A fluorochemical additive is the reaction product under polymerization
conditions of monomers that include: (a) an aromatic polycarboxylic acid
as an anhydride, ester, or ester chloride; (b) at least one fluorinated
reactant; and (c) at least one aliphatic amine, mercaptan, or alcohol.
Optionally, a crosslinking agent can be used. The components of the
additive all can be viewed as contributing to the performance of the
disclosed additive. The fluorine-containing component is generally
insoluble in molten polymers and will tend to migrate to the cooled
surface thereof where the fluorinated moieties provide repellency
characteristics when used in adequate quantities, generally at least
about 30 wt % depending on the fluorinated reactant used to make the
additive. The aromatic component appears to facilitate solubility and
speed up the orientation process of the additive within the molten
polymer. The aliphatic component to the reaction mixture appears to
assist in anchoring the reaction product additive in the bulk polymer
structure. Together, the components form a fluorinated reaction product
additive that can be added to a molten polymer for integration into the
resulting product to impart improved resistance to oil, water, and
alcohol.