Abstract: Thermoplastic foams of polystyrene, for example, are prepared with a blowing agent which is a mixture of an organic plasticizing blowing agent, such as pentane, and an atmospheric gas, such as carbon dioxide. Typically, such foams prepared with organic blowing agent alone were aged prior to thermoforming the foam into articles. Foams prepared with the mixed blowing agent of this invention exhibit the advantage of reduced atmospheric emissions on aging.

Abstract: Pressure vessels are disclosed for containing a foamable mixture of liquid and a blowing agent for incrementally or continuously dispensing a foam of constant foam-volume ratio. Liquid compositions having coating or polymeric solids are capable of being foamed and dispensed with the apparatus. The method and apparatus are especially advantageous in dispensing foamed coatings, paints or adhesives with superior control.

Abstract: Mechanically stable styrene polymer foams having highly desirable physical properties are prepared employing as a blowing agent a mixture of lower alcohols with chlorofluoromethanes.

Abstract: A low density foam product is formed from a chlorinated polyvinyl chloride polymer (CPVC) composition containing a primary blowing agent and a nucleating system comprised of an alkali metal borohydride and a proton donor activator.

Abstract: Cellular thermoplastic resin is made by the method and extrusion apparatus that is characterized by a compaction section where the resin is densified, a choke section where a barrier of the densified resin is formed that is substantially impervious to a gaseous blowing agent, and a mixing section where the particulate resin is mixed with a blowing agent and then melted before being extruded into a zone of lower pressure whereby the blowing agent expands to form the cellular product. By mixing the blowing agent with a solid rather than a molten resin, the resulting mixture can be melted at a substantially lower temperature.

Abstract: Compositions comprising propylene polymer, e.g., polypropylene, and hydrated alumina as filler precursor and sole blowing agent, wherein the alumina can be 30 to 60 weight percent of the total composition, are converted into foam having a fine and uniform cellular structure by passage through an unvented extruder at specified temperature profiles and pressures.

Abstract: A method of forming synthetic articles of polyester resin by resin transfer molding techniques or the like comprising combining a set of reactants including a major base mass of polyester resin in fluid form, at least one polyester cure accelerator, a selected quantity of isocyanate, a surfactant and at least one promoter. The isocyanate is added in sufficient quantity to react with at least one other component in the mixture to produce quantities of carbon dioxide throughout the mixture. The resultant mixture is transferred into a closed mold prior to substantial reaction. The promoter is allowed to react exothermically with at least one other component of the mixture to trigger the isocyanate to react to evolve carbon dioxide gas to generate pressure to fill the mold. Thereafter a curing reaction between the cure accelerator and the polyester occurs to cure and solidify the expanded resin to produce an expanded article.

Abstract: The invention provides a novel and improved method for the preparation of a cellular foamed body of a vinyl chloride-based resin having a very fine and uniform cellular structure with high productivity in a continuous process. According to the inventive method, a vinyl chloride-based resin is admixed with a nucleating agent and a foam conditioning resin which is a specified acrylic resin or a styrene-based resin into a resin composition and the resin composition is first heated under pressure to be converted into an at least partly gelled mass, into which a volatilizable foaming agent which is an organic solvent having a boiling point not exceeding 90.degree. C. is injected under pressure so as that the resin composition is uniformly impregnated with the foaming agent. The foaming agent-impregnated and completely gelled resin composition is then brought under a reduced pressure to be expanded into foams with simultaneous cooling.

Abstract: Cellular chlorinated polyvinyl chloride resin is made in an extruder that is characterized by a combination of multiple flights and a plurality of open slots in the mixing section to facilitate mixing of the resin and a blowing agent whereby a rigid thermoplastic cellular product of low density is made that has a predominantly closed cell structure.

Abstract: A mold release agent designed for use with ceramic/polyester molding compositions is disclosed. The mold release agent comprises 15-30 weight percent polyethylene having a molecular weight of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 Saybolt Seconds Universal (SSU) at 100.degree. F. In a preferred molding procedure the surface of the mold is uniformly coated to a thickness of 0.5-2 mm with the mineral oil/polyethylene composition by melt-flow at 200.degree.-300.degree. F.

