Patent ID: 8167999

Claim:
A powder adapted for three-dimensional printing, the powder comprising: a loose, dry, and free-flowing particulate mixture comprising: a water-soluble adhesive; plaster; a plaster accelerator; a whitening agent selected from the group consisting of titanium dioxide, hollow glass spheres, and combinations thereof, and having a brightness L* of at least about 90 and a chroma C* of up to about 5.5; and a solid particulate additive comprising an acid, wherein (i) the particulate material is adapted for use in three-dimensional printing to form an article comprised of a plurality of layers, the layers including a reaction product of the particulate mixture and an aqueous fluid that contacts the particulate material during three-dimensional printing, and (ii) the acid has an acid ionization constant pKa selected from a range of about 1 to about 4 and an octanol-water coefficient K ow selected from a range of −1 to 0.5, thereby being adapted for retarding a polymerization rate of a cyanoacrylate infiltrant to facilitate penetration of the infiltrant into the article.