JPH1088364A - Decoating type lubricating treated aluminum sheet and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a coating type lubricating treated aluminum allay sheet having an effect for the suppression of the build-up of rolls arranged on and after the open outlet side of a coating line and dies for press forming. SOLUTION: This alloy sheet is provided with dry lubricating coating of 0.5 to 3g/m<2> formed by applying the surface with an organic high polymer composition contg. alkali soluble type acrylic resin composed of alkali soluble type acrylic resin emulsion by 20 to 50% expressed in terms of dry coating, wax composed of wax emulsion having 50 to 130±C m.p. by 20 to 50% expressed in terms of dry coating and colloidal silica composed of a colloidal soln. of alkali soluble type silica fine particles by 10 to 40% expressed in terms of dry coating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricated aluminum plate (including an aluminum alloy plate; the same applies hereinafter) which is excellent in press formability, and is used particularly for home appliances and containers, without using press oil. The present invention relates to a delaminated lubricated aluminum plate which can be subjected to high-speed press molding and can remove a lubricating film by degreasing and which has excellent moldability and a method for producing the same.

[0002]

2. Description of the Related Art In many cases, aluminum plates used in the manufacture of home appliances and containers are subjected to molding such as press molding. However, in actual press molding, lubricating oil (for press molding) is used. Since press oil is often applied by spraying, there is a problem that the working environment is deteriorated. Further, in the degreasing and cleaning performed after the press working, a solvent (Freon, chlorine-based solvent) having a risk of causing an environmental problem has been used.

In order to solve these environmental problems, ordinary steel sheets for plating provided with a lubricating film have been put to practical use. When such steel sheets are used, press oil is applied and fluorocarbon or chlorine-based solvent is used. Degreasing and washing are not required. More recently, press molding using lubricated steel sheets, that is, press molding without using processing oil, has been expanding in response to interest in global environmental issues and demands for total cost reduction.

[0004] There are various types of lubrication coatings, but lubrication treatment of ordinary steel is based on the premise that the lubrication coating is not peeled off after molding (so-called non-delamination type lubrication treatment). However, it is difficult to apply the method to a method that is premised on use (use of the surface cloth of a steel sheet as it is). In this regard, a technology that can be applied to a metal plate that is assumed to be used as a normal steel plate has been developed as a delamination type lubrication plate having a lubrication film that can be delaminated by alkali degreasing. . (Hanahata et al .: Sumitomo Metal Technical Report, V
ol. 42, No. 5, (1990), pp. 60-64,
Furukawa et al .: Materia 35, (1996), p. 433)
This delamination type lubricated plate has high lubrication performance and excellent degreasing (delamination) performance, making it difficult to form during press working, reducing mold seizure, and easily by alkali degreasing. Since the film is removed, it can be handled as a normal steel sheet in the subsequent process.

[0005] However, further improvement is required also in such a delaminated lubricated plate. For example, during coating of a delamination type lubrication plate, a phenomenon (build-up) in which a delamination type lubrication coating film adheres to a roll after a baking furnace and accumulates occurs.
The build-up film may adhere again to the plate surface, making painting impossible. For this reason, it is necessary to prevent build-up of rolls and press-forming dies after the oven exit side of the coating line as much as possible. Further, in the above-mentioned stripping-type lubricating plate, it is necessary to always make an effort to enhance the stripping property in the alkali degreasing.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to remove a film having excellent press moldability, which makes it possible to easily remove the film on the surface by alkali degreasing. Provided is a film-lubricated aluminum alloy sheet, which is a die-lubricated aluminum alloy sheet, which is effective in suppressing build-up of rolls and press-forming dies after an oven exit side of a coating line, and a method of manufacturing the same. It is in.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that colloidal silica, which is a colloidal solution of ultra-fine silica particles, contains acrylic resin and wax. It has been found that by adding the compound to the organic polymer composition, the adhesiveness can be controlled, and the present invention has been completed.

That is, the aluminum alloy plate of the present invention is a film-type lubrication-treated aluminum alloy, comprising an alkali-soluble acrylic resin, wax,
And 0.5 g / m ^2- formed by applying an organic polymer composition containing silica and colloidal silica to the surface.
It is an aluminum alloy plate provided with a dry lubricating film of 3 g / m ² .

