The document discusses the joint development of new anhydride-free epoxy-based vacuum pressure impregnation (VPI) systems and mica tapes for large generators and motors. After over two years of cooperation between Huntsman and Isovolta, three potential candidate systems have been identified that are free of anhydrides and other substances of concern. The candidates show promising material properties without tapes and good performance when combined with new tapes developed specifically for them. Further testing of the system candidates is ongoing.

1. Advanced Materials
New Anhydride-free Epoxy-based
Vacuum Pressure Impregnation Systems and
New Mica-tapes for Large Generators and Motors
C. Beisele Dr. E. Kattnig
Huntsman Advanced Materials Isovolta AG
Switzerland Austria

2. Advanced Materials
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3. Advanced Materials
Outline
1. Introduction
- REACH
- Replacement issue
2. Joint development of new MHHPA-free Electrical Insulation Systems
3. Target profile
4. New candidates
- Bath material properties without tape
- System properties with new tapes
5. Next steps in the project
6. Summary & Conclusions
3

4. Advanced Materials
4
The REACH Process: Latest view: Sunset date for
(M)HHPA June 2023 if no authorisation
The REACH process and current Anhydride status
SVHC list
Proposal
list Annex
XIV
Annex
XIV
MHHPA and
HHPA were
added to the
SVHC candidate
list on Dec, 19th
2012
ECHA added
(M)HHPA to
priority list on
Sept 2018
Public
Consultation Sunset date
Until Dec 4th 2018,
affected parties
can submit info on
economic, social,
health & environ-
mental impact of
(M)HHPA inclusion
to Annex XIV
Decision process
of MSC
EC
Decision
making
Application
for
Authori-
sation of
(M)HHPA:
18 months
June
2018
* Dec 2019
Decision
making by EC
on (M)HHPA:
Expected to
take 18
months
LAD
Author
isation
* June 2020
Sunset
period for
(M)HHPA:
18 months
*June 2023
(M)HHPA use
restricted in
EU if no
authorisation
*Earliest estimated timeline, based on todays available information

5. Advanced Materials5
1. Why MHHPA is used today for VPI
• Excellent stability of the VPI-bath (distilled BLR + MHHPA)
• Low tan delta at high temperature
• High thermal aging stability
• Long term experience
2. Issues in replacement
• Alternative anhydrides tend to increase bath viscosity
• Alternative anhydrides show higher tan delta at high temperature
• Available pre-catalyzed anhydride-free VPI system:
- higher viscous
- high hot tan delta
- less thermal aging stable
O
O
O
VPI of Large Generators and Motors

6. Advanced Materials
Curing of Epoxy/Anhydride VPI Systems:
Polyaddition

7. Advanced Materials
Curing of Anhydride-free VPI epoxy systems:
Homopolymerisation

8. Advanced Materials8
Current state of the art:
Electrical Insulation System, consisting of
1.) Impregnation system, consisting of epoxy resin and MHHPA
2.) Mica tape, containing a catalyst (Zn-naphthenate) promoting the polyaddition of
epoxy and anhydrides
New Concept:
1.) New Impregnation system, epoxy-based and free of anhydride
2.) New Mica tape, containing a catalyst promoting the homopolymerisation of
epoxy
Joint development of new EIS by specialists for each part
(Huntsman for resin / Isovolta for tape)
2. Joint Development of New MHHPA-free
Electrical Insulation Systems

9. Advanced Materials
After >2 years of cooperation and intensive lab work,
3 potential candidates have been identified
9
Joint development of new ANH-free VPI system combining leading knowledge
in Mica tape (incl. catalyst) and impregnation resin
2014: 10 potential candidates have been identified
Screening of catalysts and selection of 5 promising candidates:
Pre trials on reactivity, Tg, etc
Development of bath formulations & pre-trials with catalyst in Mica tapes
Development of bath systems / determination of recommended catalyst contents
Measurement of bath data & Storage stability test
Pre-tests of combinations: new bath systems with new tapes pre-selection of 3 candidates
Next steps:
Pilot productions of tapes and bath
Application tests of system
Customer sampling of new tape and new bath
Optimisation of bath and tapes
3 potential
candidates
identified
> 2 years
cooperation and lab
work
10 candiates
2012 2013-2015 2016 2017 2017-2020
Technology approach and complexity

