JPH10204470A - Lubricating oil composition for metalworking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricating oil not containing a chlorine-based high pressure agent, excellent in processability, corrosion resistance and environmental pollution resistance, and suitable for cutting, grinding process, etc., by containing a base oil of an active lubricating oil, an active dihydrocarbylpolysulfide and an inactive sulfurated oil and fat. SOLUTION: This lubricating oil composition for a metal processing contains (A) a base oil for an active lubricating oil such as an active sulfurated mineral oil, (B) preferably 0.1-30wt.% active dihydrocarbylpolysulfide such as dibenzylpolysulfide (based on the total amount of the composition) and (C) preferably 0.1-70wt.% inactive sulfurated oil such as a sulfurated lard. Further, a value of the weight ratio of (C/B) is preferably in 0.5-30 range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lubricating oil composition for metal working, and more particularly to a water-insoluble metal working lubricating oil composition suitable for cutting or grinding.

[0002]

2. Description of the Related Art In metal processing such as cutting and grinding, chlorine-based extreme pressure agents are generally used because they are excellent in improving cutting performance and relatively inexpensive. However, in recent years, when water-insoluble cutting fluids containing chlorine-based extreme pressure agents are used, problems such as environmental pollution due to the generation of dioxin during incineration and corrosion and damage to incinerators due to generation of chlorine gas are pointed out. There is. Some chlorinated paraffins among chlorinated extreme pressure agents have also raised concerns about toxicity and possible carcinogenicity. Therefore, development of an oil agent that does not contain a chlorine-based extreme pressure agent is being promoted.

[0003] By the way, active dihydrocarbyl polysulfide and inert sulfurized fats and oils are known as sulfur-based extreme pressure agents. The term “active or inactive” as used herein means that the value of the result of a test conducted at 100 ° C. for 1 hour in the test tube method of the copper plate corrosion test (JIS K-2513) is 3 or 4, and 1 or 2 is the activity. Defined as inactive. Cutting oils containing activated dihydrocarbyl polysulfide have good workability but have corrosion problems. On the other hand, cutting oils containing inert sulfurized fats and oils have low corrosiveness, but have problems in workability.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above, does not contain a chlorine-based extreme pressure agent, does not generate harmful gases during incineration, and has problems of environmental pollution or damage to incinerators. Another object of the present invention is to provide a lubricating oil composition for metalworking that has good workability and low corrosivity.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have used active lubricating base oils,
It has been surprisingly found that the combined use of active dihydrocarbyl polysulfide and an inert sulfurized oil or fat as additives makes it possible to draw out only the good points of both.

That is, the present invention provides (A) an active lubricating base oil, (B) an active dihydrocarbyl polysulfide,
And (C) an inert sulfurized oil and fat.

[0007]

Embodiments of the present invention will be described below. The component (A) constituting the lubricating oil composition for metal working of the present invention is a copper plate corrosion test (JIS K-2513).
Is an active lubricating base oil having a value of 3 or 4.
The component (A) preferably has a sulfur content of 0.1 to 1.5% by weight.

One embodiment of the component (A) is an activated sulfide mineral oil obtained by reacting one or more inert mineral oils having a value of 1 or 2 with a copper plate corrosion test (JIS K-2513) and sulfur with sulfur. Can be mentioned. The sulfided mineral oil usually contains 0.1 to 1 sulfur per 100 parts by weight of the mineral oil.
It is sufficient to add parts by weight and react at 120 to 130 ° C. for 10 minutes to 1 hour. As the raw mineral oil, for example, a distillate obtained by distilling a paraffin-based crude oil, an intermediate-base crude oil or a naphthenic-based crude oil under normal pressure, or a residual oil obtained by normal-pressure distillation under reduced pressure, or a distillate oil obtained by ordinary distillation. Refined oils obtained by refining according to the method, for example, solvent refined oils, hydrogenated refined oils, dewaxed oils, clay treated oils and the like can be mentioned. The sulfur is not particularly limited, and may be naturally-occurring ones or those produced by desulfurization of natural gas or petroleum fraction. Further, as one embodiment of the component (A), there can be mentioned an active sulfurized synthetic oil obtained by replacing the above-mentioned mineral oil with a synthetic oil. Examples of the synthetic oil include poly-α-olefin, α-olefin copolymer,
Polybutene, alkylbenzene, polyol ester,
Dibasic acid ester, polyoxyalkylene glycol,
Examples thereof include polyoxyalkylene glycol esters, polyalkylene glycol ethers, and silicone oils. Further, as one embodiment of the component (A), there can be mentioned an active mineral oil that has not been sufficiently purified (desulfurized) with a mineral oil. Among the above three aspects,
Activated sulfide mineral oil is preferred in terms of effect.

