Cookware coated with fluoropolymers, especially polytetrafluoroethylene (PTFE), has come into widespread use in recent years. Many cooks prefer to use such cookware because of its non-stick properties and because it is so easy to clean.
While cookware of this type is quite durable, the fluoropolymer coating tends to become scratched after extended use because it is somewhat softer than the utensils used to stir and turn the food in the ware.
Fluoropolymer compositions which contain mica particles, mica particles coated with pigment, or metal flake, give fluoropolymer finishes of this general type having improved scratch resistance. This improved scratch resistance is actual and can be measured physically with instruments. However, the apparent scratch resistance, that which is perceived by the user of the cookware, may not be as high as the actual scratch resistance because food lodges in the slight scratches which may be present and becomes oxidized. These scratches become highlighted because of the high optical contrast between the finish and the oxidized food, and are therefore much more noticeable than they would ordinarily be.
USPTO Backgrounds
USPTO Backgrounds