10. Advanced Materials10
• Material properties
- EHS + REACH: SVHC-free Anhydride-free, no critical volatiles
- Viscosity: No must criteria (Ref.: 30 mPas @ 60 °C), important: good impregnation
- Bath stability: ∆η (10 d @ 60 °C) < 2.2 mPas
- Gel time: 10 min. @140 °C (wish)
• Processing requirements
- Curing temp.: <200 °C (must) <150 °C (wish)
- Curing time < 24 h
- Nr. of components: 1
- Bath temperature: <70 °C
- Stability of catalyst in tape: Comparable to reference
• Cured properties
- Tg: 120 – 160 °C (must) 140 – 150 °C (wish)
- Strength: comparable to AH-reference (~40 MPa)
- Thermal aging stability: TI >180 °C (must) TI > 200 °C (wish)
- Hot tan delta: <10 % @ 155 °C
3. Target Profile

11. Advanced Materials11
New Epoxy systems based on 3 different homo-polymerization catalysts
+ Anhydride-free
+ No REACH issue
+ Good working hygiene
+ Single-component Constance of composition
+ Superior bath stability
+ No tank cooling need
+ (Partly) lower hot tan delta
~ Various reactivity levels
- Higher viscosity
- Higher curing temperatures
4. New Bath Materials

12. Advanced Materials12
Reference New 1 New 2 New 3
Catalyst-type Zn-Napht. Catalyst "DY" Catalyst "EP" Catalyst "MA"
Bath systems
MY 790-1 /
HY 1102
LME 11173
(11243)
LME 11173
(11242)
LME 11096-1
Initial viscosity bath (Rheomat)
25°C mPa s 250 2309 2309 388
60°C mPa s 31 94 94 46
80°C mPa s 15 37 37 21
Viscosity at 60°C (VST 1000) mPa s 31,0 100,3 100,3 46,4
Viscosity at 60°C, after 10 d at 60 °C mPa s 33,0 100,3 100,3 46,0
gel time 80°C 33h 42 min > 5 days 8h 50 min
gel time 120°C 28 min 30s 2h 12 min 5 min 40s
gel time 140°C 21 min * 6 min 20s 17 min 30s 2 min
Cure condition
(for test specimen preparation)
16h 90°C +
10h 140°C
4h 100°C +
10h 170°C
4h 125°C +
12h 170°C
2h 90°C +
2h 130°C +
10h 180°C
Tg (DSC) °C 144 * 153 / 154 140 / 142 173 / 194 (TMA)
Tensile strength MPa 45* 43 49 36
Elongation at break % 1.75* 1,8 2,5 1,2
T (5% ∆m) in TGA (20K/min) °C 390* 420 420 380
Loss factor tan δ (50 Hz, 155 °C) % 8.0* 4,7 2,7 5,8
* Catalyst for testing without tape was 0.16 pbw DY 9577 / 0.04 pbw DY 073-1
New AH-free VPI Systems vs. Reference
(data without tape)

13. Advanced Materials
LME 11096-1 – Impact of lower curing T
LME 11096-1 99.84 99.84
XB 6079 A (Mayer catal.) 0.16 0.16
Initial viscosity at (without accelerator*)
25°C mPa s 388 388
30°C 291 291
40°C mPa s 142 142
60°C mPa s 46.4 46.4
80°C mPa s 21.1 21.1
DSC Reaction (10°/min / 30 - 350°C)
max. Peak / Enthalpie 153 / 477 153 / 477
GZ 70°C (Gelnorm) 18h 15 min 18h 15 min
GZ 80°C (Gelnorm) 8h 50 min 8h 50 min
GZ 90°C (Gelnorm) 3h 42 min 3h 42 min
GZ 100°C (Gelnorm) 56 min 30s 56 min 30s
GZ 120°C (Gelnorm) 5 min 40s 5 min 40s
GZ 140°C (Gelnorm) 2 min 2 min
cure cycle 2h 90°C+2h 130°C+10h 180°C 2h 90°C+2h 130°C+20h 160°C
TGA 35 - 800°C (20°/min)
5% loss °C 385 385
Tg / TMA (DSC) °C 173 / 194 140/145
E-Modulus from flexural strength MPa 3335 3295
Flexural strength MPa 77 74
Surface strain % 2.2 2.2
E-Modulus from tensile strength MPa 3215 3205
Tensile strength MPa 36 29
Elongation at break % 1.2 0.9
Shrinkage Length % 1.31 1.30
Loss factor tan δ (50 Hz)
at 155°C % 5.8 7.4

