Technical Data Sheet NXT* LowV NXT* LowV Description NXT LowV silane can provide significant reductions in ethanol evolved during tire manufacturing and use and can help elim- inate the need to mix silica compounds in multiple steps. It can also provide a faster cure rate and some improvements in compound performance properties. Compared to silanes that bear three ethoxy groups per silicon atom, NXT LowV silane can reduce ethanol emissions by more than 66%. NXT LowV silane may lead to overall systems-cost efficiencies for tire manufacturers. Figure 1: Idealized Chemical Structure of NXT LowV Silane The schematic above shows the idealized structure of NXT LowV (monomer) silane. This silane is a mixture of monomers, dimers and higher oligomers. NXT LowV silane is a blocked mercaptosilane (thiocarboxylate functional), with an octanoyl group blocking the mercapto part of the molecule. The silicon end of the monomer bears a cyclic di-alkoxy group and an ethoxy group. The di-alkoxy and ethoxy groups are released during mixing and facilitate rapid silica-silane coupling. The diol resulting from silane hydrolysis is minimally volatile and essentially remains in the compound. Ethanol Emissions Table 1 shows VOC emission measurements obtained during mixing of rubber compounds containing Silquest* A-1589 (TESPD), NXT* and NXT LowV silanes. Rubber compounds containing silica and silane were mixed in a single non-productive mix step for 8 minutes at 160 C with Silquest A-1589 silane, and at 170 C with NXT and NXT LowV silanes. Vapors emitted during compounding were collected from the vent lines onto charcoal absorption tubes, and analyzed for ethanol evolved during mixing. The results on percent reduction of ethanol shown in Table 1 compare well with the theoretical estimates. Table 1. Comparison of Ethanol Emission During Mixing with Silquest A-1289, Silquest A-1589, NXT, and NXT LowV Silanes Page 1 of 8
Silane Loading, phr Theoretical Ethanol (mg) Measured Ethanol (mg) % of Theoretical Silquest A-1589 6.2 17,000 9,320 55% 6% NXT 8.2 14,664 8.930 61% 10% NXT LowV 8.2 4,875 2,907 60% 71% % Reduction from Silquest A-1289 Key Features and Benefits Reduced ethanol (VOC) emissions during tire manufacturing and use Lower system cost due to fewer non-productive mixing steps, faster processing and VOC abatement cost avoidance. High temperature mixing without viscosity increases or premature vulcanization Enhanced vulcanization speed Substantial reduction in small strain non-linearity, G' Very low maximum in tan over the 0 to 25% strain range Excellent dynamic properties at low temperatures (+5 to -20 C) Excellent storage stability of uncured rubber due to low silica reagglomeration Typical Physical Properties Physical Form (1) Liquid Color (1) Yellow to Amber Specific Gravity at 25 C, OECD-Guideline No. 102 (1) 1.04 Flash Point, Penske Martens Closed Cup, F (1) 212 (1)Values shown only for information and are not intended for specification preparation. Patent Status Nothing contained herein shall be construed to imply the nonexistence of any relevant patents or to constitute the permission, inducement or recommendation to practice any invention covered by any patent, without authority from the owner of the patent. Product Safety, Handling and Storage Customers should review the latest Safety Data Sheet (SDS) and label for product safety information, safe handling instructions, personal protective equipment if necessary, emergency service contact information, and any special storage conditions required for safety. Momentive Performance Materials (MPM) maintains an around-the-clock emergency service for its products. SDS are available at www.momentive.com or, upon request, from any MPM representative. For product storage and handling procedures to maintain the product quality within our stated specifications, please review Certificates of Analysis, which are available in the Order Center. Use of other materials in conjunction with MPM products (for example, primers) may require Page 2 of 8
