Liquid crystal composition, liquid crystal device using the composition, liquid crystal apparatus and display method

• US 5,948,317 A
• Filed: 11/14/1997
• Issued: 09/07/1999
• Est. Priority Date: 04/14/1994
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nakamura, Katsutoshi, Nakamura, Shinichi, Sato, Koichi, Kitayama, Hiroyuki, Shinjo, Kenji
• Primary Examiner(s): Lovering, Richard D.
• Application Number:
  US08/971,163
• Time in Patent Office: 662 Days
• Field of Search: 252/299.01, 252/299.4, 252/299.61, 252/299.67
• US Class Current: 252/299.61
• CPC Class Codes: C09K 19/04 characterised by the chemical structure of the liquid crystal components , e.g. by a specific unit
• CPC Class Codes: C09K 19/3469 Pyrimidine with a specific end-group other than alkyl, alkoxy or -C*-
• CPC Class Codes: C09K 19/42 Mixtures of liquid crystal compounds covered by two or more of the preceding groups C09K19/06 - C09K19/40
• CPC Class Codes: C09K 19/588 Heterocyclic compounds
• CPC Class Codes: C09K 2019/044 the specific unit being a perfluoro chain used as an end group
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide

Abstract

A liquid crystal composition includes at least one fluorine-containing mesomorphic compound (a) having a fluorocarbon terminal portion and a hydrocarbon terminal portion, and at least one optically active compound (b) having an optically active cyclic group and a terminal alkyl group free from a perfluorocarbon atom. The compound (a) and the compound (b) are mutually soluble readily to form a homogeneous liquid crystal composition. The liquid crystal composition shows a layer structure of so-called bookshelf or a layer structure having a small inclination angle (closer to bookshelf structure). The liquid crystal composition is useful in improving response characteristics and display characteristics, particularly a contrast ratio, of a liquid crystal device using the liquid crystal composition.

Claims

1. A liquid crystal composition, comprising:

(I) at least one fluorine-containing mesomorphic compound (a) having smectic phase or having latent smectic phase, wherein the compound (a) is represented by the following formula (I);

##STR67## in which B₁, D₁ and F₁ independently denote ##STR68## a, b and c independently denote an integer of 0-3 with the proviso that a+b+c is at least 2;

M₁ and N₁ independently denote --COO--, --OCO--, --COS--, --SCO--, --COSe--, --SeCO--, --COTe--, --TeCO--, --CH₂ CH₂ --, --CH═

CH--, --C.tbd.C--, --CH═

N--, --N═

CH--, --CH₂ O--, --OCH₂ --, --CO--, --O-- or a single bond;

X, Y and Z independently denote --H, --Cl, --F, --Br, --I, --OH, --OCH₃, --CN or --NO₂ and l, m and n independently denote an integer of 0-4;

G₁ is --COO--C_e H_2e --, --O--C_e H_2e --, --C_e H_2e --, --OSOO--, --OOSO--, --OOSO-- --SOOC_e H_2e --, --OC_e H_2e --OC_e'"'"' H_2e'"'"' --, --C_e H_2e --N(C_p H_2p+1)--SO₂ --, --C_e H_2e --N(C_p H_2p+1)--CO-- wherein e and e'"'"' independently denote an integer of 1-20 and p is an integer of 0-4;

A₁ is a linear or branched group represented by --O--C_f H_2f --O--C_g H_2g+1, --C_f H_2f --O--C_g H_2g+1, --C_f H_2f --R'"'"', --O--C_f H_2f --R'"'"', --COO--C_f H_2f --R'"'"', --OCO--C_f H_2f --R'"'"' wherein R'"'"' is --Cl, --F, --CF₃, --NO₂, --CN, --H, --COO--C_f'"'"' H_2f'"'"'+1 or --OCO--C_f'"'"' H_2f'"'"'+1 in which f'"'"' is an integer of 1-20, and f and g independently denote an integer of 1-20; and

