merck chemicals - 100 years of liquid crystals at merck
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100 Years of Liquid Crystals at MerckTRANSCRIPT
100 Years of Liquid Crystals at Merck
Dr. Peer Kirsch
Merck KGaA, Liquid Crystals Division, D-64271 Darmstadt, Germany
20th International Liquid Crystal Conference (ILCC-20), Ljubljana, Slovenia, July 4-9, 2004
Dynamic Scattering (DSM)R. Williams, G. Heilmeier, 1962
Twisted Nematic Mode (TN)M. Schadt, W. Helfrich,
J. Fergason, 1971
Super Twisted Nematic (STN)T. J. Scheffer et al., 1984
Active Matrix Display (AMD)commercial production: 1989concept: B. J. Lechner, 1971
H
H HPhCOO
CH3
CH3
R CN
R CN
H
HR F
F
F
FFH
HR
O
F
F
F
H
HR OEt
F F
O CN
OR
F. Reinitzer, 1888
G. W. Gray et al., 1972
R. Eidenschink et al., 1976
D. Demus et al., 1975
RNRO
RNRO N
O
“Super Fluorinated Materials” (SFM), 1985
Dynamic Scattering (DSM)R. Williams, G.Heilmeier, 1962
Twisted Nematic Mode (TN)M. Schadt, W. Helfrich,
J. Fergason, 1971
Super Twisted Nematic (STN)T. J. Scheffer et al., 1984
Active Matrix Display (AMD)commercial production: 1989concept: B. J. Lechner, 1971
Wristwatches Pocket Calculators
Notebook PC
Desktop PC Monitor
PDA
Cellular Phone
LCD TV
In Plane Switching (IPS)commercial production: 1996
Vertical Alignment (VA)commercial production: 1998
1973
19951990
1997
2002
2000
Dr. Peer Kirsch ILCC-20 Page 4
The Pioneers - 1
H
H HO
CH3
CH3
O
F. Reinitzer (Prague), 1888
C 145 N* 179 I
F. Reinitzer, Monatsh. Chem. 1888, 9, 421
Dr. Peer Kirsch ILCC-20 Page 5
The Pioneers - 2
O. Lehmann (Karlsruhe), 1889
• "Apparently living crystals" are mesophases: a new and distinct state of matter
• Lehmann asks Merck in 1904to provide liquid crystals for research
Dr. Peer Kirsch ILCC-20 Page 6
The Pioneers - 3
D. Vorländer (Halle), early 1900s
• Systematic study on various calamitic liquid crystals
NON
O
NON
O
p-Azoxyphenetole
Dr. Peer Kirsch ILCC-20 Page 8
Milestones in the History of Merck
1668Friedrich Jacob Merck(1621–1678) buys the “Engel-Apotheke”(Angel Pharmacy) inDarmstadt, Germany
1827Emanuel Merck
(1794–1855) starts production on an
industrial scale
Dr. Peer Kirsch ILCC-20 Page 9
International Successes and Setbacks
Factory in Darmstadt, 1898
• On the basis of the international success, local subsidiaries were established in
- London (1883)
- New York (1887)
- Moscow (1899)
• The New York branch evolved into an independent US company after the World War I: Merck & Co.
Dr. Peer Kirsch ILCC-20 Page 10
Merck Today
Factory site in Darmstadt, 1995
• Merck groups its operating activities under Merck KGaA, going public in 1995
• Shareholders hold 26% of the total capital, the Merck family holds 74% through E. Merck as the general partner.
Dr. Peer Kirsch ILCC-20 Page 11
Merck Enters Liquid Crystal Business
• Since 1904 sale of reagents for liquid crystal research: – (Alkyl)ammonium oleates
– Cholesterol esters
– p-Azoxybenzoate
– p-Azophenetole
– p-Azoxyphenetole
– p-Azoxyanisole
Dr. Peer Kirsch ILCC-20 Page 12
The Skeptics
"Soft crystals do exist, floating ones may exist, but liquid ones? I tell you, no way!"
