Syl-Off Solvent-based, Platinum-Catalyzed Silicone Release Coatings from Dow Corning

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1 Release System Information Guide Syl-Off Solvent-based, Platinum-Catalyzed Silicone Release s from Dow Corning General Information Syl-Off brand solvent-based, platinum-catalyzed silicone release coatings are dispersions of high-molecular-weight, vinyl-functional siloxane polymers. When combined with their respective crosslinkers (or, in the case of Syl-Off 7430, 7460, and 7595 s, a platinum catalyst), these coatings cure via an addition reaction in the presence of heat. Platinum for Films Rhodium Tin Features Controllable cure rates and release forces Fast, low-temperature cure Cured coatings are non-blocking and non-migratory Minimal post-cure Inert against SBR adhesives; perform well with hot melts and many acrylics Low coat weights easy to obtain on conventional equipment Anchorage additive improves adhesion to films Food-contact options available Contents General Information...1 Product Range Details...2 Product Handling Information...4 Application Information...7 Formulation Suggestions...10

2 Physical Properties Syl-Off solvent-based, platinum-catalyzed silicone release coatings are versatile coatings that may be used on a wide assortment of substrates. They can be formulated to provide release ranging from medium to very tight against many different pressure sensitive adhesives. Applications Release liners for pressure sensitive adhesive laminates and tapes Industrial release papers and films Casting papers Nonstick packaging In-line, double-sided, and differential release applications Product Range Product Details Range Details Base s: The Syl-Off brand solvent-based, platinum-catalyzed silicone release coating products listed below meet the majority of industry requirements for the regions listed. However, they represent only a portion of Dow Corning s silicone release technology. Contact your Dow Corning representative for information about other, locally available product options. Syl-Off 7046 Syl-Off 7146 Syl-Off 7362 Syl-Off 7430 Syl-Off SB 7458 Syl-Off 7460 Syl-Off 7590 Silicone Paper Syl-Off 7595 Syl-Off SL 7688 A 30 percent solids dispersion of a pre-catalyzed vinyl-functional silicone polymer in an organic petroleum fraction. Recommended for use with Syl-Off 7048 or General-purpose solvent-based coating. Available in Europe. A 30 percent solids dispersion of a pre-catalyzed vinyl-functional silicone polymer in toluene. Recommended for use with Syl-Off 7048 or Available in the Americas and Europe. A 30 percent solids dispersion of a pre-catalyzed vinyl-functional silicone polymer in toluene. Suitable for fast-cure applications. Recommended for use with Syl-Off 7367 or Available in the Americas and Asia. A 30 percent solids dispersion of vinyl-functional and SiH-functional silicone polymers in toluene. Not pre-catalyzed. Recommended for use with Syl-Off 4000 Catalyst. Available in Asia. A 30 percent solids dispersion of a pre-catalyzed reactive siloxane polymer in toluene. Recommended for use with Syl-Off 7048, 7672, or Available in Asia. A 30 percent solids dispersion of vinyl-functional and SiH-functional polymers in toluene. Not pre-catalyzed. Recommended for use with Syl-Off 4000 Catalyst. Available in Asia. A 50 percent solids dispersion of a vinyl-functional silicone polymer in toluene. A high-solids general-purpose release coating that is not pre-catalyzed. Recommended for use with Syl-Off 7048 or 7599 and Syl-Off 4000 Catalyst. Available in Asia. A 50 percent solids dispersion of a reactive siloxane polymer in toluene. Not precatalyzed. Recommended for use with Syl-Off 4000 Catalyst. Available in Asia. A 100 percent solids coating of a pre-catalyzed reactive siloxane polymer. Recommended for use with Syl-Off Available in Asia. 2

