JP2009190209A - Resin-coated aluminum sheet for molding and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin-coated aluminum sheet for molding which is excellent in press moldability and can secure adhesion performance and alkali degreasing membrane removing properties. <P>SOLUTION: In the resin-coated aluminum sheet for molding with a resin paint film formed on the surface of aluminum or an aluminum alloy sheet, with regard to the resin paint film, fine zinc phosphate particles and wax are dispersed uniformly in an alkali soluble resin containing at least one of a urethane resin, an acrylic resin, an epoxy resin, and a polyester resin. The amount of the wax is 0.03-0.12 g/m<SP>2</SP>, the particle size of the zinc phosphate particles is 0.01-1 μm, the compounding ratio of the zinc phosphate particles to the alkali soluble resin is 5.3-300 wt.%, and the compounding ratio of the wax in relation to the total solid content of the alkali soluble resin and the zinc phosphate particles is 2-15 wt.%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin-coated aluminum plate that is molded and used for a can end material, a can body material, an electric / electronic equipment member, an automobile body material, or a building material.

  Aluminum plates and aluminum alloy plates (hereinafter collectively referred to as aluminum plates) have good corrosion resistance and are lightweight, so they are widely used in applications such as beverage can materials, building materials, home appliance materials including electric and electronic parts, and automobile materials. Has been applied. When applying an aluminum plate to the said use, normally, an aluminum plate is press-molded to a predetermined shape, and is applied. There are two methods for press-forming aluminum plates: one is to supply sheet-fed sheets one by one to the press, and the other is to supply coil-shaped aluminum plates to the press continuously. As an excellent manufacturing method, it is widely adopted in the business field of the above-mentioned use. In addition, the aluminum plate for the above-mentioned use is often used after the press molding, with the surface being coated for the purpose of further improving the corrosion resistance, improving the appearance and preventing scratches.

In this press molding, a method of providing a coating film having lubricity on the surface of an aluminum plate has been proposed in order to improve molding processability. For example, Patent Document 1 proposes a method of applying paraffin wax on a surface treatment film such as a coating film at a temperature equal to or higher than the melting point. In Patent Document 2, an organic composition containing 5 to 30% silica sol and 5 to 20% wax is applied to urethane, ester or epoxy resin after chromate treatment to form a film of 1 to 10 g / m ² . A method has been proposed.

  However, when an aluminum plate is assembled by bonding or the like to obtain a product shape, the use of the aluminum plate formed with the wax-containing coating as described above sufficiently absorbs the oil content of the adhesive by the coating on the surface of the aluminum plate. However, the adhesiveness may be reduced.

  In addition, when coating is performed after press molding, it is essential to remove the lubricating coating film by alkali degreasing or the like before coating. If the film removal property at this time is insufficient, the lubricating coating is not sufficiently removed, and subsequent coating cannot be performed satisfactorily.

As a surface-coated aluminum material in consideration of such circumstances, in Patent Document 3, metal fine particles other than aluminum having a particle size of 0.1 to 10 μm and a particle density of 10 ³ to 10 ⁷ pieces / m ² and oxides and hydroxides are used as cathodes. A method of depositing by an electrolysis method or an electroless method and further coating an organic film of 5 to 500 nm is disclosed. However, since the coating film thus formed does not contain a wax that greatly contributes to lubricity, sufficient press formability can be obtained when more severe overhanging and drawability are required. Can not.
JP-A-6-254490 JP-A-6-55137 Japanese Patent Laid-Open No. 10-34079

  As described above, in the conventional surface-coated aluminum plate, if it is intended to give sufficient lubricity so that the press molding can be performed satisfactorily, the adhesiveness is impaired at the time of adhesion to other members, or after press molding. There has been a problem that the alkali degreasing and film removal properties in the process are lowered.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a resin-coated aluminum plate for molding processing that is excellent in press moldability and can ensure adhesion performance and alkali degreasing delaminating performance. It is what.

