Composition capable of changing its solubility, hole transport material composition, and organic electronic element using the same

1. A method for changing solubility of an organic layer (I), formed by applying a composition comprising a polymer or oligomer (A) having a repeating unit with hole transport properties and also having a thienyl group which may have a substituent, and an initiator (B), wherein solubility of the composition is capable of being changed by applying heat, light, or both heat and light, the method comprising a step of applying heat, light, or both heat and light to the organic layer (I),

wherein the polymer or oligomer (A) has at least one type of structure selected from the group consisting of a structure represented by formula (Ia) shown below, and a structure represented by formula (Ib) shown below:

wherein, in formulas (Ia) and (Ib), each of R 1 to R 3 independently represents a hydrogen atom or an alkyl group, provided that at least one of R 1 to R 3 represents a hydrogen atom, and

wherein the polymer or oligomer (A) does not include an oxetane group.

2. The method according to claim 1 , wherein the polymer or oligomer (A) has at least one type of structure selected from the group consisting of a structure represented by formula (IIa), a structure represented by formula (IIb), a structure represented by formula (IIIa), and a structure represented by formula (IIIb), all of which are shown below:

wherein, in formulas (IIa) and (IIb), each of R 1 to R 3 independently represents a hydrogen atom or an alkyl group, provided that at least one of R 1 to R 3 represents a hydrogen atom, and Ar a represents an arenediyl group or a heteroarenediyl group,

wherein, in formulas (IIIa) and (IIIb), each of R 1 to R 3 independently represents a hydrogen atom or an alkyl group, provided that at least one of R 1 to R 3 represents a hydrogen atom, and Ar b represents an arenetriyl group or a heteroarenetriyl group.

3. The method according to claim 1 , wherein the initiator (B) is an oxidizing agent.

4. The method according to claim 1 , wherein the initiator (B) is an onium salt.

5. The method according to claim 1 , wherein a weight-average molecular weight of the polymer or oligomer (A) is from 1,000 to 1,000,000.

6. The method according to claim 1 , wherein the composition further comprises a solvent (C).

7. A method for changing solubility of an organic layer (I), formed by applying a composition comprising a polymer or oligomer (A) having a repeating unit with hole transport properties and also having a thienyl group which may have a substituent, and an initiator (B), wherein solubility of the composition is capable of being changed by applying heat, light, or both heat and light, the method comprising a step of applying heat, light, or both heat and light to the organic layer (I),

wherein the polymer or oligomer (A) has a branched structure and 3 or more terminals, and has a thienyl group at each of the 3 or more of all of the terminals.

8. The method according to claim 7 , wherein the initiator (B) is an oxidizing agent.

9. The method according to claim 7 , wherein the initiator (B) is an onium salt.

10. The method according to claim 7 , wherein a weight-average molecular weight of the polymer or oligomer (A) is from 1,000 to 1,000,000.

11. The method according to claim 7 , wherein the composition further comprises a solvent (C).

12. The method according to claim 7 , wherein the polymer or oligomer (A) has at least one type of structure selected from the group consisting of a structure represented by formula (Ia) shown below, and a structure represented by formula (Ib) shown below:

wherein, in formulas (Ia) and (Ib), each of R 1 to R 3 independently represents a hydrogen atom or an alkyl group, provided that at least one of R 1 to R 3 represents a hydrogen atom.

13. The method according to claim 7 , wherein the polymer or oligomer (A) does not include an oxetane group.