JP3016962B2 - Rust-preventive oil for both press working - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a rust prevention treatment during storage of zinc plated steel sheets, which is rapidly increasing in demand from the viewpoint of rust prevention and corrosion prevention mainly in the automobile industry, and for processing steel sheets. The present invention relates to a rust-preventive oil for both press working and zinc sheet steel, which makes it possible to carry out the pressing work with a single lubricating oil.

[0002] In this case, the zinc plated steel sheet is a molten zinc plated steel sheet, an electric zinc plated steel sheet, a vapor-deposited zinc plated steel sheet,
And all of the steel plates containing zinc as a main component, such as an alloyed zinc steel plate obtained by alloying them.

[0003]

2. Description of the Related Art The most important problem in terms of quality during the in-process period from the time when a zinc plated steel sheet is manufactured by a steelmaker to the time when it is formed and processed into various parts by a customer is prevention of rusting.

For this reason, in a normal zinc plating steel plate manufacturing process, a roll coating method, an oil dropping method, and the like just before winding on a coil or just before cutting into a sheet at the exit side of the final threading line (there are many zinc plating lines or recoiling). An appropriate amount of rust-preventive oil is applied by any one of methods such as a coating method and an electrostatic coating method.

[0005] In general, rust preventive oils used for various steel sheets, particularly Zn plated steel sheets, have low oil bleeding, do not corrode the Zn plated layer on the surface, have good degreasing properties and good chemical conversion treatment properties, and have high oil quality. In view of the economical aspect of reducing carry-out, a material having a viscosity at 40 ° C. of 20 cSt or less, preferably 5 to 10 cSt is used.

[0006] The steel sheet coated with rust-preventive oil is strictly packed with a rust-proof paper or a polyethylene film laminated with vaporizable rust-proof paper or polyethylene film, and then shipped according to the delivery date.

[0007] The shipped coil or sheet is unpacked by the user and pressed into various product shapes.

[0008] The press process in the user overhangs,
Sliding that applies large and small surface pressures to molding such as pulling and drawing is complicatedly combined, and it is required to be able to work as fast as possible, but as described above, the viscosity is low, so the oil film strength is weak, and the overhang The lubricity is insufficient to perform tension, drawing, and the like.

[0009] If the lubricating property is insufficient in the press working of the zinc plated steel sheet, for example, when the plated layer is a soft zinc η phase such as an electric zinc plated steel sheet or a molten zinc plated steel sheet, the η phase is a mold. This causes a so-called galling phenomenon, which often causes peeling of the plating layer and, in severe cases, breaks of the sheet.

[0010] For example, in the case of an alloyed molten zinc plated steel sheet produced by performing a heat diffusion treatment after the molten zinc plating, the plating layer becomes an iron-zinc alloy layer, but a relatively soft ζ phase is formed on the plating surface. If (FeZn ₁₃ ) remains, a phenomenon similar to that of the hot-dip galvanized steel sheet may occur.

[0011] Not only breakage leads to a decrease in yield,
The peeling of the plating layer also causes the product to be pressed and scratched by the peeled pieces, so that the yield is reduced, or the efficiency of the mold is reduced due to an increase in the mold cleaning frequency.

For this reason, it is an important technical point to keep the interface between the forming die and the tool and the zinc plated steel sheet in an appropriate lubrication state.

Although various techniques have been devised for the lubricating technique, the most common one is a method of immediately applying a press working oil, which is a mixture of fats and oils and a mineral oil.

[0014] Since different press working oils are used depending on the working degree, various viscosity grades (50 to 150 cSt, 40
° C), and a high viscosity of 70 to 80 cSt (40 ° C) is used for the press working of the zinc plated steel sheet which is an object of the present invention.

The most primitive method is hand-painted lubrication, but in this case, productivity is low, and it is difficult to control the type, amount, and position of the press working oil to be applied. There is a disadvantage that the degreasing in the process becomes insufficient.

In recent years, with the automation of press work, the application method has been changed to spray lubrication of press working oil to lubricating points, and productivity and control of the amount of applied oil have been improved. However, due to the high viscosity, blanks are not easily separated from each other, so that two blanks may be pressed together. In addition, equipment investment for oil coating is required, and there are problems such as environmental deterioration due to oil mist.

