JPH04314795A - Rust-preventive press oil - Google Patents

Abstract

PURPOSE:To provide a rust-preventive press oil for surface-treated steel sheets which suffices when it is applied once on delivery as rust-preventive oil to a surface-treated steel shet and excels in cleaning and degreasing performances in pretreatment before coating. CONSTITUTION:A base oil is mixed with 1-5 pts.wt. pressability improving aid selected from the group consisting of alkali metal salts of alkyl acidic phosphates and alkaline earth metal salts of alkyl acidic phosphates, 0.01-1 pt.wt. oil stain preventive selected from the group consisting of an alkyl- benzotriazole and an arylbenzotriazole, 5-50 pts.wt. rust preventive selected from the group consisting of alkali metal salts of overbased alkylsulfonic acids and alkaline earth metal salts of overbased alkylsulfonic acids and 1-10 pts.wt. solid lubricant selected from the group consisting of alkali metal carbonates and oxides and alkaline earth metal carbonates adn oxides mainly consisting of 1mum or smaller particles, and the viscosity (at 40 deg.C) of the obtained mixture is adjusted to 5-40cSt.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to various steel sheets mainly used in the automobile industry and the home appliance industry, especially surface-treated thin sheets such as electrogalvanized steel sheets, hot-dip galvanized steel sheets, and alloyed hot-dip galvanized steel sheets. This invention relates to a rust-preventing oil that can be used for both press-working and has both rust-preventive properties during storage of steel plates and suitable formability during press-working.

0002

[Prior Art] During the period from when a surface-treated steel sheet is manufactured by a steel manufacturer until it is molded and processed into automobiles and home appliances by the consumer, the most important quality concern is prevention of rust. . For this reason, in the normal thin surface-treated steel sheet production process, one of the coating roll methods, oil drop methods, electrostatic coating methods, etc. Apply an appropriate amount of anti-corrosion oil according to the purpose and use using the method described below. The first requirement for the rust preventive oil is to be able to completely prevent rust from forming on the surface-treated steel sheet immediately before use, but it is also a prerequisite that the oil can be sufficiently degreased in the degreasing process before the chemical conversion treatment during use. Surface-treated steel sheets coated with the most suitable anti-corrosion oil are tightly packed with anti-corrosive paper, laminated polyethylene film, etc., and stored in a warehouse until shipped. . The shipped coil or sheet is pressed into a product shape by the user. Actual press working is a processing method that involves a complex combination of deformations such as stretching, stretching, and drawing. For this reason, it is necessary to design the material of the surface-treated steel sheet according to the shape, and it is technically important to maintain an appropriate lubrication state at the interface between the forming die, tool, and surface-treated steel sheet. If lubricity is insufficient, press cracks, scratches, wrinkles, etc. will occur on the surface-treated steel sheet side, and scratches will occur on the processing die. Alternatively, abrasion powder generated by the mold biting the surface of the surface-treated steel sheet accumulates, causing a problem called star grain. Furthermore, even if the lack of lubrication is mild, various troubles may occur depending on the molding conditions. Although various conventional lubrication techniques have been devised, the most common one is wet lubrication, in which a mixture of oils and fats and mineral oil is directly applied. In recent years, with the rationalization of press work through mechanization,
Spray lubrication of press processing oil to the lubrication points has been replaced, but it is necessary to select various lubricants depending on the type of processing material, mold, tool, etc., and it is difficult to control the amount of application, and oil consumption due to excess oil. There are many problems, such as a high number of employees and a deterioration of the working environment. Solving these various problems and streamlining processes will be of great benefit to the steel and automobile industries, while using a single lubricant for rust prevention and stamping is an important issue. It is. Generally, the anti-rust oil used for surface-treated steel sheets has a relatively low viscosity (20 mm2/sec@
(below 40°C) is used. However, since the viscosity is low, the oil film strength is also low and the lubricity during press working is insufficient. When lowering the viscosity of press working oil to the same level as rust preventive oil, it is essential to add an extreme pressure agent to improve the lubricity during press working. Extreme pressure agents used in plastic working, including general press working, corrode the surface of surface-treated steel sheets because the working is continuous, and heat is generated due to plastic deformation of the sheet material and friction with the mold. Or they tend to discolor. It is difficult to suppress this with corrosion inhibitors and is of little practical use. In other words, with the current technology, it is difficult to satisfy both the rust prevention properties and pressability of the surface-treated steel sheet using either rust prevention oil or press oil.

