Compact Structured Polymers for Paper Dry Strength

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Solution Overview

Problem

Existing acrylamide-based dry strength agents in the papermaking industry face handling issues, process challenges, and inadequate dry strength, necessitating the development of improved polymers that can enhance paper strength, reduce basis weight, and increase filler loading while allowing for higher machine speeds.

Innovation Solution

A high molecular weight, water-soluble structured polymer with a weight-average molecular weight of 100,000 to 5,000,000 is created through the polymerization of amine-containing unsaturated monomers, including acrylamide and ethylenically unsaturated amine monomers, resulting in polymers with an apparent conformation coefficient of less than 0.40 and greater than 80% solubility, which are used as improved dry strength additives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional linear acrylamide polymers are used as dry strength agents, then adequate dry strength can be achieved, but handling issues and paper machine process issues occur

Engineering Contradiction:
Improvedry strengthVSAvoidhandling issues
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent changes the molecular architecture parameter from linear to compact structured (with apparent conformation coefficient ≤0.40), while maintaining high molecular weight (100,000 to 5,000,000). This structural parameter change resolves the contradiction by providing adequate dry strength through compact structure while improving handling characteristics and paper machine processability.

Inventive Principle:
Principle #35Parameter changes

2Strength

If higher doses of commercial dry strength agents are used, then paper strength specifications can be met, but basis weight reduction and filler loading increase are limited

Engineering Contradiction:
Improvepaper strengthVSAvoidbasis weight
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent changes the polymer structure parameter to compact structured conformation (apparent conformation coefficient ≤0.40), which increases the efficiency of the dry strength agent. This allows meeting paper strength specifications at lower doses, enabling basis weight reduction and increased filler loading while maintaining required strength levels.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If conventional polymers are used, then current paper making processes can be maintained, but machine speeds and filler loading cannot be increased

Engineering Contradiction:
Improvemachine speedsVSAvoidprocess stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the polymer conformation parameter to compact structured (apparent conformation coefficient ≤0.40) with high molecular weight (100,000 to 5,000,000), which improves handling and process characteristics. This structural modification enables increased machine speeds and filler loading while maintaining process stability and reliability in paper making operations.

Inventive Principle:
Principle #35Parameter changes

4Strength

If linear acrylamide polymers with high molecular weight are used, then dry strength is improved, but solubility and structural compactness are insufficient

Engineering Contradiction:
Improvedry strengthVSAvoidsolubility
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent changes the molecular architecture parameter from linear to compact structured conformation (apparent conformation coefficient ≤0.40), while maintaining high molecular weight (100,000 to 5,000,000). This structural parameter change simultaneously improves dry strength, enhances solubility (≥80% as determined by SEC/MALLS), and achieves the desired structural compactness.

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 polymers demonstrate superior dry strength, enabling equivalent or better paper performance at lower doses compared to commercial agents, with enhanced solubility and structural compactness, facilitating reduced fiber usage and increased filler loading.

Implementation Method 1

The polymer is obtained by polymerizing one or more amine-containing unsaturated monomers or polymers

Methodology Applied
Scientific EffectPolymerization: Chemical Bonding

Data Source

PatentEP1877622B1High molecular weight compact structured polymers, methods of making and using
Publication Date: 2014.04.16 NALCO CO

AI summary

A structured water soluble polymer produced by polymerization of amine- containing monomers or pre-formed polymers is described. Various structured polymers are prepared and characterized. The structured polymers are particularly valued in the papermaking industry.