Stock material or miscellaneous articles – Composite – Of inorganic material
Reexamination Certificate
1999-11-29
2001-06-12
Yamnitzky, Marie (Department: 1774)
Stock material or miscellaneous articles
Composite
Of inorganic material
C428S917000, C428S704000, C428S332000, C313S504000, C313S506000
Reexamination Certificate
active
06245449
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a material having a triphenylene structure, used for the production of an electroluminescence device, and an organoelectroluminscence device (to be sometimes referred to as “EL device” hereinafter) which uses the above material and is useful as a planar light source or display.
PRIOR ART
Organic photo-conductive materials are advantageously less expensive, easily processible and free from causing pollution, and a variety of compounds have been proposed. Examples of the disclosed organic photo-conductive materials include oxadiazole derivatives (U.S. Pat. No. 3,189,447), oxazole derivatives (U.S. Pat. No. 3,257,203), hydrazone derivatives (U.S. Pat. No. 3,717,462, JP-A-54-59,143, U.S. Pat. No. 4,150,978), triaryl pyrazoline derivatives (U.S. Pat. No. 3,820,989, JP-A-51-93,224, JP-A-55-108,667), arylamine derivatives (U.S. Pat. No. 3,180,730, U.S. Pat. No. 4,232,103, JP-A-55-144,250, JP-A-56-119,132), and stilbene derivatives (JP-A-58-190,9
53
, JP-A-59-195,658).
An organic EL device is one technical example to which the hole transporting capability of an organic photo-conductive material is adapted. An EL device using an organic substance is greatly expected to be usable as a solid light-emitting inexpensive large-screen, full-color display device, and developments thereof are being made in many ways. Generally, an organic EL device is composed of a light-emitting layer and a pair of mutually opposite electrodes sandwiching the light-emitting layer. The light emission by an EL device is the following phenomenon. When an electric field is applied between the two electrodes, the cathode injects electrons into the light-emitting layer, and the anode injects holes into the light-emitting layer. Further, when the electrons recombine with the holes in the light-emitting layer, their energy level shifts from a conduction band back to a valence electron band to release energy as fluorescent light.
As compared with inorganic EL devices, conventional organic EL devices require high voltage for its activation, and further, their light emission brightness and light emission efficiency are low. Further, conventional organic EL devices deteriorate in properties to a great extent, and no organic EL device has been put to practical use.
There has been recently proposed an organic EL device which is produced by laminating a thin film containing an organic compound having a fluorescent quantum effect to emit light at a low voltage as low as less than 10 V, and it attracts attention (Appl. Phy. Lett., Vol. 51, page 913, 1987). The above organic EL device has a fluorescent layer containing a metal chelate complex and a hole-injecting layer containing an amine-based compound, and emits green light having a high brightness. The above organic EL device achieves a maximum brightness of 10,000 cd/m
2
and a maximum light emission efficiency of 1.5 lm/W at a direct current voltage of 6 or 7V and thus has nearly practically usable performance.
An organic EL device has a structure in which a light-emitting layer containing an organic fluorescent compound is provided between a metal cathode layer and a transparent anode layer. Further, an electron-injecting layer and a hole-injecting layer are provided for obtaining light emission having a high brightness at a low voltage. In the organic EL device, electrons injected from a cathode and holes injected from an anode are recombined to generate excitons and the excitons radiate light in the process of radiation thereof to be deactivated (JP-A-59-194393, JP-A-63-295695). However, when the device continues to emit light in the continuous operation under the application of direct current for a long period of time, the organic compound, or an organic photo-conductive material in particular, is promoted in crystallization, and leak current is liable to occur in the device so that the device is liable to be eventually broken. For overcoming the above problem, a compound such as 4,4′,4″-tris(N,N′-diphenylamino)tiphenylamine or 4,4′,4″-tris[N-(3-methylphenyl)-N-phneylamino]-triphenylamine is used as a hole-injecting material for use in a hole-injecting layer (JP-A-4-308688). The above compounds are less crystallizable owing to their steric coordination structure and are excellent in thin film formability, while they are not yet satisfactory as an organic thin film which is to constitute an organic EL device. That is, these compounds do not much undergo crystallization immediately after a film is formed therefrom, while they undergo crystallization with the passage of time and are not feasible for practical use. The device therefore easily deteriorates in the repeated use for light emission.
