Sodium hypophosphite

About: Sodium hypophosphite is a research topic. Over the lifetime, 1695 publications have been published within this topic receiving 15932 citations.

The Mechanism of Electroless Nickel Deposition in Sodium Hypophosphite Bath

Abstract: The mechanism of electroless nickel deposition in sodium hypophosphite bath is discussed. It is assumed that the microscopic shape and ingredient homogeneousness of deposition depends on the local nickel effective content near the deposit surface and deposition front. It is suggested that the adoption of mixing complexions can lower the energy required by the homolysis of “H P” band, favorable to the growth of deposition by synusia like model. Small amount of rare earth element added in eletrolyte can enhance the depositing rates and corrosion resistant of deposition by increasing the number of the active spots in nickel surface and the rates of electron transfers in reaction.

Electroless tin plating of electric lamp leads - to permit easy machine soldering even after prolonged storage

Abstract: Wedge base electric lamps are made with current leads which can be machine soldered, the leads consisting of copper-clad wire with length is not >9 mm and having a coating of tin obtd. by electroless plating. The leads on the finished lamp are cleaned; dipped 1.5 hours in a bath (a) at 80-90 degrees C., contg. SnCl2. 2H2O; thiourea; HCl; sodium hypophosphite; a wetting agent; and deionised water. After rinsing, the leads are successively dipped in four baths (b-e), each consisting of glycerine contg. 0.3% ZnCl2 and used as follows:- (b) 30 seconds at 100 degrees C; (c) 20 seconds at 150 degrees C.; (d) 10 seconds at 200 degrees C.; (e) 5 seconds at 240 degrees C. The leads are then rinsed and dried. Machine soldering of the lamp leads is possible even after a storage time of 1 year, due to a pore-free tin coating of 3-4 mu m.

Pretreatment process for electroless copper plating on graphite powder surface

Abstract: The invention discloses a pretreatment process for electroless copper plating on the graphite powder surface. The method is as below: cleaning the dirt on the surface of graphite by using sodium hydroxide solution; conducting oxidation erosion on the graphite surface by using nitric acid solution with concentration higher than 90%, using distilled water for cleaning, and conducting vacuum filtration in the cleaning process; treating the graphite powder with stannous chloride solution with concentration of 50% to adsorb reductive colloid film on the graphite surface; reacting an oxidizing agent and a reducing agent to generate a simple substance palladium adsorbed on the surface of graphite particles, thus forming many nuclei on the surface of graphite particles; placing the graphite in a sodium hypophosphite solution with concentration of 40g / L, stirring at room temperature for 10 min, and conducting pumping filtration; and placing the graphite particles obtained from filtration in a vacuum drying box, and drying at the temperature of 85 DEG C. The processing method is simple, so that the surface of coppersurfaced graphite are easy to combine with metal atoms in copper plating solution.

Composite plating method

Abstract: PURPOSE: To obtain a composite plated film having a stable composition and a uniform thickness by dispersing insoluble fine particles in a plating soln. contg. Ni salt and hypophosphite and by applying a DC voltage between a body to be plated and an insoluble anode at a prescribed current density. CONSTITUTION: 20g/l Insoluble fine particles of silicon carbide or the like are dispersed in an aqueous soln. contg. 30g/l Ni salt and 25g/l sodium hypophosphite. A body to be plated and an insoluble anode are set in the soln., and a DC voltage is applied at 0.1W1A/dm 2 current density while agitating the soln. By this method a composite plated film having a stable composition, a uniform thickness, superior wear resistnace and lubricity is obtd. COPYRIGHT: (C)1982,JPO&Japio

High-concentration acrylamide water solution polymerization method

Abstract: The invention discloses a high-concentration acrylamide water solution polymerization method, and belongs to the field of polymer synthesis. According to the method, a water solution radical polymerization method is adopted, a C1-C5 organic solvent is used as a thermal removal solvent; a water-soluble azo compound serves as an initiating agent; sodium formate and sodium hypophosphite serves as a chain transfer agent; a polyacrylamide solution with a solid content of 70.1-79.3% and the molecular weight of 6,100-65,400 can be synthesized by performing a polymerization reaction on the thermal removal solvent, the chain transfer agent and the initiating agent at 45-56 DEG C and adjusting the amounts of the thermal removal solvent, the chain transfer agent and the initiating agent. The polyacrylamide synthesized by the method has the advantages of being high in solid content, high in dilution speed and the like, and is suitable for a high-molecular emulsifier, a dispersant, a binding agent, a tackifier, a paper reinforcing agent, a textile dye printing additive and the like.