Ashless dispersants formed from substituted acylating agents and their production and use

A process for preparing polybutenyl succinimides which comprises reacting

• (A) a substituted succinic acylating agent formed by a process which comprises reacting (i) at least one substantially aliphatic polymer of at least one lower olefin, and (ii) an acidic reactant or a mixture of two or more acidic reactants represented by the general formula
• R--CO--CH.dbd.CH--CO--R'
• wherein R and R' are independently --OH, --O-lower alkyl, a halogen atom, or taken together are a single oxygen atom;
• the process being characterized in that:
• a) the substantially aliphatic polymer is comprised predominantly or entirely of polyisobutene, at least 50% of the polyisobutene content of such polymer having an end group represented by the formula ##STR18## b) the mole ratio of said acidic reactant(s):
• said polymer(s) is at least 1:1;
• c) the reaction mixture is maintained under superatmospheric pressure during at least a substantial portion of the reaction period;
• and
• d) said acylating agent is characterized by having an average total tar rating as determined by the method described in the specification hereof that is at least 25% lower than the average total tar rating of a corresponding product made in the same way under the same reaction conditions using a polyisobutene containing up to 10% of the above-depicted end group;
• and
• (B) at least one polyamine.

A carboxylic derivative composition produced by reacting at least one substituted succinic acylating agent with a reactant selected from the group consisting of (1) at least one amine having at least one primary or secondary amino group, (2) at least one alcohol, and (3) a combination of at least one amine having at least one primary or secondary amino group and at least one alcohol, the components of (3) being reacted with said at least one substituted succinic acylating agent concurrently or sequentially in any order, said at least one succinic acylating agent being prepared by reacting (i) at least one substantially aliphatic polymer of at least one lower olefin, and (ii) an acidic reactant or a mixture of two or more acidic reactants represented by the general formula

• R--CO--CH.dbd.CH--CO--R'
• wherein R and R' are independently --OH, --O-lower alkyl, a halogen atom, or taken together are a single oxygen atom;
• the process of preparing said at least one succinic acylating agent being characterized in that:
• a) the substantially aliphatic polymer is comprised predominantly or entirely of polyisobutene, at least 50% of the polyisobutene content of such polymer having an end group represented by the formula ##STR19## b) the mole ratio of said acidic reactant(s):said polymer(s) is at least 1:1;
• and
• c) the reaction mixture is maintained under superatmospheric pressure during at least a substantial portion of the reaction period;
• and
• d) said acylating agent is characterized by having an average total tar rating as determined by the method described in the specification hereof that is at least 25% lower than the average total tar rating of a corresponding product made in the same way under the same reaction conditions using a polyisobutene containing up to 10% of the above-depicted end group.