Aromatic nitrogen-containing compounds as adjuvants for electrostatic liquid developers

Claim 2

An improved electrostatic liquid developer having improved charging characteristics consisting essentially of (A) a nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) thermoplastic resin particles having an average by area particle size of less than 10 μm having dispersed therein an aromatic nitrogen-containing compound which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl of n is 0, and (C) a nonpolar liquid soluble ionic or zwitterionic charge director compound.

Claim 3

A liquid electrostatic developer according to claim 1 wherein the aromatic nitrogen-containing compound is a polyvinyl pyridine.

Claim 4

A liquid electrostatic developer according to claim 2 wherein the aromatic nitrogen-containing compound is poly-2-vinyl pyridine.

Claim 5

A liquid electrostatic developer according to claim 1 wherein the aromatic nitrogen-containing compound is a polyaminostyrene.

Claim 6

A liquid electrostatic developer according to claim 1 wherein the aromatic nitrogen-containing compound is a copolymer of vinyl pyridine and styrene.

Claim 7

A liquid electrostatic developer according to claim 1 wherein the aromatic nitrogen-containing compound is of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 to 1; and fused ring compounds can be formed when R is aryl or substituted aryl, or n is 0.

Claim 8

A liquid electrostatic developer according to claim 6 wherein the aromatic nitrogen-containing compound is 2,2'-bipyridine.

Claim 9

A liquid electrostatic developer according to claim 1 wherein Component (A) is present in 85 to 99.9% by weight, based on the total weight of liquid developer, the total weight of developer solids is 0.1 to 15.0% by weight, and Component (C) is present in an amount of 0.1 to 10,000 mg/g developer solids.

Claim 10

A liquid electrostatic developer according to claim 8 wherein the aromatic nitrogen-containing compound is present in 0.1 to 10% by weight based on the total weight of the developer solids.

Claim 11

A liquid electrostatic developer according to claim 1 containing up to about 60% by weight of a colorant based on the total weight of developer solids.

Claim 12

A liquid electrostatic developer according to claim 10 wherein the colorant is a pigment.

Claim 13

A liquid electrostatic developer according to claim 1 wherein no colorant is present.

Claim 14

A liquid electrostatic developer according to claim 1 wherein an additional compound is present which is an adjuvant selected from the group consisting of aminoalcohol, polyhydroxy compound, polybutylene succinimide, and aromatic hydrocarbon.

Claim 15

A liquid electrostatic developer according to claim 10 wherein an additional compound is present which is an adjuvant selected from the group consisting of aminoalcohol, polyhydroxy compound, polybutylene succinimide, and an aromatic hydrocarbon.

Claim 16

A liquid electrostatic developer according to claim 14 wherein an aminoalcohol adjuvant compound is present.

Claim 17

A liquid electrostatic developer according to claim 14 wherein a polybutylene succinimide adjuvant compound is present.

Claim 18

A liquid electrostatic developer according to claim 14 wherein an aromatic hydrocarbon adjuvant compound is present.

Claim 19

A liquid electrostatic developer according to claim 14 wherein a polyhydroxy adjuvant compound is present.

Claim 20

A liquid electrostatic developer according to claim 1 wherein the thermoplastic resin is a copolymer of ethylene and an αβ-ethylenically unsaturated acid selected from the group consisting of acrylic acid and methacrylic acid.

Claim 21

A liquid electrostatic developer according to claim 1 wherein the thermoplastic resin is a terpolymer of methyl acrylate/methacrylic acid/ethylhexyl acrylate.

Claim 22

A liquid electrostatic developer according to claim 1 wherein the thermoplastic resin is a copolymer of ethylene (80 to 90.9%)/acrylic or methacrylic acid (20 to 0%)/alkyl ester of acrylic or methacrylic acid wherein alkyl is 1 to 5 carbon atoms (0 to 20%).

Claim 23

A liquid electrostatic developer according to claim 10 wherein the thermoplastic resin is a copolymer of ethylene (80 to 99.9%)/acrylic or methacrylic acid (20 to 0%)/alkyl ester of acrylic or methacrylic acid wherein alkyl is 1 to 5 carbon atoms (0 to 20%).

Claim 24

A liquid electrostatic developer according to claim 21 wherein the thermoplastic resin is a copolymer of ethylene (89%)/methacrylic acid (11%) having a melt index at 190° C. of 100.

Claim 25

A liquid electrostatic developer according to claim 1 wherein the particles have an average by area particle size of less than 5 μm.

Claim 26

A liquid electrostatic developer according to claim 1 wherein Component (C) is an oil-soluble petroleum sulfonate.

Claim 27

A liquid electrostatic developer according to claim 1 wherein Component (C) is the sodium salt of phosphated monoglyceride with acid substituents.