On the other hand, it is conceivable to use a high-viscosity press working oil as a rust-preventive oil from a different viewpoint. However, because of the high viscosity, there is a limit that the oil film can be made thin even if the coating method is considered. It is uneconomical due to the large loss caused by

This problem can be solved if the viscosity of the currently used press working oil can be reduced to the same level as that of rust preventive oil. In order to increase the pressure, the addition of an extreme pressure additive becomes indispensable.

When the extreme pressure additive comes into contact with moisture in the air, hydrolysis, dehydrochlorination, and the like occur, and a corrosive substance is formed, so that the rust prevention performance is significantly reduced. In addition, when welding a pressed product, it causes rust and also causes environmental degradation. It is difficult to suppress these phenomena by the rust-preventive additive, and the practicability of zinc plated steel sheets is poor.

That is, it is impossible to satisfy the rust prevention property and the press workability of either the commercially available rust preventive oil or the press working oil with the current technology of combining additives.

The inventors of the present invention have proposed a press working and rust preventing oil disclosed in JP-A-62-95396. The contents are (a) at least one selected from the group of sulfonic acid salts, (b) at least one selected from the group of carboxylate salts, (c) phosphate ester derivatives, diesters, polyol esters, and fats and oils. A rust preventive oil for press working, characterized by containing at least one member selected from the group and (d) an alkali / alkaline earth metal salt of boric acid whose main component is particles of 0.1 μm or less. However, the above invention can be applied to a cold rolled steel sheet having a relatively inert surface, but in the case of a zinc plated steel sheet having an active surface, it has been found that the rust prevention performance is insufficient, and there is still room for improvement. There was.

In order to solve these problems, a low-viscosity rust-preventive oil which has little oil spill, does not corrode the zinc plating layer on the surface of the steel sheet, and has excellent degreasing and chemical conversion properties is used. It is important to maintain an appropriate lubrication state at the interface between the forming die and the tool and the zinc plated steel sheet when performing press working with the oil film.

In consideration of these points, in order to develop a press-workable rust-preventive oil having a viscosity of 20 cSt or less and having a high lubricating property at the time of press-working a zinc plated steel plate, the press-workable rust-preventive oil is further used for a zinc steel plate. (Japanese Patent Laid-Open No. 2-30)
No. 5979). The content is selected from (a) at least one selected from the group of sulfonic acid salts, (b) at least one selected from the group of carboxylate salts, and (c) selected from the group of diesters, polyol esters, and fats and oils. (D) at least one selected from the group of superbasic sulfonates, and
(e) A rust-preventive oil for both press working and zinc-plated steel sheet, characterized by containing particles of 1 μm or less containing potassium borate as a main component.

However, it is desirable to apply as a rust preventive oil
If a low-viscosity base oil necessary for obtaining a viscosity of 10 cSt or less (40 ° C.) is blended, the oil film becomes thin and the press workability is reduced. If a high-viscosity base oil is blended, it will be difficult to apply as a rust-preventive oil, and it will be difficult to separate overlapping blanks during press working, causing a double blanking phenomenon, damaging the mold and reducing yield and productivity. And other problems. Further, if the amount of the lubricant is increased to improve the press workability, it becomes economically disadvantageous and there is still room for improvement.

[0025]

An object of the present invention is to reduce the viscosity.
An object of the present invention is to provide a press-workable rust-preventive oil having high lubricity at the time of press-working a zinc plated steel sheet at a pressure of 20 cSt or less, particularly 10 cSt or less.

Another object of the present invention is to provide a press-workable rust-preventive oil having excellent lubricity, rust-prevention, degreasing and chemical conversion properties for zinc plated steel sheets.

[0027]

The present invention provides (a) at least one member selected from the group consisting of sulfonic acid salts, (b) at least one member selected from the group consisting of carboxylate salts, and (c) a phosphate ester. Derivatives, diesters, polyol esters, at least one selected from the group of fats and oils, (d) at least one selected from the group of superbasic sulfonates, and (e) 1 μm or less containing potassium borate as a main component The present invention relates to a rust preventive oil for both press working and zinc working of a zinc plated steel sheet, which comprises particles and contains (f) a low-viscosity solvent.

