WO1999005645A1 - Chip card with a mechanically loadable bistable display - Google Patents

Abstract

Disclosed is a chip card with a ferroelectric liquid crystal display comprising one ferroelectric liquid crystal layer. Said card is characterized in that the liquid crystal layer contains at least one component of a high molecular weight, which in itself does not constitutes a ferroelectric phase. The inventive display can be connected at voltages </=15 V, generally </=5 V. It is recordable in a broad temperature range and is particularly resistant to daily stresses such as pressure, bending, deformation or thermal stresses.

Description

description

Chip card with a mechanically robust bistable display

A chip card is a card, usually made of plastic and in

Credit card format, provided with an integrated circuit which can electronically store and / or process information, and means for transmitting information between the card and an electronic reading and / or writing system. A smart card is a chip card that also contains means for checking / controlling access to the card. For example, this means can be an integrated circuit which controls who uses the stored information for what purpose. This can increase data security.

Chip or smart cards are, for example, as telephone and credit cards

"Medicards", "cash cards" and as ID cards for access control, already in diverse use.

In the near future, these technologies are expected to advance further into areas such as the "electronic wallet", i.e. Replacement of cash, tickets and pay TV.

A permanent, visible electronic display (display) on the card is desirable and has already been proposed for chip cards, which provides information, for example about fill level, remaining amount or dates.

Such a display should also be visible without the application of an electrical voltage, since neither the thickness nor the manufacturing costs of a card permit the installation of a battery. The display must therefore have an optical storage capacity. For reasons of optical bistability, surface-stabilized ferroelectric liquid crystal displays (SSFLCD) and bistable nematic displays (see E. Lüder et al. 1997 International Symposium, Seminar & Exhibition, Society) have so far been used for such applications of Information Display, Boston, Massachusetts, article 9.4, SID 97 DIGEST, p. 109-

112) and surface or polymer-stabilized cholesteric textures (SSCT or PSCT) are proposed.

SSFLCDs are already in use as computer displays, but their use in chip cards requires a considerably different property profile, which includes pressure and shock resistance, flexibility, low addressing voltage, legibility in daylight and particularly low thickness and weight, in addition to the optical storage capacity according to ISO 7816.

There is therefore a high demand for SSFLC displays or for ferroelectric ones

Liquid crystal mixtures (FLC) for those displays that are specially designed to meet the requirements of chip or smart cards.

It has now surprisingly been found that a ferroelectric liquid crystal mixture which contains one or more higher molecular components, which do not themselves have any ferroelectric liquid crystalline phases, as a stabilizing network (matrix) are particularly suitable for use in displays for chip cards.

The invention therefore relates to a chip card containing a ferroelectric

Liquid crystal display with a ferroelectric liquid crystal layer, characterized in that the liquid crystal layer contains one or more higher molecular components which do not themselves form a ferroelectric liquid crystalline phase. The display according to the invention can be switched at voltages <15 V, generally <5 V, can be written over a wide temperature range and is robust against everyday loads such as pressure, bending, deformation or thermal stress.

According to the invention, the liquid crystal layer contains one or more higher molecular components which stabilize the structure of the smectic liquid crystal necessary for the displays. The higher molecular weight components usually form a network (polymer matrix) in which the liquid crystal is embedded. The liquid crystal is characterized by the presence of the

Surprisingly, the structure of the polymer network is hardly disturbed.

The inclined smectic optically active (ferroelectric) liquid crystal (FLC) can consist of a mixture of low molecular weight compounds as well as a single substance. In the case of mixtures, the liquid crystal preferably contains a non-optically active base mixture, preferably in a proportion of> 50% by weight, and one or more optically active compounds (dopants). If the liquid crystal consists of a single compound, then this must itself be optically active. The FLC generally has a spontaneous polarization of 0.1 to 100 nCcm, preferably 3 to 60 nCcm ² , particularly preferably 5 to

40 nCcm ^"2 , on.

