JPH07173486A - Rust preventive lubricant for galvanized steel sheet - Google Patents

Abstract

PURPOSE:To provide a rust preventive lubricant which improves the press processability and corrosion resistance of galvanized steel sheets including steel sheets with processing difficulties, such as thickly plated steel sheets, and has excellent removability after steel sheet processing/assembling. CONSTITUTION:This lubricant contains an ether compound obtained by a reaction of at least one alcohol having two or more hydroxyl groups per molecule with at least one hydroxylated compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rust preventive lubricant for galvanized steel sheets, and more specifically, it improves the "press forming workability" and "rust preventability" of galvanized steel sheets mainly used for automobiles and home appliances. The present invention also relates to a rust preventive lubricant which is excellent in “degreasing property” after processing and assembling the steel sheet.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Galvanized steel sheets manufactured by steel makers are coated with rust-preventive oil exclusively for the purpose of rust prevention during manufacturing, storage, user delivery (transportation), processing and degreasing processes. . In addition, the consumer of the galvanized steel sheet such as an automobile manufacturer and a home electric appliance manufacturer often presses the steel sheet into a product shape without cleaning the rust preventive oil, and the rust preventive oil is a lubricating oil for press working. As well, it performs some functions.

In recent years, many automobiles and home electric appliances have been integrally formed, including the simplification of the press working process, and the product shape itself has become complicated. In addition, high-speed molding was helped, and rust preventive oil began to be required to have improved lubrication function during pressing. Furthermore, in the automotive field, in order to improve the rust prevention (durability) of the product itself, "thick galvanized steel sheets" with an increased amount of galvanizing are the mainstream, which accelerates the deterioration of press workability of steel sheets. I'm hanging. That is, the thick plating of zinc is effective as a means for improving the durability of the product, but it has a problem that it generally impairs the workability of the steel sheet and particularly lowers the press workability. Further, the galvanized steel sheet is liable to cause a problem called zinc buildup, which is referred to as build-up, in a die-processed portion during processing, and it is difficult to obtain a high-quality product.

Conventionally used rust preventive oils for galvanized steel sheets are generally adjusted to have low viscosities for the purpose of facilitating degreasing of the steel sheets after processing and assembly.
Therefore, the chemicals used may be limited, and a simple composition in which a rust preventive additive is used in mineral oil has become the mainstream. With the rust-preventing oil that has undergone such restrictions, improvement in press-molding workability is hindered. Further, the solid film type rust preventive agent has good lubricity, but has a problem that cleaning properties are deteriorated.

As described above, in recent years, with the shift to galvanized steel sheets, complicated product shapes, and speeding up of press working, conventional rust preventive oil causes press scratches due to insufficient lubrication, plating peeling, and breakage. It is the current situation that such problems remain.
Due to such a current situation, a rust preventive oil for galvanized steel sheet is required to have a performance having both press forming workability and washability in consideration of the conventional rust preventive effect.

A conventional rust preventive oil is disclosed in Japanese Patent Laid-Open No. 48-67.
The lubricating compositions described in JP-A-141 and JP-A-50-67806 and the rust preventive oil described in JP-A-62-95396 are known. However, although the lubricating composition has good lubricity due to the solid coating type, it has a problem of poor cleanability, and the rust preventive oil has a problem that sufficient lubricity cannot be obtained because the viscosity is lowered. There is. Further, a method of forming a polymer film is also known, but in view of rust resistance, degreasing property after press working, and economical efficiency, there is still no satisfactory one.

Therefore, an object of the present invention is to improve the "press forming workability" and "rust prevention" of galvanized steel sheets including hard-workable steel sheets such as thick-plated steel sheets, and An object of the present invention is to provide a rust preventive lubricant excellent in “degreasing property” after assembly.

[0008]

As a result of intensive studies, the present inventors have found that a rust preventive lubricant containing a specific ether bond compound can achieve the above object.

The present invention has been made based on the above findings, and comprises one or more polyhydric alcohols having two or more hydroxyl groups in the molecule and one or two or more compounds having a hydroxyl group. It is intended to provide a rust preventive lubricant for galvanized steel sheet containing the obtained ether bond compound.

The rust preventive lubricant for galvanized steel sheet of the present invention will be described in detail below. The "polyhydric alcohol having two or more hydroxyl groups in the molecule", which is one component used for obtaining the ether-bonded compound which is an essential component of the rust preventive lubricant of the present invention, has a molecular weight of 500 or less. Preferred are those having 2 to 8 hydroxyl groups in the molecule. Examples of the polyhydric alcohol include pentitols such as ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, erythritol, glycerol (glycerin), arabitol, and sorbitol. And hexitol such as mannitol, glucose, sucrose, sorbitan, and the like. Among these, neopentyl glycol, pentaerythritol, glycerol, sorbitan, and trimethylolpropane are preferable.

