Abstract: A depot fertilizer composition comprising an inorganic matrix and another inorganic and/or organic component of the formulaX Me(II)O.[(1-x)/2]Me(III).sub.2 O.sub.3.YA.zI.aqin whichMe (II) is at least one divalent metal,Me(III) is at least one trivalent metal,A is at least one inorganic acid or anhydride of an inorganic acid,I is at least one organic compound,aq is 0-9,X is from 0 to 1,Y is from 0.5 to 0.7, andZ is from 0 to 20,at least one of the components containing a plant nutrient element. The compositions are suited for fertilizing the leaves or full systems of plants growing in soil or in water.

Abstract: This invention relates to corrosion-inhibiting paints and lacquers containing pigments comprising an organic corrosion inhibitor intercalated into an inorganic matrix said pigment having the formula wherein ##EQU1## wherein Me(II)O is at least one divalent metal oxide;Me(III).sub.2 O.sub.3 is at least one trivalent metal oxide;A is at least one inorganic acid anhydride;I is at least one organic corrosion inhibitor;aq is from 0.5 to 9 moles of water; andx, y and z are whole or fractional numbers andx has a value of from 0 to 1,y has a value of from 0 to 0.7 andz has a value of from greater than 0 to 0.4,with the proviso that the organic corrosion inhibitor is at least 0.5% by weight of inorganic material a process for the production of these pigments and their use in paints, lacquers and lubricants.

Abstract: A zinc ferrite pigment comprising, by weight, about 99.8 to 90% of ZnFe.sub.2 O.sub.4 and about 0.2 to 10% of the component system (1-x)Al.sub.2 O.sub.3 and xP.sub.2 O.sub.5 wherein 0<x<1 is produced by calcining a suitable mixture of compounds. The resulting pigments are of high color quality and are substantially halogen-free, rendering them especially useful industrially even as anti-corrosion pigments.

Abstract: Synthetic, hexagonal, lamellar iron oxide particles, suitable as corrosion-inhibiting or decorative colored pigments, containing about 0.1 to 12% by weight of at least one oxide of an element of the IVth, Vth or VIth Main and Secondary Groups and of the IInd Secondary Group of the Periodic System of Elements.

Abstract: In the preparation of highly orientatable needle-shaped ferrimagnetic iron oxide particles by the reduction and reoxidation of needle-shaped particles of hydrated oxide of iron which have been surface treated against sintering the improvement which comprises effecting the surface treatment by applying to the particles of hydrated oxide of iron one layer of oxygen-containing anions and a further layer of polyvalent cations, each layer weighing about 0.02 to 2% by weight of the particle. Advantageously, the polyvalent cation-containing layer is applied between two oxygen-containing anion layers, the oxygen-containing anions used are selected from the group consisting of silicate, phosphate, borate, vanadate, molybdate and tungstate, the polyvalent cations used are selected from the group consisting of aluminum, chromium, manganese, iron and gallium, each layer weighs about 0.

Abstract: A process for increasing the color purity of iron oxide pigment particles admixed with color-modifying impurities and obtained by the Penniman process or the aniline process, comprising introducing the particles into a magnetic field, and removing from the magnetic field two fractions of different magnetizability, the first fraction being iron oxide pigment particles of increased color purity and the second fraction being enriched in impurities.

Abstract: Readily dispersible finely divided solids such as pigments, coated with an organo-silicone polymer of the formula ##EQU1## wherein R.sup.I, R.sup.II, R.sup.III each independently is an optionally halogenated alkyl, alkenyl or aryl radical having from 1 to 10 carbon atoms;R.sup.IV is an alkyl or alkenyl radical having from 9 to 24 carbon atom;R.sup.V is an alkyl or alkenyl radical having from 1 to 8 carbon atoms;the sum of a+b+c is from 1 to about 1.95;d is a number from about 0.2 to 2;e and f each independently is a number from 0 to 1;the sum of d+e+f is from about 0.2 to 2; andthe sum of a+b+c+d+e+f is up to 3.