0003

[Problems to be Solved by the Invention] The purpose of the present invention is to improve press moldability, oil stain resistance, rust prevention, and cleaning during pre-painting treatment by applying a rust preventive oil to surface-treated steel sheets once. The object of the present invention is to provide a rust preventive oil that can be used for press processing for surface-treated steel sheets and has excellent degreasing properties.

0004

[Means for Solving the Problems] The first aspect of the present invention is to provide a base oil with at least one type of press selected from the group consisting of: (1) alkali metal salts and alkaline earth metal salts of alkyl acidic phosphate esters; 1 to 5 parts by weight of a property improving aid, preferably 2 to 3 parts by weight; (2) 0.1 to 1 part by weight of at least one oil stain inhibitor selected from the group consisting of alkylbenzotriazoles and arylbenzotriazoles; , preferably 0.1 to 0.3 parts by weight, (3) at least one anticorrosive additive selected from the group consisting of alkali metal salts and alkaline earth metal salts of overbased alkylsulfonic acids. Parts by weight, preferably 20 to 40 parts by weight, (4) At least one solid lubricant selected from the group consisting of carbonates and oxides of alkali metals and alkaline earth metals, the main component of which is particles of 1μ or less. 1-10
parts by weight, preferably 2 to 4 parts by weight, and the viscosity is adjusted to 5 to 40 mm2/sec (at 40°C), preferably 15 to 20 mm2/sec (at 40°C). Concerning rust-preventing oil for both processing and processing purposes. The second aspect of the present invention is to add 1 to 5 parts by weight of at least one pressability improving aid selected from the group consisting of (1) alkali metal salts and alkaline earth metal salts of alkyl acidic phosphate esters to the base oil. ,(2
) At least one selected from the group consisting of alkylbenzotriazole and arylbenzotriazole
Seed oil stain inhibitor 0.1 to 1 part by weight, (3)
5 to 50 parts by weight of at least one anticorrosive additive selected from the group consisting of alkali metal salts and alkaline earth metal salts of overbased alkylsulfonic acids, (4) 1μ
1 to 10 parts by weight of at least one solid lubricant selected from the group consisting of carbonates and oxides of alkali metals and alkaline earth metals, the main component of which is the following particles: (5) (a) 12 carbon atoms; At least one oiliness improver 1-2 selected from the group consisting of partial esters of the above saturated or unsaturated fatty acids and (b) aliphatic polyols
0 parts by weight, preferably 5 to 10 parts by weight, and has a viscosity adjusted to 5 to 40 mm2/sec (at 40°C). Note that when the amount is less than the prescribed amounts of (1) to (5) mentioned above, lubricity during press molding cannot be ensured, and when it is more than the specified amount, the oil stain property is significantly reduced. The base oil is not particularly limited, but it is preferable to contain 50 to 80 parts of one or more selected from mineral oils, esters, and synthetic base oils. The alkyl acid phosphate ester for forming the alkyl acid phosphate metal salt of (1) pressability improvement aid is a partial alkyl ester such as phosphorous acid, phosphoric acid, or pyrophosphoric acid, and the alkyl is a carbon Number C10-C22
