Dynasol Elastomeros, S.a. De C.v.

Dynasol Elast¿meros, S.a. De C.v.

Gabriel Hernández Zamora

Sergio Alberto Moctezuma Espiricueto

Gabriela Elizabeth Blanco Reyes

Alejandro Claudio Esquivel De La Garza

Christopher J Hardiman

Xuan Fu

Daniel Abraham Elizarrarás Maya

Julian Maldonado Valenzuela

Jesús Eduardo Ibarra Rodríguez

José María Islas Manzur

José Luis García Vidales

Jesús Alberto Mexicano García

Enrique María Montero Carnerero

Jessica Nolasco Santiago

Martha Belem Mendieta García

Abel Zúñiga Calles

Mariana Díaz Vejo

Elisa Tierrablanca Maldonado

John Kounavis

A counter tapered diblock copolymer composition comprises a monovinyl aromatic monomer A polymerized with a conjugated diene monomer B to form the structure A-[A/B], where the [A/B] block is a copolymer of the A and B monomers that is counter tapered, which means the ratio of B to A is lower proximal to the A block relative to the ratio of B to A distal to the A block. The [A/B] block preferably has a vinyl content that is higher proximal to the A block relative to the vinyl content distal to the A block. The diblock copolymer is preferably partially coupled or formed with a multifunctional initiator to provide a mixture of the diblock copolymer composition and a linear (A-[A/B])-X-([B/A]-A) structure and/or a coupled radial and/or multiarm structure (A-[A/B])n-X, where X is the residue of a coupling agent or an initiator. Asphalt and adhesive compositions are made with the diblock copolymer composition and with the mixture.

Counter tapered thermoplastic elastomers

Dual composition block copolymers made from conjugated diene and monovinyl aromatic monomers in batch organolithium initiated polymerization show advantageous performance in the production of crosslinked microcellular rubber compounds and pressure sensitive hot melt adhesives. The dual composition block copolymers are partially coupled with a coupling agent linking inner monovinyl aromatic blocks. Their un-coupled low molecular weight fraction has greater monovinyl aromatic repeating unit content than their coupled high molecular weight fraction. Crosslinked microcellular rubber articles made from the dual composition block copolymers exhibit lower density, smaller and more homogeneous cell size, higher softness and higher resiliency than prior art block copolymers. Rubber compounding of formulations comprising the dual composition block copolymers proceed at slightly lower torque and slightly lower temperature than with prior art block copolymers. Pressure sensitive hot melt adhesives formulated with the dual composition block copolymers are very well suited for labels, exhibiting higher tack and higher softening temperature than those made from prior art block copolymers.

Dual composition block copolymers

A counter tapered thermoplastic elastomer composition comprising: (a) a counter tapered diblock A-[A/B] copolymer with a peak molecular weight from 20,000 to 250,000, which includes a monovinyl aromatic homopolymer block A with a peak molecular weight of at least 8,000 and a counter tapered copolymer block [A/B] with a vinyl content of at least 15 weight percent based on the amount of conjugated diene units in the diblock copolymer; and (b) a block copolymer selected from the group consisting of linear triblock copolymers having a peak molecular weight that is at least about 1.5 times the peak molecular weight of the counter tapered diblock A-[A/B] copolymer described in (a), multiarm coupled block copolymers having a peak molecular weight that is at least about 2.5 times the peak molecular weight of the counter tapered diblock A-[A/B] copolymer described in (a), and mixtures thereof; and (c) wherein the ratio of (a) to (b) in the counter tapered thermoplastic elastomer composition is from about 1:5 to about 5:1. The counter tapered thermoplastic elastomer compositions provide in the applications: i) easy processing such as short dispersion time, low mixing temperature, low viscosity, excellent storage stability; and ii) better reinforcement such as high elastic response, wide range of performance grade, high adherence, higher filler loading capacity, and better compromise between high and low temperature properties; which make them suitable for a broad range of applications such as road paving, roofing, shingles, waterproofing membranes, adhesive tapes and labels, contact and sprayable adhesives, and sealants.

A process is provided for making a silica masterbatch, that contains silica and solution-made rubber. The silica masterbatch has physical properties similar to those found in a comparable dry-mixed composition, but the silica masterbatch can be incorporated more easily and less expensively into tires and other rubber products than the dry-mixed composition. A process is also provided for making a masterbatch of silica, a solution-made rubber and an emulsion-made rubber.

Processes for making masterbatches of rubber and silica

The invention relates to compositions of cement and concrete having properties of resistance, modulus and expansion which are significantly improved, using an additive for cement based on thermoplastic styrene-butadiene-styrene (SBS) copolymer in cationic latex, when compared with non-modified cement and concrete references.

SBS latex for use in the modification of concrete

A tapered triblock copolymer having controlled vinyl distribution, enlarged middle block with intermediate composition and microstructure, increased compatibility between its adjacent blocks, good processing characteristics and a peak average molecular weight between 25,000 and 300,000 is made by anionically polymerizing conjugated diene and monovinyl aromatic monomers, polar modifier and initiator to make a first block rich in conjugated diene, forming a second block that is a copolymer of the conjugated diene and the monovinyl aromatic monomer and which is less rich in the conjugated diene than the first block, and forming a third block that is a homopolymer of the monovinyl aromatic monomer. The first, second and third blocks comprise 30 to 60, 20 to 50 wt % and 10 to 40 wt % of the tapered triblock copolymer, respectively. The tapered triblock copolymers may be used as asphalt modifiers, adhesives, sealants, compatibilizers, reinforcing agents and impact modifiers.

Tapered triblock copolymers

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Tampico, Mexico

Gabriel Hernández Zamora