Abstract: The present invention provides an improved process for coating titanium dioxide with precipitated alumina (aluminum oxide) for use as a pigment in plastics wherein a first coating of amorphous alumina is precipitated onto the titanium dioxide and then a second coating of crystalline alumina is precipitated over the first coating. In operation, the pH of an aqueous slurry of titanium dioxide pigment is adjusted to be within a first pH range as the first alumina coating is effected by adding an amount of sodium aluminate to the aqueous slurry and then the pH of the slurry is adjusted to be within a second pH range while a second amount of sodium aluminate is added to form the second coating over the first coating. The present invention also contemplates an improved titanium dioxide pigment having a first coating of amorphous alumina and a second coating of boehmite alumina.

Abstract: Polishing compositions for highly filled resin-bonded dental restorations comprising a dispersion of alumina having a particle size less than about 3.0 microns and for nonprecious metal used in dental construction comprising a dispersion of said alumina and diamond having a particle size at least equal to that of the alumina but less than about 3.0 microns.

Abstract: Method of removing coarse materials and chemical and mineral impurities from clay in order to produce a purified high solids suspension of said clay which method involves mixing a crude clay with water and a dispersing agent to form a high solids slurry; subjecting said slurry to intense centrifugal forces for a short period of time; separating said coarse material and said chemical and mineral impurities; and recovering the suspended clay as a fine fraction having a reduced content of coarse material and impurities.

Abstract: Iridescent pigments, of the type which comprise colorless micaceous substrates having thereon at least one overcoating of an essentially transparent material with a refractive index over about 2.0, can be enhanced in coloration by applying to them a solution of a coloring matter which possesses an absorption band complementary to the interference reflection color of the pigment, and which thereby absorbs that complementary color. The resulting vivid intensity of the iridescent coloration is far out of proportion to the concentration of the coloring matter and to the intensity of the absorption band. The enhanced colors are useful in novel colorants, printing inks, recording systems, and copy papers.

Abstract: This invention provides an improved pigment composition which blends readily with hydrophylic and oleophylic vehicles, and which can be manufactured with highly reproducible color value.A colorant, typically a dye or dye intermediate, is absorbed on an insoluble dithiocarbamate salt of a polyvalent metal. The dye-containing salts produced in this manner provide a pigment which is non-bleeding in hydrophylic or oleophylic vehicles. Aluminum and zirconium salts are the preferred salts, aluminum dithiocarbamate salts providing transparent pigments, and zirconium dithiocarbamate salts providing opaque pigments.Pigment materials of this invention can be produced by absorbing dye or dye intermediate on a dithiocarbamate metal salt in an aqueous suspension thereof. Azo dye intermediates can be diazotized and coupled in an aqueous suspension of dithiocarbamate metal salt, in accordance with this invention.

Abstract: Pigment composition in the form of free-flowing, non-dusting, non-aggregating, non sticky generally spherical beads which comprises from 50 to 80% by weight of a pigment or water insoluble dyestuff from 5 to 40% by weight of a normally solid water-insoluble organic compound carrier or mixture of carriers melting below 100.degree. C, from 2.5 to 25% of an organic acid and from 1.5 to 25% of an organic base, the amount of acid plus base being from 5 to 35% by weight of the total composition in which are compatible with inks, paints and plastics, and can be readily incorporated into the same.

Abstract: A new precipitated silica having a unique combination of physical and chemical properties is disclosed. The silicon dioxide is produced by acidulating a solution of an alkali metal silicate having a specific SiO.sub.2 /Na.sub.2 O mol ratio with an acid until precipitation just begins. At this point, the reaction mass is aged for a period of time and thereafter the acid addition is continued until the precipitated product is obtained. Products produced in this manner exhibit lower wet cake moisture and are characterized by their low structure, low oil absorption, high abrasiveness and high pack density, and as such are distinctly different from silicas used as reinforcing fillers in rubber. An adduct material, such as aluminum, is added to control the refractive index and surface area of the precipitated product. Because of the controlled refractive index and other properties, the novel silicon dioxides have particular utility for use as abrasion and gelling agents in clear toothpaste compositions.

Abstract: An acicular, magnetic iron oxide pigment containing about 0.05 to 5% by weight of an organo silicon compound is produced by treating iron oxide hydroxide seeds either dry or in suspension with an organo silicon compound. Preferred organo silicon compounds comprise polymethylphenylsiloxane, polydimethylsiloxane and polydiphenylsiloxane. Trivalent metal ions may subsequently be deposited. The resulting pigments show only minimal losses of coercive force during processing into magnetic tapes.