, preferably C16-C18 straight-chain or branched alkyls. Specific compounds include stearyl acid phosphate and oleyl acid phosphate. Specific examples of the alkylbenzotriazole and arylbenzotriazole used as the oil stain inhibitor (2) include methylbenzotriazole and methylbenzimidazole. (3) The overbased alkyl sulfonate is an alkyl sulfonate having a total base number of 200 mgKOH/gr or more, and the alkyl has 12 to 30 carbon atoms, preferably 18 to 26 carbon atoms, and the specific Examples of compounds include dinonylnaphthalene sulfonic acid metal salts (Ba, Ca, Zn
, Mg, Na, etc.), didodecylbenzenesulfonic acid metal salts (Ba, Ca, Zn, Mg, Na, etc.), and petroleum sulfonic acid metal salts. As a solid lubricant, it is preferable that the main component is an alkali/alkaline earth metal salt of carbonic acid or an oxide of an alkali/alkaline earth metal salt with a particle size of 1 μm or less. When a solid lubricant is added to antirust oil, the dispersion stability in the oil may deteriorate depending on the particle size or secondary aggregation. This may cause the lubricating components to separate and settle during storage, causing insufficient lubrication, or the solid lubricant, when applied to a metal surface, may become a core of rust formation and significantly reduce rust prevention. The solid lubricant used in the present invention can be uniformly dispersed in oil due to the synergistic effect of the overbased sulfonate and the metal alkyl phosphate. Furthermore, extreme pressure additives such as sulfur and halogen compounds chemically react with the metal of the surface-treated steel sheet due to the heat generated during press working to form an extreme pressure coating, and this coating provides lubrication. That is, since the formation of a lubricating coating depends on the temperature of the lubrication point, if the temperature is low, the lubricating coating will not be formed and the expected lubricity cannot be ensured. On the other hand, if the temperature is too high, the chemical reaction between the extreme pressure agent and the metal may proceed too much, causing discoloration and corrosion on the surface of the surface-treated steel sheet. In the case of the solid lubricant of the present invention, the formation of the extreme pressure coating is not by chemical reaction but by physical adsorption, and this adsorbed film has lubricating properties higher than the above-mentioned lubricating film, and has rust prevention and degreasing properties. It is an additive that does not adversely affect oil stain resistance. Component (a) in the oiliness improver (5) is an aliphatic carboxylic acid with a C number of 12 or more, and specific compounds include:
Examples include oleic acid, stearic acid, and lauric acid. Component (b) is a polyol having 4 to 12 carbon atoms, such as glycerin, trimethylolpropane, and pentaerythritol.

