Abstract: Disclosed herein are compositions including (a) a first component comprising (1) an epoxy-adduct that is the reaction product of reactants comprising a first epoxy compound, a polyol, and an anhydride and/or a diacid and (2) a second epoxy compound; (b) rubber particles having a core/shell structure and/or graphenic carbon particles; and (c) a second component that chemically reacts with the first component at ambient or slightly thermal conditions. Also disclosed herein are compositions including (a) an epoxy-capped flexibilizer; (b) a heat-activated latent curing agent; and optionally (c) rubber particles having a core/shell structure and/or graphenic carbon particles; (d) an epoxy/CTBN adduct; and/or (e) an epoxy/dimer acid adduct. The heat-activated latent curing agent may include at least one reaction product of reactants including an epoxy compound and an amine and/or an alkaloid.

Abstract: Provided are poly(3-hydroxyalkanoate) foam particles, which can give a foam molded article having good surface aspects and a low shrinkage ratio of a molding, and the foam molded article. The poly(3-hydroxyalkanoate) foam particles have at least two melting peaks on a DSC curve obtained by differential scanning calorimetry and in which a melting calorie (X) on a high temperature side is 0.1 to 20 J/g, a gel fraction (Y) is 20 to 75% by weight, and the melting calorie (X) and the gel fraction (Y) satisfy Formula: X+Y?30.

Abstract: The present disclosure relates to TPV compositions suitable for foaming, as well as foamed TPV compositions, methods of making the foregoing, and applications of various foamed TPV compositions, including in glass run channels. The TPV compositions comprise an at least partially vulcanized rubber component dispersed within a thermoplastic component comprising a first thermoplastic resin. According to some aspects, the TPV composition may be combined with a high melt-strength thermoplastic resin, and in particular a high melt-strength polypropylene-based thermoplastic resin, to make a foamable TPV composition. The foamable TPV composition (with or without high melt-strength thermoplastic resin) is then coextruded or otherwise combined with foaming agent (preferably comprising thermo-expandable microspheres) to form the foamed composition.

Abstract: A continuous method of producing polyamide foams by an extrusion foaming process is disclosed. The polyamide foam includes a polyamide resin compounded with a composite chain extender including an epoxy chain extender and a maleic anhydride grafted polypropylene (MAPP) wax. The produced polyamide foams have improved properties, including a smooth surface, low density, and small cell size.

Abstract: The present disclosure relates to TPV compositions suitable for foaming, as well as foamed TPV compositions, methods of making the foregoing, and applications of various foamed TPV compositions. The TPV compositions comprise an at least partially vulcanized rubber component dispersed within a thermoplastic component comprising a thermoplastic resin and a propylene-based elastomer, oil, and optionally one or more additives. According to some aspects, the TPV composition may be made in part by preloading some portion of process oil prior to addition of the curative. TPV compositions provided herein are particularly suitable for foaming with thermo-expandable microsphere foaming agents.

Abstract: A highly fire-resistant expanded polymeric material for thermal insulation, acoustic insulation and/or fire barrier contains rubber, expandable graphite, at least one alkaline earth metal component selected from alkaline earth metal carbonates, alkaline earth metal hydroxides, hydrates of either, and combinations thereof, and a component containing silica or a silicate. The expanded polymeric material is preferably manufactured by a process including decomposition of a chemical blowing agent.

Abstract: The invention relates to a biodegradable polyester mixture comprising: i) 71 to 91 wt %, based on the total weight of components i and ii, of a polyester I constructed from: a-1) 40 to 70 wt %, based on the total weight of components a and b, of an aliphatic C9-C16 dicarboxylic acid or of a C9-C16 dicarboxylic acid derivative; b-1) 30 to 60 wt %, based on the total weight of components a and b, of terephthalic acid or of a terephthalic acid derivative; c-1) 98 to 100 wt %, based on the total weight of components a and b, of a C3-C6 diol; d-1) 0 to 2 wt %, based on the total weight of components a and b, of an at least trihydric alcohol; e-1) 0 to 2 wt %, based on the total weight of components a to e, of a chain extender, and ii) 9 to 29 wt %, based on the total weight of components i and ii, of a polyester II constructed from: a-2) 40 to 70 wt %, based on the total weight of components a and b, of an aliphatic C4-C6 dicarboxylic acid or of a C4-C6 dicarboxylic acid derivative; b-2) 30 to 60 wt %, based

Abstract: Provided are a polyamide resin foam shaped product containing a polyamide resin and having a crystallinity X of 10% to 50% and a crystallite size D of 10 nm or more as calculated based on a peak having a smallest peak width in an X-ray diffraction profile of the foam shaped product, and a method of producing this polyamide resin foam shaped product.