In the present invention, the aluminum alloy plate is degreased in advance, an organic polymer composition containing an alkali-soluble acrylic resin, wax, and colloidal silica is applied to the surface, and then dried. 0.5g /
It is characterized in that a film-coated lubricated aluminum alloy plate is manufactured by forming m ² to ³ g / m ² .

The contents of the organic polymer composition are as follows. (1) Alkali-Soluble Acrylic Resin An emulsion of an alkali-soluble acrylic resin having a dry film equivalent of 20% to 50%. (2) Wax The melting point of 20% to 50% in terms of dry film is from 13 to 50 ° C.
Consists of a wax emulsion at 0 ° C. (3) Colloidal silica A colloidal solution of 10% to 40% of alkali-soluble silica fine particles having a particle size of 50 μm or less in terms of a dry film.

[0011]

Next, a water-soluble resin, a wax and colloidal silica used for a film-type lubricated aluminum alloy sheet according to the present invention will be described.

[Alkali-soluble acrylic resin]
It has the function of fixing the wax to the film layer. That is, the lubricity of the lubricated plate is given by the wax, and the wax is fixed to the coating layer by the resin. Since the film layer needs to be removable by alkali degreasing, the resin is desirably a water-soluble resin which is a chain polymer having a hydrophilic group and is soluble in water. Examples of the water-soluble resin include an acrylic resin, a urethane resin, and an epoxy resin. In particular, an emulsion-type acrylic resin that is easily dissolved in alkali is suitable. As the amount of the acrylic resin in the dry film increases, the wax can be more easily fixed. However, when the amount of the acrylic resin is increased, the ratio of the wax decreases correspondingly, and the lubricity decreases. Therefore, the amount of acrylic resin is 20
% To 50%.

[Wax] The wax is added to impart lubricity to the film layer, and the lubricity becomes maximum before and after the melting point of the wax. Since the temperature of the tool and the material in the continuous press forming is set to about 50 ° C. to 130 ° C., it is appropriate to use wax having a melting point of 50 ° C. to 130 ° C. The greater the amount of wax in the dry film, the better the lubricity. However, if the amount of wax is increased, it is difficult to fix the film in the dry film, and it is difficult to dissolve in alkali degreasing after press molding. Therefore, the amount of the wax is from 20% to
Desirably, it is 50%.

[Colloidal Silica] Colloidal silica is a colloidal solution of ultrafine particles of silicic anhydride, and has a function of adjusting the adhesiveness of a dried film. That is, the dry film containing the acrylic resin and the wax has an adhesive property, and is easily built up in a coating line for applying to an aluminum alloy plate, and easily adheres to a press-molded tool. However, by adding colloidal silica, which is a colloidal solution of ultrafine particles of silicic anhydride, to an organic polymer composition containing an acrylic resin and a wax, its tackiness can be controlled. In addition, colloidal silica is easily dissolved in an alkaline solution, and therefore has a function of accelerating the removal of a dried film in alkaline degreasing after press molding. The higher the amount of colloidal silica in the dry film, the less build-up of the dry film on the coating line and press forming tools. However, an increase in colloidal silica leads to a decrease in lubricity. Considering the thickness of the dried film (0.5 g / m ^{2 to} 3 g / m ² ), the upper limit of the particle size of the colloidal silica is 50 m μm.
And the amount is 10% in terms of dry film.
% To 40%.

[Lubricating film, aluminum plate, etc.] If the lubricating film after drying is thin with respect to the film thickness of the dry film of the delamination type lubricating film, there is a possibility that lubricity may be insufficient locally, When the film is thick, cohesive failure of the film itself may occur during press molding. The film thickness of these risk-free lubricating coating is ^{0.5g / m 2 ~3g / m 2} .

In the present specification, the term "aluminum plate" includes a so-called aluminum alloy plate. As for the “aluminum plate”, the present invention covers not only those used for manufacturing home appliances and containers, but also any aluminum plate regardless of the type or use of the final product.

[0017]

Hereinafter, examples of the present invention will be described in comparison with comparative examples. Aluminum alloy A5182 (4.5% Mg,
0.20% Mn, 0.06% Cu, 0.12% Si,
0.20% Fe, 0.02% Zn, 0.10% Cr,
0.02% Ti, Al residual) annealed plate material (O material, thickness 1.
0 mm), the surface of the plate material was degreased and washed. Next, after applying the organic polymer composition shown in Table 1, 12
It was dried in an electric furnace at 0 ° C. for 2 minutes to form a lubricating film.

