Superior Weathering Solution for PO-Based Automotive Parts Using Advanced Hindered Amine Light Stabilizers

Transcription

1 Superior Weathering Solution for P-Based Automotive Parts Using Advanced Hindered Amine Light Stabilizers Takahiro Horikoshi, Takashi Ayabe, Shinichi Ishikawa, Naoshi Kawamoto Polymer Additives R&D Laboratory, ADEKA Corporation Manabu Ishii, John Mara, Amfine Chemical Corporation

2 Contents Introduction PP degradation and stabilization Function of HALS as Light stabilizer Advanced HALS technologies in automotive parts Light stabilization of hard application Suited HALS system for soft application(tpe) Summary & Conclusions 1

3 Introduction 2

4 Degradation of Polymer Ultraviolet exposure sunlight Polymer Thermal conditions High temperature xygen radical center carbon Mechanical stress Bending Stretching Various conditions Autoxidation Reaction Degradation Appearance (Crack generation) Discoloration Fading Change of mechanical properties etc. Unstabilized polymer degrades easily under various conditions and the addition of antioxidants and light stabilizers is indispensable for long term utilization 3

5 Polymer Degradation and Stabilization Hydroperoxide Decomposer Phosphites, rganosulphur R or R H RH Polymer R-H R Auto-xidation UV, Heat,Stress, Metal ion etc. 2 UVA, Complexing agent Radical Scavenger HALS,Phenols R-H R HALS: Hindered Amine Light Stabilizer Degradation inducing species: R*, R*, Hydroperoxide Additives: Trapping degradation inducing species HALS: Mainly Radical Scavenger 4

6 Stabilization Mechanism of HALS in Polymers Species accelerating degradation in polymer R Alkyl Radical R Alkoxy Radical R Peroxy Radical H Hydroxy Radical RH Hydroperoxide Stabilization via cyclic mechanism for HALS Main active compounds in the cycle (NH, N-alkyl and N radical) HALS traps unintentionally generated free radicals or unstable intermediates, which results in inhibition of auto-oxidation 5

7 Identifying Suitable HALS for Applications Type of HALS N-H N-Me N-Alkyl -Reactivity against radicals -Adsorption to filler -Basicity Formation of salt with acidic substance which leads to deactivation of HALS Sustainability(persistency) HALS must stay inside the resin but migrating toward the surface is also important Molecular weight -Mobility in resin(high MW=low mobility) -Stability to heat, (volatility, etc) Compatibility -Similarity of the chemical structure, polarity, etc. Suited HALS depends on the application Combination of different types of HALS can also be effective 6

8 Advanced HALS technologies in automotive parts 7

9 Automotive polyolefin parts Hard materials Instrumental panel Soft materials(tpe) Glass run channel Roof molding Cowl top Roof skin material Bumper Superiority of P Trim Low density Superior mechanical properties Excellent chemical resistance Quarter window molding Belt molding Interior skin material Reference: Mitsui Chemicals HP Recyclability Ease of processing and molding Low cost, etc. 8

10 Requirement on HALS for automotive parts Exterior Exterior parts such as bumpers is exposed to direct sun light which leads to necessity of high weatherability and thermal stability. In adittion, low compatibility of HALS can affect the paintability. Interior Although the effect of sun light is suppressed by the window, interior parts require weatherability and high thermal stability because temperature inside the car could become higher than outside. Also, high compatibility with the resin is required to avoid fogging on front widow. Requirement : High performance & High compatibility 9

11 Advanced HALS system for automotive LA-1 (ADK STABILIZER LA-402AF): N-H HALS + synergist Benefits - Excellent stabilizing ability HN R R = Alkyl Surface gloss and color sustainability - Superior compatibility with polymers Lower volatility - Easy handling master batch form 50% PP Master Batch Applications - Exterior & Interior parts 10

12 Additives used in Evaluation HALS LA-1 (ADK STABLIZER LA-402AF) HN R = Alkyl R M.W. (420) + synergist Ref 1 (ADK STABILIZER LA-77Y) HN C (CH 2 ) 8 C NH Ref 2 (ADK STABILIZER LA-94G) H N H N N N N (CH 2 ) 6 N N Low M.W. (481) High M.W. (>2000) NH CH 2 n Additive Package for Evaluation Phenolic A A-1 (ADK STABILIZER A-60) Phosphites A Catalyst Residue Scavengers P-1 (ADK STABILIZER 2112) Ca-Stearate 11

