JPH0742470B2 - Anti-rust press working oil for galvanized steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electrogalvanized steel sheet, a hot-dip galvanized steel sheet,
Rust resistance (rust resistance against white rust, red rust, etc.) applied to steel plates such as zinc alloy plated steel plates and alloyed zinc plated steel plates,
The present invention relates to a press working oil having both cleaning removal property and discoloration preventing property.

[Conventional technology]

As a press oil for galvanized steel sheets, mineral oil, fats and oils, and liquid synthetic oils are used as base oils, and high-viscosity oils containing compounds of fats and sulfur are used, but press working is generally performed by continuous working. Tool temperature is 50-100
Since the temperature of the galvanized steel sheet becomes 0 ° C. and the working material also generates heat due to plastic deformation, press working under such a condition causes discoloration (darkening) of the galvanized steel sheet, which is not preferable. In addition, since the press oil generally has a low rust preventive function, white rust is likely to occur on the surface of the press-formed galvanized steel sheet during storage. In addition, the current situation is that problems such as red rust tend to occur. In addition, it may be difficult to completely remove the press oil film in the degreasing and washing step when chemical conversion treatment is performed on the galvanized steel sheet after press working as a pretreatment for coating, and further discoloration, white rust, or red rust on the surface of the galvanized steel sheet. There are many cases where they are mixed or they are mixed, and in either case, poor chemical conversion is induced, and there is a problem that the coating film quality is significantly impaired.

Next, as a rust preventive oil for galvanized steel, a base oil containing an alkyl sulfonate or a carboxylate is used, but this oil is inferior in lubricity. When pressing the coated galvanized steel sheet, it is necessary to further apply a pressing oil on it, so zinc plating that can impart discoloration resistance, rust prevention and workability with one oil application There was a demand for the development of steel sheet multifunctional oil.

[Problems to be Solved by the Invention]

The present invention aims to solve the above-mentioned problems, and as a multi-functional press working oil for galvanized steel sheet, a single application of oil allows for processing lubricity, discoloration resistance, rust resistance and pre-treatment. An object of the present invention is to provide a rust preventive / combined press working oil for galvanized steel sheets, which is excellent in cleaning and removing properties.

[Means for Solving the Problems]

Then, the present inventors, as a result of research on a press working oil for galvanized steel sheet that can solve the problems described above,
First, I got the following new tools. That is, (a) as a lubrication aid for maintaining a proper press lubrication performance, the kind of alkyl phosphite ester to be blended with the base oil, the number of carbon atoms in its molecular structure and the blending amount in the press working oil are limited. What you need to do.

(B) In order to maintain appropriate press lubrication performance, it is necessary to limit the type of sulfur-binding compound, the number of carbon atoms in its molecular structure, the content of inert sulfur, and the amount of sulfur-binding compound added to the press oil. That there is.

(C) In order to suppress discoloration of the oil-coated galvanized surface, an inert sulfur type extreme pressure agent is suitable, and the active sulfur content in the press working oil should be 0.5% (wt%, The same shall apply hereafter).

(D) Compounding a pressing oil with a compound selected from alkyl sulfonates, carboxylates and salts thereof, and amine compounds as an anti-rust additive for imparting white rust resistance and red rust resistance.

(E) The viscosity of the processing oil is limited to 5 to 30 cSt at 40 ° C. in order to provide the cleaning and removing property of the oil film of the pressing processing oil.

As a result of further study based on the above findings, the target press working oil meeting the above-mentioned demand was completed. That is, the press working oil of the present invention has both rust prevention and lubricity, and its constitution is composed of (a) a base oil, a rust preventive additive, a lubrication aid, and an extreme pressure additive. First, (b) as a limited range of each substance, a base oil: one kind or two or more kinds selected from mineral oil, fats and oils and liquid synthetic oil is contained in 65 to 90 parts (parts by weight, the same applies hereinafter), rust-preventive agent: C ₁₆ or higher alkyl sulfonates, C ₁₂
One or two selected from the above carboxylic acids and salts thereof
1-20 parts of one or more compounds are included.

Lubrication aid: 1 to 20 parts of one or more compounds selected from secondary and tertiary alkyl phosphite compounds.

Extreme pressure additive: An inert type sulfur-based extreme pressure additive, which is a fatty acid ester compound containing 5 to 15% of sulfur, a sulfur-bonded fat or oil, and a fat and fat and a C _{8 to} C ₁₈ olefin that are sulfur-bonded to each other. 1 or 2 or more selected from the compounds
Include up to 20 parts.

