To provide a process for producing a fluoroolefin copolymer powder for powder coating material, which presents excellent stability of a fluoroolefin copolymer solution obtainable by polymerization in its production process, and which is capable of forming a cured film having an excellent appearance when used for a powder coating material. A monomer mixture comprising specific monomers is polymerized in an organic solvent in the presence of specific amounts of hydrotalcite and at least one compound (B) selected from a potassium salt, a sodium salt, a magnesium salt and a hindered amine-type light stabilizer, to obtain a suspension; an insoluble component is removed from the suspension to obtain a fluoroolefin copolymer solution having a pH of from 3.8 to 6.5 and an APHA value within a range of from 1 to 200; and the organic solvent is removed from the solution to obtain the fluoroolefin copolymer powder.

The present invention addresses the problem of providing a flame treatment device which is capable of performing a flame treatment on a metal-based base material without requiring a preheat treatment. For the purpose of solving the above-described problem, a flame treatment device according to the present invention comprises: a first temperature measurement unit which measures the temperature of a metal-based base material before a flame treatment; a control unit which determines the combustion energy of flame on the basis of the temperature before a flame treatment, said temperature having been measured by the first temperature measurement unit, so that the surface temperature of the metal-based base material during the flame treatment is 56° C. or higher; and a flame treatment unit which performs a flame treatment on the metal-based base material on the basis of the combustion energy, which has been determined by the control unit.

To provide a composition for powder coating material capable of forming a coating film having excellent water and oil repellency, capable of maintaining excellent water and oil repellency even when the surface is rubbed or when used in an environment in contact with water, and having excellent resistance to adhesion of organisms such that organisms such as mold, algae, etc. are less likely to adhere thereto; a powder coating material; and a coated article. The composition for powder coating material comprises polymer (A) composed of at least one member selected from polymer (A1) and polyvinylidene fluoride, and polymer (B). The polymer (A1) is a fluorinated non-block copolymer having units based on a fluoroolefin and units based on a monomer having a crosslinkable group. The polymer (B) is a fluorinated block copolymer having a segment (α) in which the content of fluorine atoms is at least 20 mass %, and a segment (β) in which the content of fluorine atoms is less than 20 mass %, wherein the difference in the numerical value of the content of the fluorine atoms represented by mass %, between in the segment (α) and in the segment (β) is at least 10, and at least one of the segment (α) and the segment (β) has a hydroxy group.

A surface treatment method for aluminum heat exchangers including (a) a step wherein a chemical conversion coating film is formed on the surface of an aluminum heat exchanger by subjecting the aluminum heat exchanger to chemical conversion using a chemical conversion agent; (b) a step wherein the aluminum heat exchanger, the surface of which has been provided with a chemical conversion coating film in step (a), is brought into contact with a hydrophilizing agent that contains a hydrophilic resin; and (c) a step wherein a hydrophilized coating film is formed on the surface of the aluminum heat exchanger by baking the aluminum heat exchanger, which has been subjected to a contact treatment in step (b). The chemical conversion agent used in step (a) contains zirconium and/or titanium in an amount of 5-5,000 ppm by mass in total, vanadium in an amount of 10-1,000 ppm by mass and a metal stabilizer in an amount of 5-5,000 ppm by mass. In addition, the chemical conversion agent used in step (a) has a pH of 2-6.

To provide a repairing method, by which a coated article having high adhesion between a PVDF coating film and a repair coating film and favorable processability of the repair coating film can be obtained, and a repaired coated article.

A method for repairing a first coating film, which comprises applying a second coating material (repairing coating material) to a position to be repaired of a first coating film (PVDF coating film) formed by applying a first coating material to the surface of a substrate, to form a second coating film (repair coating film) thereby to repair the first coating film,

wherein the first coating material is a powder coating material containing PVDF (A) and a resin (B), wherein the second coating material is a coating material containing a fluororesin (L) and a titanium oxide pigment (M), and wherein the content of the titanium oxide pigment (M) is from 15 to 190 parts by mass per 100 parts by mass of the fluororesin (L).

A modification method of a surface of a base includes applying a composition on a surface layer of a base to form a coating film. The surface layer contains a metal atom. The coating is heated. The composition contains a polymer and a solvent. The polymer includes at an end of a main chain or at an end of a side chain thereof, a functional group that is at least one selected from: a group represented by the following formula (1); a group containing a carbon-carbon triple bond; and a group containing an aromatic hydroxy group. In the formula (1), R.sup.1 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; and n is an integer of 1 to 10, wherein in a case in which n is no less than 2, a plurality of R.sup.1s are identical or different. ##STR00001##

Disclosed are a binder composition, a slurry composition, and a method of coating the surface of a metal with a superabsorbent polymer. Even when the slurry composition contains a large amount of the superabsorbent polymer, the low viscosity thereof can be maintained, thus enabling the uniform coating of the surface of the metal with the superabsorbent polymer. Also, even when a plurality of humidification-drying cycles is repeated in the coating process, no detachment occurs, and thus the superabsorbent polymer can be applied to various fields.

A compressor assembly may include a compressor housing and a compressor impeller disposed within the compressor housing. The compressor housing may have an internal aerodynamic surface that defines a circumferentially extending volute, and the compressor impeller may have an external aerodynamic surface that faces toward at least a portion of the internal aerodynamic surface of the compressor housing. A nonstick coating may be formed on the internal aerodynamic surface of the compressor housing or on the external aerodynamic surface of the compressor impeller. The nonstick coating may prevent foreign material introduced into the compressor assembly from collecting on the internal aerodynamic surface of the compressor housing or on the external aerodynamic surface of the compressor impeller.

The present invention provides a method for printing and coating a flexible substrate web so as to attain a specified coefficient of friction on both sides of the substrate web which employs the use of controlled set-off of coated and/or printed material from the front side to the back side side of the web. Furthermore the method provides a substrate web produced therefrom and the method is useful for packaging substrate webs and, in particular, foil substrate webs.

A process for the corrosion protection of metals such as magnesium, aluminium or titanium, where at least two steps are used, including both plasma electrolytic oxidation and chemical passivation. The combination of these two processing steps enhances the corrosion resistance performance of the surface beyond the capability of either of the steps in isolation, providing a more robust protection system. This process may be used as a corrosion protective coating in its own right, or as a protection-enhancing pre-treatment for top-coats such as powder coat or e-coat. When used without an additional top-coat, the treated parts can still retain electrical continuity with and adjoining metal parts. Advantages include reduced cost and higher productivity than traditional plasma-electrolytic oxidation systems, improved corrosion protection, greater coating robustness and electrical continuity.