New High Performance Organophosphorus Flame Retardant

New High Performance Organophosphorus Flame Retardant-PDF Download

  • Date:19 May 2020
  • Views:10
  • Downloads:0
  • Pages:9
  • Size:663.41 KB

Share Pdf : New High Performance Organophosphorus Flame Retardant

Download and Preview : New High Performance Organophosphorus Flame Retardant


Report CopyRight/DMCA Form For : New High Performance Organophosphorus Flame Retardant


Description:

Volume resistivity and surface resistivity ASTM D257 The UL 94 flammability test ASTM D3801 06 was performed on 3 2 mm 1 8 inch 1 6 mm 1 16 inch 0 8 mm 1 32 inch and 0 4 mm 1 64 inch bars as noted Initial color measurements ASTM D1925 were made using Hunter Lab scale D65 illuminant 10 observer and integrated sphere geometry Initial YI and Initial L were recorded For

Transcription:

health and regulatory outlook They were predicted to be non toxic and non bio accumulative and therefore would not be. classified as Persistent Bio accumulative Toxic P B T The log of the octanol water partition coefficient log Kow was 2 4. for PFR 1 and also indicates that it is not expected to bio accumulate Another characteristic solubility in prepreg processing. solvents is desirable but not essential for high performance applications Examples of insoluble flame retardants also with. good P B T profiles used in high performance circuit boards include 1 2 bis pentabromophenyl ethane BrFR 1 and N N. ethylenebis tetrabromophthalimide BrFR 2 shown in Figure 2 4. Br Br Br Br,BFR 1 BFR 2,Figure 2 Structures of BFR 1 and BFR 2. Many phosphorus based flame retardants are suitable for only one or two application areas Some of these flame retardants. fall short of meeting broad requirements including flame retardant efficiency thermal stability physical and mechanical. properties and electrical properties of the polymers to which they are added The company s new organophosphorus flame. retardant is melt blendable in some resin systems has excellent flame retardant efficiency thermal stability and UV color. stability It can be used in both thermoplastic and thermoset polymers A variety of applications have been explored. Circuit boards epoxy hydrocarbon others,Aerospace epoxy phenolics others. Films and fibers polyolefin polyamide polyester, Connectors and light emitting diode LED parts high temperature polyamide. Wire and Cable polyolefin others, We anticipate identifying additional areas of promise for this broadly applicable new flame retardant This paper summarizes. some of the performance attributes of this new developmental organophosphorus flame retardant in a few selected polymer. Experimental,Epoxy Laminate Preparation and Testing.
A variety of 4 ply laminates were prepared by blending flame retardants with a multifunctional epoxy novolac resin solution. in methyl ethyl ketone MEK and using a phenolic curing agent and 2 phenylimidazole promoter In general stock solutions. of resin curative and promoter were all prepared and stored separately to facilitate experimentation An 85wt phenol epoxy. novolac resin solution containing 15 wt 2 butanone MEK was used along with a novolac curing agent A novolac resin. solution was prepared by dissolving 50 wt of the novolac curing agent in 50 wt MEK solvent FR 1 was ground using a. coffee bean grinder to reduce the particle size of the compound to a d50 of about 6 m prior to combining with the resin A. flame retardant resin mixture containing about 3 weight phosphorus was prepared The novolac to promoter ratio was about. 525 with a gel time of about 4 minutes The viscosity of the resin mixture was adjusted by adding additional MEK and the. formulation was thoroughly blended using a high shear mixer stirred at 6 000 rpm for 15 30 minutes The resulting varnish. was applied to 7628 woven glass fabric with 643 finish and B staged at 170 C in a forced air oven for about 3 5 minutes The. edges were removed and 4 layers of prepreg were stacked between two layers of Pacothane release film and two steel plates. 