U.S. patent application number 10/274152 was filed with the patent office on 2003-06-05 for chemical adsorbent and liquid crystal alignment layer utilizing the same and liquid crystal display device utilizing the same and methods of manufacturing them.
This patent application is currently assigned to Matsushita Electric Industrial Co., Ltd.. Invention is credited to Nomura, Takaiki, Ogawa, Kazufumi, Ohtake, Tadashi.
Application Number | 20030104145 10/274152 |
Document ID | / |
Family ID | 27476281 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030104145 |
Kind Code |
A1 |
Ogawa, Kazufumi ; et
al. |
June 5, 2003 |
Chemical adsorbent and liquid crystal alignment layer utilizing the
same and liquid crystal display device utilizing the same and
methods of manufacturing them
Abstract
The present invention provides a new chemical adsorbent which
can form an extremely thin and transparent film in nanometer order
which is fixed uniformly and firmly on a substrate, and give an
alignment characteristic of high thermal stability to the thin
film; as well as a liquid crystal alignment layer and a liquid
crystal display device having a desirable alignment characteristic,
a superior alignment control force over a liquid crystal molecule,
and a superior thermal stability by using the above-mentioned
chemical adsorbent. This purpose can be actualized by developing a
new compound which is transparent and stable in a range of a
visible ray (a wavelength from 400 nm to 700 nm), and has a
photosensitivity in a range of an ultraviolet ray and a
far-ultraviolet ray (a wavelength from 200 nm to 400 nm), and can
form a thin film in a monolayer through a chemisorption on a
substrate.
Inventors: |
Ogawa, Kazufumi; (Nara-shi,
JP) ; Ohtake, Tadashi; (Neyagawa-shi, JP) ;
Nomura, Takaiki; (Osaka-shi, JP) |
Correspondence
Address: |
PARKHURST & WENDEL, L.L.P.
1421 PRINCE STREET
SUITE 210
ALEXANDRIA
VA
22314-2805
US
|
Assignee: |
Matsushita Electric Industrial Co.,
Ltd.
Kadoma-shi
JP
|
Family ID: |
27476281 |
Appl. No.: |
10/274152 |
Filed: |
October 21, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10274152 |
Oct 21, 2002 |
|
|
|
09269636 |
May 18, 1999 |
|
|
|
6495221 |
|
|
|
|
Current U.S.
Class: |
428/1.23 ;
252/299.4; 349/124; 556/471; 556/473; 556/484 |
Current CPC
Class: |
G02F 1/133719 20130101;
C09K 2323/023 20200801 |
Class at
Publication: |
428/1.23 ;
252/299.4; 349/124; 556/471; 556/473; 556/484 |
International
Class: |
C09K 019/56; G02F
001/1337; C07F 007/08; C07F 007/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 1997 |
JP |
9-205937 |
Jul 31, 1997 |
JP |
9-205938 |
Oct 23, 1997 |
JP |
9-291307 |
Oct 23, 1997 |
JP |
9-291308 |
Claims
What is claimed is:
1. A chemical adsorbent consisting of a compound comprising: a
group of --CR.sup.1.dbd.CR.sup.2--CO--; and a functional group
having Si in its chemical structure; wherein: each of R.sup.1 and
R.sup.2 is a hydrogen, an alkyl group having 1 to 3 C or an alkoxy
group having 1 to 3 C.
2. A chemical adsorbent according to claim 1, said chemical
adsorbent being a compound represented by the following Chemical
Formula 1, wherein: R is an alkyl group having 1 to 14 C or a
phenyl group; n is an integer of 1 to 14 inclusive; X is a halogen,
an alkoxyl group or an isocyanato group; A is a functional group;
and m is an integer of 1 to 3 inclusive. 57
3. A chemical adsorbent according to claim 1, said chemical
adsorbent being a compound represented by the following Chemical
Formula 2, wherein: R is an alkyl group having 1 to 14 C or a
phenyl group; n is an integer of 1 to 14 inclusive; X is a halogen,
an alkoxyl group or an isocyanato group; A is a functional group;
and m is an integer of 1 to 3 inclusive. 58
4. A chemical adsorbent according to claim 1, said chemical
adsorbent being a compound represented by the following Chemical
Formula 3, wherein: n is an integer of 1 to 14 inclusive; R is an
alkyl group having 1 to 14 C or a phenyl group; X is a halogen, an
alkoxyl group or an isocyanato group; A is a functional group
bonded to Si; and m is an integer of 1 to 3 inclusive. 59
5. A chemical adsorbent according to claim 1, said chemical
adsorbent being a compound represented by the following Chemical
Formula 4, wherein: R is an alkyl group having 1 to 14 C or a
phenyl group; n is an integer of 1 to 14 inclusive; X is a halogen,
an alkoxyl group or an isocyanato group; A is a functional group;
and m is an integer of 1, 2. 60
6. A liquid crystal alignment layer wherein: a liquid crystal
molecule can be aligned in a particular direction; a chemical
adsorbent comprising a group of --CR.sup.1.dbd.CR.sup.2--CO-- and a
functional group having Si in its chemical structure is bonded and
fixed directly or with an interposition of a different substance
layer on a substrate surface through Si; and an adjacent component
molecule is crosslinked to each other through at least one bond of
a double bond C.dbd.C in the group of
--CR.sup.1.dbd.CR.sup.2--CO--.
7. A liquid crystal alignment layer according to claim 6, said
liquid crystal alignment layer being composed of a compound
comprising a chemical bond unit represented by the following
Chemical Formula 5, wherein: n is an integer of 1 to 14 inclusive.
61
8. A liquid crystal alignment layer according to claim 6, said
liquid crystal alignment layer being composed of a compound
comprising a chemical bond unit represented by the following
Chemical Formula 6, wherein: n is an integer of 1 to 14 inclusive;
and R is an alkyl group having 1 to 14 C or a phenyl group. 62
9. A liquid crystal alignment layer according to claim 6, said
liquid crystal alignment layer being composed of a compound
comprising a chemical bond unit represented by the following
Chemical Formula 7, wherein: n is an integer of 1 to 14 inclusive.
63
10. A liquid crystal alignment layer according to claim 6, said
liquid crystal alignment layer being composed of a compound
comprising a chemical bond unit represented by the following
Chemical Formula 8, wherein: n is an integer of 1 to 14 inclusive.
64
11. A method of manufacturing a liquid crystal alignment layer
comprising the steps of: producing a chemisorption solution by
dissolving a silane-based chemical adsorbent comprising a group of
--CR.sup.1.dbd.CR.sup.2--CO-- and a functional group having Si in a
nonaqueous solvent; forming a thin film in a monolayer which is
made of said silane-based chemical adsorbent on a substrate plane
by contacting said silane-based chemisorption solution on the
substrate plane, and chemisorbing it; and photopolymerizing an
adsorbent molecule to each other at a double bond of C.dbd.C in the
group of --CR.sup.1.dbd.CR.sup.2- --CO-- by irradiating an
ultraviolet ray or a far-ultraviolet ray on said thin film
plane.
12. A method of manufacturing a liquid crystal alignment layer
according to claim 11, comprising the step of: treating a
provisional alignment of a molecule composing a thin film by
drain-drying a nonaqueous solvent in a certain direction after
contacting said nonaqueous solvent on the thin film plane, between
said steps of forming a thin film and photopolymerizing.
13. A method of manufacturing a liquid crystal alignment layer
according to claim 11, comprising the steps of: washing a thin film
plane with a solvent to remove a chemical adsorbent which is not
yet adsorbed; and having a different molecular length from said
first silane-based chemical adsorbent are mixed at a predetermined
ratio, is used in said step of producing a chemisorption
solution.
17. A method of manufacturing a liquid crystal alignment layer
according to claim 16, comprising the step of: treating a
provisional alignment of a molecule composing a thin film by
drain-drying an nonaqueous solvent in a certain direction after
contacting said solvent on the thin film plane, between said steps
of forming a thin film and photopolymerizing.
18. A method of manufacturing a liquid crystal alignment layer
according to claim 16, comprising the steps of: washing a thin film
plane with a solvent to remove a chemical adsorbent which is not
yet adsorbed; and aligning provisionally an alignment direction of
a molecule of a silane-based chemical adsorbent which is
chemisorbed on a substrate plane by drain-drying the solvent
remaining on the substrate plane while setting up the substrate
through washing in a certain direction, between said steps of
forming a thin film and photopolymerizing.
19. A method of manufacturing a liquid crystal alignment layer
according to claim 16, wherein: an irradiation of an ultraviolet
ray or a far-ultraviolet ray in said step of photopolymerizing is
executed through a polarizer, a transparent plate having a
multitude of grooves of 0.1 to 0.3 .mu.m in width on its surface or
a transparent plate on which a rubbing is executed.
20. A method of manufacturing a liquid crystal alignment layer
according to claim 16, wherein: an irradiation of an ultraviolet
ray or a far-ultraviolet ray in said step of photopolymerizing is
executed through a patterned mask which is put further on a
polarizer a transparent plate having a multitude of grooves of 0.1
to 0.3 .mu.m in width on its surface or a transparent plate on
which a rubbing is executed; and an alignment direction of an
adsorbent molecule is changed in each patterned small section by
controlling a direction of a chemical bond between chemisorbed
molecules.
21. A liquid crystal display device comprising: at least, two
opposite substrates with an electrode on an inside plane; a liquid
crystal alignment layer which is formed on an inside plane of at
least one of said opposite substrates; and a liquid crystal which
is received into a gap between said opposite substrates; wherein:
said liquid crystal alignment layer is a thin film in a monolayer
which is formed by chemisorbing a chemical adsorbent directly or
through a different substance layer on said substrate plane; and an
adsorbent molecule is crosslinked to each other along a particular
direction.
22. A liquid crystal display device according to claim 21, wherein:
said chemical adsorbent comprises a group of
--CR.sup.1.dbd.CR.sup.2--CO-- and a functional group having Si; and
said adsorbent molecule is crosslinked to each other at a double
bond of C.dbd.C in the group of --CR.sup.1.dbd.CR.sup.2--CO--.
23. A liquid crystal display device according to claim 22, wherein:
said liquid crystal alignment layer has a different liquid crystal
alignment control direction at each of a plurality of small
patterned sections into which a pixel unit is divided.
24. A method of manufacturing a liquid crystal display device
comprising the steps of: producing a chemisorption solution by
dissolving a silane-based chemical adsorbent comprising a carbon
chain as well as a group of --CR.sup.1.dbd.CR.sup.2--CO-- and a
functional group having Si at an end of or inside said carbon chain
in a nonaqueous solvent; forming a thin film in a monolayer by
contacting said chemisorption solution on a first substrate with at
least a group of electrodes in a matrix, and chemisorbing the
chemical adsorbent on said substrate plane through Si; aligning an
adsorbent molecule in a drain direction provisionally by
drain-drying a nonaqueous solvent for washing while setting up said
substrate in a certain direction after washing said thin film with
the nonaqueous solvent; providing an alignment characteristic by
means of producing the first substrate with a liquid crystal
alignment layer having a particular alignment characteristic by
irradiating an ultraviolet ray or a far-ultraviolet ray on the
provisionally aligned thin film, and crosslinking the adsorbent
molecule to each other in a particular direction through a
photopolymerization; producing an empty cell by sticking and fixing
a periphery of the substrates after joining through the electrode
plane with a predetermined gap said first substrate with a liquid
crystal alignment layer as well as an opposite substrate or a
second substrate with a liquid crystal alignment layer having an
opposite electrode, which is produced like said first substrate
with a liquid crystal alignment layer; and injecting a liquid
crystal into said empty cell.
25. A method of manufacturing a liquid crystal display device
according to claim 24, wherein: a crosslinking direction of an
adsorbent molecule is controlled by exposing through a patterned
mask which is put on a polarizer in irradiating an ultraviolet ray
or a far-ultraviolet ray in said step of providing an alignment
characteristic; and a controlled direction of a liquid crystal
alignment is changed at each of a plurality of small patterned
sections into which a pixel unit is divided.
26. A chemical adsorbent consisting of a 4'-substitution chalcone
derivative represented by the following Chemical Formula 2-1. 65R
is an alkyl group having 1 to 3 C or an alkoxy group having 1 to 3
C, p is an integer of 0 to 2 inclusive and A is a bifunctional
group.
27. A chemical adsorbent according to claim 26, wherein: A in said
Chemical Formula 2-1 is a group of --(CH.sub.2).sub.n-- (n is an
integer of 3 to 14 inclusive).
28. A method of manufacturing a chemical adsorbent comprising: a
first step of synthesizing a substance represented by the following
Chemical Formula 2-4 by coupling a 4'-hydroxychalcone represented
by the following Chemical Formula 2-2 and a compound represented by
the following Chemical Formula 2-3; and a second step of
synthesizing a 4'-substitution chalcone derivative represented by
the following Chemical Formula 2-5 by causing a reaction of
eliminating a hydrochloric acid with a substance represented by
said Chemical Formula 2-4 and a silicon tetrachloride in an
atmosphere of an inert gas. 66Hal-(CH.sub.2).sub.n--OH [Chemical
Formula 2-3](Hal is I, Br or Cl and n is an integer of 3 to 14
inclusive.) 67 68
29. A chemical adsorbent consisting of a compound in a normal chain
comprising: a group represented by the following Chemical Formula
3-1; and a group of --SiX (X is a halogen).
--C.ident.C--C.ident.C-- [Chemical Formula 3-1]
30. A chemical adsorbent according to claim 1, wherein: said
compound is represented by the following Chemical Formula 3-2.
R--C.ident.C--C.ident.C-A-O--SiR'pX.sub.3-p [Chemical Formula
3-2](R is an alkyl group, R' is an alkyl group or an alkoxy group,
X is a halogen, p is an integer of 0 to 2 inclusive and A is a
bifunctional group.)
31. A chemical adsorbent according to claim 1, wherein: a chemical
adsorbent is represented by the following Chemical Formula 3-3.
CnH.sub.2n+1--C.ident.C--C.ident.C--(CH.sub.2)m--O--SiCl.sub.3
[Chemical Formula 3-3](n and m is an integer of 3 to 14
inclusive.)
32. A method of manufacturing a chemical adsorbent wherein: a
compound having a bond of --O--SiX.sub.3 is synthesized by causing
a condensation reaction of an alcohol comprising a group
represented by the following Chemical Formula 3-1, and SiX.sub.4 (X
is a halogen) in an atmosphere of an inert gas.
--C.ident.C--C.ident.C-- [Chemical Formula 3-1]
33. A method of manufacturing a chemical adsorbent according to
claim 3, wherein: an alcohol having an organic group represented by
said Chemical Formula 3-1 is synthesized by a condensation reaction
of a compound comprising a group represented by the following
Chemical Formula 3-4 at an end, and a compound having a group
represented by the following Chemical Formula 3-5 at an end and a
hydroxyl group at the other end. --C.ident.CH [Chemical Formula
3-4]XC.ident.C-- [Chemical Formula 3-5]
34. A liquid crystal alignment layer consisting of a thin film in a
monolayer which is chemisorbed on a substrate surface with at least
an electrode, wherein: said thin film is composed of a substance
comprising a molecule which originates in a group represented by
the following Chemical Formula 4-1. --C.ident.C--C.ident.--
[Chemical Formula 4-1]
35. A liquid crystal alignment layer according to claim 34,
wherein: said substance comprises at least one of chemical bond
units represented by the following Chemical Formula 4-2, Chemical
Formula 4-3, Chemical Formula 4-4 or Chemical Formula 4-5, and is
chemisorbed on said substrate surface through Si in said chemical
bond unit; and said chemical bond unit is crosslinked to each other
through a bond of C--C in a particular direction. 69(In said
Chemical Formulae 4-2 to 4-5, A is a bifunctional group.)
36. A method of manufacturing a liquid crystal alignment layer
comprising the steps of: forming a thin film consisting of a
chemisorbed molecule by contacting a solution comprising a chemical
adsorbent having a group represented by the following Chemical
Formula 4-1 and a group of --SiX (X is a halogen) on a substrate
surface with at least an electrode, and chemisorbing said chemical
adsorbent on said substrate surface; and crosslinking the
chemisorbed molecule composing the thin film along a particular
direction by irradiating an ultraviolet ray or a far-ultraviolet
ray on said thin film surface. --C.ident.C--C.ident.-- [Chemical
Formula 4-1]
37. A method of manufacturing a liquid crystal alignment layer
according to claim 36, comprising the steps of: washing for
removing a chemical adsorbent which is not yet adsorbed; and
draining a washing solution in a certain direction, after said step
of forming a thin film; wherein: said step of crosslinking is
executed after the step of draining.
38. A method of manufacturing a liquid crystal alignment layer
according to claim 37, wherein: a nonaqueous solvent is used as
said washing solution.
39. A method of manufacturing a liquid crystal alignment layer
according to claim 37, wherein: said draining is executed by
pulling up said substrate while holding in a vertical direction to
a solution surface after immersing the substrate with a thin film
in a washing solution comprising a nonaqueous solvent.
40. A method of manufacturing a liquid crystal alignment layer
according to claim 36, wherein: said irradiation is executed
through a polarizer or a transparent plate on which a rubbing is
executed.
41. A method of manufacturing a liquid crystal alignment layer
according to claim 36, wherein: said irradiation is executed
through a polarizer or a transparent plate on which a rubbing is
executed.
42. A method of manufacturing a liquid crystal alignment layer
according to claim 36, wherein: said irradiation is executed
through a patterned mask which is put on a polarizer or a
transparent plate on which a rubbing is executed; and an alignment
direction of an adsorbent molecule is changed in each patterned
small section by controlling a direction of a chemical bond between
adsorbent molecules.
43. A method of manufacturing a liquid crystal alignment layer
according to claim 36, wherein: said irradiation is executed
through a patterned mask which is put on a polarizer or a
transparent plate on which a rubbing is executed; and an alignment
direction of an adsorbent molecule is changed in each patterned
small section by controlling a direction of a chemical bond between
adsorbent molecules.
44. A method of manufacturing a liquid crystal alignment layer
according to claim 36, wherein: a solvent consisting of a molecule
comprising a group of alkyl, fluorocarbon, carbon chloride or
siloxane is used as a solvent in a solution comprising said
chemical adsorbent.
45. A liquid crystal display device with a structure in which two
substrates with at least an electrode are opposed through the
electrode side and a liquid crystal is sealed between the
substrates, wherein: a liquid crystal alignment layer is formed on
a surface of at least one of said substrates; and said liquid
crystal alignment layer is made by bonding and fixing a chemical
adsorbent having a functional group represented by the following
Chemical Formula 4-1 and a group of --SiX (X is a halogen) in a
molecular structure on the substrate surface.
--C.ident.C--C.ident.-- [Chemical Formula 4-1]
46. A liquid crystal alignment layer according to claim 45,
wherein: said liquid crystal alignment layer is composed of a thin
film in a monolayer which comprises at least one of chemical bond
units represented by the following Chemical Formula 4-2, Chemical
Formula 4-3, Chemical Formula 4-4 or Chemical Formula 4-5, and is
chemisorbed on a surface of said substrate through Si in the
chemical bond unit, which is crosslinked to each other through a
bond of C--C in a particular direction. 70(In said Chemical
Formulae 4-2 to 4-5, A is a bifunctional group.)
47. A liquid crystal alignment layer according to claim 46,
wherein: said liquid crystal alignment layer has a different liquid
crystal alignment direction at each of a plurality of small
sections into which a pixel unit is divided.
48. A liquid crystal display device according to claim 47, wherein:
said small section is arrayed in a pattern in a pixel area on a
substrate.
49. A liquid crystal display device of an in-plane switching type
in which an electrode and an opposite electrode are formed on the
same substrate, wherein: a liquid crystal alignment layer is formed
on a surface with the electrode and the opposite electrode of said
substrate; and said liquid crystal alignment layer is made by
bonding and fixing a chemical adsorbent having a functional group
represented by the following Chemical Formula 4-1 and a group of
--SiX (X is a halogen) in a molecular structure on a substrate
surface through a bond of --Si--O-- as well as crosslinking a
component molecule to each other in a particular direction.
50. A liquid crystal alignment layer according to claim 49,
wherein: said liquid crystal alignment layer is composed of a thin
film in a monolayer which comprises at least one of chemical bond
units represented by the following Chemical Formula 4-2, Chemical
Formula 4-3, Chemical Formula 4-4 or Chemical Formula 4-5, and is
chemisorbed on a surface of said substrate at an end of an Si group
in the chemical bond unit, which is crosslinked to each other
through a bond of C--C in a particular direction. 71(In said
Chemical Formulae 4-2 to 4-5, A is a bifunctional group.)
51. A method of manufacturing a liquid crystal display device
comprising the steps of: producing a chemisorption solution by
dissolving a chemical adsorbent comprising a functional group
represented by the following Chemical Formula 4-1 and a group of
--SiX (X is a halogen) in a molecular structure in a nonaqueous
solvent; forming a thin film in a monolayer by contacting said
chemisorption solution on a first substrate with at least a group
of electrodes in a matrix, and chemisorbing the chemical adsorbent
on said substrate plane through Si; aligning an adsorbent molecule
provisionally by drain-drying a nonaqueous solvent for washing
while setting up said substrate in a certain direction after
washing said thin film with the nonaqueous solvent; providing an
alignment characteristic by means of producing the first substrate
with a liquid crystal alignment layer having a particular alignment
characteristic by irradiating an ultraviolet ray or a
far-ultraviolet ray on the provisionally aligned thin film, and
crosslinking the adsorbent molecule to each other in a particular
direction through a photopolymerization; producing an empty cell by
sticking and fixing a periphery of the substrates after joining
through the electrode plane with a predetermined gap said first
substrate with a liquid crystal alignment layer as well as an
opposite substrate or a second substrate with a liquid crystal
alignment layer having an opposite electrode, which is produced
like said first substrate with a liquid crystal alignment layer;
and injecting a liquid crystal into said empty cell.
52. A method of manufacturing a liquid crystal display device
according to claim 51, wherein: an irradiation of an ultraviolet
ray or a far-ultraviolet ray in said step of providing an alignment
characteristic is executed through a patterned mask which is put on
a polarizer; and a first substrate with a liquid crystal alignment
layer having a different alignment direction of an adsorbent
molecule in each patterned small section is produced by controlling
a direction of a chemical bond between adsorbent molecules.
--C.ident.C--C.ident.-- [Chemical Formula 4-1]
53. A chemical adsorbent consisting of a chalcone derivative
wherein: a functional group is bonded to a benzene ring composing a
chalcone skeleton represented below; and a characteristic group
comprising a group of --SiX (X is a halogen, an alkoxyl group or an
isocyanato group) is bonded to the other benzene ring. 72
54. A chemical adsorbent according to claim 53, wherein: said
chalcone derivative is a compound represented by the following
Chemical Formula 5-1. 73(A.sub.1 is a functional group bonded to a
benzene ring in a chalcone skeleton, A.sub.2 is a bifunctional
group bonded to the other benzene ring, X is a halogen, an alkoxyl
group or an isocyanato group, A' is an alkyl group or an alkoxyl
group, and n is an integer of 0 to 3 inclusive.)
55. A chemical adsorbent according to claim 54, wherein: A.sub.1 in
said Chemical Formula 5-1 is a characteristic group represented by
the following Chemical Formula 5-2 or Chemical Formula 5-3 74(k is
an integer of 1 to 18 inclusive, m and n are an integer of 0 to 37
inclusive, p is an integer of 0 or 1, and q is an integer of 0 or
1.) 75(k is an integer of 1 to 18 inclusive, m and n are an integer
of 0 to 37 inclusive, and p is an integer of 0 or 1.)
56. A chemical adsorbent according to claim 55, wherein: A.sub.1 in
said Chemical Formula 5-1 is bonded to 4-position of a benzene ring
in a chalcone skeleton.
57. A chemical adsorbent according to claim 54, wherein: A.sub.2 in
said Chemical Formula 5-1 is represented by a group of
--(CH.sub.2).sub.n--O--- , --O--(CH.sub.2)--O--, or
--CO--(CH.sub.2).sub.n--O-- (n is an integer of 2 to 14
inclusive.).
58. A chemical adsorbent according to claim 57, wherein: A.sub.2 in
said Chemical Formula 5-1 is bonded to 4'-position of a benzene
ring in a chalcone skeleton.
59. A chemical adsorbent according to claim 54, wherein: A.sub.1 in
said Chemical Formula 5-1 is bonded to 4-position of a benzene ring
in a chalcone skeleton represented by the following Chemical
Formula 5-4; and A.sub.2 is bonded to 4'-position. 76
60. A chemical adsorbent according to claim 59, wherein: A.sub.1 in
said Chemical Formula 5-1 is a characteristic group represented by
the following Chemical Formula 5-2 or Chemical Formula 5-3; and
A.sub.2 in said Chemical Formula 5-1 is represented by a group of
--(CH.sub.2).sub.n--O--, --O--(CH.sub.2).sub.n--O--, or
--CO--(CH.sub.2).sub.n--O-- (n is an integer of 2 to 14
inclusive.).
61. A method of manufacturing a chemical adsorbent comprising the
step of: bonding a halogen or an alkoxy group to Si in a molecule
having a group of a chalcone skeleton with a functional group at
least at 4-position as well as Si in an atmosphere of an inert
gas.
