JPH09296132A - Lubricating coating composition of removable film forming type having excellent deep drawing property, mold dragging resistance and temporary corrosionproof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricating coating composition of removable film forming type having excellent deep drawing property under high pressure, mold dragging resistance and temporary corrosionproof. SOLUTION: This lubricating coating composition comprises an acrylic-based resin having Tg of 0-12 deg.C and acid value of 0-200mg-KOH/g, (b) at least one lubricant selected from higher fatty acids, higher fatty acid esters and metallic soaps in a percentage of 3-30wt.% to the solid content of (a), (c) at least one rust-preventive lubricant selected from Zn, Ca or ammonium salt of phosphoric and molybdic acids in a percentage of 2-30wt.% to the solid content of (a), and (d) polyethylene wax having melting point Tm of 70 deg.C<=Tm<=150 deg.C in a percentage of 3-20wt.% to the solid content of (8a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-removing coating composition, and more particularly to a steel plate to be pressed while maintaining film-removing property, blocking resistance, etc., such as hot-rolled pickled steel plate and cold-rolled steel plate. The present invention relates to a film-removing type lubricant coating composition which, when applied to various surface-treated steel sheets, provides excellent deep drawability, mold galling resistance and temporary rust prevention.

[0002]

2. Description of the Related Art Conventionally, when press working a steel sheet, it has been customary for a customer to apply a high-viscosity press oil immediately before working. However, the oiling work has problems such as deterioration of workability and deterioration of the work environment such as oil stains on workers and work floors. However, there were problems such as cracks and galling during processing. In order to solve such a problem, at the present time, in the steel plate supplier,
A steel sheet having a coating film of a lubricating coating composition formed on the surface of the steel sheet is commercially available.

The lubricating coating layer formed from this film-removing type lubricating coating composition has (1) good lubricity even at a thin film of about 1 g / m ² , excellent mold galling resistance, and (2) blocking resistance. (Coatings do not stick to each other after coating), (3) film removal property (easy film removal with an alkaline solution), (4) temporary rust resistance (preservation of rust resistance up to the film removal process after pressing) It is required to be excellent.

As a technique for satisfying these requirement characteristics, Japanese Patent Publication No. 51-3702, Japanese Patent Publication No. 52-34704, Japanese Patent Publication No. 53-27698, and Japanese Patent Publication No. 53-3.
Many lubricating coating compositions have been proposed in Japanese Patent No. 7817, Japanese Patent Laid-Open No. 50-18502, Japanese Patent Laid-Open No. 62-84193, Japanese Patent Laid-Open No. 63-8489, Japanese Patent Laid-Open No. 3-203996, and the like. There is. But these technologies
The emphasis was on press workability, film removal property, and blocking resistance, and it was not effective in improving rust prevention.

Therefore, as a technique for improving the rust preventive property, a technique of adding a vaporizable rust preventive agent to a lubricating coating (Japanese Patent Publication No. 53-3).
No. 7817), a technique of applying a rust preventive lubricant of an inorganic salt and an organic salt (JP-A-51-87461), and a technique of adding a rust preventive agent and a water repellent agent to a lubricating paint (JP-A No. 63
No. 223093) has been proposed.

[0006]

However, the conventional lubricating coating composition exhibits excellent performance in terms of moldability evaluated by the ordinary cylindrical press test. However, in recent years, due to processing accuracy, advanced processing levels, diversification of processing shapes, etc., the number of cases where pressing is performed under severe conditions has increased, and when pressing with a square tube or a cylindrical mold with a bead to which high surface pressure is applied, It has been found that the steel sheet having a coating film of the above conventional film-removing type lubricating coating composition has a problem that cracks and mold galling occur.

Further, in the technique described in JP-B-53-37817, the rust preventive property under wet conditions shows sufficient performance, but the rust preventive property under more severe conditions such as salt spray test (SST). The rust test does not show sufficient performance. Further, in the technique disclosed in Japanese Patent Laid-Open No. 51-87461, SST
In the above, a lubricating coating composition showing sufficient performance can be obtained, but it has not yet reached a sufficient required level.
Further, since the rust preventive lubricant is applied alone, it is inferior in mold galling resistance and deep drawing property. Furthermore, JP-A-63-223
The technique described in Japanese Patent No. 093 shows a sufficient rust preventive property under stacking conditions and wet conditions, but a lubricating coating composition capable of exhibiting sufficient rust preventive property even under severe conditions such as SST. Can't get Further, since no lubricant component is added, mold galling resistance and deep drawability are poor.