R is --C_x F_2x+1 or .paren open-st.C_x'"'"' F_2x'"'"' O.paren close-st._z C_y F_2y+1 wherein x is an integer of 1-20, x'"'"' is independently an integer of 1-10 for each C_x'"'"' F_2x'"'"' O group, y is an integer of 1-10, and z is an integer of 1-6; and

(II) at least one optically active compound (b), wherein the compound (b) is represented by the following formula (II);

##STR69## in which D₂, I₂ and K₂ independently denote a group having an aromatic ring, a group having a heteroaromatic ring, an alicyclic group, a group have a fused ring comprising these rings, or a group formed by connecting these rings, each of these rings being optionally substituted with an appropriate group;

B₂,G₂, J₂ and L₂ independently denote a single bond, --O--, --COO--, --OCO--, --C.tbd.C--, --CONR₂ --, --NR₂ CO--, --NR₂, --CH₂ --, --CH═

N--, --N═

CH--, --CH═

CH--, --COS--, --SCO--, --(CH₂)_n3 --, --CH₂ O-- or --OCH₂ -- wherein R₂ is an alkyl group having 1-5 carbon atoms and n3 is an integer of 1-20;

A₂ and N₂ independently denote hydrogen or linear or branched alkyl group capable of including at least one --CH₂ -- group which can be replaced by --Y₁ --, --Y₁ CO--, --COY₁ --, --CO--, --OCOO--, --CH═

CH-- or --C.tbd.C-- wherein Y, is O or S;

h and i are independently 0, 1 or 2; and

M₂ is a divalent group having 3 to 7 membered ring comprising carbon atom, oxygen atom or nitrogen atom each of which has sp hybrid orbital, Sp² hybrid orbital or Sp³ hybrid orbital and can be substituted with hydrogen or other elements, the ring having at least one asymmetric carbon atom.

2. A composition according to claim 1, wherein the fluorocarbon terminal portion of the compound (a) is --DC_x F_2x+1 or --D(C_x'"'"' F_2x'"'"'+1 O)_z C_y F_2y+1 in which

x is 1-20;

x'"'"' is independently 1-10 for each C_x'"'"' F_2x'"'"'+1 O group;

y is 1-10;

z is 1-10; and

D is a single bond, --COO--C_r H_2r --, --OC_r H_2r --, --OC_r H_2r O--C_r'"'"' H_2r'"'"' --, --OSO₂ --, --SO₂ --, --SO₂ --C_r H_2r --, --C_r H_2r --N(C_p H_2p+1)--SO₂ --, or --C_r H_2r --N(C_p H_2p+1)--CO-- wherein r and r'"'"' are independently 1-20, and p is 0-4.

3. A composition according to claim 1, wherein R in the formula (I) is .paren open-st.C_x'"'"' F_2x'"'"' O.paren close-st._z C_y F_2y+1 in which x'"'"', y and z have the same meanings as defined in claim 1.

4. A composition according to claim 1, wherein the compound (a) of the formula (I) is a fluorine-containing mesomorphic compound represented by the following formula (I'"'"'):

##STR70## in which n2 is an integer of 5-10; and

R" is --C_x F_2x+1 or .paren open-st.C_x" F_2x" O.paren close-st._z'"'"' C_y'"'"' F_2y'"'"'+1 wherein x is an integer of 1-20, x" is independently an integer of 1-3 for each C_x" F_2x" O group, y'"'"' is an integer of 1-4, and z'"'"' is an integer of 1-3.

