Abstract: Aggregate-TiO.sub.2 pigment products comprising in each 100 parts, by weight, at least 50 parts, by weight, particulate TiO.sub.2 materials bound intrinsically with other pigmentary, subpigmentary and nonpigmentary components with the aid of inorganic and/or organic cements/adhesives.

Abstract: A method of preparing precipitated calcium carbonate which comprises slaking quicklime in an aqueous medium, passing the suspension of calcium hydroxide through a sieve having an aperture size in the range of 40 to 70 microns, carbonating the calcium hydroxide and separating the calcium carbonate from the aqueous medium in which it is suspended. The sieved calcium hydroxide is subjected to high energy, high shear agitation which is terminated prior to carbonation. During the carbonation, the suspension of calcium hydroxide is subjected to relatively lower energy and shear agitation compared to the previous high energy, high shear agitation.

Abstract: A new process for preparing a composite pigment from titanium dioxide and calcium sulphate is provided in which the calcium sulphate is milled to a particle size less than 10 microns, mixed with titanium dioxide and the mixed particulates are coated with an oxide or hydrous oxide of a metal or silicon. The process can particularly be employed in conjunction with a sulphate-process titanium dioxide plant in which by-product sulphuric acid is converted to gypsum. The composite pigment shows improved optical properties in comparison to a mixture of titanium dioxide and gypsum.

Abstract: A process for producing rhombic or barrel shaped precipitated calcium carbonate. Quicklime is slaked in an aqueous solution containing about 0.1% to about 2% by weight of a sugar, based upon the weight of the CaCO.sub.3 to be produced. Carbon dioxide is added to the slaked lime slurry at a preferred temperature of about 50.degree. F.-70.degree. F. until the pH drops from about 11-12 to about 7-8.

Abstract: The invention relates to a process for producing polyacrylic acids and copolymers of acrylic acid with up to 50 mol-% of comonomers. These compounds have a molecular weight of less than 100,000, measured at a pH-value of 8, and 10 to 60 mol-% are neutralized with calcium hydroxide. The invention also relates to the use of these products as grinding and dispersing aids for calcium carbonate.

Abstract: An improved process for producing a aggregated kaolin pigment having desired physical and optical characteristics when used as a coating, filler or pigment in paper. The aggregated pigment is produced by contacting a substantially dry fine particle size kaolin with a previously hydrolyzed organic silicon compound, such as hydrolyzed tetraethoxysilane, and then recovering the aggregated kaolin pigment.

Abstract: A form of calcium carbonate having a blocky rhombohedral crystal structure and properties including a surface area of from about 3 to about 15 m.sup.2 g, an average discrete particle size of from about 0.2 to about 0.9 micron, wherein the discrete particles have an aspect ratio less than about, 2:1 and a particle size distribution such that at least about 60 weight percent of the particles have a size within 50 percent of the equivalent discrete particle spherical diameter, suitable for use as a filler material in papermaking to improve the optical properties of the resulting paper, is disclosed. An accelerated heat-aging process, including embodiments thereof which utilize hydrothermal techniques, for rapidly producing this form of calcium carbonate, and a related form of calcium carbonate having a hexagonal prismatic crystal structure and the same properties, in large quantities to meet the demand of the papermaking industry, as well as a method for using these materials in papermaking, are also disclosed.

Abstract: Mineral fillers, pigments and similar materials containing carbonate are described which are characterized in that they havea) a rhombohedral or primarily round particle formb) a steepness factor of between 1.1 and 1.4c) ##EQU1## and d) an average statistical particle diameter of between 0.4 and 1.5 .mu.m.These materials may be used in the paper industry both as paper fillers and as coating pigments.

Abstract: The present invention relates to a process for the preparation of substantially spherical monocrystalline vaterite, in particular, of vaterite having a determined size.

Abstract: Water soluble salts of a .beta.-polyaspartic acid, i.e., a polyaspartic acid having predominantly beta linkages in the amino acid residue chain thereof, are eminently well suited as dispersants for particulate matter in an aqueous medium.

Abstract: A natural composition for preventing the growth of barnacles, grass, worms and the like on the hull of a boat or ship. The natural, powdered crustacean shell-based composition makes it easy to remove slime and scum formation and is safe to use on all boats or ships, including aluminum and steel. The natural composition incorporates pulverized, powdered, complete crustacean shells as the active ingredient, namely powdered mussel shells or the like.

Abstract: Aggregate pigment products made of low-refractive-index raw materials, in which pigmentary, subpigmentary and nonpigmentary components are cemented intrinsically with the aid of in-situ synthesized complex microgels.