In order to achieve the above object, the resin-coated aluminum plate for molding processing of the present invention is
In a resin-coated aluminum plate for molding processing in which a resin coating is provided on the surface of an aluminum plate or an aluminum alloy plate,
The resin coating is a resin coating in which zinc phosphate fine particles and wax are uniformly dispersed in an alkali-soluble resin composed of one or more of urethane resin, acrylic resin, epoxy resin and polyester resin,
The amount of the wax is 0.03 to 0.12 g / m ² , and the particle size of the zinc phosphate fine particles is 0.01 to 1 μm,
The blending ratio of the zinc phosphate fine particles to the alkali-soluble resin is 5.3 to 300% by weight,
And the compounding ratio of the said wax with respect to the total solid content of the said alkali-soluble resin and the said zinc phosphate microparticles | fine-particles is 2 to 15 weight%, It is a resin-coated aluminum plate for shaping | molding processes characterized by the above-mentioned.

It is more preferable that the coating amount of the resin coating film is 0.2 to 1.5 g / m ² .

Moreover, the manufacturing method of the resin-coated aluminum plate for molding processing of the present invention is as follows.
To the alkali-soluble resin composed of one or more of urethane resin, acrylic resin, epoxy resin, and polyester resin, zinc phosphate fine particles having a weight ratio of 5.3 to 300% with respect to the alkali-soluble resin and the alkali A step of uniformly dispersing a wax having a weight ratio of 2 to 15% with respect to the total solid content of the soluble resin and the zinc phosphate to prepare a resin coating;
Applying the resin paint to the surface of the aluminum plate or aluminum alloy plate by a roll coater method;
It is a manufacturing method of the resin coating aluminum plate for shaping | molding processes characterized by including.

It is more preferable that the coating amount of the resin coating is 0.2 to 1.5 g / m ² .

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in press moldability, it is excellent also in coating-film adhesiveness and adhesive performance, and the resin-coated aluminum plate for shaping | molding processes which can ensure the film removal property by alkali degreasing can be obtained.

  The type of the aluminum plate or aluminum alloy plate used in the present invention is not particularly limited, but a pure aluminum alloy plate such as JIS A1100, an Al—Mn alloy plate such as JIS A3004, and an Al—Mg such as JIS A5182. An Al—Mg—Si alloy plate such as JIS A6063 can be used. Hereinafter, the aluminum plate and the aluminum alloy plate are collectively referred to as “aluminum plate”.

The resin-coated aluminum plate for molding processing according to the present invention has a resin coating described below on the surface of the aluminum plate. When the amount of the resin-coated film is 0.2 g / m ² or less, the molding die and the aluminum surface are likely to come into contact with each other, so that molding defects such as buckling and galling are likely to occur. On the other hand, if it exceeds 1.5 g / m ² , the press formability will not be improved any more, resulting in an increase in cost. Therefore, the resin coating amount is preferably in the range of 0.2 to 1.5 g / m ² .

  In addition, since the adhesiveness of a resin coating film will worsen when there is much Mg on the aluminum plate surface (it exists mainly in the form of a hydroxide etc.), it is preferable to suppress the amount of Mg on the surface. Mg on the surface of the aluminum plate can be evaluated by measuring the maximum emission intensity by GDS (glow discharge emission analysis). In the present invention, the maximum emission intensity of Mg is preferably 2 V or less.

  The resin coating provided on the surface of the aluminum plate is obtained by uniformly dispersing zinc phosphate fine particles and a wax as a lubricating component in a water-soluble and alkali-soluble polymer resin.

  As the polymer resin, a resin composed of one or more of urethane resin, acrylic resin, epoxy resin, and polyester resin can be used. Among these resins, those having water solubility and alkali solubility are selected. By using such a water-soluble and alkali-soluble polymer resin for the resin coating film, it is possible to improve the film-removability in the alkaline degreasing performed as a pretreatment when the aluminum plate is used after being coated later. Can do.

  The particle size of the zinc phosphate fine particles added to the resin coating is 0.01 to 1 μm, and the weight ratio of the alkali-soluble resin and zinc phosphate fine particles is 25:75 to 95: 5 (that is, 100 wt. Part of the zinc phosphate fine particles is 5.3 to 300 parts by weight). By setting the particle size and amount of the zinc phosphate fine particles in such a range, irregularities are formed on the surface of the resin coating, and the anchor effect is obtained when the resin-coated aluminum plates are bonded to each other or to an external member. It can work and obtain excellent adhesion performance.

