Polymeric fluorescent substance, polymeric fluorescent substance and polymer light-emitting device using the same
AssigneeSumitomo Chemical Company, Limited
InventorsToshihiro Ohnishi, Takanobu Noguchi, Yoshiaki Tsubata, Masato Ueda, Shigeru Sasaki
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Abstract
A polymeric fluorescent substance or polymeric fluorescent substance solution is disclosed which can attain higher luminous efficiency as a polymer LED. The polymeric fluorescent substance has a specific content of water or poor solvent. Also disclosed is an organic electroluminescence device comprising at least one light-emitting layer that contains substantially no particle-like foreign materials having a diameter of more than 1 μm and that has few dark spots.
Claims58
A polymeric fluorescent substance which emits fluorescence in solid state, has a number-average molecular weight in terms of polystyrene of 1×103 to 1×107, and at least one repeating unit of the following general formula (1), and the amount of water content measured by Karl-Fischer method is not more than 1000 ppm (weight):
- —Ar1—(CR1═CR2)k— (1),
- in the formula, Ar1 is a divalent group forming carbon-carbon bonds with adjacent two groups respectively, the divalent group being an arylene group having 6 to 60 carbon atoms participating in conjugation or a heterocyclic compound group having 4 to 60 carbon atoms participating in conjugation, and the arylene group and heterocyclic compound group may further have a substituent;
- each of R1 and R2 independently represents a group selected from the group consisting of hydrogen atom, linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 60 carbon atoms, heterocyclic compound groups having 4 to 60 carbon atoms and a cyano group, and the aryl group and heterocyclic compound group may further have a substituent;
- and the symbol k is 0 or 1.
A polymer fluorescent substance which emits fluorescence in solid state, has a number-average molecular weight in terms of polystyrene of 1×103 to 1×107, has at least one repeating unit of the following general formula (1), and the amount of contained poor solvent measured by gas-chromatography method is not more than 3500 ppm (weight):
- —Ar1—(CR1═CR2)k— (1)
- in the formula, Ar1 is a divalent group forming carbon-carbon bonds with adjacent two groups respectively, the divalent group being an arylene group having 6 to 60 carbon atoms participating in conjugation or a heterocyclic compound group having 4 to 60 carbon atoms participating in conjugation, and the arylene group and heterocyclic compound group may further have a substituent;
- each of R1 and R2 independently represents a group selected from the group consisting of hydrogen atom, linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 60 carbon atoms, heterocyclic compound groups having 4 to 60 carbon atoms and a cyano group, and the aryl group and heterocyclic compound group may further have a substituent;
- and the symbol k is 0 or 1.
A polymer fluorescent substance solution in which a polymer fluorescent substance is dissolved in an organic solvent in a concentration of 0.1 to 5% by weight;
- the polymer fluorescent substance emits fluorescence in solid state, has a number-average molecular weight in terms of polystyrene of 1×103 to 1×107, has at least one repeating unit represented by the general formula —Ar1—(CR1═CR2)k— (1), and an amount of a poor solvent measured by gas-chromatography method is not more than 1000 ppm (weight), wherein, in the formula, Ar1 is a divalent group forming carbon-carbon bonds with adjacent two groups respectively, the divalent group being an arylene group having 6 to 60 carbon atoms participating in conjugation or a heterocyclic compound group having 4 to 60 carbon atoms participating in conjugation, and the arylene group and heterocyclic compound group may further have a substituent;
- each of R1 and R2 independently represents a group selected from the group consisting of hydrogen atom, linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 60 carbon atoms, heterocyclic compound groups having 4 to 60 carbon atoms and a cyano group, and the aryl group and heterocyclic compound group may further have a substituent;
- and the symbol k is 0 or 1.
A polymer light-emitting device comprising at least one light-emitting layer containing a polymer fluorescent substance having a water content not more than 1000 ppm or a poor solvent content not more than 3500 ppm, placed between a pair of an anode and a cathode at least one of which is transparent or semi-transparent, wherein the light-emitting layer does not contain substantially foreign material particles having a diameter of more than 1 μm.
A process for producing a polymer light-emitting device which comprises at least one light-emitting layer containing a polymeric fluorescent substance, wherein said light-emitting layer is placed between a pair of an anode and a cathode at least one of which is transparent or semi-transparent, wherein the process comprises steps of forming a light emitting layer by:
- preparing a coating material by filtrating a polymeric fluorescent substance solution having a water content not more than 1000 ppm or a poor solvent content not more than 3500 ppm, through a filter having pore diameter of 1 μm or less;
- and
- forming a light-emitting layer using the polymeric fluorescent substance solution.
Dependencies are inferred from the claim text.