Nanosized particles of benzimidazolone pigments

1. A nanoscale pigment particle composition, comprising:

a benzimidazolone pigment, and

a sterically bulky stabilizer compound associated non-covalently with the benzimidazolone pigment, wherein the sterically bulky stabilizer compound comprises an alkylated-benzimidazolone compound;

wherein presence of the sterically bulky stabilizer limits an extent of particle growth and aggregation, to afford nanoscale pigment particles.

2. The composition of claim 1 , wherein the nanoscale pigment particles have an average particle diameter as derived from transmission electron microscopy imaging, of less than about 150 nm.

3. The composition of claim 1 , wherein the benzimidazolone pigment comprises a diazo component group and a nucleophilic coupling component group that are linked together with at least one azo group, wherein at least one of the diazo component group and the nucleophilic coupling component group comprises a benzimidazolone moiety.

4. The composition of claim 3 , wherein the diazo component group is selected from the group consisting of DC 1 to DC 7 :

wherein:

* denotes a point of attachment to an amino group (—NH 2 ) in a pigment precursor and a point of attachment to an azo group (—N═N—) in the benzimidazolone pigment,

R 1 to R 8 independently represent H; halogens; (CH 2 ) n CH 3 where n=0-6; OH; alkoxyl groups —OR′ where R′ represents H, (CH 2) ) n CH 3 , or C 6 H 5 , and n represents a number of from 1 to about 6; CO 2 H; CO 2 CH 3 ; CO 2 (CH 2 ) n CH 3 wherein n=0-5; CONH 2 ; (CO)R′ wherein R′ can independently represent H, C 6 H 5 , (CH 2 ) n CH 3 wherein n=0-12, or (CH 2 ) n N(CH 3 ) 2 wherein n=1-6; OCH 3 ; OCH 2 CH 2 OH; NO 2 ; SO 3 H; or any of the following structural groups:

in DC 2 and DC 3 R′ represents H, (CH 2 ) n CH 3 , or C 6 H 5 , and n represents a number of from 1 to about 6, and

A represents —(CH 2 ) n — where n=0-6; —[O—(CH 2 ) n —O]— where n=0-6; —[O—CH 2 CHR) n ]— where n=0-6 and R═H or CH 3 ; —(C═O)—; O; S; —(CH 2 ) n —(C═O)— where n=1-6; and —(C═O)—(CH 2 ) n —(C═O)— where n=1-6.

5. The composition of claim 3 , wherein the nucleophilic coupling component group is selected from the group consisting of:

wherein R 9 , R 10 , R 11 , R 12 , and R 13 all independently represent H, Br, Cl, I, F, CH 3 , or OCH 3 , and * denotes a point of attachment to the azo group.

6. The composition of claim 1 , wherein the sterically bulky stabilizer is non-covalently associated with the benzimidazolone pigment predominantly by at least one of intra-molecular and inter-molecular hydrogen bonding, aromatic pi-stacking, and van der Waal's forces.

7. The composition of claim 1 , wherein the sterically bulky stabilizer is a compound of the formula:

where X represents a linking group and each of R 1 , R 2 , and R 3 independently represent H, substituted or unsubstituted alkyl groups, or, when X is —NH—, —O—, or —S—, R 3 can represent groups of the formulae:

wherein the symbol DC n is a diazo moiety, provided that at least one of R 1 , R 2 , and R 3 represents H.

8. The composition of claim 7 , wherein X is selected from the group consisting of amide groups, amine groups, urea groups, carbamate groups, urethane groups, ester groups, —O—, and —S—.

9. The composition of claim 8 , wherein X is —NH—, —O—, or —S—, and R 3 is selected from the group consisting of:

wherein DC n is a diazo moiety.

10. The composition of claim 9 , wherein DC n is selected from the group consisting of:

wherein:

* denotes a point of attachment to an amino group (—NH 2 ) in a pigment precursor and a point of attachment to an azo group (—N═N—) in the benzimidazolone pigment,

R 1 to R 8 independently represent H; halogens; (CH 2 ) n CH 3 where n=0-6; OH; alkoxyl groups —OR′ where R′ represents H, (CH 2) ) n CH 3 , or C 6 H 5 , and n represents a number of from 1 to about 6; CO 2 H; CO 2 CH 3 ; CO 2 (CH 2 ) n CH 3 wherein n=0-5; CONH 2 ; (CO)R′ wherein R′ can independently represent H, C 6 H 5 , (CH 2 ) n CH 3 wherein n=0-12, or (CH 2 ) n N(CH 3 ) 2 wherein n=1-6; OCH 3 ; OCH 2 CH 2 OH; NO 2 ; SO 3 H; or any of the following structural groups:

in DC 2 and DC 3 R′ represents H, (CH 2 ) n CH 3 , or C 6 H 5 , and n represents a number of 1 to about 6, and

A represents —(CH 2 ) n — where n=0-6; —[O—(CH 2 ) n —O]— where n=0-6; —[O—CH 2 CHR) n ]— where n=0-6 and R═H or CH 3 ; —(C═O)—; O; S; —(CH 2 ) n —(C═O)— where n=1-6; and —(C═O)—(CH 2 ) n —(C═O)— where n=1-6.

11. The composition of claim 7 , wherein at least one of R 1 , R 2 , and R 3 is selected from the group consisting of substituted or unsubstituted, straight or branched or cyclic aliphatic alkyl groups having 1 to 50 carbon atoms.

12. The composition of claim 7 , wherein at least one of R 1 , R 2 , and R 3 is selected from the group consisting of:

—CO—(CH 2 ) n —CH 3 , where n is from 0 to 30.

