Showing papers on "Sodium hypophosphite published in 1979"

Method for immersion deposition of tin and tin-lead alloys

Abstract: An aqueous bath useful in, and methods for, immersion plating of tin and tin-lead alloys which give greatly increased deposition rates and thicker coatings of better quality accomplished by incorporating into immersion plating tin bath compositions soluble plumbous salts in the amount from 0.5 grams per liter calculated on the basis of elemental lead to the maximum amount soluble in the bath and a sulphur-containing complexing agent for the tin and lead such as thiourea or a thiourea-type derivative; the bath solution contains stannous chloride, lead chloride, sodium hypophosphite (as a solubility enhancer) and with hydrochloric acid used as an agent for adjusting the pH in the resulting bath from 0.5 to 1.0.

Process for producing hypophosphorous acid (H3 PO2) and non-transition metal hypophosphites

Abstract: A process for producing hypophosphorous acid (H3 PO2) by reacting, in the absence of a catalyst and under an acidic condition, phosphine with an aqueous solution of hydrogen peroxide to produce an acid solution. The acid solution is then contacted with an non-transition metal hydroxide, oxide or carbonate, e.g. sodium hydroxide, to produce a product composition containing a hypophosphite, e.g. sodium hypophosphite (NaH2 PO2.H2 O). The process of this invention finds particular utility in processes of the type wherein phosphorus is reacted with an aqueous non-transition metal hydroxide composition, e.g. an aqueous suspension of a sodium hydroxide and calcium hydroxide, to produce a hypophosphite and byproduct phosphine. The process of this invention converts a substantial portion of the byproduct phosphine to hypophosphite.

Surface treatment of al and al alloy for soldering

Abstract: PURPOSE:To raise adhesion, corrosion resistance, and solderability by the procedure in which a pretreatment for plating is made, then Zn-replacement is made, then a nickel-phosphorus alloy plating is applied, and then a solderable copper plating is made. CONSTITUTION:In the first place, a part to be treated is cleansed with Trichlene, etched with 5% caustic soda at 40 deg.C for 10 sec., and then washed with water. Then, it is treated for smut removal with nitric acid at ordinary temperature for approx. 30 sec., and then dipped, after sufficient water washing, in a Zn-replacement solution at 15 to 25 deg.C for 1 min. to form Zn film and then washed with water. Then, it is treated with nitric acid for the removal of Zn film at ordinary temperature for 30 sec. and then washed with water and subsequently dipped in a solution containing 30 g/l nickel nitrate, 15 g/l sodium hypophosphite, and 10 g/l sodium citrate at 90 deg.C for 5 min. to form Ni film approx. 0.5 microns in thick with P crystals. Afterwards, it is washed with water and then coated with solderable Cu plating. Thus, the enhancement of adhesion, corrosion resistance, and solderability can be attained.

Method for producing graft copolymers of cellulose or protein fiber with vinyl monomers

Abstract: A method for obtaining graft copolymers of cellulose or protein fiber with vinyl monomers, comprising the steps of impregnating cellulose or protein fiber with an aqueous solution of ferrous salt, removing excessive ions of ferrous iron, and grafting vinyl monomers to cellulose or protein fiber from an aqueous solution, aqueous emulsion or aqueous dispersion of a vinyl monomer, containing hydrogen peroxide and a reducing agent. The latter is hydrazine sulfate, sodium sulfide, glucose, sodium hypophosphite, sodium bitartrate or hydroquinone taken in an amount of 0.002 to 0.02 percent by mass. The method provides for a high rate of graft polymerization and rules out the formation of a free homopolymer in the reaction mixture. It can be carried out as a continuous and batch process.

無電解ニッケル-鋼-リン合金めっきについて

Abstract: Electroless nickel-copper-phosphorus alloy platings from ammonia alkaline citrate bath (A-C bath) and caustic alkaline citrate bath (C-C bath) containing sodium hypophosphite as a reducing agent were investigated to determine the effect of copper ion concentration on the deposition rate, corrosion resistance and structure of the deposits. The basic bath composition was found to be: nickel sulfate +copper sulfate 0.1M, sodium hypophosphite 0.2M, sodium citrate 0.2M, pH10 (adjusted with NH4OH or NaOH); bath temperature was 80±2°C. The copper content in the nickel-copper deposits were found to be 0% to 44.5% in A-C bath and 0% to 69.0% in C-C bath, respectively, depending on the copper ion ratio in the plating bath. In A-C bath, the deposition rate increased considerably with the copper ion concentration in the bath, but in C-C bath, this effect was very small. The corrosion resistance of the deposits, containing 16.5% copper and 4.7% phosphorus, from A-C bath, and of the deposits containing 8.0% phosphorus, from C-C bath was excellent for a 0.5M sulfuric acid solution at 30°C.

Electroless nickel plating of metals, plastics, or ceramics - using periodically replenished bath kept an constant density

Abstract: The bath contains nickel salt, sodium citrate, NH4Cl, NH4OH, sodium hypophosphite, a water-soluble polyhydroxy benzene, and a copper salt, with an initial density of 1.075-1.116 g/cm3, esp. 1.099 g/cm3 which remains at this value during plating. The initial density is pref. achieved by adding Na2SO4 as a dummy salt, and during plating, part of the bath is automatically and periodically removed at short time intervals and replaced by a replenishing soln. (R) and water to keep the density at 1.099. For Ni coating of a metal substrate, the latter is pref. first exposed as a cathode to a voltage of 8-12V for 2-10 seconds. Used e.g. for small or large relay poles made of metal sheet, or for substrates with a complex shape.

Hydrogenation of oil and fat

Abstract: PURPOSE:The hydrogenation of oil and fat is effected by using a specific nickel- phosphorous compound as a catalyst to produce hydrogenated products having arbitrary SFI curves and no problem in respect of food sanitation. CONSTITUTION:Sodium hypophosphite (0.5-5 moles) is made to act on nickel hydroxide (1 mole) to form a nickel-phosphorous compound. Using the product as a catalyst are hydrogenated a raw material of oil or fat containing unsaturated fatty acids. For example, when a catalyst with a low proportion of the sodium hypophosphite is employed, the SFI curve of the product lies horizontally, resulting in the production of fat with wide plasticization range. Whereas, when a catalyst with the high proportion is used, the curve rises vertically, thus giving products with high content of trans isomers.