A tin alloy electroplating bath, wherein the tin alloy electroplating bath includes (A) a soluble tin salt, (B) a soluble nickel salt and/or a soluble cobalt salt, (C) an oxycarboxylic acid or a salt thereof, (D) a nitrogen-containing heterocyclic unsaturated compound, and (E) a surfactant, and the pH of the tin alloy electroplating bath is 3 to 7.

An electroplated article includes a base member that includes one or more base member-metallic elements; and an electroplated layer that is formed directly on the base member. The electroplated layer includes at least a first electroplated layer-metallic element and a second electroplated layer-metallic element that is different from the first electroplated layer-metallic element. The second electroplated layer-metallic element is a metallic element that is identical to at least one of the one or more base member-metallic elements. A ratio of the second electroplated layer-metallic element in the electroplated layer is continuously decreased as being away from the base member in the thickness direction of the electroplated layer. Alloy grains including at least the first and second electroplated layer-metallic elements are distributed in the electroplated layer such that a clear interface is not formed between the base member and the electroplated layer.

An electroplated article includes a base member that includes one or more base member-metallic elements; and an electroplated layer that is formed directly on the base member. The electroplated layer includes at least a first electroplated layer-metallic element and a second electroplated layer-metallic element that is different from the first electroplated layer-metallic element. The second electroplated layer-metallic element is a metallic element that is identical to at least one of the one or more base member-metallic elements. A ratio of the second electroplated layer-metallic element in the electroplated layer is continuously decreased as being away from the base member in the thickness direction of the electroplated layer. Alloy grains including at least the first and second electroplated layer-metallic elements are distributed in the electroplated layer such that a clear interface is not formed between the base member and the electroplated layer.

What is provided is stannous oxide having an α-ray emission amount of 0.002 cph/cm.sup.2 or less after heating in an atmosphere at 100° C. for 6 hours. Tin containing lead as an impurity is dissolved in a sulfuric acid aqueous solution to prepare a tin sulfate aqueous solution, and lead sulfate is precipitated in the aqueous solution and removed. While stirring the tin sulfate aqueous solution from which lead sulfate has been removed, a lead nitrate aqueous solution containing lead having an α-ray emission amount of 10 cph/cm.sup.2 or less is added to cause lead sulfate to be precipitated in the tin sulfate aqueous solution, and simultaneously the tin sulfate aqueous solution is circulated while removing the lead sulfate from the aqueous solution. A neutralizing agent is added to the tin sulfate aqueous solution to collect stannous oxide.

The present invention provides an aqueous composition comprising tin ions and at least one compound of formula I wherein X.sub.1 is selected from a linear or branched C.sub.1-C.sub.12 alkanediyl, which may optionally be interrupted by O or S or a C.sub.5 to C.sub.12 aromatic moiety, R.sup.11 is a copolymer of ethylene oxide and a further C.sub.3 to C.sub.6 alkylene oxide, wherein the content of ethylene oxide is from 5 to 30% by weight, R.sup.12 is selected from H, R.sup.11, R.sup.40, R.sup.13, R.sup.14, are (a) independently selected from H, R.sup.11, R.sup.40, or (b) may together form a divalent group X.sup.13; X.sup.13 is selected from a linear or branched C.sub.1-C.sub.12 alkanediyl, which may optionally be interrupted by O, S or NR.sup.43; R.sup.40 is H or a linear or branched C.sub.1-C.sub.20 alkyl, R.sup.43 is selected from H, R.sup.11 and a linear or branched C.sub.1-C.sub.20 alkyl.

##STR00001##

The composition according to the present embodiment is a composition for forming a lubricant coating layer on a threaded connection for pipes or tubes, and contains Cr.sub.2O.sub.3, a metal soap, a wax and a basic metal salt of an aromatic organic acid. The threaded connection for pipes or tubes according to the present embodiment includes a pin and a box. The pin and the box each include a contact surface including a threaded portion. The threaded connection for pipes or tubes includes, as an outermost layer, a lubricant coating layer formed from the aforementioned composition on at least one of the contact surfaces of the pin and the box.

An anti-corrosion terminal material including a base material made of copper or copper alloy and a coating film laminated on the base material: the coating film includes: a first coating film, provided with a zinc layer made of zinc alloy and a tin layer made of tin or tin alloy which are laminated in this order, and formed at a planned core contact part; and a second coating film including the tin layer but not comprising the zinc layer, which is provided at a planned contact part being a contact part when the terminal is formed: and the zinc layer has a thickness not less than 0.1 μm and not more than 5.0 μm and zinc concentration not less than 30% by mass and not more than 95% by mass, and has any one or more of nickel, iron, manganese, molybdenum, cobalt, cadmium, lead and tin as a balance.

A plating solution containing a leveler is brought into contact with silica particles with an average particle diameter of 500 μm or less to remove impurities from the plating solution.

According to one embodiment, a wet-area device includes a main part, a first layer, and a second layer. The first layer is provided on an outer surface of the main part. The second layer is provided on an outer surface of the first layer. A hardness of the second layer is greater than a hardness of the first layer. The first layer includes a first unevenness at a side of the outer surface of the first layer. The first unevenness includes a plurality of recesses and a plurality of protrusions. The second layer includes a second unevenness at a side of an outer surface of the second layer. The second unevenness includes a plurality of recesses and a plurality of protrusions. The second unevenness is arranged along the first unevenness. An average height of the first unevenness is less than an average length of the first unevenness.

A tin alloy plating solution includes a soluble tin salt, a soluble salt of a metal more noble than tin, and a sulfide compound represented by General Formula (1). In the General Formula (1), (A) is a hydrocarbon group including no oxygen atom and having 1 to 2 carbon atoms, or (A) is a hydrocarbon group including one or more oxygen atoms and having 2 to 6 carbon atoms. The metal which is more noble than tin is preferably silver, copper, gold or bismuth.