Abstract: An expandable resin/rubber blend comprising a butadiene-acrylonitrile rubber, a vinyl chloride resin, and a polymethylmethacrylate, adapted to form chemically blown, predominantly closed cell foam in a density range of about 1.8-4 pounds/cu. ft.

Abstract: Incorporating 500 to 5,000, preferably 2,000 to 4,000 parts per million of Fischer-Tropsch wax of high congealing point into beads of expandable polystyrene made by suspension polymerization yields greater advantages, and conditions (time, temperatures, and recipe) of the polymerization become less critical. The drying or conditioning step before the pre-expansion under particular conditions to generate a suitable cell structure need not be followed, and a step of coating with zinc stearate or the like before the pre-expansion may be omitted. Unexpanded beads are obtained which yield consistent cell structure, independent of conditions of their storage. Beads of higher pentane content can be used, and final articles of lower density may be obtained. The throughput of the pre-expander may be increased, and the beads, after pre-expansion, have good free-flowing (reduced clumping) and mold-filling characteristics.

Abstract: A polyolefin filter for tobacco products and the like was prepared. The extruded element is an open-cell foamed polyethylene or polypropylene having a TPM filtration efficiency greater than 20%. The filter rod can be made by extruding polyethylene containing less than 0.2 moles of a volatile blowing agent per 100 grams of resin at a melt temperature between 130.degree. C. and 150.degree. C., the temperature of the die being between 120.degree. C. and 136.degree. C. Higher melt temperature and die temperature are required for polypropylenes.

Abstract: Extruded synthetic resinous thermoplastic foams of increased cell size are obtained when using volatile fluid blowing agents by incorporating a cell-size enlarging agent into the extruded composition, the cell-size enlarging agent being liquid at the foaming temperature and generally soluble in the heat-plastified foamable mixture.

Abstract: Improved polyolefin foams, particularly polystyrene foams, and improved extrusion processability thereof are obtained by employing as blowing agent a mixture of from about 3 to about 70 weight percent monochloromonofluoromethane and from about 97 to about 30 weight percent of dichlorodifluoromethane.

Abstract: The process for the preparation of shaped bodies based on expanded styrene polymers comprising: the polymerization of styrene or a mixture thereof with at least one monomer copolymerizable therewith, the addition of an expanding agent, pre-forming of the resulting expandable particles, ageing of the pre-formed particles, and molding thereof in a pressure resistant mold, is improved in the decrease of the minimum mold dwell time by carrying the polymerization in the presence of 0.0005 to less than 0.01% by weight based on the styrene polymer of organic bromine compounds which give a chain transfer constant of at least 200 and at 100.degree. C. in bidistilled water the bromine compounds split off less than one molar % of hydrogen bromide per equivalent of bromine present in the molecule.

Abstract: Low density foams from polyethylene blends having substantially closed cell structure and improved compressive strength are prepared using gel-forming extrusion technology. The polyethylene blend comprises from about 35 to about 60 weight percent of low density branched polyethylene in admixture with from about 40 to about 65 weight percent of intermediate density linear polyethylene. An exemplary blowing agent is 1,2-dichlorotetrafluoroethane, there being up to about 0.12 gram-mole of such blowing agent per 100 grams of resin blend in the flowable gel.

Abstract: Particulate self-extinguishing thermoplastic molding compositions based on styrene polymers containing volatile blowing agents are surface-coated with an organic bromine compound and, to stabilize the bromine compound against photodegradation, a N-hydroxyphenylbenzotriazole or a hydroxybenzophenone. The molding compositions may be used for the manufacture of foams by expanding the blowing agents at elevated temperatures.

Abstract: Low density, closed cell, soft foam products having dimensional stability are made from ethylenic resin blends having low stiffness by extrusion foaming, wherein the heat plastified gel comprises the ethylene polymer blend and at least one volatile blowing agent. The blends especially comprise a copolymer of ethylene and monoethylenically unsaturated carboxylic acid and a copolymer of ethylene and at least one monoethylenically unsaturated non-ionic comonomer. The starting ethylenic resin blends are preferably blends of ethylene acrylic acid copolymers and ethylene vinyl acetate copolymers, having stiffness less than about 20,000 psi. Exemplary volatile blowing agents are 1,2-dichlorotetrafluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane and 2,2-difluoropropane.

