JP3432045B2 - Emulsion type cutting oil - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting oil as a lubricant used when machining a metal material such as cutting and grinding, and particularly an emulsion even if the hardness of dispersed water increases. The present invention relates to an emulsion type cutting oil capable of stably holding an emulsion without breaking and maintaining a cutting function for a long time.

[0002]

2. Description of the Related Art Generally, for machining a metal material,
Cutting (grinding), cutting such as pressing and rolling, and plastic working are known. During the machining, the machining material and the tool come into contact with each other at a high pressure during the machining to generate a large frictional heat, and the temperature of the friction surface is significantly increased.

Therefore, the cutting oil is applied to the contact point between the working material and the tool to lubricate the contact portion between the working material and the tool and reduce the frictional force to generate frictional heat. At the same time, the contact portion is cooled to remove the generated heat, suppress the temperature rise of the friction surface, and maintain a good working state without causing baking.

However, the most suitable cutting oils of this type at present are roughly classified into water-insoluble cutting oils and water-soluble cutting oils. The former water-insoluble cutting oils are
It is an oily one to which a lubricant such as mineral oil, oil and fat, and synthetic oil is added as a base oil, and is mainly intended to improve the lubricity. The latter water-soluble cutting oil is, for example, an extreme pressure additive is optionally added to the above base oil, a surfactant is added, and the mixture is dispersed and emulsified in water to form an O / W emulsion, which is especially cooled. It is aimed at improving sex. Then, the latter emulsion type cutting oil is mixed with water in an amount of 10 to 50 times that of the oil agent at the time of use to prepare an O / W type emulsion, and is appropriately used. Here, the O / W type emulsion means that oil as a dispersoid is uniformly dispersed in fine particles in water as a dispersion medium, and oil particles are aggregated and aggregated with each other over time. It is a state that is not separated from.

[0005]

However, the conventional emulsion-type cutting oil has a problem that the water content of the emulsion is M.
When g ²⁺ or Ca ²⁺ is added, the hardness of water rises, the emulsion breaks, and the oil and water separate, causing the oil that was previously uniformly dispersed in the water to escape from the water. In particular, the concentration of the cutting oil in water, which occupies most of the O / W emulsion, is lowered, and there is a problem that the cutting function is lowered.

[0006] For example, when it is used to continue cutting an aluminum alloy having a high Mg ²⁺ content, Mg ²⁺ tends to be preferentially eluted over Al ^{3+ in} the water of the emulsion.
For this reason, the concentration of Mg ²⁺ is increased, and there is a fear that emulsion destruction may occur. That is, the emulsion-type cutting oil that has undergone such emulsion breakage remarkably deteriorates in lubricity and cooling performance, resulting in deterioration in cutting function.

Therefore, as a result of intensive studies, the present inventors have found that cellulose (which is generally referred to as cellulose acetate or bacterial cellulose) obtained by metabolizing sugar raw materials from acetic acid bacteria by aeration stirring culture method By mixing with the conventional emulsion type cutting oil,
It was found that the stability of the emulsion can be increased and the cutting function can be stably maintained for a long period of time.

Therefore, an object of the present invention is to provide an emulsion-type cutting in which a surfactant or the like is added to a base oil composed of a lubricant of at least one of mineral oil, fats and oils, and synthetic oil to disperse and emulsify it in water. An object of the present invention is to provide an emulsion type cutting oil which can improve the stability of the emulsion and maintain a stable cutting function for a long period of time.

[0009]

In order to achieve the above-mentioned object, the emulsion type cutting oil according to the present invention comprises a base oil composed of at least one kind of lubricant selected from mineral oil, fats and oils, and synthetic oil. In an emulsion type cutting oil which is dispersed and emulsified in water as an O / W type emulsion by adding agents and the like, cellulose fibers produced by acetic acid bacteria metabolizing sugar raw materials by aeration stirring culture method are mixed. .

In the above emulsion type cutting oil, cellulose fibers having a diameter of 0.01 to 0.1 μm and a length of 100 to 500 μm can be preferably used.

It is preferable that 0.01 to 0.5% of the cellulose fiber is added to and mixed with the emulsion type cutting oil.

[0012]

In the emulsion type cutting oil according to the present invention,
Cellulose, which is produced by metabolizing sugar raw materials from acetic acid bacteria by the aeration stirring culture method of mixing, that is, bacterial cellulose, has a directional property like plant cellulose fiber because microfibrils of cellulose fibers are aggregated with no directionality. It has a feature that the fiber diameter is smaller than that of the aggregate having. Here, the diameter of oil droplet dispersed particles (micelles) in water is about 1 to 10 μm, whereas bacterial cellulose has a fiber diameter of 0.01 to 0.1 μm and a length of 100 to
Since it is 500 μm, it is possible to sufficiently surround the micelle. At this time, bacterial cellulose has both hydrophilicity and lipophilicity, so part of the bacterial cellulose enters the boundary surface between the micelle and the surrounding water, and contributes to stabilizing the emulsion by creating a three-dimensional structure. It is thought that

Further, since the bacterial cellulose produced by the aeration-agitation culture method is stored in a water-retaining state, the cutting oil should be previously put in and dispersed in water added for emulsification. Thus, emulsification by mixing cutting oil and water can be effectively achieved.

In the present invention, the mineral oil as the base oil is
Refined mineral oils such as machine oils and turbine oils can be used.

As the fats and oils, vegetable oils such as rapeseed oil, soybean oil, lard oil and beef tallow, animal oils, or hydrogenated oils thereof can be used.

