Abstract: The calcium carbonate filler for a resin is provided in which a volatile component such as water present in a surface of calcium carbonate is likely to be degassed even when the filler is incorporated into and kneaded with a resin having high processing temperature at a high concentration, and foaming or the like can be suppressed. In particular, the calcium carbonate filler is useful in optical fields that require reflectivity and light resistance. The calcium carbonate filler for a resin has a content rate of particles having a particle diameter of 0.26 ?m or less is 30% or less in a number particle size distribution diameter measured from an electron micrograph, and satisfies the following expressions (a) Dms5/Dmv5?3.0, (b) 1.0?Sw?10.0 (m2/g) and (c) Dma?5.

Abstract: The calcium carbonate filler for a resin is provided in which a volatile component such as water present in a surface of calcium carbonate is likely to be degassed even when the filler is incorporated into and kneaded with a resin having high processing temperature at a high concentration, and foaming or the like can be suppressed. In particular, the calcium carbonate filler is useful in optical fields that require reflectivity and light resistance. The calcium carbonate filler for a resin has a content rate of particles having a particle diameter of 0.26 ?m or less is 30% or less in a number particle size distribution diameter measured from an electron micrograph, and satisfies the following expressions (a) Dms5/Dmv5?3.0, (b) 1.0?Sw?10.0 (m2/g) and (c) Dma?5.

Abstract: A calcium carbonate filler for a resin, in which the content rate of particles having a particle diameter of 0.26 ?m or less is 30% or less in a number particle size distribution diameter measured (Mac-VIEW manufactured by Mountech) from an electron micrograph, and which satisfies the following expressions (a) to (c) is provided. Dms5/Dmv5?3??(a) 1?Sw?8 (m2/g)??(b) Mo?300 (ppm)??(c) wherein Dms5: A 5% diameter (?m) accumulated from a small particle side in a volume particle size distribution by a laser diffraction particle size distribution measuring device (MASTERSIZER2000 manufactured by Malvern); Dmv5: A 5% diameter (?m) accumulated from a small particle side in a number particle size distribution in a particle diameter (Mac-VIEW manufactured by Mountech) measured with an electron microscope; Sw: A BET specific surface area (Macsorb manufactured by Mountech) (m2/g); Mo: A water amount (ppm) by the Karl Fischer method at 200 to 300° C.

Abstract: A calcium carbonate filler for a resin, in which the content rate of particles having a particle diameter of 0.26 ?m or less is 30% or less in a number particle size distribution diameter measured (Mac-VIEW manufactured by Mountech) from an electron micrograph, and which satisfies the following expressions (a) to (c) is provided. Dms5/Dmv5?3??(a) 1?Sw?8 (m2/g)??(b) Mo?300 (ppm)??(c) wherein Dms5: A 5% diameter (?m) accumulated from a small particle side in a volume particle size distribution by a laser diffraction particle size distribution measuring device (MASTERSIZER2000 manufactured by Malvern); Dmv5: A 5% diameter (?m) accumulated from a small particle side in a number particle size distribution in a particle diameter (Mac-VIEW manufactured by Mountech) measured with an electron microscope; Sw: A BET specific surface area (Macsorb manufactured by Mountech) (m2/g); Mo: A water amount (ppm) by the Karl Fischer method at 200 to 300° C.

Abstract: The surface-treated calcium carbonate is disclosed which is surface-treated with an organic surface treating agent, said surface-treated calcium carbonate satisfies the particular BET specific surface area (Sw), reduced heat amount per unit specific surface area (As), average pore diameter (Dxp) at which an increased amount of mercury penetration reaches the maximum value in a method of mercury penetration, and amount of an average pore diameter [maximum value of an increased amount of mercury penetration (Dyp)/average pore diameter (Dxp)]. The surface-treated calcium carbonate of the present invention is particularly useful for resins and it not only improves adhesion of resin compositions to a subject to be adhered, but forms a rigid coating film when blended into resins.

Abstract: The surface-treated calcium carbonate is disclosed which is surface-treated with an organic surface treating agent, said surface-treated calcium carbonate satisfies the particular BET specific surface area (Sw), reduced heat amount per unit specific surface area (As), average pore diameter (Dxp) at which an increased amount of mercury penetration reaches the maximum value in a method of mercury penetration, and amount of an average pore diameter [maximum value of an increased amount of mercury penetration (Dyp)/average pore diameter (Dxp)]. The surface-treated calcium carbonate of the present invention is particularly useful for resins and it not only improves adhesion of resin compositions to a subject to be adhered, but forms a rigid coating film when blended into resins.

Abstract: An additive for synthetic resins is provided which comprises composite particles obtained by depositing a calcium phosphate compound (R) on support particles (M) of a petaloid porous structure. The additive of the present invention provides synthetic resin compositions having excellent transparency, anti-scratch property, anti-blocking property and less discoloration caused by deterioration of resin.

Abstract: Disclosed is an inorganic dispersant having a high specific surface area and a high surface activity which comprises a calcium phosphate type compound having a specific particle composition, particle shape, particle size and dispersibility, and specific surface area. When used as a suspension polymerization stabilizer, it provides polymer particles having a uniform and sharp particle size distribution, and when the polymer particles are contained in an unsaturated polyester resin composition and a toner composition, the obtained compositions have excellent quality.

Abstract: An additive for synthetic resins is provided which comprises particles of a petaloid hydroxyapatite represented by a chemical formula Ca10(PO4)6(OH)2, having the specified particle diameter, degree of dispersion: and specific surface area, and a synthetic resin composition blended with the additive is also provided. By the use of the additive of the present invention, a film satisfying anti-blocking property, transparency and anti-scratch property can be obtained.

Abstract: The fine particles of peraloid porous hydroxyapatite are provided, which have an atomic ratio of Ca/P in a range of 1.62-1.72 and the chemical formula Ca.sub.5 (PO.sub.4).sub.3 (OH). The particles are comprised of micropores having a petaloid porous structure not only on the surface but also in the inside of the particles, and have the specific particle diameter of the specific particle size, micropore diameter of the specific particle size, the specific surface of the specific range, static and pressurized percentage of voids of the specific range. The particles have superior dispersibility and are useful in the fields such as carriers for pharmaceuticals and so on, adsorbents, absorbents, sustained-release materials, filtering agents, biological materials, fillers for plastics, and anti-blocking agents for films and so on.

Abstract: An additive for synthetic resins is provided. The additive comprises particles surface-coated with a petaloid porous hydroxyapatite having a chemical formula Ca.sub.5 (PO.sub.4).sub.3 (OH) and the petaloid porous hydroxyapatite is not less than 5% by weight of the particles. The additive can be added to any kinds of synthetic resins. If the additive is used in a polyethylene film, blocking of the film is not only prevented, but good transparency and good anti-scratch ability are imparted, and if the additive is used in a polyester, a film having good slipperiness, anti-abrasion and less coarse protrusions can be provided.

Abstract: An additive for synthetic resins is provided. The additive comprises particles surface-coated with a petaloid porous hydroxyapatite having a chemical formula Ca.sub.5 (PO.sub.4 ).sub.3 (OH) and the petaloid porous hydroxyapatite is not less than 5% by weight of the particles. The additive can be added to any kinds of synthetic resins. If the additive is used in a polyethylene film, blocking of the film is not only prevented, but good transparency and good anti-scratch ability are imparted, and if the additive is used in a polyester, a film having good slipperiness, anti-abrasion and less coarse protrusions can be provided.