proceeds more greatly than the sulfurization reaction. The product obtained by sulfurizing and condensing the hydroxyunsaturated fatty acid obtained by the production method of the present invention has a pale color. In the present invention, the hue of the condensate of the sulfurized hydroxyunsaturated fatty acid refers to the hue as measured according to ASTM D-1500. The hue of the condensate in the present invention,
6 or less, preferably 4 or less.

When ricinoleic acid is used as the hydroxyunsaturated fatty acid, the temperature in the production method of the present invention is 100 to 160 ° C., preferably 100 to 140 ° C.
C. is a preferable condition, the reaction is slower when the temperature is lower than 100 ° C., and when the temperature exceeds 140 ° C., the condensation reaction of ricinoleic acid, which is a sulfur cross-linking reaction and a competing reaction, excessively proceeds, and the water solubility is apt to decrease. Hue and odor tend to deteriorate, which is not preferable. The reaction time can be adjusted in the range of 2 to 18 hours. Thus, a condensate of sulfided ricinoleic acid is obtained.

The acid value of a condensate of a sulfurized hydroxyunsaturated fatty acid represented by a condensate of sulphidic ricinoleic acid varies depending on the degree of the condensing reaction, which is a competitive reaction, and can be adjusted by the reaction temperature and reaction time. To a suitable range. As described above, if the acid value is less than 100, the viscosity tends to increase, and the water solubility tends to decrease. If the acid value exceeds 160, the effect of the lubricating performance tends to decrease.

In obtaining a salt of a condensate of a sulfurized hydroxyunsaturated fatty acid, for example, in any step of obtaining the condensate, a carboxyl group contained in the molecule of the product is neutralized with a base to form a salt. You. As an example, a condensate of a sulfurized hydroxyunsaturated fatty acid is neutralized with a base to form a salt of the sulfurized hydroxyunsaturated fatty acid condensate. The ion dissociated state of this salt greatly contributes to stable water solubility. As a result, in the past, the use of a surfactant, which was necessary to provide stable solubility and dispersibility, was not necessary, or even if it was used, only a very small amount was required. The disadvantages can be greatly improved.

The condensate of sulfurized hydroxyunsaturated fatty acid represented by the condensate of sulfurized ricinoleic acid is converted into a salt with a base. Bases include metal hydroxides, metal carbonates,
Examples thereof include inorganic bases such as ammonia, and organic amines such as aliphatic primary amines, aliphatic secondary amines, and aliphatic tertiary amines. Preferred are alkali metal hydroxides and alkanolamines. To an alkali metal salt or an alkanolamine salt.

Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. Examples of the alkanolamine include mono-, di- or tri-type ethanolamine, propanolamine, butanolamine and octanolamine. I can do it. These can be used alone or in combination of two or more. As the base, mono-, di- or tri-type ethanolamine is particularly preferred.

Such a salt of a sulfurized hydroxy fatty acid condensate represented by a salt of a sulfuric acid ricinoleic acid condensate can be converted into the salt by mixing with the alkali metal hydroxide or alkanolamine. The water solubility and the defoaming property become better when the amount is increased to 1 to 3. If a smaller amount is added than is necessary for neutralization of the carboxyl groups, the condensate of sulphidic ricinoleic acid will be partly included in the extreme pressure additive of the present invention in a free state. On the other hand, if a larger amount is added than is required for neutralization of the carboxyl group, the alkanolamine will be partially contained in the extreme pressure additive of the present invention in a free state.

In order to produce a cutting fluid or a grinding fluid from the extreme pressure additive of the present invention, a known oil, rust preventive, bactericide or defoamer may be used in combination. The extreme pressure additive of the present invention may be used by adding it to a known and commonly used water-soluble cutting oil or water-soluble grinding oil.

The extreme pressure additive of the present invention can be used in combination with a salt of a condensate of a hydroxy unsaturated long chain fatty acid such as an alkali metal salt of a condensate of ricinoleic acid or an alkanolamine salt.

From the extreme pressure additive of the present invention, a cutting fluid or a grinding fluid containing the additive and water can be obtained.

