| abstract |
The present invention relates to a resin which can be prepared by reacting a phenol/formaldehyde phenolic resin with tetraethyl orthophthalate in a mass ratio of more than 28:1, wherein the phenol in the phenol/formaldehyde phenolic resin is substituted or Unsubstituted hydroxybenzene or a mixture of two or more of these phenols; and with respect to a particulate material coated with the resin. The particles can be used, for example, in a shell casting process to make a shell mold and a shell core, and can be used as a proppant in a hydraulic fracture process. |