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 inorganic pigment comprising a content of at least 0.1% by weight and at most 5% by weight of one or more polyorganosiloxanes, wherein the polyorganosiloxanes have viscosities of 10 to 100,000 mPa.s and a relative molecular weight of 500 to 500,000, have no reactive or crosslinking groups, contain at least one C.sub.9 -C.sub.25 Si-alkyl and/or one C.sub.9 -C.sub.25 Si-aryl group per molecule, the total content of these groups in the polyorganosiloxane being 7-70% by weight and the other organic radicals contained in the polyorganosiloxane having 1 to 8 carbon atoms. Such pigments can be used in lacquers, emulsion paints, plastics, toners, magnetic recording materials, building materials and enamels.

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: 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: Aqueous mineral slurries are treated prior to dewatering, to increase throughput, with a condensation product of formaldehyde and dicyandiamide, which may be further reacted with ammonia or an ammonia salt and an alkylenepolyamine or copper chloride.

Abstract: Finely divided aqueous mineral slurries such as kaolin clay and calcium carbonate are dewatered, filtered and prepared for shipment by and with the addition of an effective amount (preferably 0.01 to 4.0 pounds per ton of solids) of melamine/formaldehyde polymer.

Abstract: Particulate detergent compositions containing a detergent active system, sodium carbonate and a calcite seed crystal exhibit improved dispensibility from automatic washing machines when the mean particle size is at least 500 microns, such as above 700 microns and the level of particles with a size below 50 microns is less than 2% by weight of the overall composition. The Rosin-Rammler distribution n value should be at least 4 when the means particle size is 700 microns but may be as low as 2 when the mean is 1200 microns. When the sodium carbonate and calcite are in separate particles, the sizes thereof should be similar.

Abstract: A mineral particulate is disclosed selected from the group consisting of metal carbonates, glass fibers and layered lattice silicates, comprising particles of said mineral, the surface of which have been modified by a polymer synthesized in situ in the presence of a reactive gas selected from the group consisting of hydrogen, carbon monoxide and carbon dioxide; said particulate having a predetermined particle size distribution which substantially corresponds to the particle size distribution of the surface-unmodified feed particulate from which the product particulate is produced.

Abstract: A lipophobicating solution for an electrophotographic plate for offset printing is disclosed which comprises (a) phytic acid, (b) a diamine having the general formula NH.sub.2 --R--NH.sub.2 wherein R is an alkyl or aryl group having from 2 to 8 carbon atoms, and (c) water. The pH of the solution is in the range from about 3.0 to about 6.0. This lipophobicating solution does not cause scumming and allows an electrophotographic process to produce clean printed sheets.

Abstract: A method of producing a mineral such as calcium carbonate, glass fibers and layered lattice silicates which is surface modified with an organic material wherein said mineral in substantially dry, particulate form is contacted with an organic monomer, co-monomers or a prepolymer, and surface polymerization or reaction in situ on the mineral is carried out in the presence of gaseous carbon monoxide.

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 glass manufacturing process using a granular, free-flowing form of alkaline earth metal carbonate, e.g., barium or strontium carbonate, is disclosed. The alkaline earth metal carbonate has a relatively high bulk density and is made without sintering, grinding, or briquetting. The carbonate is prepared from a fine particle size material by the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resulting suspension, at a temperature that is elevated, but without heating the carbonate to its sintering point, for example, by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C.

Abstract: A method of converting fine particle size alkaline earth metal carbonate, e.g., barium or strontium carbonate, into a free-flowing granular form with relatively high bulk density, without sintering, grinding, or briquetting, is disclosed. It involves the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resultant suspension at a temperature that is elevated, but without heating the carbonate to its sintering point, for example by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C., which causes it to shrink, thereby increasing its bulk density by at least about 5%, preferably at least 10 or 20 percent.

Abstract: A colored thermal joint compound consists of a mixture of a thermal joint compound and a powdered coloring agent of proportions sufficient to form a colloidal solution. The thermal joint compound is, for example, a zinc oxide in either a silicone oil or mineral oil base, and the coloring agent is, for example, a colored calcium carbonate powder of colloidal size particles.

Abstract: Grinding agent based upon acrylic polymers and/or copolymers for aqueous suspension of coarse mineral materials for applications in pigments.Grinding agent for aqueous suspensions of mineral materials intended for application in pigments, consisting of an acid acrylic polymer and/or copolymer which is partially neutralized by at least one neutralizing agent having at least one monovalent function.The grinding agent according to the invention is applicable more particularly to the preparation by grinding of mineral materials such as calcium carbonate, dolomites, calcium sulphate, kaolin, titanium dioxide, intended for pigmentary applications as varied as paper coating, pigmentation of paints, fillers of rubbers or synthetic resins or matting synthetic textiles.

Abstract: The invention relates to a structured kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler or coating pigment in paper. 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, and with urea or an organic amine. The process is conducted under conditions such that the kaolinite structure is not altered.

Abstract: A modified hydrophobic colored or magnetic pigment or filler comprising a hydrophobic pigment or filler containing from 0.05 to 10% by weight, based on the weight of the pigment or filler, of an organopolysiloxane corresponding to the formula ##STR1## wherein x=0 to 500,y=5 to 500,z=5 to 500,R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 denote, independently of one another, a saturated and/or unsaturated, unbranched or branched alkyl group haviang 1 to 4 carbon atoms and/or an aryl group having 6 to 9 carbon atoms, said aryl group being unsubstituted or alkyl substituted,R.sup.7 is a straight chained or branched alkyl group having 6 to 18 carbon atoms and R.sup.7 and H each amount to at least 3% of the number of groups attached to Si.

Abstract: The invention relates to an aggregated kaolinitic pigment having improved physical and optical characteristics when incorporated as a filler or coating pigment in paper. The pigment may be produced by treating a particulate kaolin with an alkaline earth metal carbonate or hydroxide or alkali metal carbonate, and urea or an organic amine. The pigment consists of porous aggregates of kaolin particles.

Abstract: A process for producing ultrafine ground calcium carbonate is disclosed in which a dry feed stone is slurried to a 15 to 60% by weight solids slurry and dispersed with an organic dispersant. The dispersed slurry is fed to an attrition mill where it is bead ground to 50-70% less than 2 microns. The ground calcium carbonate is classified in a centrifuge into a product stream having from 70-99% of its particles less than 2 microns and an underflow stream of larger particles. The product stream is treated with ozone which serves not only to increase the brightness of the product but to return the slurry to a non-dispersed state. The calcium carbonate slurry is then dewatered to produce a 58-69% solids product suitable for preparing a higher solids slurry or for spray drying.

Abstract: Mineral particles are surface treated with an alkali metal silicate, hydrogen peroxide, an acid, or an organophosphorus compound. A preferred surface treating method utilizes sodium silicate in aqueous solution at pH greater than 9, followed by neutralization with acid to precipitate a silica coating onto surface portions of the particles. The mineral particles are preferably alumina particles. The surface-treated alumina particles may be incorporated into fluoride dentifrices or compounded with halogenated hydrocarbons and polymeric resins to form flame-retardant polymer compounds.

Abstract: A pigment composition contains a pigment and a dispersant. The dispersant is a phosphoric ester compound represented by the following general formula: ##STR1## wherein at least one of the three Rs is a residuum of a polyester chain containing as principal bonds thereof ester bonds of a polycarboxylic acid and a polyalcohol.