Formaldehyde-Free Binder System for Composite Materials

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Solution Overview

Problem

The insulation industry faces challenges with traditional binders that contain formaldehyde, which is a known human carcinogen and volatile substance, and alternative polymers are expensive, release volatile compounds, and can damage equipment, while also being petroleum-based, posing environmental concerns. Additionally, shipping aqueous binder compositions is costly and unstable over time.

Innovation Solution

A formaldehyde-free or reduced binder system using a polyol bonded to a second compound, such as melamine or urea, with optional crosslinkers like citric acid and polyacrylic acid, which is applied as a concentrated or dried form, reducing shipping costs and requiring simple on-site preparation, and can be used alone or blended with other binders to create stable, strong composite products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If traditional formaldehyde-based binders (urea formaldehyde, phenol formaldehyde) are used, then binding strength and stability are achieved, but formaldehyde emissions occur which are harmful to health and the environment

Engineering Contradiction:
Improveformaldehyde emissionsVSAvoidbinder strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The invention changes the chemical composition parameters of the binder system by replacing formaldehyde-based resins with a combination of polyol, carboxylic acid, and melamine/urea in specific weight ratios (polyol 60-90 wt%, carboxylic acid 5-30 wt%, melamine/urea 10-40 wt%). This parameter change eliminates formaldehyde emissions while maintaining binder strength through the synergistic interaction of these components.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite binder system combining multiple components (polyol, carboxylic acid, and melamine or urea) that work together to achieve both binding strength and formaldehyde-free operation. The composite nature of this binder system allows each component to contribute specific properties: polyol provides adhesion, carboxylic acid enables crosslinking, and melamine/urea enhances structural integrity.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If alternative polymers (polyacrylic acid, polyvinyl acetate, polyester) are used as formaldehyde-free binders, then formaldehyde emissions are eliminated, but these polymers are expensive and release other volatile compounds

Engineering Contradiction:
Improveformaldehyde emissionsVSAvoidcost
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The invention changes the chemical composition from expensive alternative polymers to a cost-effective combination of readily available materials (polyol, carboxylic acid, melamine/urea) in optimized ratios. This parameter change reduces material cost while eliminating formaldehyde emissions and minimizing volatile compound release through the stable crosslinked network formed by the carboxylic acid-melamine/urea system.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If alternative polymers are used as formaldehyde-free binders, then formaldehyde emissions are eliminated, but acidity can damage manufacturing equipment and metal structures

Engineering Contradiction:
Improveformaldehyde emissionsVSAvoidequipment damage
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The invention changes the pH-related parameters by using carboxylic acid in controlled amounts (5-30 wt%) within a polyol-melamine/urea system. The carboxylic acid provides necessary acidity for crosslinking reactions but is balanced by the buffering capacity of the polyol and melamine/urea, resulting in a binder that is sufficiently acidic for curing but not excessively corrosive to equipment and metal structures.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If aqueous binder compositions are shipped, then ease of application is improved, but shipping costs increase due to excess weight and volume of water

Engineering Contradiction:
Improveease of applicationVSAvoidshipping weight
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The invention changes the physical state parameter of the binder from aqueous solution to concentrated or dried form. The binder components (polyol, carboxylic acid, melamine/urea) can be supplied as concentrated compositions with minimal water content or as dry powders that are reconstituted on-site. This parameter change significantly reduces shipping weight and volume while maintaining ease of application through simple mixing with water at the application site.

Inventive Principle:
Principle #35Parameter changes

5Ease of operation

If aqueous binder compositions are shipped, then ease of application is improved, but stability over long periods deteriorates

Engineering Contradiction:
Improveease of applicationVSAvoidbinder stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The invention changes the water content parameter by providing the binder as a concentrated composition or dried powder with minimal or no water. This parameter change eliminates the stability issues associated with aqueous solutions (microbial growth, hydrolysis, phase separation) while allowing easy reconstitution at the application site by adding the required amount of water, thus maintaining ease of application.

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 binder system achieves significant strength and stability in composite materials, with reduced formaldehyde emissions and improved environmental sustainability, while minimizing equipment damage and shipping costs, and can be easily prepared on-site with minimal equipment requirements.

Implementation Method 1

a polyol bonded to a second compound. The second compound is optionally a small molecule (i.e. with a molecular weight of less than 1000 g/mol) prior to being bonded to the polyol

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Implementation Method 2

The binder may also contain an additional crosslinker or a stiffening agent or both

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Data Source

PatentUS11453798B2Formaldehyde free binder and multi-component nanoparticle
Publication Date: 2022.09.27 ECOSYNTHETIX INC

AI summary

This patent describes formaldehyde free or formaldehyde reduced binders useful, for example, in a fiber based composite material such as glass or other mineral fiber insulation, non-woven fabric or wood-based board. In one example, melamine is used as an acidic solution or a salt. The salt or solution is used to create an aqueous binder with other components such as a polyol and a crosslinker. A preferred polyol is a nanoparticle comprising high molecular weight starch. In other examples, binders include mixtures of a polyol with urea and a crosslinker. In other examples, a multi-component nanoparticle is made by reacting a polyol such as starch in an extruder with an insolubilizer such as melamine or urea. The resulting particles are mixed with water, optionally with other components such as an additional crosslinker, to create an aqueous binder.