Stock material or miscellaneous articles – Composite – Of inorganic material
Reexamination Certificate
2000-10-27
2003-09-16
Yamnitzky, Marie (Department: 1774)
Stock material or miscellaneous articles
Composite
Of inorganic material
C428S917000, C313S504000, C313S506000, C252S301160, C548S303100, C548S312700, C548S343500
Reexamination Certificate
active
06620529
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to novel compounds suitable for use as dyes for filters, color conversion filters, photographic material dyes, sensitizing dyes, dyes for dying pulp, laser dyes, fluorescent drugs for medical diagnoses and materials for light emitting devices, and light emitting devices using them.
BACKGROUND OF THE INVENTION
The promising uses of organic electroluminescence (EL) devices as solid light-emission type, low-priced, large-area, full color display devices result in many developments. In general, a light emitting device is composed of a light emitting layer and a pair of counter electrodes between which the light emitting layer intervenes. When an electric field is applied to between both electrodes, electrons are injected from a cathode, and holes are injected from an anode. Further, the electrons and the positive holes are recombined with each other at the light emitting layer to produce an excited state. When this excited state returns to a ground state, energy is released as light, thereby obtaining luminescence.
The conventional light emitting devices have been high in driving voltage, and low in light emitting luminance and light emitting efficiency. Further, they have also been significantly deteriorated in characteristics, so that they have not come in practice. In recent years, a light emitting device in which thin films containing an organic compound having high quantum efficiency and emitting light at a low voltage of 10 V or less are laminated with each other has been reported (
Applied Physics Letters
, 51, 913 (1987)), and an interest is centered around it. In this device, a metal chelate complex is used as an electron transfer and light emitting material, and laminated with a hole transfer material (amine compound), thereby obtaining green luminescence of high luminance. The luminance reaches thousands of candelas per centimeter square at a voltage of 6-7 V in d.c. However, when considering a practical device, the development of a light emitting device having higher luminance and efficiency has been desired. Further, when considering the utilization thereof as a full color display or a light source, it is practically necessary to give the three primary colors or white. In the above-mentioned device, an aluminum complex of 8-quinolinol (Alq) is used as the light emitting material, so that the light emitting color is green. Accordingly, the development of light emitting materials giving other light emitting colors has been desired. Various light emitting materials emitting colors other than green have hitherto been developed. However, they have the problems of low light emitting luminance and efficiency, and poor durability.
Further, the conventional devices good in color purity and high in light emitting efficiency are ones in which charge transfer materials are doped with fluorescent dyes in slight amounts, and have the problems with regard to the reproducibility of device characteristics from the production point of view, and that the long-term use thereof causes a reduction in luminance and changes in color because of low durability of the dyes. As means for solving the problems, the development of materials having both the charge transfer function and the luminescent function has been desired. However, the materials that have hitherto been developed have the problem that the use of fluorescent dyes at high concentrations leads to a reduction in luminance by association.
On the other hand, organic light emitting devices realizing luminescence of high luminance are devices laminated with organic materials by vapor deposition. The fabrication of the devices by coating is preferred from the viewpoints of simplification of manufacturing processes, processability and enlargement of area. However, the devices fabricated by the conventional coating systems are inferior in light emitting luminance and light emitting efficiency to the devices fabricated by vapor deposition. It has been therefore a great problem to make it possible to emit light of high luminance at high efficiency.
Further, recently, various substances having fluorescence have been used for dyes for filters, color conversion filters, photographic material dyes, sensitizing dyes, dyes for dying pulp, laser dyes, fluorescent drugs for medical diagnoses and materials for light emitting devices have been used, and the demand has increased for them. However, there are not so many compounds high in color purity of blue and strong in fluorescent intensity, so that the development of new materials has been desired.
SUMMARY OF THE INVENTION
It is therefore a primary object of the invention to provide materials for light emitting devices and the light emitting devices, in which luminescence of high luminance and efficiency is possible by driving at low voltage, and excellent in stability in repeated use thereof.
A secondary object of the invention is to provide light emitting devices excellent in color purity, and materials for the light emitting devices making it possible.
A third object of the invention is to provide blue light emitting materials excellent in color purity.
A fourth object of the invention is to provide compounds strong in fluorescent intensity and exhibiting blue fluorescent luminescence.
The above-mentioned objects have been attained by the following means:
(1) A material for a light emitting device consisting of a compound represented by the following general formula (IA):
wherein R
11
, R
12
and R
13
each represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; L
1
represents a connecting group; R
11
and R
12
, R
11
and L
1
, and R
12
and L
1
may each combine with each other to form a ring when possible; R
14
, R
15
, R
16
and R
17
each represents a hydrogen atom or a substituent; and R
13
to R
17
may each combine with each of R
11
to R
17
or L
1
to form a ring when possible;
(2) A compound represented by the following general formula (IIA):
wherein R
13
represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; L
1
represents a connecting group; Q represents an atomic group necessary for forming a 5-, 6- or 7-membered ring with N; R
14
, R
15
, R
16
and R
17
each represents a hydrogen atom or a substituent; and R
13
, R
14
, R
15
, R
16
and R
17
may each combine with each of R
14
to R
17
, the connecting group L
1
or the atomic group Q to form a ring;
(3) A light emitting device comprising a light emitting layer or a plurality of thin organic compound layers containing a light emitting layer formed between a pair of electrodes, wherein at least one layer is a layer containing at least one of the compounds represented by general formulas (IA) and (IIA) described in (1) and (2), respectively;
(4) A light emitting device comprising a light emitting layer or a plurality of thin organic compound layers containing a light emitting layer formed between a pair of electrodes, wherein at least one layer is a layer in which at least one of the compounds represented by general formulas (IA) and (IIA) described in (1) and (2), respectively, is dispersed in a polymer;
(5) A material for a light emitting device consisting of a compound represented by the following general formula (IB):
wherein R
1
and R
2
each represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; Z
1
represents an atomic group necessary to form a heterocycle; L represents a connecting group; and X represents O, S, Se, Te or N—R, wherein R represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group;
(6) A material for a light emitting device consisting of a compound represented by the following general formula (IIB):
wherein R
1
and R
2
each represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; Z
2
represents an atomic group necessary to form an aromatic heterocycle; L represents a connecting group; and X represents O, S, Se, Te or N—R, wherein R represe
Ise Toshihiro
Okada Hisashi
LandOfFree
Materials for light emitting devices and light emitting... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Materials for light emitting devices and light emitting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Materials for light emitting devices and light emitting... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3044286