Inorganic fillers such as silica balloons are used as a lightweight filler for resin moldings. But the specific gravity of these inorganic fillers is about 0.2 at most, so that there is a limit to reduction in weight. The foamed product of organic polymers is obtained as a lightweight substance, but it is hardly put to practical use because of its poor solvent resistance and thermal resistance. The microballoon of the present invention is produced by coating the surface of a hollow particle having the wall film of a thermoplastic high polymer with a thermosetting resin. The present invention provides a microballoon having excellent solvent resistance and thermal resistance as well as a very low specific gravity, and said microballoon is useful as a lightweight filler for resin moldings, aggregate for FRP, ingredient for paints, and the like.
A thin, tacky, non-pourable film of incompatible in situ-expandable thermoplastic particles and thermosettable matrix resin that contains an essentially uniform density and thickness across the breadth of the film. The in situ-expandable mass is not pourable yet can be easily dispensed in a uniform manner within a mold and thereafter expanded to the dimensions of the mold. Composites and reinforced compositions, as well as methods of molding, are disclosed.
The present invention relates to a heat-expandable microcapsule produced from acrylonitrile and N-substituted maleimide as the main polymerizable monomers, or further a monomer giving a hompolymer having a Tg of 50 to 200.degree. C. and polymerizable unsaturated carboxylic acid (including anhydrides), resin foam using this, and a process for producing a foamed resin composite. The present invention can provide a heat-expandable microcapsule that is less apt to color even upon thermal expansion at 200.degree. C. or higher, and a resin foam and a foamed resin composite capable of forming a processed surface, e.g., a matte surface giving a bulky feeling, by using this microcapsule.
A polyurethane and/or polyisocyanurate foam is made using expandable microspheres which encapsulate a primary blowing agent. By expanding during the foam making process, the microspheres function as a blowing agent. The foam preferably has at least 10% by weight expandable micro spheres which encapsulate a non-halogenated hydrocarbon chemical or a non-halogenated hydrocarbon chemical blend and less than 2% by weight of any non-encapsulated blowing agents.
A material for the production by extrusion or molding or calendering of light articles has a chemical formulation comprising at least a thermoplastic polymer. A predetermined amount of polymeric microspheres containing isopentane is added to said at least a thermoplastic polymer. A process for producing said material comprises a first step during which the thermoplastic polymer is mixed to further components (such as thermal stabilizers and/or costabilizers and/or additives) and a second step during which the mixture is granulated in order to obtain a granular compound. At the end of the first step, and advantageously immediately before the beginning of said second step, a predetermined amount of polymeric microspheres containing isopentane is added to the mixture. Said material is used for the production by injection molding or extrusion or calendering of light articles in the shoe industry, particularly of shoe soles.
The present invention provides an electrically conductive material (10) comprising a substantially spherical refractory particle (12) having an exterior surface (14) and having a diameter of no more than about 5 millimeters. An electrically conducting coating (22) substantially equally covers the entire exterior surface (14), the coating (22) having at least about 70 atomic percent carbon and being from about 10 Angstroms to about 500 Angstroms thick. A plurality of such particles (12) are useful as filler materials. Also, such particles (12) are useful as flowing electrodes. Objects containing the particles (12) have desirable electrical properties.
