(57) A novel composite comprises a substrate having a coating matrix including an initial
layer of a perfluoropolymer and an overcoat comprising a fluoroelastomer, a fluoroplastic,
a fluoroelastomer/fluoroplastic blend, or a combination thereof. The perfluoropolymer
in the initial layer may be a perfluoroplastic, a perfluoroelastomer, or blends thereof.
In a separate embodiment; the novel composite includes a substrate coated solely with
one or more layers of perfluoroelastomer alone or as a blend with a perfluoroplastic.
Where the substrate is not susceptible to hydrogen fluoride corrosion,the composite
may include solely one or more layers of a blend of a fluoroelastomer and a hydrogen-containing
perfluoroplastic. Cross-linking accelerators may be used to cross-link one or more
of the resins contained in the coating layers. Each composite may be topcoated with
the layer or layers of a fluoroplastic, fluoroelastomer, and/or a blend thereof. The
composite is flexible, exhibits good matrix cohesion and possesses substantial adhesion
of the matrix to the material acting as the reinforcement or substrate. A method for
making such a composite comprises the unique deployment of a perfluoropolymer directly
onto the substrate in a relatively small amount sufficient to protect the substrate
from chemical corrosion without impairing flexibility, followed by the application
of the overcoat layer.
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