Polymer for use in organic electroluminescent element and organic electroluminescent element employing same
Provided are a polymer for an organic electroluminescent element, which has improved luminous efficiency and is applicable to a wet process, and an organic electroluminescent element obtained therefrom. The polymer for an organic electroluminescent element has a repeating unit represented by [—(Z) l -(A) m -] n in repeating units constituting a main chain. In addition, the organic electroluminescent element includes, between an anode and a cathode laminated on a substrate, organic layers including a hole-transporting layer and a light-emitting layer, in which at least one of the organic layers contains the polymer for an organic electroluminescent element. In the repeating unit, Z represents an N-indolocarbazolyl group, A represents a repeating unit different from Z, l and m each represent an abundance molar ratio, and l is 5 to 100 mol % and m is 0 to 95 mol %, and n is 2 to 10,000.
1. A polymer for an organic electroluminescent element, comprising a repeating unit represented by the following general formula (1) in repeating units constituting a main chain:
where Z represents one or two or more kinds of repeating units selected from groups derived from indolocarbazoles represented by the following formulae (1a) to (1e), A represents one or two or more kinds of repeating units represented by the following formula (4a) or (4b) and different from Z, l and m each represent an abundance molar ratio, and when a ratio of all repeating units is defined as 100 mol %, l is 10 to 90 mol % and m is 10 to 90 mol %, and n represents an average repetition number and is 5 to 1,000;
in the formulae (1a) to (1e), Ar 1 's each independently represent a substituted or unsubstituted C 6 to C 18 arylene group, or a substituted or unsubstituted C 3 to C 18 heteroarylene group, and R 1 's each independently represent hydrogen, a C 1 to C 12 alkyl group, a C 1 to C 12 alkoxy group, a C 6 to C 18 aryl group, a C 6 to C 18 aryloxy group, a C 7 to C 30 arylalkyl group, a C 7 to C 30 arylalkyloxy group, a C 3 to C 18 heteroaryl group, a C 3 to C 18 heteroaryloxy group, or a C 3 to C 18 cycloalkyl group;
where Y 1 represents a substituted or unsubstituted C 1 to C 6 alkylene group, O, or S,
Y 2 represents a C(R 4 ) 2 group, or O,
R 3 's each independently represent hydrogen, a C 1 to C 12 alkyl group, a C 1 to C 12 alkoxy group, a C 6 to C 18 aryl group, a C 6 to C 18 aryloxy group, a C 7 to C 30 arylalkyl group, a C 7 to C 30 arylalkyloxy group, a C 3 to C 18 heteroaryl group, a C 3 to C 18 heteroaryloxy group, or a C 3 to C 18 cycloalkyl group, and
R 4 represents a hydrogen atom, a C 1 to C 12 alkyl group, a C 3 to C 18 cycloalkyl group, a C 6 to C 18 aryl group, a C 7 to C 30 arylalkyl group, a C 3 to C 18 heteroaryl group, or a C 4 to C 30 heteroarylalkyl group.
2. A polymer for an organic electroluminescent element according to claim 1 , wherein in the formulae (1a) to (1e), Ar 1 's each independently represent a group represented by the following formula (2):
where X's each independently represent any one of N or C-L, L's each independently represent a hydrogen atom, a C 6 to C 18 aryl group, a C 3 to C 18 heteroaryl group, a C 12 to C 36 diarylamino group, or a bonding hand, and one of L's represents a bonding hand.
3. A polymer for an organic electroluminescent element according to claim 1 , wherein the polymer for an organic electroluminescent element has a weight-average molecular weight of 1,000 to 1,000,000.
4. A polymer for an organic electroluminescent element according to claim 1 , wherein the polymer for an organic electroluminescent element comprises an alternating copolymer in which A and Z as repeating units in the general formula (1) are alternately bonded.
5. An organic electroluminescent element, comprising, between an anode layer and a cathode layer laminated on a substrate, organic layers including at least a hole-transporting layer, a light-emitting layer, and an electron-transporting layer, wherein at least one of the organic layers contains the polymer for an organic electroluminescent element according to claim 1 .
6. An organic electroluminescent element according to claim 5 , wherein the organic layer containing the polymer for an organic electroluminescent element comprises the hole-transporting layer.
7. An organic electroluminescent element according to claim 6 , wherein:
the light-emitting layer comprises a light-emitting layer containing a guest material and a host material; and
a difference between an HOMO energy of the polymer for an organic electroluminescent element contained in the hole-transporting layer and an HOMO energy of the host material contained in the light-emitting layer is within ±0.5 eV.
8. A polymer for an organic electroluminescent element according to claim 1 , wherein A represents one or two or more kinds of repeating units represented by formula (4a) and different from Z.
9. A polymer for an organic electroluminescent element according to claim 1 , wherein A represents two or more kinds of repeating units represented by formula (4a) or (4b) and different from Z.
10. A polymer for an organic electroluminescent element according to claim 1 , wherein all R 3 's represent hydrogen.
11. A polymer for an organic electroluminescent element according to claim 1 , wherein in the repeating unit, A represents one or two or more kinds of repeating units represented by the formula (4b) and different from Z.
12. A polymer for an organic electroluminescent element according to claim 1 , wherein in the formula (4b), Y 2 represents a C(R 4 ) 2 group.
13. A polymer for an organic electroluminescent element according to claim 1 , wherein in the formula (4b), Y 2 represents an O.
14. A polymer for an organic electroluminescent element, comprising a repeating unit represented by the following general formula (1) in repeating units constituting a main chain:
where Z represents one or two or more kinds of repeating units selected from groups derived from indolocarbazoles represented by the following formulae (1a) to (1e), A represents two or more kinds of repeating units represented by the following formula (4b) and different from Z, 1 and m each represent an abundance molar ratio, and when a ratio of all repeating units is defined as 100 mol %, 1 is 10 to 90 mol % and m is 10 to 90 mol %, and n represents an average repetition number and is 5 to 1,000;
in the formulae (1a) to (1e), Ar 1 's each independently represent a substituted or unsubstituted C 6 to C 18 arylene group, or a substituted or unsubstituted C 3 to C 18 heteroarylene group, and R 1 's each independently represent hydrogen, a C 1 to C 12 alkyl group, a C 1 to C 12 alkoxy group, a C 6 to C 18 aryl group, a C 6 to C 18 aryloxy group, a C 7 to C 30 arylalkyl group, a C 7 to C 30 arylalkyloxy group, a C 3 to C 18 heteroaryl group, a C 3 to C 18 heteroaryloxy group, or a C 3 to C 18 cycloalkyl group;
where Y 1 represents a substituted or unsubstituted C 1 to C 6 alkylene group, an N—R 4 group, O, S or a single bond,
Y 2 represents a C(R 4 ) 2 group, O, or S,
R 3 's each independently represent hydrogen, a C 1 to C 12 alkyl group, a C 1 to C 12 alkoxy group, a C 6 to C 18 aryl group, a C 6 to C 18 aryloxy group, a C 7 to C 30 arylalkyl group, a C 7 to C 30 arylalkyloxy group, a C 3 to C 18 heteroaryl group, a C 3 to C 18 heteroaryloxy group, or a C 3 to C 18 cycloalkyl group, and
R 4 represents a hydrogen atom, a C 1 to C 12 alkyl group, a C 3 to C 18 cycloalkyl group, a C 6 to C 18 aryl group, a C 7 to C 30 arylalkyl group, a C 3 to C 18 heteroaryl group, or a C 4 to C 30 heteroarylalkyl group.