62. A method of manufacturing a chemical adsorbent comprising at
least the step of: synthesizing a chalcone derivative having a bond
of --O--SX.sub.3 by causing a condensation reaction between an
alcohol comprising a group of a chalcone skeleton with a functional
group at least at 4-position of a benzene ring composing a chalcone
skeleton and SiX.sub.4 (X is a halogen) in an atmosphere of an
inert gas.
63. A method of manufacturing a chemical adsorbent comprising at
least the step of: causing an aldol condensation reaction between a
benzaldehyde with a functional group at least at 4-position and a
compound having a benzoyl group.
64. A liquid crystal alignment layer wherein: a thin film
comprising a chemical adsorbent having a characteristic group
represented by the following Chemical Formula 6-1 in a molecular
structure is chemisorbed directly or with an interposition of a
different substance layer on a substrate surface with an electrode
by a bond of --Si--O--; and an adsorbent molecule is crosslinked to
each other through at least one bond of a vinyl group in a
characteristic group represented by the following Chemical Formula
6-1. 77A.sub.1 is a functional group bonded to a benzene ring.
65. A liquid crystal alignment layer according to claim 64, said
liquid crystal alignment layer: being a thin film in a monolayer;
and having a liquid crystal alignment control force which can align
a liquid crystal molecule in a particular direction.
66. A liquid crystal alignment layer according to claim 65,
wherein: a coating thickness of said liquid crystal alignment layer
is 0.5 nm or more and below 10 nm.
67. A liquid crystal alignment layer according to claim 65,
wherein: A.sub.1 in said Chemical Formula 6-1 is a characteristic
group represented by the following Chemical Formula 6-3 or Chemical
Formula 6-4. 78(k is an integer of 1 to 18 inclusive, m and n are
an integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q
is an integer of 0 or 1.) 79(k is an integer of 1 to 18 inclusive,
m and n are an integer of 0 to 37 inclusive, and q is an integer of
0 or 1.)
68. A liquid crystal alignment layer according to claim 67,
wherein: A.sub.1 in said Chemical Formula 6-1 is bonded to
4-position of a benzene ring represented by the following Chemical
Formula 6-2. 80
69. A liquid crystal alignment layer according to claim 65, said
liquid crystal alignment layer being composed of more than two
kinds of chemical adsorbents having a characteristic group
represented by said Chemical Formula 6-1.
70. A liquid crystal alignment layer according to claim 65, said
liquid crystal alignment layer being composed of a chemical
adsorbent having a characteristic group represented by said
Chemical Formula 6-1 and a chemical substance except said chemical
adsorbent.
71. A liquid crystal alignment layer according to claim 65, said
liquid crystal alignment layer being composed of a plurality of
kinds of chemical substances, wherein: at least one kind of said
chemical substance is a chemical adsorbent having a characteristic
group represented by said Chemical Formula 6-1; and at least one of
said plurality of kinds of chemical substances has an alkyl
skeleton in a normal chain, a siloxane skeleton in a normal chain
or a fluoroalkyl skeleton in a normal chain.
72. A liquid crystal alignment layer according to claim 67, said
liquid crystal alignment layer being composed of a plurality of
kinds of chemical substances, wherein: at least one kind of said
chemical substance is a chemical adsorbent having a characteristic
group represented by said Chemical Formula 6-1; and at least one of
said plurality of kinds of chemical substances has an alkyl
skeleton in a normal chain, a siloxane skeleton in a normal chain
or a fluoroalkyl skeleton in a normal chain.
73. A liquid crystal alignment layer according to claim 67, said
liquid crystal alignment layer having a different alignment control
direction over a liquid crystal molecule at each of a plurality of
small patterned sections into which a pixel unit in an alignment
layer is divided.
74. A liquid crystal alignment layer according to claim 67,
wherein: said different substance layer is an organic layer or an
inorganic layer having a hydrophilic group.
75. A method of manufacturing a liquid crystal alignment layer
comprising the steps of: forming a thin film in a monolayer on a
substrate by contacting a material for a thin film comprising a
chemical adsorbent represented by the following Chemical Formula
6-5 on the substrate surface with at least an electrode, and
chemisorbing said material for a thin film on said substrate
surface; and treating an alignment of said thin film. 81(A.sub.1 is
a functional group bonded to a benzene ring in a chalcone skeleton,
A.sub.2 is a bifunctional group, X is a halogen or an alkoxyl
group, A' is an alkyl group or an alkoxyl group, and n is an
integer of 0 to 3 inclusive.)
76. A method of manufacturing a liquid crystal alignment layer
according to claim 75, wherein: A.sub.1 in said Chemical Formula
6-5 is represented by the following Chemical Formula 6-3 or
Chemical Formula 6-4. 82(k is an integer of 1 to 18 inclusive, m
and n are an integer of 0 to 37 inclusive, p is an integer of 0 or
1, and q is an integer of 0 or 1.) 83(k is an integer of 1 to 18
inclusive, m and n are an integer of 0 to 37 inclusive, and q is an
integer of 0 or 1.)
77. A method of manufacturing a liquid crystal alignment layer
according to claim 76, wherein: A.sub.1 in said Chemical Formula
6-5 is bonded to 4-position of a benzene ring composing a chalcone
basic skeleton represented by the following Chemical Formula 6-6.
84
78. A method of manufacturing a liquid crystal alignment layer
according to claim 77, wherein: A.sub.2 in said Chemical Formula
6-5 is represented by a group of --(CH.sub.2).sub.n--O--,
--O--(CH.sub.2).sub.n--O--, or --CO--(CH.sub.2).sub.n--O-- (n is an
integer of 2 to 14 inclusive.).
79. A method of manufacturing a liquid crystal alignment layer
according to claim 75, wherein: A.sub.1 according to claim 76 is
bonded to 4-position of a benzene ring; and A.sub.2 according to
claim 78 is bonded to 4-position of a benzene ring.
80. A method of manufacturing a liquid crystal alignment layer
according to claim 76, comprising the step of: washing a substrate
surface with a thin film with a nonaqueous solvent to remove an
excessive material for a thin film, between said steps of forming a
thin film and treating an alignment.
81. A method of manufacturing a liquid crystal alignment layer
according to claim 80, wherein: a nonaqueous solvent in said step
of washing is a nonprotic organic solvent.
82. A method of manufacturing a liquid crystal alignment layer
according to claim 80, wherein: a nonaqueous solvent in said step
of washing is a mixed solvent of a nonprotic organic solvent and a
protic organic solvent.
83. A method of manufacturing a liquid crystal alignment layer
according to claim 76, wherein: said step of treating an alignment
is a step of providing an alignment control force which can align a
liquid crystal molecule in a particular direction by irradiating a
polarized light on a substrate plane with said thin film, and
crosslinking a molecule composing the thin film to each other.
84. A method of manufacturing a liquid crystal alignment layer
according to claim 83, wherein: said irradiation of a polarized
light is a plurality of irradiations with a different light
strength and/or a different wavelength.
85. A method of manufacturing a liquid crystal alignment layer
according to claim 83, wherein: said irradiation of a polarized
light is a plurality of irradiations with a different incident
angle with a substrate.
86. A method of manufacturing a liquid crystal alignment layer
according to claim 83, wherein: said irradiation of a polarized
light is an irradiation using a polarized light with a different
polarized direction at each irradiation and to a different
irradiation section at each irradiation.
87. A method of manufacturing a liquid crystal alignment layer
according to claim 76, wherein: said step of treating an alignment
is a step of aligning a molecule composing a thin film
provisionally by drain-drying an organic solvent remaining on a
substrate plane while setting up the substrate through washing in a
certain direction.
88. A method of manufacturing a liquid crystal alignment layer
according to claim 80, wherein: said step of treating an alignment
is a step of providing an alignment control force for aligning a
liquid crystal molecule in a particular direction by irradiating a
polarized light on a substrate plane, and crosslinking a molecule
composing a thin film to each other, after aligning the molecule
composing a thin film provisionally by drain-drying an organic
solvent remaining on film substrate plane while setting up the
substrate through washing in a certain direction.
89. A method of manufacturing a liquid crystal alignment layer
according to claim 88, wherein: said irradiation of a polarized
light is a plurality of irradiations with a different light
strength and/or a different wavelength.
90. A method of manufacturing a liquid crystal alignment layer
according to claim 88, wherein: said irradiation of a polarized
light is a plurality of irradiations with a different incident
angle with a substrate.
91. A method of manufacturing a liquid crystal alignment layer
according to claim 88, wherein: said irradiation of a polarized
light is an irradiation using a polarized light with a different
polarized direction at each irradiation and to a different
irradiation section at each irradiation.
92. A method of manufacturing a liquid crystal alignment layer
comprising the steps of: forming a thin film in a monolayer on a
substrate by contacting a material for a thin film comprising a
chemical adsorbent represented by the following Chemical Formula
6-5 on the substrate surface with at least an electrode, and
chemisorbing a molecule composing said material for a thin film on
said substrate surface; aligning a molecule composing the thin film
provisionally by drain-drying an nonaqueous solvent in a certain
direction after contacting said nonaqueous solvent on the substrate
surface with a thin film; and realigning the molecule composing a
thin film by irradiating a polarized light on the provisionally
aligned substrate, and crosslinking the molecule composing a thin
film to each other; wherein: a liquid crystal alignment layer in a
multidomain alignment having a different liquid crystal alignment
control direction at each of a plurality of small patterned
sections into which a pixel unit is divided is manufactured by
repeating said steps of aligning provisionally and realigning more
than twice. 85(A.sub.1 is a functional group bonded to a benzene
ring in a chalcone skeleton, A.sub.2 is a bifunctional group, X is
a halogen or an alkoxyl group, A' is an alkyl group or an alkoxyl
group, and n is an integer of 0 to 3 inclusive.)
93. A liquid crystal display device with a structure in which two
substrates with at least an electrode are opposed through the
electrode side and a liquid crystal is sealed between two
substrates, wherein: a liquid crystal alignment layer comprising a
chemical adsorbent having a characteristic group represented by the
following Chemical Formula 6-1 in a molecular structure is
chemisorbed on a surface of at least one of said substrates by a
bond of --Si--O--; and an adsorbent molecule is crosslinked to each
other through at least one bond of a vinyl group in a
characteristic group represented by the following Chemical Formula
6-1. 86A.sub.1 is a functional group bonded to a benzene ring.
94. A liquid crystal display device according to claim 93, wherein:
A.sub.1 in said Chemical Formula 6-1 is a characteristic group
represented by the following Chemical Formula 6-3 or Chemical
Formula 6-4. 87(k is an integer of 1 to 18 inclusive, m and n are
an integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q
is an integer of 0 or 1.) 88(k is an integer of 1 to 18 inclusive,
m and n are an integer of 0 to 37 inclusive, and q is an integer of
0 or 1.)
95. A liquid crystal display device according to claim 94, wherein:
A.sub.1 in said Chemical Formula 6-1 is bonded to 4-position of a
benzene ring represented by the following Chemical Formula 6-2.
89
96. A liquid crystal display device according to claim 95, wherein:
said liquid crystal alignment layer is composed of a plurality of
kinds of chemical substances; at least one kind of said chemical
substance is a chemical adsorbent having a characteristic group
represented by said Chemical Formula 6-1; and at least one of said
plurality of kinds of chemical substances has an alkyl skeleton in
a normal chain, a siloxane skeleton in a normal chain or a
fluoroalkyl skeleton in a normal chain.
97. A liquid crystal display device according to claim 96, wherein:
said liquid crystal alignment layer is a thin film in a monolayer
and has a liquid crystal alignment control force which can align a
liquid crystal molecule in a particular direction.
98. A liquid crystal display device according to claim 97, wherein:
a coating thickness of said thin film is 0.5 nm or more and below
10 nm.
99. A liquid crystal display device according to claim 97, wherein:
said liquid crystal alignment layer has a different liquid crystal
alignment direction at each of a plurality of small sections into
which a pixel unit is divided.
100. A liquid crystal display device according to claim 99,
wherein: said small section is arrayed in a pattern in a pixel area
on a substrate.
101. A liquid crystal display device according to claim 100,
wherein: an organic layer or an inorganic layer having a
hydrophilic group is formed on an electrode of a substrate with
said alignment layer.
102. A liquid crystal display device according to claim 95,
wherein: said liquid crystal alignment layer has a different liquid
crystal alignment direction at each of a plurality of small
sections into which a pixel unit is divided.
103. A liquid crystal display device according to claim 102,
wherein: said small section is arrayed in a pattern in a pixel area
on a substrate.
104. A liquid crystal display device according to claim 103,
wherein: an organic layer or an inorganic layer having a
hydrophilic group is formed on an electrode of a substrate with
said alignment layer.
105. A liquid crystal display device of an in-plane switching type
in which an electrode and an opposite electrode are formed on the
same substrate, wherein: a liquid crystal alignment layer
comprising a chemical adsorbent having a characteristic group
represented by the following Chemical Formula 6-1 in a molecular
structure is chemisorbed on a surface with the electrode and the
opposite electrode of said substrate by a bond of --Si--O--; and an
adsorbent molecule is crosslinked to each other through at least
one bond of a vinyl group in a characteristic group represented by
the following Chemical Formula 6-1. 90A.sub.1 is a functional group
bonded to a benzene ring.
106. A liquid crystal display device according to claim 105,
wherein: A.sub.1 in said Chemical Formula 6-1 is a characteristic
group represented by the following Chemical Formula 6-3 or Chemical
Formula 6-4. 91(k is an integer of 1 to 18 inclusive, m and n are
an integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q
is an integer of 0 or 1.) 92(k is an integer of 1 to 18 inclusive,
m and n are an integer of 0 to 37 inclusive, and q is an integer of
0 or 1.)
107. A liquid crystal display device according to claim 106,
wherein: A.sub.1 in said Chemical Formula 6-1 is bonded to
4-position of a benzene ring represented by the following Chemical
Formula 6-2. 93
108. A liquid crystal display device according to claim 107,
wherein: said liquid crystal alignment layer is a thin film in a
monolayer and has a liquid crystal alignment control force which
can align a liquid crystal molecule in a particular direction.
109. A liquid crystal display device according to claim 108,
wherein: a coating thickness of said thin film is 0.5 nm or more
and below 10 nm.
110. A liquid crystal display device according to claim 108,
wherein: said liquid crystal alignment layer is composed of a
plurality of kinds of chemical substances; at least one kind of
said chemical substance is a chemical adsorbent having a
characteristic group represented by said Chemical Formula 6-1; and
at least one of said plurality of kinds of chemical substances has
an alkyl skeleton in a normal chain, a siloxane skeleton in a
normal chain or a fluoroalkyl skeleton in a normal chain.
111. A liquid crystal display device according to claim 110,
wherein: an organic layer or an inorganic layer having a
hydrophilic group is formed on an electrode of a substrate with
said alignment layer.
Description
TECHNICAL FIELD
[0001] The present invention relates to a chemical adsorbent which
can form a thin film in a monolayer wherein component molecules are
aligned in a predetermined direction, a liquid crystal alignment
layer utilizing the same and a liquid crystal display device
utilizing the same, and additionally, a method of manufacturing the
above-mentioned chemical adsorbent and the like.
BACKGROUND ART
[0002] In recent years, although a liquid crystal display device
has been spread rapidly as a means of actualizing the downsizing
and lightening of information apparatus, coating materials for
manufacturing a liquid crystal alignment layer, which is an
important constituent of the device, are limited. Consequently, a
new material for the alignment layer having an unprecedented
characteristic is desired according to the improvement of a liquid
crystal display device in performance.
[0003] A color liquid crystal display device has a structure
wherein a pair of substrates with a transparent electrode arrayed
generally in a matrix and a liquid crystal alignment layer formed
on the transparent electrode are opposed through the liquid crystal
alignment layers with a certain gap and a liquid crystal is sealed
between the gap. More specifically, a macromolecular film is formed
on each surface of a first glass substrate with a pixel electrode
and a thin-film transistor (TFT) array and a second glass substrate
with a plurality of red, blue and green color filters and a common
transparent electrode on the color filters, and an alignment of the
liquid crystal is provided by rubbing the coated planes. Secondly,
the first glass substrate and the second glass substrate are
opposed through the coated planes (the liquid crystal alignment
layers) with a spacer interposed, and an empty cell (a panel
structure) is made by adhesion of a periphery of the substrates. A
liquid crystal display device is constituted by sealing with an
injection of such a liquid crystal as twisted nematic (TN) into the
empty cell, and additionally, a liquid crystal display device as a
optical display device is constituted by disposing polarizers on
the front and back sides of the device as well as a backlight
outside the first glass substrate.
[0004] A liquid crystal display device having such a structure
applies a voltage between the electrodes to obtain an ON/OFF state
with the TFT and controls a light transmission by changing an
alignment state of the liquid crystal and displays an arbitrary
image. Therefore, the liquid crystal alignment layers for
controlling the alignment state of the liquid crystal on a path of
the light transmission play an extremely important role of
affecting a display performance.
[0005] A polyimide film has conventionally been used widely as
coating materials for such a liquid crystal alignment layer in
terms of superiority in affinity with the liquid crystal,
heat-resistance and adhesion to the substrate. The following
methods are used for manufacturing the polyimide film: a method
wherein the polyimide film is made by changing the polyamic acid
into imide while burning the substrate after rotational-coating on
a substrate a solution wherein polyamic acid, which is a precursor
polymer of polyimide, is dissolved in such an organic solvent as
xylene; and a method wherein the polyimide film is made by
evaporating the solvent after rotational-coating on a substrate a
solution wherein polyimide is dissolved in such organic solvents as
DMF (N,N-dimethylformamide), DMAc (dimethylacetamide),
butylcellosolveacetate and N-methyl-2-pyrrolidone.
[0006] However, a polyimide film has the following problems and
thereby is not enough satisfactory for a liquid crystal alignment
layer. That is:
[0007] (1) In the method by using polyamic acid which is a
precursor substance, it is necessary to burn at a high temperature
of 250.degree. C. and above in order to change into imide
sufficiently. In the method by using polyimide, it is necessary to
remove the solvent at a considerably higher temperature because of
no low boiler suitable for dissolving the polyimide. Such organic
solvents as the above-mentioned DMF, DMAc, butylcellosolveacetate
and N-methyl-2-pyrrolidone can be used as a solvent for dissolving
the polyimide. however, since every solvent has a high boiling
point (153.degree. C., 165.degree. C., 192.degree. C., 202.degree.
C. respectively) and is flammable, it is necessary to consider
explosion-protection while manufacturing the polyimide film by
evaporating and drying the solvent at a high temperature.
Consequently, a particular device is necessary for heating in
manufacturing a polyimide film, whereby its manufacturing costs are
raised. Moreover, there is the possibility that such a circuit as
TFT will be damaged by heating.
[0008] (2) Furthermore, since polyimide is not sufficiently made
into a film, it is difficult to manufacture a thin film with a
uniform coating thickness. Consequently, since display unevenness
resulting from non-uniformity of coating thickness occurs and a
thick film functions as an insulation film, another problem is that
it is difficult to actualize a liquid crystal display device having
a low driving voltage.
[0009] (3) In addition to the above, the following problems are
caused in rubbing operation for providing an alignment.
[0010] {circle over (1)} If a film has irregularities on its
surface, recessed portions fail to be rubbed, particularly, in the
case of a panel with a large area, the panel fail to be rubbed
uniformly. Accordingly, such problems are caused as the occurrence
of alignment defect and display unevenness, and display
sticking.
[0011] {circle over (2)} Furthermore, static electricity is
generated on an alignment layer and the static electricity results
in deteriorating the function of a TFT.
[0012] {circle over (3)} In addition, dust comes out of rubbing
materials (cotton cloth or the like) and the dust results in
display unevenness and a change of a substrate gap.
[0013] Consequently, various noncontact type aligning methods are
proposed for the purpose of solving the above-mentioned problems in
a rubbing method.
[0014] In Japanese Unexamined Patent Publication No. 5-53118, a
technique is proposed wherein a layer of a photosensitive
composition is formed on a substrate, grooves of a predetermined
pattern are formed on the composition layer by exposing and
heat-treating, and an alignment is provided by the grooves.
However, the technique requires high photo energy for forming the
grooves. Moreover, since it is difficult to form uniform grooves,
such problems are caused as the occurrence of display unevenness
and the like, and alignment control force is not sufficient.
[0015] In Japanese Unexamined Patent Publication No. 7-72483, a
technique is proposed wherein an alignment is provided by
polymerizing the polyimide or the like while irradiating linearly
polarized light to a compound layer for forming an alignment layer
comprising polyimide or polyimide precursor. However, since the
technique uses polyimide which is an organic polymer, the technique
can not solve a problem of a rise in a liquid crystal driving
voltage caused by a thick coating. Another problem is that the
fixing force of an alignment layer on a substrate is not
sufficient.
[0016] In Japanese Unexamined Patent Publication No. 7-318942, a
technique is proposed wherein a molecular structure having an
alignment is made by causing another reaction of combination or
decomposition in a molecular chain of the alignment layer while
irradiating from a diagonal direction to an alignment layer having
a macromolecular structure. However, since the technique also is
intended for an alignment layer which is made of such organic
polymers as polyimide, polyvinyl alcohol and polystyrene, the
technique can not solve the above-mentioned problems of a thick
coating and a low fixing force on a substrate. Moreover, the
irradiation from a diagonal direction to an alignment layer is
essential for providing a pretilt angle and the technique requires
a irradiation device with high precision for irradiating accurately
from a diagonal direction, whereby manufacturing costs are
raised.
[0017] In addition to the above-mentioned problems, the problem of
a liquid crystal display device in a twisted nematic mode or the
like is that a viewing angle is narrower than in the past. As a
method for solving the problem, in Japanese Unexamined Patent
Publication No. 5-173135, a method is proposed wherein a plurality
of areas having different alignment directions of a liquid crystal
are formed by repeating rubbing in a reverse direction after
rubbing an alignment layer in a certain direction and covering the
portions concerned with a resist.
[0018] Yet, in the rubbing (contact type) method, a troublesome
operation of rubbing while masking each divided section must be
repeated for forming a plurality of sections having different
alignment directions of a liquid crystal. Consequently, according
to this technique, even more serious problem is that the
manufacturing efficiency of an alignment layer deteriorates largely
as well as dust comes out.
[0019] On the other hand, a plurality of areas having different
alignment directions of a liquid crystal can be formed also by
applying each of such above-mentioned techniques as Japanese
Unexamined Patent Publication No. 5-53118 and the like. However, as
described above, since each of the above-mentioned techniques has
such problems as a thick coating and an insufficient fixing force
on a substrate, nevertheless a liquid crystal alignment layer,
which is enough satisfactory, can not be provided by utilizing
these techniques.
[0020] The inventors of the present invention, in Japanese
Unexamined Patent Publication No. 3-7913, proposed a technique
wherein an alignment layer with a coating thickness in nanometer
order can be manufactured with a high productivity. The technique
uses as an alignment layer a monomolecular film which is made by
chemisorbing a silane-based chemical adsorbent (or called surface
active agent) on a substrate plane. According to the technique, an
extremely thin and transparent film in a state combined and fixed
on a substrate can be formed easily and efficiently, and
additionally, an alignment layer having a certain alignment control
force over a liquid crystal molecule can be provided without
rubbing. However, the technique still leaves room for improving on
the thermal stability of alignment, the strength of alignment
control force and the like.
[0021] The present invention has been intended in response to the
above-mentioned problems. A series of the present invention
described below seeks to solve the above-mentioned problems at one
effort. The purposes of a series of the present invention are:
first, to provide a new chemical adsorbent which can form an
extremely thin and transparent film in nanometer order which is
fixed uniformly and firmly on a substrate, and give an alignment
characteristic of high thermal stability to the thin film;
secondly, to provide a liquid crystal alignment layer having a
desirable alignment characteristic, a superior alignment control
force over a liquid crystal molecule, and a superior thermal
stability by using the above-mentioned chemical adsorbent; thirdly,
to provide a liquid crystal display device which is superior in a
display performance by using the above-mentioned liquid crystal
alignment layer; lastly, to provide a method of manufacturing each
of the above-mentioned chemical adsorbent, liquid crystal alignment
layer and liquid crystal display device with a high
productivity.
[0022] Although a series of the present invention has been intended
through a series of research and development which is closely
relevant, each of a series of the present invention is described in
different embodiments. Therefore, after a series of the present
invention is divided into the first to sixth invention group, each
group will be detailed below.
DISCLOSURE OF THE FIRST INVENTION GROUP
[0023] A chemical adsorbent in the first invention group is
characterized by the following constitution.
[0024] (1) A chemical adsorbent consisting of a compound comprising
a group of --CR.sup.1.dbd.CR.sup.2--CO-- and a functional group
having Si in its chemical structure.
[0025] According to a compound having the above-mentioned
composition, the functional group having Si functions as a
chemisorbed group. Therefore, the compound can be chemically bonded
(chemisorbed) through the functional group having Si on a substrate
plane having such hydrophilic groups as OH group, COOH group,
NH.sub.2 group, NH group and SH group. Moreover, a vinyl group
functions as a photoreactive group. Therefore, a molecule can be
crosslinked to each other through the vinyl group by
irradiating.
