摘要:
A multistage method for treatment of composite metal structures containing metallic surfaces of aluminum, zinc and optionally iron, is provide wherein in a first step, selective zinc phosphating of zinc and ferrous surfaces proceeds using a phosphating solution containing a quantity of water-soluble inorganic silicon compounds sufficient to suppress white spot formation on zinc, but less than the quantity where zinc phosphating loses selectivity. In a following second step, aluminum surfaces are passivated with an acidic treatment solution. Also provided is a zinc phosphating solution suitable for said method containing at least 0.025 g/l, but less than 1 g/l of silicon as water-soluble inorganic compounds calculated as SiF6, wherein the product (Si/mM)·(F/mM) of the concentration of silicon [Si in mM] in the form of water-soluble inorganic compounds and the concentration of free fluoride [F in mM] divided by the free acid point number is no greater than 5.
摘要:
A method for treating or pre-treating parts, profiled-pieces, strips, sheet metals or wires having metallic surfaces, in which at least 5% of these surfaces consists of aluminum or of at least one aluminum alloy with an acid aqueous solution which contains fluoride, zinc and phosphate and which has the following dissolved contents in the phosphatizing solution: sodium virtually none, from 0.04 to less than 2 g/L; potassium virtually none or in a concentration ranging from 0.025 to 2.5 g/L; sodium and potassium in a concentration ranging from 0.025 to 2.5 g/L as sodium, whereby the potassium content is converted to sodium on a molar basis; zinc 0.2 to 4 g/L zinc, 5 to 65 g/L calculated as PO4; 0.03 to 0.5 g/L phosphate free fluoride wherein the total fluoride is present in a concentration ranging from 0.1 to 5 g/L. A zinc-containing phosphate layer is thereby deposited onto the metallic surfaces with a layer weight ranging from 0.5 to 10 g/m2.
摘要:
Metal surfaces are treated with acidic aqueous compositions to form conversion coatings. The acidic aqueous compositions contain fluorometallate anions, divalent and/or trivalent cations of certain elements such as zinc, phosphorus-containing inorganic oxyanions, phosphonate anions containing phosphorus atoms directly bonded to carbon atoms, and water-soluble and/or water-dispersible organic polymers and/or polymer-forming resins.
摘要:
This invention is directed to the synthesis of double-stranded conducting polymers, formulation for surface treatment reagents, and the use of water-borne double-stranded conducting polymers. The double-stranded conducting polymer provides a unique flexibility in designing molecules for surface treatment. The compositions can be used to treat metal surfaces to provide a stable interface for adhesive binding or the coating of paint or plastics on top of the chemically modified surface. The composition is useful as a replacement of chromate-based surface treatment process.
摘要:
An aqueous solution and method for applying the solution to a metal surface form a zinc phosphate coating on the metal surface. The zinc phosphate coating minimizes corrosion and improves adhesion of subsequently coated materials such as sealants and paints. The solution of the composition and method of application consume free acidity otherwise left on the metal surface, and obviate the need for subsequent rinsing or extensive drying or stoving operations. The composition includes an aqueous solution including water, zinc dihydrogen phosphate, phosphoric acid, a polyhydric polymer, a metal salt, and optionally, a fluoride.
摘要:
A process for phosphating metal surfaces by treatment with an acidic zinc- and phosphathe-containing solution which does not require rinsing. The metal substrate is contacted with a phosphating solution containing 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 g/l of phosphate ions. The solution has a pH value of 1 to 3.6, a free acid content of 0 to 100 points, a total acid content of 40 to 400 points and a ratio of free acid to total acid of 1:4 to 1:20.
摘要:
To prevent the deterioration in water-resistant secondary adherence that occurs during prolonged use of a fluoride-containing phosphate conversion coating liquid composition to form a conversion coating on metal surfaces that are at least partly aluminiferous, the aluminum compound-containing sludge produced in the phosphate conversion coating liquid composition as it is used is coagulated and sedimented by adding at least one cationic polymeric coagulant to the sludge-containing phosphate conversion coating liquid composition.
摘要:
To treat an iron-based, zinc-based, and an aluminumbased surfaces etc. with zinc phosphate using the same solution, a treating solution is adjusted in concentrations so as to contain a simple fluoride in a range of 200.about.500 mg/l upon converting into a HF concentration and to contain a fluoride complex in a range shown in the following formula; ##EQU1## and also, it is adjusted in an active fluorine concentration so as to be 15.about.130 .mu.A at a value indicated by a silicon electrode meter. Instead of such adjusting, aluminum ions in the treating solution is precipitated in an outside of a treating bath to separate them from the treating solution and then, this treating solution may be returned in to the treating bath.
摘要:
A method for treating a metal surface with zinc phosphate of this invention can treat an iron-based surface, a zinc-based surface, an aluminum-based surface as well as a metal surface having two kinds or more of these surfaces with the same zinc phosphate treating solution, and even if treating times increases, the method makes it possible to form a coating film having superior adhesion and high corrosion resistance under a stable condition, and also, it prevents a precipitate formed by a metal ion eluted from a metal surface to be treated, especially, by an aluminum ion. A complex fluoride compound contained in said zinc phosphate treating solution of coming in contact with a metal surface is added so that a concentration (unit: g/l) converted into at least one of a hexafluorosilicic acid group (SiF.sub.6.sup.2-) and a tetrafluoroboric acid group (BF.sub.4.sup.-), with an aluminum ion concentration (unit: g/l) contained in said treating solution, is satisfactory for the following equation (I). ##EQU1##
摘要:
An aqueous acidic zinc phosphate coating composition for treating a metal surface to provide a conversion coating thereon, the composition comprising chlorate anion and an aromatic nitro anion in a weight ratio of less than 2:1 to about 1:10.