The present disclosure provides a method for coating a composite structure, comprising applying a single pretreating composition on a surface of the composite structure, the single pretreating composition comprising a first acid aluminum phosphate comprising a molar ratio of aluminum to phosphate between 1 to 2 and 1 to 3, and heating the composite structure to a first temperature sufficient to form an aluminum phosphate polymer layer on the composite structure.

Provided are methods of forming stacks comprising a substrate and one or more sol-gel layers disposed on the substrate. Also provided are stacks formed by these methods. The sol-gel layers in these stacks, especially outer layers, may have a porosity of less than 1% or even less than 0.5%. In some embodiments, these layers may have a surface roughness (R.sub.a) of less than 1 nanometers. The sol-gel layers may be formed using radiative curing and/or thermal curing at temperatures of between 400° C. and 700° C. or higher. These temperatures allow application of sol-gel layers on new types of substrates. A sol-gel solution, used to form these layers, may have colloidal nanoparticles with a size of less than 20 Angstroms on average. This small size and narrow size distribution is believed to control the porosity of the resulting sol-gel layers.

Nanocomposite anticorrosion coating can be achieved by depositing alternating, multilayers of a cross-linkable polymer and dispersed and aligned inorganic platelets followed by cross-linking of the cross-linkable polymer. The cross-linkable polymer can be an externally cross-linkable polymer that is cross-linked by diffusing a cross-linking agent into the deposited multilayer coating. Alternately, the cross-linkable polymer can be a functionalized cross-linkable polymer that is cross-linked by self-curing, thermal heat curing, or light (e.g., UV) following deposition of the multilayer coating.

A galvanized steel sheet is covered with an organic resin containing an anticorrosive additive that reduces galvanic current flowing between the zinc coating and the base steel sheet, to thereby considerably suppress intrusion of hydrogen into the steel sheet to prevent delayed fracture of the steel sheet.

The invention relates to a high temperature curable coating composition comprising: (a) at least one film-forming resin, (b) at least one crosslinker for the film-forming resin, wherein the crosslinker is not substantially reactive at temperatures under 120° C., and (c) an anticorrosive agent, which comprises a combination of a magnesium compound and a water-soluble Li salt. The invention further provides a method of coating a metal substrate and a coated metal substrate. The resulting coating has excellent anticorrosive properties without the use of Cr(VI) compounds, while being suitable for high temperature cure conditions typical in coil coatings.

A detoxification method for obtaining a pigment compound free from acute and chronic aquatic ecotoxicity by mixing at least one zinc-based component with good anti-corrosive properties but high toxicity-with a phosphate or hydrogen phosphate of a magnesium, sodium, potassium, calcium, strontium, aluminum, ammonium, or organic type or any other compound based on such cations, such as carbonates, oxides, silicates, phosphites, pyrophosphates or phosphonates, said phosphates or hydrogen carbonates or carbonates or oxides or silicates or phosphites or pyrophosphates freed from toxicity enabling a very considerable reduction of the toxic power of said zinc-based component, while maintaining the good anti-corrosive properties thereof.

Anticorrosive coating compositions as disclosed comprise a binding polymer and an aluminum phosphate corrosion inhibiting pigment dispersed therein. The coating composition comprises up to 25 percent by weight aluminum phosphate. The binding polymer can include solvent-borne polymers, water-borne polymers, solventless polymers, and combinations thereof. The aluminum phosphate is made by sol gel process of combining an aluminum salt with phosphoric acid and a base material. Aluminum phosphate colloidal particles are nanometer sized, and aggregate to form substantially spherical particles. The coating composition provides a controlled delivery of phosphate anions of 100 to 1,500 ppm, depending on post-formation treatment of the aluminum phosphate, and has a total solubles content of less than 1500 ppm, The amorphous aluminum phosphate is free of alkali metals and alkaline earth metals, and has a water adsorption potential of up to about 25 percent by weight water when present in a cured film.

Provided is a graphene-based aqueous coating suspension comprising multiple graphene sheets, particles of an anti-corrosive pigment or sacrificial metal, and a waterborne binder resin dissolved or dispersed in water, wherein the multiple graphene sheets contain single-layer or few-layer graphene sheets selected from a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 47% by weight of non-carbon elements wherein the non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof and wherein the coating suspension does not contain a silicate binder or microspheres dispersed therein. Also provided is an object or structure coated at least in part with such a coating.

Anisotropic zinc phosphate particles and zinc metal mixed phosphate particles having an orthorhombic crystal structure and a platelet-shaped particle morphology are obtained from a composition comprising at least one phosphate compound; at least one zinc compound and at least one chelate complexing agent having at least two oxygen-containing groups and at least one solvent.

A corrosion resistant article including an aluminum substrate and a corrosion-inhibiting cerium based corrosion inhibitor corrosion inhibiting additive on the aluminum substrate, the corrosion inhibiting additive comprising an anodic corrosion inhibitor and a cathodic corrosion inhibitor, the anodic corrosion inhibitor greater than 25 wt % of the total inhibitor.