Novolac Resin Dispersion Stability via Polyol Mediation
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Solution Overview
Problem
There is a need for a stable and inexpensive aqueous composition of particulate novolac resins that can be applied as a film or coating to substrates like fiberglass and lignocellulosic materials without using organic solvents, while also scavenging formaldehyde effectively.
Innovation Solution
An aqueous composition comprising particulate novolac resin particles with a dropping point temperature above 127°C, combined with a polyol, which forms a stable dispersion free of organic solvents, allowing for the application as a film or coating and acting as a formaldehyde scavenger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If novolacs are dissolved in water, then the composition is environmentally friendly and non-flammable, but novolacs do not dissolve in water and are not miscible therewith
Solution Approach 1:
The patent uses polyols as intermediary substances to bridge the incompatibility between novolac resins and water. The polyols form a intermediate phase that allows novolac particles to be dispersed in aqueous environment without direct contact between the hydrophobic resin and water molecules, thereby achieving environmental safety while maintaining compositional stability
Solution Approach 2:
The invention creates a composite aqueous composition consisting of novolac resin particles, polyols, and water. This composite structure allows the hydrophobic novolac to coexist with water through the mediating polyol phase, achieving both environmental friendliness and stability through material composition rather than molecular-level mixing
2Stability of the object's composition
If novolacs are dissolved in hydroxides of alkalines or earth alkalines, then the novolacs are dissolved, but the hydroxides remain on the surface after drying or curing, thereby increasing the pH to values which are often undesirable
Solution Approach 1:
The polyol acts as an intermediary that enables novolac dissolution without requiring alkaline hydroxides. This intermediate approach allows the resin to be dissolved in a neutral or mildly acidic environment, avoiding the harmful side effect of high pH increase while maintaining solubility
Solution Approach 2:
The invention extracts the harmful alkaline hydroxides from the dissolution process entirely, replacing them with polyols as the dissolving medium. This extraction eliminates the source of the undesirable pH increase while preserving the ability to dissolve novolac resins
3Stability of the object's composition
If novolacs are dissolved in liquid resoles, then the novolacs are dissolved, but resoles exhibit a kinetically controlled self-curing process, which only has a limited storage stability
Solution Approach 1:
The invention extracts the self-curing resole component from the system, replacing it with polyols that do not exhibit kinetically controlled self-curing. This extraction eliminates the source of limited storage stability while maintaining the ability to dissolve novolacs in a liquid medium
Solution Approach 2:
The patent employs polyols as a disposable, non-reactive dissolving medium that does not participate in curing reactions. Unlike resoles that continue to cure and degrade storage stability, the polyol remains inert and stable throughout storage, providing indefinite stability without self-curing complications
4Stability of the object's composition
If novolacs are dissolved in organic solvents, then the novolacs are dissolved, but the solvents are often flammable and/or hazardous for the environment
Solution Approach 1:
The invention changes the fundamental parameter of the dissolving medium from organic to aqueous-based (polyol-water system). This parameter change transforms the system from flammable and hazardous organic solvents to non-flammable, environmentally friendly polyols and water, while maintaining dissolution capability through the composite structure
Solution Approach 2:
The polyol serves as an intermediary that enables novolac dissolution in an aqueous environment without requiring harmful organic solvents. This intermediate approach achieves solubility through a benign polyol-water system, eliminating flammability and environmental hazards associated with traditional organic solvents
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 and cost-effective aqueous dispersion of novolac resin particles with large particle sizes, maintaining stability for extended periods and effectively scavenging formaldehyde, suitable for various industrial applications.
Implementation Method 1
An aqueous composition comprising a particulate novolac resin and a polyol... in the form of a stable dispersion
Data Source
Figure 1~2
AI summary
An aqueous composition including a particulate novolac resin and a polyol, wherein >50% of the number of total particles of novolac resin have a particle size of >15µm and >5% of the number of total particles of novolac resin have a particle size of >50µm, wherein the particulate novolac resin has a dropping point temperature of >127°C, and wherein the aqueous composition is essentially free of organic solvent. The aqueous composition will form a stable dispersion which is ideal for the preparation of a film or coating of substrates such as fiberglass, nonwoven fibers, or lignocellulosic materials which include composite boards, plywoods, parquets, laminated veneer lumber (LVL), laminated flooring, doors, wood for door frames and paper.