Insite technology

G. Lancaster, J. Damen, C. Orozco, and J. Moody, Global product and application development utilizing Insite technology, MetCon 94 Proceedings, USA, May 1994. 

Copolymerization of ethylene and styrene by the INSITE technology from Dow generates a new family of ethylene-styrene interpolymers. Polymers with up to 50-wt% styrene are semicrystalline. The stress-strain behavior of the low-crystallinity polymers at ambient temperature exhibits elastomeric characteristics with low initial modulus, a gradual increase in the slope of the stress-strain curve at the higher strain and the fast instantaneous recovery [67], Similarly, ethylene-butylene copolymers may also be prepared. 

Insite technology from Dow Chemical has enabled the production of ethyl ethylene-styrene interpolymers (ESI) by copolymerisation of ethylene and styrene monomers. The properties of interpolymers vary significantly with copolymer styrene content. Interpolymers with up to about 45 wt.% copolymer styrene are semi-crystalline and exhibit good low temperature toughness. Interpolymers with greater than about 45 wt.% copolymer styrene are... 

As a result of the catalyst and process conditions used in their manufacture, the particular copolymers of current major interest are atactic, and contain typically up to about 50 mol% ( 80 wt%) styrene. These materials have been described as pseudo-random , since successive head-to-tail styrene chain insertions have been shown to be absent, even at high levels of styrene incorporation [1,2]. The term ethylene-styrene interpolymer (ESI) is used here to describe the specific ethylene-styrene copolymers produced via INSITE Technology. For convenience, all subsequent comonomer contents are expressed in weight percentages, unless otherwise stated. For example, the code ES70 refers to an interpolymer having 70 wt.% comonomer styrene incorporation. 

Y. W. Cheung INSITE, Technology R D The Dow Chemical Company Dow Texas Operations Freeport, TX 77541-3257 USA... 

Plastics Polyethylene Polystyrene Polypropylene Insite technology 20... 

A milestone was reached in 1993 with development by Dow of the Insite technology, resulting in development of the polyolefin elastomers Affinity and, 3 years later, Engage . 

The ethylene-n-octene elastomer s EOE t3rpe Engage, synthesized according to the Insite technological process, manufactured by DuPont Dow Chemical Elastomers (Table 8.1). 

In the USA Exxon Chemical and Dow Plastics were the leaders in the metallocene technology. While Exxon explored both mono- and bis-cyclopentadienyl metallocenes, Dow focused on constrained geometry catalysts based on Ti-monocyclopentadienyl metallocenes. Exxon first produced metallocene-based polymers with its Exxpol catalysts in 1991. Dow uses its INSITE technology to make ethylene-octene copolymers, introduced in 1993. Copolymers with up to 20 wt% octene are sold as AFFINITY plastomers, competing with specialty polymers in packaging, medical devices, and other applications. Dow, producing its own catalyst, considers that it leads to the uniform introduction of comonomers and long-chain branches that improve processability of otherwise linear polymers. 

Insite technology is used for homogeneous single-site catalysts which produce virtually identical molecular structure such as branching, comonomer distribution, and narrow molecular weight distribution (MWD). Solution polymerization yields Affinity polymers with uniform, consistent structures, resulting in controllable, predictable performance properties. ... 

EPM [poly(ethylene-co-propylene)] and EPDM [poly(ethylene-co-propylene-co-5-ethylidene-2-norbomene)P can be metallocene catalyst polymerized. Metallocene catalyst technologies include (1) Insite, a constrained geometry group of catalysts used to produce AfiGnity polyolefin plastomers (POP), Elite PE, Nordel EPDM, and Engage polyolefin elastomers (POP) and (2) Exxpol ionic metallocene catalyst compositions used to produce Exact plastomer octene copolymers.2 Insite technology produces EPDM-based Nordel IP with property consistency and predictability (see Sec. 3.2.2). 

The effective production of these novel copolymers has been enabled by INSITE Technology. A product development plant to produce Interpolymers (Sarnia, Canada) had a successful start-up in September 1999. This plant, having a nameplate production capacity of around 22,500 metric tons per annum, has enabled further product and process developments, and application validation. 

Fig. 15. Characteristics of ethylene-styrene copolymers made by INSITE technology. From 218. Copyright (1998). This material is used by permission of Wiley-Liss, Inc., a subsidiary of John Wiley Sons, Inc.

Ethylene/styrene copolymers are presently available commercially from Dow Chemical Company using Dow s constrained geometry catalyst (INSITE) technology. These novel, random, semicrystalline copolymers contain 20-80 wt% styrene. The copolymer melting points decreased from about 90°C to 45°C with increasing styrene content from 20 to 45 wt%, respectively [56,57]. 

Dr. Sehanobish has authored a series of publications and holds more than 25 patents in the areas of polyethylene pipes, blown and cast films, speciality fibers and films, and TPOs. His research is the basis for the INSITETM technology platform and new resin families such as ENGAGE , AERNITY , NORDEL ip and ELHE . The INSITE technology received the R D 100 Award in 1994 from R D Magazine, and the ELITE enhanced polyethylenes received the R D 100 Award in 1999. These efforts also resulted in currently more than one billion pounds per year of sales of metallocene-catalyzed polyethylene resins by The Dow Chemical Company. 

A HDPE resin in the 0.9555 density and fractional melt flow range with bimodal MWD was prepared with a 50/50 blend of high and low molecular weight resins from the slurry process using the INSITE technology. When compared with a bimodal blend of the same density and melt flow rate made with a conventional ZN catalyst, ESCR of the new resin was found to be several times higher and Charpy impact strength at —20°C improved by 60%. 

ELITE resins are produced via INSITE Technology, a constrained geometry catalyst and process technology developed by The Dow Chemical Company that provides extraordinary control over polymer arehiteeture. 

Most importantly, there is no output penalty using existing extrusion equipment. This is key since metallocene products are going to be widely accepted in the volume markets. Innovene with INSITE technology is clearly unique in this respect. 

Modeling of the melt viscosity of polyethylene and random copolymers of ethylene and a-olefins has been extensively dealt with in the past. Empirical viscosity models of the form of the Generalized Cross/Carreau models can and have been fitted to viscosity data for INSITE Technology Polymers. The shear viscosity data is usually measured at 190 °C in the molten regime from 0.1 - 100 rad/s. Of the several models available, the Cross model provides a good fit to the data with a minimum number of fitting parameters. The Cross model is of the form ... 

---