Further, the "component having a hydroxyl group" which is the other component used for obtaining the above ether bond compound may be a monohydric alcohol or a polyhydric alcohol, or may have an ether bond. .
Examples of the “compound having a hydroxyl group” include, for example, straight chain saturated alcohols such as octyl alcohol, nonyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, and oleyl alcohol. Chain unsaturated alcohols, 2-ethylhexyl alcohol, 2-octyldodecanol, branched alcohols such as isostearyl alcohol, monohydric alcohols such as natural alcohols obtained from natural fats and oils such as beef tallow, coconut oil, palm oil and olive oil. Other examples include 1,2-octanediol, 1,2-decanediol, 1,2-laurindiol, glycerol monoether and the like. Among these, oleyl alcohol, isostearyl alcohol, and glycerol monoether are preferable. Examples of alcohols that form ether bonds with glycerol of glycerol monoether include octyl alcohol, nonyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol,
Linear saturated alcohols such as stearyl alcohol and behenyl alcohol, linear unsaturated alcohols such as oleyl alcohol, 2-ethylhexyl alcohol,
2-octyldodecanol, branched alcohols such as isostearyl alcohol, beef tallow, coconut oil, palm oil,
Examples include monohydric alcohols such as natural alcohols obtained from natural fats and oils such as olive oil. As the glycerol monoether, glyceryl oleyl monoether and glyceryl isostearyl monoether obtained from oleyl alcohol and isostearyl alcohol are preferable.

Therefore, the "ether bond compound" obtained from the above-mentioned polyhydric alcohol and the above-mentioned compound having a hydroxyl group, which is an essential component of the rust preventive lubricant of the present invention, is represented by the following general formula (1) ) To (5), that is, an ether bond compound obtained from a polyhydric alcohol such as pentaerythritol, glycerol and sorbitan and an aliphatic alcohol [compounds of the general formulas (1) and (2)], Ether-bonded compounds [compounds of general formulas (3) and (4)] obtained from two kinds of polyhydric alcohols, ether-bonded compounds having two or more ether bonds in the molecule [compounds of general formula (5)], etc. Among these, the compound represented by the general formula (5) is preferable. The ether bond compound may have one of the hydroxyl groups of the polyhydric alcohol having an ether bond, and particularly preferably has one to three alkyl ether bonds in the molecule.

[0013]

[Chemical 2]

The ether bond compound is a compound represented by the general formulas (1) to (5) of the above [Chemical formula 2], wherein R in the formula is from 10 to 22 carbon atoms, especially handling In consideration of the properties, it is preferable that R is a branched chain alkyl group and that has an unsaturated bond.

The rust preventive lubricant of the present invention has 8 to 2 carbon atoms.
It is preferable to incorporate the aliphatic alcohol of No. 4 in the above. Examples of such aliphatic alcohols include octyl alcohol, nonyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol,
Linear saturated alcohols such as stearyl alcohol and behenyl alcohol, linear unsaturated alcohols such as oleyl alcohol, 2-ethylhexyl alcohol,
Branched alcohols such as isostearyl alcohol,
Examples thereof include natural alcohols obtained from natural fats and oils such as beef tallow, coconut oil, palm oil and olive oil.

The above-mentioned aliphatic alcohol is an effective agent which does not deteriorate the pressability at the time of adjusting the low viscosity when used in combination with the above ether-bonding compound, and serves as a low-viscosity adjusting agent and a press-molding processability improving agent. To fulfill. That is, most of the above aliphatic alcohols generally have a low viscosity, and particularly when combined with the above ether bond compound, the press moldability and the like are effectively improved.

When the rust preventive lubricant of the present invention is blended with an aliphatic alcohol which cannot maintain a liquid state as the aliphatic alcohol, it is preferable to use the following viscosity modifier from the viewpoint of degreasing property. preferable. Further, when a liquid aliphatic alcohol is blended as the above aliphatic alcohol, the following viscosity adjustment is carried out if the mixture of the liquid aliphatic alcohol and the ether bond compound (rust preventive lubricant of the present invention) is kept liquid. It is not necessary to mix agents. However, even in this case, it may be necessary to finely adjust the viscosity and the liquid property in handling, and in such a case, the following viscosity modifier may be used in combination.