[0005]

[Examples] Next, the present invention will be explained in detail with reference to Examples and Comparative Examples. Test oil No. of Examples of the present invention shown in Table I.
Nos. 1 to 4 were applied to a test piece using a roll coater method, and the performance was evaluated by conducting a test using the method shown below. In addition, in Table I, test oil No. Samples 5 to 9 are comparative examples, and comparative evaluations were made in the same manner as in the examples. The amount of sample oil applied was 1.5±0.2g/
Adjusted to m2. Description of test method 1) Lubricity test 1-1) Deep drawing test a. Testing machine Automatic hydraulic thin plate universal testing machine A-12 (R
oel und Korthaus K. G. Soli
ngen-OHLIGS) b. Test piece material: Alloyed hot-dip galvanized steel plate (GA60/60) Weight per side: 60 g/m2 Dimensions: 90 mmφ x 0.7 mm thickness c. Tools The tools shown in Figure 1 were used. Die diameter (Dd): 34.9mm Die shoulder radius (rd): 3.0mm Punch diameter (Dp): 33.0mm Punch shoulder radius (rp): 4.0mm d. Test conditions Squeezing speed: 3mm/sec Wrinkle holding load (H): 500kgf e. Measurement The blank diameter is changed stepwise and the drawing ratio = Db/Dd at that time is determined. Dd: Dice diameter Db: Diameter of test piece 1-2) Four-ball test a. Test machine: Four-ball lubrication test machine (Soda type) b. Rust ball for test Steel ball for ball bearing SUJ2 3/4″c. Test conditions Spindle rotation speed: 200 rpm Oil amount: 50 ml Load: 0.5 to 10 kgf/cm2 d. Measurement■ Place 3 steel balls in the test oil container , set one steel ball on the vertical main shaft. ■Pour the sample oil into a container. ■Apply a load to the steel ball while rotating the main shaft. (0.5 kgf/cm2/min) ■ Continuously Perform the operation and measure the load pressure (seize resistance load). 1-3) Sliding test a. Test piece material: Alloyed hot-dip galvanized steel plate (GA60/60) Weight per side 60 g/m2 Dimensions: 0 .7t x 20W x 3
50L mmb. Tool material: SKD11 Dimensions: A two-dimensional contact tool shown in FIG. 3 was used. Contact length with material: 10mm Inlet radius: 5mm c. Test conditions Sliding speed: 20mm/sec Sliding distance: 50mm Surface pressure: 1kgf/mm2 Tool temperature: 22.75℃ Room temperature (22℃
), and tests at high temperatures (75°C) were conducted to evaluate some lubricating oils. d. Test oil application test Rust preventive oil was 1.5±0.2g/m2 per side of the test piece.
Apply. e. Test method: The test piece shown in Figure 3 is sandwiched from both sides with the tools described above, a load P (surface pressure of 1 kgf/mm2) is applied, and in this state the test piece is pulled out as shown in the figure, and the pullout load D at that time is measured. Both P and D were measured using a load cell, and the friction coefficient was determined using the following formula. 2) Rust prevention test 2-1) Common matters a. Dimensions of the test piece The test piece had dimensions of 60 W x 80 L x 0.7 t mm, and two fishing holes (2 mmφ) were drilled at both ends of the long side. b. How to clean the test piece: Soak the test piece in hot petroleum naphtha and then warm anhydrous methanol, then wipe the gauze until no stains stick to it. c. Application of test oil: Apply 1.5±0.2 g/m2 of rust preventive oil to the test surface. A predetermined coating amount was applied to the weighed test piece in the test rust preventive oil using a roll coater, and the weight was measured. The amount of oil applied was determined from the following calculation formula. d. Number of test pieces (excluding oil stain test) Number of test piece repetitions (n number)
There are 3 pieces. 2-2) Oil stain resistance test a. Stacking method of test pieces■ 7.5W x 60L alternately on one side of 5 test pieces
× A 0.1 t (mm) Teflon spacer was inserted. ■Next, the four pieces of the sample were fixed with clips (Lion Binder Clip No. 111). ■Finally, it was wrapped according to JIS K 2246 using an opening paper (No. 5C). b. Corrosion test method ■For the test, the test piece was placed horizontally in a constant temperature and humidity chamber. ■Test conditions: temperature 60±1℃, humidity 95%RH, 30
I went for days. c. Judgment method ■After the test, the sample was left to stand until it reached room temperature and then opened. ■After opening, the test piece shall be immediately visually evaluated according to the following criteria. ■The degree of rust occurrence is based on the grid method according to JIS K 2246. Including red rust, black rust, and white rust. Judgment criteria are shown in Table 1.
Shown below.