Abstract: An adhesive composition that provides improved structural integrity and insulative properties when applied to a substrate is provided. The adhesive composition includes an emulsion-based polymer, a plurality of microspheres; and optionally, water and plasticizer.

Abstract: Disclosed is a process for production of expanded polystyrene using D-limonene as a plasticizer, which allows reducing the amount of pentane in the process, yet allows generating beads with similar cell size as if greater quantities of pentane had been used. Pentane is an organic solvent with toxicity associated with organic solvents. After forming beads, they are melted in a mold to form a variety of products, or they can be extruded in a process where limonene is used instead of or in addition to other blowing agents.

Abstract: A freeze-thaw damage resistance and scaling damage resistance admixture for a cementitious composition including an aqueous slurry comprising a water insoluble superabsorbent polymer and expandable polymeric microspheres. A method for preparing a freeze-thaw damage resistant and scaling damage resistant cementitious composition including forming a mixture of a hydraulic cement and an admixture including an aqueous slurry of a water insoluble superabsorbent polymer and expanded polymeric microspheres.

Abstract: The instant invention provides coated polymeric particulates, and a method for producing polymeric particulates. The coated polymeric particulates according to the present invention comprise (a) one or more polymeric particulates; and (b) a coating composition present on at least a portion of at least one surface of said polymeric particulate, wherein said coating composition comprises a dispersion comprising: (1) one or more base polymers, (2) one or more stabilizing agents; (3) one or more biocide agents; (4) one or more neutralizing agents; and (5) water.

Abstract: The present disclosure relates to a compound U comprising at least one urethane functional group, and its use as a fluidizing agent or fluidizing agent precursor in a process for preparing a polyamide article. The process comprises heating a composition comprising at least one polyamide PA and at least one compound U comprising at least one urethane functional group, at a temperature T, for a time t and at a pressure P, wherein the temperature T and the time t are such that CO2 is generated and the melt viscosity of the composition is decreased, in comparison with the melt viscosity of the composition without compound U, and recovering the article. The fluidizing agent can further enable the production of an article that has an unreduced density and/or in which the mean molar mass of the polymers of the composition is increased.

Abstract: A process for producing expanded polyolefin resin particles with use as a foaming agent of water contained in an aqueous dispersion medium. The process includes dispersing polyolefin resin particles together with the aqueous dispersion medium into a closed vessel; heating the polyolefin resin particles up to or above a softening temperature of the polyolefin resin particles and pressurizing the polyolefin resin particles; and releasing the polyolefin resin particles into a zone whose pressure is lower than an internal pressure of the closed vessel. The polyolefin resin particles are composed of a polyolefin resin composition including polyolefin resin, a water-absorbing substance, and a foam nucleating agent.

Abstract: A method of expanding expandable polymeric microspheres including contacting an aqueous slurry including unexpanded, expandable polymeric microspheres with steam in-situ during manufacture of a cementitious composition or article, wherein the aqueous slurry optionally further includes an admixture therefor. A method of manufacturing a cementitious composition or article includes: (i) contacting an aqueous slurry of unexpanded, expandable polymeric microspheres with steam proximate to and/or during said manufacturing of the cementitious composition to create expanded polymeric microspheres; (ii) pre-wetting the expanded polymeric microspheres; and (iii) mixing the pre-wetted, expanded polymeric microspheres with cement and water to form the cementitious composition, wherein the aqueous slurry optionally further comprises an admixture therefor.

Abstract: Modified polystyrene-based resin particles comprising polyacrylic acid ester-based resin microparticles having an average particle diameter in the range of from 30 to 1,000 nm being dispersed in polystyrene-based resin particles, such that the polyacrylic acid ester-based resin microparticles are present (1) in the area ratio of from 0.1 to 15% in a surface area, which includes areas up to 20 ?m from the surface of each resin particle, and (2) present in the area ratio of from 11 to 50% in the inner area, which includes the area between the center of each resin particle and an point 30% of the radius from the center of each particle.