Suitable compounds for FLC are known to the person skilled in the art. Generally suitable connections can e.g. describe by the general formula (I)

R ¹ (-A ¹ -M ¹ ) _a (-A ² -M ² ) _b - (- A ³ -M ³ ) _c (-A ⁴ ) -R ² (I)

where the symbols and indices have the following meanings: R ¹ , R ² are identical or different a) hydrogen, -F, -Cl, -CF ₃ , -OCF ₃ or -CN, b) a straight-chain or branched alkyl radical (with or without asymmetrical carbon atom) with 1 to 20 carbon atoms, where b1) one or more non-adjacent and non-terminal CH ₂ groups by -O-, -S-, -CO -O-, -O-CO-, -CS-O-, -O-CS-, -CS-S-, -S-CS-, -CO-S-, -S-CO-, -O-CO -O- or

-Si (CH ₃ ) ₂ - can be replaced and / or b2) one or more CH ₂ groups by -CH = CH-, -C≡C-,

Cyclopropane-1, 2-diyl, 1, 4-phenylene, 1, 4-cyclohexylene or 1, 3-cyclopentylene can be replaced and / or b3) one or more H atoms replaced by F and / or Cl and / or CN and / or b4) the terminal CH ₃ group can be replaced by one of the following chiral groups (optically active or racemic):

H H

R- -CH-- R ^ -CH. R ^ό CH.

Cl

CH,

H H H

R CH, R ^ύ CH.

CN FF with the proviso that at most one of the radicals R ¹ , R ^{2 can be} hydrogen, -F, -Cl, -CF ₃ , -OCF ₃ or -CN; R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ are the same or different a) hydrogen b) a straight-chain or branched alkyl radical (with or without asymmetric carbon atom) with 1 to 16 carbon atoms, b1) one or more not neighboring and non-terminal CH ₂ -

Groups can be replaced by -O- and / or b2) one or two CH ₂ groups can be replaced by -CH = CH-, c) R ⁴ and R ⁵ together also - (CH ₂ ) ₄ - or - (CH ₂ ) ₅ - if they are bound to an oxirane, dioxolane, tetrahydrofuran, tetrahydropyran, butyrolactone or valerolactone system;

M ¹ , M ² , M ³ , are the same or different -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CS-O-, -O-CS-, - CS-S-, -S-CS-, -CH ₂ -O-, -O-CH ₂ -, -CH ₂ -S-, -S-CH ₂ -, -CH = CH-, -C≡C- , -CH ₂ -CH ₂ -CO-O-, -O-CO-CH ₂ -CH ₂ -, -CH = N- or a single bond;

A \ A ² , A ³ , A ⁴ are identical or different 1, 4-phenylene, one or more H atoms being represented by F, Cl, OCH ₃ , CH ₃ , C ₂ H ₅ , CF ₃ , OCF ₃ and / or CN can be replaced, 1, 3-phenylene, where one or two CH groups can be replaced by N, pyridazine-3,6-diyl, where one or two H atoms can be replaced by F, Cl and / or CN can, pyridine-2,5-diyl, where one or more H atoms can be replaced by F, Cl and / or CN, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, Cl and / or CN can be replaced, 1, 4-cyclohexylene, where one or two H atoms can be replaced by CN and / or CH ₃ and / or F, 1-alkyl-1-silacyclohexane-1, h-diyl where one or two H atoms can be replaced by CH ₃ and / or F, (1, 3,4) - thiadiazole-2,5-diyl, 1, 3-dioxane-2,5-diyl, 1, 3-dithiane-2 , 5-diyl, 1, 3-thiazole-2,4-diyl, where an H atom can be replaced by F, Cl and / or CN, 1, 3-thiazole-2,5-diyl, where an H- Atom can be replaced by F, Cl and / or CN, Thioph en-2,4-diyl, one H atom being replaced by F, Cl and / or CN can, thiophene-2,5-diyl, where one or two H atoms can be replaced by F, Cl and / or CN, naphthalene-2,6-diyl, where one or more H atoms can be replaced by F, Cl and / or CN can be replaced, naphthalene-1, 4-diyl where one or more H atoms can be replaced by F, Cl and / or CN, naphthalene-1, 5-diyl, where one or more H atoms can be replaced by F, Cl and / or CN can be replaced, phenanthrene-2,7-diyl or 5,10-dihydrophenanthrene-2,7-diyl. Whereby one, two or more H atoms can be replaced by F and one or two CH- Groups can be replaced by N, indan-2,5-diyl, indan-1-one-2,5-diyl, benzothiazole-2,6-diyl, benzothiazole-2,5-diyl, benzoxazole-2,6-diyl , Benzoxazole-2,5-diyl, benzofuran-2,5-diyl, benzofuran

2,6-diyl, 2,3-dihydrobenzofuran-2,5-diyl, piperazine-1,4-diyl, piperazine-2,5-diyl or 1,3-dioxaborinane-2,5-diyl;

a, b, c, are 0 or 1, with the proviso that the compound of formula (I) may not contain more than four five or more-membered ring systems.

