Dy n e o n F l u o ro e l a s t o m e r s Compounding Fluoroelastomers

Transcription

1 Technical Information Dy n e o n F l u o ro e l a s t o m e r s Compounding Fluoroelastomers General Compounding General Compounding Ingredients Inorganic Bases Changes in Properties with variations in MgO/Ca(OH)2 Ratios (Table) Filler Systems Effect of Filler Level (black) Effect of Filler Level (Non-black) Changes in Properties with use of Non-Black Fillers (Table) Compounding with Various Fillers (Table) Low Durometer Compounds Processing Aids Cure Systems Effects of Cure Systems Pigments Effects of Contamination Blends of Fluorocarbon Elastomers Blending Fluorocarbon Elastomers (Table) Blending Incorporated Cure Gums with Raw Gum (Table) Blends with Synthetic Elastomers Blending Fluorocarbon/Fluorosilicone Elastomers (Table) Effects of Crosslink Density Compounding for O-Ring Applications Compounding for Molded Goods Applications Compounding for Calendering Process Compounding for Extrusion Process Compounding for Metal Adhesion

2 General Compounding The basics of choosing the polymer and cure system and compounding those systems with the proper acid acceptors and fillers to fulfill the rheological, physical and processing requirements are, in general, relatively simple. This is due to the limited number of ingredients that are able to withstand the harsh chemical or thermal environments that fluoroelastomers are exposed to. General Compounding Ingredients Fluoroelastomer Acid Acceptor(s) Filler Processing Aids Curatives (May be incorporated in polymer) Inorganic Bases (Acid Acceptors) Inorganic bases commonly used in compounding fluoroelastomers include the following: Ca(OH)2 Calcium Hydroxide MgO Magnesium Oxide PbO Litharge PbHPO3 Dyphos CaO Calcium Oxide ZnO Zinc Oxide Inorganic bases affect both the rheological and the physical properties. The best balance of properties will be achieved by using a combination of calcium hydroxide and magnesium oxide. The following tables illustrate the change in properties resulting from variations in the ratio of calcium hydroxide and magnesium oxide. The general compounding data was generated in our Application and Product Development Laboratory and should be used only as a guide for compounding. Potential differences may arise due to differences in raw materials and processing techniques. Materials should be processed and evaluated in the consumer s facility to verify the properties. 2

3 Changes in Properties with Variations in Calcium Hydroxide and Magnesium Oxide Ratios (Dumbbell Test Specimens) Effect of Ca(OH)2/MgO ratios using Dyneon FE 5640Q Composition Samples A B C D E F FE 5640Q N Ca(OH) Elastomag Formula Weight (grams) MDR 177 C (350 F) for 12 min. ML (in-lb) MH (in-lb) ts2 (min) t 50 (min) t 90 (min) Mooney Scorch 121 C (250 F) for 30 min. Initial Viscosity (MU) Minimum Viscosity (MU) T 3 (min) >30 >30 >30 >30 >30 >30 T 10 (min) >30 >30 >30 >30 >30 >30 T 18 (min) >30 >30 >30 >30 >30 >30 Pts. Rise in 30 min. (MU) <3 <3 <3 <3 <3 <3 Press Cure 177 C (350 F) for 10 min. Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Tear Die C on Press Cure 177 C (350 F) for 10 min. Tear (ppi) Post Cure 232 C (450 F) for 16 hours Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Tear Die C on Post Cure 232 C (450 F) for 16 hours Tear (ppi) Compression Set (Room temp for 70 hours) (O-rings) Average Compression Set (%) Compression Set (200 C (392 F) for 70 hours) (O-rings) Note: Average Compression Set (%) Compound F showed signs of blisters on the surface of the pressed sheets due to low state of cure. FE 5640Q is a medium viscosity, di-polymer of vinylidene fluoride/hexafluoropropylene with an incorporated cure package, designed primarily for o-ring applications. 3