1 8 inch thick 12 inch by 12 inch square dimensions The laminate was formed in a hot press at 5 000 psig for 1 2 5 hours. The glass transition temperature T g for the laminate was measured using a differential scanning calorimeter DSC similarly. to IPC method IPC TM 650 method 2 4 25c using a 20 C min heating rate nitrogen atmosphere with the following. differences isothermal hold temperatures were 200 C for laminates based on the phenol epoxy novalac resin 220 C for. laminates based on a higher functional phenol epoxy novolac resin and 250 C for laminates based on a higher functional. phenol epoxy novolac resin with no flame retardant In some cases a third scan was performed to determine the delta T g. between the first second and third scans Laminate decomposition temperature T d was measured as the 5 weight loss. temperature using a 10 C min heating rate nitrogen atmosphere using a thermogravimetric analyzer TGA The UL 94. flammability test was performed using ASTM D3801 06 in a UL 94 burn chamber to obtain flammability ratings for sets of. five coupons T1 T2 burn times were added to give a total burn time for 5 coupons. Compounding Molding and Testing, PFR 1 was evaluated with a thermally stable melamine based synergist N syn 2 Other additives included a primary. antioxidant a phosphite secondary antioxidant synthetic hydrotalcites DHT 4A DHT 4C an anti drip agent partial. sodium salt of ethylene methacrylic acid copolymer Na ionomer anti drip and polytetrafluroethylene PTFE anti drip. Glass fiber was fed downstream in the extrusion process to maintain good physical properties of the parent resin. Compounded resin was dried rigorously 16h 120 C before performing melt flow and rheology measurements Powder. mixing using a timed bi directional tumble mixer was also employed Various resins and flame retardants were hand mixed. in a plastic bag and or tumble mixed prior to extrusion The compounding was conducted on a twin screw extruder. Extrusion temperatures for high temperature polyamide were in the range of 265 330 C and for polyethylene in the range of. 180 240 C Extruded strands were pelletized on line Test parts were formed in an injection molding machine Molding. temperatures and pressures for the 0 4mm polyamide molds were as follows injection pressure 1000 1350 psi nozzle. 288 C zone 1 296 C 1100 psi zone 2 291 C 1050 psi zone 3 285 C 1000 psi zone 4 800 psi zone 5 700 psi. hold time of 8 sec and cooling time of 30 sec, Testing was performed on samples according to the following ASTM test standards Tensile Strength and Elongation at. Break ASTM D638 specimen type 1 Heat Distortion Temperature ASTM D648 1 8 at 264 psi and 120 C h Notched. Izod Impact Strength ASTM D256 method A Melt Flow Rate ASTM D1238 procedure A conditions as noted and. Volume resistivity and surface resistivity ASTM D257 The UL 94 flammability test ASTM D3801 06 was performed on. 3 2 mm 1 8 inch 1 6 mm 1 16 inch 0 8 mm 1 32 inch and 0 4 mm 1 64 inch bars as noted Initial color measurements. ASTM D1925 were made using Hunter Lab scale D65 illuminant 10 observer and integrated sphere geometry Initial. YI and Initial L were recorded For Xenon Arc UV weathering ASTM D4459 99 the following conditions were used. continuous light cycle 0 3W m2 at 340nm black panel temperature of 55 C chamber relative humidity of 55 100 hour. 200 hour and 300 hour exposure CIE L a b 10 observer and D65 Illuminant YI and Delta E ASTM D1925 values. were recorded Un notched charpy impact strength measurements were performed at the company s Bergheim Germany site. according to ISO179 1eU Data were recorded for samples oriented edgewise with 3 3 mm height and 12 8 mm width. Capillary rheology measurements were performed at constant 1 000 sec 1shear. Electrical property measurements were performed at Pennsylvania State University The frequency range of interest for the. polypropylene samples was between 1 GHz and 20 GHz Resonant cavity techniques were employed because of the low. dielectric loss for the samples The microwave dielectric properties of linear low density polyethylene samples with flame. retardant were investigated with a split cavity technique 5 6 Disk samples 2 diameter x 1 8 thick were individually placed. within a split cavity for microwave testing Three samples of each material were tested to ensure reproducibility of the. measurement In a second characterization technique R band and X band cavities were completely filled with powder and. the dielectric properties were obtained by the resonant cavity frequencies Two cavity sizes were used for 2 GHz R band. and 10 GHz X band All of the loss Df values were low and approached the lower threshold value of the measurement. technique The dielectric constant Dk values for the powders could not be accurately measured by this technique. Results and Discussion,Epoxy Laminates, As global data transmission speeds increase so does the need for higher performance materials in circuit boards This new. organophosphorus flame retardant PFR 1 exhibits a unique combination of excellent flame retardant efficiency high thermal. stability and exceptional electrical properties useful for fast growing wireless and wired infrastructures Typical properties of. PFR 1 are shown in Table 1,Table 1 Properties of PFR 1 Flame Retardant. Property Value,Form Solid white powder,Specific Gravity g cm3 1 4.