  If the particle diameter of the zinc phosphate fine particles is less than 0.01 μm, irregularities are not formed on the surface of the coating film after the resin coating film is formed. On the other hand, when the particle diameter exceeds 1 μm, the zinc phosphate fine particles jumping out from the surface of the coating film are excessively present, resulting in a decrease in press formability. Moreover, since unevenness | corrugation is not formed in the coating-film surface when zinc phosphate microparticles | fine-particles are smaller than 5.3 weight part with respect to 100 weight part of alkali-soluble resin, adhesive performance falls. On the other hand, if the zinc phosphate fine particles are larger than 300 parts by weight with respect to 100 parts by weight of the alkali-soluble resin, the amount of the resin component is insufficient, and the film elongation at the time of press molding is not ensured. The coating film adhesion on the plate surface will be inferior.

As the wax to be added to the resin coating film, polyethylene wax, carnauba wax, lanolin wax, crystallin wax or the like can be used, and the amount thereof is set to 0.03 to 0.12 g / m ² . The weight ratio of the wax to the total solid content of the alkali-soluble resin and the zinc phosphate fine particles is 2 to 15%. When the amount of wax is 0.03 g / m ² or less, the lubricity is insufficient, and sufficient press formability is not ensured. On the other hand, if the amount of wax exceeds 0.12 g / m ² , not only the press formability is improved, but also when the resin-coated aluminum plates are bonded to each other or bonded to an external member, wax or oil is present in the adhesive. It is not preferable because it is not sufficiently absorbed and the adhesive performance is lowered.

  Various methods can be used as a method for forming a resin coating film on the surface of the aluminum plate when the resin-coated aluminum plate of the present invention is produced. For example, a roll coater method, a roll squeeze method, a chemicoater method, a dipping method, a spray method can be used. The law etc. can be used. Among these methods, a roll coater method that is excellent in the uniformity of the coating film and good in productivity is particularly preferable. As the roll coater method, a gravure roll method with easy coating amount management, a natural coating method suitable for thick coating, a reverse coating method suitable for imparting an aesthetic appearance to the coated surface, and the like can be employed.

  After forming the resin coating film on the aluminum plate surface, drying is performed. Drying can be performed by a hot air furnace, an infrared furnace, an induction heating furnace, or the like, and among them, a hot air furnace using air heated indirectly by an electric heater, a combustion gas, or the like is particularly preferable.

[Example 1]
Next, Example 1 of the present invention will be described. As an aluminum plate, JIS A5182-O (0.8 mm thickness) subjected to final heat treatment was prepared. As pretreatment for resin coating formation, alkaline degreasing (immersion in EC-371 manufactured by Nippon Paint, 60 ° C. × 5 seconds) → water washing (at room temperature for 15 seconds, spray pressure 1.5 kg / cm ² ) → pickling (10 wt% Of H ₂ SO ₄ (30 ° C.) for 5 seconds) → water washing (at room temperature for 15 seconds, spray pressure 1.5 kg / cm ² ) → pure water washing → hot air drying. A measurement sample having a width of 50 mm and a length of 60 mm was cut out from the aluminum plate that had undergone this step, and the amount of Mg on the surface was determined by measuring the maximum emission intensity with GDS.

  As the GDS apparatus, JY5000RF manufactured by HORIBA, Ltd. was used. The measurement conditions for the amount of Mg were a pressure after replacement with argon gas of 600 Pa, an output of 30 W, a module 650, a phase 350, and an anode diameter of 4 mmφ. The Mg detection wavelength was 384 nm and the Mg sensitivity was 750V. From the oxide film surface layer of the measurement sample, the maximum peak height of Mg sputtered within 1 second of the sputtering time was measured as the emission intensity (V).

  Next, a resin paint in which zinc phosphate fine particles with various particle sizes and blending amounts and polyethylene wax with a melting point of 105 ° C. with various blending amounts are uniformly contained in a water-soluble and alkali-soluble urethane resin. It produced (Table 1). These resin paints were applied to an aluminum plate with a roll coater, and dried at PMT (plate arrival temperature) of 115 ° C. and in-furnace time of 30 seconds to obtain test pieces for performance evaluation.

