A microporous membrane has average membrane thickness of 15 μm or less, and relative impedance A after a heat compression treatment under a pressure of 4.0 MPa at 80° C. for 10 minutes of 140% or less, the relative impedance A being obtained by the equation below: Relative impedance A=(impedance measured at 80° C. after the heat compression treatment)/(impedance measured at room temperature prior to the heat compression treatment)×100.

A microporous membrane has average membrane thickness of 15 μm or less, and relative impedance A after a heat compression treatment under a pressure of 4.0 MPa at 80° C. for 10 minutes of 140% or less, the relative impedance A being obtained by the equation below: Relative impedance A=(impedance measured at 80° C. after the heat compression treatment)/(impedance measured at room temperature prior to the heat compression treatment)×100.

Implantable devices for orthopedic, including spine and other uses are formed of porous reinforced polymer scaffolds. Scaffolds include a thermoplastic polymer forming a porous matrix that has continuously interconnected pores. The porosity and the size of the pores within the scaffold are selectively formed during synthesis of the composite material, and the composite material includes a plurality of reinforcement particles integrally formed within and embedded in the matrix and exposed on the pore surfaces. The reinforcement particles provide one or more of reinforcement, bioactivity, or bioresorption.

Implantable devices for orthopedic, including spine and other uses are formed of porous reinforced polymer scaffolds. Scaffolds include a thermoplastic polymer forming a porous matrix that has continuously interconnected pores. The porosity and the size of the pores within the scaffold are selectively formed during synthesis of the composite material, and the composite material includes a plurality of reinforcement particles integrally formed within and embedded in the matrix and exposed on the pore surfaces. The reinforcement particles provide one or more of reinforcement, bioactivity, or bioresorption.

The present invention relates to a method of preparing a hierarchically porous polymer and a hierarchically porous polymer prepared thereby. The method comprises the steps of: (a) polymerizing an external oil phase of a high internal phase emulsion (HIPE) consisting aqueous droplets to produce a cross-linked block copolymer; (b) obtaining a macroporous polymer with interconnected macropores by removing the aqueous droplets; and (c) treating the obtained porous polymer with a base, thereby obtaining a hierarchically porous polymer having three-dimensional mesopores formed in the macroporous walls. According to the method, the macropore size and mesopore size of the hierarchically porous polymer can all be controlled. The hierarchically porous polymer prepared by the method can easily separate polymers having different sizes, and thus is highly useful in the polymer separation field.

A porous membrane includes a modacrylic copolymer. The modacrylic copolymer includes, with respect to 100 parts by mass of all structural units constituting the modacrylic copolymer, 15 to 85 parts by mass of a structural unit derived from acrylonitrile, 15 to 85 parts by mass of a structural unit derived from at least one halogen-containing monomer selected from the group consisting of vinyl halide and vinylidene halide, and 0 to 10 parts by mass of a structural unit derived from a vinyl monomer having an ionic substituent. The porous membrane can be produced by preparing a modacrylic copolymer solution by dissolving the modacrylic copolymer in a solvent, and bringing the modacrylic copolymer solution into contact with a non-solvent for the modacrylic copolymer such that the modacrylic copolymer solution is solidified.

The present invention provides vinyl-based resin particles capable of easily smoothing the surface of a thermosetting resin film when the particles are used as a pore-forming material for a thermosetting resin. Specifically, the present invention provides vinyl-based resin particles for use in making a thermosetting resin porous, the particles having a temperature of 230° C. or higher and lower than 300° C. at 10% mass loss when heated at a rate of 10° C./min in an air atmosphere, and the particles having a mass loss percentage of 85 to 100% after being heated at 350° C. for 5 hours in an air atmosphere.

The present invention relates to a porous layer structure containing a base material and a polyurethane porous layer formed on the base material, wherein a moisture permeability A of the porous layer structure measured by JIS L1099 A-1 (calcium chloride method) is 2000 to 10000 g/(m.sup.2.Math.24h), a moisture permeability loss rate obtained by a predetermined formula from a moisture permeability B of the base material alone measured by JIS L1099 A-1 (calcium chloride method) and the moisture permeability A is 75% or less, and a peel strength at a bonding surface between the base material and the polyurethane porous layer is 0.7 kgf/inch or more.

A method for making a composite and/or structured material includes: forming a lattice construction from a plurality of solid particles, the construction being formed so as to have one or more gaps between the particles; invading the lattice construction with a fluid material such that the fluid material at least partially penetrates the gaps; and, solidifying the material which invaded the lattice construction to form a composite material. In one suitable embodiment, the method further includes removing at least a portion of the lattice construction from the composite material thereby forming at the location of the removed portion one or more pores in the solidified material that invaded the construction.

A method for making a composite and/or structured material includes: forming a lattice construction from a plurality of solid particles, the construction being formed so as to have one or more gaps between the particles; invading the lattice construction with a fluid material such that the fluid material at least partially penetrates the gaps; and, solidifying the material which invaded the lattice construction to form a composite material. In one suitable embodiment, the method further includes removing at least a portion of the lattice construction from the composite material thereby forming at the location of the removed portion one or more pores in the solidified material that invaded the construction.