Abstract: There is disclosed a process for the preparation of expandible particles of styrene-based polymers which are useful for the production of molded bodies, especially large blocks, having a uniform cellular structure, and with a particularly short time of residence in the mold.

Abstract: The invention provides finely grained, expandable particles of a styrene homopolymer or copolymer which contain an expanding agent and a flameproofing organic halogen compound as well as, in addition a 2,4-diamino-1,3,5-triazine derivative.

Abstract: A porous, hydrophilic, assimilable prosthesis is formed by the removal of solvent, without substantial dimensional change, from a solution of (a), an assimilable polymer composed primarily of polymerized units of an alpha or beta hydroxy carboxylic acid, preferably but not necessarily those having 1 to 4 carbon atoms, and (b), a small amount of a physiologically acceptable wetting agent that is sufficient to impart hydrophilicity to the prosthesis. The preferred assimilable polymer is a polylactic acid. The preferred process for making the prosthesis involves the lyophilization of a solution of polylactic acid having a molecular weight of at least 100,000, weight average, at a concentration of at least 31/2% by weight of the solution of the polylactic acid. A variety of physiologically acceptable wetting agents is useful, a preferred class being the alkali metal soaps of fatty acids or of alkyl aryl sulfonic acids.

Abstract: A flame-retarding additive for foamed polystyrene is composed of 40 to 56 weight percent of halogenated hydrocarbon, 9 to 15 weight percent of antimony oxide, 14 to 22 weight percent of zinc borate, and 16 to 28 weight percent of hydrated alumina.

Abstract: Foamed, low density polymeric articles have been fabricated from a non-tacky hydrogel obtained by blending normally solid thermoplastic polymer resin with a normally liquid organic solvent and water, at lower molding temperatures and energy requirements than those conventionally used in melt extrusion foam processing.

Abstract: Aromatic polyamide foams having a density of 0.025 to 0.7 g./cm..sup.3 are prepared by heating N,N'-dialkyl aromatic polyamides having at least one .beta. hydrogen atom on the alkyl groups, a plasticizer and an aromatic sulfonic acid catalyst at 250.degree. to 340.degree. C. for a length of time sufficient to remove substantially all of the N-alkyl groups.

Abstract: In the production of a foamed synthetic material by the reaction of starting materials which undergo a polymerization, polycondensation or polyaddition reaction to produce a high molecular weight synthetic material in the presence of a blowing agent, e.g. a polyurethane, or by foaming an unfoamed thermoplastic synthetic material by means of a blowing agent, the improvement which comprises employing 1,1,1-trifluoro-2-chloroethane as the blowing agent, optionally in admixture with 1,1-difluoro-2-chloroethane.

Abstract: A durable, light-weight interliner exhibiting enhanced insulative and cushioning properties is produced from a blend of approximately equal parts of a thermoplastic elastomer and an ionomer foamed by a normally gaseous expanding agent.

Abstract: Silicon halides will react chemically with polyols to produce polyol silicate resinous products which will react chemically with polyisocyanates to produce polyisocyanate silicate solid or cellular solid products.

Abstract: Expandible polystyrene particles useful for making molded bodies, particularly large blocks having a uniform cellular structure and a particularly short residence time in the mold, are prepared by polymerizing styrene in the presence of at least one ether having the general formula (III) or (IV): ##STR1## wherein: R.sub.1 and R.sub.2, which may be the same or different, are alkyl or cycloalkyl radicals and/or phenyl radicals, optionally halogen-substituted;R.sub.5 is a non-halogenated alkyl radical having 4 to 30 carbon atoms or a fully or partially halogenated alkyl radical having 9 to 30 carbon atoms;X is a halogen or an alkyl radical, optionally halogenated, having 1 to 8 carbon atoms;N is an integer from 0 to 4;M is an integer from 0 to 5, andR.sub.3 and R.sub.4, which may be the same or different, are alkyl radicals, optionally halogenated, having 1 to 30 carbon atoms, with the exception that, when R.sub.1 and R.sub.2 are alkyl radicals, X is bromine and n is 2, R.sub.3 and R.sub.

