Abstract: Prefoamed crosslinked propylene-type resin particles prepared by using as a base resin a propylene random copolymer whose amount of heat of crystallization determined by a DSC method is 19 to 10 cal/g. The prefoamed particles have a gel fraction of 1 to 65%. Also provided is a molded article of a crosslinked propylene-type resin which is a fused aggregate of the aforesaid prefoamed particles in which the number of cells, N per mm.sup.2, and the density, d (g/cm.sup.3), have the relation represented by the expression 2<N.sup.1/2 /d.sup.1/3 <45.

Abstract: This invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, useful as thermal insulating plate materials or anti-shock molded vessels, and foam particles or expandable particles convenient for preparation thereof, and also a series of advantageous foaming techniques for completion of such a molding. The above foam molding can be prepared by bringing fine particles of a non-crystalline vinylidene chloride type resin obtained generally by suspension polymerization into contact with a volatile organic blowing agent thereby impregnating the resins with the blowing agent to form expandable resin particles, which are in turn subjected to expansion as such, or after forming into pre-expanded foam particles including expandable gas therein, by filling in a mold cavity which can be closed but not sealed, under heating to form a molding through fusion mutually between the expanded particles.

Abstract: A process for producing foamed particles of a polyolefin resin which comprises dispersing polyolefin resin particles in water in a closed vessel, feeding a volatile blowing agent into the closed vessel, heating the dispersion to a temperature above the softening point of the polyolefin resin particles but below their melting point, opening a discharge port provided within the closed vessel below the water surface and releasing the aqueous dispersion containing the polyolefin resin particles impregnated with the blowing agent into an atmosphere kept at a lower pressure than the pressure within the closed vessel; wherein(i) when the last portion of the aqueous dispersion containing the polyolefin resin particles impregnated with the blowing agent is released from the closed vessel, the pressure within the closed vessel is at least 5 kg/cm.sup.2.

Abstract: For use in an automobile bumper, a core material composed of a molded article of prefoamed polyolefin resin particles. The core material has a density of 0.05 to 0.15 g/cm.sup.3 and the relation represented by the following expressionE.sub.20 /.rho..gtoreq.20 kg-cm/gwherein E.sub.20 is the amount of energy absorption (kg-cm/cm.sup.3) when the core material is compressed to 50% at 20.degree. C., and .rho. is the density (g/cm.sup.3) of the core material.

Abstract: In producing a foam by foaming a melt-plasticized styrene/maleic anhydride copolymer resin, a process for producing a highly foamed styrene/maleic anhydride copolymer resin foam characterized by using as the blowing agent at least one compound selected from the group consisting of a carboxylate of a metal of group Ia of the periodic table of elements, a carbonate of a metal of group Ia, a carboxylate of a metal of group IIa and a carbonate of a metal of group IIa; or by first blending with said copolymer resin at least one compound selected from the group consisting of a carboxylate of a metal of group Ia of the periodic table of elements, a carbonate of a metal of group Ia, a carboxylate of a metal of group IIa and a carbonate of a metal of group IIa, then melt-blending the mixture, followed by extruding and granulating the blend to form a pre-expanded granular product, and thereafter foaming the granular product thus obtained.

Abstract: Preliminarily foamed particles of a non-crosslinked polypropylene resin based on an alpha-olefin/propylene random copolymer having an amount of the heat of crystallization in the range of 5 to 15 cal/g, said preliminarily foamed particles having such a crystal structure that when a DSC curve is drawn by means of a differential scanning calorimeter, by heating 1 to 3 mg of the preliminarily foamed particles to 220.degree. C. at a rate of 10.degree. C./min., a high temperature peak is observed at a higher temperature than the temperature of the peak inherent to the base resin.

Abstract: The foam of the present invention, which has a multi-cellular structure including many wrinkles having one end in the boundary portion where at least three cells are adjacent to one another and extending toward the central portion of the cell wall, is a rigid thermoplastic resin foam having an ultra-low density, a high sound-insulating property, a high heat-insulating property and a high flexibility, and it is suitable for adaption for building construction. The process of the present invention is to provide the aforesaid foam of the present invention by subjecting the foam of a rigid thermoplastic resin to expansion, contraction and aging.