G. Tammann, around 1920
Dr. Peer Kirsch ILCC-20 Page 13
Thermochromic Cholesterics:Applications
• Use of cholesteric liquid crystals as temperature indicators since 1966, e.g., for – Medical diagnostics: mammography, vascular disorders
– Non-destructive testing: welds, electric circuits
– Radiation sensing: IR, microwave
– Decorative: beer labels
Dr. Peer Kirsch ILCC-20 Page 14
Thermochromic Cholesterics:Materials
• Cholesteric mixture systems TM74A/B and TM75A/B (BDH Chemicals Ltd., Poole, UK):
• Thermotropic devices:– Dispersion of microencapsulated cholesterics
– Polymer-dispersed cholesterics
RO
O CH3
ROO
O CH3 O
O CH3R
*
*
*
Dr. Peer Kirsch ILCC-20 Page 15
Dynamic Scattering Mode (DSM)
• Developed since 1963 by R. Williams and G. Heilmeier (RCA)
• Presentation in 1968 at the ILCC-2, Kent, OH: Motivation for Merck to enter liquid crystal research
pictures: George Heilmeier with DSM prototype (left), F. Vögtle, Supramolekulare Chemie (right)
Dr. Peer Kirsch ILCC-20 Page 16
Dynamic Scattering Mode:Materials
• Schiff Bases (Eastman Kodak)
• Azoxy Compounds (Merck)
• Esters (Merck)
R = CH3: MBBAR = C2H5: EBBA
N 4
ME-35O
OH7C3
C5H11
NN C4H9
MeOO
NN C4H9
MeO
O
N C4H9
RO
Dr. Peer Kirsch ILCC-20 Page 17
Practical Problems with First Generation Materials
• Azoxy Compounds: Sensitivity against light
• Schiff Bases: Hydrolysis and transimination
NN R
ROO
N R2O
N R4O
N R2O
N R4O
N R4O
N R2O
R1
R3
R1
R3
R1
R3
Dr. Peer Kirsch ILCC-20 Page 18
The Twisted Nematic (TN) Mode
• Invented in 1971 by M. Schadt and W. Helfrich (Hoffmann-La Roche), and J. Fergason (Kent State University)
picture: TN display prototype presented to the board of directors at Hoffmann-La Roche in March 1971
off on
Dr. Peer Kirsch ILCC-20 Page 19
Liquid Crystal Production at Merck
0
20
40
60
80
100
120
140
160
180
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
Year
Liqu
id C
ryst
al P
rodu
ctio
n M
erck
Dar
mst
adt (
tons
)
STNVIPTN
TN-TFTIPS
MVA
PALC
prognosis
Dr. Peer Kirsch ILCC-20 Page 20
Cyanobiphenyls and Terphenyls
• Developed by G. Gray and coworkers (Univ. Hull) in 1972• First chemically and photochemically stable materials with
a nematic phase around room temperature
• Put to the market by BDH Chemicals Ltd. and Hoffmann-La Roche
NH11C5
NH11C5
K15: C 23 N 35.1 I∆εvirt = 21.6
T15: C 131 N 239.9 I∆εvirt = 20.2
Dr. Peer Kirsch ILCC-20 Page 21
BDH Chemicals Ltd., Poole
• Since 1972 sales of liquid crystal mixtures together with Merck
• In 2001 opening of Chilworth Technical Centre