Abstract: In a process for producing a foamed article of a polyolefin resin which comprises filling in a mold pre-foamed particles of a polyolefin resin containing a gaseous mixture consisting of an inorganic gas and a volatile organic blowing agent in their cells and heating them to mold a foamed article; the improvement wherein the pre-foamed particles of the resin are those in which the total pressure of the gaseous mixture is 1.4 to 2.5 kg/cm.sup.2 (abs.), with the partial pressure of the inorganic gas being maintained at 0.4 to 1.1 kg/cm.sup.2 (abs.) and the partial pressure of the volatile blowing agent at 0.8 to 1.6 kg/cm.sup.2 (abs.).

Abstract: Ammonium nitrate activated or catalyzed with certain chromium compounds provides an excellent, low cost blowing or expanding agent(s) for many foamable polymers, including polyethylene(s), polystyrene(s), etc.

Abstract: Extrusion apparatus and method for making a cellular resin product are characterized by a conduit that extends into the extruder whereby a blowing agent is injected therethrough into the resin through a plurality of ports provided in the conduit in order to disperse the blowing agent more uniformly through the resin before it is extruded through a die into a zone of lower pressure whereupon the blowing agent expands to form numerous cells within the resin structure.

Abstract: What is disclosed is a method for making a foamed resin sheet from a body of hot foamable synthetic resin containing a blowing agent, which method comprises heating said foamable body to a temperature which initiates foaming, limiting lateral expansion of the resulting foam by contact with a limiting surface while permitting free expansion of the foam thickness, then limiting further expansion of the foam thickness by contact with a limiting surface, and then cooling the foam below the foaming temperature while maintaining said limitations on foam expansion in the lateral and thickness directions by contact with said limiting surfaces.

Abstract: An improved process for the foaming of polyolefin materials is disclosed where the polyolefin is crosslinked by a peroxide and foamed by a chemical foaming agent combined with an auxiliary foaming agent is disclosed. According to the invention, the auxiliary foaming is a sterically hindered phenol and/or an organic phosphorus compound.

Abstract: Disclosed are low density foam planks of ethylenic polymers, which planks have a density of from about 0.8 to about 1.6 pounds per cubic foot, dimensional stability, substantially closed-cell structure, a cross-sectional area of at least six square inches and a minimum cross-sectional dimension of at least 0.5 inch. Such foam planks are made from polyethylene resins (e.g., low density polyethylene) by release to lower pressure of a flowable, foamable gel under pressure, e.g., by extrusion foaming, wherein the gel comprises at least one polyethylene resin and at least one volatile blowing agent. The process of making such foam planks is particularly characterized by the improvement wherein the flowable gel is mixed sufficiently to disperse the blowing agent in the gel to an amount from about 13.5 to 35.times.10.sup.4 moles per gram of the ethylenic polymer and such process is especially beneficial in that it enables the preparation of substantially closed-cell polyethylene foams having densities of from 0.

Abstract: A method for providing pellets of extrusion compounded expandable polymeric compositions by (a) introducing a blowing agent and polymeric compound into an extruder, (b) extruding a composition containing the blowing agent and polymeric compound with discharge of the extrusion underwater through a pelleter at a temperature below blowing agent activation temperature, (c) supplying a stream of water across the die face of the pelleter at a predetermined first temperature sufficient to produce pellets, (d) supplying additional transport water downstream of the pelleter to further cool the pellets to a second predetermined temperature, and (e) separating the cooled pellets from the transport water. In an additional embodiment collecting the separated pellets, conditioning the transport water to the first predetermined temperature, and recycling the transport water to the die face.

Abstract: The present invention relates to a composition comprising a blowing agent and an activator characterized in that the blowing agent and activator have been micronized together rather than separately as hitherto; to methods for making the composition and to the use of the compositions in expanding polymers.

Abstract: A fluid transmitting polyolefin foam having a special open-cell cellular structure as compared with the conventional polyolefin foams having all cells closed is disclosed. Such a novel fluid transmitting polyolefin foam is produced by mixing a polyolefin with a polymer other than a polyolefin, said polyolefin and/or said polymer other than a polyolefin having a blowing agent incorporated therein and/or adhered thereto and subjecting the resulting mixture to extrusion moulding. The present fluid transmitting polyolefin foam has a wide variety of uses, for example, as a synthetic leather, synthetic filter cloth, separator of storage battery, synthetic paper, package, etc.

Abstract: A low density foam product is formed from a chlorinated polyvinyl chloride polymer (CPVC) composition containing a primary blowing agent and a nucleating system comprised of an alkali metal borohydride and a proton donor activator.

Abstract: This invention concerns sprayable emulsions of a foamable polymer in water which are useful as aerosol caulking or insulating compositions.