As discussed above, the organic EL devices which have been so far developed are not sufficient in light emission brightness and light emission stability in the repeated use for light emission. It is therefore desired to develop a hole-injecting material having excellent hole-injecting capability and durability for attaining an organic EL device having a higher light emission brightness, a high light emission efficiency and excellent stability in the repeated use for light emission.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a hole-injecting material for an organic EL device, which material has excellent hole-injecting capability and durability, and an organic EL device having a high light emission efficiency and being capable of light emission in repeated and continuous emission of light due to the use of the above hole-injecting material.
According to the present invention, there is provided a material for an organic electroluminescence device, having the formula [I], [II] or [III],
wherein each of R
1
to R
6
is independently a non-substituted alkyl group, a substituted alkyl group, a non-substituted aryl group, a substituted aryl group, a non-substituted alicyclic group, a substituted alicyclic group, a non-substituted heterocyclic group or a substituted heterocyclic group, or at least one combination of adjacent X
1
—R
1
and X
2
—R
2
, X
3
—R
3
and X
4
—R
4
or X
5
—R
5
and X
6
—R
6
is a non-substituted mono-hetero-cyclic ring, a substituted mono-hetero-cyclic ring, a non-substituted fused poly-hetero-cyclic ring or a substituted fused poly-hetero-cyclic ring, and each of X
1
to x
6
is independently an oxygen atom or a sulfur atom, or each of X
1
to x6 is independently a nitrogen atom to which a hydrogen atom, an alkyl group or an aryl group may be bonding,
wherein each of R
1
, R
2
and R
4
to R
11
is independently a non-substituted alkyl group, a substituted alkyl group, a non-substituted aryl group, a substituted aryl group, a non-substituted alicyclic group, a substituted alicyclic group, a non-substituted heterocyclic group or a substituted heterocyclic group, or at least one combination of adjacent X
1
—R
1
and X
2
—R
2
, X
5
—R
5
and X
6
—R
6
, X
7
—R
7
and X
8
—R
8
, or X
9
—R
9
and X
10
—R
10
is a non-substituted mono-hetero-cyclic ring, a substituted mono-hetero-cyclic ring, a non-substituted fused poly-hetero-cyclic ring or a substituted fused poly-hetero-cyclic ring, each of X
1
to X
12
is independently an oxygen atom, a sulfur atom or a nitrogen atom to which a hydrgeon atom, an alkyl group or an aryl group may be bonding, and A
1
is a chemically rational organic residue which is composed of C, H and O, or is composed of C, H, O and S, and has a molecular weight of 500 or less,
wherein each of R
1
, R
2
, R
4
to R
11
and R
13
to R
17
is independently a non-substituted alkyl group, a substituted alkyl group, a non-substituted aryl group, a substituted aryl group, a non-substituted alicyclic group, a substituted alicyclic group, a non-substituted heterocyclic group or a substituted heterocyclic group, or at least one combination of adjacent X
1
—R
1
and X
2
—R
2
, X
5
—R
5
and X
6
—R
6
, X
7
—R
7
and X
8
—R
8
, X
9
—R
9
and X
10
—R
10
, X
13
—R
13
and X
14
—R
14
, or X
15
—R
15
Enokida Toshio
Okutsu Satoshi
Onikubo Toshikazu
Tamano Michiko
Toyo Ink Manufacturing Co. Ltd.
Wenderoth , Lind & Ponack, L.L.P.
Yamnitzky Marie
LandOfFree
Material for organoelectroluminescence device and use thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Material for organoelectroluminescence device and use thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Material for organoelectroluminescence device and use thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2486372