Abstract: Expanded composite polystyrene-based resin particles having a plurality of cells and cell membranes separating the plurality of cells, said cell membranes including a polystyrene-based resin forming a continuous phase and polyacrylic acid alkyl ester-based resin fine particles dispersed in said continuous phase to form a dispersed phase, and said polystyrene-based resin being complexed with said polyacrylic acid alkyl ester-based resin fine particles, wherein said dispersed phase is present in the form of a plurality of layers in a cell membrane thickness direction in a cell membrane cross-section of said expanded composite polystyrene-based resin particles.

Abstract: Process for the preparation of beads of expandable vinyl aromatic polymers by means of polymerization in aqueous suspension, which comprises polymerizing at least one vinyl aromatic monomer in aqueous suspension in the presence of a peroxide initiator system, active at a temperature higher than 800 C, an expanding agent, and in the presence of: —an amide having the general formula R1CONHCH2—CH2NHCOR2 (I) a flame retardant system comprising a brominated additive with a bromine content higher than 30% by weight.

Abstract: A system for applying a melted polymer/hot melt adhesive includes structure for adding one or more components to the polymer/hot melt stream at selected locations of the stream depending on the desired final characteristics of the polymer/hot melt adhesive, the heat histories of the polymer/hot melt adhesive and the modifying component, and the physical or chemical characteristics of the modifying component. The modifying component can be supplied in a fluid carrier.

Abstract: A polypropylene resin foamed bead from which a foamed bead molded article excelling in appearance, heat resistance and mechanical properties can be obtained at the molding temperature lower than that for conventional polypropylene resin foamed beads; and a foamed bead molded article obtained by molding the same. The polypropylene resin foamed bead is characterized by having such a crystal structure that in the first DSC curve obtained when the temperature of the foamed bead sample is raised from ordinary temperature to 200° C. at a temperature rising rate of 2° C./min by a differential scanning calorimetry, there appear a main endothermic peak of 100° to 140° C. endothermic peak apex temperature exhibiting 70 to 95% endothermic peak calorific value based on the total endothermic peak calorific value and two or more endothermic peaks exhibited on the high temperature side with respect to the main endothermic peak.

Abstract: An expandable composite resin bead comprises: a composite resin containing a polyethylene resin and a polystyrene resin; and a blowing agent impregnating the composite resin. The composite resin contains 5 to 20 mass % of the polyethylene resin and 80 to 95 mass % of the polystyrene resin. The blowing agent is an organic physical blowing agent. Furthermore, in the expandable composite resin bead, a predetermined swelling degree in methyl ethyl ketone at a temperature of 23° C. is not lower than 1.25.

Abstract: Disclosed is expandable modified resin beads (1), comprising a modified resin as a base resin in which a dispersion phase (3) containing a styrene resin as a major component is dispersed in a continuous phase (2) containing an olefin resin as a major component, and a physical blowing agent. Further disclosed are expanded modified resin beads obtained by expanding the expandable modified resin beads (1), and a foamed molded article formed from the expanded modified resin beads obtained by molding the expanded modified resin beads in a mold. A volume average diameter of the dispersion phase (3) dispersed in the continuous phase (2) is 0.55 ?m or more. The expandable modified resin beads (1) have, as a base resin, the modified resin contains 80 to 50 parts by mass of the styrene resin with respect to 20 to 50 parts by mass parts of the olefin resins.

Abstract: A substantially non-elastic incompressible composition, which substantially does not quickly self-level under standard operating conditions, includes: a suspending agent which reacts substantially as a solid when subjected to forces below a critical force, and which becomes substantially flowable when subjected to forces above said critical force. Aspects include compositions comprising one or more of ceramic microparticulates, flexible-walled microparticulates, celled macroparticulates, and fibers dispersed within the suspending agent, and energy absorbing applications thereof. Another aspect comprises thin-walled macrospheres containing a substantially non-elastic incompressible composition.

Abstract: Nanocomposite compositions based on expandable thermoplastic polymers which comprise: a) a polymeric matrix produced by the polymerization of a base comprising one or more polymerizable monomers; b) 1-10% by weight, calculated with respect to the polymer (a), of an expanding agent englobed in the polymeric matrix; c) 0.004-15% by weight, calculated with respect to the polymer (a), of an athermanous filler comprising nano-scaled graphene plates with a thickness (orthogonal to the graphene sheet) not greater than 150 nm, an average dimension (length, width, or diameter) not greater than 10 micrometers and a surface area>50 m2/g.

