RHOPLEX AC-3094 Emulsion Thermosetting Binder for Hardboard Primers

Transcription

1 RHOPLEX AC-3094 Emulsion Thermosetting Binder for Hardboard Primers Description RHOPLEX AC-3094, the preneutralized analogue of RHOPLEX AC-2573, is specifically designed as a more user-friendly and cost-effective vehicle for thermosetting factory-applied primers for exterior hardboard siding products. Like RHOPLEX AC-2573, this versatile hydroxyl-functional, modified-acrylic produces coatings that offer a high degree of resistance to blistering during the curing process. These coatings also demonstrate good adhesion and water resistance along with broad formulating latitude. Primers based on RHOPLEX AC-3094 demonstrate the required exterior durability on siding products which receive fieldapplied topcoats. Performance data, suggested formulating techniques and starting point formulations are presented in the following pages. Performance Features Primers formulated with RHOPLEX AC-3094 offer the following features: Handling ease and formulation latitude Blister resistance during curing Good water resistance Excellent cost/performance balance Excellent exterior primer durability Paintability with a variety of topcoats Typical Physical Properties These properties are typical but do not constitute specifications. Appearance Milky white liquid Total Solids, Wt.% 47.5 Brookfield viscosity, cp 275 ph 7.5 Neutralizing amine N,N-dimethylaminoethanol (DMAE) Density, lb/gal 8.72 Dry bulking value, gal/lb Minimum Film Forming Temperature (MFT), C Tukon hardness, KHN, As supplied As a blend with polymeric melamine, 90/10 AC-3094/melamine, solids on solids, fully baked Blister Resistance Hardboard primers based on RHOPLEX AC-3094 are less prone to blistering during the curing process than primers based on other vehicles. This has been demonstrated under stressed, high-intensity infrared curing conditions to induce blistering in all the films. Moreover, with RHOPLEX AC-3094, there is no sacrifice of other critical properties such as water resistance or cure response.

2 Resistance and Adhesion Primers based on RHOPLEX AC-3094 demonstrate excellent adhesion to hardboard. Tape adhesion was determined using #250 Scotch tape both on dry board and panels soaked for 24 hours in water. RHOPLEX AC-3094 based primers also possess excellent resistance to water penetration, as measured by the Cobb Test (See Table 1). The panels were cured in a staged oven for 2 minutes at 195 F, 2 minutes at 300 F, and 3 minutes at 390 F to attain a peak surface temperature of 320 F. Table 1 Blister Resistance, Resistance and Adhesion Performance of 55 PVC Primers Based on RHOPLEX AC-3094 vs Controls Vehicle Blister Resistance scale of 1 to 10, with 10=no blistering Resistance Cobb Test (perms) Adhesion Wet/Dry % Removal RHOPLEX AC /0 RHOPLEX AC /0 RHOPLEX AC /0 RHOPLEX AC /0 Competitive A /0 Competitive B /0 Durabilty RHOPLEX AC-3094 is designed for factory-applied primers for hardboard that receive field-applied topcoatings. Since RHOPLEX AC-3094 is the neutralized analogue of RHOPLEX AC-2573, the durability data in Tables 2 and 3 of primers based on RHOPLEX AC-2573 can be viewed as representative of the expected durability of primers based on RHOPLEX AC Hardboard panels have been coated in our laboratory under controlled conditions to simulate factory application. After exposure on our test fences at Spring House, Pennsylvania, a primer based on RHOPLEX AC-3094 demonstrated good durability when compared to those based on RHOPLEX AC-658, RHOPLEX AC-1822 and RHOPLEX AC-2045 s. This comparison is shown on Table 2.

