Anionic Polyacrylamide and Aldehyde Polymer Complex for Paper Retention

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Solution Overview

Problem

The increasing levels of dissolved and suspended solids in closed water systems of papermaking mills, particularly due to salt and anionic substances, reduce the effectiveness of retention programs for paper production, leading to decreased retention efficiency and increased solids levels, necessitating a more effective retention method.

Innovation Solution

A treatment composition comprising an anionic polyacrylamide resin and an aldehyde-functionalized polymer resin is used, forming a complex with a net cationic charge, which enhances retention and strength characteristics by forming strong interactions through electrostatic and covalent bonding, improving fiber and particulate retention in paper.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional retention chemicals (anionic flocculant and cationic coagulant) are used in closed water systems, then paper production continues, but retention efficiency decreases due to interference from dissolved and suspended solids

Engineering Contradiction:
Improveretention efficiencyVSAvoidinterference from dissolved and suspended solids
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the charge parameter of the retention chemical from traditional anionic/cationic combinations to a specifically designed cationic polymer with high charge density. This parameter change allows the retention chemical to effectively compete with dissolved solids for interaction sites on fiber surfaces, maintaining retention efficiency in closed water systems.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite approach by combining multiple functional groups within a single polymer structure - cationic charge groups for electrostatic interaction, hydrophobic groups for adsorption, and specific functional groups for covalent bonding. This composite material design enables the retention chemical to overcome interference from dissolved and suspended solids through multiple simultaneous mechanisms.

Inventive Principle:
Principle #40Composite materials

2Reliability

If more retention chemicals are added to compensate for reduced efficiency, then retention performance may improve, but dissolved and suspended solids levels increase further

Engineering Contradiction:
Improveretention performanceVSAvoiddissolved and suspended solids
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent creates a highly efficient retention chemical that replicates and enhances the desirable functions of traditional retention chemicals while eliminating their deficiencies. The cationic polymer with high charge density acts as an optimized version that achieves better retention performance at lower dosages, preventing the accumulation of dissolved and suspended solids.

Inventive Principle:
Principle #26Copying

3Strength

If GPAM is used for wet strength, then paper wet strength increases, but strength performance decreases at high pH and high alkalinity

Engineering Contradiction:
Improvewet strengthVSAvoidhigh pH and high alkalinity interference
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical structure parameters of the wet strength resin from traditional GPAM to a cationic polymer with high charge density and specific functional groups. This parameter change makes the wet strength mechanism resistant to high pH and alkalinity conditions, as the cationic charges remain effective and the hydrophobic interactions are not disrupted by alkaline environments.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If traditional retention programs are used, then paper production maintains current rates, but fiber and particulate retention performance decreases

Engineering Contradiction:
Improvepaper production rateVSAvoidfiber and particulate retention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent designs a universal retention chemical that performs multiple functions simultaneously: dewatering acceleration, fiber retention, filler retention, and wet strength enhancement. This multi-functional cationic polymer maintains high paper production rates while improving fiber and particulate retention performance through its combined mechanisms of electrostatic interaction, hydrophobic adsorption, and covalent bonding.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 use of the anionic polyacrylamide and aldehyde-functionalized polymer resin complex significantly improves retention performance and paper strength, increasing fiber dewatering rates and fixation of fines and fillers, resulting in enhanced paper quality and reduced solids levels.

Implementation Method 1

the complex of the anionic polyacrylamide resin and the aldehyde-functionalized polymer resin possesses a net cationic charge

Methodology Applied
Scientific EffectElectrostatic interaction: Electrostatics

Implementation Method 2

forming strong interactions through electrostatic and covalent bonding

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Implementation Method 3

retention chemicals accelerate the pulp dewatering process

Methodology Applied
Scientific EffectElectrostatic interaction: Electrostatics

Data Source

PatentEP2864542B1Compositions and methods of making paper products
Publication Date: 2018.11.28 KEMIRA OY

AI summary

One or more embodiments include paper, methods of making paper, compositions, and the like, are provided. In various exemplary embodiments described herein, a paper material may be formed by treating a cellulosic fiber or an aqueous pulp slurry with a treatment composition comprising an anionic polyacrylamide resin and an aldehyde- functionalized polymer resin.