ULTRA LOW DENSITY THERMALLY CLAD MICROSPHERES

摘要

Microsphere beads are mixed with a surface barrier solid, liquid or mixture of such a liquid with a solid effective to prevent agglomeration and surface bonding of the microspheres. By controlling the application of heat and balancing temperature and active mixing, expansion of the microspheres to an ultra low density is achieved. Microsphere densities of as low as 0.005 to less than 0.015 g/cm³ are realized. The surface barrier material in the present invention may be selected from among a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, fillers, pigments, plasticizers, diluents, extenders, monomers and oligomers and the like.