JP4829549B2 - Lubricating oil for plastic working - Google Patents

Description

  The present invention relates to a lubricating oil for plastic working for continuously cast-rolling or pressing non-ferrous metals such as aluminum, magnesium, zinc, or alloys thereof. In particular, the present invention relates to a lubricating oil for plastic working that does not easily deteriorate even under high temperature conditions.

  As is well known, metal plastic working oils are designed to lubricate the machined surface, prevent seizure and welding, and allow continuous machining. By the way, seizure and welding can be prevented if the oil film has a certain thickness (about 5 μm or more although it varies depending on the surface roughness or load of the processed surface) under high temperature operation conditions. However, at a temperature of 200 ° C. or higher, particularly over 300 ° C., the oil film becomes thin due to deterioration and decomposition of the oil film component. As a result, the possibility of direct contact between the machined surface and the tool increases, which can lead to wear and seizure.

  Conventionally, various methods are already known as a method of maintaining the oil film thickness on a metal surface. For example, a method in which a grease-like material is applied, a powder (graphite, aluminum powder, talc, etc.) is attached, or a wax is applied is actually used. However, it is difficult to apply grease-like substances automatically and continuously. It is also known that powders and waxes cause a problem of contamination around the apparatus, and waxes and greases decompose and deteriorate at high temperatures (for example, 300 ° C. or more), thin the oil film, and cause wear.

  In order to suppress contamination around the apparatus and thicken the oil film, it is conceivable to use an organic polymer material. Generally, however, the polymer material is decomposed at a high temperature and the oil film is likely to disappear. Therefore, it is necessary to take measures to slow the decomposition of the oil film even at high temperatures.

Conventionally, for this reason, Patent Document 1 and Non-Patent Document 1 are known. Patent Document 1 describes that a phenolic system and an amine system are blended in a plastic processing oil to prevent a decrease in cooling efficiency due to deterioration of the oil remaining in the apparatus after processing. Non-Patent Document 1 describes that when a tin plate is cold sweat rolled, a phenolic and an amine are blended in order to prevent deterioration of the remaining oil film and facilitate paint and coating.
Japanese Patent Application Laid-Open No. 11-228982 Japanese Patent Application No. 2000-017284

  The present invention has been made to solve the above-mentioned problems. By adding an antioxidant, the decomposition and deterioration of the plastic working oil at high temperatures can be delayed, and the processing can be completed before the oil film is worn. An object is to provide a lubricating oil for plastic working.

  As a result of various researches on plastic working lubricants, the present applicant has come to consider the following. That is, even if pyrolysis occurs at high temperatures, it is desirable to maintain a minimum oil film until the metal processing is completed. By the way, it is conceivable to use an antioxidant as a method of delaying thermal decomposition. Antioxidants are roughly classified into three types: phenolic, amine-based, and phosphorus / sulfur-based. Here, the phosphorus / sulfur system easily reacts with a non-ferrous metal, and sometimes changes the surface chemical composition of the processed product, which may cause a problem. Therefore, a phenol system or an amine system is preferable. However, there are cases where an economical and widely used phosphorus / sulfur antioxidant can be used. Based on these considerations, the present applicant has proposed the following invention.

The lubricating oil for plastic working according to the present invention is a lubricating oil for plastic working for continuously casting or rolling a non-ferrous metal,
A base oil (solvent) 30 to 90 parts by weight,
40 ° C. kinematic viscosity of 10 mm ² / s or more oil group and one selected from (mineral oils, synthetic oils, fats, the group consisting of fatty acids and fatty esters) or two or more in total 1 to 25 parts by weight,
And 1 to 20 parts by weight of silicone oil,
More than 0.1 parts by weight of phenolic and amine antioxidants, respectively, and 2 parts by weight or less in total ,
An additive having a lubrication performance,
And organic molybdenum comprises <br/>, wherein the flash point is in the range of 8 0 ℃ ~150 ℃.