In the rust preventive oil which is used for both press working and press working, the base oil is blended based on the base oil and the workability during coating is improved by diluting with a solvent, and the oil film during press working is controlled by adjusting the oil film thickness. The thickness can also be adjusted.

Hereinafter, the function of each additive will be described in detail.

First, sulfonates, carboxylate salts, and superbasic sulfonates are additives for the purpose of preventing rust.

The sulfonates include alkyl benzene sulfonates, alkyl naphthalene sulfonates, petroleum sulfonates and the like, and the carboxylate salts include long chain fatty acids such as stearic acid, naphthenic acid, oxidized waxes and lanolin fatty acids. Salts and the like can be mentioned.

The mechanism of action of the sulfonate forms a protective film that prevents the permeation of water due to its strong adsorbing power on the metal surface, and the polar groups are oriented inside and the hydrocarbon groups are oriented outside in the oil. It forms molecular aggregates and micelles and solubilizes water to prevent water from contacting the zinc plating surface.

The carboxylate has a strong adsorptivity to the metal surface,
It forms a protective film that prevents water permeation due to adhesion and film forming properties, and exhibits a rust-preventive effect.

Further, a superior rust-preventing property can be obtained by a synergistic effect when used in combination with the sulfonate, and the solubility of the carboxylate itself in various solvents can be improved. Ultrabasic sulfonates prevent the intrusion of corrosive components by forming calcium carbonate crystals in the dispersion contained therein in a flat plate shape, overlapping and orienting to form a barrier when forming a film. .

Further, they have a neutralizing action of boric acid generated by hydrolysis of potassium borate due to alkalinity, and are indispensable especially for zinc plated steel sheets.

Examples of the superbasic sulfonate include superbasic calcium sulfonate, superbasic barium sulfonate, superbasic magnesium sulfonate and the like.
An ultrabasic calcium sulfonate having a colloidal dispersion of 90% calcium carbonate and 10-30% calcium hydroxide is preferred.

The concentrations of the above three additives are not particularly limited, but 10% or less is sufficient for practical use, and 3 to 5% is preferable from an economic viewpoint.

Examples of the phosphate ester derivatives include phosphate amine salts, zinc dithiophosphate and molybdenum dithiophosphate, diesters such as dioctyl sebacate and dioctyl adipate, and polyol esters such as trimethylolpropane and pentaerythritol. Examples of oils and fats include esters of triglycerides and the like with fatty acids having 10 to 18 carbon atoms, and examples of oils and fats include vegetable oils and fats such as palm oil, rapeseed oil and castor oil, and animal oils and fats such as lard, lanolin, and tallow.

These are intended to improve oiliness, and provide a proper sliding action and a good surface condition at the time of press working.

Although the concentration of the additive is not particularly limited, an effect of 20% or less is sufficient, and 10 to 15% is preferable from an economic viewpoint.

The boron compound of the present invention is obtained by reacting boric acid with potassium hydroxide in the presence of a compound such as an alkali or alkaline earth metal sulfonate and a succinimide which are generally called a detergent and dispersant in an oil. A potassium borate dispersion having a particle size of 1 μm or less, preferably an average particle size of 0.1 μm is good.

The concentration of potassium borate is also not particularly limited, and the effect is sufficiently 2% or less, and preferably 0.3 to 1% from an economic viewpoint. That is, from the viewpoint of lubricity, a higher concentration is desirable, but the effect of improving lubricity is reduced, which is economically disadvantageous. Further, the above range is desirable because the dispersion stability in oil also tends to deteriorate.

As such a potassium borate dispersion, for example, trade name “OLOA 9750” (Chevron Chemical)
Company Orientite Additives Division).

The extreme pressure film formed by the boron-based solid lubricant of the present invention is not due to a chemical reaction but to physical adsorption, and this adsorbed film exhibits excellent lubricity especially in a high load region.