5. A composition according to claim 1, wherein the compound (b) of the formula (II) is an optically active compound represented by the following formula (III):

##STR71## in which R₃ is hydrogen, --CN, or a linear or branched alkyl group having 1-20 carbon atoms, and R₄ is a linear or branched alkyl group having 1-18 carbon atoms, each alkyl groups of R₃ and R₄ being capable of including at least one --CH₂ -- group which can be replaced by --O--, --S--, --CO--, --CH(CN)--, --CH═

CH--, --C.tbd.C, --COO-- or --OCO-- with the proviso that heteroatoms are not connected with each other;

A₅ is 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ or CN;

pyridine-2,5-diyl;

pyrimidine-2,5-diyl;

pyrazine-2,5-diyl;

pyridazine-3,6-diyl;

1,4-cyclohexylene;

1,3-dioxane-2,5-diyl;

1,3-dithiane-2,5-diyl;

thiophene-2,5-diyl, thiazole-2,5-diyl;

thiadizaole-2,5-diyl;

benzoxazole-2,5-diyl;

benzoxazole-2,6-diyl;

benzothiazole-2,5-diyl;

benzothiazole-2,6-diyl;

benzofuran-2,5-diyl;

benzofuran-2,6-diyl;

quinoxaline-2,6-diyl;

quinoline-2,6-diyl;

2,6-naphthylene;

indan-2,5-diyl;

2-alkylindan-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atoms;

indanone-2,6-diyl;

2-alkylindanone-2,6-diyl having a linear or branched alkyl group having 1-18 carbon atoms;

coumaran-2,5-diyl;

or 2-alkylcourmaran-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atoms;

A₃, A₃ '"'"' and A₄ independently denote a single bond or a group selected from those for A₅ independently of A₅ ;

X₃ is a single bond, --COO--, --OCO--, --CH₂ O--, --OCH₂ --, --CH₂ CH₂ --, --CH═

CH-- or --C.tbd.C--;

n3 is an integer of 1-20; and

L is optically active butanolide-2,4-diyl;

optically active 4-alkylbutanolide-2,4-diyl having a linear or branched alkyl group having 1-5 carbon atoms;

or optically active 2-alkylbutanolide-2,4-diyl having a linear or branched alkyl group having 1-5 carbon atoms.

6. A composition according to claim 5, wherein the optically active compound of the formula (III) satisfies any one of the following conditions (IIIa), (IIIb) and (IIIc):

(IIIa) A₃ and A₄ are independently selected from the group consisting of a single bond;

1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

pyridine-2,5-diyl;

pyrimidine-2,5-diyl;

pyrazine-2,5-diyl;

pyridazine-3,6-diyl;

1,4-cyclohexylene;

thiophene-2,5-diyl, thiazole-2,5-diyl;

thiadiazole-2,5-diyl;

benzoxazole-2,6-diyl;

benzothiazole-2,5-diyl;

benzothiazole-2,6-diyl;

benzofuran-2,5-diyl;

benzofuran-2,6-diyl;

quinoxaline-2,6-diyl;

quinoline-2,6-diyl;

2,6-naphthylene;

indan-2,5-diyl; and

coumaran-2,5-diyl; and

A₅ is 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

(IIIb) X₃ is A single bond;

A₄ is pyridine-2,5-diyl;

pyrimidine-2,5-diyl;

1,4-cyclohexylene;

thiophene-2,5-diyl;

thiazole-2,5-diyl;

thiadiazole-2,5-diyl;

benzothiazole-2,6-diyl;

quinoxaline-2,6-diyl;

quinoline-2,6-diyl;

2,6-naphthylene;

or indan-2,5-diyl; and

A₃ is 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN; and

(IIIc) A₃ and X₃ are a single bond;

A₄ is pyrimidine-2,5-diyl or indan-2,5-diyl; and

A₅ is 1,4-phenylene.

