Method for preparing organic pigments

• US 6,440,207 B1
• Filed: 03/03/2000
• Issued: 08/27/2002
• Est. Priority Date: 03/03/2000
• Status: Expired due to Term

• Current Assignee: Sun Chemical Corporation
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Schulz, Gregory R.
• Primary Examiner(s): Green, Anthony J.
• Application Number:
  US09/518,747
• Time in Patent Office: 907 Days
• Field of Search: 106/493, 106/494, 106/495, 106/496, 106/497, 106/498, 106/412
• US Class Current: 106/412
• CPC Class Codes: C08G 2650/50 containing nitrogen, e.g. polyetheramines or Jeffamines(r)
• CPC Class Codes: C08G 65/3326 aromatic
• CPC Class Codes: C09B 67/0002 Grinding; Milling with solid grinding or milling assistants
• CPC Class Codes: C09B 67/0022 Wet grinding of pigments
• CPC Class Codes: C09B 67/0089 non ionic dispersing agent, e.g. EO or PO addition products
• CPC Class Codes: C09D 7/41 Organic pigments; Organic dyes

Abstract

This invention relates to a process for preparing dispersible organic pigments by

(a) milling a mixture containing

(1) one or more organic pigments,

(2) at least about 1% by weight, relative to the organic pigment, of one or more aromatic polyalkylene oxide dispersants,

(3) 0 to about 10 parts by weight, relative to the organic pigment, of a milling liquid in which the organic pigment is substantially insoluble,

(4) 0 to about 50% by weight, relative to the organic pigment, of one or more milling additives other than dispersant (2), and

(5) 0 to about 20% by weight, relative to the organic pigment, of one or more surface treatment additives;

(b) optionally, adding to the milled pigment

(6) one or more liquids in which the organic pigment is substantially insoluble in amounts such that the total solids content is not reduced below about 10%, and

(7) one or more multivalent metal salts and/or one or more quaternary ammonium salt; and

(c) isolating the milled organic pigment

Claims

1. A process for preparing a dispersible organic pigment composition comprising

(a) wet-milling a mixture comprising

(1) one or more organic pigments,

(2) at least about 1% by weight, relative to the organic pigment, of one or more aromatic polyalkylene oxide dispersants,

(3) a positive amount of up to about 10 parts by weight, relative to the organic pigment, of a milling liquid in which the organic pigment is substantially insoluble,

(4) 0 to about 50% by weight, relative to the organic pigment, of one or more milling additives other than dispersant (2), and

(5) 0 to about 20% by weight, relative to the organic pigment, of one or more surface treatment additives;

(b) optionally, adding to the milled pigment

(6) one or more liquids in which the organic pigment is substantially insoluble in amounts such that the total solids content is not reduced below about 10%, and

(7) one or more multivalent metal salts and/or one or more quaternary ammonium salt; and

(c) isolating and drying the milled organic pigment.

2. A process according to claim 1 wherein the organic pigment is a perylene, quinacridone, phthalocyanine, 1,4-diketopyrrolopyrrole, or isoindoline.

3. A process according to claim 1 wherein the aromatic polyalkylene oxide dispersant is a compound having the formula

4. A process according to claim 1 wherein the aromatic polyalkylene oxide dispersant is a compound having the formula

5. A process according to claim 1 wherein the aromatic polyalkylene oxide dispersant is a compound having the formula

6. A process according to claim 1 wherein the milled organic pigment is isolated by spray drying or lyophilization.

7. A dispersible pigment composition prepared according to the process of claim 1.

8. A pigmented coating composition containing a dispersible pigment composition prepared according to claim 1.

9. An aqueous pigment dispersion comprising a dispersible organic pigment composition, prepared by the process according to claim 1, in an aqueous liquid medium.

10. A coating composition comprising a pigment dispersion according to claim 9 and an aqueous liquid medium.