These active lubricating base oils can be used alone or in combination of two or more, respectively.
Activated sulfide mineral oil, Activated mineral oil, Activated sulfide synthetic oil, Activated mineral oil, Activated sulfide mineral oil, Activated sulfide synthetic oil, Inactive sulfide mineral oil with low degree of sulfidation as appropriate Inert ones selected from sulfurized synthetic oils can be combined. In addition, about the combination of the above, the mixture of inert mineral oil and synthetic oil may be sulfurized.

The active lubricating base oil used in the present invention comprises 4
0 kinematic viscosity at ℃ is preferably has in the range of 1 to 100 mm ² / s, it is more preferably in the range of 3 to 50 mm ² / s. If the kinematic viscosity of the base oil is too high, the amount of the oil agent adhering to the workpiece and carried away increases, which is not preferable because it may not be economical. On the other hand, if it is too low, mist generation may cause deterioration of workability, which is not preferable. The pour point, which is an index of the low-temperature fluidity of the base oil, is not particularly limited, but is preferably −10 ° C. or lower.

In the lubricating oil composition for metalworking according to the present invention, when the active lubricating base oil used has a relatively low viscosity of about 10 mm ² / s or less at 40 ° C. By blending the molecular compound, mist generation during metal working can be effectively suppressed. Usually, those having a number average molecular weight of 2,000 to 300,000 are preferably used as the above-mentioned polymer compound. There are various types of such high molecular compounds, and examples thereof include polymethacrylate, polyisobutylene, and olefin copolymers (eg, ethylene-propylene copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, and the like). it can.

Regarding the compounding ratio of the polymer compound,
Although it depends on the molecular weight and the properties of the base oil, it is usually 0.01 to 20% by weight, more preferably 0.1 to 20% by weight, based on the total amount of the composition.
It can be blended at a ratio of 1 to 10% by weight. If the amount of the polymer compound is less than 0.01% by weight, mist generation may not be sufficiently suppressed. Also, if it exceeds 20% by weight,
An increase in viscosity may undesirably cause the oil agent to be carried away by the workpiece.

Next, the component (B) constituting the lubricating oil for metal working of the present invention is a copper plate corrosion test (JIS K-251).
An active dihydrocarbyl polysulfide having a value of 3 or 4 in 3). Dihydrocarbyl polysulfide is represented by the following general formula (I): R ¹ -S _x -R ² ... (I) wherein R ¹ and R ² are each an alkyl group having 1 to 20 carbon atoms or a cyclic group. An alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms, which may be the same or different, and x is 2 to 8 Is an integer.). Where R ¹ and R ²
When is an alkyl group, it is called an alkyl sulfide.

Specific examples of R ¹ and R ² in the general formula (I) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s
ec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, various dodecyl groups, cyclohexyl groups, cyclooctyl groups, phenyl groups, naphthyl groups , Tolyl, xylyl, benzyl, phenethyl and the like.

Examples of the dihydrocarbyl polysulfide include dibenzyl polysulfide and di-disulfide.
tert-nonyl polysulfide, didodecyl polysulfide, di-tert-butyl polysulfide,
Preferred are dioctyl polysulfide, diphenyl polysulfide, dicyclohexyl polysulfide and the like.

In the present invention, the component (B) may be used singly or in combination of two or more.
In addition, the compounding amount is usually 0.1% based on the total weight of the composition.
The range is preferably from 1 to 30% by weight, more preferably from 1 to 15% by weight. If it is less than 0.1% by weight, the workability of cutting and grinding may not be maintained, and if it exceeds 30% by weight, the effect corresponding to the blending amount may not be improved.

The component (C) constituting the lubricating oil composition for metal working of the present invention is a copper plate corrosion test (JIS K-2).
513) is an inert sulfurized oil having a value of 1 or 2. Sulfurized fats and oils are obtained by reacting sulfur or a sulfur-containing compound with fats and oils (such as lard oil, whale oil, vegetable oil, fish oil, etc.), and the sulfur content is not particularly limited.
Those having a concentration of about 30% by weight are suitable. Specific examples thereof include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, and sulfurized rice bran oil.

