AEROSOL® WA-300 surfactant
Wetting Agent for Pressure Sensitive Adhesives

A p p l i c a t i o n    B u l l e t i n
Introduction AEROSOL® WA-300 surfactant is a formulated product that is used as a post addition wetting agent for pressure sensitive adhesives (PSA). During the manufacture of PSA products, it is critical that the surface tension of the polymer emulsion be lowered in order to facilitate its wetting out onto the film substrate. This is important to ensure the manufacture of a high quality PSA product. AEROSOL® WA-300 surfactant imparts excellent wetting characteristics to PSA emulsions, significantly reducing both static and dynamic surface tension. Additionally, AEROSOL® WA-300 easily incorporates into the manufacturing process, is safe to handle and generates minimal foam. Technology A. Pressure Sensitive Adhesives A pressure sensitive adhesive (PSA) laminate represents a complex, multi-component product (Figure 1) comprised of a minimum of four elements. A PSA laminate contains a release liner, release coating, adhesive and facestock. Each component plays a critical role in overall performance of the product. The laminates are produced via a series of operations that combine the various layers of material into a finished product. Figure 2 illustrates a simple PSA manufacturing process. The two prevalent technologies for PSA laminate manufacture include calendaring or coextrusion of polymers. Market segments in which PSA products find application include the airline, automotive and other transportation, food and beverage, health and beauty, chemical, consumer, and pharmaceutical and health care industries. Postage stamps, tapes, clear bottle, container, packaging and address labels, decals, medical bandages, and pharmaceutical patches all represent different types of pressure sensitive adhesive laminates. B. Wetting Agents for Pressure Sensitive Adhesives During the manufacture of the multi-component PSA laminate, it is important that the layers come together uniformly and adhere to each other. Since the surface energies of the various components may differ greatly, it is important that the layers wet out properly. A common approach for ensuring adequate wetting and adherence of the products is to incorporate wetting agents. A typical wetting agent for emulsion polymers utilized in the PSA process would be based on dioctyl sulfosuccinate chemistry (i.e., DOSS, AEROSOL® OT Surfactant). Wetting agents are typically incorporated into the PSA manufacturing process at a post addition stage. The product is added at a concentration of approximately 1% to the adhesive or facestock emulsions. The wetting agent lowers the surface tension of the emulsion, allowing it to easily wet out onto the substrate to which it is being applied. PSA products are typically adhered to glass, polymers, paper, or metallic foil. In each case, the surface energy characteristics of the adhesive emulsion and substrate may vary significantly. The incorporation of the wetting agent into the adhesive emulsion leads to further benefits when this layer is applied to the final package substrate. The wetting agent in the adhesive layer assists in wetting out the adhesive onto the substrate, increasing overall compatibility and improving packaging aesthetics. Table 1 Equilibrium Surface Tensions Surfactant Surface Tension nM/m Water 1% AEROSOL® OT (DOSS) 1% AEROSOL® WA-300 71.6 24.8 24.4 Markets and Recommendations Manufacturers of PSA products are encouraged to evaluate AEROSOL® WA-300 surfactant for their specific products. AEROSOL® WA-300 surfactant should be incorporated at a 0.5 to 1.0% concentration based upon the weight of the polymer emulsion. Technical Service Information Cytec Industries provides technical service assistance for AEROSOL® WA-300 surfactant and other products. Samples of AEROSOL® WA-300 surfactant are available upon request. Handling and Shipping Handling and shipping information on the AEROSOL® WA-300 surfactant can be found on the Material Safety Data Sheets for the product. Health and Safety Information Health and safety information on the AEROSOL® WA-300 surfactant can be found on the Material Safety Data Sheets for the product.	Physical and Chemical Properties AEROSOL® WA-300 surfactant is a proprietary product. Select chemical and physical properties of the product are as follows: Type liquid Appearance 49-51 Solids, % by weight water Solvent ~1.15 Color, APHA, max. ca.0 Specific gravity @ 25°C > 100 Viscosity, cps @ 25°C 5-7 Flash Point, °C 2.5 Solubility in organic solvents 0.6 Figure 1 – Pressure Sensitive Laminate Construction (Four Elements) Figure 2 – PSA Manufacturing Process – Wetting Agent Application via Roller Coaters A surfactant wetting agent can be added to either the adhesive (3) or facestock (4) layers. The AEROSOL® WA-300 is incorporated into the tanks which contain the adhesive and facestock products which are fed to the roller coaters. AEROSOL® WA-300 Surfactant Addition Points – Incorporate into polymer emulsion tanks that feed roller coaters 3 and 4. Figures 3 and 4 illustrate the outstanding performance of this product in lowering the static and dynamic surface tensions of adhesive emulsions. Figure 3 Figure 4 Table 2 compares the foaming properties of 1% aqueous solutions of the AEROSOL® WA-300 and DOSS surfactants. AEROSOL® WA-300 surfactant generates significantly less foam than the DOSS product. Thus, AEROSOL® WA-300 will effectively wet out the adhesive emulsion product but not adversely affect production by producing high amounts of foam. Table 2 Foaming Properties of Wetting Agents   Foam Volume (ml) Time to 0 Foam (sec) 1% AEROSOL® OT (DOSS) 1% AEROSOL® WA-300 300 250 572 400-420 Benefits Allows polymer emulsion to wet out onto film substrate Dissolves easily and quickly into application solution Low volatility, safe to handle and environmentally friendly Economical May reduce need for defoamer Suitable for food applications