Description. Performance Advantages

Transcription

1 RHOPLEX EI-2000 Acrylic Polymer for Use in Exterior Insulation and Finish Systems (EIFS) with Both Excellent Dirt Pickup Resistance and Good Flexibility Description RHOPLEX EI-2000 is a 100% acrylic polymer that functions as the binder for the EIFS finish and as a modifier for the cementitious base coat/adhesive components of the EIFS. Performance Advantages In the EIFS finish, RHOPLEX EI-2000 polymer is the film-forming ingredient that binds the pigments and extenders together. In this application, RHOPLEX EI-2000 provides colorfastness, good resistance to dirt pickup, water resistance, and resistance to yellowing and chalking when properly formulated. As the modifier for Portland cement, RHOPLEX EI-2000 provides the strength, adhesion, water resistance, flexibility, and durability of the cement components. Typical Physical Properties These properties are typical but do not constitute specifications. Appearance White, milky liquid Solids Content, % 46.5 ± 0.5 ph Brookfield Viscosity, cps 30 RPM) Density (lb/gal) 8.80 Bulking Value, Dry Solids Minimum Film Formation Temperature gal/lb 5-9 C Formulation Notes The level of RHOPLEX EI-2000 polymer used in the EIFS formulation must be determined to deliver the required level of performance. In addition, there are other formulation variables and ingredients that can make the difference between a marginally performing product and a superior one. The following summary offers some guidelines to achieving good quality and durability. Finish The properties of the finish, such as water resistance, resistance to chalking, cracking, erosion and colorfastness are influenced by the amount of polymer used in the formulation. Particle size, density, particle distribution, and particle shape of the extenders, pigments, and very small particle size rheology modifiers like clay, influence the level of polymer, or binder, needed for adequate performance and durability of the finish. Increasing pigment and extender surface area increases binder demand. One of the principal parameters that can be used to measure the performance of a finish is the pigment volume concentration (PVC). While percent polymer is a convenient method to estimate the quality of an EIFS finish, PVC is better. PVC is defined as the ratio of the dry pigment volume, to the volume of dry pigment plus the volume of dry polymer. For the finish coat, the PVC is calculated by dividing the gallons of pigment and extender solids by the total gallons of finish solids and multiplying by 100. As the PVC increases, the amount of polymer in the finish decreases, and resistance to cracking, chalking, erosion, and colorfastness is reduced. Studies conducted with the attached formulations to determine the effect of PVC on the performance and durability of the finishes have shown that a PVC between 70 (15% solid polymer on the dry finish weight) and 79% (10% solid polymer on dry finish weight) provide the best balance of performance properties. Above this PVC, the level of performance begins to drop off as the PVC is increased. If the PVC is too high, the amount of binder in the finish

2 becomes insufficient to hold all the pigments and extenders together efficiently. The ability of the polymer to bind all these materials is stretched beyond its capability and at some point the finish begins to degrade as evidenced by excessive chalking, cracking, and poor color retention. As a modifier for Portland cement, 10% solid RHOPLEX EI-2000 on the weight of cement is suggested as a starting point. Higher levels of polymer relative to cement content can be used to improve flexibility and water resistance. Coalescing Agent Adequate amounts of coalescent are needed to produce a tough polymer film under a variety of curing or weather conditions. A properly coalesced coating is essential for good resistance to cracking and good exterior durability. For a RHOPLEX EI-2000 finish, use Texanol at approximately 3-5% on polymer solids to insure adequate film formation. At this level, the coatings should meet the typical job requirements that the air and surface temperatures must be 40 F or higher and must remain so for a minimum of hours. For adequate performance at a minimum application temperature 40 F and rising over the next 24-hour period, approximately 1.5% Texanol on polymer solids should be examined in a cementitious adhesive/base coat. Thickeners The level and types of thickeners used to formulate EIFS components, such as finishes, cementitious base coats and adhesives, vary. For a finish coat, use ACRYSOL ASE-60, an acid-containing, crosslinked acrylic emulsion copolymer. When the emulsion is diluted with water and neutralized with a base, such as ammonium hydroxide, each emulsion particle swells and the viscosity increases. The level of ACRYSOL ASE-60 needed will depend on the viscosity required and the formulation. The ACRYSOL ASE-60 should be diluted with water and slowly added to the mixer with good agitation. The materials in the mixer should be neutralized with base prior to adding the diluted ACRYSOL ASE-60 solution. The attached EIFS finish formulation uses approximately 0.8% ASE-60 (solid) on the solids of RHOPLEX EI-2000 to achieve a viscosity range of paste units measured on a Stormer Viscometer. Cementitious EIFS components, such as the base coat/adhesive, utilize a cellulosic thickener to adjust the viscosity of the mixture, keep the aggregate suspended during storage, and provide the proper workability. Bermocol 481FQ, a high-molecular-weight grade of ethyl hydroxyethyl cellulose, is recommended. ACRYSOL ASE-60 is not recommended for cement applications since the alkali swellable thickener will reduce the open time and workability of the cement (ph 12) based mortar. Thixotropic Agent Attagel 50, an attapulgite clay, is recommended for adjusting the flow properties of the finishes. The flow properties undergo a reduction in consistency (shear thinning) when troweled to facilitate ease of application, and recovers to its original consistency when shear is removed. The Attagel 50 also prevents slump and sag once the finish has been applied. Attagel 50 is preferred over some other commercial clay extenders because it is very efficient at low use levels. High levels of any clay can contribute to yellowing, chalking, and adversely affect colorfastness. Wet Edge Agent Low levels of ethylene glycol or propylene glycol are added to EIFS finishes to allow for sufficient open time to trowel the finish on the wall and come back and texture it. The glycol retards skin formation of the finish. Typically, 5-10 pounds/100 gallons of ethylene glycol or approximately 8-15 pounds/100 gallons of propylene glycol are normally adequate to achieve good open time. These materials are water sensitive and their use must be balanced between open time and drying time. High levels of glycols can slow down drying, especially under low temperature (40 F) and high relative humidity (>85%) weather conditions. Titanium Dioxide Titanium dioxide is a pigment added to the EIFS finish as a whitening agent and for tinting bases. To be effective, the titanium dioxide needs to be properly dispersed.

