The usage of rheological additive for water based system
(1) BK rheological additive for water based system neither need to produce pre-gel nor add activator ,For example the process of BK-887 dry powder addition directly in emulsion coatings is as follows:
a.Water (PH 6-12 but the best is PH7-8)
b.BK-887 (high speed disperse 15-30min.)
c.Additive (coalescent, dispersant, defoaming agent, antiseptic)
d.Pigment(mix and disperse)
f.Dilute to the needed viscosity
These series of bentonite dosage usually take 0.2-1% of the total system or according to your test request.
(2) Main points attention:
a.BK-887 need to be dispersed under high speed shear to exert the thickening efficiency, otherwise, the hydration may be delayed and cause post thickening.
b.Too high PH value may cause hydration act too quickly and too low PH value will reduce rheology property.
c. Surfatcant,duality alcohol will interfere the hydration effect. So they should be added after dispersion for BK-887 finished
d. BK-887 can be used separately or used combine with other acrylic thickening agent. In order to achieve the best rheological property , recommend to use acrylic thickening agent from Rodia CR company and acrylic thickening agent from Union Carbide PP102 company to adjust the shear viscosity and rheology property.
After experiment, we found that BK-887 should avoid to be combined used with PU thickener.