11/02/2011

www.gupta-verlag.de/thermoplastic-elastomers

TPE patents

Cross-linkable compositions based on polyamide and on .alpha.-olefin-vinyl acetate copolymers, where the compositions comprise a cross-linking initiator, and also a co-cross-linking agent, and cross-linkable compositions based on polyamides and on .alpha.-olefin-vinyl acetate copolymers, where these compositions comprise a cross-linking initiator and the amount of polyamide in the compositions is <30 % by weight. The present invention further relates to the preparation of the cross-linkable compositions of the invention, to the use of the cross-linkable compositions of the invention for the production of thermoplastic elastomers, to a process for the cross-linking of the compositions of the invention to give a thermoplastic elastomer, and also to the thermoplastic elastomers themselves and to their use for the production of moldings. The compositions of the invention are suitable for the production of thermoplastic elastomers which feature not only excellent heat resistance and excellent solvent resistance but in particular also very good elastic properties, with a wide range of hardness.   Cross-linkable compositions, thermoplastic elastomers obtainable therefrom and their use US Patent 7,943,694 (May 17, 2011, Vanhorn et al., to Lanxess Deutschland GmbH Cross-linkable compositions based on at least one copolyester as thermoplastic elastomer and on .alpha.-olefin-vinyl acetate copolymers having a vinyl acetate content of .gtoreq.40 % by weight, where the compositions comprise a peroxide as cross-linking initiator. The present invention further relates to the preparation of the cross-linkable compositions of the invention, to the use of the cross-linkable compositions of the invention for the production of thermoplastic elastomers, to a process for the cross-linking of the compositions of the invention to give a thermoplastic elastomer of the invention, and also to the thermoplastic elastomers of the invention themselves and to their use for the production of moldings and other products. The compositions of the invention can be processed by means of extrusion, or injection molding, or else by means of blow molding.   Process of making a heterogeneous polymer block US Patent 7,935,760 (May 3, 2011), Jiang, et al. to ExxonMobil Chemical Patents Inc. In a process for producing a heterogeneous polymer blend, at least one first monomer is polymerized in a first reaction zone in the presence of a supported catalyst to produce a thermoplastic first polymer having a crystallinity of at least 30 %. At least part of said first polymer is then contacted with at least one second monomer and at least one polyene in a second reaction zone under conditions sufficient to polymerize said second monomer to produce a second polymer having a crystallinity of less than 20 %. The second polymer is at least partially cross-linked in the second reaction zone such that at least a fraction of the second polymer is insoluble in xylene and such that the first and second polymers form different phases of the blend.   Block copolymer particles US Patent 7,947,368 (May 24, 2011) Song et al. to Boston Scientific SciMed In one aspect, the invention features a particle including a block copolymer and having at least one pore. The particle has a diameter of about 3,000 microns or less. In another aspect, the invention features a method of making a particle including a block copolymer and having at least one pore. The method includes generating a drop including the block copolymer and at least one salt, water-soluble polymer, base, or combination thereof, and forming the drop into the particle. In an additional aspect, the invention features a method of making a particle including a block copolymer and having at least one pore. The method includes forming a drop including the block copolymer and a solvent, and removing some or all of the solvent from the drop to form the particle. Embodiments can also include one or more of the following: The particle can include a therapeutic agent, such as one or more proteins, genes, or cells, DNA, RNA, insulin, or a combination thereof. The block copolymer can include at least one first block having a glass transition temperature of at most 37 °C and at least one second block having a glass transition temperature of greater than 37 °C. The first block can include at least one polyolefin block. In some embodiments, the first block can include at least one isobutylene monomer. The second block can include at least one vinyl aromatic block, methacrylate block, or a combination thereof. In certain embodiments, the first block (e.g., the polyolefin block) can include at least one isobutylene monomer, and the second block (e.g., the vinyl aromatic block) can include at least one monomer selected from styrene, .alpha.-methylstyrene and combinations thereof. The block copolymer can be styrene-isobutylene-styrene and also biocompatible. The block copolymer can form a coating on the particle.  