3 Neutralization Ammonium hydroxide can be used to neutralize the EIFS finish and the EIFS base coat admixture. Other neutralizers such as AMP95 can be used but with care since AMP95 can contribute to loss in water resistance if used in excessive amounts. Defoamer A defoamer is used for suppressing formation of foam during manufacture, for filling containers, tinting, and applying textured finishes. A defoamer is added to cementitious admixtures to maximize the density and subsequently the performance of the base coat/adhesive. Nopco NXZ is recommended with RHOPLEX EI Extenders Graded silica sands are typically the primary extenders used in EIFS finishes. In a random finish, using two different particle size sands yields good particle packing and the desired texture appearance. These extenders increase the solids content of the formulation. Silica sands usually have a narrow particle size distribution and may not self pack. Sufficient material may be needed to fill in voids between the silica sands. In some formulations, for example, the attached 79 PVC finish (see attached Formulation JR-4775), a fine particle size extender such as Minex 4 can be used. The level of fine filler used needs to be determined, since excessive amounts can result in cracking of the finish. When fine particle size extenders are used, the polymer level may need to be increased to account for the greater surface area to maintain performance and durability. Minex 4 is preferred over other fine fillers, such as calcium carbonates, because Minex 4 is more durable than some of these other fine particle size extenders. In-Can Preservative or Bactericide The finish and admixture formulations should contain an in-can preservative to protect the materials from bacteria contamination and spoilage during storage. The type and level of bactericide are influenced by the formulation and formulation ingredients. There are many commercial materials available, such as KATHON LX, that provide adequate protection. However, since the performance is dependent on specific formulations and ingredients, thorough testing must be conducted to determine whether a specific biocide is an effective in-can preservative. Mildewcide The RHOPLEX EI-2000 finish needs to be formulated with a mildewcide. A finish formulated with a high quality binder like RHOPLEX EI-2000 can still be prone to mildew problems if not adequately protected. Laboratory tests and exterior exposures have shown that SKANE M-8 stabilized with either zinc oxide or a copper nitrate solution provides good protection. The level of mildewcide protection is dependent on many factors, such as location, exposure orientation, climate, the amount of rainfall, humidity, temperature, the time of the year, the level of SKANE M-8, and the stabilizer used in the formulation. Two pounds of SKANE M-8/50 pounds of zinc oxide or two pounds of SKANE M-8/4 pounds of a 2% solution of copper nitrate, have been found to be effective mildewcide packages with RHOPLEX EI-2000 finishes. The best results have been obtained with the combination of SKANE M- 8/zinc oxide. Detailed Data The next section contains the following information on the various EIFS components made with RHOPLEX EI-2000 polymer: Starting point formulations Typical performance properties for finishes, base coats, and adhesives Exterior exposure data showing the improved dirt pickup resistance of EIFS made with RHOPLEX EI-2000 polymer over those with conventional acrylic latex.

4 Cementitious Base Coat/Adhesive Admixture Formulation Based on RHOPLEX EI-2000 Materials Pounds Gallons RHOPLEX EI Bermocoll 481FQ Water Nopco NXZ Sand (#70 Mesh) KATHON LX Texanol Totals Pigment Volume Content, % 71.7 Volume Solids, % 50.4 Weight Solids, % 69.3 Starting Point EIFS Finish Based on RHOPLEX EI-2000 High Quality (70% PVC) Formulation JR-0737 Materials Pounds Gallons RHOPLEX EI-2000 (46.5%) Ethylene Glycol Nopco NXZ TiPure R-942 (76.5%) Sand (#15 Mesh) Sand (#90 Mesh) Attagel Copper Nitrate (2% Solution) Texanol SKANE M ACRYSOL ASE-60 (28%) Water Ammonium Hydroxide Totals Pigment Volume Content, % 71.7 Volume Solids, % 50.4 Weight Solids, % 69.3