Further, in these formulations, the weight ratio of the alkyl phosphite ester to the inert type sulfur extreme pressure additive is 1:
It is required to be 15 to 2: 1 and to have an active sulfur content of 0.5% or less in the press working oil formed by the above-mentioned composition, and to make the viscosity of the working oil 5 to 30 cSt at 40 ° C.

The base oil applied to the rust preventive and press working oil for galvanized steel sheet of the present invention (hereinafter simply referred to as press working oil) is
One or two or more selected from mineral oils, fats and oils, and liquid synthetic oils can be arbitrarily selected, and although these oils and the viscosity of the oils are not specified, pressing oil is applied. In order to keep the oil film removability after processing appropriately, it is necessary to maintain the viscosity of the pressing oil at 40 ° C at 5 to 30 cSt. It is necessary to select the viscosity of the base oil in consideration of the balance.

If the viscosity of the press working oil is lower than 5 cSt at 40 ° C, the lubricating performance at the time of press working cannot be satisfactorily exerted, and if it is higher than 30 cSt, the amount of oil film becomes unnecessarily large and it is uneconomical. , And the oil film after press working has poor cleaning and removability, which is not preferable. In particular, the oil removability at the seam of spot welding becomes poor, and the oil easily exudes from the seam even after cleaning, which adversely affects the surface treatment performed thereafter. Therefore, it is important to select the viscosity of the base oil, but select a base oil with a viscosity lower than 5 cSt in advance, add a thickener if necessary after adjusting the press oil, and adjust the viscosity to less than 5 cSt. By increasing it, it is possible to improve the lubricity and form a pressing oil in accordance with the object of the present invention.

In this case, examples of the thickener include polyacrylic acid ester type and polybutene.

Next, the alkyl sulfonate added as a rust preventive additive is preferably C ₁₆ or more, and the carboxylic acid or carboxylic acid salt is preferably C ₁₂ or more. If the carbon number is less than that, the rust preventive effect is insufficient, and specifically, the following compounds can be mentioned.

Examples of the alkyl sulfonates include metal salts of dinonylnaphthalene sulfonic acid (Ba, Ca, Zn, Mg, Na, etc.),
Didodecylbenzene sulfonic acid metal salt (Ba, Ca, Zn,
Mg, Na, etc.), petroleum sulfonic acid metal salt. Examples of the carboxylic acid having C ₁₂ or more or a salt thereof include isooleic acid, oleic acid, dimer acid, alkenylsuccinic acid petroleum oxide wax or metal salts thereof (Ba, Ca, Zn, Mg, Na) and amine salts. Examples of the nitrogen-containing compound of C ₁₂ or higher carboxylic acids, for example, a C ₁₂ or higher carboxylic acid compound of benzotriazole and imidazoline.

Particularly preferred among the above compounds are barium salt of dinonylnaphthalene sulfonic acid, barium salt of didodecylbenzene sulfonic acid, barium salt of petroleum oxide wax, and the like. One kind or two or more kinds are arbitrarily selected from these compounds and mixed in the base oil. However, alkyl phosphite (especially secondary ester compound) is easily hydrolyzed and free acid tends to be generated to corrode galvanized steel sheet. To prevent this, a sulfur-based extreme pressure additive is used. By blending, the free acid is made into an alkylthiophosphite and stabilized. Further, it can be further stabilized by adding a basic compound of calcium sulfonate and barium sulfonate. It is also a suitable means to neutralize the above-mentioned free acid by adding an amine. The addition amount is
1 mol or more is suitable for 1 mol of the alkyl phosphite. The amount of these rust preventive components added to the base oil is 1 to
If it is 20 parts and less than 1 part, the rust prevention effect becomes insufficient,
The effect cannot be expected to be improved by adding more than 20 parts, so 20 parts is the upper limit in view of balance with other ingredients.

Next, as a lubricating aid, a tertiary and / or secondary ester compound of alkylphosphorous acid is used. In the present invention, even a specific compound is not specified, but a compound represented by the following general formula (I) and / or (II) is used,
Those specifically exemplified are preferable.

(1) Tertiary ester compound (RO) ₃ P (I) In the formula, R is a hydrocarbon group having 8 to 22 carbon atoms. Specifically, for example, aliphatic octyl, lauryl, cetyl, palmityl, oleyl, Examples thereof include stearyl, synthetic oil-based groups such as isodecyl, tridecyl, and isostearyl.

(2) Secondary ester compound (RO) ₂ PHO (II) In the formula, R is a hydrocarbon group having 8 to 22 carbon atoms, and specific examples thereof include fatty acid octyl, lauryl, cetyl, palmityl, oleyl, One or more groups of stearyl, synthetic oil-based isodecyl, tridecyl, isostearyl, etc. may be mentioned.