Abstract: An improved process for the manufacture of crosslinked copolymer particles from seed particles by imbibing a monomer therein and polymerizing the same under controlled suspension conditions wherein said improvement comprises expanding the seed in staged or sequential steps of feeding lower levels of crosslinking monomers in the early stages and preferably higher levels of crosslinking monomers at later stages of polymerization.

Abstract: Expandable beads and the like of thermoplastic organic polymer material, advantageously lightly-crosslinked in preparation, which are imbibed with halocarbon and/or light hydrocarbon (including mixed) blowing agents are advantageously tempered to provide excellent quality, uniformly fine-celled expanded cellular products therefrom by a quick quench from imbibition temperature to below 10 or so .degree. C. within one minute.

Abstract: In pre-foamed particles of a propylene-base resin obtained by foaming raw particles of the propylene-base resin, the relation, G.sub.1 -G.sub.2 .gtoreq.10%, exists between the content G.sub.1 (%) of matter, which is contained in the pre-foamed particles and is insoluble in boiling n-heptane, and the content G.sub.2 (%) of matter contained in the raw particles and insoluble in boiling n-heptane. The pre-foamed particles have excellent moldability and can hence provide with ease low-density (highly-expanded) molded articles, which enjoy superb dimensional accuracy, good surface conditions, low percent water absorption, excellent impact and chemical resistance.

Abstract: Polystyrene beads having antistatic properties are prepared by adding the antistatic compounds to the beads during the pre-expansion step. The beads may then be employed to prepared molded products without any further treatment with antistatic agents.

Abstract: This invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, useful as thermal insulating plate materials or anti-shock molded vessels, and foam particles or expandable particles convenient for preparation thereof, and also a series of advantageous foaming techniques for completion of such a molding. The above foam molding can be prepared by bringing fine particles of a non-crystalline vinylidene chloride type resin obtained generally by suspension polymerization into contact with a volatile organic blowing agent thereby impregnating the resins with the blowing agent to form expandable resin particles, which are in turn subjected to expansion as such, or after forming into pre-expanded foam particles including expandable gas therein, by filling in a mold cavity which can be closed but not sealed, under heating to form a molding through fusion mutually between the expanded particles.

Abstract: A pre-expanded particle suitable for foaming in a mold comprising polyolefin which has a characteristic property that an inclination of slope line obtained on a graph when logarithmic values of melt tension of the polyolefin are plotted as ordinate and reciprocals of absolute temperature at which the melt tension is measured are plotted as abscissa is less than 1,500 is provided. A foamed article produced from the pre-expanded particles has an excellent appearance, a flat surface and good mechanical strength, and is useful for wrapping material, insulating material, a container or a fender of cars.A process for preparing the above-mentioned pre-expanded particles is also disclosed.

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: A process for preparing pre-expanded particles of a thermoplastic resin which comprises; heating under an elevated pressure an aqueous dispersion comprising thermoplastic resin particles containing a volatile foaming agent and an aqueous medium in a pressure vessel; releasing the dispersion from the pressure vessel into a space within a sealed low-pressure vessel wherein the pressure is lower than that in the pressure vessel, whereby expanding the thermoplastic resin particles to give pre-expanded particles; and simultaneously recovering the foaming agent volatilized from the thermoplastic resin particles by discharging the foaming agent out of the space in the low-pressure vessel with controlling the pressure in the low-pressure vessel to substantially a given pressure. According to the process, the release of the volatile foaming agent into the air is prevented.

Abstract: A process for preparing pre-expanded particles of a thermoplastic resin which comprises; heating under an elevated pressure an aqueous dispersion comprising thermoplastic resin particles containing a volatile foaming agent and an aqueous medium in a pressure vessel; releasing the dispersion from the pressure vessel into a space within a sealed low-pressure vessel wherein the pressure is lower than that in the pressure vessel and the space is sealed with an aqueous medium which exists in the lower portion of the vessel and communicates with the outside of the vessel, whereby expanding the thermoplastic resin particles to give pre-expanded particles; and sinking the resulting pre-expanded particles under the aqueous medium by means of a rotary impeller provided in the pressure vessel so that the pre-expanded particles are taken out of the low-pressure vessel through the aqueous medium towards the outside of the vessel, while recovering the foaming agent volatilized from the thermoplastic resin particles by disc

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: A process for expanding expandable thermoplastic microspheres containing a blowing agent which will be volatilized at heating. A slurry of the unexpanded spheres is fed to a pressure zone together with steam whereby volatilization of the blowing agent occurs in the zone and the expanded microspheres are then allowed to leave the zone at a considerable pressure drop.

