JP2001181666A - Lubricant composition for metal working - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricant composition for metal workings containing no chlorine-based compound and capable of expressing excellent lubricant characteristics in cutting and grinding works and excellent in performance for preventing corrosion of non-iron metals. SOLUTION: This lubricant composition for metal workings comprises (a) a base oil containing the ester of a monohydric alcohol with a monocarboxylic acid, (b) an over based sulfonate with an alkali metal and/or an alkaline earth metal and (c) a metal salt of an organic compound. The content of (b) the over based sulfonate with the alkali metal and/or the alkaline earth metal is 1-50 pts.wt. and the content of (c) the metal salt of the organic compound is 1-50 pts.wt. based on 100 pts.wt. of the whole weight of the lubricant composition for metal workings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubricating oil composition for metalworking, and more particularly to a lubricating oil composition for metalworking, which exhibits excellent lubricating properties in cutting or grinding without containing a chlorine-based compound and prevents corrosion of non-ferrous metals. The present invention relates to a lubricating oil composition for metal working having excellent performance.

[0002]

2. Description of the Related Art Conventionally, lubricating oils for metal working used for cutting or grinding metals are provided with oily agents such as oils and fats, fatty acids and esters, and sulfur, chlorine and phosphorus for the purpose of imparting lubricity. Extreme pressure additives have been added. Among them, chlorinated compounds such as chlorinated paraffins and chlorinated fatty acid esters are
Compared to other extreme pressure agents, they are inexpensive and have excellent lubricating performance.For metal cutting or grinding, a lubricating oil composition for metal processing containing a large amount of chlorine-based compounds has been used. It had been.

[0003] However, regarding chlorinated compounds, for example, in the United States, certain chlorinated paraffins are recognized as carcinogenic substances, and furthermore, a warning of carcinogenicity is required by the enforcement of the PL law, and human health is required. Problems were pointed out. Further, when incinerating a waste liquid of a cutting or grinding lubricating oil containing a chlorine-based compound, hydrogen chloride (HCl), which causes air pollution during combustion, is generated, or
It has recently been pointed out that there is a possibility that environmental pollution may be caused due to generation of dioxin depending on the combustion temperature at the time of incineration. Given these circumstances,
In many countries, the use of metalworking fluids containing chlorinated paraffins is being shunned.

[0004] Therefore, development studies of lubricating oil compositions for metal working which do not contain chlorinated compounds such as chlorinated paraffins have been conducted, and lubricating oil compositions for metal working containing sulfur-based extreme pressure additives have been developed. Are being considered. However, when an active type sulfur-based extreme pressure additive is used, there is a problem that nonferrous metals, particularly copper alloys, are corroded or discolored. This problem of corrosion or discoloration cannot be solved by adding a nonferrous metal anticorrosive such as benzotriazole to a lubricating oil composition for metalworking. Further, when an inert type sulfur-based additive such as dibenzyl disulfide is used in place of the active type sulfur-based additive that causes a corrosion problem, sufficient cutting performance cannot be obtained particularly in machining of a stainless steel material or the like. There is a problem. As described above, a lubricating oil composition for metal working which has solved the above-mentioned problems of the sulfur-based extreme pressure additive and the chlorine-based extreme pressure additive has not yet been obtained.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and exhibits excellent lubricating properties in cutting or grinding without containing a chlorine-based compound, and at the same time, prevents corrosion of non-ferrous metals. It is an object of the present invention to provide a lubricating oil composition for metalworking having excellent performance.

[0006]

Means for Solving the Problems As a result of intensive studies on the lubricating base oil and various additives, the present inventors have formulated an overbased sulfonate and a metal salt compound into a base oil containing a specific synthetic ester. By making the composition, while exhibiting excellent lubricating properties in cutting or grinding, it has been found that a lubricating oil composition for metal working that is also excellent in the anticorrosion performance of non-ferrous metals can be obtained, leading to the completion of the present invention. Was. That is,
The lubricating oil for metal working of the first invention comprises (a) an ester of a monohydric alcohol and a monocarboxylic acid (hereinafter simply referred to as “(a)
Ingredients ". ), (B) an overbased sulfonate of an alkali metal and / or an alkaline earth metal (hereinafter simply referred to as "component (b)"), and (c) a metal salt of an organic compound (hereinafter, referred to as "component (b)"). Simply referred to as “(c) component”.)
And containing.