Examples of the viscosity modifier include mineral oils such as machine oil, synthetic hydrocarbons such as α-olefin and synthetic naphthene, liquid paraffin, and esters. This viscosity adjusting agent is for adjusting the viscosity and properties of the product, and may be any one as long as it satisfies the desired viscosity and properties, and is not limited to the above hydrocarbons and the like.
However, it is preferable to select one having a kinematic viscosity of 5 to 50 cSt at 40 ° C. in consideration of the viscosity and properties of the product. If you use a high viscosity product, the viscosity of the product will increase,
Not preferable.

The rust preventive lubricant of the present invention includes other additives generally added to ordinary rust preventive oils and lubricants such as extreme pressure agents, surfactants, antioxidants, stain inhibitors, A non-ferrous corrosion inhibitor or the like can be added.

The rust preventive lubricant of the present invention preferably contains the above ether bond compound in an amount of 5% by weight or more, particularly 5 to 60% by weight in consideration of physical properties such as viscosity. The component (remainder) other than the above ether bond compound of the rust preventive lubricant of the present invention is one or two selected appropriately from the above aliphatic alcohols, viscosity modifiers and various additives as necessary.
More than one compound. The above-mentioned aliphatic alcohol is effective when added in an amount of 3% by weight or more in the rust-preventive lubricant.
It is preferably used in the range of 60% by weight, especially 10
It is preferably used in the range of 50% by weight. Also,
The above viscosity modifier is preferably used when the viscosity cannot be adjusted with an aliphatic alcohol, and is usually used in a rust preventive lubricant.
It will be used in the range of 2% by weight or less.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Using the ether bond compounds described in the following [Table 1], rust preventive lubricant Nos. Nos. 1 and 2 having the composition shown in the following [Table 2], [Table 3] and [Table 4] are used. 1-31 were prepared. These rust preventive lubricants were subjected to the following lubrication test, rust preventive test and degreasing test to evaluate press moldability, rust preventive property and degreasing property. The results are shown in [Table 5] below. The evaluation results of commercially available rust preventive oils and press oils, beef tallow, and paraffinic mineral oils are also shown in the following [Table 5].

(1) Lubrication test (deep drawing test) A cylindrical limit drawing test die was used, and a limit drawing ratio was 2.0.
The press-formability was evaluated in the range from 1 to 2.4. [Tool] ・ Die diameter: 62.4 mm ・ Punch diameter: 50.0 mm ・ Die shoulder radius: 5.0 mm ・ Press speed: 50 strokes / min [Test piece] Alloyed hot dip galvanized steel sheet: 60/60, 1
00-120 mm (diameter) x 0.8 mm (thickness) [Amount of anti-rust lubricant applied]: 1.5 g / m ² [Method of applying anti-rust lubricant]: Hexane-ethanol mixed solvent (6: 4) Dissolve the rust preventive lubricant in and dip the test piece. The rust preventive lubricant can be uniformly applied by pulling up the test piece and drying it. A lubrication test was conducted after standing for 1 day. [Evaluation Criteria]: As the evaluation criteria, the higher the limit drawing ratio, the better the press moldability was judged to be. [Evaluation Method] A: The limiting drawing ratio is in the range of 2.3 or more and 2.4 or less. ◯: The limit drawing ratio is in the range of 2.2 or more and less than 2.3. Δ: The limiting drawing ratio is in the range of 2.1 or more and less than 2.2. X: The limiting drawing ratio is in the range of 2.0 or more and less than 2.1.

(2) Anticorrosion Test Using a constant temperature wetness tester, an anticorrosive lubricant was applied to the test pieces to evaluate the antirust property (rusting condition). [Test conditions] -Temperature: 49 ± 1 ° C-Relative humidity: 95% or more [Test piece] Alloyed hot-dip galvanized steel sheet: 60/60, 60 mm x 80
mm × 0.8 mm [Amount of rust preventive lubricant applied]: 1.5 g / m ² [Method of applying rust preventive lubricant]: Dissolve the rust preventive lubricant in a hexane-ethanol mixed solvent (6: 4), Immerse the test piece. The rust preventive lubricant can be uniformly applied by pulling up the test piece and drying it. After standing for 1 day, a rust prevention test was conducted. [Evaluation Criteria]: Set the test piece in a constant temperature wetness tester,
After 240 hours, the rust prevention property (rusting condition) was evaluated. [Evaluation description method] ⊚: No rust is observed on the test piece. ◯: Rust is observed at the edge of the test piece. Δ: Rust is observed on almost half of the test pieces. X: Rust is observed on almost the entire surface of the test piece.

