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 method for producing a millable silicone rubber sponge is a method for producing a millable silicone rubber sponge with an open cell ratio of not lower than 20%, comprising: performing a heat treatment on a silicone rubber composition at 200 C. or higher, the silicone rubber composition containing: (A) an organopolysiloxane having at least two alkenyl groups in one molecule and a polymerization degree of not lower than 3,000; (B) a reinforcing silica; (C) thermally expandable microcapsules exhibiting an expansion starting temperature of 90 to 150 C., and contracting from a maximum expansion volume by 20% or more when heated at 200 C. for 5 min; (D) a curing agent; and (E) an open cell-forming agent which is a solid high temperature decomposition-type organic foaming agent having a decomposition starting temperature of not lower than. 180 C., and starting to decompose after the component (A) is cured.

A method for producing a millable silicone rubber sponge is a method for producing a millable silicone rubber sponge with an open cell ratio of not lower than 20%, comprising: performing a heat treatment on a silicone rubber composition at 200 C. or higher, the silicone rubber composition containing: (A) an organopolysiloxane having at least two alkenyl groups in one molecule and a polymerization degree of not lower than 3,000; (B) a reinforcing silica; (C) thermally expandable microcapsules exhibiting an expansion starting temperature of 90 to 150 C., and contracting from a maximum expansion volume by 20% or more when heated at 200 C. for 5 min; (D) a curing agent; and (E) an open cell-forming agent which is a solid high temperature decomposition-type organic foaming agent having a decomposition starting temperature of not lower than. 180 C., and starting to decompose after the component (A) is cured.

The present invention is concerned with an expanded beads molded article of expanded beads comprising a crosslinked multi-block copolymer containing a polyethylene block and an ethylene/-olefin copolymer block, wherein a density is 40 to 150 g/L; a gel fraction by a hot xylene extraction method is 30 to 70% by weight; a tensile elongation is 120% or more; a bead weight of the expanded beads is 0.8 to 8 mg; and the number of expanded beads per unit area on a surface of the expanded beads molded article is 5 to 30 per cm.sup.2, and is able to provide an expanded beads molded article which is light in weight and favorable in surface properties, fusion bondability, and durability.

Thermoplastic resin foamed particles of the present invention including .[.more than.]. one .Iadd.or more .Iaddend.functional additive selected from inorganic powder and inorganic fibers each includes a core layer formed of a thermoplastic resin and a coating layer in a foamed state formed of a thermoplastic resin, the mass ratio of the coating layer to the core layer is 99:1 to 50:50, the content (X) of the functional additive in the core layer is 5 to 90% by mass, and the content of the functional additive in the coating layer is smaller than the content (X) of the functional additive in the core layer. By this way, thermoplastic resin foamed particles from which a homogeneous foamed particle molding having excellent dimension stability, fusibility and appearance can be obtained while containing functional additive are provided.

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.

The present invention relates to thermally expandable microspheres at least partially prepared from bio-based monomers and to a process of their manufacture. The microspheres comprise a thermoplastic polymer shell encapsulating a blowing agent, wherein the thermoplastic polymer shell comprises a polymer being a homo- or copolymer of a lactone according to formula (1):

##STR00001##

wherein each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, separately from one another, is selected from the group consisting of H and an alkyl group preferably with 1-4 carbon atoms. The invention further provides expanded microspheres, which can be used in a variety of applications.

Expandable polystyrene-based resin particles may include a styrene-based monomer, a polysiloxane-containing macro monomer, and a coating composition having a melting point of 40 C. or greater. A coefficient of static friction of a foamed molded product, obtained by pre-expanding the expandable polystyrene-based resin particles and molding the pre-expanded expandable polystyrene-based resin particles, may be 4.0 or less. The expandable polystyrene-based resin particles may have a surface layer part that contains polysiloxane as a main component.

A method for producing expandable polystyrene-based resin particles, the method including producing polystyrene-based resin particles that comprise a styrene-based monomer and a polysiloxane-containing macro monomer, and impregnating an expanding agent into the polystyrene-based resin particles to produce the expandable polystyrene-based resin particles. The production of the polystyrene-based resin particles comprises the simultaneous addition of an initiator and the polysiloxane-containing macro monomer. The initiator causes the generation of one or more of an alkoxy radical and a carbonate radical.

Brominated vinylaromatic-diene block copolymers (Br-SBC) comprising a vinylaromatic polymer block S and a brominated diene polymer block BB, wherein before bromination the weight-average molar mass M.sub.w of the block S is greater than or equal to M.sub.w of the block BB, use thereof as flame retardants, and also polymer compositions comprising these for unfoamed and foamed thermoplastic polymers, for example EPS and XPS.