The liquid crystal generally contains 1 to 35, preferably 2 to 25, particularly preferably 2 to 20 low molecular weight components. The components of the liquid crystal are preferably selected from the known compounds with smectic and / or nematic and / or cholesteric phases, for example of the formula (I). These include e.g. B .:

Derivatives of phenylpyrimidine, such as in WO 86/06401,

US Pat. No. 4,874,542, metasubstituted six-ring aromatics, as described, for example, in EP-A 0 578 054,

Silicon compounds, as described for example in EP-A 0 355 008, mesogenic compounds with only one side chain, as for example in EP

A 0 541 081, hydroquinone derivatives, as described for example in EP-A 0 603 786, Phenylbenzoates and biphenylbenzoates, such as those from P. Keller,

Ferroelectrics 1984, 58, 3; Liq. Cryst. 1987, 2, 63; Liq. Cryst. 1989, 5, 153 and J.W. Goodby et al., Liquid Crystals and Ordered Fluids, Vol. 4, New York

Described in 1984, thiadiazoles, as described, for example, in EP-A 0 309 514,

Biphenyls such as in EP-A-0 207 712 or Adv. Liq. Cryst. Res.

Appl. (Ed. Bata, L.) 3 (1980),

Phenylpyridines such as in Ferroelectrics 1996, 180, 269 or Liq.

Cryst. 1993, 14, 1 169, - Benzanilide such as in Liq. Cryst. 1987, 2, 757 or Ferroelectrics

1984, 58, 81,

Terphenyls such as in Mol. Cryst. Liq. Cryst. 1991, 195, 221;

WO-A-89/02425 or Ferroelectrics 1991, 114, 207,

4-cyanocyclohexyls, as described, for example, in the Freiburg liquid acid crystals working conference 1986, 16, V8,

5-alkylthiophenecarboxylic acid esters, for example in Butcher, J.L.,

Dissertation, Nottingham, UK 1991,

1, 2-Diphenylethane such as in Liq. Cryst. 1991, 9, 253,

Possible chiral, non-racemic dopants are, for example: optically active phenyl benzoates, as for example in P. Keller

Ferroelectrics 1984, 58, 3 and J.W. Goodby et al., Liquid Crystals and

Ordered Fluids, Vol. 4, New York 1984, - optically active oxirane ethers, such as, for example, in EP-A 0 263 437 and WO-A

93/13093, optically active oxirane esters, as described for example in EP-A 0 292 954, optically active dioxolane ethers, as described for example in EP-A 0 351 746, optically active dioxolane esters, as described for example in EP-A 0 361 272, optically active tetrahydrofuran-2-carboxylic acid esters, as described for example in EP-A 0 355 561, and - optically active 2-fluoroalkyl ethers, as for example in EP-A 0 237 007 and

U.S. 5,051,506.

Particularly preferred components of the liquid crystal are those from groups A to P: A. phenylazaaryl derivatives of the formula (II),

R ^I _A ¹ -A ² -R ² (II) wherein

R ¹ and R ² each alkyl with 1-15 C atoms, in which also one or two non-adjacent and non-terminal CH ₂ groups by -O-, -S-, -CO-, -O-CO-, -CO -O-, -O-CO-O-, -CO-S-, -S-CO-, -CHHalogen, -CHCN- and / or -CH = CH- can be replaced and in which one, several or all H- Atoms can be replaced by F,

A ¹ 1, 4-phenylene, trans-1, 4-cyclohexylene or a single bond,

A ²

und Z -O-CO-, -CO-O-, -S-CO-, -CO-S-, -CH₂O-, -OCH₂- oder -CH₂CH₂- bedeuten.

and Z is -O-CO-, -CO-O-, -S-CO-, -CO-S-, -CH ₂ O-, -OCH ₂ - or -CH ₂ CH ₂ -.

B. Compounds with only one side chain of the formula (III), R ¹ (-A ¹ ) _a (-M ¹ ) _b (-A ² ) _c (-M ² ) _d (-A ³ ) _e (-M ³ ) _f (-A ⁴ ) -H (III) in which mean:

R straight-chain or branched alkyl radical with 1 to 22 or 3 to 22 C atoms, one or two non-adjacent and non-terminal CH ₂ groups also being represented by -O-, -CO-, -CO-O-, -O- CO-, -O-CO-O- or -Si (CH ₃ ) ₂ - can be replaced,

A \ A ² , A ³ , A ^{4 the} same or different, 1, 4-phenylene, where one or two H atoms can be replaced by F or CN, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, (1,3,4) -thiadiazole-2,5-diyl or naphthalene-2,6-diyl,

M \ M ² , M ^{3 the} same or different, -CO-O-, -O-CO-, -CH ₂ -O-, -CH = N-, -O-CH ₂ -, -CH ₂ -CH ₂ - , a, b, c, d, e, f zero or one, provided that the sum of a + c + e is 0, 1, 2 or 3.