Melting Point C by DSC 300,TGA 10 C min nitrogen,1 weight loss C 330. 5 weight loss C 365,10 weight loss C 380, Tetrabromobisphenol A TBBPA is the leading flame retardant used in the FR 4 printed circuit board industry 7 9 DOPO. 6H Dibenz c e 1 2 oxaphosphorin 6 oxide dihydrooxaphosphaphenanthrene is the leading organophosphorus flame. retardant used in standard FR 4 markets Figure 3 9 11 Some alternate reactive phosphorus flame retardant technologies have. been proposed 12 13, Figure 3 Flame Retardants Used in Circuit Board Markets. Several 4 ply laminates were prepared by blending PFR 1 by itself or in combination with a melamine based nitrogen. synergist N syn 1 in a multifunctional epoxy novolac resin solution in MEK and using a phenolic curing agent Figure 4. A V 1 borderline V 0 rating was obtained using only PFR 1 to make a laminate containing 3wt phosphorus Combining. PFR 1 with a nitrogen synergist resulted in a solid V 0 rating at 3wt phosphorus in the laminate The phosphorus content. could be further decreased to 2 4wt phosphorus using PFR 1 in combination with a nitrogen synergist. With addition of silica filler a UL 94 V 0 rating was obtained for a formulation containing as low as 1 8wt phosphorus In. the case of silica addition the effect is not synergistic rather a simple replacement of resin with an inert filler Laminate. producers utilize fillers to lower the cost of the formulation and to improve laminate dimensional stability stiffness thermal. conductivity compressive strength and hardness 14, Figure 4 Flame Retardant Efficiency of PFR 1 in Epoxy Novolac Laminates. Glass transition temperature and thermal stability of laminates containing PFR 1 are shown in Figure 5 A higher glass. transition temperature 170 180 C was obtained upon formulating with a nitrogen synergist Though the laminate. decomposition temperature was decreased by inclusion of a nitrogen synergist a high TGA 5 weight loss temperature T d. 370 C for the laminate was still maintained, Figure 5 Glass Transition Temperature and Decomposition Temperature for Laminates Containing PFR 1.
Electrical properties Df dissipation factor of neat flame retardant powder were measured at 2 GHz Table 2 The values. obtained for PFR 1 0 001 were comparable to those values obtained for BrFR 1 0 001 and BrFR 2 0 002 brominated. flame retardants used in high performance circuit board applications At 10 GHZ values for all three flame retardants were. identical The influence of air in these measurements can be an issue so the samples were compacted under pressure R band. and X band cavities were completely filled with powder. Table 2 Neat Flame Retardant Dissipation Factors, Electrical Properties neat powder PFR 1 BrFR 1 BrFR 2. Df Dissipation Factor 2 GHz 0 001 0 001 0 002,Df Dissipation Factor 10 GHz 0 001 0 001 0 001. Polyolefins, The performance of PFR 1 in linear low density polyethylene LLDPE was compared at different loadings and with use of a. nitrogen synergist Table 3 Use of antimony trioxide ATO with brominated flame retardants is preferred in polyolefins. for example 21 BrFR 1 7 ATO and 15 talc In this case loadings of BrFRs similar to that of PFR 1 were used to. compare electrical properties and UV stability Electrical properties Df dissipation factor and Dk dielectric constant of. flame retardant containing LLDPE resin were measured at 18 GHz. Table 3 PFR 1 Evaluation Data in LLDPE Resin Flame Retardant and Electrical Properties UV Stability. Ingredient Neat Resin PFR 1 PFR 1 PFR 1 BrFR 1 BrFR 2. LLDPE Resin 100 60 70 70 70 70,FR Loading wt 40 30 20 30 30. N syn 1 10,Flame Retardant Properties,UL 94 Flammability 3 2 mm 1 8 V 0 V 2 V 0.