7. A composition according to claim 1, wherein the compound (b) of the formula (II) is an optically active compound represented by the following formula (IV);

##STR72## in which R₅ is a linear or branched alkyl group having 1-18 carbon atoms;

A₆ and A₉ independently denote 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

1,4-cyclohexylene;

pyrimidine-2,5-diyl;

pyridine-2,5-diyl;

thiadiazole-2,5-diyl;

thiazole-2,5-diyl;

thiophene-2,5-diyl;

or 2,6-naphthylene;

A₇ and A₈ independently denote a single bond or any one of the groups for A₆ and A₉ ;

B₇ is benzoxazole-2,6-diyl, benzothiazole-2,5-diyl or benzothiazole-2,6-diyl;

X₅ and X₆ independently denote a single bond, --COO--, --OCO--, --CH₂ O-- or --OCH₂ --;

m5 and n5 are independently 0 or 1; and

* denotes an optically active center.

8. A composition according to claim 1, wherein the compound (b) of the formula (II) is an optically active compound represented by the following formula (IV'"'"');

##STR73## in which R₆ is a linear or branched alkyl group having 1-18 carbon atoms;

A₁₁ is 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

1,4-cyclohexylene;

pyrimidine-2,5-diyl;

pyridine-2,5-diyl;

thiadiazole-2,5-diyl;

benzothiazole-2,6-diyl;

thiophene-2,5-diyl;

or 2,6-naphthylene;

A₁₀ is a single bond or any one of the groups for A₁₁ ;

X₇ is a single bond, --COO--, --OCO--, --CH₂ O-- or --OCH₂ --; and

* denotes an optically active center.

9. A composition according to claim 1, wherein the compound (b) of the formula (II) is an optically active compound represented by the following formula (V):

##STR74## in which R₇, R₈ and R₉ independently denote hydrogen, or a linear or branched alkyl group having 1-18 carbon atoms;

A₁₂ and A₁₃ independently denote 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

1,4-cycloyhexylene;

pyrimidine-2,5-diyl;

pyridine-2,5-diyl;

thiadiazole-2,5-diyl;

thiazole-2,5-diyl;

thiophene-2,5-diyl;

or 2,6-naphthylene;

X₈ and X₉ independently denote a single bond, --COO--, --OCO--, --CH₂ O-- or --OCH₂ --;

* denotes an optically active center; and

either one of Y₇ and Y₈ is --CO-- and the other is --O--.

10. A composition according to claim 1, wherein the compound (b) of the formula (II) is an optically active compound represented by the following formula (VI);

##STR75## in which R₁₀ is hydrogen or linear or branched alkyl group having 1-18 carbon atom capable of including at least one --CH₂ -- group which can be replaced by --Y₂ --, --Y₂ CO--, --COY₂ --, --CO--, --OCOO--, --CH═

CH-- or --C.tbd.C-- wherein Y₂ is O or S;

R₁₁ is hydrogen, a linear or branched alkyl group having 1-18 carbon atoms or a trialkylsilyl group independently having a linear or branched alkyl group having 1-10 carbon atoms, alkyl group of R₁₁ being capable of including at least one --CH₂ -- group which can be replaced by --Y₃ --, --Y₃ CO--, --COY₃ --, --CO--, --OCOO--, --CH═

CH-- or --C.tbd.C-- wherein Y₃ is O or S;

A₁₄ and A₁₅ independently denote 1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

1,4-cyclohexylene;

pyrimidine-2,5-diyl;

pyridine-2,5-diyl;

thiadiazole-2,5-diyl;

thiazole-2,5-diyl;

thiophene-2,5-diyl;

or 2,6-naphthylene;

X₁₀ and X₁₁ independently denote a single bond, --COO--, --OCO--, --CH₂ O-- or --OCH₂ --;

either one of Y₉ and Y₁₀ is ##STR76## and the other is --O--; and

* denotes an optically active center.

