Pigments with improved dispersibility

• US 9,175,168 B2
• Filed: 09/14/2007
• Issued: 11/03/2015
• Est. Priority Date: 09/14/2006
• Status: Active Grant

• Current Assignee: Sun Chemical Corporation
• Original Assignee: Sun Chemical Corporation
• Inventors: Britanak, John, Johnson, Mark W., Shen, Zhijian, Faubion, Richard Kent
• Primary Examiner(s): Mulcahy, Peter D
• Application Number:
  US11/855,791
• Publication Number:
  US 20080071010A1
• Time in Patent Office: 2,972 Days
• Field of Search: 523/351, 106/401, 106/410, 106/498, 106/413
• US Class Current: 1/1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C08J 3/22 using masterbatch techniques
• CPC Class Codes: C09C 3/08 Treatment with low-molecular-weight non-polymer organic compounds C09C3/006, C09C3/048 take precedence
• CPC Class Codes: D01F 1/04 Pigments

Abstract

A method for preparing a pigment composition for a plastics colorant is disclosed. The pigment composition is prepared by mixing a press cake of the pigment with a liquid containing a selected type of dispersant before the resulting slurry is dried. Thus prepared pigment composition has improved dispersibility in a thermoplastic or thermoset resin and greatly reduces the filter pressure rise in the molding systems for preparing masterbatches or various plastic compositions for molding, fiber, film and sheet.

Claims

1. A method for preparing a pigment composition for a plastics colorant, comprising

(i) providing a pigment press cake,

(ii) mixing the press cake with a dispersant and with water, a water miscible solvent or a mixture thereof;

and

(iii) drying the mixture,

wherein the dispersant is poly(oxyalkylene) modified phthalocyanine, and poly(oxyalkylene) is connected to phthalocyanine by a covalent bond.

2. The method of claim 1, wherein the dispersant is Pc-[SO₂—

NH—

CHCH₃CH₂O)_x(CH₂CH₂O)_y—

CH₃]_n, Pc is a phthalocyanine or metallophthalocyanine radical in which the metal is copper, cobalt, nickel, iron or aluminum, x is 0 to about 30, y is 0 to about 100, ×

plus y is at least 3, and n is 1-4.

3. The method of claim 1, wherein the pigment press cake is an indanthrone blue 60 press cake.

4. The method of claim 3, wherein the drying is spray drying.

5. A masterbatch comprising a pigment composition in combination with a plastic molding composition in which the pigment composition is about 0.0001% to about 80% of the combination,

wherein the pigment composition is prepared according to the method of claim 1.

6. A masterbatch according to claim 5 in which the press cake is an indanthrone blue 60 press cake, and the drying is spray drying.

7. A plastic article comprising the pigment composition prepared according to the method of claim 1.

8. The article of claim 7, wherein the press cake is an indanthrone blue 60 press cake, and the drying is spray drying.

9. the article of claim 7, wherein the article is a plastic molding composition, a molded plastic article, a film, a fiber or a sheet.