Monsanto Company

Other

Raymond D Burk

Gisbert Michels

Bernd Klinksiek

Richard Weider

Fred M Peng

A Hameed Bhombal

Joong-In Kim

Ralph Ostarek

Otto Schmid

A continuous process for the manufacture of impact resistant polymers is disclosed. The process comprise polymerization of a reaction mixture containing vinylaromatic monomers in the presence of soluble rubber and entails shearing at least some of said mixture at a rate of more than 30000 1/s using a device having no rotating parts. The resulting product is characterized in its low gloss and improved impact properties.

Process for the manufacture of impact resistant modified polymers

Thermoplastic polyblends having weatherability and impact strength are formed by blending a first graft copolymer containing a conjugated diene rubber substrate having a weight average particle size between about 0.6 and about 10 microns with a second graft copolymer containing an EPDM-type rubber substrate having a weight average particle size between about 0.05 and about 1 micron or an alkyl acylate rubber substrate having a weight average particle size between about 0.05 and about 0.5 micron. The superstrate of the two graft copolymers comprises a monovinylidene aromatic hydrocarbon and an unsaturated nitrile.

Impact- and weather-resistant thermoplastic polyblends

The present invention relates to an improved process for the continuous mass polymerization of solutions comprising an alkenyl aromatic monomer having a diene rubber polymer dissolved therein comprising the steps of polymerizing said solution in a first reaction zone to about 15 to 50% conversion dispersing said diene rubber or rubber particles in a partially polymerized solution, followed by further polymerization said partially polymerized solution in a second polymerization zone to about 20 to 95% conversion the improvement comprising having present in said solution, as fed to said first reaction zone, a polymer of said monomers in an amount sufficient to control the size of said diene rubber particles.

Process for the continuous polymerization of polyblends

The present invention relates to an improved process for the continuous mass polymerization of solutions comprising alkenyl aromatic monomers having about 1 to 10% by weight of a polybutadiene rubber dissolved therein, the steps comprising, (A) continuously charging said solution to a first reaction zone operating at about 10 to 40% conversion forming a first partially polymerized mixture, (B) continuously charging said first mixture to a second reaction zone operating at about 50-90% conversion forming a second partially polymerized mixture, and finally, (C) separating the residual monomer from said second mixture providing a polyblend of a matrix phase of said monomers having polybutadiene rubber particles grafted with said monomers dispersed therein, the improvement comprising: charging a monomer-polybutadiene solution in step (A) having in addition about 1 to 10% by weight of a diene block copolymer and about 1 to 20% by weight of a polymer of said monomers dissolved in said solution followed by carrying out steps (B) and (C) to provide a polyblend of a polymer of said monomers having dispersed therein rubber particles grafted with said monomers, said rubber particles containing said polybutadiene and diene block copolymer rubbers and forming a gel phase of said rubber particles containing grafted and occluded polymers of said monomers in an amount of about 0.5 to 5 parts per part of total rubber.

Process for the continuous mass polymerization of polyblends

The invention relates to a continuous mass polymerization process for polyblends having a dispersed rubber phase with a bimodal rubber particle size distribution, wherein, first and second monomer-rubber solutions are fed to a first back-mixed polymerization zone such that said first solution forms particles of about 0.5 to 1.5 microns and said second solution, having present a dissolved rubber and a dissolved polymer of said monomer, forms particles of about 2 to 5 microns during partial polymerization of 10 to 50% of said monomers. Said partially polymerized solutions are further polymerized in a second zone, with linear flow, to a conversion of 20 to 95%, forming said polyblend with a bimodal rubber particle size distribution having improved toughness and gloss.

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Wilbraham, MA, United States of America

Raymond D Burk