13 Weatherability of Exterior Parts : Surface Gloss Comparison of light stabilizers in surface gloss stability Gloss retained (%) Control Ref 1/Ref 2 (0.1)/(0.1) LA-1 (0.2) LA-1 (0.1) Acceleration test Xenon Weather--Meter (63 o C, with Water spray) Formulation ICP [60] / Engage8100 [30] / Talc[10] Black [3] A-1 [0.1] / P-1 [0.1] / Ca-St [0.1] / HALS LA-1 improved surface gloss stability greatly as compared with conventional type at lower loading level Exposure time (h)

14 Weatherability of Interior Parts : Color stability Comparison of light stabilizers in color stability delta E Control Exposure time (h) Ref 1 (0.2) LA-1 (0.2) 2500 Acceleration test Xenon Weather--Meter (89 o C, without spray) Formulation ICP [70] / Engage8100 [10] / Talc[20] Beige [3] P-1 [0.1] / P-1 [0.1] / Ca-St [0.1] / HALS LA-1 improved color stability greatly when compared with conventional type at lower loading level 13

15 Blooming of HALS from PP Comparison of light stabilizers on surface gloss at oven Acceleration test ven aging at 80 C Formulation ICP [70] / Engage8100 [10] / Talc[20] Beige [3] A-1 [0.1] / P-1 [0.1] / Ca-St [0.1] / HALS [0.2] LA-1 demonstrated lower blooming on the surface of PP compared with other low molecular weight HALS Control Ref 1 LA-1 14

16 N-Me HALS system especially for interior parts LA-2 (ADK STABILIZER LA-502XP): N-Me HALS + synergist Benefits - Superior thermal and light stabilizing activity Color sustainability and long term heat resistance - Superior compatibility with polymers Lower volatility - Easy handling master batch form 50% PP master Batch CH 3 N H 3 CN NCH 3 Applications - Especially for Interior parts N CH 3 15

17 Additives used in Evaluation HALS LA-2 (ADK STABILIZER LA-502XP) CH 3 N H 3 CN NCH 3 + synergist N CH 3 M.W. (847) Ref 1 (ADK STABILIZER LA-77Y) HN C (CH 2 ) 8 C Additive Package for Evaluation Phenolic A A-1 (ADK STABILIZER A-60) A-2 (ADK STABILIZER A-50) NH Ref 2 (ADK STABILIZER LA-94G) N N N Low M.W. (481) NH CH 2 High M.W. (>2000) H N N (CH 2 ) 6 Phosphites A Catalyst Residue Scavengers P-1 (ADK STABILIZER 2112) Ca-Stearate H N N n 16

18 Effect of HALS on thermal-stability of PP Time to crack formation (h) Ref 1 Ref 1/Ref 2 (1/1) LA-2 Acceleration test ven aging at 150 C 2mm plaque Formulation ICP [83] / Talc[17] Blue [3] A-1 [0.1] / P-1 [0.1] / Ca-St [0.1] / HALS [0.2] LA-2 provided higher thermal stability compared with commodity HALS 17

19 Effect of N-Me HALS - Model experiment - Consumption of oxygen in the presence of HALS in n-hexadecane at 180 C Consumption of xygen (X 10-6 mol/g) Ref 1 (N-H) NH of LA-2 LA-2 (N-Me) N-Me of Ref 1 n-hexadecane (100) A-2 (0.05) HALS (0.25) Time (min.) N-Me HALS have higher activity to trap free radicals or unstable intermediates, resulting in inhibition of the chain propagation reaction in auto-oxidation 18

20 Summary : Hard application Advanced N-H HALS system LA-1 provided remarkable weathering resistance compared with conventional type at low loading level in both exterior and interior formulation Advanced N-Me HALS system LA-2 provided high thermal stability which is especially required for interior parts 19

21 HALS for soft application (TPE) Nx gas resistance Blooming / Bleeding Thermal stability Weatherability Fogging resistance Exterior Required Required Interior Required Required Required General Formulation of TPV Materials Rate[%] PP, PE 20~40 EPDM 20~40 il 4~40 Filler 0-20 Due to difference in the compound formulation, performance of HALS may differ from hard PP application 20

22 Novel N-Methyl HALS system LA-3 (ADK STABILIZER LA-704type): N-Me HALS + synergist Benefits - Superior performance against Nx discoloration Low basicity compared to LA-1 with equal weatherability - Good compatibility to poly olefins Applications N R = Alkyl R - Automotive parts particularly with light color 21

