Urethane resin composition, coating agent, urethane resin composition for forming surface layer of leather-like sheet, laminate, and leather-like sheet
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Solution Overview
Problem
Existing urethane resin compositions used for forming films lack sufficient secondary adhesiveness and durability, leading to peeling issues when adhesives or putty materials are applied, and inadequate moisture-heat resistance and hydrolysis resistance.
Innovation Solution
A urethane resin composition is developed using a polyol with a specific mass ratio of oxyethylene to oxytetramethylene structures, combined with polyoxytetramethylene glycol and/or polycarbonatediol, and an anionic group-containing polyol, which forms a film with improved adhesion and durability when used in a leather-like sheet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional urethane resin compositions are used to form films, then the films can be produced with basic coating properties, but the films exhibit low secondary adhesiveness causing peeling when adhesives or putty materials are applied
Solution Approach 1:
The patent changes the chemical composition parameters of the polyol component by specifying a mass ratio of oxyethylene structure to oxyalkylene structure between 3/7 and 9/1, and setting the polyol component content at 10-50 mass%. This parameter optimization resolves the contradiction by achieving both good adhesion and flexibility simultaneously
Solution Approach 2:
The patent creates a composite urethane resin system by combining specific polyol components (oxyethylene and oxyalkylene structures) with polyisocyanate components. This composite approach enables the film to achieve both secondary adhesiveness and resistance to peeling when adhesives are applied
2Strength
If conventional coating materials are used to form films, then the films can be produced with basic coating properties, but the films exhibit insufficient adhesion to various substrates
Solution Approach 1:
The patent optimizes the polyol component parameters by specifying the mass ratio of oxyethylene structure (a1-1) to oxyalkylene structure (a1-2) between 3/7 and 9/1, and setting the polyol component content at 10-50 mass% of total isocyanate-reactive groups. This parameter optimization enables strong adhesion across diverse substrates including metals, plastics, and ceramics
Solution Approach 2:
The patent designs the urethane resin composition to be universally applicable to various substrates by optimizing the polyol-polyisocyanate ratio and molecular structure. The composition achieves multi-functional adhesion capability across different substrate types while maintaining consistent performance
3Reliability
If conventional polyurethane coating materials are used, then continuous films with surface finishing properties can be formed, but the films lack sufficient durability including moisture-heat resistance and hydrolysis resistance
Solution Approach 1:
The patent changes the chemical structure parameters of the polyol component by specifying the mass ratio of oxyethylene structure to oxyalkylene structure between 3/7 and 9/1. This structural parameter optimization enhances the film's resistance to moisture-heat and hydrolysis while maintaining flexibility
Solution Approach 2:
The patent creates a composite urethane resin system combining oxyethylene-containing polyols with polyisocyanates in specific ratios. This composite structure provides both durability against environmental factors and the required flexibility for practical applications
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 achieves excellent secondary adhesiveness, adhesion to substrates, and durability, including moisture-heat resistance and hydrolysis resistance, making it suitable for applications such as surface skin layers in laminates.
Implementation Method 1
a polyol (A) containing a polyether polyol (a1) which has an oxyethylene structure (a1-1) and an oxyalkylene structure (a1-2) other than the oxyethylene structure (a1-1), wherein said oxyalkylene structure (a1-2) other than the oxyethylene structure (a1-1) is an oxytetramethylene structure
Data Source
AI summary
A problem to be solved by the present invention is to provide a urethane resin composition capable of forming a film having excellent adhesiveness to an adhesive, a putty material, and the like and having excellent durability such as moisture-heat resistance, hydrolysis resistance, and the like. The present invention relates to a urethane resin composition containing a urethane resin (C) produced by reacting a polyol (A) with a polyisocyanate (B), the polyol (A) containing a polyether polyol (a1), which has an oxyethylene structure (a1-1) and an oxyalkylene structure (a1-2) other than the oxyethylene structure (a1-1), and a polyoxytetramethylene glycol (a2) and/or a polycarbonatediol (a3), wherein the polyether polyol has a ratio by mass [(a1-1)/(a1-2)] of the oxyethylene structure (a1-1) to the oxyalkylene structure (a1-2) in a range of 3/7 to 9/1, and the ratio by mass of the polyether polyol (a1) is 10% by mass to 50% by mass.