  According to the present invention, by adding an antioxidant, it is possible to obtain a plastic working lubricating oil that delays the decomposition and deterioration of the plastic working oil at a high temperature and can complete the processing before the oil film is worn. After that, even if the oil film is further decomposed by heat and becomes thin, there is no problem in processing. That is, the antioxidant is a so-called life extension agent for the oil film, and other components constitute the oil film.

Hereinafter, the present invention will be described in more detail.
1) In the present invention, “the kinematic viscosity at 40 ° C. is 10 mm ² / s or more” means that if it is less than 10 mm ² / s, the actual working temperature when the non-ferrous metal such as aluminum is poured between the rollers (roll surface) Is about 3 mm ² / s at 100 ° C., and it may be easy to flow down from the roll.

  In addition, blending one or more selected from the oil group is important for forming an oil film on a tool surface such as a roll or a blade edge, but tends to evaporate and decompose at a high temperature of 300 ° C or higher. The oil film strength is weak. Therefore, silicone oil is required to maintain the oil film at high temperatures. On the other hand, in a part where the working temperature is low (for example, 150 ° C.), a little silicone oil may be used, and 1% may be used. However, in a part where the working temperature exceeds 300 ° C., a higher concentration of silicone oil is preferable. However, although it depends on the molecular weight and structure of the silicone oil, the solubility of the silicone in the oil is limited, and about 20% is the limit.

  2) In the present invention, the flash point is set to 60 ° C. to 150 ° C. as described above, and it evaporates on the mold surface from the viewpoint of influence on the human body, the evaporation rate of the solvent part in the release agent and the flammability. This is to optimize the components.

  3) In this invention, it is preferable that 0.5-15 mass parts of graphite for reinforcing the lubricity at high temperature is further included. That is, it provides good load bearing performance under high temperature and high load conditions, which is an advantage of graphite. Exhibits excellent lubrication performance under operating conditions that do not bother the mechanical dirt, which is a drawback of graphite. Here, if the blending amount of graphite is less than 0.5 parts by mass, the lubricity of the lubricating oil at high temperature is not sufficient, and if it exceeds 15 parts by mass, the graphite settles during storage of the lubricating oil and the stability is lowered.

4) In the present invention, the base oil includes a solvent. However, in rolling under high temperature and high load, mist of rolling oil is inevitably generated, and the health of the operator may be impaired. Therefore, the base oil used in the present invention is preferably highly purified. Specifically, the total sulfur content in the base oil is preferably 1 ppm or less. More preferred is less than 0.1 ppm. In the first invention, the flash point of the base oil is preferably in the range of 60 to 150 ° C. in consideration of evaporability and flammability. Furthermore, the kinematic viscosity at 40 ° C. of the solvent as the base oil is preferably 1.1 mm ² / s to 10 mm ² / s, more preferably 1.1 mm ² / s to 3 mm ² / s.

  5) Examples of the mineral oil in the oil group include spindle oil, machine oil, motor oil, and cylinder oil. Examples of the synthetic oil include poly α-olefins (ethylene-propylene copolymer, polybutene, 1-octene oligomer, 1-decene oligomer, and hydrides thereof), monoesters (butyl stearate, octyl laurate). ), Diesters (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl separate), polyester (trimellitic acid ester, etc.), polyol ester (trimethylolpropane caprylate) , Trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, polyphenyl ether, dialkyl Phenyl ether phosphate esters (tricresyl phosphate, etc.).

6) Examples of the fats and oils include animal and vegetable fats and oils such as rapeseed oil, soybean oil, coconut oil, palm oil, beef tallow and lard. The fats and oils are utilized for securing lubricity in the middle and low temperature portions together with organic molybdenum and the like to be described later.
Examples of the fatty acid include coconut oil fatty acid, oleic acid, stearic acid, lauric acid, palmitic acid, and beef tallow fatty acid.