Dr. Peer Kirsch ILCC-20 Page 22
The Cyclohexane Substructure
• D. Demus and coworkers (Halle) in 1975
OH11C5
O N
D5: C 47 N 78.7 I∆εvirt = 14.8
Dr. Peer Kirsch ILCC-20 Page 23
Phenylcyclohexanes
• Developed by R. Eidenschink and coworkers (Merck) in 1976
NH11C5
H11C5 N
H11C5 C3H7
PCH-5: C 31 N 54.6 I∆εvirt = 17.9
BCH-5: C 96 N 219.3 I∆εvirt = 17.2
CBC-53: C 54 SB 237 SA 260 N 317 I
Dr. Peer Kirsch ILCC-20 Page 24
Cyclohexylcyclohexanes
• R. Eidenschink (Merck), 1979
H
HH11C5 N
CCH-5: C 67 SB (52) N 86.2 I∆εvirt = 8.3
Dr. Peer Kirsch ILCC-20 Page 25
Viewing Angle Independent Contrast (VIP)
• VIP (1980) is the basis for most modern TN LCDs
2
22
1
12
sin
21)(
u
uuT
+
⎟⎠⎞
⎜⎝⎛ +
=
π
C. H. Gooch, H. A. Tarry, J. Phys. D: Appl. Phys. 1975, 8, 1575-1584
Dr. Peer Kirsch ILCC-20 Page 26
The Super Twisted Nematic (STN) Mode
• T. J. Scheffer, J. Nehring (BBC), 1981
• Extension of the limit for multiplexing large pixel arrays: the first high resolution LCDs
picture: T. Uchida, Ekisho 1999, 3, 195-204
Dr. Peer Kirsch ILCC-20 Page 27
Alkenyls
• Merck purchased in 1996 the NLC portfolio from Hoffmann-La Roche
• Advantages:– Increased tendency to form nematic phases
– Advantageous elastic constants: large K33/K11
– Often low rotational viscosities (γ1)
H
HCH3
H
HF
F
H
HC5H11
CCP-V2-1: C 54 SB 104 N 176.6 I CCG-V-F: C 74 N 108.9 I∆εvirt = 4.3
CC-5-V: C -9 SB 52 N 62.6 I
Dr. Peer Kirsch ILCC-20 Page 28
Chiral Dopants
• Used in low concentration for inducing uniform pitch in TN and STN mixtures
• Newest generation for SSCT mode (2000)
H
HH7C3
F
F
OC6H13
CH3
*
H11C5
F
F
OC6H13
CH3
*
H11C5
O
OO
O
C5H11
*
H13C6OO
O
O
OC6H13
CH3
*
C3H7OO
14 µm-1 a
39.5 µm-1 b 13.6 µm-1 a
104 µm-1 c
a MLC-6012b ZLI-1132c MLC-6260
9.1 µm-1 c
Dr. Peer Kirsch ILCC-20 Page 29
Active Matrix Addressing
• Proposed already for the DSM mode by B. J. Lechner in 1971
• First prototypes presented by Sharp in 1987
• Technical basis for all high-resolution full colour LCDs
picture left: Scientific American 1997 (11), 87
Dr. Peer Kirsch ILCC-20 Page 30
Super Fluorinated Materials (SFM)
• 1989: Trifluorophenyl Derivatives
• 1990: Trifluoromethoxyphenyl Derivatives
• 1990: Difluoromethoxyphenyl Derivatives
H
HH7C3 F
F
F
H7C3 F
F
F
H
HH7C3 OCF3
H
HH7C3 OCHF2
F
F
Dr. Peer Kirsch ILCC-20 Page 31
Extension of the SFM Concept
• Additional lateral fluorine substituents on neighbouring rings:
• Polar rings and linking groups:
H7C3 F
F
FF
H7C3 F
F
FF
F
F
FH
HH7C3
F
H
HH7C3
O
OF
F
F H
HH7C3
O
O
F
F
F
Why Fluorinated Liquid Crystals?