T1 T2 sec 8 19 8,Electrical Properties Units, Df Dissipation factor 18 GHz 0 0002 0 0003 0 0007 0 0003 0 0003. Dk Dielectric Constant 18 GHz 2 29 2 51 2 55 2 37 2 39. Volume Resistivity Ohm cm x1017 4 0 0 5 2 7 1 7,Surface Resistivity Ohm sq x1017 3 5 1 8 4 5 5 1. UV Stability CIE L a b 10 observer D65 Illuminant,Initial Color Initial YI 3 4 3 7 2 3 12 6 15 3. Initial L 94 8 94 5 95 1 91 5 95 2,After 100 h Xenon YI 11 2 10 4 6 5 27 1 25 6. Delta E 4 7 4 1 2 6 8 4 7 2,After 200 h Xenon YI 13 1 12 8 8 8 34 3 26 5.
Delta E 5 7 5 4 3 9 12 6 8 8,After 300 h Xenon YI 14 5 14 8 10 7 41 6 26 9. Delta E 6 5 6 6 5 0 16 9 9 5, The Df values 0 0003 were low and identical for all evaluated flame retardant systems slightly higher vs the neat resin. 0 0002 The Dk values were lowest for neat resin 2 29 followed by resin with flame retardant BRFR 1 2 37 and BRFR. 2 2 39 and PFR 1 2 51 and PFR 1 with N syn 1 2 55 Retention of good resin electrical properties points towards. potential use in polyolefins and related resin systems where electrical properties are important such as those used in printed. circuit boards and wire and cable applications, PFR 1 40 wt was used to obtain a V 0 rating With 30 w PFR 1 a V 2 rating flaming drip was obtained By. decreasing the PFR 1 loading to 20 wt and adding 10 wt nitrogen synergist a V 0 rating was obtained allowing lower. loadings of PFR 1 while maintaining good flame retardant performance. Excellent UV color stability was observed with XP 7866 formulations in polyethylene with and without nitrogen synergist. where delta E was less than ten after 300 hours of xenon arc weathering Table 3 The UV stability of PFR 1 in LLDPE is. even better than the polyethylene containing BrFR 2 which is considered to have good UV performance UV. absorbers stabilizers can be used to further improve performance No UV stabilizers have been added to these formulations. Additional physical properties were also improved by formulating with a nitrogen synergist Figure 6 Properties evaluated. include melt flow index MFI Izod impact strength elongation at yield and elongation at break. Figure 6 Physical Properties of PFR 1 in LLDPE Resin. High Temperature Polyamide 6T, Both brominated flame retardants including a commercial brominated polystyrene BrFR 3 from the company and. phosphorus flame retardants including a commercial phosphorus flame retardant PFR 2 have been used extensively in. engineering thermoplastic resins including