Abstract: There are provided expandable polystyrene resin particles formed by granulating a polystyrene resin containing an expanding agent, wherein the weight-average molecular weight Mw of the polystyrene resin is in the range of 120,000 to 270,000, and the expanding agent contains, as an essential component, pentane at a proportion of 3 to 8 parts by mass based on 100 parts by mass of the polystyrene resin, while the composition of the pentane is in the range of isopentane:normal pentane=10:90 to 80:20 by mass ratio. These expandable polystyrene resin particles can utilize a recycled raw material, and can produce a molded foam product having sufficient mechanical strength, while the expandable polystyrene resin particles have a long bead life and excellent low pressure moldability.

Abstract: Expandable composite resin particles for frozen storage comprising: composite resin particles of a polyolefin-based resin and a polystyrene-based resin; 7.5 to 11% by weight of volatile blowing agent contained in the composite resin particles and containing pentane; and 0.5 to 1.5% by weight of moisture attached to surfaces of the composite resin particles.

Abstract: There is provided a thermally reversible admixture comprising (a) an ionically crosslinked polymer matrix comprising at least one (meth)acrylic polymer, a first mole fraction of an acid functional polymer, a second mole fraction of a moiety capable of forming an ionic crosslink with the acid functional polymer, wherein the first mole fraction and the second mole fraction are based on the total number of moles of repeat units in the polymer matrix; and (b) 2 to 50 weight percent microspheres.

Abstract: Expandable composite resin particles for long-term storage, comprising 500 to 5000 ppm of water and 7.5 to 11.0% by weight of pentane in composite resin of polyolefin-based resin and polystyrene-based resin.

Abstract: Polypropylene resin expanded particles comprises a polypropylene resin as a base material resin, the polypropylene resin having at least three melting peaks on a DSC curve for a second temperature rise measured at a heating rate of 10 g/min with use of a heat flux differential scanning calorimeter (DSC), the at least three melting peaks including (i) a lowest temperature melting peak of 100° C. to 130° C. and (ii) a highest temperature melting peak of 140° C. to 160° C., the polypropylene resin having a resin DSC ratio change rate of 0.5%/° C. to 3.0%/° C., the expanded particles having two melting peaks in a DSC measurement made at a first temperature rise at the heating rate of 10 g/min, the two melting peaks including, (i) on a lower temperature side, a melting peak temperature of 100° C. to 130° C. and, (ii) on a higher temperature side, a melting peak temperature of 140° C. to 160° C.

Abstract: A carbon-containing modified polystyrene type resin particle of the present invention includes: a carbon-containing polypropylene type resin, and a polystyrene type resin in an amount of not less than 100 parts by weight but less than 400 parts by weight per 100 parts by weight of the carbon-containing polypropylene type resin, wherein the polystyrene type resin ratio at the central part of the particle is at least 1.2 times the polystyrene type resin ratio of the overall particle, the polystyrene type resin ratio being calculated by using the ratio (D698/D1376) of absorbances at 698 cm?1 and 1376 cm?1 which are obtained by infrared absorption spectra measured by ATR infrared spectroscopic analysis.

Abstract: The present disclosure provides a high heat radiation composite material including a hybrid filler comprising expanded graphite filled with expandable polymeric beads, and a fabrication method thereof. In the method, a dispersion solution is prepared by dispersing expandable polymeric beads in ethanol. Expanded graphite is immersed in the dispersion solution, and heat-treated to remove ethanol, thereby producing the hybrid filler. The hybrid filler is dispersed into the matrix polymer via an extrusion/injection process, thereby producing the composite material.

Abstract: Disclosed is expandable modified resin beads (1), comprising a modified resin as a base resin in which a dispersion phase (3) containing a styrene resin as a major component is dispersed in a continuous phase (2) containing an olefin resin as a major component, and a physical blowing agent. Further disclosed are expanded modified resin beads obtained by expanding the expandable modified resin beads (1), and a foamed molded article formed from the expanded modified resin beads obtained by molding the expanded modified resin beads in a mold. A volume average diameter of the dispersion phase (3) dispersed in the continuous phase (2) is 0.55 ?m or more. The expandable modified resin beads (1) have, as a base resin, the modified resin contains 80 to 50 parts by mass of the styrene resin with respect to 20 to 50 parts by mass parts of the olefin resins.

