A surface treatment method capable of imparting exceptional corrosion resistance and moisture resistance to an NB heat exchanger. The method includes subjecting an NB heat exchanger to a chemical conversion treatment to form a chemical conversion film on the surface thereof using a chemical conversion treatment agent that contains zirconium and/or titanium in a total amount of 5-5,000 ppm by weight, vanadium in an amount of 10-1,000 ppm by weight, and has a pH of 2-6; bringing the NB heat exchanger on whose surface the chemical conversion film is formed into contact with a hydrophilization agent containing a hydrophilic resin and a guanidine compound and/or a salt thereof; and baking the NB heat exchanger subjected to the contacting process, whereby a hydrophilic film is formed on the surface thereof.

An object of the invention is to provide a fishhook for fishing or the like, the fishhook being easily stuck to a fish or the like and being also excellent in durability. The surface of a fishhook is treated with a compound selected from the group consisting of a metallic surfactant having at least one or more hydroxyl groups or hydrolyzable groups, a fluorine-based surface treating agent, a thiol compound and a disulfide compound.

Provided is a surface treatment solution composition comprising: 30 to 51 wt % of a trivalent chromium compound comprising chromium phosphate (A) and chromium nitrate (B) and having a content ratio of A/(A+B) that satisfies 0.3 to 0.6; 5 to 15 wt % of silane coupling agent; 0.2 to 3 wt % of vanadium-based anti-corrosive rust inhibitor; 3 to 12 wt % of colloidal silica; 0.5 to 5 wt % of polysiloxane copolymer; and 14 to 61.3 wt % of water, a hot dip galvanized steel sheet surface-treated using same, and a manufacturing method thereof. The hot dip galvanized steel sheet treated with the surface treatment solution composition containing trivalent chromium has an excellent corrosion resistance, blackening resistance, pipe-forming oil reactivity, and alkali resistance.

An embodiment of the present invention includes: an electrical steel sheet substrate; and an insulating coating on one or both surfaces of the electrical steel sheet substrate, wherein the insulating coating includes a silane compound and a metal hydroxide.

Disclosed is a copper foil including a copper layer and an anticorrosive layer disposed on the copper layer, wherein the copper foil has a peak to arithmetic mean roughness (PAR) of 0.8 to 12.5, a tensile strength of 29 to 58 kgf/mm.sup.2, and a weight deviation of 3% or less, wherein the PAR is calculated in accordance with the following Equation 1:
PAR=Rp/Ra  [Equation 1] wherein Rp is a maximum profile peak height and Ra is an arithmetic mean roughness.

This disclosure relates to a method for obtaining superhydrophobic corrosion-resistant coatings. State-of-the-art approaches involve etching methods with elevated temperatures and/or longer duration which are complex and use high concentration of combination of acids, alkali, and salt solutions in etching process to obtain a roughness which makes it difficult to handle usage of chemicals and controlling process. The method of the present disclosure has addressed this issue by selection of optimum concentrations of combinations of one or more type of acids, oxidizing agents which are safe, easy to handle and provide better control over the process. The method of the present disclosure is easy, inexpensive, and environmentally friendly. The superhydrophobic corrosion-resistant coatings possess water contact angles greater than 151° and coating efficiency more than 85 percent arrived at by using corrosion currents from polarization studies.

The present invention relates to an acidic aqueous composition for coating metallic surfaces, particularly of aluminium materials, that comprises, besides water and optionally further components, a) at least one compound selected from the group consisting of organoalkoxysilanes, organosilanols, polyorganosilanols, organosiloxanes and polyorganosiloxanes, b) at least one compound selected from the group consisting of titanium, zirconium, hafnium and aluminium compounds and silicon complex fluoride, and c) at least one copolymer which is stable at least in a segment of the pH range below 6 and which comprises, in alternating configuration, monomer units containing at least one carboxylic and/or phosphonic acid group and monomer units containing no acid group. The invention further relates to a corresponding coating method and to the use of the substrates coated by this method.

Provided is a solution composition for steel sheet surface treatment, comprising 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; and 27.3 wt % to 64.2 wt % of water, a zinc-based plated steel sheet surface-treated with the same, and a manufacturing method therefor, the zinc-based plated steel sheet surface-treated with the solution composition for steel sheet surface treatment containing trivalent chromium may have an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, oil resistance, and alkali resistance.

Described herein is a water-based, alkaline cleaner concentrate for producing a cleaner for metallic surfaces, the concentrate including a) at least one (meth)acrylic acid homopolymer having a weight-average molar mass in the range from 3 000 to 19 000 g/mol and b) at least one (meth)acrylic acid copolymer having a weight-average molar mass in the range from 50 000 to 100 000 g/mol. Also described herein are a corresponding cleaner for metallic surfaces with reduced pickling erosion, a process for anticorrosive treatment of metallic surfaces that includes a corresponding cleaning step, a metallic surface obtained by the process, and a method of use thereof in the sector of the metalworking industries.

A layered tetravalent metal phosphate composition (e.g., a layered zirconium phosphate composition) and a first corrosion inhibitor (e.g., cerium (III), a vanadate, a molybdate, a tungstate, a manganous, a manganate, a permanganate, an aluminate, a phosphonate, a thiazole, a triazole, and/or an imidazole) is dispersed in an aqueous solution and stirred to form a first solution. A precipitate of the first solution is collected and washed to form a first corrosion inhibiting material (CIM), which includes the first corrosion inhibitor intercalated in the layered tetravalent metal phosphate composition. The first CIM is added to a first sol-gel composition to form a first CIM-containing sol-gel composition. The first CIM-containing sol-gel composition is applied on a substrate to form a CIM-containing sol-gel layer, cured by UV radiation, and thermally cured to form a corrosion-resistant coating. One or more additional sol-gel composition may be applied on the substrate.