Polymer and organic electroluminescent element

1. A polymer, comprising:

a repeating unit having a partial structure represented by formula (1):

and

a repeating unit having a crosslinking group,

wherein, in formula (1):

Ar 1 , Ar 3 , Ar 4 , and Ar 5 each independently represent an aromatic hydrocarbon-cyclic group optionally having a substituent or an aromatic heterocyclic group optionally having a substituent;

Ar 2 represents an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent;

R 1 represents an alkyl group optionally having a substituent, or an alkoxy group optionally having a substituent;

R 2 to R 7 each independently represent a hydrogen atom, an alkyl group optionally having a substituent, an alkoxy group optionally having a substituent, an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent, wherein R 2 and R 3 may bond to each other to form a ring, R 4 and R 5 may bond to each other to form a ring, and R 6 and R 7 may bond to each other to form a ring;

l, m, and n each independently indicate an integer of from 0 to 2; and

multiple Ar 1 to Ar 5 or R 2 to R 7 may be the same or different.

2. The polymer according to claim 1 , wherein in the formula (1), at least one of l, m, and n is an integer differing from the others.

3. The polymer according to claim 1 , further comprising:

a repeating unit having a partial structure of formula (2):

wherein, in formula (2):

Ar 6 and Ar 7 each independently represent an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent;

Ar 8 represents an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent;

R 8 and R 9 each independently represent a hydrogen atom, an alkyl group optionally having a substituent, an alkoxy group optionally having a substituent, an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent;

R 8 and R 9 may bond to each other to form a ring;

p indicates an integer of from 0 to 2; and

multiple substituents of at least one of R 8 , R 9 , and Ar 7 may be the same or different.

4. The polymer according to claim 1 , wherein the crosslinking group is at least one group selected from crosslinking groups of the following formulae:

wherein:

R 21 to R 23 each independently represent a hydrogen atom, or an alkyl group optionally having a substituent;

A 10 represents an aromatic hydrocarbon-cyclic group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent; and

when multiple crosslinking groups and multiple R 21 to R 23 and Ar 10 are present, the multiple R 21 to R 23 and Ar 10 may be the same or different.

5. The polymer according to claim 1 , wherein the weight-average molecular weight (Mw) of the polymer is 20,000 or more, and the degree of dispersion (Mw/Mn, where Mn indicates the number-average molecular weight of the polymer) is 2.5 or less.

6. A material for organic electroluminescent element, comprising the polymer according to claim 1 .

7. A composition for organic electroluminescent element, comprising the polymer according to claim 1 .

8. An organic electroluminescent element, comprising:

a substrate;

an anode and a cathode on the substrate; and

an organic layer between the anode and the cathode,

wherein the organic layer contains a layer formed according to a wet film formation method using the composition for organic electroluminescent elements according to claim 7 .

9. The organic electroluminescent element according to claim 8 , wherein the layer formed according to a wet film formation method is at least one of a hole injection layer and a hole transport layer.

10. The organic electroluminescent element according to claim 9 , wherein the organic layer includes a hole injection layer, a hole transport layer, and a light-emitting layer, and

wherein all of the hole injection layer, the hole transport layer and the light-emitting layer are a layer formed according to a wet film formation method.

11. An organic EL display device, comprising the organic electroluminescent element according to claim 8 .

12. An organic EL lighting device, comprising the organic electroluminescent element according to claim 8 .