Abstract: Provided is a calcium carbonate that comprises crystals having a particular shape and structure and has a nano-order average particle size. Provided are a method for producing a calcium carbonate that comprises crystals having a particular shape and structure and has an average particle size in a particular range and a crystal growth method. The calcium carbonate has the calcite structure, has a BET specific surface area of 2 to 50 m2/g, has a number-based average particle size of 30 nm to 1.0 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

Abstract: Provided is a calcium carbonate that comprises crystals having a particular shape and structure and has a nano-order average particle size. Provided are a method for producing a calcium carbonate that comprises crystals having a particular shape and structure and has an average particle size in a particular range and a crystal growth method. The calcium carbonate has the calcite structure, has a BET specific surface area of 2 to 50 m2/g, has a number-based average particle size of 30 nm to 1.0 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

Abstract: Provided is a calcium carbonate that comprises crystals having a particular shape and structure and has a nano-order average particle size. Provided are a method for producing a calcium carbonate that comprises crystals having a particular shape and structure and has an average particle size in a particular range and a crystal growth method. The calcium carbonate has the calcite structure, has a BET specific surface area of 2 to 50 m2/g, has a number-based average particle size of 30 nm to 1.0 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

Abstract: Provided are a chemical heat storage material having excellent cyclic durability and a method for producing the same. A chemical heat storage material includes: a surface layer formed of silica and/or calcium silicate; and calcium oxide particles with the surface layer.

Abstract: Provided are a method for producing calcium carbonate having a controlled size and a method for growing crystals in order to produce calcium carbonate having a controlled size. A method for producing a calcium carbonate comprises the steps of reducing the pH of an aqueous calcium carbonate dispersion to 9.0 or less and then increasing the pH of the aqueous calcium carbonate dispersion to grow calcium carbonate particles.

Abstract: Provided is a method for producing a calcium carbonate sintered body whereby a good sintered body can be obtained without having to use any sintering aid. A method for producing a calcium carbonate sintered body includes the steps of: compacting calcium carbonate to make a green body; heating the green body under a condition of a temperature of 500° C. or lower to remove an organic component contained in the green body; and sintering the green body under conditions of a carbon dioxide atmosphere and a temperature of 450° C. or higher to obtain a calcium carbonate sintered body.

Abstract: Provided is a calcium carbonate that comprises crystals having a particular shape and structure and has a nano-order average particle size. Provided are a method for producing a calcium carbonate that comprises crystals having a particular shape and structure and has an average particle size in a particular range and a crystal growth method. The calcium carbonate has the calcite structure, has a BET specific surface area of 2 to 50 m2/g, has a number-based average particle size of 30 nm to 1.0 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

Abstract: A high-purity calcium carbonate sintered body containing less impurities and available for biological and like applications, a production method, a high-purity calcium carbonate porous sintered body containing less impurities and available for biological and like applications, and a production method. A method for producing a high-purity calcium carbonate sintered body includes the steps of: compaction molding calcium carbonate with a purity of 99.7% by mass or more to make a green body; and sintering the green body to produce a calcium carbonate sintered body. A method for producing a high-purity calcium carbonate porous sintered body according to the present invention includes the steps of: preparing a dispersion liquid containing calcium carbonate with a purity of 99.7% by mass or more; adding a foaming agent to the dispersion liquid, followed by stirring until foamy to make a foam; and sintering the foam to produce a calcium carbonate porous sintered body.

Abstract: Provided is a production method that can easily produce a calcium carbonate porous sintered body. The production method includes the steps of: preparing a dispersion liquid containing calcium carbonate and a gelling agent; adding a foaming agent to the dispersion liquid, followed by stirring until foamy to make a foam; turning the foam into a gel; and sintering the gelled foam to produce a calcium carbonate porous sintered body.

Abstract: Provided are a chemical heat storage material having excellent cyclic durability and a method for producing the same. A chemical heat storage material includes: a surface layer formed of silica and/or calcium silicate; and calcium oxide particles with the surface layer.