[0026] A significance of using a chemical adsorbent having the
above-mentioned composition as a material for a liquid crystal
alignment layer is as follows. A thin film, which is formed by
contacting the above-mentioned chemical adsorbent on a substrate
and chemisorbing it, has a structure in a monolayer wherein a
molecule, in which an end (a functional group having Si) in a
direction of its major axis is bonded on the substrate plane and
the other end is aligned in a direction opposite to the substrate,
is arrayed in a lateral direction. The film is an extremely thin
film in nanometer order, and transparent in a range of visible ray
and chemically stable. Meanwhile, the film has a characteristic in
which a photoreaction is caused in a vinyl group by irradiating a
light in a range of ultraviolet rays. Therefore, after chemisorbing
the above-mentioned chemical adsorbent on a substrate, it is
possible to crosslink and connect a component molecule to each
other by irradiating ultraviolet rays, and thereby stabilize an
alignment of the component molecule in a steric structure. In
addition, if a polarized light is used in irradiating ultraviolet
rays, it is possible to cause a crosslinking along a certain
direction and thereby control an alignment direction of the
component molecule by determining a polarized direction.
[0027] In a thin film wherein an adsorbent molecule is arrayed in
parallel with a substrate plane, a liquid crystal molecule can
enter each gap (valley) between component molecules. Therefore, a
thin film wherein the component molecules are aligned in a certain
direction has a particular alignment of a liquid crystal. Moreover,
since each of the component molecules is involved in an alignment
of a liquid crystal, the above-mentioned thin film indicates a
strong alignment control force despite an extremely thin film.
Furthermore, since a component molecule is connected to each other
by crosslinking, an alignment is not deteriorated by an external
stimulus such as heat and rubbing. In addition, since the film is
extremely thin and transparent, and not an organic polymer film, it
scarcely functions as an electrical resistance film. Therefore, the
film has an extremely appropriate characteristic for a liquid
crystal alignment layer, in which a light transmission and an
electric field for driving a liquid crystal are not hindered.
[0028] Meanwhile, a conventional liquid crystal alignment layer
(such as a polymer film made of the above-mentioned polyimide),
which is composed closely in a state wherein a long main chain is
tangled up, has difficulty in obtaining a sufficient alignment
control force since only a surface of the film can contribute to an
alignment of a liquid crystal. Moreover, in a conventional
alignment layer for which an alignment is provided by rubbing, the
alignment is changed or deteriorated by an external stimulus such
as heat and rubbing. Furthermore, since such a polymer film as
polyimide has a thick coating and a high electrical resistance, it
is a hindrance factor to a light transmission and a liquid crystal
driving.
[0029] In a chemical adsorbent having a chemical structure in which
a component molecule can not be crosslinked to each other, a thin
film in a monolayer can be formed; however, a stable alignment
characteristic can not be obtained. For instance, since a chemical
adsorbent, which is written in the above-mentioned Japanese
Unexamined Patent Publication No. 3-7913, does not have a
photoreactive group, an adsorbent molecule can not be chemically
connected to each other. Therefore, the problem is that an
alignment is deteriorated by the heat of around 200.degree. C.
[0030] A chemical adsorbent having the above-mentioned composition
is extremely useful as a material for a liquid crystal alignment
layer, and a use for the adsorbent is not limited to this. A use
for a chemical adsorbent in other invention groups is not limited,
either.
[0031] In the above-mentioned composition, it is preferable to add
the components described below in (2) to (4). According to a
composition to which the following components are added, an effect
of the above-mentioned function can be actualized even more
certainly. That is:
[0032] (2) In the above-mentioned composition, it is possible to
make a functional group having Si a compound which is bonded to an
end of CO in a group of --CR.sup.1.dbd.CR.sup.2--CO--. Each of
R.sup.1 and R.sup.2 is a hydrogen, an alkyl group having 1 to 3 C
or an alkoxy group having 1 to 3 C.
[0033] The groups of --CH.sub.3, --C.sub.2H.sub.5 and
--C.sub.3H.sub.7 can be cited as the above-mentioned alkyl group
having 1 to 3 C, and the groups of --OCH.sub.3, --OC.sub.2H.sub.5
and --OC.sub.3H.sub.7 can be cited as the above-mentioned alkoxy
group having 1 to 3 C.
[0034] (3) It is possible to make the compound in the
above-mentioned (2) a compound represented by the following
Chemical Formula 1. In Chemical Formula 1, n is an integer of 1 to
14 inclusive, R is an alkyl group having 1 to 14 C or a phenyl
group, X is a halogen, an alkoxyl group or an isocyanato group, m
is an integer of 1 to 3 inclusive and A is a functional group.
1
[0035] (4) It is possible to make the compound in the
above-mentioned (2) a compound represented by the following
Chemical Formula 2, Chemical Formula 3 or Chemical Formula 4. In
the following Chemical Formulae 2 to 4, n is an integer of 1 to 14
inclusive, R is an alkyl group having 1 to 14 C or a phenyl group,
X is a halogen, an alkoxyl group or an isocyanato group, m is an
integer of 1 to 3 inclusive (an integer of 1, 2 only in Chemical
Formula 4) and A is a functional group. 2
[0036] A liquid crystal alignment layer in the first invention
group, which is formed by using the above-mentioned chemical
adsorbent, is characterized by the following constitution.
[0037] (5) A liquid crystal alignment layer wherein a liquid
crystal molecule can be aligned in a particular direction, a
chemical adsorbent comprising a group of
--CR.sup.1.dbd.CR.sup.2--CO-- and a functional group having Si in
its chemical structure is bonded and fixed directly or with an
interposition of a different substance layer on a substrate surface
through Si, and an adjacent component molecule is crosslinked to
each other through at least one bond of a double bond of C.dbd.C in
the group of --CR.sup.1.dbd.CR.sup.2--CO--.
[0038] (6) A liquid crystal alignment layer wherein a liquid
crystal molecule can be aligned in a particular direction,
consisting of a compound comprising a chemical bond unit
represented by the following Chemical Formula 5, Chemical Formula
6, Chemical Formula 7 or Chemical Formula 8. In the following
Chemical Formulae 5 to 8, n is an integer of 1 to 14 inclusive and
R is an alkyl group having 1 to 14 C or a phenyl group.
[0039] Since this composition comprises a chemical bond unit
represented by the following Chemical Formulae 5 to 8, an alignment
function on a liquid crystal molecule is large, and particularly, a
function of aligning a twisted nematic (TN) type liquid crystal is
large. Therefore, a liquid crystal alignment layer having this
composition can be used appropriately as a liquid crystal alignment
layer for a liquid crystal display device in a TN mode. 3
[0040] The following constitutions can be adopted as a method of
manufacturing a liquid crystal alignment layer having the
above-mentioned composition.
[0041] (7) A method of manufacturing a liquid crystal alignment
layer comprising the steps of producing a chemisorption solution by
dissolving a silane-based chemical adsorbent comprising a group of
--CR.sup.1.dbd.CR.sup.2--CO-- and a functional group having Si in a
nonaqueous solvent; forming a thin film in a monolayer which is
made of the above-mentioned silane-based chemical adsorbent on a
substrate plane by contacting the above-mentioned silane-based
chemisorption solution on the substrate plane, and chemisorbing it
on the substrate plane; and photopolymerizing an adsorbent molecule
to each other at a double bond of C.dbd.C in the group of
--CR.sup.1.dbd.CR.sup.2--CO-- by irradiating an ultraviolet ray or
a far-ultraviolet ray on the above-mentioned thin film plane.
[0042] (8) In the above-mentioned composition, it is possible,
between the above-mentioned steps of forming a thin film and
photopolymerizing, to provide a step of treating a provisional
alignment of a molecule composing the thin film by drain-drying an
organic solvent in a certain direction after contacting the
above-mentioned organic solvent on the thin film plane.
[0043] According to this composition, an alignment of a liquid
crystal can be provided to some extent.
[0044] (9) It is possible, between the above-mentioned steps of
forming a thin film and photopolymerizing, to provide the steps of
washing the thin film plane with a nonaqueous solvent to remove the
chemical adsorbent which is not yet adsorbed, and aligning
provisionally an alignment direction of a molecule of the
silane-based chemical adsorbent which is chemisorbed on the
substrate plane by drain-drying the nonaqueous solvent remaining on
the substrate plane while setting up the substrate through washing
in a certain direction.
[0045] According to this composition, a liquid crystal alignment
layer, which is made of a thin film in a monolayer with a more
stable alignment function, can be provided.
[0046] (10) It is possible to execute an irradiation of the
ultraviolet ray or the far-ultraviolet ray in the above-mentioned
step of photopolymerizing through a polarizer, a transparent plate
having a multitude of grooves of 0.1 to 0.3 .mu.m in width on its
surface or a transparent plate on which rubbing is executed.
[0047] According to this composition, a direction of
photopolymerizing can be controlled in a polarized direction, a
groove direction or a rubbing direction.
[0048] (11) It is possible to execute an irradiation of the
ultraviolet ray or the far-ultraviolet ray in the above-mentioned
step of photopolymerizing through a patterned mask which is put
further on a polarizer, a transparent plate having a multitude of
grooves of 0.1 to 0.3 .mu.m in width on its surface or a
transparent plate on which rubbing is executed, and thereby control
a direction of a chemical bond between chemisorbed molecules and
change an alignment direction of an adsorbent molecule in each
patterned irradiation area.
[0049] In this composition, a liquid crystal alignment layer in a
multidomain alignment, wherein a plurality of small sections into
which a pixel is divided differ from each other in a liquid crystal
alignment direction, can be manufactured by executing a light
irradiation more than once, such as changing a polarized
direction.
[0050] (12) In the above-mentioned step of producing a
chemisorption solution, it is possible to use a multicomponent
chemisorption solution wherein a first silane-based chemical
adsorbent and a second silane-based chemical adsorbent, which
differs from the first silane-based chemical adsorbent in a
molecular length, are mixed at a predetermined ratio.
[0051] According to this composition, a degree of
photopolymerization of the first silane-based chemical adsorbent
and/or the second silane-based chemical adsorbent can be changed by
changing a mixture ratio. Moreover, an inclination of a longer
adsorbent molecule to a substrate can be controlled with a shorter
adsorbent molecule by determining a mixture ratio properly.
Furthermore, since it is possible to change a density of a
polymerizable group, a degree of photopolymerization can be
controlled.
[0052] (13) In the above-mentioned (12), it is possible, between
the above-mentioned steps of forming a thin film and
photopolymerizing, to provide a step of treating a provisional
alignment of a molecule composing the thin film by drain-drying a
nonaqueous solvent in a certain direction after contacting the
above-mentioned nonaqueous solvent on the thin film plane.
[0053] According to this composition in which a light is irradiated
after aligning an adsorbent molecule provisionally, a particular
alignment characteristic of a liquid crystal can be provided even
more certainly.
[0054] (14) In the above-mentioned (12), it is possible, between
the above-mentioned steps of forming a thin film and
photopolymerizing, to provide the steps of washing the thin film
plane with a nonaqueous solvent to remove the chemical adsorbent
which is not yet adsorbed; and aligning provisionally an alignment
direction of a molecule of the silane-based chemical adsorbent
which is chemisorbed on the substrate plane by drain-drying the
nonaqueous solvent remaining on the substrate plane while setting
up the substrate through washing in a certain direction.
[0055] According to this composition, through a series of
operations of washing and drying, the chemical adsorbent which is
not yet adsorbed can be removed as well as the adsorbent molecule
can be aligned provisionally.
[0056] (15) In the above-mentioned (12), it is possible to execute
an irradiation of the ultraviolet ray or the far-ultraviolet ray in
the above-mentioned step of photopolymerizing through a polarizer,
a transparent plate having a multitude of grooves of 0.1 to 0.3
.mu.m in width on its surface or a transparent plate on which
rubbing is executed.
[0057] (16) In the above-mentioned (12), it is possible to execute
an irradiation of the ultraviolet ray or the far-ultraviolet ray in
the above-mentioned step of photopolymerizing through a patterned
mask which is put further on a polarizer, a transparent plate
having a multitude of grooves of 0.1 to 0.3 .mu.m in width on its
surface or a transparent plate on which rubbing is executed, and
thereby control a direction of a chemical bond between chemisorbed
molecules and change an alignment direction of an adsorbent
molecule in each patterned irradiation area.
[0058] A liquid crystal display device in the first invention
group, which is formed by using a liquid crystal alignment layer
having the above-mentioned composition, can be composed as
described below.
[0059] (17) A liquid crystal display device comprising, at least,
two opposite substrates with an electrode on an inside plane, a
liquid crystal alignment layer which is formed on an inside plane
of at least one of the above-mentioned opposite substrates, and a
liquid crystal which is received into a gap between the
above-mentioned opposite substrates, wherein the above-mentioned
liquid crystal alignment layer is a thin film in a monolayer which
is formed by chemisorbing a chemical adsorbent directly or through
a different substance layer on the above-mentioned substrate plane,
and an adsorbent molecule is crosslinked to each other along a
particular direction.
[0060] Since a rubbingless liquid crystal alignment layer, which is
low in a deterioration of an alignment, is used in this
composition, a liquid crystal display device with a high
reliability can be provided.
[0061] (17-1) A liquid crystal display device of an in-plane
switching (IPS) type in which an electrode and an opposite
electrode are formed on the same substrate, wherein the
above-mentioned liquid crystal alignment layer is a thin film in a
monolayer which is formed by chemisorbing a chemical adsorbent
directly or through a different substance layer on the
above-mentioned substrate plane, and an adsorbent molecule is
crosslinked to each other along a particular direction.
[0062] Since a rubbingless liquid crystal alignment layer, which is
low in a deterioration of an alignment, is used in this
composition, a liquid crystal display device in an in-plane
switching (IPS) mode can be provided with a high productivity.
[0063] (18) In the above-mentioned (17) and (17-1), the chemical
adsorbent comprises a group of --CR.sup.1.dbd.CR.sup.2--CO-- and a
functional group having Si, and the above-mentioned adsorbent
molecule is crosslinked to each other at a double bond of C.dbd.C
in the group of --CR.sup.1.dbd.CR.sup.2--CO--.
[0064] (19) In the above-mentioned (18), the thin film has a
different liquid crystal alignment control direction at each of a
plurality of small patterned sections into which a pixel unit is
divided.
[0065] The following constitutions can be adopted as a method of
manufacturing a liquid crystal display device having the
above-mentioned composition.
[0066] (20) A method of manufacturing a liquid crystal display
device comprising the steps of producing a chemisorption solution
by dissolving a silane-based chemical adsorbent comprising a carbon
chain as well as a group of --CR.sup.1.dbd.CR.sup.2--CO-- and a
functional group having Si at an end of or inside the
above-mentioned carbon chain in a nonaqueous solvent; forming a
thin film in a monolayer by contacting the above-mentioned
chemisorption solution on a first substrate with at least a group
of electrodes in a matrix, and chemisorbing the chemical adsorbent
on the above-mentioned substrate plane at the functional group
having Si; aligning an adsorbent molecule provisionally by
dram-drying the nonaqueous solvent for washing while setting up the
above-mentioned substrate in a certain direction after washing the
above-mentioned thin film with a nonaqueous solvent; providing an
alignment characteristic by means of producing the first substrate
with a liquid crystal alignment layer having a particular alignment
characteristic by irradiating an ultraviolet ray or a
far-ultraviolet ray on the provisionally aligned thin film, and
crosslinking the adsorbent molecule to each other in a particular
direction through a photopolymerization; producing an empty cell by
sticking and fixing a periphery of the substrates after joining
through the electrode plane with a predetermined gap the
above-mentioned first substrate with a liquid crystal alignment
layer as well as an opposite substrate or a second substrate with a
liquid crystal alignment layer having an opposite electrode, which
is produced like the above-mentioned first substrate with a liquid
crystal alignment layer; and injecting a liquid crystal into the
above-mentioned empty cell.
[0067] (21) It is possible to adopt a method of exposing through a
patterned mask which is put on a polarizer in irradiating the
ultraviolet ray or the far-ultraviolet ray in the above-mentioned
step of providing an alignment characteristic.
[0068] According to this method, a controlled direction of a liquid
crystal alignment can be changed at each of a plurality of small
patterned sections into which a pixel unit is divided by
controlling a crosslinking direction of the adsorbent molecule.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE FIRST INVENTION GROUP
[0069] FIG. 1 is a view showing an ultraviolet absorption spectrum
of a chlorosilane-based chemical adsorbent (represented by Chemical
Formula 10) which is used in Embodiment 1.
[0070] FIG. 2 is a conceptional view of a cross section for
describing the step of chemisorbing which is used for manufacturing
a liquid crystal alignment layer in a monolayer in Embodiment
1.
[0071] FIG. 3 is a conceptional view of a cross section for
describing the step of washing a thin film in Embodiment 1.
[0072] FIG. 4 is a conceptional view of an enlarged cross section
to a molecule level for describing an alignment state of an
adsorbent molecule composing a thin film in a monolayer after
washing with a solvent in Embodiment 1.
[0073] FIG. 5 is a conceptional view of the step of exposing which
is used for polymerizing an adsorbent molecule to each other by
polarized exposure in Embodiment 1.
[0074] FIG. 6 is a conceptional view of an enlarged thin film to a
molecule level for describing a polymerization state of a molecule
in a thin film after polarized exposure in Embodiment 1.
[0075] FIG. 7 is a view showing an ultraviolet absorption spectrum
of a chlorosilane-based chemical adsorbent (represented by Chemical
Formula 16) which is used in Embodiment 2.
[0076] FIG. 8 is a conceptional view of an enlarged thin film to a
molecule level for describing a polymerization state of a molecule
in a thin film after polarized exposure in Embodiment 3.
[0077] FIG. 9 is a conceptional view of a cross section for
describing a method of manufacturing a liquid crystal display
device in Embodiment 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE FIRST
INVENTION GROUP
[0078] The first invention group is detailed based on embodiments
below.
[0079] (Embodiment 1)
[0080] Embodiment 1 of the present invention is described below
referring to FIGS. 1 to 6.
[0081] A glass substrate 1 (including a multitude of hydroxyl
groups on its surface) with a transparent electrode on its surface
was prepared, and washed and degreased sufficiently beforehand
Next, a chemisorption solution was produced by dissolving a
compound represented by the following Chemical Formula 11 (this
adsorbent has a photosensitive peak in a range from 240 to 370 nm
as shown in FIG. 1), as a chlorosilane-based chemical adsorbent
comprising a carbon chain as well as a group represented by the
following Chemical Formula 9 and Si at an end of or inside the
above-mentioned carbon chain, in a nonaqueous solvent at a
concentration of approximately 1 wt. %. 4
[0082] In Embodiment 1, well-dehydrated hexadecane was used as the
nonaqueous solvent A solution thus produced was made an adsorption
solution 2, and the above-mentioned substrate 1 was immersed (or
may be applied) in the adsorption solution 2 in a dry atmosphere (a
relative humidity of 30% or less) for approximately an hour (FIG.
2). Later, after pulling up the substrate 1 out of the adsorption
solution 2 and washing the substrate 1 with well-dehydrated
n-hexane 3 as a nonaqueous solvent, the substrate 1 was pulled up
out of a washing solution while setting up the substrate 1 in a
desired direction and the washing solution was drained and the
substrate 1 was exposed to an atmosphere including humidity (FIG.
3). Through a series of the above-mentioned steps, a reaction of
eliminating hydrochloric acid was caused between a group of silicon
chloride in the above-mentioned chlorosilane-based chemical
adsorbent and a hydroxyl group on the above-mentioned substrate
surface, and a bond represented by the following Chemical Formula
12 was produced, and additionally, a bond represented by the
following Chemical Formula 13 was produced by reacting with
humidity in an atmosphere. 5
[0083] Then, furthermore, the above-mentioned fixed molecule can be
aligned primarily by washing the substrate 1 with such nonaqueous
organic solvents as n-hexane and chloroform and draining while
setting up the substrate 1 in a desired direction.
[0084] By means of the above treatment, a chemisorbed monomolecular
film 4 which is formed by a reaction between the above-mentioned
chemical adsorbent and the substrate was chemically bonded to an
area including a hydroxyl group on the substrate surface through a
covalent bond of siloxane, and the bonded molecule was formed with
a coating thickness of approximately 2 nm in an alignment state in
a direction opposite to a direction 5 of draining and pulling up
(FIG. 4).
[0085] Later, furthermore, a polarizer (HNP'B) 7 (made by POLAROID
Corp.) as put on two kinds of substrates in this state so that a
polarized direction 6 was in approximately parallel with the
direction 5 of draining and pulling up, and an ultraviolet ray 8 of
100 mJ with a wavelength of 365 nm (i-line) was irradiated (2.6
mW/cm.sup.2, after transmitting a polarized film) by using an
extra-high-pressure mercury-vapor lamp of 500W (FIG. 5, 9 indicates
a transparent electrode in the Fig.).
[0086] Later, when an anisotropy of an adsorbent molecule was
examined with FT-IR, the above-mentioned photosensitive group was
photopolymerized and thereby the absorption peak of a vinyl group
did not appear. That is, a bond represented by the following
Chemical Formula 14 was produced 6
[0087] Although a direction of a bond was not clear, the polarized
direction differed from a vertical direction to the polarized
direction in an absorption of a vinyl group. This indicates that a
substance composing the above-mentioned monomolecular film is
bonded and fixed on the above-mentioned substrate surface, and
crosslinked or photopolymerized at the photosensitive group (a
vinyl group) in FIG. 9 along a predetermined direction.
[0088] Moreover, two substrates in this state were combined through
a chemisorbed film so that polarized directions were parallel and
drain directions were opposite, namely, antiparallel, and a liquid
crystal cell with a gap of 20 .mu.m was constructed, and a nematic
liquid crystal (ZLI4792; made by MELC Corp.) was injected, and an
alignment state was examined.
[0089] The injected liquid crystal molecule was aligned at an
pretilt angle of approximately 2.5.degree. with the substrate along
a direction at an angle of 90.degree. with the polarized
direction.
[0090] Then, it is necessary that the direction 5 of draining and
pulling up crosses the polarized direction 6 at an angle of not
completely 90.degree. but with a little shift from 90.degree.,
preferably more than some degrees in order to make an alignment
direction of an adsorbent molecule in an irradiated area the same
direction. In this case, the polarized direction 6 may be in
parallel with the direction 5 of draining and pulling up at the
maximum. If the direction 5 of draining and pulling up crosses the
polarized direction 6 at an angle of completely 90.degree., each
molecule is occasionally aligned in two directions.
[0091] When an ultraviolet ray of 100 to 200 mJ with a wavelength
of 365 nm was irradiated through a patterned mask on a polarizer in
order to change an alignment direction selectively, an alignment
direction changed only in an irradiated area and it was possible to
provide a plurality of parts in which an alignment direction
differs in a pattern on the same alignment layer, namely, a liquid
crystal is aligned along each of the direction 5 of draining and
pulling up and the polarized direction 6. Moreover, it was possible
to manufacture extremely easily a liquid crystal alignment layer in
a monolayer having a plurality of alignment directions which differ
in a pattern by executing the step of exposing through a desired
mask on a polarizer on the same condition a plurality of times.
That is, it was possible to provide a liquid crystal display device
wherein a pixel is in a multidomain alignment.
[0092] In Embodiment 1, hydrocarbon-based n-hexane comprising an
alkyl group was used as a nonaqueous solvent for washing, and any
nonaqueous solvent that dissolves a chemical adsorbent can be used
besides this solvent. For instance, it was possible to use a
solvent comprising the groups of fluorocarbon, carbon chloride or
siloxane such as Freon 113, chloroform and
hexamethyldisiloxane.
[0093] An effect of aligning a twisted nematic liquid crystal is
particularly great in a liquid crystal alignment layer comprising a
chemical bond unit represented by the following Chemical Formula 15
as Embodiment 1, and besides Chemical Formula 15, a substance
represented by the following Chemical Formula 16 was similarly
applicable to a substance for forming a film. 7
[0094] (In the Formulae, n is an integer of 1 to 14 inclusive.)
[0095] Then, a solvent comprising the groups of alkyl fluorocarbon,
carbon chloride or siloxane was applicable to a nonaqueous organic
solvent for producing a chemisorption solution.
[0096] (Embodiment 2)
[0097] On the condition in Embodiment 1, a substance represented by
the following Chemical Formula 17 (this substance has a
photosensitive peak in a range from 240 to 290 nm as shown in FIG.
7) was used as a chemical adsorbent comprising a photosensitive
group represented by the above-mentioned Chemical Formula 9 and Si
instead of a substance used in Embodiment. Later, an acrylic plate
having a multitude of grooves of 0.1 to 0.3 .mu.m in width through
rubbing with an abrasive of 0.3 .mu.m was put on a substrate, and a
far-ultraviolet ray of 80 mJ with a wavelength of 254 nm was
irradiated (2.1 mW/cm.sup.2, after transmitting a acrylic plate) by
using an extra-high-pressure mercury-vapor lamp of 500W. The same
experiment except the above was executed. 8
[0098] Furthermore, two substrates in this state were combined
through a chemisorbed film so as to be antiparallel, and a liquid
crystal cell with a gap of 20 .mu.m was constructed, and a nematic
liquid crystal (ZLI4792; made by MELC Corp.) was injected, and an
alignment state was examined. The injected liquid crystal molecule
was aligned at an pretilt angle of approximately 4.degree. with the
substrate along a direction at an angle of 90.degree. with the
polarized direction.
