1, The material is clean and the surface is wiped clean with white electric oil.
2, Keep away from fire source, heat source and direct sunlight
3, Please seal well immediately after use and store in a cool and dry place.
The degassing mechanism of benzoin is that benzoin consumes oxygen in the bubbles and reduces the bubble diameter, which leads to an increase in the internal pressure of the bubble. The increase in the internal pressure of the bubble makes the nitrogen dissolve in the polymer faster, and the bubble diameter decreases quickly from the surface. . Benzoin begins to vaporize at 120°C, which is another important factor for the degassing effect of benzoin.
The degassing agent for powder coating should meet the following conditions:
① In order to ensure uniform dispersion of the degassing agent, it must have good compatibility with the film-forming substances in the powder coating composition.
②The degassing agent can start to gasify after the powder coating is completely melted at 90~120℃. ③The degassing agent can start to oxidize at the same time as it volatilizes.
This mechanism has been successfully used in the development of benzoin replacement products that can effectively remove bubbles without causing yellowing of the coating film.
The results of experiments and production practices show that, during the cross-linking and curing reaction of powder coatings, degassing agents should be added to the coatings that produce small molecular compounds, generally in polyester ring, polyester and polyurethane powder coatings. The deaerator can be used without deaerator in epoxy powder coatings and matt and matt polyester epoxy powder coatings that use matting curing agents, but it is affected by the air absorption and moisture absorption of the powder coating and the appearance of the coating film. Considering stability, adding a degassing agent is beneficial and harmless.
Benzoin is the most commonly used degassing agent. The amount used in powder coatings is about 0.5% of the total film-forming material. It varies within a certain range according to the type and composition of powder coatings. In hydroxyalkylamide cured polyester powder coatings, Taking into account the effect of Anzongxiang on the yellowing of the coating film, its dosage is controlled at about 0.3% of the total amount of the film, and the amount used is as low as possible. SA500 from Jietongda Chemical Co., Ltd. is a synthetic wax-type smoothing and degassing agent that can replace benzoin. The dosage is about 1% of the total formula of powder coating. Other companies have similar products.
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