Abstract: In the production of needle-shaped magnetic iron oxide pigments by treating iron with a nitro-aromatic in the presence of .alpha.-FeOOH nuclei to form .alpha.-FeOOH particles and an amino-aromatic, and thereafter dehydrating the .alpha.-FeOOH particles and reducing them, the improvement which comprises forming the .alpha.-FeOOH nuclei at about 0.degree. to 90.degree. C. in a suspension of metallic iron, an iron-(II)-salt and a nitro-aromatic by adding a basic precipitant in about 10 to 95% of the amount required for the complete precipitation of the iron in the iron-(II)-salt. Advantageously the metallic iron comprises cast iron, the nitro-aromatic comprises nitrobenzene, the amino-aromatic comprises aniline, the basic precipitant comprises at least one of ammonia and a basically reacting alkali metal, alkaline earth metal or ammonium salt, the nuclei formation is carried out at about 10.degree. to 60.degree. C.

Abstract: In the preparation of highly orientatable needle-shaped ferrimagnetic iron oxide particles by the reduction and reoxidation of needle-shaped particles of hydrated oxide of iron which have been surface treated against sintering the improvement which comprises effecting the surface treatment by applying to the particles of hydrated oxide of iron one layer of oxygen-containing anions and a further layer of polyvalent cations, each layer weighing about 0.02 to 2% by weight of the particle. Advantageously, the polyvalent cation-containing layer is applied between two oxygen-containing anion layers, the oxygen-containing anions used are selected from the group consisting of silicate, phosphate, borate, vanadate, molybdate and tungstate, the polyvalent cations used are selected from the group consisting of aluminum, chromium, manganese, iron and gallium, each layer weighs about 0.

Abstract: A metal powder, suitable for magnetic recording, consisting essentially of iron, the individual particles being acicular and containing on average no more then 5 pores and consisting on average of no more than 2 metal cores is produced by precipitating and oxidizing an aqueous iron-(II)-salt solution to produce finely divided acicular iron-(III)-oxide-hydroxide, stabilizing it as by treatment with cadmium, lead, calcium, magnesium, zinc, aluminum, chromium, tungsten, a phosphorus oxide and/or a boron oxide, converting it into ferromagnetic iron oxide of low pore content, and reducing it to metallic iron with a gaseous reducing agent at about 300.degree. to 600.degree. C.

Abstract: An anti-corrosion pigment comprising about 30.0 to 2.0 mole % of CaO and about 70.0 to 98.0 mole % of Me.sub.2 O.sub.3, wherein Me.sub.2 O.sub.3 is (1-x) Al.sub.2 O.sub.3 and x Fe.sub.2 O.sub.3, x is from 0 to 1 and up to about 25 mole % of the Fe.sub.2 O.sub.3 may be replaced by the corresponding quantity of Mn.sub.2 O.sub.3, and having a specific surface area according to BET of about 0.1 to 200 m.sup.2 /g and a percentage weight loss per gram of pigment, as determined by the Thompson corrosion test, of less than about 0.05% per gram of pigment is produced by calcining the corresponding metal oxides or materials which form the metal oxides on calcination at about 200.degree. to 1100.degree. C. The pigments are especially useful in making up anti-corrosion paints and lacquers.

Abstract: A finely divided magnetite pigment such as is used in magnetic tapes is stabilized against oxidation by contact with a heterocyclic nitrogen compound such as morpholine, triazole, piperazine or substitution products thereof. The heterocyclic compound can be applied as a solution or in vapor form.

Abstract: In the production of an iron oxide red pigment by reducing nitrobenzene with metallic iron in the presence of an acidic iron (II) salt solution, separating off the iron oxide pigment obtained from the reaction medium by washing out, and calcining the pigment at a temperature in the range of about 600.degree. to 1100.degree. C., the improvement which comprises adding an aluminum salt solution over a period of about 5 to 360 minutes at a temperature of about 20.degree. to 100.degree. C. to the iron oxide suspension accumulating during reduction of the nitrobenzene, the suspension containing about 150 to 600 g of iron/l and a residual iron (II) chloride content of about 20 to 160 g/l expressed as iron, the initial pH-value of the iron oxide suspension of about 3 to 5 being adjusted over a period of about 5 to 180 minutes to a final pH-value of about 5.5 to 6.5.

Abstract: An anti-corrosion pigment comprising about 30 to 70 mole % of an oxide of at least one metal selected from the group consisting of magnesium, calcium and zinc, about 70 to 30 mole % of Fe.sub.2 O.sub.3, and up to about 20 mole % of Cr.sub.2 O.sub.3, the pigment having a specific surface of about 1 to 30 m.sup.2 /g and exhibiting a weight loss of less than about 0.05% per gram of pigment by the Thomson corrosion test, is produced by calcining the corresponding metal oxides. The temperature is about 200.degree. to 650.degree. C. in the absence of chromium and about 200.degree. to 900.degree. C. when chromium is present.