Claim 28

A process for preparing a liquid electrostatic developer for electrostatic imaging comprising (A) dispersing at an elevated temperature in a vessel a thermoplastic resin, an aromatic nitrogen-containing compound which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 to 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is 0, and a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin decomposes, (B) cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media with or without the presence of additional liquid; (2) with stirring to form a viscous mixture and grinding by means of particulate with or without the presence of additional liquid; or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass with or without the presence of additional liquid; (C) separating the dispersion of thermoplastic toner particles having an average by area particle size of less than 10 μm from the particulate media, and (D) adding to the dispersion during or subsequent to Step (A) a nonpolar liquid soluble ionic or zwitterionic charge director compound.

Claim 29

A process for preparing a liquid electrostatic developer for electrostatic imaging comprising (A) dispersing at an elevated temperature in a vessel a thermoplastic resin, an aromatic nitrogen-containing compound which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 to 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is 0, and a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin decomposes, (B) cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media with or without the presence of additional liquid; (2) with stirring to form a viscous mixture and grinding by means of particulate with or without the presence of additional liquid; or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass with or without the presence of additional liquid; (C) separating the dispersion of thermoplastic toner particles having an average by area particle size of less than 10 μm from the particulate media, and (D) adding to the dispersion during or subsequent to Step (A) a nonpolar liquid soluble ionic or zwitterionic charge director compound.

Claim 30

A process according to claim 27 wherein the aromatic nitrogen-containing compound is a polyvinyl pyridine.

Claim 31

A process according to claim 28 wherein the aromatic nitrogen-containing compound is poly-2-vinyl pyridine.

Claim 32

A process according to claim 27 wherein the aromatic nitrogen-containing compound is a polyaminostyrene.

Claim 33

A process according to claim 27 wherein the aromatic nitrogen-containing compound is a copolymer of vinyl pyridine and styrene.

Claim 34

A process according to claim 27 wherein the aromatic nitrogen-containing compound is of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl, or n is 0.

Claim 35

A process according to claim 32 wherein the aromatic nitrogen-containing compound is 2,2'-bipyridine.

Claim 36

A process according to claim 27 wherein there is present in the vessel up to 100% by weight of a polar additive having a Kauri-butanol value of at least 30, the percentage based on the total weight of the liquid in the developer.

Claim 37

A process according to claim 27 wherein the particulate media are selected from the group consisting of stainless steel, carbon steel, ceramic, alumina, zirconium, silica and silimanite.

Claim 38

A process according to claim 27 wherein the thermoplastic resin is a copolymer of ethylene and an αβethylenically unsaturated acid selected from the group consisting of acrylic acid and methacrylic acid.

Claim 39

A process according to claim 27 wherein the thermoplastic resin is a copolymer of ethylene (80 to 99.9%)/acrylic or methacrylic acid (20 to 0%)/alkyl ester of acrylic or methacrylic acid wherein alkyl is 1 to 5 carbon atoms (0 to 20%).

Claim 40

A process according to claim 37 wherein the thermoplastic resin is a copolymer of ethylene (89%)/methacrylic acid (11%) having a melt index at 190° C. of 100.

Claim 41

A process according to claim 27 wherein the ionic or zwitterionic compound is an oil-soluble petroleum sulfonate.

Claim 42

A process according to claim 27 wherein the ionic or zwitterionic compound is sodium salt of phosphated monoglyceride with acid substituents.

Claim 43

A process according to claim 27 wherein additional dispersant nonpolar liquid, polar liquid or combinations thereof is present to reduce the concentration of toner particles to between 0.1 to 15.0% by weight with respect to the liquid.

Claim 44

A process according to claim 41 wherein the concentration of toner particles is reduced by additional dispersant nonpolar liquid.

Claim 45

A process according to claim 27 wherein cooling the dispersion is accomplished while grinding by means of particulate media to prevent the formation of a gel or solid mass with or without the presence of additional liquid.

Claim 46

A process according to claim 27 wherein cooling the dispersion is accomplished without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media with or without the presence of additional liquid.

Claim 47

A process according to claim 27 wherein cooling the dispersion is accomplished with stirring to form a viscous mixture and grinding by means of particulate media with or without the presence of additional liquid.

Claim 48

A process according to claim 27 wherein an adjuvant compound selected from the group consisting of aminoalcohol, polyhydroxy compound, polybutylene succinimide, and aromatic hydrocarbon is added to the liquid developer.

Claim 49

A process according to claim 46 wherein the adjuvant compound is an aminoalcohol.

Claim 50

A process according to claim 47 wherein the aminoalcohol is triisopropanolamine.