In such extreme pressure additives, the effective compounding ratio (in terms of weight (mass)) of the salt of the condensate of the sulfurized hydroxy fatty acid according to the present invention is appropriately selected depending on the purpose of use and circumstances. 1 to 50%, preferably 1 to 1% in an aqueous solution (cutting fluid or grinding fluid) applied during processing
0%.

[0037]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Hereinafter,% represents weight (mass)%.

Synthesis Example 1 An autoclave was charged with 89.3 g of ricinoleic acid, 6.56 g of sulfur, and 0.53 g of dicyclohexylamine as a catalyst. The apparatus was sealed and 3.60 g of hydrogen sulfide gas was applied at 110 ° C. under a pressure of 6 kg / cm ² (588 k
Pa) and blow for 15 hours. After cooling to 70 ° C., the valve connected to the hydrogen sulfide absorbing device is opened to return the pressure to normal pressure. Air is blown from a blowing pipe to distill off residual hydrogen sulfide.

The light yellow liquid condensate of ricinoleic acid having a sulfur content of 9.8% (product) 9
8.0 g (98% yield) were obtained.

<Synthesis Examples 2 to 4> In Synthesis Example 1, the reaction temperature was 120 to 130 ° C., and the hydrogen sulfide blowing time was 4 to 12 hours.
The same processing as in Synthesis Example 1 was performed except that the time was changed.

<Comparative Synthesis Example 1> Sulfurized oleic acid was synthesized in the same manner as in Synthesis Example 2 except that oleic acid (a typical example of an unsaturated long-chain fatty acid containing no hydroxyl group) was used instead of ricinoleic acid. This sulfurized oleic acid contains the sulfur bridged structure (Y), but does not have an ester bond (X) which is a structure formed by polycondensation.

<Comparative Synthesis Example 2> Ricinoleic acid at 120 ° C
For 12 hours to synthesize condensed ricinoleic acid. This ricinoleic acid polycondensate contains an ester bond (X) equivalent to the structure formed by the condensation, but does not have a sulfur crosslinked structure (Y).

Table 1 shows the results of these synthesis examples and comparative synthesis examples.

[0044]

[Table 1]

Example 1 1.2 equivalents of triethanolamine was mixed with 1 equivalent of the condensate of ricinoleic sulfide obtained in Synthesis Example 1 to form an amine salt (salt of a condensate of sulfurized hydroxy fatty acid). % ~
Adjusted to 10% aqueous solution, performance such as load-bearing performance (fusion load, average Hertz load), wear-resistant performance (wear scar), lubrication performance (friction coefficient), water solubility, defoaming, metal The corrosivity was measured.

Example 2 A performance test was carried out in the same manner as in Example 1 by mixing 1.2 equivalents of triethanolamine with 1 equivalent of the condensate of ricinoleic sulfide obtained in Synthesis Example 2 to form an amine salt.

Example 3 A performance test was carried out in the same manner as in Example 1 by mixing 1.2 equivalents of triethanolamine with 1 equivalent of the condensate of sulfided ricinoleic acid obtained in Synthesis Example 3 to form an amine salt.

Example 4 1.9 equivalents of monoethanolamine was mixed with 1 equivalent of the condensate of ricinoleic sulfide obtained in Synthesis Example 4 to form an amine salt, and a performance test was conducted in the same manner as in Example 1.

Example 5 3.3 equivalents of monoethanolamine was mixed with 1 equivalent of the condensate of sulfided ricinoleic acid obtained in Synthesis Example 3 to form an amine salt, and a performance test was conducted in the same manner as in Example 1.

Example 6 1.9 equivalents of diethanolamine was mixed with 1 equivalent of the condensate of sulfided ricinoleic acid obtained in Synthesis Example 3 to form an amine salt.
A performance test was performed in the same manner as in Example 1.

EXAMPLE 7 3.3 equivalents of diethanolamine was mixed with 1 equivalent of the condensate of ricinoleic sulfide obtained in Synthesis Example 3 to form an amine salt.
A performance test was performed in the same manner as in Example 1.

Example 8 1.9 equivalents of triethanolamine was mixed with 1 equivalent of the condensate of sulfided ricinoleic acid obtained in Synthesis Example 3 to form an amine salt, and a performance test was conducted in the same manner as in Example 1.

