To provide a modified PTFE excellent in heat resistance. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a fluorine-free monomer, wherein the endothermic amount ratio R calculated by a prescribed method is at least 0.65.

Expanded particles of a polycarbonate-based resin containing a polycarbonate-based resin containing a component derived from bisphenol A as abase resin, the expanded particles being expanded particles of a polycarbonate-based resin satisfying any one of the following conditions (a) to (c) in a GC/MS chart: (a) a peak derived from a molecular weight of from 145 to 230 and a peak derived from a molecular weight of from 320 to 350 are shown; (b) a peak derived from a molecular weight of from 210 to 230 is shown; and (c) a peak derived from a molecular weight of from 290 to 320 is shown.

A material for sealing, adhering, or structural reinforcement or some combination thereof, comprising a primary blowing agent for imparting cellular structures within the material during initial manufacturing of the material, a polymeric base material that has adhesive characteristics, sealing characteristics, or some combination thereof, a curing agent for curing the material via a stimulus, and optionally a secondary blowing agent for forming additional cellular structures within the material.

Polyethylene resin foamed particles are obtained by foaming polyethylene resin particles containing a base resin. The base resin is a linear polyethylene resin. The polyethylene resin particles have a storage elastic modulus of 900 Pa or more and 5000 Pa or less at an angular frequency of 1 rad/second and a storage elastic modulus of 100000 Pa or less at an angular frequency of 100 rad/second, in a dynamic viscoelasticity measurement at 190 C. A differential scanning calorimetry (DSC) curve obtained by heating the polyethylene resin foamed particles using a differential scanning calorimeter at a temperature rising speed of 10 C./minute within a range of 20 C. to 220 C. has two melting peaks of a melting peak on a low temperature side and a melting peak on a high temperature side.

The invention relates to a process for the production of prefoamed poly(meth)acrylimide (P(M)I) particles which can be further processed to give foam mouldings or composites. A feature of this process is that a polymer granulate is first heated and thus prefoamed in an apparatus by means of IR radiation of a wavelength suitable for this purpose. Said granulate can be further processed in subsequent steps, e.g. in a press mould with foaming to give a moulding or a composite workpiece with foam core.

A process for producing foam particles composed of thermoplastic elastomers having polyamide segments, comprising the steps:

(a) production of a suspension of pellets of the thermoplastic elastomer in a suspension medium,
(b) addition of a blowing agent,
(c) impregnation of the pellets with the blowing agent by heating of the suspension in a pressure vessel to an impregnation temperature IMT at an impregnation pressure IMP, depressurization of the suspension by emptying of the pressure vessel via a depressurization device and work-up of the foam particles obtained, and also foam particles obtainable by the process.

The invention relates to a method for producing cellular plastic particles, including the steps of: providing a plastic material in the form of pre-expanded plastic material particles, loading the pre-expanded plastic material particles with a blowing agent under the influence of pressure, expanding the pre-expanded plastic material particles loaded with blowing agent in order to produce cellular plastic particles, more particularly, cellular plastic particles having lower density, under the influence of temperature, in which the expanding of the plastic material particles loaded with blowing agent is carried out under the influence of temperature by irradiation of the plastic material particles loaded with blowing agent with high-energy thermal radiation, more particularly, infrared radiation.

Pre-expanded polypropylene-based resin particles include a polypropylene-based resin. The polypropylene-based resin satisfies tan 0.32V+0.1, where tan represents a loss tangent at an angular frequency of 0.1 rad/s in dynamic viscoelastic behavior measurement at 200 C. and V represents a melt fracture take-up speed (m/min) at 200 C.

The present invention is concerned with expanded beads of thermoplastic polyurethane in which a water-soluble anionic surfactant is attached at 50 mg/m.sup.2 to 1,000 mg/m.sup.2 onto the surfaces of expanded beads of thermoplastic polyurethane having a dispersant attached thereto; and a method for producing an expanded beads molded article, including filling the expanded beads of thermoplastic polyurethane in a mold for molding and heating with a water vapor to mutually fuse the expanded beads with each other. The present invention provides expanded beads from which an expanded TPU beads molded article having excellent tensile strength and a method for producing an expanded TPU beads molded article.

A cover for an electronic device that transmits and receives radio waves in a high-frequency band, the cover comprising a resin and satisfying the relationship of the following formula:

(100?frontal transmittance X)?(100?oblique transmittance Y)<55

(where the frontal transmittance X (%) is a radio wave transmittance at an angle of incidence of 0? of the cover at a frequency f (Hz), and the oblique transmittance Y (%) is a radio wave transmittance of TE wave at an angle of incidence of 60? of the cover at the frequency f (Hz)).