Abstract: A method for controlling the formation of a hydroxyapatite bone filler from dry calcium phosphate precursors in an aqueous solution uses coated sodium phosphate powder. The sodium phosphate powder is coated with a water soluble cellulose. Until the cellulose dissolves in the aqueous solution setting of the calcium phosphate cements proceeds slowly but when the exposed sodium phosphate particles start to solubilize in the aqueous solution the setting rate increases.

Abstract: An investment composition is described for use in investment casting (also called lost wax casting). The composition is a phosphate bonded material that contains mono-ammonium phosphate (MAP), magnesium oxide and silica filler (quartz, cristobalite, or a mixture thereof). It has been discovered that controlling the amount and ratio of these components has a significant impact on gas permeability (porosity), set time, cast smoothness and cast softness. The most outstanding feature of the new investments is the short mold fabrication and processing time that they allow due to their high gas permeability. The investments can be placed in a bum out furnace while still wet and can be heated rapidly to the firing temperature. The casts can be broken by sandblasting the casts with glass beads. Molds made from the casts have smooth surfaces indicating that the casts are free of visible inclusions and other defects.

Abstract: A solid powder product with a Ca/P ratio of between 1.40 and 1.90 is prepared from tricalcium phosphate and tetracalcium phosphate. An aqueous solution containing calcium ions and phosphate ions with a Ca/P ratio higher than 0.20 and lower than 0.50 is prepared. The aqueous solution and the solid powder product and optionally water are mixed to obtain a mixture with a liquid/solid weight ratio of between 0.30 and 0.65 and a resulting paste with a Ca/P ratio of between 1.50 and 1.67.

Abstract: A kit and a method for making a porous cement which self sets to hydroxyapatite and has an interconnected porosity is produced by mixing a calcium source and a phosphate source with a carbonate source and mixing this powdered component with a liquid component having an acid component. The liquid component comprises water or an aqueous solution containing an acid. The acid and the carbonate react to form carbon dioxide thereby producing an interconnected porosity in the normally solid self-hardening bone cement. The method requires only a relatively low weight percent of the acid and base to be mixed with the liquid and powder cement components.

Abstract: This invention relates to a cement, which consists in its main phase of microcrystalline magnesium ammonium phosphate and nanoapatite after hardening and thus at the same time has considerable strength.

Abstract: An article is fabricated with a ceramic surface having a controllable surface finish. In one form, the ceramic is applied as a coating to a substrate article. Preferably, an aqueous coating mixture of phosphoric acid, alumina powder, and cordierite powder is prepared. The mixture is contacted to the surface of the article, and a mechanical overpressure is applied to the external surface of the mixture using a pressing tool. The surface character of the pressing tool, such as a smooth surface or an intentionally patterned surface, is reproduced on the surface of the final ceramic coating. The coating is heated to a moderate temperature to set the ceramic of the coating, and thereafter the coating Is heated to a higher, but still intermediate temperature, to cure the coating.

Abstract: A fast-setting, fibrous, Portland Cement-based building material is made by soaking wood chips in water to provide substantially saturated wood chips, combining the saturated wood chips with a slurry of Portland cement to provide a wood chip/cement slurry, mixing a slurry of monomagnesium phosphate (“MOP”) with the wood chip/cement slurry to provide a quick-setting MOP/wood chip/cement composition, and compressing the quick-setting MOP/wood chip/cement composition to make the fast-setting, fibrous, Portland Cement-based building material. The inventive composition combines the best properties of cement and wood, yet uses recycled materials to make an environmentally-friendly building material.

Abstract: A sprayed-on phosphate cement coating formed from the combination and reaction of a phosphoric acid solution and a base metal solution. The acid solution and base solution may be intermixed prior to spraying, during spraying, or on a substrate. The curing reaction rate of the phosphate cement coating and its final physical properties may be controlled by adding various retardants, accelerants, reducers, wetting agents, superplasticizers, buffers, water reducers, adhesive agents, hardening agents, and/or sequestrants to the precursor solutions. The curing rate and properties of the cement coating may be further controlled by adjusting the temperature of the precursor solutions and/or the target substrate.

Abstract: Bonded aggregate compositions such as concrete, concrete repair products, high temperature refractories, high temperature insulation and fire resistant insulation are made from an aqueous solution of phosphoric acid and a separate, storable dry mixture of suitable aggregate, monocalcium phosphate, and calcium in the form of calcium aluminate cement or calcium oxide. The proportion of wet to dry constituents is variable so as to select the working time and strength of the aggregate composition, typically on the order of ten to fifteen minutes. The mixture of the preferred dry constituents, and the binder to be mixed with the aggregate to yield the preferred dry mixture, are also disclosed.

