Factors Affecting the Performance of Fluorocarbon Powder Coatings (Ⅰ)

Global Coatings Network News:

Table 1 The influence of resin on the storage stability of coatings

Figure 1 The curing reaction mechanism of thermosetting fluorine powder resin and blocked isocyanate 

Since the resin for fluorocarbon powder coating is a hydroxy resin, in order to control the resin to have a higher glass transition temperature during the preparation of the resin, the proportion of hard monomers is large, and the performance of the resin is higher in hardness.
At the same time, the hydroxyl value content has a great influence on the adhesion, pencil hardness, impact, bending and other mechanical properties of the coating film, as well as the resistance to chemical media.
As shown in Table 2: The influence of resin hydroxyl value on the mechanical properties of the coating film, Table 3 The influence of resin hydroxyl value on the chemical properties of the coating film:

Table 2 The influence of resin hydroxyl value on the mechanical properties of coating film 

It can be seen from Table 2 that the smaller the hydroxyl value of the resin, the better the flexibility of the paint film, the lower the surface hardness, and the better the mechanical properties.

Table 3 The influence of resin hydroxyl value on the chemical properties of coating film 

Note

1.
Ⅰ-Resin hydroxyl value, ≥45KOH/mg Ⅱ-Resin hydroxyl value, 45～30KOH/mg Ⅲ-Resin hydroxyl value, <30KOH/mg

2.
All samples are tested after being placed in a constant temperature and humidity room for 24 hours, and they are resistant to medium immersion for 30 days;

3.
A-coating film has no chalking, blistering, falling off, etc.
, B-coating film has chalking, blistering, falling off and other phenomena;

1- The color of the coating film does not change, 2- The coating film turns yellow slightly

4.
The artificial accelerated aging resistance is in accordance with the provisions of GB/T16585, using the fluorescent ultraviolet/condensation cycle test method, and the light source is a UV-B (313nm) tube.
The test conditions for each cycle are UV light, 60°C, 4h; condensation, 50°C, 4h.

It can be seen from Table 2 and Table 3 that when making fluorocarbon powder coatings, choosing a resin with a suitable hydroxyl value has a great impact on the coating.
At the same time, if a resin with a larger hydroxyl value is selected, the amount of curing agent will also be Significantly improved.
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