  As the performance of the resin-coated aluminum plate obtained as described above, press moldability (drawability), press moldability (galling property), adhesion performance, and alkaline degreasing delaminating performance were evaluated.

(1) Press formability (drawability)
After commercial lubricating oil on the test piece (Yukenkogyo manufactured RP-75N) 0.5g / ^{m 2} oiling, punch diameter 50 mm [phi], in the mold of the shoulder R5 mm, BHF (blank holding load) 600N, forming speed 5mm Deep drawing was performed at a rate of / sec, and the limit drawing ratio (LDR) was determined. Evaluation / judgment criteria were as follows.

○: LDR 2.1 or higher Pass △: LDR 1.9 to 2.0 Fail ×: LDR 1.89 or lower Fail

(2) Press formability (galling resistance)
After applying 0.5 g / m ² of commercially available lubricating oil (RP-75N manufactured by Yuken Kogyo Co., Ltd.) to the test piece, using a Bowden abrasion tester, test load 500 gf, sliding speed 0.6 mm / second, steel ball The dynamic friction coefficient (μ) at the 50th reciprocation was measured under the condition of diameter = 3/16 inch. Evaluation / judgment criteria were as follows.

○: μ 0.1 or less Pass △: μ 0.1 or more Fail ×: Less than 50 round trips, galling generated Fail

(3) Adhesion performance The test piece was cut into 1 mm thickness x 25 mm width x 150 mm length, and after commercially available lube oil (RP-75N manufactured by Yuken Kogyo Co., Ltd.) was immersed in the oil, left at room temperature for 1 day to adhere to the structure. An adhesive (Sunstar # 1086) was used for adhesion at an adhesive area of 25 mm × 10 mm and an adhesive thickness of 0.2 mm, followed by heat treatment at 180 ° C. for 20 minutes. These were subjected to a tensile test at a tensile speed of 25 mm / min, and the shear strength was measured. Evaluation / judgment criteria were as follows.

◎: Shear strength 19 MPa or more Pass ○: Shear strength 17 MPa or more but less than 19 MPa Pass ×: Shear strength less than 17 MPa Fail

(4) Alkaline degreasing defilming property After applying 0.5 g / m ² of a commercially available lubricating oil (RP-75N manufactured by Yuken Kogyo Co., Ltd.), a commercially available alkaline degreasing agent (Nippon Parkerizing FC-E3003, pH = CO ₂ = 11), the degreasing property of the alkaline degreasing was evaluated based on the water-wetting area after being washed with water for 30 seconds. Evaluation / judgment criteria were as follows.

◎: Water-wetting area 100% pass ○: Water-wetting area 90% or more and less than 100% Pass ×: Water-wetting area less than 90%

  Table 2 shows the evaluation / determination results of Example 1. In the resin-coated aluminum plates of Invention Examples 1 to 11, the GDS emission intensity reflecting the amount of Mg on the surface of the aluminum plate is as low as 2 V or less, and the particle size and blending amount of zinc phosphate fine particles in the resin coating film, Since the blending amount is within the range specified in the present invention and the coating amount of the resin coating film is appropriate, all of press moldability, adhesive performance and alkali film removal property are satisfied.

  On the other hand, in Comparative Example 1, since the particle diameter of the zinc phosphate fine particles was too small as 0.005 μm, the surface of the resin-coated aluminum plate was not formed with unevenness, and the anchor effect was not obtained, resulting in poor adhesion performance. It was. On the other hand, in Comparative Example 2, since the particle diameter of the zinc phosphate fine particles was too large at 1.2 μm, the zinc phosphate fine particles jumped out from the surface of the coating film existed excessively, and press formability (anti-galling resistance) It was inferior to.

  In Comparative Example 3, since zinc phosphate fine particles were not blended in the resin coating film, unevenness was not formed on the surface of the resin-coated aluminum plate, and the anchor effect was not obtained, resulting in poor adhesion performance. On the other hand, in Comparative Example 4, since the blending ratio of the zinc phosphate fine particles with respect to the total amount of the urethane resin and zinc phosphate was too much as 80%, the resin component amount was insufficient, and the coating film elongation at the time of molding was not ensured, The press formability was poor.