The reason for limiting the particle size to 1 micron or less is that when a solid lubricant is added to the rust preventive oil,
This is because, when the diameter exceeds a micron, dispersion stability in oil is deteriorated due to secondary aggregation. If the particle size exceeds 1 micron, the lubricant components may separate and settle during storage, causing insufficient lubrication, or when lubricating the metal surface, the solid lubricant may become the core of rust generation and significantly reduce rust resistance. May lead to lowering. Potassium borate having a particle size of 1 micron or less can be transparently dispersed in oil by the synergistic effect of barium alkylbenzene sulfonate, superbasic calcium sulfonate and lanolin fatty acid barium salt. .

As described above, potassium borate has a strong hydrophilic property and may partially dissolve upon contact with water to form boric acid. Since the generated boric acid component is corrosive to metals, it is necessary to take this measure when using it in rust preventive oil.

Since the press working and rust preventive oil of the present invention is considered to absorb moisture in the use environment and to mix water in the process, the above-mentioned superbasic calcium sulfonate can be blended to neutralize the boric acid produced. It is a feature that it is done in this way.

The solvent used in the present invention includes mainly hydrocarbon-based solvents which dissolve the base oil described below and the above-mentioned additives.
For example, hydrogenated kerosene, normal paraffin, isoparaffin, naphthene-based solvent and the like can be used, and those which naturally dry after oiling a zinc plating steel plate can be used. Flash point is 70 ℃
Although those with a flash point of less than or greater than the above are included, those with a flash point of 70 ° C or more are desirable in terms of work environment and fire hazard prevention. In order to improve the pressability at the time of press working, the viscosity of the oil film remaining at the time of press working is high, and it is preferable that the number of fine particles in the oil film is large, but by mixing these solvents, the lubricating additive In addition to reducing the concentration, the addition of a high-viscosity base oil described below can also contribute to an improvement in the dispersion stability of the particles.

After the above-mentioned solvent is dried, it remains as an oil film on the zinc plated steel sheet. Mineral oils of various viscosities and synthetic oils are used as base oils for imparting rust prevention until processing and lubrication during press working. Oil can be used without any particular limitation. A base oil having a high viscosity is desirable in order to enhance the lubricity during press working, but it is necessary to keep the viscosity of the oil agent and the oil film thickness at an appropriate level.

In the present invention, the mixing ratio of the components (a) to (e) is
(a) component is 10% by weight or less, preferably 3 to 5% by weight, (b)
Component is 10% by weight or less, preferably 3 to 5% by weight, component (c) is 20% by weight or less, preferably 10 to 15% by weight, and component (d) is 10% by weight or less, preferably 3 to 5% by weight. The component (e) should be 2% by weight or less, preferably 0.3 to 1% by weight, and a base oil and a solvent which can be adjusted to an appropriate viscosity are blended therein.

The rust-preventive oil for both press working and zinc-coated steel sheet of the present invention can be easily produced according to a conventional method.
That is, a predetermined amount of a rust preventive additive, a lubricating additive, and a solid lubricant are added to a predetermined amount of a base oil, followed by stirring and mixing. For mixing, a conventional mixing tank with a stirrer can be used, and usually 60 to 100
C. and a time of 1-2 hours is sufficient. afterwards,
Preferably, after cooling to 50 ° C. or lower, a predetermined amount of a solvent is gradually added, followed by stirring and mixing.

In this way, by combining the components of the above-described composition, as shown in the examples below, a rust-preventive oil which is both press-workable and has excellent rust-prevention properties and press-ability against zinc plated steel sheets. Is obtained.

[0053]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. Nos. 1 to 3 are examples, and Nos. 4 to 6 are comparative examples. Table 1 shows the results. In the table, the alkyl portion of the alkylbenzenesulfonic acid has 13 to 18 carbon atoms, and the lanolin fatty acid has 11 to 19 carbon atoms in the fatty acid portion.

Test methods and evaluation criteria for rust prevention, lubricity, degreasing and chemical conversion treatment are as follows.

Rust prevention: Test zinc plated steel sheet a) Fused zinc plated steel sheet (plated adhesion amount 90 g / m ² ) b) Alloyed molten zinc plated steel sheet (plated adhesion amount 60 g / m ² ) Evaluation method Immersed in the present invention and comparative oil,
The sample was allowed to stand in a thermo-hygrostat at 49 ° C. and 95% RH for 60 days, and the state of corrosion of the plating layer was visually evaluated. ○: No corrosion. Δ: Discoloration due to corrosion is observed. ×: Discoloration due to corrosion is remarkable.