4 Changes in Properties with Variations in Calcium Hydroxide and Magnesium Oxide Ratios (Dumbbell Test Specimens) Effect of MgO/Ca(OH)2 ratios using Dyneon FE 5642Q Composition Samples A B C D E F FE 5642Q N Ca(OH) Elastomag Formula Weight (grams) MDR 177 C (350 F) for 12 min. ML (in-lb) MH (in-lb) ts2 (min) N/A t 50 (min) t 90 (min) Mooney Scorch 121 C (250 F) for 30 min. Initial Viscosity (MU) N/A Minimum Viscosity (MU) N/A t 3 (min) >30 >30 >30 >30 >30 N/A t 10 (min) >30 >30 >30 >30 >30 N/A t 18 (min) >30 >30 >30 >30 >30 N/A Pts. Rise in 30 min. (MU) <3 <3 <3 <3 <3 N/A Press Cure 177 C (350 F) for 10 min. Tensile (psi) N/A Elongation (%) N/A 100% Modulus (psi) N/A Hardness (Shore A) N/A Tear Die C on Press Cure 177 C (350 F) for 10 min. Tear (ppi) N/A Post Cure 232 C (450 F) for 16 hours Tensile (psi) N/A Elongation (%) N/A 100% Modulus (psi) N/A Hardness (Shore A) N/A Tear Die C on Post Cure 232 C (450 F) for 16 hours Tear (ppi) N/A Compression Set (Room temp for 70 hours) (O-rings) Average Compression Set (%) N/A Compression Set (200 C (392 F) for 70 hours) (O-rings) Average Compression Set (%) N/A Note: Compound F sheets had severe blisters upon demolding, no further testing. FE 5642Q is a medium viscosity, dipolymer of vinylidene/hexafluoropropylene with an incorporated cure package designed for molded goods application. 4

5 Filler Systems Black ASTM Code MT Medium Thermal N-990 SRF Semi-Reinforcing Furnace N-787 N-774 N-762 HAF High Abrasion Furnace N-326 N-330 Carbon Black Comparison Table (for equivalent Durometer) 1 part N330 = 2.5 parts N990 1 part N550 = 2.4 parts N990 1 part N650 = 2.3 parts N990 1 part N660 = 2.0 parts N990 1 part N787 = 1.9 parts N990 1 part N774 = 1.9 parts N990 1 part N762 = 1.6 parts N990 Non-Black (Mineral) Tradename Silica Minusil Oxides Mapico-Tan-10 (Fe2O3 Zn0) ZnS Sachtolith L CaCO Calwhite Ba(SO4) Barytes Calcium Metasilicate Nyad 400 5

6 6

7 7

8 8

9 9

10 10

11 Outlined below are typical compounds of this type: A B C Dyneon FC Dyneon FC Dyneon FC Dyneon FC Dyneon FC Dyphos H-762 Black... 3 MT Black (N-990) Ca(OH) MgO (Maglite D) Carnauba Wax Typical Rheological Properties Cure ODR 177 C (350 F) Minimum Time to 1 pt. rise Time to 30 in./lb. torque Torque at 12 min Typical Physical Properties Press Cure 10 min., 177 C (350 F) Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Post Cure C (450 F) F Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Tear Strength, Die C pli Heat Aging C (528 F) Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Compression Set (%) 22 hrs. 200 C (392 F) hrs. 200 C (392 F) hrs. 149 C (300 F) Some of the interest in low durometer fluoroelastomers is a result of upgrading from silicones to fluoroelastomer. In doing this consideration should be given to the fact that some compromises are made in properties as the fluoroelastomer durometer is reduced. These compromises include: Lower physical properties In general, the lower the durometer below 55, the lower the properties. However, the differences are not always great. Less compression set resistance The result of lower crosslink densities and process aids/plasticizers. Slower cures This can be increased using small amounts of accelerator, such as Dynamar FC 2172 or Dynamar FC Higher cost In comparing compounds over the range of duro, the higher level of fillers required at 55 duro may be partially offset by diluting with lower cost raw gum. In 45 duro stocks, plasticizers can aid processability and also help keep costs down. Before specifying a low durometer compound, it might pay to consider one with a higher durometer rating that offers similar performance characteristics. For more information on the effect of durometer ratings in specific applications, contact your Dyneon Technical Representative. 11

