JP2001200287A - Lubricant for steel plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant to be applied on a coating film of a rust preventive or the like formed on a cold-rolled steel plate, a zinc-plated steel plate or an aluminum-plated steel plate in order to further enhance lubricity. SOLUTION: The lubricant comprises 30-90 parts by mass of water, 0.1-3 parts by mass of a sodium borate compound, 1-30 parts by mass of a polyalkylene glycol compound, 0.1-3 parts by mass of a polyvinyl alcohol compound and 0.1-3 parts by mass of a surfactant comprising a fatty acid alkanolamide compound. The sodium borate compound can be an anhydride, a pentahydrate or a decahydrate. The polyalkylene glycol compound is preferably a polyethylene glycol compound having a mol.wt. of 1,000-40,000. The polyvinyl alcohol compound has preferably a polymerization degree of 200-2,000. The surfactant is preferably a 1:1 type coconut oil fatty acid diethanolamide compound. Further, the ratio of the polyalkylene glycol compound to the polyvinyl alcohol compound is preferably 1:1 to 3:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming agent (hereinafter simply referred to as a "pressing agent") used for press forming a steel sheet, and more particularly, to a cold-rolled steel sheet, an electrogalvanized steel sheet, a hot-dip galvanized steel sheet, a zinc alloy plating. The present invention relates to a press working agent applied to steel sheets, such as steel sheets, galvannealed steel sheets, aluminum-coated steel sheets, and aluminum alloy-coated steel sheets. The pressing agent of the present invention is further applied on an oil film such as rust-preventive oil or dioctyl sebacate, liquid paraffin, etc., which is applied at the time of shipment by an iron maker, etc., to improve the lubricity of difficult-to-machine parts during press working. .

[0002]

The present invention can be further applied to an anticorrosive oil applied at the time of shipment by an iron maker or the like, or to an oil film of dioctyl sebacate, liquid paraffin, or the like. It is an object of the present invention to provide a pressing agent capable of improving the lubricity of a difficult-to-machine portion in the above.

[0003] Since the press working agent of the present invention can be applied onto an oil film, it can be used before shipment by an iron maker or the like. Therefore, it is preferable that the press working agent of the present invention does not generate oil stain and rust on the steel sheet during the storage period in the coil, and can ensure good lubricity during the press working.

[0004]

Means for Solving the Problems As a result of research on a press working agent for steel sheets, the present inventors have first obtained the following new knowledge. That is, (a) As a rust preventive additive for imparting rust preventive properties, it is desirable to mix a sodium borate compound in the press working agent. However, since the solubility and lubricity are not impaired, the amount of the rust preventive additive must be specified.

(B) It is preferable to include a polyalkylene glycol compound and a polyvinyl alcohol compound as a lubricant and a lubricating aid for maintaining press working performance. In addition, it is necessary to specify the type, the number of carbon atoms in the molecular structure, and the amount of the compound in the press working agent.

(C) It is necessary to contain a surfactant in order to maintain uniform wettability on the surface of the oil film and to maintain press working performance appropriately and uniformly. Types of surfactants It is necessary to specify the number of carbon atoms in the molecular structure and the amount of the surfactant in the press working agent.

[0007] As a result of further study based on the above findings, a target press working agent meeting the above-mentioned demand has been completed. That is, the press working agent of the present invention has both rust prevention and lubricity, and has the following constitution. (A) Water, rust preventive additives, lubricants, lubricating aids, and surfactants are the main components. (B) As a limited range of each component, 30 to 90 parts (parts by mass, hereinafter the same) of a diluting solvent: water is contained. Rust prevention additive: 1 selected from sodium borate compounds
One or two or more compounds are used in an amount of 0.1 to 3 parts. Lubricant: One or two or more compounds selected from polyalkylene glycol compounds as lubricants in total
1 to 30 parts, one or more compounds selected from polyvinyl alcohol compounds as lubricating aids in a total amount of 0.1 to 30 parts.
1 to 3 parts are contained. In these formulations, it is more preferable that the content ratio between the polyalkylene glycol compound and the polyvinyl alcohol compound is 1: 1 to 3: 1 by mass. As the surfactant, one or more compounds selected from fatty acid alkanolamide compounds are used, and a total of 0.1 to 0.1% is used.
To 3 parts.

