Polyester Polyalcohol Adhesion Promoter for Plastic-Polyisocyanate Composites
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing composite elements with polyisocyanate polyaddition products and plastics face issues with adhesion loss under mechanical stressing, especially at high temperatures and humidity, leading to irreparable damage, and previous solutions result in low-quality products due to metastable or inhomogeneous mixtures.
Innovation Solution
The use of polyester polyalcohols as adhesion promoters, produced via polycondensation of specific acid components and low-molecular-weight diols, in the reaction mixture of isocyanates, catalysts, and blowing agents, to create a stable and reproducible polyisocyanate polyaddition product that maintains adhesion with plastics even after storage under harsh conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional adhesion promoters are used in polyisocyanate polyaddition products, then adhesion to plastic is improved, but adhesion is lost under mechanical stressing at high temperature and humidity
Solution Approach 1:
The patent modifies the chemical composition parameters of the polyester polyalcohol adhesion promoter by specifying precise mol% ranges of acid components (adipic acid 83-97%, phthalic/isophthalic/terephthalic acid 3-17%) and diol components (1,3-propanediol 5-66%). These parameter changes create a chemically stable adhesion promoter that maintains bond strength under thermal and mechanical stress conditions where conventional promoters fail.
2Strength
If polyester polyalcohols are used as adhesion promoters, then adhesion is improved, but the mixture becomes metastable and inhomogeneous
Solution Approach 1:
The patent resolves mixture instability by precisely controlling compositional parameters: acid component (83-97% adipic acid + 3-17% aromatic dicarboxylic acid), diol component (1,3-propanediol 5-66% + other diols), and molecular weight (100-500 g/mol). These parameter specifications ensure thermodynamic stability and homogeneity of the polyester polyalcohol in the polyol component, eliminating metastability issues.
Solution Approach 2:
The patent creates a stable composite polyol component by combining polyester polyalcohol (as adhesion promoter) with polyether polyol (as main component) in specific ratios. This composite material approach ensures both adhesion performance and mixture stability, as the polyester polyalcohol forms a stable dispersed phase within the polyether polyol matrix under the specified compositional constraints.
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 ensures excellent mechanical properties and adhesion between polyisocyanate polyaddition products and plastics, maintaining adhesion after 80 hours at 80°C and 80% humidity, and remaining watertight and functional for electrical conductor insulation, even after heat-aging.
Implementation Method 1
a polyester polyalcohol, capable of production via polycondensation of an acid component and of one or more low-molecular-weight diols
Implementation Method 2
polyisocyanate polyaddition product, where the polyisocyanate polyaddition product is obtained via mixing of (a) isocyanate with (b) compounds having groups reactive toward isocyanates
Data Source
AI summary
The present invention relates to composite elements comprising (i) plastic, adhering to which there is (ii) a polyisocyanate polyaddition product, where the polyisocyanate polyaddition product is obtained via mixing of (a) isocyanate with (b) compounds having groups reactive toward isocyanates, (c) catalysts and optionally additional products to give a reaction mixture and converting the reaction mixture to a polyisocyanate polyaddition product, where the compounds (b) comprise a polyester polyalcohol as adhesion promoter, capable of production via polycondensation of an acid component and one or more low-molecular-weight diols whose molar mass is less than 500 g/mol, in excess, where the acid component comprises from 83 to 97 mol % of adipic acid and from 3 to 17 mol % of phthalic acid, isophthalic acid, and/or terephthalic acid. The present invention also relates to components in the fitting-out or aircraft, of vehicles, or of buildings, and to insulation comprising this type of composite element.