JP2005314481A - Treatment liquid for forming lubricant coating film, and lubricated metallic plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve not only lubricity but also rustproofness in lubricated steel plate provided with inorganic material-based lubricant coating film. <P>SOLUTION: A treatment liquid for forming lubricant coating film is provided, being characterized by containing a silicate, polyethylene wax and an aliphatic dicarboxylic acid and/or its salt. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a treatment liquid for forming a lubricious coating on the surface of a metal material and a lubrication-treated metal material treated using the treatment liquid.

  Conventionally, zinc phosphate coating has been formed for the purpose of preventing seizure between the workpiece and the tool in plastic processing of steel sheets, especially cold forging processed under severe conditions with high processing pressure. Then, it is generally performed after applying a bonder + bonderube treatment (hereinafter abbreviated as a bonde treatment) in which sodium stearate is applied. However, since it is necessary to perform a bond processing step separately from the processing step, there is a problem that extra work is forced and productivity is hindered. In addition, it is desired to omit the bonder treatment from the viewpoint of equipment maintenance, waste liquid treatment, and the like.

Therefore, there is a demand that the steel strip is lubricated in advance so that the bonding process can be omitted, and that such steel strip is blanked and then plastically processed.
The lubrication treatment applied to the steel sheet can be broadly divided into a technology for forming a lubricious coating mainly composed of organic resin, and a technology for forming a lubricious coating mainly composed of an inorganic substance as in the case of the bonde treatment. is there.

  A film mainly composed of an inorganic substance has an advantage that an influence of temperature on a qualitative change of the film (for example, a change in the hardness of the film) is small as compared with a film mainly composed of an organic resin. Therefore, for example, in the case of a molding process with a high degree of processing, a film mainly composed of an inorganic substance that is not easily affected by the frictional heat of the material or the temperature rise of the mold caused by continuous molding process is more advantageous. it is conceivable that.

As a metal plate provided with a lubricating coating mainly composed of an inorganic substance, for example, Japanese Patent Application Laid-Open No. 2002-307613 (Patent Document 1) discloses a metal plate mainly composed of lithium silicate and containing wax and metal soap as a lubricant. A metal plate on which a film-type film is formed is disclosed.
JP 2002-307613 A

  When using a steel strip that has been subjected to such a lubrication treatment, it may be stored for a long period of time, so that the steel strip itself preferably has a certain degree of rust prevention. In the technique of Patent Document 1, improvement of such a rust prevention requirement has not necessarily been considered. Accordingly, an object of the present invention is to provide a lubricated metal material having a lubricious coating mainly composed of an inorganic substance, particularly a lubricated steel material, which is excellent not only in lubricity but also in rust prevention. Is to provide.

  Based on the technique disclosed in Patent Document 1, the present inventors have studied based on a lubricating treatment liquid mainly composed of silicate (silicate). As a result, it was found that by treating with a treatment liquid containing an appropriate amount of an aliphatic dicarboxylic acid, a lubricated metal material having excellent lubricity and rust resistance can be obtained.

  Therefore, the present invention provides a treatment liquid for forming a lubricious coating on the surface of a metal material, the treatment liquid comprising silicate, polyethylene wax, aliphatic dicarboxylic acid and / or a salt thereof. A feature of the treatment liquid for forming a lubricious film.

In a preferred embodiment, the silicate is one or more alkali metal silicates such as lithium silicate, sodium silicate, and potassium silicate.
The present invention also relates to a lubricated metal material having a lubricating coating formed on the surface and having an adhesion amount of 0.1 to 10 g / m ² .

  The lubrication-treated metal material of the present invention has excellent lubricity that can be used without being subjected to a bondage treatment or the like even under extremely severe processing conditions such as ironing processing in which the ironing rate reaches 30% or more. Indicates. At the same time, it is also excellent in rust prevention, and even if the metal material is a steel plate or steel strip, it can be stored for a long period of time.

In the following, embodiments of the present invention will be described, which is for illustrative purposes and is not intended to limit the present invention.
1) Treatment liquid The treatment liquid for forming a lubricating coating according to the present invention contains a silicate (silicate), a lubricant containing polyethylene wax, and an aliphatic dicarboxylic acid and / or a salt thereof.

