Orthoplumbate

Etch primers are widely used. They are mostly based on polyvinyl butyral and contain chromates and phosphoric acid. They are said to act both as primers and as etching solutions because it is believed that the chromates and phosphoric acid form an inorganic him, which provides adhesion, while oxidised polyvinyl butyral provides an organic him. For direct application to new galvanised steel, the best known primers are based on calcium orthoplumbate pigment and metallic lead, but these are now less used for environmental reasons. Zinc-dust paints and zinc-phosphate pigmented paints are also used, but the trend is to use pretreatments to assure good adhesion. 

Lead dioxide reacts with alkalies forming various types of plumbates. Fusion with caustic soda or caustic potash yields orthoplumbates and meta-plumbates, such as Na4Pb04 or Na2Pb03 (or the corresponding potassium salts). However, when dissolved in a concentrated aqueous solution of sodium or potassium hydroxide, the product is hydroxyplumbate ... 

Lead Oxide or Lead Tetroxide (Minium, Red Lead, Mineral Orange, Mineral Red, Plumbo, Puce, Orthoplumbate, Paris or Saturn Red). 

Potassium, rubidium and cesium orthoplumbates M4Pb04 (M = K, Rb, Cs) all contain isolated [Pb04] tetrahedra, as does Rb3NaPbO4.348-3S0 The structure of the metaplumbate , Li2Pb03, like Li2Sn03, is a variant of the NaCl lattice, with octahedrally coordinated lead,351... 

Red lead should be regarded as the lead salt of orthoplumbic acid, H4Pb04, i.e., it is lead(II) orthoplumbate, Pb2Pb04, in which PbOe octahedra are linked by Pb(II) ions [5.146]. 

The electrochemical action of red lead results from the fact that lead has valencies of 2 and 4 in lead orthoplumbate Pb(IV) compounds are reduced to Pb(II) in the cathodic region [5.147]. The chemical anticorrosive effect is a result of lead soaps that are formed when fatty acids in the binder react with the red lead. The lead soaps permeate the paint film as lamellae, and give good mechanical strength, water resistance, and adhesion to the steel surface. Furthermore, the corrosion-promoting chloride and sulfate ions are precipitated by lead(II) ions [5.148]. 

Lead dioxide may also be obtained by the action of concentrated nitric acid on plumbous orthoplumbate (red lead). It is most easily obtained, however, by the action of oxidizing agents on plumbous salts in alkaline medium. Hypochlorite is commonly used as the oxidant, but permanganate, sodium peroxide, ferricyanide, and many other oxidizing agents can be used. 

If it is assumed that Pb203 and Pb304 are lead metaplumbate and lead orthoplumbate, respectively, write formulas to express these facts. Write the formulas of the corresponding meta- and orthoplumbic acids. 

SYNS C.I. 77578 C.I. PIGMENT RED 105 DILEAD(II) LEAD(IV) OXIDE GOLD SATINOBRE LEAD ORTHOPLUMBATE LEAD TETRAOXIDE MINERAL ORANGE MINERAL RED MINIUM MINIUM NON-SETTING RL-95 ORANGE LEAD PARIS RED PLUMBOPLUMBIC OXIDE RED LEAD RED LEAD OXIDE SANDIX SATURN RED TRILEAD TETROXIDE... 

LEAD ORTHOPLUMBATE (1314-41-6) An oxidizer. Decomposes above 932°F/500°C, emitting oxygen. Reacts, possibly violently, with reducing agents, powdered metals aluminum, titanium, zirconium, zinc, etc., alcohols, dichloromethylsilane, hydrazine, hydrogen trisulfide, ethers, glycols, peroxyformic acid, phosphorus, selenium oxychloride, sulfur trioxide. Incompatible with ammonium nitrate, diboron tetrafluoride, hydrazinium nitrate, hydrogen sulfide, nitroalkanes, rubidium acetylide, selenium oxychloride. Forms heat-sensitive explosive material with anilinium perchlorate. Increases the thermal and/or explosive sensitivity of 2,4,6-trinitrotoluene, hydrazinium perchlorate, silver azide. Incompatible with sodium, sulfur trioxide. 

The most common coating inhibitors are zinc chromate and plumbous orthoplumbate (red lead), which passivate steel by providing chromate and plumbate ions, respectively, as well as the zinc and lead cathodic inhibitors. These inhibitors are not effective against attack by seawater or brines because the high chloride concentration prevents passivation of steel. 

Synonyms Cl 77578 Lead orthoplumbate Lead pi.lH) oxide Lead tetrox-ide Mineral orange Mineral red Minium Paris red Pigment red 105 Plumboplumbic oxide Red lead Red lead oxide Saturn red Trilead tetroxide Empirical 04Pb5 Formula 2PbO PbOj... 

Plumbate(lV) compounds were formerly referred to as orthoplumbates (Pb04 ) or metaplumbates (PbOs "). Plumbate(II) compounds were called plumbites. 

Lead octoate. See Lead 2-ethylhexoate Lead orthoplumbate. See Lead oxide, red Lead oxide Lead (II) oxide Lead (2+) oxide. See Lead oxide, yellow... 

Precooked tung oil-alkylphenolic resin combinations, chilled with drying oil modified alkyd resins. Dehydrated castor oil (DCO)-modified alkyd resin, pigmented with calcium orthoplumbate (COP) as main pigment in the priming coat. 

Pigments such as calcium orthoplumbate will oxidize the zinc surface and also form calcareous deposits with good bond properties at the interface. A similar but weaker effect has been observed by Van Eijnsbergen when primers containing red lead, zinc chromate, and basic lead sulfate are applied to zinc surfaces. 

The metaplumbates of strontium and bariiun M"Pb03 are made by fusion of strontium or barium nitrates with lead(II) oxides. The oxides of nitrogen released convert the lead(II) to lead(IV). Calcium orthoplumbate Ca2Pb04 is formed when calcium nitrate and lead(II) oxide are fused in the stoichiometry Ca(N03)2.Pb0. The barium and strontium orthoplumbates are prepared by heating barium or strontium carbonates with lead(II) oxide in the stoichiometry [MC03]2.PbO the necessary oxidation is caused by the atmo-sphere o. 

Neither the metaplumbates nor the orthoplumbates can be regarded as containing discrete PbO and PbOj ions respectively . ... 

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