JPS625960B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lubricating oil composition for metal working, and more specifically to an emulsion type rolling lubricating oil composition having excellent rolling properties and annealing properties. Conventionally, emulsion-type lubricating oil compositions used in metal processing, such as rolling, especially sheet gauge rolling, which is said to be thick, are mainly O/O/O oils based on mineral oils or fats and oils.
The W emulsion type is the mainstream. This emulsion is then sprayed onto the comparatively high-temperature friction surfaces of the rolling rolls and the rolled metal material, and is destroyed by mechanical and thermal action, and the separated oil adheres to the metal material surface. It is believed that the lubricating effect is achieved by adsorbing pressure agents and the like. Therefore, in emulsion-type lubricating oil compositions, it is recognized that emulsions that are more easily destroyed during lubrication, that is, unstable emulsions, exhibit better lubricating effects; however, in actual work, they are difficult to store and handle. From this point of view, a stable emulsion is required. Various studies have been conducted on lubricating oil compositions for emulsion type rolling. Literature on the phenomenon of emulsion failure in the lubricating action of rolling oil emulsions in hot and cold rolling, for example;
“Plasticity and Processing”, Vol.17, No.184 (1976-5), 433
Pages 444 to 444 discuss the destruction of emulsion as one of the characteristics of emulsion lubrication, and it is reported that factors such as temperature and surfactant have a large influence on this destruction phenomenon. Lubrication, Vol. 17, No. 3, pages 129-134, especially in the right column of page 130, in the section "4. Conditions that rolling oil should have," there is a description of the need for stability of rolling oil emulsions. be. As can be seen from the descriptions in these documents, emulsion-type rolling compositions are required to have the mutually contradictory requirements of easy emulsion breakability and good emulsion stability, but no efforts have yet been made to satisfactorily satisfy both of these conditions. No emulsion-type rolling lubricating composition has been obtained. In general, the HLB value of the emulsifier and the temperature of the emulsion have a large effect on the destruction of O/W emulsions, that is, the phase inversion from O/W to W/O, but on the other hand, the type of oil and emulsifier It is known that the temperature at which the phase changes (phase inversion temperature) is controlled. Recently, some attempts have been made to utilize the phase inversion phenomenon (for example, the Japan Society of Lubrication, Tohoku Conference Preprint, p. 25 (October 7, 1972)).
If the oil simply undergoes phase inversion, it cannot be used as an actual rolling oil; it is essential that the phase inversion cycle occurs during rolling and during storage, that is, the phase inversion must be reversible. The present inventors focused on the reversibility of this phase inversion, and determined the temperature range in which emulsion-type rolling lubricating oil compositions are actually used, that is, 40 to 40°C.
Tank storage conditions at 200℃ (low temperature, 40-60℃
In order to obtain a lubricating oil composition for rolling that forms a stable O/W type emulsion under rolling conditions (high temperature, 100-200°C), the emulsion is easily destroyed. It has been discovered that certain specific compounds can be added to controllably adjust the reversible phase inversion of the lubricating oil composition. In conventional emulsion-type lubricating oil compositions for metal working that use mineral oil and fat as base oils, an increase in the oil content leads to poor annealing properties, and a decrease in oil content reduces rollability. It is not possible to simultaneously impart satisfactory annealing and rolling properties by adjusting the amount added, and it has been a long-standing challenge in this industry to obtain a lubricating oil composition for metal working that has both of these properties. It was hot. However, according to research conducted by the present inventors, it has been found that the above problems can be solved by utilizing the reversible phase transition phenomenon of the emulsion-type rolling lubricating oil composition as described above. Therefore, the present invention is based on controlling the reversible phase inversion of an emulsion-type lubricating composition, and
Under rolling conditions (100 to 200℃), the emulsion breaks (phase inversion) and changes from O/W type to W/O type emulsion, and under tank storage conditions (40 to 60℃), O/W type emulsion changes.
The present invention was completed by confirming that a lubricating oil composition for rolling having a phase inversion cycle such as phase inversion and return to a mold emulsion satisfies both annealing and rolling properties at the same time. According to the present invention, a phase inversion modifier is used because the phase inversion is reversible depending on the environment in which the lubricating oil composition is placed as described above. A lubricating oil composition suitable for rolling is preferably one that undergoes phase inversion at about 70°C, but it has been found that such a lubricating oil composition can be obtained by using a specific emulsifier and a phase inversion modifier in combination. Ta. Therefore, the emulsion-type rolling lubricating oil composition according to the present invention is prepared by adding water and mineral oil, or a fat or oil to them, and having the general formula RO(-CH ₂ CH ₂ O) _o H (where R is C ₈ to C ₁₈ an alkyl group or