23 Novel N-Alkyl HALS system LA-4 (ADK STABILIZER LA-81 type): N-alkyl HALS+ synergist C 11 H 23 N N C 11 H 23 Benefits - Excellent stabilizing ability under acidic conditions Low basicity compared to conventional HALS - Good compatibility to polyolefins Applications - Automotive parts with acidic substance inside ex. Thioether A 22

24 Additives used in Evaluation HALS LA-3 (ADK STABILIZER LA-704) N R = Alkyl R M.W. (438) + synergist LA-4 (ADK STABILIZER LA-81 type) C 11 H 23 N N C 11 H 23 M.W. (681) + synergist Ref 3, Ref 4 (Competitor N-alkyl) Ref 5 (Competitor N-alkyl) Additive Package for Evaluation Phenolic A A-1 (ADK STABILIZER A-60) A-3 (ADK STABILIZER A-20) Phosphites A Catalyst Residue Scavengers P-1 (ADK STABILIZER 2112) Ca-Stearate 23

25 Weatherability -Surface deterioration(ir)- bad good Fractured in early stage Acceleration test Xenon Weather--Meter (89 o C, without Spray) N-Me HALS N-Alkyl HALS N-Alkyl HALS *calculated from C= peak at 1715 cm Formulation: -1 of IR chart TPV (100) / A-1 (0.05) / P-1 (0.05) / UVA (0.15) / HALS* (0.2) *Active component Roll : 180 ºC, Press: 180 ºC Thickness: 0.4 mm 24

26 Thermal Stability -ΔE- Acceleration test ven aging at 120 C N-Me HALS N-Alkyl HALS N-Alkyl HALS Control LA-3 LA-4 Ref 3 Ref 4 Ref 5 Formulation: TPV(100) / A-1 (0.05) / P-1 (0.05) / UVA (0.15) / HALS (0.15) Extrusion: 200 ºC, Injection: 200 ºC Mold: 50 ºC Thickness: 2.0 mm 25

27 Anti Nx discoloration(beige) Condition 700 ppm Nx gas at rt for 24hr with A-1 Thickness: 0.4 mm Control LA-3 LA-4 Ref 3 Ref 4 Ref 5 with A-3 N-Me HALS N-Alkyl HALS N-Alkyl HALS ΔE bad good good bad Formulation: TPV (HS=80, 100) / A-1 or 2 (0.05) / P-1 (0.05) / UVA (0.15) / HALS (0.2) Condition: 700ppm Nx gas, R.T, 24 h Thickness: 0.40 mm 26

28 Fogging resistance (Photometric) good bad N-Me HALS N-Alkyl HALS N-Alkyl HALS Haze ~ ~ ~ 100 ºC for 24 h Cover glass Beaker Pellet Formulation: TPV (100) / A-1 (0.05) / P-1 (0.05) / UVA (0.15) / HALS (0.2) Both LA-3 and LA-4 showed better compatibility and fogging resistance than competitor s HALS 27

29 Compatibility of HALS with Polymer Solubility of HALS HALS Heptane LA-3* (N-Me) >50 LA-4* (N-alkyl) >50 Ref 3 (N-alkyl) 0.5 Ref 4 (N-alkyl) >50 Ref 5 (N-alkyl) 0.5 * without the synergist (g/100g-solvent) Heptane : model substance for polar polymer such as polyolefin LA-3 & LA-4 is expected to have an excellent compatibility with polyolefins 28

30 Basicity of HALS LA-4* (N-alkyl) 11.6 Salt formation with carboxylic acid Ref 1 (N-H type) 4.3 Ref 2 (N-H type) pkb *measured by using ph meter in MeH Ref 1 LA-4* *without synergist LA-4 has no salt formation with carboxylic acid. LA-4 is possible to function with the existence of acidic substances 29

31 Effect of HALS with rganosulfur Acceleration test Xenon Weather--Meter (89 o C, without Spray) Formulation ICP [100] A-1 [0.1] / P-1 [0.1] / Ca-St [0.1] / HALS Control Ref 1 (0.1) N-H type LA-4* (0.1) *without synergist LA-4 can coexist with thioether A which makes it possible to give thermal stability and weaherability at the same time 30

32 Summary : soft application Novel HALS system LA-3 & LA-4 had good compatibility in polyolefins and showed high performance in formulation of soft application LA-4 showed excellent light stabilizing activity in compounds containing acidic substances 31

33 Summary and Conclusions There are multiple factors that determines the performance of HALS By selecting the suited HALS for the application, it will give the compound the performance necessary for automotive parts By combining these HALS with other additives, it should enlarge the possibility of resin for automotive parts 32

34 Thank you for your attention! 33