In view of the above-mentioned problems of the prior art, the present invention provides a film-removing type lubricating coating composition excellent in deep drawability under high surface pressure, resistance to mold galling, and temporary rust prevention. The purpose is to provide.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the inventors of the present invention have diligently studied, and as a result of various investigations on factors that greatly affect deep drawability and die galling resistance, It was found that the Tg of the resin which is the main component and the acid value of the resin are one of the largest factors. Therefore,
By maintaining a conventional film-removing property, blocking resistance, etc., by forming a lubricious film of an acrylic resin with a film-removing type lubricant coating composition in which a specific lubricant and anti-rust agent were added in a specific ratio. At the same time, it was found that it is possible to obtain a film-removal type lubricating coating composition having improved deep drawability and mold galling resistance.

Regarding the temporary anticorrosive property, in the case of the film-removing type lubricant coating composition which is removed by an alkaline aqueous solution after pressing, the film can be easily removed by an alkali, while the film of the film-removing type lubricant coating composition is wet. Since it easily penetrates, it was found that there are many problems of rusting during storage. Therefore, the present inventors have reached the present invention by paying attention to a carboxyl group that contributes to the film removal but causes the rust prevention property to be lowered.

That is, according to the present invention, (a) Tg is 0 to 1
An acrylic resin having an acid value of 30 to 200 mg-KOH / g at 20 ° C. and (b) at least one lubricant selected from higher fatty acids, higher fatty acid esters and metallic soaps as a lubricant (a) 3 for solids of
~ 30 wt%, (c) Z of phosphoric acid and molybdic acid
2 to 30 based on the solid content of (a) at least one rust preventive lubricant selected from n, Ca or ammonium salts
wt%, and (d) melting point Tm is 70 ≦ Tm ≦ 150.
A polyethylene wax at a temperature of 3 to 20 wt% with respect to the solid content of (a).
It is intended to provide a film-removing type lubricating coating composition excellent in deep drawability, mold galling resistance and temporary rust prevention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The film-removing lubricating coating composition of the present invention (hereinafter referred to as "the composition of the present invention") will be described in more detail below.

The composition of the present invention comprises (a) an acrylic resin as a main component. This acrylic resin includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and itaconic acid, and methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, styrene, etc. Polymerized or copolymerized with a monomer selected from the group by a conventional method such as emulsion polymerization or solution polymerization. These polymers or copolymers may be used alone or in combination of two or more.

In the present invention, the acrylic resin (a) has a Tg (glass transition temperature) of 0 to 120 ° C, preferably 40 to 90 ° C. When an acrylic resin having a Tg of less than 0 ° C. is used, the composition film becomes soft and the mold galling resistance and blocking resistance are poor, and the Tg is 12
If an acrylic resin having a temperature higher than 0 ° C. is used, the deep drawability will be reduced.

The acrylic resin (a) has an acid value of 30 to 2 in order to utilize the reaction between the carboxyl group and the alkali when the alkali film is removed in the step before the chemical conversion treatment.
00 mg-KOH / g, preferably 50-100 mg-
KOH / g. Acid value is 30mg-KOH / g
If it is less than 200 mg, the film removal property of the lubricating coating is poor, and 200 mg
If it exceeds -KOH / g, the rust preventive property is significantly reduced.

The component (b) of the composition is at least one lubricant selected from higher fatty acids, higher fatty acid esters and metallic soaps, which may be used alone or in combination of two or more. As higher fatty acids,
For example, lauric acid, palmitic acid, stearic acid, oleic acid and the like can be mentioned, and as the higher fatty acid ester,
Examples of the higher fatty acid ester exemplified above, and examples of the metal soap include these higher fatty acids,
Examples thereof include salts with alkaline earth metals such as calcium and barium.

In the present invention, the content of the component (b) in the lubricating coating is 3 to 30 wt%, preferably 5 to 20 wt% based on the solid content of the acrylic resin (a). If the content of the component (b) is less than 3%, the effect of resistance to mold galling is not recognized, and if it exceeds 30 wt%, the effect of improving the deep drawability and resistance to mold galling is saturated, and Since the content ratio of the resin is reduced, the coating film is not formed and the composition coating film is easily detached.

The component (c) of the composition is at least one rust preventive selected from Zn, Ca or ammonium salts of phosphoric acid and molybdic acid.
A single species or a combination of two or more species may be used. The content of the (c) anticorrosive lubricant is 2 to 30 wt% with respect to the solid content of the (a) acrylic resin, and preferably 5%.
~ 20 wt%. (C) The content of rust preventive lubricant is 2w
If it is less than t%, the effect of the addition is not recognized, and it is 30 wt.
%, The stability of the composition decreases and the effect of improving rust prevention is saturated.

