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 m.sup.2/g, has a number-based average particle size of 30 nm to 1.0 μm as determined by electron microscopy, and partially comprises substantially ring-like particles.

A graphite composition is provided. A graphite composition according to one embodiment of the present invention comprises: a graphite composite in which nanoparticles having a catecholamine layer on the surface thereof are fixed on graphite; and graphite of at least one of graphite flakes, spherical graphite, and expanded graphite. According to this, since the graphite composition has a high dispersibility in a substrate of a different material, a composite material thus realized exhibits a uniform heat dissipation performance and can prevent mechanical strength from deteriorating at a specific position. In addition, since the compatibility with the substrate of a different material is excellent and thus the interface property with the substrate is excellent, the realized composite material can exhibit a further improved heat dissipation performance and mechanical strength. Furthermore, it is very easy to form shapes during injection/extrusion molding in combination with a substrate, and molding into complicated shapes is also possible.

A graphite composition is provided. A graphite composition according to one embodiment of the present invention comprises: a graphite composite in which nanoparticles having a catecholamine layer on the surface thereof are fixed on graphite; and graphite of at least one of graphite flakes, spherical graphite, and expanded graphite. According to this, since the graphite composition has a high dispersibility in a substrate of a different material, a composite material thus realized exhibits a uniform heat dissipation performance and can prevent mechanical strength from deteriorating at a specific position. In addition, since the compatibility with the substrate of a different material is excellent and thus the interface property with the substrate is excellent, the realized composite material can exhibit a further improved heat dissipation performance and mechanical strength. Furthermore, it is very easy to form shapes during injection/extrusion molding in combination with a substrate, and molding into complicated shapes is also possible.

A resin composition includes: (A) a vinyl-containing polyphenylene ether resin; (B) a resin of Formula (1); and (C) an inorganic filler. Moreover, also provided is an article made from the resin composition described above, which comprises a prepreg, a resin film, a laminate or a printed circuit board, wherein the article achieves improvement in at least one of the following properties: dissipation factor, comparative tracking index, X-axis thermal expansion coefficient, and temperature coefficient of dielectric constant. ##STR00001##

A resin composition includes: (A) a vinyl-containing polyphenylene ether resin; (B) a resin of Formula (1); and (C) an inorganic filler. Moreover, also provided is an article made from the resin composition described above, which comprises a prepreg, a resin film, a laminate or a printed circuit board, wherein the article achieves improvement in at least one of the following properties: dissipation factor, comparative tracking index, X-axis thermal expansion coefficient, and temperature coefficient of dielectric constant. ##STR00001##

Provided is silica powder that, when used as a resin filler such as a semiconductor sealant, allows for obtaining a resin composition having excellent gap permeability and low viscosity. The silica powder is such that (1) a cumulative 50% mass diameter D.sub.50 of a mass-based particle size distribution obtained by a centrifugal sedimentation method is 300 nm to 500 nm (preferably, 330 nm to 400 nm), (2) a loose bulk density is 250 kg/m.sup.3 to 400 kg/m.sup.3 (preferably, 270 kg/m.sup.3 to 350 kg/m.sup.3), and (3) {(D.sub.90−D.sub.50)/D.sub.50}×100 is 30% to 45%. In a silica production method in which a silicon compound is burned, silica powder can be produced by installing a burner having a concentric multiple pipe structure of three or more pipes in a reactor which has a cooling jacket portion provided around the burner, and adjusting flame combustion conditions and cooling conditions.

Provided is silica powder that, when used as a resin filler such as a semiconductor sealant, allows for obtaining a resin composition having excellent gap permeability and low viscosity. The silica powder is such that (1) a cumulative 50% mass diameter D.sub.50 of a mass-based particle size distribution obtained by a centrifugal sedimentation method is 300 nm to 500 nm (preferably, 330 nm to 400 nm), (2) a loose bulk density is 250 kg/m.sup.3 to 400 kg/m.sup.3 (preferably, 270 kg/m.sup.3 to 350 kg/m.sup.3), and (3) {(D.sub.90−D.sub.50)/D.sub.50}×100 is 30% to 45%. In a silica production method in which a silicon compound is burned, silica powder can be produced by installing a burner having a concentric multiple pipe structure of three or more pipes in a reactor which has a cooling jacket portion provided around the burner, and adjusting flame combustion conditions and cooling conditions.

The present invention provides a curable composition, a pressure-sensitive adhesive, an adhesive tape and an adherend product, and belongs to the technical field of acrylate pressure-sensitive adhesives. The pressure-sensitive adhesive formed from the curable composition of the present invention features good resistance to resilience, especially resistance to resilience at high temperatures. The curable composition comprises: a monomer component, which comprises at least two polymerizable monomers, wherein the polymerizable monomers comprise a non-tertiary alcohol (meth)acrylate monomer and an acid functionalized non-ester unsaturated monomer with at least one ethylenically unsaturated group; a (meth)acrylate polymer tackifying resin with a weight-average molecular weight ranging from 10,000 to 60,000 Daltons and a glass transition temperature greater than or equal to 20° C.; and a non-(meth)acrylate polymer tackifying resin component, which comprises tackifying resins of at least two non-(meth)acrylate polymers, wherein the softening point temperature of tackifying resins of at least part of the non-(meth)acrylate polymers is greater than or equal to 130° C.

The present invention provides a curable composition, a pressure-sensitive adhesive, an adhesive tape and an adherend product, and belongs to the technical field of acrylate pressure-sensitive adhesives. The pressure-sensitive adhesive formed from the curable composition of the present invention features good resistance to resilience, especially resistance to resilience at high temperatures. The curable composition comprises: a monomer component, which comprises at least two polymerizable monomers, wherein the polymerizable monomers comprise a non-tertiary alcohol (meth)acrylate monomer and an acid functionalized non-ester unsaturated monomer with at least one ethylenically unsaturated group; a (meth)acrylate polymer tackifying resin with a weight-average molecular weight ranging from 10,000 to 60,000 Daltons and a glass transition temperature greater than or equal to 20° C.; and a non-(meth)acrylate polymer tackifying resin component, which comprises tackifying resins of at least two non-(meth)acrylate polymers, wherein the softening point temperature of tackifying resins of at least part of the non-(meth)acrylate polymers is greater than or equal to 130° C.

The present invention provides a curable composition, a pressure-sensitive adhesive, an adhesive tape and an adherend product, and belongs to the technical field of acrylate pressure-sensitive adhesives. The pressure-sensitive adhesive formed from the curable composition of the present invention features good resistance to resilience, especially resistance to resilience at high temperatures. The curable composition comprises: a monomer component, which comprises at least two polymerizable monomers, wherein the polymerizable monomers comprise a non-tertiary alcohol (meth)acrylate monomer and an acid functionalized non-ester unsaturated monomer with at least one ethylenically unsaturated group; a (meth)acrylate polymer tackifying resin with a weight-average molecular weight ranging from 10,000 to 60,000 Daltons and a glass transition temperature greater than or equal to 20° C.; and a non-(meth)acrylate polymer tackifying resin component, which comprises tackifying resins of at least two non-(meth)acrylate polymers, wherein the softening point temperature of tackifying resins of at least part of the non-(meth)acrylate polymers is greater than or equal to 130° C.