Abstract: Provided are an apatite body easily producible and having a stable apatite composition and a method for producing the apatite body. The apatite body is formed of a sintered calcium carbonate body transformed at least at a surface into apatite and the sintered calcium carbonate body may be a porous sintered body.

Abstract: Provided is a method for producing a calcium carbonate sintered compact by which sintering can be done at a lower temperature and a higher-density calcium carbonate sintered compact can be produced. A method for producing a calcium carbonate sintered compact includes the steps of: preparing calcium carbonate and a sintering aid that is a mixture of potassium fluoride, lithium fluoride, and sodium fluoride and has a melting point of 600° C. or less; compression molding a mixture of the calcium carbonate and the sintering aid mixed to contain the sintering aid in an amount of 0.1 to 3.0% by mass, thus making a green compact; and sintering the green compact to produce a calcium carbonate sintered compact.

Abstract: Provided is a production method that can easily produce a calcium carbonate porous sintered body. The production method includes the steps of: preparing a dispersion liquid containing calcium carbonate and a gelling agent; adding a foaming agent to the dispersion liquid, followed by stirring until foamy to make a foam; turning the foam into a gel; and sintering the gelled foam to produce a calcium carbonate porous sintered body.

Abstract: A high-purity calcium carbonate sintered body containing less impurities and available for biological and like applications, a production method, a high-purity calcium carbonate porous sintered body containing less impurities and available for biological and like applications, and a production method. A method for producing a high-purity calcium carbonate sintered body includes the steps of: compaction molding calcium carbonate with a purity of 99.7% by mass or more to make a green body; and sintering the green body to produce a calcium carbonate sintered body. A method for producing a high-purity calcium carbonate porous sintered body according to the present invention includes the steps of: preparing a dispersion liquid containing calcium carbonate with a purity of 99.7% by mass or more; adding a foaming agent to the dispersion liquid, followed by stirring until foamy to make a foam; and sintering the foam to produce a calcium carbonate porous sintered body.

Abstract: Provided is a resin composition that includes calcium carbonate contained in a polyester resin, a polyamide resin, or at thermosetting resin and that achieves good moldability. The resin composition includes calcium carbonate having a pH ranging from 6.0 to 8.5 and a 1N acetic acid-insoluble residue or 30% by mass or more and the calcium carbonate is contained in a polyester resin, a polyamide resin, or a thermosetting resin.

Abstract: Provided is a resin composition that includes calcium carbonate contained in a polyester resin, a polyamide resin, or at thermosetting resin and that achieves good moldability. The resin composition includes calcium carbonate having a pB ranging from 6.0 to 8.5 and a 1N acetic acid-insoluble residue or 30% by mass or more and the calcium carbonate is contained in a polyester resin, a polyamide resin, or a thermosetting resin.

Abstract: The object of the present invention is to provide a plastic molded material having uniform foamed structure at a low price. To attain said object, a method comprising; mixing particle containing 30 to 70% by weight of water in thermoplastic resin, heating and melting said thermoplastic resin in which said particles containing water are mixed under a high pressure, releasing said high pressure to form foamed structure and cooling to solidify said foamed thermoplastic resin.

Abstract: The object of the present invention is to provide a plastic molded material having uniform foamed structure at a low price. To attain said object, a method comprising; mixing particle containing 30 to 70% by weight of water in thermoplastic resin, heating and melting said thermoplastic resin in which said particles containing water are mixed under a high pressure, releasing said high pressure to form foamed structure and cooling to solidify said foamed thermoplastic resin.

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: A composition comprising a thermoplastic resin and an activated mineral filler, said mineral filler consisting of particles of at least one aluminosilicate-type mineral containing alakali metal ions as cations in its crystal structure, the surfaces of said particles being covered monomolecularly with at least one ethylenically unsaturated organic acid, having 10 or less carbon atoms, which is bonded to the metal ions on the surfaces of said particles and retains ethylenic double bonds unreacted. On being mixed under application of heat to cause reaction, this composition gives a molded article excellent in compatibility and physical properties such as stiffness, toughness, ductility, fatigue properties, water resistance, transparency, etc.