Abstract: The method of production of chemically set compositions which show no shrinkage or which increase their volume during setting finding their application in building engineering, electrotechnical engineering and other fields of technology, consists in adding a special expanding system to a composition comprising synthetic resins or elastomers. Said system consists of an expanding agent, an expansion promoter, and if need be an expansion moderator, and sodium and/or potassium and/or magnesium fluosilicate. As the expanding agent substances are used having a porous structure and sorption properties, as for instance aluminosilicates, and as the expansion promoter substances are used having a polar structure and a critical diameter of the molecule smaller than that of the pores of the expanding agent, as for instance alcohols.

Abstract: There are described expandable molding compositions of styrene polymers containing 1,2,3,4,5,6-hexabromohexene-1 or 1,2,3,4,5,6-hexabromohexene-3 or mixtures thereof as the flame-retarding agent, and showing a favorable combination of improved properties, especially high pre-foaming velocity, good welding, rapid mold-releasing and good flame-retardance.

Abstract: Certain polymeric modifiers are surprisingly effective for injection molding and extruding thermoplastic structural foam of lower density, improved appearance, more uniform cell structure, and for lowering injection molding cycle time.

Abstract: Low density, closed cell, soft foam products having dimensional stability are made from ethylenic resins having low stiffness, especially comprising copolymers consisting essentially of ethylene and monoethylenically unsaturated non-ionic comonomers, by release to lower pressure of a flowable, foamable gel under pressure, e.g., by extrusion foaming, wherein the gel comprises the ethylenic polymer and a volatile mixed blowing agent. The starting polymers are preferably copolymers of ethylene and vinyl acetate having stiffness less than about 20,000 psi. The mixed blowing agents are particularly characterized as mixtures of dichlorodifluoromethane and at least one fluorocarbon constituent A, as defined. Exemplary mixtures contain (I) dichlorodifluoromethane and (II) from 35 to 50 percent chloropentafluoroethane, octafluoropropane or octafluorocyclobutane based on the mixtures of I and II.

Abstract: Foamed, low density polymeric articles have been fabricated from a non-tacky hydrogel obtained by blending normally solid thermoplastic polymer resin with a normally liquid organic solvent and water, at lower molding temperatures and energy requirements than those conventionally used in melt extrusion foam processing.

Abstract: A rigid, dimentionally stable, distortion-free article of foamed polyvinyl aromatic resin, having a solid outer skin, is formed by incorporating in a foamable polyvinyl aromatic resin a finely, divided inert solid that has been surface treated to render the solid hydrophobic and then molding the foamable composition under foaming conditions. Foamed polyvinyl aromatic resin articles molded in accordance with the present invention have physical dimensions capable of meeting tolerances in the order of .+-. 0.002 inches and are suitable for use in the manufacture of precision measuring devices and, particularly, frames for level instruments.

Abstract: A method of producing a low density polyethylene foam by extruding a melt blend containing polyethylene, an ionomer, a nucleating system and two expanding agents having substantially different vapor pressures and solubility in the melt blend.

Abstract: Foamed thermoplastic mixture of ionomers and polyolefin polymers are produced by extruding the mix together with a volatile blowing agent at elevated temperature and pressure. The density of the foamed products is from of 15 to 45 Kg/m.sup.3 and they satisfy the requirements of extrusion foamability, compressive strength or rigidity, thermal resistance and adhesion properties.

Abstract: Low density, closed cell, soft foam products having dimensional stability are made from ethylenic resins having low stiffness, especially comprising copolymers consisting essentially of ethylene and monoethylenically unsaturated non-ionic comonomers, by release to lower pressure of a flowable, foamable gel under pressure, e.g., by extrusion foaming, wherein the gel comprises the ethylenic polymer and a volatile mixed blowing agent. The stating polymers are preferably copolymers of ethylene and vinyl acetate having stiffness less than about 20,000 psi. The mixed blowing agents are particularly characterized as mixtures of at least one fluorocarbon constituent I and at least one fluorocarbon constituent II, as defined. Exemplary mixtures contain (I) 1,2-dichloro-1,1,2,2-tetrafluoroethane and (II) from 25 to 50 percent chloropentafluoroethane, octafluoropropane or octafluorocyclobutane based on the mixtures of I and II.