Lead Feature

Maintaining technology leadership in Asia

With petrochemical giant ExxonMobil Chemical pumping in investment at its largest integrated chemical and refining complex in Singapore, it has stepped up the introduction of new elastomer/polymer grades to Asia. The second expansion in Singapore includes a world-scale steam cracker and associated derivative units, including new PE, PP and speciality elastomers plants, an aromatics extraction unit and oxo alcohol expansion, set to come on stream late 2010 through 2011.

At Chinaplas, the US company unveiled an array of polymers including an mPE 35-05 grade that allows for downgauging of films, plus adding on toughness, stiffness and high clarity. It also had new PP grades for thinwall injection moulding of rigid packaging; for toys and housewares and another grade for use in pallets and consumer products.

Others it expects to produce in Singapore include Vistamaxx propylene-based elastomers. Four new grades of Vistamaxx for film applications were introduced in China. The Singapore plant also includes a 300 kilotonne capacity addition for its Vistalon EPDM.

PRA spoke to Lynn Maenza, Asia Pacific Marketing Manager for SEB (Speciality Elastomers Business) to get a feel of the new grades and the SEB business.

PRA: Can you provide some examples of application use of Vistamaxx?

Lynn: It is being used for construction applications. For instance, extrusion coating a blend of 10 to 70% Vistamaxx with PP on to the woven membrane on the upper part of synthetic roofing underlayment enables OEMs and converters to increase the coefficient of friction (COF), making the underlayment less slippery when contractors stand on it. And, by using Vistamaxx in the compound for the underside of the membrane it helps prevent the underlayment from slipping off the roof during installation. 

For roof sheets, it is used in a concentration of 5 to 20% to modify thermoplastic polyolefin (TPO) formulations. This provides improved flexibility of up to 33% for easier installation and repair, improved welding performance and easier installation, and increased seam strength of 30% and peel strength of 17%.

Another use is in wall insulation. Compounded with over 70% fillers, Vistamaxx-based sound deadening solutions also provide excellent flexibility for ease of installation and improved functionality at competitive prices.

PRA: Can you give some examples of its use as a modifier?

Lynn: As a drop-in modifier, Vistamaxx is able to improve the performance of polymers used in storage containers and boxes. One converter reduced cost and maintained performance of a transparent box previously made of PC by using 5 to15% Vistamaxx in a random copolymer polypropylene (RCP).

Wanting to reduce breakage of a clear, rigid storage totes during shipment, storage and handling, an OEM was looking for a more cost-effective impact modifier than the styrene-ethyl-butylene-styrene (SEBS) resin it was using. Using 3 to10% Vistamaxx, enabled the OEM to create the right balance of impact performance and transparency to eliminate breakage and maintain clarity, while a lower concentration than SEBS resin reduced costs.

In another example, a food container made from homopolymer polypropylene (hPP) lacked aesthetic appeal and the sealing performance. RCP was originally evaluated as a possible replacement but the flexibility and low temperature performance did not meet the requirements of the application. By adding 5 to10% Vistamaxx to RCP, the modified compound provided a balance of flexibility for an air-tight seal, transparency, low temperature performance to eliminate breakage; hinge flexibility without stress whitening or cracking and, broad US Food and Drug Administration (FDA) and European Union (EU) Directive approval for use in contact with food. 

Vistamaxx is used as the carrier in masterbatch applications because they provide easy pigment dispersion and improved impact strength for high-end aesthetic applications. A concentration of between 20 to 30% is required for masterbatch applications, depending on the type of pigment and its surface area.

Yet, another use is to enhance the quality of recycled PP and PE, enhancing the mixing for better quality products, improving processability of the finished part, and imparting consistency of performance in the recycled product.

PRA: In the rubber industry, how is ExxonMobil addressing the growing demand for EPDM?

Lynn: Well, besides the 300 kilotonne/year plant in Singapore, which will start up next year, we are continuing to invest in higher grades. For instance, we have introduced amorphous metallocene EPDMs that are targeted at the extruded weatherseals market, which is an important market for EPDM.

The new grade is made possible due to the recent advances in metallocene solution polymerisation and amorphous EPDM prepared by metallocene technology offers improvements over conventional Ziegler Natta methods. Results indicate that polymers with uniform compositional distribution and low ethylene content prepared by metallocene catalysts offer a balance of mechanical properties and low temperature elastic properties.

We have noticed some benefits such as lower energy use and the polymers offer different performances and characteristics for a totally new portfolio, all this from a material that has been on our portfolio for 40 years.
 
PRA: How do TPVs fall into this equation, since these are also targeted at the weatherseals sector?

Lynn: Our Santoprene TPVs are meeting the increased demand for recyclable, light weight sealing solutions. There is an overlapping situation but EPDM bondable Santoprene TPV is enabling hard-soft material combinations for cost-effective system solutions.

We are able to use all the grades in sealing applications with EPDMs for moulded corners and TPVs for straight sealing applications, so these complement each other, while reducing the scrap and cycle rates.

Additionally, we have developed jointly with German company Troester a new extrusion concept, combining hard and soft thermoplastic materials that enable the replacement of the metal reinforcement in EPDM profiles with a thermoplastic alternative. This provides opportunities to lower part weight, while reducing production complexity compared with conventional EPDM sealing solutions.

PRA: What is the outlook for the SEB business?

Lynn: We will continue to focus on technology innovations that are industry focused. For the Asian market, we will provide the support that is needed for application development, at our Shanghai applications centre that was opened this year. We also have an automotive applications centre in Kawasaki, Japan and a thermoset development centre in India. All these should assist in reaching out to a broader base of the Asian market sectors.