High temperature in summer, aluminum powder paint black, tank expansion? ​Tech-8892 passivation agent to make your silver paint ‘calm’ response

Tiger to customers:
In the high-temperature environment of summer, the storage stability of water-based silver paint (containing aluminum powder) is particularly problematic. Especially during long-term transportation, such as by export ship, aluminum powder can easily oxidize and turn black or swell due to high temperatures and humidity. The Tag Tech-8892 passivation agent effectively addresses these issues, extending the storage life of aluminum-containing pastes.

1. The principle of aluminum powder passivation agent

The aluminum powder passivator forms a dense layer of aluminum oxide (Al2O3) on the surface of aluminum powder through chemical or electrochemical methods. This layer prevents aluminum from coming into contact with the external environment, such as water and oxygen, thus preventing further oxidation or reactions that produce aluminum hydroxide and hydrogen gas (reaction: 2Al + 6H2O → 2Al(OH)3↓ + 3H2↑). It helps prevent issues like blackening and swelling of the can, and aids in dispersing oily aluminum powder into an aqueous system, thereby enhancing its corrosion resistance and stability.

Ⅱ、 Advantages of Tech-8892

The general composition of passivators is inorganic acidic or alkaline solutions (such as solutions containing sodium fluorosilicate and aluminum nitrate), while Tech-8892 belongs to weakly acidic organic copolymer passivators. Based on organic acid derivative technology, the reaction is mild and does not damage the substrate, and it has the function of dispersing and stabilizing aluminum powder.

一、Dvantages and features
1. Form a transparent/light film without affecting the appearance of the workpiece
2. Excellent salt spray resistance
3. The coating has strong adhesion
4. Increase decentralization

二、Applicable scenarios
Water based metal paint, water-based plastic paint, and other aluminum powder containing systems.

三、Precautions for use
1. Front end cleaning: It is recommended to first clean the surface impurities of the oily aluminum powder with solvents such as ethanol/BCS in a 1:1 ratio
2. Passivation treatment, add 20% of aluminum powder to Tech-8892 and stir evenly. Passivation at room temperature for 24 hours before use.

 

Ⅲ、 Actual effect

1. Tech-8892 Aluminum Silver Paste Passivation Test

Step 1: We added DB solvent to the oily aluminum powder and mixed it evenly. Then, we added TAG Tech-8892 aluminum powder passivator and passivated it for 48 hours, comparing it with the blank.

Step 2: Add 50g of deionized water directly to the aluminum silver paste and mix evenly. The blank sample is severely clumped and cannot be used. The aluminum silver paste with Tech-8892 added has good fluidity.

Tech-8892 Coating TestingWe conducted tests on water-based self drying and water-based baking paint, compared blank samples, and compared the metallic feel, silver powder arrangement effect, and thermal storage stability in Tech-8892 coating testing。

(1) Aqueous acrylic lotion system. The basic formula is as follows:

In the stability test, after the water-based silver paint has been stored at 50 ℃ for 14 days, the surface of Tech-8892 in the water-based acrylic lotion system is not blackened, and the storage stability is good。

(2) Water based baking paint system

On the left is blank, on the right is Tech-8892

Spray water-based silver paint on ABS board after the same heat storage. The display of Tech-8892 has excellent metallic feel, with well arranged silver powder and no black spots on the surface of the board.

 

Ⅳ、 Summary

The experimental results show that after Tech-8892 passivates oily aluminum powder, the aluminum powder slurry exhibits excellent stability in both water-based self drying and water-based baking paint, significantly improving the metallic feel (silver powder arrangement), improving black spot problems, and no swelling of the can.