Spray-dried phenolic adhesives

Abstract

A method of preparing a modified phenol-formaldehyde resin in solid particulate form comprising reacting together, in an aqueous medium, phenol and formaldehyde, in a ratio of 1.0 mole phenol to between 1.8 and 3.5 moles of formaldehyde, in the presence of between 0.1 and 1.0 moles of a basic catalyst; continuing this reaction until a desired viscosity is reached; modifying the reaction system by adding thereto between 0 and 30%, based on the weight of phenol originally taken of a non-phenolic polyhydroxy compound; spray drying the thus modified liquid resin in a pressure nozzle drier, and chilling the spray dried particulate solid. These solid resins are redispersible in water and stable on storage, compared to the known aqueous, equivalent, systems.

Dependencies are inferred from the claim text.