12 Processing Aids Type Effect DBS (Dibutyl Sebecate) Lowers Viscosity DOP (Dioctyl Pthalate) Lowers Viscosity Carnauba Wax...Improves flow, surface, and mold release but affects compression set. Polyethylene...Improves mold release Practical Use Levels to 3 phr Use only when necessary because of adverse effect on shrinkage, heat resistance and compression set resistance. Cure Systems Diamine Added by molder Dicinnamylidene hexane diamine or Diak No. 3 Hexamethylene diamine carbamate Diak No. 1 Dihydroxy Incorporated by manufacturer in most cases Hexafluoropropylidene diphenol (crosslinker)/triphenylbenzylphosphonium chloride (accelerator) Peroxide Added by molder 2,5-dimethyl-2,5 Di(t-butyl peroxy) hexane/triallylisocyanurate (coagent) Each cure system has advantages and disadvantages Effects of Cure Systems Typical Properties of Vulcanizate Diamine Dihydroxy Peroxide Compound A B C D Dyneon FC MT Black (N-990) MgO (Maglite Y) 10 MgO (Elastomag 170) 3 Calcium Hydroxide 6 3 Varox DBPH-50 HP TAIC 3 3 Diamine (Diak No. 3) 2.5 Dihydroxy 1.8 Accelerator 0.6 Zn0 5.0 Original Properties Mooney Scorch MS Minimum t >30 >30 t >30 >30 t >30 >30 ODR, 3.0 arc, C (350 F) Minimum Torque, ML, in/lb Maximum Torque, MH, in/lb Ts2, minutes t 50, minutes t 90, minutes MDR, 0.5 arc, C (350 F) Minimum Torque, ML, in/lb Maximum Torque, MH, in/lb Ts2, minutes t 50, minutes t 90, minutes

13 Physical Properties, Press cure C (350 F) Tensile, psi Elongation, % % Modulus, psi Hardness, Shore A Physical Properties, Post cure 232 C (450 F) Tensile, psi Elongation, % % Modulus, psi Hardness, Shore A Compression Set, ASTM D C, %set

14 Pigments Color Trade Name Red...Harwick Stan-Tone D-2000, D-2005 Bayferrox 160M Yellow...Stan-Tone DC-445 Shepard No. 14 Green...Harwick Stan-Tone D-5005; Akrochem 414 Shepard No. 179 Blue...Harwick Stan-Tone D-4006, D-4900 Brown...Shepard No. 10 Mapico 617 Shepard No. 19 Orange...Harwick Stan-Tone D-7003 Mapico 297 Bayferrox 115M Use With Non-Black Fillers ZnS or ZnO Effects of Contamination Sulfur may prevent/retard cure or cause blisters Water will accelerate cure Synthetic rubbers will adversely affect: Physical properties Rheological properties Heat age properties Blends of Fluorocarbon Elastomers Can be used to change: Compound viscosity Level of curatives Can be used to affect processing or properties Blending Fluorocarbon Elastomers The blending or dilution of an incorporated cure polymer with that of a raw gum polymer will change certain physical properties and flow characteristics. The most common reasons for blending a raw gum polymer with an incorporated cure gum would be to: increase elongation Iower modulus improve tear strength increase or lower compound viscosity (depending on which polymers are involved) 14

15 Blending Dyneon Incorporated Cure Gums with Raw Gum A B C D E F G Composition FE FC FC FC N Ca(OH) Elastomag MDR 177 C (350 F) for 12 min. ML (in-lb) MH (in-lb) ts2 (min) t 50 (min) t 90 (min) Press Cure 177 C (350 F) for 10 min. Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Press Cure Tear Die C Tensile (ppi) Post Cure 232 C (450 F ) for 16 hours Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Post Cured Tear Die C Tensile (ppi) Heat Aged 270 C (518 F) for 70 hours Tensile (psi) Elongation (%) % Modulus (psi) Hardness (Shore A) Compression Set (Room Temp for 70 hours) - O-rings Compression Set (%) Compression Set (200 C (392 F) for 70 hours) - O-rings Compression Set (%)