Further, synthetic oils include synthetic hydrocarbon oils such as poly-alpha-olefin oils and polypentadiene oils, fatty acid pentaerythritol esters, ester oils such as dioctyl sebacate, polyether polyol oils, silicone oils. Etc. can be used.

As the additives other than the surfactant, all the additives generally used as additives for cutting oil can be added. For example, extreme pressure additives, rust preventives,
Antioxidants and the like.

In the present invention, the mechanism that contributes to the stabilization of the emulsion by mixing cellulose acetate (bacterial cellulose) has not been completely clarified, but this is not due to the electric double layer but due to adsorption. It is thought that this is due to steric stabilization. That is, when undried cellulose acetate is mechanically microfibrillated, it is possible to enhance the water retention performance, and such microfibrillated cellulose acetate is excellent in dispersibility and at the same time it is applied to the human body. Because of its high safety, it is known to be applied to foods, cosmetics, and pharmaceuticals. Therefore, for example, in emulsion type cutting fluid, when the emulsion is stable due to ionization, even when the emulsion is destroyed by Mg ²⁺ ions or the like, the steric stabilization by the neutral cellulose acetate works effectively. It is considered that the hardness and water resistance can be improved.

Particularly, as the cellulose acetate applied to the present invention, it is effective to use microfibrillated fibers having a diameter of 0.01 to 0.1 μm and a length of 100 to 500 μm.

The cellulose acetate fibers to be added and mixed are effective in the range of 0.01 to 0.5% based on the emulsion type cutting oil.

[0021]

EXAMPLES Next, examples of emulsion type cutting fluid according to the present invention will be described.

Example 1 "Hang Star Fur S-500" (Mitsui Oil Co., Ltd.) consisting of 20 to 30% anionic surfactant, 5 to 15% chlorinated paraffin, 1 to 5% fatty acid and the balance mineral oil Company-produced petroleum-based hydrocarbon oils and additives) "were used and diluted and mixed with 15 times water to prepare an emulsion type cutting oil. This petroleum hydrocarbon oil has a boiling point of 101 ° C., a water solubility of 100%, a specific gravity of 0.961, and a pH.
(5%) 9.1, kinematic viscosity (40 ° C) 61.0 mm ² / s
It has physical and chemical properties consisting of

Cellulose acetate fibers produced by acetic acid bacteria metabolizing sugar raw materials in this emulsion type cutting oil by aeration stirring culture method, the diameter of the fibers is 0.01 to 0.1 μm.
The emulsion-type cutting oil according to the present invention is prepared by adding wet dispersed cellulose acetate fibers having a length of 100 to 500 μm in water and adding and dispersing the cellulose dispersion water in water at a concentration of 0.07%. Was prepared.

Next, the emulsion type cutting oil thus obtained in this embodiment was mixed with Mg ²⁺ ions to form MgC.
MgC, which is added as an aqueous solution of l ₂ to cause emulsion breakage and separates oil and water by this emulsion breakage
As a result of measuring the limit concentration of l ₂ , the limit concentration is 0.3.
%Met.

Comparative Example 1 An emulsion type cutting oil was prepared in the same manner as in Example 1 except that cellulose acetate fiber was not added.

To the emulsion type cutting oil thus obtained, Mg ²⁺ ions are added in the state of an aqueous MgCl ₂ solution to cause emulsion breakage, and the limit concentration of MgCl _{2 which} separates oil and water by this emulsion breakage is set. As a result of the measurement, the limit concentration was 0.15%.

From the results of the measurement of the limiting concentration of MgCl ₂ in the emulsion type cutting oils of Example 1 and Comparative Example 1 described above, the durability of the emulsion type cutting oil according to the present invention to which cellulose acetate fiber was added and mixed against emulsion breakage was examined. It was confirmed that the property is high.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and many design changes can be made without departing from the spirit of the present invention.

[0029]

As is apparent from the above-described embodiments, according to the emulsion type cutting oil of the present invention, the interface oil is added to the base oil composed of at least one kind of lubricant selected from mineral oil, fat and oil, and synthetic oil. In an emulsion type cutting oil, which is dispersed and emulsified in water as an O / W type emulsion by adding an activator or the like, an emulsion is prepared by mixing cellulose fibers produced by acetic acid bacteria by metabolizing sugar raw materials by aeration stirring culture method. It is possible to prevent breakage of the steel and improve its stability, and maintain a stable cutting function for a long period of time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C10N 40:22 (56) References JP-A-5-117683 (JP, A) JP-A-4-178500 (JP, A) Kaihei 3-14895 (JP, A) JP-A-2-227045 (JP, A) JP-A-2-227046 (JP, A) JP-A-3-157402 (JP, A) JP-A-5-51885 ( JP, A) JP-A-7-118301 (JP, A) JP-A-8-276126 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C10M 173/00-173/02 C10M 107/36 C10M 145/40 C10N 20:06 C10N 30:00 C10N 40:20-40:24

Claims (3)

(57) [Claims] 1. At least what is selected from mineral oils, fats and oils, and synthetic oils.
In an emulsion type cutting oil, which is made by adding a surfactant to a base oil consisting of one kind of lubricant and dispersing and emulsifying in water to form an O / W type emulsion, acetic acid bacteria metabolize sugar raw materials by aeration stirring culture method. An emulsion type cutting oil characterized by adding and mixing the cellulose fibers produced by the above. 2. The cellulose fiber has a diameter of 0.01 to
The emulsion type cutting oil according to claim 1, which is 0.1 μm in length and 100 to 500 μm in length. 3. The emulsion-type cutting oil according to claim 1, wherein the cellulose fiber is added and mixed in an amount of 0.01 to 0.5% with respect to the emulsion-type cutting oil.