JPH1080664A - Surface lubricated metallic material excellent in coating film adhesion property and scratch resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricated steel sheet satisfying all performance such as scratch resistance, lubrlcity, anti-blocking property, removing property for film or the like necessary at the time of plastic working. SOLUTION: A lubricating coating film having 0.05-10μm film thickness is formed on the surface of a base material metal by applying a treating agent containing a water soluble and/or water dispersible alkali soluble resin having 10-85 deg.C glass transition point, <0.2wt.% silane coupling agent and 0.5-10wt.% metallic soap per the alkali soluble resin solid matter and drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal material having a lubricating film having excellent film adhesion and scratch resistance on the surface of a base metal.

[0002]

2. Description of the Related Art A lubricant is used in plastic working of a thin metal plate such as a steel plate to enhance the lubricity between a metal mold and a metal plate to reduce a load applied during the processing and prevent seizure. The technology has been employed conventionally. However, in recent years, in order to respond to environmental issues and reduce manufacturing costs, such as the problem of lubricant treatment when and after use, a customer applies a lubricant such as press oil during processing. Instead, a solid organic coating containing various lubricants (hereinafter referred to as a “lubricating coating” in this specification) is applied to the surface of the metal sheet in advance during the manufacturing of the metal sheet or at an appropriate stage up to the customer. Surface lubricated metal sheets have been widely used.

[0003] Such a metal sheet with a surface lubrication treatment is used after removing the lubrication treatment film by a technique such as degreasing after plastic working, and thereafter, is used without any treatment or is further subjected to a chemical conversion treatment and painting. A non-film-deposited surface lubricated metal sheet that is used without removing the lubricated film after plastic working and without removing the lubricated film, or as it is after further painting. They are roughly divided into thin plates. In general, in the case of a material that is to be made into a final product by utilizing its beautiful surface, such as a stainless steel plate or an aluminum steel plate, it is often used as a film-type surface-lubricated metal sheet.

[0004] The main performance required of such a lubricating film for plastic working of the film removal type is the following performance (1). Good lubricity even when the film thickness is small. After film formation, the films do not easily adhere to each other even when stacked
(Good blocking resistance). The film can be easily removed by washing.

[0005] The main components of a lubricating coating agent capable of forming such a lubricating coating on the surface of a metal sheet are:
Acrylic resin, epoxy resin, conventionally known dry or bake-curable film forming component such as melamine resin, and as a lubricating component, fatty acid, fatty acid salt, fatty acid metal soap, fatty acid ester, fatty acid amide, A mixture of one or more of higher alcohols, graphite, molybdenum disulfide, and fluororesin powder has been proposed. However, these conventional lubricating films do not have sufficient lubricity at the time of drawing, and have a problem of scratch resistance to a thin metal plate.

[0006]

On the other hand, in the case of a thin metal plate having a beautiful metallic luster such as the above-mentioned stainless steel plate whose surface is polished or brightly annealed, it is not sufficient to be able to form by drawing or the like. It is important to maintain a beautiful surface even after processing and removing the lubricating film. Therefore, the problem of scratch resistance is particularly serious. For this reason, at present, the thickness of 80
Generally, a vinyl film or the like having a thickness of about μm is bonded to ensure lubricity and a beautiful surface. However, when a vinyl film or the like is pasted in this way, it is necessary to peel the film after processing, and since this work usually has to be performed manually, it greatly hinders automation and labor saving of the production line, or It is also a cause of high cost. In addition, it is often difficult to peel off the film particularly at the processed part. Furthermore, the peeled film is bulky, and in many cases, it is difficult to incinerate it, and a large amount of expense is required for volume reduction and landfilling.

For this reason, there is a strong demand for improving the scratch resistance of the stripped lubricated metal sheet.
JP-A-104459 discloses a high-work stainless steel sheet having an organic compound film having a specific composition on the front and back surfaces, and forming a lubricating film on only one surface using the organic compound film as an underlayer. JP-A-53-75159 discloses a stainless steel sheet whose surface is coated with a vinyl resin or the like having a specific acid value and glass transition temperature. However, at present, there is no metal sheet having a lubricated film that satisfies the extremely high scratch resistance required by a consumer such as a home appliance manufacturer.