16 Blends with Synthetic Elastomers Peroxide Curable Fluorocarbons can be blended with: Fluorosilicones Silicones Nitriles Epichlorohydrin EPDM Blending Fluorocarbon/Fluorosilicone Elastomers A B C Compound (80/20) (60/40) (60/40) Dyneon FC Fluorosilicone* Iron Oxide (Mapico 297) Silicon Dioxide (Aerosil R-972) Fumed Silica (Cab-O-Sil HS-5) Ca(OH) Peroxide(Luperco 101 XL) TAIC (Diak No. 7) Typical Rheological Properties 177 C (350 F), 100 CPM, 3 Arc, 12 min. Minimum torque, in.-lbs Time to 1 in.-lb. rise, (minutes) Time to 80 in.-lb. torque, (minutes) Maximum 12 minutes,in.-lbs *Dow Corning LS-420 or General Electric FSE-2080 Typical Physical Properties Cure: C (350 F) Post Cure: C (392 F) Specific Gravity Tensile, psi (MPa) (14.9) 1580 (10.9) 1390 (9.6) Elongation, % % Modulus, psi (MPa) (5.1) 660 (4.6) 320 (2.2) Hardness, ShoreA Compression Set (Method B " O-ring), % C (300 F) C (392 F) TR10, C ( F) ( 6) ( 24) ( 11) Brittle Pt., C ( F) ( 22) ( 43) ( 63) Torsional Modulus, psi x C (-4 F) C (-22 F) C (-40 F) C (-58 F) C (-6 F)

17 Effects of Crosslink Density Typical Properties of Vulcanized Compound Dyneon Dyneon Dyneon FC 2176 FC 2181 FC 2174 Relative level of crosslink density...(low) (Medium) (High) Gum Viscosity ML C (250 F) Compound Formula Gum Stock MT Black (N-990) Ca(OH) MgO (Maglite D) Rheological Properties Monsanto 177 C (350 F) Minimum torque, in.-lbs Time to 1 in.-lb. rise, (minutes) Time to 50 in.-lb torque, (minutes) Maximum 12 minutes, in.-lbs Physical Properties Press cure 10 minutes 177 C (350 F)/Post cure 20 hours 260 C (500 F) Tensile Strength (psi) % Modulus (psi) Elongation (%) Hardness, Shore A Tear Strength (psi), Die C Compression Set (Method B) O-ring 70 hours - 24 C (75 F) (%) hours C (392 F) (%) hours C (392 F) (%) /2 inch disk 70 hours - 24 C (75 F) (%) hours C (392 F) (%) Compounding for O-Ring Applications Simple parts such as O-rings can be made via injection and compression molding. Polymer Selection: Polymer with high crosslink density (low compression set) Polymer must have good mold release characteristics Filler Selection: Black or non-black MT and Austin blacks yield best compression set resistance Suggested O-Ring Polymers: 17

18 Compounding for Molded Goods Applications Molded goods are typically parts that require improved mold flow, mold release characteristics and a specific state of cure in the polymer. These parts commonly have complex shapes that may include undercuts or ribbed sections that cause demolding problems, i.e. tearing, if the proper compound is not used. Successful molding techniques consist of injection, transfer and compression molding. Polymer Selection: Polymer with low crosslink density (high elongation) Polymer must have good mold release characteristics Filler Selection: Black or non-black SRF and HAF blacks yield the best hot tear strength High ratio of MgO to Ca(OH)2 improves tear strength Suggested Molded Goods Polymers: Compounding for Calendering Process Limiting Factors on Compound: Intended end-use of calendered sheet (i.e. die cut gaskets, fabric lamination, sheet stock) Temperature range of calender Thickness of stock Suggested Calendering Formulations: Low/Medium Viscosity inc. cure polymer 100 Magnesium Oxide 3 Calcium Hydroxide 6 MT Black (N-990) Carnauba Wax 1 Polyethylene 1 18