[0018]

[Table 1] << Table Note >> Acrylic resin 1: Alkali-soluble emulsion, viscosity 100 cPs Acrylic resin 2: Alkali-soluble emulsion, viscosity 500 cPs Wax 1: paraffin wax, melting point 52 ° C. Wax 2: polyethylene oxide wax, melting point 130 ° C. colloidal silica 1 : Particle size 10 ~ 20μm Colloidal silica 2: Particle size 40 ~ 50μm

The delaminated lubricated aluminum alloy sheet according to the present embodiment having the lubricating film formed thereon as described above was subjected to five steps for each of initial lubricity, high-speed press moldability, alkali degreasing property, and build-up property. Was evaluated. Table 2 shows the results. From the results shown in Table 2, it can be seen that all of the test materials according to the present invention exhibited excellent properties in initial lubricity, continuous press moldability, alkali degreasing property, and build-up property. In each evaluation test,
A practicable level of 3 or more is considered a pass level.

The evaluation method of the test material is as follows. (1) Evaluation of initial lubricity by Bowden friction test Load 4.9 N, steel ball SUJ-2, sliding speed 4.0 mm /
The initial lubricity of the stripped lubricated aluminum alloy sheet according to the example was evaluated by performing a Bowden friction test under the conditions of a measurement temperature of 30 ° C. for 30 minutes. The evaluation of slipperiness was represented by the maximum value of the coefficient of friction up to 10 times of sliding. [Evaluation points] 5: Coefficient of friction less than 0.05 4: Coefficient of friction 0.05 or more, less than 0.1 3: Coefficient of friction 0.1 or more, less than 0.2 2: Coefficient of friction 0.2 or more, 0.3 Less than 1: Friction coefficient 0.3 or more

(2) Evaluation of high-speed press formability by continuous deep drawing test Test material shape: 112.5 mm diameter, die inner diameter: 52.8 mm
(Shoulder R 5 mm), punch outer diameter 50.0 mm (shoulder R
5mm), molding speed 50mm / s, molding height 10mm
By performing a continuous deep drawability test under the conditions described above, the high-speed press formability of the stripped lubricated aluminum alloy sheet according to the example was evaluated. The evaluation of the high-speed press formability is based on the limit number of moldings immediately before breaking. [Evaluation points] 5: Limit molding number 1000 or more 4: Molding limit number 800 or more and less than 1000 3: Molding limit number 600 or more and less than 800 2: Molding limit number 400 or more and less than 600 1: Molding limit number less than 400

(3) Evaluation of Alkali Degreasing Property Alkaline degreasing property was evaluated by immersing in a 10% aqueous solution of Na0H at 65 ° C. for 15 seconds, washing with water, and inverting vertically in the air for 30 seconds after inverting water to determine the alkali degreasing property. That is, after immersing in a 10% Na0H aqueous solution at 65 ° C. for 15 seconds, washing with water at room temperature for 60 seconds,
It was left standing for 30 seconds in a state of standing vertically in the air, and the water-wetted area after the standing time of 30 seconds was visually determined to evaluate the alkali degreasing property of the stripped lubricated aluminum alloy plate according to the example. . [Evaluation points] 5: Water wet area ratio 100% 4: Water wet area ratio 90% or more and less than 100% 3: Water wet area ratio 80% or more and less than 90% 2: Water wet area ratio 50% or more and 80% Less than 1: Water wet area ratio less than 50%

(4) Evaluation of Build-up Property The build-up amount of the lubricating film on the die when the number of moldings was 200 at the time of high-speed press formability evaluation by a continuous deep drawability test (relative evaluation by visual observation) was evaluated. The build-up properties of the film-type lubricated aluminum alloy sheet were evaluated. [Evaluation points] 5: None 4: Slight 3: Small 2: Medium 1: Large

[0024]

[Table 2]

[0025]

[Comparative Example] Aluminum alloy A5182 as in Example
(4.5% Mg, 0.20% Mn, 0.06% Cu,
0.12% Si, 0.20% Fe, 0.02% Zn,
Using annealed plate material (O material, thickness 1.0 mm) of 0.10% Cr, 0.02% Ti, Al residue, degrease the surface of the plate material,
Washed. Next, the organic polymer compositions shown in Tables 3 and 4 were applied, and then dried in an electric furnace at 120 ° C. for 2 minutes to form a lubricating film. The acrylic resin 3 is an alkali-insoluble emulsion, having a viscosity of 300 cPs, the wax 3 is an oxidized paraffin wax, having a melting point of 37 ° C., the wax 4 is a polypropylene wax, having a melting point of 152 ° C., and the fine silica is having a particle diameter of 1-3. μm one was used.

