摘要:
A coating composition comprising an aqueous mixture containing acid-stable particles and one or more fluoroacids. The amount of the acid-stable particles in the coating composition is from 0.005% to 8% by weight on a dry weight basis. The acid-stable particles can be selected from aluminum-modified silica particles, nonaluminum-modified silica particles, and organic particles selected from anionically stabilized polymer dispersion particles. The invention is also directed to a coating on a metal substrate. The coating contains acid-stable particles attached to the metal substrate through a metal-oxide matrix. The metal-oxide matrix comprises a metal selected from titanium, zirconium, silicon, hafnium, boron, aluminum, germanium, or tin.
摘要:
A method and apparatus are described for removing iron cations and/or zinc cations from an autodeposition coating bath by passing a limited number of bed volumes through a column containing a gel type SAC IEX resin when iron cations are to be removed and passing a substantially larger number of bed volumes through the column when zinc cations are to be removed. To prevent clogging when zinc cations are being removed the direction of the flow through the column is periodically reversed.
摘要:
An aqueous, acidic zincating composition comprising: zinc cations; fluoride anions; and a carboxylic acid having at least one additional —OH substituent is provided that is useful in a process of making a corrosion resistant article comprising contacting an article having an aluminum surface with the zincating composition and thereafter coating the article with an autodeposition coating.
摘要:
Autodeposition compositions for polymeric coatings of reduced gloss, good corrosion resistance, and uniform appearance are prepared using a combination of acrylic and epoxy resins.
摘要:
Method for preventing the formation of coating defects in polymeric coated surfaces in a coating process comprising a plurality of steps that occur prior to the polymeric coating of said surfaces and that contact organic and metal surfaces with a plurality of aqueous compositions in which accumulate in suspension resin particles released from said metal surfaces. Suspended resin particles are prevented from re-depositing on the organic surfaces by converting said surfaces to hydrophilic character by means of oxidizing said surfaces prior to contacting the oxidized surfaces with said suspensions.
摘要:
Heavy metals are removed from paint chips by leaching with an aqueous acid. Heavy metals are also efficiently removed from contaminated soil by a process which comprises leaching or washing the soil with a mild leachant solution comprised of an aqueous solution of an acid and a salt. The heavy metals are recovered from the leachant by cementation.
摘要:
The present invention relates to an aqueous alkaline composition (A) for alkaline passivation of metallic components comprising at least in part surfaces of zinc or zinc alloys, containing iron(III) ions, phosphate ions, and one or more complexing agents, where a free alkalinity ranges from 1 to 6 points, and the pH is at least 11. The aqueous compositions (A) can additionally contain nonionic surfactants, so that such compositions are suitable for use in a method in which both cleaning and alkaline passivation of the metallic component occur in one step. The present invention further relates to a method for alkaline passivation of metallic components by contacting them with composition (A), and further a method for surface treatment in automobile body production, in which the alkaline passivation step using composition (A) is followed by an acid passivation step using a composition (B).
摘要:
The invention relates to an acidic, aqueous, chromium-free composition (A) for the anti-corrosive treatment of steel and/or galvanized steel surfaces comprising metal ions (M) selected from ions at least of the elements nickel, cobalt, molybdenum, iron or tin and a multi-stage method applying the composition (A) for the anti-corrosive pre-treatment of metal components which have steel and/or galvanized steel surfaces. The invention further relates to metal surfaces of zinc or iron having a passive layer system comprising at least 30 mg/m2 nickel and at least 10 mg/m2 zircon, titanium and/or hafnium and sulfur, wherein nickel is present in metallic form at up to at least 30 At. %, obtainable in a method according to the invention.
摘要:
Many prior art processes for cleaning predominantly organic hard surfaces have been found to be considerably less effective in removing very fine particles on such surfaces than are the best cleaners for metallic surfaces. However, it has been found, and forms the basis of this invention, that fine particles can be removed effectively from organic surfaces by an indirect process of first forming a thin solid coating over the surface and then removing the solid coating, into which the fine particles that formerly contaminated the surface to be cleaned have presumably become incorporated. Substantially hydrolyzed poly(vinyl acetate) has been found particularly useful for forming the thin solid coating when this coating is to be removed by treatment with an acidic aqueous solution; acrylate polymers are preferred if the solid coating is to be removed by an alkaline aqueous solution. In either instance, in order to obtain good wetting without damaging the surface to be cleaned, the material that forms the bulk of the solid coating is preferably applied to the surface to be cleaned in an aqueous solution or dispersion that also contains surfactant molecules that include imidazoline moieties. A method of quantifying the degree of removal of solid particles is also provided.
摘要:
A film of a polymer or polymer precursor such as an epoxy resin is autodeposited on an active metal surface and then used to form an adhesive bond directly between the metal surface and the surface of a rubber substrate. Excellent adhesion of the metal to the rubber is obtained without the need to either phosphate the metal surface or use a primer or adhesive other than the autodeposited coating.