Abstract: A monodisperse spherical, ellipsoidal or plate-like vaterite calcium carbonate almost free from secondary aggregation is disclosed. The vaterite type calcium carbonate is prepared by the steps of adding 5-20 times mol equivalent of water with respect to unslaked lime to a methanol suspension of 0.5-12 weight % of unslaked lime and/or slaked lime (in case of slaked, conversion is to be made into unslaked lime of the same mol) to prepare of a mixture of methanol, unslaked lime and/or slaked lime and water, letting carbon dioxide gas through said mixture, adjusting the temperature in the carbonation reaction systemto not less than 30.degree. C. before arrival of conductivity within carbonation reaction system at the maximal point on conductivity variation curve in the carbonation reaction system and adjusting the time from start of carbonation reaction to the point where the conductivity is 100.mu. S/cm to be less than 1,000 minutes.

Abstract: A light-modifying composition comprising a color pigment component and a pigment spacer component characterized by being a transducing material having the ability to absorb light and reflect at least part of the light absorbed, thereby modifying the light in the coating resulting from the application of the composition. Such pigment spacing component includes any material having the ability to partially absorb light. Preferred are neutral grey pigments in the form of grey powders having a minimal color producing effect. The pigments can be in the form of ground grey powders such as powders taken from granite, feldspar, quartz or limestone or in the form of spherical metallic particles such as metallic zinc.

Abstract: A form of calcium carbonate having a blocky[-six-sided] rhombohedral crystal [habit ] structure and [a morphology, with] properties including a surface area of from about 3 to about 15 m.sup.2 /g, an average discrete particle size of from about 0.2 to about 0.9 micron, wherein the discrete particles have an aspect ratio less than 2, and a particle size distribution such that at least about 60 weight percent of the particles have a size within 50 percent of the equivalent discrete particle spherical diameter, suitable for use as a filler material in papermaking to improve the optical properties of the resulting paper, is disclosed.

Abstract: A process for the continuous production of a calcined product containing a high level of reactive oxide valves, from a preheated raw material containing calcium carbonate values, said process comprising,(a) introducing the preheated raw material to the bottom of a generally vertically oriented gas suspension calcining furnace, whereby said preheated raw material is thereafter suspended in an ascending stream of heated gas to thereby pass vertically upwardly through the gas suspension calcining furnace;(b) passing the ascending gas stream through a plurality of burners, into which fuel and air are injected, that are vertically spaced from each other, in the gas suspension furnace, at a number of levels in the flow direction of the heated gas, and(c) collecting the calcined product.

Abstract: A process for forming chemically aggregated composite porous bulking pigments for use in paper filling and coating formulations. An aqueous slurry is formed of feed mineral particles selected from one or more members of the group consisting of kaolin, calcium carbonate, titanium dioxide, gypsum, and mica. A high molecular weight carboxyl-containing polymer or copolymer is added to the slurry to flocculate the mineral particles. An excess of calcium ion is added to the flocced slurry to precipitate the calcium salt of the carboxyl-containing polymer in situ on the feed mineral flocs, and thereby form aggregates of feed mineral particles interconnected by the calcium salt and having a bulk, porous, floc structure. Gaseous carbon dioxide is added to the slurry, and reacts with remaining calcium ion to precipitate calcium carbonate onto the polymeric carboxyl calcium salt. This forms additional light scattering voids or pores and strengthens the connections among the flocced feed particles.

Abstract: An improved process for producing a aggregated kaolin pigment having desired physical and optical characteristics when used as a coating, filler or pigment in paper. The aggregated pigment is produced by mixing an aqueous slurry of a fine particle kaolin with a previously hydrolyzed organic silicon compound, such as hydrolyzed tetraethoxysilane, and then spray drying the mixture to form a dry, chemically aggregated kaolin pigment.

Abstract: A calcium-magnesium carbonate composite consisting of particles of calcium carbonate and magnesium carbonate hydroxide and having excellent properties, for example, as a pigment for paper coating is proposed, which is a uniform blend of:(A) particles of calcium carbonate having a crystalline structure of aragonite with a columnar particle configuration having a length in the range from 0.5 to 3 .mu.m and a diameter in the range from 0.1 to 0.3 pm with an aspect ratio in the range from 5 to 15; and(B) particles of magnesium carbonate hydroxide having a plate-like particle configuration with a particle diameter in the range from 2 to 7 .mu.m and a thickness in the range from 0.05 to 0.5 .mu.m,the blend having an overall specific surface area in the range from 15 to 30 m.sup.2 /g and the weight proportion of the particles of calcium carbonate to the particles of magnesium carbonate hydroxide being in the range from 95:5 to 50:50 calculated as the respective hydroxides.

