Anionic Polymer Composite for Paper Wet Strength and Retention

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Solution Overview

Problem

Current wet strength additives for paper products, such as polyamidoamine epichlorohydrin (PAE) and carboxymethyl cellulose (CMC), face issues like high dosages required for effectiveness, poor retention, drainage problems, and microbiological growth, leading to operational inefficiencies and environmental concerns in paper production.

Innovation Solution

A polymer composition comprising an anionic polymer composite synthesized by polymerizing vinyl monomers in the presence of an anionic polysaccharide, providing improved wet and dry tensile strength and broad operating windows, which can be used with cationic additives to enhance retention and strength, and is more environmentally stable than CMC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high dosages of PAE resins are used to provide desired wet strength, then wet strength is improved, but PAE retention deteriorates and operational issues arise

Engineering Contradiction:
Improvewet strengthVSAvoidPAE retention
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces an anionic polymer as an intermediary substance that mediates between the cationic PAE resin and the pulp fibers. This anionic polymer acts as a bridge, improving PAE retention through electrostatic interactions while reducing the dosage required for achieving desired wet strength properties

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If high dosages of PAE resins are used to provide desired wet strength, then wet strength is improved, but drainage deteriorates due to un-retained PAE accumulation

Engineering Contradiction:
Improvewet strengthVSAvoiddrainage
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The anionic polymer serves as a mediator that enhances PAE retention, thereby reducing the amount of un-retained PAE that accumulates in the water system and causes drainage problems

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If CMC is used to provide wet and dry tensile strength improvement, then strength is improved, but handling complexity increases due to make-down requirements

Engineering Contradiction:
Improvetensile strengthVSAvoidmake-down unit complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent employs a pre-hydrolyzed anionic polymer that can be directly applied without requiring expensive make-down units. This approach replaces the need for complex hydrolysis equipment while maintaining the strength-improving benefits of CMC-like polymers

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Strength

If CMC is used to provide wet and dry tensile strength improvement, then strength is improved, but operational reliability deteriorates due to filter plugging and microbiological growth

Engineering Contradiction:
Improvetensile strengthVSAvoidoperational reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a pre-hydrolyzed anionic polymer in solution form that eliminates the need for storage and handling of dry CMC powder, thereby reducing operational issues related to filter plugging and microbiological growth while maintaining strength improvement benefits

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

5Ease of operation

If synthetic copolymers of acrylamide and acrylic acid are used as alternative to CMC, then ease of operation is improved, but strength performance deteriorates compared to CMC

Engineering Contradiction:
Improvehandling easeVSAvoidstrength development
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent modifies the parameters of synthetic polymers by controlling the hydrolysis degree and molecular weight of the anionic polymer, and by optimizing the ratio of anionic polymer to PAE resin, thereby achieving strength development comparable to or exceeding CMC while maintaining the ease of handling of synthetic polymers

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 new polymer composition delivers superior wet and dry strength performance with a broader operating window, improved retention, and reduced microbiological instability, addressing the limitations of existing additives while simplifying handling and reducing production costs.

Implementation Method 1

polymerizing vinyl monomers in the presence of an anionic polysaccharide

Methodology Applied
Scientific EffectPolymerization:

Implementation Method 2

the new polymer composition delivers superior wet and dry strength performance with a broader operating window, improved retention

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentUS11802376B2Paper strength improving additives, their manufacture and use in paper making
Publication Date: 2023.10.31 KEMIRA OY

AI summary

The present invention relates to a polymer composition comprising an anionic polymer composite having a synthesized polymer portion and a polysaccharide portion, obtainable by polymerizing vinyl monomers in the presence of the polysaccharide. The present invention further relates to a strength system and methods of production and use in providing a paper product.