| 摘要 |
The invention provides for sprayable powder comprising friable granules of agglomerated primary particles of non-fibrillatable fluoropolymer and, optionally, at least one other component, the powder having a bulk density of at least 20 g/100 cc and average particle size of 5 to 100 micrometers. The sprayable powder is preferably free of water immiscible liquid, and more preferably free of halocarbon liquid. Included among the other components are inorganic fillers, pigments, high temperature resistant polymer binders. In another embodiment, the invention provides for a sprayable powder comprising friable granules of agglomerated primary particles of a first non-fibrillatable fluoropolymer and at least one other non-fibrillatable component. The invention further provides for a process for preparing the sprayable powder by spray drying a liquid dispersion. In a preferred embodiment, the process includes densifying the granules of agglomerated primary particles that result from spray drying. Densifying may be carried out by mechanical compaction or by contacting the granules with a heated gas to form a fluidized bed. Optional steps of comminution and heat treatment may be employed to achieve a desired bulk density and particle size for specific applications. |