Abstract: A core material for automobile bumpers which is composed of a molded article of foamed particles of a polypropylene-type resin. The molded article has a density of 0.015 to 0.045 g/cm.sup.3 and a compression stress at 50% compression of at least 1 kg/cm.sup.2. The core material simultaneously has excellent energy absorbing property and dimensional recovery and a low density.

Abstract: A process for producing pre-foamed particles of a polypropylene resin which comprises expanding original pre-foamed particles of a polypropylene resin, said original pre-foamed particles having the following relation2<E.sup.1/3 .times.n.sup.1/2 <45wherein E is the expansion ratio of the original pre-foamed particles, and n is the number of cells per mm.sup.2 of the cross section of the original pre-foamed particles,by (1) imparting expanding ability to the original pre-foamed particles and then heating them with a heated gas to the heat distortion temperature of the base resin of the pre-foamed particles or a higher temperature or (2) heating the original pre-foamed particles with steam to the heat distortion temperature of the base resin of the particles or a higher temperature with or without imparting expanding ability thereto, whereby pre-foamed particles having an expansion ratio higher than the original expansion ratio E are obtained.

Abstract: A sprayable, modified polyisocyanurate solid or foam composition, with fast reaction times and excellent fire properties and capable of being sprayed in a one-to-one, fixed-volume spray system, is prepared by the reaction of a low-functionality MDI, with a polyol composition comprising a methoxy polyethylene glycol and a methyl glucoside polyol, the reaction carried out in the presence of a trimerization catalyst, to provide a sprayable polyisocyanurate composition particularly useful for spraying upright and overhead surfaces, due to the fast reaction time and rapid cure.

Abstract: Resilient foam particles and moldings are obtained employing a lightly crosslinked polymer such as a styrene polymer with volatile fluid foaming agent that has low permeability through the polymer. Multiple expansion will permit low density particles for molding.

Abstract: A polyisocyanurate coating composition, which composition comprises and is prepared by reaching 100 parts of a methylene diisocyanate, having an average functionality of less than about 2.4, with a mixture of a di or triethylene glycol and a methoxy polyethylene glycol, the reaction carried out in the presence of a trimerization catalyst, and to a polyisocyanurate-coated, rigid-foam insulation board coated with such composition.

Abstract: Prefoamed polymer particles having excellent moldability are produced by a process comprising a step (impregnating step) of impregnating carbon dioxide or carbon dioxide and a volatile blowing agent in polymer particles, a step (dispersing step) of dispersing the polymer particles into a dispersion medium in a sealed vessel, a step (heating step) of heating the polymer particles to a temperature higher than the softening point of said polymer particles, and a step (releasing step) of opening one end of said vessel and simultaneously releasing the polymer particles and dispersion medium from inside the vessel to an atmosphere held at a pressure lower than that of the vessel. In this process, the impregnating step, dispersing step and heating step need not be altogether effected separately. These steps can be performed simultaneously in one and the same vessel.

Abstract: The mixture of water and the polyolefin resin particles impregnated with a volatile blowing agent are released from the interior of the pressure-resistant container under a constant temperature and constant pressure preferably keeping the partial pressure of the blowing agent constant, through at least one orifice having an area of 0.07 to 300 mm.sup.2, into a low-pressure zone.This invention gives various advantages when applied to the practical process resulting in expanded particles with superior properties which are free of blocking and remarkably uniform in the degree of expansion, and are useful for molding.

Abstract: A method for pressurizing pre-foamed particles of a polyolefin resin by maintaining the pre-foamed particles in an atmosphere of a pressurized gas to impart a predetermined internal pressure thereto, which comprises first maintaining the particles under a pressure which does not cause shrinkage to the particles, and then increasing the applied pressure gradually under conditions which do not cause shrinkage to the particles.

Abstract: Storage stable heterogeneous systems which may be processed at low temperatures to form polyurethanes are made by mixing a specific quantity of a high molecular weight polyhydroxyl compound with a specified quantity of a 4,4'-diphenyl methane uret dione diisocyanate corresponding to a specified formula or a corresponding modified diisocyanate. A lead and/or tin catalyst is also included.