3 Table 2 Durability of Primers Based on RHOPLEX AC-2573 Emulsion After 7 Months Exposure Effect of PVC in a South Vertical Exposure Vehicle Drip Edge Dirt Pickup Mildew Fiber Raising Face Checking PVC 45% RHOPLEX AC RHOPLEX AC RHOPLEX AC RHOPLEX AC PVC 55% RHOPLEX AC RHOPLEX AC RHOPLEX AC RHOPLEX AC Ratings: 10=no change, 1=complete failure Exposure data: Series: Time: Substrate: Location: Direction: I-87B 7 months Masonite X-90, Laurel flat hardboard Spring House, PA South vertical Cure: 300 F/2 min, then 390 F/3 min to PST 320 F Film thickness: 1.2 mils Pigmentation: Ti-Pure R-960; Snowflake ; Tamsil 10 Melamine: Cymel 373 (acrylic/melamine 9/1) except RHOPLEX AC-658, a selfcontained thermosetting. Even in the more demanding south 45 exposure direction, all primers were rated 10 (unchanged) for mildew, fiber raising and face checking. Minor differences were noted in dirt pickup; these were attributed to variations in the board supplied by different manufacturers. Table 3 shows the results of an exposure series consisting of hardboard panels from different manufacturers. All the test panels were primed with coatings based on RHOPLEX AC-2573 along with RHOPLEX AC-1822 and RHOPLEX AC-2045, two other well-established Rohm and Haas thermosetting s.

4 Table 3 Durability of 55 PVC Primers Based on RHOPLEX AC-2573 Emulsion After 8 Months Exposure, South 45 Vehicle Drip Edge Dirt Pickup Mildew Fiber Raising Face Checking Masonite X-90 Hardboard RHOPLEX AC RHOPLEX AC RHOPLEX AC Abitibi Hardboard RHOPLEX AC RHOPLEX AC RHOPLEX AC Ratings: 10=no change, 1=complete failure Exposure data: Series: Time: I-87Q PVC: 55% Location: 8 months Spring House, PA Direction: South 45 Cure: 300 F/2 min, then 390 F/3 min to PST 320 F Film thickness: 1.2 mils Pigmentation: Ti-Pure R-960; Snowflake; Tamsil 10 Block Resistance Primers based on RHOPLEX AC-3094 develop good block resistance when fully cured in commercial highvelocity hot air or gas-fired infrared ovens. Based on extensive laboratory work with RHOPLEX AC-2573, we concluded that the peak board surface temperature achieved during curing and the temperature at which the board is stacked have a greater influence on blocking than do either the oven dwell time or the board stacking pressure. Formulating Guidelines Dispersant ACRYSOL I-62 resin is the recommended dispersing agent for coatings based on RHOPLEX AC-3094 because it maximizes water resistance. It is a hydroxyl-functional, polymeric resin which reacts with melamine to become part of the binder matrix. It has a high dispersing efficiency with a broad range of pigments. When ACRYSOL I-62 is used as the dispersing resin, it must first be diluted to at least 25% solids and then neutralized prior to the addition of pigments to the millbase. The dispersant demand for ACRYSOL I-62 will vary depending on the pigment level and pigment type required. A level of about 2% ACRYSOL I-62 solids based on pigment weight is recommended as a starting point. Melamine For hardboard primers, the use of a polymeric melamine is suggested for optimal durability, wax migration resistance, cure response, and block resistance. Cymel 373 has been used in most of the Rohm and Haas studies performed on RHOPLEX AC-2573, the unneutralized form of RHOPLEX AC-3094.