[0099] Like the above-mentioned substance, a substance which can be
used as a substance for forming a film is represented by the
following Chemical Formula 18, 9
[0100] (In the Formulae, n is an integer of 1 to 14 inclusive and R
is an alkyl group having 1 to 14 C or a phenyl group. However, the
sum of n and the number of C in R is 1 to 26.)
[0101] or the following Chemical Formula 19, 10
[0102] (In the Formulae, n is an integer of 1 to 14 inclusive and R
is an alkyl group having 1 to 14 C or a phenyl group. However, the
sum of n and the number of C in R is 1 to 26.)
[0103] or the following Chemical Formula 20. 11
[0104] (In the Formulae, n is an integer of 1 to 14 inclusive and R
is an alkyl group having 1 to 14 C or a phenyl group. However, the
sum of n and the number of C in R is 1 to 26.)
[0105] More specifically, a substance represented by the following
Chemical Formula 21, Chemical Formula 22, Chemical Formula 23,
Chemical Formula 24 or Chemical Formula 25 was similarly applicable
although it had a different amount of exposure. 12
[0106] (This substance has a photosensitive peak in a range from
240 to 280 nm.) 13
[0107] (This substance has a photosensitive peak in a range from
240 to 290 nm.) 14
[0108] (This substance has a photosensitive peak in a range from
240 to 310 nm.) 15
[0109] (This substance has a photosensitive peak in a range from
240 to 330 nm.) 16
[0110] (This substance has a photosensitive peak in a range from
240 to 330 nm.)
[0111] (Embodiment 3)
[0112] On the condition in Embodiment 1, a chemisorption solution
was produced by mixing a substance represented by the
above-mentioned Chemical Formula 11, as a chlorosilane-based
chemical adsorbent, and a substance represented by the following
Chemical Formula 26 at an equal mole ratio, and dissolving the
mixture in a nonaqueous solvent at a concentration of approximately
1 wt. % as a chlorosilane-based chemical adsorbent. The same
experiment except the above was executed.
H.sub.3C--(CH.sub.2).sub.2--O--SiCl.sub.3 [Chemical Formula 26]
[0113] As a result, a reaction of eliminating hydrochloric acid was
caused between a group of silicon chloride in each of the
above-mentioned two kinds of chlorosilane-based chemical adsorbents
and a hydroxyl group on the above-mentioned substrate surface, and
additionally, a thin film 10 in a monolayer (hereinafter referred
to as `monomolecular film`) comprising a bond represented by the
above-mentioned Chemical Formula 13 and the following Chemical
Formula 27 at a ratio of 1:1 approximately was formed by reacting
with humidity in an atmosphere. 17
[0114] Later, furthermore, a polarizer (HNP'B) (made by POLAROID
Corp.) was put on two kinds of substrates in this state so that a
polarized direction was in approximately parallel with the
direction of draining and pulling up, and an ultraviolet ray of 70
mJ with a wavelength of 365 nm (i-line) was irradiated (2.6
mW/cm.sup.2, after transmitting a polarized film) by using an
extra-high-pressure mercury-vapor lamp of 500W.
[0115] Later, when an anisotropy of an adsorbent molecule was
examined with FT-IR, the above-mentioned photosensitive group was
photopolymerized and thereby a vinyl group was not absorbed like
Embodiment 1. Although a direction of a bond was not clear, the
polarized direction differed from a vertical direction to the
polarized direction in an absorption of a vinyl group.
[0116] This indicates that a substance composing the
above-mentioned monomolecular film is bonded and fixed on the
above-mentioned substrate surface, and a monomolecular film 10',
which is photopolymerized at the above-mentioned photosensitive
group as shown in FIG. 8 along a predetermined direction, is
formed.
[0117] Next, two substrates in this state were combined through a
chemisorbed film so that polarized directions were parallel and
drain directions were opposite, namely, antiparallel, and a liquid
crystal cell with a gap of 20 .mu.m was constructed, and a nematic
liquid crystal (ZLI4792; made by MELC Corp.) was injected, and an
alignment state was examined. The injected liquid crystal molecule
was aligned at an pretilt angle of approximately 1.5.degree. with
the substrate along a direction at an angle of 90.degree. with the
polarized direction.
[0118] This indicates that a photopolymerized molecule is tilted
more than Embodiment 1. The film in Embodiment 3 had a larger
alignment control force than a film in Embodiment 1.
[0119] (Embodiment 4)
[0120] An actual process of manufacturing a liquid crystal display
device by using the above-mentioned liquid crystal alignment layer
is described below referring to FIG. 9.
[0121] First, as shown in FIG. 9, a similar chemisorbed film was
manufactured by applying a chemisorption solution, which was
produced under the same procedure as Embodiment 1, on a first
substrate 13 having a first group of electrodes 11 in a matrix and
a group of transistors 12 for driving the electrodes as well as a
second substrate 16 having a group of color filters 14 opposite to
the first group of electrodes and a second electrode 15.
[0122] As a result, a liquid crystal alignment layer 27, which was
realigned along an electrode pattern, was manufactured like
Embodiment 1. Next, the above-mentioned first and second substrates
13, 16 were joined so that their electrodes were opposite, and a
cell with a gap of approximately 5 .mu.m in which an alignment
direction is twisted by 90.degree. was constructed with a spacer 18
and an adhesive 19. Later, after injecting the above-mentioned
nematic liquid crystal 20 (ZLI4792; made by MELC Corp.) between the
above-mentioned first and second substrates, a display device was
completed by combining polarizers 21, 22. Then, a pretilt angle of
the injected liquid crystal was 2.3.degree..
[0123] Such a device could display a picture in a direction of an
arrow A by driving each transistor with a video signal while
irradiating a backlight 23 on the whole surface.
[0124] (Embodiment 5)
[0125] After forming a monomolecular film in Embodiment 3, it was
possible to provide four parts in which an alignment direction
differs in a pattern in the same pixel by executing the step of
exposing through a patterned mask dividing each pixel into four
sections in a check on the above-mentioned polarizer twice on the
same condition as Embodiment 1. Moreover, it was possible to
improve a conventional viewing angle of a liquid crystal display
device, 60.degree. right and left, 20.degree. up, 50.degree. down
greatly to 60.degree. right and left, 50.degree. up and down by
using the substrate with this alignment layer.
[0126] A liquid crystal display device with a superior stability of
alignment was obtained by forming the above-mentioned film on each
surface of two substrates with an opposite electrode as an
alignment layer. The alignment layer was extremely effective in a
liquid crystal display device wherein opposite electrodes are
formed on a substrate surface, namely, in-plane switching (IPS)
type because of no rubbing.
[0127] An ultraviolet ray with a wavelength of 365 nm (i-line of an
extra-high-pressure mercury-vapor lamp) and a far-ultraviolet ray
with a wavelength of 254 nm were used as a light for exposing
respectively in the above-mentioned Embodiments 1 and 2, and it is
possible to use a visible ray with a wavelength of 436 nm and 405
nm as well as a far-ultraviolet ray with a wavelength of 248 nm by
KrF excimer laser depending on an absorption of light into a film
substance. In particular, the light with a wavelength of 248 nm and
254 nm has a high efficiency in energy alignment since the light is
easily absorbed into most substances.
[0128] In addition, a substance comprising an alkoxysilyl group and
an isocyanatosilyl group could be used as a chemical adsorbent
instead of a substance comprising a group of silicon chloride such
as a chlorosilane-based chemical adsorbent used in the embodiments
of the first invention group. In this case, a film with a high
alignment was obtained.
[0129] As described above, the first invention group can provide a
liquid crystal alignment layer having a superior alignment control
force despite a remarkably uniform and thin layer as compared with
a conventional layer. Furthermore, an alignment direction of
injected liquid crystal can be controlled by irradiating for
photopolymerization with the use of an ultraviolet ray and a
far-ultraviolet ray, and a pretilt angle can be altered by changing
a composition of a monolayer. According to a manufacturing method
of the present invention, a liquid crystal alignment layer as
described above can be manufactured with a high productivity.
[0130] Moreover, a plurality of parts in which only an alignment
direction differs in a pattern on the same alignment layer can be
provided by executing the step of exposing through a patterned mask
on a polarizer a plurality of times after the step of forming a
monomolecular film, and although it was difficult to manufacture a
liquid crystal display device in a multidomain alignment, wherein
an alignment of each pixel is divided into a plurality of kinds, in
a rubbing method, the liquid crystal display device in a
multidomain alignment can be manufactured rationally with a high
efficiency.
[0131] In addition, a liquid crystal display device with a high
reliability can be provided since such an alignment layer is bonded
firmly on a substrate surface through a covalent bond.
DISCLOSURE OF THE SECOND INVENTION GROUP
[0132] The main purpose of the second invention group is to provide
a new chemical adsorbent which can form a liquid crystal alignment
layer with superior thermal stability, and a method of
manufacturing such a chemical adsorbent like the above-mentioned
first invention group. Although a description of a liquid crystal
alignment layer and a liquid crystal display device using a
chemical adsorbent is omitted in the second invention group in
order to avoid a redundancy with a description in the first
invention group, it is, needless to say, possible to manufacture a
liquid crystal alignment layer and a liquid crystal display device
by applying a manufacturing method in other invention groups to a
chemical adsorbent in the second invention group.
[0133] The invention in the second invention group is characterized
by the following constitution.
[0134] (1) A chemical adsorbent consisting of a 4'-substitution
chalcone derivative represented by the following Chemical Formula
2-1. 18
[0135] R is an alkyl group having 1 to 3 C or an alkoxy group
having 1 to 3 C, p is an integer of 0 to 2 inclusive and A is a
bifunctional group.
[0136] In the above-mentioned composition, it is possible to make A
in the above-mentioned Chemical Formula 2-1 a group of
--(CH.sub.2).sub.n-- (n is an integer of 3 to 14 inclusive).
[0137] A compound having a skeleton group of chalcone represented
by the following Chemical Formula 2-6 is generally transparent and
stable in a range of a visible ray (a wavelength from 400 nm to 700
nm), and has a photosensitivity of photopolymerizing in a range of
an ultraviolet ray and a far-ultraviolet ray. A group of silicon
chloride is chemisorbed on a substrate having a hydrophilic group.
Therefore, since a chemical adsorbent having the above-mentioned
composition can form a thin film in a monolayer by chemisorbing and
crosslink an molecule to each other by irradiating a light in a
range of an ultraviolet ray and a far-ultraviolet ray, the chemical
adsorbent is appropriate for a material for forming a liquid
crystal alignment layer. 19
[0138] (2) A chemical adsorbent having the above-mentioned
composition can be manufactured in a manufacturing method having
the following composition.
[0139] That is, a method of manufacturing a chemical adsorbent
comprising a first step of synthesizing a substance represented by
the following Chemical Formula 2-4 by coupling 4'-hydroxychalcone
represented by the following Chemical Formula 2-2 and a compound
represented by the following Chemical Formula 2-3; and a second
step of synthesizing a 4'-substitution chalcone derivative
represented by the following Chemical Formula 2-5 by causing a
reaction of eliminating hydrochloric acid with a substance
represented by the above-mentioned Chemical Formula 2-4 and silicon
tetrachloride in an atmosphere of inert gas. 20
Hal-(CH.sub.2)n--OH
[0140] (Hal is I, Br or Cl and n is an integer of 3 to 14
inclusive.) 21
[0141] The above-mentioned manufacturing method is described in
detail. 4'-substitution chalcone derivative represented by the
above-mentioned Chemical Formula 2-1 can be synthesized, for
instance, by the following steps of (1) and (2).
[0142] (1) Synthesis of 4'-Substitution Chalcone Derivative
Represented by the Above-Mentioned Chemical Formula 2-4
[0143] For instance, it is possible to synthesize by coupling
4'-hydroxychalcone (Chemical Formula 2-2) and a compound
represented by the above-mentioned Chemical Formula 2-3. That is,
it is possible to obtain 4'-substitution chalcone derivative
represented by the above-mentioned Chemical Formula 2-4 by
dissolving 4'-hydroxychalcone (Chemical Formula 2-2) in dry DMF in
an air current of inert gas, and adding sodium hydride through
dropping in ice cooling; later, heating to a room temperature, and
stirring ordinarily for 2 to 10 hours, preferably 5 hours; next,
adding a compound represented by the above-mentioned Chemical
Formula 2-3 (such as 6-chloro-1-hexanol) through dropping at a room
temperature ordinarily for 5 to 10 minutes, preferably 10 minutes;
furthermore, heating ordinarily to 60 to 85.degree. C., preferably
80.degree. C., and reacting ordinarily for 5 to 10 hours,
preferably 7 hours.
[0144] A mixture ratio of 4'-hydroxychalcone (X) and a compound
represented by the above-mentioned Chemical Formula 2-3 (Y) is
ordinarily 0.8:1 to 1:0.8 (mole ratio), preferably approximately
1:1. A mixture ratio of 4'-hydroxychalcone (X) and a basic reagent
(Z) such as sodium hydride is ordinarily 1:0.8 to 1:2, preferably
1:1.
[0145] (2) Synthesis of 4'-Substitution Chalcone Derivative
Represented by the Above-Mentioned Chemical Formula 2-5
[0146] For instance, it is possible to synthesize by causing a
reaction of eliminating hydrochloric acid between 4'-substitution
chalcone derivative represented by the above-mentioned Chemical
Formula 2-4 and silicon tetrachloride. That is, it is possible to
obtain 4'-substitution chalcone derivative represented by the
above-mentioned Chemical Formula 2-5 by stirring 4'-substitution
chalcone derivative represented by the above-mentioned Chemical
Formula 2-4 and silicon tetrachloride in a reaction flask in air
current of inert gas at a room temperature ordinarily for 1 to 10
hours, preferably 5 hours; later, removing excessive silicon
tetrachloride through distillation; furthermore, after adding
dehydrated hexane to the residue and dispersing a crystal, drying
through filtration.
[0147] A mixture ratio of 4'-substitution chalcone derivative (X)
represented by the above-mentioned Chemical Formula 24 and silicon
tetrachloride (Y) is ordinarily 0.8:1 to 1:0.8 (mole ratio),
preferably approximately 1:1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE SECOND
INVENTION GROUP
[0148] The second invention group is detailed based on embodiments
below. In embodiments below, R-1200 made by HITACHI Ltd. was used
for an analysis of .sup.1H-NMR (nuclear magnetic resonance)
spectrum, FTIR 4300 made by SHIMADZU Corp. was used for an analysis
of IR (infrared absorption) spectrum, and UV-240 made by SHIMADZU
Corp. was used for an analysis of UV (ultraviolet absorption)
spectrum.
[0149] (Embodiment 2-1)
[0150] (1) Synthesis of 4'-(6-hydroxyhexyloxy)-chalcone (Chemical
Formula 2-7)
[0151] A refined 4'-(6-hydroxyhexyloxy)-chalcone (10.7 g, 23.4
mmol) was obtained with a yield of 49.3% by adding 90 ml of dry DMF
(N,N-dimethylformamide) to 4'-hydroxychalcone (15.0 g, 67 mmol;
made by LANCASTER Corp.) in an air current of argon, and adding
sodium hydride (60%, 2.68 g, 67 mmol) through dropping in a
reaction flask of 200 ml in ice cooling for 30 minutes; later,
after heating to a room temperature and stirring for 5 hours,
adding 6-chloro-1-hexanol (19.2 g, 67 mmol; made by TOKYO CHEMICAL
INDUSTRY Co., Ltd.) through dropping at the same temperature for 10
minutes; furthermore, heating to 80.degree. C., and reacting for 7
hours; next, after injecting the solution into water with ice and
extracting the product with ethyl acetate, washing with water, and
drying the solution after washing through dehydration with
magnesium sulfate, and removing the ethyl acetate; after refining
(mobile phase, hexane:ethyl acetate=4:1) the gained coarse crystal
with silica gel column, recrystallizing with ethyl acetate. 22
[0152] (2) Synthesis of 4'-(6-trichlorosiloxyhexyloxy)-chalcone
(Chemical Formula 2-8)
[0153] A refined 4'-(6-trichlorosiloxyhexyloxy)-chalcone (6.2 g)
was obtained with a yield of 42.3% by stirring
4'-(6-hydroxyhexyloxy)-chalcon- e (10.5 g, 32 mmol) and silicon
tetrachloride (20 g, 118 mmol; made by WAKO PURE CHEMICALS
INDUSTRIES, Ltd.) in a reaction flask of 100 ml in air current of
argon at a room temperature for 5 hours; later, removing excessive
silicon tetrachloride through distillation; furthermore, after
adding dehydrated hexane to the residue and dispersing a crystal,
drying through fitration. 23
[0154] 4'-(6-trichlorosiloxyhexyloxy)-chalcone (Chemical Formula
2-8) thus obtained was a light yellow crystal in powder.
[0155] FIG. 2-1 shows a result of an analysis (CDCl.sub.3) by
.sup.1H-NMR spectrum. As shown in FIG. 2-1, the signals of .delta.
1.6 (s, CH.sub.2), 4.0 (d, olefin H), 6.9 (d), 2.4 (m), 8.0(d)
(benzene ring H) ppm existed.
[0156] FIG. 2-2 shows a result of an analysis by IR spectrum. As
shown in FIG. 2-2, an absorption was shown at 2940, 2860
(CH.sub.2), 1650 (C.dbd.O), 1600, 1580, 1450 (benzene ring
skeleton), 1230 (.phi.-O--C), 1080 (Si--O), 830 (SiCi)
cm.sup.-1.
[0157] FIG. 2-3 shows an ultraviolet absorption spectrum which was
obtained in chloroform. The ultraviolet absorption spectrum shown
in FIG. 2-3 proves no absorption in a range of visible ray and a
strong absorption in a range of an ultraviolet ray and a
far-ultraviolet ray. In FIG. 2-3, an absorption curve was omitted
because of no absorption in a range of a wavelength from 500 nm to
700 nm.
[0158] FIG. 2-4 shows a result of determining gas chromatography.
The peak at a retention time of 14.861 min. indicates
4'-(6-trichlorosiloxyhexylox- y)chalcone with a purity of 99% or
more, which was obtained in Embodiment 2-1. The peak at a retention
time of 1 to 2 min. indicates a solvent with a low boiling point of
a carrier.
[0159] (Embodiment 2-2)
[0160] (1) Synthesis of 4'-(12-hydroxydodecyloxy)-chalcone
(Chemical Formula 2-9)
[0161] A refined 4'-(12-hydroxydodecyloxy)chalcone (12.9 g, 31.6 m
mol) was obtained with a yield of 47.2% by adding 90 ml of dry DMF
to 4'-hydroxychalcone (15.0 g, 67 mmol) in an air current of argon,
and adding sodium hydride (60%, 2.68 g, 67 mmol) through dropping
in a reaction flask of 200 ml in ice cooling for 30 minutes; later,
after heating to a room temperature and stirring for 5 hours,
adding 12-chloro-1-dodecanol (14.8 g, 67 mmol) through dropping at
the same temperature for 10 minutes; furthermore, heating to
80.degree. C., and reacting for 7 hours; next, after injecting the
solution into water with ice and extracting the product with ethyl
acetate, washing with water, and drying through dehydration with
magnesium sulfate, and removing the solvent; after refining (mobile
phase, hexane:ethyl acetate=4:1) the gained coarse crystal with
silica gel column, recrystallizing with ethyl acetate. 24
[0162] (2) Synthesis of 4'-(12-trichlorosiloxydodecyloxy)-chalcone
(Chemical Formula 2-10)
[0163] A refined 4'-(12-trichlorosiloxydodecyloxy)-chalcone (5.9 g,
10.9 mmol) was obtained with a yield of 34.1% by stirring
4'-(12-hydroxydodecyloxy)-chalcone (13.1 g, 32 mmol) and silicon
tetrachloride (20 g, 118 mmol) in a reaction flask of 100 ml in air
current of argon at a room temperature for 5 hours; later, removing
excessive silicon tetrachloride through distillation; furthermore,
after adding dehydrated hexane to the residue and dispersing a
crystal, drying through filtration. 25
[0164] 4'-(12-trichlorosiloxydodecyloxy)-chalcone (Chemical Formula
2-10) thus obtained was a light yellow crystal in powder.
[0165] An ultraviolet absorption spectrum which was obtained in
chloroform was the same as FIG. 2-1. The ultraviolet absorption
spectrum proves no absorption in a range of visible ray and a
strong absorption in a range of an ultraviolet ray and a
far-ultraviolet ray.
[0166] (Embodiment 2-3)
[0167] (1) Synthesis of 4'-(14-hydroxytetradecyloxy)-chalcone
(Chemical Formula 2-11)
[0168] A refined 4'-(14-hydroxytetradecyloxy)-chalcone (13.6 g,
31.2 mmol) was obtained with a yield of 46.6% by adding 90 ml of
dry DMF to 4'-hydroxychalcone (15.0 g, 67 mmol) in an air current
of argon, and adding sodium hydride (60%, 2.68 g, 67 mmol) through
dropping in a reaction flask of 200 ml in ice cooling for 30
minutes; later, after heating to a room temperature and stirring
for 5 hours, adding 14-chloro-1-tetradecanol (16.6 g, 67 mmol)
through dropping at the same temperature for 10 minutes;
furthermore, heating to 80.degree. C., and reacting for 7 hours;
next, after injecting the solution into water with ice and
extracting the product with ethyl acetate, washing with water, and
drying through dehydration with magnesium sulfate, and removing the
solvent; after refining (mobile phase, hexane:ethyl acetate=4:1)
the gained coarse crystal with silica gel column, recrystallizing
with ethyl acetate. 26
[0169] (2) Synthesis of
4'-(14-trichlorosiloxytetradecyloxy)-chalcone (Chemical Formula
2-12)
[0170] A refined 4'-(14-trichlorosiloxytetradecyloxy)chalcone (5.34
g, 9.38 mmol) was obtained with a yield of 29.3% by stirring
4'-(14-hydroxytetradecyloxy)chalcone (10.5 g, 32 mmol) and silicon
tetrachloride (20 g, 118 mmol) in a reaction flask of 100 ml in air
current of argon at a room temperature for 5 hours; later, removing
excessive silicon tetrachloride through distillation; furthermore,
after adding dehydrated hexane to the residue and dispersing a
crystal, drying through filtration. 27
[0171] 4'-(14-trichlorosiloxytetradecyloxy)-chalcone (Chemical
Formula 2-12) thus obtained was a light yellow crystal in
powder.
[0172] An ultraviolet absorption spectrum which was obtained in
chloroform was the same as FIG. 2-1. The ultraviolet absorption
spectrum proves no absorption in a range of visible ray and a
strong absorption in a range of an ultraviolet ray and a
far-ultraviolet ray.
[0173] (Embodiment 2-4)
[0174] (1) Synthesis of 4'-(3-hydroxypropyloxy)-chalcone (Chemical
Formula 2-13)
[0175] A refined 4'-(3-hydroxypropyloxy)-chalcone (9.71 g, 34.4
mmol) was obtained with a yield of 51.4% by adding 90 ml of dry DMF
to 4'-hydroxychalcone (15.0 g, 67 mmol) in an air current of argon,
and adding sodium hydride (60%, 2.68 g, 67 mmol) through dropping
in a reaction flask of 200 ml in ice cooling for 30 minutes; later,
after heating to a room temperature and stirring for 5 hours,
adding 3-chloro-1-propanol (6.33 g, 67 mmol) through dropping at
the same temperature for 10 minutes; furthermore, heating to
80.degree. C., and reacting for 7 hours; next, after injecting the
solution into water with ice and extracting the product with ethyl
acetate, washing with water, and drying through dehydration with
magnesium sulfate, and removing the solvent; after refining (mobile
phase, hexane:ethyl acetate=4:1) the gained coarse crystal with
silica gel column, recrystallizing with ethyl acetate. 28
[0176] (2) Synthesis of 4'-(3-trichlorosiloxypropyloxy)-chalcone
(Chemical Formula 2-14)
[0177] A refined 4'-(3-trichlorosiloxypropyloxy)-chalcone (22.8 g,
55.0 mmol) was obtained with a yield of 46.6% by stirring
4'-(3-hydroxypropyloxy)-chalcone (9.02 g, 32 mmol) and silicon
tetrachloride (20 g, 118 mmol) in a reaction flask of 100 ml in air
current of argon at a room temperature for 5 hours; later, removing
excessive silicon tetrachloride through distillation; furthermore,
after adding dehydrated hexane to the residue and dispersing a
crystal, drying through filtration. 29
[0178] 4'-(3-trichlorosiloxypropyloxy)-chalcone (Chemical Formula
2-14) thus obtained was a light yellow crystal in powder.
[0179] An ultraviolet absorption spectrum which was obtained in
chloroform was the same as FIG. 2-1. The ultraviolet absorption
spectrum proves no absorption in a range of visible ray and a
strong absorption in a range of an ultraviolet ray and a
far-ultraviolet ray.