7) Examples of the fatty acid esters include monohydric alcohol esters or polyhydric alcohol esters of higher fatty acids such as coconut oil fatty acid, oleic acid, stearic acid, palmitic acid, lauric acid, and beef tallow fatty acid.
The silicone oil used in the present invention may be any of a number of different commercially available materials when used in plastic processing oil compositions, but is preferably an alkyl-modified silicone with excellent paintability. The silicone oil is a lubricant that can withstand relatively high temperatures.
The graphite used in the present invention may be any of a number of different commercially available materials when used in a plastic working oil composition.

  8) Examples of the antioxidant used in the present invention include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 4,4- Phenols such as methylenebis (2,6-di-tert-butylphenol), 2,2-methylenebis (4-ethyl-6-tert-butylphenol), monoalkyldiphenylamines such as monooctyldiphenylamine, monononyldiphenylamine, 4, 4'-dibutylphenylamine, 4,4'-dipentyldiphenylamine, 4,4'-dihexyldiphenylamine, 4,4'-diheptyldiphenylamine, 4,4'-dioctyldiphenylamine, 4,4'-dinonyldiphenylamine, etc. Dialkyldiphenylamine, tetrabutyl Polyalkyldiphenylamines such as phenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine, a-naphthylamine, phenyl-a-naphthylamine, butylphenyl-a-naphthylamine, pentylphenyl-a-naphthylamine, hexylphenyl-a- Examples include naphthylamine, heptylphenyl-a-naphthylamine, octylphenyl-a-naphthylamine and the like. Of these, dialkyldiphenylamine-based ones are preferable. Further, phosphorus / sulfur compounds such as ZnDDP and MoDTP and sulfur compounds such as MoDDC are also preferable.

  9) The effect of the antioxidant varies depending on its concentration. In general, the addition amount of an antioxidant for improving the oxidative stability of a petroleum composition is 0.01% to 5%, and the effect on concentration is expressed by a parabola. That is, if the concentration of the antioxidant is low (less than 0.01%), the effect is small, and if the concentration is too high (greater than 5%), the effect of increasing the amount cannot be expected. The level of effect also varies with other ingredients in the composition. In the present invention, the amount of antioxidant added is 0.1 to 2%, preferably 0.1 to 1.5%.

10) Also, the lubricating oil for plastic working of the present invention includes a rust inhibitor, a surfactant, a preservative, an antifoaming agent, and other additives (for example, extreme pressure additives, anticorrosives, viscosity index improvers). , Dispersants, thickeners, colorants, perfumes).
11) In the present invention, the flash point is preferably set to 80 to 150 ° C rather than 60 to 150 ° C. This is because the risk of fire is further reduced by increasing the lower limit of the flash point.

(Examples and Comparative Examples)
Hereinafter, Examples 1-4 of the present invention will be described together with Comparative Examples 1-4. In addition, although an Example demonstrates the mixing | blending of a metal plastic processing oil as an example, this invention is not limited to this mixing | blending, It can utilize widely for the lubricant used for uses, such as forging, rolling, and a press.

(1) Sample preparation
In a heatable stainless steel kettle with a stirrer, base oil (solvent), oil, silicone oil, graphite, vegetable oil, and organic molybdenum are charged in the mass ratios shown in Tables 1 and 2 below, and stirred at 30 ° C for 30 minutes. A rolled oil having a pale yellow appearance was produced. Moreover, the test-quality antioxidant performance of each sample and the continuous rolling property with a bench-top actual type tester were measured. Here, Table 1 shows Examples 1-4 and Table 2 shows Comparative Examples 1-4.

(2) Antioxidation test In accordance with JIS-K-2514, the sample and oxygen were enclosed in a rotary sealed cylinder by the RBOT method, oxidized under conditions of 150 ° C, and a sudden decrease in oxygen pressure occurred. Time (minutes) was measured.