Abstract: Composition of matter adapted to be foamed into essentially a closed cell structure, preponderance of the cells being less than 500 microns in size and containing a chlorofluoroalkane of 1 to 2 carbon atoms, said composition comprising chlorinated polyvinyl chloride resin, and effective amount of a blowing agent, an effective amount of a nucleating agent, and 5 to 20 parts of a processing aid per 100 parts of said resin, said processing aid has a dilute solution viscosity of greater than 2.5 and is selected from copolymers of styrene and acrylonitrile containing 10 to 40% of acrylonitrile.

Abstract: Disclosed are low density foam planks of ethylenic polymers, which planks have a density of from about 0.8 to about 1.6 pounds per cubic foot, dimensional stability, substantially closed-cell structure, a cross-sectional area of at least six square inches and a minimum cross-sectional dimension of at least 0.5 inch. Such foam planks are made from polyethylene resins (e.g., low density polyethylene) by release to lower pressure of a flowable, foamable gel under pressure, e.g., by extrusion foaming, wherein the gel comprises at least one polyethylene resin and at least one volatile blowing agent. The process of making such foam planks is particularly characterized by the improvement wherein the flowable gel is mixed sufficiently to disperse the blowing agent in the gel to an amount from about 13.5 to 35+10.sup.-4 moles per gram of the ethylenic polymer and such process is especially beneficial in that it enables the preparation of substantially closed-cell polyethylene foams having densities of from 0.

Abstract: The present invention relates to a composition comprising a blowing agent and an activator characterised in that the blowing agent and activator have been micronised together rather than separately as hitherto; to methods for making the composition and to the use of the compositions in expanding polymers.

Abstract: Elevated temperature distortion characteristics of freshly prepared olefin polymer foams are substantially improved by employing in the preparation thereof a small amount (e.g., from about 0.15 to about 10 weight percent based on the olefin polymer) of certain selected N-substituted fatty acid amide compounds of the formula: ##STR1## wherein R.sub.1 represents an alkyl group of from 11 to 17 carbon atoms and R.sub.2 represents an alkyl group of from 12 to 18 carbon atoms.

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: Composition of matter that can be foamed to form an expanded product having density of less than 20 lbs/ft.sup.3 and containing a preponderance of the cells in the size range of less than 500 microns comprising a mixture of chlorinated polyvinyl chloride, 5 to 50 parts by weight of the chlorofluoroalkane of 1 to 2 carbon atoms as a primary blowing agent and 0.01 to 2 parts by weight of azodicarbonamide that is dispersed through the resin and forms cell nuclei from which expanded cells are created, all based on 100 parts by weight of the resin.

Abstract: Improved polymeric foams are obtained by the introduction of a beneficial additive to the system by dissolving said additive into a liquid foaming agent which is a solvent therefor, combining the solution with the polymer and extruding the polymer in foamed form.

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: 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: The use, in an otherwise conventional polyolefin extrusion foaming process, of a stability control agent (e.g., stearamide, EAA copolymer, etc.) in conjunction with certain mixed blowing agent systems (e.g., 5-50 weight percent trichloromonofluoromethane and 50-95 weight percent dichlorodifluoromethane) provides closed-cell olefin polymer foam articles having increased maximum achievable cross-sections and good dimensional stability.

Abstract: A cellular polymeric resin sheet, slab or the like is produced by filling a pressure resistant receptacle having a cover directly releasably locked thereto with a uniform mixture of a resin such as polyvinyl chloride, a finely divided heat activated first gas generator and preferably a water activated second gas generator together with other additives such as plasticizers, stabilizers, etc. The closed receptacle is heated to effect the gelation and fusion of the resin and the activation of the first gas generator to produce a high density uniform small pore cellular resin body embryo under high pressure in the receptacle. The receptacle and embryo are cooled, the receptacle opened and the embryo removed and subjected to a high humidity atmosphere, preferably at elevated temperature to activate the second gas generator and react therewith.

Abstract: A method for manufacturing a low density synthetic resin foamed body is disclosed which is characterized by the steps of filling a mixture of 100 parts by weight of an ethylene-vinyl acetate copolymer, 20-80 parts by weight of a foaming agent, and 1.0-5.0 parts by weight of a crosslinking agent in a mold, closing the mold with a lid, heating the mold to form a foamed body, cooling the foamed body as it is kept in the mold, and opening the lid of the mold.

