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AssigneeGeorgia-Pacific Chemicals LLC
InventorsPeter C. Boyer, Jeffrey L. Mills
Estimating the term…
Storage stable aqueous dispersions of a heat-reactive hydrophilic phenolic resin (e.g., phenol/formaldehyde) are disclosed. The dispersions comprise a base resin that is the reaction product of an aromatic alcohol and an aldehyde, and an etherified resin component selected from the group consisting of an etherified phenol/aldehyde resin, an etherified cresol/aldehyde resin, and mixtures thereof. The dispersions further comprise a protective colloid (e.g., polyvinyl alcohol). The addition of the etherified resin component in an amount of at least about 20% by weight of the base resin provides storage stability, but does not adversely affect the desirable physical and chemical characteristics (e.g., chemical resistance) of end products made from such dispersions. Moreover, the dispersions of the present invention can avoid the use of etherified resin components derived from bisphenol-A and/or xylenols, which present heath concerns in food coating applications.
A storage stable aqueous dispersion of a phenolic resin, said dispersion comprising:
A method for making a storage stable aqueous dispersion of a phenolic resin, said method comprising blending, at a blending temperature of less than about 60° C., (a) a heat-reactive, non-etherified hydrophilic phenolic base resin that is the reaction product of phenol and formaldehyde, and (b) an etherified resin component selected from the group consisting of an etherified phenol/aldehyde resin, an etherified cresol/aldehyde resin, an etherified phenol/cresol/aldehyde resin, and mixtures thereof, wherein said etherified resin component is present in an amount of at least about 20% by weight of said base resin, to form a resin mixture and forming the storage stable aqueous dispersion by mixing the resin mixture with (c) a protective colloid, so that the aqueous dispersion remains visually homogeneous by not exhibiting any separation, settling, foaming, coalescence or agglomeration of a dispersed phase for at least about 3 months.
Dependencies are inferred from the claim text.