Download - Merck Chemicals - 100 Years of Liquid Crystals at Merck

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

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


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


The Pioneers - 3

D. Vorländer (Halle), early 1900s

• Systematic study on various calamitic liquid crystals

NON

O

NON

O

p-Azoxyphenetole


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


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.


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.


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


The Skeptics

"Soft crystals do exist, floating ones may exist, but liquid ones? I tell you, no way!"

G. Tammann, around 1920


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


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

*

*

*


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)


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


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


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


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


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


BDH Chemicals Ltd., Poole

• Since 1972 sales of liquid crystal mixtures together with Merck

• In 2001 opening of Chilworth Technical Centre


The Cyclohexane Substructure

• D. Demus and coworkers (Halle) in 1975

OH11C5

O N

D5: C 47 N 78.7 I∆εvirt = 14.8


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


Cyclohexylcyclohexanes

• R. Eidenschink (Merck), 1979

H

HH11C5 N

CCH-5: C 67 SB (52) N 86.2 I∆εvirt = 8.3


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


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


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


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


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


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


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


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.


Combinatorial Chemistry andAutomated Parallel Synthesis


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


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


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


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


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


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


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


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)


German Future Prize 2003

M. Bremer, M. Klasen-Memmer, K. Tarumi, Nov 13, 2003


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


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


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


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


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


The Future - 2

• In 2004 completion of a new liquid crystal production facility at Merck, Darmstadt

• Investment: 250 MioEUR

• Capacity: 150 tons per year


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)


The LC R&D Team at Darmstadt

Download - Merck Chemicals - 100 Years of Liquid Crystals at Merck

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