Abstract: A form of calcium carbonate having a blocky rhombohedral crystal structure and properties including a surface area of from about 3 to about 15 m.sup.2 /g, an average discrete particle size of from about 0.2 to about 0.9 micron, wherein the discrete particles have an aspect ratio less than about 2:1, and a particle size distribution such that at least about 60 weight percent of the particles have a size within 50 percent of the equivalent discrete particle spherical diameter, suitable for use as a filler material in papermaking to improve the optical properties of the resulting paper, is disclosed. An accelerated heat-aging process, including embodiments thereof which utilize hydrothermal techniques, for rapidly producing this form of calcium carbonate, and a related form of calcium carbonate having a hexagonal prismatic crystal structure and the same properties, in large quantities to meet the demand of the papermaking industry, as well as a method for using these materials in papermaking, are also disclosed.

Abstract: A form of calcium carbonate having a blocky rhombohedral crystal structure and properties including a surface area of from about 3 to about 15 m.sup.2 /g, an average discrete particle size of from about 0.2 to about 0.9 micron, wherein the discrete particles have an aspect ratio less than about 2:1, and a particle size distribution such that at least about 60 weight percent of the particles have a size within 50 percent of the equivalent discrete particle spherical diameter, suitable for use as a filler material in papermaking to improve the optical properties of the resulting paper, is disclosed. An accelerated heat-aging process, including embodiments thereof which utilize hydrothermal techniques, for rapidly producing this form of calcium carbonate, and a related form of calcium carbonate having a hexagonal prismatic crystal structure and the same properties, in large quantities to meet the demand of the papermaking industry, as well as a method for using these materials in papermaking, are also disclosed.

Abstract: Building materials are colored with pigments, for example iron oxide pigments, in the form of granules produced from a suspension of one or more pigments wherein the suspension also contains 0.05 to 5% of soluble salts, based on pigment weight.

Abstract: An article for rural building construction and road building obtained by a thermal treatment of a mixture of:(a) at least an altered silicate containing alumina and calcium;(b) at least a carbonatic rock;(c) a crystallization accelerator; and(d) optionally a basicity regulator.

Abstract: An aqueous coating composition is provided which reflects light, especially UV radiation, and can be colored as desired. It is prepared from a synthetic resin dispersion and inorganic pigments having a particle size ranging between 7 and 10 nm, with the exception of carbon black.

Abstract: The invention concerns a method of bleaching particles containing calcium carbonate by keeping them in contact with an aqueous solution containing hydrogen peroxide and having a pH-value below 8.

Abstract: A color concentrate pellet and a method for producing same. Pigment and carrier, both in powdered form, are placed in a high intensity bowl-type mixer. Small granules are produced. These granules are cold-pressed in a pellet mill and color concentrate pellets of a conventional size and shape are produced. These pellets contain up to 90% pigment by weight, and have a melting point of less than about 230.degree. F. The pellets are friable and are mixable and processable with commercially sized natural resin pellets without substantial settling out. The carrier in the pellet acts as a universal carrier. Pellets with additives in substitution for pigments are also disclosed.

Abstract: The bulk handling characteristics of a calcined kaolin clay powder, including the bulk density and flowability, are significantly improved by forming an aqueous slurry of the calcined kaolin clay powder and spray drying the slurry.

Abstract: A new pigment mixture consisting of 40-80% by weight calcium carbonate and/or dolomite and 20-60% by weight talc or 20-60% of a talc-kaolin mixture or 20-60% by weight of a talc-mica mixture gives substantial improvements in the use in the paper industry, in particular in the production of lightweight coated rotogravure papers.

Abstract: An improved dry ground calcium carbonate filler is provided which is less sensitive to variations in relative humidity and does not promote premature viscosity increase in polyester molding compound. This filler is dry ground from a Caribbean micritic limestone to produce Class I and Class II fillers which are acceptable for use in polyester molding compound applications. A polyester molding compound containing this dry ground filler produces a composite having superior izod impact resistance and surface quality. In some situations filler loading levels may be increased 10-15% in the SMC/BMC without detrimental effects on the final composite.

Abstract: There is disclosed a process for purifying a calcium carbonate-containing mineral which process comprises the following steps:a) mixing the calcium carbonate-containing mineral with water and a dispersing agent to form a suspension containing from 60% to 80% by weight of the dry mineral;b) comminuting the suspension of calcium carbonate-containing mineral prepared in step a) to give a product containing not more than 5% by weight of particles which are retained on a sieve having a nominal aperture of 53 microns and not more than 50% by weight of particles which are smaller than 2 microns e.s.d.