Silicate is the main film forming component of the lubricious film. Therefore, the lubricating coating formed from the treatment liquid of the present invention is a coating mainly composed of an inorganic substance.
As the silicate, alkali metal silicates such as lithium silicate, sodium silicate, and potassium silicate can be used. Only one kind of alkali metal silicate may be used, or two or more kinds may be used. Such alkali metal silicates are commercially available as aqueous solutions having various SiO 2 / alkali metal oxide molar ratios. This molar ratio can also be changed by adding SiO2 or an alkali metal oxide or precursor thereof to the aqueous solution.

  Polyethylene wax is a lubricant, and is added to the treatment liquid according to the present invention in order to improve the slidability and workability of the lubricated metal material. Therefore, when the content of polyethylene wax is small, such an improvement effect is small. On the other hand, if the polyethylene wax content is too large, the workability (molding resistance, etc.) of the lubricated metal plate is rather deteriorated. This is presumably because the wax tends to fall off from the lubricating coating. A preferable addition amount of the polyethylene wax is about 0.2 to 2.0, more preferably about 0.5 to 1.5 in terms of a mass ratio to the total amount of silicate.

The particle size of the polyethylene wax is not particularly limited, but a polyethylene wax having a particle size of about 0.05 to 10 μm can be used. The particle size of the polyethylene wax is preferably selected according to the coating amount, and a wax having a larger particle size is preferably used as the coating amount increases. For example, when the total coating amount is about 1.0 g / m ² , it is preferable to use a wax having an average particle size of about 0.01 to 1 μm.

  Only polyethylene wax may be used as the lubricant, but other lubricants may be used in combination with the polyethylene wax. Examples of other lubricants that can be used in the present invention include oxidized waxes such as paraffin wax and montan wax, other synthetic waxes, fluororesin waxes, and metal soaps. The amount of other lubricant added is not particularly limited, but it is preferably less than the content of polyethylene wax.

  The lubricating film forming treatment liquid according to the present invention further contains an aliphatic dicarboxylic acid and / or a salt thereof. By adding an appropriate amount of this component to the treatment liquid, the rust prevention property of the resulting lubricated metal material is improved. Various organic and inorganic compounds have been proposed and used as corrosion inhibitors (inhibitors) for steel. Typical organic corrosion inhibitors are nitrogen-containing compounds such as amines. In the present invention, it is not clear why the aliphatic dicarboxylic acid (salt) exhibits a corrosion-inhibiting action, but the aliphatic dicarboxylic acid (salt) acts as a corrosion inhibitor on the base metal material or a part thereof. Alternatively, a mechanism may be considered in which a coating with improved rust prevention power is formed by the esterification reaction of all dicarboxylic acids and silicates.

  Examples of the aliphatic dicarboxylic acid that can be used in the present invention include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, and tetradecanedioic acid. Pentadecanedioic acid, hexadecanedioic acid, eicosadioic acid, octynyl succinic acid, dodecenyl succinic acid, octadodecenyl succinic acid and the like. Further, sodium salts, potassium salts, ammonium salts, amine salts and the like of these dicarboxylic acids may be used. Two or more of these dicarboxylic acids and / or salts thereof may be used in combination.

  If the content of the aliphatic dicarboxylic acid and / or salt thereof is too small, the effect of improving the rust resistance of the lubricated steel sheet is small, and if it is too large, the rust resistance is inferior, and the workability is lowered. A range of 0.01 to 10% by mass% based on the total amount of silicate is preferable, and 0.05 to 2% is more preferable.

  The treatment liquid for forming a lubricating film according to the present invention includes a lubricant containing polyethylene wax as an additional component and an aliphatic dicarboxylic acid and / or a salt thereof added to an aqueous solution of an alkali metal silicate to disperse the lubricant. Can be prepared. Aliphatic dicarboxylic acids and / or their salts are soluble in water. Unless the performance of the lubricating coating formed from the treatment liquid is hindered, the treatment liquid may also contain components other than those described above. Examples of such components include a dispersant and a surfactant for improving the stability of the treatment liquid, and an etching agent (for example, a fluoride) for improving the reactivity of the steel sheet surface during the treatment. . The treatment liquid is aqueous and the solvent is water, but a water-miscible organic solvent can also be used as part of the solvent.