Broader nematic phase range, lower melting point
High dielectric anisotropy (∆ε) due to polarized C-F bond
Good voltage holding ratio, high specific resistivity 1990
1980
1985H7C3 CN
C2H5H7C3
C4H9H9C4
F
F
CF3H7C3
C 171 S? (160) N 216.8 I
C 34 N 177.7 I
∆ε ~ 21
∆ε ~ 9
NH7C3 +
H7C3 CF3 +
FF
FF
H7C3
FF
O
F
F
F
Improved mesophase rangeby fluorinated bridges 2000
TNI,virt = 128°C
Dr. Peer Kirsch ILCC-20 Page 33
Property Prediction by Molecular Modelling
Predictable:• Dielectric anisotropy (∆ε)
• Birefringence (∆n)• "Reliability" parameters (qualitative)
Not (yet) predictable:• Mesophase sequence, clearing
point (TNI)
• Viscoelastic properties (γ1, Kxy)
M. Bremer, K. Tarumi, Adv. Mater. 1993, 5, 842-848.M. Klasen, M. Bremer, A. Götz, A. Manabe, S. Naemura, K. Tarumi, Jpn. J. Appl. Phys. 1998, 37, L945-L948.
Dr. Peer Kirsch ILCC-20 Page 34
Combinatorial Chemistry andAutomated Parallel Synthesis
Dr. Peer Kirsch ILCC-20 Page 35
In Plane Switching (IPS) Mode
• Patent of the Fraunhofer Institute of Applied Solid State Physics, Freiburg, 1990
• Acquired by Merck in 1994• Co-development together with Hitachi
Ltd.
• Advantages: – Dramatically improved viewing angle
of up to 170°
– High contrast ratio
• Requires materials with strongly positive ∆ε
Dr. Peer Kirsch ILCC-20 Page 36
Low Birefringent Materials - 1
• Problem: most bicyclohexyl based liquid crystals tend to have only smectic phases or poor solubility
• 1998: Trifluoromethyl bicyclohexyls have found wide spread use in reflective and transflective LCDs
H
HCF3
C 19 SH? (8) SB? 41 I∆εvirt = 6.8 ∆nvirt = 0.059
Dr. Peer Kirsch ILCC-20 Page 37
Low Birefringent Materials - 2
• Alternative approach: Materials with negative birefringence as internal ∆n compensators in LC mixtures
• 2001: Bicyclohexyl "dimers" with triacetylene as perpendicular polarizable bridging group
C5H11H11C5
C5H11H11C5
C 90 N (63) I∆nvirt = -0.012∆n = -0.0104 (T/TNI = 0.95)
V. Reiffenrath, M. Bremer (Merck), 2001
Dr. Peer Kirsch ILCC-20 Page 38
Difluoroethers: The CF2O Bridge
• Substance class first characterized by E. Bartmann and K. Tarumi (Merck), 1995
• Technical synthesis developed by P. Kirsch, A. Taugerbeck, M. Bremer and D. Pauluth (Merck), 2000
FF
H
HR
O
F
F
FR
FF
O
F
F
F
FF
RO
F
F
F
F
F
Dr. Peer Kirsch ILCC-20 Page 39
Difluoroethers: Properties
• Comparison with directly linked materials:– Increased nematic phase range: TNI increased by 10-15 K, melting
points decreased
– ∆ε increased, ∆n decreased
– Reduction of γ1 by 10-15%
– Improved solubilityF
F
F
H
HH7C3
FF
H
HH7C3
O
F
F
F
C 66 N 94.1 I C 44 N 105.3 I∆εvirt = 9.7 ∆εvirt = 10.5∆nvirt = 0.073 ∆nvirt = 0.067γ1,virt = 171 mPa·s γ1,virt = 145 mPa·s
Dr. Peer Kirsch ILCC-20 Page 40
Other Difluoroether Materials
• High stability and enhancement of solubility makes use of "unusual" structural elements possible
F F H
H
H H
CH3
CH3
O
FF
F
FF
H
HR
O SF5
FF
FF
H7C3
FF
O
F
F
F
Dr. Peer Kirsch ILCC-20 Page 41
Tetrahydropyranes
• Tetrahydropyrane derivatives as highly polar SFM materials with improved stability