Abstract: The invention provides a method for the preparation of a calcium carbonate powder of which the particles have a platelet-like particulate configuration and which is useful as a pigment or filler in various products with superiority to kaolin clays and mica powders. The method is a two-step carbonation method of a milk of lime of which the first step is performed by blowing carbon dioxide into the milk of lime until 10 to 70% of the calcium hydroxide is carbonated and the second step is performed by admixing the thus partially carbonated milk of lime with an aqueous carbonating solution containing an alkali metal carbonate or ammonium carbonate and an alkali metal hydroxide or ammonium hydroxide in specified concentrations to complete the carbonation of the calcium hydroxide.

Abstract: There is disclosed a particulate inorganic material, suitable for use in a detergent composition, comprising base granules of a smectite clay coated with a white inorganic material. Also disclosed is a detergent composition comprising a particulate inorganic material and a process for making the particulate inorganic material.

Abstract: A form of calcium carbonate, acid-stabilized by the addition to finely divided calcium carbonate of one of a calcium- chelating agent and a conjugate base, such as sodium hexametaphosphate, followed by the addition of a weak acid, such as phosphoric acid, is disclosed. A process for producing this material, and a method for its use in the making of neutral to acidic paper in order to improve the optical properties of the paper are also disclosed.

Abstract: The invention relates to a process for the preparation of an acid-resistant coating and calcium carbonate particles, in which process a slurry of calcium carbonate particles is mixed simultaneously with the solution of a zinc compound and a solution of a silica-containing substance at a temperature of 70.degree.-95.degree. C., the pH being maintained at 8-11.The invention also relates to calcium carbonate particles having an acid-resistant coating in accordance with the above-mentioned process.In addition, the invention relates to the use of calcium carbonate particles having a acid-resistant coating in accordance with the above-mentioned process, as an acid-resistant filler in the production of paper at pH 4.0-7.0.

Abstract: An improved dry ground calcium carbonate filler is provided which is less sensitive to variations in relative humidity and does not promote premature viscosity increase in polyester molding compound. This filler is dry ground from a Caribbean micritic limestone to produce Class I and Class II fillers which are acceptable for use in polyester molding compound applications. A polyester molding compound containing this dry ground filler produces a composite having superior izod impact resistance and surface quality. In some situations filler loading levels may be increased 10-15% in the SMC/BMC without detrimental effects on the final composite.

Abstract: Disclosed is a calcium carbonate which is 25 to 55 m.sup.2 /g in BET specific surface area, 5 to 110 in the ratio of BET specific surface area (m.sup.2 /g)/mean particle size (.mu.m), at least 120 ml/100 g in oil absorption as determined by the Ogura method and at least 1.8 g/g in water absorption, and process for preparing the same. The calcium carbonate is formulated into a coating composition for forming a heat-sensitive recording layer or intermediate layer of a heat-sensitive recording paper or for forming an ink-jet recording paper.

Abstract: This invention concerns a process for the preparation of large surface area, finely divided precipitated calcium carbonate which comprises introducing carbon dioxide into an aqueous slurry of greater than about five weight percent calcium hydroxide containing an anionic organopolyphosphonate polyelectrolyte, starting the introduction at a temperature above about 7.degree. C. and below about 18.degree. C., continuing the introduction until calcite precipitation is substantially complete and adding a quantity of polybasic acid to the slurry in an amount greater than about 0.3% by weight of the precipitated calcium carbonate. This invention also concerns said large surface area, finely divided precipitated calcium carbonate which has been coated with a fatty acid derivative and polymeric compositions which contain such coated calcium carbonate.

Abstract: A precipitated alkaline earth metal carbonate is produced by calcining raw alkaline earth metal carbonate, for example a calcium carbonate, under conditions such that substantially all the chemically combined carbon dioxide is driven off to form an oxide, slaking the oxide in water to form a suspension of the corresponding alkaline earth metal hydroxide, allowing the suspension to cool to 45.degree. C. or below, and then carbonating the hydroxide in suspension in water with substantially pure carbon dioxide in the presence of a dithionite bleaching reagent to form a precipitate of an alkaline earth metal carbonate of increased brightness and purity. The precipitate may then be separated from the aqueous medium by, for example, filtration.

Abstract: Novel finely divided particulate calcium carbonate compositions comprising mixtures of a preponderance of dry ground calcium carbonate with a smaller amount of wet ground calcium carbonate, each of these components having particular particle size characteristics and particle size distributions, are disclosed. When used as all or part of the filler in thermosetting and thermoplastic resinous compositions, e.g., thermosetting polyester resinous molding compositions, paints and other finishes, sealants and the like, such mixtures provide compositions having high filler loadings coupled with acceptably low viscosities and better processability than resinous compositions containing all dry-ground fillers.