Lubricity: Test zinc plated steel sheet Alloyed molten zinc plated steel sheet (plated adhesion amount 60 g / m ² ) Evaluation method About 1 g / m ² was applied, among the load for pressing the bead die (per 25 kgf) when pulled out by passing the bead mold was evaluated under a load immediately before the zinc-plated steel sheet is broken (breaking limit load Pc, kgf). In addition, No.
Tests 1 to 3 were performed after aging at 25 ° C. for 3 weeks. The greater the breaking limit load, the better the lubricity. Sample shape: 17 x 400 x 0.7mm (width x length x thickness) Drawing speed: 500mm / min. Stroke: 200mm

Degreasing property: Test zinc plated steel sheet Alloyed molten zinc plated steel sheet (plated adhesion amount: 60 g / m ² ) Evaluation method Degreasing for 20 seconds by spray method using a sodium carbonate-based degreasing agent, and water rinsing after water washing The area ratio (%) was evaluated. The higher the wetted area ratio, the better the degreasing property.

Chemical conversion treatment: Test zinc plated steel sheet Alloyed molten zinc plated steel sheet (plated adhesion amount 60 g / m ² ) Evaluation method A chemical conversion treatment was performed by a dipping method using a zinc phosphate-based chemical conversion treatment solution. It was evaluated in crystalline form. ○: dense crystal ×: coarse crystal

For lubricity, degreasing and chemical conversion treatment, about 1 g / m ^{2 of} oil was applied to the alloyed molten zinc plated steel sheet, and prior to the evaluation, a constant temperature and humidity chamber (55 ° C., 60% RH) was applied. ) At 7
Aged for days.

As can be seen from Table 1, the product of the present invention is excellent in rust prevention and lubricity, and has no problem in degreasing and chemical conversion.
It can be seen that it has excellent performance as a rust-preventive oil for both press working and zinc plated steel sheets.

[0061]

[Table 1]

[0062]

【The invention's effect】

1. Eliminating the need for press oil and processing oil application equipment can result in significant cost savings. 2. Since the pressing oil application step can be omitted, the handling time can be reduced, which leads to an improvement in productivity. 3. Factory pollution due to the scattering and leakage of press working oil is eliminated, and the environment can be improved. 4. It is possible to prevent breakage of the zinc plated steel plate during press forming, peeling of the plated plate, and the like, thereby contributing to an improvement in yield and productivity. 5. The separation of the blank during the press working is improved, and the double blanking is eliminated, so that the yield is improved. 6. The low viscosity makes it easy to control the amount of oil applied and reduces the amount used. 7. The amount of oil that oozes from the plate or coil is reduced, which can contribute to the beautification of the environment. 8. Since the formability is improved, it is not necessary to use expensive high-quality zinc plated steel plates or alloyed plated steel plates, and it is possible to form easily with less expensive materials.

As described above, the use of the rust-preventive oil for press work of the present invention provides a great advantage in the rust-preventive oil application step and the press step, and brings great industrial effects.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 129: 26 137: 10 129: 74 159: 08 125: 26 129: 52 159: 24) C10N 10:02 10:04 20: 06 30:06 30:12 40:24 (72) Inventor Tamio Akada 14 Okakura, Mikage-cho, Higashinada-ku, Kobe, Hyogo Prefecture (72) Inventor Michihiro Yamamoto 13-3, Fujigaoka-cho, Suita-shi, Osaka (56) References JP-A-2-305979 (JP, A) JP-A-61-26695 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 135/10 C10M 129/26-129/64 C10M 137/04-137/10 C10M 129/68-129/84 C10M 159/08 C10M 159/24 C10N 20:06 C10N 40:24

Claims (1)

(57) [Claims] (1) at least one member selected from the group of sulfonic acid salts, (b) at least one member selected from the group of carboxylate salts, (c) a phosphate derivative, diester, polyol ester, At least one selected from the group of fats and oils
Species, (d) at least one selected from the group of superbasic sulfonates, and (e) 1 μm containing potassium borate as a main component.
(f) A rust-preventive oil for both press working and zinc-plated steel sheet, characterized by containing (f) a low-viscosity solvent.