摘要:
Effect pigments are prepared by a process in which a pigment substrate comprising flaky particles, of which from 10 to 90% by weight have a longest dimension of from 60 to 400 .mu.m and the remainder have a longest dimension of from 3 to 30 .mu.m, are treated, in a fluidized bed, with one or more metal chlorides and steam in the gas phase, at elevated temperatures. During this procedure, the particles are coated with metal oxide. After coating, the fraction having a particle size of from 3 to 30 .mu.m is separated off as the effect pigment.The coatings obtained adhere very firmly to the flaky particles.The pigments are used for coloring finishes, plastics, cosmetic products and glasses.
摘要:
Finely divided metal oxides produced by combustion of metal carbonyls are separated from the stream of gas by filtration. Before filtration, the stream of gas is subjected to a permanent change of direction in a tubular zone. This change of direction must be sufficient to cause a centrifugal acceleration which is from at least 1,000 to 10,000 times the acceleration due to gravity.
摘要:
In aluminum-based metal pigments produced by physical vapor deposition of a metal film and subsequent crushing of the metal film metal surfaces which are exposed after the operation of crushing the metal film and in particular fracture surfaces thereof are covered with a passivating protective layer to afford corrosion stability of those metal pigments.
摘要:
Interference pigments based on titanium dioxide-coated silicatic platelets which have been heated in a reducing atmosphere are useful for producing forgeryproof documents and packaging.
摘要:
Interference pigments based on multiply coated plateletlike silicatic substrates comprisingA) a first layer comprising a colorless or selectively absorbing metal oxide with a high refractive index,B) a second, non-selectively absorbing, semitransparent layer consisting essentially of carbon, a metal or a metal oxide, and optionallyC) a third layer comprising a colorless or selectively absorbing metal oxide in combination with scattering color pigments which are complementary in color to the reflection color of the interference pigments are useful for preparing valuable documents that are forgeryproof.
摘要:
Thermostable bismuth vanadate/molybdate pigments are prepared by precipitating onto a pigment, obtained by calcination, of the formulaBi VO.sub.4 .cndot.Bi.sub.2 Mo O.sub.6where n is 0.2-2.5, in aqueous suspension at 70.degree.-100.degree. C. within the pH range from 4 to 9.5 a first SiO.sub.2 -containing layer using an alkali metal silicate solution of a magnesium hexafluorosilicate solution, maintaining the suspension at 70.degree.-100.degree. C. for not less than 1 hour, producing a thick coating on the precoated pigment by adding further alkali metal silicate solution, magnesium hexafluorosilicate solution or a mixture of the two within the pH range from 4 to 9.5, and finally depositing wax on the SiO.sub.2 -containing layer by means of a waxing emulsion/dispersion, the products showing, compared with the starting pigment, an appreciably improved thermal stability in plastics.
摘要:
Lamellar pigments are based on iron oxide of the general formula Mn.sub.X Al.sub.Y Fe.sub.2 -(X+Y)O.sub.3, where X is from 0.01 to 0.06 and Y is from 0 to 0.2. The pigments are prepared by hydrothermal treatment of an aqueous suspension which contains an iron hydroxide or iron oxide hydroxide,and an alkali metal hydroxide and/or alkali metal carbonate, in the presence of a manganese compound which is soluble in the reaction medium and in the presence or absence of an aluminum compound.The pigments are used for pigmenting coatings, printing inks, finishes, plastics, ceramic surfaces, glasses and cosmetic products.
摘要:
The invention relates to basic chromium aluminum sulfates which are soluble in cold water and are of the general formulaCr.sub.x Al.sub.2-x (OH).sub.2 y. (SO.sub.4).sub.3-y.n H.sub.2 Owhere x is from 0.1 to 1.9, y is from 0.01 to 2 and n is from 4 to 24, and a process for the preparation thereof. The process comprises reacting chromium (III)--containing waste sulfuric acid having a water content of 20-50% by weight with aluminum oxide and/or aluminum oxide hydroxide and/or aluminum hydroxide at a temperature of 100.degree. to 200.degree. C. The molten product is converted to droplet form and allowed to solidify in free fall.
摘要翻译:本发明涉及可溶于冷水并具有通式Cr x Al 2-x(OH)2 y)的碱性铬酸铝硫酸盐。 (SO 4)3-y.nH 2 O,其中x为0.1至1.9,y为0.01至2,n为4至24,以及其制备方法。 该方法包括在100至200℃的温度下将含水量为20-50重量%的含铬(III)的废硫酸与氧化铝和/或氧化铝氢氧化物和/或氢氧化铝反应。 熔融产物转化为液滴形式,并在自由落体下固化。
摘要:
In a process for the manufacture of sodium dithionite by reacting sulfur dioxide with sodium formate and aqueous sodium hydroxide solution in the presence of methanol, an aqueous methanolic solution of sodium formate is first produced by reacting carbon monoxide with sodium hydroxide solution in an aqueous medium, containing from 1 to 50% by weight of methanol, based on the amount of water, at from 80 to 120.degree. C. under a pressure of from 10 to 40 bars. The resulting aqueous methanolic solution can be reacted directly, in the conventional manner, with sulfur dioxide and aqueous sodium hydroxide solution to give sodium dithionite.