[0180] (Embodiment 2-5)
[0181] Synthesis of 4'-(6-hydroxyhexyloxy)-chalcone (Chemical
Formula 2-7) by using 6-bromo-1-hexanol
[0182] A refined 4'-(6-hydroxyhexyloxy)-chalcone (12.2 g, 37.7
mmol) was obtained with a yield of 56.2% by adding 90 ml of dry DMF
to 4'-hydroxychalcone (15.0 g, 67 mmol) in an air current of argon,
and adding sodium hydride (60%, 2.68 g, 67 mmol) through dropping
in a reaction flask of 200 ml in ice cooling for 30 minutes; later,
after heating to a room temperature and stirring for 5 hours,
adding 6-bromo-1-hexanol (12.1 g, 67 mmol) through dropping at the
same temperature for 10 minutes; furthermore, heating to 80.degree.
C., and reacting for 7 hours; next, after injecting the solution
into water with ice and extracting the product with ethyl acetate,
washing with water, and drying through dehydration with magnesium
sulfate, and removing the solvent; after refining (mobile phase,
hexane:ethyl acetate=4:1) the gained coarse crystal with silica gel
column, recrystallizing with ethyl acetate.
[0183] A composition of the product was confirmed by .sup.1H-NMR
and IR.
[0184] (Embodiment 2-6)
[0185] Synthesis of 4'-(6-hydroxyhexyloxy)-chalcone (Chemical
Formula 2-7) by Using 6-iodo-1-hexanol
[0186] A refined 4'-(6-hydroxyhexyloxy)-chalcone (13.1 g, 40.5
mmol) was obtained with a yield of 60.5% by adding 90 ml of dry DMF
to 4'-hydroxychalcone (15.0 g, 67 mmol) in an air current of argon,
and adding sodium hydride (60%, 2.68 g, 67 mmol) through dropping
in a reaction flask of 200 ml in ice cooling for 30 minutes; later,
after heating to a room temperature and stirring for 5 hours,
adding 6-iodo-1-hexanol (15.3 g, 67 m mol) through dropping at the
same temperature for 10 minutes; furthermore, heating to 80.degree.
C., and reacting for 7 hours; next, after injecting the solution
into water with ice and extracting the product with ethyl acetate,
washing with water, and drying through dehydration with magnesium
sulfate, and removing the solvent; after refining (mobile phase,
hexane:ethyl acetate=4:1) the gained coarse crystal with silica gel
column, recrystallizing with ethyl acetate.
[0187] A composition of the product was confirmed by .sup.1H-NMR
and IR.
[0188] A group represented by the above-mentioned Chemical Formula
6 was used as a photosensitive group in the above embodiments, and
it is possible to synthesize a substance comprising a
photosensitive group represented by the following Chemical Formula
2-15 similarly. 30
[0189] (In the Formulae, each of R.sup.1 and R.sup.2 is --H,
--CH.sub.3, --C.sub.2H.sub.5 and --OCH.sub.3.)
[0190] A group of --SiCl.sub.3 was used as a group of silicon
chloride at an area for adsorbing, and it is possible to synthesize
a substance comprising a group of silicon chloride represented by
the following Chemical Formula 2-16 similarly. --SiRpCl.sub.(3-p)
[Chemical Formula 2-16]
[0191] (R is an alkyl group having 1 to 3 C or an alkoxy group
having 1 to 3 C, and p is an integer of 0 to 2 inclusive.)
[0192] However, a substance with a practical value as a chemical
adsorbent for a liquid crystal alignment layer is limited to a
substance which has a range of a photosensitive wavelength in a
range of an ultraviolet ray and a far-ultraviolet ray, and is
transparent in a range of visible ray.
[0193] As described above, 4'-substitution chalcone derivative in
the second invention group is a new and useful compound represented
by the above-mentioned Chemical Formula 2-1. This compound can be
used as an appropriate chemical adsorbent for manufacturing a
monomolecular film for a liquid crystal alignment layer since the
compound is transparent and stable in a range of a visible ray, and
has a group represented by the above-mentioned Chemical Formula 2-6
in its molecule as a photosensitive group for photopolymerizing in
a range of an ultraviolet ray and a far-ultraviolet ray, and
comprises a group of silicon chloride effective as an area for
adsorbing in the case of using a chemisorbing method
BRIEF DESCRIPTION OF THE DRAWINGS OF THE SECOND INVENTION GROUP
[0194] FIG. 2-1 is a chart showing a result of an analysis
(CDCl.sub.3) by .sup.1H-NMR spectrum of a compound which was
synthesized in Embodiment 2-1.
[0195] FIG. 2-2 is a chart showing a result of an analysis by IR
spectrum of a compound which was synthesized in Embodiment 2-1.
[0196] FIG. 2-3 is a chart showing an ultraviolet absorption
spectrum in chloroform of a compound which was synthesized in
Embodiment 2-1.
[0197] FIG. 2-4 is a chart showing a result of determining gas
chromatography of a compound which was sythesized in Embodiment
2-1.
DISCLOSURE OF THE THIRD INVENTION GROUP
[0198] The main purpose of the third invention group is to provide
a new chemical adsorbent which can form a liquid crystal alignment
layer with superior thermal stability of alignment, and a
manufacturing method thereof like the above-mentioned second
invention group. A chemical adsorbent in the third invention group
is used for a liquid crystal alignment layer and a liquid crystal
display device in the following fourth invention group.
[0199] The invention in the third invention group is characterized
by the following constitution, and this constitution can provide a
coating material which is transparent in a range of visible ray and
can be crosslinked in a range of an ultraviolet ray as well as can
be bonded and fixed on a substrate by a chemisorbing method.
[0200] (1) A chemical adsorbent consisting of a compound in a
normal chain comprising a group represented by the following
Chemical Formula 3-1 and a group of --SiX (X is a halogen).
--C.ident.C--C.ident.C-- [Chemical Formula 3-1]
[0201] (2) It is possible that the above-mentioned compound is
represented by the following Chemical Formula 3-2 in the
above-mentioned composition (1).
R--C.ident.C--C.ident.C-A-O--SiR'pX.sub.3-p [Chemical Formula
3-2]
[0202] (R is an alkyl group, R' is an alkyl group or an alkoxy
group, X is a halogen, p is an integer of 0 to 2 inclusive and A is
a bifunctional group.)
[0203] (3) It is possible that the above-mentioned compound is
represented by the following Chemical Formula 3-3 in the
above-mentioned composition (1).
CnH.sub.2n+1--C.ident.C--C.ident.C--(CH.sub.2)m--O--SiCl.sub.3
[Chemical Formula 3-3]
[0204] (n and m is an integer of 3 to 14 inclusive.)
[0205] The following constitutions can be adopted as a method of
manufacturing a chemical adsorbent having the above-mentioned
composition.
[0206] (4) A method of manufacturing a chemical adsorbent wherein a
compound having a bond of --O--SiX.sub.3 is synthesized by causing
a condensation reaction of an alcohol comprising a group
represented by the following Chemical Formula 3-1 and SiX.sub.4 (X
is a halogen) in an atmosphere of inert gas.
--C.ident.C--C.ident.C-- [Chemical Formula 3-1]
[0207] (5) In the above-mentioned composition (4), it is possible
to synthesize an alcohol having an organic group represented by the
above-mentioned Chemical Formula 3-1 by a condensation reaction of
a compound comprising a group represented by the following Chemical
Formula 3-4 at an end and a compound having a group represented by
the following Chemical Formula 3-5 at an end and a hydroxyl group
at the other end.
--C.ident.CH [Chemical Formula 3-4]
XC.ident.C-- [Chemical Formula 3-5]
BRIEF DESCRIPTION OF THE DRAWINGS OF THE THIRD INVENTION GROUP
[0208] FIG. 1 is a chart showing .sup.1H-NMR spectrum of a chemical
adsorbent in Embodiment 3-1.
[0209] FIG. 2 is a chart showing an ultraviolet and visible
absorption spectrum in chloroform of a chemical adsorbent in
Embodiment 3-1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE THIRD
INVENTION GROUP
[0210] The third invention group is detailed based on embodiments
below. In embodiments below, R-1200 made by HITACHI Ltd. was used
for an analysis of .sup.1H-NMR (nuclear magnetic resonance)
spectrum, FTIR 4300 made by SHIMADZU Corp. was used for an analysis
of IR (infrared absorption) spectrum, and UV-240 made by SHIMADZU
Corp. was used for an analysis of UV (ultraviolet absorption)
spectrum.
[0211] (Embodiment 3-1)
[0212] Reaction Process 1
[0213] A refined product of 57.5 g was obtained (a yield of 70.8%)
by preparing 115.2 g of potassium hydroxide and 300 ml of water in
a reaction flask of 1L, and cooling to -5 to 0.degree. C., and
dropping 122.4 g of bromine in this solution through a strong
stirring for 25 minutes; next, dropping 45.0 g of 5-Hexyn-1-ol
(0.459 mol) at a temperature of 15.degree. C. for 30 minutes, and
after stirring at the same temperature for 30 minutes, extracting
the mixture with isopropyl alcohol, and after washing the extracted
solution with saturated saltwater; drying on MgSO.sub.4; after
removing the solvent, gaining a coarse product of 78.6 g, and
refining this product with silica gel column while using a mobile
phase of n-hexane:ethyl acetate=2:1.
[0214] Reaction Process 2
[0215] A refined product of 12.8 g was obtained (a yield of 32.3%)
by preparing 1.16 g of copper (I) chloride and 26 ml of water and
58 ml of 70%-ethyl amine and 7.21 g of hydroxylamine hydrochloride
in a reaction flask of 1L in an air current of nitrogen, and
stirring at a room temperature for 20 minutes; later, adding a
solution of 26.0 g of 1-Tridecyne (0.144 mol) in 270 ml of methanol
to the solution, and stirring for 20 minutes; dropping a solution
of 25.5 g of 6-Bromohex-5-yn-1-ol (0.144 mol) in 70 ml of methanol
in the yellow suspension at a temperature of 40.degree. C. for 50
minutes, and after dropping, stirring at the same temperature for 1
hour; next, adding 230 ml of aqueous solution of 3.6 g of potassium
cyanide and 14.4 g of ammonium chloride through a strong stirring,
and extracting the mixture with ethyl acetate, and after washing
the extracted solution with saturated aqueous solution of ammonium
chloride, drying on MgSO4; after removing the solvent, gaining a
coarse product of 39.0 g, and refining this product with silica gel
column while using a mobile phase of n-hexane:ethyl
acetate=4:1.
[0216] Reaction Process 3
[0217] A refined product (the following general Chemical Formula
3-6) of 16.2 g was obtained (a yield of 85.3%) by preparing 12.8 g
of 5,7-Nonadecadiyne-1-ol (46.4 mol) and 20 g of SiCl.sub.4 in a
reaction flask of 100 ml in air current of argon, and stirring at a
room temperature for 1 hour; after removing excessive SiCl.sub.4,
filtering the insolubles.
C.sub.11H.sub.23--C.ident.C--C.ident.C--(CH.sub.2).sub.4--O--SiCl.sub.3
[Chemical Formula 3-6]
[0218] A product and an end product in each process were confirmed
by .sup.1H-NMR (FIG. 3-1).
[0219] FIG. 3-2 shows an ultraviolet and visible absorption
spectrum which was obtained in chloroform. The absorption spectrum
proves the existence of a signal in a range from 240 nm to 280 nm
as well as no absorption in a range of visible ray and a strong
absorption in a range of an ultraviolet ray and a far-ultraviolet
ray.
[0220] (Embodiment 3-2)
[0221] 7-Octyn-1-ol was substituted for 5-Hexyn-1-ol in Reaction
Process 1 of Embodiment 3-1. The same reaction except the above was
executed. As a result, a substance represented by the following
general Chemical Formula 3-7 was obtained with a final yield of
35.6%.
C.sub.11H.sub.23--C.ident.C--C.ident.C--(CH.sub.2).sub.6--O--SiCl.sub.3
[Chemical Formula 3-7]
[0222] (Embodiment 3-3)
[0223] 1-Dodecyne was substituted for 1-Tridecyne in Reaction
Process 2 of Embodiment 3-1. The same reaction except the above was
executed. As a result, a substance represented by the following
general Chemical Formula 3-8 was obtained with a final yield of
28.2%
C.sub.9H.sub.19--C.ident.C--C.ident.C--(CH.sub.2).sub.6--O--SiCl.sub.3
[Chemical Formula 3-8]
[0224] A group of --SiCl.sub.3 was used as an area for adsorbing in
the above embodiments, and it is possible to synthesize a substance
comprising a halosilyl group represented by the following general
Chemical Formula 3-9 similarly.
--SiRpX.sub.3-p [Chemical Formula 3-9]
[0225] (R is an alkyl group or an alkoxy group, X is a halogen and
p is an integer of 0 to 2 inclusive.)
[0226] As described above, according to the third invention group,
it is possible to efficiently manufacture a chemical adsorbent in a
normal chain which is transparent and stable in a range of a
visible ray, and has a functional group represented by the
above-mentioned Chemical Formula 3-1 in its molecule as a
photosensitive group for photopolymerizing in a range of an
ultraviolet ray, and comprises a group of --SiCl.sub.3 effective as
an area for adsorbing in the case of using a chemisorbing method.
Among a chemical adsorbent in the third invention group, it is
possible to use a chemical adsorbent, which has a range of a
photosensitive wavelength in a range of an ultraviolet ray and a
far-ultraviolet ray (a wavelength from 200 nm to 400 nm) and is
transparent in a range of visible ray (a wavelength from 400 nm to
700 nm), appropriately for a material for a liquid crystal
alignment layer.
DISCLOSURE OF THE FOURTH INVENTION GROUP
[0227] The invention in the fourth invention group is characterized
by the following constitution.
[0228] (1) A liquid crystal alignment layer consisting of a thin
film in a monolayer which is chemisorbed on a substrate surface
with at least an electrode, wherein the above-mentioned thin film
is composed of a substance comprising a molecule which originates
in a group represented by the following Chemical Formula 4-1.
--C.ident.C--C.ident.-- [Chemical Formula 4-1]
[0229] (2) In the above-mentioned (1), the above-mentioned
substance comprises at least one of chemical bond units represented
by the following Chemical Formula 4-2, Chemical Formula 4-3,
Chemical Formula 4-4 or Chemical Formula 4-5, and is chemisorbed on
the above-mentioned substrate surface through Si in the
above-mentioned chemical bond unit, which is crosslinked to each
other through a bond of C--C in a particular direction. 31
[0230] (In the above-mentioned Chemical Formulae 4-2 to 4-5, A is a
bifunctional group.)
[0231] A liquid crystal alignment layer having a structure in which
a component molecule is crosslinked to each other at a group
represented by the above-mentioned Chemical Formula 4-1 is suitable
for aligning a liquid crystal molecule. In particular, the liquid
crystal alignment layer has a large alignment control force over a
twisted nematic type liquid crystal.
[0232] A liquid crystal alignment layer having the above-mentioned
composition can be manufactured by a manufacturing method having
the following constitutions.
[0233] (3) A method of manufacturing a liquid crystal alignment
layer comprising the steps of forming a thin film consisting of a
chemisorbed molecule by contacting a solution comprising a chemical
adsorbent having a group represented by the following Chemical
Formula 4-1 and a group of --SiX (X is a halogen) on a substrate
surface with at least an electrode, and chemisorbing the
above-mentioned chemical adsorbent on the above-mentioned substrate
surface; and crosslinking the chemisorbed molecule composing the
thin film along a particular direction by irradiating an
ultraviolet ray or a far-ultraviolet ray on the above-mentioned
thin film surface.
--C.ident.C--C.ident.-- [Chemical Formula 4]
[0234] (4) In the above-mentioned (3), it is possible to add the
steps of washing for removing the chemical adsorbent which is not
yet adsorbed, and draining a washing solution in a certain
direction after the above-mentioned step of forming a thin film,
and to execute the above-mentioned step of crosslinking after the
step of draining.
[0235] According to this composition, it is easy to control a
direction of crosslinking since a removal of a molecule which is
not yet adsorbed and a provisional alignment of an adsorbent
molecule can be executed efficiently, and light is irradiated to a
provisionally aligned adsorbent molecule.
[0236] (5) In the above-mentioned (3), it is possible to use a
nonaqueous solvent as the above-mentioned washing solution.
[0237] (6) In the above-mentioned (4), it is possible to execute
the above-mentioned draining by pulling up the above-mentioned
substrate while holding in a vertical direction to a solution
surface after immersing the substrate with a thin film in a washing
solution comprising a nonaqueous solvent.
[0238] (7) In the above-mentioned (3), it is possible to execute
the above-mentioned irradiation through a polarizer or a
transparent plate on which rubbing is executed.
[0239] According to this composition, an adsorbent molecule can be
aligned in a particular direction.
[0240] (8) In the above-mentioned (4), it is possible to execute
the above-mentioned irradiation through a polarizer or a
transparent plate on which rubbing is executed.
[0241] According to this composition, an adsorbent molecule can be
aligned in a particular direction.
[0242] (9) In the above-mentioned (3), it is possible to execute
the above-mentioned irradiation through a patterned mask which is
put on a polarizer or a transparent plate on which rubbing is
executed, and thereby control a direction of a chemical bond
between adsorbent molecules and change an alignment direction of an
adsorbent molecule in each patterned small section.
[0243] (10) In the above-mentioned (4), it is possible to execute
the above-mentioned irradiation through a patterned mask which is
put on a polarizer or a transparent plate on which rubbing is
executed, and thereby control a direction of a chemical bond
between adsorbent molecules and change an alignment direction of an
adsorbent molecule in each patterned small section.
[0244] (11) In the above-mentioned (3), it is possible to use a
solvent consisting of a molecule comprising the groups of alkyl,
fluorocarbon, carbon chloride or siloxane as a solvent in a
solution comprising the above-mentioned chemical adsorbent.
[0245] A liquid crystal display device in the present invention
using a liquid crystal alignment layer manufactured by the
above-mentioned manufacturing method can be composed as described
below.
[0246] (12) A liquid crystal display device with a structure in
which two substrates with at least an electrode are opposed through
the electrode side and a liquid crystal is sealed between the
substrates, wherein a liquid crystal alignment layer is formed on a
surface of at least one of the above-mentioned substrates and the
above-mentioned liquid crystal alignment layer is made by bonding
and fixing on a substrate surface a thin film comprising a
substance which originates in a chemical adsorbent having a
functional group represented by the following Chemical Formula 4-1
and a group of --SiX (X is a halogen) in a molecular structure
--C.ident.C--C.ident.-- [Chemical Formula 4-1]
[0247] (13) In the above-mentioned (12), it is possible that the
above-mentioned liquid crystal alignment layer is composed of a
thin film in a monolayer which comprises at least one of chemical
bond units represented by the following Chemical Formula 4-2,
Chemical Formula 4-3, Chemical Formula 4-4 or Chemical Formula 4-5,
and is chemisorbed on a surface of the above-mentioned substrate at
an end of an Si group in the chemical bond unit, which is
crosslinked to each other through a bond of C--C in a particular
direction.
[0248] (14) In the above-mentioned (12), it is possible that the
above-mentioned liquid crystal alignment layer has a different
liquid crystal alignment direction at each of a plurality of small
sections into which a pixel unit is divided
[0249] (15) In the above-mentioned (14), it is possible that the
above-mentioned small section is arrayed in a pattern in a pixel
area on a substrate.
[0250] (16) In the above-mentioned (13), it is possible that the
above-mentioned liquid crystal alignment layer has a different
liquid crystal alignment direction at each of a plurality of small
sections into which a pixel unit is divided.
[0251] (17) In the above-mentioned (14), it is possible that the
above-mentioned small section is arrayed in a pattern in a pixel
area on a substrate.
[0252] A liquid crystal display device in the fourth invention
group can be composed as described below.
[0253] (18) A liquid crystal display device of an in-plane
switching type (IPS) in which an electrode and an opposite
electrode are formed on the same substrate, wherein a liquid
crystal alignment layer is formed on a surface with the electrode
and the opposite electrode of the above-mentioned substrate and the
above-mentioned liquid crystal alignment layer is made by bonding
and fixing a chemical adsorbent having a functional group
represented by the above-mentioned Chemical Formula 4-1 and a group
of --SiX (X is a halogen) in a molecular structure on a substrate
surface through a bond of --Si --O-- as well as crosslinking a
component molecule to each other in a particular direction.
[0254] (19) In the above-mentioned (18), the above-mentioned liquid
crystal alignment layer is composed of a thin film in a monolayer
which comprises at least one of chemical bond units represented by
the following Chemical Formula 4-2, Chemical Formula 4-3, Chemical
Formula 4-4 or Chemical Formula 4-5, and is chemisorbed on a
surface of the above-mentioned substrate at an end of an Si group
in the chemical bond unit, which is crosslinked to each other
through a bond of C--C in a particular direction.
[0255] The above-mentioned liquid crystal display device can be
manufactured by a manufacturing method having the following
constitutions.
[0256] (20) A method of manufacturing a liquid crystal display
device comprising the steps of producing a chemisorption solution
by dissolving a chemical adsorbent comprising a functional group
represented by the following Chemical Formula 4-1 and a group of
--SiX (X is a halogen) in a molecular structure in a nonaqueous
solvent; forming a thin film in a monolayer by contacting the
above-mentioned chemisorption solution on a first substrate with at
least a group of electrodes in a matrix, and chemisorbing the
chemical adsorbent on the above-mentioned substrate plane at the
group of --SiX; aligning an adsorbent molecule provisionally by
drain-drying the nonaqueous solvent for washing while setting up
the above-mentioned substrate in a certain direction after washing
the above-mentioned thin film with a nonaqueous solvent; providing
an alignment characteristic by means of producing the first
substrate with a liquid crystal alignment layer having a particular
alignment characteristic by irradiating an ultraviolet ray or a
far-ultraviolet ray on the provisionally aligned thin film, and
crosslinking the adsorbent molecule to each other in a particular
direction through a photopolymerization; producing an empty cell by
sticking and fixing a periphery of the substrates after joining
through the electrodes plane with a predetermined gap the
above-mentioned first substrate with a liquid crystal alignment
layer as well as an opposite substrate or a second substrate with a
liquid crystal alignment layer having an opposite electrode, which
is produced like the above-mentioned first substrate with a liquid
crystal alignment layer; and injecting a liquid crystal into the
above-mentioned empty cell.
[0257] (21) In the above-mentioned (20), it is possible to execute
an irradiation of the ultraviolet ray or the far-ultraviolet ray in
the above-mentioned step of providing an alignment characteristic
through a patterned mask which is put on a polarizer, and thereby
control a direction of a chemical bond between adsorbent molecules
and produce the first substrate with a liquid crystal alignment
layer in a multidomain alignment having a different alignment
direction of an adsorbent molecule in each patterned small
section.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE FOURTH INVENTION GROUP
[0258] FIG. 4-1 is a conceptional view of a cross section for
describing the step of chemisorbing which is used for manufacturing
a liquid crystal alignment layer in Embodiment 4-1 of the fourth
invention group.
[0259] FIG. 4-2 is a conceptional view of a cross section for
describing the step of washing in manufacturing a liquid crystal
alignment layer in Embodiment 4-1 of the fourth invention
group.
[0260] FIG. 4-3 is a view describing a light exposure treatment of
a liquid crystal alignment layer in Embodiment 4-1 of the fourth
invention group.
[0261] FIG. 4-4 is a conceptional view of the step of exposing
which is used for realigning an adsorbent molecule by light
exposure in Embodiment 4-1 of the fourth invention group.
[0262] FIG. 4-5 is a conceptional view for describing an alignment
state of a molecule in a liquid crystal alignment layer after light
exposure m Embodiment 4-1 of the fourth invention group.
[0263] FIG. 4-6 is a view showing a polymerization reaction in
Embodiment 4-1 of the fourth invention group.
[0264] FIG. 4-7 is a conceptional view of a cross section for
describing the manufacture of a liquid crystal display device in
Embodiment 4-3 of the fourth invention group.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE FOURTH
INVENTION GROUP
[0265] The fourth invention group is detailed using embodiments
below.
[0266] (Embodiment 4-1)
[0267] A glass substrate 1 (including a multitude of hydroxyl
groups on its surface) with a transparent electrode on its surface
was prepared, and washed and degreased sufficiently beforehand.
Next, a chemisorption solution was produced by dissolving a
chlorosilane-based chemical adsorbent (chemisorbed compound or
surface active agent) comprising a carbon chain as well as a group
represented by the above-mentioned Chemical Formula 4-1 and Si at
an end of or inside the above-mentioned carbon chain, such as the
following general Chemical Formula 4-6, in a nonaqueous solvent at
a concentration of approximately 1 wt. %.
C.sub.11H.sub.23--C.ident.C--C.ident.C--(CH.sub.2).sub.6--O--SiCl.sub.3
[Chemical Formula 4-6]
[0268] Well-dehydrated hexadecane was used as the nonaqueous
solvent A solution thus produced was made an adsorption solution 2,
and the above-mentioned substrate 1 was immersed (or may be
applied) in the adsorption solution 2 in a dry atmosphere (a
relative humidity of 30% or less) for approximately an hour (FIG.
4-1).