In Comparative Example 5, since the blending ratio of the wax with respect to the total solid content of the urethane resin and the zinc phosphate fine particles was too small as 1%, sufficient lubricity was not obtained and the press formability was inferior. Further, in Comparative Example 6, since the amount of the wax was too large, 0.14 g / m ² , the adhesive performance was inferior.

  In Comparative Example 7, since the pickling treatment was not performed in the pretreatment for forming the resin coating film, the amount of Mg detected on the surface of the aluminum plate increased. As a result, it was inferior to adhesive performance and alkali degreasing film removal property.

[Example 2]
Next, a second embodiment of the present invention will be described. The type of aluminum plate, pretreatment, and GDS measurement were the same as in Example 1.

  Next, zinc phosphate fine particles with a particle size of 0.3 μm and various blending amounts in a water-soluble and alkali-soluble acrylic resin, epoxy resin or polyester resin, and a polyethylene wax having a melting point of 105 ° C. with various blending amounts. Resin paints containing bismuth were prepared (Table 3). These resin coatings were applied to an aluminum plate with a roll coater and dried at PMT (plate arrival temperature) of 120 ° C. for 30 seconds in the furnace to obtain a test piece for performance evaluation.

  As the performance of the resin-coated aluminum plate obtained as described above, press moldability (drawability), press moldability (galling property), adhesion performance, and alkaline degreasing delaminating performance were evaluated. The performance evaluation method and the evaluation / determination criteria are the same as those in the first embodiment.

  Table 4 shows the evaluation / determination results of Example 2. In the resin-coated aluminum plates of Invention Examples 12 to 24, the GDS emission intensity reflecting the amount of Mg on the surface of the aluminum plate is as low as 2 V or less, and the particle size and blending amount of zinc phosphate fine particles in the resin coating film, Since the blending amount is within the range specified in the present invention and the coating amount of the resin coating film is appropriate, all of press moldability, adhesive performance and alkaline degreasing defilming property are satisfied.

  On the other hand, in Comparative Examples 19 and 20, since the blending ratio of the zinc phosphate fine particles with respect to the total amount of the resin and zinc phosphate was too high at 80%, the amount of the resin component was insufficient, and the coating film elongation during molding was not ensured. The press formability was inferior.

In Comparative Examples 21 and 22, since the compounding ratio of the wax with respect to the total solid content of the resin and zinc phosphate fine particles was too small at 1%, sufficient lubricity was not obtained and the press formability was poor. In Comparative Examples 23 and 24, the amount of the wax was too large at 0.14 g / m ^2, and thus the adhesion performance was inferior.

Claims (4)

In a resin-coated aluminum plate for molding processing in which a resin coating is provided on the surface of an aluminum plate or an aluminum alloy plate,
The resin coating is a resin coating in which zinc phosphate fine particles and wax are uniformly dispersed in an alkali-soluble resin containing one or more of urethane resin, acrylic resin, epoxy resin and polyester resin,
The amount of the wax is 0.03 to 0.12 g / m ² , and the particle size of the zinc phosphate fine particles is 0.01 to 1 μm,
The blending ratio of the zinc phosphate fine particles to the alkali-soluble resin is 5.3 to 300% by weight,
And the compounding ratio of the said wax with respect to the total solid content of the said alkali-soluble resin and the said zinc phosphate microparticles | fine-particles is 2 to 15 weight%, The resin-coated aluminum plate for shaping | molding processes characterized by the above-mentioned. Molding a resin-coated aluminum plate of claim 1, coating amount of the resin coating film characterized in that it is a 0.2 to 1.5 g / m ^2. To the alkali-soluble resin composed of one or more of urethane resin, acrylic resin, epoxy resin, and polyester resin, zinc phosphate fine particles having a weight ratio of 5.3 to 300% with respect to the alkali-soluble resin and the alkali A step of uniformly dispersing a wax having a weight ratio of 2 to 15% with respect to the total solid content of the soluble resin and the zinc phosphate to prepare a resin coating;
Applying the resin paint to the surface of the aluminum plate or aluminum alloy plate by a roll coater method;
The manufacturing method of the resin-coated aluminum plate for shaping | molding processes characterized by including. Method for producing a molding resin-coated aluminum plate according to claim 3 in which the coating amount of the resin coating material is characterized by a 0.2 to 1.5 g / m ^2.