Abstract: Hollow particles having a shell substantially composed of calcium-phosphate, methods for preparing the same, and methods of use are disclosed. The particles are obtained by differential immersion of silica-based, calcium and phosphate containing glass particles.

Abstract: A process for producing an inorganic molded product, which comprises a step of preparing a hardenable composition comprising 100 parts by mass of an acid metal phosphate, from 80 to 200 parts by mass of its hardener, and from 0.1 to 10 parts by mass of urea, a step of combining 100 parts by mass of the hardenable composition and from 5 to 100 parts by mass of an inorganic reinforcing material to obtain a molding material, a step of molding the molding material into a desired shape to obtain a semi-rigid material, and a step of heating the semi-rigid material at a temperature of at least 120° C. to complete hardening.

Abstract: A cement powder is disclosed that contains reactive tricalcium phosphate nanoparticles and other ingredients required to form a cementous material. Methods of making the reactive tricalcium phosphate nanoparticles, the cement powder, the cement paste, and cured cement are also provided, as are methods and articles for using the cement.

Abstract: A process is proposed for producing non-combustible moulded articles from blown vermiculite, the blown vermiculite granules being mixed with an inorganic binder and then pressed. The blown vermiculite granules are mixed with a solution of an inorganic binder, the vermiculite granules once mixed are pre-pressed, cut to the shape required and the cut blanks are pressed non-continuously at at least room temperature and preferably at temperatures of at least 100° C. and pressures of at least 0.3 N/mm2 to ensure that all solvent residues are removed from the finished non-combustible moulded article.

Abstract: A process for producing a fast-setting, bioresorbable calcium phosphate cement. The process of the invention includes a pre-heat treatment step to generate uniformly distributed submicron-sized apatite seed crystals.

Abstract: The invention describes biodegradable calcium phosphate cements, in particular mixtures of calcium phosphate-containing powders of different stoichiometric composition, the precipitated hydroxylapatite present being a cation-deficient hydroxylapatite of the formula 1, with the result that the mixtures have improved properties with regard to compressive strength.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like. Optionally the compositions may include proteins or serve as a depot for compositions of pharmacological interest.

Abstract: The present invention provides a synthetic silicon-substituted apatite or hydroxyapatite which comprises 0.1% to 5% by weight of silicon. The silicon-substituted apatite or hydroxyapatite may be used as a synthetic bone material for use in bone substitution, implants, fillers and cements, coatings for metallic implants, and for making hydroxyapatite-polymer composites. The silicon-substituted apatite is prepared by reacting a calcium salt or calcium hydroxide with orthophosphoric acid or a salt of orthophosphoric acid in the presence of a silicon-containing compound, the molar ratio of calcium ions to phosphorous-containing ions being from 1:0.5 to 1:0.7 and the molar ratio of calcium ions to silicon-containing ions being at least 1:0.2, whereby a precipitate of a silicon-substituted apatite is formed. On heating and/or sintering the silicon-substituted apatite at a temperature of from 500° C. to 1400° C.

Abstract: A calcium phosphate bone graft material comprising an amorphous calcium phosphate glassy phase of from about 30 to about 100 volume % is obtained by plasma spraying calcium phosphate-containing powder onto a target to produce a deposited layer and removing the deposited layer from the target to provide the calcium phosphate bone graft material.

Abstract: A pumpable ceramic composition is provided comprising an inorganic oxide, potassium phosphate, and an oxide coating material. Also provided is a method for preparing pumpable ceramic-based waste forms comprising selecting inorganic oxides based on solubility, surface area and morphology criteria; mixing the selected oxides with phosphate solution and waste to form a first mixture; combining an additive to the first mixture to create a second mixture; adding water to the second mixture to create a reactive mixture; homogenizing the reactive mixture; and allowing the reactive mixture to cure.

Abstract: An aqueous phosphoric bonding solution and coating composition slurry which are environmentally friendly in that they are generally free of molybdate or chromium. Yet the solution is stable with respect to inorganic metal particles, especially aluminum which are admixed to the bonding solution for the preparation of the coating slurry. The metal coated parts and the method of coating the parts with the coating composition are also described. The parts have very satisfactory properties.

Abstract: A method for making a cementitious material comprises forming a mixture of water and active ingredients consisting essentially of i) a compound capable of providing, in aqueous solution, magnesium ions, ii) a potassium phosphate compound and iii) optionally an additional phosphate source; wherein forming said mixture is substantially in the absence of ammonia or an ammonium ion containing compound. A method for repairing a flaw in a cementitious structure comprises applying to the flaw the cementitious binder thus prepared.