[0269] Later, after pulling up the substrate 1 out of the
adsorption solution 2 and washing the substrate 1 with
well-dehydrated n-hexane 3 as a well-dehydrated nonaqueous solvent,
the substrate 1 was pulled up out of a washing solution while
setting up the substrate 1 in a desired direction and the washing
solution was drained and the substrate 1 was exposed to an
atmosphere including humidity (FIG. 4-2). Through a series of the
above-mentioned steps, a reaction of eliminating HCl was caused
between a group of SiCl in the above-mentioned chlorosilane-based
chemical adsorbent and a hydroxyl group on the above-mentioned
substrate surface, and additionally, a bond of the following
general Chemical Formula 4-7 was produced by reacting with humidity
in an atmosphere and a thin film in a monolayer (hereinafter
referred to as `chemical adsorbent monomolecular film`) was formed.
This substance had a photosensitive peak in a range from 240 to 290
nm.
C.sub.11H.sub.23--C.ident.C--C.ident.C--(CH.sub.2).sub.6--O--Si(--O--).sub-
.3 [Chemical Formula 4-7]
[0270] Then, such an effect that the above-mentioned fixed molecule
is aligned provisionally in a drain direction is produced by
washing the substrate 1 with an organic solvent and furthermore
draining while setting up the substrate 1 in a desired direction.
By means of the above treatment, a chemisorbed monomolecular film 4
which is formed by a reaction of the above-mentioned
chlorosilane-based chemical adsorbent was fixed to an area
including a hydroxyl group on the substrate surface through a
siloxane bond, and the bonded molecule was formed with a coating
thickness of approximately 2 nm in an alignment state along the
drain direction.
[0271] Later, furthermore, a polarizer (HNP'B) 7 (made by POLAROID
Corp.) was put on two kinds of substrates in this state so that a
polarized direction 6 was in approximately parallel with the drain
direction 5, and an ultraviolet ray 8 of 100 mJ with a wavelength
of 254 nm was irradiated (2.1 mW/cm.sup.2, after transmitting a
polarized film) by using an extra-high-pressure mercury-vapor lamp
of 500W (FIG. 4-3).
[0272] Later, when an anisotropy of an adsorbent molecule was
examined with FT-IR, the above-mentioned photosensitive group was
photopolymerized and thereby the absorption peak of a diacetylene
group did not appear. Although a direction of a bond was not clear,
the polarized direction differed from a vertical direction to the
polarized direction in an absorption of a vinyl group. That is,
this indicates that a substance composing the above-mentioned
monomolecular film is photopolymerized at the above-mentioned
photosensitive group along a predetermined direction. This
indicates that a realignment is caused as shown in FIG. 4-4.
[0273] Moreover, two substrates in this state were combined through
a chemisorbed film so that polarized directions were parallel and
drain directions were opposite, namely, antiparallel, and a liquid
crystal cell with a gap of 20 .mu.m was constructed, and a nematic
liquid crystal (ZLI4792; made by MELC Corp.) was injected, and an
alignment state was examined. The injected liquid crystal molecule
was aligned at an pretilt angle of approximately 5.degree. with the
substrate along a direction at an angle of 90.degree. with the
polarized direction (FIG. 4-5). In FIG. 4-5, 1 indicates a
transparent electrode and 5 indicates a direction of pulling up in
FIG. 4-2.
[0274] It was found through the above that although a molecule
composing a film had a structure as shown in FIG. 4-5 at first, the
molecule experienced a polymerization reaction shown in FIG.
4-6.
[0275] Then, it is necessary that the drain direction crosses the
polarized direction 6 at an angle of not completely 90.degree. but
with a little shift from 90.degree., preferably more than some
degrees in order to make an alignment direction of an adsorbent
molecule in an irradiated area the same direction. In this case,
the polarized direction 13 may be in parallel with the direction 5
of draining and pulling up at the maximum. If the direction 5 of
draining and pulling up crosses the polarized direction 6 at an
angle of completely 90.degree., each molecule is occasionally
aligned in two directions.
[0276] When an ultraviolet ray of 100 to 200 mJ with a wavelength
of 365 nm was irradiated through a patterned mask on a polarizer in
order to change an alignment direction selectively, an alignment
direction changed only in an irradiated area and it was possible to
provide a plurality of parts in which an alignment direction
differs in a pattern on the same alignment layer, namely, a liquid
crystal is aligned along each of the draining direction 5 and the
polarized direction 13. Moreover, it was possible to manufacture
extremely easily a liquid crystal alignment layer in a monolayer
having a plurality of alignment directions which differ in a
pattern by executing the step of exposing through a desired mask on
a polarizer on the same condition a plurality of times. That is, it
was possible to provide a liquid crystal display device wherein a
pixel is in a multidomain alignment.
[0277] In Embodiment 4-1, hydrocarbon-based n-hexane comprising an
alkyl group was used as a nonaqueous solvent for washing, and any
nonaqueous solvent that dissolves a chemical adsorbent can be used
besides this solvent. For instance, it was possible to use a
solvent comprising the groups of fluorocarbon, carbon chloride or
siloxane such as Freon 113, chloroform and
hexamethyldisiloxane.
[0278] An effect of aligning a twisted nematic liquid crystal was
particularly great in a liquid crystal alignment layer comprising a
chemical bond unit represented by the above-mentioned Chemical
Formula 4-2 to 4-5 in Embodiment 1.
[0279] Then, a solvent comprising the groups of alkyl,
fluorocarbon, carbon chloride or siloxane was applicable to a
nonaqueous organic solvent for producing a chemisorption
solution.
[0280] (Embodiment 4-2)
[0281] In Embodiment 1, a substance represented by the following
general Chemical Formula 4-8 was used as a chlorosilane-based
chemical adsorbent comprising a photosensitive functional group
represented by the above-mentioned Chemical Formula 4-1 and Si
Later, an acrylic plate through rubbing with an abrasive of 0.3
.mu.m was put on a substrate, and a far-ultraviolet ray of 80 mJ
with a wavelength of 254 nm was irradiated (2.1 mW/cm.sup.2, after
transmitting a acrylic plate) by using an extra-high-pressure
mercury-vapor lamp of 500W. The same experiment except the above
was executed. This substance had a photosensitive peak in a range
from 240 to 280 nm.
(CH.sub.3).sub.3Si--C.ident.C--C.ident.C--(CH.sub.2).sub.8--O--SiCl.sub.3
[Chemical Formula 4-8]
[0282] Moreover, two substrates in this state were combined through
a chemisorbed film so that rubbing directions were parallel and
drain directions were opposite, namely, antiparallel, and a liquid
crystal cell with a gap of 20 .mu.m was constructed, and a nematic
liquid crystal (ZLI4792; made by MELC Corp) was injected, and an
alignment state was examined. The injected liquid crystal molecule
was aligned at an pretilt angle of approximately 3.degree. with the
substrate along a direction at an angle of 90.degree. with the
rubbing direction.
[0283] Like the above-mentioned substance, a substance which can be
used as a substance for forming a film is represented by the
following Chemical Formula 4-9 and 4-10 (n is an integer of 1 to 25
inclusive, R is an alkyl group having 1 to 3 C or a phenyl group
and Ar is a functional group comprising a heterocycle).
R.sub.3Si--C.ident.C--C.ident.C--(CH.sub.2).sub.n--SiX.sub.3
[Chemical Formula 4-9]
Ar--C.ident.C--C.ident.C--(CH.sub.2).sub.n--SiX.sub.3 [Chemical
Formula 4-10]
[0284] More specifically, a substance which can be used is
represented by the following Chemical Formula 4-11 (This substance
has a photosensitive peak in a range from 250 to 300 nm.), Chemical
Formula 4-12 This substance has a photosensitive peak in a range
from 240 to 290 nm-), Chemical Formula 4-13 This substance has a
photosensitive peak in a range from 240 to 280 nm.) or Chemical
Formula 4-14 (This substance has a photosensitive peak in a range
from 240 to 310 nm.).
(CH.sub.3).sub.3Si--C.ident.C--C.ident.C--(CH.sub.2).sub.8--SiCl.sub.3
[Chemical Formula 4-11]
(C.sub.6H.sub.5).sub.3Si--CC.ident.--C.ident.C--(CH.sub.2).sub.10--Si(CH.s-
ub.3).sub.2Cl [Chemical Formula 4-12]
C.sub.6H.sub.5--C.ident.C--C.ident.C--(CH.sub.2).sub.10--SiCl.sub.3
[Chemical Formula 4-13]
p-CH.sub.3C.sub.6H.sub.4--(CH.sub.2).sub.2--C.ident.C--C.ident.C--(CH.sub.-
2).sub.10--SiCl.sub.3 [Chemical Formula 4-14]
[0285] These compounds were similarly applicable although they had
a different amount of exposure.
[0286] (Embodiment 4-3)
[0287] An actual process of manufacturing a liquid crystal display
device by using the above-mentioned liquid crystal alignment layer
is described below referring to FIG. 4-7.
[0288] First, as shown in FIG. 4-7, a similar chemisorbed
monomolecular film was manufactured by applying a chemisorption
solution, which was produced under the same procedure as Embodiment
4-1, on a first substrate 23 having a first group of electrodes 21
in a matrix and a group of transistors 22 for driving the
electrodes as well as a second substrate 26 having a group of color
filters 24 opposite to the first group of electrodes and a second
electrode 25.
[0289] As a result, a liquid crystal alignment layer 27, which was
realigned along an electrode pattern, was manufactured like
Embodiment 4-1. Next, the above-mentioned first and second
substrates 23, 26 were joined so that their electrodes were
opposite, and a cell with a gap of approximately 5 .mu.m in which
an alignment direction is twisted by 90.degree. was constructed
with a spacer 28 and an adhesive 29. Later, after injecting the
above-mentioned nematic liquid crystal 30 (ZLI4792; made by MELC
Corp) between the above-mentioned first and second substrates, a
display device was completed by combining polarizers 31, 32. Then,
a pretilt angle of the injected liquid crystal was 5.degree..
[0290] Such a device could display a picture in a direction of an
arrow A by driving each transistor with a video signal while
irradiating a backlight 33 on the whole surface.
[0291] (Embodiment 4-4)
[0292] After forming a monomolecular film in Embodiment 4-3, it was
possible to provide four parts in which an alignment direction
differs in a pattern in the same pixel by executing the step of
exposing through a patterned mask dividing each pixel into four
sections in a check on the above-mentioned polarizer once on the
same condition as Embodiment 4-1. Moreover, it was possible to
improve a viewing angle of a liquid crystal display device greatly
by using the substrate with this alignment layer.
[0293] A liquid crystal display device with a superior stability of
alignment was obtained by forming the above-mentioned film on each
surface of a pair of substrates with an electrode as an alignment
layer.
[0294] The alignment layer was extremely effective in a liquid
crystal display device wherein opposite electrodes are formed on a
substrate surface, namely, in-plane switching (IPS) type because of
no rubbing.
[0295] A light with a wavelength of 254 nm from an
extra-high-pressure mercury-vapor lamp were used as a light for
exposing in the above-mentioned Embodiment 41, and it is possible
to use a light with a wavelength of 436 nm and 405 nm and 365 nm as
well as a light with a wavelength of 248 nm by KrF excimer laser
depending on an absorption of light into a film substance. In
particular, the light with a wavelength of 248 nm and 254 nm has a
high efficiency in energy alignment since the light is easily
absorbed into most substances.
[0296] In addition, a substance comprising an alkoxysilane group
and an isocyanatosilane group could be used as a chemical adsorbent
instead of a substance comprising a group of chlorosilane. In this
case, a film with a high alignment was obtained.
[0297] As described above, the fourth invention group can provide
without rubbing an alignment layer with a high thermal stability,
which is remarkably uniform and thin as compared with a
conventional layer, on which a liquid crystal alignment direction
is injected is controlled by irradiating for photopolymerization
with the use of an ultraviolet ray and a far-ultraviolet ray, and a
pretilt angle is controlled by a composition of a photopolymerized
monomolecular film.
[0298] Moreover, a plurality of parts in which only an alignment
direction differs in a pattern on the same alignment layer can be
provided by executing the step of exposing through a patterned mask
on a polarizer a plurality of times after the step of forming a
monomolecular film, and although it was difficult to manufacture a
liquid crystal display device in a multidomain alignment, wherein
an alignment of each pixel is divided into a plurality of kinds, by
a conventional rubbing, the liquid crystal display device in a
multidomain alignment can be manufactured rationally with a high
efficiency.
[0299] In addition, a liquid crystal display device with an
extremely high reliability can be provided since such an alignment
layer is bonded firmly on a substrate surface through a covalent
bond.
DISCLOSURE OF THE FIFTH INVENTION GROUP
[0300] The fifth invention group is completed by noticing that a
chalcone skeleton has a high photoreactivity, and the constitution
of the invention in the fifth invention group is characterized by a
chemical adsorbent consisting of a chalcone derivative wherein a
functional group is bonded to a benzene ring composing a chalcone
skeleton and a characteristic group comprising a group of --SiX (X
is a halogen, an alkoxyl group or an isocyanato group) is bonded to
the other benzene ring.
[0301] The chalcone skeleton in the above-mentioned composition
indicates a compound represented by the following Chemical Formula
5-4, and a chalcone derivative wherein a particular substituent is
bonded to two benzene rings has a particularly high reactivity. In
a chemical adsorbent having the above-mentioned composition, the
group of --SiX functions as a chemisorbed group. Therefore, the
compound can be chemically bonded (chemisorbed) through the group
of --SiX on a substrate plane having such hydrophilic groups as OH
group, COOH group, NH.sub.2 group, NH group and SH group. Moreover,
a vinyl group functions as a photoreactive group. Therefore, a
molecule can be crosslinked to each other through the vinyl group
by irradiating. 32
[0302] A significance of using a chemical adsorbent having the
above-mentioned composition as a material for a liquid crystal
alignment layer is as follows. A thin film, which is formed by
contacting the above-mentioned chemical adsorbent on a substrate
and chemisorbing it, has a structure in a monolayer wherein a
molecule, in which an end (Si) in a direction of its major axis is
bonded on the substrate plane and the other end is aligned in a
direction opposite to the substrate, is arrayed in a lateral
direction. The film is an extremely thin film in nanometer order,
and transparent in a range of visible ray and chemically stable.
Meanwhile, the film has a characteristic in which a photoreaction
is caused in a vinyl group in a chalcone skeleton by irradiating a
light in a range of ultraviolet rays. Therefore, after chemisorbing
the above-mentioned chemical adsorbent on a substrate, it is
possible to crosslink and connect a component molecule to each
other by irradiating ultraviolet ray, and thereby stabilize an
alignment of the component molecule in a steric structure. In
addition, if a polarized light is used in irradiating ultraviolet
ray, it is possible to cause a crosslinking along a certain
direction and thereby control an alignment direction of the
component molecule by determining a polarized direction.
[0303] In the above-mentioned thin film wherein a molecule is
arrayed in parallel with a substrate plane, a liquid crystal
molecule can enter each gap (valley) between component molecules.
Therefore, a thin film wherein the component molecules are aligned
in a certain direction has a particular alignment of a liquid
crystal. Moreover, since each of the component molecules is
involved in an alignment of a liquid crystal, the above-mentioned
thin film indicates a strong alignment control force despite an
extremely thin film. Furthermore, since a component molecule is
connected to each other by crosslinking, an alignment is not
deteriorated by an external stimulus such as heat and rubbing. In
addition, since the film is extremely thin and transparent, and not
an organic polymer film, it scarcely functions as an electrical
resistance film. Therefore, the film has an extremely appropriate
characteristic for a liquid crystal alignment layer, in which a
light transmission and an electric field for driving a liquid
crystal are not hindered.
[0304] Meanwhile, a conventional liquid crystal alignment layer
(such as a polymer film made of the above-mentioned polyimide),
which is composed closely in a state wherein a long main chain is
tangled up, has difficulty in obtaining a sufficient alignment
control force since only a surface of the film can contribute to an
alignment of a liquid crystal. Moreover, in a conventional
alignment layer for which an alignment is provided by rubbing, the
alignment is changed or deteriorated by an external stimulus such
as heat and rubbing. Furthermore, since such a polymer film as
polyimide has a thick coating and a high electrical resistance, it
is a hindrance factor to a light transmission and a liquid crystal
driving.
[0305] A chemical adsorbent having the above-mentioned composition
is extremely useful as a material for a liquid crystal alignment
layer, and a use for the adsorbent is not limited to this.
[0306] In the above-mentioned composition, it is preferable to add
the components described below in (1) to (4). According to a
composition to which the following components are added, an effect
of the above-mentioned function can be actualized even more
certainly.
[0307] (1) The above-mentioned chalcone derivative is a compound
represented by the following Chemical Formula 5-1. 33
[0308] (A.sub.1 is a functional group bonded to a benzene ring in a
chalcone skeleton, A.sub.2 is a bifunctional group bonded to the
other benzene ring, X is a halogen, an alkoxyl group or an
isocyanato group, A' is an alkyl group or an alkoxyl group, and n
is an integer of 0 to 3 inclusive.)
[0309] (2) A.sub.1 in the above-mentioned Chemical Formula 5-1 is
bonded to 4 position of a benzene ring in a chalcone skeleton.
[0310] (3) A.sub.1 in the above-mentioned Chemical Formula 5-1 is a
characteristic group represented by the following Chemical Formula
5-2 or Chemical Formula 5-3. 34
[0311] (k is an integer of 1 to 18 inclusive, m and n are an
integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q is
an integer of 0 or 1.) 35
[0312] (k is an integer of 1 to 18 inclusive, m and n are an
integer of 0 to 37 inclusive, and q is an integer of 0 or 1.)
[0313] (3-1) A.sub.2 in the above-mentioned Chemical Formula 5-1 is
bonded to 4'-position of a benzene ring in a chalcone skeleton.
[0314] (4) A.sub.2 in the above-mentioned Chemical Formula 5-1 is
represented by a group of --(CH.sub.2)--O--, --O--(CH).sub.n--O--,
or --CO--(CH).sub.n--O-- (n is an integer of 2 to 14
inclusive.).
[0315] (5) A.sub.1 in the above-mentioned Chemical Formula 5-1 is a
characteristic group represented by the following Chemical Formula
5-2 or Chemical Formula 5-3 which is bonded to 4-position of a
benzene ring in a chalcone skeleton, and A.sub.2 is represented by
a group of --(CH.sub.2).sub.n--O--, --O--(CH).sub.n--O--, or
--CO--(CH.sub.2).sub.n-- -O-- (n is an integer of 2 to 14
inclusive.) which is bonded to 4'-position of a benzene ring.
[0316] A method of manufacturing the above-mentioned chemical
adsorbent is as follows.
[0317] (6) A method of manufacturing a chemical adsorbent
comprising the step of bonding a halogen or an alkoxy group to Si
in a molecule having a group of a chalcone skeleton with a
functional group at least at 4-position as well as Si in an
atmosphere of inert gas.
[0318] (7) A method of manufacturing a chemical adsorbent
comprising at least the step of synthesizing a chalcone derivative
having a bond of --O--SX.sub.3 by causing a condensation reaction
between an alcohol comprising a group of a chalcone skeleton with a
functional group at least at 4-position of a benzene ring composing
a chalcone skeleton and SiX.sub.4 (X is a halogen) in an atmosphere
of inert gas.
[0319] (8) A method of manufacturing a chemical adsorbent
comprising at least the step of causing an aldol condensation
reaction between a benzaldehyde with a functional group at least at
4-position and a compound having a benzoyl group.
[0320] The invention in the fifth invention group is described in
detail. A chemical adsorbent is characterized by consisting of a
chalcone derivative wherein a functional group is bonded to a
benzene ring composing a chalcone skeleton and a characteristic
group comprising a group of --SiX (X is a halogen, an alkoxyl group
or an isocyanato group) is bonded to the other benzene ring, and
moreover, a compound represented by the following Chemical Formula
5-1 can be exemplified as a preferable form of a chalcone
derivative having this characteristic. In the Chemical Formula 5-1,
a compound in which a functional group (A.sub.1) is bonded to
4-position of a benzene ring in a chalcone skeleton is preferable
because of little steric hindrance and high reactivity in
photoreacting. However, a functional group (A.sub.1) may be bonded
to 2-position or 3-position of a benzene ring, and to 2-position
and/or 3-position as well as 4-position. 36
[0321] (A.sub.1 is a functional group bonded to a benzene ring in a
chalcone skeleton, A.sub.2 is a bifunctional group bonded to the
other benzene ring, X is a halogen, an alkoxyl group or an
isocyanato group, A' is an alkyl group or an alkoxyl group, and n
is an integer of 0 to 3 inclusive.)
[0322] A substituent mentioned below is suitable for a functional
group (A.sub.1) bonded to a benzene ring. However, these are the
examples and, needless to say, the functional group (A.sub.1) is
not limited to these examples.
[0323] (1) Hydrocarbon groups such as methyl, ethyl, n-propyl,
n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl,
n-undecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl,
n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl and phenyl
[0324] (2) A hydrocarbon group comprising a double bond of C.dbd.C
or a triple bond of C.ident.C in a part of the above-mentioned
hydrocarbon group (1)
[0325] (3) A functional group in which another functional group
(such as the groups of methyl, methyl halide, hydroxyl and cyano)
and/or an atom (such as F, Cl, Br and 1) is substituted for a
hydrogen in the above-mentioned hydrocarbon group (1) and (2)
[0326] (4) A perfluoro type functional group of the above-mentioned
hydrocarbon group (1) and (2)
[0327] (5) A functional group in which a fluorine is substituted
for a hydrogen bonded to a carbon from an end to the eighth in the
above-mentioned hydrocarbon group (1) and (2)
[0328] (6) A functional group in which a bond of C--O--C (ether) or
a bond of C--CO--C (carbonyl) is substituted for a part of a bond
of C--C in the above-mentioned hydrocarbon group (1) and (2)
[0329] (7) An alkoxyl group comprising the above-mentioned
hydrocarbon group (1) and (2)
[0330] (8) A perfluoro type functional group in which a bond of
C--O--C (ether) or a bond of C--CO--C (carbonyl) is substituted for
a part of a bond of C--C in the above-mentioned hydrocarbon group
(1) and (2)
[0331] (9) A functional group in which a bond of C--O--C (ether) or
a bond of C--CO--C (carbonyl) is substituted for a part of a bond
of C--C and a fluorine is substituted for a hydrogen bonded to a
carbon from an end to the eighth in the above-mentioned hydrocarbon
group (1) and (2)
[0332] (10) An alkoxyl group comprising a perfluoro substituent of
the above-mentioned hydrocarbon group (1) and (2)
[0333] (11) An alkoxyl group comprising a functional group in which
a fluorine is substituted for a hydrogen bonded to a carbon from an
end to the eighth in the above-mentioned hydrocarbon group (1) and
(2)
[0334] (12) A carbonyl group to which a perfluoro substituent of
the above-mentioned hydrocarbon group (1) and (2) is bonded
[0335] (13) A carbonyl group to which a functional group in which a
fluorine is substituted for a hydrogen bonded to a carbon from an
end to the eighth in the above-mentioned hydrocarbon group (1) and
(2) is bonded
[0336] A substituent having a functional group with a wide
conjugate structure in bonding to a chalcone skeleton and an
electron donative functional group is particularly preferable in
practice among the above-mentioned substituents. The reason is that
a chalcone derivative to which such a functional group is bonded
has a peak wavelength of light absorption in around 365 nm (i-line
of an extra-high-pressure mercury-vapor lamp).
[0337] Meanwhile, a bifunctional group without an atom at an end in
a substituent among the above-mentioned substituents proposed for
A.sub.1 is suitable for a bifunctional group (A.sub.2) bonding a
group of --SiX for chemisorbing (X is a halogen, an alkoxyl group
or an isocyanato group) and a chalcone skeleton. However, the
bifunctional group (A.sub.2) is not limited to the bifunctional
group.
[0338] Among a chemical adsorbent represented by the
above-mentioned Chemical Formula 5-1, a compound, which has a range
of a photosensitive wavelength in a range of an ultraviolet ray and
a far-ultraviolet ray (a wavelength from 200 nm to 400 nm) and is
transparent and colorless in a range of visible ray (a wavelength
from 400 nm to 700 nm), is appropriate for a material for a liquid
crystal alignment layer.
[0339] In a manufacturing method, a chemical adsorbent in the fifth
invention group may be synthesized by using a chalcone derivative
for a starting substance or manufactured by synthesizing a chalcone
skeleton. In order to synthesize a chalcone skeleton, it is
preferable to use an aldol condensation reaction (including the
following dehydration) between a benzaldehyde having at 4-position
a desirable functional group for bonding at 4-position of a
chalcone skeleton and a substance having a benzoyl group. In the
case of using a chalcone derivative for a starting substance, it is
preferable to use a chalcone derivative having at 4-position a
desirable functional group for bonding at 4-position of a chalcone
skeleton. The details of a manufacturing method are described in
the following embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE FIFTH INVENTION GROUP
[0340] FIG. 5-1 is showing the synthesis equations (a) to (c) in
Embodiment 5-1 of the present invention.
[0341] FIG. 5-2 is a chart showing .sup.1H-NMR spectrum of a
compound which was synthesized in Embodiment 5-1 of the present
invention.