The water used as a diluting solvent for the press working agent of the present invention may be pure water, distilled water, tap water, well water, etc.
Tap water is desirable from economical point of view.

Next, regarding the water-soluble rust preventive added as a rust preventive additive, the present inventors have proposed inorganic salts such as sodium sulfite, sodium nitrate and sodium borate, and aromatic salts such as sodium benzoate and sodium cinnamate. Carboxylic acids and salts, imidazoles, amino acids and the like were studied. According to the findings of the present inventors, sodium borate is preferred among these.

In the present invention, the amount of the rust preventive component is 0.1 to 3
Department. If less than 0.1 part, the rust prevention effect becomes insufficient,
If more than 3 parts are added, no improvement in the rust-preventing effect can be expected, and the solubility and lubricity are reduced, so the upper limit is 3 parts.

In the present invention, as a lubricant and a lubricating aid,
A polyalkylene glycol compound and a polyvinyl alcohol compound are used.

First, the polyalkylene glycol compound will be described below. Although not particularly specified in the present invention, a polyethylene glycol compound having a molecular weight of 1,000 to 40,000 is desirable. Most preferably, it is a polyethylene glycol compound having a molecular weight of 2,000 to 30,000. The polyethylene glycol compound may be modified, and may be modified by copolymerization with another alkylene oxide (3 to 4 carbon atoms) (the ratio of ethylene oxide is 80% by mass or more) and alkyl of a terminal hydroxyl group (1 to 4 carbon atoms). 22) Etherification, alkyl (C 1-22)
Esterification and the like.

[0013] One polyvinyl alcohol compound does not specify the compound, but has a polymerization degree of 200-2.
2,000 polyvinyl alcohol compounds are desirable, and most preferably a polyvinyl alcohol compound having a degree of polymerization of 500 to 1,000. The saponification degree of the polyvinyl alcohol compound is desirably 70 mol% or more.

The compounding amount of these compounds is preferably from 1 to 30 parts in total for the polyalkylene glycol compound. If it is less than 1 part, press workability becomes insufficient. Further, the upper limit is preferably 30 parts in order to prevent discoloration of the steel sheet during the steel sheet storage period or after pressing. One of the polyvinyl alcohol compounds is preferably 0.1 to 3 parts in total.
If the amount is less than 0.1 part, the press workability becomes insufficient. 3
If more than 3 parts are added, no improvement in lubricating effect can be expected, and solubility and degreasing properties are reduced. Therefore, the upper limit is 3 parts.

In the present invention, by including both the polyalkylene glycol compound (a) and the polyvinyl alcohol compound (b), excellent lubricity which cannot be obtained by the polyalkylene glycol compound alone can be achieved. The mixing ratio is preferably from 1: 1 to 3: 1.
When ((a) :( b)) is more than (1: 1), even if (b) is added excessively, the lubricating property is not so much improved, and the viscosity is significantly increased. Conversely, if it is less than 3: 1, the lubricity is poor. Therefore, the range is preferably 1: 1 to 3: 1, and more preferably (1.5: 1) to (2.5:
1).

As the surfactants, known surfactants include fatty acid derivatives of anionic surfactants, sulfonic acid type and the like, and nonionic surfactants such as polyoxyethylene type, polyhydric alcohol type and alkylolamide type. No. Specific examples thereof include polyoxyethylene polyoxyethylene nonyl phenyl ether, polyoxyethylene monooleate, such as sulfonic acid type sodium dodecylbenzenesulfonate, such as sodium stearate and potassium oleate of fatty acid derivatives. Examples thereof include polyhydric alcohol-based sorbitan monooleate and the like, and alkylolamide-based 1: 1 type and 1: 2 type oleic acid diethanolamide. According to the findings of the present inventors, among the above, a fatty acid alkanolamide compound as a nonionic surfactant is preferable, and a 1: 1 type coconut oil fatty acid diethanolamide compound is most preferable.

