Water-based coating drying method – ultraviolet drying

For water-based coatings, UV curing can be used as a drying method. UV curing is a drying method in which the UV of a water-based coating is cured under UV irradiation at a wavelength of 300-400nm.

The water-based coating contains a small amount of photosensitizer. Under UV irradiation, the photosensitizer absorbs specific wavelengths of UV light and decomposes to produce active groups, which triggers the polymerization of film-forming substances to form a net-like structure and cures the coating. UV curing has the characteristics of fast curing speed and good quality of coating film. However. This method can only be used to deal with the coating of water-based coatings, and can only dry into a flat furniture finishing board pieces.

Good matting performance, low addition can produce strong matting performance. Micron-scale synthetic silica matting agent is a porous substance. Taking commercial silica aerogel as an example, one pore volume (the volume of micropores contained in 1g ) For a 1.6mL/g sample, its silica density is 2.1g/cm, that is, the silica volume of a lg sample is only 0.47mL, that is to say, a 1g sample with a volume of 2.07mL does not account for the total volume of solid matter. To 1/4. Quartz sand with the same chemical composition has a density of 2.7g/cm, the volume of 1g quartz sand is 0.37mL, and the volume of 1g of the above matting agent is 2.07mL, that is, under the same mass, the volume of the latter is 5.6 times that of quartz sand. The relationship between the pore volume of gel-type silica and the apparent volume of the particles.

It can be seen from the figure that the apparent volume of Type 770 matting agent with 1g pore volume of 0.44mL/g is 0.91mL, while the volume of Type 350 pore volume is 1.5mL/g and the apparent volume is 2.07mL, which is more than twice the former.

The extinction rate of the coating film surface is positively related to the number of effective extinction particles per unit surface. Under the same quality, the lighter the particles, the more the number of particles, ptfe wax polish the better the extinction effect. At present, the pore volume of the matting agent can reach 1.8 mL/g, or even 2.0 mL/g, and the matting performance is better.

It has good suspension in liquid coatings and will not produce hard precipitation for long-term storage. Because synthetic silica matting agent is a porous substance, its volume is several times larger than solid particles of the same quality, with large falling resistance and slow settling speed. After treatment with polymer wax, even if it settles, a soft precipitate is formed, which is easy to redisperse.

No pollution to the environment, no harm to the human body
The current important problem in the coatings industry is that there is still environmental pollution. The main component of synthetic silica matting agent is silica, which is the main substance constituting the earth’s crust and will not cause harm to the human body. Micron-sized quartz powder will cause silicosis (formerly known as silicosis, silicosis) in people who are in frequent contact with it. However, synthetic silica matting agent is an X-ray amorphous porous substance. A large number of domestic and foreign materials and work practices have proved that it is not People who often come into contact with it will suffer from silicosis (formerly known as silicosis or silicosis).