2) Lubricated metal material The metal material used as the base material is generally a steel plate, but is not limited thereto. The present invention can also be applied to other metal materials that may be subjected to severe plastic working, such as aluminum plates. The form of the base material is typically a plate, but other forms such as a pipe, a wire, and a bar may be used. Below, this invention is demonstrated about the case where a base material is a steel plate.

  The components and properties of the steel sheet can be widely applied to general carbon steel, low carbon soft steel, very low carbon soft steel, high tensile steel, stainless steel, and the like. In addition, as long as the required performance is to ensure workability (such as galling resistance), it is not limited to hot-rolled steel sheets and cold-rolled steel sheets, but also electroplated steel sheets such as electrogalvanized and electro-Zn-Ni alloy plated, or hot-dip zinc The present invention can also be applied to hot dip plated steel sheets such as plating, hot dip zinc alloy plating, hot dip Zn-5% Al alloy plating, hot dip 55% Al-Zn alloy plating. In addition, the surface of the base steel sheet may be subjected to pretreatment such as chromate treatment or bondage treatment.

  However, it is most preferable that the lubricated steel sheet according to the present invention is applied for the purpose of making effective use of lubricity. In that sense, steel sheets used in applications that undergo ironing with a large reduction in sheet thickness (for example, machining with an ironing rate of 30% or more), especially steel sheets with relatively thick plates (for example, 2 mm or more), high-tensile steel sheets, etc. It can be said that the present invention is particularly useful when using as a base material. Further, since the lubricated steel sheet according to the present invention focuses on improving rust prevention in addition to lubricity, for example, a bare cold-rolled steel sheet or hot-rolled steel sheet whose base material is not plated. If it is, the effect of improving rust prevention can be utilized more effectively.

  The lubricated steel plate according to the present invention includes a lubricious coating formed by treating the surface of a steel plate (or other metal material) as a base material with the treatment liquid. For example, when the metal strip is continuously manufactured, the treatment method is a method of applying a predetermined amount of the treatment liquid to the steel strip of the base material with a roll coater or the like, or is the base steel strip immersed in the treatment liquid? For example, a method of spraying the treatment liquid onto the steel strip and then squeezing it to a predetermined adhesion amount with a ringer roll, etc. After the treatment as described above, a lubricating coating is formed by drying. Although it is preferable to lubricate one or both surfaces of the base steel sheet, it is possible to lubricate only a part of the base material surface.

In the lubricated steel sheet according to the present invention, the adhesion amount of the lubricating coating formed on the surface of the base steel sheet is 0.1 g / m ² or more, preferably 0.5 g / m ² or more. This is because a certain amount of coating is necessary to secure good mold resistance against severe processing. The upper limit of the adhesion amount is not particularly specified with respect to improvement of mold-resistance, but is preferably 10.0 g / m ² or less, more preferably 5.0 g / m ² or less. This is because if the amount of adhesion is excessive, there is a concern that the lubricating film peels off due to sliding by processing, adheres to and accumulates on the mold, and causes problems such as defective appearance of the press.

  Drying after applying the treatment liquid is preferably performed at a drying temperature of about 60 to 90 ° C. If the drying temperature is too high, the wax melts and the lubricity of the resulting lubricated steel sheet may change. Therefore, it is preferable that the drying temperature is such that the steel sheet temperature is not higher than the softening point of the wax. If the drying temperature is too low, the drying time becomes longer and the productivity is hindered.

  JSH 270D (plate thickness = 2.3 mm, surface roughness: Ra = 0.6 µm, PPI = 115), a hot rolled mild steel plate of the Japan Iron and Steel Federation standard, is used as the base steel plate, and is described below on one side of this steel plate. Lubricating film was formed by the method to prepare a lubricated steel sheet.

  As silicates, aqueous solutions of lithium silicate (SiO2 / Li2O molar ratio = 3.5), sodium silicate (SiO2 / Na2O molar ratio = 3.0) or potassium silicate (SiO2 / K2O molar ratio = 3.4) were used. . A predetermined amount of sebacic acid or dodecenyl succinic acid as an aliphatic dicarboxylic acid is added to this silicate aqueous solution, and an aqueous emulsion of polyethylene wax (Hitech E9014, manufactured by Toho Chemical Co., Ltd., wax softening point 106 ° C., wax average particle diameter 0.2 μm) Was added and mixed well to prepare a treatment solution.