Metasubstituted compounds of the formula (IV),

R ¹ (-A ¹ ) _a (-M ¹ ) _b (-A ₂ ) _c (-M ² ) _d (-A ³ ) _e (-M ³ ) _f

(IV) in which:

R \ R ^{2 the} same or different, a straight chain or branched

Alkyl radical with 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO-O-, -O-CO-, -O -CO-O- or -Si (CH ₃ ) ₂ - can be replaced, A \ A ² , A ^{3 the} same or different, 1, 4-phenylene, one or two

H atoms can be replaced by F, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, it being possible for one or two H atoms to be replaced by -CN and / or -CH ₃ , (1, 3,4) -Thiadiazol- 2,5-diyl,

and A ¹ too

X5 6

M ¹ , M ² , M ^{3 are the} same or different, -O-, -CO-O-, -O-CO-, -CH ₂ -O-,

-O-CH ₂ -, -CH ₂ -CH ₂ -, -CH = N-, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ CH or N, where the Number of N atoms in one

Six ring is 0, 1 or 2, a, b, c, d, e, f are zero or one, provided that the

Sum of a + c + e is 0, 1, 2 or 3.

Silicon compounds of the formula (V),

R -A (-M (-A ² UM ² ) _m (-A -R ² (V) in which:

R ¹ straight-chain or branched alkyl having 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent and non-terminal CH ₂ groups by -O-, -CO-, -CO-O-, -O -CO- or

-O-CO-O- can be replaced, R ² straight-chain or branched alkyl having 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent CH2 groups also being replaced by -O-, -CO-, - CO-O-, -O-CO- or -O-CO-O- can be replaced, with the proviso that a CH ₂ - that is not bound to oxygen

Group is replaced by -Si (CH ₃ ) ₂ -, A ¹ , A ² , A ^3, identical or different, 1, 4-phenylene, one or two H-

Atoms can be replaced by F, trans-1, 4-cyclohexylene, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, Pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, (1, 3,4) thiadiazole-2,5-diyl, M \ M ² identical or different -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -, -CH = N-, i, k, I, m, n zero or 1, with the proviso that i + I + n = Is 2 or 3.

E. hydroquinone derivatives of the formula (VI),

(VI) where: R ² or R ^{2 are} identical or different straight-chain or branched alkyl radicals having 1 or 3 to 16, preferably 1 or 3 to 10, carbon atoms, one or two non-adjacent and non-terminal CH2 groups also being represented by - O-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, preferably -O-, -O-CO-, -CO-O-, can be replaced, R ³ -CH ₃ , CF ₃ or-C ₂ H ₅ , preferably -CH ₃ , CF ₃ ,

A \ A ^{2 the} same or different, 1,4-phenylene, trans-1,4-cyclohexylene, preferably 1,4-phenylene.

F. pyridylpyrimidines of formula (VII),

FROM

^{R 7} A = BY ^~ ^ CD ^R2

(VII) where:

A is N and B is CH or A is CH and B is N, C is N and D is CH or C is CH and D is N, it being possible for one or two CH groups to be replaced by CF groups, R \ R ^{2 the} same or different, a straight chain or branched

Alkyl radical with 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO-O-, -O-CO- or -O -CO-O- can be replaced.

G. phenylbenzoates of the formula (VIII),

R ¹ (-A) _a (-M ¹ ) _b (-A) _c (-M ² ) _d (-A) _e -R ² (VIII)

where: R \ R ^{2 are the} same or different, a straight-chain or branched

Alkyl radical with 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent and non-terminal CH2 groups by -O-, -CO -, - CO-O-, -O-CO- or -O -CO-O- can be replaced, A 1, 4-phenylene, M \ M ² identical or different, -CO-O-, -O-CO-, a, b, c, d, e zero or one, under the condition that a + c + e = 2 or 3 and b + d = 1 or 2.

