Exxonmobil Chemical Patents Inc.

Hari Prasad Nadella

Jianya Cheng

Ronald DeYoung

Maria Dolores Ellul

Kuo-Shein Shen

Ronald De Young

This invention relates to the preparation of a dynamically vulcanized alloy comprising at least one elastomer and at least one thermoplastic resin, having a G' at 1% strain and 100&#xb0; C. as determined according to ASTM D7605 of about 4,500 to about 7,500 kPa. More specifically, the process produces dynamically vulcanized alloys with unique morphological features which have good impermeability and low temperature flexibility. In the process, the thermoplastic resin is added into the extruder in two stages with an intermediate addition of a compatibilizer. Also during the final addition of thermoplastic resin, the elastomeric curatives are added to the extruder.

Process for preparing dynamically vulcanized alloys

A process for preparing modified thermoplastic vulcanizate compositions, the process comprising the steps of introducing molten thermoplastic vulcanizate and a free-radical source, where the thermoplastic vulcanizate includes cured rubber dispersed within a thermoplastic matrix.

Process for forming thermoplastic vulcanizates and extruded articles therefrom

Described in one aspect is a process for preparing a low durometer thermoplastic vulcanizate composition comprising melt blending one or more thermoplastic polymer(s) with a cross-linkable elastomer under conditions of dynamic vulcanization; adding at or after the start of the melt blending at least one curative agent for the elastomer so as to cross-link the elastomer during the melt blending; introducing process oil into the melt blending before, during and/or after the addition of the curative agent; and, extruding a fully crosslinked thermoplastic vulcanizate having a Shore A Hardness of less than 25.

Dynamic vulcanization process for preparing thermoplastic elastomers

The invention relates to a method of preparing a thermoplastic vulcanizate comprising: a) melt processing a blend of thermoplastic polymer and vulcanizable elastomer in a multi-screw extruder having at least three intermeshing screws, wherein said screws have 3-170 mixing zones, and said extruder having a L/D ratio of 15-100, and a screw profile that has 3 to 17 meshes per L/D; b) adding at least one curing agent to the melt-processed blend of a) in at least one location in the first 46% of the length of said extruder, or adding at least one curing agent to the melt-processed blend of a) in a second extruder, so as to initiate curing of the blend: and, curing at least partially said elastomer by reactive melt processing. Improved processing, reaction kinetics and efficiencies are achieved, as well as thermoplastic vulcanizate products having decreased weight gain when placed in mineral oils.

Growing community of inventors

Copley, OH, United States of America

Hari Prasad Nadella