Abstract: A two component binder system comprising a highly dispersible, high specific surface area precipitated calcium carbonate (colloidal PCC) and a cationic starch, especially a cationic potato starch, for improving filler retention, opacity and strength during papermaking.

Abstract: Disclosed is a filler for ink jet recording paper, said filler being composed of amorphous silica particles having a median diameter, measured by the coulter counter method, of 2 to 15 .mu.m, an oil absorption of at least 180 ml/100 g, a refractive index, measured by the solvent method, of at least 1.450, and a moisture absorption, measured when it is caused to absorb moisture for 200 hours at a relative humidity of 90% and a temperature of 25.degree. C., of at least 35%, and a coating of a compound of a metal of Group II of the periodic table on the surface of the silica particles in an amount of 0.5 to 20% by weight.

Abstract: A novel granular composition comprises a water-insoluble powder material and a water-insoluble inorganic binder capable of binding said water-soluble powder material. Granules in the composition have a specific diameter and collapse under a load of 0.1-10 g per one grain of granule. The granular composition is preferably incorporated into a dentifrice, and granules incorporated therein can be recognized as granules in the mouth, however, polishing effect of the teeth can be acknowledged with almost no unpleasant feel of foreign substance.

Abstract: Disclosed is a novel process of producing plate-shaped calcium carbonate particles. The process comprises the steps of adding aqueous calcium hydrogen carbonate solution with a temperature of less than 50.degree. C. into an aqueous medium bath held at a temperature of not less than 50.degree. C. to generate plate-shaped calcium carbonate particles in the bath, the temperature of the bath being kept not less than 50.degree. C. during the addition of the aqueous calcium hydrogen carbonate solution; and recovering the generated plate-shape calcium carbonate particles.

Abstract: A structured kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler in paper. The pigment is also useful in paper coating applications. The pigment consists of porous aggregates of kaolin particles which are chemically bonded together. The pigment may be produced by chemically reacting a particulate kaolin with a metal chloride, such as silicon tetrachloride. The process is conducted under conditions such that the kaolinite structure is not impaired.

Abstract: An agent for increasing the pH value of dental plaque, which contains at least one highly disperse, poorly soluble oxide, hydroxide or pure salt of one or more alkaline earth metal elements and a weak acid, having a specific surface area greater than 6 m.sup.2 /g and a concentration of lattice defects which corresponds to a half width of the X-ray peaks for Cu-K.alpha. radiation at glancing angles from 20.degree. to 23.degree. of more than 0.25 degrees, and a process for its preparation.

Abstract: Novel finely divided particulate calcium carbonate compositions comprising mixtures of a preponderance of dry ground calcium carbonate with a smaller amount of wet ground calcium carbonate, each of these components having particular particle size characteristics and particle size distributions, are disclosed. When used as all or part of the filler in thermosetting and thermosplastic resinous compositions, e.g., thermosetting polyester resinous molding compositions, paints and other finishes, sealants and the like, such mixtures provide compositions having high filler loadings coupled with acceptably low viscosities and better processability than resinous compositions containing all dry-ground fillers.

Abstract: Disclosed is a novel process of producing needle-shaped calcium carbonate particles. In the process of the present invention, aqueous calcium hydroxide solution is added to an aqueous medium bath with a temperature of not less than 60.degree. C. into which carbon dioxide gas or a carbon dioxide-containing gas is being blown to generate needle-shaped calcium carbonate particles. The temperature of the aqueous medium bath is kept not less than 60.degree. C. during the addition of the aqueous calcium hydroxide solution. Then the generated needle-shaped calcium carbonate particles are recovered.

Abstract: A method for improving the brightness of limestone utilizing a chelating agent and a bleaching agent in a limestone slurry in which the pH of the slurry is normally between 9.0 and 9.6.

Abstract: A process for forming a preflocculated filler for use in making paper, which process comprises continuously bringing together an aqueous slurry of a paper filler material and a flocculating agent and imparting to the mixture for a period of not more than about 2 minutes and preferably for less than about 30 seconds, a shearing force sufficient to provide a flocculated filler of controlled particle size and most suitable for papermaking.

Abstract: Carbonate-containing mineral fillers, pigments and similar materials are disclosed which are characterized by a combination of four features. These carbonate-containing materials can be used in particular in dyes, paints, paper pulps, paper coatings and plastics to great advantage. In addition, a method of preparing these carbonate-containing materials is disclosed.