H. Optically active phenylbenzoates of the formula (IX), R ⁱ ₍ . _A ) _a (-M ¹ ) _b (-A) _c (-M ² ) _d (-A) _e -R ² (IX)

where mean:

R ¹ , R ^{2 the} same or different, a straight-chain or branched

Alkyl radical with 1 to 22 or 3 to 22 carbon atoms, one or two non-adjacent and non-terminal CH2 groups also being represented by -O-,

-CO-, -CO-O-, -O-CO- or -O-CO-O- can be replaced, and wherein at least one of the radicals R \ R ^{2 is} a branched, optically active alkyl group, A 1, 4- Phenylene, M ¹ , M ² identical or different, -CO-O-, -O-CO- or a single bond a, b, c, d, e are zero or one, provided that the sum of a + c + e is 2 or 3 and b + d = 1 or 2.

Optically active oxirane ethers of the formula (X),

(X) where the symbols and indices have the following meaning: * a chiral center

R ^{1 is} a straight-chain or branched alkyl radical having 1 to 22 or 3 to 22 carbon atoms, with one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO-O-, -O -CO-, -O-CO-O- or -Si (CH ₃ ) ₂ - can be replaced, or the subsequent optically active group

R², R³, R⁴, R⁵, R⁶, R⁷ gleich oder verschieden, H oder ein geradkettiger oder verzweigter Alkylrest mit 1 bis 16 C-Atomen, P -CH₂- oder -CO- A¹, A², A³ sind gleich oder verschieden, 1 ,4-Phenylen, wobei ein oder zwei H-Atome durch F ersetzt sein können, Pyridin-2,5-diyI, wobei ein oder zwei H-Atome jeweils durch F ersetzt sein können, Pyrimidin-2,5- diyl, wobei ein oder zwei H-Atome durch F ersetzt sein können, trans- 1 ,4-Cyclohexylen, wobei ein oder zwei H-Atome durch -CN und/oder - CH₃ ersetzt sein können, (1 ,3,4)-Thiadiazol-2,5-diyl, M¹ , M² gleich oder verschieden, -CO-O-, -O-CO-, -CH₂-O-, -O-CH₂-, -CH₂-CH₂-, -CH=N-, a, b, c, d, e null oder eins. Die asymmetrischen C-Atome des Oxiranrings oder der Oxiranringe können gleich oder verschieden R oder S konfiguriert sein.

R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ^7, identical or different, H or a straight-chain or branched alkyl radical having 1 to 16 C atoms, P -CH ₂ - or -CO- A ¹ , A ² , A ³ are the same or different, 1, 4-phenylene, where one or two H atoms can be replaced by F, pyridine-2,5-diyI, where one or two H atoms can be replaced by F, pyrimidine -2,5- diyl, where one or two H atoms can be replaced by F, trans- 1, 4-cyclohexylene, where one or two H atoms can be replaced by -CN and / or - CH ₃ , (1 , 3,4) -Thiadiazol-2,5-diyl, M ¹ , M ² identical or different, -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -, - CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one. The asymmetric carbon atoms of the oxirane ring or rings can be configured in the same or different R or S configuration.

J. Optically active oxirane esters of the formula (XI),

O

R ¹ (-A ¹ ) _a (-M ¹ ) b (-A ² ) _c (-M ² ) _d (-A ³ ) _e -0 'R

^R 2 R ^, (XI) where the symbols and indices have the following meaning: * a chiral center

R ^{1 is} a straight-chain or branched alkyl radical having 1 to 22 or 3 to 22 carbon atoms, with one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO-O-, -O -CO-, -O-CO-O- or -Si (CH ₃ ) ₂ - can be replaced, R ² , R ³ , R ⁴ identical or different, H or a straight-chain or branched alkyl radical having 1 to 16 carbon atoms , A ¹ , A ² , A ^{3 the} same or different, 1, 4-phenylene, where one or two H atoms can be replaced by F, pyridine-2,5-diyl, one or two H atoms each being F may be replaced, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, where one or two H atoms are replaced by -CN and / or - CH ₃ can be (1, 3,4) -Thiadiazol-2,5-diyl,

M \ M ^{2 the} same or different, -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -,

-CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one.

The asymmetric carbon atoms of the oxirane ring can be configured in the same or different R or S configuration. K. Optically active dioxolane ethers of the formula (XII),

(XII) wobei die Symbole und Indizes folgende Bedeutung haben: ^* ein chirales Zentrum

(XII) where the symbols and indices have the following meaning: ^* a chiral center

R ^{1 is} a straight-chain or branched alkyl radical having 1 to 22 or 3 to 22 carbon atoms, with one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO-O-, -O -CO-, -O-CO-O- or -Si (CH ₃ ) ₂ - can be replaced, R ² , R ³ , R ⁴ identical or different H, a straight-chain or branched

Alkyl radical having 1 to 16 or 3 to 10 C atoms or an alkenyl radical having 2 to 16 C atoms, where R ² and R ³ together can also be - (CH ₂ ) ₅ -, A ¹ , A ² , A ³ identical or different, 1,4-phenylene, where one or two H atoms can be replaced by F, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, pyrimidine-2,5- diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, where one or two H atoms can be replaced by -CN and / or -CH ₃ , (1, 3,4) -Thiadiazol-2,5-diyl, M \ M ² identical or different, -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -,

-CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one.