13. The composition of claim 1 , wherein the sterically bulky stabilizer compound comprises two or more benzimidazolone groups.

14. The composition of claim 1 , wherein the sterically bulky stabilizer is a compound of the formula:

where each of R 1 and R 2 independently represent H or substituted or unsubstituted alkyl groups, and R 3 represents a substituted or unsubstituted alkyl group.

15. The composition of claim 14 , wherein R 3 represents a group selected from the group consisting of —(CH 2 ) n ; —X—(CH 2 ) n X; —[(XCH 2 CH 2 ) n ]X—; —[(C═O)—(CH 2 ) n —(C═O)]—; —X—[(C═O)—(CH 2 ) n —(C═O)]—X—; —X—[(C═O)—X—(CH 2 ) n —X—(C═O)]—X—; —[(C═O)—X—(CH 2 ) n —X—(C═O)]—;

wherein X, X 1 , and X 2 independently represent O, S, or NH, and n is an integer of 1 to 50.

16. The composition of claim 1 , wherein the sterically bulky stabilizer compound comprises an alkylated-benzimidazolone selected from the group consisting of the following compounds:

Position 5

functional

Sterically Bulky Group(s)

moiety

X

R 1

R 2

R 3

NH

(CH 2 ) n CH 3 n = 2, 11, 17

—

—

NH

—

—

NH

—

—

NH

—

—

X 1 = X 2 = NH

(CH 2 ) n CH 3 n = 11, 17

—

—

X 1 = O X 2 = NH

(CH 2 ) n CH 3 n = 11, 17

—

—

N

H

(CH 2 ) n CH 3 n = 1, 17

—

N

H

—

N

(CH 2 ) n CH 3 n = 3, 11, 17

(CH 2 ) n CH 3 n = 11, 17

—

N

—

N

—

N

(CH 2 ) n CH 3 n = 1, 17

(CH 2 ) n CH 3 n = 11, 17

(CH 2 ) n CH 3 n = 11, 17

N

N

and

Position 5 functional moiety

R 1

R 2

R 3

X 1 = X 2 = NH

H

H

X 1 = O X 2 = NH

H

H

X 1 = NH

H

H

X 1 = O

H

H

X 1 = O

H

H

X 1 = NH

H

H

and

—

H

—(CH 2 ) n CH 3 n = 1, 17

—

—

—(CH 2 ) n CH 3 n = 1, 17

H

—

—

H

H

—

—

H

H

—

wherein DC n represents a diazo component group in the benzimidazolone pigment and n is an integer of 1 through 7.

17. The composition of claim 1 , wherein the sterically bulky stabilizer compound comprises an alkylated-benzimidazolone selected from the group consisting of the following compounds:

Group X

R 1

R 2

R 3

X 1 = X 2 = NH

H

H

X 1 = O X 2 = NH

H

H

X 1 = NH

H

H

X 1 = O

H

H

X 1 = O

H

H

X 1 = NH

H

H

.

18. The composition of claim 1 , wherein the sterically bulky stabilizer compound comprises an alkylated-benzimidazolone of the formula

wherein X—R 3 represents

wherein DC n represents a diazo moiety.

19. The composition of claim 18 , wherein DC n is selected from the group consisting of:

wherein:

* denotes a point of attachment to the N atom,

R 1 to R 8 independently represent H; halogens; (CH 2 ) n CH 3 where n=0-6; OH; alkoxyl groups —OR′ where R′ represents H, (CH 2 ) n CH 3 , or C 6 H 5 , and n represents a number of from 1 to about 6; CO 2 H; CO 2 CH 3 ; CO 2 (CH 2 ) n CH 3 wherein n=0-5; CONH 2 ; (CO)R′ wherein R′ can independently represent H, C 6 H 5 , (CH 2 ) n CH 3 wherein n=0-12, or (CH 2 ) n N(CH 3 ) 2 wherein n=1-6; OCH 3 ; OCH 2 CH 2 OH; NO 2 ; SO 3 H; or any of the following structural groups:

in DC 2 and DC 3 R′ represents H, (CH 2 ) n CH 3 , or C 6 H 5 , and n represents a number of from 1 to about 6, and

A represents —(CH 2 ) n — where n=0-6; —[O—(CH 2 ) n —O]— where n=0-6; —[O—CH 2 CHR) n ]— where n=0-6 and R═H or CH 3 ; —(C═O)—; O; S; —(CH 2 ) n —(C═O)— where n=1-6; and —(C═O)—(CH 2 ) n —(C═O)— where n=1-6.

20. The composition of claim 1 , further comprising a surfactant selected from the group consisting of derivatives of rosin natural products; long-chain or branched hydrocarbon alcohols; alcohol ethoxylates; acrylic-based polymers; styrene-based copolymers; copolymers of α-olefins; copolymers of vinyl pyridine, vinyl imidazole, and vinyl pyrrolidinone; polyester copolymers; polyimide copolymers; and copolymers of acetals and acetates.

21. The composition of claim 1 , wherein the nanoscale pigment particles have an aspect ratio of 1:1 to about 7:1.

22. The composition of claim 1 , wherein the nanoscale pigment particles have a shape selected from the group consisting of rods, platelets, needles, prisms, and substantially spherical.

23. A marking material composition comprising the nanoscale pigment particle composition of claim 1 , wherein the marking material composition is an ink composition or a toner composition.

24. An electrophotographic photoreceptor comprising the nanoscale pigment particle composition of claim 1 .

25. A solar cell comprising an organic photo conducting material comprising the nanoscale pigment particle composition of claim 1 .

26. A biological or chemical sensor comprising the nanoscale pigment particle composition of claim 1 .