Polyurethane Coating Composition for Scratch and Blocking Resistance
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Solution Overview
Problem
Existing polyurethane resin compositions used for coatings on films suffer from insufficient scratch resistance and blocking resistance, necessitating improvements in mechanical strength and solvent resistance.
Innovation Solution
Incorporating specific structural units derived from polyols, including polycarbonate polyol from 1,10-decanediol, polyol compounds with anionic hydrophilic groups, glycol compounds, and polyhydric alcohols into the polyurethane resin composition, with controlled molecular weights and proportions, to enhance scratch and blocking resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyurethane resin composition is used for coating on film, then the coating can be formed with basic mechanical properties, but the scratch resistance and blocking resistance are insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the polyol by specifying precise proportions: glycol compound (30-90% by mass), polycarbonate polyol (10-40% by mass), and polyhydric alcohol (5-20% by mass). These parameter changes in the resin composition directly improve the coating's scratch resistance and blocking resistance while maintaining ease of coating formation.
Solution Approach 2:
The patent creates a composite polyol system combining multiple types of polyols (glycol compound, polycarbonate polyol, and polyhydric alcohol) in specific proportions. This composite approach synergistically improves both the mechanical strength and the scratch/blocking resistance of the coating, resolving the contradiction between performance improvement and manufacturing simplicity.
2Strength
If polyol with higher molecular weight is used to improve mechanical strength, then the coating strength increases, but the dispersibility and coating uniformity deteriorate
Solution Approach 1:
The patent optimizes the molecular weight parameter of the glycol compound to a specific range (500-2500) and controls the proportion of polyhydric alcohol (5-20% by mass). This parameter optimization ensures that the polyol provides sufficient mechanical strength while maintaining appropriate dispersibility and coating uniformity, avoiding the drawbacks of excessively high molecular weights.
Solution Approach 2:
The patent applies different polyol components to different functional requirements: the glycol compound (30-90% by mass) provides the base structure and dispersibility, the polycarbonate polyol (10-40% by mass) enhances mechanical strength and scratch resistance, and the polyhydric alcohol (5-20% by mass) improves blocking resistance. This local quality differentiation resolves the contradiction between strength and uniformity.
Data Source
AI summary
Provided is a polyurethane resin composition capable of forming a coating that has high mechanical strength and solvent resistance and that also has scratch resistance and blocking resistance.In a composition containing a polyurethane resin, the polyurethane resin has a structural unit derived from a polyol, a structural unit derived from a polyisocyanate, and a structural unit derived from a polyamine, and the polyol includes a polycarbonate polyol having a structural unit derived from 1, 10-decanediol, a polyol compound having an anionic hydrophilic group, a glycol compound represented by HO—(R1—O)n—H, and a polyhydric alcohol having three or more hydroxy groups. The glycol compound has a number-average molecular weight of 500 to 2,500, the polyhydric alcohol is included in an amount of 10% by mass or less relative to a total mass of the polyol, and the glycol compound is included in an amount of 30% by mass or more and 90% by mass or less relative to the total mass of the polyol.