11. A composition according to claim 1, the compound (b) of the formula (II) is an optically active compound represented by the following formula (VII):

##STR77## in which R₁₂ and R₁₃ independently denote hydrogen, or a linear or branched alkyl group having 1-18 carbon atoms capable of including at least one --CH₂ -- group which can be replaced by --Y₄ --, --Y₄ CO--, --COY₄ --, --CO--, --OCOO--, --CH═

CH-- or --C.tbd.C-- wherein Y₄ is O or S;

A₁₆, A₁₇ and A₁₈ independently denote a single bond;

1,4-phenylene capable of having one or two substituents comprising F, Cl, Br, CH₃, CF₃ and/or CN;

pyridine-2,5-diyl;

pyrimidine-2,5-diyl;

pyrazine-2,5-diyl;

pyridazine-3,6-diyl;

1,4-cyclohexylene;

1,3-dioxane-2,5-diyl;

1,3-dithiane-2,5-diyl;

thiophene-2,5-diyl, thiazole-2,5-diyl;

thiadiazole-2,5-diyl;

benzoxazole-2,6-diyl;

benzothiazole-2,5-diyl;

benzothiazole-2,6-diyl;

benzofuran-2,5-diyl;

benzofuran-2,6-diyl;

quinoxaline-2,6-diyl;

quinoline-2,6-diyl;

2,6-naphthylene;

indan-2,5-diyl;

2-alkylindan-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atom;

indanone-2,6-diyl;

2-alkylindanone-2,6-diyl having a linear or branched alkyl group having 1-18 carbon atoms;

coumaran-2,5-diyl;

or 2-alkylcoumaran-2,5-diyl having a linear or branched alkyl group having 1-18 carbon atoms;

X₁₂ is a single bond, --O--, --COO--, --OCO--, ##STR78## --C.tbd.C--, --CONR₁₄ --, --NR₁₄ CO--, --NR₁₄ --, --CH═

N--, --N═

CH--, --CH═

CH--, --COS-- or --SCO-- wherein R₁₄ is an alkyl group having 1-5 carbon atoms, and n7 is an integer of 1-10;

X₁₃ is a single bond or an alkylene group having 1-6 carbon atoms;

m7 is 0, 1 or 2; and

* denotes an optically active center.

12. A composition according to claim 1, which comprises at least 20 wt. % of a fluorine-containing mesomorphic compound (a).

13. A composition according to claim 1, which comprises at least 30 wt. % of a fluorine-containing mesomorphic compound (a).

14. A composition according to claim 1, which comprises at least 50 wt. % of a fluorine-containing mesomorphic compound (a).

15. A composition according to claim 1, which has a chiral smectic phase.

16. A liquid crystal device, comprising a liquid crystal composition according to claim 1.

17. A device according to claim 16, comprising a pair of opposite electrode plates and the liquid crystal composition disposed between the electrode plates.

18. A device according to claim 17, which further comprises an alignment control layer.

19. A device according to claim 18, wherein the alignment control layer comprises a polyimide film which has been subjected to uniaxial alignment treatment, said polyimide having a recurring unit represented by the following formula (VIII):

##STR79## in which R₈₁ is ##STR80## R₈₂ and R₈₄ independently denote ##STR81## R₈₃ is a single bond or --O--; and

r8 is 0, 1 or 2.

20. A device according to claim 18, wherein the alignment control layer comprises a polyamide film which has been subjected to uniaxial alignment treatment, said polyamide having a recurring unit represented by the following formula (IX):

##STR82## in which R₉₁ is an alkylene group having 1-20 carbon atoms, ##STR83## R₉₂ and R₉₆ are independently --CONH-- or --NHCO--;

R₉₃ and R₉₅ are independently ##STR84## or an alkylene group having 1-20 carbon atoms;

R₉₄ is a single bond or --O--; and

r9 is 0, 1 or 2.

21. A device according to claim 18, wherein each of the pair of electrode plates is provided with an alignment control layer, at least one of which comprises a polyimide film.

22. A liquid crystal apparatus comprising a liquid crystal device according to claim 16 and drive means for said liquid crystal device.

23. An apparatus according to claim 22, wherein the liquid crystal device is a display device.

24. A display method, comprising:

providing a liquid crystal composition according to claim 1; and

controlling the alignment direction of liquid crystal molecules in accordance with image data to effect display.