Heterogeneous polymer blend with continuous phase and process making the same US Patent 7,951,872 (May 31, 2011) Jacob et al. to ExxonMobil Chemical Patents Inc. This invention relates to a heterogeneous polymer blend comprising a semi-crystalline (at least 30 % crystalline) thermoplastic first polymer that constitutes the dispersed phase and a continuous phase of a second polymer different from, and less crystalline than, the first polymer. The second polymer is at least partially cross-linked as a result of an in-situ reaction between a polyene and the second polymer that takes place concurrently with the polymerization of the second polymer. The presence and amount of such partially cross-linked polymers in the blend can be determined by a multi-step solvent extraction process. In this process the direct product of the polymerization process, without undergoing any additional curing steps, is first contacted with cyclohexane at 25 °C for 48 h to dissolve the uncross-linked and lightly branched elastomeric components of the blend and then the remaining solids are refluxed at the boiling temperature of xylene for 24 h with xylene to isolate the "at least partially cross-linked polymer". The "at least partially cross-linked polymer" is also referred to herein as "xylene insolubles".   Thermoplastic elastomer composition and process producing same US Patent 7,954,328 (June 7, 2011) Tsou et al. to ExxonMobil Chemical Patents Inc. The subject of this patent is a thermoplastic elastomer composition having excellent durability and flexibility while possessing superior air impermeability. In particular, a process for producing a thermoplastic elastomer composition having high rubber content by multistage addition of at least one vulcanizable rubber component, in which the time required to substantially cure the at least one rubber component preferably is less the mixer residence time. Such compositions are particularly useful in applications such as tire innerliners and barrier films or layers. This invention relates to a thermoplastic elastomer composition comprising (A) at least one halogenated isobutylene-containing elastomer; and (B) at least one nylon resin having a melting point of about 170 °C to about 230 °C.; wherein at least one halogenated isobutylene-containing elastomer is present as a dispersed phase of small vulcanized particles in a continuous phase of said nylon where the particles have been formed by dynamic vulcanization and the particles comprising greater than about 60 volume % of the volume of said elastomer and said resin.   Extrusion of thermoplastic elastomers US Patent 7,954,328 (June 7, 2011) Zacarias et al. to ExxonMobil Chemical Patents Inc. A method of forming a thermoplastic vulcanizate by first providing a melt-blender having a die through which melt-blended thermoplastic vulcanizate passes to form a shaped article; wherein the die comprises a flow design having at least one flow branch having a taper angle and a flow reservoir at the end of each flow branch; and wherein the taper angle of the flow design ranges from 5 to 20 degrees; followed by melt-blending a thermoplastic and an elastomer with an organic peroxide curative in the melt-blender to form a thermoplastic vulcanizate; and finally, passing the melt-blended thermoplastic vulcanizate through the flow design to form the shaped article. The melt-blender may be any suitable instrument known in the art, such as a single, double, triple or more barrel extruder. In one embodiment, the melt-blender is a smooth barrel extruder. In another embodiment, the extruder is a single barrel extruder. In yet another embodiment, the extruder is a double barrel extruder, and in yet another embodiment the extruder is a multi-barrel extruder. In any one of these embodiments the extruder is preferably smooth barreled. The blending is generally performed at a temperature not exceeding 400 °C, preferably not exceeding 300 °C and more particularly not exceeding 250 °C. The minimum temperature at which the melt blending is performed is generally higher than or equal to 130 °C, preferably higher than or equal to 150 °C and more particularly higher than 180 °C. The blending time is chosen by taking into account the nature of the compounds used in the TPV composition and the blending temperature. The time generally varies from 5 s to 120 min, and in most cases from 10 s to 30 min.   Crosslinked elastic material formed from a branched block copolymer US Patent 7,923,392 (April 12, 2011), Thomas to Kimberly Clark Worldwide, Inc. An elastic material for use in an absorbent article is provided. The elastic material contains a crosslinked network formed from a branched block copolymer having a monoalkenyl aromatic midblock positioned between conjugated diene endblocks (e.g., butadiene-styrene-butadiene ("B-S-B") triblock copolymer). Prior to crosslinking, the branched block copolymers have a relatively low viscosity and thus may be readily formed into a precursor elastic material (e.g., film, strands, web, etc.) that is subsequently crosslinked to achieve the desired elastic and mechanical properties. Crosslinking is typically achieved through the formation of free radicals (unpaired electrons) that link together to form a plurality of carbon-carbon covalent bonds at the conjugated diene endblocks. The crosslinked network contains a branched block copolymer having a monoalkenyl aromatic midblock positioned between conjugated diene endblocks, wherein the monoalkenyl aromatic midblock constitutes from about 1 wt.% to about 40 wt.% of the copolymer.

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