The polyethylene wax, which is the component (d) of the lubricating coating, has a melting point Tm of 70≤Tm≤150.
C., preferably 100 to 130.degree. These waxes may be used alone or in combination of two or more. Here, it is said that during press working, the plate temperature of the mold and the steel plate coated with the composition rise to about 50 to 100 ° C. due to friction between them. Therefore, as a result of examining the Tm of the wax which effectively acts in this temperature range,
It was concluded that a wax with ≤Tm ≤150 ° C is suitable. If the wax has a Tm of less than 70 ° C., the wax is melted during processing, so that the deep drawability is not improved, and the melted portion becomes a base point and the mold galling resistance is deteriorated. Fifteen
When a wax having a temperature higher than 0 ° C. is used, softening of the wax does not start during press working, and an effect on deep drawability cannot be expected.

In the lubricating coating, the content of the (d) polyethylene wax is 3 to 20 wt%, preferably 5 to 15 wt% based on the solid content of the (a) acrylic resin.
%. (D) Content of polyethylene wax is 3
If it is less than wt%, the deep drawability is not improved, and if it exceeds 20 wt%, the adhesion of the coating film is lowered, and the deep drawability and mold galling resistance are lowered.

In the present invention, the above (a), (b),
The lubricant composed of the components (c) and (d) can be used as it is, but it is preferably used in the form of an aqueous dispersion from the viewpoint of dispersibility and coating stability. When used as an aqueous dispersion, a surfactant or the like may be added.

In the composition of the present invention, the dry coating amount of the composition coating is preferably 0.5 to 5.0 g / m ² from the viewpoint of each performance.

The composition of the present invention is typified by deep drawability and die galling resistance in various metal plate materials such as hot-rolled pickled steel sheets, cold-rolled steel sheets and surface-treated steel sheets such as various galvanized steel sheets. It is suitable as a film-removal type lubricant coating that has excellent press workability and temporary rust resistance.

The composition of the present invention comprises the above-mentioned (a) acrylic resin, (b) higher fatty acid, higher fatty acid ester and metallic soap, (c) Z of phosphoric acid and molybdic acid.
n, Ca or ammonium salt, and (d) polyethylene-based wax, and various components to be blended as necessary at a specific blending ratio,
It may be applied to a steel sheet by a method such as roll coating, spray coating, dip coating, bar coater coating, etc., and is usually dried by a method in which the reached plate temperature after 5 to 20 seconds is 50 to 150 ° C. it can.

[0025]

In general, (a) the acrylic resin alone exhibits lubricity, but when the composition of the present invention is used for press working such as a rectangular tube drawing or a cylindrical drawing with a bead that is subjected to high surface pressure during processing. Need to further improve the level.
Therefore, in the present invention, as the lubricant, at least one lubricant selected from (b) higher fatty acid, higher fatty acid ester and metallic soap is used. These lubricants may be used alone or in combination of two or more. (Hereinafter referred to as Group B lubricant).

In the present invention, the (c) rust preventive lubricant is at least one rust preventive lubricant selected from Zn, Ca or ammonium salts of phosphoric acid and molybdic acid, and these may be used alone. It is also used by combining two or more kinds (hereinafter referred to as a group C rust preventive lubricant component).
(C) The rust preventive lubricant is to maintain the rust preventive property by reacting with a carboxyl group in the iron ion or the resin dissolved in the course of corrosion and forming a complex salt contributing to the rust preventive property. You can On the other hand, in the conventional technique that does not react with a carboxyl group, for example, a rust preventive agent that exerts an effect by being adsorbed on a metal surface is a water-repellent coating, because the carboxyl group remains. It is considered that the permeation of water in the inside cannot be prevented and the rust preventive property cannot be sufficiently changed. Further, the (c) rust preventive lubricant has an effect of improving the mold galling resistance because it prevents direct contact between the composition coating and the working die.

In the present invention, a mixed lubricant which is further used in combination with (d) polyethylene wax (hereinafter referred to as "group D lubricant") is used. Usually these C
The group rust preventive lubricant or the group D lubricant is generally used alone. In this mixed lubricant,
The group C lubricant has a large effect on the die galling resistance, but has a small effect on the deep drawability, and the group D lubricant has a large effect on the deep drawability, but has a great effect on the die galling resistance. The effect on is small. Therefore, in the present invention, a mixed lubricant containing both lubricants is used in order to achieve both deep drawability and mold galling resistance.

[0028]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples of the present invention.