Abstract: Expandable styrene-maleic anhydride copolymer particles which comprises a copolymer resin obtained by reaction of a styrene-maleic anhydride copolymer with a hydroxy compound and further impregnated with a volatile blowing agent.

Abstract: In a process for producing pre-foamed particles of a polyolefin resin which comprises impregnating a volatile blowing agent into particles of a polyolefin resin while dispersing the resin particles and the blowing agent in a dispersing medium under heat in a closed vessel, opening one end of the vessel and releasing the resin particles and the dispersing medium simultaneously into an atmosphere kept at a lower pressure than the inside pressure of the vessel; the improvement wherein the pressure of the inside of the vessel after opening its one end is maintained at a substantially constant pressure which is at least 0.7 times the vapor pressure of the blowing agent before opening the end of the vessel.

Abstract: An expanded shaped article of a heat resistant synthetic resin comprising 20 to 100 weight percent tertiary butyl styrene and 80 to 0 weight percent other monomers polymerizable therewith, and containing volatile foaming agent, wherein expandable particles of said resin are pre-expanded by application of heat and then molded by application of heat to produce shaped articles. Extrusion foaming may be used to form the article.

Abstract: Fine particulate expandable flame retardant styrene polymers having an improved minimum mold dwell time and reduced block shrinkage are prepared by:(a) mixing together styrene monomer or a mixture of styrene and a cpolymerizable monomer with an organic halogen compound and an expanding agent in an aqueous disperson;(b) adding before or during polymerization to the mixture of (a) from 0.0001 to 0.1% by weight of an epoxidation product of an aliphatic hydrocarbon of which the epoxidated aliphatic chain comprises from 6 to 18 C atoms, this epoxidation product being soluble in the monomers;(c) carrying out a polymerization in the aqueous suspension of (a) and (b) using radical forming initiators at temperatures of 80.degree. C.-130.degree. C. to form expandable particles;(d) pre-forming the expandable particles resulting from (c);(e) ageing the pre-formed particles of (d); and(f) molding the pre-formed and aged particles of (e) in a pressure resistant mold.

Abstract: Fire retardant, expanded styrene polymer shaped objects are prepared by:(a) mixing styrene monomer or a mixture thereof with at least one comonomer, an expanding agent and a fire retardant, organic halogen compound in a aqueous dispersion;(b) adding to (a) either before or during polymerization from about 0.0001 to 0.1 percent by weight esters soluble in the organic phase of (a), these esters of aliphatic dicarboxylic acids and aliphatic epoxy alcohols having at least 11 carbon atoms;(c) polymerizing the aqueous dispersion of (a) and (b) using radical forming initiators at a temperature of about 80.degree. to 130.degree. C.;(d) separating bead polymers having diameters between about 0.4 and 3 mm;(e) pre-foaming the beads;(f) ageing the pre-foamed beads; and(g) final forming the aged and pre-foamed beads in a pressure resistant mold.

Abstract: Fine particulate expandable flame retardant styrene polymers having an improved minimum mold dwell time and reduced block shrinkage are prepared by:(a) mixing together styrene monomer or a mixture of styrene and a copolymerizable monomer with an organic halogen compound and an expanding agent in an aqueous dispersion;(b) adding before or during polymerization to the mixture of (a) from 0.0001 to 0.1% by weight of an expoxidation product of an aliphatic hydrocarbon of which the epoxidated aliphatic chain comprises from 6 to 18 C atoms, this epoxidation product being soluble in the monomers;(c) carrying out a polymerization in the aqueous suspension of (a) and (b) using radical forming initiators at temperatures of 80.degree. C.-130.degree. C. to form expandable particles;(d) pre-forming the expandable particles resulting from (c);ageing the pre-formed particles of (d); and(f) molding the pre-formed and aged particles of (e) in a pressure resistant mold.

Abstract: Self-extinguishing expandable polystyrene particles containing an expanding agent, a self-extinguishing organic halogen-containing compound and a 2,4,6-triamino-1,3,5-triazine derivative.