The present invention has been made in view of such circumstances, and its object is to provide all of the properties required at the time of plastic working, such as scratch resistance, lubricity, blocking resistance, and film removal. An object of the present invention is to provide a lubricated steel sheet satisfying performance.

[0009]

Heretofore, the main idea for preventing surface flaws generated during plastic working has been as follows. (a) Increase the thickness of the lubrication coating to avoid direct contact between the mold and the sheet metal. (b) Improve the lubricity of the lubricating film by adding a solid lubricant or the like, and increase the sliding length until the occurrence of scratches.

However, it has been found that the lubricating film obtained according to such a conventional concept causes surface flaws on the base metal under severe processing conditions using a mold that has become popular in recent years.

The inventors of the present invention have conducted various studies on the mechanism of the occurrence of surface flaws during plastic working. As a result, the peeled pieces of the lubricating film deposited in the mold due to the contact with the material were found to have surface flaws themselves. It was found to be the cause of the outbreak.

That is, no matter how thick a film having good lubricity is formed, if the adhesion between the film and the base metal is low, the film is exfoliated, and the peeled film is deposited on a mold to cause surface flaws. It becomes. Therefore, it was concluded that the generation of surface flaws can be suppressed by increasing the adhesion between the film and the base metal.

From these viewpoints, the present inventors have repeatedly studied the main components and additives of the resin constituting the delaminated lubricating film, and as a result, only a small amount of the coupling agent was added to the lubricating film. It has been found that the resistance to scratches is drastically improved by increasing the adhesion between the lubricating film and the base metal by adding the same.

Here, the present invention relates to an alkali-soluble resin having a glass transition temperature of 10 ° C. or more and 85 ° C. or less, preferably one or more water-soluble and / or water-dispersible, 0.2% by weight based on resin solids
Less than (excluding no additive) silane coupling agent and 0.
Film adhesion, scratch resistance, characterized by having a lubricated film with a film thickness of 0.5 μm to 10 μm obtained by applying and drying a treatment agent containing 5% by weight or more and 10% by weight or less of metal soap It is an excellent surface lubricated metal material.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a lubricated metal material of the present invention will be described in detail. Base metal: The shape and type of the metal that is the base material of the surface lubricated metal material according to the present invention are not particularly limited. However, a thin plate-shaped material mainly used as an object of plastic working such as press working with a die is widely applied as a base metal. Examples of the type of metal include a hot-rolled steel sheet, a cold-rolled steel sheet, a plated steel sheet, a stainless steel sheet, and an aluminum steel sheet.

Base resin: The base resin constituting the lubricated film of the lubricated metal material of the present invention is a water-soluble or water-dispersible alkali-soluble resin, such as an acrylic resin, an epoxy resin, a melamine resin, or phenol. Any resin, such as a system resin, may be used as long as it is generally used for paints. There is no limitation on these polymerization methods.

The alkali-soluble resin used in the surface lubricating metal material according to the present invention must have a glass transition temperature of 10 ° C. or more and 85 ° C. or less. Glass transition temperature
If the temperature is lower than 10 ° C., the blocking resistance of the coating is insufficient, and the coatings may adhere to each other when they are stacked, and the scratch resistance is also deteriorated. On the other hand, when the glass transition temperature exceeds 85 ° C., the workability of the film deteriorates. Preferably, the glass transition temperature is between 20 and 70C.

The alkali-soluble resin used in the present invention preferably has an acid value of 20 or more. Acid number 20
If the amount is less than the above, there is a possibility that the obtained lubricating film may have insufficient film removal property with an alkali solution. Therefore, the alkali-soluble resin is preferably an alkali-soluble resin having a glass transition temperature of 20 ° C. or more and 70 ° C. or less and an acid value of 20 or more.

The surface lubricated metal material according to the present invention may preferably be one using at least one water-soluble and / or water-dispersible alkali-soluble resin,
An alkali water-soluble resin containing at least one of each of these water-soluble and water-dispersible alkali-soluble resins may be used.