The number of carbon atoms of the alkyl phosphite in the press oil is in the range of 8 to 22, and if the number of carbon atoms is less than 8, the rust-preventing property is deteriorated because it is easily hydrolyzed. It is necessary to improve the rust prevention property by chemical conversion and amine neutralization. On the other hand, if the carbon number exceeds 22, the viscosity will be high, which will adversely affect the degreasing property in the coating pretreatment step. In this case, therefore, it is necessary to reduce the compounding amount within the range of 1 to 20 parts. However, the most preferable ones are those having 12 to 16 carbon atoms.

Any one or two of the above alkyl phosphites
Select more than one species to mix with the base oil.
20 parts is preferable, and if it is less than 1 part, the lubricating performance becomes insufficient, and if it exceeds 20 parts, the rust preventive property is deteriorated.

Next, the extreme pressure additive is an inert type sulfur-based extreme pressure additive, which is a sulfur-bonded compound containing 5 to 15% of sulfur. That is, a sulfur-bonding compound such as fats and oils and fatty acid esters and a compound in which fats and oils and C _{8 to} C ₁₈ olefins are bound by sulfur are used. Fats and oils, fatty acid esters,
And particularly preferable ones in selecting the olefin are exemplified below.

(1) Fats and oils are glyceride-based lard oil, rapeseed oil, chicken oil and the like represented by the following general formula.

General formula R ₁ COO is a residue containing C ₁₂ or more unsaturated fatty acid as a main component.

(2) Fatty acid ester is orange laffy oil, oleic acid oleyl ester, oleic acid methyl ester and the like.

The general formula R ₁ COOR ₂ R ₁ is a fatty acid group similar to the above, and R ₂ is a C ₁ or more aliphatic alcohol group.

(3) C _{8 to} C ₁₈ olefin The amount of sulfur bound to the above compound must be 5 to 15% in order to impart appropriate extreme pressure properties, and if it is less than 5%, the extreme pressure properties will be insufficient. On the other hand, if it exceeds 15%, the active sulfur content in the press working oil exceeds 0.5%, which is not preferable.

Next, the active sulfur content in the rustproofing press oil is preferably 0.5% or less, and if it exceeds 0.5%, the reactivity with the zinc surface is too strong, so that the discoloration of the surface tends to be strong after processing. 0.3% or less is preferable.

The lower limit of the carbon number is determined in consideration of lubricity, and in particular, prevention of deterioration of lubricity when the processing temperature of the galvanized material increases (70 to 100 ° C).

One kind or two kinds or more are arbitrarily selected from the above sulfur-bonding compounds and mixed into the base oil. The compounding amount is 1 to 20
When the amount is less than 1 part, the lubricating performance becomes insufficient, and it is preferable that the upper limit is 20 parts in order to prevent discoloration of the galvanized material after pressing.

By mixing the alkyl phosphite (to be) and the inert type sulfur-based extreme pressure additive (to be), thiophosphate, which is a highly stable compound, is produced, but the mixing ratio (:) When the ratio is over 1:15, the effect of improving lubricity cannot be obtained even if it is added in excess, and conversely 2:
If it is less than 1, the lubricity is good, but the rust prevention property is deteriorated, which is not preferable. So the range is 1:15 to 2: 1
More preferred is 1: 4 to 2: 3.

Further, in the press-working oil of the present invention, an oil-soluble surfactant of less than several% can be added in order to enhance the oil film removability of the working oil, and such addition is rejected in the present invention. is not.

〔Example〕

Next, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples.

The test oil Nos. Of the examples of the present invention shown in Table 1 were applied to the test pieces by the roll coater method, and the deep drawing test, the rust prevention test and the degreasing test shown below were performed. In Table 1, sample oil Nos. To No. are comparative examples, and the same tests as in the examples were conducted.

The amount of oil applied was adjusted to 1.5 ± 0.1 g / m ² .

The test methods and criteria are shown below.

(1) Lubrication test (deep drawing test) a. Test piece material: Alloyed hot-dip galvanized steel sheet 45/45 Dimensions: 90mm (diameter) x 0.7mm (thickness) b. Tool die diameter: 42.5mm (diameter) Punch diameter: 40.0 mm (diameter) Punch shoulder radius: 8 mm c. Test condition Drawing speed: 400 mm / min Wrinkle holding load: 1000 kg d. Judgment Deep drawing ratio (%) = (1-D / D ₀ ) × 100 D ₀ : Diameter of test piece before test D: Average diameter of test piece after test Obtain the above deep drawing ratio and judge according to the table below. The higher the deep drawing ratio, the better the lubricity.