Abstract: Fire retardant, expanded styrene polymer shaped objects are perpared by:(a) mixing styrene monomer or a mixture thereof with at least one comonomer, an expanding agent and a fire retardant, organic halogen compound in a aqueous dispersion;(b) adding to (a) either before or during polymerization from about 0.0001 to 0.1 percent by weight esters soluble in the organic phase of (a), these esters of aliphatic dicarboxylic acids and aliphatic epoxy alcohols having at least 11 carbon atoms;(c) polymerizing the aqueous dispersion of (a) and (b) using radical forming initiators at a temperature of about 80.degree. to 130.degree. C.;(d) separating bead polymers having diameters between about 0.4 and 3 mm;(e) pre-foaming the beads;(f) ageing the pre-foamed beads; and(g) final forming the aged and pre-foamed beads in a pressure resistant mold.

Abstract: An expansion-molded product made from expanded cross-linked polyethylene particles each of which has an outer skin and inner cellular core, said outer skin each being fused and welded together to form an interfacial membrane whose average thickness is as thick as at least three times that of a cell membrane of the inner cellular core, is prepared by charging a lot of the particles into a mold, heating the particles therein to such an extent that the space among the particles is filled and then aging thus obtained molded product.The expanded particle each has a structure having an outer skin on an inner cellular core, the outer skin being as thick as at least three times cell membrane of the inner cellular core. The expandable particles are prepared by impregnating a foaming agent into the cross-linked polyethylene particles and heating so that the expandable particles are subjected to a step in which the foaming agent existing in the surface thereof is preferentially forced to evaporate.

Abstract: Expanded particles of a crosslinked polyolefin resin, each particle with uniformly spherical shape, having an average diameter of 1.4 to 5.5 mm, an average expansion ratio of 18 to 37 and specific compression coefficient of 1.6 .times. 10.sup.-3 to 4.0 .times. 10.sup.-3, are found to be produced by two-step foaming operations. They are useful for various purposes such as filtrating material, fillers in stuffed specimens and, especially for preparation of molded articles having constricted portions, giving excellent moldings having smooth surface without failure at corner or edge portions.

Abstract: Expanded particles of a crosslinked polyolefin resin, each particle with uniformly spherical shape, having an average diameter of 1.4 to 5.5 mm, an average expansion ratio of 18 to 37 and specific compression coefficient of 1.6.times.10.sup.-3 to 4.0.times.10.sup.-3, are found to be produced by two-step foaming operations. They are useful for various purposes such as filtrating material, fillers in stuffed specimens and, especially for preparation of molded articles having constricted portions, giving excellent moldings having smooth surface without failure at corner or edge portions.

Abstract: Expandable particles of a styrene polymer which comprise on the surface thereof an ester of an aliphatic carboxylic acid with an aliphatic alcohol, the ester having no hydroxyl group in the molecule and being a solid at room temperature, or a mixture of said ester and a finely divided lubricant, and a process for preparing the same.

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: Expandable particles of a styrene polymer containing therein 3 to 8% by weight of a blowing agent and having a particle size of 0.8 to 0.25 mm. in diameter, or their pre-expanded particles, which comprises an ester of sucrose represented by the formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each represent a hydrogen atom, an alkanoyl group having 6 to 22 carbon atoms or an alkenoyl group having 6 to 22 carbon atoms; and all of R.sub.1, R.sub.2 and R.sub.3 are not hydrogen atoms at the same time, or its derivative, said ester of sucrose or its derivative being coated on the surface of said particles.

Abstract: Expandible particles of styrene particles for producing molded bodies, particularly large blocks having a homogeneous fine-cell structure, and having improved characteristics, are obtained by polymerizing styrene or a mixture of styrene and one or more different monomers copolymerizable with styrene, in the presence of at least one compound of the following general formulae (I) or (II) ##STR1## wherein R.sub.1 and R.sub.4, either like or unlike each other, are an optionally halogen-substituted alkyl radical containing 1 to 30 carbon atoms;R.sub.2 and R.sub.3, like or unlike each other, are an alkyl, cycloalkyl or phenyl radical, optionally halogen-substituted;X is a halogen or an alkyl radical having 1 to 8 carbon atoms;M is an integer from 0 to 4; andN is an integer from 0 to 5.

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: Methods involving the use of high frequency heating means and temperature-compensating means to expand hollow, thermoplastic resinous microbeads in a controllable manner. The heat-expanded microbeads are suitable for use, for example, in providing viscous, flowable, pressure-compensating fitting materials or compositions.