Dispersion

• US 5,494,511 A
• Filed: 02/02/1993
• Issued: 02/27/1996
• Est. Priority Date: 02/11/1992
• Status: Expired due to Term

• Current Assignee: The Lubrizol Corporation (Berkshire Hathaway Incorporated)
• Original Assignee: Zeneca Incorporated (Astrazeneca PLC)
• Inventors: Holbrook, Mark
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): Hertzog, Scott L.
• Application Number:
  US08/012,435
• Time in Patent Office: 1,120 Days
• Field of Search: 106/499, 106/20 R, 106/23 R, 106/400, 106/401, 106/311, 106/287.26
• US Class Current: 524/141
• CPC Class Codes: C09D 11/03 characterised by features other than the chemical nature of the binder
• CPC Class Codes: C09D 17/001 in aqueous medium C09D17/003, C09D17/004 take precedence
• CPC Class Codes: C09D 5/027 Dispersing agents anti-settling agents C09D7/45

Abstract

A dispersion of a finely divided pigment in a composition of water, one or more water-compatible resins and, as dispersant, a polycyclic aromatic compound having a water-solubilising poly(C_2-4 -alkyleneoxy) chain containing from 3 to 50 alkyleneoxy groups, characterised in that the dispersion contains from 3% to 30% by weight or resin with respect to the total weight of water and resin in the dispersion. The dispersion is suitable for the preparation of water-borne paint and inks.

Claims

1. An aqueous mill-base for water-borne paints and inks comprising a finely divided pigment in a composition of water, one or more water-insoluble resins and, as dispersant, a polycyclic aromatic compound having a water-solubilising poly(C_2-4 -alkyleneoxy) chain containing from 3 to 50 alkyleneoxy groups, characterised in that the dispersion contains from 3% to 30% by weight of resin with respect to the total weight of water and resin in the dispersion, said mill-base being obtained by grinding the pigment in an aqueous dispersion with the resin and dispersant.

2. A mill-base according to claim 1 wherein the dispersant is of the formula:

space="preserve" listing-type="equation">(A--X--Y).sub.p --R

wherein;

A is a polycyclic aromatic group;

X is a bridging group selected from --O--, --C(O)O--, --S--, --N(H)-- and --N(Y)--;

Y is --(C₃ H₆ O)_m --(C₂ H₄ O)_n -- or --(C₂ H₄ O)_n --(C₃ H₆ O)_m --;

m is from 0 to 3n;

m+n is from 3 to 50;

p is 1 or 2;

R is H, C_1-4 -alkyl or --PO₃ M₂ when p is 1;

R is ═

PO₃ M when p is 2; and

M is H, a metal or optionally substituted ammonium.

3. A mill-base according to claim 2 wherein the dispersant is naphth-2-yloxy-(C₂ H₄ O)₁₀ H.

4. A mill-base according to claim 1 wherein the resin is selected from acrylic resins, styrene acrylic resins, polyester resins, polyurethane resins and acrylic-polyurethane resins.

7. A water-borne paint comprising a mill-base according to claim 1.

8. A water-borne ink comprising a mill-base according to claim 1.

9. A water-borne packaging ink comprising a mill-base according to claim 1.

5. An aqueous suspension of unmilled pigment containing one or more water-insoluble resins and a polycyclic aromatic compound having a water-solubilising poly(C_2-4 -alkyleneoxy) chain containing from 3 to 50 alkyleneoxy groups.

6. A process for the preparation of a mill-base which comprises submitting an aqueous suspension according to claim 5 to a high shear treatment.