Abstract: The present invention provides a novel process for producing a calcium phosphate cement or filler which hardens in a temperature dependent fashion in association with an endothermic reaction. In the reaction a limited amount of water is mixed with dry calcium phosphate precursors to produce a hydrated precursor paste. Hardening of the paste occurs rapidly at body temperature an is accompanied by the conversion of one or more of the reactants to poorly crystalline apatitic calcium phosphate. The hardened cements, fillers, growth matrices, orthopedic and delivery devices of the invention are rapidly resorbable and stimulate hard tissue growth and healing.

Abstract: Inorganic resin compositions comprising, in combination, an aqueous solution of metal phosphate, an oxy-boron compound, a wollastonite compound and other optional additives, inorganic composite articles and products reinforced by fillers and fibers including glass fibers obtained from these compositions and processes for preparing said products.

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calcium phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: A calcium phosphate cement or the like which shows a low viscosity and excellent handleability in the step of kneading and achieves a high strength of the hardened body even though a kneading liquid is used in a small amount. A calcium phosphate cement containing a polysaccharide powder and 0.05 to 5% by weight of an N-alkyl-D-glucamine such as N-methyl-D-glucamine; or a calcium phosphate cement containing a calcium phosphate powder and a specific alkanolamine such as monoethanolamine. A calcium phosphate cement composition containing a calcium phosphate powder and a kneading liquid comprising an aqueous solution containing 0.1 to 10% by weight of an N-alkyl-D-glucamine such as N-methyl-D-glucamine or a kneading liquid containing a definite amount of a specific alkanolamine such as monoethanolamine.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: A calcium phosphate cement and a calcium phosphate cement composition are disclosed. The calcium phosphate cement comprises a calcium phosphate powder having an average particle diameter of 20 .mu.m or smaller and a tap density of 35% or higher, and a polysaccharide. The polysaccharide is preferably a dextran sulfate (e.g., dextran sulfate sodium) having an average particle diameter of 0.1 to 100 .mu.m. The calcium phosphate cement composition comprises the above specific calcium phosphate powder and a liquid for cement mixing comprising an aqueous solution containing 30 to 60 wt % dextran sulfate (e.g., dextran sulfate sodium or dextran sulfate potassium). The calcium phosphate powder preferably comprises a tetracalcium phosphate powder and an equimolar amount of a calcium hydrogen phosphate powder as main components.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: A flowable, paste-like composition capable of setting in a clinically relevant period of time into an antimicrobial agent loaded apatitic product having sufficient compressive strength to serve as a cancellous bone structural material is provided. The subject compositions are prepared by combining dry ingredients with a physiologically acceptable lubricant and an antimicrobial agent, where the dry ingredients comprise at least two different calcium phosphates. The subject compositions find use in a variety of different applications, including orthopaedic, dental and cranio-maxillofacial applications.

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calciumim phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: The present invention is directed to a dry phosphate cement mixture and process for manufacture of same. The dry mixture includes at least Al(H.sub.2 PO.sub.4).sub.3, a group IIA metal bonded to oxygen, and an aggregate. The process for manufacturing cement includes associating the dry reagent with a substantially polar solvent, such as water. The total reagent concentration is formulated such that only nominally exothermic reactions are observed. The process accommodates variable setting times and provides resulting concrete which exhibits formidable structural integrity.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like. Optionally the compositions may include proteins or serve as a depot for compositions of phrarmacological interest.

Abstract: Metal matrix composites comprising of a solid preform comprising of a filler phase containing fly ash and a binding material having a binder to water ratio of 1:1 to 1:9, wherein the preform contains a metal homogeneously distributed within the preform.

Abstract: Bonded aggregate compositions such as concrete, concrete repair products, high temperature refractories, high temperature insulation and fire resistant insulation are made from an aqueous solution of phosphoric acid and a separate, storable dry mixture of suitable aggregate, monocalcium phosphate, and calcium in the form of calcium aluminate cement or calcium oxide. The proportion of wet to dry constituents is variable so as to select the working time and strength of the aggregate composition, typically on the order of ten to fifteen minutes. The mixture of the preferred dry constituents, and the binder to be mixed with the aggregate to yield the preferred dry mixture, are also disclosed.

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calcium phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: An aqueous phosphoric bonding solution and coating composition slurry which are environmentally friendly in that they are generally free of molybdate or chromium. Yet the solution is stable with respect to inorganic metal particles, especially aluminum which are admixed to the bonding solution for the preparation of the coating slurry. The metal coated parts and the method of coating the parts with the coating composition are also described. The parts have very satisfactory properties.

