A method for producing a syntactic foam for high-pressure environments includes providing a housing having a void volume. The housing may include an inlet and an outlet to the void volume of the housing. The method includes injecting a plurality of microspheres comprising glass into the housing. The plurality of microspheres include a first set of microspheres comprising an average diameter ranging from 5 microns to 150 microns. The method includes agitating the housing to settle the plurality of microspheres within the housing. The method includes injecting a resin from the inlet of the housing to the outlet of the housing to fill voids between the plurality of microspheres to form a resin-microsphere matrix. The resin may have a viscosity less than 100 centipoise. The method may include curing the resin-microsphere matrix in the housing to produce a cured composition.

A method for producing a syntactic foam for high-pressure environments includes providing a housing having a void volume. The housing may include an inlet and an outlet to the void volume of the housing. The method includes injecting a plurality of microspheres comprising glass into the housing. The plurality of microspheres include a first set of microspheres comprising an average diameter ranging from 5 microns to 150 microns. The method includes agitating the housing to settle the plurality of microspheres within the housing. The method includes injecting a resin from the inlet of the housing to the outlet of the housing to fill voids between the plurality of microspheres to form a resin-microsphere matrix. The resin may have a viscosity less than 100 centipoise. The method may include curing the resin-microsphere matrix in the housing to produce a cured composition.

A processing aid for foam molding comprising a copolymer obtained by the polymerization of from 50% to 100% by weight total of one or more monomers selected from the group consisting of ethyl methacrylate and propyl methacrylate, and 0 to 50% by weight of other copolymerizable monomers, the copolymer having the following properties: (a) a reduced viscosity measured according to ASTM D2857 at 1 mg/mL in chloroform at 25° C. of greater than 8 dL/g and (b) a Tg equal to or less than 77° C. is provided.

A processing aid for foam molding comprising a copolymer obtained by the polymerization of from 50% to 100% by weight total of one or more monomers selected from the group consisting of ethyl methacrylate and propyl methacrylate, and 0 to 50% by weight of other copolymerizable monomers, the copolymer having the following properties: (a) a reduced viscosity measured according to ASTM D2857 at 1 mg/mL in chloroform at 25° C. of greater than 8 dL/g and (b) a Tg equal to or less than 77° C. is provided.

The present invention is concerned with expanded beads that are olefin-based thermoplastic elastomer expanded beads containing a coloring agent, wherein an apparent density of the expanded beads is 40 to 300 g/L, and an average surface layer membrane thickness (a) is 3 to 25 μm, and a molded article thereof, and is able to provide expanded beads capable of producing an expanded beads molded article which is excellent in in-mold moldability and excellent in tensile characteristics and an expanded beads molded article using the expanded beads.

The present invention is concerned with expanded beads that are olefin-based thermoplastic elastomer expanded beads containing a coloring agent, wherein an apparent density of the expanded beads is 40 to 300 g/L, and an average surface layer membrane thickness (a) is 3 to 25 μm, and a molded article thereof, and is able to provide expanded beads capable of producing an expanded beads molded article which is excellent in in-mold moldability and excellent in tensile characteristics and an expanded beads molded article using the expanded beads.

The process for forming closed cell expanded low density polyethylene foam includes the steps of: providing a mixture including low density polyethylene pellets and an effective amount of hydrocarbon scavenger additives or degassing agents, such as glycerides; adding a primary blowing agent comprising one of liquid propane, liquid butane, and combinations thereof, to the mixture and gasifying the blowing agent to expand the low density polyethylene; forming the expanded low density polyethylene into sheets, curing the expanded low density polyethylene until 80%, generally at least 99%, of the primary blowing agent is dissipated from cells within the expanded low density polyethylene forming evacuated closed cell low density polyethylene sheets.

The process for forming closed cell expanded low density polyethylene foam includes the steps of: providing a mixture including low density polyethylene pellets and an effective amount of hydrocarbon scavenger additives or degassing agents, such as glycerides; adding a primary blowing agent comprising one of liquid propane, liquid butane, and combinations thereof, to the mixture and gasifying the blowing agent to expand the low density polyethylene; forming the expanded low density polyethylene into sheets, curing the expanded low density polyethylene until 80%, generally at least 99%, of the primary blowing agent is dissipated from cells within the expanded low density polyethylene forming evacuated closed cell low density polyethylene sheets.

An expanded bead having a through hole and including a foamed core layer which defines the through hole therein and which is constituted of a resin composition containing two kinds of polypropylene-based resins having different melting points, and a cover layer covering the foamed core layer and constituted of a polyolefin-based resin. The expanded bead gives a DSC curve in which an endothermic peak intrinsic to the resin composition and another endothermic peak on a higher temperature side thereof appear in a specific heat of fusion ratio. Molded articles include a multiplicity of the expanded beads.

An expanded bead having a through hole and including a foamed core layer which defines the through hole therein and which is constituted of a resin composition containing two kinds of polypropylene-based resins having different melting points, and a cover layer covering the foamed core layer and constituted of a polyolefin-based resin. The expanded bead gives a DSC curve in which an endothermic peak intrinsic to the resin composition and another endothermic peak on a higher temperature side thereof appear in a specific heat of fusion ratio. Molded articles include a multiplicity of the expanded beads.