Abstract: Novel surface active agents in the form of compounds of formulas (I) and (II) show higher surface activity. ##STR1## R.sup.1 and R.sup.2 are alkyl or alkenyl groups having 6 to 20 carbon atoms, Z is H, SO.sub.3 H, PO(OH).sub.2, CH.sub.2 COOH, (CH.sub.2).sub.2 SO.sub.3 H or a salt thereof, R.sup.3 and R.sup.4 are alkyl or alkenyl groups having 5 to 19 carbon atoms, R.sup.5 and R.sup.6 are alkyl groups having 1 to 4 carbon atoms, and n is a number of from 1 to 20.

Abstract: A method for continuously electro-tinplating a metallic material comprising the steps of: using an acidic electro-tinplating solution containing phenolsulfonic acid or a salt thereof and tin ion, using an insoluble anode, and causing a DC electric current to flow between the insoluble anode and a metallic material, while replenishing the acidic electro-tinplating solution with tin ion, thereby forming a tinplating layer on the surface of the metallic material. The above-mentioned anode comprises an electric-conductive substrate, and a film comprising at least iridium oxide, formed on the surface of the electric-conductive substrate.

Abstract: An adsorbing agent and a method of preparation thereof is disclosed, which agent is capable of selectively adsorbing mercury from various mercury-containing gaseous or aqueous media at high rate of efficiency. The agent essentially comprises a porous material having a specific surface area in excess of 10 m.sup.2 /g. and a conjugated diolefin lower polymer deposited in a predetermined amount on the porous material.