Abstract: Compositions foamable by exposure to microwave energy contain: (A) at least one compound bearing crosslinkable organic radicals for crosslinking, (B) at least one blowing agent which releases gas on heating, (C) at least one metal powder or metal compound, for example a metal oxide, individually, or a mixture thereof, which has microwave activity. Foams of uniform cell structure can be formulated with wide processing latitude.

Abstract: A process for preparing functionalised microporous polymers (which are also known as micro-cellular polymers or polyHIPE polymers (PHPs)) using intensified internal heating (for example by microwave irradiation).

Abstract: A plastic is converted from an initial condition with a higher density into a foamed condition with a lower density using a blowing agent, wherein the plastic is cross-linked prior to foaming by means of a first cross-linking agent and during the foaming by means of at least one second cross-linking agent.

Abstract: A silicone rubber is produced by curing a silicone rubber composition which includes (A) a curable organopolysiloxane composition and (B) at least one hollow organic resin filler whereby the filler forms cells in an open-cell state. The open-cell state gives the silicone rubber good cushioning property and a low compression set.

Abstract: The invention discloses methods for making foams by photopolymerizing emulsions comprising a reactive phase and a phase immiscible with the reactive phase components. Foams made from water-in-oil emulsions, including high internal phase emulsion are disclosed. Articles and uses for the foams are also described.

Abstract: The invention discloses methods for making foams by photopolymerizing emulsions comprising a reactive phase and a phase immiscible with the reactive phase components. Foams made from water-in-oil emulsions, including high internal phase emulsion are disclosed. Articles and uses for the foams are also described.

Abstract: The present invention aims to improve soundproof and heat insulating properties of a foamed plastic by reducing internal cells pressure inside foamed resins. A base polymer such as a polyester-based polyol and a volatile foaming agent having an conjugate unsaturated group (i. e., conjugate double carbon bonds and/or triple carbon bonds) such as chloroprene (bp. 51.degree. C.) and calcium stearate were blended and then mixed with a hardening agent such as hexamethylene diisocyanate. The volatile foaming agent existing in open cells of the foamed plastic sealed in the Al laminated film and between the film and the foamed plastic, i.e., gap, possesses an unsaturated group, such as isoprene. Thus polymerization may occur by irradiating with electron rays, and the inside of the foams and the gap region may be reduced in pressure while the bag of the laminated film retains its shape.

Abstract: Expanded graphite sealing rings having particles of PTFE captured at least in a surface layer are disclosed. The sealing rings are produced by impregnating porous rings, cut from a sheet of low density expanded graphite, with a PTFE dispersion and then compressing the rings to a desired final density. Impregnation is accomplished in the presence of an electric field.

Abstract: A process produces foam bodies having various properties and containing cellulose-containing materials broken up and/or partially broken up and/or not broken up, and additives, if need be. The cellulose-containing starting materials are first processed further for forming a moist pulp and subsequently subjected to a heat treatment by microwave radiation. The properties of the foam bodies so produced are predetermined by admixing certain substances intensifying the formation of gas in the pulp, increasing the adhesive bond between the particles in the pulp, or which completely or partially convert into a gas either under the influence of heat or of moisture, thus supporting the foaming. Furthermore, other residual and waste materials can be added during the production process, which may be materials of a silicate nature as well, preferably with the objective of reusing such materials in a useful way and of predetermining at the same time certain product properties of the foam bodies.

Abstract: Process for the preparation of aerogels by subcritical drying of inorganic and organic hydrogels and lyogels to give aerogels, dielectric drying methods being used.

Abstract: A process for producing an automotive molded roof material is provided which comprises sheeting a foamable sheet forming composition comprising a specified propylene resin, a glass fiber, a radical initiator, a crosslinking auxiliary and a foaming agent in specific proportions into a foamable sheet, lining one side of the foamable sheet with a backing sheet so as to integrate these and irradiating the foamable sheet with ionizing radiation to thereby crosslink the propylene resin, followed by heating the foamable sheet so as to cause the foamable sheet to foam, placing a cover sheet on the other side of the foamed sheet before the sheet cools to solidify and press molding the cover sheet on the foamed sheet to cover. There is also provided an automotive molded roof material produced by the above process. An automotive molded roof material is obtained which can be recycled, is lightweight and has high rigidity.

