Posted by chriscase on Tuesday, May 03, 2005 at 6:40PM :
In Reply to: Hardness posted by CGarbee on Tuesday, May 03, 2005 at 9:01AM :
The binders will hold any size partical together. The smaller the partical, the denser it packs. Varying size will allow for MORE binder, not less....but maybe thats what they want? Since most particals are metal oxides and impervious to further degradation, it is the binders that oxidise, causing paints to age.
But, Googling for "Liquid Metals" and "Metgalic Glass" lately, I've learned that varying partical size prevents crystalization of alloys, making much for flexible and fracture resistant metals, so maybe there is some advantage in paints too?
Also, I know that water borne finishes are porous because water molecules fit between the 'large chains' of oil-based binder used in the water-based finishs. Maybe the random sized 'particals' refers to the size of the 'chains'?
so, who knows where the next chemical breakthrough will be?