A method may comprise: sintering a particulate mixture comprising binder particles at about 5% to about 75% by weight of the particulate mixture and fugitive particles at about 25% to about 90% by weight of the particulate mixture, thereby forming a porous mass; and substantially removing the fugitive particles from the porous mass, thereby forming an ultra-low pressure drop (ULPD) porous mass with fugitive particles at 0% to about 5% by weight of the ULPD porous mass.

A method may comprise: sintering a particulate mixture comprising binder particles at about 5% to about 75% by weight of the particulate mixture and fugitive particles at about 25% to about 90% by weight of the particulate mixture, thereby forming a porous mass; and substantially removing the fugitive particles from the porous mass, thereby forming an ultra-low pressure drop (ULPD) porous mass with fugitive particles at 0% to about 5% by weight of the ULPD porous mass.

The invention provides networked polymeric nanofibers having a structure in which amorphous polymeric fibers are branched at multiple sites and having a diameter of from 1 nanometer to 100 nanometers. A solution of a polymer such as polystyrene in a good solvent thereof is rapidly frozen to form a nanoscale phase-separation structure of the polymer and the frozen solvent. The networked polymeric nanofibers can then be obtained upon removing the frozen solvent.

The invention provides networked polymeric nanofibers having a structure in which amorphous polymeric fibers are branched at multiple sites and having a diameter of from 1 nanometer to 100 nanometers. A solution of a polymer such as polystyrene in a good solvent thereof is rapidly frozen to form a nanoscale phase-separation structure of the polymer and the frozen solvent. The networked polymeric nanofibers can then be obtained upon removing the frozen solvent.

A foam composition that includes a polymer material such as polyurethane or polyurea and a leachable water-soluble fine powder is provided. This composition can be used in a relatively simple process to obtain a foam body (porous body) that is uniform only at the surface or uniform throughout. The foam body can be suitably used as a golf ball member in golf balls required to have good controllability on approach shots. Also provided is a method for producing a foam member, which method includes the steps of molding the foam composition to obtain a solid molded body, and then leaching out and removing the water-soluble fine powder so as to obtain a foam-molded body.

A foam composition that includes a polymer material such as polyurethane or polyurea and a leachable water-soluble fine powder is provided. This composition can be used in a relatively simple process to obtain a foam body (porous body) that is uniform only at the surface or uniform throughout. The foam body can be suitably used as a golf ball member in golf balls required to have good controllability on approach shots. Also provided is a method for producing a foam member, which method includes the steps of molding the foam composition to obtain a solid molded body, and then leaching out and removing the water-soluble fine powder so as to obtain a foam-molded body.

Provided is a polyolefin microporous membrane having a loss tangent (tan ?) at 230? C. of 0.35 or more and less than 0.60 in melt viscoelasticity measurement.

Provided is a polyolefin microporous membrane having a loss tangent (tan ?) at 230? C. of 0.35 or more and less than 0.60 in melt viscoelasticity measurement.

There is provided a conductive film having conductivity in a surface direction, being deformable, having excellent durability, and transmitting visible light.

A conductive film includes a film substrate and a conductive material layer. The conductive material layer is provided on a first substrate surface of the film substrate. A plurality of through holes penetrating the film substrate and the conductive material layer in a thickness direction are formed in the conductive film. The conductive material layer has a plurality of conductive portions, and the conductive portions are present between adjacent layer opening portions. The number of the conductive portion is 400 per 1 mm.sup.2, and an opening ratio of the conductive material layer is at least 40%.

There is provided a conductive film having conductivity in a surface direction, being deformable, having excellent durability, and transmitting visible light.

A conductive film includes a film substrate and a conductive material layer. The conductive material layer is provided on a first substrate surface of the film substrate. A plurality of through holes penetrating the film substrate and the conductive material layer in a thickness direction are formed in the conductive film. The conductive material layer has a plurality of conductive portions, and the conductive portions are present between adjacent layer opening portions. The number of the conductive portion is 400 per 1 mm.sup.2, and an opening ratio of the conductive material layer is at least 40%.