Asymmetric carbon atoms of the dioxolane ring can be configured the same or differently, R or S. L. Optically active dioxolane esters of the formula (XIII),

(XIII) in which:

* a chiral center

R ¹ straight-chain or branched alkyl radical having 1 to 16 or 3 to 16 carbon atoms, where one or more non-adjacent and non-terminal CH ₂ groups by -O-, -CO-, -O-CO- or -CO-O - can be replaced

R ² , R ³ , R ^{4 are the} same or different, H or an alkyl or alkenyl radical having 1 to 10 or 2 to 10 C atoms, where R ² and R ³ together can also be - (CH ₂ ) ₅ -, A \ A ² , A ³ identical or different 1, 4-phenylene, where one or two H atoms can be replaced by F, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, Pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, where one or two H atoms can be replaced by -CN and / or -CH ₃ , ( 1, 3,4) -Thiadiazol-2,5-diyl, M \ M ² identical or different, -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -,

-CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one.

Asymmetric carbon atoms of the dioxolane ring can be configured the same or differently, R or S. M. 5-alkylthiophenecarboxylic acid ester of the formula (XIV),

(XIV) in which:

R \ R ² straight-chain or branched alkyl radical having 1 to 22 or 3 to 22 C atoms, where one or more non-adjacent -CH ₂ groups can be replaced by -O-, -O-CO- or -CO-O- , A ¹ , A ² , A ^{3 the} same or different 1, 4-phenylene, where one or two H atoms can be replaced by F, pyridine-2,5-diyl, where one or two H atoms can be replaced by F. can, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, where one or two H atoms can be replaced by -CN and / or -CH ₃ , (1, 3,4) -Thiadiazol-2,5-diyl, M \ M ² identical or different, -CO-O-, -O-CO-, -CH ₂ -O-, -O-CH ₂ - ,

-CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one.

N. Macrocyclic compounds of the formula (XV),

(XV) in which: n: 0, 1, Y: -CO- (t-butyl), -CO- (adamantyl), Q: O, NY.

Schiff bases of the formula (XVI), R ¹ (-A) _a (-M ¹ ) _b (-A) _c (-M ² ) _d (-A) _e -R ² (XVI) in which: R \ R ^{2 the} same or different, a straight chain or branched

Alkyl radical with 1 to 22 or 3 to 22 carbon atoms, with one or two non-adjacent and non-terminal CH2 groups by -O-, -CO -.- CO-O-, -O-CO- or -O -CO-O- can be replaced,

A 1, 4-phenylene, M \ M ² identical or different, -CO-O-, -O-CO-, -CH = N- with the proviso that at least one of the groups is -CH = N-, a, b, c, d, e zero or one, provided that a + c + e = 2 or 3 and b + d = 1 or 2.

4-cyanocyclohexyls of the formula (XVII),

CN

R (-A ¹ ) _a (- ¹ ) _b (-A ² ) _c (-M ² ) _d (-A ³ ) _e ^ ^ -R ²

(XVII) where:

R ¹ , R ^{2 are the} same or different, straight-chain or branched alkyl radical having 1 to 22 or 3 to 22 carbon atoms, and one or two non-adjacent and non-terminal CH2 groups by -O-, -CO-, -CO -O-, -O-CO- or -O-CO-O- can be replaced, and in which one or more H atoms can be replaced by F,

A \ A ² , A ^{3 the} same or different, 1, 4-phenylene, one or two

H atoms can be replaced by F, pyridine-2,5-diyl, where one or two H atoms can be replaced by F, pyrimidine-2,5-diyl, where one or two H atoms can be replaced by F. , trans-1, 4- Cyclohexylene, where one or two H atoms can be replaced by -CN and / or -CH ₃ , (1, 3,4) -Thiadiazol-2,5-diyl, M \ M ² identical or different, -CO-O -, -O-CO-, -CH ₂ -O-, -O-CH ₂ -, -CH ₂ -CH ₂ -, -CH = N-, a, b, c, d, e zero or one.