Claim 51

A process according to claim 41 wherein an adjuvant compound selected from the group consisting of aminoalcohol, polyhydroxy compound, polybutylene succinimide, and aromatic hydrocarbon is added to the liquid developer.

Claim 52

A process according to claim 27 containing up to about 60% by weight of a colorant based on the total weight of developer solids.

Claim 53

A process for preparing a liquid electrostatic developer for electrostatic imaging comprising (A) dispersing in a thermoplastic resin and an aromatic nitrogen-containing compound which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 ; carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is in the absence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30 to form a solid mass (B) shredding the solid mass, (C) grinding the shredded solid mass by means of particulate media in the presence of a liquid selected from the group consisting of a polar liquid having a Kauri-butanol value of at least 30, a nonpolar liquid having a Kauri-butanol value of less than 30, and combinations thereof, thereby forming a dispersion of toner particles. (D) separating the dispersion of toner particles having an average by area particles size of less than 10 μm from the particulate media, (E) adding additional nonpolar liquid, polar liquid or combinations thereof to reduce the concentration of toner particles to between 0.1 to 15.0% by weight with respect to the liquid; and (F) adding to the dispersion a liquid soluble ionic or zwitterionic compound.

Claim 54

A process for preparing a liquid electrostatic developer for electrostatic imaging comprising (A) dispersing in a thermoplastic resin and an aromatic nitrogen-containing compound which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 ; carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is in the absence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30 to form a solid mass (B) shredding the solid mass, (C) grinding the shredded solid mass by means of particulate media in the presence of a liquid selected from the group consisting of a polar liquid having a Kauri-butanol value of at least 30, a nonpolar liquid having a Kauri-butanol value of less than 30, and combinations thereof, thereby forming a dispersion of toner particles. (D) separating the dispersion of toner particles having an average by area particles size of less than 10 μm from the particulate media, (E) adding additional nonpolar liquid, polar liquid or combinations thereof to reduce the concentration of toner particles to between 0.1 to 15.0% by weight with respect to the liquid; and (F) adding to the dispersion a liquid soluble ionic or zwitterionic compound.

Claim 55

A process according to claim 51 wherein a colorant is present in step (A).

Claim 56

A process for preparing a electrostatic liquid developer for electrostatic imaging comprising (A) dispersing in a thermoplastic resin and an aromatic nitrogen-containing which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is 0 in the absence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30 to form a solid mass, (B) shredding the solid mass, (C) redispersing the shredded solid mass at an elevated temperature in a vessel in the presence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin decomposes, (D) cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media with or without the presence of additional liquid, (2) with stirring to form a viscous mixture and grinding by means of particulate media with or without the presence of additional liquid, or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass with or without the presence of additional liquid; (E) separating the dispersion of toner particles having an average by area particle size of less than 10 μm from the particulate media, and (F) adding additional nonpolar liquid, polar liquid or combinations thereof to reduce the concentration of toner particles to between 0.1 to 15.0% by weight with respect to the liquid; and (G) adding to the dispersion a liquid soluble ionic or zwitterionic compound.

Claim 57

A process for preparing a electrostatic liquid developer for electrostatic imaging comprising (A) dispersing in a thermoplastic resin and an aromatic nitrogen-containing which is substantially insoluble or immiscible in the nonpolar liquid at ambient temperatures and is selected from the group consisting of (1) polyvinylpyridines, (2) polyaminostyrenes, (3) copolymers of vinyl pyridine, and (4) compounds of the general formula: Y--(R).sub.n --Z wherein Y is pyridine, substituted pyridine, bipyridine, aniline, or substituted aniline; R is alkyl of 1 to 30 carbon atoms, substituted alkyl of 1 to 30 carbon atoms, aryl of 6 to 30 carbon atoms, substituted aryl of 6 to 30 carbon atoms, or NH; Z is one of Y; n is 0 or 1; and fused ring compounds can be formed when R is aryl or substituted aryl or n is 0 in the absence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30 to form a solid mass, (B) shredding the solid mass, (C) redispersing the shredded solid mass at an elevated temperature in a vessel in the presence of a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin decomposes, (D) cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media with or without the presence of additional liquid, (2) with stirring to form a viscous mixture and grinding by means of particulate media with or without the presence of additional liquid, or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass with or without the presence of additional liquid; (E) separating the dispersion of toner particles having an average by area particle size of less than 10 μm from the particulate media, and (F) adding additional nonpolar liquid, polar liquid or combinations thereof to reduce the concentration of toner particles to between 0.1 to 15.0% by weight with respect to the liquid; and (G) adding to the dispersion a liquid soluble ionic or zwitterionic compound.

Claim 58

A process according to claim 53 wherein a colorant is present in redispersing Step (C), and the temperature is maintained in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin and colorant decomposes.