3 s: Syl-Off 7048 Syl-Off 7367 Syl-Off 7387 Syl-Off 7599 Syl-Off 7672 Syl-Off 7678 Catalyst: Syl-Off 4000 Catalyst Optional Additives: Syl-Off 7210 Release Modifier Syl-Off 7200 Release Modifier Syl-Off 297 Anchorage Additive A 100 percent active solids crosslinker for use with a variety of Syl-Off solventbased and solventless silicone release coatings, including Syl-Off 7046, 7146, SB 7458 and 7590 s. Recommended where optimum anchorage to substrate is required. Available globally. A 100 percent active solids SiH-functional crosslinker containing inhibitor. Designed for and recommended for use with Syl-Off Available in the Americas and Asia. A 91 percent active solids SiH-functional silicone crosslinker containing inhibitor. Recommended for use with Syl-Off Available in Asia. A 100 percent active solids silicone crosslinker containing inhibitor. Recommended for use with Syl-Off 7590 Silicone Paper. Available in Asia. A 100 percent active solids SiH-functional silicone crosslinker. Recommended for use with Syl-Off SB 7458 and SL 7688 s. Available in Asia. A 100 percent active solids silicone crosslinker. Recommended where optimum cure performance and bath life are required. Suitable for use with a variety of Syl-Off solvent-based and solventless silicone release coatings, including Syl-Off 7046, 7146, and SB 7458 s. Available globally. A reactive organo-platinum complex (5,000 ppm platinum) dispersed in polysiloxane. The standard catalyst included in Syl-Off solvent-based and solventless platinum-catalyzed release coatings. Must be used with Syl-Off 7430, 7460, 7590, and 7595 s, which are not pre-catalyzed. May be used with other coatings to reduce cure temperature required when coating temperaturesensitive substrates. Can also be used to obtain more complete cure at a given temperature, or to optimize machine capacity by speeding cure, or to overcome substrate inhibition. Available globally. A 60 percent active solids, pre-catalyzed, high-release additive. Generalpurpose release modifier recommended for use with Syl-Off solvent-based, platinum-catalyzed release coatings when higher/tighter release is required. Available globally. A 50 percent solids, pre-catalyzed release modifier. Recommended for use with Syl-Off solvent-based, platinum-catalyzed release coatings when lower/easier release is required. Available in Asia. A 100 percent active silane anchorage additive. Recommended for use where improved anchorage to paper substrates is required. Also improves abrasion resistance of cured silicone release coatings. Appropriate for use with all Syl-Off solvent-based, platinum-catalyzed release coatings. Available globally. 3

4 For Asia Region-Specific Product Lines Dow Corning has developed specific lines of Syl-Off solvent-based, platinum-catalyzed silicone release coatings to meet the unique performance and processing requirements of different regional markets: For the Americas Base Optional Release Modifier Optional Anchorage Additive Catalyst Optional 7146 Optional Note: All products are Syl-Off brand. Base Choices Optional Release Modifier Choices Optional Anchorage Additive Catalyst Optional 7430 Required SB 7458 Optional 7460 Required 7590 Required 7595 Required SL 7688 Optional Note: All products are Syl-Off brand. For Europe Base Optional Release Modifier Choices Optional Anchorage Additive Catalyst Optional 7146 Optional Note: All products are Syl-Off brand. Product Handling Product Information Handling Information Substrates Syl-Off solvent-based, platinum-catalyzed silicone release coatings have been successfully applied to super-calendered, clay-coated, and poly-coated krafts; parchment; glassine; plastic films; and metal foil. 4

5 Surface treatment, either by corona or gas flame and/or an anchorage additive, may be needed to improve anchorage to polyolefin-coated papers or films. The suitability of a substrate for use with the chosen release coating should be evaluated before commercial application. Application Equipment Syl-Off solvent-based, platinum-catalyzed silicone release coatings are generally applied using conventional roll-coating techniques such as wire-wound rod, direct gravure, air knife, squeeze roll, reverse roll, or trailing blade. Precision coating equipment may also be used. Coat Weight Coat weight can be varied by changing the coating technique and/or the concentration of silicone in the bath. In practice, coating baths vary from 4 to 12 percent silicone solids by weight. At these levels, dry coat weights from 0.6 to 1.3 g per m 2 (0.4 to 0.8 lb per 3,000 sq ft ream) can be achieved. trials should be conducted for each substrate used. Bath Life The life of the made-up bath and stock solutions varies considerably with bath concentration, the solvent, the specific formulation, and the temperature of the surroundings. Curing Syl-Off solvent-based, platinum-catalyzed release coatings are normally cured in hot-air ovens. s should be cured as quickly as possible after application to minimize soak-in of the coating into paper substrates. As the coated substrate passes through the curing ovens, three stages occur: solvent removal, polymer flow, and crosslinking. Solvent Removal The speed of solvent removal depends upon oven temperature, the solvent s boiling point, the solvent s volatility, and the rate of air circulation in the oven. Low-boiling-point solvents evaporate very quickly at elevated temperatures. Polymer Flow As the solvent evaporates, the coating enters a smear stage. A firm finger stroke on the coated surface will leave a greasy streak. At this stage, the silicone will transfer and coat anything that comes into contact with the film. During this stage, there is a tendency for the polymer to flow and level out any variations in the coating. 5