Abstract: Calcium phosphate cements are provided. The subject cements comprise amorphous calcium phosphate, at least one additional calcium source, usually an additional calcium phosphate, and a liquid component, such as a physiologically acceptable lubricant. Upon combination of the cement components, a flowable composition capable of setting in vivo into a solid calcium phosphate mineral product, such as hydroxyapatite, is produced. The subject cement compositions find use in a variety of applications, including the treatment of injured or compromised hard tissue.

Abstract: The preparation of a phosphate-bonded magnesia cement from mixtures of magnesium oxide and an aqueous solution of ammonium polyphosphate, where the mixtures further include a solid monoammonium phosphate fraction that functions to prevent undesired ammonia emission during setting up of the mixtures to produce hardened concrete.

Abstract: A corrosion inhibitor formulation for use in reinforced concrete structures, the inhibitor reducing the rate of corrosion in metallic reinforcing rods placed within the structures. The formulation comprises a mixture of alkali metal glucoheptonates and alkali metal molybdates.

Abstract: The invention relates to a phosphomagnesium cement obtained by mixing water and a binding phase based on at least one phosphorus compound, at least one magnesium compound and at least one inorganic compound, characterized in that the inorganic compound is introduced in the form:- either of particles (1) of size smaller than 0.1 .mu.m,- or of aggregates (2) of size smaller than 0.1 .mu.m,- or of agglomerates (3) capable of deagglomerating at least partially during the mixing of the said binding phase and of water, into particles of size smaller than 0.1 .mu.m or into aggregates of size smaller than 0.1 .mu.m.

Abstract: Methods for producing a room temperature stable, phase pure .alpha.-C.sub.3 P product, and compositions derived therefrom, are provided. In the subject method, a tricalcium phosphate source is heated to a temperature sufficient to convert substantially all of said tricalcium phosphate source to a substantially phase pure .alpha.-C.sub.3 P product. The temperature of the resultant product is rapidly cooled to a temperature below about 700.degree. C., resulting in a room temperature stable, reactive .alpha.-C.sub.3 P product. The resultant .alpha.-C.sub.3 P product may be milled to provide an .alpha.-C.sub.3 P composition which may find use in the preparation of calcium phosphate cements.

Abstract: Novel aluminum phosphates, in particular amorphous aluminum phosphate powders having a BET specific surface no greater than 25 m.sup.2 /g, well suited as binders/hardeners or for the production of ceramic shaped articles, are prepared by reacting at least one aluminum compound, e.g., an aluminum oxide, hydroxide or oxyhydroxide, with phosphoric acid or an aluminum phosphate, e.g., an acid aluminum orthophosphate, in a liquid reaction medium devoid of inorganic acid anions other than of phosphoric acid, and then spray- or freeze-drying the suspension thus obtained.

Abstract: The present invention provides a novel process for converting a standard inert amorphous calcium phosphate precipitate into highly reactive amorphous solids. The amorphous solids can be used to react with other calcium phosphate solids to form a poorly-crystalline synthetic hydroxyapatite that provides both bioactivity and structural integrity. This novel amorphous material can be reacted with other calcium phosphates at or below 37.degree. C. to form a bone-like material consisting of poorly crystalline hydroxyapatite.

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calcium phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: The disclosed invention provides a method of forming refractory linings for maintaining refractory linings against attack by corrosive materials such as those present in steel manufacture. The method entails spraying an aqueous mixture of a refractory composition that includes at least one refractory material onto the working surface of a refractory lining. Spraying is performed to provide one or more layers of the refractory composition on the refractory lining after each exposure of the lining to corrosive materials such as those incurred in steel manufacture.

Abstract: The invention refers to the use of a series of calcium orthophosphate cements as bio-materials, starting from a number of components by grinding and sieving to obtain the adequate grain size, the needed quantity being weighed and the blend of powder products being put into recipients to be shaken up for its homogenization, the mix being placed afterwards, in the desired portions, into a container to be supplied to the specialists, together with capsules containing water or a water solution.

Abstract: A corrosion inhibitor formulation for use in reinforced concrete structures, the inhibitor reducing the rate of corrosion in metallic reinforcing rods placed within the structures. The formulation comprises a mixture of benzoic acid, aldonic acid, and a triazole such as benzotriazole or tolyltriazole.

Abstract: Phosphomagnesia compositions settable into improvedly water-insensitive cements that retain their mechanical properties comprise an intimate admixture of (i) a binder phase including (a) at least one phosphorous compound (P.sub.2 O.sub.5 or derivative/precursor thereof) and (b) at least one magnesium compound reactive therewith in the presence of water, (ii) an effective amount of cementitious aggregate, and (iii) a water sensitivity-reducing amount of at least one silicone homogeneously distributed therethrough.