[Table 1] 2-3) MIL oil stain test (MILC 22
235A) Add 5% water to the test oil and force emulsify it, apply this to the test piece, overlap the two pieces and let them stand horizontally. Observe the occurrence of oil stain on the surface of the overlapping part. a. Test conditions Temperature: 80°C Time: 24hr Load: 100g b. Test piece combination: KTUX/KTUXKTUX/GA GA/GA KTUX/EG EG/EG 2-4) Chlorine corrosion resistance test (atmospheric exposure test) a. Sample Preparation Method ■ KCl is mixed and dissolved in water-ethanol so that the chlorine concentration is 500 ppm. The test piece was immersed in this KCl solution for 10 seconds, then pulled up and dried with hot air. ■Continue with 2-1) c. The test oil was applied using the method specified in Section 1. b. Corrosion test method ■The test piece was placed outdoors in a Hyakuba box (a product of the Japan Weather Association) facing south at an angle of 60 degrees with respect to the horizontal plane. ■The condition of the test pieces was observed and recorded on Mondays, Wednesdays, and Fridays. At the same time, change the installation position of the test piece to sequential feeding. c. Test period: The period of time until rust is observed in 50% or more of the area of two or more test pieces, which have the slowest rust growth among the rust preventive oils subjected to the test. d. Judgment method ■ The condition of the test pieces is observed on Mondays, Wednesdays, and Fridays, and when rust is observed on two or more of the specified comparative oil-coated test pieces, J
The area of rust occurrence was determined using the checkerboard method of IS K 2246. ■2-4) c. After the period specified in , the same judgment as above was made. 2-5) Chlorine corrosion resistance test (accelerated test) a. Test piece preparation method ■2-1) c. A test piece coated with anti-corrosion oil was prepared using the method specified in Section 1. (1) 1 g of KCl-containing dust prepared in the following manner is evenly applied to the test piece of 1). <Dust Preparation Method> - JIS Class 11 standard dust was added to a saturated KCl aqueous solution, mixed and stirred, and then the dust was drained and dried with warm air. After that, it is sieved to reduce the particle size to 300-500 μm.
And so. b. Corrosion test method ■The test piece was placed horizontally in a constant temperature and humidity chamber. ■Temperature 60±
The test is carried out for 30 days under the conditions of 1° C. and 95% RH. c. Judgment method: Take out the test piece on the 10th, 20th, and 30th day, and after washing,
The corrosion state was visually determined using the checkerboard method specified in IS K 2246. 2-6) Atmospheric exposure test As shown in Figure 2, a sample oil-coated steel plate placed vertically on a wooden frame is exposed under the eaves, and changes in the appearance of the coating film and rust occurrence are observed. Test conditions Time: 30 days 2-7) Zinc elution test 70 ml of anti-corrosion oil was collected in a 100 ml beaker, and two L-shaped test pieces (30 x 60) whose weight had been measured in advance were placed on top of this. One was bent on the plated side, and the other was bent on the cold-rolled steel plate side, and after being left at 80°C for two weeks, the weight change, discoloration, etc. of the test piece, and the amount of zinc eluted into the oil were measured. 3) Degreasing test 3-1) Common matters a. Dimensions of test piece 2-1) a. Same as . b. Test piece cleaning method 2-1) b. Same as . c. Application of test oil 2-1) c. Same as . d. Number of test pieces The number of test pieces repeated (n number) was 10. e. How to prepare a degreasing solution■ Using distilled water, the degreaser Ridrin SD400A is 1.5
A solution containing 0.5 wt% of SD400B was prepared. (2) 0.5 wt % of test rust preventive oil was added and stirred into the solution to obtain a test degreasing liquid. f. Degreasing test method 3-1) e. While stirring the defatted liquid prepared in
The temperature was raised to ±2℃, and when the specified temperature was reached, the test piece was immersed for 10 minutes to degrease it.
Then, it was washed with tap water. g. Judgment method f. (2) Immediately after the operation, the test piece was immersed in distilled water for 1 second, then taken out vertically, and the state of water leakage was visually observed after 30 seconds. The judgment criteria are shown in Table 2.

[Table 2] 3-2) Initial degreasing test a. Test method 2-1) c. The test piece coated with the test oil according to the method specified in Section 2.1 is left indoors for 24 hours. 3-1) f. Carry out the degreasing test specified in Section 1. 3-3) Temporal degreasing test a. Packaging method of test piece ■2-1) c. Lay out 10 test pieces coated with the test oil using the method specified in Section 1. ■The above materials were packaged in accordance with JISK 2246 using PE laminated paper with the PE side facing outward. b. Storage method - The sample was placed horizontally in a constant temperature and humidity chamber. (2) It was left for 30 days at a temperature of 60±1° C. and a humidity of 95% RH. c. Test method - After being left for a specified period of time, the sample was opened to room temperature and left indoors for 24 hours. ■After that, 3-1) f. A degreasing test was conducted as specified in Section 1. 4) Chemical conversion treatment test 4-1) Chemical conversion treatment test a. Dimensions of test piece 2-1) a. Same as . b. Test piece cleaning method 2-1) b. Same as . c. Application of test oil 2-1) c. Same as . d. Number of test pieces The number of test pieces repeated (n number) is 3. e. Method for Preparing Chemical Conversion Treatment Solution A standard solution of chemical conversion treatment agent PB3020 (manufactured by Parker Rising) was prepared using distilled water so that it met the following conditions. Table 3 shows the standard solution preparation conditions.