6 Crosslinking As the coating begins to crosslink, it begins to develop the phenomenon known as rub-off. The coating, although partially cured, has not yet developed strong adhesion to the paper and will roll up under the finger if gently abraded. However, the silicone coating is sufficiently cured not to migrate and will usually pass a tape migration test at this point. As the curing process continues, adhesive force between the coating and paper strengthens, and rub-off no longer occurs. Formulation Advice : Ratio Good cure can be achieved with formulations containing from 0.25 to 1.2 percent Syl-Off, by weight, based on the silicone coating as supplied. Note that while raising the level of crosslinker (SiH:Vi ratio) in a formulation can bring about more complete or faster cure, it can also raise the potential for adhesive interaction and reduced bath life. Catalyst To reduce the temperature of cure or to obtain faster or more complete cure, you may incorporate up to 0.5 weight percent of Syl-Off 4000 Catalyst, as supplied. In extreme cases, such as film coating where very low cure temperatures are required, up to 1.0 weight percent silicone solids of Syl-Off 4000 Catalyst may be added to the coating bath. Platinum addition should be undertaken with care. The higher the level of platinum in the formulation, the greater the potential for serious bath life reduction. Acrylic lock-up problems may be exacerbated, as well. When adding platinum to coatings that will be used in food-contact applications, consult your Dow Corning Technical Service representative. Anchorage Additive To improve anchorage of silicone coatings to difficult paper substrates, incorporate from 0.8 to 2.0 weight percent Syl-Off 297 Anchorage Additive, as supplied. Controlled Release Additive (High Release) To achieve tighter release, incorporate up to 50 percent Syl-Off 7210 Release Modifier by weight, based on the silicone coating as supplied. To achieve easier release, incorporate up to 1.0 percent Syl-Off 7200 Release Modifier by weight, based on the silicone coating as supplied. 6 Process Solvents Excellent results have been obtained using ethylacetate, toluene, hexane, heptane, and white spirits. Solvent choices should be evaluated due to their possible impact on both bath life and cure rate.

7 Bath Preparation Equipment, preferably constructed from stainless steel or glass, should be clean and dry. 1. Disperse the base coating in the process solvent. 2. Thoroughly disperse the release modifier, if required. 3. Thoroughly disperse the anchorage additive, if required. 4. Add the crosslinker and disperse thoroughly. 5. Add the catalyst, if required, and disperse thoroughly. NOTE: The platinum catalyst is sensitive to contamination by compounds containing nitrogen, sulfur, tin, phosphorus, arsenic, antimony, selenium, tellurium, and by some residual solvents or monomers. To prevent catalyst poisoning and inhibition of cure, handling equipment, transfer pumps and piping, solvents added to the bath or used during cleaning procedures, and the substrate to which the coating will be applied must be free of those contaminants. Application Information Application Information Cure Performance Time, temperature, type, and age of the substrate, coat weight, and degree of surface penetration can all affect the cure performance of Syl-Off solvent-based, platinum-catalyzed silicone release coatings. Overcoming Cure Inhibition Some resins used to make poly-coated krafts and films can inhibit cure. The precoat found on most glassines or super-calendered krafts can also affect cure. When using offset roller systems, care should be taken with the choice of the rubber-coated rolls. Materials used to vulcanize the rubber may inhibit the cure of the silicone coating. Cure inhibition can be overcome through the addition of a low level of Syl-Off 4000 Catalyst. Optimizing Cure Performance It is possible to reduce cure time, lower cure temperature, or improve completeness of cure by raising the crosslinker:coating (SiH:Vi) ratio. However, the higher the crosslinker loading, the greater the potential for unreacted crosslinker to interact with the adhesive. Bath life may be reduced as well. Another way to effectively lower cure temperature or increase cure speed is by the addition of a relatively low level of Syl-Off 4000 Catalyst. Catalyst addition should be undertaken with care in view of the product s high cost. 7

8 Figure 1. Simulated release curves for Syl-Off SB 7458, 7595, and SL 7688 s (solvent-based acrylic adhesive tesa 7475 tape). 35 Figure 2. Simulated release curve for Syl-Off SB 7458 on a polyethylenelaminated substrate (solvent-based acrylic adhesive tesa 7475 tape). 20 Release Force, g/in Syl-Off SB 7458 coating Syl-Off 7595 coating Syl-Off SL 7688 coating Weight, g/m 2 Release Force, g/in Weight, g/m 2 Release Performance Figure 1 shows the relative, unmodified release performance of Syl-Off SB 7458, 7595, and SL 7688 solvent-based, platinum-catalyzed silicone release coatings against a solvent-based acrylic adhesive. Figures 2-4 show the simulated release performance of the same coatings applied to a polyethylene-laminated substrate. Effect of Release Modifiers Figure 5 illustrates how Syl-Off 7210 Release Modifier (high release additive) can be used to achieve higher/tighter release performance. Relative release curves are shown for Syl-Off SB 7458 formulated with varying addition levels of 7210 Release Modifier against a solvent-based acrylic adhesive and an emulsion-based acrylic adhesive. Figure 6 shows how Syl-Off 7200 Release Modifier (low release additive) can be used to achieve lower/easier release performance. Food Contact Information Formulations can be prepared that would have specific food contact regulatory approval. Please check with your local Dow Corning technical service representative for assistance in proper selection of release coating components to meet your application needs. 8