Example 9 A performance test was conducted in the same manner as in Example 1 except that 1 equivalent of the condensate of sulfided ricinoleic acid obtained in Synthesis Example 3 was mixed with 3.0 equivalents of triethanolamine to form an amine salt.

Comparative Example 1 1.6 equivalents of triethanolamine were mixed with 1 equivalent of sulfurized oleic acid of Comparative Synthesis Example 1 to form an amine salt.
A performance test was performed in the same manner as described above.

Comparative Example 2 A performance test was carried out in the same manner as in Example 1 by mixing 3 equivalents of triethanolamine with 1 equivalent of the condensate of ricinoleic acid of Synthesis Comparative Example 2 to form an amine salt.

The load-bearing performance was measured at room temperature at 1770 r using a high-speed 4-ball EP tester based on ASTM D2783.
The welding load and the average Hertz load were measured under the conditions of pm and 10 seconds.

Abrasion resistance was measured at 75 ° C. and 120 ° C. using a high-speed 4-ball WEAR tester based on ASTM D4172.
The wear scar diameter was measured under the conditions of 0 rpm, 40 kg, and 60 minutes.

The lubricating performance was measured using a Soda pendulum friction tester at room temperature and 0.5 radian conditions.

The water solubility was determined by dissolving an amine salt sample in 10% water and determining the transparency in five steps. The criterion was that ◎ was completely transparent, は was transparent, Δ was slightly turbid, × was turbid, and XX was two-layer separation.

The defoaming property was determined by using a 1% aqueous solution of an amine salt sample in 20%.
0 ml was placed in a 500 ml measuring cylinder, shaken for 30 seconds, and the residual foam amount (ml) after 60 minutes was measured.

The metal corrosivity was determined by immersing an iron piece in 100 ml of a 1% aqueous solution of an amine salt sample for one and a half months, and determining the degree of rust generation in three stages. The evaluation criteria were as follows: ○: no rust, Δ: several rusts, ×: tens of rusts.

Tables 2 and 3 show the results of performance tests and measurements of the characteristics of the examples and comparative examples.

[0063]

[Table 2]

[0064]

[Table 3]

As shown in these tables, the extreme pressure additives comprising salts of the condensates of sulfided ricinoleic acid of the present invention are completely water-soluble, slightly odorous and pale, and the aqueous solution thereof is defoamable. Has excellent rust prevention properties. Also, load bearing,
Excellent lubricity.

[0066]

According to the present invention, it is possible to provide a sulfur-based extreme pressure additive which is completely water-soluble without using a surfactant, and has good odor and hue. There is provided a cutting fluid or a grinding fluid excellent in defoaming property and rust prevention property and having high load-bearing performance and lubricating performance equivalent to conventional cutting fluids and grinding fluids.

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Claims (9)

[Claims] 1. An extreme pressure additive comprising a salt of a condensate of a sulfurized hydroxyunsaturated fatty acid, wherein the condensate comprises:
An extreme pressure additive having a sulfur content of 8 to 15% by weight (mass), a hue of 6 or less, and an acid value of 80 to 200. 2. The extreme pressure additive according to claim 1, wherein the hydroxy unsaturated fatty acid is ricinoleic acid. 3. The sulfided condensate has an acid value of 100 to 3.
3. The extreme pressure additive of claim 2, wherein said additive is 160. 4. The extreme pressure additive according to claim 1, wherein the salt is an alkanolamine salt or an alkali metal hydroxide salt. 5. A method comprising reacting a hydroxyunsaturated fatty acid, sulfur and hydrogen sulfide under heat and pressure to sulphate and condense the hydroxyunsaturated fatty acid, and then neutralizing the obtained reaction product with a base. Of producing extreme pressure additives. 6. The method for producing an extreme pressure additive according to claim 5, wherein the reaction pressure is in the range of 98 to 2940 kPa. 7. The method for producing an extreme pressure additive according to claim 5, wherein the reaction temperature is 100 to 160 ° C. 8. A cutting fluid comprising the extreme pressure additive according to any one of claims 1, 2, 3 and 4, and water. 9. A grinding fluid comprising the extreme pressure additive according to claim 1, 2, 3 and water and water.