摘要:
Spherical agglomerates of surface-stabilized primary particles substantially consisting of iron, having a BET surface of about 5 to 50 m.sup.2 /g, measured on the agglomerate, in non-pyrophoric form and having a bulk density of about 0.5 to 2.0 kg/l and an agglomerate diameter of about 0.5 to 10 mm are produced by(a) reducing in dry phase particles consisting essentially of iron oxide,(b) intensively dispersing the particles in liquid phase,(c) coating the particles with an inorganic and/or organic coating optionally containing corrosion inhibitors,(d) separating the particles from the liquid phase by evaporating the volatile components with a continuously rotating and simultaneously tumbling movement, and(e) subjecting the resulting granulates to a thermal treatment. The particles are especially useful for the production of magnetic recording media.
摘要:
Sensitive magnetic pigment particles enclosed in about 0.1 to 5% by weight of a polymeric material thereby preserving the pigment magnetic properties. Advantageously, the polymer, which serves as a packing, is at least one member selected from the group consisting of polycarbonates, polyacrylates, polymethacrylates, polyesters, polyethers, polyurethanes, polyvinyl compounds, polyvinylidene compounds and cellulose compounds. These are compatible with the matrices used to make magnetic tapes.
摘要:
A magnetic pigment consisting essentially of iron, having an X-ray crystallite size with the 110 reflex of from 14 to 22 nm, a coercive force from 55 to 88 kA/m and a switching field distribution of the oriented pigment particles of less than 0.55 is produced by precipitating an iron (II)-salt with a super-stoichiometric quantity of an aqueous alkali metal carbonate solution and oxidizing it to produce .alpha.-FeOOH, .gamma.-Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4 or betholoid iron oxides, subsequently reducing it to the metal, and providing the iron oxides or oxide hydroxides with an inorganic protection from sintering at the latest during reduction.
摘要翻译:一种主要由铁组成的磁性颜料,具有X射线微晶尺寸,其反射率为14至22nm,矫顽力为55至88kA / m,取向颜料颗粒的切换场分布小于0.55 通过用超化学计量的碱金属碳酸盐水溶液沉淀铁(II) - 盐,并将其氧化以产生α-FeOOH,γ-Fe 2 O 3,Fe 3 O 4或氧化铝铁氧化物,随后将其还原成金属, 并且在还原期间最终提供具有无机保护的氧化铁或氧化物氢氧化物以免烧结。
摘要:
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.
摘要:
Pigments having the color of natural uncalcined umber contain more than 85% by weight of iron oxides, expressed as Fe.sub.2 O.sub.3, and less than 0.1% by weight of crystalline silica are obtained by mixing iron oxides of spinel structure and/or hematite structure with or without iron oxide yellow and said pigments are useful in coloring paints, lacquers and building materials.
摘要翻译:具有天然未煅烧镉颜色的颜料含有超过85重量%的铁氧化物,以Fe 2 O 3表示,并且小于0.1重量%的结晶二氧化硅通过混合尖晶石结构和/或赤铁矿结构的氧化铁与/或 氧化铁黄和所述颜料可用于着色油漆,漆和建筑材料。
摘要:
The invention relates to transparent iron oxide pigments having an average particle size, based on the longest needle axis, of less than 0.1 .mu.m, to processes for their production and to their use for pigmenting lacquers and plastics.
摘要:
Isometric iron oxide pigments are prepared by an improved process by precipitation of aqueous solutions containing iron (II) salts with alkaline precipitating agents followed by oxidation of the precipitate at temperatures of from 20.degree. C. to 100.degree. C., wherein the improvement comprises adjusting the iron (III) content to 1 to 25 mol %, based on the total iron, before precipitation.
摘要:
A black manganese/iron oxide pigment having a spinel structure and having the composition Mn.sub.x Fe.sub.3-x O.sub.4 wherein x has a value from 0.1 to 0.9, is prepared by the steps:a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese(II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency,b) additionally oxidizing the salts of (a) to establish an Fe(III) content therein with another oxidizing agent, andc) filtering, washing, drying and grinding the pigment;and the pigment is useful for pigmenting building materials to a black color.
摘要:
An improved process is disclosed for preparing iron yellow pigments from iron--(II) salt solutions, in the presence of iron scrap, by injection of air at elevated temperatures. After formation of the pigment, the reaction suspension is stirred without additional gas injection, whereby lighter, purer yellow pigments are obtained.
摘要:
Acicular magnetic iron oxide pigments are disclosed which have a Co content of 1 to 5% by weight and an FeO content of 5 to 12% by weight. The pigments may optionally contain an additional dopant selected from zinc, phosphate and SiO.sub.2. The pigments are useful in magnetic recording media such as video tapes.