Glyoxylated Polyacrylamide Pre-mixture for On-site Papermaking

Solution Overview

Problem

Glyoxylated polyacrylamide compositions face challenges in storage stability and safety due to high glyoxal content, leading to increased transportation costs and safety risks in papermaking processes, necessitating a solution for on-site production with improved stability and reduced hazard classification.

Innovation Solution

A pre-mixture of polyacrylamide base polymer with high cationicity and weight average molecular weight, combined with low levels of glyoxal, is used to create a stable aqueous prepolymer composition that can be safely processed on-site, avoiding hazardous classifications and maintaining stability for extended periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If GPAM compositions are transported and stored as aqueous solutions with low concentration (5-7 wt%), then transportation costs increase due to large volumes, but storage stability deteriorates as glyoxal continues to cross-link polyacrylamide leading to gel-formation

Engineering Contradiction:

Improveconcentration of GPAM productVSAvoidstorage stability of GPAM composition

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-mixing polyacrylamide base polymer with glyoxal at controlled ratios before use. This pre-mixing is done at the point of application rather than in advance during manufacturing, allowing the components to be prepared and ready but not yet reacted extensively, thus maintaining stability while enabling higher effective concentration during use.

Inventive Principle:

Principle #10Preliminary action

2Loss of energy

If GPAM is manufactured on-site at paper mills, then transportation costs are reduced and storage stability is improved, but safety risks increase due to handling of glyoxal which is classified as hazardous (H341, H317)

Engineering Contradiction:

Improvetransportation costsVSAvoidsafety risk from glyoxal handling

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the concentration ratio of glyoxal to polyacrylamide base polymer in the pre-mix. By optimizing these parameters, the composition achieves adequate reactivity for effective cross-linking while maintaining glyoxal levels that reduce hazard classification, thus lowering safety risks during on-site handling.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses polyacrylamide base polymer as an intermediary that reacts with glyoxal in a controlled manner. This intermediary approach allows glyoxal to be delivered in a less hazardous form (as a pre-mixed composition rather than pure glyoxal), reducing the immediate safety risks while still achieving the desired cross-linking effect when applied.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If glyoxal content in GPAM product is reduced to below 1 wt%, then hazard classification is improved (avoiding H341 and H317), but storage stability may be compromised due to reduced cross-linking capability

Engineering Contradiction:

Improvehazard classification of glyoxalVSAvoidcross-linking effectiveness of GPAM

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-mixing polyacrylamide base polymer with glyoxal at controlled ratios before use. This pre-mixing is done at the point of application rather than in advance during manufacturing, allowing the components to be prepared and ready but not yet reacted extensively, thus maintaining stability while enabling higher effective concentration during use.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by precisely controlling the concentration ratio of glyoxal to polyacrylamide base polymer in the pre-mix. By optimizing these parameters, the composition achieves adequate reactivity for effective cross-linking while maintaining glyoxal levels that reduce hazard classification, thus lowering safety risks during on-site handling.

Inventive Principle:

Principle #35Parameter changes

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 solution provides a stable, low-glyoxal pre-mixture that can be safely handled and processed on-site, offering improved storage stability and effective use as a dry strength and dewatering agent for paper or board production, reducing transportation costs and safety concerns.

Implementation Method 1

Glyoxylated polyacrylamide (GPAM) products are polyacrylamide-based polymers crosslinked by using glyoxal

Methodology Applied

Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 2

a buffering acid, wherein the pH of the aqueous prepolymer composition is in the range of 2 - 4

Methodology Applied

Scientific EffectBuffering:

Data Source

PatentUS20230140443A1Polyacrylamide composition and its use

Publication Date: 2023.05.04 KEMIRA OY

AI summary

An aqueous prepolymer composition, which comprises a polyacrylamide base polymer comprising 10 - 40 mol-% of cationic monomers and having a weight average molecular weight Mw in the range of 120 000 - 350 000 g/mol, 0.1 - 1 weight-% of glyoxal, calculated from the total weight of the aqueous prepolymer composition, and a buffering acid for adjusting pH of the composition in the range of 2 - 4. A prepolymer composition is used in a method for producing on-site glyoxylated polyacrylamide useful in paper or board manufacturing.