Abstract: The present invention relates to a process for the emulsifier-free preparation of water expandable polymer beads, which process comprises the steps of: a) providing an emulsifier-free starting composition comprising styrene and a polyphenylene ether resin, b) prepolymerizing the starting composition to obtain a prepolymer composition, c) adding an aqueous dispersion of a modifier-free nanoclay to the prepolymer composition to obtain an inverse emulsion, d) suspending the inverse emulsion obtained by step c) in an aqueous medium to yield an aqueous suspension of suspended droplets and e) polymerizing the monomers in the droplets of the suspension obtained by step d) to obtain the water expandable polymer beads.

Abstract: Expandable composite resin particles for long-term storage, comprising 500 to 5000 ppm of water and 7.5 to 11.0% by weight of pentane in composite resin of polyolefin-based resin and polystyrene-based resin.

Abstract: Expandable composite resin particles for long-term storage, comprising 500 to 5000 ppm of water and 7.5 to 11.0% by weight of pentane in composite resin of polyolefin-based resin and polystyrene-based resin.

Abstract: Expandable microspheres formed by suspension polymerization using a shot growth method are provided. The microspheres are formed of a continuous, gas impermeable shell surrounding a blowing agent. The shell includes a first polymer layer formed from primary monomers and a second layer that includes a chemically reactive monomer or a high Tg monomer. To form the microspheres, the primary monomers are polymerized in a reaction vessel to an approximate 90% polymerization, at which time a secondary monomer that is either a monomer having a Tg of at least 85° C. or a chemically reactive monomer, is added to the reaction vessel to drive the polymerization reaction to completion. The outer layer thus contains either a larger amount of the high Tg monomer or a chemically reactive monomer that possesses the ability to covalently bond a cationic species. The microspheres may be used in papermaking processes to increase the paper bulk.

Abstract: A thermally foamable resin composition includes a base resin, foamable resin particles, and a cross-linking agent, wherein each of the foamable resin particles contains a solid resin and a thermally expandable substance contained in the solid resin.

Abstract: An adhesive composition that provides improved structural integrity and insulative properties when applied to a substrate is provided. The adhesive composition includes an emulsion-based polymer, a plurality of microspheres; and optionally, water and plasticizer.

Abstract: The adhesive composition comprising emulsion polymers and microspheres and articles made therefrom are provided. The adhesive is particularly suitable for packages for consumer products that provide sufficient strength and thermal insulation while reducing the overall basis weight of the substrates.

Abstract: Disclosed are particles that have an exterior surface coated with a thin polymeric coating, such as a coating that includes a sulfur-containing polymer. Also disclosed are compositions, such as fuel-resistant sealant and coating compositions, which include such particles. Aerospace vehicles having an aperture at least partially sealed with a sealant deposited from such a sealant composition are also disclosed.

Abstract: A particulate polymeric composition capable of being processed to provide expanded articles having a density lower than or equal to 50 g/l and a closed cell content of at least 60% as specified by ASTM D-2856, wherein resulting particulates have a shape factor ranging from 0.6 to 0.99; and wherein the particulate polymeric composition is produced according to a process that prepares expandable granules based on thermoplastic polymers, through a granulation die.

Abstract: The invention relates to a process for producing expandable pelletized material which comprises polylactic acid which comprises the following steps: a) melting and incorporation by mixing of the following components: i) from 61.9 to 98.9% by weight, based on the total weight of components i to iv, of polylactic acid, ii) from 1 to 38% by weight, based on the total weight of components i to iv, of at least one polyhydroxyalkanoate, iii) from 0 to 30% by weight, based on the total weight of components i to iv, of at least one polyester based on aliphatic and/or aromatic dicarboxylic acids and on aliphatic dihydroxy compounds; iv) from 0.

Abstract: Disclosed is an expanded polypropylene copolymer resin particle whose base resin is a polypropylene random copolymer resin having a melting point of not more than 145° C., the base resin having a H/W ratio of not more than 8 where H (%) is a maximum height of an elution peak and W (° C.) is a peak width at half a height of the peak in an elution curve obtained from a differential value of eluted content measured by cross fractionation chromatography, and a ratio (Mw/Mn) of a weight-average molecular weight (Mw) and a number-average molecular weight (Mn) being not less than 3.5 in a molecular weight distribution measurement of a whole of eluted components. With such an expanded polypropylene copolymer resin particle, it is possible to provide expanded polypropylene copolymer resin particles which are capable of producing an in-mold expansion-molded article with a low molding heating vapor pressure, and which causes few deformation or shrinkage of an obtained in-mold expansion-molded article (i.e.