Abstract: A method of and apparatus for continuously foaming a polyimide prepolymer powder which is not susceptible to heating by microwave energy utilize a preheated conveyor belt to heat the powder in contact with and adjacent the surface of the conveyor belt to commence the reaction and foaming of the powder as it enters an oven which further heats the powder by convection and infrared radiation to form a continuous foam bun. The conveyor belt is cooled as it exits the oven to cool a bottom surface of the foam product to enable the foam product to be removed from the conveyor before interior portions of the foam product have cooled. Foam adhering to the conveyor belt, after the product has been removed, is cleaned from the conveyor belt, collected and mixed with and used as a filler in the prepolymer powder used in the process. In addition the mass of the powder entering the oven and the density and degree of cure of the foam bun exiting the oven are monitored to continuously control the process.

Abstract: A process for producing a foam comprising subjecting a foaming composition to foaming conditions, said foaming composition comprising (A) from 1 to 99% by weight, based on the total weight of (A) and (B), of a random copolymer comprising units derived from propylene, from 0.1 to 15 mol % of units derived from a non-conjugated diene represented by formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 each independently represents a hydrogen atom or an alkyl group having from 1 to 8 carbon atoms; and n represents a number of from 2 to 10, and, if desired, up to 4 mol % of units derived from ethylene, said random copolymer having a degree of crystallinity of at least 20% as measured by X-ray diffractometry, a melt flow rate of from 0.01 to 200 g/10 min as measured according to ASTM D1238-1986, and an elastic modulus of from 1,000 to 15,000 kg/cm.sup.2 as measured according to JIS K-7203, and (B) from 99 to 1% by weight, based on the total weight of (A) and (B), of a homopolymer of an .

Abstract: An electron-beam cured sheet-type foam comprises: a polypropylene type resin (A) of 100 parts by weight of which main component is polypropylene; a copolymer resin (B) of 5 to 40 parts by weight which is made of ethylene and at least one selected from the group consisting of acrylic acid, ethylacrylate maleic acid anhydride and vinylacetate; and a copolymer resin (C) made of ethylene and an .alpha.-olefin of 4 to 8 carbon atoms, having a melting point of 117.degree. C. to 123.degree. C. and a density of 0.890 g/cm.sup.3 to 0.910 g/cm.sup.3. This foam contains 20 to 60 percent in gel content and has an expansion ratio of 5 to 40.

Abstract: This invention provides an improved process for producing a superabsorbent polymer with reduced residual monomer content which comprises partially drying a crosslinked, partially neutralized polymer gel, then raising the temperature of the gel using microwaves or RF radiation in the absence of circulating air and thereafter completing the drying.

Abstract: The foamable silicone rubber composition is capable of giving a cured silicone rubber body having a cellular structure and suitable for use as a very reliable fire-resistant joint-sealing member in buildings. In addition to the rather conventional constituents essential in a foamable silicone rubber composition of prior art including (a) a diorganopolysiloxane, (b) a finely divided reinforcing silica filer, (f) a curing agent and (g) a blowing agent, the foamed silicone rubber body obtained by curing the inventive composition is imparted with very reliable fire resistance by virtue of the synergistic effect of the characteristic ingredients including (c) a ferrite powder, (d) a finely divided inorganic material or, in particular, mica flakes, and (e) a platinum compound, in combination, each in a specified amount.

Abstract: An efficient method for the preparation of a foamed and cured silicone rubber body having a uniform fine-cellular structure, in which a foamable silicone rubber composition is prepared by uniformly compounding a diorganopolysiloxane, finely divided silica filler, titanium dioxide powder, blowing agent and curing agent, each in a specified weight proportion, and irradiating the thus prepared composition with microwaves having a frequency of 900 to 5000 MHz which, by virtue of the titanium dioxide powder having a high dielectric constant, are efficiently absorbed and converted to heat, whereby the composition is evenly heated throughout the body to cause uniform foaming and curing.