a variety of polyamides for connectors 15 16 Table 4 summarizes comparisons of. PFR 1 with PFR 2 and BrFR 3 in glass filled high temperature nylon HTN. Use of PFR 1 in combination with a nitrogen synergist N syn 2 allowed for attainment of good flame retardancy without. sacrificing thermal properties such as heat distortion temperature HDT and physical properties such as tensile strength. Without nitrogen synergist high loadings of PFR 1 are required to achieve a UL 94 V 0 rating For a formulation containing. 20 PFR 1 and no synergist lower values were obtained for several properties including HDT 252 C tensile strength. 16x103 psi elongation at break 1 2 and charpy impact strength 27 kJ m2 compared with a formulation containing 10. PFR 1 and 10 N syn 2 where HDT 271 C tensile strength 22x103 psi elongation at break 1 7 and charpy impact. strength 39 kJ m2 values were improved by inclusion of a nitrogen synergist Such a formulation would also be more cost. advantageous Additional synergists will be explored for use with PFR 1. Use of DHT 4C in place of DHT 4A gave lower burn times for the 0 8mm thick molds With increased DHT 4C loading. from 0 1 to 0 25 a UL 94 V 0 rating was obtained for 0 4 mm thick parts More data will be collected using this new 0 4. mm mold When the partial sodium salt of ethylene methacrylic acid copolymer anti drip agent was omitted from the. formulation a V 2 rating flaming drips was obtained. Table 4 Evaluation Data for PFR 1 in High Temperature Polyamide with 30 weight Glass Fiber. Ingredient BrFR 3 PFR 1 PFR 1 PFR 1 PFR 1 PFR 1 PFR 1 PFR 2. FR Loading wt 18 6 20 11 11 10 10 10 10,Antimony trioxide 6 0.
N syn 2 11 11 10 10 10 10,PTFE 0 4 0 4 0 4 0 4 0 4 0 4 0 4 0 4. Na ionomer anti drip 2 2 2 2 2 2 2,Phosphite 0 15 0 15 0 15 0 15 0 15 0 15 0 15 0 15. DHT 4A 0 1 0 1 0 1 0 1 0 1 0 1,DHT 4C 0 1 0 25,330 0 15 0 15 0 15 0 15 0 15 0 15 0 15 0 15. 1 Antioxidant 0 15 0 15 0 15 0 15 0 15 0 15 0 15 0 15. Flammability Units,UL 94 3 2mm Burn V 0 V 0 V 0 V 0 V 0 V 0 V 0 V 0. T1 T2 Sec 346 8 7 7 7 8 7 7 12,UL 94 1 6mm Burn V 0 V 0 V 0 V 0 V 0 V 0 V 0 V 0.
T1 T2 Sec 138 8 12 11 20 12 14 8 33,UL 94 0 8mm Burn V 0 V 0 V 0 V 2 V 0 V 0 V 0 V 1. T1 T2 Sec 328 9 14 16 16 28 16 17 83,UL 94 0 4mm V 0. T1 T2 Sec 19,Properties Units,MFI g 10 min,16 17 9 19 41 19 14 18 4. 325 C 1 2 kg,Rheology Pa s 121 66 69 68 64 69 74 74 118. HDT C 290 283 252 265 268 271 271 272 279, Moisture 0 02 0 03 0 05 0 08 0 05 0 05 0 05 0 04 0 07.