19 Compounding for Extrusion Process Compound Considerations: Extrudate surface requirements Configuration of finished part Temperature capabilities of processing equipment (Choose process aid that will be effective.) End-use requirements Typical Recommendations: Medium to low viscosity gum 1-2 PHR process aid (DBS/Polyethylene/Wax) Barrel and die temperatures at 65 to 104 C (150 to 220 F) O-ring Cord Hose/Tubing Dyneon FE 5620, FE 5640Q Dyneon FC 2120, FE 5730Q, FE 5830Q Magnesium Oxide Calcium Hydroxide MT (N-990) SRF (N-762) BaSO4 or CaCO Carnauba Wax Poly AC 6A Suggested Extrusion Grade Polymers: Compounding for Metal Adhesion Acid Acceptors: Higher levels of metal oxides, e.g. MgO, promotes better adhesion. Litharge and dyphos hurt adhesion. Addition of 3-5 PHR calcium oxide improves adhesion. Fillers: Black/non-black used in fluoroelastomers that do not adversely affect cure speed or aging properties. Process aids are only used if necessary. Recommended Formulations: Dyneon FE 5642Q, FE 5622Q, FC Magnesium Oxide...3 Calcium Hydroxide...6 Calcium Oxide MT Black (N-990) Higher durometers are harder to bond. 19

20 ISO 9001/QS-9000 All Dyneon fluoroelastomers are manufactured at ISO 9001 registered facilities. Dyneon fluoroelastomers produced in North America are manufactured at QS-9000 registered facilities. Technical Information and Test Data Technical information, test data, and advice provided by Dyneon personnel are based on information and tests we believe are reliable and are intended for persons with knowledge and technical skills sufficient to analyze test types and conditions, and to handle and use raw polymers and related compounding ingredients. No license under any Dyneon or third party intellectual rights is granted or implied by virtue of this inform a t i o n. Safety/Toxicology Follow recommended handling precautions for use of Dyneon F l u o ro e l a s t o m e r s. General handling precautions include: (1) Store and use all Dyneon fluoroelastomers only in well ventilated areas. (2) Do not smoke in areas contaminated with dust from Dyneon fluoroelastomers. (3) Avoid eye contact. (4) After handling Dyneon fluoroelastomers wash any contacted skin with soap and water. Potential hazards, including evolution of toxic vapors, do exist during compounding or processing under high temperature conditions. Before processing Dyneon fluoroelastomers, consult the product MSDS (Material Safety Data Sheet) and follow all label directions and handling precautions. You should also read and follow all directions from other compound ingredient suppliers. Material Safety Data Sheets on Dyneon products are available from your Dyneon Sales Representative or by dialing Important Notice: Because conditions of product use are outside Dyneon s control and vary widely, user must evaluate and determine whether a Dyneon product will be suitable for user s intended application before using it. The following is made in lieu of all e x p ress and implied warr a n t i e s (including warr a n t i e s of merc h a n t a b i l i- ty and fitness for a part i c u l a r p u r p o s e ) : If a Dyneon product is proved to be defective, Dyneon s only obligation, and user s only re m e d y, will be, at Dyneon s option, to replace the quantity of product shown to be defective when user received it or to re f u n d u s e r s purchase price. In no event will Dyneon be liable for any direct, i n d i re c t, special, incidental, or consequential loss or damage, re g a rdless of legal t h e o ry, such as breach of w a rranty or contract, negligence, or strict liability. Dyneon 2001 Issued: 01/01 Printed in USA All Rights Reserved Dyneon LLC rd Street North Oakdale, MN Phone: Fax: Dynamar and Dyneon are trademarks of Dyneon.