9 Figure 3. Simulated release curve for Syl-Off 7595 on a polyethylenelaminated substrate (solvent-based acrylic adhesive tesa 7475 tape). Release Force, g/in Figure 4. Simulated release curve for Syl-Off SB 7458 on a polyethylene-laminated substrate (solvent-based acrylic adhesive tesa 7475 tape). Release Force, g/in Weight, g/m Weight, g/m 2 Figure 5. Release force adjustment of Syl-Off SB 7458 using Syl-Off 7210 Release Modifier (solvent-based acrylic adhesive tesa 7475 tape; emulsion-based acrylic adhesive Nitto 31B tape). Release Force, g/in RF-tesa 7475 RF-Nitto 31B wt % Syl-Off 7210 Release Modifier in Syl-Off SB 7458 Figure 6. Release force adjustment of Syl-Off SB 7458 using Syl-Off 7200 Release Modifier (solvent-based acrylic adhesive tesa 7475 tape) Release Force, g/in Syl-Off SB 7458 coating Syl-Off SB 7458 coating w% Syl-Off 7200 release modifier Weight, g/m 2 Limitations These products are neither tested nor represented as suitable for medical or pharmaceutical uses. Health and Environmental Information To support customers in their product safety needs, Dow Corning has an extensive Product Stewardship organization and a team of Product Safety and Regulatory Compliance specialists available in each geographical area. For further information, please consult your local Dow Corning representative. 9

10 Formulation Formulation Suggestions Suggestions Formulations Syl-Off solvent-based, platinum-catalyzed silicone release coating components can be combined and adjusted in many ways to meet regional processing and performance challenges. The typical formulations that follow are intended merely to serve as reference points for further discussion. Dow Corning does not warrant their merchantability, fitness for use, performance, efficacy, safety, or freedom from patent infringement. It is your responsibility to thoroughly test any formulation before use. For specific formulation advice, contact your Dow Corning Technical Service representative. Table 1. Typical formulation information Syl-Off Base Syl-Off Release Modifier Syl-Off Syl-Off Catalyst Solvent (30% solids) 7210 Release Modifier 1 (0.7 wt %) NA (Pre-catalyzed) 2 4x-6x SB (30% solids) 7210 Release Modifier 1 (0.8 wt % and up) NA (pre-catalyzed) 4x-6x (50% solids) 7210 Release Modifier 1 (0-0.4 wt %) 4000 Catalyst (1.3 wt %) 4x-9x SL (100% solids) 7210 Release Modifier 1 ( wt %) NA (pre-catalyzed) 6x-9x 1 To achieve tighter release, incorporate up to 50% Syl-Off 7210 Release Modifier by weight based on the silicone coating as supplied. 2 Although Syl-Off 7362 is pre-catalyzed, up to 0.3 wt % Syl-Off 4000 Catalyst may be added to achieve faster cure. Low-release formulation information. SB 7458 STD (30% solids) 7200 Release Modifier ( wt %) 7672 (0.6 wt %) NA (pre-catalyzed) 4x-6x 7595 STD (50% solids) 7200 Release Modifier ( wt %) NA 4000 Catalyst (1.2 wt %) 4x-9x SL 7688 STD (100% solids) 7200 Release Modifier ( wt %) 7672 (2.6 wt %) NA (pre-catalyzed) 6x-9x 10

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12 For Information and Assistance For product information, application troubleshooting, product samples, and formulation advice, visit or call one of our global Technical Information Centers: The Americas , or (Toll-Free from the USA) Asia Europe English +49 (0) German +49 (0) French +49 (0) LIMITED WARRANTY INFORMATION PLEASE READ CAREFULLY The information contained herein is offered in good faith and is believed to be accurate. However, because conditions and methods of use of our products are beyond our control, this information should not be used in substitution for customer s tests to ensure that Dow Corning s products are safe, effective, and fully satisfactory for the intended end use. Suggestions of use shall not be taken as inducements to infringe any patent. Dow Corning s sole warranty is that the product will meet the Dow Corning sales specifications in effect at the time of shipment. Your exclusive remedy for breach of such warranty is limited to refund of purchase price or replacement of any product shown to be other than as warranted. DOW CORNING SPECIFICALLY DISCLAIMS ANY OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY. DOW CORNING DISCLAIMS LIABILITY FOR ANY INCIDENTAL OR CONSEQUEN- TIAL DAMAGES. Dow Corning and Syl-Off are registered trademarks of Dow Corning Corporation. We help you invent the future is a trademark of Dow Corning Corporation. All other trademarks are the property of their respective owners Dow Corning Corporation. All rights reserved. Printed in USA AGP7830 Form No