[0026]

[Table 3]

[0027]

[Table 4]

The test material according to the comparative example in which the lubricating film was formed as described above was subjected to initial lubrication, high-speed press moldability, alkali degreasing, and build-up properties in the same manner as the test material according to the present example. The items were evaluated on a 5-point scale. Table 5 shows the results. The evaluation method of the test material according to the comparative example is the same as the evaluation method of the test material according to the present example.

[0029]

[Table 5]

Hereinafter, the evaluation results of the test materials according to the comparative examples will be described. Test No. In Test No. 1, the initial lubricity and high-speed press formability were low because the amount of the lubricating film was small. 2
Has a low alkali degreasing property and a low build-up property due to a large amount of a lubricating film. Test No. 3 and test no. 6
Has a low build-up property due to a large amount of wax. This is because the wax was peeled off very easily because the amount of the acrylic resin was reduced in accordance with the increase in the amount of the wax. In addition, since the amount of the wax was large and the amount of the acrylic resin was small, the alkali degreasing property was low.

Test No. No. 4 has a large amount of acrylic resin, so lubricity is insufficient and high-speed press moldability is reduced,
Also, the build-up property was low. Test No. Test No. 5 has low initial lubricity and high-speed press moldability due to a large amount of acrylic resin and a small amount of wax. 7
Had a low build-up property due to a small amount of colloidal silica. Test No. In No. 8, the lubricating property was reduced due to the large amount of colloidal silica, and the initial lubricating property and high-speed press moldability were low.

Test No. Test No. 9 has a low alkali degreasing property because the acrylic resin is hardly soluble. Sample No. 10 had good initial lubricity because the melting point of the wax was low, but low high-speed press moldability, in which the surface temperatures of the dies and the materials increased. Test No. Sample No. 11 had low initial lubricity and high-speed press moldability due to the high melting point of the wax. Test No. Sample No. 12 had low initial lubricity and high-speed press moldability due to the large particle size of silica.

[0033]

As described above, according to the stripped lubrication-treated aluminum alloy sheet and the method of manufacturing the same according to the present invention, the roll and press forming after the oven exit side of the coating line is performed by adding colloidal silica. By suppressing build-up on a die, build-up measures can be taken.

In addition, since the stripping-type lubricated aluminum alloy sheet and the method for producing the same according to the present invention can be processed by press forming or the like without using lubricating oil, the work at the time of press forming can be performed. Can improve the environment,
Furthermore, since the film can be easily removed by alkali degreasing, a solvent that may cause an environmental problem is not required. In addition, the film can be more easily removed by alkali degreasing by adding colloidal silica or the like. As a result, the yield and production efficiency can be improved.

Claims (2)

[Claims] 1. An alkali-soluble acrylic resin comprising an emulsion of an alkali-soluble acrylic resin of 20% to 50% in terms of a dry film, and a melting point of 50% to 130% in a dry film equivalent of 20% to 50%. An organic polymer composition containing a wax composed of a wax emulsion at a temperature of 10 ° C. and colloidal silica composed of a colloidal solution of 10% to 40% of an alkali-soluble silica fine particle having a particle size of 50 μm or less in terms of a dry film, A strip-type lubricated aluminum plate having a 0.5 g / m ² to 3 g / m ² dry lubricating film formed by being applied to the surface of an aluminum alloy plate. 2. An alkali-soluble acrylic resin comprising an emulsion of an alkali-soluble acrylic resin of 20% to 50% in terms of a dry film on a surface of an aluminum plate;
The melting point of 20% to 50% in terms of dry film is 50 ° C to 1%.
A wax consisting of a 30 ° C. wax emulsion;
An organic polymer composition containing a colloidal solution of a colloidal solution of 10% to 40% of an alkali-soluble silica particle having a particle size of 50 μm or less in terms of a dry film is applied, and the dried film layer is finally dried. 0.5 g / m ² to 3
g / m ² is formed on the surface of the aluminum plate.