(3) On-machine test machine
Please refer to FIG. A small-scale test machine for a continuous casting and rolling machine was manufactured, and molten aluminum 1 heated to 750 ° C. was poured into an iron hopper 2 as indicated by an arrow X, between a pair of rollers 3 having a diameter of 280 mm and a length of 100 mm. Pour into. Rolling is performed with a load of 1 ton or more per 1 cm roller while casting, and a rolled plate 5 having a thickness of 5 mm and a width of 50 mm is continuously produced at a speed of 1.5 m per minute. In addition, application | coating of the lubricating oil to the roller 3 is performed with the spray apparatus 4, and lubricates between the rolling plate 5 and the roller 3. FIG. Here, when the lubrication is poor and seizure occurs, the rolled plate adheres and winds on the roller side, making continuous operation impossible. Whether or not continuous operation is possible is used as a criterion for pass / fail judgment. The molten aluminum 1 is liquid in the hopper 2 but is in a semi-solid state near the outlet of the hopper 2 and in a solid state after flowing between the rollers 3.

  From Tables 1 and 2, it is clear that in the case of Examples 1 to 4 as compared with Comparative Examples 1 to 4, the time until oxidation is longer and the oxidation stability is improved. Moreover, there is almost no difference between Example 1 and Example 2, and it turns out that it is a substantially the same test result. In Comparative Example 1 and Comparative Example 2, since organic molybdenum has a little antioxidant function, it appears in the difference between the two. In summary, in the laboratory test (RBOT method), the effect of adding an antioxidant is clearly shown.

  As a result of evaluation with a small actual machine, in Comparative Examples 1 to 4, a rolled plate was wound around the roller shown in FIG. 1, and continuous rolling was difficult. As this cause, it can be presumed that the oil film was broken, adhesion occurred partially, and the plate was wound around the roller. On the other hand, in Examples 1, 2, and 4, the plate was not wound and continuous production was possible. The reason for this can be assumed that the antioxidant delayed the deterioration of the oil film and the processing step was completed before the oil film breakage, so there was no adhesion between the plate and the roller, and the plate did not wind around the roller.

  However, the unevenness of the surface was slightly cleaner in Example 2 in which graphite was blended, and it was confirmed that Examples 1, 3 and 4 without graphite were superior in surface gloss. However, in the case of Example 2 in which graphite was blended, the apparatus was dirty and it took time to clean.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

FIG. 1 is a diagram for explaining a process of continuous casting and rolling by a small actual machine of a continuous casting and rolling apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Molten metal, 2 ... Hopper, 3 ... Roller, 4 ... Spray apparatus, 5 ... Rolled sheet.

Claims (3)

It is a lubricating oil for plastic working to continuously cast or roll non-ferrous metals,
A base oil (solvent) 30 to 90 parts by weight,
40 ° C. kinematic viscosity of 10 mm ² / s or more oil group and one selected from (mineral oils, synthetic oils, fats, the group consisting of fatty acids and fatty esters) or two or more in total 1 to 25 parts by weight,
And 1 to 20 parts by weight of silicone oil,
More than 0.1 parts by weight of phenolic and amine antioxidants, respectively, and 2 parts by weight or less in total ,
An additive having a lubrication performance,
And organic molybdenum comprises <br/>, plastic working lubricant, wherein the flash point is in the range of 8 0 ℃ ~150 ℃.   The lubricating oil for plastic working according to claim 1, comprising 0.5 to 15 parts by mass of graphite for reinforcing lubricity at a high temperature. A base oil (solvent) 40 to 90 parts by weight,
40 ° C. kinematic viscosity of 10 mm ² / s or more oil group and one or two or more kinds in total 3 to 15 parts by weight selected from (a mineral oil, synthetic oil, fat, the group consisting of fatty acids and fatty acid esters),
And 3 to 15 parts by mass of silicone oil,
More than 0.1 parts by mass of phenolic and amine antioxidants, respectively, and 1.5 parts by mass or less in total ,
An additive having a lubrication performance,
The lubricating oil for plastic working according to claim 1, comprising organic molybdenum and having a flash point in the range of 80 ° C to 150 ° C.

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