Abstract: Styrene polymer foam particles of from 10 to 30 kg/m.sup.3 in density are obtained by foaming styrene polymers which, per kg, contain from 0.7 to 3 moles of blowing agent mixture composed of from 60 to 90 mol % of water and from 10 to 40 mol % of the C.sub.4 - or C.sub.5 -hydrocarbon with the aid of microwaves.

Abstract: A foamed cellular body of a cured silicone rubber composition can be obtained in a continuous process by irradiating a foamable silicone rubber composition containing, in addition to conventional diorganopolysiloxane, finely divided silica filler, blowing agent and crosslinking agent, a substantial amount of a dielectric inorganic powder, which is an iron oxide or a ferrite, with UHF microwaves. When the silicone rubber composition as molded is irradiated with UHF microwaves, the energy of the microwaves absorbed by the dielectric powder is efficiently converted into heat so that the molded body can be very evenly heated to effect foaming vulcanization of the composition giving a foamed and cured silicone rubber article having an excellently fine and uniform cellular structure.

Abstract: A copolyimide foam comprising the reaction product of one or more of an aromatic tetracarboxylic acid and a compound of the formula: ##STR1## where x is an integer from 1 to 12 and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and are hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl a mixture thereof with two or more diamines at least one of which being a heterocyclic diamine having a nitrogen atom in the ring and the other being a para- or meta-substituted aromatic diamine free of aliphatic substitution.Processes for producing the above copolyimide foam are also disclosed.

Abstract: Disclosed is new type of implantable material for replacement of cartilaginous or fibrous tissue. The material has controlled porosity and is biocompatible. A method for making this material is also disclosed.

Abstract: Disclosed is new type of implantable material for replacement of cartilaginous or fibrous tissue. The material has controlled porosity and is biocompatible. A method for making this material is also disclosed.

Abstract: Described are ways of improving the yields of specification grade polyimide foam on a consistent basis from one run to the next, by use of improved microwave-based foaming processes. In one such process, the microwave radiation is directed upon the top, sides and ends of the body of polyimide precursor and of the foam structure as it is developing, but the extent to which such radiation impinges upwardly into the bottom of said body and said foam structure is curtailed, preferably by means of a metallic shield located below the precursor and developing foam structure. Mechanisms by which the shields function to provide the improvements of the process are discussed, and methods based thereon are set forth.

Abstract: Described are ways of improving the yields of specification grade polyimide foam on a consistent basis from one run to the next by use of improvements in microwave-based foaming processes. While a body of polyimide precursor is exposed to microwave radiation, the body of polyimide precursor and of the foam structure as it is developing therefrom are kept under a substantially vapor-impermeable microwave-compatible shroud that does not substantially restrict or impede development of the foam structure. For this purpose use may be made of a shroud composed of a polymer film. Mechanisms by which the shroud produces the improved results are discussed, and methods based thereon are set forth.

Abstract: Described are ways of improving the yields of specification grade polyimide foam on a consistent basis from one run to the next, by use of improved microwave-based foaming processes. In one such process, the microwave radiation is directed upon the top, sides and ends of the body of polyimide precursor and of the foam structure as it is developing, but the extent to which such radiation impinges upwardly into the bottom of said body and said foam structure is curtailed, preferably by means of a metallic shield located below the precursor and developing foam structure. Mechanisms by which the shields function to provide the improvements of the process are discussed, and methods based thereon are set forth.

Abstract: Described are ways of improving the yields of specification grade polyimide foam on a consistent basis from one run to the next, by use of improved microwave-based foaming processes. In one such process, during the application of the microwave radiation, the body of polyimide precursor and of the foam structure as it is developing therefrom are maintained under a substantially vapor-impermeable mmicrowave-compatible shroud that does not substantially restrict or impede development of the foam structure; and the microwave radiation is directed upon the top, sides and ends of the body of polyimide precursor and of the foam structure as it is developing, but the extent to which such radiation impinges upwardly into the bottom of said body and said foam structure is curtailed, preferably by means of a metallic shield located below the precursor and developing foam structure.