5 Coalescent Ethylene glycol monobutyl ether at 15% on binder (acrylic plus melamine) solids is the coalescent generally recommended for best film formation, viscosity control, formulation stability, and block resistance. Naturally, the type and level of coalescent that is ultimately selected by the formulator will depend on how the primer is to be used. Defoamers Bubble Breaker 3056A should be added to the grind to prevent the development of foam in primers formulated with RHOPLEX AC Amine Selection/Level Tertiary amines should be incorporated in all coatings containing melamine for optimal stability. Since RHOPLEX AC-3094 contains DMAE, we recommend that the formulator control ph of the formulation within the range of 8.3 to 9.0, by adding approximately 1% DMAE (solids on solids). This will ensure a good balance between storage stability and curing rate. Choice of Pigmentation Like its precursor RHOPLEX AC-2573, RHOPLEX AC-3094 has the pigment binding ability to handle a wide variety of grades of titanium dioxide and extender pigments to meet specific objectives. Formulation P PVC Primer Based on RHOPLEX AC-3094 Materials Pounds Gallons Cowles Grind: ACRYSOL I-62 (50%) Premix Dimethylaminoethanol (DMAE)/water, 1/1 Add to the above: Bentone LT Bubble Breaker 3056-A Titanium dioxide Snowflake Tamsil 10 Aurasperse W-7012 Letdown: RHOPLEX AC-3094 (47.5%) DMAE/water = 1/1 Cymel 373 (85%) Ethylene glycol monobutyl ether/water, 80/20 Total: Formulation Constants: PVC, % Volume solids, % Weight solids, % ph Viscosity, #4 Ford cup, seconds Acrylic/melamine (solids ratio) Pigment/binder Coalescent on binder, % VOC, calculated minus water g/l lb/gal /10 75/

6 Formulation P PVC Primer Based on RHOPLEX AC-3094 Optimized for Blister and Resistance Materials Pounds Gallons Cowles Grind: ACRYSOL I-62 (50%) Premix Dimethylaminoethanol (DMAE)/water, 1/1 Add to the above: Bubble Breaker 3056-A Titanium dioxide ASP -400 Tamsil Talc Aurasperse W-7012 Bentone LT Letdown: RHOPLEX AC-3094 (47.5%) DMAE/water = 1/1 Cymel 373 (85%) Ethylene glycol monobutyl ether/water, 80/20 Total: Formulation Constants: PVC, % Volume solids, % Weight solids, % ph Viscosity, #4 Ford cup, seconds Acrylic/melamine (solids ratio) Pigment/binder Coalescent on binder, % VOC, calculated minus water g/l lb/gal /10 75/ Suppliers of Suggested Raw Materials Trade Name Type Supplier ASP-400 ACRYSOL I-62 Aurasperse W-7012 Bubble Breaker 3056A Bentone LT Cymel 373 RHOPLEX AC-658 RHOPLEX AC-1822 RHOPLEX AC-2045 RHOPLEX AC-2573 Extender pigment Dispersing resin Colorant Defoamer Thixotrope Melamineformaldehyde resin Binders Englehard Corp. Iselin, NJ Rohm and Haas Co. Philadelphia, PA Englehard Corp. Iselin, NJ Witco Corporation New York, NY Rheox Inc. Hightstown, NJ American Cyanamid Co. Wayne, NJ Rohm and Haas Co. Philadelphia, PA ECC International, Calcium Pdts. Snowflake CaCO 3 Extender pigment Atlanta, GA Whittaker, Clark & Daniels, Inc. 499 Talc Extender pigment S. Plainfield, NJ Tamsil 10 Extender pigment Unimin Specialty Minerals, Inc. Elco, IL

7 Health and Safety Information Safe Handling Information Based on its composition, RHOPLEX AC-3094 is not expected to be toxic via single acute oral, dermal, or inhalation exposure. It may be a slight to moderate skin, eye and/or inhalation irritant. Melamine-formaldehyde resins such as the Cymel products recommended in this bulletin can release free formaldehyde, a suspect animal carcinogen, under some processing conditions. It is very important to use good ventilation when working with these products. Safety handling information should be obtained from the company that supplies these products. Material Safety Data Sheets Rohm and Haas Material Safety Data Sheets (MSDS) contain pertinent information that you may need to protect your employees and customers against any known health or safety hazards associated with our products. Under the OSHA Hazard 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 its customers upon initial shipment (including samples) of all its products (whether or not they are considered OSHAhazardous). 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 annually to all customers receiving products deemed hazardous under the Superfund Amendments and Reauthorization Act. MSDS should be obtained from your suppliers of other materials recommended in this bulletin. Rohm and Haas Company is a member of the American Chemistry Council (ACC) and is committed to ACC's Responsible Care Program. ACRYSOL and RHOPLEX 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 scale. 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 to license to use any patents of the Rohm and Haas Company. Rohm and Haas, 2008 All rights reserved. December BP1