Matting agent for polyurethane T-335

T-335 is a new generation of anti-yellowing matting agent based on resin and cured with epoxy part, its curing ratio with epoxy is about excess epoxy/T-335=2~2.5/1, used in epoxy/polyester hybrid powder coatings, can provide gloss more than 3% matting. Compared with the traditional indoor anti-yellowing matting agent, its characteristics are: storage stability, compatibility, gloss stability, etc. have greatly improved.

Appearance: light yellow powder
Melting process temperature: 100～120℃
Volatile matter：≤ 1.5%
Heap density：500～600g/l

Pigment sedimentation
The pigment particles in the pigment dispersion system are in a state of non-stop motion, and the speed of motion is affected by many factors such as particle size, shape, density, and degree of flocculation.
In an infinitely expanding Newtonian fluid dispersion system, carnauba wax food additive the sedimentation velocity of a single spherical particle can be calculated by the Stokes formula.

2a*(o mpg(2-6)
9n
In the formula, Ug—the terminal speed of constant velocity motion;
a- the radius of a particle;
P-the density of the dispersed phase;
p°-the density of the dispersion medium:
Acceleration of gravity

Viscosity.
Kresse simplified the Stokes formula to (2-7) 21,
v=(pp)a²(2-7) This formula can be used to discuss the effect of particle size in the design formula on the floating color, and the tendency of pigment floating color can be grasped in advance to help overcome it, such as using alkyd resin, TiO and Fc zO, Light red paint.
Alkyd resin density 0.95g/em
TiO g density 4.20g/cm”, fineness 0.25um
Fe: Os density 5.00g/cml, fineness 0.05gm
Settling velocity of Ti Oz (4.2-0.95)×0.25²=0.2
Fe gO: the sedimentation velocity (5-0.95) × 0.05-0.01