14. Advanced Materials
Tape Materials and Composition
14
Uncalcinated mica paper: 160 g/m2
Glass carrier: 24 g/m2
Resin content: 10-15 g/m2
• Different resin components and application technics tested (design A-F) to
fine-tune:
− Mechanic properties and mica consolidation
− Mica-glass adhesion
− Catalyst immobilization
− Compatibility with VPI resin
Accelerator: MA, DY, and EP
• Accelerator amount in tapes can be adjusted to further optimize curing
behavior and dielectric properties
Mica
Resin
Glass

15. Advanced Materials
Hot Dissipation Factor of Lab Samples
15
54
69
78
46
0
20
40
60
80
100
120
EP-LME11173 DY-LME11173 MA-LME11096-1 Zn-EpoxyAnhydride
DF at 155 °C [‰]

16. Advanced Materials
Test Productions and Mechanical
Properties of Tapes
16
Sample
Number
Catalyst Design
Resin
(g/m2)
tan δδδδ
(‰)
Tensile
strength
(N/cm)
Bending
stiffness
(N/m)
Edge tear
resistance
(N)
16E114 MA A 17 78 134 67 94
16E115 DY A 20 69 131 30 -
Design A: material is too tacky
16E145 DY B 15 60 117 34 198
16E146 DY C 16 87 131 38 210
Design B and C: improved mechanical properties; Design C still tacky at 50 °°°°C
16E166 EP B 13 47 104 76 87
16E167 EP D 12 64 130 78 189
16E168 MA B 12 89 100 68 130
16E169 MA D 11 78 121 68 153
Design D: no blocking; tapes are a little stiff but otherwise good mechanics
17E167 MA E 14 57 115 44 141
17E168 MA F 15 55 116 49 142
Design E and F: more flexible tapes with good mechanics

17. Advanced Materials
Mechanical Properties and Dissipation
Factor of MA-tapes Design B, D, and F
17
68
100
130
89
68
121
153
78
49
116
142
55
0
40
80
120
160
200
bending stiffness
[N/m]
tensile strength
[N/cm]
edge tear resistance
[N]
dissipation factor at
155 °C [‰]
16E168 (MA - Design B)
16E169 (MA - Design C)
17E168 (MA - Design F)

18. Advanced Materials18
No mica detachment on roll (16 h at 40 °C)
and during processing
Good processability but small wrinkles
around corners
Flexibility should be further improved
Test Productions and Mechanical
Properties MA-tape, Design F

19. Advanced Materials19
Flexural Stiffness over Time
MA-tapes Design E and F

20. Advanced Materials20
Flexural Stiffness over Time
MA-tapes Design E and F

21. Advanced Materials21
Application Tests
MA-tapes and LME 11096-1
Six bars with MA-tape Design E (16E167) and Design F (16E168) were
prepared and tested
− Impregnation behavior (capacity trend during impregnation)
− Dissipation factor after curing of test bars
− Thermal cycling of test bars
− Voltage endurance test at 3xUn
− Compatibility with system tapes

22. Advanced Materials22
Capacity trend during impregnation
MA-tapes and LME 11096-1

23. Advanced Materials23
1st Dissipation factor after curing
MA-tapes 17E167 and 17E168
max. ∆∆∆∆ tan δδδδ (%)
17E167 17E168
0,72 0,65
0,93 0,66
0,78 0,65
0,65 0,67
0,80 0,60
0,78 0,74

24. Advanced Materials24
Hot Dissipation Factor
MA-tapes 17E167 and 17E168

25. Advanced Materials25
Dissipation factor after Hot DF
MA-tapes 17E167 and 17E168
max. ∆∆∆∆ tan δδδδ (%)
17E167 17E168
0,78 0,68
0,73 0,74
0,67 0,81

