Polyurethane Resin Dispersion Composition for Low Viscosity Coatings
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Solution Overview
Problem
Existing aqueous dispersions of polyurethane resins face challenges in reducing viscosity, improving storage stability, and enhancing heat resistance.
Innovation Solution
An aqueous dispersion of polyurethane resin is formulated through a reaction of an aromatic polyester polyol and an aliphatic diol with a hydrocarbon side chain, using specific chain extenders with primary and secondary amino groups, and alicyclic polyisocyanate, achieving a targeted acid and hydroxyl value range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional aqueous polyurethane emulsion compositions are used, then adhesion to base material films is achieved, but viscosity is high and storage stability is poor
Solution Approach 1:
The invention changes the chemical composition parameters of the polyurethane resin by using specific polyols (polyester polyol with aromatic rings, aliphatic diol with hydrocarbon side chain) and controlling the acid value (11.0-23.0 mgKOH/g) and hydroxyl value (8.0-23.0 mgKOH/g). These parameter changes result in reduced viscosity while maintaining adhesion properties.
Solution Approach 2:
The invention creates a composite aqueous dispersion system combining polyurethane resin with specific polyol components (aromatic polyester polyol and aliphatic diol) and controlling the ratio of chain extenders (C1)/(C2) = 0.3 to 1.4. This composite approach achieves both low viscosity and good storage stability while maintaining adhesion.
2Strength
If polyurethane resin with high adhesion is used, then bonding strength is improved, but storage stability deteriorates
Solution Approach 1:
The invention optimizes the acid value (11.0-23.0 mgKOH/g) and hydroxyl value (8.0-23.0 mgKOH/g) parameters to achieve the right balance between bonding strength and storage stability. The specific range of these parameters ensures the polyurethane resin has sufficient adhesion while maintaining compositional stability during storage.
Solution Approach 2:
The invention uses a composite approach with aromatic polyester polyol and aliphatic diol in specific proportions, along with controlled chain extender ratios (C1)/(C2) = 0.3 to 1.4, to create a polyurethane resin that simultaneously achieves high bonding strength and excellent storage stability.
3Stability of the object's composition
If polyurethane resin with good storage stability is used, then compositional stability is improved, but heat resistance deteriorates
Solution Approach 1:
The invention optimizes the hydroxyl value parameter (8.0-23.0 mgKOH/g) and the composition ratios of chain extenders to achieve both good storage stability and high heat resistance. The specific parameter ranges ensure the polyurethane resin maintains compositional stability while developing adequate crosslinking density for heat resistance.
Solution Approach 2:
The invention creates a composite polyurethane system with aromatic polyester polyol, aliphatic diol, and specific chain extenders (C1 and C2 compounds with amino groups) in controlled ratios. This composite structure provides both storage stability and heat resistance by combining different functional components.
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 formulation results in reduced viscosity, enhanced storage stability, and improved heat resistance of the aqueous dispersion and coating films.
Implementation Method 1
a polyurethane resin obtained by a reaction of a polyol (A), a polyisocyanate (B), and a chain extender (C)
Data Source
AI summary
A reduction in the viscosity is achieved and improvements in the storage stability and the heat resistance of the coating film are achieved.An aqueous dispersion of a polyurethane resin according to an embodiment is obtained by a reaction of a polyol (A), a polyisocyanate (B), and a chain extender (C). The polyol (A) includes an aromatic polyester polyol (A1), and an aliphatic diol (A2) having a hydrocarbon group in a side chain. The chain extender (C) includes a compound (C1) having three primary and/or secondary amino groups and not having hydroxy groups, and a compound (C2) having one or more hydroxy groups and two or more primary and/or secondary amino groups. The acid value is 11.0 to 23.0 mgKOH/g and the hydroxyl value is 8.0 to 23.0 mgKOH/g.