Technical Data Sheet
RHOPLEX™ EC-2885
100% Acrylic Latex Polymer
Introduction
RHOPLEX™ EC-2885 all-acrylic latex polymer was developed as a high performing, high tensile
strength polymer that, when formulated into a quality recommended elastomeric roof coating
formulation, delivers improved toughness, hail resistance and roof traffic protection while maintaining
excellent elastomeric properties. Coatings based on RHOPLEX™ EC-2885 also exhibit excellent
adhesion to polyurethane foam and a variety of other construction and roofing substrates, and can
exceed the expected tensile strength of typical acrylic roof coatings, as well as provide excellent
durability and dirt pickup resistance.
Advantages
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Excellent exterior durability on roof exposure
Good adhesion to polyurethane foam and many other construction substrates
Low-temperature flexibility
Polyurethane-like balance of tensile strength and elongation
Excellent elongation at temperatures down to -15°F
Excellent dirt pickup resistance
Better hail resistance than typical elastomeric roof coatings
UV light resistance
Excellent toughness to withstand foot traffic and routine rooftop maintenance activities
High solar reflectivity, reducing roof surface temperatures and helping to prolong roof life and
reduce energy costs
• Low toxicity and odor
• Easy application and simple cleanup with water
Typical Physical Properties
These properties are typical but should not be considered specifications.
Solids content, %
55.0-56.0
pH
7.2-8.0
Viscosity, cPs, max.
140
Density, lbs/gal
8.60
Glass transition temperature (Tg), -35
onset, °C
Storage stability
Protect from freezing
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®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
RHOPLEX™ EC-2885 / Dow Construction Chemicals
July 2010
Typical
Performance
Properties
Listed below are the individual properties inherent in RHOPLEX™ EC technology. It is important to
remember that it is the balance of these properties that is unique to this chemistry. Although coatings
based on other technologies may exhibit excellence in one or two performance properties, it is the
combination of all the properties that is required for a successful elastomeric roof coating.
Durability
Since the advent of Plexiglas acrylic plastic sheet (trademark of Arkema, Inc.) during World War II,
acrylics have been known for their exceptional durability, offering unequaled resistance to degradation
by sunlight and moisture. It was the UV resistance of acrylic polymer – the lack of which is the major
cause of failure in conventional roofing systems – that first led manufacturers to consider acrylic
polymers for elastomeric roof coatings. RHOPLEX™ EC-2885 technology is one example of acrylic
polymers having been tailored specifically for elastomeric roof applications.
Low-temperature Flexibility
Coatings for dimensionally unstable roofing substrates must have long-term, low-temperature
flexibility. This is necessary to accommodate thermal expansion and contraction of the substrate,
so that coatings will not fail over an extended period of time or with extreme weather conditions.
It should be remembered that the effects of extreme weather conditions are not restricted to cold
climates. Water contact after a sudden thunderstorm on a hot day in any geographic location can
rapidly drop the roof temperature as much as 100°, causing severe thermal stress to the roof
surface.
Formulations based on RHOPLEX™ EC-2885 technology can withstand a 180° flexibility bend at
-15°F without cracking. Since there is no plasticizer to migrate from the system, good flexibility is
retained over time. Long-term resistance to cracking can extend the life of the roof.
It is important to note that elastomeric roof coatings should exhibit good mechanical properties at
room and low temperatures before and after exterior exposure.
Tensile Strength and Elongation
Thermal movement of a roof requires high tensile strength and elongation. The tolerance for movement of these coatings is essential due to the dynamic nature of roofing substrates that expand
and contract due to climatic and weather conditions and the shifting and settling of the foundation.
These properties also give properly formulated elastomeric roof coatings the needed flexibility and
elasticity to withstand impact from foot traffic and other abuse without rupturing. An elastomeric
roof coating formulated properly with RHOPLEX™ EC-2885 can exceed the expected tensile
strength of other acrylic roof coatings, exhibit improved hail resistance, and maintain or exceed
expected elongation and flexibility requirements.
Dirt Pickup Resistance
Polymers designed for elastomeric roof coatings combine the inherent flexibility of pliable, low Tg
polymers with long-term resistance to dirt pickup. Without dirt pickup resistance, roof coatings would
quickly darken with age. Because dark materials tend to absorb heat, dirt pickup can significantly
increase roof surface temperatures, which in turn increases interior temperatures and energy
costs. Coatings based on RHOPLEX™ EC-2885, however, resist dirt pickup and retain their white
reflective appearance longer than typical elastomeric coatings.
Test roofs have shown that after five years of exposure, the surface temperature of the
RHOPLEX™ EC-2885 based acrylic coating was 35°F cooler than that of a conventional caulk
polymer coating and 85°F cooler than a black uncoated roof.
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®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
RHOPLEX™ EC-2885 / Dow Construction Chemicals
July 2010
Formulation
Guidelines
Although designed specifically for exceptional wet and dry adhesion to high- and low-density
polyurethane foam, elastomeric roof coatings properly formulated with RHOPLEX™ EC-2885
latex polymer exhibit excellent adhesion to other typical roofing substrates. It should be noted,
however, that significant departure from recommended formulations, especially use of other
wetting agents or water-sensitive components, may adversely affect the wet adhesion.
Deviating from the prescribed pigment volume concentration (PVC) and volume solids suggestions
can compromise the excellent tensile strength and elongation balance of RHOPLEX™ EC-2885.
Contact your local Dow representative for suggested starting point formulations and related information.
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®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
RHOPLEX™ EC-2885 / Dow Construction Chemicals
July 2010
Product
Stewardship
Dow has a fundamental concern for all who make, distribute and use its products, and for the
environment in which we live. This concern is the basis for our product stewardship philosophy
by which we assess the safety, health and environmental information on our products and
then take appropriate steps to protect employee and public health and our environment. The
success of our product stewardship program rests with each and every individual involved with
Dow products – from the initial concept and research to manufacture, use, sale, disposal and
recycle of each product.
Customer Notice
Dow strongly encourages its customers to review both their manufacturing processes and
their applications of Dow products from the standpoint of human health and environmental
quality to ensure that Dow products are not used in ways for which they are not intended or
tested. Dow personnel are available to answer your questions and to provide reasonable
technical support. Dow product literature, including safety data sheets, should be consulted
prior to use of Dow products. Current safety data sheets are available from Dow.
Disclaimer
NOTICE: No freedom from infringement of any patent owned by Dow or others is to be
inferred. Because use conditions and applicable laws may differ from one location to another
and may change with time, the Customer is responsible for determining whether products and
the information in this document are appropriate for the Customer’s use and for ensuring that
the Customer’s workplace and disposal practices are in compliance with applicable laws and
other governmental enactments. The product shown in this literature may not be available for
sale and/or available in all geographies where Dow is represented. The claims made may not
have been approved for use in all countries. Dow assumes no obligation or liability for the
information in this document. References to “Dow” or the “Company” mean the Dow legal
entity selling the products to Customer unless otherwise expressly noted.
NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.
The Dow Chemical Company
www.dowconstructionchemicals.com
215-592-3000
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®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
RHOPLEX™ EC-2885 / Dow Construction Chemicals
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July 2010