5 Starting Point EIFS Finish Based on RHOPLEX EI-2000 Quality (79% PVC) Formulation JR-4775 Materials Pounds Gallons RHOPLEX EI-2000 (46.5%) Ethylene Glycol Nopco NXZ TiPure R-942 (76.5%) Sand (#15 Mesh) Sand (#90 Mesh) Minex Attagel Copper Nitrate (2% Solution) Texanol SKANE M ACRYSOL ASE-60 (28%) Water Ammonium Hydroxide Totals Pigment Volume Content, % 78.7 Volume Solids, % 67.1 Weight Solids, % 82.7

6 Table 1 Modified Base Coat/Adhesive Properties Sample Identification Product Code of Emulsion Conventional Acrylic Latex Modified Base Coat RHOPLEX EI-2000 Modified Base Coat Water Level, % Density, gm/cc Trowelability Excellent Excellent Pot Life, hours Room Temperature >7¹ >7¹ 50 C One-day RT cure Toughness, dry Toughness, wet² Thin Section Properties, 1/16" Thick Excellent Very Good Scrim Pull Adhesion to EPS 7 days RT cure Adhesion Properties dry Excellent Excellent wet² Excellent Excellent 180 Peel Adhesion to EPS 7 days RT cure dry 7.7 (c)³ 8.2 (c)³ wet² 1.2 (c)³ 1.8 (c)³ RT 7 days RT cure Resistance to Cracking 1/16" thick Pass Pass 1/8" thick Pass Pass 1/4" thick Very Slight Cracking Very Slight Cracking 40 F 7days RT cure 1/16" thick Pass Pass 1/8" thick Slight Cracking Slight Cracking 1/4" thick Definite Cracking Definite Cracking Flexibility Mandrel Bend, RT 1/16" base coat applied over EPS reinforced with mesh Pass 1" Pass 1" Water Resistance M.O.A.T , 1/16" thick Pass 1" Pass ¹Test terminated after seven hours ²After two hours exposure in the fog box ³Cohesive failure

7 Table 2 Typical Performance Properties of a Standard Acrylic Latex vs. RHOPLEX EI-2000 Formulated into a Standard EIFS Finish Standard Acrylic Latex RHOPLEX EI-2000 ph Viscosity, KU Freeze/Thaw Stability (-18 C) Fail First Cycle Fail First Cycle After C ph Viscosity, KU Flexibility, Mandrel Bend RT40 F RT40 F 4" PP PP 2" PP PP 1" PP PP 1/2" PP PP Wet Scrub Resistance Room Temperature, 24-hour cure % Weight Loss F, 24-hour cure % Weight Loss Hour Wash Off Resistance RT 24-hour cure no effect no effect 40 F 24-hour cure no effect no effect Peel Adhesion to Polymer Modified Base Coat, lb./in. 7-day RT cure 11.0(C)¹ 10.9(C)¹ 7-day RT cure + 1 hr. fog box 10.2(C)¹ 10.3(C)¹ Dirt Pickup Resistance % Reflectance Retained Wet Iron Oxide Slurry Test ¹C-Stands for cohesive failure Constants Pigment Volume Content, % 70.0 Volume Solids, % 67.1 Weight Solids, % 81.9 Table 3 Exterior Exposure History of RHOPLEX EI-2000 After 28 Months Exterior Exposure Exposure Direction Polymer South Vertical Horizontal Face Up Standard Acrylic RHOPLEX EI-2000 Standard Acrylic RHOPLEX EI-2000 Dirt Pickup Resistance Visual Mildew Resistance Resistance to Chalking Resistance to Cracking Resistance to Erosion

8 Safe Handling Information Rohm and Haas Material Safety Data Sheets (MSDS) contain information that you need to protect your employees and customers against any known health or safety hazards associated with our products. Under the OSHA Hazardous Communication Standard, workers must have access to and understand MSDS on all hazardous substances to which they are exposed. Thus, it is important that you provide appropriate training and information to your employees and make sure they have available to them MSDS on any hazardous products in their workplace. Rohm and Haas Company sends MSDS on non-osha-hazardous as well as OSHA-hazardous products to both the "bill to" and "ship to" locations of all our customers upon initial shipment (including samples) of all our products (whether or not they are considered OSHA-hazardous). If you do not have access to one of these MSDS, please contact your local Rohm and Haas representative for an additional copy. Updated MSDS are sent upon revision to all customers of record. In addition, MSDS are sent on an annual basis to all customers of record. MSDS should be obtained from your suppliers of other materials recommended in this bulletin. ACRYSOL, KATHON, RHOPLEX and SKANE are trademarks of Rohm and Haas Company, or of its subsidiaries or affiliates, and are intended to designate goods marketed in North and South America. The same goods may be marketed in other countries, generally under other Company trademark designations. These suggestions and data are based on information we believe to be reliable. They are offered in good faith, but without guarantee, as conditions and methods of use of our products are beyond our control. We recommend that the prospective user determine the suitability of our materials and suggestions before adopting them on a commercial basis. Suggestions for uses of our products or the inclusion of descriptive material from patents and the citation of specific patents in this publication should not be understood as recommending the use of our products in violation of any patent or as permission or license to use any patents of the Rohm and Haas Company. Rohm and Haas, 2008 All rights reserved. April EIFS-6