additional precautions. Please review and follow the safety information provided by the manufacturer of such other materials. Processing Recommendations NXT LowV silane is designed to help reduce the number of non-productive mixing steps, while improving processing and performance of tread compounds. NXT LowV silane requires only a single non-productive mixing step. With NXT LowV silane, mixing temperatures as high as 180 C can be employed, depending upon the formulation. The Table 2 schematic compares processing characteristics of Silquest* A-1589, NXT* and NXT LowV silanes. Silica-reinforced tire tread formulations used to evaluate and compare polysulfide and NXT silanes are shown in Table 3. Mixing procedures used for NXT LowV silane and polysulfide silanes are shown in Table 4. Two non-productive mix steps are used for compounding Silquest A-1589 (polysulfide) silane and a single non-productive mix step for NXT LowV silane. Multiple non-productive mixing steps with cooling between are generally needed to adequately mix silica with polysulfide silanes. Polysulfide silanes may vulcanize prematurely if mixing is carried out at temperatures above 160 C. Table 2: Processing Characteristics with Silquest A-1589 silane, NXT silane and NXT LowV silane Table 3: Silica-Reinforced Tire Tread Formulation Used to Evaluate NXT LowV silane Page 3 of 8
PHR Ingredient 103.2 ssbr - (~50% vinyl content) 25 BR - (high cis butadiene rubber) 80 Silica - (precipitated) variable Silquest A-1589 silane, NXT or NXT LowV silane 5.0 Oil - (Aromatic or non-aromatic) 2.5 Zinc Oxide 1.0 Stearic Acid 2.0 6 PPD - (antioxidant/antiozonant) 1.5 Wax Final Mix Ingredients 1.4 Sulfur 1.7 CBS - (primary accelerator) 2.0 DPG - (secondary accelerator) Table 4: A Comparison of the Mixing Procedures for Polysulfide Silanes versus NXT LowV Silane Mixing Procedure for Polysulfide Silanes Mixing Procedure for NXT LowV Silane First Banbury Pass: Cooling with water at 25 C First Banbury Pass: Cooling with water at 25 C Size B mixer at 120 rpm, full cooling t 0 min Add polymers, ram down mix (RDM) 30 seconds t 0.5 min Add 50% silica, all silane RDM 30 seconds t 1 min Add remaining silica, oil RDM 30 seconds t 1.5 min Dust down, RDM 15 seconds t 1.75 min Dust down, RDM 15 seconds t 2 min Dust down, RDM @ higher speeds to 160 C t 3 min Dump, sheet off 50-60 C roll mill, cool to near room temperature Mix time for first pass: 5-6 minutes Second Banbury Pass t 0 min Add compound from first pass, RDM 30 seconds t 0.5 min Add remainder of ingredients, RDM 30 seconds t 1 min Dust down, RDM to 160 C by increasing rotor speed t 1.25 min Hold temperature while mixing for eight minutes t 9.25 min Dump, sheet off 50-60 C roll mill, cool to near room temperature Mix time for second pass: 11-12 minutes Total non-productive mix time: 16-18 minutes plus cool down time Productive Mix Add curatives on 50-60 C roll mill Size B mixer at 120 rpm, full cooling t 0 min Add polymers, ram down mix (RDM) 30 seconds t 0.5 min Add 50% silica, all silane RDM 30 seconds t 1 min Add remaining silica, oil RDM 30 seconds t 1.5 min Dust down, RDM 15 seconds t 1.75 min Add remainder of ingredients, RDM 30 seconds t 2.25 min Dust down, RDM to 170 C by increasing rotor speed t 2.5 min Hold temperature while mixing for eight minutes t 10.5 min Dump, sheet off 50-60 C roll mill, cool to near room temperature Total non-productive mix time: 12-13 minutes Productive Mix Add curatives on 50-60 C roll mill Page 4 of 8
Performance Table 5 compares performance characteristics of compounds made with Silquest* A-1589, NXT* silane and NXT LowV silane.similar reductions in Mooney viscosity versus polysulfide silanes are observed with both NXT LowV and NXT silanes. NXT LowV silane exhibits about a 30% reduction in cure time versus NXT and Silquest A-1589 silanes, with dynamic hysteresis properties similar to NXT silane. Heat buildup properties are improved with NXT LowV silane, and it exhibits higher dynamic stiffness than NXT silane. Improvement in silica dispersion with NXT silane can generate a decrease in filler-filler interactions (lowered G,?G and Shore A hardness) compared to polysulfide silanes, thus creating an opportunity to expand the performance envelope. In order to take full advantage of improved silica dispersion, reformulations to the compounds are recommended (viz. bound rubber reformation, thixotropic or hydrodynamic routes) with adjustments targeted toward equal hardness/modulus. These reformulations include addition of precipitated silica, fumed silica, or carbon black, to increase the hardness of NXT silane or NXT LowV silane compounds. Table 5 Comparison of Performance Characteristics with Silquest A-1589 silane, NXT silane and NXT LowV silane Page 5 of 8