[Formula] R''--CO-- group, where R' and R'' are C ₆ to C ₁₂ alkyl groups. n represents an integer of 2 to 10. ) and a phase inversion modifier (excluding polyoxyethylene group-containing phosphate esters). The emulsion-type rolling lubricating oil composition of the present invention having desired phase inversion conditions can be obtained by adding water, mineral oil, emulsifier, and phase inversion modifier mixed in various proportions. The mineral oil used in the emulsion type rolling lubricating oil composition of the present invention is any type of mineral oil, and the lubricating oil fraction obtained by distilling crude oil is subjected to solvent refining, sulfuric acid treatment, clay treatment, hydrogenation refining, etc. It is a thing,
Examples include 60 spindle oil, 120 machine oil, 150 neutral oil, 500 neutral oil, bright stock, etc. The content of mineral oil is 0 to 99 parts by weight. The fats and oils used in the lubricating oil composition of the present invention are common animal and vegetable oils, such as palm oil, castor oil, coconut oil,
These include rapeseed oil, soybean oil, fish oil, whale oil, beef tallow, pork fat, and mutton fat. The content of fats and oils is 0 to less than 50 parts by weight, and in consideration of annealing properties, 1 to 10 parts by weight is particularly preferable. The emulsifier used in the lubricating oil composition of the present invention has the general formula R—O(—CH ₂ CH ₂ O) _o H (wherein R is a C ₈ to C ₁₈ alkyl group or

[Formula] R'' represents a CO- group, and R' and R'' represent a C ₆ to C ₁₂ alkyl group. n represents an integer of 2 to 10. ) Polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl ester. As such emulsifiers, it is preferable to use one having a low HLB value alone, and one having a narrow distribution range of the number of added moles (n) of oxyethylene groups is particularly effective. Such emulsifiers include, for example, polyoxyethylene lauryl ether
(n=5,6,8) polyoxyethylene oleyl ether
(n=6) Polyoxyethylene octyl phenyl ether (n=3,4,5,7) Polyoxyethylene nonyl phenyl ether (n=2,3,4,5,6,7,8,9) Poly oxyethylene lauryl ester
(n=4,5,6,8) polyoxyethylene stearyl ester
(n=5, 6), etc. The amount of emulsifier added is any effective amount, but is usually in the range of 0.1 to 15 parts by weight. The following various compounds can be mentioned as the phase inversion modifier used in the lubricating oil composition of the present invention. 1 Glycols, such as ethylene glycol,
Diethylene glycol, polyethylene glycol, etc. 2 Metal sulfonic acid salts, such as alkali metal or alkaline earth metal salts of petroleum sulfonic acids or conventional sulfonic acids, such as sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, etc. 3 Nitrogen-containing compounds, such as polyoxyethylene alkylamines, alkylammonium chlorides, alkenyl succinimides (e.g.
Those with an alkenyl group having a molecular weight of 250 to 3000 obtained by the method described in Japanese Patent Publication No. 37-15778), acid amides (for example, _C12 to _C30 linear or branched carboxylic acid amides), etc. . 4. Phosphorus or sulfur compounds (excluding polyoxyethylene group-containing phosphate esters), such as Zn, Mo, W salts of dithiophosphoric acid, phosphoric esters, phosphorous esters, polysulfides, etc. 5 Mineral oil oxides or sulfides. For example, oxides with a saponification value of 20 mgKOH/g or more obtained by the oxidation reaction of mineral oil (mineral oil
Liquid-phase air oxidation at 150℃ is preferable) or active sulfur obtained by sulfidation reaction of mineral oil is preferable.
0.02% (ASTM D-1662) sulfide (mineral oil and elemental sulfur reacted at 70-160°C are good) 6. Special mineral oil, i.e. lubricating oil fraction obtained by vacuum distillation, is extracted with solvent. The extracted portion has a %CA of 20% or more by the ndM method. These phase inversion modifiers can be used alone or in combination of two or more, and the amount added is from 0.05 to 99 parts by weight. The emulsion-type rolling lubricating oil composition according to the present invention includes 0 to 99 parts by weight of mineral oil, preferably 50 to 95 parts by weight, 0 to less than 50 parts by weight of oil and fat, preferably 1 to 10 parts by weight, and 0.1 to 15 parts by weight of emulsifier. , preferably 1 to 10
parts by weight, phase inversion modifier 0.05-99 parts by weight, preferably
Obtained by adding 0.1 to 50 parts by weight. Add 100 parts by weight of the stock solution consisting of the above composition to 2 to 2 parts by weight of water.
The composition of the invention can be obtained by diluting it 200 times, preferably 5 to 100 times. The emulsion-type rolling lubricating oil composition of the present invention (1) has excellent lubricity, with a large amount of oil adhering to the coil surface and roll surface during rolling. (2) Extremely excellent annealing properties. (3) It forms a compact and stable emulsion in a circulation tank, and has excellent emulsion stability. (4) It has advantages such as a small amount of scum produced and easy management of rolling oil, and exhibits extremely excellent performance as a lubricating oil composition for rolling. The present invention will be explained in more detail with reference to the following examples. Example A composition according to the present invention was emulsified and prepared as shown in Table 1. For comparison, a product to which no phase inversion modifier was added (Comparative Product 1) and a commercially available product (Comparative Product 2) were used. Inventive products 1 to 3 and comparative product 1 have a stock solution of 100% as shown in the table.
Weight part