Abstract: Provided are polypropylene resin pre-foamed particles including, as base resin, polypropylene resin that satisfies the following requirements (a) through (c): (a) in cross fractionation chromatography, an amount of components eluted at a temperature of not more than 40° C. is not more than 2.0% by weight; (b) a melting point is not less than 100° C. but not more than 160° C.; and (c) propylene monomer units are present in an amount of not less than 90 mol % but not more than 100 mol %, and olefin units each having a carbon number of 2 or 4 or more are present in an amount of not less than 0 mol % but not more than 10 mol %. The polypropylene resin pre-foamed particles can be molded by in-mold foaming molding at a not high molding heating steam pressure, and a polypropylene resin in-mold foaming molded product excellent in dimensional stability at high temperatures can be prepared from the polypropylene resin pre-foamed particles.

Abstract: A method for producing styrene-modified linear low-density polyethylene-based resin particles, which includes the steps of: dispersing 100 parts by weight of non-crosslinked linear low-density polyethylene-based resin particles which are polymerized using a metallocene compound as a catalyst and contain an inorganic nucleating agent, 50 to 800 parts by weight of a styrene-based monomer and 0.1 to 0.9 parts by weight of a polymerization initiator relative to 100 parts by weight of the styrene-based monomer into an aqueous suspension containing a dispersant; impregnating the polyethylene-based resin particles with the styrene-based monomer under heating the resulting dispersion at such a temperature that the styrene-based monomer does not substantially polymerize; and performing polymerization of the styrene-based monomer at a temperature of (T+10) to (T+35)° C. where T° C. is a crystallization peak temperature of the polyethylene-based resin particles.

Abstract: A seed beads dispersing disperse system is obtained by dispersing olefin resin seed beads 1 with a specific tubular shape in an aqueous medium. Then, the olefin resin seed beads 1 are impregnated with styrene monomers and the styrene monomers are polymerized in the presence of a polymerization initiator by heating at a temperature in a specified range, to thereby obtain tubular thermoplastic resin composite beads. Expandable thermoplastic resin composite beads obtained by impregnating the thermoplastic resin composite beads with a blowing agent, expanded thermoplastic resin composite beads obtained by foaming and expanding the expandable thermoplastic resin composite beads, and a foamed molded article formed from the expanded thermoplastic resin composite beads by molding are also obtained.

Abstract: The present invention provides a resin composition for foam molding which can achieve high expansion ratio and can significantly improve tactile impression and vibration damping properties of the foam molding to be obtained. The present invention relates to a resin composition for foam molding comprising: a thermally expandable microcapsule that includes a shell containing an epoxy resin and a core agent that is a volatile expansion agent encapsulated by the shell; a thermoplastic resin; and a curable compound having two or more functional groups each selected from the group consisting of a carboxy group, a hydroxy group, an amino group, an amido group, and an acid anhydride group in each molecule.

Abstract: The present invention relates to a foam polystyrene-based bead. The foam polystyrene-based bead includes: a core containing a styrene-based resin, a char-generating thermoplastic resin, and an expanded inorganic material; and a skin disposed on the surface of the core, wherein the skin contains a resin of which the glass transition temperature is below around 120° C. The foam is contained in the core or skin. The core may further include a carbon filler. Foam produced from the expandable polystyrene beads is not an inherently self-extinguishing flame retardant material yet can have good non-flammability comparable to or better than that of inherently flame retardant materials (Non flammability level 3) as measured in accordance with KS F ISO 5660-1, heat insulation properties, and mechanical properties.

Abstract: Thermoplastic particle foams which have cells having a mean cell size in the range from 20 to 500 ?m and in which the cell membranes have a nanocellular or fibrous structure having pore or fiber diameters below 1500 nm, and also processes for producing them.

Abstract: An object of the present invention is to provide an in-mold foamed article having good surface appearances and high rigidity produced by using a common molding machine that withstands a pressure of up to 0.4 MPa. The present invention provides polypropylene resin pre-expanded particles containing a base resin which is a resin having a melt flow rate of 5 g/10 min or more and 20 g/10 min or less and a melting point of 140° C. or higher and 155° C. or lower and satisfying the conditional formula below, and an in-mold foamed article produced from molding the pre-expanded particles: [Heat of crystal fusion (J/g)]?1.2×[Melting point (° C.)]?96.