26. Advanced Materials26
Thermo Cycling
MA-tapes 17E167 and 17E168

27. Advanced Materials27
Voltage Endurance at 3x Un
MA-tapes 17E167 and 17E168
Bar ID
Insulation
Material
Time in h kV/mm
average
value
standard
deviation
Test
Voltage in
kV
Insulation
thickness
Organic
Content
[%]
Un in kV
17-201
Poroband
17E167
29,2 16,6
25,2 6,0 33,0
1,99 28,2
1117-202 29,8 17,0 1,94 29,2
17-203 16,7 16,9 1,95 28,6
17-207
Poroband
17E168
22,6 17,1
23,3 4,6 33,0
1,93 28,7
1117-208 29,2 17,2 1,92 27,9
17-209 18,1 17,3 1,91 27,7

28. Advanced Materials28
No wash-out during impregnation
with LME 11096-1
Insufficient bonding after curingafter impregnation
Cover Tape and OCP: MA-System
Impregnation and Curing
no adhesion after curing
Standard tape
Isosseal 4307
No wash-out during impregnation
with LME 11096-1
Insufficient bonding after curing
Conductive tape containing MA-
accelerator in development

29. Advanced Materials29
Stress Grading and MA-System
Impregnation and Curing
EGSB 4308
after impregnation
after curing
after impregnation
after curing
Standard Tape
Disintegration during impregnation
Rough and brittle surface
Stable during impregnation and cure

30. Advanced Materials30
• REACH issue with (M)HHPA due to respiratory sensitization
• MHHPA is difficult to replace for VPI - combines excellent electrical,
mechanical, aging, application technical and economic characteristics
• Isovolta and Huntsman are jointly developing new AH-free electrical
insulation systems for VPI (bath and tapes) to overcome REACH issue
• 3 new epoxy systems presented
• Single component, very good bath stability, no tank cooling
• New tapes produced on production scale
• Target of hot tan delta <10 %@155 °C could be met for all 3 systems
• Tapes show good processability and wettability
• Next steps: Further dielectric testing, tape optimization and customer
trials
• Development and optimization of system tapes (OCP, EGSB, etc.) and
auxiliary materials
Summary & Conclusion

31. Advanced Materials31
References
Beisele, C., Brasch, M., Kattnig, E.: New MHHPA-free Epoxy-based Vacuum Pressure Impregnation Systems and New Mica-tapes for
Large Generators and Motors; Insucon 2017 Conference, Birmingham, UK, May 16-18, 2017
Beisele, C.; Bär, D.; Colliard, S.: TRADITIONAL AND NEW EPOXY SYSTEMS FOR VACUUM PRESSURE IMPREGNATION OF
ELECTRICAL MACHINE, Insucon 2013 Conference, Birmingham, UK, May 29 – 31, 2013
Beisele, C. and Bär, D., “Epoxy Systems for Vacuum Pressure Impregnation of Electrical Machines”, ELROMA 2012 International
Conference on Rotating Machines, Mumbai, India, April 19-20 (2012)
AGREEMENT OF THE MEMBER STATE COMMITTEE ON THE IDENTIFICATION OF HEXAHYDROMETHYLPHTHALIC
ANHYDRIDE, HEXAHYDRO-4-METHYLPHTHALIC ANHYDRIDE, HEXAHYDRO-1-METHYLPHTHALIC ANHYDRIDE, HEXAHYDRO-
3-METHYLPHTHALIC ANHYDRIDE AS SUBSTANCES OF VERY HIGH CONCERN According to Articles 57 and 59 of Regulation
(EC) 1907/20061, Adopted on 13 December 2012
http://echa.europa.eu/documents/10162/ab858db8-5467-429c-a94d-2e563f523d01
Beisele, C.: “REACH-compliant and Anhydride-free Casting- and Impregnation Systems”, Symposium on Epoxy Resins in Electrical and
Electronic Engineering, Ostfildern, Germany, 19.04.2016 - 21.04.2016
Huntsman Technical data sheet “MY 790-1 CH / HY 1102”, pg. 6, Ed. March 2012
Huntsman Technical data sheet “XD 4410”
Vogelsang, R.; Weiers, T.; Fröhlich K.; Brütsch, R.: “Electrical Breakdown in High-Voltage Winding Insulations of Different
Manufacturing Qualities“, IEEE Electrical Insulation Magazine Vol. 22, No. 3, pp. 5-12 (2006).
Datasheet Poroband ME 2072 Isovolta AG