摘要:
This invention is based upon the unexpected discovery that styrene-butadiene block copolymers having syndiotactic polystyrene (sPS) blocks and cis-1,4-polybutadiene (PBd) blocks can be synthesized by polymerizing styrene and 1,3-butadiene utilizing certain catalyst systems when the polymerization is conducted at a pressure which is within the range of about 10 mm of mercury to about 50 mm of mercury at a temperature which is within the range of about 0° C. to about 100° C. This invention more specifically discloses a styrene-butadiene block copolymer which is comprised of (a) syndiotactic polystyrene blocks and (b) cis-1,4-polybutadiene blocks, wherein said cis-1,4-polybutadiene blocks have a vinyl content of up to about 20 percent, wherein the syndiotactic polystyrene blocks have a syndiotactic microstructure content of at least 50 percent, wherein the block copolymer contains at least five syndiotactic polystyrene blocks and wherein said block copolymer has a number average molecular weight which is within the range of about 10,000 to about 700,000.
摘要:
A tyre includes at least one structural element obtained by crosslinking a crosslinkable elastomeric composition including: (a) a crosslinkable elastomeric base comprising at least 10 phr, preferably from 30 phr to 100 phr, of (a1) at least one epoxidized elastomeric polymer including less than 10 mol %, preferably from 0.1 mol % to 5 mol %, of epoxy groups relative to the total number of moles of monomers present in the elastomeric polymer; and (b) from 2 phr to 50 phr, preferably from 5 phr to 30 phr, of at least one layered material. Preferably, the at least one structural element is selected from bead filler, sidewall insert, tread underlayer, and tread base.
摘要:
A tire, including a carcass structure, includes at least one carcass ply of a substantially toroidal shape, having opposite lateral edges associated with respective right-hand and left-hand bead structures, the bead structures including at least one bead core and at least one bead filler; a belt structure applied in a radially external position with respect to the carcass structure; a tread band radially superimposed on the belt structure; a pair of sidewalls applied laterally on opposite sides with respect to the carcass structure; and at least one layer including a crosslinked elastomeric material applied in a radially inner position with respect to the carcass structure. The crosslinked elastomeric material is obtained by crosslinking a crosslinkable elastomeric composition including (a) less than 50 phr, preferably 15 phr to 40 phr, of at least one butyl rubber; (b) not less than 50 phr, preferably 60 phr to 85 phr, of at least one polyisoprene rubber; and (c) 2 phr to 50 phr, preferably 5 phr to 35 phr, of at least one layered material. Preferably, the layer including a crosslinked elastomeric material is a tire innerliner.
摘要:
A process for producing an epoxidized elastomeric polymer by feeding at least one elastomeric polymer containing ethylenic unsaturation to a mixing device; feeding at least one hydrogen peroxide precursor to the mixing device; feeding at least one carboxylic acid or a derivative thereof to the mixing device; mixing and reacting, in the presence of water, the at least one elastomeric polymer containing ethylenic unsaturation with the at least one hydrogen peroxide precursor and the at least one carboxylic acid or a derivative thereof, to obtain an epoxidized elastomeric polymer; and discharging the resulting epoxidized elastomeric polymer from the mixing device.
摘要:
A crosslinkable elastomeric composition includes at least one thermoplastic polymer selected from amorphous polymers having a glass transition temperature higher than 80° C. or crystalline polymers having a melting temperature higher than 190° C. and at least one diene elastomeric polymer. A method for preparing the composition includes pre-mixing, at a temperature not lower than Tg or (Tm−20° C.), the at least one thermoplastic polymer with a first portion of the at least one diene elastomeric polymer to obtain a masterbatch and mixing the masterbatch with a remaining portion of the at least one diene elastomeric polymer. The composition may include from 1% to 65% of the at least one thermoplastic polymer and from 35% to 99% of the at least one diene elastomeric polymer. The at least one thermoplastic polymer may be dispersed in a form of particles having an average diameter not greater than 20 μm.
摘要:
Method for producing a crosslinkable elastomeric composition including: (a) at least one first elastomeric polymer; (b) at least one layered material having an individual layer thickness of 0.01 nm to 30 nm, preferably of 0.05 nm to 15 nm; and (c) at least one vulcanizing agent; includes the following steps: (i) feeding the at least one layered material (b) and at least one second elastomeric polymer (d), into at least one extruder including a housing, at least one screw rotatably mounted in the housing including at least one feed opening and a discharge opening, the at least one layered material being fed into the at least one extruder in an amount higher than or equal to 70 phr; (ii) mixing and softening the mixture so as to obtain a masterbatch; (iii) discharging the obtained masterbatch through a discharge opening; and (iv) mixing the obtained masterbatch with the at least one first elastomeric polymer (a) and the at least one vulcanizing agent (c), to obtain the crosslinkable elastomeric composition, the mixing being carried out in a batchwise manner.
摘要:
Tyre for vehicle wheels, comprising at least one component made of a crosslinked elastomeric material, in which said component includes an elastomeric composition comprising: (a) at least one diene elastomeric polymer, (b) at least one cycloolefin polymer, said cycloolefin polymer having a glass transition temperature (Tg) of not less 50° C. Preferably, said component including said composition is a tyre tread band.