Abstract: The dimensional stability of relatively unstable substantially closed-cell low density foams of non-ionic ethylenic polymers (e.g., polyethylene, ethylene/vinyl acetate copolymers, etc.) can be notably improved by the incorporation therein (during the preparation thereof) of from about 5 to about 95 weight percent (based on total polymer weight) of a copolymer of ethylene with from about 3 to about 45 weight percent of a monoethylenically unsaturated carboxylic acid.

Abstract: A foam composition comprising an ethylene-chlorotrifluoroethylene copolymer, a blowing agent and a nucleating agent. The nucleating agent is the carbonate or oxide of a metal cation from the group of metals consisting of magnesium, calcium, barium, zinc and lead. The invention also is a method of making the above foam copolymer composition.

Abstract: A novel method of making foamed, crosslinked low density polyethylene utilizing as dual crosslinking/blowing agents, organic peroxides of the formula: ##STR1## where each R is a t-alkyl group bonded through its tertiary carbon atom and having 4-8 carbon atoms; and R' is an alkyl group of 1-6 carbon atoms.

Abstract: A cross-linked, cellular elastomeric composition is made from a formulation which includes one or more natural and/or synthetic rubbers, a cross-linking agent, a monomeric metallic salt of an ethylenically-unsaturated carboxylic acid and a blowing agent. The metallic salt is preferably basic zinc methacrylate. The composition may be used to provide a core for a tennis-ball or a sponge for a table-tennis bat. The former use enables advantage to be taken of the properties hitherto only found in pressurized playballs, while the latter use leads to a marked increase in the speed of the ball when struck by the bat.

Abstract: Polyolefin foam having small, uniform cell size is prepared (1) by mixing a polyolefin resin with (a) a volatile organic blowing agent and (b) from about 0.1 to about 5 weight percent, based upon the polyolefin resin weight, of a cell control agent (e.g., such as amorphous silica having a pH of from 3.5 to 4.5), said cell control agent being in the form of nonporous microspheres having an average particle size of from about 5 to about 100 m.mu. and (2) by thereafter extrusion-expanding the resultant mixture.

Abstract: A blowing agent composition comprises azodicarbonamide, 0.005 to 5% by weight, based on the weight of azodicarbonamide, of a chromium sulphate, and 0.005-1% by weight, based on the weight of azodicarbonamide, of at least one zinc compound selected from zinc salts and oxides.

Abstract: A method of forming a foam-skin insulation on telephone wires, wherein a homogenuous flow of basic plastic is divided into two separate flows one of which is subjected to mixing with a foam agent while the other, intended to form an outer layer of solid plastic, is bypassed directly to an extruder tool. The apparatus used for the method comprises one single extruder, the extruder head whereof is provided with a flow dividing piece guiding one flow past foam injecting nozzles and the other flow through a separate branch channel to the extruder tool.

Abstract: A method for the preparation of polysulfone foam using methylene chloride as a blowing agent. A pressurized combination of heat-plastified foamable gel of polysulfone containing methylene chloride as a blowing agent is extruded into a zone of lower pressure through an orifice of a die. As the gel expands into a foam, it forms a product of decreased density, increased resiliency and flexibility, and improved insulation properties over conventional polysulfone foam.

Abstract: An improved foamable dielectric composition comprising a melt extrudable perfluorocarbon resin containing therein (i) a polytetrafluoroethylene (PTFE) nucleating agent and (ii) a volatile blowing agent, preferably a lower fluorocarbon blowing agent having only one or two carbon atoms; a process for forming such a composition; and, products produced therewith. More specifically, a foamed melt extrudable fluorinated ethylene-propylene (FEP) polymer containing therein a PTFE nucleating agent and blown to a foamed structure by means of a volatile fluid--e.g., a lower fluorocarbon such as fluoromethane or, preferably, fluoroethane, a process for forming such a foamed compostion; and, products produced therewith such as jacketed electrical conductors and/or coaxial cables wherein at least one conductor is bonded to such a foamed melt extrudable resin.

Abstract: A particulate concentrate, for example pellets, is provided comprising predetermined amounts of a pigment and a blowing or foaming agent in a polymer matrix. The concentrate can be added to an extruder together with a polymer insulating material for the formation of color-coded cellular insulation on a conductor wire of a cable, for example a communication cable. The composition of the concentrate is so determined that different color-coded, cellular, insulating coatings can be produced which are dielectrically matched, as required.