Tensile strength psi 103 24 4 23 8 16 2 20 3 23 8 22 2 22 4 23 6 20 2. Tensile Modulus psi 103 14 5 16 9 17 8 17 9 20 2 16 5 16 5 17 1 15 4. Elongation break 2 02 1 97 1 18 1 44 1 54 1 71 1 68 1 87 2 06. IZOD impact ft lb in 1 62 1 70 1 42 1 31 1 58 1 42 1 44 1 43 1 23. Charpy impact kJ m2 56 75 27 39 46 39 54 50 46, Molded articles of this resin are shown in Figure 7 Molds of formulations containing PFR 1 and BrFR 3 were light in color. Both of these flame retardants are melt blendable and melt flow characteristics were similar for these two systems MFI and. rheology values The PFR 2 molded articles were brown in color with some off gassing observed during processing. demonstrating that under equivalent processing conditions PFR 1 is more thermally stable than PFR 2 Significant color. differences between PFR 1 and PFR 2 molds are shown in Figure 7 Formulating and processing with better stabilization of. PFR 2 is planned to allow better property comparison with PFR 1 and BrFR 3. Figure 7 Flame Retardant High Temperature Polyamide Molds 3 2 mm 1 8. Capillary rheology data is shown in Figure 8 Only one data point at 69 Pa s was collected in the automated test for 20. PFR 1 indicating viscosity was not stable throughout the one minute duration test A continuous decrease in viscosity was. observed for PFR 2 with N syn 2 Improved stabilization should eliminate such a trend Viscosity was reasonably stable for. other flame retardant samples including BrFR 3 ATO and PFR 1 N syn 2 in high temperature polyamide Viscosity was. significantly lower for these samples compared with glass filled resin and PFR 2 N syn 2 samples BrFR 3 is commercially. used in high temperature polyamide is melt blendable higher flow and allows for rapid processing of molded parts. Figure 8 Capillary Rheology for Flame Retardant High Temperature Polyamide at 1000 1 sec Shear. Rheology data for PFR 1 similarly exhibits this potential PFR 2 is not melt blendable so there may be limitations to. achieving a high flow system as reflected in MFI and rheology values Use of PFR 1 as a flow enhancer for non halogen. flame retardant high temperature polyamides will be explored. Conclusions, As technology progresses so does the need for advanced materials Anticipating this need this material was developed as a. high performance non halogenated flame retardant technology This new flame retardant can be processed at high. temperatures and has a unique combination of high flame retardant efficiency high thermal stability and superior electrical. properties It can be applied in many different resin systems such as those used in printed circuit boards aerospace films and. fibers wire and cable and connector applications With a high melting point it is melt blendable in applications where resins. are processed at high temperature The performance characteristics of this flame retardant make it attractive for a broad range. of applications,References, Corbridge Derek E C Phosphorus Chemistry Biochemistry and Technology 6th ed CRC Press 2013. Rakotomalala M Wagner S and Doering M Materials 2010 3 4300. Levchik S V and Weil E D J Fire Sci 2006 24 5 345, Maxwell K A and Ranken P F Halogen Free Flame Retardants for PWBs Challenges and Opportunities Proceedings. of IPC EXPO 2007, Janezic M D and Baker Jarvis J Full wave analysis of a split cylinder resonator for nondestructive permittivity.
measurements Microwave Theory and Techniques IEEE Transactions 1999 47 10 2014. Kent G Nondestructive permittivity measurement of substrates Instrumentation and Measurement IEEE Transactions. 1996 45 1 102, Landry S D Tetrabromobisphenol A The Flame Retardant of Choice for Printed Wiring Boards Proceedings of IPC. APEX EXPO 2009, Hardy M Regulatory Status of the Flame Retardant Tetrabromobisphenol A Proceedings of IPC EXPO 2000. Thompson S G Hardy M L Maxwell K A Ranken P F OnBoard Technology 2005 8. Levchik S V and Wang C S Comparative Study of Phosphorus based Flame Retardants in Halogen Free Laminates. Proceedings of IPC EXPO 2007,Lin C H Wang C S Polymer 2001 42 1869. Timberlake L D Hanson M V Bol K Narayan S A Combination Flame Retardant Curing Agent Material for Non. Halogen PCB Laminates Proceedings of IPC APEX EXPO 2011. Levchik S V Weil E D Developments in Phosphorus Flame Retardants Advances in Fire Retardant Materials. Horrocks A R and Price D Eds Woodhead Publishing Cambridge UK 2008 49 66. Lau D Y H Evaluation of Halogen Free Laminates Used in Handheld Electronics University of Waterloo Waterloo. Ontario Canada 2009, Weil E D and Levchik S V Flame Retardants for Plastics and Textiles Practical Applications Hanser Gardner. Publications 2009, Troitzsch J Plastics Flammability Handbook Hanser Gardner Publications 2004.

Related Books