The use of polyamide wax in UV coatings, with the research and development of special functional coatings, the requirements for coating performance are getting higher and higher. Adding an anti-settling agent to the coating, that is, introducing a loose network thixotropic structure into the coating, can make the pigment and filler particles suspend without agglomeration, prevent the pigment from settling, improve the performance of the coating, and maintain excellent leveling, etc. . Many rheological additives have the functions of changing the rheological properties of coatings, anti-sag, anti-settling, and thickening. They can thicken and prevent sedimentation. Different from thickeners, they have good thixotropy. It has good fluidity and does not affect the processing and construction of coatings.
Polyamide wax anti-settling agent has good anti-sagging and anti-settling properties, and will not have adverse effects on UV paint film such as matting and film release. Polyamide wax needs to be activated into a paste-like thixotropic agent in a solvent in advance. Its swelling structure is network-like, and it has very good strength and heat resistance, good storage stability, and has excellent performance in uv coating system. Anti-settling effect, can improve the thixotropy of paint.
The mechanism and properties of polyamide wax:
When pigments or other fillers are added to the UV coating system, the solid particles will settle and agglomerate due to the action of gravity. The reason why polyamide wax can play the role of anti-settling is precisely because it can form a three-dimensional network structure in the entire coating system through intermolecular hydrogen bonds. This structure fixes and supports the solid particles. Thus, the sedimentation of solid particles is effectively prevented.
The effect of polyamide wax on paint film:
Polyamide wax anti-settling agent has obvious thickening effect and good anti-sagging effect, but the addition amount should be moderate, and it also has certain selectivity for different solvent systems and resin systems, and it will also affect the gloss and lubricity of the paint film. have a certain impact. Generally speaking, the addition amount of polyamide wax anti-settling agent is not more than 2%. Excessive amount will easily lead to a decrease in gloss of the paint film, which may be related to the size of the polyamide wax molecule.
During the drying process of the paint film, the concentration of polyamide wax molecules in the surface layer will be greater than that of the bulk part, and the polyamide wax molecules are much smaller than the polymer, which is easy to cause diffuse reflection of light, resulting in paint Film gloss decreased.
The influence of polyamide wax on the lubricity of uv paint film is mainly determined by the properties of polyamide wax itself and the system environment in which it is located. According to the slip-increasing mechanism, the lubricant often has poor compatibility with the polymer used in the coating. When the coating film is forming, the lubricant will float to the surface of the coating film and reduce the surface friction of the coating film. , protects the coating film and resists scratches.
Leave a message
We’ll get back to you soon