[0342] FIG. 5-3 is a chart showing an ultraviolet and visible
absorption spectrum of a compound which was synthesized in
Embodiment 5-1 of the present invention.
[0343] FIG. 5-4 is a chart showing a gas chromatography of a
compound which was synthesized in Embodiment 5-1 of the present
invention.
[0344] FIG. 5-5 is a chart showing an ultraviolet and visible
absorption spectrum of a thin film manufactured by using a compound
which was synthesized in Embodiment 5-1 of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE FIFTH
INVENTION GROUP
[0345] The fifth invention group is detailed using embodiments
below. In embodiments below, R-1200 made by HITACHI Ltd. was used
for an analysis of .sup.1H-NMR spectrum, FTIR 4300 made by SHIMADZU
Corp. was used for an analysis of IR spectrum, and UV-240 made by
SHIMADZU Corp. was used for an analysis of UV/VIS spectrum.
[0346] (Embodiment 5-1)
[0347] Reaction Process 1
[0348] A refined product (4-Methoxy-4'-hydroxychalcone) of 207 g
was obtained (a yield of 75%) by preparing 147 g of
4-Methoxybenzaldehyde (1.08 mol) and 147 g of 4-Hydroxyacetophenone
(1.08 mol) and 1.3L of ethanol in a reaction flask of 5L, and
dropping 2.16L of 10%-sodium hydroxide aqueous solution at a
temperature of 5.degree. C. or less for 3 hours; after dropping,
stirring at a room temperature for 3 days; injecting the solution
into 1.8L of water with ice, and adding 2.5L of 2N-hydrochloric
acid, and gaining precipitated crystal through filtration; washing
the gained coarse crystal with isopropyl alcohol and toluene, and
drying The equation is shown in (a) of FIG. 5-1.
[0349] Reaction Process 2
[0350] A refined product (4-Methoxy-4'-(6-hydroxyhexyloxy)chalcone)
of 134.4 g was obtained (a yield of 53.5%) by preparing 180 g of
4-Methoxy-4'-hydroxychalcone (0.709 mol) and 1260 ml of dry DMF
(N,N-dimethylformamide) in a reaction flask of 3L in an air current
of argon, and adding 28.4 g of 60%-sodium hydride (0.709 mol) in
ice cooling for 40 minutes; later, heating to a room temperature
and stirring for 20 hours; next, dropping 97 g of 6-chlorohexanol
(0.709 mol) at the same temperature for 20 minutes; later, heating
to 80.degree. C., and reacting for 20 hours; after injecting the
solution into water with ice and extracting the product with ethyl
acetate and washing with water, adding magnesium sulfate to the
ethyl acetate solution, and drying through dehydration; later,
removing the ethyl acetate; refining (mobile phase, hexane:ethyl
acetate=1:1) the gained coarse crystal with silica gel column;
furthermore, recrystallizing with ethyl acetate. The equation is
shown in (b) of FIG. 5-1.
[0351] Reaction Process 3
[0352] A refined product represented by the following Chemical
Formula 5-5 of 70 g was obtained (a yield of 56.5%) by preparing 90
g of 4-Methoxy-4'-(6-hydroxyhexyloxy)chalcone (0.245 mol) and 360 g
of silicon tetrachloride (2.12 mol) in a reaction flask of 1L in an
air current of argon, and stirring at a room temperature for 2
hours; after removing excessive silicon tetrachloride and adding
dehydrated hexane to the residue and dispersing a crystal, gaining
through filtration, and drying. The equation is shown in (c) of
FIG. 5-1. 37
[0353] It was confirmed by .sup.1H-NMR that an objective product
was obtained as regards a product and an end product in each
process. FIG. 5-2 shows .sup.1H-NMR spectrum of an end product.
[0354] FIG. 5-3 shows a result of determining an ultraviolet and
visible absorption spectrum after dissolving this substance in
chloroform. As clearly shown in FIG. 5-3, there exists no
absorption in a range of visible ray. Meanwhile, it is confirmed
that an absorption in a range of an ultraviolet ray with a peak of
340 nm. This proves that this substance has a strong absorption in
a range of an ultraviolet ray and a far-ultraviolet ray.
[0355] FIG. 5-4 shows a result of determining gas chromatography of
this substance. The signal at a retention time of 15.257 min. in
FIG. 5-4 indicates
4-Methoxy-4'-(6-trichlorosiloxyhexyloxy)-chalcone which was
obtained in Embodiment 5-1. A purity of this compound is 99.4% or
more, judging from an area ratio of the peak at a retention time of
15.257 min. to all peaks except a peak at a retention time of
approximately 1 min. The signal at a retention time of
approximately 1 min. indicates a solvent with a low boiling point
of a carrier.
[0356] [The Formation and Analysis of a Thin Film]
[0357] A thin film was formed and its characteristic was analyzed
as described below by using a substance represented by the
above-mentioned Chemical Formula 5-5.
[0358] A thin film in a monolayer was formed by washing the
substrate surface with chloroform and removing a substance which is
not yet adsorbed after immersing a quartz substrate (or a glass
substrate) in a solution of a substance represented by the
above-mentioned Chemical Formula 5-5 in a hydrocarbon-based or
silicon-based solvent for 2 hours.
[0359] The analysis of an ultraviolet and visible absorption
spectrum was executed as regards a thin film on the quartz
substrate. FIG. 5-5 shows the result. An absorption peak of 325 nm
resulting from a chalcone skeleton was confirmed by FIG. 5-5.
[0360] The result of determining a contact angle of a thin film on
a glass substrate to water was 64.degree.. Moreover, the result of
determining its thickness by using an ellipsometer with a
refractive index of 1.45 was approximately 2.6 nm.
[0361] It was confirmed through the above that a thin film in a
monolayer having a photoreactive group in a range of an ultraviolet
ray can be formed by contacting a solution of a chemical adsorbent
represented by the above-mentioned Chemical Formula 5-5 to a
substrate.
[0362] Furthermore, after irradiating a polarized light (365 nm, a
light strength of 2.1 mW/cm.sup.2) of 480 mJ/cm.sup.2 on a thin
film of a substrate with a thin film manufactured in the above, the
substrates were joined through the thin film with a gap of 20
.mu.m, and a periphery of the substrates was sealed Later, a
nematic liquid crystal (ZLI4792; made by MELC Corp.) was injected
into the gap between the substrates, and the existence of a liquid
crystal molecule alignment was examined by using a polarizer and a
transmitted light. As a result, it was confirmed that the liquid
crystal molecule was aligned in a polarized direction.
[0363] (Embodiment 5-2)
[0364] 4-Butylbenzaldehyde was substituted for
4-Methoxybenzaldehyde in Reaction Process 1 of Embodiment 5-1. The
same reaction except the above was executed. As a result, a
substance represented by the following Chemical Formula 5-6 was
obtained with a final yield of 65.5%. 38
[0365] (Embodiment 5-3)
[0366] 4-Fluorobenzaldehyde was substituted for
4-Methoxybenzaldehyde in Reaction Process 1 of Embodiment 5-1. The
same reaction except the above was executed As a result, a
substance represented by the following Chemical Formula 5-7 was
obtained with a final yield of 69.3%. 39
[0367] (Embodiment 5-4)
[0368] 4-Perfluorobenzaldehyde was substituted for
4-Methoxybenzaldehyde in Reaction Process 1 of Embodiment 5-1. The
same reaction except the above was executed. As a result, a
substance represented by the following Chemical Formula 5-8 was
obtained with a final yield of 54.2%. 40
[0369] In the above embodiments, a group of --SiCl.sub.3 was
introduced as an area for adsorbing by using a silicon
tetrachloride, and it is possible to synthesize a chemical
adsorbent represented by the following Chemical Formula 5-1 by
substituting a group of Cl--Si--X.sub.nA.sub.3-n' (X is a halogen,
an alkoxyl group or an isocyanato group, and A' is an alkyl group
or an alkoxyl group.) for a silicon tetrachloride. 41
[0370] (A.sub.1 is a functional group bonded to a benzene ring in a
chalcone skeleton, A.sub.2 is a bifunctional group bonded to the
other benzene ring, X is a halogen, an alkoxyl group or an
isocyanato group, A' is an alkyl group or an alkoxyl group, and n
is an integer of 0 to 3 inclusive.)
[0371] As described above, according to the fifth invention group,
it is possible to provide a chemical adsorbent which is transparent
and stable in a range of a visible ray, and has a photosensitive
group to a light in a range of an ultraviolet ray, and further has
a group of --SiX (X is a halogen, an alkoxyl group or an isocyanato
group.) for functioning as an area for adsorbing in the case of
using a chemisorbing method. Therefore, such a notable effect that
an appropriate liquid crystal alignment layer with a superior
alignment characteristic and no hindrance of light transmission and
electric field can be provided with a high productivity is produced
by using this chemical adsorbent.
DISCLOSURE OF THE SIXTH INVENTION GROUP
[0372] The invention in the sixth invention group is characterized
by a liquid crystal alignment layer wherein a thin film comprising
a chemical adsorbent having a characteristic group represented by
the following Chemical Formula 6-1 in a molecular structure is
bonded and fixed directly or with an interposition of a different
substance layer on a substrate surface with an electrode by a bond
of --Si--O--. 42
[0373] It is preferable that a liquid crystal alignment layer
having the above-mentioned composition is, further, a thin film in
a monolayer and has a liquid crystal alignment control force which
can align a liquid crystal molecule in a particular direction.
Furthermore, it is preferable that its coating thickness is 0.5 nm
or more and below 10 nm. Since a thin film in a monolayer has no
hindrance of light transmission and extremely little hindrance of
electric field because of its extreme thinness, it is possible to
actualize a liquid crystal display device with a superior luminance
which can be driven by a low voltage.
[0374] Although an ideal monolayer indicates a layer in which each
component molecule is arrayed along a substrate plane and thereby
is not put on each other, it is realistically difficult to form a
perfect monolayer. Even if a layer is not a perfect monolayer, the
purpose in the sixth invention group can be attained sufficiently.
Accordingly, it is preferred that `a thin film in a monolayer` in
the sixth invention group is a thin film in which a monolayer is
recognized approximately. For instance, a thin film in a monolayer
may include an area in a layer of a plurality of molecules wherein
a molecule which is not yet adsorbed is on an adsorbent molecule on
a substrate, or an area in a range of a plurality of molecules
wherein a molecule which is not bonded and fixed directly on a
substrate is bonded to a directly fixed molecule and additionally
another molecule is bonded to the former molecule. Therefore, a
thin film in a monolayer in the sixth invention group indicates a
layer with a thickness of approximately 5 nm or less.
[0375] It is preferable that A.sub.1 of Chemical Formula 6-1 in the
above-mentioned composition is bonded to 4-position of a benzene
ring in a chalcone skeleton represented by the following Chemical
Formula 6-2, and additionally that A.sub.1 of Chemical Formula 6-1
is a characteristic group represented by the following Chemical
Formula 6-3 or Chemical Formula 6-4. 43
[0376] A.sub.1 is a functional group bonded to a benzene ring.
44
[0377] (k is an integer of 1 to 18 inclusive, m and n are an
integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q is
an integer of 0 or 1.) 45
[0378] (k is an integer of 1 to 18 inclusive, m and n are an
integer of 0 to 37 inclusive, and q is an integer of 0 or 1.)
[0379] A liquid crystal alignment layer having the above-mentioned
composition can be composed of only one kind of chemical adsorbent
having a characteristic group represented by the above-mentioned
Chemical Formula 6-1, or two kinds of chemical adsorbents having a
characteristic group represented by the above-mentioned Chemical
Formula 6-1, or furthermore, more than one kind of chemical
adsorbent having a characteristic group represented by the
above-mentioned Chemical Formula 6-1 and other chemical substances.
In any of the above-mentioned conditions, it is preferable because
of forming a uniform film that at least one of substances composing
a liquid crystal alignment layer (thin film) has an alkyl skeleton
in a normal chain, a siloxane skeleton in a normal chain or a
fluoroalkyl skeleton in a normal chain. Consequently, a uniform
film can actualize a high alignment.
[0380] Moreover, it is possible that a liquid crystal alignment
layer having the above-mentioned composition has a liquid crystal
alignment control force which can align a liquid crystal molecule
in a certain direction and has a liquid crystal alignment control
force which can align in a plurality of different directions. In
the case of aligning in a plurality of different directions, it is
preferable that a small section into which a pixel unit is divided
differs from each other in a liquid crystal alignment direction,
and more preferably that the above-mentioned small section is
formed in a pattern. Consequently, an alignment layer having such
an alignment characteristic can actualize a liquid crystal display
device with a wide viewing angle.
[0381] The above-mentioned liquid crystal alignment layer can be
manufactured by a method of manufacturing a liquid crystal
alignment layer comprising the steps of forming a thin film in a
monolayer on a substrate by contacting a material for a thin film
comprising a chemical adsorbent represented by the following
Chemical Formula 6-5 on the substrate surface with at least an
electrode, and chemisorbing the above-mentioned material for a thin
film on the above-mentioned substrate surface; and treating an
alignment of the above-mentioned thin film. 46
[0382] (A.sub.1 is a functional group bonded to a benzene ring in a
chalcone skeleton, A.sub.2 is a bifunctional group, X is a halogen
or an alkoxyl group, A' is an alkyl group or an alkoxyl group, and
n is an integer of 0 to 3 inclusive.)
[0383] It is preferable that the above-mentioned chemical adsorbent
is a compound wherein A.sub.1 is bonded to 4-position of a benzene
ring and, additionally, is a characteristic group represented by
the following Chemical Formula 6-3 or Chemical Formula 6-4. 47
[0384] (k is an integer of 1 to 18 inclusive, m and n are an
integer of 0 to 37 inclusive, p is an integer of 0 or 1, and q is
an integer of 0 or 1.) 48
[0385] (k is an integer of 1 to 18 inclusive, m and n are an
integer of O to 37 inclusive, and q is an integer of 0 or 1.)
[0386] It is preferable that A.sub.2 of the above-mentioned
Chemical Formula 6-5 is a group of --(CH.sub.2).sub.n--O--,
--O--(CH.sub.2).sub.n--O--, or --CO--(CH).sub.n--O-- (n is an
integer of 2 to 14 inclusive.)
[0387] In the above-mentioned manufacturing method, it is possible
to use a material for a thin film composed of more than one kind of
chemical adsorbent having the above-mentioned functional group, and
a material for a thin film combining more than one kind of chemical
adsorbent having the above-mentioned functional group and other
compounds. The composition of a material for a thin film by a
plurality of kinds of compounds with a different chemical and
physical characteristic can change heat-resistance of a thin film,
density of a thin film, alignment control force, solubility with a
solvent, sensitivity to a polarized light and adsorption force on a
substrate, and thereby an alignment layer with a desirable
characteristic can be obtained.
[0388] Moreover, in the above-mentioned manufacturing method, it is
preferable to add the step of washing a substrate surface with a
thin film with an organic solvent to remove an excessive material
for a thin film between the above-mentioned steps of forming a thin
film and treating an alignment. A nonprotic solvent is preferable
as an organic solvent for washing in terms of washability, and a
mixed solution of a nonprotic solvent and a protic solvent can be
used. Consequently, a mixed solvent can adjust a solubility with a
material for a thin film suitably and control an evaporation rate
of a solvent.
[0389] The following methods of drain-drying and polarizing
irradiation can be exemplified as treating an alignment in the
above-mentioned manufacturing method.
[0390] The above-mentioned method of drain-drying is a method of
contacting an organic solvent on a substrate surface with a thin
film, and later drain-drying the above-mentioned organic solvent in
a certain direction. According to this method, a molecule composing
a thin film can be aligned provisionally. The above-mentioned
organic solvent for washing can be used appropriately as a solvent
for drain-drying. Therefore, washing of a substrate surface and
provisional alignment of a molecule composing a thin film can be
executed by a series of operations of drain-drying an organic
solvent remaining on the substrate plane while setting up the
substrate through washing in a certain direction.
[0391] Although an alignment control force over a liquid crystal
molecule is given by provisional alignment to some extent, a
stability with heat and other external stimuli is insufficient
merely by provisional alignment.
[0392] Meanwhile, a method of polarizing irradiation is a method of
irradiating a polarized light on a substrate plane with a thin
film. According to this method, a molecule composing a thin film
can be chemically bonded (crosslinked) to each other in a
particular direction by photo energy, and thereby an alignment
control force which can align a liquid crystal molecule can be
given to a thin film. This alignment control force is superior in
thermal stability and chemical stability since it is caused by
linking of a molecule through chemical bond.
[0393] It is preferable to execute a plurality of irradiations with
a different light strength and/or wavelength in applying a method
of polarizing irradiation. For instance, a plurality of irradiation
is executed with a weak light strength, and thereby a component
molecule can be chemically bonded to each other without causing a
rise of temperature on an irradiated surface. Moreover, a
crosslinking reaction is caused to some extent by executing the
first irradiation with a polarized light in a range of a short
wavelength closer to an absorption peak, and next the second
irradiation is executed with a polarized light of a longer
wavelength than the first irradiation. Therefore, a component
molecule can be chemically reacted to each other at a
photosensitive group more uniformly while restraining a damage of
molecular structure resulting from light irradiation.
[0394] Furthermore, in a method of polarizing irradiation, it is
possible to execute a plurality of irradiations with a different
incident angle with a substrate. According to this method, a
pretilt angle can be changed.
[0395] In addition, in a method of polarizing irradiation, it is
possible to irradiate a polarized light with a different polarized
direction at each irradiation and irradiate to a different
irradiation section at each irradiation. When a polarized light is
irradiated on a thin film, the polarized light operates chiefly on
a bond between photosensitive atoms parallel with a polarized
direction, and thereby causes a crosslinking at the above-mentioned
bond. Consequently, when a polarized light with a different
polarized direction is irradiated to a different irradiation
section at each irradiation, it is possible to form a plurality of
sections with a different bond direction between molecules. In this
method, it is preferable to make the above-mentioned section
smaller than a pixel unit. Consequently, a liquid crystal alignment
layer in a multidomain alignment with a wide viewing angle can be
manufactured.
[0396] In the above-mentioned method of polarizing irradiation, it
is preferable to control each element of light strength,
wavelength, the number of irradiation, incident angle with a
substrate and irradiation pattern synthetically. An appropriate
control over these elements can manufacture an alignment layer with
a desirable alignment characteristic.
[0397] As treating an alignment in the above-mentioned
manufacturing method, it is possible to adopt a method of
realigning by irradiating a polarized light after aligning
provisionally by a method of drain-drying. This method is
particularly preferable in terms of giving a desirable alignment
characteristic (such as alignment direction, alignment control
force and pretilt angle) certainly and stably. The reason for
obtaining an alignment layer with a strong alignment control force
by irradiating a polarized light after aligning provisionally is
not made clear. However, the fact is confirmed experimentally.
[0398] In the case of adopting the above-mentioned method of
irradiating a polarized light after aligning provisionally, it is
preferable that a polarized direction of a polarized light crosses
a provisional alignment direction (drain-drying direction) at an
angle of not completely 90.degree. but with a little shift from
90.degree., preferably more than some degrees. If a polarized light
is irradiated while crossing a polarized direction and a
provisional alignment direction at right angles, each component
molecule is in danger of being aligned at random in two
directions.
[0399] The following constitution can be adopted as a method of
manufacturing a liquid crystal alignment layer in the sixth
invention group. That is, a method of manufacturing a liquid
crystal alignment layer comprising the steps of forming a thin film
in a monolayer on a substrate by contacting a material for a thin
film comprising a chemical adsorbent represented by the
above-mentioned Chemical Formula 6-5 on the substrate surface with
at least an electrode, and chemisorbing the above-mentioned
material substance for a thin film on the above-mentioned substrate
surface; aligning a molecule composing the thin film provisionally
by drain-drying an organic solvent in a certain direction after
contacting the above-mentioned organic solvent on the substrate
surface with a thin film; and realigning the molecule composing a
thin film by irradiating a polarized light on the provisionally
aligned substrate, and crosslinking the molecule composing a thin
film to each other; wherein a liquid crystal alignment layer in a
multidomain alignment having a different liquid crystal alignment
control direction at each of a plurality of small patterned
sections into which a pixel unit is divided is manufactured by
repeating the above-mentioned steps of aligning provisionally and
realigning more than twice.
[0400] The steps of aligning provisionally and realigning is
repeated in this manufacturing method, and as described above, a
method of irradiating a polarized light after aligning
provisionally can realign efficiently by irradiating a polarized
light. Since a realignment state by crosslinking is never damaged
by drain-drying, a liquid crystal alignment layer in which a
plurality of small sections with a different alignment direction is
formed in a pixel certainly and efficiently can be manufactured by
repeating drain-drying (provisional alignment) and irradiating a
polarized light at a section unit into which a pixel is divided and
drain-drying (provisional alignment) and irradiating a polarized
light at a section unit into which a pixel is divided and so
forth.
[0401] A liquid crystal display device in the sixth invention group
which is formed by using the above-mentioned liquid crystal
alignment layer can be composed as described below. That is, a
liquid crystal display device with a structure in which two
substrates with at least an electrode are opposed through the
electrode side and a liquid crystal is sealed between two
substrates, wherein a liquid crystal alignment layer comprising a
chemical adsorbent having a characteristic group represented by the
following Chemical Formula 6-1 in a molecular structure is bonded
and fixed on a surface of at least one of the above-mentioned
substrates by a bond of --Si--O--.
[0402] A liquid crystal display device of an in-plane switching
type in which an electrode and an opposite electrode are formed on
the same substrate, wherein a liquid crystal alignment layer
comprising a chemical adsorbent having a characteristic group
represented by the following Chemical Formula 6-1 in a molecular
structure is bonded and fixed on a surface with the electrode and
the opposite electrode of the above-mentioned substrate by a bond
of --Si--O--. 49
[0403] The description as regards a liquid crystal alignment layer
such as a preferable condition for a chemical structure of a
chemical adsorbent represented by the above-mentioned Chemical
Formula 6-1 and a preferable composition of a liquid crystal
alignment layer is the same as the description as regards a liquid
crystal alignment layer in the sixth invention group. Accordingly,
a detailed description is omitted. Moreover, in a composition of
the above-mentioned liquid crystal display device, it is preferable
to use a thin film in a monolayer because of no hindrance of light
transmission and electric field and to use a liquid crystal
alignment layer of a multidomain type having different liquid
crystal alignment direction and tilt angle at each of small
sections into which a pixel is divided because of obtaining a wide
viewing angle.
[0404] In a liquid crystal alignment layer in the sixth invention
group, a material for a thin film may be bonded and fixed directly
on a substrate with an electrode through a bond of --Si--O--, or by
forming a different substance layer on an electrode plane and
bonding to the substance layer through a bond of --Si--O--. It is
preferable that a different substance layer is a layer consisting
of such substances having hydrophily as OH group, COOH group,
NH.sub.2 group, NH group and SH group A layer of SiO.sub.2, a layer
of TiO.sub.2 and the like can be exemplified as such a substance
layer.
[0405] A liquid crystal alignment layer in the sixth invention
group is described below in further detail. A liquid crystal
alignment layer in the sixth invention group is a layer wherein a
thin film comprising a chemical adsorbent having a characteristic
group represented by the following Chemical Formula 6-1 is bonded
and fixed directly or with an interposition of a different
substance layer having a hydrophilic group on a substrate with an
electrode by a bond of --Si--O--. This liquid crystal alignment
layer can be manufactured by dissolving a material for a thin film
comprising a chemical adsorbent having a characteristic group
represented by the following Chemical Formula 6-5 in an organic
solvent and contacting the solution on a substrate surface. 50
51
[0406] (A.sub.1 is a functional group bonded to a benzene ring in a
chalcone skeleton, A.sub.2 is a bifunctional group, X is a halogen
or an alkoxyl group, A' is an alkyl group or an alkoxyl group, and
n is an integer of 0 to 3 inclusive)
[0407] A chalcone skeleton (its basic skeleton is represented by
the following Chemical Formula 6-6) has a generally high
photoreactivity, and particularly, a chalcone derivative
represented by the above-mentioned Chemical Formula 6-5 in which a
particular substituent is bonded to two benzene rings has an
extremely high photoreactivity and chemisorption. Therefore,
according to the above-mentioned composition using a chemical
adsorbent represented by the above-mentioned Chemical Formula 6-5,
it is possible to easily form a thin film in a monolayer which is
chemisorbed on a substrate surface. Moreover, a crosslinking
between molecules can be caused easily by irradiating the thin
film. Accordingly, a thin film (alignment layer), which is formed
by chemisorbing a chemical adsorbent represented by the
above-mentioned Chemical Formula 6-5 on a substrate surface, is
extremely thin and bonded and fixed firmly on a substrate. Since
this thin film is not composed of a polymer, it neither hinders
light transmission nor functions as an electrical resistance film
in the case of using it as a liquid crystal alignment layer.
Furthermore, the thin film can have a strong alignment control
force over a liquid crystal molecule and is superior in thermal
stability. Accordingly, the intended purpose in the sixth invention
group can be attained sufficiently.
