JPH0742471B2 - Anti-corrosion press working oil for galvanized steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electrogalvanized steel sheet, a hot-dip galvanized steel sheet,
The present invention relates to a press working oil having anti-rust properties (anti-rust properties against white rust, red rust, etc.), cleaning removal properties and discoloration prevention properties, which are applied to steel plates such as zinc alloy plated steel plates and alloy zinc plated steel plates.

[Prior Art] As a press working oil for galvanized steel sheets, mineral oil, fats and oils and liquid synthetic oils are used as base oils, and high-viscosity oils containing a compound of fats and sulfurs are used. Generally, continuous machining is used, so the tool temperature is 50 to 10
Since the temperature becomes 0 ° C., and the processing 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 press working oil generally has a low rust preventive function, white rust is likely to occur on the surface of a galvanized steel sheet press-formed during storage, and in particular, white rust is mainly present on the edge portion of the steel sheet during transportation. The current situation is that it is more prone to problems such as red rust. In addition, it may be difficult to completely remove the press oil film during the degreasing and washing step when chemical conversion treatment is performed on the galvanized steel sheet after press working as a pre-painting treatment. Furthermore, the galvanized steel sheet surface may be discolored, white rusted, or red rusted. There are many cases where they are mixed or they are mixed, and in each case, poor chemical conversion is induced, so that there is a problem that the coating film quality is significantly impaired.

Next, as a rust preventive oil for galvanized steel sheet, 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 a single application of oil There was a demand for the development of multifunctional oils for steel sheets.

[Problems to be Solved by the Invention] The present invention provides a multi-functional press working oil for galvanized steel sheets, which is processed by a single coating process and has lubricity, discoloration resistance, rust resistance, and cleaning removal in pre-treatment. Provided is a press working oil that is also excellent in corrosion resistance for galvanized steel sheet.

[Means for Solving the Problem] As a result of research on a press working oil for galvanized steel sheet which can solve the above-mentioned problems, the present inventors first obtained the following new findings. That is, (a) As a lubrication aid for appropriately maintaining press lubrication performance, the type of trialkyltrithiophosphite to be blended with the base oil, the number of carbon atoms in its molecular structure, and the amount blended with the press working oil are limited. What you need to do.

(B) Limit the types of sulfur-binding compounds, the number of carbon atoms in the molecular structure, the content of inert sulfur, and the amount of sulfur-binding compounds blended into the pressing oil in order to maintain appropriate press lubrication performance. What you need to do.

(C) In order to suppress the discoloration of the oil-coated galvanized surface, it is appropriate to use an inert type sulfur extreme pressure agent, and the active sulfur content in the press working oil should be 0.5% or less. What you need to do.

(D) A compound selected from an alkyl sulfonate, a carboxylate and its salt, and an amine compound as an anti-rust additive for imparting white rust resistance and red rust resistance is mixed with the press oil.

(E) The viscosity of the working oil is limited to 5 to 30 cst at 40 ° C. in order to impart the cleaning and removing property of the oil film of the working oil.

As a result of further study based on the above findings, the 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 comprises (a) a base oil, a rust preventive additive, a lubrication aid, and an extreme pressure additive. And (b) as a limited range of each substance, 65 to 90 parts of a base oil: one kind or two or more kinds selected from mineral oil, fats and oils and liquid synthetic oil.

Rust-preventive agent: C ₁₆ or higher alkyl sulfonates, C ₁₂
1 to 20 parts of one or more compounds selected from the above carboxylic acids and salts thereof are contained.

Lubrication aid: 1 to 20 parts of one or more compounds selected from trialkyltrithiophosphites and trialkylcarboxytrithiophosphites.

Extreme pressure additives: a sulfur-based extreme pressure additives inert type, fatty acid ester compound containing a sulfur 5-10%, an olefin sulfur bond fats and oils and C ₈ -C ₁₈ with sulfur bond 1 to 20 selected from the compounds
Part to be included.

Furthermore, in these formulations, the weight ratio of the trialkyltrithiophosphite to the inert type sulfur-based extreme pressure additive is 1:15 to 2: 1, and the active sulfur content in the press oil produced by the above formulation is The requirement is 0.5% or less, and the viscosity of the processing oil is 5 to 30 cst at 40 ° C.

The base oil applied to the rust preventive press working oil (hereinafter referred to as the press working oil) of the galvanized steel sheet of the present invention is arbitrarily selected from one kind or two kinds or more from mineral oil, fat and oil and liquid synthetic oil. Although it does not specify the oil and the viscosity of the oil, in order to keep the oil film removability after applying and processing the pressing oil,
It is necessary to maintain the viscosity at 40 ° C. at 5 to 30 cst, and for that purpose, it is necessary to select the viscosity of the base oil in consideration of the type and amount of each component in the press oil.