Abstract: Described are ways of improving the yields of specification grade polyimide on a consistent basis from one run to the next, by use of improved microwave-based foaming processes. In one such process, during the application of the microwave radiation, the body of polyimide precursor and of the foam structure as it is developing therefrom are maintained under a substantially vapor-impermeable microwave-compatible shroud that does not substantially restrict or impede development of the foam structure; and the microwave radiation is directed upon the top, sides and ends of the body of polyimide precursor and of the foam structure as it is developing, but the extent to which such radiation impinges upwardly into the bottom of said body and said foam structure is curtailed, preferably by means of a metallic shield located below the precursor and developing foam structure.

Abstract: Described are ways of improving the yields of specification grade polyimide foam on a consistent basis from one run to the next by use of improvements in microwave-based foaming processes. While a body of polyimide precursor is exposed to microwave radiation, the body of polyimide precursor and of the foam structure as it is developing therefrom are kept under a substantially vapor-impermeable microwave-compatible shroud that does not substantially restrict or impede development of the foam structure. For this purpose use may be made of a shroud composed of a polymer film. Mechanisms by which the shroud produces the improved results are discussed, and methods based thereon are set forth.

Abstract: Polystyrene beads or beads of other thermoplastic material are expanded to a consolidated foam structure in a hollow cavity of a marine float or other structure by providing the beads with a uniform coating of a saturated brine solution or other aqueous solution of water-soluble salt and exposing the solution to microwave energy to boil the solutioln and thereby heat the beads to cause expansion and fusion to a foam structure.

Abstract: The invention relates to the process of the invention provides a radiation-crosslinked polypropylene foam by extrusion at a low temperature (about 170.degree. C.) below the decomposition point of the blowing agent. The resulting foamed item has by far better heat resistance than conventional ones.The raw resin can be prepared by mixing a resin in the pellet form and a blowing agent in the powder form on account of the low-temperature flowability. Heretofore, such mixing was impossible because the blowing agent does not disperse completely.This outstanding effect of the invention was not expected at all from the known prior arts.

Abstract: A slab of rigid heat-foamable organic synthetic resin is heated until at least a portion of its surface is at or above the softening temperature of the resin, whereupon a microwave or high frequency field is allowed to act on the slab until foaming occurs.

Abstract: An expandable fluorine-contained polymer composition comprising (A) a fluorine-contained polymer in which the ratio (tan .delta.) of dynamic loss modulus to dynamic storage modulus at a temperature 30.degree. C. higher than the melting point of the polymer ranges from 0.3 to 0.9, and (B) a blowing agent, and a foam obtained from said composition.

Abstract: A method for producing foam polyolefin products which are light-stable and weather-resistant are obtained by the combined use of the following stabilizers:(a) phenolic antioxidants,(b) substituted benzophenones and/or substituted benzotriazoles, and(c) sterically hindered amines.

Abstract: A method for producing foam polyolefin products which are light-stable and weather-resistant are obtained by the combined use of the following stabilizers:(a) phenolic antioxidants,(b) substituted benzophenones and/or substituted benzotriazoles, and(c) sterically hindered amines.

Abstract: An improved process for the production of cross-linked polyolefin foams by mixing polyolefins with conventional foaming agents and cross-linking agents known for polyolefin foam production, shaping the mixture into a plate or into a continuous sheet, substantially without cross-linking and foaming, the improvement comprises mixing said mixture with up to 50% by weight of an .alpha.,.beta.-unsaturated polyester, heating the plate or sheet optionally by IR radiation, and cross-linking the foaming by dielectric heating at a temperature above the decomposition temperature of the cross-linking and foaming agents.

Abstract: An electroconductive cross-linked polyolefin foam having electric resistance of not more than 100 M.OMEGA. and comprising uniform minute cells and proving useful for the production of IC cases, etc. is provided by a method which comprises kneading 100 parts by weight of a polyolefin, 10 to 30 parts by weight of carbon particles, and suitable amounts of a foaming agent and a cross-linking agent and heating the resultant cross-linkable and foamable composition under atmospheric pressure thereby allowing the composition to be cross-linked and foamed without being abruptly foamed or expanded or by a method which comprises heating the aforementioned cross-linkable and foamable composition in a metal mold under pressure to a temperature at which the foaming agent is not substantially decomposed thereby cross-linking the composition and then heating the resultant cross-linked foamable composition under atmospheric pressure thereby allowing the composition to be foamed without being abruptly foamed or expanded.

