Polyaminoamide-epichlorohydrin Resin Stabilization via Sequential Acid Addition
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Solution Overview
Problem
Polyaminoamide-epichlorohydrin wet strength resins face stability issues at high solid levels, leading to gellation and reduced storage stability, especially when the pH is adjusted below a certain level with strong acids.
Innovation Solution
Sequential addition of specific amounts of strong and weak acids to adjust the pH of polyaminoamide-epichlorohydrin resin solutions to a range of 3-4, enhancing stability and preventing gellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pH is adjusted below 3.0 with strong acid to prevent gellation at high solid content, then the storage stability is improved, but the resin undergoes hydrolysis and degradation
Solution Approach 1:
The patent changes the pH parameter from below 3.0 to a controlled range of 3-4, and introduces a two-stage acid addition process (strong acid followed by weak acid) to achieve this parameter change while preventing hydrolysis degradation
Solution Approach 2:
The patent uses a weak acid as an intermediary substance that buffers the pH and prevents direct contact between strong acid and the resin, thereby reducing hydrolysis while maintaining storage stability
2Productivity
If the solid content is increased to reduce manufacturing and storage costs, then the productivity is improved, but the resin stability decreases and gellation occurs
Solution Approach 1:
The patent adjusts the pH parameter to a controlled range of 3-4 through sequential acid addition, which enables the resin to maintain stability at higher solid contents without gellation, thereby improving productivity
3Stability of the object's composition
If the pH is lowered to prevent gellation, then the viscosity build-up is reduced, but the wet strength performance may be compromised
Solution Approach 1:
The patent optimizes the pH to a controlled range of 3-4 (not below 3.0) and uses sequential acid addition to achieve this parameter change, which prevents gellation while preserving wet strength performance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method significantly improves the stability and wet strength performance of polyaminoamide-epichlorohydrin resins, maintaining viscosity and preventing degradation during extended storage at elevated temperatures.
Implementation Method 1
the method involves sequentially adding a strong acid, a weak acid, and optionally additional strong acid to adjust the pH of the finished wet strength resin to about 3-4
Data Source
AI summary
A method of stabilizing an aqueous solution of polyaminoamide-epichlorohydrin resin comprising sequentially adding to the solution about 0.1 to about 10 weight percent of one or more strong acids and about 0.1 to about 10 weight percent of one or more weak acids to prepare a stabilized solution having a pH of about 3-4.