Charging member, process cartridge, and electrophotographic image forming apparatus

1. A charging member, comprising:

a support; and

a surface layer on the support, wherein

the surface layer contains a compound represented by formulae (a) or (a1):

where L1 represents a polymetalloxane having a structural unit represented by M1O n/2 ;

n represents an integer of 1 to p when a valence of a metal atom M1 is p;

M1 represents at least one metal atom selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, Al, Ga, In, and Ge;

X1 represents any one of structures represented by formulae (1) to (4):

where * represents a bonding site with A1 and ** represents a bonding site with M1 in L1;

Y1 represents a group having a site that coordinates to M1 in L1; and

(i) when X1 represents a structure represented by formula (1), A1 represents an atomic group containing an aromatic ring needed for forming a four- to eight-membered ring together with M1, X1, and Y1, and one constituent carbon atom of the aromatic ring is bonded to an oxygen atom of X1, and

(ii) when X1 represents a structure represented by any one of formulae (2) to (4), A1 represents a bond or atomic group needed for forming a four- to eight-membered ring together with M1, X1, and Y1.

2. A charging member according to claim 1 , wherein Y1 represents a hydroxy group, an alkoxy group, a substituted or unsubstituted aryloxy group, a carbonyl group, an alkylthio group, a substituted or unsubstituted arylthio group, a thiocarbonyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a group having a substituted or unsubstituted aliphatic heterocyclic skeleton, or a group having a substituted or unsubstituted aromatic heterocyclic skeleton.

3. A charging member according to claim 1 , wherein A1 represents an atomic group containing an aromatic ring selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted quinoline ring, and a substituted or unsubstituted isoquinoline ring when X1 represents a structure represented by formula (1).

4. A charging member according to claim 1 , wherein when X1 represents a structure represented by any one of formulae (2) to (4), A1 represents a bond, an alkylene group, or an atomic group containing an aromatic ring selected from the group consisting of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted quinoline ring, and a substituted or unsubstituted isoquinoline ring.

5. A charging member according to claim 1 , wherein a ring formed by A1, M1, X1, and Y1 comprises a five-membered ring or a six-membered ring.

6. A charging member according to claim 1 , wherein A1 represents a structure represented by formula (A1-1) or (A1-2):

where R11 and R13 each represent a single bond or methylene group bonded to Y1, R12 and R14 each represent a hydrogen atom, a methoxy group, or an ethoxy group, and * represents a bonding site with X1;

X1 represents a structure represented by formula (X1-1) or (X1-2):

*—O—**  (X1-1)

*—CO—O—**  (X1-2)

where * represents a bonding site with A1 and ** represents a bonding site with M1; and

Y1 represents a methoxy group, an ethoxy group, a formyl group, a methylcarbonyl group, an ethylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a dimethylamide group, a diethylamide group, a methylethylamide group, a methylthio group, an ethylthio group, a thiocarbonyl group, a dimethylamino group, a diethylamino group, an ethylmethylamino group, an unsubstituted imino group, a methylimino group, an ethylimino group, a group having a pyridine skeleton, a group having a quinoline skeleton, or a group having an isoquinoline skeleton.

7. A charging member according to claim 1 , wherein A1 represents a bond, a methylene group, an ethylene group, or a trimethylene group;

X1 represents a structure represented by any one of formulae (X1-3), (X1-4), (X1-6) or (X1-7)

where * represents a bonding site with A1 and ** represents a bonding site with M1; and

Y1 represents a methoxy group, an ethoxy group, a formyl group, a methylcarbonyl group, an ethylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a dimethylamide group, a diethylamide group, a methylethylamide group, a methylthio group, an ethylthio group, a thiocarbonyl group, a dimethylamino group, a diethylamino group, an ethylmethylamino group, an unsubstituted imino group, a methylimino group, an ethylimino group, a group having a pyridine skeleton, a group having a quinoline skeleton, or a group having an isoquinoline skeleton.

8. A charging member according to claim 1 , wherein the polymetalloxane has a structural unit represented by SiO r/2 where r represents an integer of 1 to 4.

9. A process cartridge, comprising:

an electrophotographic photosensitive member; and

a charging member placed to be capable of charging a surface of the electrophotographic photosensitive member,

the process cartridge being removably mounted onto a main body of an electrophotographic apparatus, wherein

the charging member comprises the charging member according to claim 1 .

10. An electrophotographic apparatus, comprising:

an electrophotographic photosensitive member; and

a charging member placed to be capable of charging a surface of the electrophotographic photosensitive member, wherein

the charging member comprises the charging member according to claim 1 .