[Table] is emulsified by mixing 20 times (by weight) water. 1. Rolling Experiment The above lubricating oil composition was tested using the following rolling mill and rolling conditions. Rolling machine: Reversible precision two-high rolling mill (manufactured by Yoshida Daini Kinen) Work roll specifications: 200φ×200W Central cooling type
Hardness HS97, Material SUJ-2 Maximum rolling capacity: 40t Mill motor: 100 Tension: 70-500Kg Rolling speed: Maximum 200m/min Roll roughness: 0.4μmax. Rolling conditions Rolled material: JIS-G-3141, 1.0mm x 50mm ×100m
Coil Rolling speed: 200 m/min Sample oil: 5% aqueous solution Reduction schedule (reduction rate for each pass): 10% (1 pass) - 30% (2 passes) -30% (3 passes) - 30% (4 pass) -30% (5 passes) Lubrication amount: 5/min Evaluation was performed by calculating the friction coefficient using the commonly used stone formula. Table 2 shows the results of rolling experiments for inventive product 1 and comparative product 2.
It was shown to. Furthermore, Figure 1 shows the friction coefficient for five passes with severe lubrication conditions.

[Table] As shown in Table 2 above and FIG. 1, it can be seen that the products of the present invention have a small friction coefficient and excellent rollability. On the other hand, Comparative Products 1 and 2, which do not contain a phase inversion modifier and do not undergo reversible phase inversion, have high friction coefficients and show poor rolling properties. Annealing property test 0.5 g of sample oil was sealed in a steel plate with a recess in the center, and the steel plate was covered with a flat plate and annealed. The evaluation was based on the presence or absence of carbonaceous substances after annealing. Annealing conditions Temperature: 700℃ x 30 minutes (heating rate 1℃/min) Atmosphere gas: _N2 gas 100% (50/min)

[Table] As can be seen from Table 3, the products of the present invention have no carbonaceous substances, indicating that they have good annealing properties. On the other hand, comparative product 2 contains a lot of carbonaceous substances and has poor annealing properties. Comparative product 1 has a low amount of oil and fat, so it has good annealing properties. Phase inversion cycle test In order to confirm the storage stability in a circulation tank due to reversible phase inversion, the present invention product 1 was placed in a 1KL capacity tank.
700 ml of water was poured into the tank, and the tank was circulated at a rate of 100 ml per minute for 60 days between the tank and a high-temperature plate at about 150°C installed outside, and scum in the tank liquid was observed. The oil temperature in the tank is
It was kept at 50℃. Even after 60 days, there is very little scum in the tank liquid. It can be seen that the emulsion stability in the tank is good and phase inversion is reversible. A similar experiment was conducted on Comparative Product 2. The amount of scum generated was quite large, and the emulsion stability was poor. As explained in detail above, it is clear that the emulsion-type rolling lubricating oil composition according to the present invention has excellent rolling properties and annealing properties, and also has excellent emulsion stability in a tank.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the friction coefficient of the fifth pass of the rolling experiment.

Claims (1)

[Claims] 1 Water and mineral oil, or fats and oils are added to these, and the general formula R—O(—CH ₂ CH ₂ O) _o H (wherein R is a C ₈ to C ₁₈ alkyl group or [Formula] R″—Represents a CO— group. However, R′ and R″ are C ₆ to C ₁₂ alkyl groups. n is 2 to
Indicates an integer of 10. ) emulsifiers and glycols, sulfonic acid metal salts, nitrogen-containing compounds, phosphorus or sulfur compounds (excluding polyoxyethylene group-containing phosphate esters), mineral oil oxides or sulfides,
An emulsion type rolling lubricating oil composition comprising a phase inversion modifier selected from one or more mineral oils having a %CA of 20 or more.