The monohydric alcohol constituting the component (a) in the first invention generally has 1 to 1 carbon atoms.
20, preferably 1 to 18 monohydric alcohols are used. If the carbon number exceeds 20, the melting point becomes too high, which is not preferred. Polyhydric alcohols such as trimethylolpropane are not preferred because they have poor compatibility with the component (b). As the monocarboxylic acid, a monocarboxylic acid having 8 to 20 carbon atoms, preferably 10 to 20 carbon atoms, and more preferably 12 to 18 carbon atoms is used. If the number of carbon atoms is less than 8, it is not preferable because the odor is strong. On the other hand, if it exceeds 20, the melting point becomes too high. Further, polyvalent carboxylic acids such as sebacic acid are not preferred because they have poor compatibility with the component (b).

The acid value of the ester (a) is not particularly limited, but may be more than 1 mgKOH / g. As the base oil of the lubricating composition for metal working of the present invention, the above-mentioned component (a) may be used as it is as long as it contains the above-mentioned component (a). The base oil component used in the lubricating oil may be added to form a base oil mixture. Such base oil components include, for example, mineral oil, synthetic oil (poly-α-olefin, alkylbenzene, alkylnaphthalene, boribene, polyoxyalkylene glycol, polyoxyalkylene glycol ether, silicone oil, polyol ester, etc.)
And the like. In this case, the content of the component (a) in the base oil is not particularly limited, but usually, as shown in the second invention, the components (b) and ( c) When the amount excluding the components is 100 parts by weight,
It is usually at least 60 parts by weight, preferably at least 70 parts by weight, more preferably at least 80 parts by weight, most preferably at least 90 parts by weight. If the content is less than 60 parts by weight, the cutting performance is undesirably reduced.

The component (b) in the first invention is an oil-soluble dispersion (basic organic / inorganic dispersion) containing a metal salt of an organic sulfonic acid, a basic alkaline earth metal salt and an organic solvent.
It is. Examples of the alkali metal constituting the component (b) include sodium and potassium, and examples of the alkaline earth metal include calcium, barium, and magnesium. Of these, calcium is particularly preferable. These may be used alone or in combination of two or more. The total basicity (TBN) of the overbased sulfonate in the first invention is usually 300
mgKOH / g or more, preferably 350 mgKOH / g
That is all. If the value of TBN is less than 300 mgKOH / g, the cutting performance is inferior, which is not preferable.

Although the content of the component (b) is not particularly limited, it is usually 1 to 50 parts by weight when the total amount of the lubricating oil composition for metal working is 100 parts by weight as shown in the third invention. Parts, preferably 3 to 40 parts by weight, more preferably 5 to 3 parts by weight.
0 parts by weight. If the content is less than 1 part by weight, the cutting performance is inferior because it is inferior. On the other hand, if it exceeds 50 parts by weight, the viscosity becomes high and the supply of the oil agent becomes difficult. Further, the haze value of the component (b) (mineral oil [trade name "Neutral Oil 10" manufactured by Nisseki Mitsubishi Co., Ltd.)]
A solution prepared by dissolving the solution at a concentration of 1% by weight to a value of 1% by weight and using a 1 mm wide cell in accordance with JIS K6714 is not particularly limited.
It can be a value less than 0.