Silane Coupling Agent: The surface lubricated metal material according to the present invention is prepared by applying a resin solution obtained by dissolving or dispersing an alkali water-soluble resin in water, for example, as a treatment agent on the surface of the base metal as described below. The resin liquid contains a silane coupling agent. This silane coupling agent has the function of enhancing the adhesive strength between the resin film and the base metal, thereby greatly improving the scratch resistance.

Content of silane coupling agent (addition amount)
Is less than 0.2% by weight based on resin solids (excluding no additives)
It is necessary to be. If it is not added, there is no effect of enhancing the adhesion between the resin film and the base metal, and the scratch resistance is not improved at all. The content (addition amount) is 0.2
When the amount is more than the weight percentage, the crosslinking of the resin film itself progresses remarkably, and the film removing property after the plastic working is significantly deteriorated.

The type of coupling agent to be added is not particularly limited. For example, vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2
-Aminoethyl) 3-aminopropylmethylmethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane and the like.

Metal soap: The above resin solution contains a metal soap in addition to the silane coupling agent. Metal soap has both lubricating and water-breaking effects. However, if the content (addition amount) is less than 0.5% by weight, the lubricating property is insufficient, and if it exceeds 10% by weight, the effect of improving the lubricating property is saturated. In addition, the cohesive strength of the resin film decreases, and the scratch resistance deteriorates.

Therefore, it is necessary that the amount of the metal soap is 0.5% by weight or more and 10% by weight or less based on the solid content of the resin. Preferably, it is 1% by weight or more and 5% by weight or less. Examples of the metal soap include aluminum stearate, calcium stearate, zinc stearate, and magnesium stearate.

Lubricating film: The surface lubricating metal material of the present invention is a lubricating film formed by applying the above-mentioned treating agent containing an alkali-soluble resin, a silane coupling agent and a metal soap to the surface of a base metal. Is a metal material having
The film thickness is 0.5 μm or more and 10 μm or less. If it is less than 0.5 μm, the scratch resistance is insufficient, and if it exceeds 10 μm, the problem of film deposition on the mold occurs. The preferred film thickness is 1.0 μm or more and 5.0 μm or less. The method of forming the lubricating film is not particularly limited, but a standard method is exemplified below.

"Pretreatment" The treating agent used for forming the lubricating film is an aqueous one in which an alkali-soluble resin or the like is dissolved or dispersed in water, so that the base metal is sufficiently degreased by alkali degreasing or the like. Must be in state. If the degreasing is insufficient, defects such as repelling or uneven coating are generated on the formed film.

"Treatment agent" The treatment agent is prepared by first adding a metal soap to a resin solution controlled so as to exhibit a predetermined glass transition temperature and a preferable acid value, and then thoroughly dispersing the resin, and then adding a silane coupling agent. And adjust by stirring. If the silane coupling agent is added first, foaming may occur, which may hinder the adjustment. At the time of adjustment, dilution is performed using ion-exchanged water, but an organic solvent having good compatibility with water may be added to improve wettability and defoaming / drying. The solid content of the treating agent is adjusted according to the thickness of the lubricating film to be formed and the application method.

"Application of treatment agent" The method of applying the treatment agent varies depending on the shape of the base metal. In the case of a plate shape, application by a bar coater or a roll coater is most preferable. When a bar coater or a roll coater is used, it is easy to adjust the coating film thickness, and beautiful coating is possible. In addition, a spray method, a brush coating method, a dipping method, and the like can be applied. In particular, a spray method or the like is practical for those having a complicated shape.

After the "drying" treatment agent is applied, it is dried to form a lubricating film. The drying temperature may be such that the water evaporates, but it is preferable to carry out the drying under the condition that the maximum temperature of the plate reaches 40 to 100 ° C. efficiently. As a drying method, a commonly used method such as hot air drying or infrared drying can be applied.

The lubricated metal material of the present invention has a strong adhesion between the lubricated film and the substrate metal, and has excellent scratch resistance. sex,
Excellent blocking resistance.

[0031]

The present invention will be described in detail with reference to the following examples. The basic resins shown in Table 1 and the glass transition temperature (T
g) and various alkali-soluble resins having an acid value, a silane coupling agent and a metal soap were added to prepare a treating agent having a solid content composition as shown in Table 2. The addition amount of the silane coupling agent and the metal soap is represented by the weight ratio to the resin solid content. The total solid content of the treating agent was adjusted to 20% by weight, and adjusted by adding ion-exchanged water.