A predetermined amount of this treatment solution was applied to one side of the steel plate with a spin coater, followed by drying (drying temperature = 70 ° C.), thereby forming a lubricating coating.
As a conventional material for comparison, a material subjected to a known mill bond treatment (a kind of organic coating treatment) and a material subjected to a known bond treatment (bonding treatment + bonded rube treatment) were also used for the test. These processing conditions are as follows.

Mill bond treatment: used chemicals-MC560J (manufactured by NOF Corporation), adhesion amount = 1.2 g / m ² .
Bonde treatment: (All drugs used are manufactured by Nihon Parkerizing Co., Ltd.)
Bonding treatment: chemical used = PB-181X, adhesion amount = 4 g / m ² ;
Bonderube treatment: chemical used = LUB-235, adhesion amount = 2 g / m ²
Each lubricated steel sheet was examined for mold galling resistance and seizure resistance as well as rust resistance. The test contents and pass / fail judgment are as follows. The test results are shown in Table 1 together with the treatment liquid composition.

(Type galling resistance)
The process shown in Fig. 1 (squeezing rate = 30%) forcibly reduces the plate thickness up to 100 sheets continuously, and observes the occurrence of mold galling on the sliding part of the 100th workpiece. The normal part remaining rate was evaluated.

Processing conditions:
Sample size: 25 mm x 150 mm,
Clearance: 1.61 mm (ironing rate = 30%),
Lubrication: General anti-rust oil (Nox-Rust 550HN, manufactured by Parker Kosan),
Number of processed sheets: 100 (Does not care for mold in the middle).

Judgment criteria:
A: Normal part remaining rate = 100% (no galling),
○: Residual ratio of normal part = 100 to 95%
Δ: Residual ratio of normal part <95% (causing generation),
×: Processing crack occurred on the 100th sheet (or earlier).

(Seizure resistance)
Evaluation was performed using the friction and wear tester shown in FIG. 2 under the following test conditions and criteria.
Processing conditions:
Sample size: 60 mm x 60 mm,
Indenter: Steel ball,
Load: 200 N,
Rotational speed: 10 rpm (rotating radius = 10 mm),
Plate temperature: 50 ℃
Evaluation method: The coefficient of friction was continuously measured, and the evaluation was performed based on the sliding distance until the coefficient of friction suddenly increased.

Judgment criteria:
A: Sliding distance ≧ 10 m
○: Sliding distance = 5-10 m
Δ: sliding distance = 2-5 m,
X: Sliding distance <2 m.

(Rust prevention)
Rust prevention was evaluated by a composite corrosion test. Corrosion state at 10th cycle (area where red rust occurs) with 1 cycle (3 cycles per day) as “4 hours left in high temperature and high humidity condition with a relative humidity of 98% at 50 ° C. and 4 hours left at 50 ° C. dry condition” Rate) was visually observed and judged according to the following criteria.

Judgment criteria:
A: Red rust 0% (no red rust),
○: Red rust <5% (minor red rust),
Δ: red rust> 5-10%
X: Red rust> 10%.

  As shown in Table 1, the lubricated steel sheets (Nos. 1 to 17) according to the present invention exhibited good mold galling resistance, seizure resistance, and rust resistance. However, too little or too much polyethylene wax in the silicate coating was inferior in mold galling resistance and seizure resistance. Further, when the amount of the lubricating coating was too much or too little, the mold galling resistance and seizure resistance were poor. Further, when the content of the aliphatic dicarboxylic acid is too small, the rust prevention property is insufficient, and when it is too much, the rust prevention property is lowered and the galling resistance is also inferior.

It is a figure which shows the measurement and evaluation method of mold-proof galling resistance. It is a figure which shows the measuring method of the slidability by a friction abrasion test.

Claims (3)

  A treatment liquid for forming a lubricious coating on the surface of a metal material, wherein the treatment liquid contains a silicate, a polyethylene wax, an aliphatic dicarboxylic acid and / or a salt thereof, Treatment liquid for film formation.   The processing solution for film formation according to claim 1, wherein the silicate is composed of one or more alkali metal silicates. A lubricated metal material, comprising a lubricious coating formed on the surface of the treatment liquid according to claim 1 and having an adhesion amount of 0.1 to 10 g / m ² .

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