Abstract: [PROBLEMS] The present invention provides a novel cleaner having bacteria-proof, fungi-proof and algae-proof effects, which is added to a reaction thermostat using water as medium in scientific apparatus, particularly a thermostatic water bath in an automatic analyzer. [SOUTLIN] A cleaner for a thermostatic water bath, which comprises a quaternary ammonium salt as shown by the general formula [1] described below and/or a preservative agent having amphoteric surface activity, and a surface active agent, wherein R1 to R4 independently represent an alkyl group, provided that at least one among R1 to R4 is an alkyl group having 8 to 18 carbon atoms, and at least one among them is a lower alkyl group having 1 to 3 carbon atoms; and X? represents an anion derived from a carboxylic acid having two or more carbon atoms; and a cleaning method of a thermostatic water bath, wherein the cleaner is added to a thermostatic water bath.

Abstract: A novel cleaner is disclosed, which is added to a reaction thermostat with water as medium in a scientific apparatus, particularly a thermostatic water bath in an automatic analyzer, and has becteria-proof, fungi-proof and algae-proof effects. The cleaner comprises a triazine derivative and a surface active agent. Furthermore, the cleaner preferably contains a compound represented by a formula [I]: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently represent a hydrogen atom, a methyl group or a hydroxymethyl group, and n is an integer of 1 to 5.

Abstract: A heat exchanger made of aluminum includes a plurality of tubes made of aluminum through which a fluid to be heat exchanged flows, the tubes having a metal surface of aluminum; fins made of aluminum arranged between the tubes for accelerating heat exchange between the fluid to be heat-exchanged and air, the fins having a metal surface of aluminum; a first protecting film of a chemical conversion coating formed on the metal surfaces of the tubes and fins and containing a metal component; and a second protecting film of an antimicrobial agent coating on the first protecting film, at least on the fins among the tubes and fins, the second protecting film having a chemical bond with the metal component of the first protecting film. An example of the antimicrobial agent is 2,2'-dithiobis(pyridine-1-oxide).

Abstract: An electrolytic processing method for electrolytically processing the surface of a metallic member. A paste containing an electrolyte is prepared by mixing a paste-forming agent with a liquid electrolyte. The paste is placed between the metallic member and an opposing electrode. The metallic member and the opposing electrode are connected to an electrical power supply so that an electrical current is made to flow between the metallic member and the opposing electrode through the paste containing electrolyte, whereby the surface of the metallic member is electrolytically processed. Descaling, passivity treatment, coloring, polishing, plating and other electrolytic process can be performed on any type of metallic member at any desired place, by suitably selecting factors such as the compositon of the paste, condition of the electrical power supply and so forth.

Abstract: A heat exchanger made of aluminum comprises a plurality of tubes made of aluminum through which a fluid to be heat exchanged flows, the tubes having a metal surface of aluminum; fins made of aluminum arranged between the tubes for accelerating heat exchange between the fluid to be heat-exchanged and air, the fins having a metal surface of aluminum; a first protecting film of a chemical conversion coating formed on the metal surfaces of the tubes and fins and containing a metal component; and a second protecting film of an antimicrobial agent coating on the first protecting film, at least on the fins among the tubes and fins, the second protecting film having a chemical bond with the metal component of the first protecting film. An example of the antimicrobial agent is 2,2'-dithiobis(pyridine-1-oxide).