Carbon steel substrates are protected from corrosive environments by a coating of nonconductive poly(aniline) which has been chemically prepared and cast onto the substrate from solution. The coating can also include other polymers which are miscible with the poly(aniline) but do not protonate it so as to make it conductive. Such polymers can include polyimides, epoxies, and urethane linked diisocyanates, among others. In these blends, a weight composition of at least 5% poly(aniline) to the other polymer is preferred. Overall, the nonconductive form of polyaniline has been found to be more effective in this service than the conductive form. Air oxidation of the poly(aniline) coating before exposure to a corrosive environment enhances the benefits.
The present invention relates to a corrosion resistant metal article which comprises: (a) a metal body normally prone to corrosion when subjected to potentially corrosive conditions; and (b) a coating of neutral, undoped polyaniline in the emeraldine base form on a portion of the metal body (e.g., a side coating or undercoating) of the neutral, undoped polyaniline in the emeraldine base form on the metal body, where the distance (for example, not more than about one centimeter) between coated and uncoated portions of the metal is effective to protect the uncoated portion of the metal as well as the coated portion.
The present invention relates to a corrosion resistant metal article which comprises: (a) a metal body normally prone to corrosion when subjected to potentially corrosive conditions, other than stainless steel or a metal similar to stainless steel; and (b) a neat coating of neutral, undoped polyaniline in the emeraldine base form on the metal body.
Corrosion resistance is provided for a power cylinder by providing a preloaded molded urethane elastomer sleeve liner within an outer cylinder of material such as a copper/nickel alloy which is subject to corrosion from long-term exposure to ambient fluids such as sea water. Preloading is preferably provided by thermal shrink fitting of the molded urethane sleeve liner to the inner bore of an outer metal cylinder. Preloading of a structure which has high structural integrity and low permeability thus effectively prevents incursion of fluids and gases at the interface between the outer cylinder and the sleeve liner as well as providing a surface which can be machined to a high degree of smoothness and against which reciprocating piston seals and wear assemblies can directly ride and which is resistant to abrasion therefrom even at high piston speeds.
The present invention relates to a corrosion resistant metal article which comprises: (a) a metal body normally prone to corrosion when subjected to potentially corrosive conditions, other than stainless steel or a metal similar to stainless steel; and (b) a neat coating of neutral, undoped polyaniline in the emeraldine base form on the metal body.
A two-component curable paint composition comprises a base component containing at least one curable resin, and a hardening component which contains a non-conducting polyaniline, and a liquid-phase or molten-phase curing agent capable of curing said curable resin of the resin component and capable of dissolving non-conducting polyaniline. According to the invention, the curing agent comprises an organic amine compound having at least two primary amine functions linked together by a hydrocarbon chain which is optionally interrupted by at least one heteroatom, said amine compound exhibiting irregularities in the chemical structure of its hydrocarbon chain. The invention also provides a method of preparing paint compositions, a method of forming a paint coating on the surface as well as a coated metal surface. The solutions produced by the invention are stable over extended periods of time, and the anti-corrosive erect of the paint compositions is good even at very low concentrations of the polyaniline.
