The flow properties of the coating colors containing polyvinyl alcohol (PVA) derivatives, such as carboxymethylated PVA (CMP), phosphated PVA (PP), cyanoethylated PVA (CEP) and acrylamidemethylated PVA (AAMP), were studied at shear rate up to 1.5 × 10
5 sec
-1 in a high pressure capillary viscometer and a IGT printability tester.
It was found that the flow properties of the coating colors were modified considerably by using the PVA derivatives. Particularly, CMP and PP gave the colors excellent flow properties.
It was also found that the covering capacity of the coating colors was improved markedly by using CMP and PP, and almost no “orange peel” pattern or ridges on the coated surface was observed.
At such high shear rates, the coating colors made with the anionic PVA such as CMP and PP had better flow properties than those containing the nonionic PVA such as unsubstituted PVA, CEP and AAMP.
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