Electrophotographic photoreceptor and image forming apparatus

1. An electrophotographic photoreceptor comprising:

a conductive support; and

a charge generation layer and a charge transport layer on the conductive support, said charge transport layer located on top of said charge generation layer,

wherein said charge generation layer comprises α-chloronaphthalene and a hydroxygallium phthalocyanine,

wherein said charge transport layer comprises a polyester resin having a structural unit represented by one of the following formulae B-1 and B-2 in an amount effective to function as a binder resin, and said charge transport layer is formed using only a non-halogen solvent:

wherein the content of said α-chloronaphthalene in the charge generation layer is from 0.2 to 1.0 ng/cm 2 and a content of chlorobenzene in the charge transport layer is 0.2 ng/cm 2 or less, and

wherein said charge transport layer further comprises a charge transport substance represented by the following formula (5):

wherein

each of R 6 and R 7 independently represents a hydrogen atom or an alkyl group having a carbon number of 4 or less, and

each of Ar 8 and Ar 9 independently represents an aryl group having a carbon number of 30 or less, which may have a substituent.

2. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises 40 parts by weight or more of the charge transport substance represented by formula (5) per 100 parts by weight of the binder resin.

3. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises 60 parts by weight or more of the charge transport substance represented by formula (5) per 100 parts by weight of the binder resin.

4. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises 70 parts by weight or more of the charge transport substance represented by formula (5) per 100 parts by weight of the binder resin.

5. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises 110 parts by weight or more of the charge transport substance represented by formula (5) per 100 parts by weight of the binder resin.

6. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises 150 parts by weight or more of the charge transport substance represented by formula (5) per 100 parts by weight of the binder resin.

7. The electrophotographic photoreceptor of claim 1 , wherein the charge generation layer comprises the hydroxygallium phthalocyanine in an amount from 30 parts by mass to 500 parts by mass, per 100 parts by mass of the binder resin.

8. An image forming apparatus, comprising:

the electrophotographic photoreceptor of claim 1 ;

a printing member; and

toner,

wherein the toner developed on the electrophotographic photoreceptor is directly transferred onto the printing member without intervention of an intermediate transfer member.

9. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer further comprises a charge transport substance represented by the following formula (2):

wherein

each of Ar 4 to Ar 7 independently represents an aryl group having a carbon number of 30 or less, which may have a substituent,

W represents a divalent substituent represented by formula (3) or (4):

and

each of R 1 to R 5 represents a hydrogen atom or an alkyl group having a carbon number of 4 or less.

10. The electrophotographic photoreceptor of claim 9 , wherein W represents a divalent substituent represented by formula (3).

11. The electrophotographic photoreceptor of claim 1 , wherein the conductive support comprises a metal material.

12. The electrophotographic photoreceptor of claim 1 , wherein a content of halogen solvent in the charge generation layer is from 0.3 to 0.9 ng/cm 2 .

13. The electrophotographic photoreceptor of claim 1 , wherein a content of halogen solvent in the charge generation layer is from 0.4 to 0.8 ng/cm 2 .

14. The electrophotographic photoreceptor of claim 1 , wherein the charge transport layer comprises no chlorobenzene.

15. A method for producing the electrophotographic photoreceptor according to claim 1 , comprising:

forming the charge generation layer on the conductive support, and

forming the charge transport layer on the conductive support with a coating solution comprising a non-halogen solvent.

16. The electrophotographic photoreceptor of claim 1 , wherein said charge transport layer comprises a polyester resin consisting of a structural unit represented by formula B-1.

17. The electrophotographic photoreceptor of claim 1 , wherein said charge transport layer comprises a polyester resin consisting of a structural unit represented by formula B-2.

18. The electrophotographic photoreceptor of claim 1 , wherein said charge transport layer comprises a charge transport substance represented by the following formula (1)-2:

19. The electrophotographic photoreceptor of claim 16 , wherein said charge transport layer comprises a charge transport substance represented by the following formula (1)-2:

20. The electrophotographic photoreceptor of claim 17 , wherein said charge transport layer comprises a charge transport substance represented by the following formula (1)-2:

21. The electrophotographic photoreceptor of claim 1 , wherein the hydroxygallium phthalocyanine is a V-type hydroxygallium phthalocyanine.

22. The electrophotographic photoreceptor of claim 1 , wherein the hydroxygallium phthalocyanine is a hydroxygallium phthalocyanine having a strongest peak at 28.1°.