Improved method of preparing high molecular weight polyamines
AssigneeNalco Chemical Company
InventorsKenneth G. Phillips, Paul J. Harris
Life of this patent
Estimating the term…
Abstract
An improved process for synthesizing high molecular weight polyamines utilizing a self-limiting neutralizing agent to maintain a generally constant alkaline pH over the course of the synthesis reaction, and the improved high molecular weight polyamines produced thereby.
Claims11
An improved process for making high molecular weight polyamines comprising:
- reacting, in the presence of a self-limiting neutralizing agent, an alkylene dihalide selected from the group consisting of ethylene and 1,2-propylene dihalides with a nitrogen containing compound having the structural formula ##STR3## where x is an integer of 0-5 and R is an alkylene radical selected from the group consisting of ##STR4## to produce said polyamines and an acid by-product, said self-limiting agent being present at the outset of the reaction in an amount sufficient to neutralize substantially all of said acid by-product expected from the reaction,
- said self-limiting agent being a basic reagent with a sufficiently low aqueous solubility and K.sub.b for neutralizing said acid by-product as it is produced while maintaining the pH of said reaction at a generally constant alkaline value.
An improved process for making high molecular weight polyamines comprising:
- reacting, in the presence of a self-limiting neutralizing agent, ethylene dihalide with ammonia to produce said polyamines and an acid by-product,
- said self-limiting agent consisting of Ca(OH).sub.2, said Ca(OH).sub.2 being present at the outset of the reaction in an amount sufficient to neutralize all of said acid by-product as it is produced while maintaining the pH of said reaction at a generally constant value of pH 12.0.
In a process for making high molecular weight polyamines by reacting an alkylene dihalide selected from the group consisting of ethylene and 1,2-propylene dihalides with an amine having the structural formula ##STR5## where x is an integer of 0-5 and R is an alkylene radical selected from the group consisting of ##STR6## to produce said polyamines and an acid by-product, the improvement comprising:
- carrying out said reaction in the presence of a self-limiting neutralizing agent, said self-limiting agent being present at the outset of the reaction in an amount sufficient to neutralize all of said acid by-product as it is produced,
- said self-limiting agent being a basic reagent with a sufficiently low aqueous solubility and K.sub.b for maintaining the pH of said reaction at a generally constant alkaline value.
Dependencies are inferred from the claim text.