Liquid pigment dispersions
View Patent ↗The present invention provides fluid compositions comprising at least one hydrophobic liquid, at least one inorganic pigment, and at least one compatibilization agent comprising at least one phosphate monoester.
1. A fluid composition, comprising:
at least one hydrophobic liquid,
at least one inorganic pigment, and
at least one phosphate monoester compatibilizer substantially free of carboxylic ester linkages;
wherein the weight of phosphate monoester compatibilizer to inorganic pigment is above 1.5 weight percent and less than about 4.5 weight percent,
wherein when the hydrophobic liquid is a mineral oil with a viscosity of about 0.60 Poise, the phosphate monoester compatibilizer is a phosphate monoester rich composition where ester functionality is an ethoxylated oleyl alcohol with a hydrophilic/lipophilic balance of 5.7 and an estimated chain length of 27; and
wherein when the hydrophobic liquid is a vegetable oil with a viscosity of about 0.60 Poise and a higher polarity than the mineral oil, the phosphate monoester compatibilizer is selected from the group consisting of (a) a phosphate monoester rich composition where phosphate ester functionality is an ethoxylated C10-C14 alcohol with a hydrophilic/lipophilic balance of 11.2 and an estimated chain length of 30 and (b) a phosphate monoester rich composition where phosphate ester functionality is an ethoxylated tridecyl alcohol with a hydrophilic/lipophilic balance of about 9.6 and an estimated chain length of about 27.
2. The fluid composition according to claim 1 , wherein the composition has a viscosity less than about 500 poise at room temperature.
3. The fluid composition according to claim 1 , wherein ester functionality of the phosphate monoester compatibilizer comprises a solubility parameter similar to a solubility parameter of the hydrophobic liquid.
4. The fluid composition according to claim 3 , wherein the ester functionality of the phosphate monoester compatibilizer is miscible with the hydrophobic liquid.
5. The fluid composition according to claim 3 , wherein the ester functionality of the phosphate monoester compatibilizer has an HLB value within +/−2 units of an HLB value of the hydrophobic liquid.
6. The fluid composition according to claim 1 , wherein the inorganic pigment comprises particles whose surface comprises metal oxides or hydroxides.
7. The fluid composition according to claim 1 , wherein the hydrophobic liquid comprises more than one chemical species.
8. The fluid composition according to claim 1 , wherein the phosphate monoester compatibilizer is provided and used in free acid form.
9. The fluid composition according to claim 2 , wherein ester functionality of the phosphate monoester compatibilizer comprises a solubility parameter similar to a solubility parameter of the hydrophobic liquid.
10. The fluid composition according to claim 9 , wherein the ester functionality of the phosphate monoester compatibilizer is miscible with the hydrophobic liquid.
11. The fluid composition according to claim 9 , wherein the ester functionality of the phosphate monoester compatibilizer has an HLB value within +/−2 units of an HLB value of the hydrophobic liquid.
12. The fluid composition according to claim 2 , wherein the inorganic pigment comprises particles whose surface comprises metal oxides or hydroxides.
13. The fluid composition according to claim 2 , wherein the hydrophobic liquid comprises more than one chemical species.
14. The fluid composition according to claim 2 , wherein the phosphate monoester compatibilizer is provided and used in free acid form.