[Table 3] f. Chemical conversion treatment test method The prepared chemical conversion treatment solution was heated to a predetermined temperature, and the test piece was subjected to immersion chemical conversion treatment for a predetermined time. g. After the determination method operation, the test piece was immediately dried, and the amount of chemical conversion film deposited on the surface of the test piece was measured, and the crystalline state of the film was visually observed using a microscope. The judgment criteria are shown in Table 4.

[Table 4] As is clear from the results in Table 6, the composition of the present invention is superior to the comparative examples in terms of lubricity, rust prevention, and degreasing properties.

[Table 5]

[Table 6] (○: Excellent △: Fair ×: Poor) *1 The coefficient of friction (μ) was determined by performing the aforementioned sliding test using the tool in Figure 3, and creating a graph like that in Figure 4 from the measured values. , P and D
The average value within the broken line where the value of is stable is adopted as the value of P and D in equation (1), and μ is calculated according to equation (1). In order to raise the temperature to a predetermined temperature, a flexible heater was attached to the tool 1, and the temperature was monitored with a CA thermocouple.

[0006]

[Effect] When the rust preventive oil for press forming of the present invention is used, excellent press formability and resistance can be achieved by applying the oil once as a shipping rust preventive oil at a steel manufacturer during press forming of surface-treated steel sheets, etc. Oil stain resistance, rust prevention, and cleaning and degreasing properties can be achieved in the pre-painting process.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a mold (die and punch) in a deep drawing test.

FIG. 2 is a diagram showing a wooden frame for holding a test piece in an atmospheric exposure test, which is one of the rust prevention evaluations.

FIG. 3 is a diagram showing the appearance of a sliding test tool.

FIG. 4 is an example of a diagram showing a load chart obtained by a sliding test.

[Explanation of symbols]

Dd Die diameter Dp Punch diameter Db Test piece diameter H Wrinkle pressing pressure P Press load rd die shoulder radius rp punch shoulder radius

Claims (2)

[Claims] 1. The base oil contains: (1) 1 to 5 parts by weight of at least one pressability improving aid selected from the group consisting of alkali metal salts and alkaline earth metal salts of alkyl acidic phosphate esters; 2
) At least one selected from the group consisting of alkylbenzotriazole and arylbenzotriazole
Seed oil stain inhibitor 0.1 to 1 part by weight, (3)
5 to 50 parts by weight of at least one anticorrosive additive selected from the group consisting of alkali metal salts and alkaline earth metal salts of overbased alkylsulfonic acids, (4) 1μ
Contains 1 to 10 parts by weight of at least one solid lubricant selected from the group consisting of carbonates and oxides of alkali metals and alkaline earth metals whose main component is the following particles, and has a viscosity of 5 to 10 parts by weight. A rust-preventing oil for press processing, characterized by being adjusted to 40 mm2/sec (at 40°C). 2. The base oil contains: (1) 1 to 5 parts by weight of at least one pressability improving aid selected from the group consisting of alkali metal salts and alkaline earth metal salts of alkyl acidic phosphate esters; 2
) At least one selected from the group consisting of alkylbenzotriazole and arylbenzotriazole
Seed oil stain inhibitor 0.1 to 1 part by weight, (3)
5 to 50 parts by weight of at least one anticorrosive additive selected from the group consisting of alkali metal salts and alkaline earth metal salts of overbased alkylsulfonic acids, (4) 1μ
1 to 10 parts by weight of at least one solid lubricant selected from the group consisting of carbonates and oxides of alkali metals and alkaline earth metals, the main component of which is the following particles: (5) (a) 12 carbon atoms; At least one oiliness improver 1-2 selected from the group consisting of partial esters of the above saturated or unsaturated fatty acids and (b) aliphatic polyols
0 parts by weight, and the viscosity is 5 to 40 mm2/s.
A rust-preventing oil for press processing, which is characterized by being adjusted to EC (at 40°C).