US Patent 9138981 Water soluble ink-jet composition for 3D printing

The invention relates to a material composition, which may be a support material, for three-dimensional (3D) inkjet printing, comprising a glycol polymer, a low molecular weight polar substance and a surface active agent. The invention further provides a method for 3D inkjet printing comprising building a 3D object in layers, wherein at least one layer comprises a model material composition and a support material composition comprising PEG and a low molecular weight polar substance, wherein the layers are solidified before deposition of subsequent layers; and wherein, after solidification, the support material composition is removed by immersion of the solidified objet with the support in a liquid composition comprising a solvent.