Recommendation To Treated Type
- Type of Treatment for ALPASTE
- Improvement of Adhesion & Peeling-proof
- Electrostatic Property
- Chemical Resistance
(resistance to acid/alkali) - Water borne (Gas evolution)
Type of Treatment for ALPASTE
A Treated ALPASTE
| Type | Treatment | Function |
|---|---|---|
| F Type | Polymer coating | Chemical resistance, |
| W Type | Treatment by inhibiter | Water borne metallic Paint |
B Unique ALPASTE
| Type | Treatment | Function |
|---|---|---|
| D Type | Deodorized | Printing ink |
| PCF Type | Resin coated flake | Powder Coating |
| Dry flake | Aluminium Flake Powder | ALC, Slurry Explosive, Plastic coloring |
| Solvent changed Type | Base solvent exchange | Printing ink, Marine, Plastic coloring |
C Alloy Paste
| Type | Treatment | Function |
|---|---|---|
| RFA Type | Stain less Paste | Exterior (chemical resistance) |
Treated ALPASTE and its property
| Treatment | Non treated | Resin coating | ||
|---|---|---|---|---|
| Type | FX | FZ | ||
| Color appearance | ◎ | 〇 | 〇 | |
| Resistance to peeling | × | ◎ | ◎ | |
| Electrostatic property addition | × | ◎ | ◎ | |
| Chemical resistance |
Acid | 〇 | ◎ | ◎ |
| Alkali | × | 〇 | ◎ | |
Improvement of Adhesion & Peeling-proof
When being used to the plastic coating with 1-coat, ALPASTE may cause the poor adhesive problem, which is resulted in the poor scotch tape peeling test, by being affected by fatty acid on the aluminium flake surface. (No problem happens in the case of 2-coat film in which a clear-coat is applied.)
It is effective to prevent such problem to use the treated grades mentioned as below:
Resin coated flake (FX or FZ type)：Coated with acrylic resin
Electrostatic Property
When the high voltage is applied to the metallic paint the oxidized film and fatty acid covering the aluminium pigments may cause the dielectric breakdown by being applied with high voltage, and the aluminium pigments are connected just like a conductor and let the electric current go to the earth side. Then the voltage cannot be applied to the paint for electrostatic coating.
The following processed grades are effective to prevent the said problem.
Resin coated flake (FX or FZ type)：Coated with acrylic resin
Chemical Resistance ( resistance to acid / alkali )
It is recommendable to use resin coated ALPASTE, which is uniformly coated with special polymer on the aluminium flake surface, for chemical resistant application.
Resin coated flake (FX or FZ type etc.) (There are some grades depending on the required application)
Paint/ink for plastic coating / Plastic coloring Other general paint (It is also effective to improve adhesion and electrostatic property.)
Water borne ( Gas evolution )
Aluminium is well known as an amphoteric metal and generate the hydrogen gas by reaction with water at both pH areas, shown as below:
Acidic area: 2Al + 6H+ 2Al3+ + 3H2
Alkaline area: 2Al + 2OH- + 2H2O 2AlO2- + 6H2
The oleic acid or stearic acid used as the milling agent of aluminium paste is thought to be absorbed on -OH and -O of the oxidized film of aluminium surface. But the fatty acid film is apt to be removed in the presence of water, and the surface oxidized film is too thin to prevent from reaction with water.
There are three typical measures to treat the aluminium flake surface so as to give it the water resistance:
- ●Treatment with inorganic compound (WJ, WX treatment,etc.)
- ●Treatment with organic compound (WE, WB treatment,etc.)
- ●Treatment in the paint manufacturing process
The stability and effect of the treatment to aluminium flake surface largely depend on the composition of binder to be dispersed and the pH area to be used.
