JPH0730349B2 - Anti-corrosion oil for steel plate for press work - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to various steel sheets used mainly in the automobile industry and the like, and particularly to a rust-preventive treatment during the storage period of a thin steel sheet and a press for processing the steel sheet. The present invention relates to a rust preventive oil that can be used for both press working and processing that can be processed with a single lubricating oil.

(Prior Art) Generally, a thin steel sheet manufactured by a steel manufacturer is coated with rust-preventive oil and then wound into a coil or stacked in a stack and shipped to users in the automobile industry and the like. The user finishes the processed product by combining various press moldings such as punching, bending, pulling and drawing.

The rust-preventive oil applied at the time of shipment generally has sufficient rust-preventive oil even during long-term storage, and also has good degreasing properties, low oil bleeding, and low oil carry-out amount. In order to satisfy these additional required performances, a low viscosity one having a viscosity at 40 ° C. of about 25 cSt or less is usually used. On the other hand, when pressing,
The rust preventive oil is degreased in advance, or while the rust preventive oil is still applied, the press working is usually performed by applying a medium or high viscosity press oil having a viscosity of 50 to 100 cSt at 40 ° C.

In recent years, in order to achieve rationalization by simplifying the pressing process, there is a demand that the rust preventive oil applied at the time of user delivery in the automobile industry and the like also serves as the lubricating oil in the pressing process. If this requirement is satisfied, it will be a great advantage for the steel industry, the automobile industry, etc. Therefore, it is an important issue to treat rust prevention and pressing with a single lubricating oil.

In this case, increasing the viscosity of the rust-preventing oil to a medium or high viscosity comparable to that of conventional pressing oil reduces the degreasing property as described above, reduces the economic efficiency due to an increase in the amount of oil taken out, and reduces the handling property of the steel sheet. It is not appropriate due to deterioration. On the other hand, there is a problem in diverting the conventional press working oil to rust preventive oil as it is. When the viscosity of the conventional press oil is reduced, the oil film is extremely reduced during press working, and troubles frequently occur due to damage such as press cracks and scratches on the worked surface. Therefore, in order to enhance the lubricity, it is conceivable to add a general extreme pressure additive such as one containing an element such as chlorine, sulfur, phosphorus or molybdenum. However, the addition of a general extreme pressure agent to this type of rust preventive oil significantly reduces its rust preventive property. For example, the water in the air and the extreme pressure agent react with each other to generate an acidic substance, resulting in the generation of rust, oil stain, and discoloration of the plate surface. In particular, in recent years when the ratio of surface-treated steel sheets to steel sheets is increasing, conventional hot rolling,
Compared to cold-rolled steel sheets, these surface-treated steel sheets are more likely to have problems with peeling of the plating layer and powdering during press working, so the lubricating oil used must have better lubricity than before. On the other hand, the surface plating layer easily reacts with the additives in the lubricating oil, especially the extreme pressure agent, resulting in oil burn of the steel sheet, corrosion of the plating layer, discoloration and the like.

As described above, it is impossible to satisfy both the rust preventive property and the press workability with either the commercially available rust preventive oil for steel plates or the press working oil with the current combination of additives.

(Problems to be Solved by the Invention) The present invention solves the above problems and provides a rust preventive oil for steel sheet, which has excellent press working lubricity without deteriorating the rust preventive performance.

(Means for Solving the Problem) That is, the inventors of the present invention have made diligent studies to solve the above-mentioned problems, and as a result, the processability of the rust preventive oil is remarkably improved by adding an ultrahigh basic sulfonate at a certain concentration or more. The inventors have found that they can do this and completed the present invention.

That is, the present invention comprises a petroleum base oil and an ultra-highly basic sulfonate, and the final product has a base number of 15 mgKOH /
It exists in rust-preventing oil for steel plates for press working, which is characterized by being g or more.

The petroleum base oil in the present invention may be a usual one, and examples thereof include motor oil, machine oil, turbine oil, spindle oil, light oil, white kerosene, petrolatum, and the like, and one or more of these may be used. Can be used.

The ultra high salt sulfonate in the present invention is a petroleum sulfonic acid obtained by sulfonation of an aromatic hydrocarbon component in a petroleum-based base oil fraction, or a synthetic sulfonic acid such as dinonylnaphthalene sulfonic acid or heavy alkylbenzene sulfonic acid. It is an alkali metal or alkaline earth metal salt in which a hydroxide, oxide or carbonate of these metals is excessively contained. Na as the alkali metal, Ca, Ba, Mg as the alkaline earth metal, and the base number (JIS
K 2501) is about 100 mg KOH / g or more, preferably about 300-40
One with 0 mg KOH / g can be used.

Ultra-salt sulfonates can be obtained by methods well known in the art. For example, Group I metals such as Na or Ba, C
A neutral or basic sulfonate is obtained in advance by reacting a group II metal oxide such as a or Mg, a hydroxide or a carbonate with a sulfonic acid.

Suitable sulfonic acids have the formula (Wherein R is an alkyl group; R can contain from 8 to 50 carbon atoms, and preferably contains from 8 to 35 carbon atoms), which is an alkylbenzenesulfonic acid represented by wax benzene. Sulfonic acid, octadecyl sulfonic acid and C ₁₄ -C ₃₄ mixed alkylbenzene sulfonic acids are preferred.

The ultra-basic sulfonate used in the present invention is a neutral salt of the sulfonate thus obtained, an oil solution of a basic salt or a mixture of both, a hydroxide such as Na, Ca or Ba, and an oxide. It is manufactured by blowing carbon dioxide into a mixed slurry of a substance, a carbonate and the like.