[0408] It is preferable that a substituent (A.sub.1) in the
above-mentioned composition is bonded to 4-position of a benzene
ring and also 2-position or 3-position. In addition, it is
preferable that a functional group for chemisorbing on a substrate
is bonded to either of 2'-position, 3'-position and 4'-position of
the other benzene ring, and a characteristic group comprising a
group of --SiX represented by the above-mentioned Chemical Formula
6-5 can be exemplified as such a functional group. 52
[0409] A substituent mentioned below is preferable as the
above-mentioned substituent (A.sub.1). However, the substituent
(A.sub.1) is not limited to these substituents.
[0410] (1) Hydrocarbon groups such as methyl, ethyl, n-propyl,
n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl,
n-undecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl,
n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl and phenyl
[0411] (2) A hydrocarbon group comprising a double bond of C.dbd.C
or a triple bond of C.ident.C in a part of the above-mentioned
hydrocarbon group (1)
[0412] (3) A functional group in which another functional group
(such as the groups of methyl, methyl halide, hydroxyl and cyano)
and/or an atom (such as Cl, Br and I) is substituted for a hydrogen
in the above-mentioned hydrocarbon group (1) and (2)
[0413] (4) A perfluoro type functional group of the above-mentioned
hydrocarbon group (1) and (2)
[0414] (5) A functional group in which a fluorine is substituted
for a hydrogen bonded to a carbon from an end to the eighth in the
above-mentioned hydrocarbon group (1) and (2)
[0415] (6) A functional group in which a bond of C--O--C (ether) or
a bond of C--CO--C (carbonyl) is substituted for a part of a bond
of C--C in the above-mentioned hydrocarbon group (1) and (2)
[0416] (7) An alkoxyl group comprising the above-mentioned
hydrocarbon group (1) and (2)
[0417] (8) A perfluoro type functional group in which a bond of
C--O--C (ether) or a bond of C--CO--C (carbonyl) is substituted for
a part of a bond of C--C in the above-mentioned hydrocarbon group
(1) and (2)
[0418] (9) A functional group in which a bond of C--O--C (ether) or
a bond of C--CO--C (carbonyl) is substituted for a part of a bond
of C--C and a fluorine is substituted for a hydrogen bonded to a
carbon from an end to the eighth in the above-mentioned hydrocarbon
group (1) and (2)
[0419] (10) An alkoxyl group comprising a perfluoro substituent of
the above-mentioned hydrocarbon group (1) and (2)
[0420] (11) An alkoxyl group comprising a functional group in which
a fluorine is substituted for a hydrogen bonded to a carbon from an
end to the eighth in the above-mentioned hydrocarbon group (1) and
(2)
[0421] (12) A carbonyl group to which a perfluoro substituent of
the above-mentioned hydrocarbon group (1) and (2) is bonded
[0422] (13) A carbonyl group to which a functional group in which a
fluorine is substituted for a hydrogen bonded to a carbon from an
end to the eighth in the above-mentioned hydrocarbon group (1) and
(2) is bonded
[0423] A substituent having a functional group with a wide
conjugate structure in bonding to a chalcone skeleton and an
electron donative functional group is particularly preferable in
practice among the above-mentioned substituents. The reason is that
a chalcone derivative to which such a functional group is bonded
has a peak wavelength of light absorption in around 365 nm (i-line
of an extra-high-pressure mercury-vapor lamp).
[0424] Meanwhile, a bifunctional group which is a substituent
described in the above-mentioned (1) to (13) without an atom at an
end is suitable for a bifunctional group (A.sub.2) bonding a group
of --SiX essential for chemisorbing the above-mentioned compound on
a substrate (X is a halogen or an alkoxyl group) and a chalcone
skeleton. However, the bifunctional group (A.sub.2) is not limited
to the bifunctional group.
[0425] The above-mentioned compound can be manufactured by
synthesizing a chalcone basic skeleton represented by the
above-mentioned Chemical Formula 6-6 or synthesized by using a
chalcone derivative for a starting substance. In order to
synthesize a chalcone basic skeleton, it is preferable to cause an
aldol condensation reaction (including the following dehydration)
between a benzaldehyde having at 4-position a desirable functional
group for bonding at 4-position of a chalcone skeleton and a
substance having a benzoyl group. Meanwhile, in order to obtain an
objective compound by using a chalcone derivative, it is preferable
to use a chalcone derivative having at 4-position a desirable
functional group for bonding at 4-position of a chalcone skeleton.
However, a method of manufacturing the above-mentioned compound is
not limited to these methods of synthesizing.
[0426] A thin film (an alignment layer precursor) in the sixth
invention group can be manufactured by contacting a solution of the
above-mentioned chemical adsorbent in a nonaqueous solvent on a
substrate with at least an electrode, and it is preferable to
immerse a substrate with an electrode in the above-mentioned
solution. A nonaqueous organic solvent comprising the groups of
alkyl, fluorocarbon, carbon chloride or siloxane can be used as the
above-mentioned nonaqueous solvent Moreover, a thin film consisting
of more than two kinds of composite components can be manufactured
by using a solution comprising the above-mentioned chemical
adsorbent as well as other compounds.
[0427] It is preferable to wash a thin film manufactured by using
the above-mentioned chemical adsorbent to remove a compound which
is not yet adsorbed. A nonprotic solvent is preferable as a solvent
for washing, and a protic solvent and a mixed solvent of both
solvents can be used. A method of mixing a nonprotic solvent and a
protic solvent has an advantage in that a solubility with a
compound can be adjusted suitably.
[0428] A chlorine-based solvent such as chloroform, an aromatic
solvent such as benzene and toluene, a lactone-based solvent such
as .gamma.-butyrolactone, and an ester-based solvent such as ethyl
acetate are suitable for a nonprotic solvent. An alcohol-based
solvent such as methanol and ethanol are suitable for a protic
solvent. However, needless to say, a solvent for washing is not
limited to these solvents.
[0429] A method of drain-drying in a certain direction after
attaching a solvent on a film plane is considered as a method of
treating an alignment More specifically, the methods of
drain-drying are as follows: a method of immersing a coated
substrate approximately vertically to a solvent plane in a vessel
containing the above-mentioned solvent for a certain time, later
pulling up the substrate out of the vessel approximately
vertically, and drying in this state; and a method of flowing a
solvent from above an approximately upright substrate, and later
drying the solvent. According to these methods, a solvent goes down
gradually from an upper edge of a wet plane, and drying progresses
from upper to lower. Therefore, it is possible to align a component
molecule along a progressive direction of drying, and to wash down
an excessive component molecule which is not bonded on a substrate.
An alignment by drain-drying is named a provisional alignment in
the present specification. Since a provisional alignment does not
result from a bond between molecules, it is weaker in an alignment
force than the following method by irradiating a polarized
light.
[0430] A method of irradiating a polarized light on a substrate
surface with a thin film can be exemplified as the other method of
treating an alignment. This method is a method of operating photo
energy on a bond between photosensitive atoms in a molecule
composing a thin film parallel with a polarized direction by
irradiating a polarized light, causing a chemical reaction at the
above-mentioned bond, crosslinking the molecule composing a thin
film to each other, and giving a liquid crystal alignment control
force in a certain direction. This method can give an alignment
characteristic of superior stability. This aligning method is named
a realignment in the present specification.
[0431] A linearly polarized light is preferable as a polarized
light used in the above-mentioned realignment because of causing a
bond between atoms in a certain direction. As a method of obtaining
a linearly polarized light, it is possible to use a method by an
absorption type ordinary polarizer and a method by a non-absorption
type polarized separating element such as a polarized beam
splitter. A wavelength at which a photoreaction is caused in a
material substance for a film is preferable as a wavelength of a
polarized light, and ordinarily a light in a range of an
ultraviolet ray is used. Ordinarily, a temperature from
approximately a room temperature to around 100.degree. C. is used
as a temperature in exposing, and a temperature except this range
is usable. However, a method of treating an alignment which is
applicable to the sixth invention group is not limited to the
above-mentioned methods.
[0432] A characteristic of a liquid crystal alignment layer in the
sixth invention group such as pretilt angle and alignment direction
can be changed by changing the kind of a compound composing a thin
film within a prescribed range in the sixth invention group, and
additionally by changing the kind of a solvent and a condition for
drying in the case of using a method of drain-drying, and
furthermore by changing a condition for irradiating a polarized
light in a method of polarizing irradiation. A change of a
condition for irradiating a polarized light, such as the quantity
of irradiation energy, irradiation angle and the number of
irradiation, is particularly effective in changing a pretilt angle
largely.
[0433] Nematic liquid crystal, smectic liquid crystal, discotic
liquid crystal, ferroelectric liquid crystal and the like can be
used in a liquid crystal display device in the sixth invention
group, and particularly nematic liquid crystal is appropriately
usable in terms of molecular form. A liquid crystal which is
mentioned as nematic liquid crystal are as follows: biphenyl-based,
terphenyl-based, azoxy-based, Schiff base-based,
phenylcydohexane-based, biphenylcydohexane-based, ester-based,
pyrimidine-based, dioxane-based, bicyclooctane-based, cubane-based
and the like.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE SIXTH INVENTION GROUP
[0434] FIG. 6-1 is a conceptional view for describing the step of
chemisorbing for manufacturing a thin film in a monolayer in the
sixth invention group.
[0435] FIG. 6-2 is a conceptional view for describing the step of
washing a thin film in a monolayer in the sixth invention
group.
[0436] FIG. 6-3 is a conceptional view of the step of treating an
alignment by realigning a molecule composing a thin film through
light irradiation.
[0437] FIG. 6-4 is a conceptional view for describing an alignment
state of a molecule composing a thin film after light
irradiation.
[0438] FIG. 6-5 is a cross sectional for describing a liquid
crystal cell in Embodiment 6-1.
[0439] FIG. 6-6 is a cross sectional for describing a liquid
crystal cell in Embodiment 6-5.
[0440] FIG. 6-7 is a model view showing a cross section of a liquid
crystal display device in Embodiment 6-6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE SIXTH
INVENTION GROUP
[0441] The sixth invention group is detailed using embodiments
below.
[0442] (Embodiment 6-1)
[0443] First, a chlorosilane-based chemical adsorbent (or a
chlorosilane-based surface active agent) represented by the
following Chemical Formula 6-7 comprising a carbon chain as well as
a chalcone skeleton and Si at an end of or inside the carbon chain
was synthesized by the same method as Embodiment 5-1 in the fifth
invention group. 53
[0444] Next, a liquid crystal alignment layer was manufactured by
using a chlorosilane-based chemical adsorbent which was synthesized
in the above. A manufacturing method is described below in
sequence.
[0445] A glass substrate with a transparent electrode consisting of
indium stannic oxide on its surface and a layer of SiO.sub.2 on the
transparent electrode was washed and degreased sufficiently
beforehand, and the glass substrate was made a substrate 1.
Meanwhile, a chemisorption solution 2 of the above-mentioned
chemical adsorbent at a concentration of approximately 1 wt. % was
prepared by dissolving the chemical adsorbent in a mixed solvent of
well-dehydrated siloxane-based solvent (KF16L; made by SHIN-ETU
CHEMICAL) and chloroform. This mixed solvent was a nonprotic
solvent.
[0446] Next, as shown in FIG. 6-1, the above-mentioned substrate 1
was immersed (or may be applied) in the above-mentioned
chemisorption solution 2 in a dry atmosphere with a relative
humidity of 30% or less for approximately an hour. Later, the
above-mentioned chemisorption solution 2 was washed out by
immersing in well-dehydrated chloroform 3, a nonprotic solvent, (a
solution for washing), and later after pulling up the substrate 1
in a direction parallel with gravitation (upward) and draining
(FIG. 6-2), the substrate 1 was exposed to an atmosphere including
humidity while setting up it.
[0447] Consequently, a reaction of eliminating HCl was caused
between a group of SiCl in the above-mentioned chemical adsorbent
(chlorosilane-based surface active agent) and a hydroxyl group on
the substrate surface, and additionally, a compound of the
following Chemical Formula 6-8 was produced by reacting with
humidity in an atmosphere. 54
[0448] A thin film in a monolayer which is made by fixing
(chemisorbing) a molecule (hereinafter referred to as `component
molecule`) of a chemical adsorbent (chlorosilane-based surface
active agent) to a hydroxyl group on a substrate surface through a
siloxane bond was formed by a series of the above treatments. The
thickness of this thin film was approximately 25 nm in the case of
using an ellipsometer with a refractive index of 1.45. Moreover, an
opposite substrate with a thin film was prepared by executing the
same operation at a substrate with an opposite electrode.
[0449] An end of a component molecule in a thin film manufactured
in the above is chemisorbed on a substrate surface, and the other
end is aligned along a drain direction to some extent. The reason
why a component molecule is aligned to some extent by the
above-mentioned method is that drain-drying is executed while
setting up a substrate in a certain direction. An alignment by this
method is named a provisional alignment.
[0450] Next, a polarizer 7 (HNP'B; made by POLAROID Corp.) was put
on a provisionally aligned thin film so that a polarized direction
6 was in approximately parallel with the drain direction 5, and an
ultraviolet ray 8 of 480 mJ with a wavelength of 365 nm was
irradiated (a photo strength of 2.1 mW/cm.sup.2, after transmitting
a polarized film) by using an extra-high-pressure mercury-vapor
lamp of 500W (FIG. 6-3).
[0451] An anisotropy of a component molecule in a thin film after
irradiating an ultraviolet ray was examined with FR-IR (Fourier
transform infrared spectroscopy). As a result, although a direction
of a bond between molecules was not made clear, it was confirmed
that the polarized direction differed from a vertical direction to
the polarized direction in an IR absorption, an IR absorption in
the polarized direction was remarkably lower than the vertical
direction. This indicates that a photosensitive group in a chalcone
skeleton was crosslinked by photo energy in the polarized
direction. When a component molecule is crosslinked to each other,
an alignment with a higher stability than a provisional alignment
is given because of fixing an alignment direction of a component
molecule stereostructurally. FIG. 6-4 shows conceptionally a state
in which a component molecule is crosslinked to each other. 34 in
FIG. 6-4 indicates a crosslinked part.
[0452] Next, a liquid crystal cell was constituted by opposing the
substrate 1 and the opposite substrate manufactured in the above
through an alignment layer plane, joining them with a gap of 20
.mu.m through a spacer, and injecting a nematic liquid crystal
(ZLI4792; made by MELC Corp.) into the gap. Two substrates were
disposed so that drain directions of each substrate were opposite
(antiparallel).
[0453] When an alignment direction of a liquid crystal molecule in
this liquid crystal cell was examined by using two polarizers, it
was confirmed that a liquid crystal molecule was aligned along a
drain direction. Moreover, when a pretilt angle was determined by
using an optical crystal rotation method, it was confirmed that a
liquid crystal molecule was aligned at an pretilt angle of
approximately 3.degree. with the substrate plane along a polarized
direction. FIG. 6-5 shows like a model an alignment state of a
liquid crystal molecule in this liquid crystal cell. 10 in FIG. 6-5
indicates a transparent electrode and 11 indicates a layer of a
chemisorbed film.
[0454] (Embodiment 6-2)
[0455] In Embodiment 6-2, a liquid crystal alignment layer having a
different alignment direction at each area was manufactured by
irradiating an ultraviolet ray through a patterned mask. Embodiment
6-2 differs from the above-mentioned Embodiment 6-1 only in a
condition for irradiating an ultraviolet ray, and thereby a
condition for irradiating an ultraviolet ray is chiefly
described.
[0456] First, like Embodiment 6-1, a thin film was formed on a
substrate, and a component molecule was aligned provisionally.
Next, after preparing a patterned mask and putting it on a
polarizer, an ultraviolet ray of 400 to 800 mJ with a wavelength of
365 nm was irradiated on the above-mentioned thin film, and a
liquid crystal cell was produced like Embodiment 6-1.
[0457] An alignment characteristic of a liquid crystal in this
liquid crystal cell was examined by using the same method as the
above. As a result, it was confirmed that an alignment direction in
an area without a mask was changed and an area having a different
alignment direction was formed in a pattern. This indicates that an
alignment area along a provisional alignment direction and an
alignment area along a polarized direction were formed since an
alignment direction in only an area on which a polarized light was
irradiated was changed.
[0458] (Embodiment 6-3)
[0459] In Embodiment 6-3, an ultraviolet ray was irradiated four
times through a mask produced so that a polarized light was
irradiated on a plurality of small sections into which a pixel unit
is divided while changing a position relation between a thin film
plane and a polarized direction each time. A liquid crystal cell
was produced like the above-mentioned Embodiment 6-1, 2 except the
above.
[0460] When an alignment characteristic of a liquid crystal in this
liquid crystal cell of Embodiment 6-3 was examined by using the
same method as the above, it was confirmed that a liquid crystal
cell in a multidomain alignment in a pixel was formed.
[0461] (Embodiment 6-4)
[0462] A compound represented by the following Chemical Formula
6-10 was used as a chemical adsorbent (chlorosilane-based surface
active agent) having a chalcone skeleton and an Si group. A liquid
crystal cell was produced like the above-mentioned Embodiment 6-1
except the above. 55
[0463] When an alignment state in this liquid crystal cell was
examined by using the same method as the above-mentioned Embodiment
6-1, it was confirmed that a liquid crystal molecule was aligned at
an pretilt angle of approximately 3.degree. with the substrate
plane along a polarized direction.
[0464] (Embodiment 6-5)
[0465] In Embodiment 6-5, a thin film 14 was formed by producing a
substrate 2 having a transparent electrode 12 consisting of indium
stannic oxide on a glass plate (having a hydroxyl group on its
surface) and additionally a layer 13 of SiO.sub.2 with a thickness
of 50 nm on the transparent electrode, and using a chemical
adsorbent represented by the above-mentioned Chemical Formula 6-10
on a surface of the substrate 2. A liquid crystal cell of
Embodiment 6-5 was produced like the above-mentioned Embodiment 6-4
except the above. FIG. 6-6 shows a conceptional view of this liquid
crystal cell.
[0466] When an alignment state in the above-mentioned liquid
crystal cell was examined by using the same method as the
above-mentioned Embodiment 6-1, it was confirmed that a liquid
crystal molecule was aligned at an pretilt angle of approximately
4.degree. with the substrate plane along a polarized direction.
[0467] (Embodiment 6-6)
[0468] In Embodiment 6-6, a liquid crystal display device was
manufactured by using the above-mentioned liquid crystal alignment
layer. A process of manufacturing this liquid crystal display
device is described below using FIG. 6-7.
[0469] First, as shown in FIG. 6-7, a similar chemisorbed
monomolecular film was manufactured by applying a chemisorption
solution, which was produced under the same procedure as Embodiment
6-1, on a first substrate 20 having a first group of electrodes 21
in a matrix and a group of TFTs (Thin Film Transistor) 22 for
driving the electrodes as well as a second substrate 24 having a
group of color filters 25 opposite to the first group of electrodes
and a second electrode 26 (opposite electrode). Consequently,
liquid crystal alignment layers 23 and 27, which were realigned
along an electrode pattern, were manufactured like Embodiment
6-1.
[0470] Next, the above-mentioned first and second substrates 20, 24
were joined so that their electrodes were opposite, and a cell with
a gap of 4.5 .mu.m in which an alignment direction is twisted by
90.degree. was constructed with a spacer 29 and an adhesive 30.
Later, a liquid crystal display device was made by injecting the
above-mentioned nematic liquid crystal 28 (ZLI4792; made by MELC
Corp.) between the above-mentioned first and second substrates, and
additionally a liquid crystal display device was completed by
disposing polarizers 31, 32 on both outsides of this device and a
backlight 33 outside the polarizer 31.
[0471] When a tilt angle of a liquid crystal molecule in the
above-mentioned liquid crystal display device was determined by
using the same method as the above-mentioned Embodiment 6-1, it was
approximately 5.degree.. When each transistor was driven with a
video signal while irradiating a backlight 33 from the side of the
first substrate 20 in this device, a clear picture with a superior
luminance could be displayed in a direction of an arrow A
[0472] (Embodiment 6-7)
[0473] After manufacturing the same thin film as Embodiment 6-5,
the step of exposing through a mask in a check dividing each pixel
into four sections on the above-mentioned polarizer was executed
four times by the same method as Embodiment 6-3. A liquid crystal
display device of Embodiment 6-7 was manufactured like the
above-mentioned Embodiment 6-6 except the above.
[0474] When an alignment of a liquid crystal molecule in a liquid
crystal cell of the above-mentioned liquid crystal display device
was examined by using the same method as the above, it was
confirmed that four small sections with a different alignment
direction in the same pixel were formed in a pattern. In addition,
when a viewing angle was observed with the naked eye by using this
device, a viewing angle was improved greatly as compared to a
device with a certain alignment direction in Embodiment 6-6.
[0475] [Other Matters]
[0476] In the above-mentioned Embodiments, a chemisorbed
monomolecular film having an alignment was formed on each of a pair
of substrates with an electrode, and a chemisorbed monomolecular
film having an alignment may be formed on only one of the
substrates. However, it is preferable to form a chemisorbed
monomolecular film having an alignment on both substrates in order
to improve an alignment stability.
[0477] Moreover, in the above-mentioned Embodiments, a chemical
adsorbent having a group of chlorosilane was used, and it is
possible to use a chemical adsorbent introducing an alkoxysilane
group and an isocyanatosilane group instead of a group of
chlorosilane, and to obtain a liquid crystal alignment layer with
superior alignment control force and adsorption force on a
substrate in the case of using these adsorbents as well.
[0478] Furthermore, in the above-mentioned Embodiments, chloroform
was used as a nonaqueous solvent for washing, and any nonaqueous
solvent that can dissolve a chemical adsorbent (surface active
agent) can be used besides this. The following solvents can be
exemplified as such a solvent: for instance, a solvent comprising
the groups of fluorocarbon, carbon chloride or siloxane, more
specifically Freon 113, chloroform and hexamethyldisiloxane.
[0479] In addition, in the above-mentioned Embodiments, a light
with a wavelength of 365 nm from an extra-high-pressure
mercury-vapor lamp were used as a light for exposing, and besides
this, it is possible to use a light with a wavelength of 436 nm and
405 nm and 25 nm as well as a light with a wavelength of 248 nm by
KrF excimer laser depending on an absorption of light into a
chemisorbed monomolecular film. Among lights with these
wavelengths, the light with a wavelength of 248 nm and 254 nm is
superior in terms of efficiency in energy alignment since the light
is easily absorbed into a chemisorbed thin film in the sixth
invention group.
[0480] A liquid crystal alignment layer in the sixth invention
group comprises a chemical bond unit represented by the following
Chemical Formula 6-9, and an alignment layer comprising a chemical
bond unit represented by the following Chemical Formula 6-9 has a
strong alignment control force over a twisted nematic (TN) liquid
crystal. Accordingly, the sixth invention group is particularly
appropriately applicable to a liquid crystal display device of this
type. A chemical adsorbent comprising a chemical bond unit
represented by the following Chemical Formula 6-9 is generally
dissolved in a nonaqueous organic solvent comprising the groups of
alkyl, fluorocarbon, carbon chloride or siloxane. Therefore, these
organic solvents are appropriately usable in producing a
chemisorption solution. 56
[0481] Moreover, in the above-mentioned Embodiments, a liquid
crystal display device, which is made by joining a pair of
substrates with an electrode, is described. According to the sixth
invention group, since an alignment layer having diverse alignment
characteristics can be manufactured without rubbing, the sixth
invention group is appropriately applicable to an in-plane
switching (IPS) type liquid crystal display device wherein an
electrode is formed on a substrate on only either side.
[0482] Furthermore, it is possible to form a thin film by using a
chemical adsorbent used in the above-mentioned Embodiments as well
as a composite chemical adsorbent mixing another chemical
adsorbent, such as octadecyltrichlorosilane. Therefore, it is
possible to change a pretilt angle by mixing another chemical
adsorbent.
INDUSTRIAL APPLICABILITY
[0483] As described above, according to the invention in the first
to sixth invention group, it is possible to form a remarkably thin
and uniform film as compared with a conventional organic polymer
thin film. Moreover, a component molecule in this thin film is
bonded and fixed firmly on a substrate by adsorbing, and a
component molecule is crosslinked to each other. Therefore, this
thin film indicates an alignment which is superior in thermal
stability.
[0484] Furthermore, a liquid crystal alignment layer in the present
invention having a desirable alignment characteristic of a liquid
crystal and no hindrance of a transmission of visible ray and
electric field for driving a liquid crystal can be obtained by
applying an easy method of drain-drying and a method of polarizing
irradiation with the use of an ultraviolet ray and a
far-ultraviolet ray to the above-mentioned thin film. Moreover, a
liquid crystal alignment layer having a different alignment
direction at each small section which is divided in a pattern can
be manufactured extremely efficiently by using a method of
manufacturing a liquid crystal alignment layer in the present
invention wherein an exposure is executed through a patterned mask
on a polarizer a plurality of times after manufacturing a thin
film.
[0485] In addition, a liquid crystal display device with a superior
display performance can be provided by using such a liquid crystal
alignment layer in the present invention. Moreover, a liquid
crystal display device with a wide viewing angle can be actualized
by using a liquid crystal alignment layer of a multidomain type
having a different alignment direction at each small section which
is divided in a pattern.
[0486] Therefore, a significance of a series of the present
invention is great in industry.
* * * * *