The total amount of the surfactant is 0.1 to
Three parts are preferred. If the amount is less than 0.1 part, the lubricating effect becomes insufficient, and if the amount is more than 3 parts, the improvement of the lubricating effect cannot be expected and it becomes uneconomical, so the upper limit is 3 parts.

The press working agent of the present invention can be applied to a rust-preventive oil applied to a steel plate surface at the time of shipment by an iron maker or the like, or to an oil film such as dioctyl sebacate or liquid paraffin.

In order to form a thin film on a steel sheet using the press working agent of the present invention, a thin film can be applied by a spray method, a dipping method or a roll coater by a rubber roll. It is more desirable that the film be dried, but it shows sufficient lubricity even in a semi-dry state or immediately after application.

It is preferable to use the pressing agent of the present invention roughly in the following two steps. One is to apply a rust preventive oil, dioctyl sebacate, liquid paraffin, or the like to a steel plate by a steel maker or the like, and then apply the oil in a process before winding the coil. The other one is applied after the uncoiling, leveling, shirring, and washing processes in the pressing process of an automobile manufacturer, and before the pressing process.

Further, depending on the intended use, after forming a lubricating film of the pressing agent of the present invention, a commonly used pressing oil film layer may be further formed thereon. It is effective when is required.

The pressing agent of the present invention contains less than a few% of methyl alcohol in order to enhance the drying property when used.
Ethyl alcohol and the like can be added. In use, a drying step may be further provided, or a press working agent may be heated and applied.

Further, if necessary, a plurality of surfactants may be added to the press-working agent of the present invention as a compatibilizer in order to enhance the storage stability. Furthermore, it does not refuse to add a pour point depressant, an antioxidant, a viscosity index improver, an antifoaming agent and the like.

[0024]

EXAMPLES The present inventors assumed that the test material had a thickness of 0.8 m.
A cold-rolled steel sheet, a hot-dip galvanized steel sheet, and an aluminum-plated steel sheet having a thickness of m were subjected to various types of lubrication for press working, and their lubricity, rust prevention and degreasing properties were investigated.

The lubricity is evaluated by a draw bead test.
FIG. 1 is an outline of the test apparatus. In FIG. 1, the tip of the bead 1 has an R of 1.0 mm, and protrudes 5 mm from the right side surfaces of the molds 2 and 2 ′. Board width is 30mm and length is 300
The test material 3 having a width of 5 mm is a mold 4 and 4 'each having a width of 5 mm.
Is sandwiched between the left side surface of the mold and the right side surfaces of the molds 2 and 2 '.
mm. The corners R of 2, 2 'and 4, 4' are all 2 mm. If the crimping load P is increased in this test, the specimen 3 breaks during the drawing. The present inventors measured a critical pressure-bonding load that does not cause breakage, and evaluated according to the evaluation criteria in Table 1.

Evaluation of rust prevention by a wet test is based on JIS K 224.
According to 6, 5.34, temperature is 49 ± 1 ℃ and relative humidity is 95
% In a humid atmosphere of not less than 60% and a length of 80 mm
The test was performed by holding each lubricated specimen for press working of 5 mm for 5 days. After the wet test, each test material was visually inspected and evaluated according to the evaluation criteria in Table 2.

The evaluation of rust prevention by a stack test was conducted by using a lubricated plate 70 mm long and 150 mm long for press working.
5 specimens are superimposed on each other with a force of 7 N · m.
It was kept in a humid atmosphere at 1 ° C. and a relative humidity of 95% or more for 5 days. The test piece taken out was visually inspected and evaluated according to the same evaluation criteria as shown in Table 2.