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 exhibited, and conversely, if it is higher than 30 cst, the amount of oil film is unnecessarily large and it is uneconomical. , And the oil film after cleaning is poor in cleanliness 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, and after adjusting the press oil, add a thickener if necessary to raise the viscosity above 5 cst. As a result, it is possible to improve the lubricity and form a press working oil according to 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 a carboxylic acid,
The carboxylic acid salt is preferably C ₁₂ or more. If the number of carbon atoms is less than that, the rust preventive effect is insufficient, and specific examples thereof include the following compounds.

Examples of the alkyl sulfonate include dinonylnaphthalene sulfonic acid metal salt (Ba, Ca, Zn, Mg, Na, etc.), didodecylbenzene sulfonic acid metal salt (Ba, Ca, Zn, Mg, Na).
Etc.), petroleum sulfonic acid metal salt. C ₁₂ or higher carboxylic acids or salts thereof are, for example, isooleic acid, oleic acid, dimer acid, alkenylsuccinic acid, petroleum oxide wax, and their metal salts (Ba, Ca, Zn, Mg, Na, etc.) and amine salts. Examples of the nitrogen-containing compound of C ₁₂ or more carboxylic acid include benzotriazole-based and imidazoline-based compounds.
There are C ₁₂ or higher carboxylic acid compounds.

Particularly preferred among the above-mentioned compounds are barium salt of dinonylnaphthalene sulfonic acid, barium salt of didodecylbenzene sulfonic acid, barium salt of petroleum oxide wax, and the like. One or more of these compounds are arbitrarily selected and blended in the base oil. Further, the addition of basic compounds of calcium sulphonate and barium sulphonate and amines can be expected to improve rust prevention. It is appropriate that the amount of addition is 1 mol or more per 1 mol of trialkyltrithiophosphite.

The amount of these rust preventive components added to the base oil is 1 to 20 parts,
If it is less than 1 part, the rust preventive effect will be insufficient, and if it is added more than 20 parts, the effect cannot be expected to be improved. Therefore, in view of balance with other components, the upper limit is 20 parts.

Trialkyltrithiophosphite is then suitable as a lubricating aid. Although the present invention does not specify these compounds, those represented by the following general formula are more preferable.

(1) Trialkyltrithiophosphite (RS) ₃ P In the formula, R is a hydrocarbon group having 8 to 22 carbon atoms. Specifically, for example, aliphatic octyl, lauryl, cetyl, palmityl, oleyl, stearyl, synthetic oil type. Examples thereof include isodecyl, tridecyl, isostearyl and the like.

(2) Trialkylcarboxytrithiophosphite (RCOOS) ₃ P 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, stearyl, and synthetic oil. Examples include one or more compounds such as isodecyl, tridecyl, and isostearyl.

The carbon number of the trialkyltrithiophosphite in the press working oil is preferably in the range of 8 to 22, and if the carbon number is less than 8, the stability will be poor. On the other hand, if the carbon number exceeds 22, the viscosity is high and the degreasing property in the coating pretreatment process is adversely affected. In this case, therefore, it is necessary to reduce the compounding amount within the range of 1 to 20 parts. However, the most preferable one is one having 12 to 16 carbon atoms.

One kind or two or more kinds are arbitrarily selected from the above trialkyltrithiophosphites to be blended with the base oil, but the blending amount is preferably 1 to 20 parts, and if less than 1 part, lubricating performance becomes insufficient, and more than 20 parts In that case, the rust resistance is reduced.

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, examples thereof include sulfur-bonded compounds such as fats and oils and fatty acid esters, and compounds in which fats and oils and C _{8 to} C ₁₈ olefins are bound by sulfur. Particularly preferable examples in the selection of fats and oils, fatty acid esters, and olefins are shown 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 group whose main component is unsaturated fatty acid having C ₁₂ or more.

(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 the same fatty acid group as described above, and R ₂ is an aliphatic alcohol.

(3) C _{8 to} C ₁₈ olefin The amount of sulfur bound to the compound must be 5 to 15% in order to impart appropriate extreme pressure properties. 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 press working oil is preferably 0.5% or less, and when it exceeds 0.5%, the discoloration of the surface tends to become strong after processing because the reactivity with the zinc surface is too strong. It is more preferably 0.3% or less.

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 rises (70 to 100 ° C.).

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

By mixing the trialkyltrithiophosphite {designated as (a)} and the inert type sulfur-based extreme pressure additive {designated as (b)}, a more stable compound is produced. If the mixing ratio {(a) :( b)} exceeds 1:15, the effect of improving the lubricity cannot be obtained even if the excess amount of (b) is added, and conversely, if it is less than 2: 1, the lubricity is good. However, it is not preferable because the rust prevention property is lowered. Therefore, the range is 1:15 to 2: 1, more preferably 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 processing oil, and in the present invention, such addition is not rejected. Absent.