As the component (c) in the present invention, for example, zinc dialkyldithiophosphate, zinc dialkyldithiocarbamate, molybdenum dialkyldithiophosphate, molybdenum dialkyldithiocarbamate and the like can be used. The organic compound constituting the component (c) is not particularly limited, but a sulfur-containing inorganic compound or a sulfur-containing organic compound is usually used. For example, thiophosphoric acid, thiomolybdic acid, and thiophosphoric acid and thiomolybdic acid having a hydrocarbon group, which are obtained by introducing a hydrocarbon group into them, may be mentioned. The hydrocarbon group in this case includes an alkyl group and an aryl group, and the number of hydrocarbon groups and the number of carbon atoms in the hydrocarbon group are not particularly limited, but may be 3 to
Twelve are preferably used. The metal constituting the component (c) is not particularly limited, but is preferably a polyvalent metal such as a transition metal, and more preferably zinc, molybdenum or the like.

The content of the component (c) is not particularly limited, but is usually 1 to 50 parts by weight when the total amount of the lubricating oil composition for metal working is 100 parts by weight as shown in the third invention. Parts, preferably 3 to 40 parts by weight, more preferably 5 to 3 parts by weight.
0 parts by weight. If this content is less than 1 part by weight, the cutting performance is inferior because it is inferior. On the other hand, if it exceeds 50 parts by weight, the performance does not change and is uneconomical.

The lubricating oil composition for metalworking of the present invention is excellent in lubricity even without containing a chlorine-based additive, and has a worked surface roughness measured by the conditions and measuring methods described in the following examples. Can be set to 15 μm or less, preferably 10 μm or less, and more preferably 8 μm or less.

[0014] The lubricating oil composition for metalworking of the present invention, in addition to the above-mentioned components, usually maintains the basic performance of the lubricating oil composition for metalworking, so that the object of the present invention is not impaired. Thus, various additives can be appropriately added as needed. For example, an antioxidant, a rust inhibitor, an anticorrosive, and the like can be appropriately added. Of course, it is preferable not to contain a chlorine compound or an active type sulfur extreme pressure additive.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the lubricating oil composition for metal working of the present invention will be specifically described with reference to Examples and Comparative Examples. (1) Preparation of lubricating oil composition for metal working By mixing the following components in a ratio of parts by weight shown in Table 1, lubricating oil compositions for metal working of Examples 1 to 3 and Comparative Examples 1 to 5 were prepared. Was prepared. (A) Base oil: methyl oleate (b) Overbased sulfonate: Overbased Ca sulfonate, trade name "Calcinate C400C", Wi
tco (TBN: 400 mgKOH / g) (c) Organometallic compound: zinc dialkyldithiophosphate, trade name "Adition RC3180", Bayer (alkyl chain; 2-ethylhexyl) (d) Other components Polysulfide A : Dioctyl pentasulfide, trade name "DAILUBEGS400", manufactured by Dainippon Ink and Chemicals, Inc. (sulfur content 39%) Polysulfide B: dibenzyl disulfide, manufactured by Wako Pure Chemical Industries, Ltd. (sulfur content 29%) Chlorinated paraffin: trade name "Empara K50" Mineral oil: trade name "Spindle oil", Cosmo Oil Co., Ltd.

[0016]

[Table 1]

(2) Evaluation of the performance of the lubricating oil composition for metal working In order to clarify the performance of the lubricating oil composition for metal working of the present invention, each of the lubricating oil compositions of Examples 1-3 and Comparative Examples 1-5 was used. The following performance tests were performed using the lubricating oil composition. The results are shown in Table 1 above. Machinability (Working Surface Roughness) Stainless steel (SUS304) was used as a work material, and the working surface roughness (μm, Rz) when this was cut under the following test conditions was measured. Cutting depth: 0.1 mm Cutting speed: 60 m / min Feed: 0.12 mm / rev Tool: Carbide Nose radius 0.4 Note that the machining surface roughness is measured using Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.). did.

Effect on Non-Ferrous Metals The lubricating oil compositions for metal working of Examples 1 to 3 and Comparative Examples 1 to 5 were dropped on brass polished with # 360 emery paper and then discolored when allowed to stand at 50 ° C. Was evaluated by visual observation. In Table 1, “◎” indicates that there was no discoloration, and “×” indicates that discoloration appeared.

