Negative charge control agents and their preparation
The present invention provides an electrostatographic toner that has a condensation polymer binder having carboxylic acid end groups and an acid number of 4 or greater. The carboxylic end groups are converted to metal salts having the structure; (—COO −1 ) n M +n where M is selected from groups IB, IIB, IIIB, IVB, VB, or IA, IIA, IIIA, IVA, VA, VIA, VIIA and VIIIA of the periodic table and n is an integer from 1-4. The present invention also provides a developer of carrier particles and the electrostatographic toner.
1. An electrostatographic toner comprising: a condensation polymer binder having carboxylic acid end group and an acid value of 4 or greater, wherein the carboxylic acid end groups have been converted to metal carbonate salts having the structure:
(—COO −1 ) n M +n
where M is selected from groups IB, IIB, IIIB, IVB, VB, or IA, IIA, IIIA, IVA, VA, VIA, VIIA and VIIIA of the periodic table, and n is an integer from 1- 4, wherein the metal carbonate salts comprise from about 0.1 to about 6 parts per 100 parts by weight of the condensation polymer binder.
2. The electrostatographic toner of claim 1 wherein M is selected from the group consisting of zinc, lithium, sodium and potassium.
3. The electrostatographic toner of claim 1 wherein said condensation polymer binder is selected from the group consisting of resin-modified maleic alkyd polymers, polyamides, phenol-formaldehyde polymers, and polyester condensates.
4. The electrostatographic toner of claim 3 wherein said condensation polymer binder comprises polyester condensates of fumaric acid with propoxylated bis-phenol-A.
5. The electrostatographic toner of claim 1 comprising particles having an average diameter between about 0.1 μm and about 100 μm.
6. The electrostatographic toner of claim 1 wherein the acid value is greater than 6.
7. The electrostatographic toner of claim 1 wherein the acid value is greater than 11.
8. The electrostatographic toner of claim 1 further comprising colorant materials.
9. The electrostatographic toner of claim 1 further comprising release agents.
10. An electrostatographic developer comprising:
a condensation polymer binder having carboxylic acid end groups and an acid value of 4 or greater that have been converted to metal carbonate salts having the structure;
—COOM
where M is selected from groups IB, IIB, IIIB, IVB, VB, or IA, IIA, IIIA, IVA, VA, VIA, VIIA and VIIIA of the periodic table, wherein the metal carbonate salts comprise from about 0.1 to about 6 parts per 100 parts by weight of the condensation polymer binder; and carrier particles.
11. The electrostatographic developer of claim 8 wherein said polymer binder is selected from the group consisting of resin-modified maleic alkyd polymers, polyamides, phenol-formaldehyde polymers, and polyester condensates.
12. The electrostatographic developer of claim 10 wherein the acid value is greater than 6.
13. The electrostatographic developer of claim 10 wherein the acid value is greater than 11.