Abstract: Described are novel inexpensive opacifying pigments having a color ranging from tan to light dun and useful, for example, in the manufacture of paints and plastics. The pigments are composed of a mixture of a major weight proportion of particles of iron-bearing titania concentrated from a sedimentary kaolin clay ore and a minor proportion of particles of thermally dehydrated kaolin clay. Also described are methods for manufacturing such pigments from the waste product of clay beneficiation, preferably "Ultraflotation" beneficiation.

Abstract: Process for the manufacture of pigment preparations by comminution in the presence of surface-active agents which can be saponified under acid or alkaline conditions and which contain at least one group which confers solubility in a radical which is to be split off during the saponification.

Abstract: Organic photochromic materials comprise a photochromic pigment stabilized with a protective inorganic coating which serves to protect the pigments from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful organic photochromic pigments include the anils, hydrazones, semicarbozones, osazones, sydnones, fulgides and others. Inorganic coatings comprising such materials as zinc oxide, titanium dioxide, aluminum oxide, antimony oxide and silicon dioxide are useful in the preparation of photochromic plastic films, sheets, ophthalmic lenses such as lenses for sunglasses and in camera lenses and filters.

Abstract: Described is a process for the production of fillers from solid waste which is first ground, magnetically freed from iron particles, supplied with sewage sludge or water, fractionated into portions of different size and treated in a fermentation process for about 24 hours at 65.degree. C while air is continuously fed such that while the compost is being fermented, added thereto is a solvent in a range of 1 to 2-4 parts by weight, compost to solvent, said treatment continuing for ten to sixteen hours, dried, and to the dried product, chlorinated paraffin and antimony trioxide are added thereto.

Abstract: Disclosed are pigments, being co-condensate mixtures of compounds of formula I, ##STR1## wherein R.sub.1 is chlorine, bromine, fluorine, methyl, methoxy or ethoxy, preferably chlorine or methyl,R.sub.2 is hydrogen or has one of the significances of R.sub.1, preferably hydrogen, chlorine or methyl,At least two of the compounds in said mixture being present in an amount of at least 0.1 mol per mol of mixture.

Abstract: Aqueous carbon black compositions are made containing fluorine containing wetting agents to increase the stability to weather. The carbon black compositions are useful in mineral binder systems, for example for concrete, slate, clear concrete, asbestos concrete and exterior plaster formulations.

Abstract: There is provided an improved polypropylene/pigment concentrate for use in preparing pigmented fibers. The improvement comprises at least 95 weight percent of the polypropylene particles have a maximum chord of less than 50 microns. Fibers prepared from concentrates containing 10-75% by weight of pigment have improved color, fewer pigment agglomerates and fewer broken filaments.

Abstract: In a process for treating raw kaolin clay to improve the color and brightness by treating the clay in an aqueous dispersion with sodium dithionite, the improvement consisting of treating the dispersion with hydroxylamine or salt thereof after the treatment with sodium dithionite is complete.

Abstract: A substantially stoichiometric mixture of calcic aluminate and calcium sulphate, as white as possible, formed at a temperature in the range of about 20.degree. to 90.degree. C, is hydrated simultaneously; water is added at least in stoichiometric proportions for the reaction and at a maximum in an amount such that after the reaction a product is obtained containing 5% (dry) ettringite and 95% (by weight) water, stoichiometry being defined, for example by the reactionCaO,Al.sub.2 O.sub.3 + (CaO, H.sub.2 O) + 3(CaSO.sub.4, 2H.sub.2 O) + 24 H.sub.2 O.fwdarw.(CaO).sub.3, Al.sub.2 O.sub.3, 3 CaSO.sub.4, 32 H.sub.2 O (ettringite)It is thus possible to obtain in an economical and very flexible manner, ettringite, or suspensions containing same, for all industrial uses, notably for paper-making.

Abstract: A high temperature coating composition composed of a solvent mixture of zinc chloride, titanium dioxide, and an organo-substituted phosphinic acid.

Abstract: Aqueous pigment dispersions which contain organic or inorganic pigments and water-soluble oxalkylation products of compounds which are obtainable by condensation of aromatic compounds, containing phenolic OH groups, or their ethers, especially lower alkyl ethers, with formaldehyde and amines which contain at least 2 NH groups which are reactive towards formaldehyde, or derivatives of such oxalkylation products are suitable for pigmenting natural or synthetic materials.

Abstract: A compound of calcium carbonate and of hydrated tobermorites, constituted of 70 to 15% tobermorites, which may contain free hydrated silica in amounts to 0 to 15% in weight expressed in SiO.sub.2, and of 30 to 85% calcium carbonate. The process includes completely hydrating white Portland cements between about 5 and 100.degree. C to form a paste having a dry extract of 5 to 70% by weight until at least a decrease in the pH-value occurs.The compound is an industrial charge particularly for paper-making and paint-making industries.