Ingredient (phr) Solution SBR Butadiene Rubber Silica Silquest A-1589 silane NXT silane NXT LowV silane Compound Properties Processing Mooney Viscosity Scorch Time (min) Cure Time t90 (min) ML (dnm) MH (dnm) Properties in the Cured State - Non-linearity (0-10 @ 60 C G initial (MPa)? G (MPa) G max (MPa) tan d max Heat Build Up (? T C) Wet-Skid Indicator, 10 Hz, 1 DSA tan d 0 C Properties in the Cured State - Reinforcement Hardness (Shore A) M 25% (MPa) M 100% (MPa) M 300% (MPa) M 300%/M100% Elongation at Rupture (%) Stress at Rupture (MPa) Abrasion Loss (mm 3 ) DIN Silquest A-1589 (TESPD) silane 103.2 25.0 80 6.2 69 9.1 18.4 8.6 28.0 5.20 3.20 0.62 0.19 34 0.408 62 0.87 1.88 10.42 5.5 523.0 23.5 189 NXT silane 103.2 25.0 80 8.2 62 15.1 17.0 7.4 25.9 2.95 1.41 0.32 0.14 32 0.430 57 0.833 1.81 9.63 5.3 534.0 22.7 156 NXT LowV silane 103.2 25.0 80 8.2 61 10.4 11.3 7.3 28.3 3.65 1.87 0.396 0.135 28 0.435 58 0.877 2.16 11.83 5.5 477.0 21.7 157 Figure 2 compares tan d versus temperature (at 10Hz and 1% dynamic strain amplitude) response for Silquest* A-1589 silane, NXT* silane and NXT LowV silane compounds. The higher tan d values at low temperatures (0 to -15 C) observed in Figure 2 indicate the potential to improve wet traction properties of tire treads made with NXT LowV silane. Figure 2: Low Temperature Viscoelastic Response with Silquest A-1589 (TESPD) silane, NXT silane and NXT LowV silane Containing Rubber Compounds Page 6 of 8
How to Use Please refer to Tables 2 and 3 for details regarding formulation and mixing procedures using NXT LowV silane. Our experimental observations are that an 80-90% loading of NXT LowV silane, (based on a silicon-molar equivalent) of Silquest* A-1589 silane, provides optimal compound performance.this is equivalent to 7.8-8.7 phr of NXT LowV silane in an 80 phr silica formulation. The coupling strength of NXT LowV silane mayimprove with higher mixing temperatures and higher vinyl content SBR polymer. In formulations where NXT LowV silane coupling strength is lower than expected (e.g. due to low vinyl content of SBR), then one to two phr of a suitable activator (proton donors,e.g. alcohols and amines) can be added to optimize coupling to the rubber. Limitations Customers must evaluate Momentive Performance Materials products and make their own determination as to fitness of use in their particular applications. Contact Information For product prices, availability, or order placement, contact our customer service at Momentive.com/CustomerService/ For literature and technical assistance, visit our website at: www.momentive.com DISCLAIMER: THE MATERIALS, PRODUCTS AND SERVICES OF MOMENTIVE PERFORMANCE MATERIALS INC. AND ITS SUBSIDIARIES AND AFFILIATES (COLLECTIVELY SUPPLIER ), ARE SOLD SUBJECT TO SUPPLIER S STANDARD CONDITIONS OF SALE, WHICH ARE INCLUDED IN THE APPLICABLE DISTRIBUTOR OR OTHER SALES AGREEMENT, PRINTED ON THE BACK OF ORDER ACKNOWLEDGMENTS AND INVOICES, AND AVAILABLE UPON REQUEST. ALTHOUGH ANY INFORMATION, RECOMMENDATIONS, OR ADVICE CONTAINED HEREIN IS GIVEN IN GOOD FAITH, SUPPLIER MAKES NO WARRANTY OR GUARANTEE, EXPRESS OR Page 7 of 8
IMPLIED, (i) THAT THE RESULTS DESCRIBED HEREIN WILL BE OBTAINED UNDER END-USE CONDITIONS, OR (ii) AS TO THE EFFECTIVENESS OR SAFETY OF ANY DESIGN INCORPORATING ITS PRODUCTS, MATERIALS, SERVICES, RECOMMENDATIONS OR ADVICE. EXCEPT AS PROVIDED IN SUPPLIER S STANDARD CONDITIONS OF SALE, SUPPLIER AND ITS REPRESENTATIVES SHALL IN NO EVENT BE RESPONSIBLE FOR ANY LOSS RESULTING FROM ANY USE OF ITS MATERIALS, PRODUCTS OR SERVICES DESCRIBED HEREIN. Each user bears full responsibility for making its own determination as to the suitability of Supplier s materials, services, recommendations, or advice for its own particular use. Each user must identify and perform all tests and analyses necessary to assure that its finished parts incorporating Supplier s products, materials, or services will be safe and suitable for use under end-use conditions. Nothing in this or any other document, nor any oral recommendation or advice, shall be deemed to alter, vary, supersede, or waive any provision of Supplier s standard Conditions of Sale or this Disclaimer, unless any such modification is specifically agreed to in a writing signed by Supplier. No statement contained herein concerning a possible or suggested use of any material, product, service or design is intended, or should be construed, to grant any license under any patent or other intellectual property right of Supplier covering such use or design, or as a recommendation for the use of such material, product, service or design in the infringement of any patent or other intellectual property right. Momentive and the Momentive logo are trademarks of Momentive Performance Materials Inc. HCD-10189 (Rev. 2018-03-13 9:47 AM) Page 8 of 8