The liquid crystal components are produced by methods known per se to those skilled in the art, such as, for example, in Houben Weyl, methods of organic chemistry. Georg Thieme Verlag Stuttgart or the cited writings.

The mixture is prepared by methods known per se.

The higher molecular weight component used according to the invention is preferably a polymer. It can be both inorganic and, preferably, organic.

Suitable types of higher molecular weight compounds are, for example, polymethacrylates, polyacrylates or polystyrenes.

Such polymers are known and commercially available.

The liquid crystal layer according to the invention generally contains 0.01 to 25, preferably 0.05 to 10, particularly preferably 0.1 to 4, very particularly preferably 0.5 to 2,% by weight of one or more higher molecular weight components. In general 1 to 3, preferably 1, higher molecular weight component is used.

The liquid crystal layer is produced from high and low molecular weight components by methods known per se and familiar to the person skilled in the art. In a preferred variant, one or more substances are admixed in a first step of a low molecular weight liquid crystal mixture which, after the display has been filled, can be polymerized to the desired matrix in a second step. The components are, for example, monomers, and suitable initiators can also be present. This makes it easy to ensure that the liquid crystal can assume the structure suitable for operating the display, for example a surface-stabilized S _c ^* phase (SSFLC). The polymer can be produced, for example, by irradiation with electromagnetic radiation, preferably with a shorter wavelength than visible light, or by irradiation with ultrasound. The monomers themselves can also be liquid crystalline. It is contained in the mixture in a proportion of up to 25%, preferably a proportion less than 10%, very particularly preferably less than 4% and particularly preferably less than 2%.

The ferroelectric liquid crystal (FLC) display used according to the invention contains two carrier plates, these can be made of glass or, because of the flexibility, preferably plastic or one each made of glass and the other made of plastic. Suitable plastics are, for example, known plastics such as polyarylates, polyether sulfone, cycloolefin copolymers, polyetherimides, polycarbonate, polystyrene, polyesters, polymethyl methacrylates, and the like

Copolymers or blends. The inside of these carrier plates are provided with conductive transparent layers, as well as orientation layers and possibly other auxiliary layers, such as insulation layers.

Conventional orientation layers, such as obliquely vaporized SiO or, are suitable

Polymers, e.g. Polyimides, such as nylon-6,6, which have been subjected to a rubbing step.

The decisive factor for the electro-optical properties and storage properties of the display is the approx. 1-3 μm thick FLC layer, the layer thickness, is preferably determined by spacers. These spacers can be mixed-in particles, such as spheres, or structured columns inside the display.

The entire cell, usually closed with an adhesive frame, can be electrically, for example by soldering, bonding, pressing or the like. be contacted. The display is controlled with a voltage or voltage pulses by a suitable electronic circuit. The control is generally direct or as a multiplex control (see, for example, Jean Dijon in Liquid Crystals, Application and Uses (Ed. B. Bahadur) Vol. 1, 1990, Chapter 13, pp. 305-

360) or T. Harada, M. Taguchi, K. Iwasa, M. Kai SID 85 Digest, 131 (1985).

The electrode spacing is generally 1 to 3 μm, preferably at least 1.5 μm, particularly preferably at least 1.8 μm.

The production of the FLC display for the chip card according to the invention can thus basically follow known methods, as described, for example, by E. Lüder et al., 1997 International Symposium, Seminar & Exhibition, Society of Information Display, Boston, Massachusetts, Article 9.4, SID 97 DIGEST, pp. 109-1 12.

To produce a chip card, the FLC display is embedded or applied in or on a plastic card provided with one or more electronic microchips.

The microchips contain the program and / or memory functions which ensure the desired function of the chip card. Such chips and their manufacture are known to the person skilled in the art. The card also contains means for data exchange with an external write and / or read system, for example electrically conductive contacts or an "antenna" in the form of flat coils.

The card body is generally made of plastic, preferably

Polyvinyl chloride (PVC) or acrylic-butadiene-styrene copolymers (ABS) or Biopol® (a biodegradable plastic, from renewable resources, from Monsanto, USA).

The plastic cards used are known and the majority are commercially available (e.g. Gemplus, http://www.gemplus.fr).