(3) Effects of the Examples According to Table 1, Comparative Example 1, which does not contain the zinc dialkyldithiophosphate as the component (c), contains the active type sulfur-based extreme pressure additive polysulfide A. This indicates that the processed surface roughness is 6.1 μm, which is an excellent value, but that the brass is discolored. In order to prevent this, in Comparative Example 2 using an inert type sulfur-based extreme pressure additive, polysulfide B, discoloration of brass was prevented. Is 17.
This is a considerably large value of 9 μm, which indicates that the lubricity is poor.

In Comparative Example 3 in which methyl oleate as the component (a) was not used as the base oil, discoloration of brass was prevented as in Comparative Example 2, but the processed surface roughness was 15%. This is a considerably large value of 0.9 μm, which indicates that the lubricity is poor. Further, even in Comparative Example 5 which does not contain the overbased calcium sulfonate as the component (b), the lubricating property tends to be slightly improved to 10.6 μm, but shows a large value as before. At the same time, it can be seen that it caused the discoloration of the brass. From these results, it can be seen that in order to improve lubricity and prevent discoloration of the non-ferrous metal, it is essential to use the above three components (a) to (c) in combination.

On the other hand, in Examples 1 to 3 containing all of the above components (a) to (c), the processed surface roughness showed an excellent value of 6.1 to 7.2 μm, and It can be seen that the discoloration of brass is also prevented. Moreover, Examples 1 to 3
Has a performance comparable to that of Comparative Example 4 containing a chlorine-based compound, despite containing no chlorine-based compound, and therefore has a conventional lubricating oil composition for metalworking containing a chlorine-based compound. It turns out that it can be used enough as a substitute for a product.

In the present invention, the present invention is not limited to the specific embodiments described above, but may be variously modified within the scope of the present invention in accordance with the purpose and application. That is,
The lubricating oil composition for metalworking of the present invention is not limited to the compositions and mixing ratios shown in Table 1, but may be various compositions and mixing ratios within the scope of the present invention.

[0023]

According to the lubricating oil composition for metalworking of the present invention, a cutting or grinding process is carried out by forming a composition comprising a specific synthetic ester as a base oil and an overbased sulfonate and an organometallic compound. In addition to exhibiting excellent lubricity, it also has an excellent effect on the anticorrosion performance of non-ferrous metals. As a result, it can be sufficiently used as a substitute for a conventional metalworking lubricating oil composition containing a chlorine-based compound, and can prevent environmental pollution caused by a metalworking lubricating oil composition containing a chlorine-based compound. it can.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C10N 10:02 C10N 10:02 10:04 10:04 30:04 30:04 30:12 30:12 40:22 40 : 22 (72) Inventor Nobuomi Kuroi 1580 Tabata, Samukawa-cho, Koza-gun, Kanagawa Prefecture F-term in Yushiro Chemical Industry Co., Ltd. (reference) 4H104 BB32A BG10C BH07C DB07C FA01 FA02 FA06 LA06 PA21

Claims (3)

[Claims] 1. A base oil containing (a) an ester of a monohydric alcohol and a monocarboxylic acid, and (b) an alkali metal and / or
Or an overbased sulfonate with an alkaline earth metal,
(C) a metal salt of an organic compound; and a lubricating oil composition for metalworking. 2. The amount excluding (b) the overbased sulfonate of an alkali metal and / or an alkaline earth metal and (c) a metal salt of an organic compound from the total amount of the lubricating oil composition for metal working. In the case of 100 parts by weight, the above (a)
When the amount of the ester of the monohydric alcohol and the monocarboxylic acid is 6
The lubricating oil composition for metalworking according to claim 1, wherein the amount is 0 part by weight or more. 3. The total amount of the lubricating oil composition for metal working is 10
When the amount is 0 parts by weight, the content of the overbased sulfonate component (b) by the alkali metal and / or alkaline earth metal is 1 to 50 parts by weight, and the content of the metal salt of the organic compound (c) is The lubricating oil composition for metalworking according to claim 1 or 2, which is 1 to 50 parts by weight.