Unsaturated polyester coating active crosslinking agent

Unsaturated polyester coating active crosslinking agent

Unsaturated polyester coatings, commonly referred to as PE paint, are diluted by unsaturated diacid, saturated diacid and diglycol, and then diluted with active crosslinking agents.

Unsaturated polyester coating is mainly used in the construction of air spraying, electrostatic spraying, brush painting, spraying, etc. Adding cross-linking agent, promoter can rapidly at room temperature crosslinking, and can be used "wet touch wet process, the formation of the coating with high gloss, high hardness, good fullness, excellent chemical resistance and other properties, are widely used in instruments and high-grade furniture and other wood surfaces.

Unsaturated polyester coatings are interlinked in the presence of initiators and promoters, but this polymerization can be blocked in the presence of oxygen. Therefore, when the paint film is crosslinked in the air, it will always be crosslinked first, and the crosslinking will be hard, and the surface will be sticky due to contact with oxygen.

There are needle holes or pores like pores in the paint film. The aperture is about 100 mu m, and the piano industry is also known as the white spot. Causes:

High viscosity of paint construction;

The coating environment temperature is too low to dissolve the wax in the paint;

The wax of the wax is too high or added too much, and the wax quickly rises to the skin to stop the bubble from overflowing;

The gelation time is too fast;

The long period of intense stirring, mixing the paint into the air, the formation of numerous bubbles;

A film is too thick;

High environmental humidity or spraying equipment oil and water separator failure. Solution:

Adjust the paint to the proper construction viscosity, usually spraying the viscosity of 25 ~ 30s; The drizzle is 60 ~ 70s;

Coating cannot below 15 ℃ ambient temperature, when the temperature below 15 ℃, the coating must be in more than 30 ~ 40 ℃ placed 10 h, guarantee the coating of wax dissolved in full, to construction;

Adjusting the melting point and adding quantity of wax;

Adjust the amount of the crosslinking agent and the accelerant, extend the gel time, usually control the time of the fingers of the spray coating for 15 ~ 25min, and the touch drying time for each coating is 40 ~ 60min.

Follow the wall of the container and keep stirring in one direction;

Generally, the coating thickness of each layer is 100 ~ 125 mu m. The thickness of each layer is 250 ~ 350 mu m.

The humidity of the construction environment is no more than 75%, the spray air must be divided by oil and water by oil and water separator.




Chinese name: Diethyl toluene diamine(DETDA)

Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.

Density 1.022

Viscosity (20 ℃) ??mPa·ss290±10

Pour Point ℃-9

Boiling point of310°C

Flash Point°C161.1°C


grinding difference

Phenomenon: the main performance is in the paint film polishing, the sticky sandpaper phenomenon is serious.

Causes:

The crosslinking temperature is low or the crosslinking time is short, the crosslinking is not complete;

The crosslinking agent is small and the coating cannot be completely cross-linked.

The construction environment temperature is too high or relative humidity is too high, the wax is not floating, can not get the effect of avoiding oxygen;

The wax is low or added too little.

Solution:

Artifacts after coating, at least for 48 h under room temperature (25 ℃); Under the condition of low temperature, can improve the crosslinking temperature, in 38 ~ 45 ℃ heating at least 10 h, for grinding process;

The amount of acetone is 1% ~ 2%, and the amount of cyclohexanone is 2% ~ 4%. In the case of high temperature, the addition of crosslinking agent can not be reduced, and the inhibitor can be added appropriately.

Construction environment temperature < 38 ℃, when relative humidity > 75%, the advice is not construction or construction environment with dehumidifier;

Increase the amount of wax or increase the melting point of wax.

Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd 

Diethyl toluene diamine(DETDA)  http://www.yaruichem.com