(Examples 1 to 24, Comparative Examples 1 to 17) In each example, the composition containing the resin and the lubricant shown in Table 1 was applied to both sides of the degreased steel sheet at a dry coating weight of 1 per side. It was coated so as to have a concentration of 0.5 g / m ² and baked using a hot air dryer so that the reached plate temperature after 10 seconds was 80 ° C. Anti-rust oil (16.3 CST / 40
(° C) was applied to both surfaces to prepare a test piece. This test piece was evaluated for deep drawability, mold galling resistance, rust prevention, film removal property and blocking resistance according to the following methods. Table 2 shows the results.

(1) Deep drawability and mold galling resistance The test piece was subjected to a drawing test using an Erichsen cup drawing tester to change the drawing pressure into square cylinders and cylinders with beads, and the limit drawing at room temperature. The pressure and mold galling resistance were evaluated. The press conditions and evaluation criteria at this time are as follows. (Press conditions) Punch diameter 33 mmφ (cylinder, cylinder with beads) 40 mmφ (square tube) Blank diameter 66 mmφ (cylinder, cylinder with beads) 98 mmφ (square tube) Drawing speed 60 mm / sec Drawing pressure 1-9 t (Evaluation of mold galling resistance) Criteria) ◎ = No mold galling ○ = Slight mold galling △ = Slight mold galling × = Many mold galling

(2) Anticorrosion property A wet test was carried out under the conditions of a temperature of 50 ° C. and a humidity of 98%, and evaluation was made by the time until 5% of red rust was generated. JIS Z2
SST is performed under the conditions specified in 371, and red rust is 5%.
The time to occur was measured. The corrosion resistance was evaluated by the results of these two tests.

(3) Defatting property A degreasing liquid (Fine Cleaner 4460 (manufactured by Nippon Parker Rising Co., Ltd.)) having a concentration of 3% and a liquid temperature of 40 ° C. was sprayed on the test piece for 10 seconds for degreasing. To
The test piece was dipped in a 3% copper sulfate aqueous solution for 40 seconds, the state of Cu substitution and precipitation was observed, and the film removal property was evaluated according to the following criteria. (Evaluation Criteria for Film Removal Property) ○ = Cu is deposited on the entire surface △ = Cu is partially deposited × = Cu is not deposited at all

(4) Blocking resistance Two test pieces which were laminated with the coated surfaces inside were 30
It was left in a constant temperature bath at 60 ° C. for 6 hours while being tightened with a torque of 0 kg-cm. After that, the stacked test pieces were peeled off, and the blocking resistance was evaluated according to the following criteria depending on the adhesion state when peeled off. (Blocking resistance) ◎ = No sticking ○ = Slight sticking △ = Sticking × = Large sticking

Table 1 Resins used, additives ──────────────────────────────────── (Product name) ──────────────────────────────────── A acrylic resin manufactured by Mitsubishi Rayon Co., Ltd. ( (Dialal) Resin B Maleic anhydride Mitsui Toatsu Co., Ltd. C Styrene Mitsubishi Yuka Co., Ltd. ────────────────────────── ──────────── Group B a Palmitic acid Wako Pure Chemical Industries, Ltd. Lubricant b Stearic acid c Calcium stearate d Barium stearate ──────────────── ───────────────────── Group C e Zinc Phosphate Wako Pure Chemical Industries, Ltd. Lubricant f Calcium Phosphate g Zinc Molybdate h Ammonium Budenate ──────────────────────────────────── Group D i Polyethylene Wax Mitsui Petrochemical Industry Co., Ltd. ) Tm: 65 ° C lubricant (Mitsui High Wax) j polyethylene wax 111 k polyethylene wax 130 l polyethylene wax 140 m polyethylene wax 157 ──────────────────────── ──────────────

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

The film-removing type lubricating coating composition of the present invention is excellent in deep drawability, mold galling resistance and primary rust prevention while maintaining film removal property and blocking resistance. Therefore, the present invention has high practical value when applied to, for example, hot-rolled pickled steel sheets, cold-rolled steel sheets, and various surface-treated steel sheets.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 137: 06) C10N 30:12

Claims (1)

[Claims] 1. (a) Tg is 0 to 120 ° C. and acid value is 3.
0 to 200 mg-KOH / g acrylic resin,
As a lubricant, (b) at least one lubricant selected from higher fatty acids, higher fatty acid esters and metallic soaps is used in an amount of 3 to 30 wt% based on the solid content of (a), and (c) Zn of phosphoric acid and molybdic acid. 2 to 30 wt% with respect to the solid content of (a), and (d) a polyethylene wax having a melting point Tm of 70 ≦ Tm ≦ 150 ° C. 3 to 20 wt% with respect to the solid content of (a)
%, A film-removing type lubricating coating composition excellent in deep drawability, mold galling resistance and temporary rust resistance.