Aqueous Polyurethane Resin Composition for Adhesion and Chipping Resistance
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Solution Overview
Problem
Existing aqueous polyurethane resin compositions lack sufficient impact resistance, such as chipping resistance, and adhesion, particularly when used for coatings on electrodeposited metal substrates.
Innovation Solution
Aqueous polyurethane resin compositions are formulated with specific combinations of organic diisocyanate compounds, polyol compounds, acidic group-containing compounds, and chain extenders, achieving a viscosity range of 500 to 50,000 Pa·s, which enhances both finished appearance and impact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the polyurethane resin is used for coating on electrodeposited metal substrate, then adhesion to substrate is improved, but impact resistance and chipping resistance are insufficient
Solution Approach 1:
The patent uses a composite polyurethane resin system combining multiple diisocyanate compounds (aliphatic and alicyclic types), polyols with specific molecular weights, and chain extenders to create a resin composition that simultaneously achieves strong adhesion and high impact resistance. The synergistic combination of these materials allows the coating to bond strongly to electrodeposited substrates while maintaining toughness and chip resistance.
Solution Approach 2:
The patent optimizes specific parameters including the molecular weight of polyol compounds (400-6000 g/mol), the ratio of different diisocyanate compounds, the type and amount of chain extender, and the solid content concentration (30-70%) to achieve the desired balance between adhesion and impact resistance. These parameter adjustments enable the resin to form a coating with both strong bonding and high toughness.
2Strength
If the polyurethane resin is used for coating on electrodeposited metal substrate, then adhesion to substrate is improved, but finished appearance is insufficient
Solution Approach 1:
The patent controls the viscosity of the aqueous polyurethane resin composition (500-50,000 Pa·s at 65% solid content) and adjusts the molecular weight distribution and composition of polyol compounds to optimize the flow properties and surface morphology of the coating film, achieving both good adhesion and excellent finished appearance simultaneously.
Solution Approach 2:
The use of composite materials including alicyclic diisocyanate compounds and specific polyol combinations creates a coating system that produces a smooth, uniform film with good adhesion. The alicyclic diisocyanate contributes to film formation and surface quality while the polyol matrix provides adhesion, achieving both appearance and bonding performance.
3Quantity of substance
If the viscosity of the aqueous polyurethane resin composition is increased to improve coating coverage, then coating uniformity is improved, but flow property and finished appearance deteriorate
Solution Approach 1:
The patent establishes an optimal viscosity range (500-50,000 Pa·s at 65% solid content) that balances coating coverage and flow properties. This parameter optimization allows the coating to achieve uniform coverage while maintaining sufficient flowability for proper leveling and surface formation, preventing both insufficient coverage and poor flow.
Solution Approach 2:
The patent accounts for viscosity changes during the coating process, noting that viscosity decreases as water evaporates and resin particles fuse. The initial viscosity is set to provide adequate coverage, while the dynamic thinning during drying allows for proper flow and surface formation, achieving both coverage and appearance quality.
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 composition provides coatings with improved adhesion and chipping resistance, maintaining a desirable appearance and durability.
Implementation Method 1
a polyurethane resin obtained from constituents including: (a) at least two types of organic diisocyanate compounds and/or polyisocyanate compounds which are different from each other; (b) a polyol compound
Implementation Method 2
even in a state where water after application is volatilized and the resin particles are fused and solidified
Implementation Method 3
water after application is volatilized and the resin particles are fused and solidified
Data Source
AI summary
Provided is an aqueous polyurethane resin composition which is excellent in finished appearance as well as excellent in impact resistance, such as chipping resistance, and adhesion.The aqueous polyurethane resin composition includes a polyurethane resin obtained from at least (a) at least two types of organic diisocyanate compounds and/or polyisocyanate compounds which are different from each other, (b) a polyol compound; (c) an acidic group-containing compounds comprising at least two types of compounds which are a compound containing a carboxyl group as the acid group (a carboxyl group-containing compound) and a compound containing a sulfo group as the acid group (a sulfo group-containing compound); and (d) a chain extender of a polyamine compound, a diamine compound, a polyol compound and/or an alkanolamine compound with a molecular weight of not more than 400, in which the aqueous polyurethane resin composition has a viscosity of not less than 500 Pa·s and not more than 50,000 Pa·s when the polyurethane resin is contained in an amount of 65% by weight.