This treating agent is applied to both surfaces of a stainless steel plate (SUS430, 2B finish, plate thickness 1.2 mm) whose surface is alkali-degreased with a bar coater, and dried in a hot-air oven so that the maximum temperature reaches 60 ° C. To obtain a test plate. This test plate was subjected to the following tests to examine its performance.

"Evaluation of Scratch Resistance" Using a simple sliding test apparatus as shown in FIG. 1, a test material 1 was placed on a slide table 5 and a die 2 with a load 4 applied to the surface of the material 1. While holding it with the holder 3,
By moving the slide table 5 in the direction of the arrow to slide the lubricating film of the material 1 and the die tip, a scratch resistance test was performed under the following conditions. At this time, the scratches of the sliding portion were visually observed, and the scratch resistance was evaluated according to the following criteria. ◎ or ○ indicates good.

Dice polishing paper: # 600 Die polishing direction: Parallel polishing Pressing pressure: 0.66 MPa (66 g / mm ² ) Test specimen collection direction: Rolling direction Test specimen shape: 1.2 mm thick × 30 mm width × 150 mm length Sliding Length: 50 mm Visual criteria: Completely scratch free ○: Slight scratches (no problem on appearance) △: Slight scratches (no problem on appearance) ×: Clear scratching.

"Evaluation of film-removing property" Spraying was performed for 10 seconds at a temperature of 40 ° C and a spray pressure of 1 kg / cm ² using a 2% aqueous solution of a commercially available alkaline degreasing solution (FC-L-4480 manufactured by Nippon Parkerizing Co., Ltd.). After removing the film, the presence or absence of water repelling was visually determined, and the film removing property was determined according to the following criteria.で あ れ ば: good ：: No water repelling △: Part of water repelling ×: Water repelling occurred all over.

"Evaluation of Blocking Resistance" The evaluation of blocking resistance is to examine the resistance of the lubricated coatings to sticking (blocking) when the lubricated plates are stacked and stored. When this sticking occurs, workability decreases and plastic workability deteriorates.

In the test, the films of two test pieces having a film formed only on one side were superimposed on each other, pressed at 40 ° C. under a pressure of 200 kg / cm ² for 3 hours.
It was evaluated on a scale. ◎ or ○ indicates good. A: Peeled off by its own weight, and no sticking mark was found. ：: Peeled off by its own weight, but adhesive marks were observed. Δ: Adhered, but peeled off by tapping lightly. X: It sticks and does not peel off when hit.

The evaluation results are also shown in Table 2. As is clear from the results, the lubricated metal material of the present invention shown as an example was excellent in scratch resistance, and also good in film removal property and blocking resistance.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

The lubricated metal material of the present invention does not suffer from surface flaws due to contact with a mold during plastic working such as press working, and has excellent film removal properties and blocking resistance after molding. It can be replaced with a metal material formed by pasting a conventional vinyl sheet.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a simple sliding test apparatus used for evaluating scratch resistance in Examples.

[Explanation of symbols]

1: material, 2: die, 3: holder, 4: load, 5: slide table

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication // B21J 3/00 B21J 3/00 C10N 20:00 40:20 (72) Inventor Hiroshi Mukaiyama Kashima-shi, Ibaraki Sumitomo Metal Industries Co., Ltd.Kashima Works (72) Inventor Yukihiro Yoshikawa 4-33 Kitahama, Chuo-ku, Osaka City Sumitomo Metal Industries Co., Ltd.

Claims (1)

[Claims] 1. A glass transition temperature of 10 on a surface of a base metal.
Applying and drying a treating agent containing an alkali-soluble resin having a temperature of not less than 85 ° C. and not more than 0.2% by weight and a metal soap having a content of not less than 0.5% by weight and not more than 10% by weight based on the solid content of the alkali-soluble resin. 0.5 μm
A surface lubricated metal material excellent in film adhesion and scratch resistance, characterized by having a lubricated film of not less than 10 m and not more than 10 m.