Method of preparing a pigment press cake and uses thereof
AssigneeE. I. Du Pont de Nemours and Company
InventorsJames A. Silver, Chad C. Roberts, Christian Jackson
Life of this patent
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Abstract
A process for preparing a pigment press cake is provided in which a pigment, a grinding agent, a polyetheramine, and a vehicle are subjected to grinding, followed by removal of the grinding agent and the vehicle to form a press cake. Also disclosed are a process to disperse the press cake with a polymeric dispersant in an aqueous vehicle to form a pigment dispersion and using the dispersion to form an aqueous ink jet ink.
Claims11
A process for making a pigment press cake comprising the steps of:
- (a) grinding a mixture comprising a pigment, a grinding agent and a vehicle to form a premix, wherein said grinding agent is insoluble in said vehicle and soluble in water,
- (b) adding to said premix a polyetheramine having the formula (I):
- (c) grinding said premix and said polyetheramine together;
- and
- (d) washing with an aqueous medium to remove said grinding agent to form a press cake;
- wherein each Q1 and Q3 is independently —OCH2CH2— or —OCH2CH(CH3)—;
- each Q2 is —OCH2CH(CH3)—;
- R1 is CH2CH(NH2)(CH3) or NH2;
- each R2 and R3 is independently C1-C4 alkyl or a straight bond;
- each R4 is H, C1-C4 alkyl or -(Q3)q-NH2;
- each R5 is C1-C4 alkyl or a straight bond;
- n is an integer from 0 to 60;
- m is an integer from 2 to 30;
- p is 0;
- each q is an integer from 0 to 30;
- and said grinding agent is an inorganic salt.
A process for making an aqueous pigment dispersion comprising the steps of:
- (a) grinding a mixture comprising a pigment, a grinding agent and a vehicle to form a premix, wherein said grinding agent is insoluble in said vehicle and soluble in water,
- (b) adding to said premix a polyetheramine having the formula (I):
- (c) grinding said premix and said polyetheramine together;
- (d) washing with an aqueous medium to remove said grinding agent to form a press cake;
- and
- (e) adding an aqueous vehicle and a polymeric dispersant, and dispersing said press cake from step (d), in this order or any other workable orders, to form a dispersion;
- wherein each Q1, Q2 and Q3 is independently —OCH2CH2— or —OCH2CH(CH3)—;
- R1 is C1-C4 alkyl, —CH2CH(NH2)(CH3) or NH2;
- each R2 and R3 is independently C1-C4 alkyl or a straight bond;
- each R4 is H, C1-C4 alkyl or -(Q3)q-NH2;
- each R5 is C1-C4 alkyl or a straight bond;
- n is an integer from 0 to 60;
- m is an integer from 2 to 30;
- p is an integer from 0 to 5;
- each q is an integer from 0 to 30;
- and said polymeric dispersant contains a cross-linkable moiety.
An ink-jet ink comprising an aqueous ink-jet vehicle and an aqueous pigment dispersion, wherein said aqueous pigment dispersion is prepared by a process comprising the steps of:
- (a) grinding a mixture comprising a pigment, a grinding agent and a vehicle to form a premix, wherein said grinding agent is insoluble in said vehicle and soluble in water,
- (b) adding to said premix a polyetheramine having the formula (I):
- (c) grinding said premix and said polyetheramine together;
- (d) washing with an aqueous medium to remove said grinding agent to form a press cake;
- and
- (e) adding an aqueous vehicle and a polymeric dispersant, and dispersing said press cake from step (d), in this order or any other workable orders, to form a dispersion;
- wherein each Q1, Q2 and Q3 is independently —OCH2CH2— or —OCH2CH(CH3)—;
- R1 is C1-C4 alkyl, —CH2CH(NH2)(CH3) or NH2;
- each R2 and R3 is independently C1-C4 alkyl or a straight bond;
- each R4 is H, C1-C4 alkyl or -(Q3)q-NH2;
- each R5 is C1-C4 alkyl or a straight bond;
- n is an integer from 0 to 60;
- m is an integer from 2 to 30;
- p is an integer from 0 to 5;
- each q is an integer from 0 to 30;
- and said polymeric dispersant contains a cross-linkable moiety.
Dependencies are inferred from the claim text.