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 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

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 ?m as determined by electron microscopy, and partially comprises substantially ring-like particles.

One object of the present invention is to provide an emulsion composition comprising a silicone and an emulsion of a resin having a film forming property, which emulsion composition may provide a coating agent which effectively exhibits slidability of silicone on a substrate, while maintaining transparency. Another object of the present invention is to provide a laminate having a film made of the coating agent. The present invention provides an emulsion composition comprising (I) an emulsion of a resin having a film forming property in a solid content of 60 to 99.9 parts by mass and (II) an emulsion of a silicone-acrylic core-shell resin in solid content of 0.1 to 40 parts by mass, a total mass of the solid contents of components (I) and (II) being 100 parts by mass, wherein a core of the silicone-acrylic core-shell resin (II) is composed of an organopolysiloxane (A), a shell layer of the silicone-acrylic core-shell resin (II) is composed of a poly(meth)acrylate ester (B), a mass ratio of the organopolysiloxane (A) to the poly(meth)acrylate ester (B) is in a range of 40:60 to 95:5, and a covering ratio by the poly(meth)acrylate ester on a surface of the silicone-acrylic core-shell resin is at least 50%.

One object of the present invention is to provide an emulsion composition comprising a silicone and an emulsion of a resin having a film forming property, which emulsion composition may provide a coating agent which effectively exhibits slidability of silicone on a substrate, while maintaining transparency. Another object of the present invention is to provide a laminate having a film made of the coating agent. The present invention provides an emulsion composition comprising (I) an emulsion of a resin having a film forming property in a solid content of 60 to 99.9 parts by mass and (II) an emulsion of a silicone-acrylic core-shell resin in solid content of 0.1 to 40 parts by mass, a total mass of the solid contents of components (I) and (II) being 100 parts by mass, wherein a core of the silicone-acrylic core-shell resin (II) is composed of an organopolysiloxane (A), a shell layer of the silicone-acrylic core-shell resin (II) is composed of a poly(meth)acrylate ester (B), a mass ratio of the organopolysiloxane (A) to the poly(meth)acrylate ester (B) is in a range of 40:60 to 95:5, and a covering ratio by the poly(meth)acrylate ester on a surface of the silicone-acrylic core-shell resin is at least 50%.

Graphene is an allotrope or one of the several physical forms of carbon, other examples being graphite, fullerenes, and diamond. At the atomic level, it is in the form a sheet with a thickness nominally under 1.0 nanometer and up to 1 micron in diameter. Sheets of such dimensions when added to other composites facilitate increases in thermal and electrical conductivity and in the case of elastomer nanocomposites, improvements in hysteresis, compounding ingredient dispersion, aging resistance, and reductions in permeability. In the case of conveyor belt cover compounds, natural rubber based formulations are preferred due to high tensile strength, tear strength and damage resistance, and high resistance to abrasion. Graphene as a performance additive enables further improvement in these critical properties.

Graphene is an allotrope or one of the several physical forms of carbon, other examples being graphite, fullerenes, and diamond. At the atomic level, it is in the form a sheet with a thickness nominally under 1.0 nanometer and up to 1 micron in diameter. Sheets of such dimensions when added to other composites facilitate increases in thermal and electrical conductivity and in the case of elastomer nanocomposites, improvements in hysteresis, compounding ingredient dispersion, aging resistance, and reductions in permeability. In the case of conveyor belt cover compounds, natural rubber based formulations are preferred due to high tensile strength, tear strength and damage resistance, and high resistance to abrasion. Graphene as a performance additive enables further improvement in these critical properties.

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.

According to the rubber composition of the present invention comprising 0.1 to 10 parts by mass of -9 fatty acid amide and 0.1 to 100 parts by mass of an adhesive resin based on 100 parts by mass of a rubber component, the rubber composition being excellent in processability, mold release characteristics and abrasion resistance can be provided.

According to the rubber composition of the present invention comprising 0.1 to 10 parts by mass of -9 fatty acid amide and 0.1 to 100 parts by mass of an adhesive resin based on 100 parts by mass of a rubber component, the rubber composition being excellent in processability, mold release characteristics and abrasion resistance can be provided.