(3) Degreasing Test An alkaline degreasing agent having the following composition was prepared, and the degreasing property of the test piece coated with the anticorrosive lubricant was evaluated by dip cleaning. [Alkaline-type degreasing agent] -Sodium hydroxide: 1.7% -EDTA-4Na: 0.2% -Nonionic surfactant (HLB12.4): 0.05
% Defoaming agent: 0.05% [Degreasing agent concentration]: 2.0% [Degreasing temperature]: 40 ° C [Degreasing time]: 60 seconds [Test piece] Alloyed hot dip galvanized steel sheet: 60/60, 50 mm × 12
0 mm x 0.8 mm [Amount of rust preventive lubricant applied]: 1.5 g / m ² [Method of applying rust preventive lubricant]: Dissolve the rust preventive lubricant in a hexane-ethanol mixed solvent (6: 4), Immerse the test piece. The rust preventive lubricant can be uniformly applied by pulling up the test piece and drying it. After leaving for 10 days, a degreasing test was performed. [Evaluation Criteria]: The test piece is immersed and washed for 60 seconds, and after washing with water, the remaining oil is extracted with carbon tetrachloride and quantified with an IR analyzer. The cleaning degreasing rate was obtained from the coating amount of the rust preventive lubricant before cleaning, and the degreasing property was evaluated. [Method of writing evaluation] A: Degreasing rate of 80% or more. ◯: Degreasing rate is 60% or more and less than 80%. Δ: Degreasing rate is 40% or more and less than 60%. X: Degreasing rate is less than 40%.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

The following can be seen from the results shown in Table 5 above. [Effects depending on the type of ether bond compound] Anticorrosive lubricant N
o. As can be seen from the results of 1 to 20, the five kinds of ether-bonded compounds used in the examples showed the same effect.

[Effect of Combined Use of Ether Bonding Compound and Aliphatic Alcohol] Anticorrosion Lubricant No. 2, No. 12, N
o. 21 and No. 21. As can be seen from the results of No. 22, 4 of lauryl alcohol, oleyl alcohol, Guerbet branched alcohol (C20), and Guerbet branched stearyl alcohol.
There was almost no difference between the two. In addition, rust preventive lubricant No. 2 and No. As can be seen from the results of Nos. 23 to 27, when the addition amount of the ether bond compound was kept constant and the addition amount of the aliphatic alcohol was changed, the press moldability was improved as the addition amount of the aliphatic alcohol increased. Was given.

[Effect of Addition Amount of Ether Bond Compound] Anticorrosion Lubricant No. 2 and No. As can be seen from the results of Nos. 29 to 31, when no ether bond compound is added (rust preventive lubricant No. 29), the press moldability and the rust preventive property are remarkably poor, while the product containing the ether bond compound is used. Inventive anti-rust lubricant (No. 2, No. 30 and N
o. In No. 31), as the amount of the ether bond compound added was increased, the press moldability and the rust preventive property were improved.

[0034]

The anticorrosive lubricant for galvanized steel sheets of the present invention improves the "press forming workability" and "rust prevention" of galvanized steel sheets including difficult-to-form steel sheets such as thick galvanized steel sheets. It is also excellent in "degreasing" after processing and assembling the steel sheet.

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Claims (7)

[Claims] 1. An anti-galvanized steel sheet containing an ether bond compound obtained from one or more polyhydric alcohols having two or more hydroxyl groups in the molecule and one or two or more hydroxyl group-containing compounds. Rust lubricant. 2. The rust preventive lubricant for galvanized steel sheet according to claim 1, further comprising an aliphatic alcohol having 8 to 24 carbon atoms and / or a viscosity modifier. 3. The rust preventive lubricant for galvanized steel sheet according to claim 1, wherein the polyhydric alcohol has a molecular weight of 500 or less. 4. The rust preventive lubricant for galvanized steel sheet according to claim 1, wherein the ether bond compound has 1 to 3 alkyl ether bonds in the molecule. 5. The rust preventive lubricant for galvanized steel sheet according to claim 1, wherein the ether bond compound is a compound represented by the following general formulas (1) to (5). [Chemical 1] 6. R in the general formulas (1) to (5) of [Chemical Formula 1]
Is a branched chain alkyl group or a hydrocarbon group having an unsaturated bond, The rust preventive lubricant for galvanized steel sheet according to claim 5. 7. The rust preventive lubricant for galvanized steel sheet according to claim 5, wherein the ether bond compound is a compound represented by the general formula (5) of [Chemical Formula 1].