Waterproof membrane
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Solution Overview
Problem
Existing waterproofing systems for building applications, particularly in roofing, face issues with adhesion, compatibility, and aging, and are affected by environmental factors, leading to reduced performance and increased costs due to the use of materials like polyvinylchloride and the need for complex application processes.
Innovation Solution
A waterproof membrane comprising a support carrier and a cross-linked two-component polyurethane coating composition, where a layer with hydroxyl-functional groups is applied and cured at controlled temperatures to form a durable, long-lasting barrier, with an optional pre-coating layer for enhanced bonding and surface appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid two-component polyurethane systems are applied and cured under outdoor conditions, then a waterproof barrier is formed, but the curing speed varies with ambient temperature and humidity leading to inconsistent cross-linking density and thickness
Solution Approach 1:
The patent applies a primer layer containing isocyanate groups to the support substrate before applying the polyol layer. This preliminary action ensures that the cross-linking reaction has a consistent foundation regardless of ambient conditions, improving the uniformity of cross-linking density and thickness in the final waterproof barrier.
Solution Approach 2:
The patent modifies the chemical parameters of the coating system by using specific polyols with defined molecular weights and hydroxyl values, combined with isocyanate-containing primers. This parameter control allows consistent cross-linking behavior across varying temperature and humidity conditions, ensuring reliable waterproofing performance.
2Ease of operation
If polyvinylchloride-based waterproofing sheets are used, then adhesion can be achieved with adhesives, but the adhesives contain ingredients incompatible with the waterproofing sheet material leading to reduced resistances to ageing
Solution Approach 1:
The patent uses polyol-based waterproofing layers that are chemically compatible with polyurethane adhesives and primers. This homogeneity in chemical family eliminates incompatibility issues between adhesive ingredients and waterproofing sheet material, ensuring maintained ageing resistance while achieving reliable adhesion.
Solution Approach 2:
The patent creates a composite system where the polyol-based waterproofing layer is chemically bonded to the support substrate through isocyanate-containing primers. This composite structure provides both adhesion capability and long-term ageing resistance through compatible material selection and chemical bonding.
3Ease of manufacture
If bitumen-based waterproofing sheets are fixed by flame heating, then the sheets can be installed, but the support sheet must be flameproof increasing material requirements and cost
Solution Approach 1:
The patent replaces the mechanical/thermal flame heating installation method with a chemical bonding system using isocyanate-containing primers and polyol-based waterproofing layers. This substitution eliminates the need for flameproof support sheets while maintaining installation capability through chemical adhesion.
4Reliability
If liquid polyurethane layers are applied and cured, then a waterproof barrier is formed, but drying and curing take several hours at 10-20°C and even fewer hours at 30-40°C affecting productivity
Solution Approach 1:
The patent uses polyols with specific molecular weights (1000-4000) and hydroxyl values (25-150) combined with isocyanate-containing primers to optimize the cross-linking reaction kinetics. This parameter optimization reduces curing time while maintaining waterproof barrier quality, improving productivity without sacrificing reliability.
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 provides a waterproof membrane that is easier and faster to install, with improved durability and resistance to weather and UV aging, reducing costs and ensuring consistent performance regardless of ambient conditions.
Implementation Method 1
applying a layer of a coating composition comprising at least one compound having hydroxyl-functional groups, and at least one polyisocyanate cross-linking agent with free isocyanate groups to form at least one topcoat layer of a two component polyurethane coating composition
Implementation Method 2
curing the layer of the coating composition at temperatures in the range of 50° to 160 °C to produce a cross-linked waterproof membrane
Data Source
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AI summary
The invention relates to a waterproof membrane for building applications comprising at least one support carrier and at least one layer of a cross-linked coating composition comprising at least one polyurethane. The invention also relates to a waterproof membrane comprising at least one support carrier and at least one layer of a cross-linked coating composition comprising at least one polyurethane, an optional pre-coating layer to facilitate the manufacturing process, and to join the support carrier with the cross-linked coating composition in the most optimal and durable manner to achieve good surface appearance and chemical bonding between reinforcing carrier and crosslinked polyurethane coating. The waterproof membrane can be prepared and installed with lower cost in comparison to current flat roof waterproofing systems based on liquid two-component polyurethane systems.