(2) Anticorrosion test (2) -1 Wet test a. Test piece material: Alloyed hot-dip galvanized steel sheet 45/45 Dimensions: 70 mm × 150 mm × 0.7 mm b. Test conditions Wet test method (JIS K22464.32 compliant) Temperature: 49 ± 1 ℃ Relative humidity: 95% or more Time: 10 days, 30 days c. Judgment: The degree of discoloration and white rust on the test piece is judged according to the table below.

(2) -2 Stack test a. Specimen material: Alloyed hot-dip galvanized steel sheet 45/45 Dimension: 70mm × 150mm × 0.7mm b. Test condition Constant temperature and humidity tester temperature: 49 ± 1 ℃ Relative humidity: 95 % Or more Stacking force: 70 kgf-cm Period: 10 days / 30 days c. Judgment: The degree of discoloration and white rust of the test piece is judged in the same manner as in the wet test.

(3) Degreasing test a. Specimen material: Hot dip galvanized steel sheet 45/45 Dimension: 70mm x 150mm x 0.7mm b. Adjustment of test piece After applying each test piece to a 70kgf-cm stack, Temperature 50
The test material was left for 7 days in a constant temperature and constant humidity tester at ℃ and 95% relative humidity.

c. Test conditions Dip degreasing was performed in a completely static bath.

Degreasing agent: Trade name Fine Cleaner L4480 (manufactured by Nippon Parkerizing Co., Ltd.) Concentration 1.8%, temperature 40 ° C, time 3 minutes d. Judgment: After washing the degreased test piece for 30 seconds in the flow, 30
It was judged by the water-wetting area (%) after being left indoors for a second. The judgment is as shown in the table below.

Table 2 shows the results of each test.

[Effects of the Invention] As can be seen from Table 2, the compositions of the examples of the present invention are superior to those of the comparative examples in all of lubricity, rust prevention and degreasing properties.

As described above, the rust preventive and press working oil for galvanized steel sheet of the present invention has excellent lubricity equivalent to that of the press oil and discoloration resistance comparable to that of the rust preventive oil, when the galvanized steel sheet is press-processed by applying oil once. And the anti-rust property and the degreasing property in the pre-treatment before coating are good, which is very useful.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 159: 20 159: 24 137: 02 135: 02) C10N 10:04 20:02 30:00 A 30:06 30:12 40:24 Z (72) Inventor, Yasuo Tanizawa, 1-1-15, Nihonbashi, Chuo-ku, Tokyo Within Nihon Parkerizing Co., Ltd. (72) Inventor, Naoyuki Hayashi, 2-15, Nihonbashi, Chuo-ku, Tokyo 5 Within Parka Kosan Co., Ltd. (72) Inventor Mitsumi Iida 2-15-5 Nihonbashi, Chuo-ku, Tokyo Within Parka Kosan Co., Ltd. (56) Reference JP-A-62-95396 (JP, A) JP-A-SHO 61-60791 (JP, A) JP-A-1-156398 (JP, A) JP-B-59-22757 (JP, B2)

Claims (2)

[Claims] 1. A base oil comprising one or more oils selected from the group consisting of mineral oils, fats and oils, and liquid synthetic oils in an amount of 65 to 95.
Parts by weight, 1 to 20 parts by weight of a compound selected from the group consisting of C ₁₆ or more alkyl sulfonates, C ₁₂ or more carboxylic acids and salts thereof as a rust preventive additive, and R as a lubricating aid. A general formula (R is a hydrocarbon group having 8 to 22 carbon atoms)
O) tertiary alkyl phosphite and R is represented by ₃ P is a hydrocarbon group having 8 to 22 carbon atoms general formula (RO) ₂ P
1 to 20 parts by weight of one or more compounds selected from the group consisting of secondary alkyl phosphites represented by HO, and a sulfur content of 5 as an inert sulfur extreme pressure additive. From 1 to 20 parts by weight of one or more compounds selected from the group consisting of fatty acid ester compounds containing 15 to 15% by weight, sulfur-bonded fats and oils and compounds having sulfur-bonded fats and C _{8 to} C ₁₈ olefins. A press oil consisting of:
The processing oil has a content ratio of an alkyl phosphite and an inert type sulfur-based extreme pressure additive of 1:15 to 2: 1, an active sulfur content of 0.5% by weight or less, and a viscosity of 40%. ℃
Press working oil for galvanized steel, which has a corrosion resistance of 5 to 30 cst. 2. A rustproofing press working oil for galvanized steel sheet according to claim 1, which contains a basic alkyl sulfonate salt as a rustproofing additive.