Usual technical specifications for chip or smart cards according to the invention can be found, for example, in: ICC Card Specification for Payment Systems, Version 3 (1996) and the literature cited therein, in particular:

Europay, MasterCard, and Visa (EMV): June 30, 1996

Integrated Circuit Card Application Specification for Payment Systems

ISO / IEC 7813: 1990 Identification cards - Financial transaction cards

ISO 7816: 1987

Identification cards - Integrated circuit (s) cards with contacts

- Part 1: Physical characteristics ISO 7816-2: 1988 Identification cards - Integrated circuit (s) cards with contacts

- Part 2: Dimensions and location of contacts ISO / IEC 7816-3: 1989

Identification cards - Integrated circuit (s) cards with contacts

- Part 3: Electronic Signals and transmission protocols - ISO / IEC 7816-3: 1992 Identification cards - Integrated circuit (s) cards with contacts

- Part 3, Amendment 1: Protocol type T = 1, asynchronous half duplex block transmission protocol

ISO / IEC 7816-3: 1994 Identification cards - Integrated circuit (s) cards with contacts

- Part 3, Amendment 2: Protocol type selection (Draft International Standard) ISO / IEC 7816-4: 1995

Identification cards - Integrated circuit (s) cards with contacts

- Part 4, Inter-industry commands for interchange - ISO / IEC 7816-5: 1994

Identification cards - Integrated circuit (s) cards with contacts

- Part 5: Numbering System and registration procedure for application identifiers

ISO / IEC 7816-6: 1995 Identification cards - Integrated circuit (s) cards with contacts

- Part 6: Inter-industry data elements (Draft International Standard).

The chip card according to the invention is suitable, for example, for access control, as a check card, electronic ticket, telephone card, parking garage card, "electronic wallet" or for Pay TV.

Reference is expressly made to the references cited in this application; through quotation they are part of the description.

The invention is further illustrated by the following example, without wishing to restrict it thereby.

example

Display and chip card

A flexible plastic film (available, for example, from Sumitomo Bakelite, product name FST 5352, thickness 100 μm, 200 Ω / indium tin oxide coated) is patterned in a photolithographic process so that an electrode pattern is obtained. The transparent conductor tracks of this electrode structure are used for the electrical control of the display. The substrates are coated with an orientation layer and rubbed with a roller. Two such structured foils, the top and bottom of the display - that is

Support plates - form, are put together with the help of an adhesive frame and with a commercial ferroelectric liquid crystal mixture (®Felix M-4851, Hoechst Aktiengesellschaft, Frankfurt, Germany), in which 1, 0 wt .-% methyl methacrylate were dissolved, with the addition of a concentration of 0 , 5% by weight spacer balls with a diameter of 2 μm. The adhesive is hardened by careful heating, the cell is sealed, and the liquid crystal mixture is oriented by slowly cooling down to the operating temperature. The polymerization is then carried out by irradiation with UV light, the temperature being kept constant so as not to impair the smectic layer structure. The contacts of the electrodes of the switch cell which are led outwards are connected to the corresponding contacts or flat coils of the "chip card". When a voltage of 10 V is applied, this cell can be operated at 25 ° C.

Claims

Claims: 1. Chip card containing a ferroelectric liquid crystal display with a ferroelectric liquid crystal layer, characterized in that the liquid crystal layer contains one or more higher molecular weight components which do not form a ferroelectric liquid crystal phase itself. 2. Chip card according to claim 1, characterized in that it is a smart card. 3. Chip card according to claim 1 or 2, characterized in that it contains 0.1 to 25 wt .-%, based on the liquid crystal layer, of one or more higher molecular weight components. 4. Chip card according to one or more of the preceding claims, characterized in that the higher molecular weight component is a polymer. 5. Chip card according to claim 4, characterized in that the polymer is a polyacrylate, polymethylacrylate or polystyrene. 6. A method for producing a chip card according to one or more of claims 1 to 5, characterized in that a ferroelectric liquid crystal display with a ferroelectric liquid crystal layer containing one or more higher molecular components, which do not form ferroelectric phases, is embedded in or on a plastic card or introduces, wherein the plastic card contains an integrated circuit, which can store and / or edit information electronically, and means for information transfer between the card and an electronic reading and / or writing system. 7. The method according to claim 6 for the production of a smart card. 8. Use of a ferrolectric liquid crystal display with a ferroelectric liquid crystal layer containing one or more higher molecular weight components which are not themselves ferroelectric Form liquid crystal phase for the production of chip cards with permanent bistable display. 9. A method for improving the flexural strength of chip cards with a permanent bistable display, characterized in that a ferroelectric liquid crystal display is used as the display, the liquid crystal layer of which contains one or more higher molecular weight components which do not themselves form a ferroelectric phase. 10. Use of a chip card, according to one or more of claims 1 to 5, for access control, as a check card, electronic ticket, telephone card, parking garage card, "electronic wallet" or for Pay TV.