In the degreasing test, the board width was 70 mm and the length was 150 m
m specimens are superimposed on each other with a force of 7 N
It was kept for 5 days in an atmosphere at a temperature of 95 ° C. and a relative humidity of 95%. The removed test piece is a general-purpose degreasing solution (Fine Cleaner L
4480, manufactured by Nippon Parkerizing Co., Ltd., 1.8% 4
(Solution at 0 ° C.) for 5 minutes in a stationary state. The degreased test material was washed with water for 30 seconds and then evaluated according to the evaluation criteria shown in Table 3.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

Table 4 summarizes the test methods and the results.
No. 1 to 3 are examples using the press working agent of the present invention. No. 1 using the press working agent of the present invention. Nos. 1 to 3 have favorable lubricity, rust prevention and degreasing properties for all of the cold rolled steel sheets, galvanized steel sheets, and aluminum plated steel sheets.

No. No. 4 is a comparative example, which is an example in which there is no already applied oil layer of rust preventive oil. In this case, rust prevention is insufficient. No. No. 5 is an example in which the content of polyvinyl alcohol (b) is small. Lubricity is insufficient compared with 1-3.

No. No. 6 is an example which does not contain sodium borate as a rust preventive additive, but the test result of the stack is insufficient. No. No. 7 is an example which does not contain a 1: 1 coconut oil fatty acid diethanolamide as a surfactant, but has poor lubricity. No. No. 8 is an example in which the molecular weight of polyethylene glycol is 1000 or less. Inferior to 1 to 3. No. No. 9 is an example in which the degree of polymerization of polyvinyl alcohol is 2000 or more. Inferior to 1 to 3. No. No. 10 is an example using a commercially available press working agent. However, in this draw bead test, excellent lubrication performance was required. No. 10 had insufficient lubrication performance.

[0036]

As described above, when the lubricant for a steel sheet of the present invention is applied onto an oil film such as a rust-preventive oil or a press oil which has already been applied to a steel sheet, extremely excellent lubricity in press working can be obtained. Demonstrate. For this reason, the lubricity of difficult-to-machine portions is greatly improved. Further, the lubricant for steel sheets of the present invention has extremely good rust prevention and degreasing properties. Therefore, the lubricant for steel sheets of the present invention is extremely useful.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method of evaluating lubricity (draw bead test).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C10N 10:02 C10N 10:02 20:04 20:04 30:06 30:06 30:12 30:12 40 : 24 40:24 AZ 50:02 50:02 80:00 80:00 (72) Inventor Takeshi Takeshi 2-14-12 Nakaikegami, Ota-ku, Tokyo Parker Kosan Co., Ltd. F-term (reference) 4H104 AA01C AA26C BE11C CB02C CB14A EA02A FA01 LA06 LA11 PA23 PA34 QA01 QA08

Claims (6)

[Claims] 1 to 30 parts by mass of water, 0.1 to 3 parts by mass in total of one or more selected from sodium borate compounds as a rust preventive additive, and polyalkylene glycol as a lubricant 1 to 30 parts by mass in total of one or more selected from compounds, 0.1 to 3 parts by mass in total of one or more selected from polyvinyl alcohol compounds as lubricating aids, surface activity One or two or more selected from fatty acid alkanolamide compounds as agents are contained in a total amount of 0.1 to 3 parts by mass, and are applied onto an oil film such as a rust-preventive oil or a press oil already applied to a steel plate. A lubricant for steel sheets, characterized in that: 2. The lubricant for a steel sheet according to claim 1, wherein the sodium borate compound is an anhydride, pentahydrate or decahydrate. 3. The steel sheet lubricant according to claim 1, wherein the polyalkylene glycol compound is a polyethylene glycol compound having a molecular weight of 1,000 to 40,000. 4. The polyvinyl alcohol compound having a degree of polymerization of 2
The lubricant for a steel sheet according to any one of claims 1 to 3, which is a polyvinyl alcohol compound having a molecular weight of 00 to 2000. 5. The lubricant for a steel sheet according to claim 1, wherein the fatty acid alkanolamide compound as a surfactant is a 1: 1 type coconut oil diethanolamide compound. 6. The content ratio of the polyalkylene glycol compound to the polyvinyl alcohol compound is 1: 1 to 1 by mass.
The lubricant for a steel sheet according to any one of claims 1 to 5, wherein the lubricant is 3: 1.