In the present invention, the above component (C) may be used alone or in combination of two or more.
The compounding amount is usually 0.1% based on the total weight of the composition.
The range is preferably from 70 to 70% by weight, more preferably from 1 to 30% by weight. If it is less than 0.1% by weight, the workability of cutting and grinding may not be maintained, and if it exceeds 70% by weight, the effect corresponding to the compounding amount may not be improved.

The weight ratio of component (C) to component (B) is such that the value of component (C) / component (B) is
0.5 to 30 is preferable, and 1 to 10 is more preferable. The lubricating oil composition for metalworking of the present invention can be obtained by blending the components (A) to (C). Usually, the purpose of the present invention is to maintain basic performance as a metalworking oil. Various known additives can be appropriately compounded within a range not to inhibit the above. For example, sulfur-based extreme pressure agents other than the components (B) and (C) such as sulfurized olefins and sulfurized esters, phosphorus-based extreme pressure agents such as phosphate esters and phosphite esters, and alkali metal or alkaline earth metal sulfonates , Phenate, salicylate and other metal-based detergents and dispersants such as alkenyl succinic acid or its esters and imides; ash-based dispersants such as oleic acid, stearic acid, and dimer acid; Zinc (ZnDTP, excluding aryl type), zinc dithiocarbamate (ZnDTC), sulfurized oxymolybdenum dithiocarbamate (MoDTC), nickel dithiophosphate (NiDTP), nickel dithiocarbamate (NiD
TC) and other anti-wear agents; amine and phenolic antioxidants; metal deactivators such as thiadiazole and benzotriazole; rust inhibitors such as sorbitan esters and petroleum sulfonic acid; dimethylpolysiloxane and polyacrylate. Defoamers and the like can be mentioned.

[0020]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 and Comparative Examples 1 to 5 The components were blended at the ratios shown in Table 1 to prepare cutting oil compositions of Examples and Comparative Examples. With respect to the compositions of these Examples and Comparative Examples, a round bar turning experiment and a copper plate corrosion test were performed in the following manner to evaluate the processing performance and corrosivity of the oil agent. Table 1 shows the results. [Cutting Experiment] A round bar turning experiment was performed under the following cutting conditions, and the machining performance of the oil agent was evaluated by measuring the cutting resistance (main component force) and the finished surface roughness (R _Z ). Cutting conditions Cutting speed: 20 m / min Cutting depth: 0.5 mm Feeding speed: 0.1 mm / rev Work material: JIS SUS304 φ25 round bar Tool: Bite-Toshiba Tungaloy ESBNR1919R
43 chip-Mitsubishi Materials SNGG120404R (Carbide K10 class) Dynamometer: Kistler TYPE 9257B [Copper plate corrosion test] The test was carried out under the test tube method of JIS K-2513 at 100 ° C for 1 hour.

[0021]

[Table 1]

[0022]

[Table 2]

(Note) * 1: Paraffin mineral oil reacted with sulfur powder. (Sulfur content 0.6% by weight, kinematic viscosity at 40 ° C. 10 mm ² / s) * 2: paraffinic mineral oil (kinematic viscosity at 40 ° C. 10 m)
m ² / s) * 3: Di-tert-nonyl polysulfide * 4: Di-tert-dodecyl trisulfide * 5: Lard sulfide (sulfur content: 11% by weight) * 6: Lard The processing performance of the oil agent is Comparative Examples 1-4.
It is understood that it is equal to or more than the active oil agent and has low corrosiveness. Further, it can be seen that the processing performance is superior to that of the inactive oil agent of Comparative Example 5.

[0024]

The lubricating oil composition for metalworking of the present invention does not contain chlorinated extreme pressure agents, does not generate harmful gases during incineration, has no problem of environmental pollution or damage to incinerators, Good corrosion resistance and low corrosiveness.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10N 30:00 30:06 30:12 40:22 60:10

Claims (4)

[Claims] 1. A lubricating oil composition for metalworking comprising: (A) an active lubricating base oil, (B) an active dihydrocarbyl polysulfide, and (C) an inert sulfurized oil. 2. The lubricating oil composition for metalworking according to claim 1, wherein the component (A) is an active sulfide mineral oil. 3. Component (B) is 0.1% based on the total amount of the composition.
The lubricating oil composition for metalworking according to claim 1 or 2, wherein the content of the component (C) is 0.1 to 70% by weight. 4. The lubricating oil composition for metal working according to claim 1, wherein the value of (C) component / (B) component (weight ratio) is 0.5 to 30.