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Control of Positive/Negative Contact Charging using Acid/Base Stoichiometry

IP.com Disclosure Number: IPCOM000103118D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 32K

Publishing Venue

IBM

Related People

Diaz, A: AUTHOR [+2]

Abstract

Using an aromatic sulfonic acid alkylamine salt with non-equivalent stoichiometry as a charge additive in toner (for electrophotographic development processes) permits positive or negative charge control.

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Control of Positive/Negative Contact Charging using Acid/Base Stoichiometry

      Using an aromatic sulfonic acid alkylamine salt with
non-equivalent stoichiometry as a charge additive in toner (for
electrophotographic development processes) permits positive or
negative charge control.

      Organic salts, such as dodecyldiammonium
dodecylbenzenesulfonate, can be used to generate a controlled
positive or negative contact charge on polymeric toners by varying
the acid/base stoichiometry in the salt. Toners containing only the
sulfonic acid or the salts (with excess acid) are found to charge
negative, while toners containing salts (with excess amine base)
charge positive. This observation is consistent with proton transfer
from the acid in the toner to the carrier (when there is excess acid
in the salt), and from the carrier to the amine in the toner (when
there is excess "free" amine).  To be consistent with this charging
mode, both the acid and the base should have reasonably large
molecular size and be compatible with the toner resin to avoid
contamination of the carrier surface.

      Disclosed anonymously.