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

〔Example〕

The test oils Nos. 1 to 8 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 addition, sample oil Nos. 9 to 13 in Table 1 are comparative examples, and were tested in the same manner as the examples. 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. Specimen material: Alloyed hot-dip galvanized steel sheet 45/45 Dimensions: 90 mm (diameter) x 0.7 mm (thickness) b. Tool dies diameter: 42.5 mm (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 the test piece before the test D: Average diameter of the test piece after the test Obtain the deep drawing ratio by the above calculation formula and judge according to the table below. The higher the deep drawing ratio, the better the lubricity.

(2) Rust prevention test (2) -1 Wet test a. Test piece Material: Alloyed hot dip galvanized steel sheet 45/45 Dimensions: 70mm x 150mm x 0.7mm b. Test condition Wet test method (JIS K2246 4,32 compliant) Temperature: 49 ± 1 ℃ Relative humidity: 95% or more Time: 240 hours, 720 hours c. Judgment: Judge the degree of discoloration and white rust on the test piece according to the table below.

(2) -2 Stack test a. Specimen material: Alloyed hot-dip galvanized steel sheet 45/45 Dimension: 700mm × 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: 240 hours, 720 hours 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 Dimensions: 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 a temperature of 95 ° C and a relative humidity of 95%.

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

Degreasing agent: Brand name Fine Cleaner L4480 (manufactured by Nippon Parkerizing Co., Ltd.) Concentration 1.8%, temperature 40 ° C, time 3 minutes d. Judgment: After degreasing, the test piece was washed in running water for 30 seconds, then 30
It was judged by the water-wetting area (%) after being left indoors for a second. The judgment was based on the table below.

Table 2 shows the results of these tests.

[Effects of the Invention] As is clear from Table 2, when the galvanized steel sheet rust preventive and press working oil of the present invention is used, one-time application of oil is as excellent as that of a press oil when press working the galvanized steel sheet. It has the same discoloration resistance and rust resistance as a lubricant and rust preventive oil, and has good degreasing properties in the pretreatment process of coating.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C10M 159: 20 159: 24 137: 10 Z 135: 02) C10N 10:04 20:02 30:00 A 30:06 30:12 40:24 Z (72) Inventor Yukio Numakura 5-3 Tokai-cho, Tokai-shi, Aichi Prefecture Nippon Steel Co., Ltd. Nagoya Works (72) Inventor Naoyuki Hayashi Nihonbashi, Chuo-ku, Tokyo 2-15-5 Parka Kosan Co., Ltd. (72) Inventor Mitsumi Iida Nihonbashi, Chuo-ku, Tokyo 2-15-5 Parker Kosan Co., Ltd. (72) Inventor Yoshiei Nagaei 1-15 Nihonbashi, Chuo-ku, Tokyo No. 1 in Japan Parkerizing Co., Ltd. (72) Inventor Yasuo Okumura 1-15-1 Nihonbashi, Chuo-ku, Tokyo Inside Parkerizing Co., Ltd. Japan (56) Reference JP-A-62-95396 (JP, A) Akira 61-60791 (JP, A) JP Akira 61-211398 (JP, A) JP flat 1-156398 (JP, A) Tokuoyake Akira 59-22757 (JP, B2)

Claims (2)

[Claims] 1. 65 to 95 parts by weight of one or more oils selected from mineral oils, fats and oils, and liquid synthetic oils as base oils (parts by weight,
Hereinafter the same), an alkyl sulfonate or more C ₁₆ as antirust additives, and 1-20 parts of a compound selected from C ₁₂ or higher carboxylic acids and their salts, trialkyl trithiophosphite compound as a lubricating aid and 1 to 20 parts, including 5-15% sulfur as the inert type sulfur-based extreme pressure additive, a fatty acid ester compounds, sulfur bond fats and oils and C ₈ -C
1 selected from compounds with ₁₈ olefins and sulfur bonds
It is a rustproofing press working oil consisting of 1 to 20 parts of one kind or two or more kinds of compounds, wherein the working oil contains a trialkyltrithiophosphite and an inert type sulfur extreme pressure additive in a weight ratio. Is 1:15 to 2: 1, and the active sulfur content is 0.5
% (Same as below for% by weight) or less, and a viscosity of 5 at 40 ° C
Press working oil for rust prevention of galvanized steel sheet, characterized by ~ 30cst 2. A trialkyltrithiophosphite represented by the following general formula: A press working oil for rust-preventing galvanized steel sheet according to claim 1, having the general formula (RS) ₃ P trialkyl. Trithiophosphite (RCOOS) ₃ P trialkylcarboxytrithiophosphite In the formula, R is a hydrocarbon group having 8 to 22 carbon atoms.