Abstract: A heat-foamable olefinic resin composition comprising(a) an ethylenic polymer,(b) a propylene/alpha-olefin copolymer having a melting point of 130.degree. to 160.degree. C.,(c) a propylene polymer having a melting point at least 10.degree. C. higher than the melting point of the propylene/alpha-olefin copolymer, and(d) a blowing agent, and optionally(e) a crosslinking agent and/or a crosslinking promoting agent; anda process for producing an olefinic resin foam comprising crosslinking and heat-foaming the aforesaid heat-foamable olefinic resin composition.

Abstract: A method of providing cured latex-based compositions is disclosed which permits in situ curing of latexes disposed in plastic container closures or other heat sensitive receptacles without adverse effect on the closure or receptacle. The method comprises heating a fluid latex composition to gel the latex and effect removal of at least a portion of the water initially contained therein and subjecting the resultant composition to modulated microwave energy to effect curing thereof. Modulation of the microwave energy is achieved by applying same in an intermittent or pulsed fashion. The method is of particular interest for the in situ formation of cured latex-based gaskets in polyalkylene container closures.

Abstract: A molded object having a sponge-like interior surrounded by a skin, molding composition from which it is produced, and the method for producing the article. Copolymers of vinyl-substituted aromatic compounds containing from 8-18 carbon atoms copolymerized with conjugated diene having from 4-12 carbon atoms and polymer chosen from among solid resinous polymers of vinyl-substituted aromatic compounds present in amounts ranging from about 10 to about 75 parts by weight per 100 parts by weight of the copolymer and solid resinous copolymers of ethylene present in an amount of about 5 to about 50 parts by weight per 100 parts by weight of the copolymer are blended with a sufficient amount of polarizing agent to achieve rapid heating through response to microwave treatment, blowing agent in an amount sufficient to provide a sponge-like, rubbery porosity to an article molded therefrom, and, optionally, cellular control agent.

Abstract: A crosslinked foam having an expansion ratio of 25 to 60 which comprises a composition containing 100 parts by weight of a resin component consisting of an ethylenevinyl acetate copolymer or a mixture thereof with a thermoplastic resin and 50 to 500 parts by weight of an inorganic powder material.

Abstract: Methods of converting essentially unpolymerized precursors into polyimides in which the precursors are exposed to microwave radiation. Preheating, thermal post-curing, and other techniques may be employed to promote the development of optimum properties; and reinforcements can be employed to impart strength and rigidity to the final product. Also disclosed are processes for making various composite artifacts in which non-polymeric precursors are converted to polyimides by using the techniques described above.

Abstract: This invention provides a method of continuously manufacturing a cross-linked polyvinyl chloride resin foam sheet which has a low density, uniformly fine cell, excellent thermal moldability and high heat resistance and is neither deformed nor deteriorated even by long storage characterized by uniformly kneading the polyvinyl chloride resin with a blowing agent, stabilizer, plasticizer and cross-linking promoter without causing the blowing agent to decompose itself, thereby providing an unfoamed kneaded composition in which the polyvinyl chloride resin is gelled and forming said composition into a continuing sheet, irradiating said sheet with ionizing radiation to cross-link the resin; and thermally foaming the cross-linked sheet.

Abstract: A method of making light weight flame resistant structures from bonded polyimide macroballoons and products thereof. An aromatic tetracarboxylic acid dianhydride is reacted with an oxoimine to produce an N-substituted imide, which is then esterfied with a suitable alcohol. The resulting liquid is dried and the dry residue is reduced to a uniform powder having particles with diameters generally in the 0.5 to 10 mm. range. The powder is preferably further dried, either before or after final size reduction, in a moderate vacuum at moderate temperature to remove any excess residual alcohol. The powder spontaneously expands to form a closed cell foam when heated to a temperature in the range of about 90.degree. to 150.degree. C. for a suitable period. When the powder is expanded in a closed mold, a well consolidated, uniform, closed cell foam product results. The closed cell foam produced has excellent flexibility and resistance to heat and flame, and does not shrink appreciably when exposed to flame.