Abstract: A pigment of high anti-corrosion properties comprises(a) about 30 to 70 mole percent of at least one of MgO, ZnO and CaO, and(b) about 70 to 30 mole percent of Me.sub.2 O.sub.3 wherein Me.sub.2 O.sub.3 has the approximate molar percent compositionFe.sub.2 O.sub.3 : 0-100, preferably 0.5-100, most preferably 1-95, mole %Al.sub.2 O.sub.3 +Mn.sub.2 O.sub.3 : 0-100, preferably 0.5-100, most preferably 1-95, mole %Cr.sub.2 O.sub.3 : 0-20 mole %Is produced by calcining such oxides or compounds yielding such oxides at from about 200.degree. .RTM. to 650.degree. C. with the option of going up to about 950.degree. C. if the Al+Mn+Cr oxides total 10 mole % or more.

Abstract: An anticorrosion pigment suited for paints and lacquers and consisting of CaZn.sub.2 (PO.sub.4).sub.2 . 2H.sub.2 O crystallizing in the Scholzite lattice and having a specific surface according to BET of from 0.1 to 50 m.sup.2 /g is produced by a process wherein(a) (i) a salt solution containing calcium and zinc cations in a ratio of about 1:2 is normally, inversely or simultaneously precipitated in air at temperatures of up to about 100.degree. C. with an equivalent or substantially equivalent quantity of a solution containing an alkali metal or ammonium phosphate ion; or (ii) compounds of calcium and zinc, which can be decomposed with relatively strong acids or neutralized with acids, in a ratio of about 1:2, have phosphoric acid or ammonium phosphate added to them in approximately the quantity which is required for decomposition or neutralization, or in a slight excess of that quantity, at temperatures of up to about 100.degree. C.

Abstract: An acicular to prismatic ferrimagnetic iron oxide pigment with a porosity of less than about 10% by volume, and optionally containing up to about 15% by weight of other metal oxides such as Zn or especially Co, are produced by heating a suspension of iron(III)oxide hydroxide in an autoclave to a temperature above about 100.degree. C in the presence of at least one mono-, di- or tri-saccharide, at least one alkali metal or alkaline earth metal hydroxide or carbonate and excess water, and washing, filtering and drying the resulting pigments.

Abstract: An anti-corrosion pigment comprising about 30 to 70 mole % of an oxide of at least one metal selected from the group consisting of magnesium, calcium and zinc, about 70 to 30 mole % of Fe.sub.2 O.sub.3, and up to about 20 mole % of Cr.sub.2 O.sub.3, the pigment having a specific surface of about 1 to 30 m.sup.2 /g and exhibiting a weight loss of less than about 0.05% per gram of pigment by the Thomson corrosion test, is produced by calcining the corresponding metal oxides. The temperature is about 200 to 650.degree. C. in the absence of chromium and about 200 to 900.degree. C. when chromium is present.

Abstract: In the production of an FeOOH seed suspension, comprising contacting an iron(II) salt solution with a basic precipitant to form a basic iron(II) salt or hydroxide suspension, oxidizing the salt or hydroxide, the precipitation and oxidation steps being carried out locally separate from one another and recovering a suspension of FeOOH, the improvement which comprises(a) effecting the precipitation by mixing an about 1 to 20% by weight iron(II) salt solution with sufficient basic precipitant to precipitate about 25 to 95 atom % of the iron(II),(b) at another location oxidizing 10 to 50% of the iron(II) precipitated in (a) over a period of from about 0.5 to 5 hours at a temperature in the range from about 20.degree. C to 65.degree. C,(c) at another location oxidizing the suspension obtained in (b) with intensive mixing over a period of from about 0.

Abstract: In a two-stage process for producing black iron oxide pigments wherein an iron salt solution is alkalized in a first stage to precipitate about 55 to 70% of the iron, the solution is oxidized to convert the precipitate to goethite, the solution is further alkalized in a second stage to precipitate the balance of the iron, the precipitated iron II hydroxide is allowed to react with goethite to form magnetite, the improvement which comprises effecting the second stage in the presence of an inorganic ionic compound of at least one metal selected from the group consisting of copper, nickel, aluminum, chromium, titanium, zirconium and vanadium in about 0.05 to 5% calculated as metal based on the weight of the final pigment. The resulting pigment is of high color intensity, narrow grain distribution range and pronounced magnetite structure.