FF
H
HH7C3
O
O
F
F
F
FF
O
F
F
F
F
FO
H7C3
F
F
P. Kirsch, E. Poetsch (Merck), 2001
C 35 N 66.3 I∆εvirt = 14.0 ∆nvirt = 0.065γ1,virt = 158 mPa·s
C 83 N (83.0) I∆εvirt = 35.6 ∆nvirt = 0.132γ1,virt = 457 mPa·s
Dr. Peer Kirsch ILCC-20 Page 42
Vertical Alignment (VA) Mode
• MVA monitors by Fujitsu since 1996• ASV TV by Sharp since 2002• Advantages:
– Viewing angle of up to 170°
– High contrast ratio
– Fast response times
• Requires materials with negative ∆ε
pictures: MVA (Fujitsu), ASV (Sharp)
Dr. Peer Kirsch ILCC-20 Page 43
German Future Prize 2003
M. Bremer, M. Klasen-Memmer, K. Tarumi, Nov 13, 2003
Dr. Peer Kirsch ILCC-20 Page 44
2,3-Difluorophenylene Derivatives
• 1989: First SFM materials with strongly negative ∆εdeveloped within FLC project (sold in 1995 to Hoechst)
H
HR
F F
OEtR
F F
OEt
R OEt
F F
OEt
N N
O
O
H
HR
RR
N
Dr. Peer Kirsch ILCC-20 Page 45
Difluoroindanes
• Fluorinated indanes are the first fundamentally new type of materials with negative ∆ε since the 2,3-difluorophenylene derivatives: M. Bremer, L. Lietzau (Merck), 2001
F F
H7C3
FF
F FH
HH7C3
FF
C 85 I∆εvirt = -8.6
C 130 SB 168 N 203.7 I∆εvirt = -8.4
Dr. Peer Kirsch ILCC-20 Page 46
The Past
2004: New LC production plant in Darmstadt2002: Merck Ltd., Hong Kong1997: Together with Fujitsu co-development of VA mode
Merck Display Technologies Ltd., Taiwan1996: Purchase of NLC patent portfolio from Hoffmann-La Roche
Application laboratory in Taiwan1995: Together with Hitachi co-development of IPS mode
Sales of FLC patent portfolio to Hoechst1993: Joint venture with Balzers on ITO glass1989: Application laboratory in Seoul, Korea1985: Purchase of BBC patent portfolio1980: Application laboratory in Atsugi, Japan1968: Start of active LC research at Darmstadt
Dr. Peer Kirsch ILCC-20 Page 47
The Present:The Liquid Crystals Division
• Employees woldwide: 400 people, including 150 people in R&D
• Production volume: 60 tons of liquid crystals in 2002
• Sales 2003: over 400 Mio EUR
Dr. Peer Kirsch ILCC-20 Page 48
025.00050.00075.000
100.000125.000150.000175.000200.000225.000250.000
2002 2003 2004 2005 2006 2007
Thou
sand
s of
Uni
ts
CRT (TV + Monitor)
LCD (TV + Monitor)
The Future -1:Transition from CRT to LCD
Source – iSuppli/Stanford Resources
Dr. Peer Kirsch ILCC-20 Page 49
The Future - 2
• In 2004 completion of a new liquid crystal production facility at Merck, Darmstadt
• Investment: 250 MioEUR
• Capacity: 150 tons per year
Dr. Peer Kirsch ILCC-20 Page 50
Acknowledgements
Chemistry PhysicsDr. M. Bremer Dr. M. HeckmeierDr. J. Krause Dr. M. Klasen-MemmerDr. L. Lietzau Dr. G. LüssemDr. E. Montenegro A. ManabeDr. D. Pauluth Dr. K. TarumiDr. E. PoetschV. ReiffenrathDr. A. Taugerbeck
Dr. W. Becker and Dr. S. Bernschneider-Reif is thanked for historical data and market forecasts
Financial Support (€ & ¥)Ministry of International Trade and Industry (MITI)Bundesministerium für Bildung und Forschung (01 B 621/1, 01 BM 904)
Dr. Peer Kirsch ILCC-20 Page 51
The LC R&D Team at Darmstadt