Showing papers on "Sodium hypophosphite published in 1982"

Cathode for electrolyzing water and its manufacture

Abstract: PURPOSE:To obtain a cathode for electrolyzing water having remarkably lower hydrogen overvoltage than a conventional cathode during electrolysis as well as high mechanical strength by forming an iron plated layer contg. P on at least part of the surface of the substrate metal of a cathode. CONSTITUTION:A cathode for electrlyzing water is manufactured by forming an iron plated layer contg. P on at least part of the surface of a cathode body made of material such as iron, Ni or Ti which is used as the base material of a cathode in general. To an iron plating bath contg. water soluble iron salt by 0.1-1.7mol/l as ferrous ions are added 0;1-1mol/l hypophosphite ions such as sodium hypophosphite, and an ordinary water soluble buffer or a complexing agent is added preferably. This plating bath is adjusted to 1.5-9pH, and said cathode base material is plated at 20-90 deg.C and 2-20A/dm current density. It is desirable to prevent the oxidation of ferrous ions by carrying out the plating in a nonoexidizing atmosphere.

Process for sodium hypophosphite

Abstract: Either commercial yellow phosphorus or a phosphorus sludge is reacted with a slurry of calcium hydroxide in aqueous sodium hydroxide to form a sodium hypophosphite solution containing calcium and hydroxide ions. The solution is neutralized with phosphoric acid or an acid phosphate salt with the co-production of an insoluble calcium phosphate. The neutral solution is contacted with an ion exchange resin charged with sodium ions to remove any remaining calcium ions.

Metal-plating method of polyamide resin

Abstract: PURPOSE:To form a high-quality plating layer on polyamide resin, by etching the resin with a water solution containing a halogen compound and a surfactant, dipping the etched resin in an aqueous mineral acid solution, sensitizing and activating the resin, post-treating the resin in a water solution containing a reducing agent and then plating the treated resin. CONSTITUTION:Polyamide resin containing an inorganic filler is etched in a water solution containing a halogen compound selected from alkylene halohydrine and halogened aldehyde, a surfactant selected from a nonionic surfactant, tetramethyl ammonium chloride and tetraethyl ammonium chloride, and optionally aromatic sulfonic acid. The resin is then dipped in an aqueous mineral acid solution, and sensitized and activated by a known method. Thereafter, the resin is post-treated in a water solution containing a reducing agent such as hydrazine or sodium hypophosphite. The treated resin is electrolessly or electrically plated.

Nickel electroless plating method

Abstract: PURPOSE:To provide Ni electroless functional plating having excellent adhesion, by adding sodium saccharin or 1,5-naphthalene sodium disulfonate to a Ni plating liquid containing NaPH2O2 as a reducing agent. CONSTITUTION:In the Ni electroless plating method employing sodium hypophosphite (NaPH2O2) as a reducing agent, one or more compounds of sodium saccharin and 1,5-naphthalene sodium disulfonate are added to the plating liquid. This results in improvement in adhesion of the resulting plating coating. Therefore, even if a plating coating several tens mu thick is formed, the coating maintains a good condition so that it can be used as functional plating.

Duplicate die for information recording carrier

Abstract: PURPOSE:To increase the hardness of the surface layer of a stamper by using an alloy layer of nickel and phosphorus or boron by an electroless plating method as the surface layer. CONSTITUTION:On a mother 20, an electroless nickel-plating layer 21 is formed and on it, a nickel electroforming layer 22 is formed by an ordinary method, thus forming the mother 20 and electroless nickel-plating layer 22. Then, the mother 20 and eletroless nickel-plating layer 21 are peeled mutually to obtain a duplicate die consisting of the electroless nickel-plating layer 21 and nickel- electroforming layer 22, i.e. a stamper 23. A nickel electroless solution 2 generally consists of 20g/l nickel sulfate, 25g/l sodium hypophosphite, and 0.5g/l organic acid, and the dipping is carried out at 80 deg.C liquid temperature for 20min to form the electroless nickel-plating layer 21 with 10mum thickness. This is treated thermally to obtain 1,100 Vickers hardness.