Abstract: A composition for a crosslinked polyolefin foam is prepared from 20 to 75% by weight of a crystalline propylene copolymer containing 1 to 15% by weight of ethylene and having a crystallinity higher than 50% and 80 to 25% by weight of polyethylene.

Abstract: A simplified method of manufacturing a silicone elastomeric foam comprises mechanically generating a stable froth of an aqueous emulsion, while adding surfactant and thickener, then exposing the stable froth to microwave energy to remove the water. The emulsion consists essentially of anionically stabilized hydroxyl endblocked polydiorganosiloxane, colloidal silica, an organic tin compound, and water, the emulsion having a pH in the range of 9 to 11.5 inclusive. The dried froth is an elastomeric, cellular structure possessing typical silicone elastomer heat stability and long-term aging stability.

Abstract: This application is directed to light-weight and hard foam materials. The foams of this invention are prepared by extruding thermoplastic crystalline plastics in the presence of highly volatile organic liquids as the foaming agents. In accordance with the present method crystalline polyolefins, in the presence of polybutadiene, ethylenevinylacetate copolymers, ethylene-propylenes and/or ethylene-propylene terpolymer rubbers, and optionally radical formers such as suitable peroxides, azidene, sulfonyl azidene or the like, and inhibitors for radical decomposition, such as triallylcyanurate or an acrylate selected from the group consisting of trimethylolpropane-trimethacrylate, allyl-methacrylate, tetrahydrofurfurylmethacrylate, triethyleneglycol-dimethacrylate, polyethyleneglycol-dimethacrylate or the like, are converted into foam-like molded bodies by means of a highly volatile organic liquid foaming agent.

Abstract: A process for the manufacture of a resilient foam based on a melamine-formaldehyde condensate, wherein an aqueous or alcoholic solution or dispersion containing a melamine-formaldehyde precondensate, an emulsifier, a blowing agent and a hardener is foamed by ultra-high-frequency irradiation and the foam is hardened by crosslinking the precondensate. The foam may be employed for heat and sound insulation, and as a packaging material.

Abstract: A process for the production of foamed products from an unsaturated polyester resin composition, said composition comprising polyester resin, unsaturated monomer, a promotor, initiator, physical blowing agent, and compatible surfactant whereby a known gel time "T" results, foaming said composition by exposing it to microwave radiation prior to 1 T, thereafter permitting said foam structure to exotherm to obtain a fully cured product. Preferably the resin composition is exposed to the radiation between 0.2 and 0.7 T. Due to the foamed nature of these products, they will find many uses where insulation and light weight is important. End products include foamed unsaturated polyester resins and products incorporating the same such as patio blocks containing a polyester gel-coat, the gel-coat containing sand, decorative chips, or other decorative aggregate. The foam is a mixture of polyester resin and fillers and has a density of about 35 pounds per cubic foot.

Abstract: A molded article simulating the appearance of natural plantation crepe rubber and a method for producing this article. Styrene/butadiene linear or radial block copolymer having a polymerized styrene content of the range of about 20 to about 50 weight percent of the total block copolymer and resinous polymer of vinyl-substituted aromatic compound in the range of about 10 to about 60 parts resinous polymer per 100 parts block copolymer are blended with a sufficient amount of polarizing agent to achieve rapid heating through response to microwave treatment. The composition is melted, molded against a surface mirroring the appearance of plantation crepe rubber, and removed from the mold as an article simulating plantation crepe rubber.

Abstract: A molded article simulating the appearance of natural plantation crepe rubber and a method for producing this article. Styrene/butadiene linear or radial block copolymer having a polymerized styrene content of the range of about 20 to about 50 weight percent of the total block copolymer and resinous polymer of vinyl-substituted aromatic compound in the range of about 10 to about 60 parts resinous polymer per 100 parts block copolymer are blended with a sufficient amount of polarizing agent to achieve rapid heating through response to microwave treatment. The composition is melted, molded against a surface mirroring the appearance of plantation crepe rubber, and removed from the mold as an article simulating plantation crepe rubber.