Abstract: Foams of polypropylene resin composition having remarkably improved extrusion foaming characteristics are prepared by a non-crosslinking extrusion foaming process comprising mixing and kneading polypropylene resin and 1,2-polybutadiene resin so that 1,2-polybutadiene resin reacts under the influence of the heat and shearing stress in the extruder, and extruding thereafter.

Abstract: Injection moldings have excellent surface gloss and freedom from sink marks are obtained using a pressurized mold and molding composition containing a volatile fluid foaming agent, a thermally decomposable foaming agent and a finely divided nucleating agent.

Abstract: A mat material suitable for use for reinforcing plastics, as an upholstery material, filter material and various other purposes is made by melt spinning a synthetic polymeric material onto a moving embossed surface where the filaments become melt fused together at mutual points of contact. A gas or gas producing substance is mixed with the melt prior to extrusion to produce a plurality of adjacent, separate, discontinuous cavities in the filament.

Abstract: The instant invention is directed to a process for the production of microcellular elastomeric moldings comprising:(A) introducing a reaction mixture into a closed mold, said reaction mixture comprising:(i) an organic polyisocyanate,(ii) a hydroxyl group containing compound having a molecular weight of from 1800 to 12,000,(iii) a catalyst for the reaction between hydroxyl groups and isocyanate groups,(iv) an active aromatic diamine having at least one alkyl substituent in the orthoposition to a first amino group and two alkyl substituents in ortho-position to a second group, and(v) air and/or nitrogen dissolved under pressure in any one or more of Components (i), (ii), (iii) or (iv),(B) allowing said reaction mixture to react in said mold and(C) removing the resultant product from said mold, the improvement wherein in any of Components (i), (ii), (iii) or (iv) which does contain said air and/or nitrogen dissolved therein there is included an inorganic, finely divided, nitrogen adsorbing agent in an amount suf

Abstract: This invention provides a commercially advantageous process for producing a foamed article of an aromatic polyester, especially a large-sized foamed article of aromatic polyester having a high expansion ratio. The process comprises mixing an aromatic polyester, a polyepoxy compound, a compound of a metal of Group Ia, IIa or IIIa of the periodic table and a blowing agent in a melt extrusion molding machine optionally with a fibrous filler while introducing the blowing agent thereinto under pressure, extruding the molten mixture from the molding machine, further expanding the foamed unsolidified extrudate in an atmosphere maintained at reduced pressure, and solidifying it by cooling in an atmosphere maintained at reduced pressure. The resulting aromatic polyester foamed article has numerous fine cells having uniform volumes, shapes and distribution.

Abstract: Novel polyester diols are described containing aliphatically saturated divalent diacyl moieties and olefinically unsaturated divalent diacyl moieties in a mole ratio of 0.25:1 to 3:1; and divalent dioxy moieties which are linear and/or branched, preferably divalent branched dioxy moieties and divalent linear dioxy moieties in a mole ratio of 0.3:1 to 3:1, the diacyl moieties being bonded through ester linkage to the dioxy moieties in a mole ratio of at least 1.75 dioxy moieties per diacyl moiety, wherein the polyester diol is end-blocked essentially only by alcoholic hydroxyl groups and has an acid number of less than 3. The novel polyester diols are highly useful in the production of polyurethane/vinyl polymer copolymers by reaction with polyisocyanates and polymerizable ethylenically unsaturated monomers.

Abstract: A mixture of azodicarbonamide and an .alpha.-amidosulphone corresponding to the general formula: ##STR1## in which R represents hydrogen, a C.sub.1 -C.sub.4 -alkyl residue and/or halogen,x represents numbers from 0 to 5,y represents numbers from 1 to 3, corresponding to the valency of R.sub.1,R.sup.1 represents an aromatic carboxylic acid residue or sulphonic acid residue with 6 carbon atoms, which is optionally substituted once or several times by halogen, C.sub.1 -C.sub.4 alkyl residues, C.sub.1 -C.sub.4 alkoxy residues, nitro and/or cyano, or represents an aliphatic carboxylic acid residue or a sulphonic acid residue with 1-4 carbon atoms, a carbonic acid residue, a thiocarbonic acid residue or a phosphoric acid residue which, corresponding to the numerical value of y, contains 0-2 phenoxy residues or C.sub.1 -C.sub.4 alkoxy residues optionally substituted with C.sub.1 -C.sub.4 alkyl or halogen,R.sup.2 represents R.sup.1, or hydrogen, a C.sub.1 -C.sub.4 alkyl residue, a C.sub.5 -C.sub.