The addition ratio of the ultra high basic sulfonate is such that the base number of the final product is about 15 mg KOH / g or more, preferably about 17 mg KOH / g or more, more preferably about 20 mg KOH / g or more and about 50 mg KOH / g or less. The addition amount can be increased or decreased according to the base number of the basic sulfonate, and is preferably about 3% by weight or more, and preferably about 5.5% by weight or more and 20% by weight or less based on the base oil. If the amount is too small, the press workability is poor, and if it is too large, the effects of rust prevention and press workability do not significantly extend.

Although ultra-basic sulfonates are known as detergent dispersants, they have never been known to have performance as processability improvers.

The present invention may include a known oil-soluble organic rust preventive or antioxidant in addition to the above compounds. For example, neutral and basic sulfonates (Na salt, Ba salt, Ca salt of petroleum sulfonate and synthetic sulfonate), esters (sorbitan monooleate, pentaerythritol monooleate, sorbitan trioleate, wax oxide ester, etc.) , Carboxylic acids (oleyl sarcosine, dimer acid, etc.), thiophosphoric acid esters, organic amine salts (coconut amine oleate, etc.) and the like, and they can be used usually in one kind or in combination of two or more kinds. The amount of the oil-soluble organic rust preventive oil used is usually relative to the petroleum base oil.
It may be selected in the range of 0.2% by weight or more, preferably 0.5 to 20% by weight. If the amount is too small, the rust preventive effect cannot be sufficiently exerted, and if the amount is too large, problems occur in terms of solubility.

The final viscosity of the press-working steel plate rust preventive oil of the present invention is
Approximately 7 cSt or more and 27 cSt or less at 40 ° C is preferable, 12 cSt or more and 25 cS
It is more preferably t or less. If it is too low, the rust resistance and press workability are poor, and if it is too high, the degreasing property deteriorates and the amount of oil taken out increases, which is not preferable.

(Effects of the Invention) By applying the steel sheet for press working and rust preventive oil of the present invention to a steel sheet, not only rust resistance but also sufficient lubricity for press working can be obtained. That is, a single lubricating oil can serve as both the rust preventive property of the conventional steel plate rust preventive oil and the press workability of the press working oil, and the processing steps can be simplified.

(Example) Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

Table 1 shows the compositions of Examples and Comparative Examples. The numerical values in the table indicate parts by weight. Comparative Example 5 is a representative commercially available press working oil that is used in large quantities for press working of thin steel sheets in the automobile industry. The results are shown in Table 2.

The rust prevention property and press workability were evaluated by carrying out the following performance tests.

[Press workability evaluation test]

(1) Shell-type four-ball wear test (based on ASTM D 2266): Rotation speed 1200rpm, load 20kgf, test time 30 minutes wear test, after the test, the average of wear marks diameter of three fixed balls Then, the wear resistance was evaluated according to the following criteria.

Average wear scar diameter 0.5 mm or more; × 〃 0.4 to 0.5 mm; △ 〃 0.4 mm to ≤ (2) Cylindrical drawing test: A circular electrogalvanized steel sheet is used, and the punch diameter is 40.0 mmφ.
A cylindrical deep drawing test was performed at a processing speed of 3 m / min, the maximum blank diameter that could be drawn through was measured for each rust preventive oil, and the limiting drawing ratio was calculated by the following formula.

Next, similarly obtain the limiting drawing ratio (B) of the bare plate to which no rust preventive oil is applied, and use the following criteria to determine the cylinder depth based on the ratio (A / B) when applying oil to the limiting drawing ratio when uncoated. The drawability was evaluated.

A / B <2.0; × 2.0 A / B <2.5; △ A / B2.5; 〇 [Rust-prevention evaluation test] (3) Rust-prevention test during stacking: Cold rolling with dimensions of 100 × 100 × 0.8 mm 2.0g / m of rust preventive oil is used on both sides of steel sheet and electrogalvanized steel sheet.
^{2 After} application, stack and fix at 4 corners with clips, 50
After standing for 30 days in a constant temperature bath at ℃ and 95% or higher humidity, the degree of rust formation on the stacking surface was observed. The evaluation was based on the following criteria.

Occurrence of rust: × Slight rust or discoloration of plating layer: △ No rust or discoloration; 〇 (4) Wet rust test (according to JIS K 2246): Cold rolling according to the test method as a test piece In addition to the steel sheet, an electrogalvanized steel sheet was tested by the same method (test time 2 weeks).

The evaluation of wet rust resistance was according to the following criteria.

Occurrence of rust: × Slight rust, or discoloration of plating layer: △ No rust or discoloration; 〇 (5) Degreasing test: 100 × 100 × 0.8 mm cold rolled steel sheet and electrogalvanized steel sheet with each rust preventive oil After soaking in, leave it outdoors for 1 week. Then, degreasing cleaning is performed by spraying a 1% concentration aqueous solution of Fine Cleaner FC4326 (Nippon Parker Rising Co., Ltd.) at a temperature of 60 ° C. for 10 seconds.

The degreasing property was evaluated by the water-wetted area (percentage%) of the steel sheet after degreasing and cleaning.

50% or less; × 50 to 90%; △ 90 to 100%; 〇 As can be seen from Table 2, Examples 1 to 3 are excellent in rust prevention and press workability. As shown in Comparative Examples 1, 2, and 3, when the sulfonate is neutral or basic, the lubricity is insufficient and good processing performance cannot be obtained. On the other hand, it can be seen that the commercial press working oil of Comparative Example 5 has good press workability, but has problems in rust prevention and degreasing.

Further, as shown in Comparative Example 4, phenate, which is also known as ultra-highly basic, does not give satisfactory results in each test other than degreasing.

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Claims (1)

[Claims] 1. A steel sheet rust preventive oil for press working, which comprises a petroleum base oil and an ultra-highly basic sulfonate and has a final product base number of 15 mgKOH / g or more.