Abstract:
Microporous film having a microporous surface layer, and a method of producing it are provided. The method comprises placing a dope containing a film-forming polymer, a solvent therefor and an ionizable organic compound on a support and passing the dope bearing support through a coagulation bath under the application of an electric current. The resultant film has a microporous structure made up of open, vertically elongated and uniform cells.
Abstract:
A shoe upper having in place of the upper leather thereof a fleeceless water vapor permeable microporous sheet of elastomeric polyurethane material having a thickness of about 0.8 - 1.8 mm. and having an extension at break of at least 200%.
Abstract:
A water vapor permeable artificial leather material is disclosed which consists essentially of tough microporous elastomeric polymer material free from fibrous reinforcement having a thickness of at least 0.8 mm and a microporous appearance modifying surface layer or finish.
Abstract:
ANISOTROPIC POLYMER PARTICLES COMPRISING A THIN SKIN WHICH FORMS EITHER A MIXROPOROUS OR DIFFUSIVE BARRIER LAYER AND A SUBSTANTIALLY HOLLOW INTERIOR WHICH INTERIOR, HOWEVER, COMPRISES SUFFICIENT MACROPOROUS POLYMER SUPPORT STRUCTURE TO SUBSTANTIALLY ENHANCE THE PHYSICAL STRENGTH, PARTICULARLY THE RESISTANCE TO COMPRESSION, OF THE PARTICLES. THESE PARTICLES HAVE EXCELLENT UTILITY FOR ENCAPSULATING VARIOUS MATERIALS FOR CONTROLLED RELEASE
THEREFROM, FOR IMMOBILIZING SOME CHEMICAL REACTANTS WHILE ALLOWING FREE ACCESS AND EGRESS OF OTHER REACTANTS OR REACTION PRODUCTS FROM THE PARTICLE, AND FOR EFFECTING SEPARATIONS BSED ON DIFFUSION OF DIFFERENT-SIZE MOLECULES THERETHROUGH. THE VERSATILE PROCESS BY WHICH THESE PARTICLES ARE FORMED IS ALSO A SUBJECT OF THE INSTANT INVENTION.
Abstract:
The present invention relates to a porous membrane including a polymer including a polyvinylidene fluoride-based resin as a main component, and a branched polyvinylidene fluoride-based resin as the polyvinylidene fluoride-based resin, in which the polymer has a value of a of 0.32 to 0.41 and a value of b of 0.18 to 0.42, each of which is determined by approximation according to the formula 1 below from a radius of gyration 1/2 and an absolute molecular weight Mw of the polymer which are measured by GPC-MALS (gel permeation chromatograph equipped with a multi-angle light scattering detector). 1/2=bMwa (Formula 1).
Abstract:
Polyphenylene sulfide microparticles have a linseed oil absorption amount of 40 to 1,000 mL/100 g and a number average particle diameter of 1 to 200 μm. The porous PPS microparticles have a large specific surface area and therefore promote fusion of particles when molded into various molded bodies by applying thermal energy, thus enabling formation or molding of a coating layer of particles at a lower temperature in a shorter time. The porous PPS microparticles have a porous shape and therefore enable scattering light in multiple directions and suppression of specific reflection of reflected light in a specific direction, thus making it possible to impart shading effect and matte effect when added to a medium.
Abstract:
By a silk fibroin porous material containing silk fibroin and an amino acid and a method for producing a silk fibroin porous material including freezing a fibroin solution having an amino acid added to a fibroin aqueous solution and subsequently thawing the solution to obtain a porous material, a porous material which does not contain a solvent and which is high in safety and a method for producing the same are provided.
Abstract:
A method for preparing an open pourous polymer material, comprises forming of a polymer solution, addition of a porogen to the polymer solution and precipitation with water of polymer from the polymer solution, and the method then comprises removal of solvent and porogen from the polymer material wherein the precipitation is homogenous through that the water is in form of crystal water and that the crystal water is bonded to the porogen, wherein the porogen is a sugar hydrate. An open porous polymer material, a mixture comprising a sugar hydrate and a polymer solution, and a designed material, and uses thereof are also disclosed.
Abstract:
Provided is a porous para-oriented aromatic polyamide film which contains fine particles composed of a heat-resistant resin in an amount of 10 to 400 parts by weight based on 100 parts by weight of a pare-oriented aromatic polyamide and has a linear thermal expansion coefficient at 200 to 300null C. of from null50null10null6/null C. to null50null10null6/null C. The porous para-oriented aromatic polyamide film shows excellent tear propagation resistance and has light weight and low linear thermal expansion coefficient, and is suitable as a prepreg material used for a base substrate for printed circuit board.
Abstract:
A microporous biocompatible material is formed by preparing a segmented polyether urethane urea solution containing 25%.+-.1.5% solids dissolved in a solvent. The solution has sufficient viscosity to be preshaped and formed into the desired thickness of the finished article, then immediately immersed into a precipitation bath in which the solvent in the solution is miscible for a time interval sufficient to cause the solution to set up into an opaque elastomeric article. The article is immediately removed from the bath, any excess solvent extracted and then dried at a temperature on the order of 35.degree. C. to 70.degree. C. followed by heat treating by annealing for approximately sixty minutes at a temperature at 100.degree. C. to 130.degree. C. The void volume of the membrane solution is controlled to within the 50% to 80% range and the pore size from ca