Branched amido-amine dispersant additives (PT-739)

A fuel oil composition containing about 0.001 to 0.5 wt. % of a dispersant additive prepared by a process which comprises:

• (a) contacting in a first liquid reaction mixture a first nitrogen-containing compound having at least two reactive nitrogen moieties with a polyfunctional reactant having within its structure a first functional group reactive with a --NH-- group, and at least one additional functional group reactive with a --NH-- group, in an amount and under conditions sufficient to selectively react at least a portion of said first functional groups in said polyfunctional reactant with said reactive nitrogen moieties to form a first adduct;
• (b) contacting said first adduct with a second nitrogen-containing compound having at least two --NH-- groups in an amount and under conditions sufficient to react said additional functional groups in said first adduct with said --NH-- groups in said second nitrogen-containing compound to form a second adduct characterized by having within its structure on average (i) at least two nitrogen-containing moieties derived from said second nitrogen-containing moieties derived from said second nitrogen-containing compound per nitrogen-containing moiety derived from said first nitrogen-containing compound and (ii) at least two unreacted primary or secondary amine groups per molecule;
• and
• (c) contacting said second adduct in a second liquid reaction mixture with at least one member selected from the group consisting of;
• (A) long chain hydrocarbons substituted with mono- or dicarboxylic acid, anhydride or ester groups;
• (B) halogenated long chain hydrocarbons;
• (C) mixtures of an aldehyde and a long chain hydrocarbyl substituted phenol;
• and
• (D) mixtures of an aldehyde and a reaction product formed by reaction of long chain hydrocarbons substituted with mono- or dicarboxylic acid, anhydride or ester groups and an amino-substituted, optionally hydrocarbyl-substituted phenol.